osfmk/i386/read_fault.c

   1 /*
   2  * Copyright (c) 2000-2004 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_OSREFERENCE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License.  The rights granted to you under the
  10  * License may not be used to create, or enable the creation or
  11  * redistribution of, unlawful or unlicensed copies of an Apple operating
  12  * system, or to circumvent, violate, or enable the circumvention or
  13  * violation of, any terms of an Apple operating system software license
  14  * agreement.
  15  *
  16  * Please obtain a copy of the License at
  17  * http://www.opensource.apple.com/apsl/ and read it before using this
  18  * file.
  19  *
  20  * The Original Code and all software distributed under the License are
  21  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  22  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  23  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  24  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  25  * Please see the License for the specific language governing rights and
  26  * limitations under the License.
  27  *
  28  * @APPLE_LICENSE_OSREFERENCE_HEADER_END@
  29  */
  30 /*
  31  * @OSF_COPYRIGHT@
  32  */
  33 /*
  34  * Mach Operating System
  35  * Copyright (c) 1991,1990 Carnegie Mellon University
  36  * All Rights Reserved.
  37  *
  38  * Permission to use, copy, modify and distribute this software and its
  39  * documentation is hereby granted, provided that both the copyright
  40  * notice and this permission notice appear in all copies of the
  41  * software, derivative works or modified versions, and any portions
  42  * thereof, and that both notices appear in supporting documentation.
  43  *
  44  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
  45  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
  46  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
  47  *
  48  * Carnegie Mellon requests users of this software to return to
  49  *
  50  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
  51  *  School of Computer Science
  52  *  Carnegie Mellon University
  53  *  Pittsburgh PA 15213-3890
  54  *
  55  * any improvements or extensions that they make and grant Carnegie Mellon
  56  * the rights to redistribute these changes.
  57  */
  58 /*
  59  */
  60
  61 #include <kern/thread.h>
  62 #include <vm/vm_fault.h>
  63 #include <mach/kern_return.h>
  64 #include <mach/vm_behavior.h>
  65 #include <vm/vm_map.h>
  66 #include <vm/vm_object.h>
  67 #include <vm/vm_page.h>
  68 #include <vm/pmap.h>
  69
  70 #include <i386/intel_read_fault.h>
  71
  72 #include <kern/macro_help.h>
  73
  74 /*
  75  *      Expansion of vm_fault for read fault in kernel mode.
  76  *      Must enter the mapping as writable, since the i386
  77  *      (and i860 in i386 compatability mode) ignores write
  78  *      protection in kernel mode.
  79  *
  80  *      Note that this routine can be called for pmap's other
  81  *      than the kernel_pmap, in which case it just enters
  82  *      a read-only mapping.  (See e.g. kernel_trap().)
  83  */
  84 kern_return_t
  85 intel_read_fault(
  86         vm_map_t        map,
  87         vm_offset_t     vaddr)
  88 {
  89         vm_map_version_t        version;        /* Map version for
  90                                                    verification */
  91         vm_object_t             object;         /* Top-level object */
  92         vm_object_offset_t      offset;         /* Top-level offset */
  93         vm_prot_t               prot;           /* Protection for mapping */
  94         vm_behavior_t           behavior;       /* Expected paging behavior */
  95         vm_map_offset_t         lo_offset, hi_offset;
  96         vm_page_t               result_page;    /* Result of vm_fault_page */
  97         vm_page_t               top_page;       /* Placeholder page */
  98         boolean_t               wired;          /* Is map region wired? */
  99         kern_return_t           result;
 100         register vm_page_t      m;
 101         vm_map_t                map_pmap;
 102         vm_map_t                original_map = map;
 103         thread_t                cur_thread;
 104         boolean_t               funnel_set;
 105         funnel_t                *curflock = NULL;
 106
 107         cur_thread = current_thread();
 108         if ((cur_thread->funnel_state & TH_FN_OWNED) == TH_FN_OWNED) {
 109                 funnel_set = TRUE;
 110                 curflock = cur_thread->funnel_lock;
 111                 thread_funnel_set( curflock , FALSE);
 112         } else {
 113                 funnel_set = FALSE;
 114         }
 115
 116     RetryFault:
 117
 118         map = original_map;
 119
 120         /*
 121          *      Find the backing store object and offset into it
 122          *      to begin search.
 123          */
 124         vm_map_lock_read(map);
 125         result = vm_map_lookup_locked(&map, vaddr, VM_PROT_READ, &version,
 126                                       &object, &offset, &prot, &wired,
 127                                       &behavior, &lo_offset,
 128                                       &hi_offset, &map_pmap);
 129
 130         vm_map_unlock_read(map);
 131
 132         if (result != KERN_SUCCESS) {
 133                 if (funnel_set)
 134                         thread_funnel_set( curflock, TRUE);
 135                 return (result);
 136         }
 137
 138         if(map_pmap != map) {
 139                 vm_map_reference(map_pmap);
 140                 vm_map_unlock_read(map_pmap);
 141         }
 142
 143         /*
 144          *      Make a reference to this object to prevent its
 145          *      disposal while we are playing with it.
 146          */
 147         assert(object->ref_count > 0);
 148         object->ref_count++;
 149         vm_object_res_reference(object);
 150         vm_object_paging_begin(object);
 151
 152         result = vm_fault_page(object, offset, VM_PROT_READ, FALSE,
 153                                THREAD_ABORTSAFE,
 154                                lo_offset, hi_offset, behavior,
 155                                &prot, &result_page, &top_page, (int *)0,
 156                                0, map->no_zero_fill, FALSE, map, vaddr);
 157
 158         if (result != VM_FAULT_SUCCESS) {
 159             vm_object_deallocate(object);
 160             if(map_pmap != map) {
 161                         vm_map_deallocate(map_pmap);
 162            }
 163
 164             switch (result) {
 165                 case VM_FAULT_RETRY:
 166                     goto RetryFault;
 167                 case VM_FAULT_INTERRUPTED:
 168                         if (funnel_set)
 169                                 thread_funnel_set( curflock, TRUE);
 170                     return (KERN_SUCCESS);
 171                 case VM_FAULT_MEMORY_SHORTAGE:
 172                     VM_PAGE_WAIT();
 173                     goto RetryFault;
 174                 case VM_FAULT_FICTITIOUS_SHORTAGE:
 175                     vm_page_more_fictitious();
 176                     goto RetryFault;
 177                 case VM_FAULT_MEMORY_ERROR:
 178                     return (KERN_MEMORY_ERROR);
 179             }
 180         }
 181
 182         m = result_page;
 183
 184         /*
 185          *      How to clean up the result of vm_fault_page.  This
 186          *      happens whether the mapping is entered or not.
 187          */
 188
 189 #define UNLOCK_AND_DEALLOCATE                           \
 190         MACRO_BEGIN                                     \
 191         vm_fault_cleanup(m->object, top_page);          \
 192         vm_object_deallocate(object);                   \
 193         MACRO_END
 194
 195         /*
 196          *      What to do with the resulting page from vm_fault_page
 197          *      if it doesn't get entered into the physical map:
 198          */
 199
 200 #define RELEASE_PAGE(m)                                 \
 201         MACRO_BEGIN                                     \
 202         PAGE_WAKEUP_DONE(m);                            \
 203         vm_page_lock_queues();                          \
 204         if (!m->active && !m->inactive)                 \
 205                 vm_page_activate(m);                    \
 206         vm_page_unlock_queues();                        \
 207         MACRO_END
 208
 209         /*
 210          *      We must verify that the maps have not changed.
 211          */
 212         vm_object_unlock(m->object);
 213
 214         if ((map != original_map) || !vm_map_verify(map, &version)) {
 215             vm_object_t         retry_object;
 216             vm_object_offset_t  retry_offset;
 217             vm_prot_t           retry_prot;
 218
 219                 if (map != map_pmap) {
 220                         vm_map_deallocate(map_pmap);
 221                 }
 222
 223                 map = original_map;
 224                 vm_map_lock_read(map);
 225
 226             result = vm_map_lookup_locked(&map, vaddr, VM_PROT_READ, &version,
 227                                 &retry_object, &retry_offset, &retry_prot,
 228                                 &wired, &behavior, &lo_offset,
 229                                 &hi_offset, &map_pmap);
 230
 231             if (result != KERN_SUCCESS) {
 232                 vm_map_unlock_read(map);
 233                         vm_object_lock(m->object);
 234                         RELEASE_PAGE(m);
 235                         UNLOCK_AND_DEALLOCATE;
 236                         if (funnel_set)
 237                                 thread_funnel_set( curflock, TRUE);
 238                         return (result);
 239             }
 240
 241                 if (map != map_pmap) {
 242                         vm_map_reference(map_pmap);
 243                 }
 244
 245             vm_object_unlock(retry_object);
 246
 247             if (retry_object != object || retry_offset != offset) {
 248                         vm_object_lock(m->object);
 249                         RELEASE_PAGE(m);
 250                 vm_map_unlock_read(map);
 251                 if(map_pmap != map) {
 252                                 vm_map_unlock_read(map_pmap);
 253                                 vm_map_deallocate(map_pmap);
 254                         }
 255                         UNLOCK_AND_DEALLOCATE;
 256                         goto RetryFault;
 257             }
 258         }
 259
 260         /*
 261          *      Put the page in the physical map.
 262          */
 263
 264         PMAP_ENTER(map_pmap->pmap, vaddr, m, VM_PROT_READ, PMAP_DEFAULT_CACHE, wired);
 265
 266         if(map_pmap != map) {
 267                 vm_map_unlock_read(map_pmap);
 268                 vm_map_deallocate(map_pmap);
 269         }
 270
 271         vm_object_lock(m->object);
 272         vm_page_lock_queues();
 273         if (!m->active && !m->inactive)
 274                 vm_page_activate(m);
 275         m->reference = TRUE;
 276         vm_page_unlock_queues();
 277
 278         vm_map_verify_done(map, &version);
 279         PAGE_WAKEUP_DONE(m);
 280
 281         UNLOCK_AND_DEALLOCATE;
 282
 283 #undef  UNLOCK_AND_DEALLOCATE
 284 #undef  RELEASE_PAGE
 285         if (funnel_set)
 286                 thread_funnel_set( curflock, TRUE);
 287         return (KERN_SUCCESS);
 288 }
 289