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__ 4
  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 };
 103
 104
 105 // DYLD_CHAINED_PTR_ARM64E
 106 struct dyld_chained_ptr_arm64e_rebase
 107 {
 108     uint64_t    target   : 43,
 109                 high8    :  8,
 110                 next     : 11,    // 4 or 8-byte stide
 111                 bind     :  1,    // == 0
 112                 auth     :  1;    // == 0
 113 };
 114
 115 // DYLD_CHAINED_PTR_ARM64E
 116 struct dyld_chained_ptr_arm64e_bind
 117 {
 118     uint64_t    ordinal   : 16,
 119                 zero      : 16,
 120                 addend    : 19,    // +/-256K
 121                 next      : 11,    // 4 or 8-byte stide
 122                 bind      :  1,    // == 1
 123                 auth      :  1;    // == 0
 124 };
 125
 126 // DYLD_CHAINED_PTR_ARM64E
 127 struct dyld_chained_ptr_arm64e_auth_rebase
 128 {
 129     uint64_t    target    : 32,   // runtimeOffset
 130                 diversity : 16,
 131                 addrDiv   :  1,
 132                 key       :  2,
 133                 next      : 11,    // 4 or 8-byte stide
 134                 bind      :  1,    // == 0
 135                 auth      :  1;    // == 1
 136 };
 137
 138 // DYLD_CHAINED_PTR_ARM64E
 139 struct dyld_chained_ptr_arm64e_auth_bind
 140 {
 141     uint64_t    ordinal   : 16,
 142                 zero      : 16,
 143                 diversity : 16,
 144                 addrDiv   :  1,
 145                 key       :  2,
 146                 next      : 11,    // 4 or 8-byte stide
 147                 bind      :  1,    // == 1
 148                 auth      :  1;    // == 1
 149 };
 150
 151 // DYLD_CHAINED_PTR_64/DYLD_CHAINED_PTR_64_OFFSET
 152 struct dyld_chained_ptr_64_rebase
 153 {
 154     uint64_t    target    : 36,    // 64GB max image size (DYLD_CHAINED_PTR_64 => vmAddr, DYLD_CHAINED_PTR_64_OFFSET => runtimeOffset)
 155                 high8     :  8,    // top 8 bits set to this (DYLD_CHAINED_PTR_64 => after slide added, DYLD_CHAINED_PTR_64_OFFSET => before slide added)
 156                 reserved  :  7,    // all zeros
 157                 next      : 12,    // 4-byte stride
 158                 bind      :  1;    // == 0
 159 };
 160
 161 // DYLD_CHAINED_PTR_64
 162 struct dyld_chained_ptr_64_bind
 163 {
 164     uint64_t    ordinal   : 24,
 165                 addend    :  8,   // 0 thru 255
 166                 reserved  : 19,   // all zeros
 167                 next      : 12,   // 4-byte stride
 168                 bind      :  1;   // == 1
 169 };
 170
 171 // DYLD_CHAINED_PTR_64_KERNEL_CACHE
 172 struct dyld_chained_ptr_64_kernel_cache_rebase
 173 {
 174     uint64_t    target     : 30,   // basePointers[cacheLevel] + target
 175                 cacheLevel :  2,   // what level of cache to bind to (indexes a mach_header array)
 176                 diversity  : 16,
 177                 addrDiv    :  1,
 178                 key        :  2,
 179                 next       : 12,    // 4-byte stide
 180                 isAuth     :  1;    // 0 -> not authenticated.  1 -> authenticated
 181 };
 182
 183 // DYLD_CHAINED_PTR_32
 184 // Note: for DYLD_CHAINED_PTR_32 some non-pointer values are co-opted into the chain
 185 // as out of range rebases.  If an entry in the chain is > max_valid_pointer, then it
 186 // is not a pointer.  To restore the value, subtract off the bias, which is
 187 // (64MB+max_valid_pointer)/2.
 188 struct dyld_chained_ptr_32_rebase
 189 {
 190     uint32_t    target    : 26,   // vmaddr, 64MB max image size
 191                 next      :  5,   // 4-byte stride
 192                 bind      :  1;   // == 0
 193 };
 194
 195 // DYLD_CHAINED_PTR_32
 196 struct dyld_chained_ptr_32_bind
 197 {
 198     uint32_t    ordinal   : 20,
 199                 addend    :  6,   // 0 thru 63
 200                 next      :  5,   // 4-byte stride
 201                 bind      :  1;   // == 1
 202 };
 203
 204 // DYLD_CHAINED_PTR_32_CACHE
 205 struct dyld_chained_ptr_32_cache_rebase
 206 {
 207     uint32_t    target    : 30,   // 1GB max dyld cache TEXT and DATA
 208                 next      :  2;   // 4-byte stride
 209 };
 210
 211
 212 // DYLD_CHAINED_PTR_32_FIRMWARE
 213 struct dyld_chained_ptr_32_firmware_rebase
 214 {
 215     uint32_t    target   : 26,   // 64MB max firmware TEXT and DATA
 216                 next     :  6;   // 4-byte stride
 217 };
 218
 219
 220
 221 // values for dyld_chained_fixups_header.imports_format
 222 enum {
 223     DYLD_CHAINED_IMPORT          = 1,
 224     DYLD_CHAINED_IMPORT_ADDEND   = 2,
 225     DYLD_CHAINED_IMPORT_ADDEND64 = 3,
 226 };
 227
 228 // DYLD_CHAINED_IMPORT
 229 struct dyld_chained_import
 230 {
 231     uint32_t    lib_ordinal :  8,
 232                 weak_import :  1,
 233                 name_offset : 23;
 234 };
 235
 236 // DYLD_CHAINED_IMPORT_ADDEND
 237 struct dyld_chained_import_addend
 238 {
 239     uint32_t    lib_ordinal :  8,
 240                 weak_import :  1,
 241                 name_offset : 23;
 242     int32_t     addend;
 243 };
 244
 245 // DYLD_CHAINED_IMPORT_ADDEND64
 246 struct dyld_chained_import_addend64
 247 {
 248     uint64_t    lib_ordinal : 16,
 249                 weak_import :  1,
 250                 reserved    : 15,
 251                 name_offset : 32;
 252     uint64_t    addend;
 253 };
 254
 255 #endif // __MACH_O_FIXUP_CHAINS__
 256