]> git.saurik.com Git - apple/xnu.git/blobdiff - osfmk/vm/vm_map.c
xnu-1504.3.12.tar.gz
[apple/xnu.git] / osfmk / vm / vm_map.c
index 050faad8aa2558d4f5e37b5609bc1be5cac3e3c7..a0f5e8c9b07fc7a2a75eb431f1098c2a1b55425a 100644 (file)
@@ -1,16 +1,19 @@
 /*
- * Copyright (c) 2000-2002 Apple Computer, Inc. All rights reserved.
+ * Copyright (c) 2000-2007 Apple Inc. All rights reserved.
  *
- * @APPLE_LICENSE_HEADER_START@
- * 
- * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
  * 
  * This file contains Original Code and/or Modifications of Original Code
  * as defined in and that are subject to the Apple Public Source License
  * Version 2.0 (the 'License'). You may not use this file except in
- * compliance with the License. Please obtain a copy of the License at
- * http://www.opensource.apple.com/apsl/ and read it before using this
- * file.
+ * compliance with the License. The rights granted to you under the License
+ * may not be used to create, or enable the creation or redistribution of,
+ * unlawful or unlicensed copies of an Apple operating system, or to
+ * circumvent, violate, or enable the circumvention or violation of, any
+ * terms of an Apple operating system software license agreement.
+ * 
+ * Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this file.
  * 
  * The Original Code and all software distributed under the License are
  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
@@ -20,7 +23,7 @@
  * Please see the License for the specific language governing rights and
  * limitations under the License.
  * 
- * @APPLE_LICENSE_HEADER_END@
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  */
 /*
  * @OSF_COPYRIGHT@
  *     Virtual memory mapping module.
  */
 
-#include <cpus.h>
 #include <task_swapper.h>
 #include <mach_assert.h>
+#include <libkern/OSAtomic.h>
 
 #include <mach/kern_return.h>
 #include <mach/port.h>
 #include <mach/vm_attributes.h>
 #include <mach/vm_param.h>
 #include <mach/vm_behavior.h>
+#include <mach/vm_statistics.h>
+#include <mach/memory_object.h>
+#include <mach/mach_vm.h>
+#include <machine/cpu_capabilities.h>
+#include <mach/sdt.h>
+
 #include <kern/assert.h>
 #include <kern/counters.h>
+#include <kern/kalloc.h>
 #include <kern/zalloc.h>
+
+#include <vm/cpm.h>
 #include <vm/vm_init.h>
 #include <vm/vm_fault.h>
 #include <vm/vm_map.h>
 #include <vm/vm_object.h>
 #include <vm/vm_page.h>
+#include <vm/vm_pageout.h>
 #include <vm/vm_kern.h>
 #include <ipc/ipc_port.h>
 #include <kern/sched_prim.h>
 #include <kern/misc_protos.h>
-#include <mach/vm_map_server.h>
-#include <mach/mach_host_server.h>
-#include <ddb/tr.h>
 #include <machine/db_machdep.h>
 #include <kern/xpr.h>
 
+#include <mach/vm_map_server.h>
+#include <mach/mach_host_server.h>
+#include <vm/vm_protos.h>
+#include <vm/vm_purgeable_internal.h>
+
+#ifdef ppc
+#include <ppc/mappings.h>
+#endif /* ppc */
+
+#include <vm/vm_protos.h>
+#include <vm/vm_shared_region.h>
+
 /* Internal prototypes
  */
-extern boolean_t vm_map_range_check(
-                               vm_map_t        map,
-                               vm_offset_t     start,
-                               vm_offset_t     end,
-                               vm_map_entry_t  *entry);
-
-extern vm_map_entry_t  _vm_map_entry_create(
-                               struct vm_map_header    *map_header);
-
-extern void            _vm_map_entry_dispose(
-                               struct vm_map_header    *map_header,
-                               vm_map_entry_t          entry);
-
-extern void            vm_map_pmap_enter(
-                               vm_map_t                map,
-                               vm_offset_t             addr,
-                               vm_offset_t             end_addr,
-                               vm_object_t             object,
-                               vm_object_offset_t      offset,
-                               vm_prot_t               protection);
-
-extern void            _vm_map_clip_end(
-                               struct vm_map_header    *map_header,
-                               vm_map_entry_t          entry,
-                               vm_offset_t             end);
-
-extern void            vm_map_entry_delete(
-                               vm_map_t        map,
-                               vm_map_entry_t  entry);
-
-extern kern_return_t   vm_map_delete(
-                               vm_map_t        map,
-                               vm_offset_t     start,
-                               vm_offset_t     end,
-                               int             flags);
-
-extern void            vm_map_copy_steal_pages(
-                               vm_map_copy_t   copy);
-
-extern kern_return_t   vm_map_copy_overwrite_unaligned(
-                               vm_map_t        dst_map,
-                               vm_map_entry_t  entry,
-                               vm_map_copy_t   copy,
-                               vm_offset_t     start);
-
-extern kern_return_t   vm_map_copy_overwrite_aligned(
-                               vm_map_t        dst_map,
-                               vm_map_entry_t  tmp_entry,
-                               vm_map_copy_t   copy,
-                               vm_offset_t     start,
-                               pmap_t          pmap);
-
-extern kern_return_t   vm_map_copyin_kernel_buffer(
-                               vm_map_t        src_map,
-                               vm_offset_t     src_addr,
-                               vm_size_t       len,
-                               boolean_t       src_destroy,
-                               vm_map_copy_t   *copy_result);  /* OUT */
-
-extern kern_return_t   vm_map_copyout_kernel_buffer(
-                               vm_map_t        map,
-                               vm_offset_t     *addr,  /* IN/OUT */
-                               vm_map_copy_t   copy,
-                               boolean_t       overwrite);
-
-extern void            vm_map_fork_share(
-                               vm_map_t        old_map,
-                               vm_map_entry_t  old_entry,
-                               vm_map_t        new_map);
-
-extern boolean_t       vm_map_fork_copy(
-                               vm_map_t        old_map,
-                               vm_map_entry_t  *old_entry_p,
-                               vm_map_t        new_map);
-
-extern kern_return_t   vm_remap_range_allocate(
-                               vm_map_t        map,
-                               vm_offset_t     *address,       /* IN/OUT */
-                               vm_size_t       size,
-                               vm_offset_t     mask,
-                               boolean_t       anywhere,
-                               vm_map_entry_t  *map_entry);    /* OUT */
-
-extern void            _vm_map_clip_start(
-                               struct vm_map_header    *map_header,
-                               vm_map_entry_t          entry,
-                               vm_offset_t             start);
-
-void                   vm_region_top_walk(
-                               vm_map_entry_t             entry,
-                               vm_region_top_info_t       top);
-
-void                   vm_region_walk(
-                               vm_map_entry_t             entry,
-                               vm_region_extended_info_t  extended,
-                               vm_object_offset_t         offset,
-                               vm_offset_t                range,
-                               vm_map_t                   map,
-                               vm_offset_t                va);
+
+static void vm_map_simplify_range(
+       vm_map_t        map,
+       vm_map_offset_t start,
+       vm_map_offset_t end);   /* forward */
+
+static boolean_t       vm_map_range_check(
+       vm_map_t        map,
+       vm_map_offset_t start,
+       vm_map_offset_t end,
+       vm_map_entry_t  *entry);
+
+static vm_map_entry_t  _vm_map_entry_create(
+       struct vm_map_header    *map_header);
+
+static void            _vm_map_entry_dispose(
+       struct vm_map_header    *map_header,
+       vm_map_entry_t          entry);
+
+static void            vm_map_pmap_enter(
+       vm_map_t                map,
+       vm_map_offset_t         addr,
+       vm_map_offset_t         end_addr,
+       vm_object_t             object,
+       vm_object_offset_t      offset,
+       vm_prot_t               protection);
+
+static void            _vm_map_clip_end(
+       struct vm_map_header    *map_header,
+       vm_map_entry_t          entry,
+       vm_map_offset_t         end);
+
+static void            _vm_map_clip_start(
+       struct vm_map_header    *map_header,
+       vm_map_entry_t          entry,
+       vm_map_offset_t         start);
+
+static void            vm_map_entry_delete(
+       vm_map_t        map,
+       vm_map_entry_t  entry);
+
+static kern_return_t   vm_map_delete(
+       vm_map_t        map,
+       vm_map_offset_t start,
+       vm_map_offset_t end,
+       int             flags,
+       vm_map_t        zap_map);
+
+static kern_return_t   vm_map_copy_overwrite_unaligned(
+       vm_map_t        dst_map,
+       vm_map_entry_t  entry,
+       vm_map_copy_t   copy,
+       vm_map_address_t start);
+
+static kern_return_t   vm_map_copy_overwrite_aligned(
+       vm_map_t        dst_map,
+       vm_map_entry_t  tmp_entry,
+       vm_map_copy_t   copy,
+       vm_map_offset_t start,
+       pmap_t          pmap);
+
+static kern_return_t   vm_map_copyin_kernel_buffer(
+       vm_map_t        src_map,
+       vm_map_address_t src_addr,
+       vm_map_size_t   len,
+       boolean_t       src_destroy,
+       vm_map_copy_t   *copy_result);  /* OUT */
+
+static kern_return_t   vm_map_copyout_kernel_buffer(
+       vm_map_t        map,
+       vm_map_address_t *addr, /* IN/OUT */
+       vm_map_copy_t   copy,
+       boolean_t       overwrite);
+
+static void            vm_map_fork_share(
+       vm_map_t        old_map,
+       vm_map_entry_t  old_entry,
+       vm_map_t        new_map);
+
+static boolean_t       vm_map_fork_copy(
+       vm_map_t        old_map,
+       vm_map_entry_t  *old_entry_p,
+       vm_map_t        new_map);
+
+void           vm_map_region_top_walk(
+       vm_map_entry_t             entry,
+       vm_region_top_info_t       top);
+
+void           vm_map_region_walk(
+       vm_map_t                   map,
+       vm_map_offset_t            va,
+       vm_map_entry_t             entry,
+       vm_object_offset_t         offset,
+       vm_object_size_t           range,
+       vm_region_extended_info_t  extended,
+       boolean_t                  look_for_pages);
+
+static kern_return_t   vm_map_wire_nested(
+       vm_map_t                   map,
+       vm_map_offset_t            start,
+       vm_map_offset_t            end,
+       vm_prot_t                  access_type,
+       boolean_t                  user_wire,
+       pmap_t                     map_pmap, 
+       vm_map_offset_t            pmap_addr);
+
+static kern_return_t   vm_map_unwire_nested(
+       vm_map_t                   map,
+       vm_map_offset_t            start,
+       vm_map_offset_t            end,
+       boolean_t                  user_wire,
+       pmap_t                     map_pmap,
+       vm_map_offset_t            pmap_addr);
+
+static kern_return_t   vm_map_overwrite_submap_recurse(
+       vm_map_t                   dst_map,
+       vm_map_offset_t            dst_addr,
+       vm_map_size_t              dst_size);
+
+static kern_return_t   vm_map_copy_overwrite_nested(
+       vm_map_t                   dst_map,
+       vm_map_offset_t            dst_addr,
+       vm_map_copy_t              copy,
+       boolean_t                  interruptible,
+       pmap_t                     pmap);
+
+static kern_return_t   vm_map_remap_extract(
+       vm_map_t                map,
+       vm_map_offset_t         addr,
+       vm_map_size_t           size,
+       boolean_t               copy,
+       struct vm_map_header    *map_header,
+       vm_prot_t               *cur_protection,
+       vm_prot_t               *max_protection,
+       vm_inherit_t            inheritance,
+       boolean_t               pageable);
+
+static kern_return_t   vm_map_remap_range_allocate(
+       vm_map_t                map,
+       vm_map_address_t        *address,
+       vm_map_size_t           size,
+       vm_map_offset_t         mask,
+       boolean_t               anywhere,
+       vm_map_entry_t          *map_entry);
+
+static void            vm_map_region_look_for_page(
+       vm_map_t                   map,
+       vm_map_offset_t            va,
+       vm_object_t                object,
+       vm_object_offset_t         offset,
+       int                        max_refcnt,
+       int                        depth,
+       vm_region_extended_info_t  extended);
+
+static int             vm_map_region_count_obj_refs(
+       vm_map_entry_t             entry,
+       vm_object_t                object);
+
+
+static kern_return_t   vm_map_willneed(
+       vm_map_t        map,
+       vm_map_offset_t start,
+       vm_map_offset_t end);
+
+static kern_return_t   vm_map_reuse_pages(
+       vm_map_t        map,
+       vm_map_offset_t start,
+       vm_map_offset_t end);
+
+static kern_return_t   vm_map_reusable_pages(
+       vm_map_t        map,
+       vm_map_offset_t start,
+       vm_map_offset_t end);
+
+static kern_return_t   vm_map_can_reuse(
+       vm_map_t        map,
+       vm_map_offset_t start,
+       vm_map_offset_t end);
 
 /*
  * Macros to copy a vm_map_entry. We must be careful to correctly
@@ -200,16 +301,70 @@ void                      vm_region_walk(
  */
 #define vm_map_entry_copy(NEW,OLD) \
 MACRO_BEGIN                                     \
-                *(NEW) = *(OLD);                \
-                (NEW)->is_shared = FALSE;      \
-                (NEW)->needs_wakeup = FALSE;    \
-                (NEW)->in_transition = FALSE;   \
-                (NEW)->wired_count = 0;         \
-                (NEW)->user_wired_count = 0;    \
+       *(NEW) = *(OLD);                \
+       (NEW)->is_shared = FALSE;       \
+       (NEW)->needs_wakeup = FALSE;    \
+       (NEW)->in_transition = FALSE;   \
+       (NEW)->wired_count = 0;         \
+       (NEW)->user_wired_count = 0;    \
+       (NEW)->permanent = FALSE;       \
 MACRO_END
 
 #define vm_map_entry_copy_full(NEW,OLD)        (*(NEW) = *(OLD))
 
+/*
+ *     Decide if we want to allow processes to execute from their data or stack areas.
+ *     override_nx() returns true if we do.  Data/stack execution can be enabled independently 
+ *     for 32 and 64 bit processes.  Set the VM_ABI_32 or VM_ABI_64 flags in allow_data_exec
+ *     or allow_stack_exec to enable data execution for that type of data area for that particular
+ *     ABI (or both by or'ing the flags together).  These are initialized in the architecture
+ *     specific pmap files since the default behavior varies according to architecture.  The 
+ *     main reason it varies is because of the need to provide binary compatibility with old 
+ *     applications that were written before these restrictions came into being.  In the old 
+ *     days, an app could execute anything it could read, but this has slowly been tightened 
+ *     up over time.  The default behavior is:
+ *
+ *     32-bit PPC apps         may execute from both stack and data areas
+ *     32-bit Intel apps       may exeucte from data areas but not stack
+ *     64-bit PPC/Intel apps   may not execute from either data or stack
+ *
+ *     An application on any architecture may override these defaults by explicitly
+ *     adding PROT_EXEC permission to the page in question with the mprotect(2) 
+ *     system call.  This code here just determines what happens when an app tries to
+ *     execute from a page that lacks execute permission.
+ *
+ *     Note that allow_data_exec or allow_stack_exec may also be modified by sysctl to change the
+ *     default behavior for both 32 and 64 bit apps on a system-wide basis.
+ */
+
+extern int allow_data_exec, allow_stack_exec;
+
+int
+override_nx(vm_map_t map, uint32_t user_tag) /* map unused on arm */
+{
+       int current_abi;
+
+       /*
+        * Determine if the app is running in 32 or 64 bit mode.
+        */
+
+       if (vm_map_is_64bit(map))
+               current_abi = VM_ABI_64;
+       else
+               current_abi = VM_ABI_32;
+
+       /*
+        * Determine if we should allow the execution based on whether it's a 
+        * stack or data area and the current architecture.
+        */
+
+       if (user_tag == VM_MEMORY_STACK)
+               return allow_stack_exec & current_abi;
+
+       return allow_data_exec & current_abi;
+}
+
+
 /*
  *     Virtual memory maps provide for the mapping, protection,
  *     and sharing of virtual memory objects.  In addition,
@@ -253,10 +408,10 @@ MACRO_END
  *     vm_object_copy_strategically() in vm_object.c.
  */
 
-zone_t         vm_map_zone;            /* zone for vm_map structures */
-zone_t         vm_map_entry_zone;      /* zone for vm_map_entry structures */
-zone_t         vm_map_kentry_zone;     /* zone for kernel entry structures */
-zone_t         vm_map_copy_zone;       /* zone for vm_map_copy structures */
+static zone_t  vm_map_zone;            /* zone for vm_map structures */
+static zone_t  vm_map_entry_zone;      /* zone for vm_map_entry structures */
+static zone_t  vm_map_kentry_zone;     /* zone for kernel entry structures */
+static zone_t  vm_map_copy_zone;       /* zone for vm_map_copy structures */
 
 
 /*
@@ -267,6 +422,120 @@ zone_t            vm_map_copy_zone;       /* zone for vm_map_copy structures */
 
 vm_object_t    vm_submap_object;
 
+static void            *map_data;
+static vm_size_t       map_data_size;
+static void            *kentry_data;
+static vm_size_t       kentry_data_size;
+static int             kentry_count = 2048;            /* to init kentry_data_size */
+
+#define         NO_COALESCE_LIMIT  ((1024 * 128) - 1)
+
+
+/* Skip acquiring locks if we're in the midst of a kernel core dump */
+unsigned int not_in_kdp = 1;
+
+#if CONFIG_CODE_DECRYPTION
+/*
+ * vm_map_apple_protected:
+ * This remaps the requested part of the object with an object backed by 
+ * the decrypting pager.
+ * crypt_info contains entry points and session data for the crypt module.
+ * The crypt_info block will be copied by vm_map_apple_protected. The data structures
+ * referenced in crypt_info must remain valid until crypt_info->crypt_end() is called.
+ */
+kern_return_t
+vm_map_apple_protected(
+       vm_map_t        map,
+       vm_map_offset_t start,
+       vm_map_offset_t end,
+       struct pager_crypt_info *crypt_info)
+{
+       boolean_t       map_locked;
+       kern_return_t   kr;
+       vm_map_entry_t  map_entry;
+       memory_object_t protected_mem_obj;
+       vm_object_t     protected_object;
+       vm_map_offset_t map_addr;
+
+       vm_map_lock_read(map);
+       map_locked = TRUE;
+
+       /* lookup the protected VM object */
+       if (!vm_map_lookup_entry(map,
+                                start,
+                                &map_entry) ||
+           map_entry->vme_end < end ||
+           map_entry->is_sub_map) {
+               /* that memory is not properly mapped */
+               kr = KERN_INVALID_ARGUMENT;
+               goto done;
+       }
+       protected_object = map_entry->object.vm_object;
+       if (protected_object == VM_OBJECT_NULL) {
+               /* there should be a VM object here at this point */
+               kr = KERN_INVALID_ARGUMENT;
+               goto done;
+       }
+
+       /* make sure protected object stays alive while map is unlocked */
+       vm_object_reference(protected_object);
+
+       vm_map_unlock_read(map);
+       map_locked = FALSE;
+
+       /*
+        * Lookup (and create if necessary) the protected memory object
+        * matching that VM object.
+        * If successful, this also grabs a reference on the memory object,
+        * to guarantee that it doesn't go away before we get a chance to map
+        * it.
+        */
+       protected_mem_obj = apple_protect_pager_setup(protected_object, crypt_info);
+
+       /* release extra ref on protected object */
+       vm_object_deallocate(protected_object);
+
+       if (protected_mem_obj == NULL) {
+               kr = KERN_FAILURE;
+               goto done;
+       }
+
+       /* map this memory object in place of the current one */
+       map_addr = start;
+       kr = vm_map_enter_mem_object(map,
+                                    &map_addr,
+                                    end - start,
+                                    (mach_vm_offset_t) 0,
+                                    VM_FLAGS_FIXED | VM_FLAGS_OVERWRITE,
+                                    (ipc_port_t) protected_mem_obj,
+                                    (map_entry->offset +
+                                     (start - map_entry->vme_start)),
+                                    TRUE,
+                                    map_entry->protection,
+                                    map_entry->max_protection,
+                                    map_entry->inheritance);
+       assert(map_addr == start);
+       /*
+        * Release the reference obtained by apple_protect_pager_setup().
+        * The mapping (if it succeeded) is now holding a reference on the
+        * memory object.
+        */
+       memory_object_deallocate(protected_mem_obj);
+
+done:
+       if (map_locked) {
+               vm_map_unlock_read(map);
+       }
+       return kr;
+}
+#endif /* CONFIG_CODE_DECRYPTION */
+
+
+lck_grp_t              vm_map_lck_grp;
+lck_grp_attr_t vm_map_lck_grp_attr;
+lck_attr_t             vm_map_lck_attr;
+
+
 /*
  *     vm_map_init:
  *
@@ -288,38 +557,23 @@ vm_object_t       vm_submap_object;
  *     empty since the very act of allocating memory implies the creation
  *     of a new entry.
  */
-
-vm_offset_t    map_data;
-vm_size_t      map_data_size;
-vm_offset_t    kentry_data;
-vm_size_t      kentry_data_size;
-int            kentry_count = 2048;            /* to init kentry_data_size */
-
-#define         NO_COALESCE_LIMIT  (1024 * 128)
-
-/*
- *     Threshold for aggressive (eager) page map entering for vm copyout
- *     operations.  Any copyout larger will NOT be aggressively entered.
- */
-vm_size_t vm_map_aggressive_enter_max;         /* set by bootstrap */
-
 void
 vm_map_init(
        void)
 {
-       vm_map_zone = zinit((vm_size_t) sizeof(struct vm_map), 40*1024,
-                                       PAGE_SIZE, "maps");
+       vm_map_zone = zinit((vm_map_size_t) sizeof(struct _vm_map), 40*1024,
+                           PAGE_SIZE, "maps");
 
-       vm_map_entry_zone = zinit((vm_size_t) sizeof(struct vm_map_entry),
-                                       1024*1024, PAGE_SIZE*5,
-                                       "non-kernel map entries");
+       vm_map_entry_zone = zinit((vm_map_size_t) sizeof(struct vm_map_entry),
+                                 1024*1024, PAGE_SIZE*5,
+                                 "non-kernel map entries");
 
-       vm_map_kentry_zone = zinit((vm_size_t) sizeof(struct vm_map_entry),
-                                       kentry_data_size, kentry_data_size,
-                                       "kernel map entries");
+       vm_map_kentry_zone = zinit((vm_map_size_t) sizeof(struct vm_map_entry),
+                                  kentry_data_size, kentry_data_size,
+                                  "kernel map entries");
 
-       vm_map_copy_zone = zinit((vm_size_t) sizeof(struct vm_map_copy),
-                                       16*1024, PAGE_SIZE, "map copies");
+       vm_map_copy_zone = zinit((vm_map_size_t) sizeof(struct vm_map_copy),
+                                16*1024, PAGE_SIZE, "map copies");
 
        /*
         *      Cram the map and kentry zones with initial data.
@@ -328,15 +582,20 @@ vm_map_init(
        zone_change(vm_map_zone, Z_COLLECT, FALSE);
        zone_change(vm_map_kentry_zone, Z_COLLECT, FALSE);
        zone_change(vm_map_kentry_zone, Z_EXPAND, FALSE);
+       zone_change(vm_map_kentry_zone, Z_FOREIGN, TRUE);
        zcram(vm_map_zone, map_data, map_data_size);
        zcram(vm_map_kentry_zone, kentry_data, kentry_data_size);
+       
+       lck_grp_attr_setdefault(&vm_map_lck_grp_attr);
+       lck_grp_init(&vm_map_lck_grp, "vm_map", &vm_map_lck_grp_attr);
+       lck_attr_setdefault(&vm_map_lck_attr);  
 }
 
 void
 vm_map_steal_memory(
        void)
 {
-       map_data_size = round_page_32(10 * sizeof(struct vm_map));
+       map_data_size = round_page(10 * sizeof(struct _vm_map));
        map_data = pmap_steal_memory(map_data_size);
 
 #if 0
@@ -352,7 +611,7 @@ vm_map_steal_memory(
 
 
        kentry_data_size =
-               round_page_32(kentry_count * sizeof(struct vm_map_entry));
+               round_page(kentry_count * sizeof(struct vm_map_entry));
        kentry_data = pmap_steal_memory(kentry_data_size);
 }
 
@@ -365,11 +624,12 @@ vm_map_steal_memory(
  */
 vm_map_t
 vm_map_create(
-       pmap_t          pmap,
-       vm_offset_t     min,
-       vm_offset_t     max,
-       boolean_t       pageable)
+       pmap_t                  pmap,
+       vm_map_offset_t min,
+       vm_map_offset_t max,
+       boolean_t               pageable)
 {
+       static int              color_seed = 0;
        register vm_map_t       result;
 
        result = (vm_map_t) zalloc(vm_map_zone);
@@ -382,6 +642,8 @@ vm_map_create(
        result->hdr.entries_pageable = pageable;
 
        result->size = 0;
+       result->user_wire_limit = MACH_VM_MAX_ADDRESS;  /* default limit is unlimited */
+       result->user_wire_size  = 0;
        result->ref_count = 1;
 #if    TASK_SWAPPER
        result->res_count = 1;
@@ -394,11 +656,13 @@ vm_map_create(
        result->no_zero_fill = FALSE;
        result->mapped = FALSE;
        result->wait_for_space = FALSE;
+       result->switch_protect = FALSE;
        result->first_free = vm_map_to_entry(result);
        result->hint = vm_map_to_entry(result);
+       result->color_rr = (color_seed++) & vm_color_mask;
        vm_map_lock_init(result);
-       mutex_init(&result->s_lock, ETAP_VM_RESULT);
-
+       lck_mtx_init_ext(&result->s_lock, &result->s_lock_ext, &vm_map_lck_grp, &vm_map_lck_attr);
+       
        return(result);
 }
 
@@ -409,12 +673,12 @@ vm_map_create(
  *     given map (or map copy).  No fields are filled.
  */
 #define        vm_map_entry_create(map) \
-           _vm_map_entry_create(&(map)->hdr)
+       _vm_map_entry_create(&(map)->hdr)
 
 #define        vm_map_copy_entry_create(copy) \
-           _vm_map_entry_create(&(copy)->cpy_hdr)
+       _vm_map_entry_create(&(copy)->cpy_hdr)
 
-vm_map_entry_t
+static vm_map_entry_t
 _vm_map_entry_create(
        register struct vm_map_header   *map_header)
 {
@@ -422,9 +686,9 @@ _vm_map_entry_create(
        register vm_map_entry_t entry;
 
        if (map_header->entries_pageable)
-           zone = vm_map_entry_zone;
+               zone = vm_map_entry_zone;
        else
-           zone = vm_map_kentry_zone;
+               zone = vm_map_kentry_zone;
 
        entry = (vm_map_entry_t) zalloc(zone);
        if (entry == VM_MAP_ENTRY_NULL)
@@ -437,20 +701,24 @@ _vm_map_entry_create(
  *     vm_map_entry_dispose:   [ internal use only ]
  *
  *     Inverse of vm_map_entry_create.
+ *
+ *     write map lock held so no need to
+ *     do anything special to insure correctness
+ *     of the stores
  */
 #define        vm_map_entry_dispose(map, entry)                        \
-MACRO_BEGIN                                                    \
+       MACRO_BEGIN                                             \
        if((entry) == (map)->first_free)                        \
                (map)->first_free = vm_map_to_entry(map);       \
        if((entry) == (map)->hint)                              \
                (map)->hint = vm_map_to_entry(map);             \
        _vm_map_entry_dispose(&(map)->hdr, (entry));            \
-MACRO_END
+       MACRO_END
 
 #define        vm_map_copy_entry_dispose(map, entry) \
        _vm_map_entry_dispose(&(copy)->cpy_hdr, (entry))
 
-void
+static void
 _vm_map_entry_dispose(
        register struct vm_map_header   *map_header,
        register vm_map_entry_t         entry)
@@ -458,16 +726,17 @@ _vm_map_entry_dispose(
        register zone_t         zone;
 
        if (map_header->entries_pageable)
-           zone = vm_map_entry_zone;
+               zone = vm_map_entry_zone;
        else
-           zone = vm_map_kentry_zone;
+               zone = vm_map_kentry_zone;
 
-       zfree(zone, (vm_offset_t) entry);
+       zfree(zone, entry);
 }
 
-boolean_t first_free_is_valid(vm_map_t map);   /* forward */
-boolean_t first_free_check = FALSE;
-boolean_t
+#if MACH_ASSERT
+static boolean_t first_free_is_valid(vm_map_t map);    /* forward */
+static boolean_t first_free_check = FALSE;
+static boolean_t
 first_free_is_valid(
        vm_map_t        map)
 {
@@ -475,11 +744,11 @@ first_free_is_valid(
 
        if (!first_free_check)
                return TRUE;
-               
+       
        entry = vm_map_to_entry(map);
        next = entry->vme_next;
-       while (trunc_page_32(next->vme_start) == trunc_page_32(entry->vme_end) ||
-              (trunc_page_32(next->vme_start) == trunc_page_32(entry->vme_start) &&
+       while (vm_map_trunc_page(next->vme_start) == vm_map_trunc_page(entry->vme_end) ||
+              (vm_map_trunc_page(next->vme_start) == vm_map_trunc_page(entry->vme_start) &&
                next != vm_map_to_entry(map))) {
                entry = next;
                next = entry->vme_next;
@@ -487,12 +756,13 @@ first_free_is_valid(
                        break;
        }
        if (map->first_free != entry) {
-               printf("Bad first_free for map 0x%x: 0x%x should be 0x%x\n",
+               printf("Bad first_free for map %p: %p should be %p\n",
                       map, map->first_free, entry);
                return FALSE;
        }
        return TRUE;
 }
+#endif /* MACH_ASSERT */
 
 /*
  *     UPDATE_FIRST_FREE:
@@ -502,17 +772,17 @@ first_free_is_valid(
  *     The map should be locked.
  */
 #define UPDATE_FIRST_FREE(map, new_first_free)                                 \
-MACRO_BEGIN                                                            \
+       MACRO_BEGIN                                                     \
        vm_map_t        UFF_map;                                        \
        vm_map_entry_t  UFF_first_free;                                 \
        vm_map_entry_t  UFF_next_entry;                                 \
        UFF_map = (map);                                                \
        UFF_first_free = (new_first_free);                              \
        UFF_next_entry = UFF_first_free->vme_next;                      \
-       while (trunc_page_32(UFF_next_entry->vme_start) ==              \
-              trunc_page_32(UFF_first_free->vme_end) ||                        \
-              (trunc_page_32(UFF_next_entry->vme_start) ==             \
-               trunc_page_32(UFF_first_free->vme_start) &&             \
+       while (vm_map_trunc_page(UFF_next_entry->vme_start) ==          \
+              vm_map_trunc_page(UFF_first_free->vme_end) ||                    \
+              (vm_map_trunc_page(UFF_next_entry->vme_start) ==                 \
+               vm_map_trunc_page(UFF_first_free->vme_start) &&         \
                UFF_next_entry != vm_map_to_entry(UFF_map))) {          \
                UFF_first_free = UFF_next_entry;                        \
                UFF_next_entry = UFF_first_free->vme_next;              \
@@ -521,7 +791,7 @@ MACRO_BEGIN                                                                 \
        }                                                               \
        UFF_map->first_free = UFF_first_free;                           \
        assert(first_free_is_valid(UFF_map));                           \
-MACRO_END
+       MACRO_END
 
 /*
  *     vm_map_entry_{un,}link:
@@ -529,14 +799,14 @@ MACRO_END
  *     Insert/remove entries from maps (or map copies).
  */
 #define vm_map_entry_link(map, after_where, entry)                     \
-MACRO_BEGIN                                                            \
+       MACRO_BEGIN                                                     \
        vm_map_t VMEL_map;                                              \
        vm_map_entry_t VMEL_entry;                                      \
        VMEL_map = (map);                                               \
        VMEL_entry = (entry);                                           \
        _vm_map_entry_link(&VMEL_map->hdr, after_where, VMEL_entry);    \
        UPDATE_FIRST_FREE(VMEL_map, VMEL_map->first_free);              \
-MACRO_END
+       MACRO_END
 
 
 #define vm_map_copy_entry_link(copy, after_where, entry)               \
@@ -551,7 +821,7 @@ MACRO_END
        MACRO_END
 
 #define vm_map_entry_unlink(map, entry)                                        \
-MACRO_BEGIN                                                            \
+       MACRO_BEGIN                                                     \
        vm_map_t VMEU_map;                                              \
        vm_map_entry_t VMEU_entry;                                      \
        vm_map_entry_t VMEU_first_free;                                 \
@@ -563,7 +833,7 @@ MACRO_BEGIN                                                                 \
                VMEU_first_free = VMEU_map->first_free;                 \
        _vm_map_entry_unlink(&VMEU_map->hdr, VMEU_entry);               \
        UPDATE_FIRST_FREE(VMEU_map, VMEU_first_free);                   \
-MACRO_END
+       MACRO_END
 
 #define vm_map_copy_entry_unlink(copy, entry)                          \
        _vm_map_entry_unlink(&(copy)->cpy_hdr, (entry))
@@ -591,10 +861,10 @@ void vm_map_res_reference(register vm_map_t map)
        assert(map->res_count >= 0);
        assert(map->ref_count >= map->res_count);
        if (map->res_count == 0) {
-               mutex_unlock(&map->s_lock);
+               lck_mtx_unlock(&map->s_lock);
                vm_map_lock(map);
                vm_map_swapin(map);
-               mutex_lock(&map->s_lock);
+               lck_mtx_lock(&map->s_lock);
                ++map->res_count;
                vm_map_unlock(map);
        } else
@@ -612,12 +882,12 @@ void vm_map_res_reference(register vm_map_t map)
 void vm_map_reference_swap(register vm_map_t map)
 {
        assert(map != VM_MAP_NULL);
-       mutex_lock(&map->s_lock);
+       lck_mtx_lock(&map->s_lock);
        assert(map->res_count >= 0);
        assert(map->ref_count >= map->res_count);
        map->ref_count++;
        vm_map_res_reference(map);
-       mutex_unlock(&map->s_lock);
+       lck_mtx_unlock(&map->s_lock);
 }
 
 /*
@@ -634,11 +904,11 @@ void vm_map_res_deallocate(register vm_map_t map)
 {
        assert(map->res_count > 0);
        if (--map->res_count == 0) {
-               mutex_unlock(&map->s_lock);
+               lck_mtx_unlock(&map->s_lock);
                vm_map_lock(map);
                vm_map_swapout(map);
                vm_map_unlock(map);
-               mutex_lock(&map->s_lock);
+               lck_mtx_lock(&map->s_lock);
        }
        assert(map->ref_count >= map->res_count);
 }
@@ -651,17 +921,39 @@ void vm_map_res_deallocate(register vm_map_t map)
  */
 void
 vm_map_destroy(
-       register vm_map_t       map)
-{
+       vm_map_t        map,
+       int             flags)
+{      
        vm_map_lock(map);
-       (void) vm_map_delete(map, map->min_offset,
-                            map->max_offset, VM_MAP_NO_FLAGS);
+
+       /* clean up regular map entries */
+       (void) vm_map_delete(map, map->min_offset, map->max_offset,
+                            flags, VM_MAP_NULL);
+       /* clean up leftover special mappings (commpage, etc...) */
+#ifdef __ppc__
+       /*
+        * PPC51: ppc64 is limited to 51-bit addresses.
+        * Memory beyond this 51-bit limit is mapped specially at the
+        * pmap level, so do not interfere.
+        * On PPC64, the commpage is mapped beyond the addressable range
+        * via a special pmap hack, so ask pmap to clean it explicitly...
+        */
+       if (map->pmap) {
+               pmap_unmap_sharedpage(map->pmap);
+       }
+       /* ... and do not let regular pmap cleanup apply here */
+       flags |= VM_MAP_REMOVE_NO_PMAP_CLEANUP;
+#endif /* __ppc__ */
+       (void) vm_map_delete(map, 0x0, 0xFFFFFFFFFFFFF000ULL,
+                            flags, VM_MAP_NULL);
        vm_map_unlock(map);
 
+       assert(map->hdr.nentries == 0);
+       
        if(map->pmap)
                pmap_destroy(map->pmap);
 
-       zfree(vm_map_zone, (vm_offset_t) map);
+       zfree(vm_map_zone, map);
 }
 
 #if    TASK_SWAPPER
@@ -717,7 +1009,7 @@ int vm_map_swap_enable = 1;
 void vm_map_swapin (vm_map_t map)
 {
        register vm_map_entry_t entry;
-       
+
        if (!vm_map_swap_enable)        /* debug */
                return;
 
@@ -762,9 +1054,9 @@ void vm_map_swapin (vm_map_t map)
                if (entry->object.vm_object != VM_OBJECT_NULL) {
                        if (entry->is_sub_map) {
                                vm_map_t lmap = entry->object.sub_map;
-                               mutex_lock(&lmap->s_lock);
+                               lck_mtx_lock(&lmap->s_lock);
                                vm_map_res_reference(lmap);
-                               mutex_unlock(&lmap->s_lock);
+                               lck_mtx_unlock(&lmap->s_lock);
                        } else {
                                vm_object_t object = entry->object.vm_object;
                                vm_object_lock(object);
@@ -792,12 +1084,12 @@ void vm_map_swapout(vm_map_t map)
         * If we raced with a swapin and lost, the residence count
         * will have been incremented to 1, and we simply return.
         */
-       mutex_lock(&map->s_lock);
+       lck_mtx_lock(&map->s_lock);
        if (map->res_count != 0) {
-               mutex_unlock(&map->s_lock);
+               lck_mtx_unlock(&map->s_lock);
                return;
        }
-       mutex_unlock(&map->s_lock);
+       lck_mtx_unlock(&map->s_lock);
 
        /*
         * There are no intermediate states of a map going out or
@@ -823,9 +1115,9 @@ void vm_map_swapout(vm_map_t map)
                if (entry->object.vm_object != VM_OBJECT_NULL) {
                        if (entry->is_sub_map) {
                                vm_map_t lmap = entry->object.sub_map;
-                               mutex_lock(&lmap->s_lock);
+                               lck_mtx_lock(&lmap->s_lock);
                                vm_map_res_deallocate(lmap);
-                               mutex_unlock(&lmap->s_lock);
+                               lck_mtx_unlock(&lmap->s_lock);
                        } else {
                                vm_object_t object = entry->object.vm_object;
                                vm_object_lock(object);
@@ -849,15 +1141,33 @@ void vm_map_swapout(vm_map_t map)
 
 
 /*
- *     SAVE_HINT:
+ *     SAVE_HINT_MAP_READ:
+ *
+ *     Saves the specified entry as the hint for
+ *     future lookups.  only a read lock is held on map,
+ *     so make sure the store is atomic... OSCompareAndSwap
+ *     guarantees this... also, we don't care if we collide
+ *     and someone else wins and stores their 'hint'
+ */
+#define        SAVE_HINT_MAP_READ(map,value) \
+       MACRO_BEGIN                                                     \
+       OSCompareAndSwapPtr((map)->hint, value, &(map)->hint); \
+       MACRO_END
+
+
+/*
+ *     SAVE_HINT_MAP_WRITE:
  *
  *     Saves the specified entry as the hint for
- *     future lookups.  Performs necessary interlocks.
+ *     future lookups.  write lock held on map,
+ *     so no one else can be writing or looking
+ *     until the lock is dropped, so it's safe
+ *     to just do an assignment
  */
-#define        SAVE_HINT(map,value) \
-               mutex_lock(&(map)->s_lock); \
-               (map)->hint = (value); \
-               mutex_unlock(&(map)->s_lock);
+#define        SAVE_HINT_MAP_WRITE(map,value) \
+       MACRO_BEGIN                    \
+       (map)->hint = (value);         \
+       MACRO_END
 
 /*
  *     vm_map_lookup_entry:    [ internal use only ]
@@ -871,8 +1181,8 @@ void vm_map_swapout(vm_map_t map)
  */
 boolean_t
 vm_map_lookup_entry(
-       register vm_map_t       map,
-       register vm_offset_t    address,
+       register vm_map_t               map,
+       register vm_map_offset_t        address,
        vm_map_entry_t          *entry)         /* OUT */
 {
        register vm_map_entry_t         cur;
@@ -882,16 +1192,13 @@ vm_map_lookup_entry(
         *      Start looking either from the head of the
         *      list, or from the hint.
         */
-
-       mutex_lock(&map->s_lock);
        cur = map->hint;
-       mutex_unlock(&map->s_lock);
 
        if (cur == vm_map_to_entry(map))
                cur = cur->vme_next;
 
        if (address >= cur->vme_start) {
-               /*
+               /*
                 *      Go from hint to end of list.
                 *
                 *      But first, make a quick check to see if
@@ -909,7 +1216,7 @@ vm_map_lookup_entry(
                }
        }
        else {
-               /*
+               /*
                 *      Go from start to hint, *inclusively*
                 */
                last = cur->vme_next;
@@ -923,13 +1230,14 @@ vm_map_lookup_entry(
        while (cur != last) {
                if (cur->vme_end > address) {
                        if (address >= cur->vme_start) {
-                               /*
+                               /*
                                 *      Save this lookup for future
                                 *      hints, and return
                                 */
 
                                *entry = cur;
-                               SAVE_HINT(map, cur);
+                               SAVE_HINT_MAP_READ(map, cur);
+
                                return(TRUE);
                        }
                        break;
@@ -937,7 +1245,8 @@ vm_map_lookup_entry(
                cur = cur->vme_next;
        }
        *entry = cur->vme_prev;
-       SAVE_HINT(map, *entry);
+       SAVE_HINT_MAP_READ(map, *entry);
+
        return(FALSE);
 }
 
@@ -957,14 +1266,25 @@ vm_map_lookup_entry(
 kern_return_t
 vm_map_find_space(
        register vm_map_t       map,
-       vm_offset_t             *address,       /* OUT */
-       vm_size_t               size,
-       vm_offset_t             mask,
+       vm_map_offset_t         *address,       /* OUT */
+       vm_map_size_t           size,
+       vm_map_offset_t         mask,
+       int                     flags,
        vm_map_entry_t          *o_entry)       /* OUT */
 {
        register vm_map_entry_t entry, new_entry;
-       register vm_offset_t    start;
-       register vm_offset_t    end;
+       register vm_map_offset_t        start;
+       register vm_map_offset_t        end;
+
+       if (size == 0) {
+               *address = 0;
+               return KERN_INVALID_ARGUMENT;
+       }
+
+       if (flags & VM_FLAGS_GUARD_AFTER) {
+               /* account for the back guard page in the size */
+               size += PAGE_SIZE_64;
+       }
 
        new_entry = vm_map_entry_create(map);
 
@@ -995,7 +1315,12 @@ vm_map_find_space(
                 *      wrap around the address.
                 */
 
+               if (flags & VM_FLAGS_GUARD_BEFORE) {
+                       /* reserve space for the front guard page */
+                       start += PAGE_SIZE_64;
+               }
                end = ((start + mask) & ~mask);
+                       
                if (end < start) {
                        vm_map_entry_dispose(map, new_entry);
                        vm_map_unlock(map);
@@ -1044,6 +1369,10 @@ vm_map_find_space(
         *              the map should be locked.
         */
 
+       if (flags & VM_FLAGS_GUARD_BEFORE) {
+               /* go back for the front guard page */
+               start -= PAGE_SIZE_64;
+       }
        *address = start;
 
        new_entry->vme_start = start;
@@ -1068,6 +1397,14 @@ vm_map_find_space(
 
        new_entry->in_transition = FALSE;
        new_entry->needs_wakeup = FALSE;
+       new_entry->no_cache = FALSE;
+       new_entry->permanent = FALSE;
+       new_entry->superpage_size = 0;
+
+       new_entry->alias = 0;
+       new_entry->zero_wired_pages = FALSE;
+
+       VM_GET_FLAGS_ALIAS(flags, new_entry->alias);
 
        /*
         *      Insert the new entry into the list
@@ -1080,7 +1417,7 @@ vm_map_find_space(
        /*
         *      Update the lookup hint
         */
-       SAVE_HINT(map, new_entry);
+       SAVE_HINT_MAP_WRITE(map, new_entry);
 
        *o_entry = new_entry;
        return(KERN_SUCCESS);
@@ -1090,7 +1427,7 @@ int vm_map_pmap_enter_print = FALSE;
 int vm_map_pmap_enter_enable = FALSE;
 
 /*
- *     Routine:        vm_map_pmap_enter
+ *     Routine:        vm_map_pmap_enter [internal only]
  *
  *     Description:
  *             Force pages from the specified object to be entered into
@@ -1103,16 +1440,17 @@ int vm_map_pmap_enter_enable = FALSE;
  *     In/out conditions:
  *             The source map should not be locked on entry.
  */
-void
+static void
 vm_map_pmap_enter(
        vm_map_t                map,
-       register vm_offset_t    addr,
-       register vm_offset_t    end_addr,
+       register vm_map_offset_t        addr,
+       register vm_map_offset_t        end_addr,
        register vm_object_t    object,
        vm_object_offset_t      offset,
        vm_prot_t               protection)
 {
-       unsigned int            cache_attr;
+       int                     type_of_fault;
+       kern_return_t           kr;
 
        if(map->pmap == 0)
                return;
@@ -1121,51 +1459,70 @@ vm_map_pmap_enter(
                register vm_page_t      m;
 
                vm_object_lock(object);
-               vm_object_paging_begin(object);
 
                m = vm_page_lookup(object, offset);
-               if (m == VM_PAGE_NULL || m->busy ||
-                   (m->unusual && ( m->error || m->restart || m->absent ||
-                                   protection & m->page_lock))) {
-
-                       vm_object_paging_end(object);
+               /*
+                * ENCRYPTED SWAP:
+                * The user should never see encrypted data, so do not
+                * enter an encrypted page in the page table.
+                */
+               if (m == VM_PAGE_NULL || m->busy || m->encrypted ||
+                   m->fictitious ||
+                   (m->unusual && ( m->error || m->restart || m->absent))) {
                        vm_object_unlock(object);
                        return;
                }
 
-               assert(!m->fictitious); /* XXX is this possible ??? */
-
                if (vm_map_pmap_enter_print) {
                        printf("vm_map_pmap_enter:");
-                       printf("map: %x, addr: %x, object: %x, offset: %x\n",
-                               map, addr, object, offset);
-               }
-               m->busy = TRUE;
-
-               if (m->no_isync == TRUE) {
-                       pmap_sync_caches_phys(m->phys_page);
-                       m->no_isync = FALSE;
+                       printf("map: %p, addr: %llx, object: %p, offset: %llx\n",
+                              map, (unsigned long long)addr, object, (unsigned long long)offset);
                }
+               type_of_fault = DBG_CACHE_HIT_FAULT;
+               kr = vm_fault_enter(m, map->pmap, addr, protection,
+                                   VM_PAGE_WIRED(m), FALSE, FALSE,
+                                   &type_of_fault);
 
-               cache_attr = ((unsigned int)object->wimg_bits) & VM_WIMG_MASK;
                vm_object_unlock(object);
 
-               PMAP_ENTER(map->pmap, addr, m, 
-                               protection, cache_attr, FALSE);
+               offset += PAGE_SIZE_64;
+               addr += PAGE_SIZE;
+       }
+}
 
-               vm_object_lock(object);
+boolean_t vm_map_pmap_is_empty(
+       vm_map_t        map,
+       vm_map_offset_t start,
+       vm_map_offset_t end);
+boolean_t vm_map_pmap_is_empty(
+       vm_map_t        map,
+       vm_map_offset_t start,
+       vm_map_offset_t end)
+{
+#ifdef MACHINE_PMAP_IS_EMPTY
+       return pmap_is_empty(map->pmap, start, end);
+#else  /* MACHINE_PMAP_IS_EMPTY */
+       vm_map_offset_t offset;
+       ppnum_t         phys_page;
 
-               PAGE_WAKEUP_DONE(m);
-               vm_page_lock_queues();
-               if (!m->active && !m->inactive)
-                   vm_page_activate(m);
-               vm_page_unlock_queues();
-               vm_object_paging_end(object);
-               vm_object_unlock(object);
+       if (map->pmap == NULL) {
+               return TRUE;
+       }
 
-               offset += PAGE_SIZE_64;
-               addr += PAGE_SIZE;
+       for (offset = start;
+            offset < end;
+            offset += PAGE_SIZE) {
+               phys_page = pmap_find_phys(map->pmap, offset);
+               if (phys_page) {
+                       kprintf("vm_map_pmap_is_empty(%p,0x%llx,0x%llx): "
+                               "page %d at 0x%llx\n",
+                               map, (long long)start, (long long)end,
+                               phys_page, (long long)offset);
+                       return FALSE;
+               }
        }
+       return TRUE;
+#endif /* MACHINE_PMAP_IS_EMPTY */
 }
 
 /*
@@ -1178,12 +1535,15 @@ vm_map_pmap_enter(
  *
  *             Arguments are as defined in the vm_map call.
  */
+int _map_enter_debug = 0;
+static unsigned int vm_map_enter_restore_successes = 0;
+static unsigned int vm_map_enter_restore_failures = 0;
 kern_return_t
 vm_map_enter(
-       register vm_map_t       map,
-       vm_offset_t             *address,       /* IN/OUT */
-       vm_size_t               size,
-       vm_offset_t             mask,
+       vm_map_t                map,
+       vm_map_offset_t         *address,       /* IN/OUT */
+       vm_map_size_t           size,
+       vm_map_offset_t         mask,
        int                     flags,
        vm_object_t             object,
        vm_object_offset_t      offset,
@@ -1192,34 +1552,160 @@ vm_map_enter(
        vm_prot_t               max_protection,
        vm_inherit_t            inheritance)
 {
-       vm_map_entry_t          entry;
-       register vm_offset_t    start;
-       register vm_offset_t    end;
+       vm_map_entry_t          entry, new_entry;
+       vm_map_offset_t         start, tmp_start, tmp_offset;
+       vm_map_offset_t         end, tmp_end;
+       vm_map_offset_t         tmp2_start, tmp2_end;
+       vm_map_offset_t         step;
        kern_return_t           result = KERN_SUCCESS;
-
-       boolean_t               anywhere = VM_FLAGS_ANYWHERE & flags;
+       vm_map_t                zap_old_map = VM_MAP_NULL;
+       vm_map_t                zap_new_map = VM_MAP_NULL;
+       boolean_t               map_locked = FALSE;
+       boolean_t               pmap_empty = TRUE;
+       boolean_t               new_mapping_established = FALSE;
+       boolean_t               anywhere = ((flags & VM_FLAGS_ANYWHERE) != 0);
+       boolean_t               purgable = ((flags & VM_FLAGS_PURGABLE) != 0);
+       boolean_t               overwrite = ((flags & VM_FLAGS_OVERWRITE) != 0);
+       boolean_t               no_cache = ((flags & VM_FLAGS_NO_CACHE) != 0);
+       boolean_t               is_submap = ((flags & VM_FLAGS_SUBMAP) != 0);
+       boolean_t               permanent = ((flags & VM_FLAGS_PERMANENT) != 0);
+       unsigned int            superpage_size = ((flags & VM_FLAGS_SUPERPAGE_MASK) >> VM_FLAGS_SUPERPAGE_SHIFT);
        char                    alias;
+       vm_map_offset_t         effective_min_offset, effective_max_offset;
+       kern_return_t           kr;
 
-       VM_GET_FLAGS_ALIAS(flags, alias);
-
-#define        RETURN(value)   { result = value; goto BailOut; }
-
-       assert(page_aligned(*address));
-       assert(page_aligned(size));
- StartAgain: ;
+       if (superpage_size) {
+               switch (superpage_size) {
+                       /*
+                        * Note that the current implementation only supports
+                        * a single size for superpages, SUPERPAGE_SIZE, per
+                        * architecture. As soon as more sizes are supposed
+                        * to be supported, SUPERPAGE_SIZE has to be replaced
+                        * with a lookup of the size depending on superpage_size.
+                        */
+#ifdef __x86_64__
+                       case SUPERPAGE_SIZE_2MB:
+                               break;
+#endif
+                       default:
+                               return KERN_INVALID_ARGUMENT;
+               }
+               mask = SUPERPAGE_SIZE-1;
+               if (size & (SUPERPAGE_SIZE-1))
+                       return KERN_INVALID_ARGUMENT;
+               inheritance = VM_INHERIT_NONE;  /* fork() children won't inherit superpages */
+       }
 
-       start = *address;
+#if CONFIG_EMBEDDED
+       if (cur_protection & VM_PROT_WRITE) {
+               if (cur_protection & VM_PROT_EXECUTE) {
+                       printf("EMBEDDED: %s curprot cannot be write+execute. turning off execute\n", __PRETTY_FUNCTION__);
+                       cur_protection &= ~VM_PROT_EXECUTE;
+               }
+       }
+#endif /* CONFIG_EMBEDDED */
 
-       if (anywhere) {
-               vm_map_lock(map);
+       if (is_submap) {
+               if (purgable) {
+                       /* submaps can not be purgeable */
+                       return KERN_INVALID_ARGUMENT;
+               }
+               if (object == VM_OBJECT_NULL) {
+                       /* submaps can not be created lazily */
+                       return KERN_INVALID_ARGUMENT;
+               }
+       }
+       if (flags & VM_FLAGS_ALREADY) {
+               /*
+                * VM_FLAGS_ALREADY says that it's OK if the same mapping
+                * is already present.  For it to be meaningul, the requested
+                * mapping has to be at a fixed address (!VM_FLAGS_ANYWHERE) and
+                * we shouldn't try and remove what was mapped there first
+                * (!VM_FLAGS_OVERWRITE).
+                */
+               if ((flags & VM_FLAGS_ANYWHERE) ||
+                   (flags & VM_FLAGS_OVERWRITE)) {
+                       return KERN_INVALID_ARGUMENT;
+               }
+       }
 
+       if (flags & VM_FLAGS_BELOW_MIN) {
                /*
-                *      Calculate the first possible address.
+                * Allow an insertion below the map's min offset.
                 */
+               effective_min_offset = 0ULL;
+       } else {
+               effective_min_offset = map->min_offset;
+       }
 
-               if (start < map->min_offset)
-                       start = map->min_offset;
-               if (start > map->max_offset)
+       if (flags & VM_FLAGS_BEYOND_MAX) {
+               /*
+                * Allow an insertion beyond the map's max offset.
+                */
+               if (vm_map_is_64bit(map))
+                       effective_max_offset = 0xFFFFFFFFFFFFF000ULL;
+               else
+                       effective_max_offset = 0x00000000FFFFF000ULL;
+       } else {
+               effective_max_offset = map->max_offset;
+       }
+
+       if (size == 0 ||
+           (offset & PAGE_MASK_64) != 0) {
+               *address = 0;
+               return KERN_INVALID_ARGUMENT;
+       }
+
+       VM_GET_FLAGS_ALIAS(flags, alias);
+
+#define        RETURN(value)   { result = value; goto BailOut; }
+
+       assert(page_aligned(*address));
+       assert(page_aligned(size));
+
+       /*
+        * Only zero-fill objects are allowed to be purgable.
+        * LP64todo - limit purgable objects to 32-bits for now
+        */
+       if (purgable &&
+           (offset != 0 ||
+            (object != VM_OBJECT_NULL &&
+             (object->size != size ||
+              object->purgable == VM_PURGABLE_DENY))
+            || size > ANON_MAX_SIZE)) /* LP64todo: remove when dp capable */
+               return KERN_INVALID_ARGUMENT;
+
+       if (!anywhere && overwrite) {
+               /*
+                * Create a temporary VM map to hold the old mappings in the
+                * affected area while we create the new one.
+                * This avoids releasing the VM map lock in
+                * vm_map_entry_delete() and allows atomicity
+                * when we want to replace some mappings with a new one.
+                * It also allows us to restore the old VM mappings if the
+                * new mapping fails.
+                */
+               zap_old_map = vm_map_create(PMAP_NULL,
+                                           *address,
+                                           *address + size,
+                                           map->hdr.entries_pageable);
+       }
+
+StartAgain: ;
+
+       start = *address;
+
+       if (anywhere) {
+               vm_map_lock(map);
+               map_locked = TRUE;
+
+               /*
+                *      Calculate the first possible address.
+                */
+
+               if (start < effective_min_offset)
+                       start = effective_min_offset;
+               if (start > effective_max_offset)
                        RETURN(KERN_NO_SPACE);
 
                /*
@@ -1229,7 +1715,7 @@ vm_map_enter(
                 */
 
                assert(first_free_is_valid(map));
-               if (start == map->min_offset) {
+               if (start == effective_min_offset) {
                        if ((entry = map->first_free) != vm_map_to_entry(map))
                                start = entry->vme_end;
                } else {
@@ -1248,7 +1734,7 @@ vm_map_enter(
                while (TRUE) {
                        register vm_map_entry_t next;
 
-                       /*
+                       /*
                         *      Find the end of the proposed new region.
                         *      Be sure we didn't go beyond the end, or
                         *      wrap around the address.
@@ -1260,14 +1746,15 @@ vm_map_enter(
                        start = end;
                        end += size;
 
-                       if ((end > map->max_offset) || (end < start)) {
+                       if ((end > effective_max_offset) || (end < start)) {
                                if (map->wait_for_space) {
-                                       if (size <= (map->max_offset -
-                                                    map->min_offset)) {
+                                       if (size <= (effective_max_offset -
+                                                    effective_min_offset)) {
                                                assert_wait((event_t)map,
                                                            THREAD_ABORTSAFE);
                                                vm_map_unlock(map);
-                                               thread_block((void (*)(void))0);
+                                               map_locked = FALSE;
+                                               thread_block(THREAD_CONTINUE_NULL);
                                                goto StartAgain;
                                        }
                                }
@@ -1299,8 +1786,6 @@ vm_map_enter(
                }
                *address = start;
        } else {
-               vm_map_entry_t          temp_entry;
-
                /*
                 *      Verify that:
                 *              the address doesn't itself violate
@@ -1308,6 +1793,7 @@ vm_map_enter(
                 */
 
                vm_map_lock(map);
+               map_locked = TRUE;
                if ((start & mask) != 0)
                        RETURN(KERN_NO_SPACE);
 
@@ -1317,20 +1803,99 @@ vm_map_enter(
 
                end = start + size;
 
-               if ((start < map->min_offset) ||
-                   (end > map->max_offset) ||
+               if ((start < effective_min_offset) ||
+                   (end > effective_max_offset) ||
                    (start >= end)) {
                        RETURN(KERN_INVALID_ADDRESS);
                }
 
+               if (overwrite && zap_old_map != VM_MAP_NULL) {
+                       /*
+                        * Fixed mapping and "overwrite" flag: attempt to
+                        * remove all existing mappings in the specified
+                        * address range, saving them in our "zap_old_map".
+                        */
+                       (void) vm_map_delete(map, start, end,
+                                            VM_MAP_REMOVE_SAVE_ENTRIES,
+                                            zap_old_map);
+               }
+
                /*
                 *      ...     the starting address isn't allocated
                 */
 
-               if (vm_map_lookup_entry(map, start, &temp_entry))
-                       RETURN(KERN_NO_SPACE);
+               if (vm_map_lookup_entry(map, start, &entry)) {
+                       if (! (flags & VM_FLAGS_ALREADY)) {
+                               RETURN(KERN_NO_SPACE);
+                       }
+                       /*
+                        * Check if what's already there is what we want.
+                        */
+                       tmp_start = start;
+                       tmp_offset = offset;
+                       if (entry->vme_start < start) {
+                               tmp_start -= start - entry->vme_start;
+                               tmp_offset -= start - entry->vme_start;
+                               
+                       }
+                       for (; entry->vme_start < end;
+                            entry = entry->vme_next) {
+                               /*
+                                * Check if the mapping's attributes
+                                * match the existing map entry.
+                                */
+                               if (entry == vm_map_to_entry(map) ||
+                                   entry->vme_start != tmp_start ||
+                                   entry->is_sub_map != is_submap ||
+                                   entry->offset != tmp_offset ||
+                                   entry->needs_copy != needs_copy ||
+                                   entry->protection != cur_protection ||
+                                   entry->max_protection != max_protection ||
+                                   entry->inheritance != inheritance ||
+                                   entry->alias != alias) {
+                                       /* not the same mapping ! */
+                                       RETURN(KERN_NO_SPACE);
+                               }
+                               /*
+                                * Check if the same object is being mapped.
+                                */
+                               if (is_submap) {
+                                       if (entry->object.sub_map !=
+                                           (vm_map_t) object) {
+                                               /* not the same submap */
+                                               RETURN(KERN_NO_SPACE);
+                                       }
+                               } else {
+                                       if (entry->object.vm_object != object) {
+                                               /* not the same VM object... */
+                                               vm_object_t obj2;
+
+                                               obj2 = entry->object.vm_object;
+                                               if ((obj2 == VM_OBJECT_NULL ||
+                                                    obj2->internal) &&
+                                                   (object == VM_OBJECT_NULL ||
+                                                    object->internal)) {
+                                                       /*
+                                                        * ... but both are
+                                                        * anonymous memory,
+                                                        * so equivalent.
+                                                        */
+                                               } else {
+                                                       RETURN(KERN_NO_SPACE);
+                                               }
+                                       }
+                               }
 
-               entry = temp_entry;
+                               tmp_offset += entry->vme_end - entry->vme_start;
+                               tmp_start += entry->vme_end - entry->vme_start;
+                               if (entry->vme_end >= end) {
+                                       /* reached the end of our mapping */
+                                       break;
+                               }
+                       }
+                       /* it all matches:  let's use what's already there ! */
+                       RETURN(KERN_MEMORY_PRESENT);
+               }
 
                /*
                 *      ...     the next region doesn't overlap the
@@ -1355,28 +1920,43 @@ vm_map_enter(
        /*
         *      See whether we can avoid creating a new entry (and object) by
         *      extending one of our neighbors.  [So far, we only attempt to
-        *      extend from below.]
+        *      extend from below.]  Note that we can never extend/join
+        *      purgable objects because they need to remain distinct
+        *      entities in order to implement their "volatile object"
+        *      semantics.
         */
 
-       if ((object == VM_OBJECT_NULL) &&
-           (entry != vm_map_to_entry(map)) &&
-           (entry->vme_end == start) &&
-           (!entry->is_shared) &&
-           (!entry->is_sub_map) &&
-           (entry->alias == alias) &&
-           (entry->inheritance == inheritance) &&
-           (entry->protection == cur_protection) &&
-           (entry->max_protection == max_protection) &&
-           (entry->behavior == VM_BEHAVIOR_DEFAULT) &&
-           (entry->in_transition == 0) &&
-           ((entry->vme_end - entry->vme_start) + size < NO_COALESCE_LIMIT) &&
-           (entry->wired_count == 0)) { /* implies user_wired_count == 0 */
+       if (purgable) {
+               if (object == VM_OBJECT_NULL) {
+                       object = vm_object_allocate(size);
+                       object->copy_strategy = MEMORY_OBJECT_COPY_NONE;
+                       object->purgable = VM_PURGABLE_NONVOLATILE;
+                       offset = (vm_object_offset_t)0;
+               }
+       } else if ((is_submap == FALSE) &&
+                  (object == VM_OBJECT_NULL) &&
+                  (entry != vm_map_to_entry(map)) &&
+                  (entry->vme_end == start) &&
+                  (!entry->is_shared) &&
+                  (!entry->is_sub_map) &&
+                  (entry->alias == alias) &&
+                  (entry->inheritance == inheritance) &&
+                  (entry->protection == cur_protection) &&
+                  (entry->max_protection == max_protection) &&
+                  (entry->behavior == VM_BEHAVIOR_DEFAULT) &&
+                  (entry->in_transition == 0) &&
+                  (entry->no_cache == no_cache) &&
+                  ((entry->vme_end - entry->vme_start) + size <=
+                   (alias == VM_MEMORY_REALLOC ?
+                    ANON_CHUNK_SIZE :
+                    NO_COALESCE_LIMIT)) &&
+                  (entry->wired_count == 0)) { /* implies user_wired_count == 0 */
                if (vm_object_coalesce(entry->object.vm_object,
-                               VM_OBJECT_NULL,
-                               entry->offset,
-                               (vm_object_offset_t) 0,
-                               (vm_size_t)(entry->vme_end - entry->vme_start),
-                               (vm_size_t)(end - entry->vme_end))) {
+                                      VM_OBJECT_NULL,
+                                      entry->offset,
+                                      (vm_object_offset_t) 0,
+                                      (vm_map_size_t)(entry->vme_end - entry->vme_start),
+                                      (vm_map_size_t)(end - entry->vme_end))) {
 
                        /*
                         *      Coalesced the two objects - can extend
@@ -1390,27 +1970,132 @@ vm_map_enter(
                }
        }
 
-       /*
-        *      Create a new entry
-        */
+       step = superpage_size ? SUPERPAGE_SIZE : (end - start);
+       new_entry = NULL;
 
-       { /**/
-       register vm_map_entry_t new_entry;
+       for (tmp2_start = start; tmp2_start<end; tmp2_start += step) {
+               tmp2_end = tmp2_start + step;
+               /*
+                *      Create a new entry
+                *      LP64todo - for now, we can only allocate 4GB internal objects
+                *      because the default pager can't page bigger ones.  Remove this
+                *      when it can.
+                *
+                * XXX FBDP
+                * The reserved "page zero" in each process's address space can
+                * be arbitrarily large.  Splitting it into separate 4GB objects and
+                * therefore different VM map entries serves no purpose and just
+                * slows down operations on the VM map, so let's not split the
+                * allocation into 4GB chunks if the max protection is NONE.  That
+                * memory should never be accessible, so it will never get to the
+                * default pager.
+                */
+               tmp_start = tmp2_start;
+               if (object == VM_OBJECT_NULL &&
+                   size > (vm_map_size_t)ANON_CHUNK_SIZE &&
+                   max_protection != VM_PROT_NONE &&
+                   superpage_size == 0) 
+                       tmp_end = tmp_start + (vm_map_size_t)ANON_CHUNK_SIZE;
+               else
+                       tmp_end = tmp2_end;
+               do {
+                       new_entry = vm_map_entry_insert(map, entry, tmp_start, tmp_end,
+                                                       object, offset, needs_copy,
+                                                       FALSE, FALSE,
+                                                       cur_protection, max_protection,
+                                                       VM_BEHAVIOR_DEFAULT,
+                                                       inheritance, 0, no_cache,
+                                                       permanent, superpage_size);
+                       new_entry->alias = alias;
+                       if (is_submap) {
+                               vm_map_t        submap;
+                               boolean_t       submap_is_64bit;
+                               boolean_t       use_pmap;
+
+                               new_entry->is_sub_map = TRUE;
+                               submap = (vm_map_t) object;
+                               submap_is_64bit = vm_map_is_64bit(submap);
+                               use_pmap = (alias == VM_MEMORY_SHARED_PMAP);
+       #ifndef NO_NESTED_PMAP 
+                               if (use_pmap && submap->pmap == NULL) {
+                                       /* we need a sub pmap to nest... */
+                                       submap->pmap = pmap_create(0, submap_is_64bit);
+                                       if (submap->pmap == NULL) {
+                                               /* let's proceed without nesting... */
+                                       }
+                               }
+                               if (use_pmap && submap->pmap != NULL) {
+                                       kr = pmap_nest(map->pmap,
+                                                      submap->pmap,
+                                                      tmp_start,
+                                                      tmp_start,
+                                                      tmp_end - tmp_start);
+                                       if (kr != KERN_SUCCESS) {
+                                               printf("vm_map_enter: "
+                                                      "pmap_nest(0x%llx,0x%llx) "
+                                                      "error 0x%x\n",
+                                                      (long long)tmp_start,
+                                                      (long long)tmp_end,
+                                                      kr);
+                                       } else {
+                                               /* we're now nested ! */
+                                               new_entry->use_pmap = TRUE;
+                                               pmap_empty = FALSE;
+                                       }
+                               }
+       #endif /* NO_NESTED_PMAP */
+                       }
+                       entry = new_entry;
+
+                       if (superpage_size) {
+                               vm_page_t pages, m;
+                               vm_object_t sp_object;
+
+                               entry->offset = 0;
+
+                               /* allocate one superpage */
+                               kr = cpm_allocate(SUPERPAGE_SIZE, &pages, 0, SUPERPAGE_NBASEPAGES-1, TRUE, 0);
+                               if (kr != KERN_SUCCESS) {
+                                       new_mapping_established = TRUE; /* will cause deallocation of whole range */
+                                       RETURN(kr);
+                               }
+
+                               /* create one vm_object per superpage */
+                               sp_object = vm_object_allocate((vm_map_size_t)(entry->vme_end - entry->vme_start));
+                               sp_object->phys_contiguous = TRUE;
+                               sp_object->shadow_offset = (vm_object_offset_t)pages->phys_page*PAGE_SIZE;
+                               entry->object.vm_object = sp_object;
+
+                               /* enter the base pages into the object */
+                               vm_object_lock(sp_object);
+                               for (offset = 0; offset < SUPERPAGE_SIZE; offset += PAGE_SIZE) {
+                                       m = pages;
+                                       pmap_zero_page(m->phys_page);
+                                       pages = NEXT_PAGE(m);
+                                       *(NEXT_PAGE_PTR(m)) = VM_PAGE_NULL;
+                                       vm_page_insert(m, sp_object, offset);
+                               }
+                               vm_object_unlock(sp_object);
+                       }
+               } while (tmp_end != tmp2_end && 
+                        (tmp_start = tmp_end) &&
+                        (tmp_end = (tmp2_end - tmp_end > (vm_map_size_t)ANON_CHUNK_SIZE) ? 
+                         tmp_end + (vm_map_size_t)ANON_CHUNK_SIZE : tmp2_end));
+       }
 
-       new_entry = vm_map_entry_insert(map, entry, start, end, object,
-                                       offset, needs_copy, FALSE, FALSE,
-                                       cur_protection, max_protection,
-                                       VM_BEHAVIOR_DEFAULT, inheritance, 0);
-       new_entry->alias = alias;
        vm_map_unlock(map);
+       map_locked = FALSE;
+
+       new_mapping_established = TRUE;
 
        /*      Wire down the new entry if the user
         *      requested all new map entries be wired.
         */
-       if (map->wiring_required) {
+       if ((map->wiring_required)||(superpage_size)) {
+               pmap_empty = FALSE; /* pmap won't be empty */
                result = vm_map_wire(map, start, end,
-                                   new_entry->protection, TRUE);
-               return(result);
+                                    new_entry->protection, TRUE);
+               RETURN(result);
        }
 
        if ((object != VM_OBJECT_NULL) &&
@@ -1418,7798 +2103,10244 @@ vm_map_enter(
            (!anywhere)  &&
            (!needs_copy) && 
            (size < (128*1024))) {
+               pmap_empty = FALSE; /* pmap won't be empty */
+
+               if (override_nx(map, alias) && cur_protection)
+                       cur_protection |= VM_PROT_EXECUTE;
+
                vm_map_pmap_enter(map, start, end, 
                                  object, offset, cur_protection);
        }
 
-       return(result);
-       } /**/
+BailOut: ;
+       if (result == KERN_SUCCESS) {
+               vm_prot_t pager_prot;
+               memory_object_t pager;
 
- BailOut: ;
-       vm_map_unlock(map);
-       return(result);
+               if (pmap_empty &&
+                   !(flags & VM_FLAGS_NO_PMAP_CHECK)) {
+                       assert(vm_map_pmap_is_empty(map,
+                                                   *address,
+                                                   *address+size));
+               }
 
-#undef RETURN
-}
+               /*
+                * For "named" VM objects, let the pager know that the
+                * memory object is being mapped.  Some pagers need to keep
+                * track of this, to know when they can reclaim the memory
+                * object, for example.
+                * VM calls memory_object_map() for each mapping (specifying
+                * the protection of each mapping) and calls
+                * memory_object_last_unmap() when all the mappings are gone.
+                */
+               pager_prot = max_protection;
+               if (needs_copy) {
+                       /*
+                        * Copy-On-Write mapping: won't modify
+                        * the memory object.
+                        */
+                       pager_prot &= ~VM_PROT_WRITE;
+               }
+               if (!is_submap &&
+                   object != VM_OBJECT_NULL &&
+                   object->named &&
+                   object->pager != MEMORY_OBJECT_NULL) {
+                       vm_object_lock(object);
+                       pager = object->pager;
+                       if (object->named &&
+                           pager != MEMORY_OBJECT_NULL) {
+                               assert(object->pager_ready);
+                               vm_object_mapping_wait(object, THREAD_UNINT);
+                               vm_object_mapping_begin(object);
+                               vm_object_unlock(object);
 
-/*
- *     vm_map_clip_start:      [ internal use only ]
- *
- *     Asserts that the given entry begins at or after
- *     the specified address; if necessary,
- *     it splits the entry into two.
- */
-#ifndef i386
-#define vm_map_clip_start(map, entry, startaddr)                       \
-MACRO_BEGIN                                                            \
-       vm_map_t VMCS_map;                                              \
-       vm_map_entry_t VMCS_entry;                                      \
-       vm_offset_t VMCS_startaddr;                                     \
-       VMCS_map = (map);                                               \
-       VMCS_entry = (entry);                                           \
-       VMCS_startaddr = (startaddr);                                   \
-       if (VMCS_startaddr > VMCS_entry->vme_start) {                   \
-               if(entry->use_pmap) {                                   \
-                       vm_offset_t     pmap_base_addr;                 \
-                                                                       \
-                       pmap_base_addr = 0xF0000000 & entry->vme_start; \
-                       pmap_unnest(map->pmap, (addr64_t)pmap_base_addr); \
-                       entry->use_pmap = FALSE;                        \
-               } else if(entry->object.vm_object                       \
-                       && !entry->is_sub_map                           \
-                       && entry->object.vm_object->phys_contiguous) {  \
-                       pmap_remove(map->pmap,                          \
-                               (addr64_t)(entry->vme_start),           \
-                               (addr64_t)(entry->vme_end));            \
-               }                                                       \
-               _vm_map_clip_start(&VMCS_map->hdr,VMCS_entry,VMCS_startaddr);\
-       }                                                               \
-       UPDATE_FIRST_FREE(VMCS_map, VMCS_map->first_free);              \
-MACRO_END
-#else
-#define vm_map_clip_start(map, entry, startaddr)                       \
-MACRO_BEGIN                                                            \
-       vm_map_t VMCS_map;                                              \
-       vm_map_entry_t VMCS_entry;                                      \
-       vm_offset_t VMCS_startaddr;                                     \
-       VMCS_map = (map);                                               \
-       VMCS_entry = (entry);                                           \
-       VMCS_startaddr = (startaddr);                                   \
-       if (VMCS_startaddr > VMCS_entry->vme_start) {                   \
-               _vm_map_clip_start(&VMCS_map->hdr,VMCS_entry,VMCS_startaddr);\
-       }                                                               \
-       UPDATE_FIRST_FREE(VMCS_map, VMCS_map->first_free);              \
-MACRO_END
-#endif
+                               kr = memory_object_map(pager, pager_prot);
+                               assert(kr == KERN_SUCCESS);
 
-#define vm_map_copy_clip_start(copy, entry, startaddr) \
-       MACRO_BEGIN \
-       if ((startaddr) > (entry)->vme_start) \
-               _vm_map_clip_start(&(copy)->cpy_hdr,(entry),(startaddr)); \
-       MACRO_END
+                               vm_object_lock(object);
+                               vm_object_mapping_end(object);
+                       }
+                       vm_object_unlock(object);
+               }
+       } else {
+               if (new_mapping_established) {
+                       /*
+                        * We have to get rid of the new mappings since we
+                        * won't make them available to the user.
+                        * Try and do that atomically, to minimize the risk
+                        * that someone else create new mappings that range.
+                        */
+                       zap_new_map = vm_map_create(PMAP_NULL,
+                                                   *address,
+                                                   *address + size,
+                                                   map->hdr.entries_pageable);
+                       if (!map_locked) {
+                               vm_map_lock(map);
+                               map_locked = TRUE;
+                       }
+                       (void) vm_map_delete(map, *address, *address+size,
+                                            VM_MAP_REMOVE_SAVE_ENTRIES,
+                                            zap_new_map);
+               }
+               if (zap_old_map != VM_MAP_NULL &&
+                   zap_old_map->hdr.nentries != 0) {
+                       vm_map_entry_t  entry1, entry2;
 
-/*
- *     This routine is called only when it is known that
- *     the entry must be split.
- */
-void
-_vm_map_clip_start(
-       register struct vm_map_header   *map_header,
-       register vm_map_entry_t         entry,
-       register vm_offset_t            start)
-{
-       register vm_map_entry_t new_entry;
+                       /*
+                        * The new mapping failed.  Attempt to restore
+                        * the old mappings, saved in the "zap_old_map".
+                        */
+                       if (!map_locked) {
+                               vm_map_lock(map);
+                               map_locked = TRUE;
+                       }
 
-       /*
-        *      Split off the front portion --
-        *      note that we must insert the new
-        *      entry BEFORE this one, so that
-        *      this entry has the specified starting
-        *      address.
-        */
+                       /* first check if the coast is still clear */
+                       start = vm_map_first_entry(zap_old_map)->vme_start;
+                       end = vm_map_last_entry(zap_old_map)->vme_end;
+                       if (vm_map_lookup_entry(map, start, &entry1) ||
+                           vm_map_lookup_entry(map, end, &entry2) ||
+                           entry1 != entry2) {
+                               /*
+                                * Part of that range has already been
+                                * re-mapped:  we can't restore the old
+                                * mappings...
+                                */
+                               vm_map_enter_restore_failures++;
+                       } else {
+                               /*
+                                * Transfer the saved map entries from
+                                * "zap_old_map" to the original "map",
+                                * inserting them all after "entry1".
+                                */
+                               for (entry2 = vm_map_first_entry(zap_old_map);
+                                    entry2 != vm_map_to_entry(zap_old_map);
+                                    entry2 = vm_map_first_entry(zap_old_map)) {
+                                       vm_map_size_t entry_size;
+
+                                       entry_size = (entry2->vme_end -
+                                                     entry2->vme_start);
+                                       vm_map_entry_unlink(zap_old_map,
+                                                           entry2);
+                                       zap_old_map->size -= entry_size;
+                                       vm_map_entry_link(map, entry1, entry2);
+                                       map->size += entry_size;
+                                       entry1 = entry2;
+                               }
+                               if (map->wiring_required) {
+                                       /*
+                                        * XXX TODO: we should rewire the
+                                        * old pages here...
+                                        */
+                               }
+                               vm_map_enter_restore_successes++;
+                       }
+               }
+       }
 
-       new_entry = _vm_map_entry_create(map_header);
-       vm_map_entry_copy_full(new_entry, entry);
+       if (map_locked) {
+               vm_map_unlock(map);
+       }
 
-       new_entry->vme_end = start;
-       entry->offset += (start - entry->vme_start);
-       entry->vme_start = start;
+       /*
+        * Get rid of the "zap_maps" and all the map entries that
+        * they may still contain.
+        */
+       if (zap_old_map != VM_MAP_NULL) {
+               vm_map_destroy(zap_old_map, VM_MAP_REMOVE_NO_PMAP_CLEANUP);
+               zap_old_map = VM_MAP_NULL;
+       }
+       if (zap_new_map != VM_MAP_NULL) {
+               vm_map_destroy(zap_new_map, VM_MAP_REMOVE_NO_PMAP_CLEANUP);
+               zap_new_map = VM_MAP_NULL;
+       }
 
-       _vm_map_entry_link(map_header, entry->vme_prev, new_entry);
+       return result;
 
-       if (entry->is_sub_map)
-               vm_map_reference(new_entry->object.sub_map);
-       else
-               vm_object_reference(new_entry->object.vm_object);
+#undef RETURN
 }
 
-
-/*
- *     vm_map_clip_end:        [ internal use only ]
- *
- *     Asserts that the given entry ends at or before
- *     the specified address; if necessary,
- *     it splits the entry into two.
- */
-#ifndef i386
-#define vm_map_clip_end(map, entry, endaddr)                           \
-MACRO_BEGIN                                                            \
-       vm_map_t VMCE_map;                                              \
-       vm_map_entry_t VMCE_entry;                                      \
-       vm_offset_t VMCE_endaddr;                                       \
-       VMCE_map = (map);                                               \
-       VMCE_entry = (entry);                                           \
-       VMCE_endaddr = (endaddr);                                       \
-       if (VMCE_endaddr < VMCE_entry->vme_end) {                       \
-               if(entry->use_pmap) {                                   \
-                       vm_offset_t     pmap_base_addr;                 \
-                                                                       \
-                       pmap_base_addr = 0xF0000000 & entry->vme_start; \
-                       pmap_unnest(map->pmap, (addr64_t)pmap_base_addr); \
-                       entry->use_pmap = FALSE;                        \
-               } else if(entry->object.vm_object                       \
-                       && !entry->is_sub_map                           \
-                       && entry->object.vm_object->phys_contiguous) {  \
-                       pmap_remove(map->pmap,                          \
-                               (addr64_t)(entry->vme_start),           \
-                               (addr64_t)(entry->vme_end));            \
-               }                                                       \
-               _vm_map_clip_end(&VMCE_map->hdr,VMCE_entry,VMCE_endaddr); \
-       }                                                               \
-       UPDATE_FIRST_FREE(VMCE_map, VMCE_map->first_free);              \
-MACRO_END
-#else
-#define vm_map_clip_end(map, entry, endaddr)                           \
-MACRO_BEGIN                                                            \
-       vm_map_t VMCE_map;                                              \
-       vm_map_entry_t VMCE_entry;                                      \
-       vm_offset_t VMCE_endaddr;                                       \
-       VMCE_map = (map);                                               \
-       VMCE_entry = (entry);                                           \
-       VMCE_endaddr = (endaddr);                                       \
-       if (VMCE_endaddr < VMCE_entry->vme_end) {                       \
-               _vm_map_clip_end(&VMCE_map->hdr,VMCE_entry,VMCE_endaddr); \
-       }                                                               \
-       UPDATE_FIRST_FREE(VMCE_map, VMCE_map->first_free);              \
-MACRO_END
-#endif
-
-#define vm_map_copy_clip_end(copy, entry, endaddr) \
-       MACRO_BEGIN \
-       if ((endaddr) < (entry)->vme_end) \
-               _vm_map_clip_end(&(copy)->cpy_hdr,(entry),(endaddr)); \
-       MACRO_END
-
-/*
- *     This routine is called only when it is known that
- *     the entry must be split.
- */
-void
-_vm_map_clip_end(
-       register struct vm_map_header   *map_header,
-       register vm_map_entry_t         entry,
-       register vm_offset_t            end)
+kern_return_t
+vm_map_enter_mem_object(
+       vm_map_t                target_map,
+       vm_map_offset_t         *address,
+       vm_map_size_t           initial_size,
+       vm_map_offset_t         mask,
+       int                     flags,
+       ipc_port_t              port,
+       vm_object_offset_t      offset,
+       boolean_t               copy,
+       vm_prot_t               cur_protection,
+       vm_prot_t               max_protection,
+       vm_inherit_t            inheritance)
 {
-       register vm_map_entry_t new_entry;
+       vm_map_address_t        map_addr;
+       vm_map_size_t           map_size;
+       vm_object_t             object;
+       vm_object_size_t        size;
+       kern_return_t           result;
 
        /*
-        *      Create a new entry and insert it
-        *      AFTER the specified entry
+        * Check arguments for validity
         */
+       if ((target_map == VM_MAP_NULL) ||
+           (cur_protection & ~VM_PROT_ALL) ||
+           (max_protection & ~VM_PROT_ALL) ||
+           (inheritance > VM_INHERIT_LAST_VALID) ||
+           initial_size == 0)
+               return KERN_INVALID_ARGUMENT;
 
-       new_entry = _vm_map_entry_create(map_header);
-       vm_map_entry_copy_full(new_entry, entry);
+       map_addr = vm_map_trunc_page(*address);
+       map_size = vm_map_round_page(initial_size);
+       size = vm_object_round_page(initial_size);      
 
-       new_entry->vme_start = entry->vme_end = end;
-       new_entry->offset += (end - entry->vme_start);
+       /*
+        * Find the vm object (if any) corresponding to this port.
+        */
+       if (!IP_VALID(port)) {
+               object = VM_OBJECT_NULL;
+               offset = 0;
+               copy = FALSE;
+       } else if (ip_kotype(port) == IKOT_NAMED_ENTRY) {
+               vm_named_entry_t        named_entry;
+
+               named_entry = (vm_named_entry_t) port->ip_kobject;
+               /* a few checks to make sure user is obeying rules */
+               if (size == 0) {
+                       if (offset >= named_entry->size)
+                               return KERN_INVALID_RIGHT;
+                       size = named_entry->size - offset;
+               }
+               if ((named_entry->protection & max_protection) !=
+                   max_protection)
+                       return KERN_INVALID_RIGHT;
+               if ((named_entry->protection & cur_protection) !=
+                   cur_protection)
+                       return KERN_INVALID_RIGHT;
+               if (named_entry->size < (offset + size))
+                       return KERN_INVALID_ARGUMENT;
+
+               /* the callers parameter offset is defined to be the */
+               /* offset from beginning of named entry offset in object */
+               offset = offset + named_entry->offset;
+               
+               named_entry_lock(named_entry);
+               if (named_entry->is_sub_map) {
+                       vm_map_t                submap;
 
-       _vm_map_entry_link(map_header, entry, new_entry);
+                       submap = named_entry->backing.map;
+                       vm_map_lock(submap);
+                       vm_map_reference(submap);
+                       vm_map_unlock(submap);
+                       named_entry_unlock(named_entry);
+
+                       result = vm_map_enter(target_map,
+                                             &map_addr,
+                                             map_size,
+                                             mask,
+                                             flags | VM_FLAGS_SUBMAP,
+                                             (vm_object_t) submap,
+                                             offset,
+                                             copy,
+                                             cur_protection,
+                                             max_protection,
+                                             inheritance);
+                       if (result != KERN_SUCCESS) {
+                               vm_map_deallocate(submap);
+                       } else {
+                               /*
+                                * No need to lock "submap" just to check its
+                                * "mapped" flag: that flag is never reset
+                                * once it's been set and if we race, we'll
+                                * just end up setting it twice, which is OK.
+                                */
+                               if (submap->mapped == FALSE) {
+                                       /*
+                                        * This submap has never been mapped.
+                                        * Set its "mapped" flag now that it
+                                        * has been mapped.
+                                        * This happens only for the first ever
+                                        * mapping of a "submap".
+                                        */
+                                       vm_map_lock(submap);
+                                       submap->mapped = TRUE;
+                                       vm_map_unlock(submap);
+                               }
+                               *address = map_addr;
+                       }
+                       return result;
+
+               } else if (named_entry->is_pager) {
+                       unsigned int    access;
+                       vm_prot_t       protections;
+                       unsigned int    wimg_mode;
+                       boolean_t       cache_attr;
+
+                       protections = named_entry->protection & VM_PROT_ALL;
+                       access = GET_MAP_MEM(named_entry->protection);
+
+                       object = vm_object_enter(named_entry->backing.pager, 
+                                                named_entry->size, 
+                                                named_entry->internal, 
+                                                FALSE,
+                                                FALSE);
+                       if (object == VM_OBJECT_NULL) {
+                               named_entry_unlock(named_entry);
+                               return KERN_INVALID_OBJECT;
+                       }
 
-       if (entry->is_sub_map)
-               vm_map_reference(new_entry->object.sub_map);
-       else
-               vm_object_reference(new_entry->object.vm_object);
-}
+                       /* JMM - drop reference on pager here */
 
+                       /* create an extra ref for the named entry */
+                       vm_object_lock(object);
+                       vm_object_reference_locked(object);
+                       named_entry->backing.object = object;
+                       named_entry->is_pager = FALSE;
+                       named_entry_unlock(named_entry);
+
+                       wimg_mode = object->wimg_bits;
+                       if (access == MAP_MEM_IO) {
+                               wimg_mode = VM_WIMG_IO;
+                       } else if (access == MAP_MEM_COPYBACK) {
+                               wimg_mode = VM_WIMG_USE_DEFAULT;
+                       } else if (access == MAP_MEM_WTHRU) {
+                               wimg_mode = VM_WIMG_WTHRU;
+                       } else if (access == MAP_MEM_WCOMB) {
+                               wimg_mode = VM_WIMG_WCOMB;
+                       }
+                       if (wimg_mode == VM_WIMG_IO ||
+                           wimg_mode == VM_WIMG_WCOMB)
+                               cache_attr = TRUE;
+                       else 
+                               cache_attr = FALSE;
 
-/*
- *     VM_MAP_RANGE_CHECK:     [ internal use only ]
- *
- *     Asserts that the starting and ending region
- *     addresses fall within the valid range of the map.
- */
-#define        VM_MAP_RANGE_CHECK(map, start, end)             \
-               {                                       \
-               if (start < vm_map_min(map))            \
-                       start = vm_map_min(map);        \
-               if (end > vm_map_max(map))              \
-                       end = vm_map_max(map);          \
-               if (start > end)                        \
-                       start = end;                    \
+                       /* wait for object (if any) to be ready */
+                       if (!named_entry->internal) {
+                               while (!object->pager_ready) {
+                                       vm_object_wait(
+                                               object,
+                                               VM_OBJECT_EVENT_PAGER_READY,
+                                               THREAD_UNINT);
+                                       vm_object_lock(object);
+                               }
+                       }
+
+                       if (object->wimg_bits != wimg_mode) {
+                               vm_page_t p;
+
+                               vm_object_paging_wait(object, THREAD_UNINT);
+
+                               object->wimg_bits = wimg_mode;
+                               queue_iterate(&object->memq, p, vm_page_t, listq) {
+                                       if (!p->fictitious) {
+                                               if (p->pmapped)
+                                                       pmap_disconnect(p->phys_page);
+                                               if (cache_attr)
+                                                       pmap_sync_page_attributes_phys(p->phys_page);
+                                       }
+                               }
+                       }
+                       object->true_share = TRUE;
+                       if (object->copy_strategy == MEMORY_OBJECT_COPY_SYMMETRIC)
+                               object->copy_strategy = MEMORY_OBJECT_COPY_DELAY;
+                       vm_object_unlock(object);
+               } else {
+                       /* This is the case where we are going to map */
+                       /* an already mapped object.  If the object is */
+                       /* not ready it is internal.  An external     */
+                       /* object cannot be mapped until it is ready  */
+                       /* we can therefore avoid the ready check     */
+                       /* in this case.  */
+                       object = named_entry->backing.object;
+                       assert(object != VM_OBJECT_NULL);
+                       named_entry_unlock(named_entry);
+                       vm_object_reference(object);
+               }
+       } else if (ip_kotype(port) == IKOT_MEMORY_OBJECT) {
+               /*
+                * JMM - This is temporary until we unify named entries
+                * and raw memory objects.
+                *
+                * Detected fake ip_kotype for a memory object.  In
+                * this case, the port isn't really a port at all, but
+                * instead is just a raw memory object.
+                */
+                
+               object = vm_object_enter((memory_object_t)port,
+                                        size, FALSE, FALSE, FALSE);
+               if (object == VM_OBJECT_NULL)
+                       return KERN_INVALID_OBJECT;
+
+               /* wait for object (if any) to be ready */
+               if (object != VM_OBJECT_NULL) {
+                       if (object == kernel_object) {
+                               printf("Warning: Attempt to map kernel object"
+                                       " by a non-private kernel entity\n");
+                               return KERN_INVALID_OBJECT;
+                       }
+                       if (!object->pager_ready) {
+                               vm_object_lock(object);
+
+                               while (!object->pager_ready) {
+                                       vm_object_wait(object,
+                                                      VM_OBJECT_EVENT_PAGER_READY,
+                                                      THREAD_UNINT);
+                                       vm_object_lock(object);
+                               }
+                               vm_object_unlock(object);
+                       }
                }
+       } else {
+               return KERN_INVALID_OBJECT;
+       }
 
-/*
- *     vm_map_range_check:     [ internal use only ]
- *     
- *     Check that the region defined by the specified start and
- *     end addresses are wholly contained within a single map
- *     entry or set of adjacent map entries of the spacified map,
- *     i.e. the specified region contains no unmapped space.
- *     If any or all of the region is unmapped, FALSE is returned.
- *     Otherwise, TRUE is returned and if the output argument 'entry'
- *     is not NULL it points to the map entry containing the start
- *     of the region.
- *
- *     The map is locked for reading on entry and is left locked.
- */
-boolean_t
-vm_map_range_check(
-       register vm_map_t       map,
-       register vm_offset_t    start,
-       register vm_offset_t    end,
-       vm_map_entry_t          *entry)
-{
-       vm_map_entry_t          cur;
-       register vm_offset_t    prev;
+       if (object != VM_OBJECT_NULL &&
+           object->named &&
+           object->pager != MEMORY_OBJECT_NULL &&
+           object->copy_strategy != MEMORY_OBJECT_COPY_NONE) {
+               memory_object_t pager;
+               vm_prot_t       pager_prot;
+               kern_return_t   kr;
 
-       /*
-        *      Basic sanity checks first
-        */
-       if (start < vm_map_min(map) || end > vm_map_max(map) || start > end)
-               return (FALSE);
+               /*
+                * For "named" VM objects, let the pager know that the
+                * memory object is being mapped.  Some pagers need to keep
+                * track of this, to know when they can reclaim the memory
+                * object, for example.
+                * VM calls memory_object_map() for each mapping (specifying
+                * the protection of each mapping) and calls
+                * memory_object_last_unmap() when all the mappings are gone.
+                */
+               pager_prot = max_protection;
+               if (copy) {
+                       /*
+                        * Copy-On-Write mapping: won't modify the
+                        * memory object.
+                        */
+                       pager_prot &= ~VM_PROT_WRITE;
+               }
+               vm_object_lock(object);
+               pager = object->pager;
+               if (object->named &&
+                   pager != MEMORY_OBJECT_NULL &&
+                   object->copy_strategy != MEMORY_OBJECT_COPY_NONE) {
+                       assert(object->pager_ready);
+                       vm_object_mapping_wait(object, THREAD_UNINT);
+                       vm_object_mapping_begin(object);
+                       vm_object_unlock(object);
 
-       /*
-        *      Check first if the region starts within a valid
-        *      mapping for the map.
-        */
-       if (!vm_map_lookup_entry(map, start, &cur))
-               return (FALSE);
+                       kr = memory_object_map(pager, pager_prot);
+                       assert(kr == KERN_SUCCESS);
 
-       /*
-        *      Optimize for the case that the region is contained 
-        *      in a single map entry.
-        */
-       if (entry != (vm_map_entry_t *) NULL)
-               *entry = cur;
-       if (end <= cur->vme_end)
-               return (TRUE);
+                       vm_object_lock(object);
+                       vm_object_mapping_end(object);
+               }
+               vm_object_unlock(object);
+       }
 
        /*
-        *      If the region is not wholly contained within a
-        *      single entry, walk the entries looking for holes.
+        *      Perform the copy if requested
         */
-       prev = cur->vme_end;
-       cur = cur->vme_next;
-       while ((cur != vm_map_to_entry(map)) && (prev == cur->vme_start)) {
-               if (end <= cur->vme_end)
-                       return (TRUE);
-               prev = cur->vme_end;
-               cur = cur->vme_next;
+
+       if (copy) {
+               vm_object_t             new_object;
+               vm_object_offset_t      new_offset;
+
+               result = vm_object_copy_strategically(object, offset, size,
+                                                     &new_object, &new_offset,
+                                                     &copy);
+
+
+               if (result == KERN_MEMORY_RESTART_COPY) {
+                       boolean_t success;
+                       boolean_t src_needs_copy;
+
+                       /*
+                        * XXX
+                        * We currently ignore src_needs_copy.
+                        * This really is the issue of how to make
+                        * MEMORY_OBJECT_COPY_SYMMETRIC safe for
+                        * non-kernel users to use. Solution forthcoming.
+                        * In the meantime, since we don't allow non-kernel
+                        * memory managers to specify symmetric copy,
+                        * we won't run into problems here.
+                        */
+                       new_object = object;
+                       new_offset = offset;
+                       success = vm_object_copy_quickly(&new_object,
+                                                        new_offset, size,
+                                                        &src_needs_copy,
+                                                        &copy);
+                       assert(success);
+                       result = KERN_SUCCESS;
+               }
+               /*
+                *      Throw away the reference to the
+                *      original object, as it won't be mapped.
+                */
+
+               vm_object_deallocate(object);
+
+               if (result != KERN_SUCCESS)
+                       return result;
+
+               object = new_object;
+               offset = new_offset;
        }
-       return (FALSE);
+
+       result = vm_map_enter(target_map,
+                             &map_addr, map_size,
+                             (vm_map_offset_t)mask,
+                             flags,
+                             object, offset,
+                             copy,
+                             cur_protection, max_protection, inheritance);
+       if (result != KERN_SUCCESS)
+               vm_object_deallocate(object);
+       *address = map_addr;
+       return result;
 }
 
-/*
- *     vm_map_submap:          [ kernel use only ]
- *
- *     Mark the given range as handled by a subordinate map.
- *
- *     This range must have been created with vm_map_find using
- *     the vm_submap_object, and no other operations may have been
- *     performed on this range prior to calling vm_map_submap.
- *
- *     Only a limited number of operations can be performed
- *     within this rage after calling vm_map_submap:
- *             vm_fault
- *     [Don't try vm_map_copyin!]
- *
- *     To remove a submapping, one must first remove the
- *     range from the superior map, and then destroy the
- *     submap (if desired).  [Better yet, don't try it.]
- */
+
+
+
 kern_return_t
-vm_map_submap(
-       register vm_map_t       map,
-       register vm_offset_t    start,
-       register vm_offset_t    end,
-       vm_map_t                submap,
-       vm_offset_t             offset,
-       boolean_t               use_pmap)
+vm_map_enter_mem_object_control(
+       vm_map_t                target_map,
+       vm_map_offset_t         *address,
+       vm_map_size_t           initial_size,
+       vm_map_offset_t         mask,
+       int                     flags,
+       memory_object_control_t control,
+       vm_object_offset_t      offset,
+       boolean_t               copy,
+       vm_prot_t               cur_protection,
+       vm_prot_t               max_protection,
+       vm_inherit_t            inheritance)
 {
-       vm_map_entry_t          entry;
-       register kern_return_t  result = KERN_INVALID_ARGUMENT;
-       register vm_object_t    object;
+       vm_map_address_t        map_addr;
+       vm_map_size_t           map_size;
+       vm_object_t             object;
+       vm_object_size_t        size;
+       kern_return_t           result;
+       memory_object_t         pager;
+       vm_prot_t               pager_prot;
+       kern_return_t           kr;
 
-       vm_map_lock(map);
+       /*
+        * Check arguments for validity
+        */
+       if ((target_map == VM_MAP_NULL) ||
+           (cur_protection & ~VM_PROT_ALL) ||
+           (max_protection & ~VM_PROT_ALL) ||
+           (inheritance > VM_INHERIT_LAST_VALID) ||
+           initial_size == 0)
+               return KERN_INVALID_ARGUMENT;
 
-       submap->mapped = TRUE;
+       map_addr = vm_map_trunc_page(*address);
+       map_size = vm_map_round_page(initial_size);
+       size = vm_object_round_page(initial_size);      
 
-       VM_MAP_RANGE_CHECK(map, start, end);
+       object = memory_object_control_to_vm_object(control);
 
-       if (vm_map_lookup_entry(map, start, &entry)) {
-               vm_map_clip_start(map, entry, start);
+       if (object == VM_OBJECT_NULL)
+               return KERN_INVALID_OBJECT;
+
+       if (object == kernel_object) {
+               printf("Warning: Attempt to map kernel object"
+                      " by a non-private kernel entity\n");
+               return KERN_INVALID_OBJECT;
        }
-       else
-               entry = entry->vme_next;
 
-       if(entry == vm_map_to_entry(map)) {
-               vm_map_unlock(map);
-               return KERN_INVALID_ARGUMENT;
+       vm_object_lock(object);
+       object->ref_count++;
+       vm_object_res_reference(object);
+
+       /*
+        * For "named" VM objects, let the pager know that the
+        * memory object is being mapped.  Some pagers need to keep
+        * track of this, to know when they can reclaim the memory
+        * object, for example.
+        * VM calls memory_object_map() for each mapping (specifying
+        * the protection of each mapping) and calls
+        * memory_object_last_unmap() when all the mappings are gone.
+        */
+       pager_prot = max_protection;
+       if (copy) {
+               pager_prot &= ~VM_PROT_WRITE;
+       }
+       pager = object->pager;
+       if (object->named &&
+           pager != MEMORY_OBJECT_NULL &&
+           object->copy_strategy != MEMORY_OBJECT_COPY_NONE) {
+               assert(object->pager_ready);
+               vm_object_mapping_wait(object, THREAD_UNINT);
+               vm_object_mapping_begin(object);
+               vm_object_unlock(object);
+
+               kr = memory_object_map(pager, pager_prot);
+               assert(kr == KERN_SUCCESS);
+
+               vm_object_lock(object);
+               vm_object_mapping_end(object);
        }
+       vm_object_unlock(object);
 
-       vm_map_clip_end(map, entry, end);
+       /*
+        *      Perform the copy if requested
+        */
 
-       if ((entry->vme_start == start) && (entry->vme_end == end) &&
-           (!entry->is_sub_map) &&
-           ((object = entry->object.vm_object) == vm_submap_object) &&
-           (object->resident_page_count == 0) &&
-           (object->copy == VM_OBJECT_NULL) &&
-           (object->shadow == VM_OBJECT_NULL) &&
-           (!object->pager_created)) {
-                       entry->offset = (vm_object_offset_t)offset;
-                       entry->object.vm_object = VM_OBJECT_NULL;
-                       vm_object_deallocate(object);
-                       entry->is_sub_map = TRUE;
-                       entry->object.sub_map = submap;
-                       vm_map_reference(submap);
-#ifndef i386
-                       if ((use_pmap) && (offset == 0)) {
-                               /* nest if platform code will allow */
-                               if(submap->pmap == NULL) {
-                                       submap->pmap = pmap_create((vm_size_t) 0);
-                                       if(submap->pmap == PMAP_NULL) {
-                                               return(KERN_NO_SPACE);
-                                       }
-                               }
-                               result = pmap_nest(map->pmap, (entry->object.sub_map)->pmap, 
-                                                               (addr64_t)start, (addr64_t)start, (uint64_t)(end - start));
-                               if(result)
-                                       panic("vm_map_submap: pmap_nest failed, rc = %08X\n", result);
-                               entry->use_pmap = TRUE;
-                       }
-#endif
-#ifdef i386
-                       pmap_remove(map->pmap, (addr64_t)start, (addr64_t)end);
-#endif
+       if (copy) {
+               vm_object_t             new_object;
+               vm_object_offset_t      new_offset;
+
+               result = vm_object_copy_strategically(object, offset, size,
+                                                     &new_object, &new_offset,
+                                                     &copy);
+
+
+               if (result == KERN_MEMORY_RESTART_COPY) {
+                       boolean_t success;
+                       boolean_t src_needs_copy;
+
+                       /*
+                        * XXX
+                        * We currently ignore src_needs_copy.
+                        * This really is the issue of how to make
+                        * MEMORY_OBJECT_COPY_SYMMETRIC safe for
+                        * non-kernel users to use. Solution forthcoming.
+                        * In the meantime, since we don't allow non-kernel
+                        * memory managers to specify symmetric copy,
+                        * we won't run into problems here.
+                        */
+                       new_object = object;
+                       new_offset = offset;
+                       success = vm_object_copy_quickly(&new_object,
+                                                        new_offset, size,
+                                                        &src_needs_copy,
+                                                        &copy);
+                       assert(success);
                        result = KERN_SUCCESS;
+               }
+               /*
+                *      Throw away the reference to the
+                *      original object, as it won't be mapped.
+                */
+
+               vm_object_deallocate(object);
+
+               if (result != KERN_SUCCESS)
+                       return result;
+
+               object = new_object;
+               offset = new_offset;
        }
-       vm_map_unlock(map);
 
-       return(result);
+       result = vm_map_enter(target_map,
+                             &map_addr, map_size,
+                             (vm_map_offset_t)mask,
+                             flags,
+                             object, offset,
+                             copy,
+                             cur_protection, max_protection, inheritance);
+       if (result != KERN_SUCCESS)
+               vm_object_deallocate(object);
+       *address = map_addr;
+
+       return result;
 }
 
+
+#if    VM_CPM
+
+#ifdef MACH_ASSERT
+extern pmap_paddr_t    avail_start, avail_end;
+#endif
+
 /*
- *     vm_map_protect:
+ *     Allocate memory in the specified map, with the caveat that
+ *     the memory is physically contiguous.  This call may fail
+ *     if the system can't find sufficient contiguous memory.
+ *     This call may cause or lead to heart-stopping amounts of
+ *     paging activity.
  *
- *     Sets the protection of the specified address
- *     region in the target map.  If "set_max" is
- *     specified, the maximum protection is to be set;
- *     otherwise, only the current protection is affected.
+ *     Memory obtained from this call should be freed in the
+ *     normal way, viz., via vm_deallocate.
  */
 kern_return_t
-vm_map_protect(
-       register vm_map_t       map,
-       register vm_offset_t    start,
-       register vm_offset_t    end,
-       register vm_prot_t      new_prot,
-       register boolean_t      set_max)
+vm_map_enter_cpm(
+       vm_map_t                map,
+       vm_map_offset_t *addr,
+       vm_map_size_t           size,
+       int                     flags)
 {
-       register vm_map_entry_t         current;
-       register vm_offset_t            prev;
-       vm_map_entry_t                  entry;
-       vm_prot_t                       new_max;
-       boolean_t                       clip;
+       vm_object_t             cpm_obj;
+       pmap_t                  pmap;
+       vm_page_t               m, pages;
+       kern_return_t           kr;
+       vm_map_offset_t         va, start, end, offset;
+#if    MACH_ASSERT
+       vm_map_offset_t         prev_addr;
+#endif /* MACH_ASSERT */
 
-       XPR(XPR_VM_MAP,
-               "vm_map_protect, 0x%X start 0x%X end 0x%X, new 0x%X %d",
-               (integer_t)map, start, end, new_prot, set_max);
+       boolean_t               anywhere = ((VM_FLAGS_ANYWHERE & flags) != 0);
 
-       vm_map_lock(map);
+       if (!vm_allocate_cpm_enabled)
+               return KERN_FAILURE;
 
-       /*
-        *      Lookup the entry.  If it doesn't start in a valid
-        *      entry, return an error.  Remember if we need to
-        *      clip the entry.  We don't do it here because we don't
-        *      want to make any changes until we've scanned the 
-        *      entire range below for address and protection
-        *      violations.
-        */
-       if (!(clip = vm_map_lookup_entry(map, start, &entry))) {
-               vm_map_unlock(map);
-               return(KERN_INVALID_ADDRESS);
+       if (size == 0) {
+               *addr = 0;
+               return KERN_SUCCESS;
        }
+       if (anywhere)
+               *addr = vm_map_min(map);
+       else
+               *addr = vm_map_trunc_page(*addr);
+       size = vm_map_round_page(size);
 
        /*
-        *      Make a first pass to check for protection and address
-        *      violations.
+        * LP64todo - cpm_allocate should probably allow
+        * allocations of >4GB, but not with the current
+        * algorithm, so just cast down the size for now.
         */
+       if (size > VM_MAX_ADDRESS)
+               return KERN_RESOURCE_SHORTAGE;
+       if ((kr = cpm_allocate(CAST_DOWN(vm_size_t, size),
+                              &pages, 0, 0, TRUE, flags)) != KERN_SUCCESS)
+               return kr;
+
+       cpm_obj = vm_object_allocate((vm_object_size_t)size);
+       assert(cpm_obj != VM_OBJECT_NULL);
+       assert(cpm_obj->internal);
+       assert(cpm_obj->size == (vm_object_size_t)size);
+       assert(cpm_obj->can_persist == FALSE);
+       assert(cpm_obj->pager_created == FALSE);
+       assert(cpm_obj->pageout == FALSE);
+       assert(cpm_obj->shadow == VM_OBJECT_NULL);
 
-       current = entry;
-       prev = current->vme_start;
-       while ((current != vm_map_to_entry(map)) &&
-              (current->vme_start < end)) {
+       /*
+        *      Insert pages into object.
+        */
 
+       vm_object_lock(cpm_obj);
+       for (offset = 0; offset < size; offset += PAGE_SIZE) {
+               m = pages;
+               pages = NEXT_PAGE(m);
+               *(NEXT_PAGE_PTR(m)) = VM_PAGE_NULL;
+
+               assert(!m->gobbled);
+               assert(!m->wanted);
+               assert(!m->pageout);
+               assert(!m->tabled);
+               assert(VM_PAGE_WIRED(m));
                /*
-                * If there is a hole, return an error.
+                * ENCRYPTED SWAP:
+                * "m" is not supposed to be pageable, so it
+                * should not be encrypted.  It wouldn't be safe
+                * to enter it in a new VM object while encrypted.
                 */
-               if (current->vme_start != prev) {
-                       vm_map_unlock(map);
-                       return(KERN_INVALID_ADDRESS);
-               }
-
-               new_max = current->max_protection;
-               if(new_prot & VM_PROT_COPY) {
-                       new_max |= VM_PROT_WRITE;
-                       if ((new_prot & (new_max | VM_PROT_COPY)) != new_prot) {
-                               vm_map_unlock(map);
-                               return(KERN_PROTECTION_FAILURE);
-                       }
-               } else {
-                       if ((new_prot & new_max) != new_prot) {
-                               vm_map_unlock(map);
-                               return(KERN_PROTECTION_FAILURE);
-                       }
-               }
+               ASSERT_PAGE_DECRYPTED(m);
+               assert(m->busy);
+               assert(m->phys_page>=(avail_start>>PAGE_SHIFT) && m->phys_page<=(avail_end>>PAGE_SHIFT));
 
-               prev = current->vme_end;
-               current = current->vme_next;
-       }
-       if (end > prev) {
-               vm_map_unlock(map);
-               return(KERN_INVALID_ADDRESS);
+               m->busy = FALSE;
+               vm_page_insert(m, cpm_obj, offset);
        }
+       assert(cpm_obj->resident_page_count == size / PAGE_SIZE);
+       vm_object_unlock(cpm_obj);
 
        /*
-        *      Go back and fix up protections.
-        *      Clip to start here if the range starts within
-        *      the entry.
+        *      Hang onto a reference on the object in case a
+        *      multi-threaded application for some reason decides
+        *      to deallocate the portion of the address space into
+        *      which we will insert this object.
+        *
+        *      Unfortunately, we must insert the object now before
+        *      we can talk to the pmap module about which addresses
+        *      must be wired down.  Hence, the race with a multi-
+        *      threaded app.
         */
+       vm_object_reference(cpm_obj);
 
-       current = entry;
-       if (clip) {
-               vm_map_clip_start(map, entry, start);
+       /*
+        *      Insert object into map.
+        */
+
+       kr = vm_map_enter(
+               map,
+               addr,
+               size,
+               (vm_map_offset_t)0,
+               flags,
+               cpm_obj,
+               (vm_object_offset_t)0,
+               FALSE,
+               VM_PROT_ALL,
+               VM_PROT_ALL,
+               VM_INHERIT_DEFAULT);
+
+       if (kr != KERN_SUCCESS) {
+               /*
+                *      A CPM object doesn't have can_persist set,
+                *      so all we have to do is deallocate it to
+                *      free up these pages.
+                */
+               assert(cpm_obj->pager_created == FALSE);
+               assert(cpm_obj->can_persist == FALSE);
+               assert(cpm_obj->pageout == FALSE);
+               assert(cpm_obj->shadow == VM_OBJECT_NULL);
+               vm_object_deallocate(cpm_obj); /* kill acquired ref */
+               vm_object_deallocate(cpm_obj); /* kill creation ref */
        }
-       while ((current != vm_map_to_entry(map)) &&
-              (current->vme_start < end)) {
 
-               vm_prot_t       old_prot;
+       /*
+        *      Inform the physical mapping system that the
+        *      range of addresses may not fault, so that
+        *      page tables and such can be locked down as well.
+        */
+       start = *addr;
+       end = start + size;
+       pmap = vm_map_pmap(map);
+       pmap_pageable(pmap, start, end, FALSE);
 
-               vm_map_clip_end(map, current, end);
+       /*
+        *      Enter each page into the pmap, to avoid faults.
+        *      Note that this loop could be coded more efficiently,
+        *      if the need arose, rather than looking up each page
+        *      again.
+        */
+       for (offset = 0, va = start; offset < size;
+            va += PAGE_SIZE, offset += PAGE_SIZE) {
+               int type_of_fault;
 
-               old_prot = current->protection;
+               vm_object_lock(cpm_obj);
+               m = vm_page_lookup(cpm_obj, (vm_object_offset_t)offset);
+               assert(m != VM_PAGE_NULL);
 
-               if(new_prot & VM_PROT_COPY) {
-                       /* caller is asking specifically to copy the      */
-                       /* mapped data, this implies that max protection  */
-                       /* will include write.  Caller must be prepared   */
-                       /* for loss of shared memory communication in the */
-                       /* target area after taking this step */
-                       current->needs_copy = TRUE;
-                       current->max_protection |= VM_PROT_WRITE;
-               }
+               vm_page_zero_fill(m);
 
-               if (set_max)
-                       current->protection =
-                               (current->max_protection = 
-                                       new_prot & ~VM_PROT_COPY) &
-                                       old_prot;
-               else
-                       current->protection = new_prot & ~VM_PROT_COPY;
+               type_of_fault = DBG_ZERO_FILL_FAULT;
 
-               /*
-                *      Update physical map if necessary.
-                *      If the request is to turn off write protection, 
-                *      we won't do it for real (in pmap). This is because 
-                *      it would cause copy-on-write to fail.  We've already 
-                *      set, the new protection in the map, so if a 
-                *      write-protect fault occurred, it will be fixed up 
-                *      properly, COW or not.
-                */
-               /* the 256M hack for existing hardware limitations */
-               if (current->protection != old_prot) {
-                  if(current->is_sub_map && current->use_pmap) {
-                       vm_offset_t     pmap_base_addr;
-                       vm_offset_t     pmap_end_addr;
-                       vm_map_entry_t  local_entry;
-
-                       pmap_base_addr = 0xF0000000 & current->vme_start;
-                       pmap_end_addr = (pmap_base_addr + 0x10000000) - 1;
-#ifndef i386
-                       if(!vm_map_lookup_entry(map, 
-                                       pmap_base_addr, &local_entry))
-                          panic("vm_map_protect: nested pmap area is missing");
-                          while ((local_entry != vm_map_to_entry(map)) &&
-                                 (local_entry->vme_start < pmap_end_addr)) {
-                               local_entry->use_pmap = FALSE;
-                               local_entry = local_entry->vme_next;
-                          }
-                          pmap_unnest(map->pmap, (addr64_t)pmap_base_addr);
-#endif
-                  }
-                  if (!(current->protection & VM_PROT_WRITE)) {
-                       /* Look one level in we support nested pmaps */
-                       /* from mapped submaps which are direct entries */
-                       /* in our map */
-                       if(current->is_sub_map && current->use_pmap) {
-                               pmap_protect(current->object.sub_map->pmap, 
-                                       current->vme_start,
-                                       current->vme_end,
-                                       current->protection);
-                       } else {
-                               pmap_protect(map->pmap, current->vme_start,
-                                       current->vme_end,
-                                       current->protection);
+               vm_fault_enter(m, pmap, va, VM_PROT_ALL,
+                              VM_PAGE_WIRED(m), FALSE, FALSE,
+                              &type_of_fault);
+
+               vm_object_unlock(cpm_obj);
+       }
+
+#if    MACH_ASSERT
+       /*
+        *      Verify ordering in address space.
+        */
+       for (offset = 0; offset < size; offset += PAGE_SIZE) {
+               vm_object_lock(cpm_obj);
+               m = vm_page_lookup(cpm_obj, (vm_object_offset_t)offset);
+               vm_object_unlock(cpm_obj);
+               if (m == VM_PAGE_NULL)
+                       panic("vm_allocate_cpm:  obj 0x%x off 0x%x no page",
+                             cpm_obj, offset);
+               assert(m->tabled);
+               assert(!m->busy);
+               assert(!m->wanted);
+               assert(!m->fictitious);
+               assert(!m->private);
+               assert(!m->absent);
+               assert(!m->error);
+               assert(!m->cleaning);
+               assert(!m->precious);
+               assert(!m->clustered);
+               if (offset != 0) {
+                       if (m->phys_page != prev_addr + 1) {
+                               printf("start 0x%x end 0x%x va 0x%x\n",
+                                      start, end, va);
+                               printf("obj 0x%x off 0x%x\n", cpm_obj, offset);
+                               printf("m 0x%x prev_address 0x%x\n", m,
+                                      prev_addr);
+                               panic("vm_allocate_cpm:  pages not contig!");
                        }
-                  }
                }
-               current = current->vme_next;
+               prev_addr = m->phys_page;
        }
+#endif /* MACH_ASSERT */
 
-       vm_map_unlock(map);
-       return(KERN_SUCCESS);
+       vm_object_deallocate(cpm_obj); /* kill extra ref */
+
+       return kr;
 }
 
+
+#else  /* VM_CPM */
+
 /*
- *     vm_map_inherit:
- *
- *     Sets the inheritance of the specified address
- *     range in the target map.  Inheritance
- *     affects how the map will be shared with
- *     child maps at the time of vm_map_fork.
+ *     Interface is defined in all cases, but unless the kernel
+ *     is built explicitly for this option, the interface does
+ *     nothing.
  */
+
 kern_return_t
-vm_map_inherit(
-       register vm_map_t       map,
-       register vm_offset_t    start,
-       register vm_offset_t    end,
-       register vm_inherit_t   new_inheritance)
+vm_map_enter_cpm(
+       __unused vm_map_t       map,
+       __unused vm_map_offset_t        *addr,
+       __unused vm_map_size_t  size,
+       __unused int            flags)
 {
-       register vm_map_entry_t entry;
-       vm_map_entry_t  temp_entry;
+       return KERN_FAILURE;
+}
+#endif /* VM_CPM */
 
-       vm_map_lock(map);
+/* Not used without nested pmaps */
+#ifndef NO_NESTED_PMAP
+/*
+ * Clip and unnest a portion of a nested submap mapping.
+ */
 
-       VM_MAP_RANGE_CHECK(map, start, end);
 
-       if (vm_map_lookup_entry(map, start, &temp_entry)) {
-               entry = temp_entry;
-               vm_map_clip_start(map, entry, start);
-       }
-       else {
-               temp_entry = temp_entry->vme_next;
-               entry = temp_entry;
-       }
+static void
+vm_map_clip_unnest(
+       vm_map_t        map,
+       vm_map_entry_t  entry,
+       vm_map_offset_t start_unnest,
+       vm_map_offset_t end_unnest)
+{
+       vm_map_offset_t old_start_unnest = start_unnest;
+       vm_map_offset_t old_end_unnest = end_unnest;
 
-       /* first check entire range for submaps which can't support the */
-       /* given inheritance. */
-       while ((entry != vm_map_to_entry(map)) && (entry->vme_start < end)) {
-               if(entry->is_sub_map) {
-                       if(new_inheritance == VM_INHERIT_COPY)
-                               return(KERN_INVALID_ARGUMENT);
-               }
+       assert(entry->is_sub_map);
+       assert(entry->object.sub_map != NULL);
 
-               entry = entry->vme_next;
+       /*
+        * Query the platform for the optimal unnest range.
+        * DRK: There's some duplication of effort here, since
+        * callers may have adjusted the range to some extent. This
+        * routine was introduced to support 1GiB subtree nesting
+        * for x86 platforms, which can also nest on 2MiB boundaries
+        * depending on size/alignment.
+        */
+       if (pmap_adjust_unnest_parameters(map->pmap, &start_unnest, &end_unnest)) {
+               log_unnest_badness(map, old_start_unnest, old_end_unnest);
        }
 
-       entry = temp_entry;
-
-       while ((entry != vm_map_to_entry(map)) && (entry->vme_start < end)) {
-               vm_map_clip_end(map, entry, end);
-
-               entry->inheritance = new_inheritance;
+       if (entry->vme_start > start_unnest ||
+           entry->vme_end < end_unnest) {
+               panic("vm_map_clip_unnest(0x%llx,0x%llx): "
+                     "bad nested entry: start=0x%llx end=0x%llx\n",
+                     (long long)start_unnest, (long long)end_unnest,
+                     (long long)entry->vme_start, (long long)entry->vme_end);
+       }
 
-               entry = entry->vme_next;
+       if (start_unnest > entry->vme_start) {
+               _vm_map_clip_start(&map->hdr,
+                                  entry,
+                                  start_unnest);
+               UPDATE_FIRST_FREE(map, map->first_free);
+       }
+       if (entry->vme_end > end_unnest) {
+               _vm_map_clip_end(&map->hdr,
+                                entry,
+                                end_unnest);
+               UPDATE_FIRST_FREE(map, map->first_free);
        }
 
-       vm_map_unlock(map);
-       return(KERN_SUCCESS);
+       pmap_unnest(map->pmap,
+                   entry->vme_start,
+                   entry->vme_end - entry->vme_start);
+       if ((map->mapped) && (map->ref_count)) {
+               /* clean up parent map/maps */
+               vm_map_submap_pmap_clean(
+                       map, entry->vme_start,
+                       entry->vme_end,
+                       entry->object.sub_map,
+                       entry->offset);
+       }
+       entry->use_pmap = FALSE;
 }
+#endif /* NO_NESTED_PMAP */
 
 /*
- *     vm_map_wire:
- *
- *     Sets the pageability of the specified address range in the
- *     target map as wired.  Regions specified as not pageable require
- *     locked-down physical memory and physical page maps.  The
- *     access_type variable indicates types of accesses that must not
- *     generate page faults.  This is checked against protection of
- *     memory being locked-down.
+ *     vm_map_clip_start:      [ internal use only ]
  *
- *     The map must not be locked, but a reference must remain to the
- *     map throughout the call.
+ *     Asserts that the given entry begins at or after
+ *     the specified address; if necessary,
+ *     it splits the entry into two.
  */
-kern_return_t
-vm_map_wire_nested(
-       register vm_map_t       map,
-       register vm_offset_t    start,
-       register vm_offset_t    end,
-       register vm_prot_t      access_type,
-       boolean_t               user_wire,
-       pmap_t                  map_pmap, 
-       vm_offset_t             pmap_addr)
+static void
+vm_map_clip_start(
+       vm_map_t        map,
+       vm_map_entry_t  entry,
+       vm_map_offset_t startaddr)
 {
-       register vm_map_entry_t entry;
-       struct vm_map_entry     *first_entry, tmp_entry;
-       vm_map_t                pmap_map;
-       register vm_offset_t    s,e;
-       kern_return_t           rc;
-       boolean_t               need_wakeup;
-       boolean_t               main_map = FALSE;
-       wait_interrupt_t        interruptible_state;
-       thread_t                cur_thread;
-       unsigned int            last_timestamp;
-       vm_size_t               size;
-
-       vm_map_lock(map);
-       if(map_pmap == NULL)
-               main_map = TRUE;
-       last_timestamp = map->timestamp;
+#ifndef NO_NESTED_PMAP
+       if (entry->use_pmap &&
+           startaddr >= entry->vme_start) {
+               vm_map_offset_t start_unnest, end_unnest;
 
-       VM_MAP_RANGE_CHECK(map, start, end);
-       assert(page_aligned(start));
-       assert(page_aligned(end));
-       if (start == end) {
-               /* We wired what the caller asked for, zero pages */
-               vm_map_unlock(map);
-               return KERN_SUCCESS;
+               /*
+                * Make sure "startaddr" is no longer in a nested range
+                * before we clip.  Unnest only the minimum range the platform
+                * can handle.
+                * vm_map_clip_unnest may perform additional adjustments to
+                * the unnest range.
+                */
+               start_unnest = startaddr & ~(pmap_nesting_size_min - 1);
+               end_unnest = start_unnest + pmap_nesting_size_min;
+               vm_map_clip_unnest(map, entry, start_unnest, end_unnest);
+       }
+#endif /* NO_NESTED_PMAP */
+       if (startaddr > entry->vme_start) {
+               if (entry->object.vm_object &&
+                   !entry->is_sub_map &&
+                   entry->object.vm_object->phys_contiguous) {
+                       pmap_remove(map->pmap,
+                                   (addr64_t)(entry->vme_start),
+                                   (addr64_t)(entry->vme_end));
+               }
+               _vm_map_clip_start(&map->hdr, entry, startaddr);
+               UPDATE_FIRST_FREE(map, map->first_free);
        }
+}
 
-       if (vm_map_lookup_entry(map, start, &first_entry)) {
-               entry = first_entry;
-               /* vm_map_clip_start will be done later. */
-       } else {
-               /* Start address is not in map */
-               vm_map_unlock(map);
-               return(KERN_INVALID_ADDRESS);
-       }
 
-       s=start;
-       need_wakeup = FALSE;
-       cur_thread = current_thread();
-       while ((entry != vm_map_to_entry(map)) && (entry->vme_start < end)) {
-               /*
-                * If another thread is wiring/unwiring this entry then
-                * block after informing other thread to wake us up.
-                */
-               if (entry->in_transition) {
-                       wait_result_t wait_result;
+#define vm_map_copy_clip_start(copy, entry, startaddr) \
+       MACRO_BEGIN \
+       if ((startaddr) > (entry)->vme_start) \
+               _vm_map_clip_start(&(copy)->cpy_hdr,(entry),(startaddr)); \
+       MACRO_END
 
-                       /*
-                        * We have not clipped the entry.  Make sure that
-                        * the start address is in range so that the lookup
-                        * below will succeed.
-                        */
-                       s = entry->vme_start < start? start: entry->vme_start;
+/*
+ *     This routine is called only when it is known that
+ *     the entry must be split.
+ */
+static void
+_vm_map_clip_start(
+       register struct vm_map_header   *map_header,
+       register vm_map_entry_t         entry,
+       register vm_map_offset_t                start)
+{
+       register vm_map_entry_t new_entry;
 
-                       entry->needs_wakeup = TRUE;
+       /*
+        *      Split off the front portion --
+        *      note that we must insert the new
+        *      entry BEFORE this one, so that
+        *      this entry has the specified starting
+        *      address.
+        */
 
-                       /*
-                        * wake up anybody waiting on entries that we have
-                        * already wired.
-                        */
-                       if (need_wakeup) {
-                               vm_map_entry_wakeup(map);
-                               need_wakeup = FALSE;
-                       }
-                       /*
-                        * User wiring is interruptible
-                        */
-                       wait_result = vm_map_entry_wait(map, 
-                                         (user_wire) ? THREAD_ABORTSAFE :
-                                                       THREAD_UNINT);
-                       if (user_wire && wait_result == THREAD_INTERRUPTED) {
-                               /*
-                                * undo the wirings we have done so far
-                                * We do not clear the needs_wakeup flag,
-                                * because we cannot tell if we were the
-                                * only one waiting.
-                                */
-                               vm_map_unlock(map);
-                               vm_map_unwire(map, start, s, user_wire);
-                               return(KERN_FAILURE);
-                       }
+       new_entry = _vm_map_entry_create(map_header);
+       vm_map_entry_copy_full(new_entry, entry);
 
-                       /*
-                        * Cannot avoid a lookup here. reset timestamp.
-                        */
-                       last_timestamp = map->timestamp;
+       new_entry->vme_end = start;
+       entry->offset += (start - entry->vme_start);
+       entry->vme_start = start;
 
-                       /*
-                        * The entry could have been clipped, look it up again.
-                        * Worse that can happen is, it may not exist anymore.
-                        */
-                       if (!vm_map_lookup_entry(map, s, &first_entry)) {
-                               if (!user_wire)
-                                       panic("vm_map_wire: re-lookup failed");
+       _vm_map_entry_link(map_header, entry->vme_prev, new_entry);
 
-                               /*
-                                * User: undo everything upto the previous
-                                * entry.  let vm_map_unwire worry about
-                                * checking the validity of the range.
-                                */
-                               vm_map_unlock(map);
-                               vm_map_unwire(map, start, s, user_wire);
-                               return(KERN_FAILURE);
-                       }
-                       entry = first_entry;
-                       continue;
-               }
-               
-               if(entry->is_sub_map) {
-                       vm_offset_t     sub_start;
-                       vm_offset_t     sub_end;
-                       vm_offset_t     local_start;
-                       vm_offset_t     local_end;
-                       pmap_t          pmap;
-                       
-                       vm_map_clip_start(map, entry, start);
-                       vm_map_clip_end(map, entry, end);
-
-                       sub_start = entry->offset;
-                       sub_end = entry->vme_end - entry->vme_start;
-                       sub_end += entry->offset;
-                       
-                       local_end = entry->vme_end;
-                       if(map_pmap == NULL) {
-                               if(entry->use_pmap) {
-                                       pmap = entry->object.sub_map->pmap;
-                                       /* ppc implementation requires that */
-                                       /* submaps pmap address ranges line */
-                                       /* up with parent map */
-#ifdef notdef
-                                       pmap_addr = sub_start;
-#endif
-                                       pmap_addr = start;
-                               } else {
-                                       pmap = map->pmap;
-                                       pmap_addr = start;
-                               }
-                               if (entry->wired_count) {
-                                       if (entry->wired_count 
-                                                       >= MAX_WIRE_COUNT)
-                                       panic("vm_map_wire: too many wirings");
-
-                                       if (user_wire &&
-                                               entry->user_wired_count 
-                                                       >= MAX_WIRE_COUNT) {
-                                          vm_map_unlock(map);
-                                          vm_map_unwire(map, start,
-                                               entry->vme_start, user_wire);
-                                          return(KERN_FAILURE);
-                                       }
-                                       if(user_wire)
-                                               entry->user_wired_count++;
-                                       if((!user_wire) ||
-                                            (entry->user_wired_count == 0))
-                                               entry->wired_count++;
-                                       entry = entry->vme_next;
-                                       continue;
-
-                               } else {
-                                       vm_object_t             object;
-                                       vm_object_offset_t      offset_hi;
-                                       vm_object_offset_t      offset_lo;
-                                       vm_object_offset_t      offset;
-                                       vm_prot_t               prot;
-                                       boolean_t               wired;
-                                       vm_behavior_t           behavior;
-                                       vm_map_entry_t          local_entry;
-                                       vm_map_version_t         version;
-                                       vm_map_t                lookup_map;
-
-                                       /* call vm_map_lookup_locked to */
-                                       /* cause any needs copy to be   */
-                                       /* evaluated */
-                                       local_start = entry->vme_start;
-                                       lookup_map = map;
-                                       vm_map_lock_write_to_read(map);
-                                       if(vm_map_lookup_locked(
-                                               &lookup_map, local_start, 
-                                               access_type,
-                                               &version, &object,
-                                               &offset, &prot, &wired,
-                                               &behavior, &offset_lo,
-                                               &offset_hi, &pmap_map)) {
-                                               
-                                               vm_map_unlock(lookup_map);
-                                               vm_map_unwire(map, start,
-                                                  entry->vme_start, user_wire);
-                                               return(KERN_FAILURE);
-                                       }
-                                       if(pmap_map != lookup_map)
-                                               vm_map_unlock(pmap_map);
-                                       vm_map_unlock_read(lookup_map);
-                                       vm_map_lock(map);
-                                       vm_object_unlock(object);
-
-                                       if (!vm_map_lookup_entry(map, 
-                                               local_start, &local_entry)) {
-                                               vm_map_unlock(map);
-                                               vm_map_unwire(map, start,
-                                                  entry->vme_start, user_wire);
-                                               return(KERN_FAILURE);
-                                       }
-                                       /* did we have a change of type? */
-                                       if (!local_entry->is_sub_map) {
-                                               last_timestamp = map->timestamp;
-                                               continue;
-                                       }
-                                       entry = local_entry;
-                                       if (user_wire)
-                                               entry->user_wired_count++;
-                                       if((!user_wire) || 
-                                               (entry->user_wired_count == 1))
-                                       entry->wired_count++;
-
-                                       entry->in_transition = TRUE;
-
-                                       vm_map_unlock(map);
-                                       rc = vm_map_wire_nested(
-                                               entry->object.sub_map, 
-                                               sub_start, sub_end,
-                                               access_type, 
-                                               user_wire, pmap, pmap_addr);
-                                       vm_map_lock(map);
-                               }
-                       } else {
-                               local_start = entry->vme_start;
-                               if (user_wire)
-                                       entry->user_wired_count++;
-                               if((!user_wire) || 
-                                       (entry->user_wired_count == 1))
-                                       entry->wired_count++;
-                               vm_map_unlock(map);
-                               rc = vm_map_wire_nested(entry->object.sub_map, 
-                                               sub_start, sub_end,
-                                               access_type, 
-                                               user_wire, pmap, pmap_addr);
-                               vm_map_lock(map);
-                       }
-                       s = entry->vme_start;
-                       e = entry->vme_end;
-
-                       /*
-                        * Find the entry again.  It could have been clipped
-                        * after we unlocked the map.
-                        */
-                       if (!vm_map_lookup_entry(map, local_start,
-                                                &first_entry))
-                               panic("vm_map_wire: re-lookup failed");
-                       entry = first_entry;
+       if (entry->is_sub_map)
+               vm_map_reference(new_entry->object.sub_map);
+       else
+               vm_object_reference(new_entry->object.vm_object);
+}
 
-                       last_timestamp = map->timestamp;
-                       while ((entry != vm_map_to_entry(map)) &&
-                                    (entry->vme_start < e)) {
-                               assert(entry->in_transition);
-                               entry->in_transition = FALSE;
-                               if (entry->needs_wakeup) {
-                                       entry->needs_wakeup = FALSE;
-                                       need_wakeup = TRUE;
-                               }
-                               if (rc != KERN_SUCCESS) {/* from vm_*_wire */
-                                       if (user_wire)
-                                               entry->user_wired_count--;
-                                       if ((!user_wire) || 
-                                               (entry->user_wired_count == 0))
-                                               entry->wired_count--;
-                               }
-                               entry = entry->vme_next;
-                       }
-                       if (rc != KERN_SUCCESS) {       /* from vm_*_wire */
-                               vm_map_unlock(map);
-                               if (need_wakeup)
-                                       vm_map_entry_wakeup(map);
-                               /*
-                                * undo everything upto the previous entry.
-                                */
-                               (void)vm_map_unwire(map, start, s, user_wire);
-                               return rc;
-                       }
-                       continue;
-               }
 
+/*
+ *     vm_map_clip_end:        [ internal use only ]
+ *
+ *     Asserts that the given entry ends at or before
+ *     the specified address; if necessary,
+ *     it splits the entry into two.
+ */
+static void
+vm_map_clip_end(
+       vm_map_t        map,
+       vm_map_entry_t  entry,
+       vm_map_offset_t endaddr)
+{
+       if (endaddr > entry->vme_end) {
                /*
-                * If this entry is already wired then increment
-                * the appropriate wire reference count.
+                * Within the scope of this clipping, limit "endaddr" to
+                * the end of this map entry...
                 */
-               if (entry->wired_count) {
-                       /* sanity check: wired_count is a short */
-                       if (entry->wired_count >= MAX_WIRE_COUNT)
-                               panic("vm_map_wire: too many wirings");
-
-                       if (user_wire &&
-                           entry->user_wired_count >= MAX_WIRE_COUNT) {
-                               vm_map_unlock(map);
-                               vm_map_unwire(map, start,
-                                               entry->vme_start, user_wire);
-                               return(KERN_FAILURE);
-                       }
-                       /*
-                        * entry is already wired down, get our reference
-                        * after clipping to our range.
-                        */
-                       vm_map_clip_start(map, entry, start);
-                       vm_map_clip_end(map, entry, end);
-                       if (user_wire)
-                               entry->user_wired_count++;
-                       if ((!user_wire) || (entry->user_wired_count == 1))
-                               entry->wired_count++;
-
-                       entry = entry->vme_next;
-                       continue;
-               }
+               endaddr = entry->vme_end;
+       }
+#ifndef NO_NESTED_PMAP
+       if (entry->use_pmap) {
+               vm_map_offset_t start_unnest, end_unnest;
 
                /*
-                * Unwired entry or wire request transmitted via submap
+                * Make sure the range between the start of this entry and
+                * the new "endaddr" is no longer nested before we clip.
+                * Unnest only the minimum range the platform can handle.
+                * vm_map_clip_unnest may perform additional adjustments to
+                * the unnest range.
                 */
+               start_unnest = entry->vme_start;
+               end_unnest =
+                       (endaddr + pmap_nesting_size_min - 1) &
+                       ~(pmap_nesting_size_min - 1);
+               vm_map_clip_unnest(map, entry, start_unnest, end_unnest);
+       }
+#endif /* NO_NESTED_PMAP */
+       if (endaddr < entry->vme_end) {
+               if (entry->object.vm_object &&
+                   !entry->is_sub_map &&
+                   entry->object.vm_object->phys_contiguous) {
+                       pmap_remove(map->pmap,
+                                   (addr64_t)(entry->vme_start),
+                                   (addr64_t)(entry->vme_end));
+               }
+               _vm_map_clip_end(&map->hdr, entry, endaddr);
+               UPDATE_FIRST_FREE(map, map->first_free);
+       }
+}
 
 
-               /*
-                * Perform actions of vm_map_lookup that need the write
-                * lock on the map: create a shadow object for a
-                * copy-on-write region, or an object for a zero-fill
-                * region.
-                */
-               size = entry->vme_end - entry->vme_start;
-               /*
-                * If wiring a copy-on-write page, we need to copy it now
-                * even if we're only (currently) requesting read access.
-                * This is aggressive, but once it's wired we can't move it.
-                */
-               if (entry->needs_copy) {
-                       vm_object_shadow(&entry->object.vm_object,
-                                        &entry->offset, size);
-                       entry->needs_copy = FALSE;
-               } else if (entry->object.vm_object == VM_OBJECT_NULL) {
-                       entry->object.vm_object = vm_object_allocate(size);
-                       entry->offset = (vm_object_offset_t)0;
-               }
-
-               vm_map_clip_start(map, entry, start);
-               vm_map_clip_end(map, entry, end);
+#define vm_map_copy_clip_end(copy, entry, endaddr) \
+       MACRO_BEGIN \
+       if ((endaddr) < (entry)->vme_end) \
+               _vm_map_clip_end(&(copy)->cpy_hdr,(entry),(endaddr)); \
+       MACRO_END
 
-               s = entry->vme_start;
-               e = entry->vme_end;
+/*
+ *     This routine is called only when it is known that
+ *     the entry must be split.
+ */
+static void
+_vm_map_clip_end(
+       register struct vm_map_header   *map_header,
+       register vm_map_entry_t         entry,
+       register vm_map_offset_t        end)
+{
+       register vm_map_entry_t new_entry;
 
-               /*
-                * Check for holes and protection mismatch.
-                * Holes: Next entry should be contiguous unless this
-                *        is the end of the region.
-                * Protection: Access requested must be allowed, unless
-                *      wiring is by protection class
-                */
-               if ((((entry->vme_end < end) &&
-                    ((entry->vme_next == vm_map_to_entry(map)) ||
-                     (entry->vme_next->vme_start > entry->vme_end))) ||
-                    ((entry->protection & access_type) != access_type))) {
-                       /*
-                        * Found a hole or protection problem.
-                        * Unwire the region we wired so far.
-                        */
-                       if (start != entry->vme_start) {
-                               vm_map_unlock(map);
-                               vm_map_unwire(map, start, s, user_wire);
-                       } else {
-                               vm_map_unlock(map);
-                       }
-                       return((entry->protection&access_type) != access_type?
-                               KERN_PROTECTION_FAILURE: KERN_INVALID_ADDRESS);
-               }
+       /*
+        *      Create a new entry and insert it
+        *      AFTER the specified entry
+        */
 
-               assert(entry->wired_count == 0 && entry->user_wired_count == 0);
+       new_entry = _vm_map_entry_create(map_header);
+       vm_map_entry_copy_full(new_entry, entry);
 
-               if (user_wire)
-                       entry->user_wired_count++;
-               if ((!user_wire) || (entry->user_wired_count == 1))
-                       entry->wired_count++;
+       new_entry->vme_start = entry->vme_end = end;
+       new_entry->offset += (end - entry->vme_start);
 
-               entry->in_transition = TRUE;
+       _vm_map_entry_link(map_header, entry, new_entry);
 
-               /*
-                * This entry might get split once we unlock the map.
-                * In vm_fault_wire(), we need the current range as
-                * defined by this entry.  In order for this to work
-                * along with a simultaneous clip operation, we make a
-                * temporary copy of this entry and use that for the
-                * wiring.  Note that the underlying objects do not
-                * change during a clip.
-                */
-               tmp_entry = *entry;
+       if (entry->is_sub_map)
+               vm_map_reference(new_entry->object.sub_map);
+       else
+               vm_object_reference(new_entry->object.vm_object);
+}
 
-               /*
-                * The in_transition state guarentees that the entry
-                * (or entries for this range, if split occured) will be
-                * there when the map lock is acquired for the second time.
-                */
-               vm_map_unlock(map);
 
-               if (!user_wire && cur_thread != THREAD_NULL)
-                       interruptible_state = thread_interrupt_level(THREAD_UNINT);
+/*
+ *     VM_MAP_RANGE_CHECK:     [ internal use only ]
+ *
+ *     Asserts that the starting and ending region
+ *     addresses fall within the valid range of the map.
+ */
+#define        VM_MAP_RANGE_CHECK(map, start, end)     \
+       MACRO_BEGIN                             \
+       if (start < vm_map_min(map))            \
+               start = vm_map_min(map);        \
+       if (end > vm_map_max(map))              \
+               end = vm_map_max(map);          \
+       if (start > end)                        \
+               start = end;                    \
+       MACRO_END
 
-               if(map_pmap)
-                       rc = vm_fault_wire(map, 
-                                       &tmp_entry, map_pmap, pmap_addr);
-               else
-                       rc = vm_fault_wire(map, 
-                                       &tmp_entry, map->pmap, 
-                                       tmp_entry.vme_start);
+/*
+ *     vm_map_range_check:     [ internal use only ]
+ *     
+ *     Check that the region defined by the specified start and
+ *     end addresses are wholly contained within a single map
+ *     entry or set of adjacent map entries of the spacified map,
+ *     i.e. the specified region contains no unmapped space.
+ *     If any or all of the region is unmapped, FALSE is returned.
+ *     Otherwise, TRUE is returned and if the output argument 'entry'
+ *     is not NULL it points to the map entry containing the start
+ *     of the region.
+ *
+ *     The map is locked for reading on entry and is left locked.
+ */
+static boolean_t
+vm_map_range_check(
+       register vm_map_t       map,
+       register vm_map_offset_t        start,
+       register vm_map_offset_t        end,
+       vm_map_entry_t          *entry)
+{
+       vm_map_entry_t          cur;
+       register vm_map_offset_t        prev;
 
-               if (!user_wire && cur_thread != THREAD_NULL)
-                       thread_interrupt_level(interruptible_state);
+       /*
+        *      Basic sanity checks first
+        */
+       if (start < vm_map_min(map) || end > vm_map_max(map) || start > end)
+               return (FALSE);
 
-               vm_map_lock(map);
-
-               if (last_timestamp+1 != map->timestamp) {
-                       /*
-                        * Find the entry again.  It could have been clipped
-                        * after we unlocked the map.
-                        */
-                       if (!vm_map_lookup_entry(map, tmp_entry.vme_start,
-                                                               &first_entry))
-                               panic("vm_map_wire: re-lookup failed");
-
-                       entry = first_entry;
-               }
-
-               last_timestamp = map->timestamp;
-
-               while ((entry != vm_map_to_entry(map)) &&
-                      (entry->vme_start < tmp_entry.vme_end)) {
-                       assert(entry->in_transition);
-                       entry->in_transition = FALSE;
-                       if (entry->needs_wakeup) {
-                               entry->needs_wakeup = FALSE;
-                               need_wakeup = TRUE;
-                       }
-                       if (rc != KERN_SUCCESS) {       /* from vm_*_wire */
-                               if (user_wire)
-                                       entry->user_wired_count--;
-                               if ((!user_wire) || 
-                                               (entry->user_wired_count == 0))
-                                       entry->wired_count--;
-                       }
-                       entry = entry->vme_next;
-               }
-
-               if (rc != KERN_SUCCESS) {               /* from vm_*_wire */
-                       vm_map_unlock(map);
-                       if (need_wakeup)
-                               vm_map_entry_wakeup(map);
-                       /*
-                        * undo everything upto the previous entry.
-                        */
-                       (void)vm_map_unwire(map, start, s, user_wire);
-                       return rc;
-               }
-       } /* end while loop through map entries */
-       vm_map_unlock(map);
+       /*
+        *      Check first if the region starts within a valid
+        *      mapping for the map.
+        */
+       if (!vm_map_lookup_entry(map, start, &cur))
+               return (FALSE);
 
        /*
-        * wake up anybody waiting on entries we wired.
+        *      Optimize for the case that the region is contained 
+        *      in a single map entry.
         */
-       if (need_wakeup)
-               vm_map_entry_wakeup(map);
-
-       return(KERN_SUCCESS);
-
-}
-
-kern_return_t
-vm_map_wire(
-       register vm_map_t       map,
-       register vm_offset_t    start,
-       register vm_offset_t    end,
-       register vm_prot_t      access_type,
-       boolean_t               user_wire)
-{
-
-       kern_return_t   kret;
+       if (entry != (vm_map_entry_t *) NULL)
+               *entry = cur;
+       if (end <= cur->vme_end)
+               return (TRUE);
 
-#ifdef ppc
-        /*
-        * the calls to mapping_prealloc and mapping_relpre
-        * (along with the VM_MAP_RANGE_CHECK to insure a
-        * resonable range was passed in) are
-        * currently necessary because
-        * we haven't enabled kernel pre-emption
-        * and/or the pmap_enter cannot purge and re-use
-        * existing mappings
+       /*
+        *      If the region is not wholly contained within a
+        *      single entry, walk the entries looking for holes.
         */
-       VM_MAP_RANGE_CHECK(map, start, end);
-        mapping_prealloc(end - start);
-#endif
-       kret = vm_map_wire_nested(map, start, end, access_type, 
-                                               user_wire, (pmap_t)NULL, 0);
-#ifdef ppc
-       mapping_relpre();
-#endif
-       return kret;
+       prev = cur->vme_end;
+       cur = cur->vme_next;
+       while ((cur != vm_map_to_entry(map)) && (prev == cur->vme_start)) {
+               if (end <= cur->vme_end)
+                       return (TRUE);
+               prev = cur->vme_end;
+               cur = cur->vme_next;
+       }
+       return (FALSE);
 }
 
 /*
- *     vm_map_unwire:
+ *     vm_map_submap:          [ kernel use only ]
  *
- *     Sets the pageability of the specified address range in the target
- *     as pageable.  Regions specified must have been wired previously.
+ *     Mark the given range as handled by a subordinate map.
  *
- *     The map must not be locked, but a reference must remain to the map
- *     throughout the call.
+ *     This range must have been created with vm_map_find using
+ *     the vm_submap_object, and no other operations may have been
+ *     performed on this range prior to calling vm_map_submap.
  *
- *     Kernel will panic on failures.  User unwire ignores holes and
- *     unwired and intransition entries to avoid losing memory by leaving
- *     it unwired.
+ *     Only a limited number of operations can be performed
+ *     within this rage after calling vm_map_submap:
+ *             vm_fault
+ *     [Don't try vm_map_copyin!]
+ *
+ *     To remove a submapping, one must first remove the
+ *     range from the superior map, and then destroy the
+ *     submap (if desired).  [Better yet, don't try it.]
  */
 kern_return_t
-vm_map_unwire_nested(
-       register vm_map_t       map,
-       register vm_offset_t    start,
-       register vm_offset_t    end,
-       boolean_t               user_wire,
-       pmap_t                  map_pmap,
-       vm_offset_t             pmap_addr)
+vm_map_submap(
+       vm_map_t                map,
+       vm_map_offset_t start,
+       vm_map_offset_t end,
+       vm_map_t                submap,
+       vm_map_offset_t offset,
+#ifdef NO_NESTED_PMAP
+       __unused
+#endif /* NO_NESTED_PMAP */
+       boolean_t               use_pmap)
 {
-       register vm_map_entry_t entry;
-       struct vm_map_entry     *first_entry, tmp_entry;
-       boolean_t               need_wakeup;
-       boolean_t               main_map = FALSE;
-       unsigned int            last_timestamp;
+       vm_map_entry_t          entry;
+       register kern_return_t  result = KERN_INVALID_ARGUMENT;
+       register vm_object_t    object;
 
        vm_map_lock(map);
-       if(map_pmap == NULL)
-               main_map = TRUE;
-       last_timestamp = map->timestamp;
-
-       VM_MAP_RANGE_CHECK(map, start, end);
-       assert(page_aligned(start));
-       assert(page_aligned(end));
 
-       if (vm_map_lookup_entry(map, start, &first_entry)) {
-               entry = first_entry;
-               /*      vm_map_clip_start will be done later. */
+       if (! vm_map_lookup_entry(map, start, &entry)) {
+               entry = entry->vme_next;
        }
-       else {
-               /*      Start address is not in map. */
+
+       if (entry == vm_map_to_entry(map) ||
+           entry->is_sub_map) {
                vm_map_unlock(map);
-               return(KERN_INVALID_ADDRESS);
+               return KERN_INVALID_ARGUMENT;
        }
 
-       need_wakeup = FALSE;
-       while ((entry != vm_map_to_entry(map)) && (entry->vme_start < end)) {
-               if (entry->in_transition) {
-                       /*
-                        * 1)
-                        * Another thread is wiring down this entry. Note
-                        * that if it is not for the other thread we would
-                        * be unwiring an unwired entry.  This is not
-                        * permitted.  If we wait, we will be unwiring memory
-                        * we did not wire.
-                        *
-                        * 2)
-                        * Another thread is unwiring this entry.  We did not
-                        * have a reference to it, because if we did, this
-                        * entry will not be getting unwired now.
-                        */
-                       if (!user_wire)
-                               panic("vm_map_unwire: in_transition entry");
+       assert(!entry->use_pmap); /* we don't want to unnest anything here */
+       vm_map_clip_start(map, entry, start);
+       vm_map_clip_end(map, entry, end);
 
-                       entry = entry->vme_next;
-                       continue;
+       if ((entry->vme_start == start) && (entry->vme_end == end) &&
+           (!entry->is_sub_map) &&
+           ((object = entry->object.vm_object) == vm_submap_object) &&
+           (object->resident_page_count == 0) &&
+           (object->copy == VM_OBJECT_NULL) &&
+           (object->shadow == VM_OBJECT_NULL) &&
+           (!object->pager_created)) {
+               entry->offset = (vm_object_offset_t)offset;
+               entry->object.vm_object = VM_OBJECT_NULL;
+               vm_object_deallocate(object);
+               entry->is_sub_map = TRUE;
+               entry->object.sub_map = submap;
+               vm_map_reference(submap);
+               submap->mapped = TRUE;
+
+#ifndef NO_NESTED_PMAP
+               if (use_pmap) {
+                       /* nest if platform code will allow */
+                       if(submap->pmap == NULL) {
+                               submap->pmap = pmap_create((vm_map_size_t) 0, FALSE);
+                               if(submap->pmap == PMAP_NULL) {
+                                       vm_map_unlock(map);
+                                       return(KERN_NO_SPACE);
+                               }
+                       }
+                       result = pmap_nest(map->pmap,
+                                          (entry->object.sub_map)->pmap, 
+                                          (addr64_t)start,
+                                          (addr64_t)start,
+                                          (uint64_t)(end - start));
+                       if(result)
+                               panic("vm_map_submap: pmap_nest failed, rc = %08X\n", result);
+                       entry->use_pmap = TRUE;
                }
+#else  /* NO_NESTED_PMAP */
+               pmap_remove(map->pmap, (addr64_t)start, (addr64_t)end);
+#endif /* NO_NESTED_PMAP */
+               result = KERN_SUCCESS;
+       }
+       vm_map_unlock(map);
 
-               if(entry->is_sub_map) {
-                       vm_offset_t     sub_start;
-                       vm_offset_t     sub_end;
-                       vm_offset_t     local_end;
-                       pmap_t          pmap;
-                       
-
-                       vm_map_clip_start(map, entry, start);
-                       vm_map_clip_end(map, entry, end);
+       return(result);
+}
 
-                       sub_start = entry->offset;
-                       sub_end = entry->vme_end - entry->vme_start;
-                       sub_end += entry->offset;
-                       local_end = entry->vme_end;
-                       if(map_pmap == NULL) {
-                          if(entry->use_pmap) {
-                                       pmap = entry->object.sub_map->pmap;
-                                       pmap_addr = sub_start;
-                          } else {
-                                       pmap = map->pmap;
-                                       pmap_addr = start;
-                          }
-                          if (entry->wired_count == 0 ||
-                              (user_wire && entry->user_wired_count == 0)) {
-                               if (!user_wire)
-                                  panic("vm_map_unwire: entry is unwired");
-                             entry = entry->vme_next;
-                             continue;
-                          }
-
-                          /*
-                           * Check for holes
-                           * Holes: Next entry should be contiguous unless
-                           * this is the end of the region.
-                           */
-                          if (((entry->vme_end < end) && 
-                               ((entry->vme_next == vm_map_to_entry(map)) ||
-                               (entry->vme_next->vme_start 
-                                               > entry->vme_end)))) {
-                               if (!user_wire)
-                                 panic("vm_map_unwire: non-contiguous region");
 /*
-                               entry = entry->vme_next;
-                               continue;
-*/
-                          }
-
-                          if (!user_wire || (--entry->user_wired_count == 0))
-                               entry->wired_count--;
-
-                          if (entry->wired_count != 0) {
-                               entry = entry->vme_next;
-                               continue;
-                          }
+ *     vm_map_protect:
+ *
+ *     Sets the protection of the specified address
+ *     region in the target map.  If "set_max" is
+ *     specified, the maximum protection is to be set;
+ *     otherwise, only the current protection is affected.
+ */
+kern_return_t
+vm_map_protect(
+       register vm_map_t       map,
+       register vm_map_offset_t        start,
+       register vm_map_offset_t        end,
+       register vm_prot_t      new_prot,
+       register boolean_t      set_max)
+{
+       register vm_map_entry_t         current;
+       register vm_map_offset_t        prev;
+       vm_map_entry_t                  entry;
+       vm_prot_t                       new_max;
 
-                          entry->in_transition = TRUE;
-                          tmp_entry = *entry;/* see comment in vm_map_wire() */
+       XPR(XPR_VM_MAP,
+           "vm_map_protect, 0x%X start 0x%X end 0x%X, new 0x%X %d",
+           map, start, end, new_prot, set_max);
 
-                          /*
-                           * We can unlock the map now. The in_transition state
-                           * guarantees existance of the entry.
-                           */
-                          vm_map_unlock(map);
-                          vm_map_unwire_nested(entry->object.sub_map, 
-                               sub_start, sub_end, user_wire, pmap, pmap_addr);
-                          vm_map_lock(map);
+       vm_map_lock(map);
 
-                          if (last_timestamp+1 != map->timestamp) {
-                               /*
-                                * Find the entry again.  It could have been 
-                                * clipped or deleted after we unlocked the map.
-                                */
-                               if (!vm_map_lookup_entry(map, 
-                                               tmp_entry.vme_start,
-                                                       &first_entry)) {
-                                       if (!user_wire)
-                                         panic("vm_map_unwire: re-lookup failed");
-                                       entry = first_entry->vme_next;
-                               } else
-                                       entry = first_entry;
-                          }
-                          last_timestamp = map->timestamp;
-
-                          /*
-                           * clear transition bit for all constituent entries
-                           * that were in the original entry (saved in 
-                           * tmp_entry).  Also check for waiters.
-                           */
-                          while ((entry != vm_map_to_entry(map)) &&
-                               (entry->vme_start < tmp_entry.vme_end)) {
-                               assert(entry->in_transition);
-                               entry->in_transition = FALSE;
-                               if (entry->needs_wakeup) {
-                                       entry->needs_wakeup = FALSE;
-                                       need_wakeup = TRUE;
-                               }
-                               entry = entry->vme_next;
-                          }
-                          continue;
-                       } else {
-                          vm_map_unlock(map);
-                          vm_map_unwire_nested(entry->object.sub_map, 
-                               sub_start, sub_end, user_wire, pmap, pmap_addr);
-                          vm_map_lock(map);
+       /* LP64todo - remove this check when vm_map_commpage64()
+        * no longer has to stuff in a map_entry for the commpage
+        * above the map's max_offset.
+        */
+       if (start >= map->max_offset) {
+               vm_map_unlock(map);
+               return(KERN_INVALID_ADDRESS);
+       }
 
-                          if (last_timestamp+1 != map->timestamp) {
-                               /*
-                                * Find the entry again.  It could have been 
-                                * clipped or deleted after we unlocked the map.
-                                */
-                               if (!vm_map_lookup_entry(map, 
-                                               tmp_entry.vme_start,
-                                                       &first_entry)) {
-                                       if (!user_wire)
-                                         panic("vm_map_unwire: re-lookup failed");
-                                       entry = first_entry->vme_next;
-                               } else
-                                       entry = first_entry;
-                          }
-                          last_timestamp = map->timestamp;
-                       }
+       while(1) {
+               /*
+                *      Lookup the entry.  If it doesn't start in a valid
+                *      entry, return an error.
+                */
+               if (! vm_map_lookup_entry(map, start, &entry)) {
+                       vm_map_unlock(map);
+                       return(KERN_INVALID_ADDRESS);
                }
 
-
-               if ((entry->wired_count == 0) ||
-                  (user_wire && entry->user_wired_count == 0)) {
-                       if (!user_wire)
-                               panic("vm_map_unwire: entry is unwired");
-
-                       entry = entry->vme_next;
+               if (entry->superpage_size && (start & (SUPERPAGE_SIZE-1))) { /* extend request to whole entry */
+                       start = SUPERPAGE_ROUND_DOWN(start);
                        continue;
                }
-               
-               assert(entry->wired_count > 0 &&
-                       (!user_wire || entry->user_wired_count > 0));
+               break;
+       }
+       if (entry->superpage_size)
+               end = SUPERPAGE_ROUND_UP(end);
 
-               vm_map_clip_start(map, entry, start);
-               vm_map_clip_end(map, entry, end);
+       /*
+        *      Make a first pass to check for protection and address
+        *      violations.
+        */
 
-               /*
-                * Check for holes
-                * Holes: Next entry should be contiguous unless
-                *        this is the end of the region.
-                */
-               if (((entry->vme_end < end) && 
-                   ((entry->vme_next == vm_map_to_entry(map)) ||
-                    (entry->vme_next->vme_start > entry->vme_end)))) {
+       current = entry;
+       prev = current->vme_start;
+       while ((current != vm_map_to_entry(map)) &&
+              (current->vme_start < end)) {
 
-                       if (!user_wire)
-                               panic("vm_map_unwire: non-contiguous region");
-                       entry = entry->vme_next;
-                       continue;
+               /*
+                * If there is a hole, return an error.
+                */
+               if (current->vme_start != prev) {
+                       vm_map_unlock(map);
+                       return(KERN_INVALID_ADDRESS);
                }
 
-               if (!user_wire || (--entry->user_wired_count == 0))
-                       entry->wired_count--;
-
-               if (entry->wired_count != 0) {
-                       entry = entry->vme_next;
-                       continue;
+               new_max = current->max_protection;
+               if(new_prot & VM_PROT_COPY) {
+                       new_max |= VM_PROT_WRITE;
+                       if ((new_prot & (new_max | VM_PROT_COPY)) != new_prot) {
+                               vm_map_unlock(map);
+                               return(KERN_PROTECTION_FAILURE);
+                       }
+               } else {
+                       if ((new_prot & new_max) != new_prot) {
+                               vm_map_unlock(map);
+                               return(KERN_PROTECTION_FAILURE);
+                       }
                }
 
-               entry->in_transition = TRUE;
-               tmp_entry = *entry;     /* see comment in vm_map_wire() */
+#if CONFIG_EMBEDDED
+               if (new_prot & VM_PROT_WRITE) {
+                       if (new_prot & VM_PROT_EXECUTE) {
+                               printf("EMBEDDED: %s can't have both write and exec at the same time\n", __FUNCTION__);
+                               new_prot &= ~VM_PROT_EXECUTE;
+                       }
+               }
+#endif
 
-               /*
-                * We can unlock the map now. The in_transition state
-                * guarantees existance of the entry.
-                */
+               prev = current->vme_end;
+               current = current->vme_next;
+       }
+       if (end > prev) {
                vm_map_unlock(map);
-               if(map_pmap) {
-                       vm_fault_unwire(map, 
-                               &tmp_entry, FALSE, map_pmap, pmap_addr);
-               } else {
-                       vm_fault_unwire(map, 
-                               &tmp_entry, FALSE, map->pmap, 
-                               tmp_entry.vme_start);
-               }
-               vm_map_lock(map);
+               return(KERN_INVALID_ADDRESS);
+       }
 
-               if (last_timestamp+1 != map->timestamp) {
-                       /*
-                        * Find the entry again.  It could have been clipped
-                        * or deleted after we unlocked the map.
-                        */
-                       if (!vm_map_lookup_entry(map, tmp_entry.vme_start,
-                                                               &first_entry)) {
-                               if (!user_wire)
-                                      panic("vm_map_unwire: re-lookup failed");
-                               entry = first_entry->vme_next;
-                       } else
-                               entry = first_entry;
+       /*
+        *      Go back and fix up protections.
+        *      Clip to start here if the range starts within
+        *      the entry.
+        */
+
+       current = entry;
+       if (current != vm_map_to_entry(map)) {
+               /* clip and unnest if necessary */
+               vm_map_clip_start(map, current, start);
+       }
+
+       while ((current != vm_map_to_entry(map)) &&
+              (current->vme_start < end)) {
+
+               vm_prot_t       old_prot;
+
+               vm_map_clip_end(map, current, end);
+
+               assert(!current->use_pmap); /* clipping did unnest if needed */
+
+               old_prot = current->protection;
+
+               if(new_prot & VM_PROT_COPY) {
+                       /* caller is asking specifically to copy the      */
+                       /* mapped data, this implies that max protection  */
+                       /* will include write.  Caller must be prepared   */
+                       /* for loss of shared memory communication in the */
+                       /* target area after taking this step */
+                       current->needs_copy = TRUE;
+                       current->max_protection |= VM_PROT_WRITE;
                }
-               last_timestamp = map->timestamp;
+
+               if (set_max)
+                       current->protection =
+                               (current->max_protection = 
+                                new_prot & ~VM_PROT_COPY) &
+                               old_prot;
+               else
+                       current->protection = new_prot & ~VM_PROT_COPY;
 
                /*
-                * clear transition bit for all constituent entries that
-                * were in the original entry (saved in tmp_entry).  Also
-                * check for waiters.
+                *      Update physical map if necessary.
+                *      If the request is to turn off write protection, 
+                *      we won't do it for real (in pmap). This is because 
+                *      it would cause copy-on-write to fail.  We've already 
+                *      set, the new protection in the map, so if a 
+                *      write-protect fault occurred, it will be fixed up 
+                *      properly, COW or not.
                 */
-               while ((entry != vm_map_to_entry(map)) &&
-                      (entry->vme_start < tmp_entry.vme_end)) {
-                       assert(entry->in_transition);
-                       entry->in_transition = FALSE;
-                       if (entry->needs_wakeup) {
-                               entry->needs_wakeup = FALSE;
-                               need_wakeup = TRUE;
+               if (current->protection != old_prot) {
+                       /* Look one level in we support nested pmaps */
+                       /* from mapped submaps which are direct entries */
+                       /* in our map */
+
+                       vm_prot_t prot;
+
+                       prot = current->protection & ~VM_PROT_WRITE;
+
+                       if (override_nx(map, current->alias) && prot)
+                               prot |= VM_PROT_EXECUTE;
+
+                       if (current->is_sub_map && current->use_pmap) {
+                               pmap_protect(current->object.sub_map->pmap, 
+                                            current->vme_start,
+                                            current->vme_end,
+                                            prot);
+                       } else {
+                               pmap_protect(map->pmap,
+                                            current->vme_start,
+                                            current->vme_end,
+                                            prot);
                        }
-                       entry = entry->vme_next;
                }
+               current = current->vme_next;
+       }
+
+       current = entry;
+       while ((current != vm_map_to_entry(map)) &&
+              (current->vme_start <= end)) {
+               vm_map_simplify_entry(map, current);
+               current = current->vme_next;
        }
+
        vm_map_unlock(map);
-       /*
-        * wake up anybody waiting on entries that we have unwired.
-        */
-       if (need_wakeup)
-               vm_map_entry_wakeup(map);
        return(KERN_SUCCESS);
-
 }
 
+/*
+ *     vm_map_inherit:
+ *
+ *     Sets the inheritance of the specified address
+ *     range in the target map.  Inheritance
+ *     affects how the map will be shared with
+ *     child maps at the time of vm_map_fork.
+ */
 kern_return_t
-vm_map_unwire(
+vm_map_inherit(
        register vm_map_t       map,
-       register vm_offset_t    start,
-       register vm_offset_t    end,
-       boolean_t               user_wire)
+       register vm_map_offset_t        start,
+       register vm_map_offset_t        end,
+       register vm_inherit_t   new_inheritance)
 {
-       return vm_map_unwire_nested(map, start, end, 
-                                       user_wire, (pmap_t)NULL, 0);
-}
+       register vm_map_entry_t entry;
+       vm_map_entry_t  temp_entry;
 
+       vm_map_lock(map);
 
-/*
- *     vm_map_entry_delete:    [ internal use only ]
- *
- *     Deallocate the given entry from the target map.
- */            
-void
-vm_map_entry_delete(
-       register vm_map_t       map,
-       register vm_map_entry_t entry)
-{
-       register vm_offset_t    s, e;
-       register vm_object_t    object;
-       register vm_map_t       submap;
-       extern vm_object_t      kernel_object;
+       VM_MAP_RANGE_CHECK(map, start, end);
 
-       s = entry->vme_start;
-       e = entry->vme_end;
-       assert(page_aligned(s));
-       assert(page_aligned(e));
-       assert(entry->wired_count == 0);
-       assert(entry->user_wired_count == 0);
+       if (vm_map_lookup_entry(map, start, &temp_entry)) {
+               entry = temp_entry;
+       }
+       else {
+               temp_entry = temp_entry->vme_next;
+               entry = temp_entry;
+       }
 
-       if (entry->is_sub_map) {
-               object = NULL;
-               submap = entry->object.sub_map;
-       } else {
-               submap = NULL;
-               object = entry->object.vm_object;
+       /* first check entire range for submaps which can't support the */
+       /* given inheritance. */
+       while ((entry != vm_map_to_entry(map)) && (entry->vme_start < end)) {
+               if(entry->is_sub_map) {
+                       if(new_inheritance == VM_INHERIT_COPY) {
+                               vm_map_unlock(map);
+                               return(KERN_INVALID_ARGUMENT);
+                       }
+               }
+
+               entry = entry->vme_next;
        }
 
-       vm_map_entry_unlink(map, entry);
-       map->size -= e - s;
+       entry = temp_entry;
+       if (entry != vm_map_to_entry(map)) {
+               /* clip and unnest if necessary */
+               vm_map_clip_start(map, entry, start);
+       }
 
-       vm_map_entry_dispose(map, entry);
+       while ((entry != vm_map_to_entry(map)) && (entry->vme_start < end)) {
+               vm_map_clip_end(map, entry, end);
+               assert(!entry->use_pmap); /* clip did unnest if needed */
 
-       vm_map_unlock(map);
-       /*
-        *      Deallocate the object only after removing all
-        *      pmap entries pointing to its pages.
-        */
-       if (submap)
-               vm_map_deallocate(submap);
-       else
-               vm_object_deallocate(object);
+               entry->inheritance = new_inheritance;
+
+               entry = entry->vme_next;
+       }
 
+       vm_map_unlock(map);
+       return(KERN_SUCCESS);
 }
 
-void
-vm_map_submap_pmap_clean(
+/*
+ * Update the accounting for the amount of wired memory in this map.  If the user has
+ * exceeded the defined limits, then we fail.  Wiring on behalf of the kernel never fails.
+ */
+
+static kern_return_t
+add_wire_counts(
        vm_map_t        map,
-       vm_offset_t     start,
-       vm_offset_t     end,
-       vm_map_t        sub_map,
-       vm_offset_t     offset)
-{
-       vm_offset_t     submap_start;
-       vm_offset_t     submap_end;
-       vm_offset_t     addr;
-       vm_size_t       remove_size;
-       vm_map_entry_t  entry;
+       vm_map_entry_t  entry, 
+       boolean_t       user_wire)
+{ 
+       vm_map_size_t   size;
 
-       submap_end = offset + (end - start);
-       submap_start = offset;
-       if(vm_map_lookup_entry(sub_map, offset, &entry)) {
-                       
-               remove_size = (entry->vme_end - entry->vme_start);
-               if(offset > entry->vme_start)
-                       remove_size -= offset - entry->vme_start;
-                       
+       if (user_wire) {
 
-               if(submap_end < entry->vme_end) {
-                       remove_size -=
-                               entry->vme_end - submap_end;
-               }
-               if(entry->is_sub_map) {
-                       vm_map_submap_pmap_clean(
-                               sub_map,
-                               start,
-                               start + remove_size,
-                               entry->object.sub_map,
-                               entry->offset);
-               } else {
+               /*
+                * We're wiring memory at the request of the user.  Check if this is the first time the user is wiring
+                * this map entry.
+                */
 
-                       if((map->mapped) && (map->ref_count)
-                               && (entry->object.vm_object != NULL)) {
-                               vm_object_pmap_protect(
-                                       entry->object.vm_object,
-                                       entry->offset,
-                                       remove_size,
-                                       PMAP_NULL,
-                                       entry->vme_start,
-                                       VM_PROT_NONE);
-                       } else {
-                               pmap_remove(map->pmap, 
-                                       (addr64_t)start, 
-                                       (addr64_t)(start + remove_size));
-                       }
+               if (entry->user_wired_count == 0) {
+                       size = entry->vme_end - entry->vme_start;
+                       /*
+                        * Since this is the first time the user is wiring this map entry, check to see if we're
+                        * exceeding the user wire limits.  There is a per map limit which is the smaller of either
+                        * the process's rlimit or the global vm_user_wire_limit which caps this value.  There is also
+                        * a system-wide limit on the amount of memory all users can wire.  If the user is over either
+                        * limit, then we fail.
+                        */
+
+                       if(size + map->user_wire_size > MIN(map->user_wire_limit, vm_user_wire_limit) ||
+                          size + ptoa_64(vm_page_wire_count) > vm_global_user_wire_limit ||
+                          size + ptoa_64(vm_page_wire_count) > max_mem - vm_global_no_user_wire_amount)
+                               return KERN_RESOURCE_SHORTAGE;
+
+                       /*
+                        * The first time the user wires an entry, we also increment the wired_count and add this to
+                        * the total that has been wired in the map.
+                        */
+
+                       if (entry->wired_count >= MAX_WIRE_COUNT)
+                               return KERN_FAILURE;
+
+                       entry->wired_count++;
+                       map->user_wire_size += size;
                }
+
+               if (entry->user_wired_count >= MAX_WIRE_COUNT)
+                       return KERN_FAILURE;
+
+               entry->user_wired_count++;
+
+       } else {
+
+               /*
+                * The kernel's wiring the memory.  Just bump the count and continue.
+                */
+
+               if (entry->wired_count >= MAX_WIRE_COUNT)
+                       panic("vm_map_wire: too many wirings");
+
+               entry->wired_count++;
        }
 
-       entry = entry->vme_next;
-       
-       while((entry != vm_map_to_entry(sub_map)) 
-                       && (entry->vme_start < submap_end)) {
-               remove_size = (entry->vme_end - entry->vme_start); 
-               if(submap_end < entry->vme_end) {
-                       remove_size -= entry->vme_end - submap_end;
-               }
-               if(entry->is_sub_map) {
-                       vm_map_submap_pmap_clean(
-                               sub_map,
-                               (start + entry->vme_start) - offset,
-                               ((start + entry->vme_start) - offset) + remove_size,
-                               entry->object.sub_map,
-                               entry->offset);
-               } else {
-                       if((map->mapped) && (map->ref_count)
-                               && (entry->object.vm_object != NULL)) {
-                               vm_object_pmap_protect(
-                                       entry->object.vm_object,
-                                       entry->offset,
-                                       remove_size,
-                                       PMAP_NULL,
-                                       entry->vme_start,
-                                       VM_PROT_NONE);
-                       } else {
-                               pmap_remove(map->pmap, 
-                                  (addr64_t)((start + entry->vme_start) 
-                                                               - offset),
-                                  (addr64_t)(((start + entry->vme_start) 
-                                       - offset) + remove_size));
-                       }
+       return KERN_SUCCESS;
+}
+
+/*
+ * Update the memory wiring accounting now that the given map entry is being unwired.
+ */
+
+static void
+subtract_wire_counts(
+       vm_map_t        map,
+       vm_map_entry_t  entry, 
+       boolean_t       user_wire)
+{ 
+
+       if (user_wire) {
+
+               /*
+                * We're unwiring memory at the request of the user.  See if we're removing the last user wire reference.
+                */
+
+               if (entry->user_wired_count == 1) {
+
+                       /*
+                        * We're removing the last user wire reference.  Decrement the wired_count and the total
+                        * user wired memory for this map.
+                        */
+
+                       assert(entry->wired_count >= 1);
+                       entry->wired_count--;
+                       map->user_wire_size -= entry->vme_end - entry->vme_start;
                }
-               entry = entry->vme_next;
-       } 
-       return;
+
+               assert(entry->user_wired_count >= 1);
+               entry->user_wired_count--;
+
+       } else {
+
+               /*
+                * The kernel is unwiring the memory.   Just update the count.
+                */
+
+               assert(entry->wired_count >= 1);
+               entry->wired_count--;
+       }
 }
 
 /*
- *     vm_map_delete:  [ internal use only ]
+ *     vm_map_wire:
  *
- *     Deallocates the given address range from the target map.
- *     Removes all user wirings. Unwires one kernel wiring if
- *     VM_MAP_REMOVE_KUNWIRE is set.  Waits for kernel wirings to go
- *     away if VM_MAP_REMOVE_WAIT_FOR_KWIRE is set.  Sleeps
- *     interruptibly if VM_MAP_REMOVE_INTERRUPTIBLE is set.
+ *     Sets the pageability of the specified address range in the
+ *     target map as wired.  Regions specified as not pageable require
+ *     locked-down physical memory and physical page maps.  The
+ *     access_type variable indicates types of accesses that must not
+ *     generate page faults.  This is checked against protection of
+ *     memory being locked-down.
  *
- *     This routine is called with map locked and leaves map locked.
+ *     The map must not be locked, but a reference must remain to the
+ *     map throughout the call.
  */
-kern_return_t
-vm_map_delete(
+static kern_return_t
+vm_map_wire_nested(
        register vm_map_t       map,
-       vm_offset_t             start,
-       register vm_offset_t    end,
-       int                     flags)
+       register vm_map_offset_t        start,
+       register vm_map_offset_t        end,
+       register vm_prot_t      access_type,
+       boolean_t               user_wire,
+       pmap_t                  map_pmap, 
+       vm_map_offset_t         pmap_addr)
 {
-       vm_map_entry_t          entry, next;
-       struct   vm_map_entry   *first_entry, tmp_entry;
-       register vm_offset_t    s, e;
-       register vm_object_t    object;
+       register vm_map_entry_t entry;
+       struct vm_map_entry     *first_entry, tmp_entry;
+       vm_map_t                real_map;
+       register vm_map_offset_t        s,e;
+       kern_return_t           rc;
        boolean_t               need_wakeup;
-       unsigned int            last_timestamp = ~0; /* unlikely value */
-       int                     interruptible;
-       extern vm_map_t         kernel_map;
+       boolean_t               main_map = FALSE;
+       wait_interrupt_t        interruptible_state;
+       thread_t                cur_thread;
+       unsigned int            last_timestamp;
+       vm_map_size_t           size;
 
-       interruptible = (flags & VM_MAP_REMOVE_INTERRUPTIBLE) ? 
-                       THREAD_ABORTSAFE : THREAD_UNINT;
+       vm_map_lock(map);
+       if(map_pmap == NULL)
+               main_map = TRUE;
+       last_timestamp = map->timestamp;
 
-       /*
-        * All our DMA I/O operations in IOKit are currently done by
-        * wiring through the map entries of the task requesting the I/O.
-        * Because of this, we must always wait for kernel wirings
-        * to go away on the entries before deleting them.
-        *
-        * Any caller who wants to actually remove a kernel wiring
-        * should explicitly set the VM_MAP_REMOVE_KUNWIRE flag to
-        * properly remove one wiring instead of blasting through
-        * them all.
-        */
-       flags |= VM_MAP_REMOVE_WAIT_FOR_KWIRE;
+       VM_MAP_RANGE_CHECK(map, start, end);
+       assert(page_aligned(start));
+       assert(page_aligned(end));
+       if (start == end) {
+               /* We wired what the caller asked for, zero pages */
+               vm_map_unlock(map);
+               return KERN_SUCCESS;
+       }
 
-       /*
-        *      Find the start of the region, and clip it
-        */
-       if (vm_map_lookup_entry(map, start, &first_entry)) {
-               entry = first_entry;
-               vm_map_clip_start(map, entry, start);
+       need_wakeup = FALSE;
+       cur_thread = current_thread();
+
+       s = start;
+       rc = KERN_SUCCESS;
 
+       if (vm_map_lookup_entry(map, s, &first_entry)) {
+               entry = first_entry;
                /*
-                *      Fix the lookup hint now, rather than each
-                *      time through the loop.
+                * vm_map_clip_start will be done later.
+                * We don't want to unnest any nested submaps here !
                 */
-               SAVE_HINT(map, entry->vme_prev);
        } else {
-               entry = first_entry->vme_next;
+               /* Start address is not in map */
+               rc = KERN_INVALID_ADDRESS;
+               goto done;
        }
 
-       need_wakeup = FALSE;
-       /*
-        *      Step through all entries in this region
-        */
-       while ((entry != vm_map_to_entry(map)) && (entry->vme_start < end)) {
+       while ((entry != vm_map_to_entry(map)) && (s < end)) {
+               /*
+                * At this point, we have wired from "start" to "s".
+                * We still need to wire from "s" to "end".
+                *
+                * "entry" hasn't been clipped, so it could start before "s"
+                * and/or end after "end".
+                */
 
-               vm_map_clip_end(map, entry, end);
+               /* "e" is how far we want to wire in this entry */
+               e = entry->vme_end;
+               if (e > end)
+                       e = end;
+
+               /*
+                * If another thread is wiring/unwiring this entry then
+                * block after informing other thread to wake us up.
+                */
                if (entry->in_transition) {
                        wait_result_t wait_result;
 
                        /*
-                        * Another thread is wiring/unwiring this entry.
-                        * Let the other thread know we are waiting.
+                        * We have not clipped the entry.  Make sure that
+                        * the start address is in range so that the lookup
+                        * below will succeed.
+                        * "s" is the current starting point: we've already
+                        * wired from "start" to "s" and we still have
+                        * to wire from "s" to "end".
                         */
-                       s = entry->vme_start;
+
                        entry->needs_wakeup = TRUE;
 
                        /*
                         * wake up anybody waiting on entries that we have
-                        * already unwired/deleted.
+                        * already wired.
                         */
                        if (need_wakeup) {
                                vm_map_entry_wakeup(map);
                                need_wakeup = FALSE;
                        }
-
-                       wait_result = vm_map_entry_wait(map, interruptible);
-
-                       if (interruptible &&
-                           wait_result == THREAD_INTERRUPTED) {
+                       /*
+                        * User wiring is interruptible
+                        */
+                       wait_result = vm_map_entry_wait(map, 
+                                                       (user_wire) ? THREAD_ABORTSAFE :
+                                                       THREAD_UNINT);
+                       if (user_wire && wait_result == THREAD_INTERRUPTED) {
                                /*
+                                * undo the wirings we have done so far
                                 * We do not clear the needs_wakeup flag,
-                                * since we cannot tell if we were the only one.
+                                * because we cannot tell if we were the
+                                * only one waiting.
                                 */
-                               vm_map_unlock(map);
-                               return KERN_ABORTED;
+                               rc = KERN_FAILURE;
+                               goto done;
                        }
 
                        /*
-                        * The entry could have been clipped or it
-                        * may not exist anymore.  Look it up again.
+                        * Cannot avoid a lookup here. reset timestamp.
                         */
-                       if (!vm_map_lookup_entry(map, s, &first_entry)) {
-                               assert((map != kernel_map) && 
-                                      (!entry->is_sub_map));
-                               /*
-                                * User: use the next entry
-                                */
-                               entry = first_entry->vme_next;
-                       } else {
-                               entry = first_entry;
-                               SAVE_HINT(map, entry->vme_prev);
-                       }
                        last_timestamp = map->timestamp;
-                       continue;
-               } /* end in_transition */
 
-               if (entry->wired_count) {
                        /*
-                        *      Remove a kernel wiring if requested or if
-                        *      there are user wirings.
+                        * The entry could have been clipped, look it up again.
+                        * Worse that can happen is, it may not exist anymore.
                         */
-                       if ((flags & VM_MAP_REMOVE_KUNWIRE) || 
-                          (entry->user_wired_count > 0))
-                               entry->wired_count--;
-
-                       /* remove all user wire references */
-                       entry->user_wired_count = 0;
+                       if (!vm_map_lookup_entry(map, s, &first_entry)) {
+                               if (!user_wire)
+                                       panic("vm_map_wire: re-lookup failed");
 
-                       if (entry->wired_count != 0) {
-                               assert((map != kernel_map) && 
-                                      (!entry->is_sub_map));
                                /*
-                                * Cannot continue.  Typical case is when
-                                * a user thread has physical io pending on
-                                * on this page.  Either wait for the
-                                * kernel wiring to go away or return an
-                                * error.
+                                * User: undo everything upto the previous
+                                * entry.  let vm_map_unwire worry about
+                                * checking the validity of the range.
                                 */
-                               if (flags & VM_MAP_REMOVE_WAIT_FOR_KWIRE) {
-                                       wait_result_t wait_result;
+                               rc = KERN_FAILURE;
+                               goto done;
+                       }
+                       entry = first_entry;
+                       continue;
+               }
+       
+               if (entry->is_sub_map) {
+                       vm_map_offset_t sub_start;
+                       vm_map_offset_t sub_end;
+                       vm_map_offset_t local_start;
+                       vm_map_offset_t local_end;
+                       pmap_t          pmap;
 
-                                       s = entry->vme_start;
-                                       entry->needs_wakeup = TRUE;
-                                       wait_result = vm_map_entry_wait(map,
-                                                               interruptible);
+                       vm_map_clip_start(map, entry, s);
+                       vm_map_clip_end(map, entry, end);
 
-                                       if (interruptible &&
-                                           wait_result == THREAD_INTERRUPTED) {
-                                               /*
-                                                * We do not clear the 
-                                                * needs_wakeup flag, since we 
-                                                * cannot tell if we were the 
-                                                * only one.
-                                                */
-                                               vm_map_unlock(map);
-                                               return KERN_ABORTED;
-                                       }
+                       sub_start = entry->offset;
+                       sub_end = entry->vme_end;
+                       sub_end += entry->offset - entry->vme_start;
+               
+                       local_end = entry->vme_end;
+                       if(map_pmap == NULL) {
+                               vm_object_t             object;
+                               vm_object_offset_t      offset;
+                               vm_prot_t               prot;
+                               boolean_t               wired;
+                               vm_map_entry_t          local_entry;
+                               vm_map_version_t         version;
+                               vm_map_t                lookup_map;
 
-                                       /*
-                                        * The entry could have been clipped or
-                                        * it may not exist anymore.  Look it
-                                        * up again.
-                                        */
-                                       if (!vm_map_lookup_entry(map, s, 
-                                                               &first_entry)) {
-                                               assert((map != kernel_map) && 
-                                               (!entry->is_sub_map));
-                                               /*
-                                                * User: use the next entry
-                                                */
-                                               entry = first_entry->vme_next;
-                                       } else {
-                                               entry = first_entry;
-                                               SAVE_HINT(map, entry->vme_prev);
-                                       }
-                                       last_timestamp = map->timestamp;
-                                       continue;
+                               if(entry->use_pmap) {
+                                       pmap = entry->object.sub_map->pmap;
+                                       /* ppc implementation requires that */
+                                       /* submaps pmap address ranges line */
+                                       /* up with parent map */
+#ifdef notdef
+                                       pmap_addr = sub_start;
+#endif
+                                       pmap_addr = s;
+                               } else {
+                                       pmap = map->pmap;
+                                       pmap_addr = s;
                                }
-                               else {
-                                       return KERN_FAILURE;
+
+                               if (entry->wired_count) {
+                                       if ((rc = add_wire_counts(map, entry, user_wire)) != KERN_SUCCESS)
+                                               goto done;
+
+                                       /*
+                                        * The map was not unlocked:
+                                        * no need to goto re-lookup.
+                                        * Just go directly to next entry.
+                                        */
+                                       entry = entry->vme_next;
+                                       s = entry->vme_start;
+                                       continue;
+
                                }
-                       }
 
-                       entry->in_transition = TRUE;
-                       /*
-                        * copy current entry.  see comment in vm_map_wire()
-                        */
-                       tmp_entry = *entry;
-                       s = entry->vme_start;
-                       e = entry->vme_end;
+                               /* call vm_map_lookup_locked to */
+                               /* cause any needs copy to be   */
+                               /* evaluated */
+                               local_start = entry->vme_start;
+                               lookup_map = map;
+                               vm_map_lock_write_to_read(map);
+                               if(vm_map_lookup_locked(
+                                          &lookup_map, local_start, 
+                                          access_type,
+                                          OBJECT_LOCK_EXCLUSIVE,
+                                          &version, &object,
+                                          &offset, &prot, &wired,
+                                          NULL,
+                                          &real_map)) {
 
-                       /*
-                        * We can unlock the map now. The in_transition
-                        * state guarentees existance of the entry.
-                        */
-                       vm_map_unlock(map);
-                       vm_fault_unwire(map, &tmp_entry,
-                               tmp_entry.object.vm_object == kernel_object,
-                               map->pmap, tmp_entry.vme_start);
-                       vm_map_lock(map);
+                                       vm_map_unlock_read(lookup_map);
+                                       vm_map_unwire(map, start,
+                                                     s, user_wire);
+                                       return(KERN_FAILURE);
+                               }
+                               if(real_map != lookup_map)
+                                       vm_map_unlock(real_map);
+                               vm_map_unlock_read(lookup_map);
+                               vm_map_lock(map);
+                               vm_object_unlock(object);
+
+                               /* we unlocked, so must re-lookup */
+                               if (!vm_map_lookup_entry(map, 
+                                                        local_start,
+                                                        &local_entry)) {
+                                       rc = KERN_FAILURE;
+                                       goto done;
+                               }
 
-                       if (last_timestamp+1 != map->timestamp) {
                                /*
-                                * Find the entry again.  It could have
-                                * been clipped after we unlocked the map.
+                                * entry could have been "simplified",
+                                * so re-clip
                                 */
-                               if (!vm_map_lookup_entry(map, s, &first_entry)){
-                                       assert((map != kernel_map) && 
-                                              (!entry->is_sub_map));
-                                       first_entry = first_entry->vme_next;
-                               } else {
-                                       SAVE_HINT(map, entry->vme_prev);
+                               entry = local_entry;
+                               assert(s == local_start);
+                               vm_map_clip_start(map, entry, s);
+                               vm_map_clip_end(map, entry, end);
+                               /* re-compute "e" */
+                               e = entry->vme_end;
+                               if (e > end)
+                                       e = end;
+
+                               /* did we have a change of type? */
+                               if (!entry->is_sub_map) {
+                                       last_timestamp = map->timestamp;
+                                       continue;
                                }
                        } else {
-                               SAVE_HINT(map, entry->vme_prev);
-                               first_entry = entry;
+                               local_start = entry->vme_start;
+                               pmap = map_pmap;
                        }
 
-                       last_timestamp = map->timestamp;
+                       if ((rc = add_wire_counts(map, entry, user_wire)) != KERN_SUCCESS)
+                               goto done;
+
+                       entry->in_transition = TRUE;
+
+                       vm_map_unlock(map);
+                       rc = vm_map_wire_nested(entry->object.sub_map, 
+                                               sub_start, sub_end,
+                                               access_type, 
+                                               user_wire, pmap, pmap_addr);
+                       vm_map_lock(map);
 
+                       /*
+                        * Find the entry again.  It could have been clipped
+                        * after we unlocked the map.
+                        */
+                       if (!vm_map_lookup_entry(map, local_start,
+                                                &first_entry))
+                               panic("vm_map_wire: re-lookup failed");
                        entry = first_entry;
+
+                       assert(local_start == s);
+                       /* re-compute "e" */
+                       e = entry->vme_end;
+                       if (e > end)
+                               e = end;
+
+                       last_timestamp = map->timestamp;
                        while ((entry != vm_map_to_entry(map)) &&
-                              (entry->vme_start < tmp_entry.vme_end)) {
+                              (entry->vme_start < e)) {
                                assert(entry->in_transition);
                                entry->in_transition = FALSE;
                                if (entry->needs_wakeup) {
                                        entry->needs_wakeup = FALSE;
                                        need_wakeup = TRUE;
                                }
+                               if (rc != KERN_SUCCESS) {/* from vm_*_wire */
+                                       subtract_wire_counts(map, entry, user_wire);
+                               }
                                entry = entry->vme_next;
                        }
+                       if (rc != KERN_SUCCESS) {       /* from vm_*_wire */
+                               goto done;
+                       }
+
+                       /* no need to relookup again */
+                       s = entry->vme_start;
+                       continue;
+               }
+
+               /*
+                * If this entry is already wired then increment
+                * the appropriate wire reference count.
+                */
+               if (entry->wired_count) {
                        /*
-                        * We have unwired the entry(s).  Go back and
-                        * delete them.
+                        * entry is already wired down, get our reference
+                        * after clipping to our range.
                         */
-                       entry = first_entry;
+                       vm_map_clip_start(map, entry, s);
+                       vm_map_clip_end(map, entry, end);
+
+                       if ((rc = add_wire_counts(map, entry, user_wire)) != KERN_SUCCESS)
+                               goto done;
+
+                       /* map was not unlocked: no need to relookup */
+                       entry = entry->vme_next;
+                       s = entry->vme_start;
                        continue;
                }
 
-               /* entry is unwired */
-               assert(entry->wired_count == 0);
-               assert(entry->user_wired_count == 0);
+               /*
+                * Unwired entry or wire request transmitted via submap
+                */
 
-               if ((!entry->is_sub_map &&
-                   entry->object.vm_object != kernel_object) ||
-                   entry->is_sub_map) {
-                       if(entry->is_sub_map) {
-                          if(entry->use_pmap) {
-#ifndef i386
-                               pmap_unnest(map->pmap, (addr64_t)entry->vme_start);
-#endif
-                               if((map->mapped) && (map->ref_count)) {
-                                       /* clean up parent map/maps */
-                                       vm_map_submap_pmap_clean(
-                                               map, entry->vme_start,
-                                               entry->vme_end,
-                                               entry->object.sub_map,
-                                               entry->offset);
-                               }
-                          } else {
-                               vm_map_submap_pmap_clean(
-                                       map, entry->vme_start, entry->vme_end,
-                                       entry->object.sub_map,
-                                       entry->offset);
-                          }
-                       } else {
-                               if((map->mapped) && (map->ref_count)) {
-                                       vm_object_pmap_protect(
-                                               entry->object.vm_object,
-                                               entry->offset,
-                                               entry->vme_end - entry->vme_start,
-                                               PMAP_NULL,
-                                               entry->vme_start,
-                                               VM_PROT_NONE);
-                               } else {
-                                       pmap_remove(map->pmap, 
-                                               (addr64_t)(entry->vme_start), 
-                                               (addr64_t)(entry->vme_end));
-                               }
-                       }
+
+               /*
+                * Perform actions of vm_map_lookup that need the write
+                * lock on the map: create a shadow object for a
+                * copy-on-write region, or an object for a zero-fill
+                * region.
+                */
+               size = entry->vme_end - entry->vme_start;
+               /*
+                * If wiring a copy-on-write page, we need to copy it now
+                * even if we're only (currently) requesting read access.
+                * This is aggressive, but once it's wired we can't move it.
+                */
+               if (entry->needs_copy) {
+                       vm_object_shadow(&entry->object.vm_object,
+                                        &entry->offset, size);
+                       entry->needs_copy = FALSE;
+               } else if (entry->object.vm_object == VM_OBJECT_NULL) {
+                       entry->object.vm_object = vm_object_allocate(size);
+                       entry->offset = (vm_object_offset_t)0;
                }
 
-               next = entry->vme_next;
-               s = next->vme_start;
-               last_timestamp = map->timestamp;
-               vm_map_entry_delete(map, entry);
-               /* vm_map_entry_delete unlocks the map */
-               vm_map_lock(map);
-               entry = next;
+               vm_map_clip_start(map, entry, s);
+               vm_map_clip_end(map, entry, end);
 
-               if(entry == vm_map_to_entry(map)) {
-                       break;
+               /* re-compute "e" */
+               e = entry->vme_end;
+               if (e > end)
+                       e = end;
+
+               /*
+                * Check for holes and protection mismatch.
+                * Holes: Next entry should be contiguous unless this
+                *        is the end of the region.
+                * Protection: Access requested must be allowed, unless
+                *      wiring is by protection class
+                */
+               if ((entry->vme_end < end) &&
+                   ((entry->vme_next == vm_map_to_entry(map)) ||
+                    (entry->vme_next->vme_start > entry->vme_end))) {
+                       /* found a hole */
+                       rc = KERN_INVALID_ADDRESS;
+                       goto done;
                }
-               if (last_timestamp+1 != map->timestamp) {
-                       /*
-                        * we are responsible for deleting everything
-                        * from the give space, if someone has interfered
-                        * we pick up where we left off, back fills should
-                        * be all right for anyone except map_delete and
-                        * we have to assume that the task has been fully
-                        * disabled before we get here
-                        */
-                       if (!vm_map_lookup_entry(map, s, &entry)){
-                               entry = entry->vme_next;
-                       } else {
-                                SAVE_HINT(map, entry->vme_prev);
-                               }
-                       /* 
-                        * others can not only allocate behind us, we can 
-                        * also see coalesce while we don't have the map lock 
-                        */
-                       if(entry == vm_map_to_entry(map)) {
-                               break;
-                       }
-                       vm_map_clip_start(map, entry, s);
+               if ((entry->protection & access_type) != access_type) {
+                       /* found a protection problem */
+                       rc = KERN_PROTECTION_FAILURE;
+                       goto done;
                }
-               last_timestamp = map->timestamp;
-       }
 
-       if (map->wait_for_space)
-               thread_wakeup((event_t) map);
-       /*
-        * wake up anybody waiting on entries that we have already deleted.
-        */
-       if (need_wakeup)
-               vm_map_entry_wakeup(map);
+               assert(entry->wired_count == 0 && entry->user_wired_count == 0);
 
-       return KERN_SUCCESS;
-}
+               if ((rc = add_wire_counts(map, entry, user_wire)) != KERN_SUCCESS)
+                       goto done;
 
-/*
- *     vm_map_remove:
- *
- *     Remove the given address range from the target map.
- *     This is the exported form of vm_map_delete.
- */
-kern_return_t
-vm_map_remove(
-       register vm_map_t       map,
-       register vm_offset_t    start,
-       register vm_offset_t    end,
-       register boolean_t      flags)
-{
-       register kern_return_t  result;
-       boolean_t       funnel_set = FALSE;
-       funnel_t        *curflock;
-       thread_t        cur_thread;
+               entry->in_transition = TRUE;
 
-       cur_thread = current_thread();
+               /*
+                * This entry might get split once we unlock the map.
+                * In vm_fault_wire(), we need the current range as
+                * defined by this entry.  In order for this to work
+                * along with a simultaneous clip operation, we make a
+                * temporary copy of this entry and use that for the
+                * wiring.  Note that the underlying objects do not
+                * change during a clip.
+                */
+               tmp_entry = *entry;
 
-       if ((cur_thread->funnel_state & TH_FN_OWNED) == TH_FN_OWNED) {
-               funnel_set = TRUE;
-               curflock = cur_thread->funnel_lock;
-               thread_funnel_set( curflock , FALSE);
-       }
-       vm_map_lock(map);
-       VM_MAP_RANGE_CHECK(map, start, end);
-       result = vm_map_delete(map, start, end, flags);
-       vm_map_unlock(map);
-       if (funnel_set) {
-               thread_funnel_set( curflock, TRUE);
-               funnel_set = FALSE;
-       }
-       return(result);
-}
+               /*
+                * The in_transition state guarentees that the entry
+                * (or entries for this range, if split occured) will be
+                * there when the map lock is acquired for the second time.
+                */
+               vm_map_unlock(map);
 
+               if (!user_wire && cur_thread != THREAD_NULL)
+                       interruptible_state = thread_interrupt_level(THREAD_UNINT);
+               else
+                       interruptible_state = THREAD_UNINT;
 
-/*
- *     Routine:        vm_map_copy_discard
- *
- *     Description:
- *             Dispose of a map copy object (returned by
- *             vm_map_copyin).
- */
-void
-vm_map_copy_discard(
-       vm_map_copy_t   copy)
-{
-       TR_DECL("vm_map_copy_discard");
+               if(map_pmap)
+                       rc = vm_fault_wire(map, 
+                                          &tmp_entry, map_pmap, pmap_addr);
+               else
+                       rc = vm_fault_wire(map, 
+                                          &tmp_entry, map->pmap, 
+                                          tmp_entry.vme_start);
 
-/*     tr3("enter: copy 0x%x type %d", copy, copy->type);*/
-free_next_copy:
-       if (copy == VM_MAP_COPY_NULL)
-               return;
+               if (!user_wire && cur_thread != THREAD_NULL)
+                       thread_interrupt_level(interruptible_state);
 
-       switch (copy->type) {
-       case VM_MAP_COPY_ENTRY_LIST:
-               while (vm_map_copy_first_entry(copy) !=
-                                       vm_map_copy_to_entry(copy)) {
-                       vm_map_entry_t  entry = vm_map_copy_first_entry(copy);
+               vm_map_lock(map);
 
-                       vm_map_copy_entry_unlink(copy, entry);
-                       vm_object_deallocate(entry->object.vm_object);
-                       vm_map_copy_entry_dispose(copy, entry);
-               }
-               break;
-        case VM_MAP_COPY_OBJECT:
-               vm_object_deallocate(copy->cpy_object);
-               break;
-       case VM_MAP_COPY_KERNEL_BUFFER:
+               if (last_timestamp+1 != map->timestamp) {
+                       /*
+                        * Find the entry again.  It could have been clipped
+                        * after we unlocked the map.
+                        */
+                       if (!vm_map_lookup_entry(map, tmp_entry.vme_start,
+                                                &first_entry))
+                               panic("vm_map_wire: re-lookup failed");
 
-               /*
-                * The vm_map_copy_t and possibly the data buffer were
-                * allocated by a single call to kalloc(), i.e. the
-                * vm_map_copy_t was not allocated out of the zone.
-                */
-               kfree((vm_offset_t) copy, copy->cpy_kalloc_size);
-               return;
-       }
-       zfree(vm_map_copy_zone, (vm_offset_t) copy);
-}
+                       entry = first_entry;
+               }
 
-/*
- *     Routine:        vm_map_copy_copy
- *
- *     Description:
- *                     Move the information in a map copy object to
- *                     a new map copy object, leaving the old one
- *                     empty.
- *
- *                     This is used by kernel routines that need
- *                     to look at out-of-line data (in copyin form)
- *                     before deciding whether to return SUCCESS.
- *                     If the routine returns FAILURE, the original
- *                     copy object will be deallocated; therefore,
- *                     these routines must make a copy of the copy
- *                     object and leave the original empty so that
- *                     deallocation will not fail.
- */
-vm_map_copy_t
-vm_map_copy_copy(
-       vm_map_copy_t   copy)
-{
-       vm_map_copy_t   new_copy;
+               last_timestamp = map->timestamp;
 
-       if (copy == VM_MAP_COPY_NULL)
-               return VM_MAP_COPY_NULL;
+               while ((entry != vm_map_to_entry(map)) &&
+                      (entry->vme_start < tmp_entry.vme_end)) {
+                       assert(entry->in_transition);
+                       entry->in_transition = FALSE;
+                       if (entry->needs_wakeup) {
+                               entry->needs_wakeup = FALSE;
+                               need_wakeup = TRUE;
+                       }
+                       if (rc != KERN_SUCCESS) {       /* from vm_*_wire */
+                               subtract_wire_counts(map, entry, user_wire);
+                       }
+                       entry = entry->vme_next;
+               }
 
-       /*
-        * Allocate a new copy object, and copy the information
-        * from the old one into it.
-        */
+               if (rc != KERN_SUCCESS) {               /* from vm_*_wire */
+                       goto done;
+               }
 
-       new_copy = (vm_map_copy_t) zalloc(vm_map_copy_zone);
-       *new_copy = *copy;
+               s = entry->vme_start;
+       } /* end while loop through map entries */
 
-       if (copy->type == VM_MAP_COPY_ENTRY_LIST) {
-               /*
-                * The links in the entry chain must be
-                * changed to point to the new copy object.
-                */
-               vm_map_copy_first_entry(copy)->vme_prev
-                       = vm_map_copy_to_entry(new_copy);
-               vm_map_copy_last_entry(copy)->vme_next
-                       = vm_map_copy_to_entry(new_copy);
+done:
+       if (rc == KERN_SUCCESS) {
+               /* repair any damage we may have made to the VM map */
+               vm_map_simplify_range(map, start, end);
        }
 
-       /*
-        * Change the old copy object into one that contains
-        * nothing to be deallocated.
-        */
-       copy->type = VM_MAP_COPY_OBJECT;
-       copy->cpy_object = VM_OBJECT_NULL;
+       vm_map_unlock(map);
 
        /*
-        * Return the new object.
+        * wake up anybody waiting on entries we wired.
         */
-       return new_copy;
+       if (need_wakeup)
+               vm_map_entry_wakeup(map);
+
+       if (rc != KERN_SUCCESS) {
+               /* undo what has been wired so far */
+               vm_map_unwire(map, start, s, user_wire);
+       }
+
+       return rc;
+
 }
 
 kern_return_t
-vm_map_overwrite_submap_recurse(
-       vm_map_t        dst_map,
-       vm_offset_t     dst_addr,
-       vm_size_t       dst_size)
+vm_map_wire(
+       register vm_map_t       map,
+       register vm_map_offset_t        start,
+       register vm_map_offset_t        end,
+       register vm_prot_t      access_type,
+       boolean_t               user_wire)
 {
-       vm_offset_t     dst_end;
-       vm_map_entry_t  tmp_entry;
-       vm_map_entry_t  entry;
-       kern_return_t   result;
-       boolean_t       encountered_sub_map = FALSE;
-
 
+       kern_return_t   kret;
 
-       /*
-        *      Verify that the destination is all writeable
-        *      initially.  We have to trunc the destination
-        *      address and round the copy size or we'll end up
-        *      splitting entries in strange ways.
+#ifdef ppc
+        /*
+        * the calls to mapping_prealloc and mapping_relpre
+        * (along with the VM_MAP_RANGE_CHECK to insure a
+        * resonable range was passed in) are
+        * currently necessary because
+        * we haven't enabled kernel pre-emption
+        * and/or the pmap_enter cannot purge and re-use
+        * existing mappings
         */
+       VM_MAP_RANGE_CHECK(map, start, end);
+       assert((unsigned int) (end - start) == (end - start));
+       mapping_prealloc((unsigned int) (end - start));
+#endif
+       kret = vm_map_wire_nested(map, start, end, access_type, 
+                                 user_wire, (pmap_t)NULL, 0);
+#ifdef ppc
+       mapping_relpre();
+#endif
+       return kret;
+}
 
-       dst_end = round_page_32(dst_addr + dst_size);
-       vm_map_lock(dst_map);
+/*
+ *     vm_map_unwire:
+ *
+ *     Sets the pageability of the specified address range in the target
+ *     as pageable.  Regions specified must have been wired previously.
+ *
+ *     The map must not be locked, but a reference must remain to the map
+ *     throughout the call.
+ *
+ *     Kernel will panic on failures.  User unwire ignores holes and
+ *     unwired and intransition entries to avoid losing memory by leaving
+ *     it unwired.
+ */
+static kern_return_t
+vm_map_unwire_nested(
+       register vm_map_t       map,
+       register vm_map_offset_t        start,
+       register vm_map_offset_t        end,
+       boolean_t               user_wire,
+       pmap_t                  map_pmap,
+       vm_map_offset_t         pmap_addr)
+{
+       register vm_map_entry_t entry;
+       struct vm_map_entry     *first_entry, tmp_entry;
+       boolean_t               need_wakeup;
+       boolean_t               main_map = FALSE;
+       unsigned int            last_timestamp;
 
-start_pass_1:
-       if (!vm_map_lookup_entry(dst_map, dst_addr, &tmp_entry)) {
-               vm_map_unlock(dst_map);
-               return(KERN_INVALID_ADDRESS);
-       }
+       vm_map_lock(map);
+       if(map_pmap == NULL)
+               main_map = TRUE;
+       last_timestamp = map->timestamp;
 
-       vm_map_clip_start(dst_map, tmp_entry, trunc_page_32(dst_addr));
+       VM_MAP_RANGE_CHECK(map, start, end);
+       assert(page_aligned(start));
+       assert(page_aligned(end));
 
-       for (entry = tmp_entry;;) {
-               vm_map_entry_t  next;
+       if (start == end) {
+               /* We unwired what the caller asked for: zero pages */
+               vm_map_unlock(map);
+               return KERN_SUCCESS;
+       }
 
-               next = entry->vme_next;
-               while(entry->is_sub_map) {
-                       vm_offset_t     sub_start;
-                       vm_offset_t     sub_end;
-                       vm_offset_t     local_end;
+       if (vm_map_lookup_entry(map, start, &first_entry)) {
+               entry = first_entry;
+               /*
+                * vm_map_clip_start will be done later.
+                * We don't want to unnest any nested sub maps here !
+                */
+       }
+       else {
+               if (!user_wire) {
+                       panic("vm_map_unwire: start not found");
+               }
+               /*      Start address is not in map. */
+               vm_map_unlock(map);
+               return(KERN_INVALID_ADDRESS);
+       }
 
-                       if (entry->in_transition) {
-                        /*
-                         * Say that we are waiting, and wait for entry.
-                         */
-                               entry->needs_wakeup = TRUE;
-                               vm_map_entry_wait(dst_map, THREAD_UNINT);
+       if (entry->superpage_size) {
+               /* superpages are always wired */
+               vm_map_unlock(map);
+               return KERN_INVALID_ADDRESS;
+       }
 
-                               goto start_pass_1;
+       need_wakeup = FALSE;
+       while ((entry != vm_map_to_entry(map)) && (entry->vme_start < end)) {
+               if (entry->in_transition) {
+                       /*
+                        * 1)
+                        * Another thread is wiring down this entry. Note
+                        * that if it is not for the other thread we would
+                        * be unwiring an unwired entry.  This is not
+                        * permitted.  If we wait, we will be unwiring memory
+                        * we did not wire.
+                        *
+                        * 2)
+                        * Another thread is unwiring this entry.  We did not
+                        * have a reference to it, because if we did, this
+                        * entry will not be getting unwired now.
+                        */
+                       if (!user_wire) {
+                               /*
+                                * XXX FBDP
+                                * This could happen:  there could be some
+                                * overlapping vslock/vsunlock operations
+                                * going on.
+                                * We should probably just wait and retry,
+                                * but then we have to be careful that this
+                                * entry could get "simplified" after 
+                                * "in_transition" gets unset and before
+                                * we re-lookup the entry, so we would
+                                * have to re-clip the entry to avoid
+                                * re-unwiring what we have already unwired...
+                                * See vm_map_wire_nested().
+                                *
+                                * Or we could just ignore "in_transition"
+                                * here and proceed to decement the wired
+                                * count(s) on this entry.  That should be fine
+                                * as long as "wired_count" doesn't drop all
+                                * the way to 0 (and we should panic if THAT
+                                * happens).
+                                */
+                               panic("vm_map_unwire: in_transition entry");
                        }
 
-                       encountered_sub_map = TRUE;
-                       sub_start = entry->offset;
+                       entry = entry->vme_next;
+                       continue;
+               }
 
-                       if(entry->vme_end < dst_end)
-                               sub_end = entry->vme_end;
-                       else 
-                               sub_end = dst_end;
-                       sub_end -= entry->vme_start;
+               if (entry->is_sub_map) {
+                       vm_map_offset_t sub_start;
+                       vm_map_offset_t sub_end;
+                       vm_map_offset_t local_end;
+                       pmap_t          pmap;
+               
+                       vm_map_clip_start(map, entry, start);
+                       vm_map_clip_end(map, entry, end);
+
+                       sub_start = entry->offset;
+                       sub_end = entry->vme_end - entry->vme_start;
                        sub_end += entry->offset;
                        local_end = entry->vme_end;
-                       vm_map_unlock(dst_map);
-                       
-                       result = vm_map_overwrite_submap_recurse(
-                                       entry->object.sub_map,
-                                       sub_start,
-                                       sub_end - sub_start);
-
-                       if(result != KERN_SUCCESS)
-                               return result;
-                       if (dst_end <= entry->vme_end)
-                               return KERN_SUCCESS;
-                       vm_map_lock(dst_map);
-                       if(!vm_map_lookup_entry(dst_map, local_end, 
-                                               &tmp_entry)) {
-                               vm_map_unlock(dst_map);
-                               return(KERN_INVALID_ADDRESS);
+                       if(map_pmap == NULL) {
+                               if(entry->use_pmap) {
+                                       pmap = entry->object.sub_map->pmap;
+                                       pmap_addr = sub_start;
+                               } else {
+                                       pmap = map->pmap;
+                                       pmap_addr = start;
+                               }
+                               if (entry->wired_count == 0 ||
+                                   (user_wire && entry->user_wired_count == 0)) {
+                                       if (!user_wire)
+                                               panic("vm_map_unwire: entry is unwired");
+                                       entry = entry->vme_next;
+                                       continue;
+                               }
+
+                               /*
+                                * Check for holes
+                                * Holes: Next entry should be contiguous unless
+                                * this is the end of the region.
+                                */
+                               if (((entry->vme_end < end) && 
+                                    ((entry->vme_next == vm_map_to_entry(map)) ||
+                                     (entry->vme_next->vme_start 
+                                      > entry->vme_end)))) {
+                                       if (!user_wire)
+                                               panic("vm_map_unwire: non-contiguous region");
+/*
+                                       entry = entry->vme_next;
+                                       continue;
+*/
+                               }
+
+                               subtract_wire_counts(map, entry, user_wire);
+
+                               if (entry->wired_count != 0) {
+                                       entry = entry->vme_next;
+                                       continue;
+                               }
+
+                               entry->in_transition = TRUE;
+                               tmp_entry = *entry;/* see comment in vm_map_wire() */
+
+                               /*
+                                * We can unlock the map now. The in_transition state
+                                * guarantees existance of the entry.
+                                */
+                               vm_map_unlock(map);
+                               vm_map_unwire_nested(entry->object.sub_map, 
+                                                    sub_start, sub_end, user_wire, pmap, pmap_addr);
+                               vm_map_lock(map);
+
+                               if (last_timestamp+1 != map->timestamp) {
+                                       /*
+                                        * Find the entry again.  It could have been 
+                                        * clipped or deleted after we unlocked the map.
+                                        */
+                                       if (!vm_map_lookup_entry(map, 
+                                                                tmp_entry.vme_start,
+                                                                &first_entry)) {
+                                               if (!user_wire)
+                                                       panic("vm_map_unwire: re-lookup failed");
+                                               entry = first_entry->vme_next;
+                                       } else
+                                               entry = first_entry;
+                               }
+                               last_timestamp = map->timestamp;
+
+                               /*
+                                * clear transition bit for all constituent entries
+                                * that were in the original entry (saved in 
+                                * tmp_entry).  Also check for waiters.
+                                */
+                               while ((entry != vm_map_to_entry(map)) &&
+                                      (entry->vme_start < tmp_entry.vme_end)) {
+                                       assert(entry->in_transition);
+                                       entry->in_transition = FALSE;
+                                       if (entry->needs_wakeup) {
+                                               entry->needs_wakeup = FALSE;
+                                               need_wakeup = TRUE;
+                                       }
+                                       entry = entry->vme_next;
+                               }
+                               continue;
+                       } else {
+                               vm_map_unlock(map);
+                               vm_map_unwire_nested(entry->object.sub_map,
+                                                    sub_start, sub_end, user_wire, map_pmap,
+                                                    pmap_addr);
+                               vm_map_lock(map);
+
+                               if (last_timestamp+1 != map->timestamp) {
+                                       /*
+                                        * Find the entry again.  It could have been 
+                                        * clipped or deleted after we unlocked the map.
+                                        */
+                                       if (!vm_map_lookup_entry(map, 
+                                                                tmp_entry.vme_start,
+                                                                &first_entry)) {
+                                               if (!user_wire)
+                                                       panic("vm_map_unwire: re-lookup failed");
+                                               entry = first_entry->vme_next;
+                                       } else
+                                               entry = first_entry;
+                               }
+                               last_timestamp = map->timestamp;
                        }
-                       entry = tmp_entry;
-                       next = entry->vme_next;
                }
 
-               if ( ! (entry->protection & VM_PROT_WRITE)) {
-                       vm_map_unlock(dst_map);
-                       return(KERN_PROTECTION_FAILURE);
+
+               if ((entry->wired_count == 0) ||
+                   (user_wire && entry->user_wired_count == 0)) {
+                       if (!user_wire)
+                               panic("vm_map_unwire: entry is unwired");
+
+                       entry = entry->vme_next;
+                       continue;
                }
+       
+               assert(entry->wired_count > 0 &&
+                      (!user_wire || entry->user_wired_count > 0));
+
+               vm_map_clip_start(map, entry, start);
+               vm_map_clip_end(map, entry, end);
 
                /*
-                *      If the entry is in transition, we must wait
-                *      for it to exit that state.  Anything could happen
-                *      when we unlock the map, so start over.
+                * Check for holes
+                * Holes: Next entry should be contiguous unless
+                *        this is the end of the region.
                 */
-                if (entry->in_transition) {
+               if (((entry->vme_end < end) && 
+                    ((entry->vme_next == vm_map_to_entry(map)) ||
+                     (entry->vme_next->vme_start > entry->vme_end)))) {
 
-                        /*
-                         * Say that we are waiting, and wait for entry.
-                         */
-                        entry->needs_wakeup = TRUE;
-                        vm_map_entry_wait(dst_map, THREAD_UNINT);
+                       if (!user_wire)
+                               panic("vm_map_unwire: non-contiguous region");
+                       entry = entry->vme_next;
+                       continue;
+               }
 
-                       goto start_pass_1;
+               subtract_wire_counts(map, entry, user_wire);
+
+               if (entry->wired_count != 0) {
+                       entry = entry->vme_next;
+                       continue;
                }
 
-/*
- *             our range is contained completely within this map entry
- */
-               if (dst_end <= entry->vme_end) {
-                       vm_map_unlock(dst_map);
-                       return KERN_SUCCESS;
+               if(entry->zero_wired_pages) {
+                       entry->zero_wired_pages = FALSE;
                }
-/*
- *             check that range specified is contiguous region
- */
-               if ((next == vm_map_to_entry(dst_map)) ||
-                   (next->vme_start != entry->vme_end)) {
-                       vm_map_unlock(dst_map);
-                       return(KERN_INVALID_ADDRESS);
+
+               entry->in_transition = TRUE;
+               tmp_entry = *entry;     /* see comment in vm_map_wire() */
+
+               /*
+                * We can unlock the map now. The in_transition state
+                * guarantees existance of the entry.
+                */
+               vm_map_unlock(map);
+               if(map_pmap) {
+                       vm_fault_unwire(map, 
+                                       &tmp_entry, FALSE, map_pmap, pmap_addr);
+               } else {
+                       vm_fault_unwire(map, 
+                                       &tmp_entry, FALSE, map->pmap, 
+                                       tmp_entry.vme_start);
+               }
+               vm_map_lock(map);
+
+               if (last_timestamp+1 != map->timestamp) {
+                       /*
+                        * Find the entry again.  It could have been clipped
+                        * or deleted after we unlocked the map.
+                        */
+                       if (!vm_map_lookup_entry(map, tmp_entry.vme_start,
+                                                &first_entry)) {
+                               if (!user_wire)
+                                       panic("vm_map_unwire: re-lookup failed");
+                               entry = first_entry->vme_next;
+                       } else
+                               entry = first_entry;
                }
+               last_timestamp = map->timestamp;
 
                /*
-                *      Check for permanent objects in the destination.
+                * clear transition bit for all constituent entries that
+                * were in the original entry (saved in tmp_entry).  Also
+                * check for waiters.
                 */
-               if ((entry->object.vm_object != VM_OBJECT_NULL) &&
-                          ((!entry->object.vm_object->internal) ||
-                          (entry->object.vm_object->true_share))) {
-                       if(encountered_sub_map) {
-                               vm_map_unlock(dst_map);
-                               return(KERN_FAILURE);
+               while ((entry != vm_map_to_entry(map)) &&
+                      (entry->vme_start < tmp_entry.vme_end)) {
+                       assert(entry->in_transition);
+                       entry->in_transition = FALSE;
+                       if (entry->needs_wakeup) {
+                               entry->needs_wakeup = FALSE;
+                               need_wakeup = TRUE;
                        }
+                       entry = entry->vme_next;
                }
+       }
 
+       /*
+        * We might have fragmented the address space when we wired this
+        * range of addresses.  Attempt to re-coalesce these VM map entries
+        * with their neighbors now that they're no longer wired.
+        * Under some circumstances, address space fragmentation can
+        * prevent VM object shadow chain collapsing, which can cause
+        * swap space leaks.
+        */
+       vm_map_simplify_range(map, start, end);
 
-               entry = next;
-       }/* for */
-       vm_map_unlock(dst_map);
+       vm_map_unlock(map);
+       /*
+        * wake up anybody waiting on entries that we have unwired.
+        */
+       if (need_wakeup)
+               vm_map_entry_wakeup(map);
        return(KERN_SUCCESS);
-}
 
-/*
- *     Routine:        vm_map_copy_overwrite
- *
- *     Description:
- *             Copy the memory described by the map copy
- *             object (copy; returned by vm_map_copyin) onto
- *             the specified destination region (dst_map, dst_addr).
- *             The destination must be writeable.
- *
- *             Unlike vm_map_copyout, this routine actually
- *             writes over previously-mapped memory.  If the
- *             previous mapping was to a permanent (user-supplied)
- *             memory object, it is preserved.
- *
- *             The attributes (protection and inheritance) of the
- *             destination region are preserved.
- *
- *             If successful, consumes the copy object.
- *             Otherwise, the caller is responsible for it.
- *
- *     Implementation notes:
- *             To overwrite aligned temporary virtual memory, it is
- *             sufficient to remove the previous mapping and insert
- *             the new copy.  This replacement is done either on
- *             the whole region (if no permanent virtual memory
- *             objects are embedded in the destination region) or
- *             in individual map entries.
- *
- *             To overwrite permanent virtual memory , it is necessary
- *             to copy each page, as the external memory management
- *             interface currently does not provide any optimizations.
- *
- *             Unaligned memory also has to be copied.  It is possible
- *             to use 'vm_trickery' to copy the aligned data.  This is
- *             not done but not hard to implement.
- *
- *             Once a page of permanent memory has been overwritten,
- *             it is impossible to interrupt this function; otherwise,
- *             the call would be neither atomic nor location-independent.
- *             The kernel-state portion of a user thread must be
- *             interruptible.
- *
- *             It may be expensive to forward all requests that might
- *             overwrite permanent memory (vm_write, vm_copy) to
- *             uninterruptible kernel threads.  This routine may be
- *             called by interruptible threads; however, success is
- *             not guaranteed -- if the request cannot be performed
- *             atomically and interruptibly, an error indication is
- *             returned.
- */
+}
 
 kern_return_t
-vm_map_copy_overwrite_nested(
-       vm_map_t        dst_map,
-       vm_offset_t     dst_addr,
-       vm_map_copy_t   copy,
-       boolean_t       interruptible,
-       pmap_t          pmap)
+vm_map_unwire(
+       register vm_map_t       map,
+       register vm_map_offset_t        start,
+       register vm_map_offset_t        end,
+       boolean_t               user_wire)
 {
-       vm_offset_t     dst_end;
-       vm_map_entry_t  tmp_entry;
-       vm_map_entry_t  entry;
-       kern_return_t   kr;
-       boolean_t       aligned = TRUE;
-       boolean_t       contains_permanent_objects = FALSE;
-       boolean_t       encountered_sub_map = FALSE;
-       vm_offset_t     base_addr;
-       vm_size_t       copy_size;
-       vm_size_t       total_size;
+       return vm_map_unwire_nested(map, start, end, 
+                                   user_wire, (pmap_t)NULL, 0);
+}
 
 
-       /*
-        *      Check for null copy object.
-        */
+/*
+ *     vm_map_entry_delete:    [ internal use only ]
+ *
+ *     Deallocate the given entry from the target map.
+ */            
+static void
+vm_map_entry_delete(
+       register vm_map_t       map,
+       register vm_map_entry_t entry)
+{
+       register vm_map_offset_t        s, e;
+       register vm_object_t    object;
+       register vm_map_t       submap;
 
-       if (copy == VM_MAP_COPY_NULL)
-               return(KERN_SUCCESS);
+       s = entry->vme_start;
+       e = entry->vme_end;
+       assert(page_aligned(s));
+       assert(page_aligned(e));
+       assert(entry->wired_count == 0);
+       assert(entry->user_wired_count == 0);
+       assert(!entry->permanent);
 
-       /*
-        *      Check for special kernel buffer allocated
-        *      by new_ipc_kmsg_copyin.
-        */
-
-       if (copy->type == VM_MAP_COPY_KERNEL_BUFFER) {
-               return(vm_map_copyout_kernel_buffer(
-                                               dst_map, &dst_addr, 
-                                               copy, TRUE));
+       if (entry->is_sub_map) {
+               object = NULL;
+               submap = entry->object.sub_map;
+       } else {
+               submap = NULL;
+               object = entry->object.vm_object;
        }
 
+       vm_map_entry_unlink(map, entry);
+       map->size -= e - s;
+
+       vm_map_entry_dispose(map, entry);
+
+       vm_map_unlock(map);
        /*
-        *      Only works for entry lists at the moment.  Will
-        *      support page lists later.
+        *      Deallocate the object only after removing all
+        *      pmap entries pointing to its pages.
         */
+       if (submap)
+               vm_map_deallocate(submap);
+       else
+               vm_object_deallocate(object);
 
-       assert(copy->type == VM_MAP_COPY_ENTRY_LIST);
+}
 
-       if (copy->size == 0) {
-               vm_map_copy_discard(copy);
-               return(KERN_SUCCESS);
-       }
+void
+vm_map_submap_pmap_clean(
+       vm_map_t        map,
+       vm_map_offset_t start,
+       vm_map_offset_t end,
+       vm_map_t        sub_map,
+       vm_map_offset_t offset)
+{
+       vm_map_offset_t submap_start;
+       vm_map_offset_t submap_end;
+       vm_map_size_t   remove_size;
+       vm_map_entry_t  entry;
 
-       /*
-        *      Verify that the destination is all writeable
-        *      initially.  We have to trunc the destination
-        *      address and round the copy size or we'll end up
-        *      splitting entries in strange ways.
-        */
+       submap_end = offset + (end - start);
+       submap_start = offset;
 
-       if (!page_aligned(copy->size) ||
-               !page_aligned (copy->offset) ||
-               !page_aligned (dst_addr))
-       {
-               aligned = FALSE;
-               dst_end = round_page_32(dst_addr + copy->size);
-       } else {
-               dst_end = dst_addr + copy->size;
-       }
+       vm_map_lock_read(sub_map);
+       if(vm_map_lookup_entry(sub_map, offset, &entry)) {
+               
+               remove_size = (entry->vme_end - entry->vme_start);
+               if(offset > entry->vme_start)
+                       remove_size -= offset - entry->vme_start;
+               
 
-       vm_map_lock(dst_map);
+               if(submap_end < entry->vme_end) {
+                       remove_size -=
+                               entry->vme_end - submap_end;
+               }
+               if(entry->is_sub_map) {
+                       vm_map_submap_pmap_clean(
+                               sub_map,
+                               start,
+                               start + remove_size,
+                               entry->object.sub_map,
+                               entry->offset);
+               } else {
 
-start_pass_1:
-       if (!vm_map_lookup_entry(dst_map, dst_addr, &tmp_entry)) {
-               vm_map_unlock(dst_map);
-               return(KERN_INVALID_ADDRESS);
+                       if((map->mapped) && (map->ref_count)
+                          && (entry->object.vm_object != NULL)) {
+                               vm_object_pmap_protect(
+                                       entry->object.vm_object,
+                                       entry->offset,
+                                       remove_size,
+                                       PMAP_NULL,
+                                       entry->vme_start,
+                                       VM_PROT_NONE);
+                       } else {
+                               pmap_remove(map->pmap, 
+                                           (addr64_t)start, 
+                                           (addr64_t)(start + remove_size));
+                       }
+               }
        }
-       vm_map_clip_start(dst_map, tmp_entry, trunc_page_32(dst_addr));
-       for (entry = tmp_entry;;) {
-               vm_map_entry_t  next = entry->vme_next;
 
-               while(entry->is_sub_map) {
-                       vm_offset_t     sub_start;
-                       vm_offset_t     sub_end;
-                       vm_offset_t     local_end;
+       entry = entry->vme_next;
 
-                       if (entry->in_transition) {
+       while((entry != vm_map_to_entry(sub_map)) 
+             && (entry->vme_start < submap_end)) {
+               remove_size = (entry->vme_end - entry->vme_start); 
+               if(submap_end < entry->vme_end) {
+                       remove_size -= entry->vme_end - submap_end;
+               }
+               if(entry->is_sub_map) {
+                       vm_map_submap_pmap_clean(
+                               sub_map,
+                               (start + entry->vme_start) - offset,
+                               ((start + entry->vme_start) - offset) + remove_size,
+                               entry->object.sub_map,
+                               entry->offset);
+               } else {
+                       if((map->mapped) && (map->ref_count)
+                          && (entry->object.vm_object != NULL)) {
+                               vm_object_pmap_protect(
+                                       entry->object.vm_object,
+                                       entry->offset,
+                                       remove_size,
+                                       PMAP_NULL,
+                                       entry->vme_start,
+                                       VM_PROT_NONE);
+                       } else {
+                               pmap_remove(map->pmap, 
+                                           (addr64_t)((start + entry->vme_start) 
+                                                      - offset),
+                                           (addr64_t)(((start + entry->vme_start) 
+                                                       - offset) + remove_size));
+                       }
+               }
+               entry = entry->vme_next;
+       }
+       vm_map_unlock_read(sub_map);
+       return;
+}
 
-                        /*
-                         * Say that we are waiting, and wait for entry.
-                         */
-                               entry->needs_wakeup = TRUE;
-                               vm_map_entry_wait(dst_map, THREAD_UNINT);
+/*
+ *     vm_map_delete:  [ internal use only ]
+ *
+ *     Deallocates the given address range from the target map.
+ *     Removes all user wirings. Unwires one kernel wiring if
+ *     VM_MAP_REMOVE_KUNWIRE is set.  Waits for kernel wirings to go
+ *     away if VM_MAP_REMOVE_WAIT_FOR_KWIRE is set.  Sleeps
+ *     interruptibly if VM_MAP_REMOVE_INTERRUPTIBLE is set.
+ *
+ *     This routine is called with map locked and leaves map locked.
+ */
+static kern_return_t
+vm_map_delete(
+       vm_map_t                map,
+       vm_map_offset_t         start,
+       vm_map_offset_t         end,
+       int                     flags,
+       vm_map_t                zap_map)
+{
+       vm_map_entry_t          entry, next;
+       struct   vm_map_entry   *first_entry, tmp_entry;
+       register vm_map_offset_t s;
+       register vm_object_t    object;
+       boolean_t               need_wakeup;
+       unsigned int            last_timestamp = ~0; /* unlikely value */
+       int                     interruptible;
 
-                               goto start_pass_1;
-                       }
+       interruptible = (flags & VM_MAP_REMOVE_INTERRUPTIBLE) ? 
+               THREAD_ABORTSAFE : THREAD_UNINT;
 
-                       local_end = entry->vme_end;
-                       if (!(entry->needs_copy)) {
-                               /* if needs_copy we are a COW submap */
-                               /* in such a case we just replace so */
-                               /* there is no need for the follow-  */
-                               /* ing check.                        */
-                               encountered_sub_map = TRUE;
-                               sub_start = entry->offset;
+       /*
+        * All our DMA I/O operations in IOKit are currently done by
+        * wiring through the map entries of the task requesting the I/O.
+        * Because of this, we must always wait for kernel wirings
+        * to go away on the entries before deleting them.
+        *
+        * Any caller who wants to actually remove a kernel wiring
+        * should explicitly set the VM_MAP_REMOVE_KUNWIRE flag to
+        * properly remove one wiring instead of blasting through
+        * them all.
+        */
+       flags |= VM_MAP_REMOVE_WAIT_FOR_KWIRE;
 
-                               if(entry->vme_end < dst_end)
-                                       sub_end = entry->vme_end;
-                               else 
-                                       sub_end = dst_end;
-                               sub_end -= entry->vme_start;
-                               sub_end += entry->offset;
-                               vm_map_unlock(dst_map);
-                       
-                               kr = vm_map_overwrite_submap_recurse(
-                                       entry->object.sub_map,
-                                       sub_start,
-                                       sub_end - sub_start);
-                               if(kr != KERN_SUCCESS)
-                                       return kr;
-                               vm_map_lock(dst_map);
+       while(1) {
+               /*
+                *      Find the start of the region, and clip it
+                */
+               if (vm_map_lookup_entry(map, start, &first_entry)) {
+                       entry = first_entry;
+                       if (entry->superpage_size && (start & ~SUPERPAGE_MASK)) { /* extend request to whole entry */                           start = SUPERPAGE_ROUND_DOWN(start);
+                               start = SUPERPAGE_ROUND_DOWN(start);
+                               continue;
                        }
-
-                       if (dst_end <= entry->vme_end)
-                               goto start_overwrite;
-                       if(!vm_map_lookup_entry(dst_map, local_end, 
-                                               &entry)) {
-                               vm_map_unlock(dst_map);
-                               return(KERN_INVALID_ADDRESS);
+                       if (start == entry->vme_start) {
+                               /*
+                                * No need to clip.  We don't want to cause
+                                * any unnecessary unnesting in this case...
+                                */
+                       } else {
+                               vm_map_clip_start(map, entry, start);
                        }
-                       next = entry->vme_next;
-               }
 
-               if ( ! (entry->protection & VM_PROT_WRITE)) {
-                       vm_map_unlock(dst_map);
-                       return(KERN_PROTECTION_FAILURE);
+                       /*
+                        *      Fix the lookup hint now, rather than each
+                        *      time through the loop.
+                        */
+                       SAVE_HINT_MAP_WRITE(map, entry->vme_prev);
+               } else {
+                       entry = first_entry->vme_next;
                }
+               break;
+       }
+       if (entry->superpage_size)
+               end = SUPERPAGE_ROUND_UP(end);
 
+       need_wakeup = FALSE;
+       /*
+        *      Step through all entries in this region
+        */
+       s = entry->vme_start;
+       while ((entry != vm_map_to_entry(map)) && (s < end)) {
                /*
-                *      If the entry is in transition, we must wait
-                *      for it to exit that state.  Anything could happen
-                *      when we unlock the map, so start over.
+                * At this point, we have deleted all the memory entries
+                * between "start" and "s".  We still need to delete
+                * all memory entries between "s" and "end".
+                * While we were blocked and the map was unlocked, some
+                * new memory entries could have been re-allocated between
+                * "start" and "s" and we don't want to mess with those.
+                * Some of those entries could even have been re-assembled
+                * with an entry after "s" (in vm_map_simplify_entry()), so
+                * we may have to vm_map_clip_start() again.
                 */
-                if (entry->in_transition) {
-
-                        /*
-                         * Say that we are waiting, and wait for entry.
-                         */
-                        entry->needs_wakeup = TRUE;
-                        vm_map_entry_wait(dst_map, THREAD_UNINT);
 
-                       goto start_pass_1;
+               if (entry->vme_start >= s) {
+                       /*
+                        * This entry starts on or after "s"
+                        * so no need to clip its start.
+                        */
+               } else {
+                       /*
+                        * This entry has been re-assembled by a
+                        * vm_map_simplify_entry().  We need to
+                        * re-clip its start.
+                        */
+                       vm_map_clip_start(map, entry, s);
                }
-
-/*
- *             our range is contained completely within this map entry
- */
-               if (dst_end <= entry->vme_end)
-                       break;
-/*
- *             check that range specified is contiguous region
- */
-               if ((next == vm_map_to_entry(dst_map)) ||
-                   (next->vme_start != entry->vme_end)) {
-                       vm_map_unlock(dst_map);
-                       return(KERN_INVALID_ADDRESS);
+               if (entry->vme_end <= end) {
+                       /*
+                        * This entry is going away completely, so no need
+                        * to clip and possibly cause an unnecessary unnesting.
+                        */
+               } else {
+                       vm_map_clip_end(map, entry, end);
                }
 
-
-               /*
-                *      Check for permanent objects in the destination.
-                */
-               if ((entry->object.vm_object != VM_OBJECT_NULL) &&
-                          ((!entry->object.vm_object->internal) ||
-                          (entry->object.vm_object->true_share))) {
-                       contains_permanent_objects = TRUE;
+               if (entry->permanent) {
+                       panic("attempt to remove permanent VM map entry "
+                             "%p [0x%llx:0x%llx]\n",
+                             entry, (uint64_t) s, (uint64_t) end);
                }
 
-               entry = next;
-       }/* for */
 
-start_overwrite:
+               if (entry->in_transition) {
+                       wait_result_t wait_result;
+
+                       /*
+                        * Another thread is wiring/unwiring this entry.
+                        * Let the other thread know we are waiting.
+                        */
+                       assert(s == entry->vme_start);
+                       entry->needs_wakeup = TRUE;
+
+                       /*
+                        * wake up anybody waiting on entries that we have
+                        * already unwired/deleted.
+                        */
+                       if (need_wakeup) {
+                               vm_map_entry_wakeup(map);
+                               need_wakeup = FALSE;
+                       }
+
+                       wait_result = vm_map_entry_wait(map, interruptible);
+
+                       if (interruptible &&
+                           wait_result == THREAD_INTERRUPTED) {
+                               /*
+                                * We do not clear the needs_wakeup flag,
+                                * since we cannot tell if we were the only one.
+                                */
+                               vm_map_unlock(map);
+                               return KERN_ABORTED;
+                       }
+
+                       /*
+                        * The entry could have been clipped or it
+                        * may not exist anymore.  Look it up again.
+                        */
+                       if (!vm_map_lookup_entry(map, s, &first_entry)) {
+                               assert((map != kernel_map) && 
+                                      (!entry->is_sub_map));
+                               /*
+                                * User: use the next entry
+                                */
+                               entry = first_entry->vme_next;
+                               s = entry->vme_start;
+                       } else {
+                               entry = first_entry;
+                               SAVE_HINT_MAP_WRITE(map, entry->vme_prev);
+                       }
+                       last_timestamp = map->timestamp;
+                       continue;
+               } /* end in_transition */
+
+               if (entry->wired_count) {
+                       boolean_t       user_wire;
+
+                       user_wire = entry->user_wired_count > 0;
+
+                       /*
+                        *      Remove a kernel wiring if requested
+                        */
+                       if (flags & VM_MAP_REMOVE_KUNWIRE) {
+                               entry->wired_count--;
+                       }
+                       
+                       /*
+                        *      Remove all user wirings for proper accounting
+                        */
+                       if (entry->user_wired_count > 0) {
+                               while (entry->user_wired_count)
+                                       subtract_wire_counts(map, entry, user_wire);
+                       }
+
+                       if (entry->wired_count != 0) {
+                               assert(map != kernel_map);
+                               /*
+                                * Cannot continue.  Typical case is when
+                                * a user thread has physical io pending on
+                                * on this page.  Either wait for the
+                                * kernel wiring to go away or return an
+                                * error.
+                                */
+                               if (flags & VM_MAP_REMOVE_WAIT_FOR_KWIRE) {
+                                       wait_result_t wait_result;
+
+                                       assert(s == entry->vme_start);
+                                       entry->needs_wakeup = TRUE;
+                                       wait_result = vm_map_entry_wait(map,
+                                                                       interruptible);
+
+                                       if (interruptible &&
+                                           wait_result == THREAD_INTERRUPTED) {
+                                               /*
+                                                * We do not clear the 
+                                                * needs_wakeup flag, since we 
+                                                * cannot tell if we were the 
+                                                * only one.
+                                                */
+                                               vm_map_unlock(map);
+                                               return KERN_ABORTED;
+                                       }
+
+                                       /*
+                                        * The entry could have been clipped or
+                                        * it may not exist anymore.  Look it
+                                        * up again.
+                                        */
+                                       if (!vm_map_lookup_entry(map, s, 
+                                                                &first_entry)) {
+                                               assert(map != kernel_map);
+                                               /*
+                                                * User: use the next entry
+                                                */
+                                               entry = first_entry->vme_next;
+                                               s = entry->vme_start;
+                                       } else {
+                                               entry = first_entry;
+                                               SAVE_HINT_MAP_WRITE(map, entry->vme_prev);
+                                       }
+                                       last_timestamp = map->timestamp;
+                                       continue;
+                               }
+                               else {
+                                       return KERN_FAILURE;
+                               }
+                       }
+
+                       entry->in_transition = TRUE;
+                       /*
+                        * copy current entry.  see comment in vm_map_wire()
+                        */
+                       tmp_entry = *entry;
+                       assert(s == entry->vme_start);
+
+                       /*
+                        * We can unlock the map now. The in_transition
+                        * state guarentees existance of the entry.
+                        */
+                       vm_map_unlock(map);
+
+                       if (tmp_entry.is_sub_map) {
+                               vm_map_t sub_map;
+                               vm_map_offset_t sub_start, sub_end;
+                               pmap_t pmap;
+                               vm_map_offset_t pmap_addr;
+                               
+
+                               sub_map = tmp_entry.object.sub_map;
+                               sub_start = tmp_entry.offset;
+                               sub_end = sub_start + (tmp_entry.vme_end -
+                                                      tmp_entry.vme_start);
+                               if (tmp_entry.use_pmap) {
+                                       pmap = sub_map->pmap;
+                                       pmap_addr = tmp_entry.vme_start;
+                               } else {
+                                       pmap = map->pmap;
+                                       pmap_addr = tmp_entry.vme_start;
+                               }
+                               (void) vm_map_unwire_nested(sub_map,
+                                                           sub_start, sub_end,
+                                                           user_wire,
+                                                           pmap, pmap_addr);
+                       } else {
+
+                               vm_fault_unwire(map, &tmp_entry,
+                                               tmp_entry.object.vm_object == kernel_object,
+                                               map->pmap, tmp_entry.vme_start);
+                       }
+
+                       vm_map_lock(map);
+
+                       if (last_timestamp+1 != map->timestamp) {
+                               /*
+                                * Find the entry again.  It could have
+                                * been clipped after we unlocked the map.
+                                */
+                               if (!vm_map_lookup_entry(map, s, &first_entry)){
+                                       assert((map != kernel_map) && 
+                                              (!entry->is_sub_map));
+                                       first_entry = first_entry->vme_next;
+                                       s = first_entry->vme_start;
+                               } else {
+                                       SAVE_HINT_MAP_WRITE(map, entry->vme_prev);
+                               }
+                       } else {
+                               SAVE_HINT_MAP_WRITE(map, entry->vme_prev);
+                               first_entry = entry;
+                       }
+
+                       last_timestamp = map->timestamp;
+
+                       entry = first_entry;
+                       while ((entry != vm_map_to_entry(map)) &&
+                              (entry->vme_start < tmp_entry.vme_end)) {
+                               assert(entry->in_transition);
+                               entry->in_transition = FALSE;
+                               if (entry->needs_wakeup) {
+                                       entry->needs_wakeup = FALSE;
+                                       need_wakeup = TRUE;
+                               }
+                               entry = entry->vme_next;
+                       }
+                       /*
+                        * We have unwired the entry(s).  Go back and
+                        * delete them.
+                        */
+                       entry = first_entry;
+                       continue;
+               }
+
+               /* entry is unwired */
+               assert(entry->wired_count == 0);
+               assert(entry->user_wired_count == 0);
+
+               assert(s == entry->vme_start);
+
+               if (flags & VM_MAP_REMOVE_NO_PMAP_CLEANUP) {
+                       /*
+                        * XXX with the VM_MAP_REMOVE_SAVE_ENTRIES flag to
+                        * vm_map_delete(), some map entries might have been
+                        * transferred to a "zap_map", which doesn't have a
+                        * pmap.  The original pmap has already been flushed
+                        * in the vm_map_delete() call targeting the original
+                        * map, but when we get to destroying the "zap_map",
+                        * we don't have any pmap to flush, so let's just skip
+                        * all this.
+                        */
+               } else if (entry->is_sub_map) {
+                       if (entry->use_pmap) {
+#ifndef NO_NESTED_PMAP
+                               pmap_unnest(map->pmap,
+                                           (addr64_t)entry->vme_start,
+                                           entry->vme_end - entry->vme_start);
+#endif /* NO_NESTED_PMAP */
+                               if ((map->mapped) && (map->ref_count)) {
+                                       /* clean up parent map/maps */
+                                       vm_map_submap_pmap_clean(
+                                               map, entry->vme_start,
+                                               entry->vme_end,
+                                               entry->object.sub_map,
+                                               entry->offset);
+                               }
+                       } else {
+                               vm_map_submap_pmap_clean(
+                                       map, entry->vme_start, entry->vme_end,
+                                       entry->object.sub_map,
+                                       entry->offset);
+                       }
+               } else if (entry->object.vm_object != kernel_object) {
+                       object = entry->object.vm_object;
+                       if((map->mapped) && (map->ref_count)) {
+                               vm_object_pmap_protect(
+                                       object, entry->offset,
+                                       entry->vme_end - entry->vme_start,
+                                       PMAP_NULL,
+                                       entry->vme_start,
+                                       VM_PROT_NONE);
+                       } else {
+                               pmap_remove(map->pmap,
+                                           (addr64_t)entry->vme_start,
+                                           (addr64_t)entry->vme_end);
+                       }
+               }
+
+               /*
+                * All pmap mappings for this map entry must have been
+                * cleared by now.
+                */
+               assert(vm_map_pmap_is_empty(map,
+                                           entry->vme_start,
+                                           entry->vme_end));
+
+               next = entry->vme_next;
+               s = next->vme_start;
+               last_timestamp = map->timestamp;
+
+               if ((flags & VM_MAP_REMOVE_SAVE_ENTRIES) &&
+                   zap_map != VM_MAP_NULL) {
+                       vm_map_size_t entry_size;
+                       /*
+                        * The caller wants to save the affected VM map entries
+                        * into the "zap_map".  The caller will take care of
+                        * these entries.
+                        */
+                       /* unlink the entry from "map" ... */
+                       vm_map_entry_unlink(map, entry);
+                       /* ... and add it to the end of the "zap_map" */
+                       vm_map_entry_link(zap_map,
+                                         vm_map_last_entry(zap_map),
+                                         entry);
+                       entry_size = entry->vme_end - entry->vme_start;
+                       map->size -= entry_size;
+                       zap_map->size += entry_size;
+                       /* we didn't unlock the map, so no timestamp increase */
+                       last_timestamp--;
+               } else {
+                       vm_map_entry_delete(map, entry);
+                       /* vm_map_entry_delete unlocks the map */
+                       vm_map_lock(map);
+               }
+
+               entry = next;
+
+               if(entry == vm_map_to_entry(map)) {
+                       break;
+               }
+               if (last_timestamp+1 != map->timestamp) {
+                       /*
+                        * we are responsible for deleting everything
+                        * from the give space, if someone has interfered
+                        * we pick up where we left off, back fills should
+                        * be all right for anyone except map_delete and
+                        * we have to assume that the task has been fully
+                        * disabled before we get here
+                        */
+                       if (!vm_map_lookup_entry(map, s, &entry)){
+                               entry = entry->vme_next;
+                               s = entry->vme_start;
+                       } else {
+                               SAVE_HINT_MAP_WRITE(map, entry->vme_prev);
+                               }
+                       /* 
+                        * others can not only allocate behind us, we can 
+                        * also see coalesce while we don't have the map lock 
+                        */
+                       if(entry == vm_map_to_entry(map)) {
+                               break;
+                       }
+               }
+               last_timestamp = map->timestamp;
+       }
+
+       if (map->wait_for_space)
+               thread_wakeup((event_t) map);
        /*
-        *      If there are permanent objects in the destination, then
-        *      the copy cannot be interrupted.
+        * wake up anybody waiting on entries that we have already deleted.
         */
+       if (need_wakeup)
+               vm_map_entry_wakeup(map);
 
-       if (interruptible && contains_permanent_objects) {
-               vm_map_unlock(dst_map);
-               return(KERN_FAILURE);   /* XXX */
-       }
+       return KERN_SUCCESS;
+}
+
+/*
+ *     vm_map_remove:
+ *
+ *     Remove the given address range from the target map.
+ *     This is the exported form of vm_map_delete.
+ */
+kern_return_t
+vm_map_remove(
+       register vm_map_t       map,
+       register vm_map_offset_t        start,
+       register vm_map_offset_t        end,
+       register boolean_t      flags)
+{
+       register kern_return_t  result;
+
+       vm_map_lock(map);
+       VM_MAP_RANGE_CHECK(map, start, end);
+       result = vm_map_delete(map, start, end, flags, VM_MAP_NULL);
+       vm_map_unlock(map);
+
+       return(result);
+}
+
+
+/*
+ *     Routine:        vm_map_copy_discard
+ *
+ *     Description:
+ *             Dispose of a map copy object (returned by
+ *             vm_map_copyin).
+ */
+void
+vm_map_copy_discard(
+       vm_map_copy_t   copy)
+{
+       if (copy == VM_MAP_COPY_NULL)
+               return;
+
+       switch (copy->type) {
+       case VM_MAP_COPY_ENTRY_LIST:
+               while (vm_map_copy_first_entry(copy) !=
+                      vm_map_copy_to_entry(copy)) {
+                       vm_map_entry_t  entry = vm_map_copy_first_entry(copy);
+
+                       vm_map_copy_entry_unlink(copy, entry);
+                       vm_object_deallocate(entry->object.vm_object);
+                       vm_map_copy_entry_dispose(copy, entry);
+               }
+               break;
+        case VM_MAP_COPY_OBJECT:
+               vm_object_deallocate(copy->cpy_object);
+               break;
+       case VM_MAP_COPY_KERNEL_BUFFER:
+
+               /*
+                * The vm_map_copy_t and possibly the data buffer were
+                * allocated by a single call to kalloc(), i.e. the
+                * vm_map_copy_t was not allocated out of the zone.
+                */
+               kfree(copy, copy->cpy_kalloc_size);
+               return;
+       }
+       zfree(vm_map_copy_zone, copy);
+}
+
+/*
+ *     Routine:        vm_map_copy_copy
+ *
+ *     Description:
+ *                     Move the information in a map copy object to
+ *                     a new map copy object, leaving the old one
+ *                     empty.
+ *
+ *                     This is used by kernel routines that need
+ *                     to look at out-of-line data (in copyin form)
+ *                     before deciding whether to return SUCCESS.
+ *                     If the routine returns FAILURE, the original
+ *                     copy object will be deallocated; therefore,
+ *                     these routines must make a copy of the copy
+ *                     object and leave the original empty so that
+ *                     deallocation will not fail.
+ */
+vm_map_copy_t
+vm_map_copy_copy(
+       vm_map_copy_t   copy)
+{
+       vm_map_copy_t   new_copy;
+
+       if (copy == VM_MAP_COPY_NULL)
+               return VM_MAP_COPY_NULL;
+
+       /*
+        * Allocate a new copy object, and copy the information
+        * from the old one into it.
+        */
+
+       new_copy = (vm_map_copy_t) zalloc(vm_map_copy_zone);
+       *new_copy = *copy;
+
+       if (copy->type == VM_MAP_COPY_ENTRY_LIST) {
+               /*
+                * The links in the entry chain must be
+                * changed to point to the new copy object.
+                */
+               vm_map_copy_first_entry(copy)->vme_prev
+                       = vm_map_copy_to_entry(new_copy);
+               vm_map_copy_last_entry(copy)->vme_next
+                       = vm_map_copy_to_entry(new_copy);
+       }
+
+       /*
+        * Change the old copy object into one that contains
+        * nothing to be deallocated.
+        */
+       copy->type = VM_MAP_COPY_OBJECT;
+       copy->cpy_object = VM_OBJECT_NULL;
+
+       /*
+        * Return the new object.
+        */
+       return new_copy;
+}
+
+static kern_return_t
+vm_map_overwrite_submap_recurse(
+       vm_map_t        dst_map,
+       vm_map_offset_t dst_addr,
+       vm_map_size_t   dst_size)
+{
+       vm_map_offset_t dst_end;
+       vm_map_entry_t  tmp_entry;
+       vm_map_entry_t  entry;
+       kern_return_t   result;
+       boolean_t       encountered_sub_map = FALSE;
+
+
+
+       /*
+        *      Verify that the destination is all writeable
+        *      initially.  We have to trunc the destination
+        *      address and round the copy size or we'll end up
+        *      splitting entries in strange ways.
+        */
+
+       dst_end = vm_map_round_page(dst_addr + dst_size);
+       vm_map_lock(dst_map);
+
+start_pass_1:
+       if (!vm_map_lookup_entry(dst_map, dst_addr, &tmp_entry)) {
+               vm_map_unlock(dst_map);
+               return(KERN_INVALID_ADDRESS);
+       }
+
+       vm_map_clip_start(dst_map, tmp_entry, vm_map_trunc_page(dst_addr));
+       assert(!tmp_entry->use_pmap); /* clipping did unnest if needed */
+
+       for (entry = tmp_entry;;) {
+               vm_map_entry_t  next;
+
+               next = entry->vme_next;
+               while(entry->is_sub_map) {
+                       vm_map_offset_t sub_start;
+                       vm_map_offset_t sub_end;
+                       vm_map_offset_t local_end;
+
+                       if (entry->in_transition) {
+                               /*
+                                * Say that we are waiting, and wait for entry.
+                                */
+                               entry->needs_wakeup = TRUE;
+                               vm_map_entry_wait(dst_map, THREAD_UNINT);
+
+                               goto start_pass_1;
+                       }
+
+                       encountered_sub_map = TRUE;
+                       sub_start = entry->offset;
+
+                       if(entry->vme_end < dst_end)
+                               sub_end = entry->vme_end;
+                       else 
+                               sub_end = dst_end;
+                       sub_end -= entry->vme_start;
+                       sub_end += entry->offset;
+                       local_end = entry->vme_end;
+                       vm_map_unlock(dst_map);
+                       
+                       result = vm_map_overwrite_submap_recurse(
+                               entry->object.sub_map,
+                               sub_start,
+                               sub_end - sub_start);
+
+                       if(result != KERN_SUCCESS)
+                               return result;
+                       if (dst_end <= entry->vme_end)
+                               return KERN_SUCCESS;
+                       vm_map_lock(dst_map);
+                       if(!vm_map_lookup_entry(dst_map, local_end, 
+                                               &tmp_entry)) {
+                               vm_map_unlock(dst_map);
+                               return(KERN_INVALID_ADDRESS);
+                       }
+                       entry = tmp_entry;
+                       next = entry->vme_next;
+               }
+
+               if ( ! (entry->protection & VM_PROT_WRITE)) {
+                       vm_map_unlock(dst_map);
+                       return(KERN_PROTECTION_FAILURE);
+               }
+
+               /*
+                *      If the entry is in transition, we must wait
+                *      for it to exit that state.  Anything could happen
+                *      when we unlock the map, so start over.
+                */
+                if (entry->in_transition) {
+
+                        /*
+                         * Say that we are waiting, and wait for entry.
+                         */
+                        entry->needs_wakeup = TRUE;
+                        vm_map_entry_wait(dst_map, THREAD_UNINT);
+
+                       goto start_pass_1;
+               }
+
+/*
+ *             our range is contained completely within this map entry
+ */
+               if (dst_end <= entry->vme_end) {
+                       vm_map_unlock(dst_map);
+                       return KERN_SUCCESS;
+               }
+/*
+ *             check that range specified is contiguous region
+ */
+               if ((next == vm_map_to_entry(dst_map)) ||
+                   (next->vme_start != entry->vme_end)) {
+                       vm_map_unlock(dst_map);
+                       return(KERN_INVALID_ADDRESS);
+               }
+
+               /*
+                *      Check for permanent objects in the destination.
+                */
+               if ((entry->object.vm_object != VM_OBJECT_NULL) &&
+                   ((!entry->object.vm_object->internal) ||
+                    (entry->object.vm_object->true_share))) {
+                       if(encountered_sub_map) {
+                               vm_map_unlock(dst_map);
+                               return(KERN_FAILURE);
+                       }
+               }
+
+
+               entry = next;
+       }/* for */
+       vm_map_unlock(dst_map);
+       return(KERN_SUCCESS);
+}
+
+/*
+ *     Routine:        vm_map_copy_overwrite
+ *
+ *     Description:
+ *             Copy the memory described by the map copy
+ *             object (copy; returned by vm_map_copyin) onto
+ *             the specified destination region (dst_map, dst_addr).
+ *             The destination must be writeable.
+ *
+ *             Unlike vm_map_copyout, this routine actually
+ *             writes over previously-mapped memory.  If the
+ *             previous mapping was to a permanent (user-supplied)
+ *             memory object, it is preserved.
+ *
+ *             The attributes (protection and inheritance) of the
+ *             destination region are preserved.
+ *
+ *             If successful, consumes the copy object.
+ *             Otherwise, the caller is responsible for it.
+ *
+ *     Implementation notes:
+ *             To overwrite aligned temporary virtual memory, it is
+ *             sufficient to remove the previous mapping and insert
+ *             the new copy.  This replacement is done either on
+ *             the whole region (if no permanent virtual memory
+ *             objects are embedded in the destination region) or
+ *             in individual map entries.
+ *
+ *             To overwrite permanent virtual memory , it is necessary
+ *             to copy each page, as the external memory management
+ *             interface currently does not provide any optimizations.
+ *
+ *             Unaligned memory also has to be copied.  It is possible
+ *             to use 'vm_trickery' to copy the aligned data.  This is
+ *             not done but not hard to implement.
+ *
+ *             Once a page of permanent memory has been overwritten,
+ *             it is impossible to interrupt this function; otherwise,
+ *             the call would be neither atomic nor location-independent.
+ *             The kernel-state portion of a user thread must be
+ *             interruptible.
+ *
+ *             It may be expensive to forward all requests that might
+ *             overwrite permanent memory (vm_write, vm_copy) to
+ *             uninterruptible kernel threads.  This routine may be
+ *             called by interruptible threads; however, success is
+ *             not guaranteed -- if the request cannot be performed
+ *             atomically and interruptibly, an error indication is
+ *             returned.
+ */
+
+static kern_return_t
+vm_map_copy_overwrite_nested(
+       vm_map_t                dst_map,
+       vm_map_address_t        dst_addr,
+       vm_map_copy_t           copy,
+       boolean_t               interruptible,
+       pmap_t                  pmap)
+{
+       vm_map_offset_t         dst_end;
+       vm_map_entry_t          tmp_entry;
+       vm_map_entry_t          entry;
+       kern_return_t           kr;
+       boolean_t               aligned = TRUE;
+       boolean_t               contains_permanent_objects = FALSE;
+       boolean_t               encountered_sub_map = FALSE;
+       vm_map_offset_t         base_addr;
+       vm_map_size_t           copy_size;
+       vm_map_size_t           total_size;
+
+
+       /*
+        *      Check for null copy object.
+        */
+
+       if (copy == VM_MAP_COPY_NULL)
+               return(KERN_SUCCESS);
+
+       /*
+        *      Check for special kernel buffer allocated
+        *      by new_ipc_kmsg_copyin.
+        */
+
+       if (copy->type == VM_MAP_COPY_KERNEL_BUFFER) {
+               return(vm_map_copyout_kernel_buffer(
+                              dst_map, &dst_addr, 
+                              copy, TRUE));
+       }
+
+       /*
+        *      Only works for entry lists at the moment.  Will
+        *      support page lists later.
+        */
+
+       assert(copy->type == VM_MAP_COPY_ENTRY_LIST);
+
+       if (copy->size == 0) {
+               vm_map_copy_discard(copy);
+               return(KERN_SUCCESS);
+       }
+
+       /*
+        *      Verify that the destination is all writeable
+        *      initially.  We have to trunc the destination
+        *      address and round the copy size or we'll end up
+        *      splitting entries in strange ways.
+        */
+
+       if (!page_aligned(copy->size) ||
+           !page_aligned (copy->offset) ||
+           !page_aligned (dst_addr))
+       {
+               aligned = FALSE;
+               dst_end = vm_map_round_page(dst_addr + copy->size);
+       } else {
+               dst_end = dst_addr + copy->size;
+       }
+
+       vm_map_lock(dst_map);
+
+       /* LP64todo - remove this check when vm_map_commpage64()
+        * no longer has to stuff in a map_entry for the commpage
+        * above the map's max_offset.
+        */
+       if (dst_addr >= dst_map->max_offset) {
+               vm_map_unlock(dst_map);
+               return(KERN_INVALID_ADDRESS);
+       }
+        
+start_pass_1:
+       if (!vm_map_lookup_entry(dst_map, dst_addr, &tmp_entry)) {
+               vm_map_unlock(dst_map);
+               return(KERN_INVALID_ADDRESS);
+       }
+       vm_map_clip_start(dst_map, tmp_entry, vm_map_trunc_page(dst_addr));
+       for (entry = tmp_entry;;) {
+               vm_map_entry_t  next = entry->vme_next;
+
+               while(entry->is_sub_map) {
+                       vm_map_offset_t sub_start;
+                       vm_map_offset_t sub_end;
+                       vm_map_offset_t local_end;
+
+                       if (entry->in_transition) {
+
+                               /*
+                                * Say that we are waiting, and wait for entry.
+                                */
+                               entry->needs_wakeup = TRUE;
+                               vm_map_entry_wait(dst_map, THREAD_UNINT);
+
+                               goto start_pass_1;
+                       }
+
+                       local_end = entry->vme_end;
+                       if (!(entry->needs_copy)) {
+                               /* if needs_copy we are a COW submap */
+                               /* in such a case we just replace so */
+                               /* there is no need for the follow-  */
+                               /* ing check.                        */
+                               encountered_sub_map = TRUE;
+                               sub_start = entry->offset;
+
+                               if(entry->vme_end < dst_end)
+                                       sub_end = entry->vme_end;
+                               else 
+                                       sub_end = dst_end;
+                               sub_end -= entry->vme_start;
+                               sub_end += entry->offset;
+                               vm_map_unlock(dst_map);
+                       
+                               kr = vm_map_overwrite_submap_recurse(
+                                       entry->object.sub_map,
+                                       sub_start,
+                                       sub_end - sub_start);
+                               if(kr != KERN_SUCCESS)
+                                       return kr;
+                               vm_map_lock(dst_map);
+                       }
+
+                       if (dst_end <= entry->vme_end)
+                               goto start_overwrite;
+                       if(!vm_map_lookup_entry(dst_map, local_end, 
+                                               &entry)) {
+                               vm_map_unlock(dst_map);
+                               return(KERN_INVALID_ADDRESS);
+                       }
+                       next = entry->vme_next;
+               }
+
+               if ( ! (entry->protection & VM_PROT_WRITE)) {
+                       vm_map_unlock(dst_map);
+                       return(KERN_PROTECTION_FAILURE);
+               }
+
+               /*
+                *      If the entry is in transition, we must wait
+                *      for it to exit that state.  Anything could happen
+                *      when we unlock the map, so start over.
+                */
+                if (entry->in_transition) {
+
+                        /*
+                         * Say that we are waiting, and wait for entry.
+                         */
+                        entry->needs_wakeup = TRUE;
+                        vm_map_entry_wait(dst_map, THREAD_UNINT);
+
+                       goto start_pass_1;
+               }
+
+/*
+ *             our range is contained completely within this map entry
+ */
+               if (dst_end <= entry->vme_end)
+                       break;
+/*
+ *             check that range specified is contiguous region
+ */
+               if ((next == vm_map_to_entry(dst_map)) ||
+                   (next->vme_start != entry->vme_end)) {
+                       vm_map_unlock(dst_map);
+                       return(KERN_INVALID_ADDRESS);
+               }
+
+
+               /*
+                *      Check for permanent objects in the destination.
+                */
+               if ((entry->object.vm_object != VM_OBJECT_NULL) &&
+                   ((!entry->object.vm_object->internal) ||
+                    (entry->object.vm_object->true_share))) {
+                       contains_permanent_objects = TRUE;
+               }
+
+               entry = next;
+       }/* for */
+
+start_overwrite:
+       /*
+        *      If there are permanent objects in the destination, then
+        *      the copy cannot be interrupted.
+        */
+
+       if (interruptible && contains_permanent_objects) {
+               vm_map_unlock(dst_map);
+               return(KERN_FAILURE);   /* XXX */
+       }
+
+       /*
+        *
+        *      Make a second pass, overwriting the data
+        *      At the beginning of each loop iteration,
+        *      the next entry to be overwritten is "tmp_entry"
+        *      (initially, the value returned from the lookup above),
+        *      and the starting address expected in that entry
+        *      is "start".
+        */
+
+       total_size = copy->size;
+       if(encountered_sub_map) {
+               copy_size = 0;
+               /* re-calculate tmp_entry since we've had the map */
+               /* unlocked */
+               if (!vm_map_lookup_entry( dst_map, dst_addr, &tmp_entry)) {
+                       vm_map_unlock(dst_map);
+                       return(KERN_INVALID_ADDRESS);
+               }
+       } else {
+               copy_size = copy->size;
+       }
+       
+       base_addr = dst_addr;
+       while(TRUE) {
+               /* deconstruct the copy object and do in parts */
+               /* only in sub_map, interruptable case */
+               vm_map_entry_t  copy_entry;
+               vm_map_entry_t  previous_prev = VM_MAP_ENTRY_NULL;
+               vm_map_entry_t  next_copy = VM_MAP_ENTRY_NULL;
+               int             nentries;
+               int             remaining_entries = 0;
+               vm_map_offset_t new_offset = 0;
+       
+               for (entry = tmp_entry; copy_size == 0;) {
+                       vm_map_entry_t  next;
+
+                       next = entry->vme_next;
+
+                       /* tmp_entry and base address are moved along */
+                       /* each time we encounter a sub-map.  Otherwise */
+                       /* entry can outpase tmp_entry, and the copy_size */
+                       /* may reflect the distance between them */
+                       /* if the current entry is found to be in transition */
+                       /* we will start over at the beginning or the last */
+                       /* encounter of a submap as dictated by base_addr */
+                       /* we will zero copy_size accordingly. */
+                       if (entry->in_transition) {
+                                       /*
+                                        * Say that we are waiting, and wait for entry.
+                                        */
+                                       entry->needs_wakeup = TRUE;
+                                       vm_map_entry_wait(dst_map, THREAD_UNINT);
+
+                               if(!vm_map_lookup_entry(dst_map, base_addr, 
+                                                       &tmp_entry)) {
+                                       vm_map_unlock(dst_map);
+                                       return(KERN_INVALID_ADDRESS);
+                               }
+                               copy_size = 0;
+                               entry = tmp_entry;
+                               continue;
+                       }
+                       if(entry->is_sub_map) {
+                               vm_map_offset_t sub_start;
+                               vm_map_offset_t sub_end;
+                               vm_map_offset_t local_end;
+
+                               if (entry->needs_copy) {
+                                       /* if this is a COW submap */
+                                       /* just back the range with a */
+                                       /* anonymous entry */
+                                       if(entry->vme_end < dst_end)
+                                               sub_end = entry->vme_end;
+                                       else 
+                                               sub_end = dst_end;
+                                       if(entry->vme_start < base_addr)
+                                               sub_start = base_addr;
+                                       else 
+                                               sub_start = entry->vme_start;
+                                       vm_map_clip_end(
+                                               dst_map, entry, sub_end);
+                                       vm_map_clip_start(
+                                               dst_map, entry, sub_start);
+                                       assert(!entry->use_pmap);
+                                       entry->is_sub_map = FALSE;
+                                       vm_map_deallocate(
+                                               entry->object.sub_map);
+                                       entry->object.sub_map = NULL;
+                                       entry->is_shared = FALSE;
+                                       entry->needs_copy = FALSE;
+                                       entry->offset = 0;
+                                       /*
+                                        * XXX FBDP
+                                        * We should propagate the protections
+                                        * of the submap entry here instead
+                                        * of forcing them to VM_PROT_ALL...
+                                        * Or better yet, we should inherit
+                                        * the protection of the copy_entry.
+                                        */
+                                       entry->protection = VM_PROT_ALL;
+                                       entry->max_protection = VM_PROT_ALL;
+                                       entry->wired_count = 0;
+                                       entry->user_wired_count = 0;
+                                       if(entry->inheritance 
+                                          == VM_INHERIT_SHARE) 
+                                               entry->inheritance = VM_INHERIT_COPY;
+                                       continue;
+                               }
+                               /* first take care of any non-sub_map */
+                               /* entries to send */
+                               if(base_addr < entry->vme_start) {
+                                       /* stuff to send */
+                                       copy_size = 
+                                               entry->vme_start - base_addr;
+                                       break;
+                               }
+                               sub_start = entry->offset;
+
+                               if(entry->vme_end < dst_end)
+                                       sub_end = entry->vme_end;
+                               else 
+                                       sub_end = dst_end;
+                               sub_end -= entry->vme_start;
+                               sub_end += entry->offset;
+                               local_end = entry->vme_end;
+                               vm_map_unlock(dst_map);
+                               copy_size = sub_end - sub_start;
+
+                               /* adjust the copy object */
+                               if (total_size > copy_size) {
+                                       vm_map_size_t   local_size = 0;
+                                       vm_map_size_t   entry_size;
+
+                                       nentries = 1;
+                                       new_offset = copy->offset;
+                                       copy_entry = vm_map_copy_first_entry(copy);
+                                       while(copy_entry != 
+                                             vm_map_copy_to_entry(copy)){
+                                               entry_size = copy_entry->vme_end - 
+                                                       copy_entry->vme_start;
+                                               if((local_size < copy_size) &&
+                                                  ((local_size + entry_size) 
+                                                   >= copy_size)) {
+                                                       vm_map_copy_clip_end(copy, 
+                                                                            copy_entry, 
+                                                                            copy_entry->vme_start +
+                                                                            (copy_size - local_size));
+                                                       entry_size = copy_entry->vme_end - 
+                                                               copy_entry->vme_start;
+                                                       local_size += entry_size;
+                                                       new_offset += entry_size;
+                                               }
+                                               if(local_size >= copy_size) {
+                                                       next_copy = copy_entry->vme_next;
+                                                       copy_entry->vme_next = 
+                                                               vm_map_copy_to_entry(copy);
+                                                       previous_prev = 
+                                                               copy->cpy_hdr.links.prev;
+                                                       copy->cpy_hdr.links.prev = copy_entry;
+                                                       copy->size = copy_size;
+                                                       remaining_entries = 
+                                                               copy->cpy_hdr.nentries;
+                                                       remaining_entries -= nentries;
+                                                       copy->cpy_hdr.nentries = nentries;
+                                                       break;
+                                               } else {
+                                                       local_size += entry_size;
+                                                       new_offset += entry_size;
+                                                       nentries++;
+                                               }
+                                               copy_entry = copy_entry->vme_next;
+                                       }
+                               }
+                       
+                               if((entry->use_pmap) && (pmap == NULL)) {
+                                       kr = vm_map_copy_overwrite_nested(
+                                               entry->object.sub_map,
+                                               sub_start,
+                                               copy,
+                                               interruptible, 
+                                               entry->object.sub_map->pmap);
+                               } else if (pmap != NULL) {
+                                       kr = vm_map_copy_overwrite_nested(
+                                               entry->object.sub_map,
+                                               sub_start,
+                                               copy,
+                                               interruptible, pmap);
+                               } else {
+                                       kr = vm_map_copy_overwrite_nested(
+                                               entry->object.sub_map,
+                                               sub_start,
+                                               copy,
+                                               interruptible,
+                                               dst_map->pmap);
+                               }
+                               if(kr != KERN_SUCCESS) {
+                                       if(next_copy != NULL) {
+                                               copy->cpy_hdr.nentries += 
+                                                       remaining_entries;
+                                               copy->cpy_hdr.links.prev->vme_next = 
+                                                       next_copy;
+                                               copy->cpy_hdr.links.prev 
+                                                       = previous_prev;
+                                               copy->size = total_size;
+                                       }
+                                       return kr;
+                               }
+                               if (dst_end <= local_end) {
+                                       return(KERN_SUCCESS);
+                               }
+                               /* otherwise copy no longer exists, it was */
+                               /* destroyed after successful copy_overwrite */
+                               copy = (vm_map_copy_t) 
+                                       zalloc(vm_map_copy_zone);
+                               vm_map_copy_first_entry(copy) =
+                                       vm_map_copy_last_entry(copy) =
+                                       vm_map_copy_to_entry(copy);
+                               copy->type = VM_MAP_COPY_ENTRY_LIST;
+                               copy->offset = new_offset;
+
+                               total_size -= copy_size;
+                               copy_size = 0;
+                               /* put back remainder of copy in container */
+                               if(next_copy != NULL) {
+                                       copy->cpy_hdr.nentries = remaining_entries;
+                                       copy->cpy_hdr.links.next = next_copy;
+                                       copy->cpy_hdr.links.prev = previous_prev;
+                                       copy->size = total_size;
+                                       next_copy->vme_prev = 
+                                               vm_map_copy_to_entry(copy);
+                                       next_copy = NULL;
+                               }
+                               base_addr = local_end;
+                               vm_map_lock(dst_map);
+                               if(!vm_map_lookup_entry(dst_map, 
+                                                       local_end, &tmp_entry)) {
+                                       vm_map_unlock(dst_map);
+                                       return(KERN_INVALID_ADDRESS);
+                               }
+                               entry = tmp_entry;
+                               continue;
+                       } 
+                       if (dst_end <= entry->vme_end) {
+                               copy_size = dst_end - base_addr;
+                               break;
+                       }
+
+                       if ((next == vm_map_to_entry(dst_map)) ||
+                           (next->vme_start != entry->vme_end)) {
+                               vm_map_unlock(dst_map);
+                               return(KERN_INVALID_ADDRESS);
+                       }
+
+                       entry = next;
+               }/* for */
+
+               next_copy = NULL;
+               nentries = 1;
+
+               /* adjust the copy object */
+               if (total_size > copy_size) {
+                       vm_map_size_t   local_size = 0;
+                       vm_map_size_t   entry_size;
+
+                       new_offset = copy->offset;
+                       copy_entry = vm_map_copy_first_entry(copy);
+                       while(copy_entry != vm_map_copy_to_entry(copy)) {
+                               entry_size = copy_entry->vme_end - 
+                                       copy_entry->vme_start;
+                               if((local_size < copy_size) &&
+                                  ((local_size + entry_size) 
+                                   >= copy_size)) {
+                                       vm_map_copy_clip_end(copy, copy_entry, 
+                                                            copy_entry->vme_start +
+                                                            (copy_size - local_size));
+                                       entry_size = copy_entry->vme_end - 
+                                               copy_entry->vme_start;
+                                       local_size += entry_size;
+                                       new_offset += entry_size;
+                               }
+                               if(local_size >= copy_size) {
+                                       next_copy = copy_entry->vme_next;
+                                       copy_entry->vme_next = 
+                                               vm_map_copy_to_entry(copy);
+                                       previous_prev = 
+                                               copy->cpy_hdr.links.prev;
+                                       copy->cpy_hdr.links.prev = copy_entry;
+                                       copy->size = copy_size;
+                                       remaining_entries = 
+                                               copy->cpy_hdr.nentries;
+                                       remaining_entries -= nentries;
+                                       copy->cpy_hdr.nentries = nentries;
+                                       break;
+                               } else {
+                                       local_size += entry_size;
+                                       new_offset += entry_size;
+                                       nentries++;
+                               }
+                               copy_entry = copy_entry->vme_next;
+                       }
+               }
+
+               if (aligned) {
+                       pmap_t  local_pmap;
+
+                       if(pmap)
+                               local_pmap = pmap;
+                       else
+                               local_pmap = dst_map->pmap;
+
+                       if ((kr =  vm_map_copy_overwrite_aligned( 
+                                    dst_map, tmp_entry, copy,
+                                    base_addr, local_pmap)) != KERN_SUCCESS) {
+                               if(next_copy != NULL) {
+                                       copy->cpy_hdr.nentries += 
+                                               remaining_entries;
+                                       copy->cpy_hdr.links.prev->vme_next = 
+                                               next_copy;
+                                       copy->cpy_hdr.links.prev = 
+                                               previous_prev;
+                                       copy->size += copy_size;
+                               }
+                               return kr;
+                       }
+                       vm_map_unlock(dst_map);
+               } else {
+                       /*
+                        * Performance gain:
+                        *
+                        * if the copy and dst address are misaligned but the same
+                        * offset within the page we can copy_not_aligned the
+                        * misaligned parts and copy aligned the rest.  If they are
+                        * aligned but len is unaligned we simply need to copy
+                        * the end bit unaligned.  We'll need to split the misaligned
+                        * bits of the region in this case !
+                        */
+                       /* ALWAYS UNLOCKS THE dst_map MAP */
+                       if ((kr =  vm_map_copy_overwrite_unaligned( dst_map,
+                                                                   tmp_entry, copy, base_addr)) != KERN_SUCCESS) {
+                               if(next_copy != NULL) {
+                                       copy->cpy_hdr.nentries +=
+                                               remaining_entries;
+                                       copy->cpy_hdr.links.prev->vme_next = 
+                                               next_copy;
+                                       copy->cpy_hdr.links.prev = 
+                                               previous_prev;
+                                       copy->size += copy_size;
+                               }
+                               return kr;
+                       }
+               }
+               total_size -= copy_size;
+               if(total_size == 0)
+                       break;
+               base_addr += copy_size;
+               copy_size = 0;
+               copy->offset = new_offset;
+               if(next_copy != NULL) {
+                       copy->cpy_hdr.nentries = remaining_entries;
+                       copy->cpy_hdr.links.next = next_copy;
+                       copy->cpy_hdr.links.prev = previous_prev;
+                       next_copy->vme_prev = vm_map_copy_to_entry(copy);
+                       copy->size = total_size;
+               }
+               vm_map_lock(dst_map);
+               while(TRUE) {
+                       if (!vm_map_lookup_entry(dst_map, 
+                                                base_addr, &tmp_entry)) {
+                               vm_map_unlock(dst_map);
+                               return(KERN_INVALID_ADDRESS);
+                       }
+                       if (tmp_entry->in_transition) {
+                                       entry->needs_wakeup = TRUE;
+                                       vm_map_entry_wait(dst_map, THREAD_UNINT);
+                       } else {
+                               break;
+                       }
+               }
+               vm_map_clip_start(dst_map, tmp_entry, vm_map_trunc_page(base_addr));
+
+               entry = tmp_entry;
+       } /* while */
+
+       /*
+        *      Throw away the vm_map_copy object
+        */
+       vm_map_copy_discard(copy);
+
+       return(KERN_SUCCESS);
+}/* vm_map_copy_overwrite */
+
+kern_return_t
+vm_map_copy_overwrite(
+       vm_map_t        dst_map,
+       vm_map_offset_t dst_addr,
+       vm_map_copy_t   copy,
+       boolean_t       interruptible)
+{
+       return vm_map_copy_overwrite_nested(
+               dst_map, dst_addr, copy, interruptible, (pmap_t) NULL);
+}
+
+
+/*
+ *     Routine: vm_map_copy_overwrite_unaligned        [internal use only]
+ *
+ *     Decription:
+ *     Physically copy unaligned data
+ *
+ *     Implementation:
+ *     Unaligned parts of pages have to be physically copied.  We use
+ *     a modified form of vm_fault_copy (which understands none-aligned
+ *     page offsets and sizes) to do the copy.  We attempt to copy as
+ *     much memory in one go as possibly, however vm_fault_copy copies
+ *     within 1 memory object so we have to find the smaller of "amount left"
+ *     "source object data size" and "target object data size".  With
+ *     unaligned data we don't need to split regions, therefore the source
+ *     (copy) object should be one map entry, the target range may be split
+ *     over multiple map entries however.  In any event we are pessimistic
+ *     about these assumptions.
+ *
+ *     Assumptions:
+ *     dst_map is locked on entry and is return locked on success,
+ *     unlocked on error.
+ */
+
+static kern_return_t
+vm_map_copy_overwrite_unaligned(
+       vm_map_t        dst_map,
+       vm_map_entry_t  entry,
+       vm_map_copy_t   copy,
+       vm_map_offset_t start)
+{
+       vm_map_entry_t          copy_entry = vm_map_copy_first_entry(copy);
+       vm_map_version_t        version;
+       vm_object_t             dst_object;
+       vm_object_offset_t      dst_offset;
+       vm_object_offset_t      src_offset;
+       vm_object_offset_t      entry_offset;
+       vm_map_offset_t         entry_end;
+       vm_map_size_t           src_size,
+                               dst_size,
+                               copy_size,
+                               amount_left;
+       kern_return_t           kr = KERN_SUCCESS;
+
+       vm_map_lock_write_to_read(dst_map);
+
+       src_offset = copy->offset - vm_object_trunc_page(copy->offset);
+       amount_left = copy->size;
+/*
+ *     unaligned so we never clipped this entry, we need the offset into
+ *     the vm_object not just the data.
+ */    
+       while (amount_left > 0) {
+
+               if (entry == vm_map_to_entry(dst_map)) {
+                       vm_map_unlock_read(dst_map);
+                       return KERN_INVALID_ADDRESS;
+               }
+
+               /* "start" must be within the current map entry */
+               assert ((start>=entry->vme_start) && (start<entry->vme_end));
+
+               dst_offset = start - entry->vme_start;
+
+               dst_size = entry->vme_end - start;
+
+               src_size = copy_entry->vme_end -
+                       (copy_entry->vme_start + src_offset);
+
+               if (dst_size < src_size) {
+/*
+ *                     we can only copy dst_size bytes before
+ *                     we have to get the next destination entry
+ */
+                       copy_size = dst_size;
+               } else {
+/*
+ *                     we can only copy src_size bytes before
+ *                     we have to get the next source copy entry
+ */
+                       copy_size = src_size;
+               }
+
+               if (copy_size > amount_left) {
+                       copy_size = amount_left;
+               }
+/*
+ *             Entry needs copy, create a shadow shadow object for
+ *             Copy on write region.
+ */
+               if (entry->needs_copy &&
+                   ((entry->protection & VM_PROT_WRITE) != 0))
+               {
+                       if (vm_map_lock_read_to_write(dst_map)) {
+                               vm_map_lock_read(dst_map);
+                               goto RetryLookup;
+                       }
+                       vm_object_shadow(&entry->object.vm_object,
+                                        &entry->offset,
+                                        (vm_map_size_t)(entry->vme_end
+                                                        - entry->vme_start));
+                       entry->needs_copy = FALSE;
+                       vm_map_lock_write_to_read(dst_map);
+               }
+               dst_object = entry->object.vm_object;
+/*
+ *             unlike with the virtual (aligned) copy we're going
+ *             to fault on it therefore we need a target object.
+ */
+                if (dst_object == VM_OBJECT_NULL) {
+                       if (vm_map_lock_read_to_write(dst_map)) {
+                               vm_map_lock_read(dst_map);
+                               goto RetryLookup;
+                       }
+                       dst_object = vm_object_allocate((vm_map_size_t)
+                                                       entry->vme_end - entry->vme_start);
+                       entry->object.vm_object = dst_object;
+                       entry->offset = 0;
+                       vm_map_lock_write_to_read(dst_map);
+               }
+/*
+ *             Take an object reference and unlock map. The "entry" may
+ *             disappear or change when the map is unlocked.
+ */
+               vm_object_reference(dst_object);
+               version.main_timestamp = dst_map->timestamp;
+               entry_offset = entry->offset;
+               entry_end = entry->vme_end;
+               vm_map_unlock_read(dst_map);
+/*
+ *             Copy as much as possible in one pass
+ */
+               kr = vm_fault_copy(
+                       copy_entry->object.vm_object,
+                       copy_entry->offset + src_offset,
+                       &copy_size,
+                       dst_object,
+                       entry_offset + dst_offset,
+                       dst_map,
+                       &version,
+                       THREAD_UNINT );
+
+               start += copy_size;
+               src_offset += copy_size;
+               amount_left -= copy_size;
+/*
+ *             Release the object reference
+ */
+               vm_object_deallocate(dst_object);
+/*
+ *             If a hard error occurred, return it now
+ */
+               if (kr != KERN_SUCCESS)
+                       return kr;
+
+               if ((copy_entry->vme_start + src_offset) == copy_entry->vme_end
+                   || amount_left == 0)
+               {
+/*
+ *                     all done with this copy entry, dispose.
+ */
+                       vm_map_copy_entry_unlink(copy, copy_entry);
+                       vm_object_deallocate(copy_entry->object.vm_object);
+                       vm_map_copy_entry_dispose(copy, copy_entry);
+
+                       if ((copy_entry = vm_map_copy_first_entry(copy))
+                           == vm_map_copy_to_entry(copy) && amount_left) {
+/*
+ *                             not finished copying but run out of source
+ */
+                               return KERN_INVALID_ADDRESS;
+                       }
+                       src_offset = 0;
+               }
+
+               if (amount_left == 0)
+                       return KERN_SUCCESS;
+
+               vm_map_lock_read(dst_map);
+               if (version.main_timestamp == dst_map->timestamp) {
+                       if (start == entry_end) {
+/*
+ *                             destination region is split.  Use the version
+ *                             information to avoid a lookup in the normal
+ *                             case.
+ */
+                               entry = entry->vme_next;
+/*
+ *                             should be contiguous. Fail if we encounter
+ *                             a hole in the destination.
+ */
+                               if (start != entry->vme_start) {
+                                       vm_map_unlock_read(dst_map);
+                                       return KERN_INVALID_ADDRESS ;
+                               }
+                       }
+               } else {
+/*
+ *                     Map version check failed.
+ *                     we must lookup the entry because somebody
+ *                     might have changed the map behind our backs.
+ */
+               RetryLookup:
+                       if (!vm_map_lookup_entry(dst_map, start, &entry))
+                       {
+                               vm_map_unlock_read(dst_map);
+                               return KERN_INVALID_ADDRESS ;
+                       }
+               }
+       }/* while */
+
+       return KERN_SUCCESS;
+}/* vm_map_copy_overwrite_unaligned */
+
+/*
+ *     Routine: vm_map_copy_overwrite_aligned  [internal use only]
+ *
+ *     Description:
+ *     Does all the vm_trickery possible for whole pages.
+ *
+ *     Implementation:
+ *
+ *     If there are no permanent objects in the destination,
+ *     and the source and destination map entry zones match,
+ *     and the destination map entry is not shared,
+ *     then the map entries can be deleted and replaced
+ *     with those from the copy.  The following code is the
+ *     basic idea of what to do, but there are lots of annoying
+ *     little details about getting protection and inheritance
+ *     right.  Should add protection, inheritance, and sharing checks
+ *     to the above pass and make sure that no wiring is involved.
+ */
+
+static kern_return_t
+vm_map_copy_overwrite_aligned(
+       vm_map_t        dst_map,
+       vm_map_entry_t  tmp_entry,
+       vm_map_copy_t   copy,
+       vm_map_offset_t start,
+       __unused pmap_t pmap)
+{
+       vm_object_t     object;
+       vm_map_entry_t  copy_entry;
+       vm_map_size_t   copy_size;
+       vm_map_size_t   size;
+       vm_map_entry_t  entry;
+               
+       while ((copy_entry = vm_map_copy_first_entry(copy))
+              != vm_map_copy_to_entry(copy))
+       {
+               copy_size = (copy_entry->vme_end - copy_entry->vme_start);
+               
+               entry = tmp_entry;
+               assert(!entry->use_pmap); /* unnested when clipped earlier */
+               if (entry == vm_map_to_entry(dst_map)) {
+                       vm_map_unlock(dst_map);
+                       return KERN_INVALID_ADDRESS;
+               }
+               size = (entry->vme_end - entry->vme_start);
+               /*
+                *      Make sure that no holes popped up in the
+                *      address map, and that the protection is
+                *      still valid, in case the map was unlocked
+                *      earlier.
+                */
+
+               if ((entry->vme_start != start) || ((entry->is_sub_map)
+                                                   && !entry->needs_copy)) {
+                       vm_map_unlock(dst_map);
+                       return(KERN_INVALID_ADDRESS);
+               }
+               assert(entry != vm_map_to_entry(dst_map));
+
+               /*
+                *      Check protection again
+                */
+
+               if ( ! (entry->protection & VM_PROT_WRITE)) {
+                       vm_map_unlock(dst_map);
+                       return(KERN_PROTECTION_FAILURE);
+               }
+
+               /*
+                *      Adjust to source size first
+                */
+
+               if (copy_size < size) {
+                       vm_map_clip_end(dst_map, entry, entry->vme_start + copy_size);
+                       size = copy_size;
+               }
+
+               /*
+                *      Adjust to destination size
+                */
+
+               if (size < copy_size) {
+                       vm_map_copy_clip_end(copy, copy_entry,
+                                            copy_entry->vme_start + size);
+                       copy_size = size;
+               }
+
+               assert((entry->vme_end - entry->vme_start) == size);
+               assert((tmp_entry->vme_end - tmp_entry->vme_start) == size);
+               assert((copy_entry->vme_end - copy_entry->vme_start) == size);
+
+               /*
+                *      If the destination contains temporary unshared memory,
+                *      we can perform the copy by throwing it away and
+                *      installing the source data.
+                */
+
+               object = entry->object.vm_object;
+               if ((!entry->is_shared && 
+                    ((object == VM_OBJECT_NULL) || 
+                     (object->internal && !object->true_share))) ||
+                   entry->needs_copy) {
+                       vm_object_t     old_object = entry->object.vm_object;
+                       vm_object_offset_t      old_offset = entry->offset;
+                       vm_object_offset_t      offset;
+
+                       /*
+                        * Ensure that the source and destination aren't
+                        * identical
+                        */
+                       if (old_object == copy_entry->object.vm_object &&
+                           old_offset == copy_entry->offset) {
+                               vm_map_copy_entry_unlink(copy, copy_entry);
+                               vm_map_copy_entry_dispose(copy, copy_entry);
+
+                               if (old_object != VM_OBJECT_NULL)
+                                       vm_object_deallocate(old_object);
+
+                               start = tmp_entry->vme_end;
+                               tmp_entry = tmp_entry->vme_next;
+                               continue;
+                       }
+
+                       if (old_object != VM_OBJECT_NULL) {
+                               if(entry->is_sub_map) {
+                                       if(entry->use_pmap) {
+#ifndef NO_NESTED_PMAP
+                                               pmap_unnest(dst_map->pmap, 
+                                                           (addr64_t)entry->vme_start,
+                                                           entry->vme_end - entry->vme_start);
+#endif /* NO_NESTED_PMAP */
+                                               if(dst_map->mapped) {
+                                                       /* clean up parent */
+                                                       /* map/maps */
+                                                       vm_map_submap_pmap_clean(
+                                                               dst_map, entry->vme_start,
+                                                               entry->vme_end,
+                                                               entry->object.sub_map,
+                                                               entry->offset);
+                                               }
+                                       } else {
+                                               vm_map_submap_pmap_clean(
+                                                       dst_map, entry->vme_start, 
+                                                       entry->vme_end,
+                                                       entry->object.sub_map,
+                                                       entry->offset);
+                                       }
+                                       vm_map_deallocate(
+                                               entry->object.sub_map);
+                               } else {
+                                       if(dst_map->mapped) {
+                                               vm_object_pmap_protect(
+                                                       entry->object.vm_object,
+                                                       entry->offset,
+                                                       entry->vme_end 
+                                                       - entry->vme_start,
+                                                       PMAP_NULL,
+                                                       entry->vme_start,
+                                                       VM_PROT_NONE);
+                                       } else {
+                                               pmap_remove(dst_map->pmap, 
+                                                           (addr64_t)(entry->vme_start), 
+                                                           (addr64_t)(entry->vme_end));
+                                       }
+                                       vm_object_deallocate(old_object);
+                               }
+                       }
+
+                       entry->is_sub_map = FALSE;
+                       entry->object = copy_entry->object;
+                       object = entry->object.vm_object;
+                       entry->needs_copy = copy_entry->needs_copy;
+                       entry->wired_count = 0;
+                       entry->user_wired_count = 0;
+                       offset = entry->offset = copy_entry->offset;
+
+                       vm_map_copy_entry_unlink(copy, copy_entry);
+                       vm_map_copy_entry_dispose(copy, copy_entry);
+
+                       /*
+                        * we could try to push pages into the pmap at this point, BUT
+                        * this optimization only saved on average 2 us per page if ALL
+                        * the pages in the source were currently mapped
+                        * and ALL the pages in the dest were touched, if there were fewer
+                        * than 2/3 of the pages touched, this optimization actually cost more cycles
+                        * it also puts a lot of pressure on the pmap layer w/r to mapping structures
+                        */
+
+                       /*
+                        *      Set up for the next iteration.  The map
+                        *      has not been unlocked, so the next
+                        *      address should be at the end of this
+                        *      entry, and the next map entry should be
+                        *      the one following it.
+                        */
+
+                       start = tmp_entry->vme_end;
+                       tmp_entry = tmp_entry->vme_next;
+               } else {
+                       vm_map_version_t        version;
+                       vm_object_t             dst_object = entry->object.vm_object;
+                       vm_object_offset_t      dst_offset = entry->offset;
+                       kern_return_t           r;
+
+                       /*
+                        *      Take an object reference, and record
+                        *      the map version information so that the
+                        *      map can be safely unlocked.
+                        */
 
-       /*
-        *
-        *      Make a second pass, overwriting the data
-        *      At the beginning of each loop iteration,
-        *      the next entry to be overwritten is "tmp_entry"
-        *      (initially, the value returned from the lookup above),
-        *      and the starting address expected in that entry
-        *      is "start".
-        */
+                       vm_object_reference(dst_object);
+
+                       /* account for unlock bumping up timestamp */
+                       version.main_timestamp = dst_map->timestamp + 1;
 
-       total_size = copy->size;
-       if(encountered_sub_map) {
-               copy_size = 0;
-               /* re-calculate tmp_entry since we've had the map */
-               /* unlocked */
-               if (!vm_map_lookup_entry( dst_map, dst_addr, &tmp_entry)) {
                        vm_map_unlock(dst_map);
-                       return(KERN_INVALID_ADDRESS);
-               }
-       } else {
-               copy_size = copy->size;
-       }
-       
-       base_addr = dst_addr;
-       while(TRUE) {
-               /* deconstruct the copy object and do in parts */
-               /* only in sub_map, interruptable case */
-               vm_map_entry_t  copy_entry;
-               vm_map_entry_t  previous_prev;
-               vm_map_entry_t  next_copy;
-               int             nentries;
-               int             remaining_entries;
-               int             new_offset;
-       
-               for (entry = tmp_entry; copy_size == 0;) {
-                       vm_map_entry_t  next;
 
-                       next = entry->vme_next;
+                       /*
+                        *      Copy as much as possible in one pass
+                        */
 
-                       /* tmp_entry and base address are moved along */
-                       /* each time we encounter a sub-map.  Otherwise */
-                       /* entry can outpase tmp_entry, and the copy_size */
-                       /* may reflect the distance between them */
-                       /* if the current entry is found to be in transition */
-                       /* we will start over at the beginning or the last */
-                       /* encounter of a submap as dictated by base_addr */
-                       /* we will zero copy_size accordingly. */
-                       if (entry->in_transition) {
-                                       /*
-                                        * Say that we are waiting, and wait for entry.
-                                        */
-                                       entry->needs_wakeup = TRUE;
-                                       vm_map_entry_wait(dst_map, THREAD_UNINT);
+                       copy_size = size;
+                       r = vm_fault_copy(
+                               copy_entry->object.vm_object,
+                               copy_entry->offset,
+                               &copy_size,
+                               dst_object,
+                               dst_offset,
+                               dst_map,
+                               &version,
+                               THREAD_UNINT );
 
-                               if(!vm_map_lookup_entry(dst_map, base_addr, 
-                                                               &tmp_entry)) {
+                       /*
+                        *      Release the object reference
+                        */
+
+                       vm_object_deallocate(dst_object);
+
+                       /*
+                        *      If a hard error occurred, return it now
+                        */
+
+                       if (r != KERN_SUCCESS)
+                               return(r);
+
+                       if (copy_size != 0) {
+                               /*
+                                *      Dispose of the copied region
+                                */
+
+                               vm_map_copy_clip_end(copy, copy_entry,
+                                                    copy_entry->vme_start + copy_size);
+                               vm_map_copy_entry_unlink(copy, copy_entry);
+                               vm_object_deallocate(copy_entry->object.vm_object);
+                               vm_map_copy_entry_dispose(copy, copy_entry);
+                       }
+
+                       /*
+                        *      Pick up in the destination map where we left off.
+                        *
+                        *      Use the version information to avoid a lookup
+                        *      in the normal case.
+                        */
+
+                       start += copy_size;
+                       vm_map_lock(dst_map);
+                       if (version.main_timestamp == dst_map->timestamp) {
+                               /* We can safely use saved tmp_entry value */
+
+                               vm_map_clip_end(dst_map, tmp_entry, start);
+                               tmp_entry = tmp_entry->vme_next;
+                       } else {
+                               /* Must do lookup of tmp_entry */
+
+                               if (!vm_map_lookup_entry(dst_map, start, &tmp_entry)) {
                                        vm_map_unlock(dst_map);
                                        return(KERN_INVALID_ADDRESS);
                                }
-                               copy_size = 0;
-                               entry = tmp_entry;
-                               continue;
+                               vm_map_clip_start(dst_map, tmp_entry, start);
                        }
-                       if(entry->is_sub_map) {
-                               vm_offset_t     sub_start;
-                               vm_offset_t     sub_end;
-                               vm_offset_t     local_end;
+               }
+       }/* while */
+
+       return(KERN_SUCCESS);
+}/* vm_map_copy_overwrite_aligned */
+
+/*
+ *     Routine: vm_map_copyin_kernel_buffer [internal use only]
+ *
+ *     Description:
+ *             Copy in data to a kernel buffer from space in the
+ *             source map. The original space may be optionally
+ *             deallocated.
+ *
+ *             If successful, returns a new copy object.
+ */
+static kern_return_t
+vm_map_copyin_kernel_buffer(
+       vm_map_t        src_map,
+       vm_map_offset_t src_addr,
+       vm_map_size_t   len,
+       boolean_t       src_destroy,
+       vm_map_copy_t   *copy_result)
+{
+       kern_return_t kr;
+       vm_map_copy_t copy;
+       vm_size_t kalloc_size;
+
+       if ((vm_size_t) len != len) {
+               /* "len" is too big and doesn't fit in a "vm_size_t" */
+               return KERN_RESOURCE_SHORTAGE;
+       }
+       kalloc_size = (vm_size_t) (sizeof(struct vm_map_copy) + len);
+       assert((vm_map_size_t) kalloc_size == sizeof (struct vm_map_copy) + len);
+
+       copy = (vm_map_copy_t) kalloc(kalloc_size);
+       if (copy == VM_MAP_COPY_NULL) {
+               return KERN_RESOURCE_SHORTAGE;
+       }
+       copy->type = VM_MAP_COPY_KERNEL_BUFFER;
+       copy->size = len;
+       copy->offset = 0;
+       copy->cpy_kdata = (void *) (copy + 1);
+       copy->cpy_kalloc_size = kalloc_size;
+
+       kr = copyinmap(src_map, src_addr, copy->cpy_kdata, (vm_size_t) len);
+       if (kr != KERN_SUCCESS) {
+               kfree(copy, kalloc_size);
+               return kr;
+       }
+       if (src_destroy) {
+               (void) vm_map_remove(src_map, vm_map_trunc_page(src_addr), 
+                                    vm_map_round_page(src_addr + len),
+                                    VM_MAP_REMOVE_INTERRUPTIBLE |
+                                    VM_MAP_REMOVE_WAIT_FOR_KWIRE |
+                                    (src_map == kernel_map) ?
+                                    VM_MAP_REMOVE_KUNWIRE : 0);
+       }
+       *copy_result = copy;
+       return KERN_SUCCESS;
+}
+
+/*
+ *     Routine: vm_map_copyout_kernel_buffer   [internal use only]
+ *
+ *     Description:
+ *             Copy out data from a kernel buffer into space in the
+ *             destination map. The space may be otpionally dynamically
+ *             allocated.
+ *
+ *             If successful, consumes the copy object.
+ *             Otherwise, the caller is responsible for it.
+ */
+static int vm_map_copyout_kernel_buffer_failures = 0;
+static kern_return_t
+vm_map_copyout_kernel_buffer(
+       vm_map_t                map,
+       vm_map_address_t        *addr,  /* IN/OUT */
+       vm_map_copy_t           copy,
+       boolean_t               overwrite)
+{
+       kern_return_t kr = KERN_SUCCESS;
+       thread_t thread = current_thread();
+
+       if (!overwrite) {
+
+               /*
+                * Allocate space in the target map for the data
+                */
+               *addr = 0;
+               kr = vm_map_enter(map, 
+                                 addr, 
+                                 vm_map_round_page(copy->size),
+                                 (vm_map_offset_t) 0, 
+                                 VM_FLAGS_ANYWHERE,
+                                 VM_OBJECT_NULL, 
+                                 (vm_object_offset_t) 0, 
+                                 FALSE,
+                                 VM_PROT_DEFAULT, 
+                                 VM_PROT_ALL,
+                                 VM_INHERIT_DEFAULT);
+               if (kr != KERN_SUCCESS)
+                       return kr;
+       }
+
+       /*
+        * Copyout the data from the kernel buffer to the target map.
+        */     
+       if (thread->map == map) {
+       
+               /*
+                * If the target map is the current map, just do
+                * the copy.
+                */
+               assert((vm_size_t) copy->size == copy->size);
+               if (copyout(copy->cpy_kdata, *addr, (vm_size_t) copy->size)) {
+                       kr = KERN_INVALID_ADDRESS;
+               }
+       }
+       else {
+               vm_map_t oldmap;
+
+               /*
+                * If the target map is another map, assume the
+                * target's address space identity for the duration
+                * of the copy.
+                */
+               vm_map_reference(map);
+               oldmap = vm_map_switch(map);
+
+               assert((vm_size_t) copy->size == copy->size);
+               if (copyout(copy->cpy_kdata, *addr, (vm_size_t) copy->size)) {
+                       vm_map_copyout_kernel_buffer_failures++;
+                       kr = KERN_INVALID_ADDRESS;
+               }
+       
+               (void) vm_map_switch(oldmap);
+               vm_map_deallocate(map);
+       }
+
+       if (kr != KERN_SUCCESS) {
+               /* the copy failed, clean up */
+               if (!overwrite) {
+                       /*
+                        * Deallocate the space we allocated in the target map.
+                        */
+                       (void) vm_map_remove(map,
+                                            vm_map_trunc_page(*addr),
+                                            vm_map_round_page(*addr +
+                                                              vm_map_round_page(copy->size)),
+                                            VM_MAP_NO_FLAGS);
+                       *addr = 0;
+               }
+       } else {
+               /* copy was successful, dicard the copy structure */
+               kfree(copy, copy->cpy_kalloc_size);
+       }
+
+       return kr;
+}
+               
+/*
+ *     Macro:          vm_map_copy_insert
+ *     
+ *     Description:
+ *             Link a copy chain ("copy") into a map at the
+ *             specified location (after "where").
+ *     Side effects:
+ *             The copy chain is destroyed.
+ *     Warning:
+ *             The arguments are evaluated multiple times.
+ */
+#define        vm_map_copy_insert(map, where, copy)                            \
+MACRO_BEGIN                                                            \
+       vm_map_t VMCI_map;                                              \
+       vm_map_entry_t VMCI_where;                                      \
+       vm_map_copy_t VMCI_copy;                                        \
+       VMCI_map = (map);                                               \
+       VMCI_where = (where);                                           \
+       VMCI_copy = (copy);                                             \
+       ((VMCI_where->vme_next)->vme_prev = vm_map_copy_last_entry(VMCI_copy))\
+               ->vme_next = (VMCI_where->vme_next);                    \
+       ((VMCI_where)->vme_next = vm_map_copy_first_entry(VMCI_copy))   \
+               ->vme_prev = VMCI_where;                                \
+       VMCI_map->hdr.nentries += VMCI_copy->cpy_hdr.nentries;          \
+       UPDATE_FIRST_FREE(VMCI_map, VMCI_map->first_free);              \
+       zfree(vm_map_copy_zone, VMCI_copy);                             \
+MACRO_END
+
+/*
+ *     Routine:        vm_map_copyout
+ *
+ *     Description:
+ *             Copy out a copy chain ("copy") into newly-allocated
+ *             space in the destination map.
+ *
+ *             If successful, consumes the copy object.
+ *             Otherwise, the caller is responsible for it.
+ */
+kern_return_t
+vm_map_copyout(
+       vm_map_t                dst_map,
+       vm_map_address_t        *dst_addr,      /* OUT */
+       vm_map_copy_t           copy)
+{
+       vm_map_size_t           size;
+       vm_map_size_t           adjustment;
+       vm_map_offset_t         start;
+       vm_object_offset_t      vm_copy_start;
+       vm_map_entry_t          last;
+       register
+       vm_map_entry_t          entry;
 
-                               if (entry->needs_copy) {
-                                       /* if this is a COW submap */
-                                       /* just back the range with a */
-                                       /* anonymous entry */
-                                       if(entry->vme_end < dst_end)
-                                               sub_end = entry->vme_end;
-                                       else 
-                                               sub_end = dst_end;
-                                       if(entry->vme_start < base_addr)
-                                               sub_start = base_addr;
-                                       else 
-                                               sub_start = entry->vme_start;
-                                       vm_map_clip_end(
-                                               dst_map, entry, sub_end);
-                                       vm_map_clip_start(
-                                               dst_map, entry, sub_start);
-                                       entry->is_sub_map = FALSE;
-                                       vm_map_deallocate(
-                                               entry->object.sub_map);
-                                       entry->object.sub_map = NULL;
-                                       entry->is_shared = FALSE;
-                                       entry->needs_copy = FALSE;
-                                       entry->offset = 0;
-                                       entry->protection = VM_PROT_ALL;
-                                       entry->max_protection = VM_PROT_ALL;
-                                       entry->wired_count = 0;
-                                       entry->user_wired_count = 0;
-                                       if(entry->inheritance 
-                                                       == VM_INHERIT_SHARE) 
-                                          entry->inheritance = VM_INHERIT_COPY;
-                                       continue;
-                               }
-                               /* first take care of any non-sub_map */
-                               /* entries to send */
-                               if(base_addr < entry->vme_start) {
-                                       /* stuff to send */
-                                       copy_size = 
-                                               entry->vme_start - base_addr;
-                                       break;
-                               }
-                               sub_start = entry->offset;
+       /*
+        *      Check for null copy object.
+        */
 
-                               if(entry->vme_end < dst_end)
-                                       sub_end = entry->vme_end;
-                               else 
-                                       sub_end = dst_end;
-                               sub_end -= entry->vme_start;
-                               sub_end += entry->offset;
-                               local_end = entry->vme_end;
-                               vm_map_unlock(dst_map);
-                               copy_size = sub_end - sub_start;
+       if (copy == VM_MAP_COPY_NULL) {
+               *dst_addr = 0;
+               return(KERN_SUCCESS);
+       }
 
-                               /* adjust the copy object */
-                               if (total_size > copy_size) {
-                                       vm_size_t       local_size = 0;
-                                       vm_size_t       entry_size;
-
-                                  nentries = 1;
-                                  new_offset = copy->offset;
-                                  copy_entry = vm_map_copy_first_entry(copy);
-                                  while(copy_entry != 
-                                                vm_map_copy_to_entry(copy)){
-                                      entry_size = copy_entry->vme_end - 
-                                                     copy_entry->vme_start;
-                                      if((local_size < copy_size) &&
-                                               ((local_size + entry_size) 
-                                                >= copy_size)) {
-                                         vm_map_copy_clip_end(copy, 
-                                                copy_entry, 
-                                                copy_entry->vme_start +
-                                                (copy_size - local_size));
-                                         entry_size = copy_entry->vme_end - 
-                                                        copy_entry->vme_start;
-                                         local_size += entry_size;
-                                         new_offset += entry_size;
-                                      }
-                                      if(local_size >= copy_size) {
-                                         next_copy = copy_entry->vme_next;
-                                         copy_entry->vme_next = 
-                                                   vm_map_copy_to_entry(copy);
-                                         previous_prev = 
-                                                  copy->cpy_hdr.links.prev;
-                                         copy->cpy_hdr.links.prev = copy_entry;
-                                         copy->size = copy_size;
-                                         remaining_entries = 
-                                                       copy->cpy_hdr.nentries;
-                                         remaining_entries -= nentries;
-                                         copy->cpy_hdr.nentries = nentries;
-                                         break;
-                                      } else {
-                                         local_size += entry_size;
-                                         new_offset += entry_size;
-                                         nentries++;
-                                      }
-                                      copy_entry = copy_entry->vme_next;
-                                  }
-                               }
-                       
-                               if((entry->use_pmap) && (pmap == NULL)) {
-                                       kr = vm_map_copy_overwrite_nested(
-                                               entry->object.sub_map,
-                                               sub_start,
-                                               copy,
-                                               interruptible, 
-                                               entry->object.sub_map->pmap);
-                               } else if (pmap != NULL) {
-                                       kr = vm_map_copy_overwrite_nested(
-                                               entry->object.sub_map,
-                                               sub_start,
-                                               copy,
-                                               interruptible, pmap);
-                               } else {
-                                       kr = vm_map_copy_overwrite_nested(
-                                               entry->object.sub_map,
-                                               sub_start,
-                                               copy,
-                                               interruptible,
-                                               dst_map->pmap);
-                               }
-                               if(kr != KERN_SUCCESS) {
-                                       if(next_copy != NULL) {
-                                          copy->cpy_hdr.nentries += 
-                                                          remaining_entries;
-                                          copy->cpy_hdr.links.prev->vme_next = 
-                                                          next_copy;
-                                          copy->cpy_hdr.links.prev 
-                                                          = previous_prev;
-                                          copy->size = total_size;
-                                       }
-                                       return kr;
-                               }
-                               if (dst_end <= local_end) {
-                                       return(KERN_SUCCESS);
-                               }
-                               /* otherwise copy no longer exists, it was */
-                               /* destroyed after successful copy_overwrite */
-                               copy = (vm_map_copy_t) 
-                                               zalloc(vm_map_copy_zone);
-                               vm_map_copy_first_entry(copy) =
-                                  vm_map_copy_last_entry(copy) =
-                                  vm_map_copy_to_entry(copy);
-                               copy->type = VM_MAP_COPY_ENTRY_LIST;
-                               copy->offset = new_offset;
+       /*
+        *      Check for special copy object, created
+        *      by vm_map_copyin_object.
+        */
 
-                               total_size -= copy_size;
-                               copy_size = 0;
-                               /* put back remainder of copy in container */
-                               if(next_copy != NULL) {
-                                  copy->cpy_hdr.nentries = remaining_entries;
-                                  copy->cpy_hdr.links.next = next_copy;
-                                  copy->cpy_hdr.links.prev = previous_prev;
-                                  copy->size = total_size;
-                                  next_copy->vme_prev = 
-                                                vm_map_copy_to_entry(copy);
-                                  next_copy = NULL;
-                               }
-                               base_addr = local_end;
-                               vm_map_lock(dst_map);
-                               if(!vm_map_lookup_entry(dst_map, 
-                                               local_end, &tmp_entry)) {
-                                       vm_map_unlock(dst_map);
-                                       return(KERN_INVALID_ADDRESS);
-                               }
-                               entry = tmp_entry;
-                               continue;
-                       } 
-                       if (dst_end <= entry->vme_end) {
-                               copy_size = dst_end - base_addr;
-                               break;
-                       }
+       if (copy->type == VM_MAP_COPY_OBJECT) {
+               vm_object_t             object = copy->cpy_object;
+               kern_return_t           kr;
+               vm_object_offset_t      offset;
 
-                       if ((next == vm_map_to_entry(dst_map)) ||
-                                   (next->vme_start != entry->vme_end)) {
-                               vm_map_unlock(dst_map);
-                               return(KERN_INVALID_ADDRESS);
-                       }
+               offset = vm_object_trunc_page(copy->offset);
+               size = vm_map_round_page(copy->size + 
+                                        (vm_map_size_t)(copy->offset - offset));
+               *dst_addr = 0;
+               kr = vm_map_enter(dst_map, dst_addr, size,
+                                 (vm_map_offset_t) 0, VM_FLAGS_ANYWHERE,
+                                 object, offset, FALSE,
+                                 VM_PROT_DEFAULT, VM_PROT_ALL,
+                                 VM_INHERIT_DEFAULT);
+               if (kr != KERN_SUCCESS)
+                       return(kr);
+               /* Account for non-pagealigned copy object */
+               *dst_addr += (vm_map_offset_t)(copy->offset - offset);
+               zfree(vm_map_copy_zone, copy);
+               return(KERN_SUCCESS);
+       }
 
-                       entry = next;
-               }/* for */
+       /*
+        *      Check for special kernel buffer allocated
+        *      by new_ipc_kmsg_copyin.
+        */
 
-               next_copy = NULL;
-               nentries = 1;
+       if (copy->type == VM_MAP_COPY_KERNEL_BUFFER) {
+               return(vm_map_copyout_kernel_buffer(dst_map, dst_addr, 
+                                                   copy, FALSE));
+       }
 
-               /* adjust the copy object */
-               if (total_size > copy_size) {
-                       vm_size_t       local_size = 0;
-                       vm_size_t       entry_size;
+       /*
+        *      Find space for the data
+        */
 
-                       new_offset = copy->offset;
-                       copy_entry = vm_map_copy_first_entry(copy);
-                       while(copy_entry != vm_map_copy_to_entry(copy)) {
-                               entry_size = copy_entry->vme_end - 
-                                               copy_entry->vme_start;
-                               if((local_size < copy_size) &&
-                                               ((local_size + entry_size) 
-                                               >= copy_size)) {
-                                       vm_map_copy_clip_end(copy, copy_entry, 
-                                               copy_entry->vme_start +
-                                               (copy_size - local_size));
-                                       entry_size = copy_entry->vme_end - 
-                                                  copy_entry->vme_start;
-                                       local_size += entry_size;
-                                       new_offset += entry_size;
-                               }
-                               if(local_size >= copy_size) {
-                                       next_copy = copy_entry->vme_next;
-                                       copy_entry->vme_next = 
-                                               vm_map_copy_to_entry(copy);
-                                       previous_prev = 
-                                               copy->cpy_hdr.links.prev;
-                                       copy->cpy_hdr.links.prev = copy_entry;
-                                       copy->size = copy_size;
-                                       remaining_entries = 
-                                               copy->cpy_hdr.nentries;
-                                       remaining_entries -= nentries;
-                                       copy->cpy_hdr.nentries = nentries;
-                                       break;
-                               } else {
-                                       local_size += entry_size;
-                                       new_offset += entry_size;
-                                       nentries++;
-                               }
-                               copy_entry = copy_entry->vme_next;
-                       }
-               }
+       vm_copy_start = vm_object_trunc_page(copy->offset);
+       size =  vm_map_round_page((vm_map_size_t)copy->offset + copy->size) 
+               - vm_copy_start;
 
-               if (aligned) {
-                       pmap_t  local_pmap;
+StartAgain: ;
 
-                       if(pmap)
-                               local_pmap = pmap;
-                       else
-                               local_pmap = dst_map->pmap;
+       vm_map_lock(dst_map);
+       assert(first_free_is_valid(dst_map));
+       start = ((last = dst_map->first_free) == vm_map_to_entry(dst_map)) ?
+               vm_map_min(dst_map) : last->vme_end;
 
-                       if ((kr =  vm_map_copy_overwrite_aligned( 
-                               dst_map, tmp_entry, copy,
-                               base_addr, local_pmap)) != KERN_SUCCESS) {
-                               if(next_copy != NULL) {
-                                       copy->cpy_hdr.nentries += 
-                                                          remaining_entries;
-                                       copy->cpy_hdr.links.prev->vme_next = 
-                                                          next_copy;
-                                       copy->cpy_hdr.links.prev = 
-                                                       previous_prev;
-                                       copy->size += copy_size;
+       while (TRUE) {
+               vm_map_entry_t  next = last->vme_next;
+               vm_map_offset_t end = start + size;
+
+               if ((end > dst_map->max_offset) || (end < start)) {
+                       if (dst_map->wait_for_space) {
+                               if (size <= (dst_map->max_offset - dst_map->min_offset)) {
+                                       assert_wait((event_t) dst_map,
+                                                   THREAD_INTERRUPTIBLE);
+                                       vm_map_unlock(dst_map);
+                                       thread_block(THREAD_CONTINUE_NULL);
+                                       goto StartAgain;
                                }
-                               return kr;
                        }
                        vm_map_unlock(dst_map);
-               } else {
-               /*
-                * Performance gain:
-                *
-                * if the copy and dst address are misaligned but the same
-                * offset within the page we can copy_not_aligned the
-                * misaligned parts and copy aligned the rest.  If they are
-                * aligned but len is unaligned we simply need to copy
-                * the end bit unaligned.  We'll need to split the misaligned
-                * bits of the region in this case !
-                */
-               /* ALWAYS UNLOCKS THE dst_map MAP */
-                       if ((kr =  vm_map_copy_overwrite_unaligned( dst_map,
-                               tmp_entry, copy, base_addr)) != KERN_SUCCESS) {
-                               if(next_copy != NULL) {
-                                       copy->cpy_hdr.nentries +=
-                                                            remaining_entries;
-                                       copy->cpy_hdr.links.prev->vme_next = 
-                                                            next_copy;
-                                       copy->cpy_hdr.links.prev = 
-                                               previous_prev;
-                                       copy->size += copy_size;
-                               }
-                               return kr;
-                       }
-               }
-               total_size -= copy_size;
-               if(total_size == 0)
-                       break;
-               base_addr += copy_size;
-               copy_size = 0;
-               copy->offset = new_offset;
-               if(next_copy != NULL) {
-                       copy->cpy_hdr.nentries = remaining_entries;
-                       copy->cpy_hdr.links.next = next_copy;
-                       copy->cpy_hdr.links.prev = previous_prev;
-                       next_copy->vme_prev = vm_map_copy_to_entry(copy);
-                       copy->size = total_size;
-               }
-               vm_map_lock(dst_map);
-               while(TRUE) {
-                       if (!vm_map_lookup_entry(dst_map, 
-                                               base_addr, &tmp_entry)) {
-                               vm_map_unlock(dst_map);
-                               return(KERN_INVALID_ADDRESS);
-                       }
-                       if (tmp_entry->in_transition) {
-                                       entry->needs_wakeup = TRUE;
-                                       vm_map_entry_wait(dst_map, THREAD_UNINT);
-                       } else {
-                               break;
-                       }
+                       return(KERN_NO_SPACE);
                }
-               vm_map_clip_start(dst_map, tmp_entry, trunc_page_32(base_addr));
 
-               entry = tmp_entry;
-       } /* while */
+               if ((next == vm_map_to_entry(dst_map)) ||
+                   (next->vme_start >= end))
+                       break;
+
+               last = next;
+               start = last->vme_end;
+       }
 
        /*
-        *      Throw away the vm_map_copy object
+        *      Since we're going to just drop the map
+        *      entries from the copy into the destination
+        *      map, they must come from the same pool.
         */
-       vm_map_copy_discard(copy);
 
-       return(KERN_SUCCESS);
-}/* vm_map_copy_overwrite */
+       if (copy->cpy_hdr.entries_pageable != dst_map->hdr.entries_pageable) {
+               /*
+                * Mismatches occur when dealing with the default
+                * pager.
+                */
+               zone_t          old_zone;
+               vm_map_entry_t  next, new;
 
-kern_return_t
-vm_map_copy_overwrite(
-       vm_map_t        dst_map,
-       vm_offset_t     dst_addr,
-       vm_map_copy_t   copy,
-       boolean_t       interruptible)
-{
-       return vm_map_copy_overwrite_nested(
-                       dst_map, dst_addr, copy, interruptible, (pmap_t) NULL);
-}
+               /*
+                * Find the zone that the copies were allocated from
+                */
+               old_zone = (copy->cpy_hdr.entries_pageable)
+                       ? vm_map_entry_zone
+                       : vm_map_kentry_zone;
+               entry = vm_map_copy_first_entry(copy);
 
+               /*
+                * Reinitialize the copy so that vm_map_copy_entry_link
+                * will work.
+                */
+               copy->cpy_hdr.nentries = 0;
+               copy->cpy_hdr.entries_pageable = dst_map->hdr.entries_pageable;
+               vm_map_copy_first_entry(copy) =
+                       vm_map_copy_last_entry(copy) =
+                       vm_map_copy_to_entry(copy);
 
-/*
- *     Routine: vm_map_copy_overwrite_unaligned
- *
- *     Decription:
- *     Physically copy unaligned data
- *
- *     Implementation:
- *     Unaligned parts of pages have to be physically copied.  We use
- *     a modified form of vm_fault_copy (which understands none-aligned
- *     page offsets and sizes) to do the copy.  We attempt to copy as
- *     much memory in one go as possibly, however vm_fault_copy copies
- *     within 1 memory object so we have to find the smaller of "amount left"
- *     "source object data size" and "target object data size".  With
- *     unaligned data we don't need to split regions, therefore the source
- *     (copy) object should be one map entry, the target range may be split
- *     over multiple map entries however.  In any event we are pessimistic
- *     about these assumptions.
- *
- *     Assumptions:
- *     dst_map is locked on entry and is return locked on success,
- *     unlocked on error.
- */
+               /*
+                * Copy each entry.
+                */
+               while (entry != vm_map_copy_to_entry(copy)) {
+                       new = vm_map_copy_entry_create(copy);
+                       vm_map_entry_copy_full(new, entry);
+                       new->use_pmap = FALSE;  /* clr address space specifics */
+                       vm_map_copy_entry_link(copy,
+                                              vm_map_copy_last_entry(copy),
+                                              new);
+                       next = entry->vme_next;
+                       zfree(old_zone, entry);
+                       entry = next;
+               }
+       }
 
-kern_return_t
-vm_map_copy_overwrite_unaligned(
-       vm_map_t        dst_map,
-       vm_map_entry_t  entry,
-       vm_map_copy_t   copy,
-       vm_offset_t     start)
-{
-       vm_map_entry_t          copy_entry = vm_map_copy_first_entry(copy);
-       vm_map_version_t        version;
-       vm_object_t             dst_object;
-       vm_object_offset_t      dst_offset;
-       vm_object_offset_t      src_offset;
-       vm_object_offset_t      entry_offset;
-       vm_offset_t             entry_end;
-       vm_size_t               src_size,
-                               dst_size,
-                               copy_size,
-                               amount_left;
-       kern_return_t           kr = KERN_SUCCESS;
+       /*
+        *      Adjust the addresses in the copy chain, and
+        *      reset the region attributes.
+        */
 
-       vm_map_lock_write_to_read(dst_map);
+       adjustment = start - vm_copy_start;
+       for (entry = vm_map_copy_first_entry(copy);
+            entry != vm_map_copy_to_entry(copy);
+            entry = entry->vme_next) {
+               entry->vme_start += adjustment;
+               entry->vme_end += adjustment;
 
-       src_offset = copy->offset - trunc_page_64(copy->offset);
-       amount_left = copy->size;
-/*
- *     unaligned so we never clipped this entry, we need the offset into
- *     the vm_object not just the data.
- */    
-       while (amount_left > 0) {
+               entry->inheritance = VM_INHERIT_DEFAULT;
+               entry->protection = VM_PROT_DEFAULT;
+               entry->max_protection = VM_PROT_ALL;
+               entry->behavior = VM_BEHAVIOR_DEFAULT;
 
-               if (entry == vm_map_to_entry(dst_map)) {
-                       vm_map_unlock_read(dst_map);
-                       return KERN_INVALID_ADDRESS;
-               }
+               /*
+                * If the entry is now wired,
+                * map the pages into the destination map.
+                */
+               if (entry->wired_count != 0) {
+                       register vm_map_offset_t va;
+                       vm_object_offset_t       offset;
+                       register vm_object_t object;
+                       vm_prot_t prot;
+                       int     type_of_fault;
 
-               /* "start" must be within the current map entry */
-               assert ((start>=entry->vme_start) && (start<entry->vme_end));
+                       object = entry->object.vm_object;
+                       offset = entry->offset;
+                       va = entry->vme_start;
 
-               dst_offset = start - entry->vme_start;
+                       pmap_pageable(dst_map->pmap,
+                                     entry->vme_start,
+                                     entry->vme_end,
+                                     TRUE);
 
-               dst_size = entry->vme_end - start;
+                       while (va < entry->vme_end) {
+                               register vm_page_t      m;
 
-               src_size = copy_entry->vme_end -
-                       (copy_entry->vme_start + src_offset);
+                               /*
+                                * Look up the page in the object.
+                                * Assert that the page will be found in the
+                                * top object:
+                                * either
+                                *      the object was newly created by
+                                *      vm_object_copy_slowly, and has
+                                *      copies of all of the pages from
+                                *      the source object
+                                * or
+                                *      the object was moved from the old
+                                *      map entry; because the old map
+                                *      entry was wired, all of the pages
+                                *      were in the top-level object.
+                                *      (XXX not true if we wire pages for
+                                *       reading)
+                                */
+                               vm_object_lock(object);
 
-               if (dst_size < src_size) {
-/*
- *                     we can only copy dst_size bytes before
- *                     we have to get the next destination entry
- */
-                       copy_size = dst_size;
-               } else {
-/*
- *                     we can only copy src_size bytes before
- *                     we have to get the next source copy entry
- */
-                       copy_size = src_size;
-               }
+                               m = vm_page_lookup(object, offset);
+                               if (m == VM_PAGE_NULL || !VM_PAGE_WIRED(m) ||
+                                   m->absent)
+                                       panic("vm_map_copyout: wiring %p", m);
 
-               if (copy_size > amount_left) {
-                       copy_size = amount_left;
-               }
-/*
- *             Entry needs copy, create a shadow shadow object for
- *             Copy on write region.
- */
-               if (entry->needs_copy &&
-                        ((entry->protection & VM_PROT_WRITE) != 0))
-               {
-                       if (vm_map_lock_read_to_write(dst_map)) {
-                               vm_map_lock_read(dst_map);
-                               goto RetryLookup;
-                       }
-                       vm_object_shadow(&entry->object.vm_object,
-                                       &entry->offset,
-                                       (vm_size_t)(entry->vme_end
-                                               - entry->vme_start));
-                       entry->needs_copy = FALSE;
-                       vm_map_lock_write_to_read(dst_map);
-               }
-               dst_object = entry->object.vm_object;
-/*
- *             unlike with the virtual (aligned) copy we're going
- *             to fault on it therefore we need a target object.
- */
-                if (dst_object == VM_OBJECT_NULL) {
-                       if (vm_map_lock_read_to_write(dst_map)) {
-                               vm_map_lock_read(dst_map);
-                               goto RetryLookup;
-                       }
-                       dst_object = vm_object_allocate((vm_size_t)
-                                       entry->vme_end - entry->vme_start);
-                       entry->object.vm_object = dst_object;
-                       entry->offset = 0;
-                       vm_map_lock_write_to_read(dst_map);
-               }
-/*
- *             Take an object reference and unlock map. The "entry" may
- *             disappear or change when the map is unlocked.
- */
-               vm_object_reference(dst_object);
-               version.main_timestamp = dst_map->timestamp;
-               entry_offset = entry->offset;
-               entry_end = entry->vme_end;
-               vm_map_unlock_read(dst_map);
-/*
- *             Copy as much as possible in one pass
- */
-               kr = vm_fault_copy(
-                       copy_entry->object.vm_object,
-                       copy_entry->offset + src_offset,
-                       &copy_size,
-                       dst_object,
-                       entry_offset + dst_offset,
-                       dst_map,
-                       &version,
-                       THREAD_UNINT );
+                               /*
+                                * ENCRYPTED SWAP:
+                                * The page is assumed to be wired here, so it
+                                * shouldn't be encrypted.  Otherwise, we
+                                * couldn't enter it in the page table, since
+                                * we don't want the user to see the encrypted
+                                * data.
+                                */
+                               ASSERT_PAGE_DECRYPTED(m);
 
-               start += copy_size;
-               src_offset += copy_size;
-               amount_left -= copy_size;
-/*
- *             Release the object reference
- */
-               vm_object_deallocate(dst_object);
-/*
- *             If a hard error occurred, return it now
- */
-               if (kr != KERN_SUCCESS)
-                       return kr;
+                               prot = entry->protection;
 
-               if ((copy_entry->vme_start + src_offset) == copy_entry->vme_end
-                       || amount_left == 0)
-               {
-/*
- *                     all done with this copy entry, dispose.
- */
-                       vm_map_copy_entry_unlink(copy, copy_entry);
-                       vm_object_deallocate(copy_entry->object.vm_object);
-                       vm_map_copy_entry_dispose(copy, copy_entry);
+                               if (override_nx(dst_map, entry->alias) && prot)
+                                       prot |= VM_PROT_EXECUTE;
 
-                       if ((copy_entry = vm_map_copy_first_entry(copy))
-                               == vm_map_copy_to_entry(copy) && amount_left) {
-/*
- *                             not finished copying but run out of source
- */
-                               return KERN_INVALID_ADDRESS;
+                               type_of_fault = DBG_CACHE_HIT_FAULT;
+
+                               vm_fault_enter(m, dst_map->pmap, va, prot,
+                                              VM_PAGE_WIRED(m), FALSE, FALSE,
+                                              &type_of_fault);
+
+                               vm_object_unlock(object);
+
+                               offset += PAGE_SIZE_64;
+                               va += PAGE_SIZE;
                        }
-                       src_offset = 0;
                }
+       }
 
-               if (amount_left == 0)
-                       return KERN_SUCCESS;
+       /*
+        *      Correct the page alignment for the result
+        */
+
+       *dst_addr = start + (copy->offset - vm_copy_start);
+
+       /*
+        *      Update the hints and the map size
+        */
+
+       SAVE_HINT_MAP_WRITE(dst_map, vm_map_copy_last_entry(copy));
+
+       dst_map->size += size;
+
+       /*
+        *      Link in the copy
+        */
+
+       vm_map_copy_insert(dst_map, last, copy);
+
+       vm_map_unlock(dst_map);
+
+       /*
+        * XXX  If wiring_required, call vm_map_pageable
+        */
+
+       return(KERN_SUCCESS);
+}
 
-               vm_map_lock_read(dst_map);
-               if (version.main_timestamp == dst_map->timestamp) {
-                       if (start == entry_end) {
-/*
- *                             destination region is split.  Use the version
- *                             information to avoid a lookup in the normal
- *                             case.
- */
-                               entry = entry->vme_next;
-/*
- *                             should be contiguous. Fail if we encounter
- *                             a hole in the destination.
- */
-                               if (start != entry->vme_start) {
-                                       vm_map_unlock_read(dst_map);
-                                       return KERN_INVALID_ADDRESS ;
-                               }
-                       }
-               } else {
 /*
- *                     Map version check failed.
- *                     we must lookup the entry because somebody
- *                     might have changed the map behind our backs.
+ *     Routine:        vm_map_copyin
+ *
+ *     Description:
+ *             see vm_map_copyin_common.  Exported via Unsupported.exports.
+ *
  */
-RetryLookup:
-                       if (!vm_map_lookup_entry(dst_map, start, &entry))
-                       {
-                               vm_map_unlock_read(dst_map);
-                               return KERN_INVALID_ADDRESS ;
-                       }
-               }
-       }/* while */
 
-       /* NOTREACHED ?? */
-       vm_map_unlock_read(dst_map);
+#undef vm_map_copyin
 
-       return KERN_SUCCESS;
-}/* vm_map_copy_overwrite_unaligned */
+kern_return_t
+vm_map_copyin(
+       vm_map_t                        src_map,
+       vm_map_address_t        src_addr,
+       vm_map_size_t           len,
+       boolean_t                       src_destroy,
+       vm_map_copy_t           *copy_result)   /* OUT */
+{
+       return(vm_map_copyin_common(src_map, src_addr, len, src_destroy,
+                                       FALSE, copy_result, FALSE));
+}
 
 /*
- *     Routine:        vm_map_copy_overwrite_aligned
+ *     Routine:        vm_map_copyin_common
  *
  *     Description:
- *     Does all the vm_trickery possible for whole pages.
+ *             Copy the specified region (src_addr, len) from the
+ *             source address space (src_map), possibly removing
+ *             the region from the source address space (src_destroy).
  *
- *     Implementation:
+ *     Returns:
+ *             A vm_map_copy_t object (copy_result), suitable for
+ *             insertion into another address space (using vm_map_copyout),
+ *             copying over another address space region (using
+ *             vm_map_copy_overwrite).  If the copy is unused, it
+ *             should be destroyed (using vm_map_copy_discard).
  *
- *     If there are no permanent objects in the destination,
- *     and the source and destination map entry zones match,
- *     and the destination map entry is not shared,
- *     then the map entries can be deleted and replaced
- *     with those from the copy.  The following code is the
- *     basic idea of what to do, but there are lots of annoying
- *     little details about getting protection and inheritance
- *     right.  Should add protection, inheritance, and sharing checks
- *     to the above pass and make sure that no wiring is involved.
+ *     In/out conditions:
+ *             The source map should not be locked on entry.
  */
 
+typedef struct submap_map {
+       vm_map_t        parent_map;
+       vm_map_offset_t base_start;
+       vm_map_offset_t base_end;
+       vm_map_size_t   base_len;
+       struct submap_map *next;
+} submap_map_t;
+
 kern_return_t
-vm_map_copy_overwrite_aligned(
-       vm_map_t        dst_map,
-       vm_map_entry_t  tmp_entry,
-       vm_map_copy_t   copy,
-       vm_offset_t     start,
-       pmap_t          pmap)
+vm_map_copyin_common(
+       vm_map_t        src_map,
+       vm_map_address_t src_addr,
+       vm_map_size_t   len,
+       boolean_t       src_destroy,
+       __unused boolean_t      src_volatile,
+       vm_map_copy_t   *copy_result,   /* OUT */
+       boolean_t       use_maxprot)
 {
-       vm_object_t     object;
-       vm_map_entry_t  copy_entry;
-       vm_size_t       copy_size;
-       vm_size_t       size;
-       vm_map_entry_t  entry;
-               
-       while ((copy_entry = vm_map_copy_first_entry(copy))
-               != vm_map_copy_to_entry(copy))
-       {
-               copy_size = (copy_entry->vme_end - copy_entry->vme_start);
-               
-               entry = tmp_entry;
-               if (entry == vm_map_to_entry(dst_map)) {
-                       vm_map_unlock(dst_map);
-                       return KERN_INVALID_ADDRESS;
-               }
-               size = (entry->vme_end - entry->vme_start);
-               /*
-                *      Make sure that no holes popped up in the
-                *      address map, and that the protection is
-                *      still valid, in case the map was unlocked
-                *      earlier.
-                */
+       vm_map_entry_t  tmp_entry;      /* Result of last map lookup --
+                                        * in multi-level lookup, this
+                                        * entry contains the actual
+                                        * vm_object/offset.
+                                        */
+       register
+       vm_map_entry_t  new_entry = VM_MAP_ENTRY_NULL;  /* Map entry for copy */
 
-               if ((entry->vme_start != start) || ((entry->is_sub_map)
-                               && !entry->needs_copy)) {
-                       vm_map_unlock(dst_map);
-                       return(KERN_INVALID_ADDRESS);
-               }
-               assert(entry != vm_map_to_entry(dst_map));
+       vm_map_offset_t src_start;      /* Start of current entry --
+                                        * where copy is taking place now
+                                        */
+       vm_map_offset_t src_end;        /* End of entire region to be
+                                        * copied */
+       vm_map_offset_t src_base;
+       vm_map_t        base_map = src_map;
+       boolean_t       map_share=FALSE;
+       submap_map_t    *parent_maps = NULL;
 
-               /*
-                *      Check protection again
-                */
+       register
+       vm_map_copy_t   copy;           /* Resulting copy */
+       vm_map_address_t        copy_addr;
 
-               if ( ! (entry->protection & VM_PROT_WRITE)) {
-                       vm_map_unlock(dst_map);
-                       return(KERN_PROTECTION_FAILURE);
-               }
+       /*
+        *      Check for copies of zero bytes.
+        */
 
-               /*
-                *      Adjust to source size first
-                */
+       if (len == 0) {
+               *copy_result = VM_MAP_COPY_NULL;
+               return(KERN_SUCCESS);
+       }
 
-               if (copy_size < size) {
-                       vm_map_clip_end(dst_map, entry, entry->vme_start + copy_size);
-                       size = copy_size;
-               }
+       /*
+        *      Check that the end address doesn't overflow
+        */
+       src_end = src_addr + len;
+       if (src_end < src_addr)
+               return KERN_INVALID_ADDRESS;
 
-               /*
-                *      Adjust to destination size
-                */
+       /*
+        * If the copy is sufficiently small, use a kernel buffer instead
+        * of making a virtual copy.  The theory being that the cost of
+        * setting up VM (and taking C-O-W faults) dominates the copy costs
+        * for small regions.
+        */
+       if ((len < msg_ool_size_small) && !use_maxprot)
+               return vm_map_copyin_kernel_buffer(src_map, src_addr, len,
+                                                  src_destroy, copy_result);
 
-               if (size < copy_size) {
-                       vm_map_copy_clip_end(copy, copy_entry,
-                               copy_entry->vme_start + size);
-                       copy_size = size;
+       /*
+        *      Compute (page aligned) start and end of region
+        */
+       src_start = vm_map_trunc_page(src_addr);
+       src_end = vm_map_round_page(src_end);
+
+       XPR(XPR_VM_MAP, "vm_map_copyin_common map 0x%x addr 0x%x len 0x%x dest %d\n", src_map, src_addr, len, src_destroy, 0);
+
+       /*
+        *      Allocate a header element for the list.
+        *
+        *      Use the start and end in the header to 
+        *      remember the endpoints prior to rounding.
+        */
+
+       copy = (vm_map_copy_t) zalloc(vm_map_copy_zone);
+       vm_map_copy_first_entry(copy) =
+               vm_map_copy_last_entry(copy) = vm_map_copy_to_entry(copy);
+       copy->type = VM_MAP_COPY_ENTRY_LIST;
+       copy->cpy_hdr.nentries = 0;
+       copy->cpy_hdr.entries_pageable = TRUE;
+
+       copy->offset = src_addr;
+       copy->size = len;
+       
+       new_entry = vm_map_copy_entry_create(copy);
+
+#define        RETURN(x)                                               \
+       MACRO_BEGIN                                             \
+       vm_map_unlock(src_map);                                 \
+       if(src_map != base_map)                                 \
+               vm_map_deallocate(src_map);                     \
+       if (new_entry != VM_MAP_ENTRY_NULL)                     \
+               vm_map_copy_entry_dispose(copy,new_entry);      \
+       vm_map_copy_discard(copy);                              \
+       {                                                       \
+               submap_map_t    *_ptr;                          \
+                                                               \
+               for(_ptr = parent_maps; _ptr != NULL; _ptr = parent_maps) { \
+                       parent_maps=parent_maps->next;          \
+                       if (_ptr->parent_map != base_map)       \
+                               vm_map_deallocate(_ptr->parent_map);    \
+                       kfree(_ptr, sizeof(submap_map_t));      \
+               }                                               \
+       }                                                       \
+       MACRO_RETURN(x);                                        \
+       MACRO_END
+
+       /*
+        *      Find the beginning of the region.
+        */
+
+       vm_map_lock(src_map);
+
+       if (!vm_map_lookup_entry(src_map, src_start, &tmp_entry))
+               RETURN(KERN_INVALID_ADDRESS);
+       if(!tmp_entry->is_sub_map) {
+               vm_map_clip_start(src_map, tmp_entry, src_start);
+       }
+       /* set for later submap fix-up */
+       copy_addr = src_start;
+
+       /*
+        *      Go through entries until we get to the end.
+        */
+
+       while (TRUE) {
+               register
+               vm_map_entry_t  src_entry = tmp_entry;  /* Top-level entry */
+               vm_map_size_t   src_size;               /* Size of source
+                                                        * map entry (in both
+                                                        * maps)
+                                                        */
+
+               register
+               vm_object_t             src_object;     /* Object to copy */
+               vm_object_offset_t      src_offset;
+
+               boolean_t       src_needs_copy;         /* Should source map
+                                                        * be made read-only
+                                                        * for copy-on-write?
+                                                        */
+
+               boolean_t       new_entry_needs_copy;   /* Will new entry be COW? */
+
+               boolean_t       was_wired;              /* Was source wired? */
+               vm_map_version_t version;               /* Version before locks
+                                                        * dropped to make copy
+                                                        */
+               kern_return_t   result;                 /* Return value from
+                                                        * copy_strategically.
+                                                        */
+               while(tmp_entry->is_sub_map) {
+                       vm_map_size_t submap_len;
+                       submap_map_t *ptr;
+
+                       ptr = (submap_map_t *)kalloc(sizeof(submap_map_t));
+                       ptr->next = parent_maps;
+                       parent_maps = ptr;
+                       ptr->parent_map = src_map;
+                       ptr->base_start = src_start;
+                       ptr->base_end = src_end;
+                       submap_len = tmp_entry->vme_end - src_start;
+                       if(submap_len > (src_end-src_start))
+                               submap_len = src_end-src_start;
+                       ptr->base_len = submap_len;
+       
+                       src_start -= tmp_entry->vme_start;
+                       src_start += tmp_entry->offset;
+                       src_end = src_start + submap_len;
+                       src_map = tmp_entry->object.sub_map;
+                       vm_map_lock(src_map);
+                       /* keep an outstanding reference for all maps in */
+                       /* the parents tree except the base map */
+                       vm_map_reference(src_map);
+                       vm_map_unlock(ptr->parent_map);
+                       if (!vm_map_lookup_entry(
+                                   src_map, src_start, &tmp_entry))
+                               RETURN(KERN_INVALID_ADDRESS);
+                       map_share = TRUE;
+                       if(!tmp_entry->is_sub_map)
+                               vm_map_clip_start(src_map, tmp_entry, src_start);
+                       src_entry = tmp_entry;
+               }
+               /* we are now in the lowest level submap... */
+
+               if ((tmp_entry->object.vm_object != VM_OBJECT_NULL) && 
+                   (tmp_entry->object.vm_object->phys_contiguous)) {
+                       /* This is not, supported for now.In future */
+                       /* we will need to detect the phys_contig   */
+                       /* condition and then upgrade copy_slowly   */
+                       /* to do physical copy from the device mem  */
+                       /* based object. We can piggy-back off of   */
+                       /* the was wired boolean to set-up the      */
+                       /* proper handling */
+                       RETURN(KERN_PROTECTION_FAILURE);
                }
-
-               assert((entry->vme_end - entry->vme_start) == size);
-               assert((tmp_entry->vme_end - tmp_entry->vme_start) == size);
-               assert((copy_entry->vme_end - copy_entry->vme_start) == size);
-
                /*
-                *      If the destination contains temporary unshared memory,
-                *      we can perform the copy by throwing it away and
-                *      installing the source data.
+                *      Create a new address map entry to hold the result. 
+                *      Fill in the fields from the appropriate source entries.
+                *      We must unlock the source map to do this if we need
+                *      to allocate a map entry.
                 */
+               if (new_entry == VM_MAP_ENTRY_NULL) {
+                       version.main_timestamp = src_map->timestamp;
+                       vm_map_unlock(src_map);
 
-               object = entry->object.vm_object;
-               if ((!entry->is_shared && 
-                   ((object == VM_OBJECT_NULL) || 
-                   (object->internal && !object->true_share))) ||
-                   entry->needs_copy) {
-                       vm_object_t     old_object = entry->object.vm_object;
-                       vm_object_offset_t      old_offset = entry->offset;
-                       vm_object_offset_t      offset;
-
-                       /*
-                        * Ensure that the source and destination aren't
-                        * identical
-                        */
-                       if (old_object == copy_entry->object.vm_object &&
-                           old_offset == copy_entry->offset) {
-                               vm_map_copy_entry_unlink(copy, copy_entry);
-                               vm_map_copy_entry_dispose(copy, copy_entry);
-
-                               if (old_object != VM_OBJECT_NULL)
-                                       vm_object_deallocate(old_object);
+                       new_entry = vm_map_copy_entry_create(copy);
 
-                               start = tmp_entry->vme_end;
-                               tmp_entry = tmp_entry->vme_next;
-                               continue;
+                       vm_map_lock(src_map);
+                       if ((version.main_timestamp + 1) != src_map->timestamp) {
+                               if (!vm_map_lookup_entry(src_map, src_start,
+                                                        &tmp_entry)) {
+                                       RETURN(KERN_INVALID_ADDRESS);
+                               }
+                               if (!tmp_entry->is_sub_map)
+                                       vm_map_clip_start(src_map, tmp_entry, src_start);
+                               continue; /* restart w/ new tmp_entry */
                        }
+               }
 
-                       if (old_object != VM_OBJECT_NULL) {
-                               if(entry->is_sub_map) {
-                                       if(entry->use_pmap) {
-#ifndef i386
-                                               pmap_unnest(dst_map->pmap, 
-                                                       entry->vme_start,
-                                                       entry->vme_end 
-                                                         - entry->vme_start);
-#endif
-                                               if(dst_map->mapped) {
-                                                       /* clean up parent */
-                                                       /* map/maps */
-                                                  vm_map_submap_pmap_clean(
-                                                       dst_map, entry->vme_start,
-                                                       entry->vme_end,
-                                                       entry->object.sub_map,
-                                                       entry->offset);
-                                               }
-                                       } else {
-                                               vm_map_submap_pmap_clean(
-                                                       dst_map, entry->vme_start, 
-                                                       entry->vme_end,
-                                                       entry->object.sub_map,
-                                                       entry->offset);
-                                       }
-                                       vm_map_deallocate(
-                                               entry->object.sub_map);
-                               } else {
-                                       if(dst_map->mapped) {
-                                               vm_object_pmap_protect(
-                                                       entry->object.vm_object,
-                                                       entry->offset,
-                                                       entry->vme_end 
-                                                               - entry->vme_start,
-                                                       PMAP_NULL,
-                                                       entry->vme_start,
-                                                       VM_PROT_NONE);
-                                       } else {
-                                          pmap_remove(dst_map->pmap, 
-                                            (addr64_t)(entry->vme_start), 
-                                            (addr64_t)(entry->vme_end));
-                                       }
-                                       vm_object_deallocate(old_object);
-                               }
-                       }
+               /*
+                *      Verify that the region can be read.
+                */
+               if (((src_entry->protection & VM_PROT_READ) == VM_PROT_NONE &&
+                    !use_maxprot) ||
+                   (src_entry->max_protection & VM_PROT_READ) == 0)
+                       RETURN(KERN_PROTECTION_FAILURE);
 
-                       entry->is_sub_map = FALSE;
-                       entry->object = copy_entry->object;
-                       object = entry->object.vm_object;
-                       entry->needs_copy = copy_entry->needs_copy;
-                       entry->wired_count = 0;
-                       entry->user_wired_count = 0;
-                       offset = entry->offset = copy_entry->offset;
+               /*
+                *      Clip against the endpoints of the entire region.
+                */
 
-                       vm_map_copy_entry_unlink(copy, copy_entry);
-                       vm_map_copy_entry_dispose(copy, copy_entry);
-#if BAD_OPTIMIZATION
-                       /*
-                        * if we turn this optimization back on
-                        * we need to revisit our use of pmap mappings
-                        * large copies will cause us to run out and panic
-                        * this optimization only saved on average 2 us per page if ALL
-                        * the pages in the source were currently mapped
-                        * and ALL the pages in the dest were touched, if there were fewer
-                        * than 2/3 of the pages touched, this optimization actually cost more cycles
-                        */
+               vm_map_clip_end(src_map, src_entry, src_end);
 
-                       /*
-                        * Try to aggressively enter physical mappings
-                        * (but avoid uninstantiated objects)
-                        */
-                       if (object != VM_OBJECT_NULL) {
-                           vm_offset_t va = entry->vme_start;
+               src_size = src_entry->vme_end - src_start;
+               src_object = src_entry->object.vm_object;
+               src_offset = src_entry->offset;
+               was_wired = (src_entry->wired_count != 0);
 
-                           while (va < entry->vme_end) {
-                               register vm_page_t      m;
-                               vm_prot_t               prot;
+               vm_map_entry_copy(new_entry, src_entry);
+               new_entry->use_pmap = FALSE; /* clr address space specifics */
 
-                               /*
-                                * Look for the page in the top object
-                                */
-                               prot = entry->protection;
-                               vm_object_lock(object);
-                               vm_object_paging_begin(object);
-
-                               if ((m = vm_page_lookup(object,offset)) !=
-                                   VM_PAGE_NULL && !m->busy && 
-                                   !m->fictitious &&
-                                   (!m->unusual || (!m->error &&
-                                       !m->restart && !m->absent &&
-                                        (prot & m->page_lock) == 0))) {
-                                       
-                                       m->busy = TRUE;
-                                       vm_object_unlock(object);
-                                       
-                                       /* 
-                                        * Honor COW obligations
-                                        */
-                                       if (entry->needs_copy)
-                                               prot &= ~VM_PROT_WRITE;
-                                       /* It is our policy to require */
-                                       /* explicit sync from anyone   */
-                                       /* writing code and then       */
-                                       /* a pc to execute it.         */
-                                       /* No isync here */
-
-                                       PMAP_ENTER(pmap, va, m, prot, 
-                                               ((unsigned int)
-                                                       (m->object->wimg_bits)) 
-                                                       & VM_WIMG_MASK,
-                                               FALSE);
-               
-                                       vm_object_lock(object);
-                                       vm_page_lock_queues();
-                                       if (!m->active && !m->inactive)
-                                               vm_page_activate(m);
-                                       vm_page_unlock_queues();
-                                        PAGE_WAKEUP_DONE(m);
-                               }
-                               vm_object_paging_end(object);
-                               vm_object_unlock(object);
+               /*
+                *      Attempt non-blocking copy-on-write optimizations.
+                */
 
-                               offset += PAGE_SIZE_64;
-                               va += PAGE_SIZE;
-                           } /* end while (va < entry->vme_end) */
-                       } /* end if (object) */
-#endif
+               if (src_destroy && 
+                   (src_object == VM_OBJECT_NULL || 
+                    (src_object->internal && !src_object->true_share
+                     && !map_share))) {
                        /*
-                        *      Set up for the next iteration.  The map
-                        *      has not been unlocked, so the next
-                        *      address should be at the end of this
-                        *      entry, and the next map entry should be
-                        *      the one following it.
+                        * If we are destroying the source, and the object
+                        * is internal, we can move the object reference
+                        * from the source to the copy.  The copy is
+                        * copy-on-write only if the source is.
+                        * We make another reference to the object, because
+                        * destroying the source entry will deallocate it.
                         */
-
-                       start = tmp_entry->vme_end;
-                       tmp_entry = tmp_entry->vme_next;
-               } else {
-                       vm_map_version_t        version;
-                       vm_object_t             dst_object = entry->object.vm_object;
-                       vm_object_offset_t      dst_offset = entry->offset;
-                       kern_return_t           r;
+                       vm_object_reference(src_object);
 
                        /*
-                        *      Take an object reference, and record
-                        *      the map version information so that the
-                        *      map can be safely unlocked.
+                        * Copy is always unwired.  vm_map_copy_entry
+                        * set its wired count to zero.
                         */
 
-                       vm_object_reference(dst_object);
-
-                       /* account for unlock bumping up timestamp */
-                       version.main_timestamp = dst_map->timestamp + 1;
+                       goto CopySuccessful;
+               }
 
-                       vm_map_unlock(dst_map);
 
-                       /*
-                        *      Copy as much as possible in one pass
-                        */
+       RestartCopy:
+               XPR(XPR_VM_MAP, "vm_map_copyin_common src_obj 0x%x ent 0x%x obj 0x%x was_wired %d\n",
+                   src_object, new_entry, new_entry->object.vm_object,
+                   was_wired, 0);
+               if ((src_object == VM_OBJECT_NULL ||
+                    (!was_wired && !map_share && !tmp_entry->is_shared)) &&
+                   vm_object_copy_quickly(
+                           &new_entry->object.vm_object,
+                           src_offset,
+                           src_size,
+                           &src_needs_copy,
+                           &new_entry_needs_copy)) {
 
-                       copy_size = size;
-                       r = vm_fault_copy(
-                                       copy_entry->object.vm_object,
-                                       copy_entry->offset,
-                                       &copy_size,
-                                       dst_object,
-                                       dst_offset,
-                                       dst_map,
-                                       &version,
-                                       THREAD_UNINT );
+                       new_entry->needs_copy = new_entry_needs_copy;
 
                        /*
-                        *      Release the object reference
+                        *      Handle copy-on-write obligations
                         */
 
-                       vm_object_deallocate(dst_object);
+                       if (src_needs_copy && !tmp_entry->needs_copy) {
+                               vm_prot_t prot;
 
-                       /*
-                        *      If a hard error occurred, return it now
-                        */
+                               prot = src_entry->protection & ~VM_PROT_WRITE;
 
-                       if (r != KERN_SUCCESS)
-                               return(r);
+                               if (override_nx(src_map, src_entry->alias) && prot)
+                                       prot |= VM_PROT_EXECUTE;
 
-                       if (copy_size != 0) {
-                               /*
-                                *      Dispose of the copied region
-                                */
+                               vm_object_pmap_protect(
+                                       src_object,
+                                       src_offset,
+                                       src_size,
+                                       (src_entry->is_shared ? 
+                                        PMAP_NULL
+                                        : src_map->pmap),
+                                       src_entry->vme_start,
+                                       prot);
 
-                               vm_map_copy_clip_end(copy, copy_entry,
-                                       copy_entry->vme_start + copy_size);
-                               vm_map_copy_entry_unlink(copy, copy_entry);
-                               vm_object_deallocate(copy_entry->object.vm_object);
-                               vm_map_copy_entry_dispose(copy, copy_entry);
+                               tmp_entry->needs_copy = TRUE;
                        }
 
                        /*
-                        *      Pick up in the destination map where we left off.
-                        *
-                        *      Use the version information to avoid a lookup
-                        *      in the normal case.
+                        *      The map has never been unlocked, so it's safe
+                        *      to move to the next entry rather than doing
+                        *      another lookup.
                         */
 
-                       start += copy_size;
-                       vm_map_lock(dst_map);
-                       if (version.main_timestamp == dst_map->timestamp) {
-                               /* We can safely use saved tmp_entry value */
+                       goto CopySuccessful;
+               }
 
-                               vm_map_clip_end(dst_map, tmp_entry, start);
-                               tmp_entry = tmp_entry->vme_next;
-                       } else {
-                               /* Must do lookup of tmp_entry */
+               /*
+                *      Take an object reference, so that we may
+                *      release the map lock(s).
+                */
 
-                               if (!vm_map_lookup_entry(dst_map, start, &tmp_entry)) {
-                                       vm_map_unlock(dst_map);
-                                       return(KERN_INVALID_ADDRESS);
-                               }
-                               vm_map_clip_start(dst_map, tmp_entry, start);
-                       }
-               }
-       }/* while */
+               assert(src_object != VM_OBJECT_NULL);
+               vm_object_reference(src_object);
 
-       return(KERN_SUCCESS);
-}/* vm_map_copy_overwrite_aligned */
+               /*
+                *      Record the timestamp for later verification.
+                *      Unlock the map.
+                */
 
-/*
- *     Routine:        vm_map_copyin_kernel_buffer
- *
- *     Description:
- *             Copy in data to a kernel buffer from space in the
- *             source map. The original space may be otpionally
- *             deallocated.
- *
- *             If successful, returns a new copy object.
- */
-kern_return_t
-vm_map_copyin_kernel_buffer(
-       vm_map_t        src_map,
-       vm_offset_t     src_addr,
-       vm_size_t       len,
-       boolean_t       src_destroy,
-       vm_map_copy_t   *copy_result)
-{
-       boolean_t flags;
-       vm_map_copy_t copy;
-       vm_size_t kalloc_size = sizeof(struct vm_map_copy) + len;
+               version.main_timestamp = src_map->timestamp;
+               vm_map_unlock(src_map); /* Increments timestamp once! */
 
-       copy = (vm_map_copy_t) kalloc(kalloc_size);
-       if (copy == VM_MAP_COPY_NULL) {
-               return KERN_RESOURCE_SHORTAGE;
-       }
-       copy->type = VM_MAP_COPY_KERNEL_BUFFER;
-       copy->size = len;
-       copy->offset = 0;
-       copy->cpy_kdata = (vm_offset_t) (copy + 1);
-       copy->cpy_kalloc_size = kalloc_size;
+               /*
+                *      Perform the copy
+                */
+
+               if (was_wired) {
+               CopySlowly:
+                       vm_object_lock(src_object);
+                       result = vm_object_copy_slowly(
+                               src_object,
+                               src_offset,
+                               src_size,
+                               THREAD_UNINT,
+                               &new_entry->object.vm_object);
+                       new_entry->offset = 0;
+                       new_entry->needs_copy = FALSE;
 
-       if (src_map == kernel_map) {
-               bcopy((char *)src_addr, (char *)copy->cpy_kdata, len);
-               flags = VM_MAP_REMOVE_KUNWIRE | VM_MAP_REMOVE_WAIT_FOR_KWIRE |
-                       VM_MAP_REMOVE_INTERRUPTIBLE;
-       } else {
-               kern_return_t kr;
-               kr = copyinmap(src_map, src_addr, copy->cpy_kdata, len);
-               if (kr != KERN_SUCCESS) {
-                       kfree((vm_offset_t)copy, kalloc_size);
-                       return kr;
                }
-               flags = VM_MAP_REMOVE_WAIT_FOR_KWIRE |
-                       VM_MAP_REMOVE_INTERRUPTIBLE;
-       }
-       if (src_destroy) {
-               (void) vm_map_remove(src_map, trunc_page_32(src_addr), 
-                                    round_page_32(src_addr + len),
-                                    flags);
-       }
-       *copy_result = copy;
-       return KERN_SUCCESS;
-}
+               else if (src_object->copy_strategy == MEMORY_OBJECT_COPY_SYMMETRIC &&
+                        (tmp_entry->is_shared  || map_share)) {
+                       vm_object_t new_object;
 
-/*
- *     Routine:        vm_map_copyout_kernel_buffer
- *
- *     Description:
- *             Copy out data from a kernel buffer into space in the
- *             destination map. The space may be otpionally dynamically
- *             allocated.
- *
- *             If successful, consumes the copy object.
- *             Otherwise, the caller is responsible for it.
- */
-kern_return_t
-vm_map_copyout_kernel_buffer(
-       vm_map_t        map,
-       vm_offset_t     *addr,  /* IN/OUT */
-       vm_map_copy_t   copy,
-       boolean_t       overwrite)
-{
-       kern_return_t kr = KERN_SUCCESS;
-       thread_act_t thr_act = current_act();
+                       vm_object_lock_shared(src_object);
+                       new_object = vm_object_copy_delayed(
+                               src_object,
+                               src_offset,     
+                               src_size,
+                               TRUE);
+                       if (new_object == VM_OBJECT_NULL)
+                               goto CopySlowly;
 
-       if (!overwrite) {
+                       new_entry->object.vm_object = new_object;
+                       new_entry->needs_copy = TRUE;
+                       result = KERN_SUCCESS;
+
+               } else {
+                       result = vm_object_copy_strategically(src_object,
+                                                             src_offset,
+                                                             src_size,
+                                                             &new_entry->object.vm_object,
+                                                             &new_entry->offset,
+                                                             &new_entry_needs_copy);
+
+                       new_entry->needs_copy = new_entry_needs_copy;
+               }
+
+               if (result != KERN_SUCCESS &&
+                   result != KERN_MEMORY_RESTART_COPY) {
+                       vm_map_lock(src_map);
+                       RETURN(result);
+               }
 
                /*
-                * Allocate space in the target map for the data
+                *      Throw away the extra reference
                 */
-               *addr = 0;
-               kr = vm_map_enter(map, 
-                                 addr, 
-                                 round_page_32(copy->size),
-                                 (vm_offset_t) 0, 
-                                 TRUE,
-                                 VM_OBJECT_NULL, 
-                                 (vm_object_offset_t) 0, 
-                                 FALSE,
-                                 VM_PROT_DEFAULT, 
-                                 VM_PROT_ALL,
-                                 VM_INHERIT_DEFAULT);
-               if (kr != KERN_SUCCESS)
-                       return(kr);
-       }
 
-       /*
-        * Copyout the data from the kernel buffer to the target map.
-        */     
-       if (thr_act->map == map) {
-       
+               vm_object_deallocate(src_object);
+
                /*
-                * If the target map is the current map, just do
-                * the copy.
+                *      Verify that the map has not substantially
+                *      changed while the copy was being made.
                 */
-               if (copyout((char *)copy->cpy_kdata, (char *)*addr,
-                               copy->size)) {
-                       return(KERN_INVALID_ADDRESS);
-               }
-       }
-       else {
-               vm_map_t oldmap;
+
+               vm_map_lock(src_map);
+
+               if ((version.main_timestamp + 1) == src_map->timestamp)
+                       goto VerificationSuccessful;
 
                /*
-                * If the target map is another map, assume the
-                * target's address space identity for the duration
-                * of the copy.
+                *      Simple version comparison failed.
+                *
+                *      Retry the lookup and verify that the
+                *      same object/offset are still present.
+                *
+                *      [Note: a memory manager that colludes with
+                *      the calling task can detect that we have
+                *      cheated.  While the map was unlocked, the
+                *      mapping could have been changed and restored.]
                 */
-               vm_map_reference(map);
-               oldmap = vm_map_switch(map);
 
-               if (copyout((char *)copy->cpy_kdata, (char *)*addr,
-                               copy->size)) {
-                       return(KERN_INVALID_ADDRESS);
+               if (!vm_map_lookup_entry(src_map, src_start, &tmp_entry)) {
+                       RETURN(KERN_INVALID_ADDRESS);
                }
-       
-               (void) vm_map_switch(oldmap);
-               vm_map_deallocate(map);
-       }
 
-       kfree((vm_offset_t)copy, copy->cpy_kalloc_size);
+               src_entry = tmp_entry;
+               vm_map_clip_start(src_map, src_entry, src_start);
 
-       return(kr);
-}
-               
-/*
- *     Macro:          vm_map_copy_insert
- *     
- *     Description:
- *             Link a copy chain ("copy") into a map at the
- *             specified location (after "where").
- *     Side effects:
- *             The copy chain is destroyed.
- *     Warning:
- *             The arguments are evaluated multiple times.
- */
-#define        vm_map_copy_insert(map, where, copy)                            \
-MACRO_BEGIN                                                            \
-       vm_map_t VMCI_map;                                              \
-       vm_map_entry_t VMCI_where;                                      \
-       vm_map_copy_t VMCI_copy;                                        \
-       VMCI_map = (map);                                               \
-       VMCI_where = (where);                                           \
-       VMCI_copy = (copy);                                             \
-       ((VMCI_where->vme_next)->vme_prev = vm_map_copy_last_entry(VMCI_copy))\
-               ->vme_next = (VMCI_where->vme_next);                    \
-       ((VMCI_where)->vme_next = vm_map_copy_first_entry(VMCI_copy))   \
-               ->vme_prev = VMCI_where;                                \
-       VMCI_map->hdr.nentries += VMCI_copy->cpy_hdr.nentries;          \
-       UPDATE_FIRST_FREE(VMCI_map, VMCI_map->first_free);              \
-       zfree(vm_map_copy_zone, (vm_offset_t) VMCI_copy);               \
-MACRO_END
+               if ((((src_entry->protection & VM_PROT_READ) == VM_PROT_NONE) &&
+                    !use_maxprot) ||
+                   ((src_entry->max_protection & VM_PROT_READ) == 0))
+                       goto VerificationFailed;
 
-/*
- *     Routine:        vm_map_copyout
- *
- *     Description:
- *             Copy out a copy chain ("copy") into newly-allocated
- *             space in the destination map.
- *
- *             If successful, consumes the copy object.
- *             Otherwise, the caller is responsible for it.
- */
-kern_return_t
-vm_map_copyout(
-       register vm_map_t       dst_map,
-       vm_offset_t             *dst_addr,      /* OUT */
-       register vm_map_copy_t  copy)
-{
-       vm_size_t               size;
-       vm_size_t               adjustment;
-       vm_offset_t             start;
-       vm_object_offset_t      vm_copy_start;
-       vm_map_entry_t          last;
-       register
-       vm_map_entry_t          entry;
+               if (src_entry->vme_end < new_entry->vme_end)
+                       src_size = (new_entry->vme_end = src_entry->vme_end) - src_start;
 
-       /*
-        *      Check for null copy object.
-        */
+               if ((src_entry->object.vm_object != src_object) ||
+                   (src_entry->offset != src_offset) ) {
 
-       if (copy == VM_MAP_COPY_NULL) {
-               *dst_addr = 0;
-               return(KERN_SUCCESS);
-       }
+                       /*
+                        *      Verification failed.
+                        *
+                        *      Start over with this top-level entry.
+                        */
 
-       /*
-        *      Check for special copy object, created
-        *      by vm_map_copyin_object.
-        */
+               VerificationFailed: ;
 
-       if (copy->type == VM_MAP_COPY_OBJECT) {
-               vm_object_t             object = copy->cpy_object;
-               kern_return_t           kr;
-               vm_object_offset_t      offset;
+                       vm_object_deallocate(new_entry->object.vm_object);
+                       tmp_entry = src_entry;
+                       continue;
+               }
 
-               offset = trunc_page_64(copy->offset);
-               size = round_page_32(copy->size + 
-                               (vm_size_t)(copy->offset - offset));
-               *dst_addr = 0;
-               kr = vm_map_enter(dst_map, dst_addr, size,
-                                 (vm_offset_t) 0, TRUE,
-                                 object, offset, FALSE,
-                                 VM_PROT_DEFAULT, VM_PROT_ALL,
-                                 VM_INHERIT_DEFAULT);
-               if (kr != KERN_SUCCESS)
-                       return(kr);
-               /* Account for non-pagealigned copy object */
-               *dst_addr += (vm_offset_t)(copy->offset - offset);
-               zfree(vm_map_copy_zone, (vm_offset_t) copy);
-               return(KERN_SUCCESS);
-       }
+               /*
+                *      Verification succeeded.
+                */
 
-       /*
-        *      Check for special kernel buffer allocated
-        *      by new_ipc_kmsg_copyin.
-        */
+       VerificationSuccessful: ;
 
-       if (copy->type == VM_MAP_COPY_KERNEL_BUFFER) {
-               return(vm_map_copyout_kernel_buffer(dst_map, dst_addr, 
-                                                   copy, FALSE));
-       }
+               if (result == KERN_MEMORY_RESTART_COPY)
+                       goto RestartCopy;
 
-       /*
-        *      Find space for the data
-        */
+               /*
+                *      Copy succeeded.
+                */
 
-       vm_copy_start = trunc_page_64(copy->offset);
-       size =  round_page_32((vm_size_t)copy->offset + copy->size) 
-                                                       - vm_copy_start;
+       CopySuccessful: ;
 
- StartAgain: ;
+               /*
+                *      Link in the new copy entry.
+                */
 
-       vm_map_lock(dst_map);
-       assert(first_free_is_valid(dst_map));
-       start = ((last = dst_map->first_free) == vm_map_to_entry(dst_map)) ?
-               vm_map_min(dst_map) : last->vme_end;
+               vm_map_copy_entry_link(copy, vm_map_copy_last_entry(copy),
+                                      new_entry);
+               
+               /*
+                *      Determine whether the entire region
+                *      has been copied.
+                */
+               src_base = src_start;
+               src_start = new_entry->vme_end;
+               new_entry = VM_MAP_ENTRY_NULL;
+               while ((src_start >= src_end) && (src_end != 0)) {
+                       if (src_map != base_map) {
+                               submap_map_t    *ptr;
 
-       while (TRUE) {
-               vm_map_entry_t  next = last->vme_next;
-               vm_offset_t     end = start + size;
+                               ptr = parent_maps;
+                               assert(ptr != NULL);
+                               parent_maps = parent_maps->next;
 
-               if ((end > dst_map->max_offset) || (end < start)) {
-                       if (dst_map->wait_for_space) {
-                               if (size <= (dst_map->max_offset - dst_map->min_offset)) {
-                                       assert_wait((event_t) dst_map,
-                                                   THREAD_INTERRUPTIBLE);
-                                       vm_map_unlock(dst_map);
-                                       thread_block((void (*)(void))0);
-                                       goto StartAgain;
-                               }
-                       }
-                       vm_map_unlock(dst_map);
-                       return(KERN_NO_SPACE);
+                               /* fix up the damage we did in that submap */
+                               vm_map_simplify_range(src_map,
+                                                     src_base,
+                                                     src_end);
+
+                               vm_map_unlock(src_map);
+                               vm_map_deallocate(src_map);
+                               vm_map_lock(ptr->parent_map);
+                               src_map = ptr->parent_map;
+                               src_base = ptr->base_start;
+                               src_start = ptr->base_start + ptr->base_len;
+                               src_end = ptr->base_end;
+                               if ((src_end > src_start) &&
+                                   !vm_map_lookup_entry(
+                                           src_map, src_start, &tmp_entry))
+                                       RETURN(KERN_INVALID_ADDRESS);
+                               kfree(ptr, sizeof(submap_map_t));
+                               if(parent_maps == NULL)
+                                       map_share = FALSE;
+                               src_entry = tmp_entry->vme_prev;
+                       } else
+                               break;
                }
-
-               if ((next == vm_map_to_entry(dst_map)) ||
-                   (next->vme_start >= end))
+               if ((src_start >= src_end) && (src_end != 0))
                        break;
 
-               last = next;
-               start = last->vme_end;
+               /*
+                *      Verify that there are no gaps in the region
+                */
+
+               tmp_entry = src_entry->vme_next;
+               if ((tmp_entry->vme_start != src_start) || 
+                   (tmp_entry == vm_map_to_entry(src_map)))
+                       RETURN(KERN_INVALID_ADDRESS);
        }
 
        /*
-        *      Since we're going to just drop the map
-        *      entries from the copy into the destination
-        *      map, they must come from the same pool.
+        * If the source should be destroyed, do it now, since the
+        * copy was successful. 
         */
-
-       if (copy->cpy_hdr.entries_pageable != dst_map->hdr.entries_pageable) {
-           /*
-            * Mismatches occur when dealing with the default
-            * pager.
-            */
-           zone_t              old_zone;
-           vm_map_entry_t      next, new;
-
-           /*
-            * Find the zone that the copies were allocated from
-            */
-           old_zone = (copy->cpy_hdr.entries_pageable)
-                       ? vm_map_entry_zone
-                       : vm_map_kentry_zone;
-           entry = vm_map_copy_first_entry(copy);
-
-           /*
-            * Reinitialize the copy so that vm_map_copy_entry_link
-            * will work.
-            */
-           copy->cpy_hdr.nentries = 0;
-           copy->cpy_hdr.entries_pageable = dst_map->hdr.entries_pageable;
-           vm_map_copy_first_entry(copy) =
-            vm_map_copy_last_entry(copy) =
-               vm_map_copy_to_entry(copy);
-
-           /*
-            * Copy each entry.
-            */
-           while (entry != vm_map_copy_to_entry(copy)) {
-               new = vm_map_copy_entry_create(copy);
-               vm_map_entry_copy_full(new, entry);
-               new->use_pmap = FALSE;  /* clr address space specifics */
-               vm_map_copy_entry_link(copy,
-                               vm_map_copy_last_entry(copy),
-                               new);
-               next = entry->vme_next;
-               zfree(old_zone, (vm_offset_t) entry);
-               entry = next;
-           }
+       if (src_destroy) {
+               (void) vm_map_delete(src_map,
+                                    vm_map_trunc_page(src_addr),
+                                    src_end,
+                                    (src_map == kernel_map) ?
+                                    VM_MAP_REMOVE_KUNWIRE :
+                                    VM_MAP_NO_FLAGS,
+                                    VM_MAP_NULL);
+       } else {
+               /* fix up the damage we did in the base map */
+               vm_map_simplify_range(src_map,
+                                     vm_map_trunc_page(src_addr), 
+                                     vm_map_round_page(src_end));
        }
 
-       /*
-        *      Adjust the addresses in the copy chain, and
-        *      reset the region attributes.
-        */
+       vm_map_unlock(src_map);
 
-       adjustment = start - vm_copy_start;
-       for (entry = vm_map_copy_first_entry(copy);
-            entry != vm_map_copy_to_entry(copy);
-            entry = entry->vme_next) {
-               entry->vme_start += adjustment;
-               entry->vme_end += adjustment;
+       /* Fix-up start and end points in copy.  This is necessary */
+       /* when the various entries in the copy object were picked */
+       /* up from different sub-maps */
 
-               entry->inheritance = VM_INHERIT_DEFAULT;
-               entry->protection = VM_PROT_DEFAULT;
-               entry->max_protection = VM_PROT_ALL;
-               entry->behavior = VM_BEHAVIOR_DEFAULT;
+       tmp_entry = vm_map_copy_first_entry(copy);
+       while (tmp_entry != vm_map_copy_to_entry(copy)) {
+               tmp_entry->vme_end = copy_addr + 
+                       (tmp_entry->vme_end - tmp_entry->vme_start);
+               tmp_entry->vme_start = copy_addr;
+               copy_addr += tmp_entry->vme_end - tmp_entry->vme_start;
+               tmp_entry = (struct vm_map_entry *)tmp_entry->vme_next;
+       }
 
-               /*
-                * If the entry is now wired,
-                * map the pages into the destination map.
-                */
-               if (entry->wired_count != 0) {
-                   register vm_offset_t va;
-                   vm_object_offset_t   offset;
-                   register vm_object_t object;
+       *copy_result = copy;
+       return(KERN_SUCCESS);
 
-                   object = entry->object.vm_object;
-                   offset = entry->offset;
-                   va = entry->vme_start;
+#undef RETURN
+}
 
-                   pmap_pageable(dst_map->pmap,
-                                 entry->vme_start,
-                                 entry->vme_end,
-                                 TRUE);
+/*
+ *     vm_map_copyin_object:
+ *
+ *     Create a copy object from an object.
+ *     Our caller donates an object reference.
+ */
 
-                   while (va < entry->vme_end) {
-                       register vm_page_t      m;
+kern_return_t
+vm_map_copyin_object(
+       vm_object_t             object,
+       vm_object_offset_t      offset, /* offset of region in object */
+       vm_object_size_t        size,   /* size of region in object */
+       vm_map_copy_t   *copy_result)   /* OUT */
+{
+       vm_map_copy_t   copy;           /* Resulting copy */
 
-                       /*
-                        * Look up the page in the object.
-                        * Assert that the page will be found in the
-                        * top object:
-                        * either
-                        *      the object was newly created by
-                        *      vm_object_copy_slowly, and has
-                        *      copies of all of the pages from
-                        *      the source object
-                        * or
-                        *      the object was moved from the old
-                        *      map entry; because the old map
-                        *      entry was wired, all of the pages
-                        *      were in the top-level object.
-                        *      (XXX not true if we wire pages for
-                        *       reading)
-                        */
-                       vm_object_lock(object);
-                       vm_object_paging_begin(object);
+       /*
+        *      We drop the object into a special copy object
+        *      that contains the object directly.
+        */
 
-                       m = vm_page_lookup(object, offset);
-                       if (m == VM_PAGE_NULL || m->wire_count == 0 ||
-                           m->absent)
-                           panic("vm_map_copyout: wiring 0x%x", m);
+       copy = (vm_map_copy_t) zalloc(vm_map_copy_zone);
+       copy->type = VM_MAP_COPY_OBJECT;
+       copy->cpy_object = object;
+       copy->offset = offset;
+       copy->size = size;
 
-                       m->busy = TRUE;
-                       vm_object_unlock(object);
+       *copy_result = copy;
+       return(KERN_SUCCESS);
+}
 
-                       PMAP_ENTER(dst_map->pmap, va, m, entry->protection, 
-                                               ((unsigned int)
-                                                       (m->object->wimg_bits)) 
-                                                       & VM_WIMG_MASK,
-                                               TRUE);
+static void
+vm_map_fork_share(
+       vm_map_t        old_map,
+       vm_map_entry_t  old_entry,
+       vm_map_t        new_map)
+{
+       vm_object_t     object;
+       vm_map_entry_t  new_entry;
 
-                       vm_object_lock(object);
-                       PAGE_WAKEUP_DONE(m);
-                       /* the page is wired, so we don't have to activate */
-                       vm_object_paging_end(object);
-                       vm_object_unlock(object);
+       /*
+        *      New sharing code.  New map entry
+        *      references original object.  Internal
+        *      objects use asynchronous copy algorithm for
+        *      future copies.  First make sure we have
+        *      the right object.  If we need a shadow,
+        *      or someone else already has one, then
+        *      make a new shadow and share it.
+        */
+       
+       object = old_entry->object.vm_object;
+       if (old_entry->is_sub_map) {
+               assert(old_entry->wired_count == 0);
+#ifndef NO_NESTED_PMAP
+               if(old_entry->use_pmap) {
+                       kern_return_t   result;
 
-                       offset += PAGE_SIZE_64;
-                       va += PAGE_SIZE;
-                   }
+                       result = pmap_nest(new_map->pmap, 
+                                          (old_entry->object.sub_map)->pmap, 
+                                          (addr64_t)old_entry->vme_start,
+                                          (addr64_t)old_entry->vme_start,
+                                          (uint64_t)(old_entry->vme_end - old_entry->vme_start));
+                       if(result)
+                               panic("vm_map_fork_share: pmap_nest failed!");
                }
-               else if (size <= vm_map_aggressive_enter_max) {
-
-                       register vm_offset_t    va;
-                       vm_object_offset_t      offset;
-                       register vm_object_t    object;
-                       vm_prot_t               prot;
+#endif /* NO_NESTED_PMAP */
+       } else if (object == VM_OBJECT_NULL) {
+               object = vm_object_allocate((vm_map_size_t)(old_entry->vme_end -
+                                                           old_entry->vme_start));
+               old_entry->offset = 0;
+               old_entry->object.vm_object = object;
+               assert(!old_entry->needs_copy);
+       } else if (object->copy_strategy !=
+                  MEMORY_OBJECT_COPY_SYMMETRIC) {
+               
+               /*
+                *      We are already using an asymmetric
+                *      copy, and therefore we already have
+                *      the right object.
+                */
+               
+               assert(! old_entry->needs_copy);
+       }
+       else if (old_entry->needs_copy ||       /* case 1 */
+                object->shadowed ||            /* case 2 */
+                (!object->true_share &&        /* case 3 */
+                 !old_entry->is_shared &&
+                 (object->size >
+                  (vm_map_size_t)(old_entry->vme_end -
+                                  old_entry->vme_start)))) {
+               
+               /*
+                *      We need to create a shadow.
+                *      There are three cases here.
+                *      In the first case, we need to
+                *      complete a deferred symmetrical
+                *      copy that we participated in.
+                *      In the second and third cases,
+                *      we need to create the shadow so
+                *      that changes that we make to the
+                *      object do not interfere with
+                *      any symmetrical copies which
+                *      have occured (case 2) or which
+                *      might occur (case 3).
+                *
+                *      The first case is when we had
+                *      deferred shadow object creation
+                *      via the entry->needs_copy mechanism.
+                *      This mechanism only works when
+                *      only one entry points to the source
+                *      object, and we are about to create
+                *      a second entry pointing to the
+                *      same object. The problem is that
+                *      there is no way of mapping from
+                *      an object to the entries pointing
+                *      to it. (Deferred shadow creation
+                *      works with one entry because occurs
+                *      at fault time, and we walk from the
+                *      entry to the object when handling
+                *      the fault.)
+                *
+                *      The second case is when the object
+                *      to be shared has already been copied
+                *      with a symmetric copy, but we point
+                *      directly to the object without
+                *      needs_copy set in our entry. (This
+                *      can happen because different ranges
+                *      of an object can be pointed to by
+                *      different entries. In particular,
+                *      a single entry pointing to an object
+                *      can be split by a call to vm_inherit,
+                *      which, combined with task_create, can
+                *      result in the different entries
+                *      having different needs_copy values.)
+                *      The shadowed flag in the object allows
+                *      us to detect this case. The problem
+                *      with this case is that if this object
+                *      has or will have shadows, then we
+                *      must not perform an asymmetric copy
+                *      of this object, since such a copy
+                *      allows the object to be changed, which
+                *      will break the previous symmetrical
+                *      copies (which rely upon the object
+                *      not changing). In a sense, the shadowed
+                *      flag says "don't change this object".
+                *      We fix this by creating a shadow
+                *      object for this object, and sharing
+                *      that. This works because we are free
+                *      to change the shadow object (and thus
+                *      to use an asymmetric copy strategy);
+                *      this is also semantically correct,
+                *      since this object is temporary, and
+                *      therefore a copy of the object is
+                *      as good as the object itself. (This
+                *      is not true for permanent objects,
+                *      since the pager needs to see changes,
+                *      which won't happen if the changes
+                *      are made to a copy.)
+                *
+                *      The third case is when the object
+                *      to be shared has parts sticking
+                *      outside of the entry we're working
+                *      with, and thus may in the future
+                *      be subject to a symmetrical copy.
+                *      (This is a preemptive version of
+                *      case 2.)
+                */
+               
+               vm_object_shadow(&old_entry->object.vm_object,
+                                &old_entry->offset,
+                                (vm_map_size_t) (old_entry->vme_end -
+                                                 old_entry->vme_start));
+               
+               /*
+                *      If we're making a shadow for other than
+                *      copy on write reasons, then we have
+                *      to remove write permission.
+                */
 
-                       object = entry->object.vm_object;
-                       if (object != VM_OBJECT_NULL) {
+               if (!old_entry->needs_copy &&
+                   (old_entry->protection & VM_PROT_WRITE)) {
+                       vm_prot_t prot;
 
-                               offset = entry->offset;
-                               va = entry->vme_start;
-                               while (va < entry->vme_end) {
-                                       register vm_page_t      m;
-                                   
-                                       /*
-                                        * Look up the page in the object.
-                                        * Assert that the page will be found
-                                        * in the top object if at all...
-                                        */
-                                       vm_object_lock(object);
-                                       vm_object_paging_begin(object);
+                       prot = old_entry->protection & ~VM_PROT_WRITE;
 
-                                       if (((m = vm_page_lookup(object,
-                                                                offset))
-                                            != VM_PAGE_NULL) &&
-                                           !m->busy && !m->fictitious &&
-                                           !m->absent && !m->error) {
-                                               m->busy = TRUE;
-                                               vm_object_unlock(object);
-
-                                               /* honor cow obligations */
-                                               prot = entry->protection;
-                                               if (entry->needs_copy)
-                                                       prot &= ~VM_PROT_WRITE;
-
-                                               PMAP_ENTER(dst_map->pmap, va, 
-                                                       m, prot, 
-                                                       ((unsigned int)
-                                                       (m->object->wimg_bits)) 
-                                                          & VM_WIMG_MASK,
-                                                       FALSE);
-
-                                               vm_object_lock(object);
-                                               vm_page_lock_queues();
-                                               if (!m->active && !m->inactive)
-                                                       vm_page_activate(m);
-                                               vm_page_unlock_queues();
-                                               PAGE_WAKEUP_DONE(m);
-                                       }
-                                       vm_object_paging_end(object);
-                                       vm_object_unlock(object);
+                       if (override_nx(old_map, old_entry->alias) && prot)
+                               prot |= VM_PROT_EXECUTE;
 
-                                       offset += PAGE_SIZE_64;
-                                       va += PAGE_SIZE;
-                               }
+                       if (old_map->mapped) {
+                               vm_object_pmap_protect(
+                                       old_entry->object.vm_object,
+                                       old_entry->offset,
+                                       (old_entry->vme_end -
+                                        old_entry->vme_start),
+                                       PMAP_NULL,
+                                       old_entry->vme_start,
+                                       prot);
+                       } else {
+                               pmap_protect(old_map->pmap,
+                                            old_entry->vme_start,
+                                            old_entry->vme_end,
+                                            prot);
                        }
                }
+               
+               old_entry->needs_copy = FALSE;
+               object = old_entry->object.vm_object;
        }
-
+       
        /*
-        *      Correct the page alignment for the result
+        *      If object was using a symmetric copy strategy,
+        *      change its copy strategy to the default
+        *      asymmetric copy strategy, which is copy_delay
+        *      in the non-norma case and copy_call in the
+        *      norma case. Bump the reference count for the
+        *      new entry.
         */
-
-       *dst_addr = start + (copy->offset - vm_copy_start);
-
+       
+       if(old_entry->is_sub_map) {
+               vm_map_lock(old_entry->object.sub_map);
+               vm_map_reference(old_entry->object.sub_map);
+               vm_map_unlock(old_entry->object.sub_map);
+       } else {
+               vm_object_lock(object);
+               vm_object_reference_locked(object);
+               if (object->copy_strategy == MEMORY_OBJECT_COPY_SYMMETRIC) {
+                       object->copy_strategy = MEMORY_OBJECT_COPY_DELAY;
+               }
+               vm_object_unlock(object);
+       }
+       
        /*
-        *      Update the hints and the map size
+        *      Clone the entry, using object ref from above.
+        *      Mark both entries as shared.
         */
-
-       SAVE_HINT(dst_map, vm_map_copy_last_entry(copy));
-
-       dst_map->size += size;
-
+       
+       new_entry = vm_map_entry_create(new_map);
+       vm_map_entry_copy(new_entry, old_entry);
+       old_entry->is_shared = TRUE;
+       new_entry->is_shared = TRUE;
+       
        /*
-        *      Link in the copy
+        *      Insert the entry into the new map -- we
+        *      know we're inserting at the end of the new
+        *      map.
         */
-
-       vm_map_copy_insert(dst_map, last, copy);
-
-       vm_map_unlock(dst_map);
-
+       
+       vm_map_entry_link(new_map, vm_map_last_entry(new_map), new_entry);
+       
        /*
-        * XXX  If wiring_required, call vm_map_pageable
+        *      Update the physical map
         */
-
-       return(KERN_SUCCESS);
+       
+       if (old_entry->is_sub_map) {
+               /* Bill Angell pmap support goes here */
+       } else {
+               pmap_copy(new_map->pmap, old_map->pmap, new_entry->vme_start,
+                         old_entry->vme_end - old_entry->vme_start,
+                         old_entry->vme_start);
+       }
 }
 
-boolean_t       vm_map_aggressive_enter;        /* not used yet */
-
-
-/*
- *     Routine:        vm_map_copyin
- *
- *     Description:
- *             Copy the specified region (src_addr, len) from the
- *             source address space (src_map), possibly removing
- *             the region from the source address space (src_destroy).
- *
- *     Returns:
- *             A vm_map_copy_t object (copy_result), suitable for
- *             insertion into another address space (using vm_map_copyout),
- *             copying over another address space region (using
- *             vm_map_copy_overwrite).  If the copy is unused, it
- *             should be destroyed (using vm_map_copy_discard).
- *
- *     In/out conditions:
- *             The source map should not be locked on entry.
- */
-
-typedef struct submap_map {
-       vm_map_t        parent_map;
-       vm_offset_t     base_start;
-       vm_offset_t     base_end;
-       struct submap_map *next;
-} submap_map_t;
-
-kern_return_t
-vm_map_copyin_common(
-       vm_map_t        src_map,
-       vm_offset_t     src_addr,
-       vm_size_t       len,
-       boolean_t       src_destroy,
-       boolean_t       src_volatile,
-       vm_map_copy_t   *copy_result,   /* OUT */
-       boolean_t       use_maxprot)
+static boolean_t
+vm_map_fork_copy(
+       vm_map_t        old_map,
+       vm_map_entry_t  *old_entry_p,
+       vm_map_t        new_map)
 {
-       extern int      msg_ool_size_small;
-
-       vm_map_entry_t  tmp_entry;      /* Result of last map lookup --
-                                        * in multi-level lookup, this
-                                        * entry contains the actual
-                                        * vm_object/offset.
-                                        */
-       register
-       vm_map_entry_t  new_entry = VM_MAP_ENTRY_NULL;  /* Map entry for copy */
-
-       vm_offset_t     src_start;      /* Start of current entry --
-                                        * where copy is taking place now
-                                        */
-       vm_offset_t     src_end;        /* End of entire region to be
-                                        * copied */
-       vm_offset_t     base_start;     /* submap fields to save offsets */
-                                       /* in original map */
-       vm_offset_t     base_end;
-       vm_map_t        base_map=src_map;
-       vm_map_entry_t  base_entry;
-       boolean_t       map_share=FALSE;
-       submap_map_t    *parent_maps = NULL;
-
-       register
-       vm_map_copy_t   copy;           /* Resulting copy */
-       vm_offset_t     copy_addr;
+       vm_map_entry_t old_entry = *old_entry_p;
+       vm_map_size_t entry_size = old_entry->vme_end - old_entry->vme_start;
+       vm_map_offset_t start = old_entry->vme_start;
+       vm_map_copy_t copy;
+       vm_map_entry_t last = vm_map_last_entry(new_map);
 
+       vm_map_unlock(old_map);
        /*
-        *      Check for copies of zero bytes.
+        *      Use maxprot version of copyin because we
+        *      care about whether this memory can ever
+        *      be accessed, not just whether it's accessible
+        *      right now.
         */
+       if (vm_map_copyin_maxprot(old_map, start, entry_size, FALSE, &copy)
+           != KERN_SUCCESS) {
+               /*
+                *      The map might have changed while it
+                *      was unlocked, check it again.  Skip
+                *      any blank space or permanently
+                *      unreadable region.
+                */
+               vm_map_lock(old_map);
+               if (!vm_map_lookup_entry(old_map, start, &last) ||
+                   (last->max_protection & VM_PROT_READ) == VM_PROT_NONE) {
+                       last = last->vme_next;
+               }
+               *old_entry_p = last;
 
-       if (len == 0) {
-               *copy_result = VM_MAP_COPY_NULL;
-               return(KERN_SUCCESS);
+               /*
+                * XXX  For some error returns, want to
+                * XXX  skip to the next element.  Note
+                *      that INVALID_ADDRESS and
+                *      PROTECTION_FAILURE are handled above.
+                */
+               
+               return FALSE;
        }
-
+       
        /*
-        * If the copy is sufficiently small, use a kernel buffer instead
-        * of making a virtual copy.  The theory being that the cost of
-        * setting up VM (and taking C-O-W faults) dominates the copy costs
-        * for small regions.
+        *      Insert the copy into the new map
         */
-       if ((len < msg_ool_size_small) && !use_maxprot)
-         return vm_map_copyin_kernel_buffer(src_map, src_addr, len,
-                                            src_destroy, copy_result);
-
+       
+       vm_map_copy_insert(new_map, last, copy);
+       
        /*
-        *      Compute start and end of region
+        *      Pick up the traversal at the end of
+        *      the copied region.
         */
+       
+       vm_map_lock(old_map);
+       start += entry_size;
+       if (! vm_map_lookup_entry(old_map, start, &last)) {
+               last = last->vme_next;
+       } else {
+               if (last->vme_start == start) {
+                       /*
+                        * No need to clip here and we don't
+                        * want to cause any unnecessary
+                        * unnesting...
+                        */
+               } else {
+                       vm_map_clip_start(old_map, last, start);
+               }
+       }
+       *old_entry_p = last;
 
-       src_start = trunc_page_32(src_addr);
-       src_end = round_page_32(src_addr + len);
+       return TRUE;
+}
 
-       XPR(XPR_VM_MAP, "vm_map_copyin_common map 0x%x addr 0x%x len 0x%x dest %d\n", (natural_t)src_map, src_addr, len, src_destroy, 0);
+/*
+ *     vm_map_fork:
+ *
+ *     Create and return a new map based on the old
+ *     map, according to the inheritance values on the
+ *     regions in that map.
+ *
+ *     The source map must not be locked.
+ */
+vm_map_t
+vm_map_fork(
+       vm_map_t        old_map)
+{
+       pmap_t          new_pmap;
+       vm_map_t        new_map;
+       vm_map_entry_t  old_entry;
+       vm_map_size_t   new_size = 0, entry_size;
+       vm_map_entry_t  new_entry;
+       boolean_t       src_needs_copy;
+       boolean_t       new_entry_needs_copy;
 
-       /*
-        *      Check that the end address doesn't overflow
-        */
+       new_pmap = pmap_create((vm_map_size_t) 0,
+#if defined(__i386__) || defined(__x86_64__)
+                              old_map->pmap->pm_task_map != TASK_MAP_32BIT
+#else
+                              0
+#endif
+                              );
+#if defined(__i386__)
+       if (old_map->pmap->pm_task_map == TASK_MAP_64BIT_SHARED)
+               pmap_set_4GB_pagezero(new_pmap);
+#endif
 
-       if (src_end <= src_start)
-               if ((src_end < src_start) || (src_start != 0))
-                       return(KERN_INVALID_ADDRESS);
+       vm_map_reference_swap(old_map);
+       vm_map_lock(old_map);
 
-       /*
-        *      Allocate a header element for the list.
-        *
-        *      Use the start and end in the header to 
-        *      remember the endpoints prior to rounding.
-        */
+       new_map = vm_map_create(new_pmap,
+                               old_map->min_offset,
+                               old_map->max_offset,
+                               old_map->hdr.entries_pageable);
 
-       copy = (vm_map_copy_t) zalloc(vm_map_copy_zone);
-       vm_map_copy_first_entry(copy) =
-        vm_map_copy_last_entry(copy) = vm_map_copy_to_entry(copy);
-       copy->type = VM_MAP_COPY_ENTRY_LIST;
-       copy->cpy_hdr.nentries = 0;
-       copy->cpy_hdr.entries_pageable = TRUE;
+       for (
+               old_entry = vm_map_first_entry(old_map);
+               old_entry != vm_map_to_entry(old_map);
+               ) {
 
-       copy->offset = src_addr;
-       copy->size = len;
-       
-       new_entry = vm_map_copy_entry_create(copy);
+               entry_size = old_entry->vme_end - old_entry->vme_start;
 
-#define        RETURN(x)                                               \
-       MACRO_BEGIN                                             \
-       vm_map_unlock(src_map);                                 \
-       if(src_map != base_map)                                 \
-               vm_map_deallocate(src_map);                     \
-       if (new_entry != VM_MAP_ENTRY_NULL)                     \
-               vm_map_copy_entry_dispose(copy,new_entry);      \
-       vm_map_copy_discard(copy);                              \
-       {                                                       \
-               submap_map_t    *ptr;                           \
-                                                               \
-               for(ptr = parent_maps; ptr != NULL; ptr = parent_maps) { \
-                       parent_maps=parent_maps->next;          \
-                       if (ptr->parent_map != base_map)        \
-                               vm_map_deallocate(ptr->parent_map);     \
-                       kfree((vm_offset_t)ptr, sizeof(submap_map_t));  \
-               }                                               \
-       }                                                       \
-       MACRO_RETURN(x);                                        \
-       MACRO_END
+               switch (old_entry->inheritance) {
+               case VM_INHERIT_NONE:
+                       break;
 
-       /*
-        *      Find the beginning of the region.
-        */
+               case VM_INHERIT_SHARE:
+                       vm_map_fork_share(old_map, old_entry, new_map);
+                       new_size += entry_size;
+                       break;
 
-       vm_map_lock(src_map);
+               case VM_INHERIT_COPY:
 
-       if (!vm_map_lookup_entry(src_map, src_start, &tmp_entry))
-               RETURN(KERN_INVALID_ADDRESS);
-       if(!tmp_entry->is_sub_map) {
-               vm_map_clip_start(src_map, tmp_entry, src_start);
-       }
-       /* set for later submap fix-up */
-       copy_addr = src_start;
+                       /*
+                        *      Inline the copy_quickly case;
+                        *      upon failure, fall back on call
+                        *      to vm_map_fork_copy.
+                        */
 
-       /*
-        *      Go through entries until we get to the end.
-        */
+                       if(old_entry->is_sub_map)
+                               break;
+                       if ((old_entry->wired_count != 0) ||
+                           ((old_entry->object.vm_object != NULL) &&
+                            (old_entry->object.vm_object->true_share))) {
+                               goto slow_vm_map_fork_copy;
+                       }
 
-       while (TRUE) {
-               register
-               vm_map_entry_t  src_entry = tmp_entry;  /* Top-level entry */
-               vm_size_t       src_size;               /* Size of source
-                                                        * map entry (in both
-                                                        * maps)
-                                                        */
+                       new_entry = vm_map_entry_create(new_map);
+                       vm_map_entry_copy(new_entry, old_entry);
+                       /* clear address space specifics */
+                       new_entry->use_pmap = FALSE;
 
-               register
-               vm_object_t             src_object;     /* Object to copy */
-               vm_object_offset_t      src_offset;
+                       if (! vm_object_copy_quickly(
+                                   &new_entry->object.vm_object,
+                                   old_entry->offset,
+                                   (old_entry->vme_end -
+                                    old_entry->vme_start),
+                                   &src_needs_copy,
+                                   &new_entry_needs_copy)) {
+                               vm_map_entry_dispose(new_map, new_entry);
+                               goto slow_vm_map_fork_copy;
+                       }
 
-               boolean_t       src_needs_copy;         /* Should source map
-                                                        * be made read-only
-                                                        * for copy-on-write?
-                                                        */
+                       /*
+                        *      Handle copy-on-write obligations
+                        */
+                       
+                       if (src_needs_copy && !old_entry->needs_copy) {
+                               vm_prot_t prot;
 
-               boolean_t       new_entry_needs_copy;   /* Will new entry be COW? */
+                               prot = old_entry->protection & ~VM_PROT_WRITE;
 
-               boolean_t       was_wired;              /* Was source wired? */
-               vm_map_version_t version;               /* Version before locks
-                                                        * dropped to make copy
-                                                        */
-               kern_return_t   result;                 /* Return value from
-                                                        * copy_strategically.
-                                                        */
-               while(tmp_entry->is_sub_map) {
-                       vm_size_t submap_len;
-                       submap_map_t *ptr;
+                               if (override_nx(old_map, old_entry->alias) && prot)
+                                       prot |= VM_PROT_EXECUTE;
 
-                       ptr = (submap_map_t *)kalloc(sizeof(submap_map_t));
-                       ptr->next = parent_maps;
-                       parent_maps = ptr;
-                       ptr->parent_map = src_map;
-                       ptr->base_start = src_start;
-                       ptr->base_end = src_end;
-                       submap_len = tmp_entry->vme_end - src_start;
-                       if(submap_len > (src_end-src_start))
-                               submap_len = src_end-src_start;
-                       ptr->base_start += submap_len;
-       
-                       src_start -= tmp_entry->vme_start;
-                       src_start += tmp_entry->offset;
-                       src_end = src_start + submap_len;
-                       src_map = tmp_entry->object.sub_map;
-                       vm_map_lock(src_map);
-                       /* keep an outstanding reference for all maps in */
-                       /* the parents tree except the base map */
-                       vm_map_reference(src_map);
-                       vm_map_unlock(ptr->parent_map);
-                       if (!vm_map_lookup_entry(
-                                       src_map, src_start, &tmp_entry))
-                               RETURN(KERN_INVALID_ADDRESS);
-                       map_share = TRUE;
-                       if(!tmp_entry->is_sub_map)
-                          vm_map_clip_start(src_map, tmp_entry, src_start);
-                       src_entry = tmp_entry;
-               }
-               if ((tmp_entry->object.vm_object != VM_OBJECT_NULL) && 
-                   (tmp_entry->object.vm_object->phys_contiguous)) {
-                       /* This is not, supported for now.In future */
-                       /* we will need to detect the phys_contig   */
-                       /* condition and then upgrade copy_slowly   */
-                       /* to do physical copy from the device mem  */
-                       /* based object. We can piggy-back off of   */
-                       /* the was wired boolean to set-up the      */
-                       /* proper handling */
-                       RETURN(KERN_PROTECTION_FAILURE);
-               }
-               /*
-                *      Create a new address map entry to hold the result. 
-                *      Fill in the fields from the appropriate source entries.
-                *      We must unlock the source map to do this if we need
-                *      to allocate a map entry.
-                */
-               if (new_entry == VM_MAP_ENTRY_NULL) {
-                   version.main_timestamp = src_map->timestamp;
-                   vm_map_unlock(src_map);
+                               vm_object_pmap_protect(
+                                       old_entry->object.vm_object,
+                                       old_entry->offset,
+                                       (old_entry->vme_end -
+                                        old_entry->vme_start),
+                                       ((old_entry->is_shared 
+                                         || old_map->mapped)
+                                        ? PMAP_NULL :
+                                        old_map->pmap),
+                                       old_entry->vme_start,
+                                       prot);
 
-                   new_entry = vm_map_copy_entry_create(copy);
+                               old_entry->needs_copy = TRUE;
+                       }
+                       new_entry->needs_copy = new_entry_needs_copy;
+                       
+                       /*
+                        *      Insert the entry at the end
+                        *      of the map.
+                        */
+                       
+                       vm_map_entry_link(new_map, vm_map_last_entry(new_map),
+                                         new_entry);
+                       new_size += entry_size;
+                       break;
 
-                   vm_map_lock(src_map);
-                   if ((version.main_timestamp + 1) != src_map->timestamp) {
-                       if (!vm_map_lookup_entry(src_map, src_start,
-                                       &tmp_entry)) {
-                               RETURN(KERN_INVALID_ADDRESS);
+               slow_vm_map_fork_copy:
+                       if (vm_map_fork_copy(old_map, &old_entry, new_map)) {
+                               new_size += entry_size;
                        }
-                       vm_map_clip_start(src_map, tmp_entry, src_start);
-                       continue; /* restart w/ new tmp_entry */
-                   }
+                       continue;
                }
+               old_entry = old_entry->vme_next;
+       }
 
-               /*
-                *      Verify that the region can be read.
-                */
-               if (((src_entry->protection & VM_PROT_READ) == VM_PROT_NONE &&
-                       !use_maxprot) ||
-                   (src_entry->max_protection & VM_PROT_READ) == 0)
-                       RETURN(KERN_PROTECTION_FAILURE);
-
-               /*
-                *      Clip against the endpoints of the entire region.
-                */
+       new_map->size = new_size;
+       vm_map_unlock(old_map);
+       vm_map_deallocate(old_map);
 
-               vm_map_clip_end(src_map, src_entry, src_end);
+       return(new_map);
+}
 
-               src_size = src_entry->vme_end - src_start;
-               src_object = src_entry->object.vm_object;
-               src_offset = src_entry->offset;
-               was_wired = (src_entry->wired_count != 0);
+/*
+ * vm_map_exec:
+ *
+ *     Setup the "new_map" with the proper execution environment according
+ *     to the type of executable (platform, 64bit, chroot environment).
+ *     Map the comm page and shared region, etc...
+ */
+kern_return_t
+vm_map_exec(
+       vm_map_t        new_map,
+       task_t          task,
+       void            *fsroot,
+       cpu_type_t      cpu)
+{
+       SHARED_REGION_TRACE_DEBUG(
+               ("shared_region: task %p: vm_map_exec(%p,%p,%p,0x%x): ->\n",
+                current_task(), new_map, task, fsroot, cpu));
+       (void) vm_commpage_enter(new_map, task);
+       (void) vm_shared_region_enter(new_map, task, fsroot, cpu);
+       SHARED_REGION_TRACE_DEBUG(
+               ("shared_region: task %p: vm_map_exec(%p,%p,%p,0x%x): <-\n",
+                current_task(), new_map, task, fsroot, cpu));
+       return KERN_SUCCESS;
+}
 
-               vm_map_entry_copy(new_entry, src_entry);
-               new_entry->use_pmap = FALSE; /* clr address space specifics */
+/*
+ *     vm_map_lookup_locked:
+ *
+ *     Finds the VM object, offset, and
+ *     protection for a given virtual address in the
+ *     specified map, assuming a page fault of the
+ *     type specified.
+ *
+ *     Returns the (object, offset, protection) for
+ *     this address, whether it is wired down, and whether
+ *     this map has the only reference to the data in question.
+ *     In order to later verify this lookup, a "version"
+ *     is returned.
+ *
+ *     The map MUST be locked by the caller and WILL be
+ *     locked on exit.  In order to guarantee the
+ *     existence of the returned object, it is returned
+ *     locked.
+ *
+ *     If a lookup is requested with "write protection"
+ *     specified, the map may be changed to perform virtual
+ *     copying operations, although the data referenced will
+ *     remain the same.
+ */
+kern_return_t
+vm_map_lookup_locked(
+       vm_map_t                *var_map,       /* IN/OUT */
+       vm_map_offset_t         vaddr,
+       vm_prot_t               fault_type,
+       int                     object_lock_type,
+       vm_map_version_t        *out_version,   /* OUT */
+       vm_object_t             *object,        /* OUT */
+       vm_object_offset_t      *offset,        /* OUT */
+       vm_prot_t               *out_prot,      /* OUT */
+       boolean_t               *wired,         /* OUT */
+       vm_object_fault_info_t  fault_info,     /* OUT */
+       vm_map_t                *real_map)
+{
+       vm_map_entry_t                  entry;
+       register vm_map_t               map = *var_map;
+       vm_map_t                        old_map = *var_map;
+       vm_map_t                        cow_sub_map_parent = VM_MAP_NULL;
+       vm_map_offset_t                 cow_parent_vaddr = 0;
+       vm_map_offset_t                 old_start = 0;
+       vm_map_offset_t                 old_end = 0;
+       register vm_prot_t              prot;
 
-               /*
-                *      Attempt non-blocking copy-on-write optimizations.
-                */
+       *real_map = map;
+RetryLookup: ;
 
-               if (src_destroy && 
-                   (src_object == VM_OBJECT_NULL || 
-                   (src_object->internal && !src_object->true_share
-                   && !map_share))) {
-                   /*
-                    * If we are destroying the source, and the object
-                    * is internal, we can move the object reference
-                    * from the source to the copy.  The copy is
-                    * copy-on-write only if the source is.
-                    * We make another reference to the object, because
-                    * destroying the source entry will deallocate it.
-                    */
-                   vm_object_reference(src_object);
+       /*
+        *      If the map has an interesting hint, try it before calling
+        *      full blown lookup routine.
+        */
+       entry = map->hint;
 
-                   /*
-                    * Copy is always unwired.  vm_map_copy_entry
-                    * set its wired count to zero.
-                    */
+       if ((entry == vm_map_to_entry(map)) ||
+           (vaddr < entry->vme_start) || (vaddr >= entry->vme_end)) {
+               vm_map_entry_t  tmp_entry;
 
-                   goto CopySuccessful;
+               /*
+                *      Entry was either not a valid hint, or the vaddr
+                *      was not contained in the entry, so do a full lookup.
+                */
+               if (!vm_map_lookup_entry(map, vaddr, &tmp_entry)) {
+                       if((cow_sub_map_parent) && (cow_sub_map_parent != map))
+                               vm_map_unlock(cow_sub_map_parent);
+                       if((*real_map != map) 
+                          && (*real_map != cow_sub_map_parent))
+                               vm_map_unlock(*real_map);
+                       return KERN_INVALID_ADDRESS;
                }
 
+               entry = tmp_entry;
+       }
+       if(map == old_map) {
+               old_start = entry->vme_start;
+               old_end = entry->vme_end;
+       }
 
-RestartCopy:
-               XPR(XPR_VM_MAP, "vm_map_copyin_common src_obj 0x%x ent 0x%x obj 0x%x was_wired %d\n",
-                   src_object, new_entry, new_entry->object.vm_object,
-                   was_wired, 0);
-               if ((src_object == VM_OBJECT_NULL ||
-                       (!was_wired && !map_share && !tmp_entry->is_shared)) &&
-                       vm_object_copy_quickly(
-                               &new_entry->object.vm_object,
-                               src_offset,
-                               src_size,
-                               &src_needs_copy,
-                               &new_entry_needs_copy)) {
+       /*
+        *      Handle submaps.  Drop lock on upper map, submap is
+        *      returned locked.
+        */
 
-                       new_entry->needs_copy = new_entry_needs_copy;
+submap_recurse:
+       if (entry->is_sub_map) {
+               vm_map_offset_t         local_vaddr;
+               vm_map_offset_t         end_delta;
+               vm_map_offset_t         start_delta; 
+               vm_map_entry_t          submap_entry;
+               boolean_t               mapped_needs_copy=FALSE;
 
-                       /*
-                        *      Handle copy-on-write obligations
-                        */
+               local_vaddr = vaddr;
 
-                       if (src_needs_copy && !tmp_entry->needs_copy) {
-                               vm_object_pmap_protect(
-                                       src_object,
-                                       src_offset,
-                                       src_size,
-                                       (src_entry->is_shared ? 
-                                               PMAP_NULL
-                                               : src_map->pmap),
-                                       src_entry->vme_start,
-                                       src_entry->protection &
-                                               ~VM_PROT_WRITE);
-                               tmp_entry->needs_copy = TRUE;
+               if ((entry->use_pmap && !(fault_type & VM_PROT_WRITE))) {
+                       /* if real_map equals map we unlock below */
+                       if ((*real_map != map) && 
+                           (*real_map != cow_sub_map_parent))
+                               vm_map_unlock(*real_map);
+                       *real_map = entry->object.sub_map;
+               }
+
+               if(entry->needs_copy && (fault_type & VM_PROT_WRITE)) {
+                       if (!mapped_needs_copy) {
+                               if (vm_map_lock_read_to_write(map)) {
+                                       vm_map_lock_read(map);
+                                       /* XXX FBDP: entry still valid ? */
+                                       if(*real_map == entry->object.sub_map)
+                                               *real_map = map;
+                                       goto RetryLookup;
+                               }
+                               vm_map_lock_read(entry->object.sub_map);
+                               cow_sub_map_parent = map;
+                               /* reset base to map before cow object */
+                               /* this is the map which will accept   */
+                               /* the new cow object */
+                               old_start = entry->vme_start;
+                               old_end = entry->vme_end;
+                               cow_parent_vaddr = vaddr;
+                               mapped_needs_copy = TRUE;
+                       } else {
+                               vm_map_lock_read(entry->object.sub_map);
+                               if((cow_sub_map_parent != map) &&
+                                  (*real_map != map))
+                                       vm_map_unlock(map);
                        }
-
-                       /*
-                        *      The map has never been unlocked, so it's safe
-                        *      to move to the next entry rather than doing
-                        *      another lookup.
-                        */
-
-                       goto CopySuccessful;
+               } else {
+                       vm_map_lock_read(entry->object.sub_map);
+                       /* leave map locked if it is a target */
+                       /* cow sub_map above otherwise, just  */
+                       /* follow the maps down to the object */
+                       /* here we unlock knowing we are not  */
+                       /* revisiting the map.  */
+                       if((*real_map != map) && (map != cow_sub_map_parent))
+                               vm_map_unlock_read(map);
                }
 
-               /*
-                *      Take an object reference, so that we may
-                *      release the map lock(s).
-                */
-
-               assert(src_object != VM_OBJECT_NULL);
-               vm_object_reference(src_object);
-
-               /*
-                *      Record the timestamp for later verification.
-                *      Unlock the map.
-                */
-
-               version.main_timestamp = src_map->timestamp;
-               vm_map_unlock(src_map); /* Increments timestamp once! */
-
-               /*
-                *      Perform the copy
-                */
+               /* XXX FBDP: map has been unlocked, what protects "entry" !? */
+               *var_map = map = entry->object.sub_map;
 
-               if (was_wired) {
-               CopySlowly:
-                       vm_object_lock(src_object);
-                       result = vm_object_copy_slowly(
-                                       src_object,
-                                       src_offset,
-                                       src_size,
-                                       THREAD_UNINT,
-                                       &new_entry->object.vm_object);
-                       new_entry->offset = 0;
-                       new_entry->needs_copy = FALSE;
+               /* calculate the offset in the submap for vaddr */
+               local_vaddr = (local_vaddr - entry->vme_start) + entry->offset;
 
+       RetrySubMap:
+               if(!vm_map_lookup_entry(map, local_vaddr, &submap_entry)) {
+                       if((cow_sub_map_parent) && (cow_sub_map_parent != map)){
+                               vm_map_unlock(cow_sub_map_parent);
+                       }
+                       if((*real_map != map) 
+                          && (*real_map != cow_sub_map_parent)) {
+                               vm_map_unlock(*real_map);
+                       }
+                       *real_map = map;
+                       return KERN_INVALID_ADDRESS;
                }
-               else if (src_object->copy_strategy == MEMORY_OBJECT_COPY_SYMMETRIC &&
-                       (tmp_entry->is_shared  || map_share)) {
-                       vm_object_t new_object;
 
-                       vm_object_lock(src_object);
-                       new_object = vm_object_copy_delayed(
-                                       src_object,
-                                       src_offset,     
-                                       src_size);
-                       if (new_object == VM_OBJECT_NULL)
-                               goto CopySlowly;
+               /* find the attenuated shadow of the underlying object */
+               /* on our target map */
 
-                       new_entry->object.vm_object = new_object;
-                       new_entry->needs_copy = TRUE;
-                       result = KERN_SUCCESS;
+               /* in english the submap object may extend beyond the     */
+               /* region mapped by the entry or, may only fill a portion */
+               /* of it.  For our purposes, we only care if the object   */
+               /* doesn't fill.  In this case the area which will        */
+               /* ultimately be clipped in the top map will only need    */
+               /* to be as big as the portion of the underlying entry    */
+               /* which is mapped */
+               start_delta = submap_entry->vme_start > entry->offset ?
+                       submap_entry->vme_start - entry->offset : 0;
 
-               } else {
-                       result = vm_object_copy_strategically(src_object,
-                               src_offset,
-                               src_size,
-                               &new_entry->object.vm_object,
-                               &new_entry->offset,
-                               &new_entry_needs_copy);
+               end_delta = 
+                       (entry->offset + start_delta + (old_end - old_start)) <=
+                       submap_entry->vme_end ?
+                       0 : (entry->offset + 
+                            (old_end - old_start))
+                       - submap_entry->vme_end; 
 
-                       new_entry->needs_copy = new_entry_needs_copy;
-               }
+               old_start += start_delta;
+               old_end -= end_delta;
 
-               if (result != KERN_SUCCESS &&
-                   result != KERN_MEMORY_RESTART_COPY) {
-                       vm_map_lock(src_map);
-                       RETURN(result);
+               if(submap_entry->is_sub_map) {
+                       entry = submap_entry;
+                       vaddr = local_vaddr;
+                       goto submap_recurse;
                }
 
-               /*
-                *      Throw away the extra reference
-                */
-
-               vm_object_deallocate(src_object);
+               if(((fault_type & VM_PROT_WRITE) && cow_sub_map_parent)) {
 
-               /*
-                *      Verify that the map has not substantially
-                *      changed while the copy was being made.
-                */
+                       vm_object_t     sub_object, copy_object;
+                       vm_object_offset_t copy_offset;
+                       vm_map_offset_t local_start;
+                       vm_map_offset_t local_end;
+                       boolean_t               copied_slowly = FALSE;
 
-               vm_map_lock(src_map);
+                       if (vm_map_lock_read_to_write(map)) {
+                               vm_map_lock_read(map);
+                               old_start -= start_delta;
+                               old_end += end_delta;
+                               goto RetrySubMap;
+                       }
 
-               if ((version.main_timestamp + 1) == src_map->timestamp)
-                       goto VerificationSuccessful;
 
-               /*
-                *      Simple version comparison failed.
-                *
-                *      Retry the lookup and verify that the
-                *      same object/offset are still present.
-                *
-                *      [Note: a memory manager that colludes with
-                *      the calling task can detect that we have
-                *      cheated.  While the map was unlocked, the
-                *      mapping could have been changed and restored.]
-                */
+                       sub_object = submap_entry->object.vm_object;
+                       if (sub_object == VM_OBJECT_NULL) {
+                               sub_object =
+                                       vm_object_allocate(
+                                               (vm_map_size_t)
+                                               (submap_entry->vme_end -
+                                                submap_entry->vme_start));
+                               submap_entry->object.vm_object = sub_object;
+                               submap_entry->offset = 0;
+                       }
+                       local_start =  local_vaddr - 
+                               (cow_parent_vaddr - old_start);
+                       local_end = local_vaddr + 
+                               (old_end - cow_parent_vaddr);
+                       vm_map_clip_start(map, submap_entry, local_start);
+                       vm_map_clip_end(map, submap_entry, local_end);
+                       /* unnesting was done in vm_map_clip_start/end() */
+                       assert(!submap_entry->use_pmap);
 
-               if (!vm_map_lookup_entry(src_map, src_start, &tmp_entry)) {
-                       RETURN(KERN_INVALID_ADDRESS);
-               }
+                       /* This is the COW case, lets connect */
+                       /* an entry in our space to the underlying */
+                       /* object in the submap, bypassing the  */
+                       /* submap. */
 
-               src_entry = tmp_entry;
-               vm_map_clip_start(src_map, src_entry, src_start);
 
-               if ((src_entry->protection & VM_PROT_READ == VM_PROT_NONE &&
-                       !use_maxprot) ||
-                   src_entry->max_protection & VM_PROT_READ == 0)
-                       goto VerificationFailed;
+                       if(submap_entry->wired_count != 0 ||
+                          (sub_object->copy_strategy ==
+                           MEMORY_OBJECT_COPY_NONE)) {
+                               vm_object_lock(sub_object);
+                               vm_object_copy_slowly(sub_object,
+                                                     submap_entry->offset,
+                                                     (submap_entry->vme_end -
+                                                      submap_entry->vme_start),
+                                                     FALSE,
+                                                     &copy_object);
+                               copied_slowly = TRUE;
+                       } else {
+                               
+                               /* set up shadow object */
+                               copy_object = sub_object;
+                               vm_object_reference(copy_object);
+                               sub_object->shadowed = TRUE;
+                               submap_entry->needs_copy = TRUE;
 
-               if (src_entry->vme_end < new_entry->vme_end)
-                       src_size = (new_entry->vme_end = src_entry->vme_end) - src_start;
+                               prot = submap_entry->protection & ~VM_PROT_WRITE;
 
-               if ((src_entry->object.vm_object != src_object) ||
-                   (src_entry->offset != src_offset) ) {
+                               if (override_nx(map, submap_entry->alias) && prot)
+                                       prot |= VM_PROT_EXECUTE;
 
+                               vm_object_pmap_protect(
+                                       sub_object,
+                                       submap_entry->offset,
+                                       submap_entry->vme_end - 
+                                       submap_entry->vme_start,
+                                       (submap_entry->is_shared 
+                                        || map->mapped) ?
+                                       PMAP_NULL : map->pmap,
+                                       submap_entry->vme_start,
+                                       prot);
+                       }
+                       
                        /*
-                        *      Verification failed.
-                        *
-                        *      Start over with this top-level entry.
+                        * Adjust the fault offset to the submap entry.
                         */
+                       copy_offset = (local_vaddr -
+                                      submap_entry->vme_start +
+                                      submap_entry->offset);
 
-                VerificationFailed: ;
-
-                       vm_object_deallocate(new_entry->object.vm_object);
-                       tmp_entry = src_entry;
-                       continue;
-               }
-
-               /*
-                *      Verification succeeded.
-                */
-
-        VerificationSuccessful: ;
+                       /* This works diffently than the   */
+                       /* normal submap case. We go back  */
+                       /* to the parent of the cow map and*/
+                       /* clip out the target portion of  */
+                       /* the sub_map, substituting the   */
+                       /* new copy object,                */
 
-               if (result == KERN_MEMORY_RESTART_COPY)
-                       goto RestartCopy;
+                       vm_map_unlock(map);
+                       local_start = old_start;
+                       local_end = old_end;
+                       map = cow_sub_map_parent;
+                       *var_map = cow_sub_map_parent;
+                       vaddr = cow_parent_vaddr;
+                       cow_sub_map_parent = NULL;
 
-               /*
-                *      Copy succeeded.
-                */
+                       if(!vm_map_lookup_entry(map, 
+                                               vaddr, &entry)) {
+                               vm_object_deallocate(
+                                       copy_object);
+                               vm_map_lock_write_to_read(map);
+                               return KERN_INVALID_ADDRESS;
+                       }
+                                       
+                       /* clip out the portion of space */
+                       /* mapped by the sub map which   */
+                       /* corresponds to the underlying */
+                       /* object */
 
-        CopySuccessful: ;
+                       /*
+                        * Clip (and unnest) the smallest nested chunk
+                        * possible around the faulting address...
+                        */
+                       local_start = vaddr & ~(pmap_nesting_size_min - 1);
+                       local_end = local_start + pmap_nesting_size_min;
+                       /*
+                        * ... but don't go beyond the "old_start" to "old_end"
+                        * range, to avoid spanning over another VM region
+                        * with a possibly different VM object and/or offset.
+                        */
+                       if (local_start < old_start) {
+                               local_start = old_start;
+                       }
+                       if (local_end > old_end) {
+                               local_end = old_end;
+                       }
+                       /*
+                        * Adjust copy_offset to the start of the range.
+                        */
+                       copy_offset -= (vaddr - local_start);
 
-               /*
-                *      Link in the new copy entry.
-                */
+                       vm_map_clip_start(map, entry, local_start);
+                       vm_map_clip_end(map, entry, local_end);
+                       /* unnesting was done in vm_map_clip_start/end() */
+                       assert(!entry->use_pmap);
 
-               vm_map_copy_entry_link(copy, vm_map_copy_last_entry(copy),
-                                      new_entry);
-               
-               /*
-                *      Determine whether the entire region
-                *      has been copied.
-                */
-               src_start = new_entry->vme_end;
-               new_entry = VM_MAP_ENTRY_NULL;
-               while ((src_start >= src_end) && (src_end != 0)) {
-                       if (src_map != base_map) {
-                               submap_map_t    *ptr;
+                       /* substitute copy object for */
+                       /* shared map entry           */
+                       vm_map_deallocate(entry->object.sub_map);
+                       entry->is_sub_map = FALSE;
+                       entry->object.vm_object = copy_object;
 
-                               ptr = parent_maps;
-                               assert(ptr != NULL);
-                               parent_maps = parent_maps->next;
-                               vm_map_unlock(src_map);
-                               vm_map_deallocate(src_map);
-                               vm_map_lock(ptr->parent_map);
-                               src_map = ptr->parent_map;
-                               src_start = ptr->base_start;
-                               src_end = ptr->base_end;
-                               if ((src_end > src_start) &&
-                                             !vm_map_lookup_entry(
-                                             src_map, src_start, &tmp_entry))
-                                       RETURN(KERN_INVALID_ADDRESS);
-                               kfree((vm_offset_t)ptr, sizeof(submap_map_t));
-                               if(parent_maps == NULL)
-                                       map_share = FALSE;
-                               src_entry = tmp_entry->vme_prev;
-                       } else
-                               break;
-               }
-               if ((src_start >= src_end) && (src_end != 0))
-                       break;
+                       /* propagate the submap entry's protections */
+                       entry->protection |= submap_entry->protection;
+                       entry->max_protection |= submap_entry->max_protection;
 
-               /*
-                *      Verify that there are no gaps in the region
-                */
+                       if(copied_slowly) {
+                               entry->offset = local_start - old_start;
+                               entry->needs_copy = FALSE;
+                               entry->is_shared = FALSE;
+                       } else {
+                               entry->offset = copy_offset;
+                               entry->needs_copy = TRUE;
+                               if(entry->inheritance == VM_INHERIT_SHARE) 
+                                       entry->inheritance = VM_INHERIT_COPY;
+                               if (map != old_map)
+                                       entry->is_shared = TRUE;
+                       }
+                       if(entry->inheritance == VM_INHERIT_SHARE) 
+                               entry->inheritance = VM_INHERIT_COPY;
 
-               tmp_entry = src_entry->vme_next;
-               if ((tmp_entry->vme_start != src_start) || 
-                               (tmp_entry == vm_map_to_entry(src_map)))
-                       RETURN(KERN_INVALID_ADDRESS);
+                       vm_map_lock_write_to_read(map);
+               } else {
+                       if((cow_sub_map_parent)
+                          && (cow_sub_map_parent != *real_map)
+                          && (cow_sub_map_parent != map)) {
+                               vm_map_unlock(cow_sub_map_parent);
+                       }
+                       entry = submap_entry;
+                       vaddr = local_vaddr;
+               }
        }
-
+               
        /*
-        * If the source should be destroyed, do it now, since the
-        * copy was successful. 
+        *      Check whether this task is allowed to have
+        *      this page.
         */
-       if (src_destroy) {
-               (void) vm_map_delete(src_map,
-                                    trunc_page_32(src_addr),
-                                    src_end,
-                                    (src_map == kernel_map) ?
-                                       VM_MAP_REMOVE_KUNWIRE :
-                                       VM_MAP_NO_FLAGS);
-       }
-
-       vm_map_unlock(src_map);
 
-       /* Fix-up start and end points in copy.  This is necessary */
-       /* when the various entries in the copy object were picked */
-       /* up from different sub-maps */
+       prot = entry->protection;
 
-       tmp_entry = vm_map_copy_first_entry(copy);
-       while (tmp_entry != vm_map_copy_to_entry(copy)) {
-               tmp_entry->vme_end = copy_addr + 
-                       (tmp_entry->vme_end - tmp_entry->vme_start);
-               tmp_entry->vme_start = copy_addr;
-               copy_addr += tmp_entry->vme_end - tmp_entry->vme_start;
-               tmp_entry = (struct vm_map_entry *)tmp_entry->vme_next;
+       if (override_nx(map, entry->alias) && prot) {
+               /*
+                * HACK -- if not a stack, then allow execution
+                */
+               prot |= VM_PROT_EXECUTE;
        }
 
-       *copy_result = copy;
-       return(KERN_SUCCESS);
-
-#undef RETURN
-}
+       if ((fault_type & (prot)) != fault_type) {
+               if (*real_map != map) {
+                       vm_map_unlock(*real_map);
+               }
+               *real_map = map;
 
-/*
- *     vm_map_copyin_object:
- *
- *     Create a copy object from an object.
- *     Our caller donates an object reference.
- */
+               if ((fault_type & VM_PROT_EXECUTE) && prot)
+                       log_stack_execution_failure((addr64_t)vaddr, prot);
 
-kern_return_t
-vm_map_copyin_object(
-       vm_object_t             object,
-       vm_object_offset_t      offset, /* offset of region in object */
-       vm_object_size_t        size,   /* size of region in object */
-       vm_map_copy_t   *copy_result)   /* OUT */
-{
-       vm_map_copy_t   copy;           /* Resulting copy */
+               DTRACE_VM2(prot_fault, int, 1, (uint64_t *), NULL);
+               return KERN_PROTECTION_FAILURE;
+       }
 
        /*
-        *      We drop the object into a special copy object
-        *      that contains the object directly.
+        *      If this page is not pageable, we have to get
+        *      it for all possible accesses.
         */
 
-       copy = (vm_map_copy_t) zalloc(vm_map_copy_zone);
-       copy->type = VM_MAP_COPY_OBJECT;
-       copy->cpy_object = object;
-       copy->cpy_index = 0;
-       copy->offset = offset;
-       copy->size = size;
-
-       *copy_result = copy;
-       return(KERN_SUCCESS);
-}
-
-void
-vm_map_fork_share(
-       vm_map_t        old_map,
-       vm_map_entry_t  old_entry,
-       vm_map_t        new_map)
-{
-       vm_object_t     object;
-       vm_map_entry_t  new_entry;
-       kern_return_t   result;
+       *wired = (entry->wired_count != 0);
+       if (*wired)
+               fault_type = prot;
 
        /*
-        *      New sharing code.  New map entry
-        *      references original object.  Internal
-        *      objects use asynchronous copy algorithm for
-        *      future copies.  First make sure we have
-        *      the right object.  If we need a shadow,
-        *      or someone else already has one, then
-        *      make a new shadow and share it.
+        *      If the entry was copy-on-write, we either ...
         */
-       
-       object = old_entry->object.vm_object;
-       if (old_entry->is_sub_map) {
-               assert(old_entry->wired_count == 0);
-#ifndef i386
-               if(old_entry->use_pmap) {
-                       result = pmap_nest(new_map->pmap, 
-                               (old_entry->object.sub_map)->pmap, 
-                               (addr64_t)old_entry->vme_start,
-                               (addr64_t)old_entry->vme_start,
-                               (uint64_t)(old_entry->vme_end - old_entry->vme_start));
-                       if(result)
-                               panic("vm_map_fork_share: pmap_nest failed!");
-               }
-#endif
-       } else if (object == VM_OBJECT_NULL) {
-               object = vm_object_allocate((vm_size_t)(old_entry->vme_end -
-                                                       old_entry->vme_start));
-               old_entry->offset = 0;
-               old_entry->object.vm_object = object;
-               assert(!old_entry->needs_copy);
-       } else if (object->copy_strategy !=
-                MEMORY_OBJECT_COPY_SYMMETRIC) {
-               
-               /*
-                *      We are already using an asymmetric
-                *      copy, and therefore we already have
-                *      the right object.
-                */
-               
-               assert(! old_entry->needs_copy);
-       }
-       else if (old_entry->needs_copy ||       /* case 1 */
-                object->shadowed ||            /* case 2 */
-                (!object->true_share &&        /* case 3 */
-                !old_entry->is_shared &&
-                (object->size >
-                 (vm_size_t)(old_entry->vme_end -
-                             old_entry->vme_start)))) {
-               
-               /*
-                *      We need to create a shadow.
-                *      There are three cases here.
-                *      In the first case, we need to
-                *      complete a deferred symmetrical
-                *      copy that we participated in.
-                *      In the second and third cases,
-                *      we need to create the shadow so
-                *      that changes that we make to the
-                *      object do not interfere with
-                *      any symmetrical copies which
-                *      have occured (case 2) or which
-                *      might occur (case 3).
-                *
-                *      The first case is when we had
-                *      deferred shadow object creation
-                *      via the entry->needs_copy mechanism.
-                *      This mechanism only works when
-                *      only one entry points to the source
-                *      object, and we are about to create
-                *      a second entry pointing to the
-                *      same object. The problem is that
-                *      there is no way of mapping from
-                *      an object to the entries pointing
-                *      to it. (Deferred shadow creation
-                *      works with one entry because occurs
-                *      at fault time, and we walk from the
-                *      entry to the object when handling
-                *      the fault.)
-                *
-                *      The second case is when the object
-                *      to be shared has already been copied
-                *      with a symmetric copy, but we point
-                *      directly to the object without
-                *      needs_copy set in our entry. (This
-                *      can happen because different ranges
-                *      of an object can be pointed to by
-                *      different entries. In particular,
-                *      a single entry pointing to an object
-                *      can be split by a call to vm_inherit,
-                *      which, combined with task_create, can
-                *      result in the different entries
-                *      having different needs_copy values.)
-                *      The shadowed flag in the object allows
-                *      us to detect this case. The problem
-                *      with this case is that if this object
-                *      has or will have shadows, then we
-                *      must not perform an asymmetric copy
-                *      of this object, since such a copy
-                *      allows the object to be changed, which
-                *      will break the previous symmetrical
-                *      copies (which rely upon the object
-                *      not changing). In a sense, the shadowed
-                *      flag says "don't change this object".
-                *      We fix this by creating a shadow
-                *      object for this object, and sharing
-                *      that. This works because we are free
-                *      to change the shadow object (and thus
-                *      to use an asymmetric copy strategy);
-                *      this is also semantically correct,
-                *      since this object is temporary, and
-                *      therefore a copy of the object is
-                *      as good as the object itself. (This
-                *      is not true for permanent objects,
-                *      since the pager needs to see changes,
-                *      which won't happen if the changes
-                *      are made to a copy.)
+
+       if (entry->needs_copy) {
+               /*
+                *      If we want to write the page, we may as well
+                *      handle that now since we've got the map locked.
                 *
-                *      The third case is when the object
-                *      to be shared has parts sticking
-                *      outside of the entry we're working
-                *      with, and thus may in the future
-                *      be subject to a symmetrical copy.
-                *      (This is a preemptive version of
-                *      case 2.)
-                */
-               
-               assert(!(object->shadowed && old_entry->is_shared));
-               vm_object_shadow(&old_entry->object.vm_object,
-                                &old_entry->offset,
-                                (vm_size_t) (old_entry->vme_end -
-                                             old_entry->vme_start));
-               
-               /*
-                *      If we're making a shadow for other than
-                *      copy on write reasons, then we have
-                *      to remove write permission.
+                *      If we don't need to write the page, we just
+                *      demote the permissions allowed.
                 */
 
-               if (!old_entry->needs_copy &&
-                   (old_entry->protection & VM_PROT_WRITE)) {
-                       if(old_map->mapped) {
-                               vm_object_pmap_protect(
-                                       old_entry->object.vm_object,
-                                       old_entry->offset,
-                                       (old_entry->vme_end -
-                                                       old_entry->vme_start),
-                                       PMAP_NULL,
-                                       old_entry->vme_start,
-                                       old_entry->protection & ~VM_PROT_WRITE);
-                       } else {
-                               pmap_protect(old_map->pmap,
-                                    old_entry->vme_start,
-                                    old_entry->vme_end,
-                                    old_entry->protection & ~VM_PROT_WRITE);
+               if ((fault_type & VM_PROT_WRITE) || *wired) {
+                       /*
+                        *      Make a new object, and place it in the
+                        *      object chain.  Note that no new references
+                        *      have appeared -- one just moved from the
+                        *      map to the new object.
+                        */
+
+                       if (vm_map_lock_read_to_write(map)) {
+                               vm_map_lock_read(map);
+                               goto RetryLookup;
                        }
+                       vm_object_shadow(&entry->object.vm_object,
+                                        &entry->offset,
+                                        (vm_map_size_t) (entry->vme_end -
+                                                         entry->vme_start));
+
+                       entry->object.vm_object->shadowed = TRUE;
+                       entry->needs_copy = FALSE;
+                       vm_map_lock_write_to_read(map);
+               }
+               else {
+                       /*
+                        *      We're attempting to read a copy-on-write
+                        *      page -- don't allow writes.
+                        */
+
+                       prot &= (~VM_PROT_WRITE);
                }
-               
-               old_entry->needs_copy = FALSE;
-               object = old_entry->object.vm_object;
        }
-       
-       /*
-        *      If object was using a symmetric copy strategy,
-        *      change its copy strategy to the default
-        *      asymmetric copy strategy, which is copy_delay
-        *      in the non-norma case and copy_call in the
-        *      norma case. Bump the reference count for the
-        *      new entry.
+
+       /*
+        *      Create an object if necessary.
         */
-       
-       if(old_entry->is_sub_map) {
-               vm_map_lock(old_entry->object.sub_map);
-               vm_map_reference(old_entry->object.sub_map);
-               vm_map_unlock(old_entry->object.sub_map);
-       } else {
-               vm_object_lock(object);
-               object->ref_count++;
-               vm_object_res_reference(object);
-               if (object->copy_strategy == MEMORY_OBJECT_COPY_SYMMETRIC) {
-                       object->copy_strategy = MEMORY_OBJECT_COPY_DELAY;
+       if (entry->object.vm_object == VM_OBJECT_NULL) {
+
+               if (vm_map_lock_read_to_write(map)) {
+                       vm_map_lock_read(map);
+                       goto RetryLookup;
                }
-               vm_object_unlock(object);
+
+               entry->object.vm_object = vm_object_allocate(
+                       (vm_map_size_t)(entry->vme_end - entry->vme_start));
+               entry->offset = 0;
+               vm_map_lock_write_to_read(map);
        }
-       
+
        /*
-        *      Clone the entry, using object ref from above.
-        *      Mark both entries as shared.
+        *      Return the object/offset from this entry.  If the entry
+        *      was copy-on-write or empty, it has been fixed up.  Also
+        *      return the protection.
         */
-       
-       new_entry = vm_map_entry_create(new_map);
-       vm_map_entry_copy(new_entry, old_entry);
-       old_entry->is_shared = TRUE;
-       new_entry->is_shared = TRUE;
-       
+
+        *offset = (vaddr - entry->vme_start) + entry->offset;
+        *object = entry->object.vm_object;
+       *out_prot = prot;
+
+       if (fault_info) {
+               fault_info->interruptible = THREAD_UNINT; /* for now... */
+               /* ... the caller will change "interruptible" if needed */
+               fault_info->cluster_size = 0;
+               fault_info->user_tag = entry->alias;
+               fault_info->behavior = entry->behavior;
+               fault_info->lo_offset = entry->offset;
+               fault_info->hi_offset = (entry->vme_end - entry->vme_start) + entry->offset;
+               fault_info->no_cache  = entry->no_cache;
+               fault_info->stealth = FALSE;
+       }
+
        /*
-        *      Insert the entry into the new map -- we
-        *      know we're inserting at the end of the new
-        *      map.
+        *      Lock the object to prevent it from disappearing
         */
-       
-       vm_map_entry_link(new_map, vm_map_last_entry(new_map), new_entry);
+       if (object_lock_type == OBJECT_LOCK_EXCLUSIVE)
+               vm_object_lock(*object);
+       else
+               vm_object_lock_shared(*object);
        
        /*
-        *      Update the physical map
+        *      Save the version number
         */
-       
-       if (old_entry->is_sub_map) {
-               /* Bill Angell pmap support goes here */
-       } else {
-               pmap_copy(new_map->pmap, old_map->pmap, new_entry->vme_start,
-                 old_entry->vme_end - old_entry->vme_start,
-                 old_entry->vme_start);
-       }
+
+       out_version->main_timestamp = map->timestamp;
+
+       return KERN_SUCCESS;
 }
 
+
+/*
+ *     vm_map_verify:
+ *
+ *     Verifies that the map in question has not changed
+ *     since the given version.  If successful, the map
+ *     will not change until vm_map_verify_done() is called.
+ */
 boolean_t
-vm_map_fork_copy(
-       vm_map_t        old_map,
-       vm_map_entry_t  *old_entry_p,
-       vm_map_t        new_map)
+vm_map_verify(
+       register vm_map_t               map,
+       register vm_map_version_t       *version)       /* REF */
 {
-       vm_map_entry_t old_entry = *old_entry_p;
-       vm_size_t entry_size = old_entry->vme_end - old_entry->vme_start;
-       vm_offset_t start = old_entry->vme_start;
-       vm_map_copy_t copy;
-       vm_map_entry_t last = vm_map_last_entry(new_map);
+       boolean_t       result;
 
-       vm_map_unlock(old_map);
-       /*
-        *      Use maxprot version of copyin because we
-        *      care about whether this memory can ever
-        *      be accessed, not just whether it's accessible
-        *      right now.
-        */
-       if (vm_map_copyin_maxprot(old_map, start, entry_size, FALSE, &copy)
-           != KERN_SUCCESS) {
-               /*
-                *      The map might have changed while it
-                *      was unlocked, check it again.  Skip
-                *      any blank space or permanently
-                *      unreadable region.
-                */
-               vm_map_lock(old_map);
-               if (!vm_map_lookup_entry(old_map, start, &last) ||
-                   last->max_protection & VM_PROT_READ ==
-                                        VM_PROT_NONE) {
-                       last = last->vme_next;
-               }
-               *old_entry_p = last;
+       vm_map_lock_read(map);
+       result = (map->timestamp == version->main_timestamp);
 
-               /*
-                * XXX  For some error returns, want to
-                * XXX  skip to the next element.  Note
-                *      that INVALID_ADDRESS and
-                *      PROTECTION_FAILURE are handled above.
-                */
-               
-               return FALSE;
-       }
-       
-       /*
-        *      Insert the copy into the new map
-        */
-       
-       vm_map_copy_insert(new_map, last, copy);
-       
-       /*
-        *      Pick up the traversal at the end of
-        *      the copied region.
-        */
-       
-       vm_map_lock(old_map);
-       start += entry_size;
-       if (! vm_map_lookup_entry(old_map, start, &last)) {
-               last = last->vme_next;
-       } else {
-               vm_map_clip_start(old_map, last, start);
-       }
-       *old_entry_p = last;
+       if (!result)
+               vm_map_unlock_read(map);
 
-       return TRUE;
+       return(result);
 }
 
 /*
- *     vm_map_fork:
+ *     vm_map_verify_done:
  *
- *     Create and return a new map based on the old
- *     map, according to the inheritance values on the
- *     regions in that map.
+ *     Releases locks acquired by a vm_map_verify.
  *
- *     The source map must not be locked.
+ *     This is now a macro in vm/vm_map.h.  It does a
+ *     vm_map_unlock_read on the map.
  */
-vm_map_t
-vm_map_fork(
-       vm_map_t        old_map)
-{
-       pmap_t          new_pmap = pmap_create((vm_size_t) 0);
-       vm_map_t        new_map;
-       vm_map_entry_t  old_entry;
-       vm_size_t       new_size = 0, entry_size;
-       vm_map_entry_t  new_entry;
-       boolean_t       src_needs_copy;
-       boolean_t       new_entry_needs_copy;
 
-       vm_map_reference_swap(old_map);
-       vm_map_lock(old_map);
 
-       new_map = vm_map_create(new_pmap,
-                       old_map->min_offset,
-                       old_map->max_offset,
-                       old_map->hdr.entries_pageable);
+/*
+ *     TEMPORARYTEMPORARYTEMPORARYTEMPORARYTEMPORARYTEMPORARY
+ *     Goes away after regular vm_region_recurse function migrates to
+ *     64 bits
+ *     vm_region_recurse: A form of vm_region which follows the
+ *     submaps in a target map
+ *
+ */
 
-       for (
-           old_entry = vm_map_first_entry(old_map);
-           old_entry != vm_map_to_entry(old_map);
-           ) {
+kern_return_t
+vm_map_region_recurse_64(
+       vm_map_t                 map,
+       vm_map_offset_t *address,               /* IN/OUT */
+       vm_map_size_t           *size,                  /* OUT */
+       natural_t               *nesting_depth, /* IN/OUT */
+       vm_region_submap_info_64_t      submap_info,    /* IN/OUT */
+       mach_msg_type_number_t  *count) /* IN/OUT */
+{
+       vm_region_extended_info_data_t  extended;
+       vm_map_entry_t                  tmp_entry;
+       vm_map_offset_t                 user_address;
+       unsigned int                    user_max_depth;
 
-               entry_size = old_entry->vme_end - old_entry->vme_start;
+       /*
+        * "curr_entry" is the VM map entry preceding or including the
+        * address we're looking for.
+        * "curr_map" is the map or sub-map containing "curr_entry".
+        * "curr_offset" is the cumulated offset of "curr_map" in the
+        * target task's address space.
+        * "curr_depth" is the depth of "curr_map" in the chain of
+        * sub-maps.
+        * "curr_max_offset" is the maximum offset we should take into
+        * account in the current map.  It may be smaller than the current
+        * map's "max_offset" because we might not have mapped it all in
+        * the upper level map.
+        */
+       vm_map_entry_t                  curr_entry;
+       vm_map_offset_t                 curr_offset;
+       vm_map_t                        curr_map;
+       unsigned int                    curr_depth;
+       vm_map_offset_t                 curr_max_offset;
 
-               switch (old_entry->inheritance) {
-               case VM_INHERIT_NONE:
-                       break;
+       /*
+        * "next_" is the same as "curr_" but for the VM region immediately
+        * after the address we're looking for.  We need to keep track of this
+        * too because we want to return info about that region if the
+        * address we're looking for is not mapped.
+        */
+       vm_map_entry_t                  next_entry;
+       vm_map_offset_t                 next_offset;
+       vm_map_t                        next_map;
+       unsigned int                    next_depth;
+       vm_map_offset_t                 next_max_offset;
 
-               case VM_INHERIT_SHARE:
-                       vm_map_fork_share(old_map, old_entry, new_map);
-                       new_size += entry_size;
-                       break;
+       boolean_t                       look_for_pages;
+       vm_region_submap_short_info_64_t short_info;
 
-               case VM_INHERIT_COPY:
+       if (map == VM_MAP_NULL) {
+               /* no address space to work on */
+               return KERN_INVALID_ARGUMENT;
+       }
 
+       if (*count < VM_REGION_SUBMAP_INFO_COUNT_64) {
+               if (*count < VM_REGION_SUBMAP_SHORT_INFO_COUNT_64) {
                        /*
-                        *      Inline the copy_quickly case;
-                        *      upon failure, fall back on call
-                        *      to vm_map_fork_copy.
+                        * "info" structure is not big enough and
+                        * would overflow
                         */
+                       return KERN_INVALID_ARGUMENT;
+               } else {
+                       look_for_pages = FALSE;
+                       *count = VM_REGION_SUBMAP_SHORT_INFO_COUNT_64;
+                       short_info = (vm_region_submap_short_info_64_t) submap_info;
+                       submap_info = NULL;
+               }
+       } else {
+               look_for_pages = TRUE;
+               *count = VM_REGION_SUBMAP_INFO_COUNT_64;
+               short_info = NULL;
+       }
 
-                       if(old_entry->is_sub_map)
+
+       user_address = *address;
+       user_max_depth = *nesting_depth;
+       
+       curr_entry = NULL;
+       curr_map = map;
+       curr_offset = 0;
+       curr_depth = 0;
+       curr_max_offset = curr_map->max_offset;
+
+       next_entry = NULL;
+       next_map = NULL;
+       next_offset = 0;
+       next_depth = 0;
+       next_max_offset = curr_max_offset;
+
+       if (not_in_kdp) {
+               vm_map_lock_read(curr_map);
+       }
+
+       for (;;) {
+               if (vm_map_lookup_entry(curr_map,
+                                       user_address - curr_offset,
+                                       &tmp_entry)) {
+                       /* tmp_entry contains the address we're looking for */
+                       curr_entry = tmp_entry;
+               } else {
+                       /*
+                        * The address is not mapped.  "tmp_entry" is the
+                        * map entry preceding the address.  We want the next
+                        * one, if it exists.
+                        */
+                       curr_entry = tmp_entry->vme_next;
+                       if (curr_entry == vm_map_to_entry(curr_map) ||
+                           curr_entry->vme_start >= curr_max_offset) {
+                               /* no next entry at this level: stop looking */
+                               if (not_in_kdp) {
+                                       vm_map_unlock_read(curr_map);
+                               }
+                               curr_entry = NULL;
+                               curr_map = NULL;
+                               curr_offset = 0;
+                               curr_depth = 0;
+                               curr_max_offset = 0;
                                break;
-                       if ((old_entry->wired_count != 0) ||
-                               ((old_entry->object.vm_object != NULL) &&
-                               (old_entry->object.vm_object->true_share))) {
-                               goto slow_vm_map_fork_copy;
                        }
+               }
 
-                       new_entry = vm_map_entry_create(new_map);
-                       vm_map_entry_copy(new_entry, old_entry);
-                       /* clear address space specifics */
-                       new_entry->use_pmap = FALSE;
-
-                       if (! vm_object_copy_quickly(
-                                               &new_entry->object.vm_object,
-                                               old_entry->offset,
-                                               (old_entry->vme_end -
-                                                       old_entry->vme_start),
-                                               &src_needs_copy,
-                                               &new_entry_needs_copy)) {
-                               vm_map_entry_dispose(new_map, new_entry);
-                               goto slow_vm_map_fork_copy;
+               /*
+                * Is the next entry at this level closer to the address (or
+                * deeper in the submap chain) than the one we had
+                * so far ?
+                */
+               tmp_entry = curr_entry->vme_next;
+               if (tmp_entry == vm_map_to_entry(curr_map)) {
+                       /* no next entry at this level */
+               } else if (tmp_entry->vme_start >= curr_max_offset) {
+                       /*
+                        * tmp_entry is beyond the scope of what we mapped of
+                        * this submap in the upper level: ignore it.
+                        */
+               } else if ((next_entry == NULL) ||
+                          (tmp_entry->vme_start + curr_offset <=
+                           next_entry->vme_start + next_offset)) {
+                       /*
+                        * We didn't have a "next_entry" or this one is
+                        * closer to the address we're looking for:
+                        * use this "tmp_entry" as the new "next_entry".
+                        */
+                       if (next_entry != NULL) {
+                               /* unlock the last "next_map" */
+                               if (next_map != curr_map && not_in_kdp) {
+                                       vm_map_unlock_read(next_map);
+                               }
                        }
+                       next_entry = tmp_entry;
+                       next_map = curr_map;
+                       next_offset = curr_offset;
+                       next_depth = curr_depth;
+                       next_max_offset = curr_max_offset;
+               }
 
+               if (!curr_entry->is_sub_map ||
+                   curr_depth >= user_max_depth) {
                        /*
-                        *      Handle copy-on-write obligations
+                        * We hit a leaf map or we reached the maximum depth
+                        * we could, so stop looking.  Keep the current map
+                        * locked.
                         */
-                       
-                       if (src_needs_copy && !old_entry->needs_copy) {
-                               vm_object_pmap_protect(
-                                       old_entry->object.vm_object,
-                                       old_entry->offset,
-                                       (old_entry->vme_end -
-                                                       old_entry->vme_start),
-                                       ((old_entry->is_shared 
-                                               || old_map->mapped)
-                                                       ? PMAP_NULL :
-                                                       old_map->pmap),
-                                       old_entry->vme_start,
-                                       old_entry->protection & ~VM_PROT_WRITE);
+                       break;
+               }
+
+               /*
+                * Get down to the next submap level.
+                */
+
+               /*
+                * Lock the next level and unlock the current level,
+                * unless we need to keep it locked to access the "next_entry"
+                * later.
+                */
+               if (not_in_kdp) {
+                       vm_map_lock_read(curr_entry->object.sub_map);
+               }
+               if (curr_map == next_map) {
+                       /* keep "next_map" locked in case we need it */
+               } else {
+                       /* release this map */
+                       if (not_in_kdp)
+                               vm_map_unlock_read(curr_map);
+               }
+
+               /*
+                * Adjust the offset.  "curr_entry" maps the submap
+                * at relative address "curr_entry->vme_start" in the
+                * curr_map but skips the first "curr_entry->offset"
+                * bytes of the submap.
+                * "curr_offset" always represents the offset of a virtual
+                * address in the curr_map relative to the absolute address
+                * space (i.e. the top-level VM map).
+                */
+               curr_offset +=
+                       (curr_entry->vme_start - curr_entry->offset);
+               /* switch to the submap */
+               curr_map = curr_entry->object.sub_map;
+               curr_depth++;
+               /*
+                * "curr_max_offset" allows us to keep track of the
+                * portion of the submap that is actually mapped at this level:
+                * the rest of that submap is irrelevant to us, since it's not
+                * mapped here.
+                * The relevant portion of the map starts at
+                * "curr_entry->offset" up to the size of "curr_entry".
+                */
+               curr_max_offset =
+                       curr_entry->vme_end - curr_entry->vme_start +
+                       curr_entry->offset;
+               curr_entry = NULL;
+       }
+
+       if (curr_entry == NULL) {
+               /* no VM region contains the address... */
+               if (next_entry == NULL) {
+                       /* ... and no VM region follows it either */
+                       return KERN_INVALID_ADDRESS;
+               }
+               /* ... gather info about the next VM region */
+               curr_entry = next_entry;
+               curr_map = next_map;    /* still locked ... */
+               curr_offset = next_offset;
+               curr_depth = next_depth;
+               curr_max_offset = next_max_offset;
+       } else {
+               /* we won't need "next_entry" after all */
+               if (next_entry != NULL) {
+                       /* release "next_map" */
+                       if (next_map != curr_map && not_in_kdp) {
+                               vm_map_unlock_read(next_map);
+                       }
+               }
+       }
+       next_entry = NULL;
+       next_map = NULL;
+       next_offset = 0;
+       next_depth = 0;
+       next_max_offset = 0;
+
+       *nesting_depth = curr_depth;
+       *size = curr_entry->vme_end - curr_entry->vme_start;
+       *address = curr_entry->vme_start + curr_offset;
+
+// LP64todo: all the current tools are 32bit, obviously never worked for 64b
+// so probably should be a real 32b ID vs. ptr.
+// Current users just check for equality
+#define INFO_MAKE_OBJECT_ID(p) ((uint32_t)(uintptr_t)p)
+
+       if (look_for_pages) {
+               submap_info->user_tag = curr_entry->alias;
+               submap_info->offset = curr_entry->offset; 
+               submap_info->protection = curr_entry->protection;
+               submap_info->inheritance = curr_entry->inheritance;
+               submap_info->max_protection = curr_entry->max_protection;
+               submap_info->behavior = curr_entry->behavior;
+               submap_info->user_wired_count = curr_entry->user_wired_count;
+               submap_info->is_submap = curr_entry->is_sub_map;
+               submap_info->object_id = INFO_MAKE_OBJECT_ID(curr_entry->object.vm_object);
+       } else {
+               short_info->user_tag = curr_entry->alias;
+               short_info->offset = curr_entry->offset; 
+               short_info->protection = curr_entry->protection;
+               short_info->inheritance = curr_entry->inheritance;
+               short_info->max_protection = curr_entry->max_protection;
+               short_info->behavior = curr_entry->behavior;
+               short_info->user_wired_count = curr_entry->user_wired_count;
+               short_info->is_submap = curr_entry->is_sub_map;
+               short_info->object_id = INFO_MAKE_OBJECT_ID(curr_entry->object.vm_object);
+       }
+
+       extended.pages_resident = 0;
+       extended.pages_swapped_out = 0;
+       extended.pages_shared_now_private = 0;
+       extended.pages_dirtied = 0;
+       extended.external_pager = 0;
+       extended.shadow_depth = 0;
 
-                               old_entry->needs_copy = TRUE;
+       if (not_in_kdp) {
+               if (!curr_entry->is_sub_map) {
+                       vm_map_region_walk(curr_map,
+                                          curr_entry->vme_start,
+                                          curr_entry,
+                                          curr_entry->offset,
+                                          (curr_entry->vme_end -
+                                           curr_entry->vme_start),
+                                          &extended,
+                                          look_for_pages);
+                       if (extended.external_pager &&
+                           extended.ref_count == 2 &&
+                           extended.share_mode == SM_SHARED) {
+                               extended.share_mode = SM_PRIVATE;
                        }
-                       new_entry->needs_copy = new_entry_needs_copy;
-                       
-                       /*
-                        *      Insert the entry at the end
-                        *      of the map.
-                        */
-                       
-                       vm_map_entry_link(new_map, vm_map_last_entry(new_map),
-                                         new_entry);
-                       new_size += entry_size;
-                       break;
-
-               slow_vm_map_fork_copy:
-                       if (vm_map_fork_copy(old_map, &old_entry, new_map)) {
-                               new_size += entry_size;
+               } else {
+                       if (curr_entry->use_pmap) {
+                               extended.share_mode = SM_TRUESHARED;
+                       } else {
+                               extended.share_mode = SM_PRIVATE;
                        }
-                       continue;
+                       extended.ref_count =
+                               curr_entry->object.sub_map->ref_count;
                }
-               old_entry = old_entry->vme_next;
        }
 
-       new_map->size = new_size;
-       vm_map_unlock(old_map);
-       vm_map_deallocate(old_map);
+       if (look_for_pages) {
+               submap_info->pages_resident = extended.pages_resident;
+               submap_info->pages_swapped_out = extended.pages_swapped_out;
+               submap_info->pages_shared_now_private =
+                       extended.pages_shared_now_private;
+               submap_info->pages_dirtied = extended.pages_dirtied;
+               submap_info->external_pager = extended.external_pager;
+               submap_info->shadow_depth = extended.shadow_depth;
+               submap_info->share_mode = extended.share_mode;
+               submap_info->ref_count = extended.ref_count;
+       } else {
+               short_info->external_pager = extended.external_pager;
+               short_info->shadow_depth = extended.shadow_depth;
+               short_info->share_mode = extended.share_mode;
+               short_info->ref_count = extended.ref_count;
+       }
 
-       return(new_map);
-}
+       if (not_in_kdp) {
+               vm_map_unlock_read(curr_map);
+       }
 
+       return KERN_SUCCESS;
+}
 
 /*
- *     vm_map_lookup_locked:
- *
- *     Finds the VM object, offset, and
- *     protection for a given virtual address in the
- *     specified map, assuming a page fault of the
- *     type specified.
- *
- *     Returns the (object, offset, protection) for
- *     this address, whether it is wired down, and whether
- *     this map has the only reference to the data in question.
- *     In order to later verify this lookup, a "version"
- *     is returned.
+ *     vm_region:
  *
- *     The map MUST be locked by the caller and WILL be
- *     locked on exit.  In order to guarantee the
- *     existence of the returned object, it is returned
- *     locked.
+ *     User call to obtain information about a region in
+ *     a task's address map. Currently, only one flavor is
+ *     supported.
  *
- *     If a lookup is requested with "write protection"
- *     specified, the map may be changed to perform virtual
- *     copying operations, although the data referenced will
- *     remain the same.
+ *     XXX The reserved and behavior fields cannot be filled
+ *         in until the vm merge from the IK is completed, and
+ *         vm_reserve is implemented.
  */
+
 kern_return_t
-vm_map_lookup_locked(
-       vm_map_t                *var_map,       /* IN/OUT */
-       register vm_offset_t    vaddr,
-       register vm_prot_t      fault_type,
-       vm_map_version_t        *out_version,   /* OUT */
-       vm_object_t             *object,        /* OUT */
-       vm_object_offset_t      *offset,        /* OUT */
-       vm_prot_t               *out_prot,      /* OUT */
-       boolean_t               *wired,         /* OUT */
-       int                     *behavior,      /* OUT */
-       vm_object_offset_t      *lo_offset,     /* OUT */
-       vm_object_offset_t      *hi_offset,     /* OUT */
-       vm_map_t                *pmap_map)
+vm_map_region(
+       vm_map_t                 map,
+       vm_map_offset_t *address,               /* IN/OUT */
+       vm_map_size_t           *size,                  /* OUT */
+       vm_region_flavor_t       flavor,                /* IN */
+       vm_region_info_t         info,                  /* OUT */
+       mach_msg_type_number_t  *count, /* IN/OUT */
+       mach_port_t             *object_name)           /* OUT */
 {
-       vm_map_entry_t                  entry;
-       register vm_map_t               map = *var_map;
-       vm_map_t                        old_map = *var_map;
-       vm_map_t                        cow_sub_map_parent = VM_MAP_NULL;
-       vm_offset_t                     cow_parent_vaddr;
-       vm_offset_t                     old_start;
-       vm_offset_t                     old_end;
-       register vm_prot_t              prot;
+       vm_map_entry_t          tmp_entry;
+       vm_map_entry_t          entry;
+       vm_map_offset_t         start;
 
-       *pmap_map = map;
-       RetryLookup: ;
+       if (map == VM_MAP_NULL) 
+               return(KERN_INVALID_ARGUMENT);
 
-       /*
-        *      If the map has an interesting hint, try it before calling
-        *      full blown lookup routine.
-        */
+       switch (flavor) {
 
-       mutex_lock(&map->s_lock);
-       entry = map->hint;
-       mutex_unlock(&map->s_lock);
+       case VM_REGION_BASIC_INFO:
+               /* legacy for old 32-bit objects info */
+       {
+               vm_region_basic_info_t  basic;
 
-       if ((entry == vm_map_to_entry(map)) ||
-           (vaddr < entry->vme_start) || (vaddr >= entry->vme_end)) {
-               vm_map_entry_t  tmp_entry;
+               if (*count < VM_REGION_BASIC_INFO_COUNT)
+                       return(KERN_INVALID_ARGUMENT);
 
-               /*
-                *      Entry was either not a valid hint, or the vaddr
-                *      was not contained in the entry, so do a full lookup.
-                */
-               if (!vm_map_lookup_entry(map, vaddr, &tmp_entry)) {
-                       if((cow_sub_map_parent) && (cow_sub_map_parent != map))
-                               vm_map_unlock(cow_sub_map_parent);
-                       if((*pmap_map != map) 
-                                       && (*pmap_map != cow_sub_map_parent))
-                               vm_map_unlock(*pmap_map);
-                       return KERN_INVALID_ADDRESS;
+               basic = (vm_region_basic_info_t) info;
+               *count = VM_REGION_BASIC_INFO_COUNT;
+
+               vm_map_lock_read(map);
+
+               start = *address;
+               if (!vm_map_lookup_entry(map, start, &tmp_entry)) {
+                       if ((entry = tmp_entry->vme_next) == vm_map_to_entry(map)) {
+                               vm_map_unlock_read(map);
+                               return(KERN_INVALID_ADDRESS);
+                       }
+               } else {
+                       entry = tmp_entry;
                }
 
-               entry = tmp_entry;
-       }
-       if(map == old_map) {
-               old_start = entry->vme_start;
-               old_end = entry->vme_end;
+               start = entry->vme_start;
+
+               basic->offset = (uint32_t)entry->offset;
+               basic->protection = entry->protection;
+               basic->inheritance = entry->inheritance;
+               basic->max_protection = entry->max_protection;
+               basic->behavior = entry->behavior;
+               basic->user_wired_count = entry->user_wired_count;
+               basic->reserved = entry->is_sub_map;
+               *address = start;
+               *size = (entry->vme_end - start);
+
+               if (object_name) *object_name = IP_NULL;
+               if (entry->is_sub_map) {
+                       basic->shared = FALSE;
+               } else {
+                       basic->shared = entry->is_shared;
+               }
+
+               vm_map_unlock_read(map);
+               return(KERN_SUCCESS);
        }
 
-       /*
-        *      Handle submaps.  Drop lock on upper map, submap is
-        *      returned locked.
-        */
+       case VM_REGION_BASIC_INFO_64:
+       {
+               vm_region_basic_info_64_t       basic;
 
-submap_recurse:
-       if (entry->is_sub_map) {
-               vm_offset_t             local_vaddr;
-               vm_offset_t             end_delta;
-               vm_offset_t             start_delta; 
-               vm_offset_t             object_start_delta; 
-               vm_map_entry_t          submap_entry;
-               boolean_t               mapped_needs_copy=FALSE;
+               if (*count < VM_REGION_BASIC_INFO_COUNT_64)
+                       return(KERN_INVALID_ARGUMENT);
 
-               local_vaddr = vaddr;
+               basic = (vm_region_basic_info_64_t) info;
+               *count = VM_REGION_BASIC_INFO_COUNT_64;
 
-               if ((!entry->needs_copy) && (entry->use_pmap)) {
-                       /* if pmap_map equals map we unlock below */
-                       if ((*pmap_map != map) && 
-                                       (*pmap_map != cow_sub_map_parent))
-                               vm_map_unlock(*pmap_map);
-                       *pmap_map = entry->object.sub_map;
-               }
+               vm_map_lock_read(map);
 
-               if(entry->needs_copy) {
-                       if (!mapped_needs_copy) {
-                               if (vm_map_lock_read_to_write(map)) {
-                                       vm_map_lock_read(map);
-                                       if(*pmap_map == entry->object.sub_map)
-                                               *pmap_map = map;
-                                       goto RetryLookup;
-                               }
-                               vm_map_lock_read(entry->object.sub_map);
-                               cow_sub_map_parent = map;
-                               /* reset base to map before cow object */
-                               /* this is the map which will accept   */
-                               /* the new cow object */
-                               old_start = entry->vme_start;
-                               old_end = entry->vme_end;
-                               cow_parent_vaddr = vaddr;
-                               mapped_needs_copy = TRUE;
-                       } else {
-                               vm_map_lock_read(entry->object.sub_map);
-                               if((cow_sub_map_parent != map) &&
-                                                       (*pmap_map != map))
-                                       vm_map_unlock(map);
+               start = *address;
+               if (!vm_map_lookup_entry(map, start, &tmp_entry)) {
+                       if ((entry = tmp_entry->vme_next) == vm_map_to_entry(map)) {
+                               vm_map_unlock_read(map);
+                               return(KERN_INVALID_ADDRESS);
                        }
                } else {
-                       vm_map_lock_read(entry->object.sub_map);
-                       /* leave map locked if it is a target */
-                       /* cow sub_map above otherwise, just  */
-                       /* follow the maps down to the object */
-                       /* here we unlock knowing we are not  */
-                       /* revisiting the map.  */
-                       if((*pmap_map != map) && (map != cow_sub_map_parent))
-                               vm_map_unlock_read(map);
+                       entry = tmp_entry;
                }
 
-               *var_map = map = entry->object.sub_map;
+               start = entry->vme_start;
 
-               /* calculate the offset in the submap for vaddr */
-               local_vaddr = (local_vaddr - entry->vme_start) + entry->offset;
+               basic->offset = entry->offset;
+               basic->protection = entry->protection;
+               basic->inheritance = entry->inheritance;
+               basic->max_protection = entry->max_protection;
+               basic->behavior = entry->behavior;
+               basic->user_wired_count = entry->user_wired_count;
+               basic->reserved = entry->is_sub_map;
+               *address = start;
+               *size = (entry->vme_end - start);
 
-RetrySubMap:
-               if(!vm_map_lookup_entry(map, local_vaddr, &submap_entry)) {
-                       if((cow_sub_map_parent) && (cow_sub_map_parent != map)){
-                               vm_map_unlock(cow_sub_map_parent);
-                       }
-                       if((*pmap_map != map) 
-                                       && (*pmap_map != cow_sub_map_parent)) {
-                               vm_map_unlock(*pmap_map);
-                       }
-                       *pmap_map = map;
-                       return KERN_INVALID_ADDRESS;
+               if (object_name) *object_name = IP_NULL;
+               if (entry->is_sub_map) {
+                       basic->shared = FALSE;
+               } else {
+                       basic->shared = entry->is_shared;
                }
-               /* find the attenuated shadow of the underlying object */
-               /* on our target map */
 
-               /* in english the submap object may extend beyond the     */
-               /* region mapped by the entry or, may only fill a portion */
-               /* of it.  For our purposes, we only care if the object   */
-               /* doesn't fill.  In this case the area which will        */
-               /* ultimately be clipped in the top map will only need    */
-               /* to be as big as the portion of the underlying entry    */
-               /* which is mapped */
-               start_delta = submap_entry->vme_start > entry->offset ?
-                           submap_entry->vme_start - entry->offset : 0;
+               vm_map_unlock_read(map);
+               return(KERN_SUCCESS);
+       }
+       case VM_REGION_EXTENDED_INFO:
+       {
+               vm_region_extended_info_t       extended;
 
-               end_delta = 
-                  (entry->offset + start_delta + (old_end - old_start)) <=
-                       submap_entry->vme_end ?
-                               0 : (entry->offset + 
-                                       (old_end - old_start))
-                                       - submap_entry->vme_end; 
+               if (*count < VM_REGION_EXTENDED_INFO_COUNT)
+                       return(KERN_INVALID_ARGUMENT);
 
-               old_start += start_delta;
-               old_end -= end_delta;
+               extended = (vm_region_extended_info_t) info;
+               *count = VM_REGION_EXTENDED_INFO_COUNT;
 
-               if(submap_entry->is_sub_map) {
-                       entry = submap_entry;
-                       vaddr = local_vaddr;
-                       goto submap_recurse;
+               vm_map_lock_read(map);
+
+               start = *address;
+               if (!vm_map_lookup_entry(map, start, &tmp_entry)) {
+                       if ((entry = tmp_entry->vme_next) == vm_map_to_entry(map)) {
+                               vm_map_unlock_read(map);
+                               return(KERN_INVALID_ADDRESS);
+                       }
+               } else {
+                       entry = tmp_entry;
                }
+               start = entry->vme_start;
 
-               if(((fault_type & VM_PROT_WRITE) && cow_sub_map_parent)) {
+               extended->protection = entry->protection;
+               extended->user_tag = entry->alias;
+               extended->pages_resident = 0;
+               extended->pages_swapped_out = 0;
+               extended->pages_shared_now_private = 0;
+               extended->pages_dirtied = 0;
+               extended->external_pager = 0;
+               extended->shadow_depth = 0;
 
-                       vm_object_t     copy_object;
-                       vm_offset_t     local_start;
-                       vm_offset_t     local_end;
-                       boolean_t               copied_slowly = FALSE;
+               vm_map_region_walk(map, start, entry, entry->offset, entry->vme_end - start, extended, TRUE);
 
-                       if (vm_map_lock_read_to_write(map)) {
-                               vm_map_lock_read(map);
-                               old_start -= start_delta;
-                               old_end += end_delta;
-                               goto RetrySubMap;
-                       }
+               if (extended->external_pager && extended->ref_count == 2 && extended->share_mode == SM_SHARED)
+                       extended->share_mode = SM_PRIVATE;
 
+               if (object_name)
+                       *object_name = IP_NULL;
+               *address = start;
+               *size = (entry->vme_end - start);
 
-                       if (submap_entry->object.vm_object == VM_OBJECT_NULL) {
-                               submap_entry->object.vm_object = 
-                                       vm_object_allocate(
-                                               (vm_size_t)
-                                               (submap_entry->vme_end 
-                                               - submap_entry->vme_start));
-                                       submap_entry->offset = 0;
+               vm_map_unlock_read(map);
+               return(KERN_SUCCESS);
+       }
+       case VM_REGION_TOP_INFO:
+       {   
+               vm_region_top_info_t    top;
+
+               if (*count < VM_REGION_TOP_INFO_COUNT)
+                       return(KERN_INVALID_ARGUMENT);
+
+               top = (vm_region_top_info_t) info;
+               *count = VM_REGION_TOP_INFO_COUNT;
+
+               vm_map_lock_read(map);
+
+               start = *address;
+               if (!vm_map_lookup_entry(map, start, &tmp_entry)) {
+                       if ((entry = tmp_entry->vme_next) == vm_map_to_entry(map)) {
+                               vm_map_unlock_read(map);
+                               return(KERN_INVALID_ADDRESS);
                        }
-                       local_start =  local_vaddr - 
-                                       (cow_parent_vaddr - old_start);
-                       local_end = local_vaddr + 
-                                       (old_end - cow_parent_vaddr);
-                       vm_map_clip_start(map, submap_entry, local_start);
-                       vm_map_clip_end(map, submap_entry, local_end);
+               } else {
+                       entry = tmp_entry;
 
-                       /* This is the COW case, lets connect */
-                       /* an entry in our space to the underlying */
-                       /* object in the submap, bypassing the  */
-                       /* submap. */
+               }
+               start = entry->vme_start;
+
+               top->private_pages_resident = 0;
+               top->shared_pages_resident = 0;
 
+               vm_map_region_top_walk(entry, top);
+
+               if (object_name)
+                       *object_name = IP_NULL;
+               *address = start;
+               *size = (entry->vme_end - start);
+
+               vm_map_unlock_read(map);
+               return(KERN_SUCCESS);
+       }
+       default:
+               return(KERN_INVALID_ARGUMENT);
+       }
+}
+
+#define OBJ_RESIDENT_COUNT(obj, entry_size)                            \
+       MIN((entry_size),                                               \
+           ((obj)->all_reusable ?                                      \
+            (obj)->wired_page_count :                                  \
+            (obj)->resident_page_count - (obj)->reusable_page_count))
+
+void
+vm_map_region_top_walk(
+        vm_map_entry_t            entry,
+       vm_region_top_info_t       top)
+{
 
-                       if(submap_entry->wired_count != 0) {
-                                       vm_object_lock(
-                                            submap_entry->object.vm_object);
-                                       vm_object_copy_slowly(
-                                               submap_entry->object.vm_object,
-                                               submap_entry->offset,
-                                               submap_entry->vme_end -
-                                                       submap_entry->vme_start,
-                                               FALSE,
-                                               &copy_object);
-                                       copied_slowly = TRUE;
-                       } else {
-                               
-                               /* set up shadow object */
-                               copy_object = submap_entry->object.vm_object;
-                               vm_object_reference(copy_object);
-                               submap_entry->object.vm_object->shadowed = TRUE;
-                               submap_entry->needs_copy = TRUE;
-                               vm_object_pmap_protect(
-                                       submap_entry->object.vm_object,
-                                       submap_entry->offset,
-                                       submap_entry->vme_end - 
-                                               submap_entry->vme_start,
-                                       (submap_entry->is_shared 
-                                               || map->mapped) ?
-                                               PMAP_NULL : map->pmap,
-                                       submap_entry->vme_start,
-                                       submap_entry->protection &
-                                               ~VM_PROT_WRITE);
-                       }
-                       
+       if (entry->object.vm_object == 0 || entry->is_sub_map) {
+               top->share_mode = SM_EMPTY;
+               top->ref_count = 0;
+               top->obj_id = 0;
+               return;
+       }
 
-                       /* This works diffently than the   */
-                       /* normal submap case. We go back  */
-                       /* to the parent of the cow map and*/
-                       /* clip out the target portion of  */
-                       /* the sub_map, substituting the   */
-                       /* new copy object,                */
+       {
+               struct  vm_object *obj, *tmp_obj;
+               int             ref_count;
+               uint32_t        entry_size;
 
-                       vm_map_unlock(map);
-                       local_start = old_start;
-                       local_end = old_end;
-                       map = cow_sub_map_parent;
-                       *var_map = cow_sub_map_parent;
-                       vaddr = cow_parent_vaddr;
-                       cow_sub_map_parent = NULL;
+               entry_size = (uint32_t) ((entry->vme_end - entry->vme_start) / PAGE_SIZE_64);
 
-                       if(!vm_map_lookup_entry(map, 
-                                       vaddr, &entry)) {
-                                       vm_object_deallocate(
-                                                       copy_object);
-                                       vm_map_lock_write_to_read(map);
-                                       return KERN_INVALID_ADDRESS;
-                       }
-                                       
-                       /* clip out the portion of space */
-                       /* mapped by the sub map which   */
-                       /* corresponds to the underlying */
-                       /* object */
-                       vm_map_clip_start(map, entry, local_start);
-                       vm_map_clip_end(map, entry, local_end);
+               obj = entry->object.vm_object;
 
+               vm_object_lock(obj);
 
-                       /* substitute copy object for */
-                       /* shared map entry           */
-                       vm_map_deallocate(entry->object.sub_map);
-                       entry->is_sub_map = FALSE;
-                       entry->object.vm_object = copy_object;
+               if ((ref_count = obj->ref_count) > 1 && obj->paging_in_progress)
+                       ref_count--;
 
-                       entry->protection |= VM_PROT_WRITE;
-                       entry->max_protection |= VM_PROT_WRITE;
-                       if(copied_slowly) {
-                               entry->offset = 0;
-                               entry->needs_copy = FALSE;
-                               entry->is_shared = FALSE;
-                       } else {
-                               entry->offset = submap_entry->offset;
-                               entry->needs_copy = TRUE;
-                               if(entry->inheritance == VM_INHERIT_SHARE) 
-                                       entry->inheritance = VM_INHERIT_COPY;
-                               if (map != old_map)
-                                       entry->is_shared = TRUE;
+               assert(obj->reusable_page_count <= obj->resident_page_count);
+               if (obj->shadow) {
+                       if (ref_count == 1)
+                               top->private_pages_resident =
+                                       OBJ_RESIDENT_COUNT(obj, entry_size);
+                       else
+                               top->shared_pages_resident =
+                                       OBJ_RESIDENT_COUNT(obj, entry_size);
+                       top->ref_count  = ref_count;
+                       top->share_mode = SM_COW;
+           
+                       while ((tmp_obj = obj->shadow)) {
+                               vm_object_lock(tmp_obj);
+                               vm_object_unlock(obj);
+                               obj = tmp_obj;
+
+                               if ((ref_count = obj->ref_count) > 1 && obj->paging_in_progress)
+                                       ref_count--;
+
+                               assert(obj->reusable_page_count <= obj->resident_page_count);
+                               top->shared_pages_resident +=
+                                       OBJ_RESIDENT_COUNT(obj, entry_size);
+                               top->ref_count += ref_count - 1;
                        }
-                       if(entry->inheritance == VM_INHERIT_SHARE) 
-                               entry->inheritance = VM_INHERIT_COPY;
-
-                       vm_map_lock_write_to_read(map);
                } else {
-                       if((cow_sub_map_parent)
-                                       && (cow_sub_map_parent != *pmap_map)
-                                       && (cow_sub_map_parent != map)) {
-                               vm_map_unlock(cow_sub_map_parent);
+                       if (entry->needs_copy) {
+                               top->share_mode = SM_COW;
+                               top->shared_pages_resident =
+                                       OBJ_RESIDENT_COUNT(obj, entry_size);
+                       } else {
+                               if (ref_count == 1 ||
+                                   (ref_count == 2 && !(obj->pager_trusted) && !(obj->internal))) {
+                                       top->share_mode = SM_PRIVATE;
+                                       top->private_pages_resident =
+                                               OBJ_RESIDENT_COUNT(obj,
+                                                                  entry_size);
+                               } else {
+                                       top->share_mode = SM_SHARED;
+                                       top->shared_pages_resident =
+                                               OBJ_RESIDENT_COUNT(obj,
+                                                                 entry_size);
+                               }
                        }
-                       entry = submap_entry;
-                       vaddr = local_vaddr;
+                       top->ref_count = ref_count;
                }
-       }
-               
-       /*
-        *      Check whether this task is allowed to have
-        *      this page.
-        */
+               /* XXX K64: obj_id will be truncated */
+               top->obj_id = (unsigned int) (uintptr_t)obj;
 
-       prot = entry->protection;
-       if ((fault_type & (prot)) != fault_type) {
-         if (*pmap_map != map) {
-               vm_map_unlock(*pmap_map);
-         }
-         *pmap_map = map;
-         return KERN_PROTECTION_FAILURE;
+               vm_object_unlock(obj);
        }
+}
 
-       /*
-        *      If this page is not pageable, we have to get
-        *      it for all possible accesses.
-        */
-
-       if (*wired = (entry->wired_count != 0))
-               prot = fault_type = entry->protection;
-
-       /*
-        *      If the entry was copy-on-write, we either ...
-        */
+void
+vm_map_region_walk(
+       vm_map_t                        map,
+       vm_map_offset_t                 va,
+       vm_map_entry_t                  entry,
+       vm_object_offset_t              offset,
+       vm_object_size_t                range,
+       vm_region_extended_info_t       extended,
+       boolean_t                       look_for_pages)
+{
+        register struct vm_object *obj, *tmp_obj;
+       register vm_map_offset_t       last_offset;
+       register int               i;
+       register int               ref_count;
+       struct vm_object        *shadow_object;
+       int                     shadow_depth;
 
-       if (entry->needs_copy) {
-               /*
-                *      If we want to write the page, we may as well
-                *      handle that now since we've got the map locked.
-                *
-                *      If we don't need to write the page, we just
-                *      demote the permissions allowed.
-                */
+       if ((entry->object.vm_object == 0) ||
+           (entry->is_sub_map) ||
+           (entry->object.vm_object->phys_contiguous)) {
+               extended->share_mode = SM_EMPTY;
+               extended->ref_count = 0;
+               return;
+       }
+       {
+               obj = entry->object.vm_object;
 
-               if (fault_type & VM_PROT_WRITE || *wired) {
-                       /*
-                        *      Make a new object, and place it in the
-                        *      object chain.  Note that no new references
-                        *      have appeared -- one just moved from the
-                        *      map to the new object.
-                        */
+               vm_object_lock(obj);
 
-                       if (vm_map_lock_read_to_write(map)) {
-                               vm_map_lock_read(map);
-                               goto RetryLookup;
+               if ((ref_count = obj->ref_count) > 1 && obj->paging_in_progress)
+                       ref_count--;
+
+               if (look_for_pages) {
+                       for (last_offset = offset + range;
+                            offset < last_offset;
+                            offset += PAGE_SIZE_64, va += PAGE_SIZE)
+                               vm_map_region_look_for_page(map, va, obj,
+                                                           offset, ref_count,
+                                                           0, extended);
+               } else {
+                       shadow_object = obj->shadow;
+                       shadow_depth = 0;
+
+                       if ( !(obj->pager_trusted) && !(obj->internal))
+                               extended->external_pager = 1;
+
+                       if (shadow_object != VM_OBJECT_NULL) {
+                               vm_object_lock(shadow_object);
+                               for (;
+                                    shadow_object != VM_OBJECT_NULL;
+                                    shadow_depth++) {
+                                       vm_object_t     next_shadow;
+
+                                       if ( !(shadow_object->pager_trusted) &&
+                                            !(shadow_object->internal))
+                                               extended->external_pager = 1;
+
+                                       next_shadow = shadow_object->shadow;
+                                       if (next_shadow) {
+                                               vm_object_lock(next_shadow);
+                                       }
+                                       vm_object_unlock(shadow_object);
+                                       shadow_object = next_shadow;
+                               }
                        }
-                       vm_object_shadow(&entry->object.vm_object,
-                                        &entry->offset,
-                                        (vm_size_t) (entry->vme_end -
-                                                     entry->vme_start));
-
-                       entry->object.vm_object->shadowed = TRUE;
-                       entry->needs_copy = FALSE;
-                       vm_map_lock_write_to_read(map);
+                       extended->shadow_depth = shadow_depth;
                }
-               else {
-                       /*
-                        *      We're attempting to read a copy-on-write
-                        *      page -- don't allow writes.
-                        */
 
-                       prot &= (~VM_PROT_WRITE);
+               if (extended->shadow_depth || entry->needs_copy)
+                       extended->share_mode = SM_COW;
+               else {
+                       if (ref_count == 1)
+                               extended->share_mode = SM_PRIVATE;
+                       else {
+                               if (obj->true_share)
+                                       extended->share_mode = SM_TRUESHARED;
+                               else
+                                       extended->share_mode = SM_SHARED;
+                       }
                }
-       }
+               extended->ref_count = ref_count - extended->shadow_depth;
+           
+               for (i = 0; i < extended->shadow_depth; i++) {
+                       if ((tmp_obj = obj->shadow) == 0)
+                               break;
+                       vm_object_lock(tmp_obj);
+                       vm_object_unlock(obj);
 
-       /*
-        *      Create an object if necessary.
-        */
-       if (entry->object.vm_object == VM_OBJECT_NULL) {
+                       if ((ref_count = tmp_obj->ref_count) > 1 && tmp_obj->paging_in_progress)
+                               ref_count--;
 
-               if (vm_map_lock_read_to_write(map)) {
-                       vm_map_lock_read(map);
-                       goto RetryLookup;
+                       extended->ref_count += ref_count;
+                       obj = tmp_obj;
                }
+               vm_object_unlock(obj);
 
-               entry->object.vm_object = vm_object_allocate(
-                       (vm_size_t)(entry->vme_end - entry->vme_start));
-               entry->offset = 0;
-               vm_map_lock_write_to_read(map);
+               if (extended->share_mode == SM_SHARED) {
+                       register vm_map_entry_t      cur;
+                       register vm_map_entry_t      last;
+                       int      my_refs;
+
+                       obj = entry->object.vm_object;
+                       last = vm_map_to_entry(map);
+                       my_refs = 0;
+
+                       if ((ref_count = obj->ref_count) > 1 && obj->paging_in_progress)
+                               ref_count--;
+                       for (cur = vm_map_first_entry(map); cur != last; cur = cur->vme_next)
+                               my_refs += vm_map_region_count_obj_refs(cur, obj);
+
+                       if (my_refs == ref_count)
+                               extended->share_mode = SM_PRIVATE_ALIASED;
+                       else if (my_refs > 1)
+                               extended->share_mode = SM_SHARED_ALIASED;
+               }
        }
+}
 
-       /*
-        *      Return the object/offset from this entry.  If the entry
-        *      was copy-on-write or empty, it has been fixed up.  Also
-        *      return the protection.
-        */
 
-        *offset = (vaddr - entry->vme_start) + entry->offset;
-        *object = entry->object.vm_object;
-       *out_prot = prot;
-       *behavior = entry->behavior;
-       *lo_offset = entry->offset;
-       *hi_offset = (entry->vme_end - entry->vme_start) + entry->offset;
+/* object is locked on entry and locked on return */
 
-       /*
-        *      Lock the object to prevent it from disappearing
-        */
 
-       vm_object_lock(*object);
+static void
+vm_map_region_look_for_page(
+       __unused vm_map_t               map,
+       __unused vm_map_offset_t        va,
+       vm_object_t                     object,
+       vm_object_offset_t              offset,
+       int                             max_refcnt,
+       int                             depth,
+       vm_region_extended_info_t       extended)
+{
+        register vm_page_t     p;
+        register vm_object_t   shadow;
+       register int            ref_count;
+       vm_object_t             caller_object;
+#if    MACH_PAGEMAP
+       kern_return_t           kr;
+#endif
+       shadow = object->shadow;
+       caller_object = object;
 
-       /*
-        *      Save the version number
-        */
+       
+       while (TRUE) {
 
-       out_version->main_timestamp = map->timestamp;
+               if ( !(object->pager_trusted) && !(object->internal))
+                       extended->external_pager = 1;
 
-       return KERN_SUCCESS;
-}
+               if ((p = vm_page_lookup(object, offset)) != VM_PAGE_NULL) {
+                       if (shadow && (max_refcnt == 1))
+                               extended->pages_shared_now_private++;
 
+                       if (!p->fictitious && 
+                           (p->dirty || pmap_is_modified(p->phys_page)))
+                               extended->pages_dirtied++;
 
-/*
- *     vm_map_verify:
- *
- *     Verifies that the map in question has not changed
- *     since the given version.  If successful, the map
- *     will not change until vm_map_verify_done() is called.
- */
-boolean_t
-vm_map_verify(
-       register vm_map_t               map,
-       register vm_map_version_t       *version)       /* REF */
-{
-       boolean_t       result;
+                       extended->pages_resident++;
 
-       vm_map_lock_read(map);
-       result = (map->timestamp == version->main_timestamp);
+                       if(object != caller_object)
+                               vm_object_unlock(object);
 
-       if (!result)
-               vm_map_unlock_read(map);
+                       return;
+               }
+#if    MACH_PAGEMAP
+               if (object->existence_map) {
+                       if (vm_external_state_get(object->existence_map, offset) == VM_EXTERNAL_STATE_EXISTS) {
 
-       return(result);
-}
+                               extended->pages_swapped_out++;
 
-/*
- *     vm_map_verify_done:
- *
- *     Releases locks acquired by a vm_map_verify.
- *
- *     This is now a macro in vm/vm_map.h.  It does a
- *     vm_map_unlock_read on the map.
- */
+                               if(object != caller_object)
+                                       vm_object_unlock(object);
 
+                               return;
+                       }
+               } else if (object->internal &&
+                          object->alive &&
+                          !object->terminating &&
+                          object->pager_ready) {
 
-/*
- *     vm_region:
- *
- *     User call to obtain information about a region in
- *     a task's address map. Currently, only one flavor is
- *     supported.
- *
- *     XXX The reserved and behavior fields cannot be filled
- *         in until the vm merge from the IK is completed, and
- *         vm_reserve is implemented.
- *
- *     XXX Dependency: syscall_vm_region() also supports only one flavor.
- */
+                       memory_object_t pager;
 
-kern_return_t
-vm_region(
-       vm_map_t                 map,
-       vm_offset_t             *address,               /* IN/OUT */
-       vm_size_t               *size,                  /* OUT */
-       vm_region_flavor_t       flavor,                /* IN */
-       vm_region_info_t         info,                  /* OUT */
-       mach_msg_type_number_t  *count,                 /* IN/OUT */
-       ipc_port_t              *object_name)           /* OUT */
-{
-       vm_map_entry_t          tmp_entry;
-       register
-       vm_map_entry_t          entry;
-       register
-       vm_offset_t             start;
-       vm_region_basic_info_t  basic;
-       vm_region_extended_info_t       extended;
-       vm_region_top_info_t    top;
+                       vm_object_paging_begin(object);
+                       pager = object->pager;
+                       vm_object_unlock(object);
 
-       if (map == VM_MAP_NULL) 
-               return(KERN_INVALID_ARGUMENT);
+                       kr = memory_object_data_request(
+                               pager,
+                               offset + object->paging_offset,
+                               0, /* just poke the pager */
+                               VM_PROT_READ,
+                               NULL);
 
-       switch (flavor) {
-       
-       case VM_REGION_BASIC_INFO:
-       {
-           if (*count < VM_REGION_BASIC_INFO_COUNT)
-               return(KERN_INVALID_ARGUMENT);
+                       vm_object_lock(object);
+                       vm_object_paging_end(object);
+
+                       if (kr == KERN_SUCCESS) {
+                               /* the pager has that page */
+                               extended->pages_swapped_out++;
+                               if (object != caller_object)
+                                       vm_object_unlock(object);
+                               return;
+                       }
+               }
+#endif /* MACH_PAGEMAP */
+
+               if (shadow) {
+                       vm_object_lock(shadow);
 
-           basic = (vm_region_basic_info_t) info;
-           *count = VM_REGION_BASIC_INFO_COUNT;
+                       if ((ref_count = shadow->ref_count) > 1 && shadow->paging_in_progress)
+                               ref_count--;
 
-           vm_map_lock_read(map);
+                       if (++depth > extended->shadow_depth)
+                               extended->shadow_depth = depth;
 
-           start = *address;
-           if (!vm_map_lookup_entry(map, start, &tmp_entry)) {
-               if ((entry = tmp_entry->vme_next) == vm_map_to_entry(map)) {
-                       vm_map_unlock_read(map);
-                       return(KERN_INVALID_ADDRESS);
+                       if (ref_count > max_refcnt)
+                               max_refcnt = ref_count;
+                       
+                       if(object != caller_object)
+                               vm_object_unlock(object);
+
+                       offset = offset + object->shadow_offset;
+                       object = shadow;
+                       shadow = object->shadow;
+                       continue;
                }
-           } else {
-               entry = tmp_entry;
-           }
-
-           start = entry->vme_start;
-
-           basic->offset = entry->offset;
-           basic->protection = entry->protection;
-           basic->inheritance = entry->inheritance;
-           basic->max_protection = entry->max_protection;
-           basic->behavior = entry->behavior;
-           basic->user_wired_count = entry->user_wired_count;
-           basic->reserved = entry->is_sub_map;
-           *address = start;
-           *size = (entry->vme_end - start);
-
-           if (object_name) *object_name = IP_NULL;
-           if (entry->is_sub_map) {
-               basic->shared = FALSE;
-           } else {
-               basic->shared = entry->is_shared;
-           }
-
-           vm_map_unlock_read(map);
-           return(KERN_SUCCESS);
+               if(object != caller_object)
+                       vm_object_unlock(object);
+               break;
        }
-       case VM_REGION_EXTENDED_INFO:
-       {
+}
 
-           if (*count < VM_REGION_EXTENDED_INFO_COUNT)
-               return(KERN_INVALID_ARGUMENT);
+static int
+vm_map_region_count_obj_refs(
+        vm_map_entry_t    entry,
+       vm_object_t       object)
+{
+        register int ref_count;
+       register vm_object_t chk_obj;
+       register vm_object_t tmp_obj;
 
-           extended = (vm_region_extended_info_t) info;
-           *count = VM_REGION_EXTENDED_INFO_COUNT;
+       if (entry->object.vm_object == 0)
+               return(0);
 
-           vm_map_lock_read(map);
+        if (entry->is_sub_map)
+               return(0);
+       else {
+               ref_count = 0;
 
-           start = *address;
-           if (!vm_map_lookup_entry(map, start, &tmp_entry)) {
-               if ((entry = tmp_entry->vme_next) == vm_map_to_entry(map)) {
-                       vm_map_unlock_read(map);
-                       return(KERN_INVALID_ADDRESS);
-               }
-           } else {
-               entry = tmp_entry;
-           }
-           start = entry->vme_start;
+               chk_obj = entry->object.vm_object;
+               vm_object_lock(chk_obj);
 
-           extended->protection = entry->protection;
-           extended->user_tag = entry->alias;
-           extended->pages_resident = 0;
-           extended->pages_swapped_out = 0;
-           extended->pages_shared_now_private = 0;
-           extended->pages_dirtied = 0;
-           extended->external_pager = 0;
-           extended->shadow_depth = 0;
+               while (chk_obj) {
+                       if (chk_obj == object)
+                               ref_count++;
+                       tmp_obj = chk_obj->shadow;
+                       if (tmp_obj)
+                               vm_object_lock(tmp_obj);
+                       vm_object_unlock(chk_obj);
 
-           vm_region_walk(entry, extended, entry->offset, entry->vme_end - start, map, start);
+                       chk_obj = tmp_obj;
+               }
+       }
+       return(ref_count);
+}
 
-           if (extended->external_pager && extended->ref_count == 2 && extended->share_mode == SM_SHARED)
-                   extended->share_mode = SM_PRIVATE;
 
-           if (object_name)
-               *object_name = IP_NULL;
-           *address = start;
-           *size = (entry->vme_end - start);
+/*
+ *     Routine:        vm_map_simplify
+ *
+ *     Description:
+ *             Attempt to simplify the map representation in
+ *             the vicinity of the given starting address.
+ *     Note:
+ *             This routine is intended primarily to keep the
+ *             kernel maps more compact -- they generally don't
+ *             benefit from the "expand a map entry" technology
+ *             at allocation time because the adjacent entry
+ *             is often wired down.
+ */
+void
+vm_map_simplify_entry(
+       vm_map_t        map,
+       vm_map_entry_t  this_entry)
+{
+       vm_map_entry_t  prev_entry;
 
-           vm_map_unlock_read(map);
-           return(KERN_SUCCESS);
+       counter(c_vm_map_simplify_entry_called++);
+
+       prev_entry = this_entry->vme_prev;
+
+       if ((this_entry != vm_map_to_entry(map)) &&
+           (prev_entry != vm_map_to_entry(map)) &&
+
+           (prev_entry->vme_end == this_entry->vme_start) &&
+
+           (prev_entry->is_sub_map == this_entry->is_sub_map) &&
+
+           (prev_entry->object.vm_object == this_entry->object.vm_object) &&
+           ((prev_entry->offset + (prev_entry->vme_end -
+                                   prev_entry->vme_start))
+            == this_entry->offset) &&
+
+           (prev_entry->inheritance == this_entry->inheritance) &&
+           (prev_entry->protection == this_entry->protection) &&
+           (prev_entry->max_protection == this_entry->max_protection) &&
+           (prev_entry->behavior == this_entry->behavior) &&
+           (prev_entry->alias == this_entry->alias) &&
+           (prev_entry->zero_wired_pages == this_entry->zero_wired_pages) &&
+           (prev_entry->no_cache == this_entry->no_cache) &&
+           (prev_entry->wired_count == this_entry->wired_count) &&
+           (prev_entry->user_wired_count == this_entry->user_wired_count) &&
+
+           (prev_entry->needs_copy == this_entry->needs_copy) &&
+           (prev_entry->permanent == this_entry->permanent) &&
+
+           (prev_entry->use_pmap == FALSE) &&
+           (this_entry->use_pmap == FALSE) &&
+           (prev_entry->in_transition == FALSE) &&
+           (this_entry->in_transition == FALSE) &&
+           (prev_entry->needs_wakeup == FALSE) &&
+           (this_entry->needs_wakeup == FALSE) &&
+           (prev_entry->is_shared == FALSE) &&
+           (this_entry->is_shared == FALSE)
+               ) {
+               _vm_map_entry_unlink(&map->hdr, prev_entry);
+               this_entry->vme_start = prev_entry->vme_start;
+               this_entry->offset = prev_entry->offset;
+               if (prev_entry->is_sub_map) {
+                       vm_map_deallocate(prev_entry->object.sub_map);
+               } else {
+                       vm_object_deallocate(prev_entry->object.vm_object);
+               }
+               vm_map_entry_dispose(map, prev_entry);
+               SAVE_HINT_MAP_WRITE(map, this_entry);
+               counter(c_vm_map_simplified++);
        }
-       case VM_REGION_TOP_INFO:
-       {   
-
-           if (*count < VM_REGION_TOP_INFO_COUNT)
-               return(KERN_INVALID_ARGUMENT);
-
-           top = (vm_region_top_info_t) info;
-           *count = VM_REGION_TOP_INFO_COUNT;
+}
 
-           vm_map_lock_read(map);
+void
+vm_map_simplify(
+       vm_map_t        map,
+       vm_map_offset_t start)
+{
+       vm_map_entry_t  this_entry;
 
-           start = *address;
-           if (!vm_map_lookup_entry(map, start, &tmp_entry)) {
-               if ((entry = tmp_entry->vme_next) == vm_map_to_entry(map)) {
-                       vm_map_unlock_read(map);
-                       return(KERN_INVALID_ADDRESS);
-               }
-           } else {
-               entry = tmp_entry;
+       vm_map_lock(map);
+       if (vm_map_lookup_entry(map, start, &this_entry)) {
+               vm_map_simplify_entry(map, this_entry);
+               vm_map_simplify_entry(map, this_entry->vme_next);
+       }
+       counter(c_vm_map_simplify_called++);
+       vm_map_unlock(map);
+}
 
-           }
-           start = entry->vme_start;
+static void
+vm_map_simplify_range(
+       vm_map_t        map,
+       vm_map_offset_t start,
+       vm_map_offset_t end)
+{
+       vm_map_entry_t  entry;
 
-           top->private_pages_resident = 0;
-           top->shared_pages_resident = 0;
+       /*
+        * The map should be locked (for "write") by the caller.
+        */
 
-           vm_region_top_walk(entry, top);
+       if (start >= end) {
+               /* invalid address range */
+               return;
+       }
 
-           if (object_name)
-               *object_name = IP_NULL;
-           *address = start;
-           *size = (entry->vme_end - start);
+       start = vm_map_trunc_page(start);
+       end = vm_map_round_page(end);
 
-           vm_map_unlock_read(map);
-           return(KERN_SUCCESS);
+       if (!vm_map_lookup_entry(map, start, &entry)) {
+               /* "start" is not mapped and "entry" ends before "start" */
+               if (entry == vm_map_to_entry(map)) {
+                       /* start with first entry in the map */
+                       entry = vm_map_first_entry(map);
+               } else {
+                       /* start with next entry */
+                       entry = entry->vme_next;
+               }
        }
-       default:
-           return(KERN_INVALID_ARGUMENT);
+               
+       while (entry != vm_map_to_entry(map) &&
+              entry->vme_start <= end) {
+               /* try and coalesce "entry" with its previous entry */
+               vm_map_simplify_entry(map, entry);
+               entry = entry->vme_next;
        }
 }
 
+
 /*
- *     vm_region_recurse: A form of vm_region which follows the
- *     submaps in a target map
- *
+ *     Routine:        vm_map_machine_attribute
+ *     Purpose:
+ *             Provide machine-specific attributes to mappings,
+ *             such as cachability etc. for machines that provide
+ *             them.  NUMA architectures and machines with big/strange
+ *             caches will use this.
+ *     Note:
+ *             Responsibilities for locking and checking are handled here,
+ *             everything else in the pmap module. If any non-volatile
+ *             information must be kept, the pmap module should handle
+ *             it itself. [This assumes that attributes do not
+ *             need to be inherited, which seems ok to me]
  */
-
 kern_return_t
-vm_region_recurse(
-       vm_map_t                 map,
-       vm_offset_t             *address,               /* IN/OUT */
-       vm_size_t               *size,                  /* OUT */
-       natural_t               *nesting_depth,         /* IN/OUT */
-       vm_region_recurse_info_t info,                  /* IN/OUT */
-       mach_msg_type_number_t  *count)                 /* IN/OUT */
+vm_map_machine_attribute(
+       vm_map_t                        map,
+       vm_map_offset_t         start,
+       vm_map_offset_t         end,
+       vm_machine_attribute_t  attribute,
+       vm_machine_attribute_val_t* value)              /* IN/OUT */
 {
-       vm_map_entry_t          tmp_entry;
-       register
-       vm_map_entry_t          entry;
-       register
-       vm_offset_t             start;
-
-       unsigned int                    recurse_count;
-       vm_map_t                        submap;
-       vm_map_t                        base_map;
-       vm_map_entry_t                  base_entry;
-       vm_offset_t                     base_next;
-       vm_offset_t                     base_addr;
-       vm_offset_t                     baddr_start_delta;
-       vm_region_submap_info_t         submap_info;
-       vm_region_extended_info_data_t  extended;
+       kern_return_t   ret;
+       vm_map_size_t sync_size;
+       vm_map_entry_t entry;
+       
+       if (start < vm_map_min(map) || end > vm_map_max(map))
+               return KERN_INVALID_ADDRESS;
 
-       if (map == VM_MAP_NULL) 
-               return(KERN_INVALID_ARGUMENT);
+       /* Figure how much memory we need to flush (in page increments) */
+       sync_size = end - start;
+
+       vm_map_lock(map);
+       
+       if (attribute != MATTR_CACHE) { 
+               /* If we don't have to find physical addresses, we */
+               /* don't have to do an explicit traversal here.    */
+               ret = pmap_attribute(map->pmap, start, end-start,
+                                    attribute, value);
+               vm_map_unlock(map);
+               return ret;
+       }
 
-       submap_info = (vm_region_submap_info_t) info;
-       *count = VM_REGION_SUBMAP_INFO_COUNT;
+       ret = KERN_SUCCESS;                                                                             /* Assume it all worked */
 
-       if (*count < VM_REGION_SUBMAP_INFO_COUNT)
-               return(KERN_INVALID_ARGUMENT);
+       while(sync_size) {
+               if (vm_map_lookup_entry(map, start, &entry)) {
+                       vm_map_size_t   sub_size;
+                       if((entry->vme_end - start) > sync_size) {
+                               sub_size = sync_size;
+                               sync_size = 0;
+                       } else {
+                               sub_size = entry->vme_end - start;
+                               sync_size -= sub_size;
+                       }
+                       if(entry->is_sub_map) {
+                               vm_map_offset_t sub_start;
+                               vm_map_offset_t sub_end;
 
-       start = *address;
-       base_map = map;
-       recurse_count = *nesting_depth;
+                               sub_start = (start - entry->vme_start) 
+                                       + entry->offset;
+                               sub_end = sub_start + sub_size;
+                               vm_map_machine_attribute(
+                                       entry->object.sub_map, 
+                                       sub_start,
+                                       sub_end,
+                                       attribute, value);
+                       } else {
+                               if(entry->object.vm_object) {
+                                       vm_page_t               m;
+                                       vm_object_t             object;
+                                       vm_object_t             base_object;
+                                       vm_object_t             last_object;
+                                       vm_object_offset_t      offset;
+                                       vm_object_offset_t      base_offset;
+                                       vm_map_size_t           range;
+                                       range = sub_size;
+                                       offset = (start - entry->vme_start)
+                                               + entry->offset;
+                                       base_offset = offset;
+                                       object = entry->object.vm_object;
+                                       base_object = object;
+                                       last_object = NULL;
 
-LOOKUP_NEXT_BASE_ENTRY:
-       vm_map_lock_read(map);
-        if (!vm_map_lookup_entry(map, start, &tmp_entry)) {
-               if ((entry = tmp_entry->vme_next) == vm_map_to_entry(map)) {
-                       vm_map_unlock_read(map);
-                       return(KERN_INVALID_ADDRESS);
+                                       vm_object_lock(object);
+
+                                       while (range) {
+                                               m = vm_page_lookup(
+                                                       object, offset);
+
+                                               if (m && !m->fictitious) {
+                                                       ret = 
+                                                               pmap_attribute_cache_sync(
+                                                                       m->phys_page,   
+                                                                       PAGE_SIZE, 
+                                                                       attribute, value);
+                                                       
+                                               } else if (object->shadow) {
+                                                       offset = offset + object->shadow_offset;
+                                                       last_object = object;
+                                                       object = object->shadow;
+                                                       vm_object_lock(last_object->shadow);
+                                                       vm_object_unlock(last_object);
+                                                       continue;
+                                               }
+                                               range -= PAGE_SIZE;
+
+                                               if (base_object != object) {
+                                                       vm_object_unlock(object);
+                                                       vm_object_lock(base_object);
+                                                       object = base_object;
+                                               }
+                                               /* Bump to the next page */
+                                               base_offset += PAGE_SIZE;
+                                               offset = base_offset;
+                                       }
+                                       vm_object_unlock(object);
+                               }
+                       }
+                       start += sub_size;
+               } else {
+                       vm_map_unlock(map);
+                       return KERN_FAILURE;
                }
-       } else {
-               entry = tmp_entry;
+               
        }
-       *size = entry->vme_end - entry->vme_start;
-       start = entry->vme_start;
-       base_addr = start;
-       baddr_start_delta = *address - start;
-       base_next = entry->vme_end;
-       base_entry = entry;
 
-       while(entry->is_sub_map && recurse_count) {
-               recurse_count--;
-               vm_map_lock_read(entry->object.sub_map);
+       vm_map_unlock(map);
+
+       return ret;
+}
 
+/*
+ *     vm_map_behavior_set:
+ *
+ *     Sets the paging reference behavior of the specified address
+ *     range in the target map.  Paging reference behavior affects
+ *     how pagein operations resulting from faults on the map will be 
+ *     clustered.
+ */
+kern_return_t 
+vm_map_behavior_set(
+       vm_map_t        map,
+       vm_map_offset_t start,
+       vm_map_offset_t end,
+       vm_behavior_t   new_behavior)
+{
+       register vm_map_entry_t entry;
+       vm_map_entry_t  temp_entry;
 
-               if(entry == base_entry) {
-                       start = entry->offset;
-               start += *address - entry->vme_start;
-               }
+       XPR(XPR_VM_MAP,
+           "vm_map_behavior_set, 0x%X start 0x%X end 0x%X behavior %d",
+           map, start, end, new_behavior, 0);
 
-               submap = entry->object.sub_map;
-               vm_map_unlock_read(map);
-               map = submap;
+       switch (new_behavior) {
 
-               if (!vm_map_lookup_entry(map, start, &tmp_entry)) {
-                       if ((entry = tmp_entry->vme_next) 
-                                               == vm_map_to_entry(map)) {
-                               vm_map_unlock_read(map);
-                               map = base_map;
-                               start = base_next;
-                               recurse_count = 0;
-                               *nesting_depth = 0;
-                               goto LOOKUP_NEXT_BASE_ENTRY;
-                       }
-               } else {
-                       entry = tmp_entry;
+       /*
+        * This first block of behaviors all set a persistent state on the specified
+        * memory range.  All we have to do here is to record the desired behavior
+        * in the vm_map_entry_t's.
+        */
 
+       case VM_BEHAVIOR_DEFAULT:
+       case VM_BEHAVIOR_RANDOM:
+       case VM_BEHAVIOR_SEQUENTIAL:
+       case VM_BEHAVIOR_RSEQNTL:
+       case VM_BEHAVIOR_ZERO_WIRED_PAGES:
+               vm_map_lock(map);
+       
+               /*
+                *      The entire address range must be valid for the map.
+                *      Note that vm_map_range_check() does a 
+                *      vm_map_lookup_entry() internally and returns the
+                *      entry containing the start of the address range if
+                *      the entire range is valid.
+                */
+               if (vm_map_range_check(map, start, end, &temp_entry)) {
+                       entry = temp_entry;
+                       vm_map_clip_start(map, entry, start);
                }
-               if(start <= entry->vme_start) {
-                       vm_offset_t     old_start = start;
-                       if(baddr_start_delta) {
-                               base_addr += (baddr_start_delta);
-                               *size -= baddr_start_delta;
-                               baddr_start_delta = 0;
-                       }
-                       if(base_next <= 
-                               (base_addr += (entry->vme_start - start))) {
-                               vm_map_unlock_read(map);
-                               map = base_map;
-                               start = base_next;
-                               recurse_count = 0;
-                               *nesting_depth = 0;
-                               goto LOOKUP_NEXT_BASE_ENTRY;
-                       }
-                       *size -= entry->vme_start - start;
-                       if (*size > (entry->vme_end - entry->vme_start)) {
-                               *size = entry->vme_end - entry->vme_start;
-                       }
-                       start = 0;
-               } else {
-                       if(baddr_start_delta) {
-                               if((start - entry->vme_start) 
-                                               < baddr_start_delta) {
-                                       base_addr += start - entry->vme_start;
-                                       *size -= start - entry->vme_start;
-                               } else {
-                                       base_addr += baddr_start_delta;
-                                       *size += baddr_start_delta;
-                               }
-                               baddr_start_delta = 0;
-                       }
-                       base_addr += entry->vme_start;
-                       if(base_addr >= base_next) {
-                               vm_map_unlock_read(map);
-                               map = base_map;
-                               start = base_next;
-                               recurse_count = 0;
-                               *nesting_depth = 0;
-                               goto LOOKUP_NEXT_BASE_ENTRY;
+               else {
+                       vm_map_unlock(map);
+                       return(KERN_INVALID_ADDRESS);
+               }
+       
+               while ((entry != vm_map_to_entry(map)) && (entry->vme_start < end)) {
+                       vm_map_clip_end(map, entry, end);
+                       assert(!entry->use_pmap);
+       
+                       if( new_behavior == VM_BEHAVIOR_ZERO_WIRED_PAGES ) {
+                               entry->zero_wired_pages = TRUE;
+                       } else {
+                               entry->behavior = new_behavior;
                        }
-                       if (*size > (entry->vme_end - start))
-                               *size = entry->vme_end - start;
-
-                       start = entry->vme_start - start;
+                       entry = entry->vme_next;
                }
+       
+               vm_map_unlock(map);
+               break;
 
-               start += entry->offset;
+       /*
+        * The rest of these are different from the above in that they cause
+        * an immediate action to take place as opposed to setting a behavior that 
+        * affects future actions.
+        */
 
-       }
-       *nesting_depth -= recurse_count;
-       if(entry != base_entry) {
-               start = entry->vme_start + (start - entry->offset);
-       }
+       case VM_BEHAVIOR_WILLNEED:
+               return vm_map_willneed(map, start, end);
 
+       case VM_BEHAVIOR_DONTNEED:
+               return vm_map_msync(map, start, end - start, VM_SYNC_DEACTIVATE | VM_SYNC_CONTIGUOUS);
 
-       submap_info->user_tag = entry->alias;
-       submap_info->offset = entry->offset;
-       submap_info->protection = entry->protection;
-       submap_info->inheritance = entry->inheritance;
-       submap_info->max_protection = entry->max_protection;
-       submap_info->behavior = entry->behavior;
-       submap_info->user_wired_count = entry->user_wired_count;
-       submap_info->is_submap = entry->is_sub_map;
-       submap_info->object_id = (vm_offset_t)entry->object.vm_object;
-       *address = base_addr;
+       case VM_BEHAVIOR_FREE:
+               return vm_map_msync(map, start, end - start, VM_SYNC_KILLPAGES | VM_SYNC_CONTIGUOUS);
 
+       case VM_BEHAVIOR_REUSABLE:
+               return vm_map_reusable_pages(map, start, end);
 
-       extended.pages_resident = 0;
-       extended.pages_swapped_out = 0;
-       extended.pages_shared_now_private = 0;
-       extended.pages_dirtied = 0;
-       extended.external_pager = 0;
-       extended.shadow_depth = 0;
+       case VM_BEHAVIOR_REUSE:
+               return vm_map_reuse_pages(map, start, end);
 
-       if(!entry->is_sub_map) {
-               vm_region_walk(entry, &extended, entry->offset, 
-                               entry->vme_end - start, map, start);
-               submap_info->share_mode = extended.share_mode;
-               if (extended.external_pager && extended.ref_count == 2 
-                                       && extended.share_mode == SM_SHARED)
-                       submap_info->share_mode = SM_PRIVATE;
-               submap_info->ref_count = extended.ref_count;
-       } else {
-               if(entry->use_pmap) 
-                       submap_info->share_mode =  SM_TRUESHARED;
-               else
-                       submap_info->share_mode = SM_PRIVATE;
-               submap_info->ref_count = entry->object.sub_map->ref_count;
-       }
+       case VM_BEHAVIOR_CAN_REUSE:
+               return vm_map_can_reuse(map, start, end);
 
-       submap_info->pages_resident = extended.pages_resident;
-       submap_info->pages_swapped_out = extended.pages_swapped_out;
-       submap_info->pages_shared_now_private = 
-                               extended.pages_shared_now_private;
-       submap_info->pages_dirtied = extended.pages_dirtied;
-       submap_info->external_pager = extended.external_pager;
-       submap_info->shadow_depth = extended.shadow_depth;
+       default:
+               return(KERN_INVALID_ARGUMENT);
+       }
 
-       vm_map_unlock_read(map);
        return(KERN_SUCCESS);
 }
 
+
 /*
- *     TEMPORARYTEMPORARYTEMPORARYTEMPORARYTEMPORARYTEMPORARY
- *     Goes away after regular vm_region_recurse function migrates to
- *     64 bits
- *     vm_region_recurse: A form of vm_region which follows the
- *     submaps in a target map
+ * Internals for madvise(MADV_WILLNEED) system call.
  *
+ * The present implementation is to do a read-ahead if the mapping corresponds
+ * to a mapped regular file.  If it's an anonymous mapping, then we do nothing
+ * and basically ignore the "advice" (which we are always free to do).
  */
 
-kern_return_t
-vm_region_recurse_64(
-       vm_map_t                 map,
-       vm_offset_t             *address,               /* IN/OUT */
-       vm_size_t               *size,                  /* OUT */
-       natural_t               *nesting_depth,         /* IN/OUT */
-       vm_region_recurse_info_t info,                  /* IN/OUT */
-       mach_msg_type_number_t  *count)                 /* IN/OUT */
-{
-       vm_map_entry_t          tmp_entry;
-       register
-       vm_map_entry_t          entry;
-       register
-       vm_offset_t             start;
-
-       unsigned int                    recurse_count;
-       vm_map_t                        submap;
-       vm_map_t                        base_map;
-       vm_map_entry_t                  base_entry;
-       vm_offset_t                     base_next;
-       vm_offset_t                     base_addr;
-       vm_offset_t                     baddr_start_delta;
-       vm_region_submap_info_64_t      submap_info;
-       vm_region_extended_info_data_t  extended;
 
-       if (map == VM_MAP_NULL) 
-               return(KERN_INVALID_ARGUMENT);
+static kern_return_t
+vm_map_willneed(
+       vm_map_t        map,
+       vm_map_offset_t start,
+       vm_map_offset_t end
+)
+{
+       vm_map_entry_t                  entry;
+       vm_object_t                     object;
+       memory_object_t                 pager;
+       struct vm_object_fault_info     fault_info;
+       kern_return_t                   kr;
+       vm_object_size_t                len;
+       vm_object_offset_t              offset;
 
-       submap_info = (vm_region_submap_info_64_t) info;
-       *count = VM_REGION_SUBMAP_INFO_COUNT;
+       /*
+        * Fill in static values in fault_info.  Several fields get ignored by the code
+        * we call, but we'll fill them in anyway since uninitialized fields are bad
+        * when it comes to future backwards compatibility.
+        */
 
-       if (*count < VM_REGION_SUBMAP_INFO_COUNT)
-               return(KERN_INVALID_ARGUMENT);
+       fault_info.interruptible = THREAD_UNINT;                /* ignored value */
+       fault_info.behavior      = VM_BEHAVIOR_SEQUENTIAL;
+       fault_info.no_cache      = FALSE;                       /* ignored value */
+       fault_info.stealth       = TRUE;
 
-       start = *address;
-       base_map = map;
-       recurse_count = *nesting_depth;
+       /*
+        * The MADV_WILLNEED operation doesn't require any changes to the
+        * vm_map_entry_t's, so the read lock is sufficient.
+        */
 
-LOOKUP_NEXT_BASE_ENTRY:
        vm_map_lock_read(map);
-        if (!vm_map_lookup_entry(map, start, &tmp_entry)) {
-               if ((entry = tmp_entry->vme_next) == vm_map_to_entry(map)) {
-                       vm_map_unlock_read(map);
-                       return(KERN_INVALID_ADDRESS);
-               }
-       } else {
-               entry = tmp_entry;
-       }
-       *size = entry->vme_end - entry->vme_start;
-       start = entry->vme_start;
-       base_addr = start;
-       baddr_start_delta = *address - start;
-       base_next = entry->vme_end;
-       base_entry = entry;
 
-       while(entry->is_sub_map && recurse_count) {
-               recurse_count--;
-               vm_map_lock_read(entry->object.sub_map);
+       /*
+        * The madvise semantics require that the address range be fully
+        * allocated with no holes.  Otherwise, we're required to return
+        * an error.
+        */
 
+       if (vm_map_range_check(map, start, end, &entry)) {
 
-               if(entry == base_entry) {
-                       start = entry->offset;
-               start += *address - entry->vme_start;
-               }
+               /*
+                * Examine each vm_map_entry_t in the range.
+                */
 
-               submap = entry->object.sub_map;
-               vm_map_unlock_read(map);
-               map = submap;
+               for (; entry->vme_start < end; start += len, entry = entry->vme_next) {
 
-               if (!vm_map_lookup_entry(map, start, &tmp_entry)) {
-                       if ((entry = tmp_entry->vme_next) 
-                                               == vm_map_to_entry(map)) {
-                               vm_map_unlock_read(map);
-                               map = base_map;
-                               start = base_next;
-                               recurse_count = 0;
-                               *nesting_depth = 0;
-                               goto LOOKUP_NEXT_BASE_ENTRY;
-                       }
-               } else {
-                       entry = tmp_entry;
+                       /*
+                        * The first time through, the start address could be anywhere within the 
+                        * vm_map_entry we found.  So adjust the offset to correspond.  After that,
+                        * the offset will always be zero to correspond to the beginning of the current
+                        * vm_map_entry.
+                        */
+                       
+                       offset = (start - entry->vme_start) + entry->offset;
 
-               }
-               if(start <= entry->vme_start) {
-                       vm_offset_t     old_start = start;
-                       if(baddr_start_delta) {
-                               base_addr += (baddr_start_delta);
-                               *size -= baddr_start_delta;
-                               baddr_start_delta = 0;
-                       }
-                       if(base_next <= 
-                               (base_addr += (entry->vme_start - start))) {
-                               vm_map_unlock_read(map);
-                               map = base_map;
-                               start = base_next;
-                               recurse_count = 0;
-                               *nesting_depth = 0;
-                               goto LOOKUP_NEXT_BASE_ENTRY;
-                       }
-                       *size -= entry->vme_start - start;
-                       if (*size > (entry->vme_end - entry->vme_start)) {
-                               *size = entry->vme_end - entry->vme_start;
-                       }
-                       start = 0;
-               } else {
-                       if(baddr_start_delta) {
-                               if((start - entry->vme_start) 
-                                               < baddr_start_delta) {
-                                       base_addr += start - entry->vme_start;
-                                       *size -= start - entry->vme_start;
-                               } else {
-                                       base_addr += baddr_start_delta;
-                                       *size += baddr_start_delta;
-                               }
-                               baddr_start_delta = 0;
+                       /*
+                        * Set the length so we don't go beyond the end of the map_entry or beyond the
+                        * end of the range we were given.  This range could span also multiple map 
+                        * entries all of which map different files, so make sure we only do the right
+                        * amount of I/O for each object.  Note that it's possible for there to be
+                        * multiple map entries all referring to the same object but with different
+                        * page permissions, but it's not worth trying to optimize that case.
+                        */
+
+                       len = MIN(entry->vme_end - start, end - start);
+
+                       if ((vm_size_t) len != len) {
+                               /* 32-bit overflow */
+                               len = (vm_size_t) (0 - PAGE_SIZE);
                        }
-                       base_addr += entry->vme_start;
-                       if(base_addr >= base_next) {
-                               vm_map_unlock_read(map);
-                               map = base_map;
-                               start = base_next;
-                               recurse_count = 0;
-                               *nesting_depth = 0;
-                               goto LOOKUP_NEXT_BASE_ENTRY;
+                       fault_info.cluster_size = (vm_size_t) len;
+                       fault_info.lo_offset    = offset; 
+                       fault_info.hi_offset    = offset + len;
+                       fault_info.user_tag     = entry->alias;
+
+                       /*
+                        * If there's no read permission to this mapping, then just skip it.
+                        */
+
+                       if ((entry->protection & VM_PROT_READ) == 0) {
+                               continue;
                        }
-                       if (*size > (entry->vme_end - start))
-                               *size = entry->vme_end - start;
 
-                       start = entry->vme_start - start;
-               }
+                       /*
+                        * Find the file object backing this map entry.  If there is none,
+                        * then we simply ignore the "will need" advice for this entry and
+                        * go on to the next one.
+                        */
 
-               start += entry->offset;
+                       if ((object = find_vnode_object(entry)) == VM_OBJECT_NULL) {
+                               continue;
+                       }
 
-       }
-       *nesting_depth -= recurse_count;
-       if(entry != base_entry) {
-               start = entry->vme_start + (start - entry->offset);
-       }
+                       vm_object_paging_begin(object);
+                       pager = object->pager;
+                       vm_object_unlock(object);
 
+                       /*
+                        * Get the data from the object asynchronously.
+                        *
+                        * Note that memory_object_data_request() places limits on the amount
+                        * of I/O it will do.  Regardless of the len we specified, it won't do
+                        * more than MAX_UPL_TRANSFER and it silently truncates the len to that
+                        * size.  This isn't necessarily bad since madvise shouldn't really be 
+                        * used to page in unlimited amounts of data.  Other Unix variants limit
+                        * the willneed case as well.  If this turns out to be an issue for
+                        * developers, then we can always adjust the policy here and still be
+                        * backwards compatible since this is all just "advice".
+                        */
 
-       submap_info->user_tag = entry->alias;
-       submap_info->offset = entry->offset;
-       submap_info->protection = entry->protection;
-       submap_info->inheritance = entry->inheritance;
-       submap_info->max_protection = entry->max_protection;
-       submap_info->behavior = entry->behavior;
-       submap_info->user_wired_count = entry->user_wired_count;
-       submap_info->is_submap = entry->is_sub_map;
-       submap_info->object_id = (vm_offset_t)entry->object.vm_object;
-       *address = base_addr;
+                       kr = memory_object_data_request(
+                               pager,
+                               offset + object->paging_offset,
+                               0,      /* ignored */
+                               VM_PROT_READ,
+                               (memory_object_fault_info_t)&fault_info);
 
+                       vm_object_lock(object);
+                       vm_object_paging_end(object);
+                       vm_object_unlock(object);
 
-       extended.pages_resident = 0;
-       extended.pages_swapped_out = 0;
-       extended.pages_shared_now_private = 0;
-       extended.pages_dirtied = 0;
-       extended.external_pager = 0;
-       extended.shadow_depth = 0;
+                       /*
+                        * If we couldn't do the I/O for some reason, just give up on the
+                        * madvise.  We still return success to the user since madvise isn't
+                        * supposed to fail when the advice can't be taken.
+                        */
 
-       if(!entry->is_sub_map) {
-               vm_region_walk(entry, &extended, entry->offset, 
-                               entry->vme_end - start, map, start);
-               submap_info->share_mode = extended.share_mode;
-               if (extended.external_pager && extended.ref_count == 2 
-                                       && extended.share_mode == SM_SHARED)
-                       submap_info->share_mode = SM_PRIVATE;
-               submap_info->ref_count = extended.ref_count;
-       } else {
-               if(entry->use_pmap) 
-                       submap_info->share_mode =  SM_TRUESHARED;
-               else
-                       submap_info->share_mode = SM_PRIVATE;
-               submap_info->ref_count = entry->object.sub_map->ref_count;
-       }
+                       if (kr != KERN_SUCCESS) {
+                               break;
+                       }
+               }
 
-       submap_info->pages_resident = extended.pages_resident;
-       submap_info->pages_swapped_out = extended.pages_swapped_out;
-       submap_info->pages_shared_now_private = 
-                               extended.pages_shared_now_private;
-       submap_info->pages_dirtied = extended.pages_dirtied;
-       submap_info->external_pager = extended.external_pager;
-       submap_info->shadow_depth = extended.shadow_depth;
+               kr = KERN_SUCCESS;
+       } else
+               kr = KERN_INVALID_ADDRESS;
 
        vm_map_unlock_read(map);
-       return(KERN_SUCCESS);
+       return kr;
 }
 
+static boolean_t
+vm_map_entry_is_reusable(
+       vm_map_entry_t entry)
+{
+       vm_object_t object;
+
+       if (entry->is_shared ||
+           entry->is_sub_map ||
+           entry->in_transition ||
+           entry->protection != VM_PROT_DEFAULT ||
+           entry->max_protection != VM_PROT_ALL ||
+           entry->inheritance != VM_INHERIT_DEFAULT ||
+           entry->no_cache ||
+           entry->permanent ||
+           entry->superpage_size != 0 ||
+           entry->zero_wired_pages ||
+           entry->wired_count != 0 ||
+           entry->user_wired_count != 0) {
+               return FALSE;
+       }
 
-/*
- *     TEMPORARYTEMPORARYTEMPORARYTEMPORARYTEMPORARYTEMPORARY
- *     Goes away after regular vm_region function migrates to
- *     64 bits
- */
-
+       object = entry->object.vm_object;
+       if (object == VM_OBJECT_NULL) {
+               return TRUE;
+       }
+       if (object->ref_count == 1 &&
+           object->wired_page_count == 0 &&
+           object->copy == VM_OBJECT_NULL &&
+           object->shadow == VM_OBJECT_NULL &&
+           object->copy_strategy == MEMORY_OBJECT_COPY_SYMMETRIC &&
+           object->internal &&
+           !object->true_share &&
+           object->wimg_bits == VM_WIMG_DEFAULT &&
+           !object->code_signed) {
+               return TRUE;
+       }
+       return FALSE;
+           
+           
+}
 
-kern_return_t
-vm_region_64(
-       vm_map_t                 map,
-       vm_offset_t             *address,               /* IN/OUT */
-       vm_size_t               *size,                  /* OUT */
-       vm_region_flavor_t       flavor,                /* IN */
-       vm_region_info_t         info,                  /* OUT */
-       mach_msg_type_number_t  *count,                 /* IN/OUT */
-       ipc_port_t              *object_name)           /* OUT */
+static kern_return_t
+vm_map_reuse_pages(
+       vm_map_t        map,
+       vm_map_offset_t start,
+       vm_map_offset_t end)
 {
-       vm_map_entry_t          tmp_entry;
-       register
-       vm_map_entry_t          entry;
-       register
-       vm_offset_t             start;
-       vm_region_basic_info_64_t       basic;
-       vm_region_extended_info_t       extended;
-       vm_region_top_info_t    top;
+       vm_map_entry_t                  entry;
+       vm_object_t                     object;
+       vm_object_offset_t              start_offset, end_offset;
 
-       if (map == VM_MAP_NULL) 
-               return(KERN_INVALID_ARGUMENT);
+       /*
+        * The MADV_REUSE operation doesn't require any changes to the
+        * vm_map_entry_t's, so the read lock is sufficient.
+        */
 
-       switch (flavor) {
-       
-       case VM_REGION_BASIC_INFO:
-       {
-           if (*count < VM_REGION_BASIC_INFO_COUNT)
-               return(KERN_INVALID_ARGUMENT);
+       vm_map_lock_read(map);
 
-           basic = (vm_region_basic_info_64_t) info;
-           *count = VM_REGION_BASIC_INFO_COUNT;
+       /*
+        * The madvise semantics require that the address range be fully
+        * allocated with no holes.  Otherwise, we're required to return
+        * an error.
+        */
 
-           vm_map_lock_read(map);
+       if (!vm_map_range_check(map, start, end, &entry)) {
+               vm_map_unlock_read(map);
+               vm_page_stats_reusable.reuse_pages_failure++;
+               return KERN_INVALID_ADDRESS;
+       }
 
-           start = *address;
-           if (!vm_map_lookup_entry(map, start, &tmp_entry)) {
-               if ((entry = tmp_entry->vme_next) == vm_map_to_entry(map)) {
+       /*
+        * Examine each vm_map_entry_t in the range.
+        */
+       for (; entry != vm_map_to_entry(map) && entry->vme_start < end;
+            entry = entry->vme_next) {
+               /*
+                * Sanity check on the VM map entry.
+                */
+               if (! vm_map_entry_is_reusable(entry)) {
                        vm_map_unlock_read(map);
-                       return(KERN_INVALID_ADDRESS);
+                       vm_page_stats_reusable.reuse_pages_failure++;
+                       return KERN_INVALID_ADDRESS;
+               }
+
+               /*
+                * The first time through, the start address could be anywhere
+                * within the vm_map_entry we found.  So adjust the offset to
+                * correspond.
+                */
+               if (entry->vme_start < start) {
+                       start_offset = start - entry->vme_start;
+               } else {
+                       start_offset = 0;
+               }
+               end_offset = MIN(end, entry->vme_end) - entry->vme_start;
+               start_offset += entry->offset;
+               end_offset += entry->offset;
+
+               object = entry->object.vm_object;
+               if (object != VM_OBJECT_NULL) {
+                       vm_object_lock(object);
+                       vm_object_reuse_pages(object, start_offset, end_offset,
+                                             TRUE);
+                       vm_object_unlock(object);
+               }
+
+               if (entry->alias == VM_MEMORY_MALLOC_LARGE_REUSABLE) {
+                       /*
+                        * XXX
+                        * We do not hold the VM map exclusively here.
+                        * The "alias" field is not that critical, so it's
+                        * safe to update it here, as long as it is the only
+                        * one that can be modified while holding the VM map
+                        * "shared".
+                        */
+                       entry->alias = VM_MEMORY_MALLOC_LARGE_REUSED;
                }
-           } else {
-               entry = tmp_entry;
-           }
-
-           start = entry->vme_start;
-
-           basic->offset = entry->offset;
-           basic->protection = entry->protection;
-           basic->inheritance = entry->inheritance;
-           basic->max_protection = entry->max_protection;
-           basic->behavior = entry->behavior;
-           basic->user_wired_count = entry->user_wired_count;
-           basic->reserved = entry->is_sub_map;
-           *address = start;
-           *size = (entry->vme_end - start);
-
-           if (object_name) *object_name = IP_NULL;
-           if (entry->is_sub_map) {
-               basic->shared = FALSE;
-           } else {
-               basic->shared = entry->is_shared;
-           }
-
-           vm_map_unlock_read(map);
-           return(KERN_SUCCESS);
        }
-       case VM_REGION_EXTENDED_INFO:
-       {
+       
+       vm_map_unlock_read(map);
+       vm_page_stats_reusable.reuse_pages_success++;
+       return KERN_SUCCESS;
+}
 
-           if (*count < VM_REGION_EXTENDED_INFO_COUNT)
-               return(KERN_INVALID_ARGUMENT);
 
-           extended = (vm_region_extended_info_t) info;
-           *count = VM_REGION_EXTENDED_INFO_COUNT;
+static kern_return_t
+vm_map_reusable_pages(
+       vm_map_t        map,
+       vm_map_offset_t start,
+       vm_map_offset_t end)
+{
+       vm_map_entry_t                  entry;
+       vm_object_t                     object;
+       vm_object_offset_t              start_offset, end_offset;
+
+       /*
+        * The MADV_REUSABLE operation doesn't require any changes to the
+        * vm_map_entry_t's, so the read lock is sufficient.
+        */
+
+       vm_map_lock_read(map);
+
+       /*
+        * The madvise semantics require that the address range be fully
+        * allocated with no holes.  Otherwise, we're required to return
+        * an error.
+        */
+
+       if (!vm_map_range_check(map, start, end, &entry)) {
+               vm_map_unlock_read(map);
+               vm_page_stats_reusable.reusable_pages_failure++;
+               return KERN_INVALID_ADDRESS;
+       }
 
-           vm_map_lock_read(map);
+       /*
+        * Examine each vm_map_entry_t in the range.
+        */
+       for (; entry != vm_map_to_entry(map) && entry->vme_start < end;
+            entry = entry->vme_next) {
+               int kill_pages = 0;
 
-           start = *address;
-           if (!vm_map_lookup_entry(map, start, &tmp_entry)) {
-               if ((entry = tmp_entry->vme_next) == vm_map_to_entry(map)) {
+               /*
+                * Sanity check on the VM map entry.
+                */
+               if (! vm_map_entry_is_reusable(entry)) {
                        vm_map_unlock_read(map);
-                       return(KERN_INVALID_ADDRESS);
+                       vm_page_stats_reusable.reusable_pages_failure++;
+                       return KERN_INVALID_ADDRESS;
                }
-           } else {
-               entry = tmp_entry;
-           }
-           start = entry->vme_start;
 
-           extended->protection = entry->protection;
-           extended->user_tag = entry->alias;
-           extended->pages_resident = 0;
-           extended->pages_swapped_out = 0;
-           extended->pages_shared_now_private = 0;
-           extended->pages_dirtied = 0;
-           extended->external_pager = 0;
-           extended->shadow_depth = 0;
+               /*
+                * The first time through, the start address could be anywhere
+                * within the vm_map_entry we found.  So adjust the offset to
+                * correspond.
+                */
+               if (entry->vme_start < start) {
+                       start_offset = start - entry->vme_start;
+               } else {
+                       start_offset = 0;
+               }
+               end_offset = MIN(end, entry->vme_end) - entry->vme_start;
+               start_offset += entry->offset;
+               end_offset += entry->offset;
 
-           vm_region_walk(entry, extended, entry->offset, entry->vme_end - start, map, start);
+               object = entry->object.vm_object;
+               if (object == VM_OBJECT_NULL)
+                       continue;
 
-           if (extended->external_pager && extended->ref_count == 2 && extended->share_mode == SM_SHARED)
-                   extended->share_mode = SM_PRIVATE;
 
-           if (object_name)
-               *object_name = IP_NULL;
-           *address = start;
-           *size = (entry->vme_end - start);
+               vm_object_lock(object);
+               if (object->ref_count == 1 && !object->shadow)
+                       kill_pages = 1;
+               else
+                       kill_pages = -1;
+               if (kill_pages != -1) {
+                       vm_object_deactivate_pages(object,
+                                                  start_offset,
+                                                  end_offset - start_offset,
+                                                  kill_pages,
+                                                  TRUE /*reusable_pages*/);
+               } else {
+                       vm_page_stats_reusable.reusable_pages_shared++;
+               }
+               vm_object_unlock(object);
 
-           vm_map_unlock_read(map);
-           return(KERN_SUCCESS);
+               if (entry->alias == VM_MEMORY_MALLOC_LARGE ||
+                   entry->alias == VM_MEMORY_MALLOC_LARGE_REUSED) {
+                       /*
+                        * XXX
+                        * We do not hold the VM map exclusively here.
+                        * The "alias" field is not that critical, so it's
+                        * safe to update it here, as long as it is the only
+                        * one that can be modified while holding the VM map
+                        * "shared".
+                        */
+                       entry->alias = VM_MEMORY_MALLOC_LARGE_REUSABLE;
+               }
        }
-       case VM_REGION_TOP_INFO:
-       {   
+       
+       vm_map_unlock_read(map);
+       vm_page_stats_reusable.reusable_pages_success++;
+       return KERN_SUCCESS;
+}
 
-           if (*count < VM_REGION_TOP_INFO_COUNT)
-               return(KERN_INVALID_ARGUMENT);
 
-           top = (vm_region_top_info_t) info;
-           *count = VM_REGION_TOP_INFO_COUNT;
+static kern_return_t
+vm_map_can_reuse(
+       vm_map_t        map,
+       vm_map_offset_t start,
+       vm_map_offset_t end)
+{
+       vm_map_entry_t                  entry;
+
+       /*
+        * The MADV_REUSABLE operation doesn't require any changes to the
+        * vm_map_entry_t's, so the read lock is sufficient.
+        */
+
+       vm_map_lock_read(map);
+
+       /*
+        * The madvise semantics require that the address range be fully
+        * allocated with no holes.  Otherwise, we're required to return
+        * an error.
+        */
 
-           vm_map_lock_read(map);
+       if (!vm_map_range_check(map, start, end, &entry)) {
+               vm_map_unlock_read(map);
+               vm_page_stats_reusable.can_reuse_failure++;
+               return KERN_INVALID_ADDRESS;
+       }
 
-           start = *address;
-           if (!vm_map_lookup_entry(map, start, &tmp_entry)) {
-               if ((entry = tmp_entry->vme_next) == vm_map_to_entry(map)) {
+       /*
+        * Examine each vm_map_entry_t in the range.
+        */
+       for (; entry != vm_map_to_entry(map) && entry->vme_start < end;
+            entry = entry->vme_next) {
+               /*
+                * Sanity check on the VM map entry.
+                */
+               if (! vm_map_entry_is_reusable(entry)) {
                        vm_map_unlock_read(map);
-                       return(KERN_INVALID_ADDRESS);
+                       vm_page_stats_reusable.can_reuse_failure++;
+                       return KERN_INVALID_ADDRESS;
                }
-           } else {
-               entry = tmp_entry;
+       }
+       
+       vm_map_unlock_read(map);
+       vm_page_stats_reusable.can_reuse_success++;
+       return KERN_SUCCESS;
+}
+
+
+
+#include <mach_kdb.h>
+#if    MACH_KDB
+#include <ddb/db_output.h>
+#include <vm/vm_print.h>
+
+#define        printf  db_printf
 
-           }
-           start = entry->vme_start;
+/*
+ * Forward declarations for internal functions.
+ */
+extern void vm_map_links_print(
+       struct vm_map_links     *links);
 
-           top->private_pages_resident = 0;
-           top->shared_pages_resident = 0;
+extern void vm_map_header_print(
+       struct vm_map_header    *header);
 
-           vm_region_top_walk(entry, top);
+extern void vm_map_entry_print(
+       vm_map_entry_t          entry);
 
-           if (object_name)
-               *object_name = IP_NULL;
-           *address = start;
-           *size = (entry->vme_end - start);
+extern void vm_follow_entry(
+       vm_map_entry_t          entry);
 
-           vm_map_unlock_read(map);
-           return(KERN_SUCCESS);
-       }
-       default:
-           return(KERN_INVALID_ARGUMENT);
-       }
-}
+extern void vm_follow_map(
+       vm_map_t                map);
 
+/*
+ *     vm_map_links_print:     [ debug ]
+ */
 void
-vm_region_top_walk(
-        vm_map_entry_t            entry,
-       vm_region_top_info_t       top)
+vm_map_links_print(
+       struct vm_map_links     *links)
 {
-        register struct vm_object *obj, *tmp_obj;
-       register int    ref_count;
-
-       if (entry->object.vm_object == 0 || entry->is_sub_map) {
-           top->share_mode = SM_EMPTY;
-           top->ref_count = 0;
-           top->obj_id = 0;
-           return;
-       }
-       {
-           obj = entry->object.vm_object;
+       iprintf("prev = %08X  next = %08X  start = %016llX  end = %016llX\n",
+               links->prev,
+               links->next,
+               (unsigned long long)links->start,
+               (unsigned long long)links->end);
+}
 
-           vm_object_lock(obj);
+/*
+ *     vm_map_header_print:    [ debug ]
+ */
+void
+vm_map_header_print(
+       struct vm_map_header    *header)
+{
+       vm_map_links_print(&header->links);
+       iprintf("nentries = %08X, %sentries_pageable\n",
+               header->nentries,
+               (header->entries_pageable ? "" : "!"));
+}
 
-           if ((ref_count = obj->ref_count) > 1 && obj->paging_in_progress)
-               ref_count--;
+/*
+ *     vm_follow_entry:        [ debug ]
+ */
+void
+vm_follow_entry(
+       vm_map_entry_t entry)
+{
+       int shadows;
 
-           if (obj->shadow) {
-               if (ref_count == 1)
-                   top->private_pages_resident = obj->resident_page_count;
-               else
-                   top->shared_pages_resident = obj->resident_page_count;
-               top->ref_count  = ref_count;
-               top->share_mode = SM_COW;
-           
-               while (tmp_obj = obj->shadow) {
-                   vm_object_lock(tmp_obj);
-                   vm_object_unlock(obj);
-                   obj = tmp_obj;
+       iprintf("map entry %08X\n", entry);
 
-                   if ((ref_count = obj->ref_count) > 1 && obj->paging_in_progress)
-                       ref_count--;
+       db_indent += 2;
 
-                   top->shared_pages_resident += obj->resident_page_count;
-                   top->ref_count += ref_count - 1;
-               }
-           } else {
-               if (entry->needs_copy) {
-                   top->share_mode = SM_COW;
-                   top->shared_pages_resident = obj->resident_page_count;
-               } else {
-                   if (ref_count == 1 ||
-                      (ref_count == 2 && !(obj->pager_trusted) && !(obj->internal))) {
-                       top->share_mode = SM_PRIVATE;
-                       top->private_pages_resident = obj->resident_page_count;
-                   } else {
-                       top->share_mode = SM_SHARED;
-                       top->shared_pages_resident = obj->resident_page_count;
-                   }
-               }
-               top->ref_count = ref_count;
-           }
-           top->obj_id = (int)obj;
+       shadows = vm_follow_object(entry->object.vm_object);
+       iprintf("Total objects : %d\n",shadows);
 
-           vm_object_unlock(obj);
-       }
+       db_indent -= 2;
 }
 
+/*
+ *     vm_map_entry_print:     [ debug ]
+ */
 void
-vm_region_walk(
-        vm_map_entry_t            entry,
-       vm_region_extended_info_t  extended,
-       vm_object_offset_t         offset,
-       vm_offset_t                range,
-       vm_map_t                   map,
-       vm_offset_t                va)
+vm_map_entry_print(
+       register vm_map_entry_t entry)
 {
-        register struct vm_object *obj, *tmp_obj;
-       register vm_offset_t       last_offset;
-       register int               i;
-       register int               ref_count;
-       void vm_region_look_for_page();
-
-       if ((entry->object.vm_object == 0) ||
-               (entry->is_sub_map) ||
-               (entry->object.vm_object->phys_contiguous)) {
-           extended->share_mode = SM_EMPTY;
-           extended->ref_count = 0;
-           return;
-       }
-       {
-           obj = entry->object.vm_object;
+       static const char *inheritance_name[4] =
+               { "share", "copy", "none", "?"};
+       static const char *behavior_name[4] =
+               { "dflt", "rand", "seqtl", "rseqntl" };
+       
+       iprintf("map entry %08X - prev = %08X  next = %08X\n", entry, entry->vme_prev, entry->vme_next);
 
-           vm_object_lock(obj);
+       db_indent += 2;
 
-           if ((ref_count = obj->ref_count) > 1 && obj->paging_in_progress)
-               ref_count--;
+       vm_map_links_print(&entry->links);
 
-           for (last_offset = offset + range; offset < last_offset; offset += PAGE_SIZE_64, va += PAGE_SIZE)
-               vm_region_look_for_page(obj, extended, offset, ref_count, 0, map, va);
+       iprintf("start = %016llX  end = %016llX - prot=%x/%x/%s\n",
+               (unsigned long long)entry->vme_start,
+               (unsigned long long)entry->vme_end,
+               entry->protection,
+               entry->max_protection,
+               inheritance_name[(entry->inheritance & 0x3)]);
 
-           if (extended->shadow_depth || entry->needs_copy)
-               extended->share_mode = SM_COW;
-           else {
-               if (ref_count == 1)
-                   extended->share_mode = SM_PRIVATE;
-               else {
-                   if (obj->true_share)
-                       extended->share_mode = SM_TRUESHARED;
-                   else
-                       extended->share_mode = SM_SHARED;
-               }
-           }
-           extended->ref_count = ref_count - extended->shadow_depth;
-           
-           for (i = 0; i < extended->shadow_depth; i++) {
-               if ((tmp_obj = obj->shadow) == 0)
-                   break;
-               vm_object_lock(tmp_obj);
-               vm_object_unlock(obj);
+       iprintf("behavior = %s, wired_count = %d, user_wired_count = %d\n",
+               behavior_name[(entry->behavior & 0x3)],
+               entry->wired_count,
+               entry->user_wired_count);
+       iprintf("%sin_transition, %sneeds_wakeup\n",
+               (entry->in_transition ? "" : "!"),
+               (entry->needs_wakeup ? "" : "!"));
 
-               if ((ref_count = tmp_obj->ref_count) > 1 && tmp_obj->paging_in_progress)
-                   ref_count--;
+       if (entry->is_sub_map) {
+               iprintf("submap = %08X - offset = %016llX\n",
+                       entry->object.sub_map,
+                       (unsigned long long)entry->offset);
+       } else {
+               iprintf("object = %08X  offset = %016llX - ",
+                       entry->object.vm_object,
+                       (unsigned long long)entry->offset);
+               printf("%sis_shared, %sneeds_copy\n",
+                      (entry->is_shared ? "" : "!"),
+                      (entry->needs_copy ? "" : "!"));
+       }
 
-               extended->ref_count += ref_count;
-               obj = tmp_obj;
-           }
-           vm_object_unlock(obj);
+       db_indent -= 2;
+}
 
-           if (extended->share_mode == SM_SHARED) {
-               register vm_map_entry_t      cur;
-               register vm_map_entry_t      last;
-               int      my_refs;
+/*
+ *     vm_follow_map:  [ debug ]
+ */
+void
+vm_follow_map(
+       vm_map_t map)
+{
+       register vm_map_entry_t entry;
 
-               obj = entry->object.vm_object;
-               last = vm_map_to_entry(map);
-               my_refs = 0;
+       iprintf("task map %08X\n", map);
 
-               if ((ref_count = obj->ref_count) > 1 && obj->paging_in_progress)
-                       ref_count--;
-               for (cur = vm_map_first_entry(map); cur != last; cur = cur->vme_next)
-                   my_refs += vm_region_count_obj_refs(cur, obj);
+       db_indent += 2;
 
-               if (my_refs == ref_count)
-                   extended->share_mode = SM_PRIVATE_ALIASED;
-               else if (my_refs > 1)
-                   extended->share_mode = SM_SHARED_ALIASED;
-           }
+       for (entry = vm_map_first_entry(map);
+            entry && entry != vm_map_to_entry(map);
+            entry = entry->vme_next) {
+               vm_follow_entry(entry);
        }
+
+       db_indent -= 2;
 }
 
+/*
+ *     vm_map_print:   [ debug ]
+ */
+void
+vm_map_print(
+       db_addr_t inmap)
+{
+       register vm_map_entry_t entry;
+       vm_map_t map;
+#if TASK_SWAPPER
+       char *swstate;
+#endif /* TASK_SWAPPER */
 
-/* object is locked on entry and locked on return */
+       map = (vm_map_t)(long)
+               inmap;  /* Make sure we have the right type */
 
+       iprintf("task map %08X\n", map);
 
-void
-vm_region_look_for_page(
-        vm_object_t               object,
-       vm_region_extended_info_t  extended,
-       vm_object_offset_t         offset,
-       int                        max_refcnt,
-        int                        depth,
-       vm_map_t                   map,
-       vm_offset_t                va)
-{
-        register vm_page_t        p;
-        register vm_object_t      shadow;
-       register int               ref_count;
-       vm_object_t                caller_object;
-        
-       shadow = object->shadow;
-       caller_object = object;
+       db_indent += 2;
 
-       
-       while (TRUE) {
+       vm_map_header_print(&map->hdr);
 
-               if ( !(object->pager_trusted) && !(object->internal))
-                           extended->external_pager = 1;
+       iprintf("pmap = %08X  size = %08X  ref = %d  hint = %08X  first_free = %08X\n",
+               map->pmap,
+               map->size,
+               map->ref_count,
+               map->hint,
+               map->first_free);
 
-               if ((p = vm_page_lookup(object, offset)) != VM_PAGE_NULL) {
-                       if (shadow && (max_refcnt == 1))
-                               extended->pages_shared_now_private++;
+       iprintf("%swait_for_space, %swiring_required, timestamp = %d\n",
+               (map->wait_for_space ? "" : "!"),
+               (map->wiring_required ? "" : "!"),
+               map->timestamp);
 
-                       if (!p->fictitious && 
-                               (p->dirty || pmap_is_modified(p->phys_page)))
-                               extended->pages_dirtied++;
-                       extended->pages_resident++;
+#if    TASK_SWAPPER
+       switch (map->sw_state) {
+       case MAP_SW_IN:
+               swstate = "SW_IN";
+               break;
+       case MAP_SW_OUT:
+               swstate = "SW_OUT";
+               break;
+       default:
+               swstate = "????";
+               break;
+       }
+       iprintf("res = %d, sw_state = %s\n", map->res_count, swstate);
+#endif /* TASK_SWAPPER */
 
-                       if(object != caller_object)
-                               vm_object_unlock(object);
+       for (entry = vm_map_first_entry(map);
+            entry && entry != vm_map_to_entry(map);
+            entry = entry->vme_next) {
+               vm_map_entry_print(entry);
+       }
 
-                       return;
-               }
-               if (object->existence_map) {
-                       if (vm_external_state_get(object->existence_map, offset) == VM_EXTERNAL_STATE_EXISTS) {
+       db_indent -= 2;
+}
 
-                               extended->pages_swapped_out++;
+/*
+ *     Routine:        vm_map_copy_print
+ *     Purpose:
+ *             Pretty-print a copy object for ddb.
+ */
 
-                               if(object != caller_object)
-                                       vm_object_unlock(object);
+void
+vm_map_copy_print(
+       db_addr_t       incopy)
+{
+       vm_map_copy_t copy;
+       vm_map_entry_t entry;
 
-                               return;
-                       }
-               }
-               if (shadow) {
-                       vm_object_lock(shadow);
+       copy = (vm_map_copy_t)(long)
+               incopy; /* Make sure we have the right type */
 
-                       if ((ref_count = shadow->ref_count) > 1 && shadow->paging_in_progress)
-                               ref_count--;
+       printf("copy object 0x%x\n", copy);
 
-                       if (++depth > extended->shadow_depth)
-                               extended->shadow_depth = depth;
+       db_indent += 2;
 
-                       if (ref_count > max_refcnt)
-                               max_refcnt = ref_count;
-                       
-                       if(object != caller_object)
-                               vm_object_unlock(object);
+       iprintf("type=%d", copy->type);
+       switch (copy->type) {
+       case VM_MAP_COPY_ENTRY_LIST:
+               printf("[entry_list]");
+               break;
+               
+       case VM_MAP_COPY_OBJECT:
+               printf("[object]");
+               break;
+               
+       case VM_MAP_COPY_KERNEL_BUFFER:
+               printf("[kernel_buffer]");
+               break;
 
-                       object = shadow;
-                       shadow = object->shadow;
-                       offset = offset + object->shadow_offset;
-                       continue;
-               }
-               if(object != caller_object)
-                       vm_object_unlock(object);
+       default:
+               printf("[bad type]");
                break;
        }
-}
-
-
-vm_region_count_obj_refs(
-        vm_map_entry_t    entry,
-       vm_object_t       object)
-{
-        register int ref_count;
-       register vm_object_t chk_obj;
-       register vm_object_t tmp_obj;
+       printf(", offset=0x%llx", (unsigned long long)copy->offset);
+       printf(", size=0x%x\n", copy->size);
 
-       if (entry->object.vm_object == 0)
-           return(0);
+       switch (copy->type) {
+       case VM_MAP_COPY_ENTRY_LIST:
+               vm_map_header_print(&copy->cpy_hdr);
+               for (entry = vm_map_copy_first_entry(copy);
+                    entry && entry != vm_map_copy_to_entry(copy);
+                    entry = entry->vme_next) {
+                       vm_map_entry_print(entry);
+               }
+               break;
 
-        if (entry->is_sub_map)
-           return(0);
-       else {
-           ref_count = 0;
+       case VM_MAP_COPY_OBJECT:
+               iprintf("object=0x%x\n", copy->cpy_object);
+               break;
 
-           chk_obj = entry->object.vm_object;
-           vm_object_lock(chk_obj);
+       case VM_MAP_COPY_KERNEL_BUFFER:
+               iprintf("kernel buffer=0x%x", copy->cpy_kdata);
+               printf(", kalloc_size=0x%x\n", copy->cpy_kalloc_size);
+               break;
 
-           while (chk_obj) {
-               if (chk_obj == object)
-                   ref_count++;
-               if (tmp_obj = chk_obj->shadow)
-                   vm_object_lock(tmp_obj);
-               vm_object_unlock(chk_obj);
-               
-               chk_obj = tmp_obj;
-           }
        }
-       return(ref_count);
-}
 
+       db_indent -=2;
+}
 
 /*
- *     Routine:        vm_map_simplify
+ *     db_vm_map_total_size(map)       [ debug ]
  *
- *     Description:
- *             Attempt to simplify the map representation in
- *             the vicinity of the given starting address.
- *     Note:
- *             This routine is intended primarily to keep the
- *             kernel maps more compact -- they generally don't
- *             benefit from the "expand a map entry" technology
- *             at allocation time because the adjacent entry
- *             is often wired down.
+ *     return the total virtual size (in bytes) of the map
  */
-void
-vm_map_simplify(
-       vm_map_t        map,
-       vm_offset_t     start)
+vm_map_size_t
+db_vm_map_total_size(
+       db_addr_t       inmap)
 {
-       vm_map_entry_t  this_entry;
-       vm_map_entry_t  prev_entry;
-       vm_map_entry_t  next_entry;
+       vm_map_entry_t  entry;
+       vm_map_size_t   total;
+       vm_map_t map;
 
-       vm_map_lock(map);
-       if (
-               (vm_map_lookup_entry(map, start, &this_entry)) &&
-               ((prev_entry = this_entry->vme_prev) != vm_map_to_entry(map)) &&
-
-               (prev_entry->vme_end == this_entry->vme_start) &&
-
-               (prev_entry->is_shared == FALSE) &&
-               (prev_entry->is_sub_map == FALSE) &&
-
-               (this_entry->is_shared == FALSE) &&
-               (this_entry->is_sub_map == FALSE) &&
-
-               (prev_entry->inheritance == this_entry->inheritance) &&
-               (prev_entry->protection == this_entry->protection) &&
-               (prev_entry->max_protection == this_entry->max_protection) &&
-               (prev_entry->behavior == this_entry->behavior) &&
-               (prev_entry->wired_count == this_entry->wired_count) &&
-               (prev_entry->user_wired_count == this_entry->user_wired_count)&&
-               (prev_entry->in_transition == FALSE) &&
-               (this_entry->in_transition == FALSE) &&
-
-               (prev_entry->needs_copy == this_entry->needs_copy) &&
-
-               (prev_entry->object.vm_object == this_entry->object.vm_object)&&
-               ((prev_entry->offset +
-                (prev_entry->vme_end - prev_entry->vme_start))
-                    == this_entry->offset)
-       ) {
-               SAVE_HINT(map, prev_entry);
-               vm_map_entry_unlink(map, this_entry);
-               prev_entry->vme_end = this_entry->vme_end;
-               UPDATE_FIRST_FREE(map, map->first_free);
-               vm_object_deallocate(this_entry->object.vm_object);
-               vm_map_entry_dispose(map, this_entry);
-               counter(c_vm_map_simplified_lower++);
-       }
-       if (
-               (vm_map_lookup_entry(map, start, &this_entry)) &&
-               ((next_entry = this_entry->vme_next) != vm_map_to_entry(map)) &&
-
-               (next_entry->vme_start == this_entry->vme_end) &&
-
-               (next_entry->is_shared == FALSE) &&
-               (next_entry->is_sub_map == FALSE) &&
-
-               (next_entry->is_shared == FALSE) &&
-               (next_entry->is_sub_map == FALSE) &&
-
-               (next_entry->inheritance == this_entry->inheritance) &&
-               (next_entry->protection == this_entry->protection) &&
-               (next_entry->max_protection == this_entry->max_protection) &&
-               (next_entry->behavior == this_entry->behavior) &&
-               (next_entry->wired_count == this_entry->wired_count) &&
-               (next_entry->user_wired_count == this_entry->user_wired_count)&&
-               (this_entry->in_transition == FALSE) &&
-               (next_entry->in_transition == FALSE) &&
-
-               (next_entry->needs_copy == this_entry->needs_copy) &&
-
-               (next_entry->object.vm_object == this_entry->object.vm_object)&&
-               ((this_entry->offset +
-                (this_entry->vme_end - this_entry->vme_start))
-                    == next_entry->offset)
-       ) {
-               vm_map_entry_unlink(map, next_entry);
-               this_entry->vme_end = next_entry->vme_end;
-               UPDATE_FIRST_FREE(map, map->first_free);
-               vm_object_deallocate(next_entry->object.vm_object);
-               vm_map_entry_dispose(map, next_entry);
-               counter(c_vm_map_simplified_upper++);
+       map = (vm_map_t)(long)
+               inmap;  /* Make sure we have the right type */
+
+       total = 0;
+       for (entry = vm_map_first_entry(map);
+            entry != vm_map_to_entry(map);
+            entry = entry->vme_next) {
+               total += entry->vme_end - entry->vme_start;
        }
-       counter(c_vm_map_simplify_called++);
-       vm_map_unlock(map);
+
+       return total;
 }
 
+#endif /* MACH_KDB */
 
 /*
- *     Routine:        vm_map_machine_attribute
- *     Purpose:
- *             Provide machine-specific attributes to mappings,
- *             such as cachability etc. for machines that provide
- *             them.  NUMA architectures and machines with big/strange
- *             caches will use this.
- *     Note:
- *             Responsibilities for locking and checking are handled here,
- *             everything else in the pmap module. If any non-volatile
- *             information must be kept, the pmap module should handle
- *             it itself. [This assumes that attributes do not
- *             need to be inherited, which seems ok to me]
+ *     Routine:        vm_map_entry_insert
+ *
+ *     Descritpion:    This routine inserts a new vm_entry in a locked map.
  */
-kern_return_t
-vm_map_machine_attribute(
-       vm_map_t        map,
-       vm_offset_t     address,
-       vm_size_t       size,
-       vm_machine_attribute_t  attribute,
-       vm_machine_attribute_val_t* value)              /* IN/OUT */
+vm_map_entry_t
+vm_map_entry_insert(
+       vm_map_t                map,
+       vm_map_entry_t          insp_entry,
+       vm_map_offset_t         start,
+       vm_map_offset_t         end,
+       vm_object_t             object,
+       vm_object_offset_t      offset,
+       boolean_t               needs_copy,
+       boolean_t               is_shared,
+       boolean_t               in_transition,
+       vm_prot_t               cur_protection,
+       vm_prot_t               max_protection,
+       vm_behavior_t           behavior,
+       vm_inherit_t            inheritance,
+       unsigned                wired_count,
+       boolean_t               no_cache,
+       boolean_t               permanent,
+       unsigned int            superpage_size)
 {
-       kern_return_t   ret;
-       vm_size_t sync_size;
-       vm_offset_t     start;
-       vm_map_entry_t entry;
-       
-       if (address < vm_map_min(map) ||
-           (address + size) > vm_map_max(map))
-               return KERN_INVALID_ADDRESS;
+       vm_map_entry_t  new_entry;
 
-       vm_map_lock(map);
-       
-       if (attribute != MATTR_CACHE) { 
-               /* If we don't have to find physical addresses, we */
-               /* don't have to do an explicit traversal here.    */
-               ret = pmap_attribute(map->pmap, 
-                               address, size, attribute, value);
-               vm_map_unlock(map);
-               return ret;
-       }
+       assert(insp_entry != (vm_map_entry_t)0);
 
-       /* Get the starting address */
-       start = trunc_page_32(address);
-       /* Figure how much memory we need to flush (in page increments) */
-       sync_size = round_page_32(start + size) - start;        
+       new_entry = vm_map_entry_create(map);
 
+       new_entry->vme_start = start;
+       new_entry->vme_end = end;
+       assert(page_aligned(new_entry->vme_start));
+       assert(page_aligned(new_entry->vme_end));
 
-       ret = KERN_SUCCESS;                                                                             /* Assume it all worked */
+       new_entry->object.vm_object = object;
+       new_entry->offset = offset;
+       new_entry->is_shared = is_shared;
+       new_entry->is_sub_map = FALSE;
+       new_entry->needs_copy = needs_copy;
+       new_entry->in_transition = in_transition;
+       new_entry->needs_wakeup = FALSE;
+       new_entry->inheritance = inheritance;
+       new_entry->protection = cur_protection;
+       new_entry->max_protection = max_protection;
+       new_entry->behavior = behavior;
+       new_entry->wired_count = wired_count;
+       new_entry->user_wired_count = 0;
+       new_entry->use_pmap = FALSE;
+       new_entry->alias = 0;
+       new_entry->zero_wired_pages = FALSE;
+       new_entry->no_cache = no_cache;
+       new_entry->permanent = permanent;
+       new_entry->superpage_size = superpage_size;
 
-       while(sync_size) {
-               if (vm_map_lookup_entry(map, start, &entry)) {
-                       vm_size_t       sub_size;
-                       if((entry->vme_end - start) > sync_size) {
-                               sub_size = sync_size;
-                               sync_size = 0;
-                       } else {
-                               sub_size = entry->vme_end - start;
-                                       sync_size -= sub_size;
-                       }
-                       if(entry->is_sub_map) {
-                               vm_map_machine_attribute(
-                                       entry->object.sub_map, 
-                                       (start - entry->vme_start) 
-                                                       + entry->offset,
-                                       sub_size,
-                                       attribute, value);
-                       } else {
-                               if(entry->object.vm_object) {
-                                       vm_page_t               m;
-                                       vm_object_t             object;
-                                       vm_object_t             base_object;
-                                       vm_object_offset_t      offset;
-                                       vm_object_offset_t      base_offset;
-                                       vm_size_t               range;
-                                       range = sub_size;
-                                       offset = (start - entry->vme_start)
-                                                       + entry->offset;
-                                       base_offset = offset;
-                                       object = entry->object.vm_object;
-                                       base_object = object;
-                                       while(range) {
-                                               m = vm_page_lookup(
-                                                       object, offset);
-                                               if(m && !m->fictitious) {
-       
-                                                 ret = 
-                                                    pmap_attribute_cache_sync(
-                                                       m->phys_page,   
-                                                       PAGE_SIZE, 
-                                                       attribute, value);
-                                               } else if (object->shadow) {
-                                                  offset = offset + 
-                                                       object->shadow_offset;
-                                                  object = object->shadow;
-                                                  continue;
-                                               }
-                                               range -= PAGE_SIZE;
-                                               /* Bump to the next page */
-                                               base_offset += PAGE_SIZE;
-                                               offset = base_offset;
-                                               object = base_object;
-                                               
-                                       }
-                               }
-                       }
-                       start += sub_size;
-               } else {
-                       vm_map_unlock(map);
-                       return KERN_FAILURE;
-               }
-               
-       }
+       /*
+        *      Insert the new entry into the list.
+        */
 
-       vm_map_unlock(map);
+       vm_map_entry_link(map, insp_entry, new_entry);
+       map->size += end - start;
 
-       return ret;
+       /*
+        *      Update the free space hint and the lookup hint.
+        */
+
+       SAVE_HINT_MAP_WRITE(map, new_entry);
+       return new_entry;
 }
 
 /*
- *     vm_map_behavior_set:
+ *     Routine:        vm_map_remap_extract
  *
- *     Sets the paging reference behavior of the specified address
- *     range in the target map.  Paging reference behavior affects
- *     how pagein operations resulting from faults on the map will be 
- *     clustered.
+ *     Descritpion:    This routine returns a vm_entry list from a map.
  */
-kern_return_t 
-vm_map_behavior_set(
-       vm_map_t        map,
-       vm_offset_t     start,
-       vm_offset_t     end,
-       vm_behavior_t   new_behavior)
+static kern_return_t
+vm_map_remap_extract(
+       vm_map_t                map,
+       vm_map_offset_t         addr,
+       vm_map_size_t           size,
+       boolean_t               copy,
+       struct vm_map_header    *map_header,
+       vm_prot_t               *cur_protection,
+       vm_prot_t               *max_protection,
+       /* What, no behavior? */
+       vm_inherit_t            inheritance,
+       boolean_t               pageable)
 {
-       register vm_map_entry_t entry;
-       vm_map_entry_t  temp_entry;
-
-       XPR(XPR_VM_MAP,
-               "vm_map_behavior_set, 0x%X start 0x%X end 0x%X behavior %d",
-               (integer_t)map, start, end, new_behavior, 0);
+       kern_return_t           result;
+       vm_map_size_t           mapped_size;
+       vm_map_size_t           tmp_size;
+       vm_map_entry_t          src_entry;     /* result of last map lookup */
+       vm_map_entry_t          new_entry;
+       vm_object_offset_t      offset;
+       vm_map_offset_t         map_address;
+       vm_map_offset_t         src_start;     /* start of entry to map */
+       vm_map_offset_t         src_end;       /* end of region to be mapped */
+       vm_object_t             object;    
+       vm_map_version_t        version;
+       boolean_t               src_needs_copy;
+       boolean_t               new_entry_needs_copy;
 
-       switch (new_behavior) {
-       case VM_BEHAVIOR_DEFAULT:
-       case VM_BEHAVIOR_RANDOM:
-       case VM_BEHAVIOR_SEQUENTIAL:
-       case VM_BEHAVIOR_RSEQNTL:
-               break;
-       case VM_BEHAVIOR_WILLNEED:
-       case VM_BEHAVIOR_DONTNEED:
-               new_behavior = VM_BEHAVIOR_DEFAULT;
-               break;
-       default:
-               return(KERN_INVALID_ARGUMENT);
-       }
+       assert(map != VM_MAP_NULL);
+       assert(size != 0 && size == vm_map_round_page(size));
+       assert(inheritance == VM_INHERIT_NONE ||
+              inheritance == VM_INHERIT_COPY ||
+              inheritance == VM_INHERIT_SHARE);
 
-       vm_map_lock(map);
+       /*
+        *      Compute start and end of region.
+        */
+       src_start = vm_map_trunc_page(addr);
+       src_end = vm_map_round_page(src_start + size);
 
        /*
-        *      The entire address range must be valid for the map.
-        *      Note that vm_map_range_check() does a 
-        *      vm_map_lookup_entry() internally and returns the
-        *      entry containing the start of the address range if
-        *      the entire range is valid.
+        *      Initialize map_header.
         */
-       if (vm_map_range_check(map, start, end, &temp_entry)) {
-               entry = temp_entry;
-               vm_map_clip_start(map, entry, start);
-       }
-       else {
-               vm_map_unlock(map);
-               return(KERN_INVALID_ADDRESS);
-       }
+       map_header->links.next = (struct vm_map_entry *)&map_header->links;
+       map_header->links.prev = (struct vm_map_entry *)&map_header->links;
+       map_header->nentries = 0;
+       map_header->entries_pageable = pageable;
 
-       while ((entry != vm_map_to_entry(map)) && (entry->vme_start < end)) {
-               vm_map_clip_end(map, entry, end);
+       *cur_protection = VM_PROT_ALL;
+       *max_protection = VM_PROT_ALL;
+
+       map_address = 0;
+       mapped_size = 0;
+       result = KERN_SUCCESS;
+
+       /*  
+        *      The specified source virtual space might correspond to
+        *      multiple map entries, need to loop on them.
+        */
+       vm_map_lock(map);
+       while (mapped_size != size) {
+               vm_map_size_t   entry_size;
+
+               /*
+                *      Find the beginning of the region.
+                */ 
+               if (! vm_map_lookup_entry(map, src_start, &src_entry)) {
+                       result = KERN_INVALID_ADDRESS;
+                       break;
+               }
 
-               entry->behavior = new_behavior;
+               if (src_start < src_entry->vme_start ||
+                   (mapped_size && src_start != src_entry->vme_start)) {
+                       result = KERN_INVALID_ADDRESS;
+                       break;
+               }
 
-               entry = entry->vme_next;
-       }
+               tmp_size = size - mapped_size;
+               if (src_end > src_entry->vme_end)
+                       tmp_size -= (src_end - src_entry->vme_end);
 
-       vm_map_unlock(map);
-       return(KERN_SUCCESS);
-}
+               entry_size = (vm_map_size_t)(src_entry->vme_end -
+                                            src_entry->vme_start);
 
+               if(src_entry->is_sub_map) {
+                       vm_map_reference(src_entry->object.sub_map);
+                       object = VM_OBJECT_NULL;
+               } else {
+                       object = src_entry->object.vm_object;
 
-#include <mach_kdb.h>
-#if    MACH_KDB
-#include <ddb/db_output.h>
-#include <vm/vm_print.h>
+                       if (object == VM_OBJECT_NULL) {
+                               object = vm_object_allocate(entry_size);
+                               src_entry->offset = 0;
+                               src_entry->object.vm_object = object;
+                       } else if (object->copy_strategy !=
+                                  MEMORY_OBJECT_COPY_SYMMETRIC) {
+                               /*
+                                *      We are already using an asymmetric
+                                *      copy, and therefore we already have
+                                *      the right object.
+                                */
+                               assert(!src_entry->needs_copy);
+                       } else if (src_entry->needs_copy || object->shadowed ||
+                                  (object->internal && !object->true_share &&
+                                   !src_entry->is_shared &&
+                                   object->size > entry_size)) {
 
-#define        printf  db_printf
+                               vm_object_shadow(&src_entry->object.vm_object,
+                                                &src_entry->offset,
+                                                entry_size);
 
-/*
- * Forward declarations for internal functions.
- */
-extern void vm_map_links_print(
-               struct vm_map_links     *links);
+                               if (!src_entry->needs_copy &&
+                                   (src_entry->protection & VM_PROT_WRITE)) {
+                                       vm_prot_t prot;
 
-extern void vm_map_header_print(
-               struct vm_map_header    *header);
+                                       prot = src_entry->protection & ~VM_PROT_WRITE;
 
-extern void vm_map_entry_print(
-               vm_map_entry_t          entry);
+                                       if (override_nx(map, src_entry->alias) && prot)
+                                               prot |= VM_PROT_EXECUTE;
 
-extern void vm_follow_entry(
-               vm_map_entry_t          entry);
+                                       if(map->mapped) {
+                                               vm_object_pmap_protect(
+                                                       src_entry->object.vm_object,
+                                                       src_entry->offset,
+                                                       entry_size,
+                                                       PMAP_NULL,
+                                                       src_entry->vme_start,
+                                                       prot);
+                                       } else {
+                                               pmap_protect(vm_map_pmap(map),
+                                                            src_entry->vme_start,
+                                                            src_entry->vme_end,
+                                                            prot);
+                                       }
+                               }
 
-extern void vm_follow_map(
-               vm_map_t                map);
+                               object = src_entry->object.vm_object;
+                               src_entry->needs_copy = FALSE;
+                       }
 
-/*
- *     vm_map_links_print:     [ debug ]
- */
-void
-vm_map_links_print(
-       struct vm_map_links     *links)
-{
-       iprintf("prev = %08X  next = %08X  start = %08X  end = %08X\n",
-               links->prev,
-               links->next,
-               links->start,
-               links->end);
-}
 
-/*
- *     vm_map_header_print:    [ debug ]
- */
-void
-vm_map_header_print(
-       struct vm_map_header    *header)
-{
-       vm_map_links_print(&header->links);
-       iprintf("nentries = %08X, %sentries_pageable\n",
-               header->nentries,
-               (header->entries_pageable ? "" : "!"));
-}
+                       vm_object_lock(object);
+                       vm_object_reference_locked(object); /* object ref. for new entry */
+                       if (object->copy_strategy == 
+                           MEMORY_OBJECT_COPY_SYMMETRIC) {
+                               object->copy_strategy = 
+                                       MEMORY_OBJECT_COPY_DELAY;
+                       }
+                       vm_object_unlock(object);
+               }
 
-/*
- *     vm_follow_entry:        [ debug ]
- */
-void
-vm_follow_entry(
-       vm_map_entry_t entry)
-{
-       extern int db_indent;
-       int shadows;
+               offset = src_entry->offset + (src_start - src_entry->vme_start);
 
-       iprintf("map entry %08X\n", entry);
+               new_entry = _vm_map_entry_create(map_header);
+               vm_map_entry_copy(new_entry, src_entry);
+               new_entry->use_pmap = FALSE; /* clr address space specifics */
 
-       db_indent += 2;
+               new_entry->vme_start = map_address;
+               new_entry->vme_end = map_address + tmp_size;
+               new_entry->inheritance = inheritance;
+               new_entry->offset = offset;
 
-       shadows = vm_follow_object(entry->object.vm_object);
-       iprintf("Total objects : %d\n",shadows);
+               /*
+                * The new region has to be copied now if required.
+                */
+       RestartCopy:
+               if (!copy) {
+                       src_entry->is_shared = TRUE;
+                       new_entry->is_shared = TRUE;
+                       if (!(new_entry->is_sub_map)) 
+                               new_entry->needs_copy = FALSE;
 
-       db_indent -= 2;
-}
+               } else if (src_entry->is_sub_map) {
+                       /* make this a COW sub_map if not already */
+                       new_entry->needs_copy = TRUE;
+                       object = VM_OBJECT_NULL;
+               } else if (src_entry->wired_count == 0 &&
+                          vm_object_copy_quickly(&new_entry->object.vm_object,
+                                                 new_entry->offset,
+                                                 (new_entry->vme_end -
+                                                  new_entry->vme_start),
+                                                 &src_needs_copy,
+                                                 &new_entry_needs_copy)) {
 
-/*
- *     vm_map_entry_print:     [ debug ]
- */
-void
-vm_map_entry_print(
-       register vm_map_entry_t entry)
-{
-       extern int db_indent;
-       static char *inheritance_name[4] = { "share", "copy", "none", "?"};
-       static char *behavior_name[4] = { "dflt", "rand", "seqtl", "rseqntl" };
-       
-       iprintf("map entry %08X n", entry);
+                       new_entry->needs_copy = new_entry_needs_copy;
+                       new_entry->is_shared = FALSE;
 
-       db_indent += 2;
+                       /*
+                        * Handle copy_on_write semantics.
+                        */
+                       if (src_needs_copy && !src_entry->needs_copy) {
+                               vm_prot_t prot;
 
-       vm_map_links_print(&entry->links);
+                               prot = src_entry->protection & ~VM_PROT_WRITE;
 
-       iprintf("start = %08X  end = %08X, prot=%x/%x/%s\n",
-               entry->vme_start,
-               entry->vme_end,
-               entry->protection,
-               entry->max_protection,
-               inheritance_name[(entry->inheritance & 0x3)]);
+                               if (override_nx(map, src_entry->alias) && prot)
+                                       prot |= VM_PROT_EXECUTE;
 
-       iprintf("behavior = %s, wired_count = %d, user_wired_count = %d\n",
-               behavior_name[(entry->behavior & 0x3)],
-               entry->wired_count,
-               entry->user_wired_count);
-       iprintf("%sin_transition, %sneeds_wakeup\n",
-               (entry->in_transition ? "" : "!"),
-               (entry->needs_wakeup ? "" : "!"));
+                               vm_object_pmap_protect(object,
+                                                      offset,
+                                                      entry_size,
+                                                      ((src_entry->is_shared 
+                                                        || map->mapped) ?
+                                                       PMAP_NULL : map->pmap),
+                                                      src_entry->vme_start,
+                                                      prot);
 
-       if (entry->is_sub_map) {
-               iprintf("submap = %08X - offset=%08X\n",
-                      entry->object.sub_map,
-                      entry->offset);
-       } else {
-               iprintf("object=%08X, offset=%08X, ",
-                       entry->object.vm_object,
-                       entry->offset);
-               printf("%sis_shared, %sneeds_copy\n",
-                      (entry->is_shared ? "" : "!"),
-                      (entry->needs_copy ? "" : "!"));
-       }
+                               src_entry->needs_copy = TRUE;
+                       }
+                       /*
+                        * Throw away the old object reference of the new entry.
+                        */
+                       vm_object_deallocate(object);
 
-       db_indent -= 2;
-}
+               } else {
+                       new_entry->is_shared = FALSE;
 
-/*
- *     vm_follow_map:  [ debug ]
- */
-void
-vm_follow_map(
-       vm_map_t map)
-{
-       register vm_map_entry_t entry;
-       extern int db_indent;
+                       /*
+                        * The map can be safely unlocked since we
+                        * already hold a reference on the object.
+                        *
+                        * Record the timestamp of the map for later
+                        * verification, and unlock the map.
+                        */
+                       version.main_timestamp = map->timestamp;
+                       vm_map_unlock(map);     /* Increments timestamp once! */
 
-       iprintf("task map %08X\n", map);
+                       /*
+                        * Perform the copy.
+                        */
+                       if (src_entry->wired_count > 0) {
+                               vm_object_lock(object);
+                               result = vm_object_copy_slowly(
+                                       object,
+                                       offset,
+                                       entry_size,
+                                       THREAD_UNINT,
+                                       &new_entry->object.vm_object);
 
-       db_indent += 2;
+                               new_entry->offset = 0;
+                               new_entry->needs_copy = FALSE;
+                       } else {
+                               result = vm_object_copy_strategically(
+                                       object,
+                                       offset,
+                                       entry_size,
+                                       &new_entry->object.vm_object,
+                                       &new_entry->offset,
+                                       &new_entry_needs_copy);
 
-       for (entry = vm_map_first_entry(map);
-            entry && entry != vm_map_to_entry(map);
-            entry = entry->vme_next) {
-           vm_follow_entry(entry);
-       }
+                               new_entry->needs_copy = new_entry_needs_copy;
+                       }
 
-       db_indent -= 2;
-}
+                       /*
+                        * Throw away the old object reference of the new entry.
+                        */
+                       vm_object_deallocate(object);
 
-/*
- *     vm_map_print:   [ debug ]
- */
-void
-vm_map_print(
-       db_addr_t inmap)
-{
-       register vm_map_entry_t entry;
-       vm_map_t map;
-       extern int db_indent;
-       char *swstate;
+                       if (result != KERN_SUCCESS &&
+                           result != KERN_MEMORY_RESTART_COPY) {
+                               _vm_map_entry_dispose(map_header, new_entry);
+                               break;
+                       }
 
-       map = (vm_map_t)inmap;                          /* Make sure we have the right type */
+                       /*
+                        * Verify that the map has not substantially
+                        * changed while the copy was being made.
+                        */
 
-       iprintf("task map %08X\n", map);
+                       vm_map_lock(map);
+                       if (version.main_timestamp + 1 != map->timestamp) {
+                               /*
+                                * Simple version comparison failed.
+                                *
+                                * Retry the lookup and verify that the
+                                * same object/offset are still present.
+                                */
+                               vm_object_deallocate(new_entry->
+                                                    object.vm_object);
+                               _vm_map_entry_dispose(map_header, new_entry);
+                               if (result == KERN_MEMORY_RESTART_COPY)
+                                       result = KERN_SUCCESS;
+                               continue;
+                       }
 
-       db_indent += 2;
+                       if (result == KERN_MEMORY_RESTART_COPY) {
+                               vm_object_reference(object);
+                               goto RestartCopy;
+                       }
+               }
 
-       vm_map_header_print(&map->hdr);
+               _vm_map_entry_link(map_header,
+                                  map_header->links.prev, new_entry);
 
-       iprintf("pmap = %08X, size = %08X, ref = %d, hint = %08X, first_free = %08X\n",
-               map->pmap,
-               map->size,
-               map->ref_count,
-               map->hint,
-               map->first_free);
+               *cur_protection &= src_entry->protection;
+               *max_protection &= src_entry->max_protection;
 
-       iprintf("%swait_for_space, %swiring_required, timestamp = %d\n",
-               (map->wait_for_space ? "" : "!"),
-               (map->wiring_required ? "" : "!"),
-               map->timestamp);
+               map_address += tmp_size;
+               mapped_size += tmp_size;
+               src_start += tmp_size;
 
-#if    TASK_SWAPPER
-       switch (map->sw_state) {
-           case MAP_SW_IN:
-               swstate = "SW_IN";
-               break;
-           case MAP_SW_OUT:
-               swstate = "SW_OUT";
-               break;
-           default:
-               swstate = "????";
-               break;
-       }
-       iprintf("res = %d, sw_state = %s\n", map->res_count, swstate);
-#endif /* TASK_SWAPPER */
+       } /* end while */
 
-       for (entry = vm_map_first_entry(map);
-            entry && entry != vm_map_to_entry(map);
-            entry = entry->vme_next) {
-               vm_map_entry_print(entry);
+       vm_map_unlock(map);
+       if (result != KERN_SUCCESS) {
+               /*
+                * Free all allocated elements.
+                */
+               for (src_entry = map_header->links.next;
+                    src_entry != (struct vm_map_entry *)&map_header->links;
+                    src_entry = new_entry) {
+                       new_entry = src_entry->vme_next;
+                       _vm_map_entry_unlink(map_header, src_entry);
+                       vm_object_deallocate(src_entry->object.vm_object);
+                       _vm_map_entry_dispose(map_header, src_entry);
+               }
        }
-
-       db_indent -= 2;
+       return result;
 }
 
 /*
- *     Routine:        vm_map_copy_print
- *     Purpose:
- *             Pretty-print a copy object for ddb.
+ *     Routine:        vm_remap
+ *
+ *                     Map portion of a task's address space.
+ *                     Mapped region must not overlap more than
+ *                     one vm memory object. Protections and
+ *                     inheritance attributes remain the same
+ *                     as in the original task and are out parameters.
+ *                     Source and Target task can be identical
+ *                     Other attributes are identical as for vm_map()
  */
-
-void
-vm_map_copy_print(
-       db_addr_t       incopy)
+kern_return_t
+vm_map_remap(
+       vm_map_t                target_map,
+       vm_map_address_t        *address,
+       vm_map_size_t           size,
+       vm_map_offset_t         mask,
+       boolean_t               anywhere,
+       vm_map_t                src_map,
+       vm_map_offset_t         memory_address,
+       boolean_t               copy,
+       vm_prot_t               *cur_protection,
+       vm_prot_t               *max_protection,
+       vm_inherit_t            inheritance)
 {
-       extern int db_indent;
-       vm_map_copy_t copy;
-       int i, npages;
-       vm_map_entry_t entry;
-
-       copy = (vm_map_copy_t)incopy;   /* Make sure we have the right type */
-
-       printf("copy object 0x%x\n", copy);
-
-       db_indent += 2;
+       kern_return_t           result;
+       vm_map_entry_t          entry;
+       vm_map_entry_t          insp_entry = VM_MAP_ENTRY_NULL;
+       vm_map_entry_t          new_entry;
+       struct vm_map_header    map_header;
 
-       iprintf("type=%d", copy->type);
-       switch (copy->type) {
-               case VM_MAP_COPY_ENTRY_LIST:
-               printf("[entry_list]");
-               break;
-               
-               case VM_MAP_COPY_OBJECT:
-               printf("[object]");
-               break;
-               
-               case VM_MAP_COPY_KERNEL_BUFFER:
-               printf("[kernel_buffer]");
-               break;
+       if (target_map == VM_MAP_NULL)
+               return KERN_INVALID_ARGUMENT;
 
-               default:
-               printf("[bad type]");
-               break;
+       switch (inheritance) {
+       case VM_INHERIT_NONE:
+       case VM_INHERIT_COPY:
+       case VM_INHERIT_SHARE:
+               if (size != 0 && src_map != VM_MAP_NULL)
+                       break;
+               /*FALL THRU*/
+       default:
+               return KERN_INVALID_ARGUMENT;
        }
-       printf(", offset=0x%x", copy->offset);
-       printf(", size=0x%x\n", copy->size);
-
-       switch (copy->type) {
-               case VM_MAP_COPY_ENTRY_LIST:
-               vm_map_header_print(&copy->cpy_hdr);
-               for (entry = vm_map_copy_first_entry(copy);
-                    entry && entry != vm_map_copy_to_entry(copy);
-                    entry = entry->vme_next) {
-                       vm_map_entry_print(entry);
-               }
-               break;
 
-               case VM_MAP_COPY_OBJECT:
-               iprintf("object=0x%x\n", copy->cpy_object);
-               break;
+       size = vm_map_round_page(size);
 
-               case VM_MAP_COPY_KERNEL_BUFFER:
-               iprintf("kernel buffer=0x%x", copy->cpy_kdata);
-               printf(", kalloc_size=0x%x\n", copy->cpy_kalloc_size);
-               break;
+       result = vm_map_remap_extract(src_map, memory_address,
+                                     size, copy, &map_header,
+                                     cur_protection,
+                                     max_protection,
+                                     inheritance,
+                                     target_map->hdr.
+                                     entries_pageable);
 
+       if (result != KERN_SUCCESS) {
+               return result;
        }
 
-       db_indent -=2;
-}
-
-/*
- *     db_vm_map_total_size(map)       [ debug ]
- *
- *     return the total virtual size (in bytes) of the map
- */
-vm_size_t
-db_vm_map_total_size(
-       db_addr_t       inmap)
-{
-       vm_map_entry_t  entry;
-       vm_size_t       total;
-       vm_map_t map;
+       /*
+        * Allocate/check a range of free virtual address
+        * space for the target
+        */
+       *address = vm_map_trunc_page(*address);
+       vm_map_lock(target_map);
+       result = vm_map_remap_range_allocate(target_map, address, size,
+                                            mask, anywhere, &insp_entry);
 
-       map = (vm_map_t)inmap;  /* Make sure we have the right type */
+       for (entry = map_header.links.next;
+            entry != (struct vm_map_entry *)&map_header.links;
+            entry = new_entry) {
+               new_entry = entry->vme_next;
+               _vm_map_entry_unlink(&map_header, entry);
+               if (result == KERN_SUCCESS) {
+                       entry->vme_start += *address;
+                       entry->vme_end += *address;
+                       vm_map_entry_link(target_map, insp_entry, entry);
+                       insp_entry = entry;
+               } else {
+                       if (!entry->is_sub_map) {
+                               vm_object_deallocate(entry->object.vm_object);
+                       } else {
+                               vm_map_deallocate(entry->object.sub_map);
+                       }
+                       _vm_map_entry_dispose(&map_header, entry);
+               }
+       }
 
-       total = 0;
-       for (entry = vm_map_first_entry(map);
-            entry != vm_map_to_entry(map);
-            entry = entry->vme_next) {
-               total += entry->vme_end - entry->vme_start;
+       if (result == KERN_SUCCESS) {
+               target_map->size += size;
+               SAVE_HINT_MAP_WRITE(target_map, insp_entry);
        }
+       vm_map_unlock(target_map);
 
-       return total;
+       if (result == KERN_SUCCESS && target_map->wiring_required)
+               result = vm_map_wire(target_map, *address,
+                                    *address + size, *cur_protection, TRUE);
+       return result;
 }
 
-#endif /* MACH_KDB */
-
 /*
- *     Routine:        vm_map_entry_insert
+ *     Routine:        vm_map_remap_range_allocate
  *
- *     Descritpion:    This routine inserts a new vm_entry in a locked map.
+ *     Description:
+ *             Allocate a range in the specified virtual address map.
+ *             returns the address and the map entry just before the allocated
+ *             range
+ *
+ *     Map must be locked.
  */
-vm_map_entry_t
-vm_map_entry_insert(
+
+static kern_return_t
+vm_map_remap_range_allocate(
        vm_map_t                map,
-       vm_map_entry_t          insp_entry,
-       vm_offset_t             start,
-       vm_offset_t             end,
-       vm_object_t             object,
-       vm_object_offset_t      offset,
-       boolean_t               needs_copy,
-       boolean_t               is_shared,
-       boolean_t               in_transition,
-       vm_prot_t               cur_protection,
-       vm_prot_t               max_protection,
-       vm_behavior_t           behavior,
-       vm_inherit_t            inheritance,
-       unsigned                wired_count)
+       vm_map_address_t        *address,       /* IN/OUT */
+       vm_map_size_t           size,
+       vm_map_offset_t         mask,
+       boolean_t               anywhere,
+       vm_map_entry_t          *map_entry)     /* OUT */
 {
-       vm_map_entry_t  new_entry;
-
-       assert(insp_entry != (vm_map_entry_t)0);
-
-       new_entry = vm_map_entry_create(map);
+       register vm_map_entry_t entry;
+       register vm_map_offset_t        start;
+       register vm_map_offset_t        end;
 
-       new_entry->vme_start = start;
-       new_entry->vme_end = end;
-       assert(page_aligned(new_entry->vme_start));
-       assert(page_aligned(new_entry->vme_end));
+StartAgain: ;
 
-       new_entry->object.vm_object = object;
-       new_entry->offset = offset;
-       new_entry->is_shared = is_shared;
-       new_entry->is_sub_map = FALSE;
-       new_entry->needs_copy = needs_copy;
-       new_entry->in_transition = in_transition;
-       new_entry->needs_wakeup = FALSE;
-       new_entry->inheritance = inheritance;
-       new_entry->protection = cur_protection;
-       new_entry->max_protection = max_protection;
-       new_entry->behavior = behavior;
-       new_entry->wired_count = wired_count;
-       new_entry->user_wired_count = 0;
-       new_entry->use_pmap = FALSE;
+       start = *address;
 
-       /*
-        *      Insert the new entry into the list.
-        */
+       if (anywhere)
+       {
+               /*
+                *      Calculate the first possible address.
+                */
 
-       vm_map_entry_link(map, insp_entry, new_entry);
-       map->size += end - start;
+               if (start < map->min_offset)
+                       start = map->min_offset;
+               if (start > map->max_offset)
+                       return(KERN_NO_SPACE);
+               
+               /*
+                *      Look for the first possible address;
+                *      if there's already something at this
+                *      address, we have to start after it.
+                */
 
-       /*
-        *      Update the free space hint and the lookup hint.
-        */
+               assert(first_free_is_valid(map));
+               if (start == map->min_offset) {
+                       if ((entry = map->first_free) != vm_map_to_entry(map))
+                               start = entry->vme_end;
+               } else {
+                       vm_map_entry_t  tmp_entry;
+                       if (vm_map_lookup_entry(map, start, &tmp_entry))
+                               start = tmp_entry->vme_end;
+                       entry = tmp_entry;
+               }
+               
+               /*
+                *      In any case, the "entry" always precedes
+                *      the proposed new region throughout the
+                *      loop:
+                */
 
-       SAVE_HINT(map, new_entry);
-       return new_entry;
-}
+               while (TRUE) {
+                       register vm_map_entry_t next;
 
-/*
- *     Routine:        vm_remap_extract
- *
- *     Descritpion:    This routine returns a vm_entry list from a map.
- */
-kern_return_t
-vm_remap_extract(
-       vm_map_t                map,
-       vm_offset_t             addr,
-       vm_size_t               size,
-       boolean_t               copy,
-       struct vm_map_header    *map_header,
-       vm_prot_t               *cur_protection,
-       vm_prot_t               *max_protection,
-       /* What, no behavior? */
-       vm_inherit_t            inheritance,
-       boolean_t               pageable)
-{
-       kern_return_t           result;
-       vm_size_t               mapped_size;
-       vm_size_t               tmp_size;
-       vm_map_entry_t          src_entry;     /* result of last map lookup */
-       vm_map_entry_t          new_entry;
-       vm_object_offset_t      offset;
-       vm_offset_t             map_address;
-       vm_offset_t             src_start;     /* start of entry to map */
-       vm_offset_t             src_end;       /* end of region to be mapped */
-       vm_object_t             object;    
-       vm_map_version_t        version;
-       boolean_t               src_needs_copy;
-       boolean_t               new_entry_needs_copy;
+                       /*
+                        *      Find the end of the proposed new region.
+                        *      Be sure we didn't go beyond the end, or
+                        *      wrap around the address.
+                        */
 
-       assert(map != VM_MAP_NULL);
-       assert(size != 0 && size == round_page_32(size));
-       assert(inheritance == VM_INHERIT_NONE ||
-              inheritance == VM_INHERIT_COPY ||
-              inheritance == VM_INHERIT_SHARE);
+                       end = ((start + mask) & ~mask);
+                       if (end < start)
+                               return(KERN_NO_SPACE);
+                       start = end;
+                       end += size;
 
-       /*
-        *      Compute start and end of region.
-        */
-       src_start = trunc_page_32(addr);
-       src_end = round_page_32(src_start + size);
+                       if ((end > map->max_offset) || (end < start)) {
+                               if (map->wait_for_space) {
+                                       if (size <= (map->max_offset -
+                                                    map->min_offset)) {
+                                               assert_wait((event_t) map, THREAD_INTERRUPTIBLE);
+                                               vm_map_unlock(map);
+                                               thread_block(THREAD_CONTINUE_NULL);
+                                               vm_map_lock(map);
+                                               goto StartAgain;
+                                       }
+                               }
+               
+                               return(KERN_NO_SPACE);
+                       }
 
-       /*
-        *      Initialize map_header.
-        */
-       map_header->links.next = (struct vm_map_entry *)&map_header->links;
-       map_header->links.prev = (struct vm_map_entry *)&map_header->links;
-       map_header->nentries = 0;
-       map_header->entries_pageable = pageable;
+                       /*
+                        *      If there are no more entries, we must win.
+                        */
 
-       *cur_protection = VM_PROT_ALL;
-       *max_protection = VM_PROT_ALL;
+                       next = entry->vme_next;
+                       if (next == vm_map_to_entry(map))
+                               break;
 
-       map_address = 0;
-       mapped_size = 0;
-       result = KERN_SUCCESS;
+                       /*
+                        *      If there is another entry, it must be
+                        *      after the end of the potential new region.
+                        */
 
-       /*  
-        *      The specified source virtual space might correspond to
-        *      multiple map entries, need to loop on them.
-        */
-       vm_map_lock(map);
-       while (mapped_size != size) {
-               vm_size_t       entry_size;
+                       if (next->vme_start >= end)
+                               break;
 
-               /*
-                *      Find the beginning of the region.
-                */ 
-               if (! vm_map_lookup_entry(map, src_start, &src_entry)) {
-                       result = KERN_INVALID_ADDRESS;
-                       break;
-               }
+                       /*
+                        *      Didn't fit -- move to the next entry.
+                        */
 
-               if (src_start < src_entry->vme_start ||
-                   (mapped_size && src_start != src_entry->vme_start)) {
-                       result = KERN_INVALID_ADDRESS;
-                       break;
+                       entry = next;
+                       start = entry->vme_end;
                }
+               *address = start;
+       } else {
+               vm_map_entry_t          temp_entry;
+       
+               /*
+                *      Verify that:
+                *              the address doesn't itself violate
+                *              the mask requirement.
+                */
 
-               if(src_entry->is_sub_map) {
-                       result = KERN_INVALID_ADDRESS;
-                       break;
-               }
+               if ((start & mask) != 0)
+                       return(KERN_NO_SPACE);
 
-               tmp_size = size - mapped_size;
-               if (src_end > src_entry->vme_end)
-                       tmp_size -= (src_end - src_entry->vme_end);
 
-               entry_size = (vm_size_t)(src_entry->vme_end -
-                                        src_entry->vme_start);
+               /*
+                *      ...     the address is within bounds
+                */
 
-               if(src_entry->is_sub_map) {
-                       vm_map_reference(src_entry->object.sub_map);
-               } else {
-                       object = src_entry->object.vm_object;
+               end = start + size;
 
-                       if (object == VM_OBJECT_NULL) {
-                               object = vm_object_allocate(entry_size);
-                               src_entry->offset = 0;
-                               src_entry->object.vm_object = object;
-                       } else if (object->copy_strategy !=
-                                  MEMORY_OBJECT_COPY_SYMMETRIC) {
-                               /*
-                                *      We are already using an asymmetric
-                                *      copy, and therefore we already have
-                                *      the right object.
-                                */
-                               assert(!src_entry->needs_copy);
-                       } else if (src_entry->needs_copy || object->shadowed ||
-                                  (object->internal && !object->true_share &&
-                                  !src_entry->is_shared &&
-                                   object->size > entry_size)) {
+               if ((start < map->min_offset) ||
+                   (end > map->max_offset) ||
+                   (start >= end)) {
+                       return(KERN_INVALID_ADDRESS);
+               }
 
-                               vm_object_shadow(&src_entry->object.vm_object,
-                                                &src_entry->offset,
-                                                entry_size);
+               /*
+                *      ...     the starting address isn't allocated
+                */
 
-                               if (!src_entry->needs_copy &&
-                                   (src_entry->protection & VM_PROT_WRITE)) {
-                                       if(map->mapped) {
-                                          vm_object_pmap_protect(
-                                               src_entry->object.vm_object,
-                                               src_entry->offset,
-                                               entry_size,
-                                               PMAP_NULL,
-                                               src_entry->vme_start,
-                                               src_entry->protection &
-                                                      ~VM_PROT_WRITE);
-                                       } else {
-                                          pmap_protect(vm_map_pmap(map),
-                                                src_entry->vme_start,
-                                               src_entry->vme_end,
-                                               src_entry->protection &
-                                                    ~VM_PROT_WRITE);
-                                       }
-                               }
+               if (vm_map_lookup_entry(map, start, &temp_entry))
+                       return(KERN_NO_SPACE);
 
-                               object = src_entry->object.vm_object;
-                               src_entry->needs_copy = FALSE;
-                       }
+               entry = temp_entry;
 
+               /*
+                *      ...     the next region doesn't overlap the
+                *              end point.
+                */
 
-                       vm_object_lock(object);
-                       object->ref_count++;    /* object ref. for new entry */
-                       VM_OBJ_RES_INCR(object);
-                       if (object->copy_strategy == 
-                                       MEMORY_OBJECT_COPY_SYMMETRIC) {
-                               object->copy_strategy = 
-                                       MEMORY_OBJECT_COPY_DELAY;
-                       }
-                       vm_object_unlock(object);
-               }
+               if ((entry->vme_next != vm_map_to_entry(map)) &&
+                   (entry->vme_next->vme_start < end))
+                       return(KERN_NO_SPACE);
+       }
+       *map_entry = entry;
+       return(KERN_SUCCESS);
+}
 
-               offset = src_entry->offset + (src_start - src_entry->vme_start);
+/*
+ *     vm_map_switch:
+ *
+ *     Set the address map for the current thread to the specified map
+ */
 
-               new_entry = _vm_map_entry_create(map_header);
-               vm_map_entry_copy(new_entry, src_entry);
-               new_entry->use_pmap = FALSE; /* clr address space specifics */
+vm_map_t
+vm_map_switch(
+       vm_map_t        map)
+{
+       int             mycpu;
+       thread_t        thread = current_thread();
+       vm_map_t        oldmap = thread->map;
 
-               new_entry->vme_start = map_address;
-               new_entry->vme_end = map_address + tmp_size;
-               new_entry->inheritance = inheritance;
-               new_entry->offset = offset;
+       mp_disable_preemption();
+       mycpu = cpu_number();
 
-               /*
-                * The new region has to be copied now if required.
-                */
-       RestartCopy:
-               if (!copy) {
-                       src_entry->is_shared = TRUE;
-                       new_entry->is_shared = TRUE;
-                       if (!(new_entry->is_sub_map)) 
-                               new_entry->needs_copy = FALSE;
+       /*
+        *      Deactivate the current map and activate the requested map
+        */
+       PMAP_SWITCH_USER(thread, map, mycpu);
 
-               } else if (src_entry->is_sub_map) {
-                       /* make this a COW sub_map if not already */
-                       new_entry->needs_copy = TRUE;
-               } else if (src_entry->wired_count == 0 &&
-                        vm_object_copy_quickly(&new_entry->object.vm_object,
-                                               new_entry->offset,
-                                               (new_entry->vme_end -
-                                                   new_entry->vme_start),
-                                               &src_needs_copy,
-                                               &new_entry_needs_copy)) {
+       mp_enable_preemption();
+       return(oldmap);
+}
 
-                       new_entry->needs_copy = new_entry_needs_copy;
-                       new_entry->is_shared = FALSE;
 
-                       /*
-                        * Handle copy_on_write semantics.
-                        */
-                       if (src_needs_copy && !src_entry->needs_copy) {
-                               vm_object_pmap_protect(object,
-                                                      offset,
-                                                      entry_size,
-                                                      ((src_entry->is_shared 
-                                                         || map->mapped) ?
-                                                       PMAP_NULL : map->pmap),
-                                                      src_entry->vme_start,
-                                                      src_entry->protection &
-                                                      ~VM_PROT_WRITE);
+/*
+ *     Routine:        vm_map_write_user
+ *
+ *     Description:
+ *             Copy out data from a kernel space into space in the
+ *             destination map. The space must already exist in the
+ *             destination map.
+ *             NOTE:  This routine should only be called by threads
+ *             which can block on a page fault. i.e. kernel mode user
+ *             threads.
+ *
+ */
+kern_return_t
+vm_map_write_user(
+       vm_map_t                map,
+       void                    *src_p,
+       vm_map_address_t        dst_addr,
+       vm_size_t               size)
+{
+       kern_return_t   kr = KERN_SUCCESS;
 
-                               src_entry->needs_copy = TRUE;
-                       }
-                       /*
-                        * Throw away the old object reference of the new entry.
-                        */
-                       vm_object_deallocate(object);
+       if(current_map() == map) {
+               if (copyout(src_p, dst_addr, size)) {
+                       kr = KERN_INVALID_ADDRESS;
+               }
+       } else {
+               vm_map_t        oldmap;
 
-               } else {
-                       new_entry->is_shared = FALSE;
+               /* take on the identity of the target map while doing */
+               /* the transfer */
 
-                       /*
-                        * The map can be safely unlocked since we
-                        * already hold a reference on the object.
-                        *
-                        * Record the timestamp of the map for later
-                        * verification, and unlock the map.
-                        */
-                       version.main_timestamp = map->timestamp;
-                       vm_map_unlock(map);     /* Increments timestamp once! */
+               vm_map_reference(map);
+               oldmap = vm_map_switch(map);
+               if (copyout(src_p, dst_addr, size)) {
+                       kr = KERN_INVALID_ADDRESS;
+               }
+               vm_map_switch(oldmap);
+               vm_map_deallocate(map);
+       }
+       return kr;
+}
 
-                       /*
-                        * Perform the copy.
-                        */
-                       if (src_entry->wired_count > 0) {
-                               vm_object_lock(object);
-                               result = vm_object_copy_slowly(
-                                               object,
-                                               offset,
-                                               entry_size,
-                                               THREAD_UNINT,
-                                               &new_entry->object.vm_object);
+/*
+ *     Routine:        vm_map_read_user
+ *
+ *     Description:
+ *             Copy in data from a user space source map into the
+ *             kernel map. The space must already exist in the
+ *             kernel map.
+ *             NOTE:  This routine should only be called by threads
+ *             which can block on a page fault. i.e. kernel mode user
+ *             threads.
+ *
+ */
+kern_return_t
+vm_map_read_user(
+       vm_map_t                map,
+       vm_map_address_t        src_addr,
+       void                    *dst_p,
+       vm_size_t               size)
+{
+       kern_return_t   kr = KERN_SUCCESS;
 
-                               new_entry->offset = 0;
-                               new_entry->needs_copy = FALSE;
-                       } else {
-                               result = vm_object_copy_strategically(
-                                               object,
-                                               offset,
-                                               entry_size,
-                                               &new_entry->object.vm_object,
-                                               &new_entry->offset,
-                                               &new_entry_needs_copy);
+       if(current_map() == map) {
+               if (copyin(src_addr, dst_p, size)) {
+                       kr = KERN_INVALID_ADDRESS;
+               }
+       } else {
+               vm_map_t        oldmap;
 
-                               new_entry->needs_copy = new_entry_needs_copy;
-                       }
+               /* take on the identity of the target map while doing */
+               /* the transfer */
 
-                       /*
-                        * Throw away the old object reference of the new entry.
-                        */
-                       vm_object_deallocate(object);
+               vm_map_reference(map);
+               oldmap = vm_map_switch(map);
+               if (copyin(src_addr, dst_p, size)) {
+                       kr = KERN_INVALID_ADDRESS;
+               }
+               vm_map_switch(oldmap);
+               vm_map_deallocate(map);
+       }
+       return kr;
+}
 
-                       if (result != KERN_SUCCESS &&
-                           result != KERN_MEMORY_RESTART_COPY) {
-                               _vm_map_entry_dispose(map_header, new_entry);
-                               break;
-                       }
 
-                       /*
-                        * Verify that the map has not substantially
-                        * changed while the copy was being made.
-                        */
+/*
+ *     vm_map_check_protection:
+ *
+ *     Assert that the target map allows the specified
+ *     privilege on the entire address region given.
+ *     The entire region must be allocated.
+ */
+boolean_t
+vm_map_check_protection(vm_map_t map, vm_map_offset_t start,
+                       vm_map_offset_t end, vm_prot_t protection)
+{
+       vm_map_entry_t entry;
+       vm_map_entry_t tmp_entry;
 
-                       vm_map_lock(map);
-                       if (version.main_timestamp + 1 != map->timestamp) {
-                               /*
-                                * Simple version comparison failed.
-                                *
-                                * Retry the lookup and verify that the
-                                * same object/offset are still present.
-                                */
-                               vm_object_deallocate(new_entry->
-                                                    object.vm_object);
-                               _vm_map_entry_dispose(map_header, new_entry);
-                               if (result == KERN_MEMORY_RESTART_COPY)
-                                       result = KERN_SUCCESS;
-                               continue;
-                       }
+       vm_map_lock(map);
 
-                       if (result == KERN_MEMORY_RESTART_COPY) {
-                               vm_object_reference(object);
-                               goto RestartCopy;
-                       }
-               }
+       if (start < vm_map_min(map) || end > vm_map_max(map) || start > end)
+       {
+               vm_map_unlock(map);
+               return (FALSE);
+       }
 
-               _vm_map_entry_link(map_header,
-                                  map_header->links.prev, new_entry);
+       if (!vm_map_lookup_entry(map, start, &tmp_entry)) {
+               vm_map_unlock(map);
+               return(FALSE);
+       }
 
-               *cur_protection &= src_entry->protection;
-               *max_protection &= src_entry->max_protection;
+       entry = tmp_entry;
 
-               map_address += tmp_size;
-               mapped_size += tmp_size;
-               src_start += tmp_size;
+       while (start < end) {
+               if (entry == vm_map_to_entry(map)) {
+                       vm_map_unlock(map);
+                       return(FALSE);
+               }
 
-       } /* end while */
+               /*
+                *      No holes allowed!
+                */
+
+               if (start < entry->vme_start) {
+                       vm_map_unlock(map);
+                       return(FALSE);
+               }
 
-       vm_map_unlock(map);
-       if (result != KERN_SUCCESS) {
                /*
-                * Free all allocated elements.
+                * Check protection associated with entry.
                 */
-               for (src_entry = map_header->links.next;
-                    src_entry != (struct vm_map_entry *)&map_header->links;
-                    src_entry = new_entry) {
-                       new_entry = src_entry->vme_next;
-                       _vm_map_entry_unlink(map_header, src_entry);
-                       vm_object_deallocate(src_entry->object.vm_object);
-                       _vm_map_entry_dispose(map_header, src_entry);
+
+               if ((entry->protection & protection) != protection) {
+                       vm_map_unlock(map);
+                       return(FALSE);
                }
+
+               /* go to next entry */
+
+               start = entry->vme_end;
+               entry = entry->vme_next;
        }
-       return result;
+       vm_map_unlock(map);
+       return(TRUE);
 }
 
-/*
- *     Routine:        vm_remap
- *
- *                     Map portion of a task's address space.
- *                     Mapped region must not overlap more than
- *                     one vm memory object. Protections and
- *                     inheritance attributes remain the same
- *                     as in the original task and are out parameters.
- *                     Source and Target task can be identical
- *                     Other attributes are identical as for vm_map()
- */
 kern_return_t
-vm_remap(
-       vm_map_t                target_map,
-       vm_offset_t             *address,
-       vm_size_t               size,
-       vm_offset_t             mask,
-       boolean_t               anywhere,
-       vm_map_t                src_map,
-       vm_offset_t             memory_address,
-       boolean_t               copy,
-       vm_prot_t               *cur_protection,
-       vm_prot_t               *max_protection,
-       vm_inherit_t            inheritance)
+vm_map_purgable_control(
+       vm_map_t                map,
+       vm_map_offset_t         address,
+       vm_purgable_t           control,
+       int                     *state)
 {
-       kern_return_t           result;
        vm_map_entry_t          entry;
-       vm_map_entry_t          insp_entry;
-       vm_map_entry_t          new_entry;
-       struct vm_map_header    map_header;
+       vm_object_t             object;
+       kern_return_t           kr;
 
-       if (target_map == VM_MAP_NULL)
-               return KERN_INVALID_ARGUMENT;
+       /*
+        * Vet all the input parameters and current type and state of the
+        * underlaying object.  Return with an error if anything is amiss.
+        */
+       if (map == VM_MAP_NULL)
+               return(KERN_INVALID_ARGUMENT);
 
-       switch (inheritance) {
-           case VM_INHERIT_NONE:
-           case VM_INHERIT_COPY:
-           case VM_INHERIT_SHARE:
-               if (size != 0 && src_map != VM_MAP_NULL)
-                       break;
-               /*FALL THRU*/
-           default:
-               return KERN_INVALID_ARGUMENT;
+       if (control != VM_PURGABLE_SET_STATE &&
+           control != VM_PURGABLE_GET_STATE &&
+           control != VM_PURGABLE_PURGE_ALL)
+               return(KERN_INVALID_ARGUMENT);
+
+       if (control == VM_PURGABLE_PURGE_ALL) {
+               vm_purgeable_object_purge_all();
+               return KERN_SUCCESS;
        }
 
-       size = round_page_32(size);
+       if (control == VM_PURGABLE_SET_STATE &&
+           (((*state & ~(VM_PURGABLE_ALL_MASKS)) != 0) ||
+            ((*state & VM_PURGABLE_STATE_MASK) > VM_PURGABLE_STATE_MASK)))
+               return(KERN_INVALID_ARGUMENT);
+
+       vm_map_lock_read(map);
 
-       result = vm_remap_extract(src_map, memory_address,
-                                 size, copy, &map_header,
-                                 cur_protection,
-                                 max_protection,
-                                 inheritance,
-                                 target_map->hdr.
-                                 entries_pageable);
+       if (!vm_map_lookup_entry(map, address, &entry) || entry->is_sub_map) {
 
-       if (result != KERN_SUCCESS) {
-               return result;
+               /*
+                * Must pass a valid non-submap address.
+                */
+               vm_map_unlock_read(map);
+               return(KERN_INVALID_ADDRESS);
        }
 
-       /*
-        * Allocate/check a range of free virtual address
-        * space for the target
-        */
-       *address = trunc_page_32(*address);
-       vm_map_lock(target_map);
-       result = vm_remap_range_allocate(target_map, address, size,
-                                        mask, anywhere, &insp_entry);
+       if ((entry->protection & VM_PROT_WRITE) == 0) {
+               /*
+                * Can't apply purgable controls to something you can't write.
+                */
+               vm_map_unlock_read(map);
+               return(KERN_PROTECTION_FAILURE);
+       }
 
-       for (entry = map_header.links.next;
-            entry != (struct vm_map_entry *)&map_header.links;
-            entry = new_entry) {
-               new_entry = entry->vme_next;
-               _vm_map_entry_unlink(&map_header, entry);
-               if (result == KERN_SUCCESS) {
-                       entry->vme_start += *address;
-                       entry->vme_end += *address;
-                       vm_map_entry_link(target_map, insp_entry, entry);
-                       insp_entry = entry;
-               } else {
-                       if (!entry->is_sub_map) {
-                               vm_object_deallocate(entry->object.vm_object);
-                       } else {
-                               vm_map_deallocate(entry->object.sub_map);
-                          }
-                       _vm_map_entry_dispose(&map_header, entry);
-               }
+       object = entry->object.vm_object;
+       if (object == VM_OBJECT_NULL) {
+               /*
+                * Object must already be present or it can't be purgable.
+                */
+               vm_map_unlock_read(map);
+               return KERN_INVALID_ARGUMENT;
        }
+                    
+       vm_object_lock(object);
 
-       if (result == KERN_SUCCESS) {
-               target_map->size += size;
-               SAVE_HINT(target_map, insp_entry);
+       if (entry->offset != 0 || 
+           entry->vme_end - entry->vme_start != object->size) {
+               /*
+                * Can only apply purgable controls to the whole (existing)
+                * object at once.
+                */
+               vm_map_unlock_read(map);
+               vm_object_unlock(object);
+               return KERN_INVALID_ARGUMENT;
        }
-       vm_map_unlock(target_map);
+               
+       vm_map_unlock_read(map);
 
-       if (result == KERN_SUCCESS && target_map->wiring_required)
-               result = vm_map_wire(target_map, *address,
-                                    *address + size, *cur_protection, TRUE);
-       return result;
+       kr = vm_object_purgable_control(object, control, state);
+
+       vm_object_unlock(object);
+
+       return kr;
 }
 
-/*
- *     Routine:        vm_remap_range_allocate
- *
- *     Description:
- *             Allocate a range in the specified virtual address map.
- *             returns the address and the map entry just before the allocated
- *             range
- *
- *     Map must be locked.
- */
+kern_return_t
+vm_map_page_query_internal(
+       vm_map_t        target_map,
+       vm_map_offset_t offset,
+       int             *disposition,
+       int             *ref_count)
+{
+       kern_return_t                   kr;
+       vm_page_info_basic_data_t       info;
+       mach_msg_type_number_t          count;
+
+       count = VM_PAGE_INFO_BASIC_COUNT;
+       kr = vm_map_page_info(target_map,
+                             offset,
+                             VM_PAGE_INFO_BASIC,
+                             (vm_page_info_t) &info,
+                             &count);
+       if (kr == KERN_SUCCESS) {
+               *disposition = info.disposition;
+               *ref_count = info.ref_count;
+       } else {
+               *disposition = 0;
+               *ref_count = 0;
+       }
 
+       return kr;
+}
+               
 kern_return_t
-vm_remap_range_allocate(
-       vm_map_t        map,
-       vm_offset_t     *address,       /* IN/OUT */
-       vm_size_t       size,
-       vm_offset_t     mask,
-       boolean_t       anywhere,
-       vm_map_entry_t  *map_entry)     /* OUT */
+vm_map_page_info(
+       vm_map_t                map,
+       vm_map_offset_t         offset,
+       vm_page_info_flavor_t   flavor,
+       vm_page_info_t          info,
+       mach_msg_type_number_t  *count)
 {
-       register vm_map_entry_t entry;
-       register vm_offset_t    start;
-       register vm_offset_t    end;
-       kern_return_t           result = KERN_SUCCESS;
+       vm_map_entry_t          map_entry;
+       vm_object_t             object;
+       vm_page_t               m;
+       kern_return_t           kr;
+       kern_return_t           retval = KERN_SUCCESS;
+       boolean_t               top_object;
+       int                     disposition;
+       int                     ref_count;
+       vm_object_id_t          object_id;
+       vm_page_info_basic_t    basic_info;
+       int                     depth;
 
- StartAgain: ;
+       switch (flavor) {
+       case VM_PAGE_INFO_BASIC:
+               if (*count != VM_PAGE_INFO_BASIC_COUNT) {
+                       return KERN_INVALID_ARGUMENT;
+               }
+               break;
+       default:
+               return KERN_INVALID_ARGUMENT;
+       }
 
-    start = *address;
+       disposition = 0;
+       ref_count = 0;
+       object_id = 0;
+       top_object = TRUE;
+       depth = 0;
 
-    if (anywhere)
-    {
-       /*
-        *      Calculate the first possible address.
-        */
+       retval = KERN_SUCCESS;
+       offset = vm_map_trunc_page(offset);
 
-       if (start < map->min_offset)
-           start = map->min_offset;
-       if (start > map->max_offset)
-           return(KERN_NO_SPACE);
-               
-       /*
-        *      Look for the first possible address;
-        *      if there's already something at this
-        *      address, we have to start after it.
-        */
+       vm_map_lock_read(map);
 
-       assert(first_free_is_valid(map));
-       if (start == map->min_offset) {
-           if ((entry = map->first_free) != vm_map_to_entry(map))
-               start = entry->vme_end;
-       } else {
-           vm_map_entry_t      tmp_entry;
-           if (vm_map_lookup_entry(map, start, &tmp_entry))
-               start = tmp_entry->vme_end;
-           entry = tmp_entry;
-       }
-               
        /*
-        *      In any case, the "entry" always precedes
-        *      the proposed new region throughout the
-        *      loop:
+        * First, find the map entry covering "offset", going down
+        * submaps if necessary.
         */
-
-       while (TRUE) {
-           register vm_map_entry_t     next;
-
-           /*
-            *  Find the end of the proposed new region.
-            *  Be sure we didn't go beyond the end, or
-            *  wrap around the address.
-            */
-
-           end = ((start + mask) & ~mask);
-           if (end < start)
-                   return(KERN_NO_SPACE);
-           start = end;
-           end += size;
-
-           if ((end > map->max_offset) || (end < start)) {
-               if (map->wait_for_space) {
-                   if (size <= (map->max_offset -
-                                map->min_offset)) {
-                       assert_wait((event_t) map, THREAD_INTERRUPTIBLE);
-                       vm_map_unlock(map);
-                       thread_block((void (*)(void))0);
-                       vm_map_lock(map);
-                       goto StartAgain;
-                   }
+       for (;;) {
+               if (!vm_map_lookup_entry(map, offset, &map_entry)) {
+                       vm_map_unlock_read(map);
+                       return KERN_INVALID_ADDRESS;
                }
-               
-               return(KERN_NO_SPACE);
-           }
+               /* compute offset from this map entry's start */
+               offset -= map_entry->vme_start;
+               /* compute offset into this map entry's object (or submap) */
+               offset += map_entry->offset;
 
-           /*
-            *  If there are no more entries, we must win.
-            */
+               if (map_entry->is_sub_map) {
+                       vm_map_t sub_map;
 
-           next = entry->vme_next;
-           if (next == vm_map_to_entry(map))
-               break;
+                       sub_map = map_entry->object.sub_map;
+                       vm_map_lock_read(sub_map);
+                       vm_map_unlock_read(map);
 
-           /*
-            *  If there is another entry, it must be
-            *  after the end of the potential new region.
-            */
+                       map = sub_map;
 
-           if (next->vme_start >= end)
+                       ref_count = MAX(ref_count, map->ref_count);
+                       continue;
+               }
                break;
+       }
 
-           /*
-            *  Didn't fit -- move to the next entry.
-            */
-
-           entry = next;
-           start = entry->vme_end;
+       object = map_entry->object.vm_object;
+       if (object == VM_OBJECT_NULL) {
+               /* no object -> no page */
+               vm_map_unlock_read(map);
+               goto done;
        }
-       *address = start;
-    } else {
-       vm_map_entry_t          temp_entry;
-       
+
+       vm_object_lock(object);
+       vm_map_unlock_read(map);
+
        /*
-        *      Verify that:
-        *              the address doesn't itself violate
-        *              the mask requirement.
+        * Go down the VM object shadow chain until we find the page
+        * we're looking for.
         */
+       for (;;) {
+               ref_count = MAX(ref_count, object->ref_count);
 
-       if ((start & mask) != 0)
-           return(KERN_NO_SPACE);
+               m = vm_page_lookup(object, offset);
 
+               if (m != VM_PAGE_NULL) {
+                       disposition |= VM_PAGE_QUERY_PAGE_PRESENT;
+                       break;
+               } else {
+#if MACH_PAGEMAP
+                       if (object->existence_map) {
+                               if (vm_external_state_get(object->existence_map,
+                                                         offset) ==
+                                   VM_EXTERNAL_STATE_EXISTS) {
+                                       /*
+                                        * this page has been paged out
+                                        */
+                                       disposition |= VM_PAGE_QUERY_PAGE_PAGED_OUT;
+                                       break;
+                               }
+                       } else
+#endif
+                       {
+                               if (object->internal &&
+                                   object->alive &&
+                                   !object->terminating &&
+                                   object->pager_ready) {
 
-       /*
-        *      ...     the address is within bounds
-        */
+                                       memory_object_t pager;
 
-       end = start + size;
+                                       vm_object_paging_begin(object);
+                                       pager = object->pager;
+                                       vm_object_unlock(object);
 
-       if ((start < map->min_offset) ||
-           (end > map->max_offset) ||
-           (start >= end)) {
-           return(KERN_INVALID_ADDRESS);
-       }
+                                       /*
+                                        * Ask the default pager if
+                                        * it has this page.
+                                        */
+                                       kr = memory_object_data_request(
+                                               pager,
+                                               offset + object->paging_offset,
+                                               0, /* just poke the pager */
+                                               VM_PROT_READ,
+                                               NULL);
 
-       /*
-        *      ...     the starting address isn't allocated
-        */
+                                       vm_object_lock(object);
+                                       vm_object_paging_end(object);
 
-       if (vm_map_lookup_entry(map, start, &temp_entry))
-           return(KERN_NO_SPACE);
+                                       if (kr == KERN_SUCCESS) {
+                                               /* the default pager has it */
+                                               disposition |= VM_PAGE_QUERY_PAGE_PAGED_OUT;
+                                               break;
+                                       }
+                               }
+                       }
 
-       entry = temp_entry;
+                       if (object->shadow != VM_OBJECT_NULL) {
+                               vm_object_t shadow;
 
-       /*
-        *      ...     the next region doesn't overlap the
-        *              end point.
-        */
+                               offset += object->shadow_offset;
+                               shadow = object->shadow;
+                               
+                               vm_object_lock(shadow);
+                               vm_object_unlock(object);
 
-       if ((entry->vme_next != vm_map_to_entry(map)) &&
-           (entry->vme_next->vme_start < end))
-           return(KERN_NO_SPACE);
-    }
-    *map_entry = entry;
-    return(KERN_SUCCESS);
-}
+                               object = shadow;
+                               top_object = FALSE;
+                               depth++;
+                       } else {
+//                             if (!object->internal)
+//                                     break;
+//                             retval = KERN_FAILURE;
+//                             goto done_with_object;
+                               break;
+                       }
+               }
+       }
+       /* The ref_count is not strictly accurate, it measures the number   */
+       /* of entities holding a ref on the object, they may not be mapping */
+       /* the object or may not be mapping the section holding the         */
+       /* target page but its still a ball park number and though an over- */
+       /* count, it picks up the copy-on-write cases                       */
 
-/*
- *     vm_map_switch:
- *
- *     Set the address map for the current thr_act to the specified map
- */
+       /* We could also get a picture of page sharing from pmap_attributes */
+       /* but this would under count as only faulted-in mappings would     */
+       /* show up.                                                         */
 
-vm_map_t
-vm_map_switch(
-       vm_map_t        map)
-{
-       int             mycpu;
-       thread_act_t    thr_act = current_act();
-       vm_map_t        oldmap = thr_act->map;
+       if (top_object == TRUE && object->shadow)
+               disposition |= VM_PAGE_QUERY_PAGE_COPIED;
 
-       mp_disable_preemption();
-       mycpu = cpu_number();
+       if (! object->internal)
+               disposition |= VM_PAGE_QUERY_PAGE_EXTERNAL;
 
-       /*
-        *      Deactivate the current map and activate the requested map
-        */
-       PMAP_SWITCH_USER(thr_act, map, mycpu);
+       if (m == VM_PAGE_NULL)
+               goto done_with_object;
 
-       mp_enable_preemption();
-       return(oldmap);
-}
+       if (m->fictitious) {
+               disposition |= VM_PAGE_QUERY_PAGE_FICTITIOUS;
+               goto done_with_object;
+       }
+       if (m->dirty || pmap_is_modified(m->phys_page))
+               disposition |= VM_PAGE_QUERY_PAGE_DIRTY;
 
+       if (m->reference || pmap_is_referenced(m->phys_page))
+               disposition |= VM_PAGE_QUERY_PAGE_REF;
 
-/*
- *     Routine:        vm_map_write_user
- *
- *     Description:
- *             Copy out data from a kernel space into space in the
- *             destination map. The space must already exist in the
- *             destination map.
- *             NOTE:  This routine should only be called by threads
- *             which can block on a page fault. i.e. kernel mode user
- *             threads.
- *
- */
-kern_return_t
-vm_map_write_user(
-       vm_map_t        map,
-       vm_offset_t     src_addr,
-       vm_offset_t     dst_addr,
-       vm_size_t       size)
-{
-       thread_act_t    thr_act = current_act();
-       kern_return_t   kr = KERN_SUCCESS;
+       if (m->speculative)
+               disposition |= VM_PAGE_QUERY_PAGE_SPECULATIVE;
 
-       if(thr_act->map == map) {
-               if (copyout((char *)src_addr, (char *)dst_addr, size)) {
-                       kr = KERN_INVALID_ADDRESS;
-               }
-       } else {
-               vm_map_t        oldmap;
+       if (m->cs_validated)
+               disposition |= VM_PAGE_QUERY_PAGE_CS_VALIDATED;
+       if (m->cs_tainted)
+               disposition |= VM_PAGE_QUERY_PAGE_CS_TAINTED;
 
-               /* take on the identity of the target map while doing */
-               /* the transfer */
+done_with_object:
+       vm_object_unlock(object);
+done:
 
-               vm_map_reference(map);
-               oldmap = vm_map_switch(map);
-               if (copyout((char *)src_addr, (char *)dst_addr, size)) {
-                       kr = KERN_INVALID_ADDRESS;
-               }
-               vm_map_switch(oldmap);
-               vm_map_deallocate(map);
+       switch (flavor) {
+       case VM_PAGE_INFO_BASIC:
+               basic_info = (vm_page_info_basic_t) info;
+               basic_info->disposition = disposition;
+               basic_info->ref_count = ref_count;
+               basic_info->object_id = (vm_object_id_t) (uintptr_t) object;
+               basic_info->offset = (memory_object_offset_t) offset;
+               basic_info->depth = depth;
+               break;
        }
-       return kr;
+
+       return retval;
 }
 
 /*
- *     Routine:        vm_map_read_user
+ *     vm_map_msync
  *
- *     Description:
- *             Copy in data from a user space source map into the
- *             kernel map. The space must already exist in the
- *             kernel map.
- *             NOTE:  This routine should only be called by threads
- *             which can block on a page fault. i.e. kernel mode user
- *             threads.
+ *     Synchronises the memory range specified with its backing store
+ *     image by either flushing or cleaning the contents to the appropriate
+ *     memory manager engaging in a memory object synchronize dialog with
+ *     the manager.  The client doesn't return until the manager issues
+ *     m_o_s_completed message.  MIG Magically converts user task parameter
+ *     to the task's address map.
+ *
+ *     interpretation of sync_flags
+ *     VM_SYNC_INVALIDATE      - discard pages, only return precious
+ *                               pages to manager.
+ *
+ *     VM_SYNC_INVALIDATE & (VM_SYNC_SYNCHRONOUS | VM_SYNC_ASYNCHRONOUS)
+ *                             - discard pages, write dirty or precious
+ *                               pages back to memory manager.
+ *
+ *     VM_SYNC_SYNCHRONOUS | VM_SYNC_ASYNCHRONOUS
+ *                             - write dirty or precious pages back to
+ *                               the memory manager.
+ *
+ *     VM_SYNC_CONTIGUOUS      - does everything normally, but if there
+ *                               is a hole in the region, and we would
+ *                               have returned KERN_SUCCESS, return
+ *                               KERN_INVALID_ADDRESS instead.
+ *
+ *     NOTE
+ *     The memory object attributes have not yet been implemented, this
+ *     function will have to deal with the invalidate attribute
  *
+ *     RETURNS
+ *     KERN_INVALID_TASK               Bad task parameter
+ *     KERN_INVALID_ARGUMENT           both sync and async were specified.
+ *     KERN_SUCCESS                    The usual.
+ *     KERN_INVALID_ADDRESS            There was a hole in the region.
  */
+
 kern_return_t
-vm_map_read_user(
-       vm_map_t        map,
-       vm_offset_t     src_addr,
-       vm_offset_t     dst_addr,
-       vm_size_t       size)
+vm_map_msync(
+       vm_map_t                map,
+       vm_map_address_t        address,
+       vm_map_size_t           size,
+       vm_sync_t               sync_flags)
 {
-       thread_act_t    thr_act = current_act();
-       kern_return_t   kr = KERN_SUCCESS;
+       msync_req_t             msr;
+       msync_req_t             new_msr;
+       queue_chain_t           req_q;  /* queue of requests for this msync */
+       vm_map_entry_t          entry;
+       vm_map_size_t           amount_left;
+       vm_object_offset_t      offset;
+       boolean_t               do_sync_req;
+       boolean_t               had_hole = FALSE;
+       memory_object_t         pager;
+       
+       if ((sync_flags & VM_SYNC_ASYNCHRONOUS) &&
+           (sync_flags & VM_SYNC_SYNCHRONOUS))
+               return(KERN_INVALID_ARGUMENT);
 
-       if(thr_act->map == map) {
-               if (copyin((char *)src_addr, (char *)dst_addr, size)) {
-                       kr = KERN_INVALID_ADDRESS;
-               }
-       } else {
-               vm_map_t        oldmap;
+       /*
+        * align address and size on page boundaries
+        */
+       size = vm_map_round_page(address + size) - vm_map_trunc_page(address);
+       address = vm_map_trunc_page(address);
 
-               /* take on the identity of the target map while doing */
-               /* the transfer */
+        if (map == VM_MAP_NULL)
+                return(KERN_INVALID_TASK);
 
-               vm_map_reference(map);
-               oldmap = vm_map_switch(map);
-               if (copyin((char *)src_addr, (char *)dst_addr, size)) {
-                       kr = KERN_INVALID_ADDRESS;
-               }
-               vm_map_switch(oldmap);
-               vm_map_deallocate(map);
-       }
-       return kr;
-}
+       if (size == 0)
+               return(KERN_SUCCESS);
 
-/* Takes existing source and destination sub-maps and clones the contents of */
-/* the source map */
+       queue_init(&req_q);
+       amount_left = size;
 
-kern_return_t
-vm_region_clone(
-       ipc_port_t      src_region, 
-       ipc_port_t      dst_region)
-{
-       vm_named_entry_t        src_object;
-       vm_named_entry_t        dst_object;
-       vm_map_t                src_map;
-       vm_map_t                dst_map;
-       vm_offset_t             addr;
-       vm_offset_t             max_off;
-       vm_map_entry_t          entry;
-       vm_map_entry_t          new_entry;
-       vm_map_entry_t          insert_point;
+       while (amount_left > 0) {
+               vm_object_size_t        flush_size;
+               vm_object_t             object;
 
-       src_object = (vm_named_entry_t)src_region->ip_kobject;
-       dst_object = (vm_named_entry_t)dst_region->ip_kobject;
-       if((!src_object->is_sub_map) || (!dst_object->is_sub_map)) {
-               return KERN_INVALID_ARGUMENT;
-       }
-       src_map = (vm_map_t)src_object->backing.map;
-       dst_map = (vm_map_t)dst_object->backing.map;
-       /* destination map is assumed to be unavailable to any other */
-       /* activity.  i.e. it is new */
-       vm_map_lock(src_map);
-       if((src_map->min_offset != dst_map->min_offset) 
-                       || (src_map->max_offset != dst_map->max_offset)) {
-               vm_map_unlock(src_map);
-               return KERN_INVALID_ARGUMENT;
-       }
-       addr = src_map->min_offset;
-       vm_map_lookup_entry(dst_map, addr, &entry);
-       if(entry == vm_map_to_entry(dst_map)) {
-               entry = entry->vme_next;
-       }
-       if(entry == vm_map_to_entry(dst_map)) {
-               max_off = src_map->max_offset;
-       } else {
-               max_off =  entry->vme_start;
-       }
-       vm_map_lookup_entry(src_map, addr, &entry);
-       if(entry == vm_map_to_entry(src_map)) {
-               entry = entry->vme_next;
-       }
-       vm_map_lookup_entry(dst_map, addr, &insert_point);
-       while((entry != vm_map_to_entry(src_map)) && 
-                                       (entry->vme_end <= max_off)) {
-               addr = entry->vme_start;
-               new_entry = vm_map_entry_create(dst_map);
-               vm_map_entry_copy(new_entry, entry);
-               vm_map_entry_link(dst_map, insert_point, new_entry);
-               insert_point = new_entry;
-               if (entry->object.vm_object != VM_OBJECT_NULL) {
-                       if (new_entry->is_sub_map) {
-                               vm_map_reference(new_entry->object.sub_map);
-                       } else {
-                               vm_object_reference(
-                                       new_entry->object.vm_object);
+               vm_map_lock(map);
+               if (!vm_map_lookup_entry(map,
+                                        vm_map_trunc_page(address), &entry)) {
+
+                       vm_map_size_t   skip;
+
+                       /*
+                        * hole in the address map.
+                        */
+                       had_hole = TRUE;
+
+                       /*
+                        * Check for empty map.
+                        */
+                       if (entry == vm_map_to_entry(map) &&
+                           entry->vme_next == entry) {
+                               vm_map_unlock(map);
+                               break;
+                       }
+                       /*
+                        * Check that we don't wrap and that
+                        * we have at least one real map entry.
+                        */
+                       if ((map->hdr.nentries == 0) ||
+                           (entry->vme_next->vme_start < address)) {
+                               vm_map_unlock(map);
+                               break;
                        }
+                       /*
+                        * Move up to the next entry if needed
+                        */
+                       skip = (entry->vme_next->vme_start - address);
+                       if (skip >= amount_left)
+                               amount_left = 0;
+                       else
+                               amount_left -= skip;
+                       address = entry->vme_next->vme_start;
+                       vm_map_unlock(map);
+                       continue;
                }
-               dst_map->size += new_entry->vme_end - new_entry->vme_start;
-               entry = entry->vme_next;
-       }
-       vm_map_unlock(src_map);
-       return KERN_SUCCESS;
-}
 
-/*
- * Export routines to other components for the things we access locally through
- * macros.
- */
-#undef current_map
-vm_map_t
-current_map(void)
-{
-       return (current_map_fast());
-}
+               offset = address - entry->vme_start;
 
-/*
- *     vm_map_check_protection:
- *
- *     Assert that the target map allows the specified
- *     privilege on the entire address region given.
- *     The entire region must be allocated.
- */
-boolean_t vm_map_check_protection(map, start, end, protection)
-       register vm_map_t       map;
-       register vm_offset_t    start;
-       register vm_offset_t    end;
-       register vm_prot_t      protection;
-{
-       register vm_map_entry_t entry;
-       vm_map_entry_t          tmp_entry;
+               /*
+                * do we have more to flush than is contained in this
+                * entry ?
+                */
+               if (amount_left + entry->vme_start + offset > entry->vme_end) {
+                       flush_size = entry->vme_end -
+                               (entry->vme_start + offset);
+               } else {
+                       flush_size = amount_left;
+               }
+               amount_left -= flush_size;
+               address += flush_size;
 
-       vm_map_lock(map);
+               if (entry->is_sub_map == TRUE) {
+                       vm_map_t        local_map;
+                       vm_map_offset_t local_offset;
+
+                       local_map = entry->object.sub_map;
+                       local_offset = entry->offset;
+                       vm_map_unlock(map);
+                       if (vm_map_msync(
+                                   local_map,
+                                   local_offset,
+                                   flush_size,
+                                   sync_flags) == KERN_INVALID_ADDRESS) {
+                               had_hole = TRUE;
+                       }
+                       continue;
+               }
+               object = entry->object.vm_object;
 
-    if (start < vm_map_min(map) || end > vm_map_max(map) || start > end)
-       {
+               /*
+                * We can't sync this object if the object has not been
+                * created yet
+                */
+               if (object == VM_OBJECT_NULL) {
                        vm_map_unlock(map);
-                       return (FALSE);
-       }
+                       continue;
+               }
+               offset += entry->offset;
 
-       if (!vm_map_lookup_entry(map, start, &tmp_entry)) {
-               vm_map_unlock(map);
-               return(FALSE);
-       }
+                vm_object_lock(object);
 
-       entry = tmp_entry;
+               if (sync_flags & (VM_SYNC_KILLPAGES | VM_SYNC_DEACTIVATE)) {
+                       int kill_pages = 0;
+                       boolean_t reusable_pages = FALSE;
 
-       while (start < end) {
-               if (entry == vm_map_to_entry(map)) {
+                       if (sync_flags & VM_SYNC_KILLPAGES) {
+                               if (object->ref_count == 1 && !object->shadow)
+                                       kill_pages = 1;
+                               else
+                                       kill_pages = -1;
+                       }
+                       if (kill_pages != -1)
+                               vm_object_deactivate_pages(object, offset, 
+                                                          (vm_object_size_t)flush_size, kill_pages, reusable_pages);
+                       vm_object_unlock(object);
                        vm_map_unlock(map);
-                       return(FALSE);
+                       continue;
+               }
+               /*
+                * We can't sync this object if there isn't a pager.
+                * Don't bother to sync internal objects, since there can't
+                * be any "permanent" storage for these objects anyway.
+                */
+               if ((object->pager == MEMORY_OBJECT_NULL) ||
+                   (object->internal) || (object->private)) {
+                       vm_object_unlock(object);
+                       vm_map_unlock(map);
+                       continue;
                }
+               /*
+                * keep reference on the object until syncing is done
+                */
+               vm_object_reference_locked(object);
+               vm_object_unlock(object);
+
+               vm_map_unlock(map);
 
+               do_sync_req = vm_object_sync(object,
+                                            offset,
+                                            flush_size,
+                                            sync_flags & VM_SYNC_INVALIDATE,
+                                            ((sync_flags & VM_SYNC_SYNCHRONOUS) ||
+                                             (sync_flags & VM_SYNC_ASYNCHRONOUS)),
+                                            sync_flags & VM_SYNC_SYNCHRONOUS);
                /*
-                *      No holes allowed!
+                * only send a m_o_s if we returned pages or if the entry
+                * is writable (ie dirty pages may have already been sent back)
                 */
+               if (!do_sync_req) {
+                       if ((sync_flags & VM_SYNC_INVALIDATE) && object->resident_page_count == 0) {
+                               /*
+                                * clear out the clustering and read-ahead hints
+                                */
+                               vm_object_lock(object);
 
-               if (start < entry->vme_start) {
-                       vm_map_unlock(map);
-                       return(FALSE);
+                               object->pages_created = 0;
+                               object->pages_used = 0;
+                               object->sequential = 0;
+                               object->last_alloc = 0;
+
+                               vm_object_unlock(object);
+                       }
+                       vm_object_deallocate(object);
+                       continue;
                }
+               msync_req_alloc(new_msr);
+
+                vm_object_lock(object);
+               offset += object->paging_offset;
+
+               new_msr->offset = offset;
+               new_msr->length = flush_size;
+               new_msr->object = object;
+               new_msr->flag = VM_MSYNC_SYNCHRONIZING;
+       re_iterate:
 
                /*
-                * Check protection associated with entry.
+                * We can't sync this object if there isn't a pager.  The
+                * pager can disappear anytime we're not holding the object
+                * lock.  So this has to be checked anytime we goto re_iterate.
                 */
 
-               if ((entry->protection & protection) != protection) {
-                       vm_map_unlock(map);
-                       return(FALSE);
+               pager = object->pager;
+
+               if (pager == MEMORY_OBJECT_NULL) {
+                       vm_object_unlock(object);
+                       vm_object_deallocate(object);
+                       continue;
                }
 
-               /* go to next entry */
+               queue_iterate(&object->msr_q, msr, msync_req_t, msr_q) {
+                       /*
+                        * need to check for overlapping entry, if found, wait
+                        * on overlapping msr to be done, then reiterate
+                        */
+                       msr_lock(msr);
+                       if (msr->flag == VM_MSYNC_SYNCHRONIZING &&
+                           ((offset >= msr->offset && 
+                             offset < (msr->offset + msr->length)) ||
+                            (msr->offset >= offset &&
+                             msr->offset < (offset + flush_size))))
+                       {
+                               assert_wait((event_t) msr,THREAD_INTERRUPTIBLE);
+                               msr_unlock(msr);
+                               vm_object_unlock(object);
+                               thread_block(THREAD_CONTINUE_NULL);
+                               vm_object_lock(object);
+                               goto re_iterate;
+                       }
+                       msr_unlock(msr);
+               }/* queue_iterate */
 
-               start = entry->vme_end;
-               entry = entry->vme_next;
+               queue_enter(&object->msr_q, new_msr, msync_req_t, msr_q);
+
+               vm_object_paging_begin(object);
+               vm_object_unlock(object);
+
+               queue_enter(&req_q, new_msr, msync_req_t, req_q);
+
+               (void) memory_object_synchronize(
+                       pager,
+                       offset,
+                       flush_size,
+                       sync_flags & ~VM_SYNC_CONTIGUOUS);
+
+               vm_object_lock(object);
+               vm_object_paging_end(object);
+               vm_object_unlock(object);
+       }/* while */
+
+       /*
+        * wait for memory_object_sychronize_completed messages from pager(s)
+        */
+
+       while (!queue_empty(&req_q)) {
+               msr = (msync_req_t)queue_first(&req_q);
+               msr_lock(msr);
+               while(msr->flag != VM_MSYNC_DONE) {
+                       assert_wait((event_t) msr, THREAD_INTERRUPTIBLE);
+                       msr_unlock(msr);
+                       thread_block(THREAD_CONTINUE_NULL);
+                       msr_lock(msr);
+               }/* while */
+               queue_remove(&req_q, msr, msync_req_t, req_q);
+               msr_unlock(msr);
+               vm_object_deallocate(msr->object);
+               msync_req_free(msr);
+       }/* queue_iterate */
+
+       /* for proper msync() behaviour */
+       if (had_hole == TRUE && (sync_flags & VM_SYNC_CONTIGUOUS))
+               return(KERN_INVALID_ADDRESS);
+
+       return(KERN_SUCCESS);
+}/* vm_msync */
+
+/*
+ *     Routine:        convert_port_entry_to_map
+ *     Purpose:
+ *             Convert from a port specifying an entry or a task
+ *             to a map. Doesn't consume the port ref; produces a map ref,
+ *             which may be null.  Unlike convert_port_to_map, the
+ *             port may be task or a named entry backed.
+ *     Conditions:
+ *             Nothing locked.
+ */
+
+
+vm_map_t
+convert_port_entry_to_map(
+       ipc_port_t      port)
+{
+       vm_map_t map;
+       vm_named_entry_t        named_entry;
+       uint32_t        try_failed_count = 0;
+
+       if(IP_VALID(port) && (ip_kotype(port) == IKOT_NAMED_ENTRY)) {
+               while(TRUE) {
+                       ip_lock(port);
+                       if(ip_active(port) && (ip_kotype(port) 
+                                              == IKOT_NAMED_ENTRY)) {
+                               named_entry =
+                                       (vm_named_entry_t)port->ip_kobject;
+                               if (!(lck_mtx_try_lock(&(named_entry)->Lock))) {
+                                               ip_unlock(port);
+
+                                       try_failed_count++;
+                                               mutex_pause(try_failed_count);
+                                               continue;
+                               }
+                               named_entry->ref_count++;
+                               lck_mtx_unlock(&(named_entry)->Lock);
+                               ip_unlock(port);
+                               if ((named_entry->is_sub_map) &&
+                                   (named_entry->protection 
+                                    & VM_PROT_WRITE)) {
+                                       map = named_entry->backing.map;
+                               } else {
+                                       mach_destroy_memory_entry(port);
+                                       return VM_MAP_NULL;
+                               }
+                               vm_map_reference_swap(map);
+                               mach_destroy_memory_entry(port);
+                               break;
+                       }
+                       else 
+                               return VM_MAP_NULL;
+               }
        }
-       vm_map_unlock(map);
-       return(TRUE);
+       else
+               map = convert_port_to_map(port);
+
+       return map;
 }
 
 /*
- *      This routine is obsolete, but included for backward
- *      compatibility for older drivers.
+ *     Routine:        convert_port_entry_to_object
+ *     Purpose:
+ *             Convert from a port specifying a named entry to an
+ *             object. Doesn't consume the port ref; produces a map ref,
+ *             which may be null. 
+ *     Conditions:
+ *             Nothing locked.
  */
-void
-kernel_vm_map_reference(
-       vm_map_t map)
+
+
+vm_object_t
+convert_port_entry_to_object(
+       ipc_port_t      port)
+{
+       vm_object_t object;
+       vm_named_entry_t        named_entry;
+       uint32_t        try_failed_count = 0;
+
+       if(IP_VALID(port) && (ip_kotype(port) == IKOT_NAMED_ENTRY)) {
+               while(TRUE) {
+                       ip_lock(port);
+                       if(ip_active(port) && (ip_kotype(port) 
+                                              == IKOT_NAMED_ENTRY)) {
+                               named_entry =
+                                       (vm_named_entry_t)port->ip_kobject;
+                               if (!(lck_mtx_try_lock(&(named_entry)->Lock))) {
+                                               ip_unlock(port);
+
+                                       try_failed_count++;
+                                               mutex_pause(try_failed_count);
+                                               continue;
+                               }
+                               named_entry->ref_count++;
+                               lck_mtx_unlock(&(named_entry)->Lock);
+                               ip_unlock(port);
+                               if ((!named_entry->is_sub_map) &&
+                                   (!named_entry->is_pager) &&
+                                   (named_entry->protection 
+                                    & VM_PROT_WRITE)) {
+                                       object = named_entry->backing.object;
+                               } else {
+                                       mach_destroy_memory_entry(port);
+                                       return (vm_object_t)NULL;
+                               }
+                               vm_object_reference(named_entry->backing.object);
+                               mach_destroy_memory_entry(port);
+                               break;
+                       }
+                       else 
+                               return (vm_object_t)NULL;
+               }
+       } else {
+               return (vm_object_t)NULL;
+       }
+
+       return object;
+}
+
+/*
+ * Export routines to other components for the things we access locally through
+ * macros.
+ */
+#undef current_map
+vm_map_t
+current_map(void)
 {
-       vm_map_reference(map);
+       return (current_map_fast());
 }
 
 /*
@@ -9227,14 +12358,14 @@ vm_map_reference(
        if (map == VM_MAP_NULL)
                return;
 
-       mutex_lock(&map->s_lock);
+       lck_mtx_lock(&map->s_lock);
 #if    TASK_SWAPPER
        assert(map->res_count > 0);
        assert(map->ref_count >= map->res_count);
        map->res_count++;
 #endif
        map->ref_count++;
-       mutex_unlock(&map->s_lock);
+       lck_mtx_unlock(&map->s_lock);
 }
 
 /*
@@ -9253,15 +12384,15 @@ vm_map_deallocate(
        if (map == VM_MAP_NULL)
                return;
 
-       mutex_lock(&map->s_lock);
+       lck_mtx_lock(&map->s_lock);
        ref = --map->ref_count;
        if (ref > 0) {
                vm_map_res_deallocate(map);
-               mutex_unlock(&map->s_lock);
+               lck_mtx_unlock(&map->s_lock);
                return;
        }
        assert(map->ref_count == 0);
-       mutex_unlock(&map->s_lock);
+       lck_mtx_unlock(&map->s_lock);
 
 #if    TASK_SWAPPER
        /*
@@ -9272,5 +12403,242 @@ vm_map_deallocate(
         */
 #endif
 
-       vm_map_destroy(map);
+       vm_map_destroy(map, VM_MAP_NO_FLAGS);
 }
+
+
+void
+vm_map_disable_NX(vm_map_t map)
+{
+        if (map == NULL)
+               return;
+        if (map->pmap == NULL)
+               return;
+
+        pmap_disable_NX(map->pmap);
+}
+
+/* XXX Consider making these constants (VM_MAX_ADDRESS and MACH_VM_MAX_ADDRESS)
+ * more descriptive.
+ */
+void
+vm_map_set_32bit(vm_map_t map)
+{
+       map->max_offset = (vm_map_offset_t)VM_MAX_ADDRESS;
+}
+
+
+void
+vm_map_set_64bit(vm_map_t map)
+{
+       map->max_offset = (vm_map_offset_t)MACH_VM_MAX_ADDRESS;
+}
+
+vm_map_offset_t
+vm_compute_max_offset(unsigned is64)
+{
+       return (is64 ? (vm_map_offset_t)MACH_VM_MAX_ADDRESS : (vm_map_offset_t)VM_MAX_ADDRESS);
+}
+
+boolean_t
+vm_map_is_64bit(
+               vm_map_t map)
+{
+       return map->max_offset > ((vm_map_offset_t)VM_MAX_ADDRESS);
+}
+
+boolean_t
+vm_map_has_4GB_pagezero(
+               vm_map_t map)
+{
+       /*
+        * XXX FBDP
+        * We should lock the VM map (for read) here but we can get away
+        * with it for now because there can't really be any race condition:
+        * the VM map's min_offset is changed only when the VM map is created
+        * and when the zero page is established (when the binary gets loaded),
+        * and this routine gets called only when the task terminates and the
+        * VM map is being torn down, and when a new map is created via
+        * load_machfile()/execve().
+        */
+       return (map->min_offset >= 0x100000000ULL);
+}
+
+void
+vm_map_set_4GB_pagezero(vm_map_t map)
+{
+#ifdef __i386__
+       pmap_set_4GB_pagezero(map->pmap);
+#else
+#pragma unused(map)
+#endif
+
+}
+
+void
+vm_map_clear_4GB_pagezero(vm_map_t map)
+{
+#ifdef __i386__
+       pmap_clear_4GB_pagezero(map->pmap);
+#else
+#pragma unused(map)
+#endif
+}
+
+/*
+ * Raise a VM map's minimum offset.
+ * To strictly enforce "page zero" reservation.
+ */
+kern_return_t
+vm_map_raise_min_offset(
+       vm_map_t        map,
+       vm_map_offset_t new_min_offset)
+{
+       vm_map_entry_t  first_entry;
+
+       new_min_offset = vm_map_round_page(new_min_offset);
+
+       vm_map_lock(map);
+
+       if (new_min_offset < map->min_offset) {
+               /*
+                * Can't move min_offset backwards, as that would expose
+                * a part of the address space that was previously, and for
+                * possibly good reasons, inaccessible.
+                */
+               vm_map_unlock(map);
+               return KERN_INVALID_ADDRESS;
+       }
+
+       first_entry = vm_map_first_entry(map);
+       if (first_entry != vm_map_to_entry(map) &&
+           first_entry->vme_start < new_min_offset) {
+               /*
+                * Some memory was already allocated below the new
+                * minimun offset.  It's too late to change it now...
+                */
+               vm_map_unlock(map);
+               return KERN_NO_SPACE;
+       }
+
+       map->min_offset = new_min_offset;
+
+       vm_map_unlock(map);
+
+       return KERN_SUCCESS;
+}
+
+/*
+ * Set the limit on the maximum amount of user wired memory allowed for this map.
+ * This is basically a copy of the MEMLOCK rlimit value maintained by the BSD side of
+ * the kernel.  The limits are checked in the mach VM side, so we keep a copy so we
+ * don't have to reach over to the BSD data structures.
+ */
+
+void
+vm_map_set_user_wire_limit(vm_map_t    map,
+                          vm_size_t    limit)
+{
+       map->user_wire_limit = limit;
+}
+
+
+void vm_map_switch_protect(vm_map_t    map, 
+                          boolean_t    val) 
+{
+       vm_map_lock(map);
+       map->switch_protect=val;
+       vm_map_unlock(map);
+}
+
+/* Add (generate) code signature for memory range */
+#if CONFIG_DYNAMIC_CODE_SIGNING
+kern_return_t vm_map_sign(vm_map_t map, 
+                vm_map_offset_t start, 
+                vm_map_offset_t end)
+{
+       vm_map_entry_t entry;
+       vm_page_t m;
+       vm_object_t object;
+       
+       /*
+        * Vet all the input parameters and current type and state of the
+        * underlaying object.  Return with an error if anything is amiss.
+        */
+       if (map == VM_MAP_NULL)
+               return(KERN_INVALID_ARGUMENT);
+               
+       vm_map_lock_read(map);
+       
+       if (!vm_map_lookup_entry(map, start, &entry) || entry->is_sub_map) {
+               /*
+                * Must pass a valid non-submap address.
+                */
+               vm_map_unlock_read(map);
+               return(KERN_INVALID_ADDRESS);
+       }
+       
+       if((entry->vme_start > start) || (entry->vme_end < end)) {
+               /*
+                * Map entry doesn't cover the requested range. Not handling
+                * this situation currently.
+                */
+               vm_map_unlock_read(map);
+               return(KERN_INVALID_ARGUMENT);
+       }
+       
+       object = entry->object.vm_object;
+       if (object == VM_OBJECT_NULL) {
+               /*
+                * Object must already be present or we can't sign.
+                */
+               vm_map_unlock_read(map);
+               return KERN_INVALID_ARGUMENT;
+       }
+       
+       vm_object_lock(object);
+       vm_map_unlock_read(map);
+       
+       while(start < end) {
+               uint32_t refmod;
+               
+               m = vm_page_lookup(object, start - entry->vme_start + entry->offset );
+               if (m==VM_PAGE_NULL) {
+                       /* shoud we try to fault a page here? we can probably 
+                        * demand it exists and is locked for this request */
+                       vm_object_unlock(object);
+                       return KERN_FAILURE;
+               }
+               /* deal with special page status */
+               if (m->busy || 
+                   (m->unusual && (m->error || m->restart || m->private || m->absent))) {
+                       vm_object_unlock(object);
+                       return KERN_FAILURE;
+               }
+               
+               /* Page is OK... now "validate" it */
+               /* This is the place where we'll call out to create a code 
+                * directory, later */
+               m->cs_validated = TRUE;
+
+               /* The page is now "clean" for codesigning purposes. That means
+                * we don't consider it as modified (wpmapped) anymore. But 
+                * we'll disconnect the page so we note any future modification
+                * attempts. */
+               m->wpmapped = FALSE;
+               refmod = pmap_disconnect(m->phys_page);
+               
+               /* Pull the dirty status from the pmap, since we cleared the 
+                * wpmapped bit */
+               if ((refmod & VM_MEM_MODIFIED) && !m->dirty) {
+                       m->dirty = TRUE;
+               }
+               
+               /* On to the next page */
+               start += PAGE_SIZE;
+       }
+       vm_object_unlock(object);
+       
+       return KERN_SUCCESS;
+}
+#endif