1 //===- ELFTypes.h - Endian specific types for ELF ---------------*- C++ -*-===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 #ifndef LLVM_OBJECT_ELFTYPES_H 10 #define LLVM_OBJECT_ELFTYPES_H 11 12 #include "llvm/ADT/ArrayRef.h" 13 #include "llvm/ADT/StringRef.h" 14 #include "llvm/BinaryFormat/ELF.h" 15 #include "llvm/Object/Error.h" 16 #include "llvm/Support/Endian.h" 17 #include "llvm/Support/Error.h" 18 #include <cassert> 19 #include <cstdint> 20 #include <cstring> 21 #include <type_traits> 22 23 namespace llvm { 24 namespace object { 25 26 using support::endianness; 27 28 template <class ELFT> struct Elf_Ehdr_Impl; 29 template <class ELFT> struct Elf_Shdr_Impl; 30 template <class ELFT> struct Elf_Sym_Impl; 31 template <class ELFT> struct Elf_Dyn_Impl; 32 template <class ELFT> struct Elf_Phdr_Impl; 33 template <class ELFT, bool isRela> struct Elf_Rel_Impl; 34 template <class ELFT> struct Elf_Verdef_Impl; 35 template <class ELFT> struct Elf_Verdaux_Impl; 36 template <class ELFT> struct Elf_Verneed_Impl; 37 template <class ELFT> struct Elf_Vernaux_Impl; 38 template <class ELFT> struct Elf_Versym_Impl; 39 template <class ELFT> struct Elf_Hash_Impl; 40 template <class ELFT> struct Elf_GnuHash_Impl; 41 template <class ELFT> struct Elf_Chdr_Impl; 42 template <class ELFT> struct Elf_Nhdr_Impl; 43 template <class ELFT> class Elf_Note_Impl; 44 template <class ELFT> class Elf_Note_Iterator_Impl; 45 template <class ELFT> struct Elf_CGProfile_Impl; 46 template <class ELFT> struct Elf_BBAddrMap_Impl; 47 48 template <endianness E, bool Is64> struct ELFType { 49 private: 50 template <typename Ty> 51 using packed = support::detail::packed_endian_specific_integral<Ty, E, 1>; 52 53 public: 54 static const endianness TargetEndianness = E; 55 static const bool Is64Bits = Is64; 56 57 using uint = std::conditional_t<Is64, uint64_t, uint32_t>; 58 using Ehdr = Elf_Ehdr_Impl<ELFType<E, Is64>>; 59 using Shdr = Elf_Shdr_Impl<ELFType<E, Is64>>; 60 using Sym = Elf_Sym_Impl<ELFType<E, Is64>>; 61 using Dyn = Elf_Dyn_Impl<ELFType<E, Is64>>; 62 using Phdr = Elf_Phdr_Impl<ELFType<E, Is64>>; 63 using Rel = Elf_Rel_Impl<ELFType<E, Is64>, false>; 64 using Rela = Elf_Rel_Impl<ELFType<E, Is64>, true>; 65 using Relr = packed<uint>; 66 using Verdef = Elf_Verdef_Impl<ELFType<E, Is64>>; 67 using Verdaux = Elf_Verdaux_Impl<ELFType<E, Is64>>; 68 using Verneed = Elf_Verneed_Impl<ELFType<E, Is64>>; 69 using Vernaux = Elf_Vernaux_Impl<ELFType<E, Is64>>; 70 using Versym = Elf_Versym_Impl<ELFType<E, Is64>>; 71 using Hash = Elf_Hash_Impl<ELFType<E, Is64>>; 72 using GnuHash = Elf_GnuHash_Impl<ELFType<E, Is64>>; 73 using Chdr = Elf_Chdr_Impl<ELFType<E, Is64>>; 74 using Nhdr = Elf_Nhdr_Impl<ELFType<E, Is64>>; 75 using Note = Elf_Note_Impl<ELFType<E, Is64>>; 76 using NoteIterator = Elf_Note_Iterator_Impl<ELFType<E, Is64>>; 77 using CGProfile = Elf_CGProfile_Impl<ELFType<E, Is64>>; 78 using BBAddrMap = Elf_BBAddrMap_Impl<ELFType<E, Is64>>; 79 using DynRange = ArrayRef<Dyn>; 80 using ShdrRange = ArrayRef<Shdr>; 81 using SymRange = ArrayRef<Sym>; 82 using RelRange = ArrayRef<Rel>; 83 using RelaRange = ArrayRef<Rela>; 84 using RelrRange = ArrayRef<Relr>; 85 using PhdrRange = ArrayRef<Phdr>; 86 87 using Half = packed<uint16_t>; 88 using Word = packed<uint32_t>; 89 using Sword = packed<int32_t>; 90 using Xword = packed<uint64_t>; 91 using Sxword = packed<int64_t>; 92 using Addr = packed<uint>; 93 using Off = packed<uint>; 94 }; 95 96 using ELF32LE = ELFType<support::little, false>; 97 using ELF32BE = ELFType<support::big, false>; 98 using ELF64LE = ELFType<support::little, true>; 99 using ELF64BE = ELFType<support::big, true>; 100 101 // Use an alignment of 2 for the typedefs since that is the worst case for 102 // ELF files in archives. 103 104 // I really don't like doing this, but the alternative is copypasta. 105 #define LLVM_ELF_IMPORT_TYPES_ELFT(ELFT) \ 106 using Elf_Addr = typename ELFT::Addr; \ 107 using Elf_Off = typename ELFT::Off; \ 108 using Elf_Half = typename ELFT::Half; \ 109 using Elf_Word = typename ELFT::Word; \ 110 using Elf_Sword = typename ELFT::Sword; \ 111 using Elf_Xword = typename ELFT::Xword; \ 112 using Elf_Sxword = typename ELFT::Sxword; \ 113 using uintX_t = typename ELFT::uint; \ 114 using Elf_Ehdr = typename ELFT::Ehdr; \ 115 using Elf_Shdr = typename ELFT::Shdr; \ 116 using Elf_Sym = typename ELFT::Sym; \ 117 using Elf_Dyn = typename ELFT::Dyn; \ 118 using Elf_Phdr = typename ELFT::Phdr; \ 119 using Elf_Rel = typename ELFT::Rel; \ 120 using Elf_Rela = typename ELFT::Rela; \ 121 using Elf_Relr = typename ELFT::Relr; \ 122 using Elf_Verdef = typename ELFT::Verdef; \ 123 using Elf_Verdaux = typename ELFT::Verdaux; \ 124 using Elf_Verneed = typename ELFT::Verneed; \ 125 using Elf_Vernaux = typename ELFT::Vernaux; \ 126 using Elf_Versym = typename ELFT::Versym; \ 127 using Elf_Hash = typename ELFT::Hash; \ 128 using Elf_GnuHash = typename ELFT::GnuHash; \ 129 using Elf_Nhdr = typename ELFT::Nhdr; \ 130 using Elf_Note = typename ELFT::Note; \ 131 using Elf_Note_Iterator = typename ELFT::NoteIterator; \ 132 using Elf_CGProfile = typename ELFT::CGProfile; \ 133 using Elf_BBAddrMap = typename ELFT::BBAddrMap; \ 134 using Elf_Dyn_Range = typename ELFT::DynRange; \ 135 using Elf_Shdr_Range = typename ELFT::ShdrRange; \ 136 using Elf_Sym_Range = typename ELFT::SymRange; \ 137 using Elf_Rel_Range = typename ELFT::RelRange; \ 138 using Elf_Rela_Range = typename ELFT::RelaRange; \ 139 using Elf_Relr_Range = typename ELFT::RelrRange; \ 140 using Elf_Phdr_Range = typename ELFT::PhdrRange; 141 142 #define LLVM_ELF_COMMA , 143 #define LLVM_ELF_IMPORT_TYPES(E, W) \ 144 LLVM_ELF_IMPORT_TYPES_ELFT(ELFType<E LLVM_ELF_COMMA W>) 145 146 // Section header. 147 template <class ELFT> struct Elf_Shdr_Base; 148 149 template <endianness TargetEndianness> 150 struct Elf_Shdr_Base<ELFType<TargetEndianness, false>> { 151 LLVM_ELF_IMPORT_TYPES(TargetEndianness, false) 152 Elf_Word sh_name; // Section name (index into string table) 153 Elf_Word sh_type; // Section type (SHT_*) 154 Elf_Word sh_flags; // Section flags (SHF_*) 155 Elf_Addr sh_addr; // Address where section is to be loaded 156 Elf_Off sh_offset; // File offset of section data, in bytes 157 Elf_Word sh_size; // Size of section, in bytes 158 Elf_Word sh_link; // Section type-specific header table index link 159 Elf_Word sh_info; // Section type-specific extra information 160 Elf_Word sh_addralign; // Section address alignment 161 Elf_Word sh_entsize; // Size of records contained within the section 162 }; 163 164 template <endianness TargetEndianness> 165 struct Elf_Shdr_Base<ELFType<TargetEndianness, true>> { 166 LLVM_ELF_IMPORT_TYPES(TargetEndianness, true) 167 Elf_Word sh_name; // Section name (index into string table) 168 Elf_Word sh_type; // Section type (SHT_*) 169 Elf_Xword sh_flags; // Section flags (SHF_*) 170 Elf_Addr sh_addr; // Address where section is to be loaded 171 Elf_Off sh_offset; // File offset of section data, in bytes 172 Elf_Xword sh_size; // Size of section, in bytes 173 Elf_Word sh_link; // Section type-specific header table index link 174 Elf_Word sh_info; // Section type-specific extra information 175 Elf_Xword sh_addralign; // Section address alignment 176 Elf_Xword sh_entsize; // Size of records contained within the section 177 }; 178 179 template <class ELFT> 180 struct Elf_Shdr_Impl : Elf_Shdr_Base<ELFT> { 181 using Elf_Shdr_Base<ELFT>::sh_entsize; 182 using Elf_Shdr_Base<ELFT>::sh_size; 183 184 /// Get the number of entities this section contains if it has any. 185 unsigned getEntityCount() const { 186 if (sh_entsize == 0) 187 return 0; 188 return sh_size / sh_entsize; 189 } 190 }; 191 192 template <class ELFT> struct Elf_Sym_Base; 193 194 template <endianness TargetEndianness> 195 struct Elf_Sym_Base<ELFType<TargetEndianness, false>> { 196 LLVM_ELF_IMPORT_TYPES(TargetEndianness, false) 197 Elf_Word st_name; // Symbol name (index into string table) 198 Elf_Addr st_value; // Value or address associated with the symbol 199 Elf_Word st_size; // Size of the symbol 200 unsigned char st_info; // Symbol's type and binding attributes 201 unsigned char st_other; // Must be zero; reserved 202 Elf_Half st_shndx; // Which section (header table index) it's defined in 203 }; 204 205 template <endianness TargetEndianness> 206 struct Elf_Sym_Base<ELFType<TargetEndianness, true>> { 207 LLVM_ELF_IMPORT_TYPES(TargetEndianness, true) 208 Elf_Word st_name; // Symbol name (index into string table) 209 unsigned char st_info; // Symbol's type and binding attributes 210 unsigned char st_other; // Must be zero; reserved 211 Elf_Half st_shndx; // Which section (header table index) it's defined in 212 Elf_Addr st_value; // Value or address associated with the symbol 213 Elf_Xword st_size; // Size of the symbol 214 }; 215 216 template <class ELFT> 217 struct Elf_Sym_Impl : Elf_Sym_Base<ELFT> { 218 using Elf_Sym_Base<ELFT>::st_info; 219 using Elf_Sym_Base<ELFT>::st_shndx; 220 using Elf_Sym_Base<ELFT>::st_other; 221 using Elf_Sym_Base<ELFT>::st_value; 222 223 // These accessors and mutators correspond to the ELF32_ST_BIND, 224 // ELF32_ST_TYPE, and ELF32_ST_INFO macros defined in the ELF specification: 225 unsigned char getBinding() const { return st_info >> 4; } 226 unsigned char getType() const { return st_info & 0x0f; } 227 uint64_t getValue() const { return st_value; } 228 void setBinding(unsigned char b) { setBindingAndType(b, getType()); } 229 void setType(unsigned char t) { setBindingAndType(getBinding(), t); } 230 231 void setBindingAndType(unsigned char b, unsigned char t) { 232 st_info = (b << 4) + (t & 0x0f); 233 } 234 235 /// Access to the STV_xxx flag stored in the first two bits of st_other. 236 /// STV_DEFAULT: 0 237 /// STV_INTERNAL: 1 238 /// STV_HIDDEN: 2 239 /// STV_PROTECTED: 3 240 unsigned char getVisibility() const { return st_other & 0x3; } 241 void setVisibility(unsigned char v) { 242 assert(v < 4 && "Invalid value for visibility"); 243 st_other = (st_other & ~0x3) | v; 244 } 245 246 bool isAbsolute() const { return st_shndx == ELF::SHN_ABS; } 247 248 bool isCommon() const { 249 return getType() == ELF::STT_COMMON || st_shndx == ELF::SHN_COMMON; 250 } 251 252 bool isDefined() const { return !isUndefined(); } 253 254 bool isProcessorSpecific() const { 255 return st_shndx >= ELF::SHN_LOPROC && st_shndx <= ELF::SHN_HIPROC; 256 } 257 258 bool isOSSpecific() const { 259 return st_shndx >= ELF::SHN_LOOS && st_shndx <= ELF::SHN_HIOS; 260 } 261 262 bool isReserved() const { 263 // ELF::SHN_HIRESERVE is 0xffff so st_shndx <= ELF::SHN_HIRESERVE is always 264 // true and some compilers warn about it. 265 return st_shndx >= ELF::SHN_LORESERVE; 266 } 267 268 bool isUndefined() const { return st_shndx == ELF::SHN_UNDEF; } 269 270 bool isExternal() const { 271 return getBinding() != ELF::STB_LOCAL; 272 } 273 274 Expected<StringRef> getName(StringRef StrTab) const; 275 }; 276 277 template <class ELFT> 278 Expected<StringRef> Elf_Sym_Impl<ELFT>::getName(StringRef StrTab) const { 279 uint32_t Offset = this->st_name; 280 if (Offset >= StrTab.size()) 281 return createStringError(object_error::parse_failed, 282 "st_name (0x%" PRIx32 283 ") is past the end of the string table" 284 " of size 0x%zx", 285 Offset, StrTab.size()); 286 return StringRef(StrTab.data() + Offset); 287 } 288 289 /// Elf_Versym: This is the structure of entries in the SHT_GNU_versym section 290 /// (.gnu.version). This structure is identical for ELF32 and ELF64. 291 template <class ELFT> 292 struct Elf_Versym_Impl { 293 LLVM_ELF_IMPORT_TYPES_ELFT(ELFT) 294 Elf_Half vs_index; // Version index with flags (e.g. VERSYM_HIDDEN) 295 }; 296 297 /// Elf_Verdef: This is the structure of entries in the SHT_GNU_verdef section 298 /// (.gnu.version_d). This structure is identical for ELF32 and ELF64. 299 template <class ELFT> 300 struct Elf_Verdef_Impl { 301 LLVM_ELF_IMPORT_TYPES_ELFT(ELFT) 302 Elf_Half vd_version; // Version of this structure (e.g. VER_DEF_CURRENT) 303 Elf_Half vd_flags; // Bitwise flags (VER_DEF_*) 304 Elf_Half vd_ndx; // Version index, used in .gnu.version entries 305 Elf_Half vd_cnt; // Number of Verdaux entries 306 Elf_Word vd_hash; // Hash of name 307 Elf_Word vd_aux; // Offset to the first Verdaux entry (in bytes) 308 Elf_Word vd_next; // Offset to the next Verdef entry (in bytes) 309 310 /// Get the first Verdaux entry for this Verdef. 311 const Elf_Verdaux *getAux() const { 312 return reinterpret_cast<const Elf_Verdaux *>((const char *)this + vd_aux); 313 } 314 }; 315 316 /// Elf_Verdaux: This is the structure of auxiliary data in the SHT_GNU_verdef 317 /// section (.gnu.version_d). This structure is identical for ELF32 and ELF64. 318 template <class ELFT> 319 struct Elf_Verdaux_Impl { 320 LLVM_ELF_IMPORT_TYPES_ELFT(ELFT) 321 Elf_Word vda_name; // Version name (offset in string table) 322 Elf_Word vda_next; // Offset to next Verdaux entry (in bytes) 323 }; 324 325 /// Elf_Verneed: This is the structure of entries in the SHT_GNU_verneed 326 /// section (.gnu.version_r). This structure is identical for ELF32 and ELF64. 327 template <class ELFT> 328 struct Elf_Verneed_Impl { 329 LLVM_ELF_IMPORT_TYPES_ELFT(ELFT) 330 Elf_Half vn_version; // Version of this structure (e.g. VER_NEED_CURRENT) 331 Elf_Half vn_cnt; // Number of associated Vernaux entries 332 Elf_Word vn_file; // Library name (string table offset) 333 Elf_Word vn_aux; // Offset to first Vernaux entry (in bytes) 334 Elf_Word vn_next; // Offset to next Verneed entry (in bytes) 335 }; 336 337 /// Elf_Vernaux: This is the structure of auxiliary data in SHT_GNU_verneed 338 /// section (.gnu.version_r). This structure is identical for ELF32 and ELF64. 339 template <class ELFT> 340 struct Elf_Vernaux_Impl { 341 LLVM_ELF_IMPORT_TYPES_ELFT(ELFT) 342 Elf_Word vna_hash; // Hash of dependency name 343 Elf_Half vna_flags; // Bitwise Flags (VER_FLAG_*) 344 Elf_Half vna_other; // Version index, used in .gnu.version entries 345 Elf_Word vna_name; // Dependency name 346 Elf_Word vna_next; // Offset to next Vernaux entry (in bytes) 347 }; 348 349 /// Elf_Dyn_Base: This structure matches the form of entries in the dynamic 350 /// table section (.dynamic) look like. 351 template <class ELFT> struct Elf_Dyn_Base; 352 353 template <endianness TargetEndianness> 354 struct Elf_Dyn_Base<ELFType<TargetEndianness, false>> { 355 LLVM_ELF_IMPORT_TYPES(TargetEndianness, false) 356 Elf_Sword d_tag; 357 union { 358 Elf_Word d_val; 359 Elf_Addr d_ptr; 360 } d_un; 361 }; 362 363 template <endianness TargetEndianness> 364 struct Elf_Dyn_Base<ELFType<TargetEndianness, true>> { 365 LLVM_ELF_IMPORT_TYPES(TargetEndianness, true) 366 Elf_Sxword d_tag; 367 union { 368 Elf_Xword d_val; 369 Elf_Addr d_ptr; 370 } d_un; 371 }; 372 373 /// Elf_Dyn_Impl: This inherits from Elf_Dyn_Base, adding getters. 374 template <class ELFT> 375 struct Elf_Dyn_Impl : Elf_Dyn_Base<ELFT> { 376 using Elf_Dyn_Base<ELFT>::d_tag; 377 using Elf_Dyn_Base<ELFT>::d_un; 378 using intX_t = std::conditional_t<ELFT::Is64Bits, int64_t, int32_t>; 379 using uintX_t = std::conditional_t<ELFT::Is64Bits, uint64_t, uint32_t>; 380 intX_t getTag() const { return d_tag; } 381 uintX_t getVal() const { return d_un.d_val; } 382 uintX_t getPtr() const { return d_un.d_ptr; } 383 }; 384 385 template <endianness TargetEndianness> 386 struct Elf_Rel_Impl<ELFType<TargetEndianness, false>, false> { 387 LLVM_ELF_IMPORT_TYPES(TargetEndianness, false) 388 static const bool IsRela = false; 389 Elf_Addr r_offset; // Location (file byte offset, or program virtual addr) 390 Elf_Word r_info; // Symbol table index and type of relocation to apply 391 392 uint32_t getRInfo(bool isMips64EL) const { 393 assert(!isMips64EL); 394 return r_info; 395 } 396 void setRInfo(uint32_t R, bool IsMips64EL) { 397 assert(!IsMips64EL); 398 r_info = R; 399 } 400 401 // These accessors and mutators correspond to the ELF32_R_SYM, ELF32_R_TYPE, 402 // and ELF32_R_INFO macros defined in the ELF specification: 403 uint32_t getSymbol(bool isMips64EL) const { 404 return this->getRInfo(isMips64EL) >> 8; 405 } 406 unsigned char getType(bool isMips64EL) const { 407 return (unsigned char)(this->getRInfo(isMips64EL) & 0x0ff); 408 } 409 void setSymbol(uint32_t s, bool IsMips64EL) { 410 setSymbolAndType(s, getType(IsMips64EL), IsMips64EL); 411 } 412 void setType(unsigned char t, bool IsMips64EL) { 413 setSymbolAndType(getSymbol(IsMips64EL), t, IsMips64EL); 414 } 415 void setSymbolAndType(uint32_t s, unsigned char t, bool IsMips64EL) { 416 this->setRInfo((s << 8) + t, IsMips64EL); 417 } 418 }; 419 420 template <endianness TargetEndianness> 421 struct Elf_Rel_Impl<ELFType<TargetEndianness, false>, true> 422 : public Elf_Rel_Impl<ELFType<TargetEndianness, false>, false> { 423 LLVM_ELF_IMPORT_TYPES(TargetEndianness, false) 424 static const bool IsRela = true; 425 Elf_Sword r_addend; // Compute value for relocatable field by adding this 426 }; 427 428 template <endianness TargetEndianness> 429 struct Elf_Rel_Impl<ELFType<TargetEndianness, true>, false> { 430 LLVM_ELF_IMPORT_TYPES(TargetEndianness, true) 431 static const bool IsRela = false; 432 Elf_Addr r_offset; // Location (file byte offset, or program virtual addr) 433 Elf_Xword r_info; // Symbol table index and type of relocation to apply 434 435 uint64_t getRInfo(bool isMips64EL) const { 436 uint64_t t = r_info; 437 if (!isMips64EL) 438 return t; 439 // Mips64 little endian has a "special" encoding of r_info. Instead of one 440 // 64 bit little endian number, it is a little endian 32 bit number followed 441 // by a 32 bit big endian number. 442 return (t << 32) | ((t >> 8) & 0xff000000) | ((t >> 24) & 0x00ff0000) | 443 ((t >> 40) & 0x0000ff00) | ((t >> 56) & 0x000000ff); 444 } 445 446 void setRInfo(uint64_t R, bool IsMips64EL) { 447 if (IsMips64EL) 448 r_info = (R >> 32) | ((R & 0xff000000) << 8) | ((R & 0x00ff0000) << 24) | 449 ((R & 0x0000ff00) << 40) | ((R & 0x000000ff) << 56); 450 else 451 r_info = R; 452 } 453 454 // These accessors and mutators correspond to the ELF64_R_SYM, ELF64_R_TYPE, 455 // and ELF64_R_INFO macros defined in the ELF specification: 456 uint32_t getSymbol(bool isMips64EL) const { 457 return (uint32_t)(this->getRInfo(isMips64EL) >> 32); 458 } 459 uint32_t getType(bool isMips64EL) const { 460 return (uint32_t)(this->getRInfo(isMips64EL) & 0xffffffffL); 461 } 462 void setSymbol(uint32_t s, bool IsMips64EL) { 463 setSymbolAndType(s, getType(IsMips64EL), IsMips64EL); 464 } 465 void setType(uint32_t t, bool IsMips64EL) { 466 setSymbolAndType(getSymbol(IsMips64EL), t, IsMips64EL); 467 } 468 void setSymbolAndType(uint32_t s, uint32_t t, bool IsMips64EL) { 469 this->setRInfo(((uint64_t)s << 32) + (t & 0xffffffffL), IsMips64EL); 470 } 471 }; 472 473 template <endianness TargetEndianness> 474 struct Elf_Rel_Impl<ELFType<TargetEndianness, true>, true> 475 : public Elf_Rel_Impl<ELFType<TargetEndianness, true>, false> { 476 LLVM_ELF_IMPORT_TYPES(TargetEndianness, true) 477 static const bool IsRela = true; 478 Elf_Sxword r_addend; // Compute value for relocatable field by adding this. 479 }; 480 481 template <class ELFT> 482 struct Elf_Ehdr_Impl { 483 LLVM_ELF_IMPORT_TYPES_ELFT(ELFT) 484 unsigned char e_ident[ELF::EI_NIDENT]; // ELF Identification bytes 485 Elf_Half e_type; // Type of file (see ET_*) 486 Elf_Half e_machine; // Required architecture for this file (see EM_*) 487 Elf_Word e_version; // Must be equal to 1 488 Elf_Addr e_entry; // Address to jump to in order to start program 489 Elf_Off e_phoff; // Program header table's file offset, in bytes 490 Elf_Off e_shoff; // Section header table's file offset, in bytes 491 Elf_Word e_flags; // Processor-specific flags 492 Elf_Half e_ehsize; // Size of ELF header, in bytes 493 Elf_Half e_phentsize; // Size of an entry in the program header table 494 Elf_Half e_phnum; // Number of entries in the program header table 495 Elf_Half e_shentsize; // Size of an entry in the section header table 496 Elf_Half e_shnum; // Number of entries in the section header table 497 Elf_Half e_shstrndx; // Section header table index of section name 498 // string table 499 500 bool checkMagic() const { 501 return (memcmp(e_ident, ELF::ElfMagic, strlen(ELF::ElfMagic))) == 0; 502 } 503 504 unsigned char getFileClass() const { return e_ident[ELF::EI_CLASS]; } 505 unsigned char getDataEncoding() const { return e_ident[ELF::EI_DATA]; } 506 }; 507 508 template <endianness TargetEndianness> 509 struct Elf_Phdr_Impl<ELFType<TargetEndianness, false>> { 510 LLVM_ELF_IMPORT_TYPES(TargetEndianness, false) 511 Elf_Word p_type; // Type of segment 512 Elf_Off p_offset; // FileOffset where segment is located, in bytes 513 Elf_Addr p_vaddr; // Virtual Address of beginning of segment 514 Elf_Addr p_paddr; // Physical address of beginning of segment (OS-specific) 515 Elf_Word p_filesz; // Num. of bytes in file image of segment (may be zero) 516 Elf_Word p_memsz; // Num. of bytes in mem image of segment (may be zero) 517 Elf_Word p_flags; // Segment flags 518 Elf_Word p_align; // Segment alignment constraint 519 }; 520 521 template <endianness TargetEndianness> 522 struct Elf_Phdr_Impl<ELFType<TargetEndianness, true>> { 523 LLVM_ELF_IMPORT_TYPES(TargetEndianness, true) 524 Elf_Word p_type; // Type of segment 525 Elf_Word p_flags; // Segment flags 526 Elf_Off p_offset; // FileOffset where segment is located, in bytes 527 Elf_Addr p_vaddr; // Virtual Address of beginning of segment 528 Elf_Addr p_paddr; // Physical address of beginning of segment (OS-specific) 529 Elf_Xword p_filesz; // Num. of bytes in file image of segment (may be zero) 530 Elf_Xword p_memsz; // Num. of bytes in mem image of segment (may be zero) 531 Elf_Xword p_align; // Segment alignment constraint 532 }; 533 534 // ELFT needed for endianness. 535 template <class ELFT> 536 struct Elf_Hash_Impl { 537 LLVM_ELF_IMPORT_TYPES_ELFT(ELFT) 538 Elf_Word nbucket; 539 Elf_Word nchain; 540 541 ArrayRef<Elf_Word> buckets() const { 542 return ArrayRef<Elf_Word>(&nbucket + 2, &nbucket + 2 + nbucket); 543 } 544 545 ArrayRef<Elf_Word> chains() const { 546 return ArrayRef<Elf_Word>(&nbucket + 2 + nbucket, 547 &nbucket + 2 + nbucket + nchain); 548 } 549 }; 550 551 // .gnu.hash section 552 template <class ELFT> 553 struct Elf_GnuHash_Impl { 554 LLVM_ELF_IMPORT_TYPES_ELFT(ELFT) 555 Elf_Word nbuckets; 556 Elf_Word symndx; 557 Elf_Word maskwords; 558 Elf_Word shift2; 559 560 ArrayRef<Elf_Off> filter() const { 561 return ArrayRef<Elf_Off>(reinterpret_cast<const Elf_Off *>(&shift2 + 1), 562 maskwords); 563 } 564 565 ArrayRef<Elf_Word> buckets() const { 566 return ArrayRef<Elf_Word>( 567 reinterpret_cast<const Elf_Word *>(filter().end()), nbuckets); 568 } 569 570 ArrayRef<Elf_Word> values(unsigned DynamicSymCount) const { 571 assert(DynamicSymCount >= symndx); 572 return ArrayRef<Elf_Word>(buckets().end(), DynamicSymCount - symndx); 573 } 574 }; 575 576 // Compressed section headers. 577 // http://www.sco.com/developers/gabi/latest/ch4.sheader.html#compression_header 578 template <endianness TargetEndianness> 579 struct Elf_Chdr_Impl<ELFType<TargetEndianness, false>> { 580 LLVM_ELF_IMPORT_TYPES(TargetEndianness, false) 581 Elf_Word ch_type; 582 Elf_Word ch_size; 583 Elf_Word ch_addralign; 584 }; 585 586 template <endianness TargetEndianness> 587 struct Elf_Chdr_Impl<ELFType<TargetEndianness, true>> { 588 LLVM_ELF_IMPORT_TYPES(TargetEndianness, true) 589 Elf_Word ch_type; 590 Elf_Word ch_reserved; 591 Elf_Xword ch_size; 592 Elf_Xword ch_addralign; 593 }; 594 595 /// Note header 596 template <class ELFT> 597 struct Elf_Nhdr_Impl { 598 LLVM_ELF_IMPORT_TYPES_ELFT(ELFT) 599 Elf_Word n_namesz; 600 Elf_Word n_descsz; 601 Elf_Word n_type; 602 603 /// The alignment of the name and descriptor. 604 /// 605 /// Implementations differ from the specification here: in practice all 606 /// variants align both the name and descriptor to 4-bytes. 607 static const unsigned int Align = 4; 608 609 /// Get the size of the note, including name, descriptor, and padding. 610 size_t getSize() const { 611 return sizeof(*this) + alignTo<Align>(n_namesz) + alignTo<Align>(n_descsz); 612 } 613 }; 614 615 /// An ELF note. 616 /// 617 /// Wraps a note header, providing methods for accessing the name and 618 /// descriptor safely. 619 template <class ELFT> 620 class Elf_Note_Impl { 621 LLVM_ELF_IMPORT_TYPES_ELFT(ELFT) 622 623 const Elf_Nhdr_Impl<ELFT> &Nhdr; 624 625 template <class NoteIteratorELFT> friend class Elf_Note_Iterator_Impl; 626 627 public: 628 Elf_Note_Impl(const Elf_Nhdr_Impl<ELFT> &Nhdr) : Nhdr(Nhdr) {} 629 630 /// Get the note's name, excluding the terminating null byte. 631 StringRef getName() const { 632 if (!Nhdr.n_namesz) 633 return StringRef(); 634 return StringRef(reinterpret_cast<const char *>(&Nhdr) + sizeof(Nhdr), 635 Nhdr.n_namesz - 1); 636 } 637 638 /// Get the note's descriptor. 639 ArrayRef<uint8_t> getDesc() const { 640 if (!Nhdr.n_descsz) 641 return ArrayRef<uint8_t>(); 642 return ArrayRef<uint8_t>( 643 reinterpret_cast<const uint8_t *>(&Nhdr) + sizeof(Nhdr) + 644 alignTo<Elf_Nhdr_Impl<ELFT>::Align>(Nhdr.n_namesz), 645 Nhdr.n_descsz); 646 } 647 648 /// Get the note's descriptor as StringRef 649 StringRef getDescAsStringRef() const { 650 ArrayRef<uint8_t> Desc = getDesc(); 651 return StringRef(reinterpret_cast<const char *>(Desc.data()), Desc.size()); 652 } 653 654 /// Get the note's type. 655 Elf_Word getType() const { return Nhdr.n_type; } 656 }; 657 658 template <class ELFT> class Elf_Note_Iterator_Impl { 659 public: 660 using iterator_category = std::forward_iterator_tag; 661 using value_type = Elf_Note_Impl<ELFT>; 662 using difference_type = std::ptrdiff_t; 663 using pointer = value_type *; 664 using reference = value_type &; 665 666 private: 667 // Nhdr being a nullptr marks the end of iteration. 668 const Elf_Nhdr_Impl<ELFT> *Nhdr = nullptr; 669 size_t RemainingSize = 0u; 670 Error *Err = nullptr; 671 672 template <class ELFFileELFT> friend class ELFFile; 673 674 // Stop iteration and indicate an overflow. 675 void stopWithOverflowError() { 676 Nhdr = nullptr; 677 *Err = make_error<StringError>("ELF note overflows container", 678 object_error::parse_failed); 679 } 680 681 // Advance Nhdr by NoteSize bytes, starting from NhdrPos. 682 // 683 // Assumes NoteSize <= RemainingSize. Ensures Nhdr->getSize() <= RemainingSize 684 // upon returning. Handles stopping iteration when reaching the end of the 685 // container, either cleanly or with an overflow error. 686 void advanceNhdr(const uint8_t *NhdrPos, size_t NoteSize) { 687 RemainingSize -= NoteSize; 688 if (RemainingSize == 0u) { 689 // Ensure that if the iterator walks to the end, the error is checked 690 // afterwards. 691 *Err = Error::success(); 692 Nhdr = nullptr; 693 } else if (sizeof(*Nhdr) > RemainingSize) 694 stopWithOverflowError(); 695 else { 696 Nhdr = reinterpret_cast<const Elf_Nhdr_Impl<ELFT> *>(NhdrPos + NoteSize); 697 if (Nhdr->getSize() > RemainingSize) 698 stopWithOverflowError(); 699 else 700 *Err = Error::success(); 701 } 702 } 703 704 Elf_Note_Iterator_Impl() {} 705 explicit Elf_Note_Iterator_Impl(Error &Err) : Err(&Err) {} 706 Elf_Note_Iterator_Impl(const uint8_t *Start, size_t Size, Error &Err) 707 : RemainingSize(Size), Err(&Err) { 708 consumeError(std::move(Err)); 709 assert(Start && "ELF note iterator starting at NULL"); 710 advanceNhdr(Start, 0u); 711 } 712 713 public: 714 Elf_Note_Iterator_Impl &operator++() { 715 assert(Nhdr && "incremented ELF note end iterator"); 716 const uint8_t *NhdrPos = reinterpret_cast<const uint8_t *>(Nhdr); 717 size_t NoteSize = Nhdr->getSize(); 718 advanceNhdr(NhdrPos, NoteSize); 719 return *this; 720 } 721 bool operator==(Elf_Note_Iterator_Impl Other) const { 722 if (!Nhdr && Other.Err) 723 (void)(bool)(*Other.Err); 724 if (!Other.Nhdr && Err) 725 (void)(bool)(*Err); 726 return Nhdr == Other.Nhdr; 727 } 728 bool operator!=(Elf_Note_Iterator_Impl Other) const { 729 return !(*this == Other); 730 } 731 Elf_Note_Impl<ELFT> operator*() const { 732 assert(Nhdr && "dereferenced ELF note end iterator"); 733 return Elf_Note_Impl<ELFT>(*Nhdr); 734 } 735 }; 736 737 template <class ELFT> struct Elf_CGProfile_Impl { 738 LLVM_ELF_IMPORT_TYPES_ELFT(ELFT) 739 Elf_Word cgp_from; 740 Elf_Word cgp_to; 741 Elf_Xword cgp_weight; 742 }; 743 744 // MIPS .reginfo section 745 template <class ELFT> 746 struct Elf_Mips_RegInfo; 747 748 template <support::endianness TargetEndianness> 749 struct Elf_Mips_RegInfo<ELFType<TargetEndianness, false>> { 750 LLVM_ELF_IMPORT_TYPES(TargetEndianness, false) 751 Elf_Word ri_gprmask; // bit-mask of used general registers 752 Elf_Word ri_cprmask[4]; // bit-mask of used co-processor registers 753 Elf_Addr ri_gp_value; // gp register value 754 }; 755 756 template <support::endianness TargetEndianness> 757 struct Elf_Mips_RegInfo<ELFType<TargetEndianness, true>> { 758 LLVM_ELF_IMPORT_TYPES(TargetEndianness, true) 759 Elf_Word ri_gprmask; // bit-mask of used general registers 760 Elf_Word ri_pad; // unused padding field 761 Elf_Word ri_cprmask[4]; // bit-mask of used co-processor registers 762 Elf_Addr ri_gp_value; // gp register value 763 }; 764 765 // .MIPS.options section 766 template <class ELFT> struct Elf_Mips_Options { 767 LLVM_ELF_IMPORT_TYPES_ELFT(ELFT) 768 uint8_t kind; // Determines interpretation of variable part of descriptor 769 uint8_t size; // Byte size of descriptor, including this header 770 Elf_Half section; // Section header index of section affected, 771 // or 0 for global options 772 Elf_Word info; // Kind-specific information 773 774 Elf_Mips_RegInfo<ELFT> &getRegInfo() { 775 assert(kind == ELF::ODK_REGINFO); 776 return *reinterpret_cast<Elf_Mips_RegInfo<ELFT> *>( 777 (uint8_t *)this + sizeof(Elf_Mips_Options)); 778 } 779 const Elf_Mips_RegInfo<ELFT> &getRegInfo() const { 780 return const_cast<Elf_Mips_Options *>(this)->getRegInfo(); 781 } 782 }; 783 784 // .MIPS.abiflags section content 785 template <class ELFT> struct Elf_Mips_ABIFlags { 786 LLVM_ELF_IMPORT_TYPES_ELFT(ELFT) 787 Elf_Half version; // Version of the structure 788 uint8_t isa_level; // ISA level: 1-5, 32, and 64 789 uint8_t isa_rev; // ISA revision (0 for MIPS I - MIPS V) 790 uint8_t gpr_size; // General purpose registers size 791 uint8_t cpr1_size; // Co-processor 1 registers size 792 uint8_t cpr2_size; // Co-processor 2 registers size 793 uint8_t fp_abi; // Floating-point ABI flag 794 Elf_Word isa_ext; // Processor-specific extension 795 Elf_Word ases; // ASEs flags 796 Elf_Word flags1; // General flags 797 Elf_Word flags2; // General flags 798 }; 799 800 // Struct representing the BBAddrMap for one function. 801 template <class ELFT> struct Elf_BBAddrMap_Impl { 802 LLVM_ELF_IMPORT_TYPES_ELFT(ELFT) 803 uintX_t Addr; // Function address 804 // Struct representing the BBAddrMap information for one basic block. 805 struct BBEntry { 806 uint32_t Offset; // Offset of basic block relative to function start. 807 uint32_t Size; // Size of the basic block. 808 809 // The following fields are decoded from the Metadata field. The encoding 810 // happens in AsmPrinter.cpp:getBBAddrMapMetadata. 811 bool HasReturn; // If this block ends with a return (or tail call). 812 bool HasTailCall; // If this block ends with a tail call. 813 bool IsEHPad; // If this is an exception handling block. 814 bool CanFallThrough; // If this block can fall through to its next. 815 816 BBEntry(uint32_t Offset, uint32_t Size, uint32_t Metadata) 817 : Offset(Offset), Size(Size), HasReturn(Metadata & 1), 818 HasTailCall(Metadata & (1 << 1)), IsEHPad(Metadata & (1 << 2)), 819 CanFallThrough(Metadata & (1 << 3)){}; 820 }; 821 std::vector<BBEntry> BBEntries; // Basic block entries for this function. 822 }; 823 824 } // end namespace object. 825 } // end namespace llvm. 826 827 #endif // LLVM_OBJECT_ELFTYPES_H 828