]> git.saurik.com Git - apple/xnu.git/blobdiff - osfmk/vm/vm_kern.c
xnu-2050.48.11.tar.gz
[apple/xnu.git] / osfmk / vm / vm_kern.c
index 7d957c220af0d7c5639694bdbe6e1ee0b89cc584..0629a9900775add9449040a93f2626b8ea90feb9 100644 (file)
@@ -1,23 +1,29 @@
 /*
- * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
+ * Copyright (c) 2000-2007 Apple Inc. All rights reserved.
  *
- * @APPLE_LICENSE_HEADER_START@
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
  * 
- * The contents of this file constitute Original Code as defined in and
- * are subject to the Apple Public Source License Version 1.1 (the
- * "License").  You may not use this file except in compliance with the
- * License.  Please obtain a copy of the License at
- * http://www.apple.com/publicsource and read it before using this file.
+ * 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. 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.
  * 
- * This Original Code and all software distributed under the License are
- * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * 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
  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
- * License for the specific language governing rights and limitations
- * under the License.
+ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
+ * 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@
@@ -57,7 +63,6 @@
  *     Kernel memory management.
  */
 
-#include <cpus.h>
 #include <mach/kern_return.h>
 #include <mach/vm_param.h>
 #include <kern/assert.h>
 #include <vm/cpm.h>
 
 #include <string.h>
+
+#include <libkern/OSDebug.h>
+#include <sys/kdebug.h>
+
 /*
  *     Variables exported by this module.
  */
 vm_map_t       kernel_map;
 vm_map_t       kernel_pageable_map;
 
+extern boolean_t vm_kernel_ready;
+
 /*
  * Forward declarations for internal functions.
  */
 extern kern_return_t kmem_alloc_pages(
        register vm_object_t            object,
        register vm_object_offset_t     offset,
-       register vm_offset_t            start,
-       register vm_offset_t            end,
-       vm_prot_t                       protection);
+       register vm_object_size_t       size);
 
 extern void kmem_remap_pages(
        register vm_object_t            object,
@@ -98,89 +107,101 @@ extern void kmem_remap_pages(
 
 kern_return_t
 kmem_alloc_contig(
-       vm_map_t        map,
-       vm_offset_t     *addrp,
-       vm_size_t       size,
-       vm_offset_t     mask,
-       int             flags)
+       vm_map_t                map,
+       vm_offset_t             *addrp,
+       vm_size_t               size,
+       vm_offset_t             mask,
+       ppnum_t                 max_pnum,
+       ppnum_t                 pnum_mask,
+       int                     flags)
 {
        vm_object_t             object;
-       vm_page_t               m, pages;
-       kern_return_t           kr;
-       vm_offset_t             addr, i; 
        vm_object_offset_t      offset;
+       vm_map_offset_t         map_addr; 
+       vm_map_offset_t         map_mask;
+       vm_map_size_t           map_size, i;
        vm_map_entry_t          entry;
+       vm_page_t               m, pages;
+       kern_return_t           kr;
 
-       if (map == VM_MAP_NULL || (flags && (flags ^ KMA_KOBJECT))) 
+       if (map == VM_MAP_NULL || (flags & ~(KMA_KOBJECT | KMA_LOMEM | KMA_NOPAGEWAIT))) 
                return KERN_INVALID_ARGUMENT;
+
+       map_size = vm_map_round_page(size);
+       map_mask = (vm_map_offset_t)mask;
        
-       if (size == 0) {
+       /* Check for zero allocation size (either directly or via overflow) */
+       if (map_size == 0) {
                *addrp = 0;
                return KERN_INVALID_ARGUMENT;
        }
 
-       size = round_page(size);
-       if ((flags & KMA_KOBJECT) == 0) {
-               object = vm_object_allocate(size);
-               kr = vm_map_find_space(map, &addr, size, mask, &entry);
-       }
-       else {
+       /*
+        *      Allocate a new object (if necessary) and the reference we
+        *      will be donating to the map entry.  We must do this before
+        *      locking the map, or risk deadlock with the default pager.
+        */
+       if ((flags & KMA_KOBJECT) != 0) {
                object = kernel_object;
-               kr = vm_map_find_space(map, &addr, size, mask, &entry);
-       }
-
-       if ((flags & KMA_KOBJECT) == 0) {
-               entry->object.vm_object = object;
-               entry->offset = offset = 0;
+               vm_object_reference(object);
        } else {
-               offset = addr - VM_MIN_KERNEL_ADDRESS;
-
-               if (entry->object.vm_object == VM_OBJECT_NULL) {
-                       vm_object_reference(object);
-                       entry->object.vm_object = object;
-                       entry->offset = offset;
-               }
+               object = vm_object_allocate(map_size);
        }
 
-       if (kr != KERN_SUCCESS) {
-               if ((flags & KMA_KOBJECT) == 0)
-                       vm_object_deallocate(object);
+       kr = vm_map_find_space(map, &map_addr, map_size, map_mask, 0, &entry);
+       if (KERN_SUCCESS != kr) {
+               vm_object_deallocate(object);
                return kr;
        }
 
+       entry->object.vm_object = object;
+       entry->offset = offset = (object == kernel_object) ? 
+                       map_addr : 0;
+
+       /* Take an extra object ref in case the map entry gets deleted */
+       vm_object_reference(object);
        vm_map_unlock(map);
 
-       kr = cpm_allocate(size, &pages, FALSE);
+       kr = cpm_allocate(CAST_DOWN(vm_size_t, map_size), &pages, max_pnum, pnum_mask, FALSE, flags);
 
        if (kr != KERN_SUCCESS) {
-               vm_map_remove(map, addr, addr + size, 0);
+               vm_map_remove(map, vm_map_trunc_page(map_addr),
+                             vm_map_round_page(map_addr + map_size), 0);
+               vm_object_deallocate(object);
                *addrp = 0;
                return kr;
        }
 
        vm_object_lock(object);
-       for (i = 0; i < size; i += PAGE_SIZE) {
+       for (i = 0; i < map_size; i += PAGE_SIZE) {
                m = pages;
                pages = NEXT_PAGE(m);
+               *(NEXT_PAGE_PTR(m)) = VM_PAGE_NULL;
                m->busy = FALSE;
                vm_page_insert(m, object, offset + i);
        }
        vm_object_unlock(object);
 
-       if ((kr = vm_map_wire(map, addr, addr + size, VM_PROT_DEFAULT, FALSE)) 
+       if ((kr = vm_map_wire(map, vm_map_trunc_page(map_addr),
+                             vm_map_round_page(map_addr + map_size), VM_PROT_DEFAULT, FALSE)) 
                != KERN_SUCCESS) {
                if (object == kernel_object) {
                        vm_object_lock(object);
-                       vm_object_page_remove(object, offset, offset + size);
+                       vm_object_page_remove(object, offset, offset + map_size);
                        vm_object_unlock(object);
                }
-               vm_map_remove(map, addr, addr + size, 0);
+               vm_map_remove(map, vm_map_trunc_page(map_addr), 
+                             vm_map_round_page(map_addr + map_size), 0);
+               vm_object_deallocate(object);
                return kr;
        }
+       vm_object_deallocate(object);
+
        if (object == kernel_object)
-               vm_map_simplify(map, addr);
+               vm_map_simplify(map, map_addr);
 
-       *addrp = addr;
+       *addrp = (vm_offset_t) map_addr;
+       assert((vm_map_offset_t) *addrp == map_addr);
        return KERN_SUCCESS;
 }
 
@@ -195,6 +216,10 @@ kmem_alloc_contig(
  *               KMA_HERE              *addrp is base address, else "anywhere"
  *               KMA_NOPAGEWAIT        don't wait for pages if unavailable
  *               KMA_KOBJECT           use kernel_object
+ *               KMA_LOMEM             support for 32 bit devices in a 64 bit world
+ *                                     if set and a lomemory pool is available
+ *                                     grab pages from it... this also implies
+ *                                     KMA_NOPAGEWAIT
  */
 
 kern_return_t
@@ -205,103 +230,255 @@ kernel_memory_allocate(
        register vm_offset_t    mask,
        int                     flags)
 {
-       vm_object_t             object = VM_OBJECT_NULL;
-       vm_map_entry_t          entry;
-       vm_object_offset_t              offset;
-       vm_offset_t             addr;
-       vm_offset_t             i;
+       vm_object_t             object;
+       vm_object_offset_t      offset;
+       vm_object_offset_t      pg_offset;
+       vm_map_entry_t          entry = NULL;
+       vm_map_offset_t         map_addr, fill_start;
+       vm_map_offset_t         map_mask;
+       vm_map_size_t           map_size, fill_size;
        kern_return_t           kr;
+       vm_page_t               mem;
+       vm_page_t               guard_page_list = NULL;
+       vm_page_t               wired_page_list = NULL;
+       int                     guard_page_count = 0;
+       int                     wired_page_count = 0;
+       int                     i;
+       int                     vm_alloc_flags;
+       vm_prot_t               kma_prot;
+
+       if (! vm_kernel_ready) {
+               panic("kernel_memory_allocate: VM is not ready");
+       }
 
-       size = round_page(size);
-       if ((flags & KMA_KOBJECT) == 0) {
-               /*
-                *      Allocate a new object.  We must do this before locking
-                *      the map, or risk deadlock with the default pager:
-                *              device_read_alloc uses kmem_alloc,
-                *              which tries to allocate an object,
-                *              which uses kmem_alloc_wired to get memory,
-                *              which blocks for pages.
-                *              then the default pager needs to read a block
-                *              to process a memory_object_data_write,
-                *              and device_read_alloc calls kmem_alloc
-                *              and deadlocks on the map lock.
-                */
-               object = vm_object_allocate(size);
-               kr = vm_map_find_space(map, &addr, size, mask, &entry);
+       map_size = vm_map_round_page(size);
+       map_mask = (vm_map_offset_t) mask;
+       vm_alloc_flags = 0;
+
+       /* Check for zero allocation size (either directly or via overflow) */
+       if (map_size == 0) {
+               *addrp = 0;
+               return KERN_INVALID_ARGUMENT;
        }
-       else {
-               object = kernel_object;
-               kr = vm_map_find_space(map, &addr, size, mask, &entry);
+
+       /*
+        * limit the size of a single extent of wired memory
+        * to try and limit the damage to the system if
+        * too many pages get wired down
+        */
+        if (map_size > (1 << 30)) {
+                return KERN_RESOURCE_SHORTAGE;
+        }
+
+       /*
+        * Guard pages:
+        *
+        * Guard pages are implemented as ficticious pages.  By placing guard pages
+        * on either end of a stack, they can help detect cases where a thread walks
+        * off either end of its stack.  They are allocated and set up here and attempts
+        * to access those pages are trapped in vm_fault_page().
+        *
+        * The map_size we were passed may include extra space for
+        * guard pages.  If those were requested, then back it out of fill_size
+        * since vm_map_find_space() takes just the actual size not including
+        * guard pages.  Similarly, fill_start indicates where the actual pages
+        * will begin in the range.
+        */
+
+       fill_start = 0;
+       fill_size = map_size;
+
+       if (flags & KMA_GUARD_FIRST) {
+               vm_alloc_flags |= VM_FLAGS_GUARD_BEFORE;
+               fill_start += PAGE_SIZE_64;
+               fill_size -= PAGE_SIZE_64;
+               if (map_size < fill_start + fill_size) {
+                       /* no space for a guard page */
+                       *addrp = 0;
+                       return KERN_INVALID_ARGUMENT;
+               }
+               guard_page_count++;
        }
-       if (kr != KERN_SUCCESS) {
-               if ((flags & KMA_KOBJECT) == 0)
-                       vm_object_deallocate(object);
-               return kr;
+       if (flags & KMA_GUARD_LAST) {
+               vm_alloc_flags |= VM_FLAGS_GUARD_AFTER;
+               fill_size -= PAGE_SIZE_64;
+               if (map_size <= fill_start + fill_size) {
+                       /* no space for a guard page */
+                       *addrp = 0;
+                       return KERN_INVALID_ARGUMENT;
+               }
+               guard_page_count++;
        }
+       wired_page_count = (int) (fill_size / PAGE_SIZE_64);
+       assert(wired_page_count * PAGE_SIZE_64 == fill_size);
 
-       if ((flags & KMA_KOBJECT) == 0) {
-               entry->object.vm_object = object;
-               entry->offset = offset = 0;
-       } else {
-               offset = addr - VM_MIN_KERNEL_ADDRESS;
+       for (i = 0; i < guard_page_count; i++) {
+               for (;;) {
+                       mem = vm_page_grab_guard();
 
-               if (entry->object.vm_object == VM_OBJECT_NULL) {
-                       vm_object_reference(object);
-                       entry->object.vm_object = object;
-                       entry->offset = offset;
+                       if (mem != VM_PAGE_NULL)
+                               break;
+                       if (flags & KMA_NOPAGEWAIT) {
+                               kr = KERN_RESOURCE_SHORTAGE;
+                               goto out;
+                       }
+                       vm_page_more_fictitious();
                }
+               mem->pageq.next = (queue_entry_t)guard_page_list;
+               guard_page_list = mem;
        }
 
-       /*
-        *      Since we have not given out this address yet,
-        *      it is safe to unlock the map.
-        */
-       vm_map_unlock(map);
+       for (i = 0; i < wired_page_count; i++) {
+               uint64_t        unavailable;
+               
+               for (;;) {
+                       if (flags & KMA_LOMEM)
+                               mem = vm_page_grablo();
+                       else
+                               mem = vm_page_grab();
 
-       vm_object_lock(object);
-       for (i = 0; i < size; i += PAGE_SIZE) {
-               vm_page_t       mem;
+                       if (mem != VM_PAGE_NULL)
+                               break;
 
-               while ((mem = vm_page_alloc(object, 
-                                       offset + (vm_object_offset_t)i))
-                           == VM_PAGE_NULL) {
                        if (flags & KMA_NOPAGEWAIT) {
-                               if (object == kernel_object)
-                                       vm_object_page_remove(object, offset,
-                                               offset + (vm_object_offset_t)i);
-                               vm_object_unlock(object);
-                               vm_map_remove(map, addr, addr + size, 0);
-                               return KERN_RESOURCE_SHORTAGE;
+                               kr = KERN_RESOURCE_SHORTAGE;
+                               goto out;
+                       }
+                       if ((flags & KMA_LOMEM) && (vm_lopage_needed == TRUE)) {
+                               kr = KERN_RESOURCE_SHORTAGE;
+                               goto out;
+                       }
+                       unavailable = (vm_page_wire_count + vm_page_free_target) * PAGE_SIZE;
+
+                       if (unavailable > max_mem || map_size > (max_mem - unavailable)) {
+                               kr = KERN_RESOURCE_SHORTAGE;
+                               goto out;
                        }
-                       vm_object_unlock(object);
                        VM_PAGE_WAIT();
-                       vm_object_lock(object);
                }
+               mem->pageq.next = (queue_entry_t)wired_page_list;
+               wired_page_list = mem;
+       }
+
+       /*
+        *      Allocate a new object (if necessary).  We must do this before
+        *      locking the map, or risk deadlock with the default pager.
+        */
+       if ((flags & KMA_KOBJECT) != 0) {
+               object = kernel_object;
+               vm_object_reference(object);
+       } else {
+               object = vm_object_allocate(map_size);
+       }
+
+       kr = vm_map_find_space(map, &map_addr,
+                              fill_size, map_mask,
+                              vm_alloc_flags, &entry);
+       if (KERN_SUCCESS != kr) {
+               vm_object_deallocate(object);
+               goto out;
+       }
+
+       entry->object.vm_object = object;
+       entry->offset = offset = (object == kernel_object) ? 
+                       map_addr : 0;
+
+       entry->wired_count++;
+
+       if (flags & KMA_PERMANENT)
+               entry->permanent = TRUE;
+
+       if (object != kernel_object)
+               vm_object_reference(object);
+
+       vm_object_lock(object);
+       vm_map_unlock(map);
+
+       pg_offset = 0;
+
+       if (fill_start) {
+               if (guard_page_list == NULL)
+                       panic("kernel_memory_allocate: guard_page_list == NULL");
+
+               mem = guard_page_list;
+               guard_page_list = (vm_page_t)mem->pageq.next;
+               mem->pageq.next = NULL;
+
+               vm_page_insert(mem, object, offset + pg_offset);
+
                mem->busy = FALSE;
+               pg_offset += PAGE_SIZE_64;
        }
-       vm_object_unlock(object);
 
-       if ((kr = vm_map_wire(map, addr, addr + size, VM_PROT_DEFAULT, FALSE)) 
-               != KERN_SUCCESS) {
-               if (object == kernel_object) {
-                       vm_object_lock(object);
-                       vm_object_page_remove(object, offset, offset + size);
-                       vm_object_unlock(object);
+       kma_prot = VM_PROT_READ | VM_PROT_WRITE;
+
+       for (pg_offset = fill_start; pg_offset < fill_start + fill_size; pg_offset += PAGE_SIZE_64) {
+               if (wired_page_list == NULL)
+                       panic("kernel_memory_allocate: wired_page_list == NULL");
+
+               mem = wired_page_list;
+               wired_page_list = (vm_page_t)mem->pageq.next;
+               mem->pageq.next = NULL;
+               mem->wire_count++;
+
+               vm_page_insert(mem, object, offset + pg_offset);
+
+               mem->busy = FALSE;
+               mem->pmapped = TRUE;
+               mem->wpmapped = TRUE;
+
+               PMAP_ENTER(kernel_pmap, map_addr + pg_offset, mem, 
+                          kma_prot, VM_PROT_NONE, ((flags & KMA_KSTACK) ? VM_MEM_STACK : 0), TRUE);
+
+               if (flags & KMA_NOENCRYPT) {
+                       bzero(CAST_DOWN(void *, (map_addr + pg_offset)), PAGE_SIZE);
+
+                       pmap_set_noencrypt(mem->phys_page);
                }
-               vm_map_remove(map, addr, addr + size, 0);
-               return (kr);
        }
+       if ((fill_start + fill_size) < map_size) {
+               if (guard_page_list == NULL)
+                       panic("kernel_memory_allocate: guard_page_list == NULL");
+
+               mem = guard_page_list;
+               guard_page_list = (vm_page_t)mem->pageq.next;
+               mem->pageq.next = NULL;
+
+               vm_page_insert(mem, object, offset + pg_offset);
+
+               mem->busy = FALSE;
+       }
+       if (guard_page_list || wired_page_list)
+               panic("kernel_memory_allocate: non empty list\n");
+
+       vm_page_lockspin_queues();
+       vm_page_wire_count += wired_page_count;
+       vm_page_unlock_queues();
+
+       vm_object_unlock(object);
+
+       /*
+        * now that the pages are wired, we no longer have to fear coalesce
+        */
        if (object == kernel_object)
-               vm_map_simplify(map, addr);
+               vm_map_simplify(map, map_addr);
+       else
+               vm_object_deallocate(object);
 
        /*
         *      Return the memory, not zeroed.
         */
-#if    (NCPUS > 1)  &&  i860
-       bzero( addr, size );
-#endif                                  /* #if (NCPUS > 1)  &&  i860 */
-       *addrp = addr;
+       *addrp = CAST_DOWN(vm_offset_t, map_addr);
        return KERN_SUCCESS;
+
+out:
+       if (guard_page_list)
+               vm_page_free_list(guard_page_list, FALSE);
+
+       if (wired_page_list)
+               vm_page_free_list(wired_page_list, FALSE);
+
+       return kr;
 }
 
 /*
@@ -317,7 +494,9 @@ kmem_alloc(
        vm_offset_t     *addrp,
        vm_size_t       size)
 {
-       return kernel_memory_allocate(map, addrp, size, 0, 0);
+       kern_return_t kr = kernel_memory_allocate(map, addrp, size, 0, 0);
+       TRACE_MACHLEAKS(KMEM_ALLOC_CODE, KMEM_ALLOC_CODE_2, size, *addrp);
+       return kr;
 }
 
 /*
@@ -332,38 +511,37 @@ kmem_alloc(
  */
 kern_return_t
 kmem_realloc(
-       vm_map_t        map,
-       vm_offset_t     oldaddr,
-       vm_size_t       oldsize,
-       vm_offset_t     *newaddrp,
-       vm_size_t       newsize)
+       vm_map_t                map,
+       vm_offset_t             oldaddr,
+       vm_size_t               oldsize,
+       vm_offset_t             *newaddrp,
+       vm_size_t               newsize)
 {
-       vm_offset_t oldmin, oldmax;
-       vm_offset_t newaddr;
-       vm_object_t object;
-       vm_map_entry_t oldentry, newentry;
-       kern_return_t kr;
-
-       oldmin = trunc_page(oldaddr);
-       oldmax = round_page(oldaddr + oldsize);
-       oldsize = oldmax - oldmin;
-       newsize = round_page(newsize);
+       vm_object_t             object;
+       vm_object_offset_t      offset;
+       vm_map_offset_t         oldmapmin;
+       vm_map_offset_t         oldmapmax;
+       vm_map_offset_t         newmapaddr;
+       vm_map_size_t           oldmapsize;
+       vm_map_size_t           newmapsize;
+       vm_map_entry_t          oldentry;
+       vm_map_entry_t          newentry;
+       vm_page_t               mem;
+       kern_return_t           kr;
 
-       /*
-        *      Find space for the new region.
-        */
+       oldmapmin = vm_map_trunc_page(oldaddr);
+       oldmapmax = vm_map_round_page(oldaddr + oldsize);
+       oldmapsize = oldmapmax - oldmapmin;
+       newmapsize = vm_map_round_page(newsize);
 
-       kr = vm_map_find_space(map, &newaddr, newsize, (vm_offset_t) 0,
-                              &newentry);
-       if (kr != KERN_SUCCESS) {
-               return kr;
-       }
 
        /*
         *      Find the VM object backing the old region.
         */
 
-       if (!vm_map_lookup_entry(map, oldmin, &oldentry))
+       vm_map_lock(map);
+
+       if (!vm_map_lookup_entry(map, oldmapmin, &oldentry))
                panic("kmem_realloc");
        object = oldentry->object.vm_object;
 
@@ -373,43 +551,72 @@ kmem_realloc(
         */
 
        vm_object_reference(object);
+       /* by grabbing the object lock before unlocking the map */
+       /* we guarantee that we will panic if more than one     */
+       /* attempt is made to realloc a kmem_alloc'd area       */
        vm_object_lock(object);
-       if (object->size != oldsize)
+       vm_map_unlock(map);
+       if (object->vo_size != oldmapsize)
                panic("kmem_realloc");
-       object->size = newsize;
+       object->vo_size = newmapsize;
        vm_object_unlock(object);
 
-       newentry->object.vm_object = object;
-       newentry->offset = 0;
-       assert (newentry->wired_count == 0);
-       newentry->wired_count = 1;
+       /* allocate the new pages while expanded portion of the */
+       /* object is still not mapped */
+       kmem_alloc_pages(object, vm_object_round_page(oldmapsize),
+                        vm_object_round_page(newmapsize-oldmapsize));
 
        /*
-        *      Since we have not given out this address yet,
-        *      it is safe to unlock the map.  We are trusting
-        *      that nobody will play with either region.
+        *      Find space for the new region.
         */
 
-       vm_map_unlock(map);
+       kr = vm_map_find_space(map, &newmapaddr, newmapsize,
+                              (vm_map_offset_t) 0, 0, &newentry);
+       if (kr != KERN_SUCCESS) {
+               vm_object_lock(object);
+               for(offset = oldmapsize; 
+                   offset < newmapsize; offset += PAGE_SIZE) {
+                       if ((mem = vm_page_lookup(object, offset)) != VM_PAGE_NULL) {
+                               VM_PAGE_FREE(mem);
+                       }
+               }
+               object->vo_size = oldmapsize;
+               vm_object_unlock(object);
+               vm_object_deallocate(object);
+               return kr;
+       }
+       newentry->object.vm_object = object;
+       newentry->offset = 0;
+       assert (newentry->wired_count == 0);
 
-       /*
-        *      Remap the pages in the old region and
-        *      allocate more pages for the new region.
-        */
+       
+       /* add an extra reference in case we have someone doing an */
+       /* unexpected deallocate */
+       vm_object_reference(object);
+       vm_map_unlock(map);
 
-       kmem_remap_pages(object, 0,
-                        newaddr, newaddr + oldsize,
-                        VM_PROT_DEFAULT);
-       kmem_alloc_pages(object, oldsize,
-                        newaddr + oldsize, newaddr + newsize,
-                        VM_PROT_DEFAULT);
+       kr = vm_map_wire(map, newmapaddr, newmapaddr + newmapsize, VM_PROT_DEFAULT, FALSE);
+       if (KERN_SUCCESS != kr) {
+               vm_map_remove(map, newmapaddr, newmapaddr + newmapsize, 0);
+               vm_object_lock(object);
+               for(offset = oldsize; offset < newmapsize; offset += PAGE_SIZE) {
+                       if ((mem = vm_page_lookup(object, offset)) != VM_PAGE_NULL) {
+                               VM_PAGE_FREE(mem);
+                       }
+               }
+               object->vo_size = oldmapsize;
+               vm_object_unlock(object);
+               vm_object_deallocate(object);
+               return (kr);
+       }
+       vm_object_deallocate(object);
 
-       *newaddrp = newaddr;
+       *newaddrp = CAST_DOWN(vm_offset_t, newmapaddr);
        return KERN_SUCCESS;
 }
 
 /*
- *     kmem_alloc_wired:
+ *     kmem_alloc_kobject:
  *
  *     Allocate wired-down memory in the kernel's address map
  *     or a submap.  The memory is not zero-filled.
@@ -420,7 +627,7 @@ kmem_realloc(
  */
 
 kern_return_t
-kmem_alloc_wired(
+kmem_alloc_kobject(
        vm_map_t        map,
        vm_offset_t     *addrp,
        vm_size_t       size)
@@ -431,7 +638,7 @@ kmem_alloc_wired(
 /*
  *     kmem_alloc_aligned:
  *
- *     Like kmem_alloc_wired, except that the memory is aligned.
+ *     Like kmem_alloc_kobject, except that the memory is aligned.
  *     The size should be a power-of-2.
  */
 
@@ -458,22 +665,26 @@ kmem_alloc_pageable(
        vm_offset_t     *addrp,
        vm_size_t       size)
 {
-       vm_offset_t addr;
+       vm_map_offset_t map_addr;
+       vm_map_size_t   map_size;
        kern_return_t kr;
 
 #ifndef normal
-       addr = (vm_map_min(map)) + 0x1000;
+       map_addr = (vm_map_min(map)) + 0x1000;
 #else
-       addr = vm_map_min(map);
+       map_addr = vm_map_min(map);
 #endif
-       kr = vm_map_enter(map, &addr, round_page(size),
-                         (vm_offset_t) 0, TRUE,
+       map_size = vm_map_round_page(size);
+
+       kr = vm_map_enter(map, &map_addr, map_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;
 
-       *addrp = addr;
+       *addrp = CAST_DOWN(vm_offset_t, map_addr);
        return KERN_SUCCESS;
 }
 
@@ -481,7 +692,7 @@ kmem_alloc_pageable(
  *     kmem_free:
  *
  *     Release a region of kernel virtual memory allocated
- *     with kmem_alloc, kmem_alloc_wired, or kmem_alloc_pageable,
+ *     with kmem_alloc, kmem_alloc_kobject, or kmem_alloc_pageable,
  *     and return the physical pages associated with that region.
  */
 
@@ -493,67 +704,57 @@ kmem_free(
 {
        kern_return_t kr;
 
-       kr = vm_map_remove(map, trunc_page(addr),
-                          round_page(addr + size), VM_MAP_REMOVE_KUNWIRE);
+       assert(addr >= VM_MIN_KERNEL_AND_KEXT_ADDRESS);
+
+       TRACE_MACHLEAKS(KMEM_FREE_CODE, KMEM_FREE_CODE_2, size, addr);
+
+       if(size == 0) {
+#if MACH_ASSERT
+               printf("kmem_free called with size==0 for map: %p with addr: 0x%llx\n",map,(uint64_t)addr);
+#endif
+               return;
+       }
+
+       kr = vm_map_remove(map, vm_map_trunc_page(addr),
+                               vm_map_round_page(addr + size), 
+                               VM_MAP_REMOVE_KUNWIRE);
        if (kr != KERN_SUCCESS)
                panic("kmem_free");
 }
 
 /*
- *     Allocate new wired pages in an object.
- *     The object is assumed to be mapped into the kernel map or
- *     a submap.
+ *     Allocate new pages in an object.
  */
 
 kern_return_t
 kmem_alloc_pages(
        register vm_object_t            object,
        register vm_object_offset_t     offset,
-       register vm_offset_t            start,
-       register vm_offset_t            end,
-       vm_prot_t                       protection)
+       register vm_object_size_t       size)
 {
-       /*
-        *      Mark the pmap region as not pageable.
-        */
-       pmap_pageable(kernel_pmap, start, end, FALSE);
+       vm_object_size_t                alloc_size;
 
-       while (start < end) {
+       alloc_size = vm_object_round_page(size);
+        vm_object_lock(object);
+       while (alloc_size) {
            register vm_page_t  mem;
 
-           vm_object_lock(object);
 
            /*
             *  Allocate a page
             */
-           while ((mem = vm_page_alloc(object, offset))
-                        == VM_PAGE_NULL) {
+           while (VM_PAGE_NULL == 
+                 (mem = vm_page_alloc(object, offset))) {
                vm_object_unlock(object);
                VM_PAGE_WAIT();
                vm_object_lock(object);
            }
+           mem->busy = FALSE;
 
-           /*
-            *  Wire it down
-            */
-           vm_page_lock_queues();
-           vm_page_wire(mem);
-           vm_page_unlock_queues();
-           vm_object_unlock(object);
-
-           /*
-            *  Enter it in the kernel pmap
-            */
-           PMAP_ENTER(kernel_pmap, start, mem,
-                      protection, TRUE);
-
-           vm_object_lock(object);
-           PAGE_WAKEUP_DONE(mem);
-           vm_object_unlock(object);
-
-           start += PAGE_SIZE;
-           offset += PAGE_SIZE_64;
+           alloc_size -= PAGE_SIZE;
+           offset += PAGE_SIZE;
        }
+       vm_object_unlock(object);
        return KERN_SUCCESS;
 }
 
@@ -570,12 +771,19 @@ kmem_remap_pages(
        register vm_offset_t            end,
        vm_prot_t                       protection)
 {
+
+       vm_map_offset_t                 map_start;
+       vm_map_offset_t                 map_end;
+
        /*
         *      Mark the pmap region as not pageable.
         */
-       pmap_pageable(kernel_pmap, start, end, FALSE);
+       map_start = vm_map_trunc_page(start);
+       map_end = vm_map_round_page(end);
+
+       pmap_pageable(kernel_pmap, map_start, map_end, FALSE);
 
-       while (start < end) {
+       while (map_start < map_end) {
            register vm_page_t  mem;
 
            vm_object_lock(object);
@@ -589,19 +797,30 @@ kmem_remap_pages(
            /*
             *  Wire it down (again)
             */
-           vm_page_lock_queues();
+           vm_page_lockspin_queues();
            vm_page_wire(mem);
            vm_page_unlock_queues();
            vm_object_unlock(object);
 
+           /*
+            * ENCRYPTED SWAP:
+            * The page is supposed to be wired now, so it
+            * shouldn't be encrypted at this point.  It can
+            * safely be entered in the page table.
+            */
+           ASSERT_PAGE_DECRYPTED(mem);
+
            /*
             *  Enter it in the kernel pmap.  The page isn't busy,
             *  but this shouldn't be a problem because it is wired.
             */
-           PMAP_ENTER(kernel_pmap, start, mem,
-                      protection, TRUE);
 
-           start += PAGE_SIZE;
+           mem->pmapped = TRUE;
+           mem->wpmapped = TRUE;
+
+           PMAP_ENTER(kernel_pmap, map_start, mem, protection, VM_PROT_NONE, 0, TRUE);
+
+           map_start += PAGE_SIZE;
            offset += PAGE_SIZE;
        }
 }
@@ -627,13 +846,15 @@ kmem_suballoc(
        vm_offset_t     *addr,
        vm_size_t       size,
        boolean_t       pageable,
-       boolean_t       anywhere,
+       int             flags,
        vm_map_t        *new_map)
 {
-       vm_map_t map;
-       kern_return_t kr;
+       vm_map_t        map;
+       vm_map_offset_t map_addr;
+       vm_map_size_t   map_size;
+       kern_return_t   kr;
 
-       size = round_page(size);
+       map_size = vm_map_round_page(size);
 
        /*
         *      Need reference on submap object because it is internal
@@ -642,10 +863,11 @@ kmem_suballoc(
         */
        vm_object_reference(vm_submap_object);
 
-       if (anywhere == TRUE)
-               *addr = (vm_offset_t)vm_map_min(parent);
-       kr = vm_map_enter(parent, addr, size,
-                         (vm_offset_t) 0, anywhere,
+       map_addr = (flags & VM_FLAGS_ANYWHERE) ?
+                  vm_map_min(parent) : vm_map_trunc_page(*addr);
+
+       kr = vm_map_enter(parent, &map_addr, map_size,
+                         (vm_map_offset_t) 0, flags,
                          vm_submap_object, (vm_object_offset_t) 0, FALSE,
                          VM_PROT_DEFAULT, VM_PROT_ALL, VM_INHERIT_DEFAULT);
        if (kr != KERN_SUCCESS) {
@@ -654,21 +876,21 @@ kmem_suballoc(
        }
 
        pmap_reference(vm_map_pmap(parent));
-       map = vm_map_create(vm_map_pmap(parent), *addr, *addr + size, pageable);
+       map = vm_map_create(vm_map_pmap(parent), map_addr, map_addr + map_size, pageable);
        if (map == VM_MAP_NULL)
                panic("kmem_suballoc: vm_map_create failed");   /* "can't happen" */
 
-       kr = vm_map_submap(parent, *addr, *addr + size, map, *addr, FALSE);
+       kr = vm_map_submap(parent, map_addr, map_addr + map_size, map, map_addr, FALSE);
        if (kr != KERN_SUCCESS) {
                /*
                 * See comment preceding vm_map_submap().
                 */
-               vm_map_remove(parent, *addr, *addr + size, VM_MAP_NO_FLAGS);
+               vm_map_remove(parent, map_addr, map_addr + map_size, VM_MAP_NO_FLAGS);
                vm_map_deallocate(map); /* also removes ref to pmap */
                vm_object_deallocate(vm_submap_object);
                return (kr);
        }
-
+       *addr = CAST_DOWN(vm_offset_t, map_addr);
        *new_map = map;
        return (KERN_SUCCESS);
 }
@@ -684,242 +906,56 @@ kmem_init(
        vm_offset_t     start,
        vm_offset_t     end)
 {
-       kernel_map = vm_map_create(pmap_kernel(),
-                                  VM_MIN_KERNEL_ADDRESS, end,
-                                  FALSE);
-
-       /*
-        *      Reserve virtual memory allocated up to this time.
-        */
-
-       if (start != VM_MIN_KERNEL_ADDRESS) {
-               vm_offset_t addr = VM_MIN_KERNEL_ADDRESS;
-               (void) vm_map_enter(kernel_map,
-                                   &addr, start - VM_MIN_KERNEL_ADDRESS,
-                                   (vm_offset_t) 0, TRUE,
-                                   VM_OBJECT_NULL, 
-                                   (vm_object_offset_t) 0, FALSE,
-                                   VM_PROT_DEFAULT, VM_PROT_ALL,
-                                   VM_INHERIT_DEFAULT);
-       }
-
-        /*
-         * Account for kernel memory (text, data, bss, vm shenanigans).
-         * This may include inaccessible "holes" as determined by what
-         * the machine-dependent init code includes in mem_size.
-         */
-        vm_page_wire_count = (atop(mem_size) - (vm_page_free_count
-                                                + vm_page_active_count
-                                                + vm_page_inactive_count));
-}
+       vm_map_offset_t map_start;
+       vm_map_offset_t map_end;
 
-/*
- *     kmem_io_map_copyout:
- *
- *     Establish temporary mapping in designated map for the memory
- *     passed in.  Memory format must be a page_list vm_map_copy.
- */
-
-kern_return_t
-kmem_io_map_copyout(
-       vm_map_t        map,
-       vm_offset_t     *addr,          /* actual addr of data */
-       vm_size_t       *alloc_size,    /* size allocated */
-       vm_map_copy_t   copy,
-       vm_size_t       min_size,       /* Do at least this much */
-       vm_prot_t       prot)           /* Protection of mapping */
-{
-       vm_offset_t     myaddr, offset;
-       vm_size_t       mysize, copy_size;
-       kern_return_t   ret;
-       register
-       vm_page_t       *page_list;
-       vm_map_copy_t   new_copy;
-       register
-       int             i;
-
-       assert(copy->type == VM_MAP_COPY_PAGE_LIST);
-       assert(min_size != 0);
-
-       /*
-        *      Figure out the size in vm pages.
-        */
-       min_size += (vm_size_t)(copy->offset - trunc_page_64(copy->offset));
-       min_size = round_page(min_size);
-       mysize = (vm_size_t)(round_page_64(
-                       copy->offset + (vm_object_offset_t)copy->size) -
-                       trunc_page_64(copy->offset));
+       map_start = vm_map_trunc_page(start);
+       map_end = vm_map_round_page(end);
 
+       kernel_map = vm_map_create(pmap_kernel(),VM_MIN_KERNEL_AND_KEXT_ADDRESS,
+                           map_end, FALSE);
        /*
-        *      If total size is larger than one page list and
-        *      we don't have to do more than one page list, then
-        *      only do one page list.  
-        *
-        * XXX  Could be much smarter about this ... like trimming length
-        * XXX  if we need more than one page list but not all of them.
-        */
-
-       copy_size = ptoa(copy->cpy_npages);
-       if (mysize > copy_size && copy_size > min_size)
-               mysize = copy_size;
-
-       /*
-        *      Allocate some address space in the map (must be kernel
-        *      space).
-        */
-       myaddr = vm_map_min(map);
-       ret = vm_map_enter(map, &myaddr, mysize,
-                         (vm_offset_t) 0, TRUE,
-                         VM_OBJECT_NULL, (vm_object_offset_t) 0, FALSE,
-                         prot, prot, VM_INHERIT_DEFAULT);
-
-       if (ret != KERN_SUCCESS)
-               return(ret);
-
-       /*
-        *      Tell the pmap module that this will be wired, and
-        *      enter the mappings.
+        *      Reserve virtual memory allocated up to this time.
         */
-       pmap_pageable(vm_map_pmap(map), myaddr, myaddr + mysize, TRUE);
-
-       *addr = myaddr + (vm_offset_t)
-                               (copy->offset - trunc_page_64(copy->offset));
-       *alloc_size = mysize;
-
-       offset = myaddr;
-       page_list = &copy->cpy_page_list[0];
-       while (TRUE) {
-               for ( i = 0; i < copy->cpy_npages; i++, offset+=PAGE_SIZE_64) {
-                       PMAP_ENTER(vm_map_pmap(map), 
-                                  (vm_offset_t)offset, *page_list,
-                                  prot, TRUE);
-                       page_list++;
-               }
-
-               if (offset == (myaddr + mysize))
-                       break;
-
-               /*
-                *      Onward to the next page_list.  The extend_cont
-                *      leaves the current page list's pages alone; 
-                *      they'll be cleaned up at discard.  Reset this
-                *      copy's continuation to discard the next one.
-                */
-               vm_map_copy_invoke_extend_cont(copy, &new_copy, &ret);
-
-               if (ret != KERN_SUCCESS) {
-                       kmem_io_map_deallocate(map, myaddr, mysize);
-                       return(ret);
-               }
-               copy->cpy_cont = vm_map_copy_discard_cont;
-               copy->cpy_cont_args = (vm_map_copyin_args_t) new_copy;
-               assert(new_copy != VM_MAP_COPY_NULL);
-               assert(new_copy->type == VM_MAP_COPY_PAGE_LIST);
-               copy = new_copy;
-               page_list = &copy->cpy_page_list[0];
+       if (start != VM_MIN_KERNEL_AND_KEXT_ADDRESS) {
+               vm_map_offset_t map_addr;
+               kern_return_t kr;
+               map_addr = VM_MIN_KERNEL_AND_KEXT_ADDRESS;
+               kr = vm_map_enter(kernel_map,
+                       &map_addr, 
+                       (vm_map_size_t)(map_start - VM_MIN_KERNEL_AND_KEXT_ADDRESS),
+                       (vm_map_offset_t) 0,
+                       VM_FLAGS_FIXED | VM_FLAGS_NO_PMAP_CHECK,
+                       VM_OBJECT_NULL, 
+                       (vm_object_offset_t) 0, FALSE,
+                       VM_PROT_NONE, VM_PROT_NONE,
+                       VM_INHERIT_DEFAULT);
+               
+               if (kr != KERN_SUCCESS) {
+                       panic("kmem_init(0x%llx,0x%llx): vm_map_enter(0x%llx,0x%llx) error 0x%x\n",
+                             (uint64_t) start, (uint64_t) end,
+                             (uint64_t) VM_MIN_KERNEL_AND_KEXT_ADDRESS,
+                             (uint64_t) (map_start - VM_MIN_KERNEL_AND_KEXT_ADDRESS),
+                             kr);
+               }       
        }
 
-       return(ret);
-}
-
-/*
- *     kmem_io_map_deallocate:
- *
- *     Get rid of the mapping established by kmem_io_map_copyout.
- *     Assumes that addr and size have been rounded to page boundaries.
- */
-
-void
-kmem_io_map_deallocate(
-       vm_map_t        map,
-       vm_offset_t     addr,
-       vm_size_t       size)
-{
-
-       register vm_offset_t    va, end;
-
-       end = round_page(addr + size);
-       for (va = trunc_page(addr); va < end; va += PAGE_SIZE)
-           pmap_change_wiring(vm_map_pmap(map), va, FALSE);
-
        /*
-        *      Remove the mappings.  The pmap_remove is needed.
+        * Set the default global user wire limit which limits the amount of
+        * memory that can be locked via mlock().  We set this to the total
+        * amount of memory that are potentially usable by a user app (max_mem)
+        * minus a certain amount.  This can be overridden via a sysctl.
         */
+       vm_global_no_user_wire_amount = MIN(max_mem*20/100,
+                                           VM_NOT_USER_WIREABLE);
+       vm_global_user_wire_limit = max_mem - vm_global_no_user_wire_amount;
        
-       pmap_remove(vm_map_pmap(map), addr, addr + size);
-       vm_map_remove(map, addr, addr + size, VM_MAP_REMOVE_KUNWIRE);
+       /* the default per user limit is the same as the global limit */
+       vm_user_wire_limit = vm_global_user_wire_limit;
 }
 
 
-/*
- *     kmem_io_object_trunc:
- *
- *     Truncate an object vm_map_copy_t.
- *     Called by the scatter/gather list network code to remove pages from
- *     the tail end of a packet. Also unwires the objects pages.
- */
-
-kern_return_t
-kmem_io_object_trunc(copy, new_size)
-     vm_map_copy_t     copy;           /* IN/OUT copy object */
-     register vm_size_t new_size;      /* IN new object size */
-{
-       register vm_size_t      offset, old_size;
-
-       assert(copy->type == VM_MAP_COPY_OBJECT);
-
-       old_size = (vm_size_t)round_page_64(copy->size);
-       copy->size = new_size;
-       new_size = round_page(new_size);
-
-        vm_object_lock(copy->cpy_object);
-        vm_object_page_remove(copy->cpy_object,
-               (vm_object_offset_t)new_size, (vm_object_offset_t)old_size);
-        for (offset = 0; offset < new_size; offset += PAGE_SIZE) {
-               register vm_page_t      mem;
-
-               if ((mem = vm_page_lookup(copy->cpy_object, 
-                               (vm_object_offset_t)offset)) == VM_PAGE_NULL)
-                   panic("kmem_io_object_trunc: unable to find object page");
-
-               /*
-                * Make sure these pages are marked dirty
-                */
-               mem->dirty = TRUE;
-               vm_page_lock_queues();
-               vm_page_unwire(mem);
-               vm_page_unlock_queues();
-       }
-        copy->cpy_object->size = new_size;     /*  adjust size of object */
-        vm_object_unlock(copy->cpy_object);
-        return(KERN_SUCCESS);
-}
-
-/*
- *     kmem_io_object_deallocate:
- *
- *     Free an vm_map_copy_t.
- *     Called by the scatter/gather list network code to free a packet.
- */
-
-void
-kmem_io_object_deallocate(
-     vm_map_copy_t     copy)           /* IN/OUT copy object */
-{
-       kern_return_t   ret;
-
-       /*
-        * Clear out all the object pages (this will leave an empty object).
-        */
-       ret = kmem_io_object_trunc(copy, 0);
-       if (ret != KERN_SUCCESS)
-               panic("kmem_io_object_deallocate: unable to truncate object");
-       /*
-        * ...and discard the copy object.
-        */
-       vm_map_copy_discard(copy);
-}
-
 /*
  *     Routine:        copyinmap
  *     Purpose:
@@ -928,23 +964,36 @@ kmem_io_object_deallocate(
  *             is incomplete; it handles the current user map
  *             and the kernel map/submaps.
  */
-boolean_t
+kern_return_t
 copyinmap(
-       vm_map_t        map,
-       vm_offset_t     fromaddr,
-       vm_offset_t     toaddr,
-       vm_size_t       length)
+       vm_map_t                map,
+       vm_map_offset_t         fromaddr,
+       void                    *todata,
+       vm_size_t               length)
 {
-       if (vm_map_pmap(map) == pmap_kernel()) {
+       kern_return_t   kr = KERN_SUCCESS;
+       vm_map_t oldmap;
+
+       if (vm_map_pmap(map) == pmap_kernel())
+       {
                /* assume a correct copy */
-               memcpy((void *)toaddr, (void *)fromaddr, length);
-               return FALSE;
+               memcpy(todata, CAST_DOWN(void *, fromaddr), length);
+       } 
+       else if (current_map() == map)
+       {
+               if (copyin(fromaddr, todata, length) != 0)
+                       kr = KERN_INVALID_ADDRESS;
        }
-
-       if (current_map() == map)
-               return copyin((char *)fromaddr, (char *)toaddr, length);
-
-       return TRUE;
+       else
+       {
+               vm_map_reference(map);
+               oldmap = vm_map_switch(map);
+               if (copyin(fromaddr, todata, length) != 0)
+                       kr = KERN_INVALID_ADDRESS;
+               vm_map_switch(oldmap);
+               vm_map_deallocate(map);
+       }
+       return kr;
 }
 
 /*
@@ -955,21 +1004,138 @@ copyinmap(
  *             is incomplete; it handles the current user map
  *             and the kernel map/submaps.
  */
-boolean_t
+kern_return_t
 copyoutmap(
-       vm_map_t        map,
-       vm_offset_t     fromaddr,
-       vm_offset_t     toaddr,
-       vm_size_t       length)
+       vm_map_t                map,
+       void                    *fromdata,
+       vm_map_address_t        toaddr,
+       vm_size_t               length)
 {
        if (vm_map_pmap(map) == pmap_kernel()) {
                /* assume a correct copy */
-               memcpy((void *)toaddr, (void *)fromaddr, length);
-               return FALSE;
+               memcpy(CAST_DOWN(void *, toaddr), fromdata, length);
+               return KERN_SUCCESS;
        }
 
-       if (current_map() == map)
-               return copyout((char *)fromaddr, (char *)toaddr, length);
+       if (current_map() != map)
+               return KERN_NOT_SUPPORTED;
+
+       if (copyout(fromdata, toaddr, length) != 0)
+               return KERN_INVALID_ADDRESS;
+
+       return KERN_SUCCESS;
+}
+
 
-       return TRUE;
+kern_return_t
+vm_conflict_check(
+       vm_map_t                map,
+       vm_map_offset_t off,
+       vm_map_size_t           len,
+       memory_object_t pager,
+       vm_object_offset_t      file_off)
+{
+       vm_map_entry_t          entry;
+       vm_object_t             obj;
+       vm_object_offset_t      obj_off;
+       vm_map_t                base_map;
+       vm_map_offset_t         base_offset;
+       vm_map_offset_t         original_offset;
+       kern_return_t           kr;
+       vm_map_size_t           local_len;
+
+       base_map = map;
+       base_offset = off;
+       original_offset = off;
+       kr = KERN_SUCCESS;
+       vm_map_lock(map);
+       while(vm_map_lookup_entry(map, off, &entry)) {
+               local_len = len;
+
+               if (entry->object.vm_object == VM_OBJECT_NULL) {
+                       vm_map_unlock(map);
+                       return KERN_SUCCESS;
+               }
+               if (entry->is_sub_map) {
+                       vm_map_t        old_map;
+
+                       old_map = map;
+                       vm_map_lock(entry->object.sub_map);
+                       map = entry->object.sub_map;
+                       off = entry->offset + (off - entry->vme_start);
+                       vm_map_unlock(old_map);
+                       continue;
+               }
+               obj = entry->object.vm_object;
+               obj_off = (off - entry->vme_start) + entry->offset;
+               while(obj->shadow) {
+                       obj_off += obj->vo_shadow_offset;
+                       obj = obj->shadow;
+               }
+               if((obj->pager_created) && (obj->pager == pager)) {
+                       if(((obj->paging_offset) + obj_off) == file_off) {
+                               if(off != base_offset) {
+                                       vm_map_unlock(map);
+                                       return KERN_FAILURE;
+                               }
+                               kr = KERN_ALREADY_WAITING;
+                       } else {
+                               vm_object_offset_t      obj_off_aligned;
+                               vm_object_offset_t      file_off_aligned;
+
+                               obj_off_aligned = obj_off & ~PAGE_MASK;
+                               file_off_aligned = file_off & ~PAGE_MASK;
+
+                               if (file_off_aligned == (obj->paging_offset + obj_off_aligned)) {
+                                       /*
+                                        * the target map and the file offset start in the same page
+                                        * but are not identical... 
+                                        */
+                                       vm_map_unlock(map);
+                                       return KERN_FAILURE;
+                               }
+                               if ((file_off < (obj->paging_offset + obj_off_aligned)) &&
+                                   ((file_off + len) > (obj->paging_offset + obj_off_aligned))) {
+                                       /*
+                                        * some portion of the tail of the I/O will fall
+                                        * within the encompass of the target map
+                                        */
+                                       vm_map_unlock(map);
+                                       return KERN_FAILURE;
+                               }
+                               if ((file_off_aligned > (obj->paging_offset + obj_off)) &&
+                                   (file_off_aligned < (obj->paging_offset + obj_off) + len)) {
+                                       /*
+                                        * the beginning page of the file offset falls within
+                                        * the target map's encompass
+                                        */
+                                       vm_map_unlock(map);
+                                       return KERN_FAILURE;
+                               }
+                       }
+               } else if(kr != KERN_SUCCESS) {
+                       vm_map_unlock(map);
+                       return KERN_FAILURE;
+               }
+
+               if(len <= ((entry->vme_end - entry->vme_start) -
+                                               (off - entry->vme_start))) {
+                       vm_map_unlock(map);
+                       return kr;
+               } else {
+                       len -= (entry->vme_end - entry->vme_start) -
+                                               (off - entry->vme_start);
+               }
+               base_offset = base_offset + (local_len - len);
+               file_off = file_off + (local_len - len);
+               off = base_offset;
+               if(map != base_map) {
+                       vm_map_unlock(map);
+                       vm_map_lock(base_map);
+                       map = base_map;
+               }
+       }
+
+       vm_map_unlock(map);
+       return kr;
 }