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 /*
  37  *      Beginning in Mac OS X 10.4, this is how gdb discovers which mach-o images are loaded in a process.
  38  *
  39  *      gdb looks for the symbol "_dyld_all_image_infos" in dyld.  It contains the fields below.
  40  *
  41  *      For a snashot of what images are currently loaded, the infoArray fields contain a pointer
  42  *      to an array of all images. If infoArray is NULL, it means it is being modified, come back later.
  43  *
  44  *      To be notified of changes, gdb sets a break point on the address pointed to by the notificationn
  45  *      field.  The function it points to is called by dyld with an array of information about what images
  46  *      have been added (dyld_image_adding) or are about to be removed (dyld_image_removing).
  47  *
  48  * The notification is called after infoArray is updated.  This means that if gdb attaches to a process
  49  * and infoArray is NULL, gdb can set a break point on notification and let the proccess continue to
  50  * run until the break point.  Then gdb can inspect the full infoArray.
  51  *
  52  * The dyldVersion field always points to a C string that contains the dyld version.  For instance,
  53  * in dyld-127.3, dyldVersion would contain a pointer to "127.3".
  54  *
  55  * The errorMessage and terminationFlags fields are normally zero.  If dyld terminates a process
  56  * (for instance because a required dylib or symbol is missing), then the errorMessage field will
  57  * be set to point to a C string message buffer containing the reason dyld terminate the process.
  58  * The low bit of the terminationFlags will be set if dyld terminated the process before any user
  59  * code ran, in which case there is no need for the crash log to contain the backtrace.
  60  *
  61  * When dyld terminates a process because some required dylib or symbol cannot be bound, in
  62  * addition to the errorMessage field, it now sets the errorKind field and the corresponding
  63  * fields: errorClientOfDylibPath, errorTargetDylibPath, errorSymbol.
  64  *
  65  */
  66
  67 enum dyld_image_mode { dyld_image_adding=0, dyld_image_removing=1, dyld_image_info_change=2 };
  68
  69 struct dyld_image_info {
  70         const struct mach_header*       imageLoadAddress;       /* base address image is mapped into */
  71         const char*                                     imageFilePath;          /* path dyld used to load the image */
  72         uintptr_t                                       imageFileModDate;       /* time_t of image file */
  73                                                                                                         /* if stat().st_mtime of imageFilePath does not match imageFileModDate, */
  74                                                                                                         /* then file has been modified since dyld loaded it */
  75 };
  76
  77 struct dyld_uuid_info {
  78         const struct mach_header*       imageLoadAddress;       /* base address image is mapped into */
  79         uuid_t                                          imageUUID;                      /* UUID of image */
  80 };
  81
  82 typedef void (*dyld_image_notifier)(enum dyld_image_mode mode, uint32_t infoCount, const struct dyld_image_info info[]);
  83
  84 /* for use in dyld_all_image_infos.errorKind field */
  85 enum {  dyld_error_kind_none=0,
  86                 dyld_error_kind_dylib_missing=1,
  87                 dyld_error_kind_dylib_wrong_arch=2,
  88                 dyld_error_kind_dylib_version=3,
  89                 dyld_error_kind_symbol_missing=4
  90         };
  91
  92 /* internal limit */
  93 #define DYLD_MAX_PROCESS_INFO_NOTIFY_COUNT  8
  94
  95 struct dyld_all_image_infos {
  96         uint32_t                                                version;                /* 1 in Mac OS X 10.4 and 10.5 */
  97         uint32_t                                                infoArrayCount;
  98         const struct dyld_image_info*   infoArray;
  99         dyld_image_notifier                             notification;
 100         bool                                                    processDetachedFromSharedRegion;
 101         /* the following fields are only in version 2 (Mac OS X 10.6, iPhoneOS 2.0) and later */
 102         bool                                                    libSystemInitialized;
 103         const struct mach_header*               dyldImageLoadAddress;
 104         /* the following field is only in version 3 (Mac OS X 10.6, iPhoneOS 3.0) and later */
 105         void*                                                   jitInfo;
 106         /* the following fields are only in version 5 (Mac OS X 10.6, iPhoneOS 3.0) and later */
 107         const char*                                             dyldVersion;
 108         const char*                                             errorMessage;
 109         uintptr_t                                               terminationFlags;
 110         /* the following field is only in version 6 (Mac OS X 10.6, iPhoneOS 3.1) and later */
 111         void*                                                   coreSymbolicationShmPage;
 112         /* the following field is only in version 7 (Mac OS X 10.6, iPhoneOS 3.1) and later */
 113         uintptr_t                                               systemOrderFlag;
 114         /* the following field is only in version 8 (Mac OS X 10.7, iPhoneOS 3.1) and later */
 115         uintptr_t                                               uuidArrayCount;
 116         const struct dyld_uuid_info*    uuidArray;              /* only images not in dyld shared cache */
 117         /* the following field is only in version 9 (Mac OS X 10.7, iOS 4.0) and later */
 118         struct dyld_all_image_infos*    dyldAllImageInfosAddress;
 119         /* the following field is only in version 10 (Mac OS X 10.7, iOS 4.2) and later */
 120         uintptr_t                                               initialImageCount;
 121         /* the following field is only in version 11 (Mac OS X 10.7, iOS 4.2) and later */
 122         uintptr_t                                               errorKind;
 123         const char*                                             errorClientOfDylibPath;
 124         const char*                                             errorTargetDylibPath;
 125         const char*                                             errorSymbol;
 126         /* the following field is only in version 12 (Mac OS X 10.7, iOS 4.3) and later */
 127         uintptr_t                                               sharedCacheSlide;
 128         /* the following field is only in version 13 (Mac OS X 10.9, iOS 7.0) and later */
 129         uint8_t                                                 sharedCacheUUID[16];
 130         /* the following field is only in version 15 (macOS 10.12, iOS 10.0) and later */
 131         uintptr_t                                               sharedCacheBaseAddress;
 132         uint64_t                                                infoArrayChangeTimestamp;
 133         const char*                                             dyldPath;
 134         mach_port_t                                             notifyPorts[DYLD_MAX_PROCESS_INFO_NOTIFY_COUNT];
 135 #if __LP64__
 136         uintptr_t                                               reserved[13-(DYLD_MAX_PROCESS_INFO_NOTIFY_COUNT/2)];
 137 #else
 138         uintptr_t                                               reserved[13-DYLD_MAX_PROCESS_INFO_NOTIFY_COUNT];
 139 #endif
 140         /* the following field is only in version 16 (macOS 10.13, iOS 11.0) and later */
 141     uintptr_t                       compact_dyld_image_info_addr;
 142     size_t                          compact_dyld_image_info_size;
 143 };
 144
 145 /*
 146  * Beginning in Mac OS X 10.5, this is how gdb discovers where the shared cache is in a process.
 147  * Images that are in the shared cache have their segments rearranged, so when using imageFilePath
 148  * to load the file from disk, you have to know to adjust addresses based on how their segment
 149  * was rearranged.
 150  *
 151  * gdb looks for the symbol "_dyld_shared_region_ranges" in dyld.
 152  *
 153  * It contains information the count of shared regions used by the process.  The count is
 154  * the number of start/length pairs.
 155  */
 156 struct dyld_shared_cache_ranges {
 157         uintptr_t                                       sharedRegionsCount;     /* how many ranges follow */
 158         struct {
 159                 uintptr_t       start;
 160                 uintptr_t       length;
 161         }                                                       ranges[4];                      /* max regions */
 162 };
 163 extern struct dyld_shared_cache_ranges dyld_shared_cache_ranges __attribute__((visibility("hidden")));
 164
 165
 166
 167 #ifdef __cplusplus
 168 }
 169 #endif
 170
 171 #endif /* _DYLD_IMAGES_ */