include/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__
  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,
  92     DYLD_CHAINED_PTR_64          = 2,
  93     DYLD_CHAINED_PTR_32          = 3,
  94     DYLD_CHAINED_PTR_32_CACHE    = 4,
  95     DYLD_CHAINED_PTR_32_FIRMWARE = 5,
  96 };
  97
  98
  99 // DYLD_CHAINED_PTR_ARM64E
 100 struct dyld_chained_ptr_arm64e_rebase
 101 {
 102     uint64_t    target   : 43,    // vmaddr
 103                 high8    :  8,
 104                 next     : 11,    // 8-byte stide
 105                 bind     :  1,    // == 0
 106                 auth     :  1;    // == 0
 107 };
 108
 109 // DYLD_CHAINED_PTR_ARM64E
 110 struct dyld_chained_ptr_arm64e_bind
 111 {
 112     uint64_t    ordinal   : 16,
 113                 zero      : 16,
 114                 addend    : 19,
 115                 next      : 11,    // 8-byte stide
 116                 bind      :  1,    // == 1
 117                 auth      :  1;    // == 0
 118 };
 119
 120 // DYLD_CHAINED_PTR_ARM64E
 121 struct dyld_chained_ptr_arm64e_auth_rebase
 122 {
 123     uint64_t    target    : 32,   // runtimeOffset
 124                 diversity : 16,
 125                 addrDiv   :  1,
 126                 key       :  2,
 127                 next      : 11,    // 8-byte stide
 128                 bind      :  1,    // == 0
 129                 auth      :  1;    // == 1
 130 };
 131
 132 // DYLD_CHAINED_PTR_ARM64E
 133 struct dyld_chained_ptr_arm64e_auth_bind
 134 {
 135     uint64_t    ordinal   : 16,
 136                 zero      : 16,
 137                 diversity : 16,
 138                 addrDiv   :  1,
 139                 key       :  2,
 140                 next      : 11,    // 8-byte stide
 141                 bind      :  1,    // == 1
 142                 auth      :  1;    // == 1
 143 };
 144
 145 // DYLD_CHAINED_PTR_64
 146 struct dyld_chained_ptr_64_rebase
 147 {
 148     uint64_t    target    : 36,    // vmaddr, 64GB max image size
 149                 high8     :  8,    // top 8 bits set to this after slide added
 150                 reserved  :  7,    // all zeros
 151                 next      : 12,    // 4-byte stride
 152                 bind      :  1;    // == 0
 153 };
 154
 155 // DYLD_CHAINED_PTR_64
 156 struct dyld_chained_ptr_64_bind
 157 {
 158     uint64_t    ordinal   : 24,
 159                 addend    :  8,   // 0 thru 255
 160                 reserved  : 19,   // all zeros
 161                 next      : 12,   // 4-byte stride
 162                 bind      :  1;   // == 1
 163 };
 164
 165 // DYLD_CHAINED_PTR_32
 166 // Note: for DYLD_CHAINED_PTR_32 some non-pointer values are co-opted into the chain
 167 // as out of range rebases.  If an entry in the chain is > max_valid_pointer, then it
 168 // is not a pointer.  To restore the value, subtract off the bias, which is
 169 // (64MB+max_valid_pointer)/2.
 170 struct dyld_chained_ptr_32_rebase
 171 {
 172     uint32_t    target    : 26,   // vmaddr, 64MB max image size
 173                 next      :  5,   // 4-byte stride
 174                 bind      :  1;   // == 0
 175 };
 176
 177 // DYLD_CHAINED_PTR_32
 178 struct dyld_chained_ptr_32_bind
 179 {
 180     uint32_t    ordinal   : 20,
 181                 addend    :  6,   // 0 thru 63
 182                 next      :  5,   // 4-byte stride
 183                 bind      :  1;   // == 1
 184 };
 185
 186 // DYLD_CHAINED_PTR_32_CACHE
 187 struct dyld_chained_ptr_32_cache_rebase
 188 {
 189     uint32_t    target    : 30,   // 1GB max dyld cache TEXT and DATA
 190                 next      :  2;   // 4-byte stride
 191 };
 192
 193
 194 // DYLD_CHAINED_PTR_32_FIRMWARE
 195 struct dyld_chained_ptr_32_firmware_rebase
 196 {
 197     uint32_t    target   : 26,   // 64MB max firmware TEXT and DATA
 198                 next     :  6;   // 4-byte stride
 199 };
 200
 201
 202
 203 // values for dyld_chained_fixups_header.imports_format
 204 enum {
 205     DYLD_CHAINED_IMPORT          = 1,
 206     DYLD_CHAINED_IMPORT_ADDEND   = 2,
 207     DYLD_CHAINED_IMPORT_ADDEND64 = 3,
 208 };
 209
 210 // DYLD_CHAINED_IMPORT
 211 struct dyld_chained_import
 212 {
 213     uint32_t    lib_ordinal :  8,
 214                 weak_import :  1,
 215                 name_offset : 23;
 216 };
 217
 218 // DYLD_CHAINED_IMPORT_ADDEND
 219 struct dyld_chained_import_addend
 220 {
 221     uint32_t    lib_ordinal :  8,
 222                 weak_import :  1,
 223                 name_offset : 23;
 224     int32_t     addend;
 225 };
 226
 227 // DYLD_CHAINED_IMPORT_ADDEND64
 228 struct dyld_chained_import_addend64
 229 {
 230     uint64_t    lib_ordinal : 16,
 231                 weak_import :  1,
 232                 reserved    : 15,
 233                 name_offset : 32;
 234     uint64_t    addend;
 235 };
 236
 237 #endif // __MACH_O_FIXUP_CHAINS__
 238