include/mach-o/dyld_images.h

   1 /*
   2  * Copyright (c) 2006-2010 Apple Inc. All rights reserved.
   3  *
   4  * @APPLE_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. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23 #ifndef _DYLD_IMAGES_
  24 #define _DYLD_IMAGES_
  25
  26 #include <stdbool.h>
  27 #include <unistd.h>
  28 #include <mach/mach.h>
  29
  30 #ifdef __cplusplus
  31 extern "C" {
  32 #endif
  33
  34
  35 /*
  36  *      Beginning in Mac OS X 10.4, this is how gdb discovers which mach-o images are loaded in a process.
  37  *
  38  *      gdb looks for the symbol "_dyld_all_image_infos" in dyld.  It contains the fields below.
  39  *
  40  *      For a snashot of what images are currently loaded, the infoArray fields contain a pointer
  41  *      to an array of all images. If infoArray is NULL, it means it is being modified, come back later.
  42  *
  43  *      To be notified of changes, gdb sets a break point on the address pointed to by the notificationn
  44  *      field.  The function it points to is called by dyld with an array of information about what images
  45  *      have been added (dyld_image_adding) or are about to be removed (dyld_image_removing).
  46  *
  47  * The notification is called after infoArray is updated.  This means that if gdb attaches to a process
  48  * and infoArray is NULL, gdb can set a break point on notification and let the proccess continue to
  49  * run until the break point.  Then gdb can inspect the full infoArray.
  50  *
  51  * The dyldVersion field always points to a C string that contains the dyld version.  For instance,
  52  * in dyld-127.3, dyldVersion would contain a pointer to "127.3".
  53  *
  54  * The errorMessage and terminationFlags fields are normally zero.  If dyld terminates a process
  55  * (for instance because a required dylib or symbol is missing), then the errorMessage field will
  56  * be set to point to a C string message buffer containing the reason dyld terminate the process.
  57  * The low bit of the terminationFlags will be set if dyld terminated the process before any user
  58  * code ran, in which case there is no need for the crash log to contain the backtrace.
  59  *
  60  * When dyld terminates a process because some required dylib or symbol cannot be bound, in
  61  * addition to the errorMessage field, it now sets the errorKind field and the corresponding
  62  * fields: errorClientOfDylibPath, errorTargetDylibPath, errorSymbol.
  63  *
  64  */
  65
  66 enum dyld_image_mode { dyld_image_adding=0, dyld_image_removing=1 };
  67
  68 struct dyld_image_info {
  69         const struct mach_header*       imageLoadAddress;       /* base address image is mapped into */
  70         const char*                                     imageFilePath;          /* path dyld used to load the image */
  71         uintptr_t                                       imageFileModDate;       /* time_t of image file */
  72                                                                                                         /* if stat().st_mtime of imageFilePath does not match imageFileModDate, */
  73                                                                                                         /* then file has been modified since dyld loaded it */
  74 };
  75
  76 struct dyld_uuid_info {
  77         const struct mach_header*       imageLoadAddress;       /* base address image is mapped into */
  78         uuid_t                                          imageUUID;                      /* UUID of image */
  79 };
  80
  81 typedef void (*dyld_image_notifier)(enum dyld_image_mode mode, uint32_t infoCount, const struct dyld_image_info info[]);
  82
  83 /* for use in dyld_all_image_infos.errorKind field */
  84 enum {  dyld_error_kind_none=0,
  85                 dyld_error_kind_dylib_missing=1,
  86                 dyld_error_kind_dylib_wrong_arch=2,
  87                 dyld_error_kind_dylib_version=3,
  88                 dyld_error_kind_symbol_missing=4
  89         };
  90
  91
  92 struct dyld_all_image_infos {
  93         uint32_t                                                version;                /* 1 in Mac OS X 10.4 and 10.5 */
  94         uint32_t                                                infoArrayCount;
  95         const struct dyld_image_info*   infoArray;
  96         dyld_image_notifier                             notification;
  97         bool                                                    processDetachedFromSharedRegion;
  98         /* the following fields are only in version 2 (Mac OS X 10.6, iPhoneOS 2.0) and later */
  99         bool                                                    libSystemInitialized;
 100         const struct mach_header*               dyldImageLoadAddress;
 101         /* the following field is only in version 3 (Mac OS X 10.6, iPhoneOS 3.0) and later */
 102         void*                                                   jitInfo;
 103         /* the following fields are only in version 5 (Mac OS X 10.6, iPhoneOS 3.0) and later */
 104         const char*                                             dyldVersion;
 105         const char*                                             errorMessage;
 106         uintptr_t                                               terminationFlags;
 107         /* the following field is only in version 6 (Mac OS X 10.6, iPhoneOS 3.1) and later */
 108         void*                                                   coreSymbolicationShmPage;
 109         /* the following field is only in version 7 (Mac OS X 10.6, iPhoneOS 3.1) and later */
 110         uintptr_t                                               systemOrderFlag;
 111         /* the following field is only in version 8 (Mac OS X 10.7, iPhoneOS 3.1) and later */
 112         uintptr_t                                               uuidArrayCount;
 113         const struct dyld_uuid_info*    uuidArray;              /* only images not in dyld shared cache */
 114         /* the following field is only in version 9 (Mac OS X 10.7, iOS 4.0) and later */
 115         struct dyld_all_image_infos*    dyldAllImageInfosAddress;
 116         /* the following field is only in version 10 (Mac OS X 10.7, iOS 4.2) and later */
 117         uintptr_t                                               initialImageCount;
 118         /* the following field is only in version 11 (Mac OS X 10.7, iOS 4.2) and later */
 119         uintptr_t                                               errorKind;
 120         const char*                                             errorClientOfDylibPath;
 121         const char*                                             errorTargetDylibPath;
 122         const char*                                             errorSymbol;
 123         /* the following field is only in version 12 (Mac OS X 10.7, iOS 4.3) and later */
 124         uintptr_t                                               sharedCacheSlide;
 125 };
 126 extern struct dyld_all_image_infos  dyld_all_image_infos;
 127
 128 /*
 129  * Beginning in Mac OS X 10.6, rather than looking up the symbol "_dyld_all_image_infos"
 130  * in dyld's symbol table, you can add DYLD_ALL_IMAGE_INFOS_OFFSET_OFFSET to the mach_header
 131  * for dyld and read the 32-bit unsigned int at that location.  Adding that value to dyld's
 132  * mach_header address gets you the address of dyld_all_image_infos in dyld.
 133  */
 134 #define DYLD_ALL_IMAGE_INFOS_OFFSET_OFFSET 0x1010
 135
 136
 137
 138 /*
 139  * Beginning in Mac OS X 10.5, this is how gdb discovers where the shared cache is in a process.
 140  * Images that are in the shared cache have their segments rearranged, so when using imageFilePath
 141  * to load the file from disk, you have to know to adjust addresses based on how their segment
 142  * was rearranged.
 143  *
 144  * gdb looks for the symbol "_dyld_shared_region_ranges" in dyld.
 145  *
 146  * It contains information the count of shared regions used by the process.  The count is
 147  * the number of start/length pairs.
 148  */
 149 struct dyld_shared_cache_ranges {
 150         uintptr_t                                       sharedRegionsCount;     /* how many ranges follow */
 151         struct {
 152                 uintptr_t       start;
 153                 uintptr_t       length;
 154         }                                                       ranges[4];                      /* max regions */
 155 };
 156 extern struct dyld_shared_cache_ranges dyld_shared_cache_ranges;
 157
 158
 159
 160 #ifdef __cplusplus
 161 }
 162 #endif
 163
 164 #endif /* _DYLD_IMAGES_ */