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__ 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