osfmk/i386/read_fault.c

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