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comparison: mozglue/linker/Elfxx.h
mozglue/linker/Elfxx.h
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- TOR_BUG_9701
- changeset 15
- b8a032363ba2
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| -1:000000000000 | 0:1108bdedc995 |
|---|---|
| 1 /* This Source Code Form is subject to the terms of the Mozilla Public | |
| 2 * License, v. 2.0. If a copy of the MPL was not distributed with this file, | |
| 3 * You can obtain one at http://mozilla.org/MPL/2.0/. */ | |
| 4 | |
| 5 #ifndef Elfxx_h | |
| 6 #define Elfxx_h | |
| 7 | |
| 8 /** | |
| 9 * Android system headers have two different elf.h file. The one under linux/ | |
| 10 * is the most complete. | |
| 11 */ | |
| 12 #ifdef ANDROID | |
| 13 #include <linux/elf.h> | |
| 14 #else | |
| 15 #include <elf.h> | |
| 16 #endif | |
| 17 #include <endian.h> | |
| 18 | |
| 19 #if defined(__ARM_EABI__) && !defined(PT_ARM_EXIDX) | |
| 20 #define PT_ARM_EXIDX 0x70000001 | |
| 21 #endif | |
| 22 | |
| 23 /** | |
| 24 * Generic ELF macros for the target system | |
| 25 */ | |
| 26 #ifdef __LP64__ | |
| 27 #define Elf_(type) Elf64_ ## type | |
| 28 #define ELFCLASS ELFCLASS64 | |
| 29 #define ELF_R_TYPE ELF64_R_TYPE | |
| 30 #define ELF_R_SYM ELF64_R_SYM | |
| 31 #ifndef ELF_ST_BIND | |
| 32 #define ELF_ST_BIND ELF64_ST_BIND | |
| 33 #endif | |
| 34 #else | |
| 35 #define Elf_(type) Elf32_ ## type | |
| 36 #define ELFCLASS ELFCLASS32 | |
| 37 #define ELF_R_TYPE ELF32_R_TYPE | |
| 38 #define ELF_R_SYM ELF32_R_SYM | |
| 39 #ifndef ELF_ST_BIND | |
| 40 #define ELF_ST_BIND ELF32_ST_BIND | |
| 41 #endif | |
| 42 #endif | |
| 43 | |
| 44 #ifndef __BYTE_ORDER | |
| 45 #error Cannot find endianness | |
| 46 #endif | |
| 47 | |
| 48 #if __BYTE_ORDER == __LITTLE_ENDIAN | |
| 49 #define ELFDATA ELFDATA2LSB | |
| 50 #elif __BYTE_ORDER == __BIG_ENDIAN | |
| 51 #define ELFDATA ELFDATA2MSB | |
| 52 #endif | |
| 53 | |
| 54 #ifdef __linux__ | |
| 55 #define ELFOSABI ELFOSABI_LINUX | |
| 56 #ifdef EI_ABIVERSION | |
| 57 #define ELFABIVERSION 0 | |
| 58 #endif | |
| 59 #else | |
| 60 #error Unknown ELF OSABI | |
| 61 #endif | |
| 62 | |
| 63 #if defined(__i386__) | |
| 64 #define ELFMACHINE EM_386 | |
| 65 | |
| 66 // Doing this way probably doesn't scale to other architectures | |
| 67 #define R_ABS R_386_32 | |
| 68 #define R_GLOB_DAT R_386_GLOB_DAT | |
| 69 #define R_JMP_SLOT R_386_JMP_SLOT | |
| 70 #define R_RELATIVE R_386_RELATIVE | |
| 71 #define RELOC(n) DT_REL ## n | |
| 72 #define UNSUPPORTED_RELOC(n) DT_RELA ## n | |
| 73 #define STR_RELOC(n) "DT_REL" # n | |
| 74 #define Reloc Rel | |
| 75 | |
| 76 #elif defined(__x86_64__) | |
| 77 #define ELFMACHINE EM_X86_64 | |
| 78 | |
| 79 #define R_ABS R_X86_64_64 | |
| 80 #define R_GLOB_DAT R_X86_64_GLOB_DAT | |
| 81 #define R_JMP_SLOT R_X86_64_JUMP_SLOT | |
| 82 #define R_RELATIVE R_X86_64_RELATIVE | |
| 83 #define RELOC(n) DT_RELA ## n | |
| 84 #define UNSUPPORTED_RELOC(n) DT_REL ## n | |
| 85 #define STR_RELOC(n) "DT_RELA" # n | |
| 86 #define Reloc Rela | |
| 87 | |
| 88 #elif defined(__arm__) | |
| 89 #define ELFMACHINE EM_ARM | |
| 90 | |
| 91 #ifndef R_ARM_ABS32 | |
| 92 #define R_ARM_ABS32 2 | |
| 93 #endif | |
| 94 #ifndef R_ARM_GLOB_DAT | |
| 95 #define R_ARM_GLOB_DAT 21 | |
| 96 #endif | |
| 97 #ifndef R_ARM_JUMP_SLOT | |
| 98 #define R_ARM_JUMP_SLOT 22 | |
| 99 #endif | |
| 100 #ifndef R_ARM_RELATIVE | |
| 101 #define R_ARM_RELATIVE 23 | |
| 102 #endif | |
| 103 | |
| 104 #define R_ABS R_ARM_ABS32 | |
| 105 #define R_GLOB_DAT R_ARM_GLOB_DAT | |
| 106 #define R_JMP_SLOT R_ARM_JUMP_SLOT | |
| 107 #define R_RELATIVE R_ARM_RELATIVE | |
| 108 #define RELOC(n) DT_REL ## n | |
| 109 #define UNSUPPORTED_RELOC(n) DT_RELA ## n | |
| 110 #define STR_RELOC(n) "DT_REL" # n | |
| 111 #define Reloc Rel | |
| 112 | |
| 113 #else | |
| 114 #error Unknown ELF machine type | |
| 115 #endif | |
| 116 | |
| 117 /** | |
| 118 * Android system headers don't have all definitions | |
| 119 */ | |
| 120 #ifndef STN_UNDEF | |
| 121 #define STN_UNDEF 0 | |
| 122 #endif | |
| 123 #ifndef DT_INIT_ARRAY | |
| 124 #define DT_INIT_ARRAY 25 | |
| 125 #endif | |
| 126 #ifndef DT_FINI_ARRAY | |
| 127 #define DT_FINI_ARRAY 26 | |
| 128 #endif | |
| 129 #ifndef DT_INIT_ARRAYSZ | |
| 130 #define DT_INIT_ARRAYSZ 27 | |
| 131 #endif | |
| 132 #ifndef DT_FINI_ARRAYSZ | |
| 133 #define DT_FINI_ARRAYSZ 28 | |
| 134 #endif | |
| 135 #ifndef DT_RELACOUNT | |
| 136 #define DT_RELACOUNT 0x6ffffff9 | |
| 137 #endif | |
| 138 #ifndef DT_RELCOUNT | |
| 139 #define DT_RELCOUNT 0x6ffffffa | |
| 140 #endif | |
| 141 #ifndef DT_VERSYM | |
| 142 #define DT_VERSYM 0x6ffffff0 | |
| 143 #endif | |
| 144 #ifndef DT_VERDEF | |
| 145 #define DT_VERDEF 0x6ffffffc | |
| 146 #endif | |
| 147 #ifndef DT_VERDEFNUM | |
| 148 #define DT_VERDEFNUM 0x6ffffffd | |
| 149 #endif | |
| 150 #ifndef DT_VERNEED | |
| 151 #define DT_VERNEED 0x6ffffffe | |
| 152 #endif | |
| 153 #ifndef DT_VERNEEDNUM | |
| 154 #define DT_VERNEEDNUM 0x6fffffff | |
| 155 #endif | |
| 156 #ifndef DT_FLAGS_1 | |
| 157 #define DT_FLAGS_1 0x6ffffffb | |
| 158 #endif | |
| 159 #ifndef DT_FLAGS | |
| 160 #define DT_FLAGS 30 | |
| 161 #endif | |
| 162 #ifndef DF_SYMBOLIC | |
| 163 #define DF_SYMBOLIC 0x00000002 | |
| 164 #endif | |
| 165 #ifndef DF_TEXTREL | |
| 166 #define DF_TEXTREL 0x00000004 | |
| 167 #endif | |
| 168 | |
| 169 namespace Elf { | |
| 170 | |
| 171 /** | |
| 172 * Define a few basic Elf Types | |
| 173 */ | |
| 174 typedef Elf_(Phdr) Phdr; | |
| 175 typedef Elf_(Dyn) Dyn; | |
| 176 typedef Elf_(Sym) Sym; | |
| 177 typedef Elf_(Addr) Addr; | |
| 178 typedef Elf_(Word) Word; | |
| 179 typedef Elf_(Half) Half; | |
| 180 | |
| 181 /** | |
| 182 * Helper class around the standard Elf header struct | |
| 183 */ | |
| 184 struct Ehdr: public Elf_(Ehdr) | |
| 185 { | |
| 186 /** | |
| 187 * Equivalent to reinterpret_cast<const Ehdr *>(buf), but additionally | |
| 188 * checking that this is indeed an Elf header and that the Elf type | |
| 189 * corresponds to that of the system | |
| 190 */ | |
| 191 static const Ehdr *validate(const void *buf); | |
| 192 }; | |
| 193 | |
| 194 /** | |
| 195 * Elf String table | |
| 196 */ | |
| 197 class Strtab: public UnsizedArray<const char> | |
| 198 { | |
| 199 public: | |
| 200 /** | |
| 201 * Returns the string at the given index in the table | |
| 202 */ | |
| 203 const char *GetStringAt(off_t index) const | |
| 204 { | |
| 205 return &UnsizedArray<const char>::operator[](index); | |
| 206 } | |
| 207 }; | |
| 208 | |
| 209 /** | |
| 210 * Helper class around Elf relocation. | |
| 211 */ | |
| 212 struct Rel: public Elf_(Rel) | |
| 213 { | |
| 214 /** | |
| 215 * Returns the addend for the relocation, which is the value stored | |
| 216 * at r_offset. | |
| 217 */ | |
| 218 Addr GetAddend(void *base) const | |
| 219 { | |
| 220 return *(reinterpret_cast<const Addr *>( | |
| 221 reinterpret_cast<const char *>(base) + r_offset)); | |
| 222 } | |
| 223 }; | |
| 224 | |
| 225 /** | |
| 226 * Helper class around Elf relocation with addend. | |
| 227 */ | |
| 228 struct Rela: public Elf_(Rela) | |
| 229 { | |
| 230 /** | |
| 231 * Returns the addend for the relocation. | |
| 232 */ | |
| 233 Addr GetAddend(void *base) const | |
| 234 { | |
| 235 return r_addend; | |
| 236 } | |
| 237 }; | |
| 238 | |
| 239 } /* namespace Elf */ | |
| 240 | |
| 241 #endif /* Elfxx_h */ |
