include/mach-o/fixup-chains.h

   1 /* -*- mode: C++; c-basic-offset: 4; tab-width: 4 -*-
   2  *
   3  * Copyright (c) 2018 Apple Inc. All rights reserved.
   4  *
   5  * @APPLE_LICENSE_HEADER_START@
   6  *
   7  * This file contains Original Code and/or Modifications of Original Code
   8  * as defined in and that are subject to the Apple Public Source License
   9  * Version 2.0 (the 'License'). You may not use this file except in
  10  * compliance with the License. Please obtain a copy of the License at
  11  * http://www.opensource.apple.com/apsl/ and read it before using this
  12  * file.
  13  *
  14  * The Original Code and all software distributed under the License are
  15  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  16  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  17  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  19  * Please see the License for the specific language governing rights and
  20  * limitations under the License.
  21  *
  22  * @APPLE_LICENSE_HEADER_END@
  23  */
  24
  25 #ifndef __MACH_O_FIXUP_CHAINS__
  26 #define __MACH_O_FIXUP_CHAINS__ 6
  27
  28
  29 #include <stdint.h>
  30
  31
  32 //#define LC_DYLD_EXPORTS_TRIE   0x80000033 // used with linkedit_data_command
  33 //#define LC_DYLD_CHAINED_FIXUPS 0x80000034 // used with linkedit_data_command, payload is dyld_chained_fixups_header
  34
  35
  36 // header of the LC_DYLD_CHAINED_FIXUPS payload
  37 struct dyld_chained_fixups_header
  38 {
  39     uint32_t    fixups_version;    // 0
  40     uint32_t    starts_offset;     // offset of dyld_chained_starts_in_image in chain_data
  41     uint32_t    imports_offset;    // offset of imports table in chain_data
  42     uint32_t    symbols_offset;    // offset of symbol strings in chain_data
  43     uint32_t    imports_count;     // number of imported symbol names
  44     uint32_t    imports_format;    // DYLD_CHAINED_IMPORT*
  45     uint32_t    symbols_format;    // 0 => uncompressed, 1 => zlib compressed
  46 };
  47
  48 // This struct is embedded in LC_DYLD_CHAINED_FIXUPS payload
  49 struct dyld_chained_starts_in_image
  50 {
  51     uint32_t    seg_count;
  52     uint32_t    seg_info_offset[1];  // each entry is offset into this struct for that segment
  53     // followed by pool of dyld_chain_starts_in_segment data
  54 };
  55
  56 // This struct is embedded in dyld_chain_starts_in_image
  57 // and passed down to the kernel for page-in linking
  58 struct dyld_chained_starts_in_segment
  59 {
  60     uint32_t    size;               // size of this (amount kernel needs to copy)
  61     uint16_t    page_size;          // 0x1000 or 0x4000
  62     uint16_t    pointer_format;     // DYLD_CHAINED_PTR_*
  63     uint64_t    segment_offset;     // offset in memory to start of segment
  64     uint32_t    max_valid_pointer;  // for 32-bit OS, any value beyond this is not a pointer
  65     uint16_t    page_count;         // how many pages are in array
  66     uint16_t    page_start[1];      // each entry is offset in each page of first element in chain
  67                                     // or DYLD_CHAINED_PTR_START_NONE if no fixups on page
  68  // uint16_t    chain_starts[1];    // some 32-bit formats may require multiple starts per page.
  69                                     // for those, if high bit is set in page_starts[], then it
  70                                     // is index into chain_starts[] which is a list of starts
  71                                     // the last of which has the high bit set
  72 };
  73
  74 enum {
  75     DYLD_CHAINED_PTR_START_NONE   = 0xFFFF, // used in page_start[] to denote a page with no fixups
  76     DYLD_CHAINED_PTR_START_MULTI  = 0x8000, // used in page_start[] to denote a page which has multiple starts
  77     DYLD_CHAINED_PTR_START_LAST   = 0x8000, // used in chain_starts[] to denote last start in list for page
  78 };
  79
  80 // This struct is embedded in __TEXT,__chain_starts section in firmware
  81 struct dyld_chained_starts_offsets
  82 {
  83     uint32_t    pointer_format;     // DYLD_CHAINED_PTR_32_FIRMWARE
  84     uint32_t    starts_count;       // number of starts in array
  85     uint32_t    chain_starts[1];    // array chain start offsets
  86 };
  87
  88
  89 // values for dyld_chained_starts_in_segment.pointer_format
  90 enum {
  91     DYLD_CHAINED_PTR_ARM64E                 =  1,    // stride 8, unauth target is vmaddr
  92     DYLD_CHAINED_PTR_64                     =  2,    // target is vmaddr
  93     DYLD_CHAINED_PTR_32                     =  3,
  94     DYLD_CHAINED_PTR_32_CACHE               =  4,
  95     DYLD_CHAINED_PTR_32_FIRMWARE            =  5,
  96     DYLD_CHAINED_PTR_64_OFFSET              =  6,    // target is vm offset
  97     DYLD_CHAINED_PTR_ARM64E_OFFSET          =  7,    // old name
  98     DYLD_CHAINED_PTR_ARM64E_KERNEL          =  7,    // stride 4, unauth target is vm offset
  99     DYLD_CHAINED_PTR_64_KERNEL_CACHE        =  8,
 100     DYLD_CHAINED_PTR_ARM64E_USERLAND        =  9,    // stride 8, unauth target is vm offset
 101     DYLD_CHAINED_PTR_ARM64E_FIRMWARE        = 10,    // stride 4, unauth target is vmaddr
 102     DYLD_CHAINED_PTR_X86_64_KERNEL_CACHE    = 11,    // stride 1, x86_64 kernel caches
 103     DYLD_CHAINED_PTR_ARM64E_USERLAND24      = 12,    // stride 8, unauth target is vm offset, 24-bit bind
 104 };
 105
 106
 107 // DYLD_CHAINED_PTR_ARM64E
 108 struct dyld_chained_ptr_arm64e_rebase
 109 {
 110     uint64_t    target   : 43,
 111                 high8    :  8,
 112                 next     : 11,    // 4 or 8-byte stide
 113                 bind     :  1,    // == 0
 114                 auth     :  1;    // == 0
 115 };
 116
 117 // DYLD_CHAINED_PTR_ARM64E
 118 struct dyld_chained_ptr_arm64e_bind
 119 {
 120     uint64_t    ordinal   : 16,
 121                 zero      : 16,
 122                 addend    : 19,    // +/-256K
 123                 next      : 11,    // 4 or 8-byte stide
 124                 bind      :  1,    // == 1
 125                 auth      :  1;    // == 0
 126 };
 127
 128 // DYLD_CHAINED_PTR_ARM64E
 129 struct dyld_chained_ptr_arm64e_auth_rebase
 130 {
 131     uint64_t    target    : 32,   // runtimeOffset
 132                 diversity : 16,
 133                 addrDiv   :  1,
 134                 key       :  2,
 135                 next      : 11,    // 4 or 8-byte stide
 136                 bind      :  1,    // == 0
 137                 auth      :  1;    // == 1
 138 };
 139
 140 // DYLD_CHAINED_PTR_ARM64E
 141 struct dyld_chained_ptr_arm64e_auth_bind
 142 {
 143     uint64_t    ordinal   : 16,
 144                 zero      : 16,
 145                 diversity : 16,
 146                 addrDiv   :  1,
 147                 key       :  2,
 148                 next      : 11,    // 4 or 8-byte stide
 149                 bind      :  1,    // == 1
 150                 auth      :  1;    // == 1
 151 };
 152
 153 // DYLD_CHAINED_PTR_64/DYLD_CHAINED_PTR_64_OFFSET
 154 struct dyld_chained_ptr_64_rebase
 155 {
 156     uint64_t    target    : 36,    // 64GB max image size (DYLD_CHAINED_PTR_64 => vmAddr, DYLD_CHAINED_PTR_64_OFFSET => runtimeOffset)
 157                 high8     :  8,    // top 8 bits set to this (DYLD_CHAINED_PTR_64 => after slide added, DYLD_CHAINED_PTR_64_OFFSET => before slide added)
 158                 reserved  :  7,    // all zeros
 159                 next      : 12,    // 4-byte stride
 160                 bind      :  1;    // == 0
 161 };
 162
 163
 164 // DYLD_CHAINED_PTR_ARM64E_USERLAND24
 165 struct dyld_chained_ptr_arm64e_bind24
 166 {
 167     uint64_t    ordinal   : 24,
 168                 zero      :  8,
 169                 addend    : 19,    // +/-256K
 170                 next      : 11,    // 8-byte stide
 171                 bind      :  1,    // == 1
 172                 auth      :  1;    // == 0
 173 };
 174
 175 // DYLD_CHAINED_PTR_ARM64E_USERLAND24
 176 struct dyld_chained_ptr_arm64e_auth_bind24
 177 {
 178     uint64_t    ordinal   : 24,
 179                 zero      :  8,
 180                 diversity : 16,
 181                 addrDiv   :  1,
 182                 key       :  2,
 183                 next      : 11,    // 8-byte stide
 184                 bind      :  1,    // == 1
 185                 auth      :  1;    // == 1
 186 };
 187
 188
 189 // DYLD_CHAINED_PTR_64
 190 struct dyld_chained_ptr_64_bind
 191 {
 192     uint64_t    ordinal   : 24,
 193                 addend    :  8,   // 0 thru 255
 194                 reserved  : 19,   // all zeros
 195                 next      : 12,   // 4-byte stride
 196                 bind      :  1;   // == 1
 197 };
 198
 199 // DYLD_CHAINED_PTR_64_KERNEL_CACHE, DYLD_CHAINED_PTR_X86_64_KERNEL_CACHE
 200 struct dyld_chained_ptr_64_kernel_cache_rebase
 201 {
 202     uint64_t    target     : 30,   // basePointers[cacheLevel] + target
 203                 cacheLevel :  2,   // what level of cache to bind to (indexes a mach_header array)
 204                 diversity  : 16,
 205                 addrDiv    :  1,
 206                 key        :  2,
 207                 next       : 12,    // 1 or 4-byte stide
 208                 isAuth     :  1;    // 0 -> not authenticated.  1 -> authenticated
 209 };
 210
 211 // DYLD_CHAINED_PTR_32
 212 // Note: for DYLD_CHAINED_PTR_32 some non-pointer values are co-opted into the chain
 213 // as out of range rebases.  If an entry in the chain is > max_valid_pointer, then it
 214 // is not a pointer.  To restore the value, subtract off the bias, which is
 215 // (64MB+max_valid_pointer)/2.
 216 struct dyld_chained_ptr_32_rebase
 217 {
 218     uint32_t    target    : 26,   // vmaddr, 64MB max image size
 219                 next      :  5,   // 4-byte stride
 220                 bind      :  1;   // == 0
 221 };
 222
 223 // DYLD_CHAINED_PTR_32
 224 struct dyld_chained_ptr_32_bind
 225 {
 226     uint32_t    ordinal   : 20,
 227                 addend    :  6,   // 0 thru 63
 228                 next      :  5,   // 4-byte stride
 229                 bind      :  1;   // == 1
 230 };
 231
 232 // DYLD_CHAINED_PTR_32_CACHE
 233 struct dyld_chained_ptr_32_cache_rebase
 234 {
 235     uint32_t    target    : 30,   // 1GB max dyld cache TEXT and DATA
 236                 next      :  2;   // 4-byte stride
 237 };
 238
 239
 240 // DYLD_CHAINED_PTR_32_FIRMWARE
 241 struct dyld_chained_ptr_32_firmware_rebase
 242 {
 243     uint32_t    target   : 26,   // 64MB max firmware TEXT and DATA
 244                 next     :  6;   // 4-byte stride
 245 };
 246
 247
 248
 249 // values for dyld_chained_fixups_header.imports_format
 250 enum {
 251     DYLD_CHAINED_IMPORT          = 1,
 252     DYLD_CHAINED_IMPORT_ADDEND   = 2,
 253     DYLD_CHAINED_IMPORT_ADDEND64 = 3,
 254 };
 255
 256 // DYLD_CHAINED_IMPORT
 257 struct dyld_chained_import
 258 {
 259     uint32_t    lib_ordinal :  8,
 260                 weak_import :  1,
 261                 name_offset : 23;
 262 };
 263
 264 // DYLD_CHAINED_IMPORT_ADDEND
 265 struct dyld_chained_import_addend
 266 {
 267     uint32_t    lib_ordinal :  8,
 268                 weak_import :  1,
 269                 name_offset : 23;
 270     int32_t     addend;
 271 };
 272
 273 // DYLD_CHAINED_IMPORT_ADDEND64
 274 struct dyld_chained_import_addend64
 275 {
 276     uint64_t    lib_ordinal : 16,
 277                 weak_import :  1,
 278                 reserved    : 15,
 279                 name_offset : 32;
 280     uint64_t    addend;
 281 };
 282
 283 #endif // __MACH_O_FIXUP_CHAINS__
 284