EXTERNAL_HEADERS/mach-o/fixup-chains.h

   1 /* -*- mode: C++; c-basic-offset: 4; tab-width: 4 -*-
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  24
  25 #ifndef __MACH_O_FIXUP_CHAINS__
  26 #define __MACH_O_FIXUP_CHAINS__ 5
  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 };
 104
 105
 106 // DYLD_CHAINED_PTR_ARM64E
 107 struct dyld_chained_ptr_arm64e_rebase
 108 {
 109     uint64_t    target   : 43,
 110                 high8    :  8,
 111                 next     : 11,    // 4 or 8-byte stide
 112                 bind     :  1,    // == 0
 113                 auth     :  1;    // == 0
 114 };
 115
 116 // DYLD_CHAINED_PTR_ARM64E
 117 struct dyld_chained_ptr_arm64e_bind
 118 {
 119     uint64_t    ordinal   : 16,
 120                 zero      : 16,
 121                 addend    : 19,    // +/-256K
 122                 next      : 11,    // 4 or 8-byte stide
 123                 bind      :  1,    // == 1
 124                 auth      :  1;    // == 0
 125 };
 126
 127 // DYLD_CHAINED_PTR_ARM64E
 128 struct dyld_chained_ptr_arm64e_auth_rebase
 129 {
 130     uint64_t    target    : 32,   // runtimeOffset
 131                 diversity : 16,
 132                 addrDiv   :  1,
 133                 key       :  2,
 134                 next      : 11,    // 4 or 8-byte stide
 135                 bind      :  1,    // == 0
 136                 auth      :  1;    // == 1
 137 };
 138
 139 // DYLD_CHAINED_PTR_ARM64E
 140 struct dyld_chained_ptr_arm64e_auth_bind
 141 {
 142     uint64_t    ordinal   : 16,
 143                 zero      : 16,
 144                 diversity : 16,
 145                 addrDiv   :  1,
 146                 key       :  2,
 147                 next      : 11,    // 4 or 8-byte stide
 148                 bind      :  1,    // == 1
 149                 auth      :  1;    // == 1
 150 };
 151
 152 // DYLD_CHAINED_PTR_64/DYLD_CHAINED_PTR_64_OFFSET
 153 struct dyld_chained_ptr_64_rebase
 154 {
 155     uint64_t    target    : 36,    // 64GB max image size (DYLD_CHAINED_PTR_64 => vmAddr, DYLD_CHAINED_PTR_64_OFFSET => runtimeOffset)
 156                 high8     :  8,    // top 8 bits set to this (DYLD_CHAINED_PTR_64 => after slide added, DYLD_CHAINED_PTR_64_OFFSET => before slide added)
 157                 reserved  :  7,    // all zeros
 158                 next      : 12,    // 4-byte stride
 159                 bind      :  1;    // == 0
 160 };
 161
 162 // DYLD_CHAINED_PTR_64
 163 struct dyld_chained_ptr_64_bind
 164 {
 165     uint64_t    ordinal   : 24,
 166                 addend    :  8,   // 0 thru 255
 167                 reserved  : 19,   // all zeros
 168                 next      : 12,   // 4-byte stride
 169                 bind      :  1;   // == 1
 170 };
 171
 172 // DYLD_CHAINED_PTR_64_KERNEL_CACHE, DYLD_CHAINED_PTR_X86_64_KERNEL_CACHE
 173 struct dyld_chained_ptr_64_kernel_cache_rebase
 174 {
 175     uint64_t    target     : 30,   // basePointers[cacheLevel] + target
 176                 cacheLevel :  2,   // what level of cache to bind to (indexes a mach_header array)
 177                 diversity  : 16,
 178                 addrDiv    :  1,
 179                 key        :  2,
 180                 next       : 12,    // 1 or 4-byte stide
 181                 isAuth     :  1;    // 0 -> not authenticated.  1 -> authenticated
 182 };
 183
 184 // DYLD_CHAINED_PTR_32
 185 // Note: for DYLD_CHAINED_PTR_32 some non-pointer values are co-opted into the chain
 186 // as out of range rebases.  If an entry in the chain is > max_valid_pointer, then it
 187 // is not a pointer.  To restore the value, subtract off the bias, which is
 188 // (64MB+max_valid_pointer)/2.
 189 struct dyld_chained_ptr_32_rebase
 190 {
 191     uint32_t    target    : 26,   // vmaddr, 64MB max image size
 192                 next      :  5,   // 4-byte stride
 193                 bind      :  1;   // == 0
 194 };
 195
 196 // DYLD_CHAINED_PTR_32
 197 struct dyld_chained_ptr_32_bind
 198 {
 199     uint32_t    ordinal   : 20,
 200                 addend    :  6,   // 0 thru 63
 201                 next      :  5,   // 4-byte stride
 202                 bind      :  1;   // == 1
 203 };
 204
 205 // DYLD_CHAINED_PTR_32_CACHE
 206 struct dyld_chained_ptr_32_cache_rebase
 207 {
 208     uint32_t    target    : 30,   // 1GB max dyld cache TEXT and DATA
 209                 next      :  2;   // 4-byte stride
 210 };
 211
 212
 213 // DYLD_CHAINED_PTR_32_FIRMWARE
 214 struct dyld_chained_ptr_32_firmware_rebase
 215 {
 216     uint32_t    target   : 26,   // 64MB max firmware TEXT and DATA
 217                 next     :  6;   // 4-byte stride
 218 };
 219
 220
 221
 222 // values for dyld_chained_fixups_header.imports_format
 223 enum {
 224     DYLD_CHAINED_IMPORT          = 1,
 225     DYLD_CHAINED_IMPORT_ADDEND   = 2,
 226     DYLD_CHAINED_IMPORT_ADDEND64 = 3,
 227 };
 228
 229 // DYLD_CHAINED_IMPORT
 230 struct dyld_chained_import
 231 {
 232     uint32_t    lib_ordinal :  8,
 233                 weak_import :  1,
 234                 name_offset : 23;
 235 };
 236
 237 // DYLD_CHAINED_IMPORT_ADDEND
 238 struct dyld_chained_import_addend
 239 {
 240     uint32_t    lib_ordinal :  8,
 241                 weak_import :  1,
 242                 name_offset : 23;
 243     int32_t     addend;
 244 };
 245
 246 // DYLD_CHAINED_IMPORT_ADDEND64
 247 struct dyld_chained_import_addend64
 248 {
 249     uint64_t    lib_ordinal : 16,
 250                 weak_import :  1,
 251                 reserved    : 15,
 252                 name_offset : 32;
 253     uint64_t    addend;
 254 };
 255
 256 #endif // __MACH_O_FIXUP_CHAINS__
 257