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 "llvm/Support/MathExtras.h" 19 #include <cassert> 20 #include <cstdint> 21 #include <cstring> 22 #include <type_traits> 23 24 namespace llvm { 25 namespace object { 26 27 using support::endianness; 28 29 template <class ELFT> struct Elf_Ehdr_Impl; 30 template <class ELFT> struct Elf_Shdr_Impl; 31 template <class ELFT> struct Elf_Sym_Impl; 32 template <class ELFT> struct Elf_Dyn_Impl; 33 template <class ELFT> struct Elf_Phdr_Impl; 34 template <class ELFT, bool isRela> struct Elf_Rel_Impl; 35 template <class ELFT> struct Elf_Verdef_Impl; 36 template <class ELFT> struct Elf_Verdaux_Impl; 37 template <class ELFT> struct Elf_Verneed_Impl; 38 template <class ELFT> struct Elf_Vernaux_Impl; 39 template <class ELFT> struct Elf_Versym_Impl; 40 template <class ELFT> struct Elf_Hash_Impl; 41 template <class ELFT> struct Elf_GnuHash_Impl; 42 template <class ELFT> struct Elf_Chdr_Impl; 43 template <class ELFT> struct Elf_Nhdr_Impl; 44 template <class ELFT> class Elf_Note_Impl; 45 template <class ELFT> class Elf_Note_Iterator_Impl; 46 template <class ELFT> struct Elf_CGProfile_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 DynRange = ArrayRef<Dyn>; 79 using ShdrRange = ArrayRef<Shdr>; 80 using SymRange = ArrayRef<Sym>; 81 using RelRange = ArrayRef<Rel>; 82 using RelaRange = ArrayRef<Rela>; 83 using RelrRange = ArrayRef<Relr>; 84 using PhdrRange = ArrayRef<Phdr>; 85 86 using Half = packed<uint16_t>; 87 using Word = packed<uint32_t>; 88 using Sword = packed<int32_t>; 89 using Xword = packed<uint64_t>; 90 using Sxword = packed<int64_t>; 91 using Addr = packed<uint>; 92 using Off = packed<uint>; 93 }; 94 95 using ELF32LE = ELFType<support::little, false>; 96 using ELF32BE = ELFType<support::big, false>; 97 using ELF64LE = ELFType<support::little, true>; 98 using ELF64BE = ELFType<support::big, true>; 99 100 // Use an alignment of 2 for the typedefs since that is the worst case for 101 // ELF files in archives. 102 103 // I really don't like doing this, but the alternative is copypasta. 104 #define LLVM_ELF_IMPORT_TYPES_ELFT(ELFT) \ 105 using Elf_Addr = typename ELFT::Addr; \ 106 using Elf_Off = typename ELFT::Off; \ 107 using Elf_Half = typename ELFT::Half; \ 108 using Elf_Word = typename ELFT::Word; \ 109 using Elf_Sword = typename ELFT::Sword; \ 110 using Elf_Xword = typename ELFT::Xword; \ 111 using Elf_Sxword = typename ELFT::Sxword; \ 112 using uintX_t = typename ELFT::uint; \ 113 using Elf_Ehdr = typename ELFT::Ehdr; \ 114 using Elf_Shdr = typename ELFT::Shdr; \ 115 using Elf_Sym = typename ELFT::Sym; \ 116 using Elf_Dyn = typename ELFT::Dyn; \ 117 using Elf_Phdr = typename ELFT::Phdr; \ 118 using Elf_Rel = typename ELFT::Rel; \ 119 using Elf_Rela = typename ELFT::Rela; \ 120 using Elf_Relr = typename ELFT::Relr; \ 121 using Elf_Verdef = typename ELFT::Verdef; \ 122 using Elf_Verdaux = typename ELFT::Verdaux; \ 123 using Elf_Verneed = typename ELFT::Verneed; \ 124 using Elf_Vernaux = typename ELFT::Vernaux; \ 125 using Elf_Versym = typename ELFT::Versym; \ 126 using Elf_Hash = typename ELFT::Hash; \ 127 using Elf_GnuHash = typename ELFT::GnuHash; \ 128 using Elf_Chdr = typename ELFT::Chdr; \ 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_Dyn_Range = typename ELFT::DynRange; \ 134 using Elf_Shdr_Range = typename ELFT::ShdrRange; \ 135 using Elf_Sym_Range = typename ELFT::SymRange; \ 136 using Elf_Rel_Range = typename ELFT::RelRange; \ 137 using Elf_Rela_Range = typename ELFT::RelaRange; \ 138 using Elf_Relr_Range = typename ELFT::RelrRange; \ 139 using Elf_Phdr_Range = typename ELFT::PhdrRange; 140 141 #define LLVM_ELF_COMMA , 142 #define LLVM_ELF_IMPORT_TYPES(E, W) \ 143 LLVM_ELF_IMPORT_TYPES_ELFT(ELFType<E LLVM_ELF_COMMA W>) 144 145 // Section header. 146 template <class ELFT> struct Elf_Shdr_Base; 147 148 template <endianness TargetEndianness> 149 struct Elf_Shdr_Base<ELFType<TargetEndianness, false>> { 150 LLVM_ELF_IMPORT_TYPES(TargetEndianness, false) 151 Elf_Word sh_name; // Section name (index into string table) 152 Elf_Word sh_type; // Section type (SHT_*) 153 Elf_Word sh_flags; // Section flags (SHF_*) 154 Elf_Addr sh_addr; // Address where section is to be loaded 155 Elf_Off sh_offset; // File offset of section data, in bytes 156 Elf_Word sh_size; // Size of section, in bytes 157 Elf_Word sh_link; // Section type-specific header table index link 158 Elf_Word sh_info; // Section type-specific extra information 159 Elf_Word sh_addralign; // Section address alignment 160 Elf_Word sh_entsize; // Size of records contained within the section 161 }; 162 163 template <endianness TargetEndianness> 164 struct Elf_Shdr_Base<ELFType<TargetEndianness, true>> { 165 LLVM_ELF_IMPORT_TYPES(TargetEndianness, true) 166 Elf_Word sh_name; // Section name (index into string table) 167 Elf_Word sh_type; // Section type (SHT_*) 168 Elf_Xword sh_flags; // Section flags (SHF_*) 169 Elf_Addr sh_addr; // Address where section is to be loaded 170 Elf_Off sh_offset; // File offset of section data, in bytes 171 Elf_Xword sh_size; // Size of section, in bytes 172 Elf_Word sh_link; // Section type-specific header table index link 173 Elf_Word sh_info; // Section type-specific extra information 174 Elf_Xword sh_addralign; // Section address alignment 175 Elf_Xword sh_entsize; // Size of records contained within the section 176 }; 177 178 template <class ELFT> 179 struct Elf_Shdr_Impl : Elf_Shdr_Base<ELFT> { 180 using Elf_Shdr_Base<ELFT>::sh_entsize; 181 using Elf_Shdr_Base<ELFT>::sh_size; 182 183 /// Get the number of entities this section contains if it has any. 184 unsigned getEntityCount() const { 185 if (sh_entsize == 0) 186 return 0; 187 return sh_size / sh_entsize; 188 } 189 }; 190 191 template <class ELFT> struct Elf_Sym_Base; 192 193 template <endianness TargetEndianness> 194 struct Elf_Sym_Base<ELFType<TargetEndianness, false>> { 195 LLVM_ELF_IMPORT_TYPES(TargetEndianness, false) 196 Elf_Word st_name; // Symbol name (index into string table) 197 Elf_Addr st_value; // Value or address associated with the symbol 198 Elf_Word st_size; // Size of the symbol 199 unsigned char st_info; // Symbol's type and binding attributes 200 unsigned char st_other; // Must be zero; reserved 201 Elf_Half st_shndx; // Which section (header table index) it's defined in 202 }; 203 204 template <endianness TargetEndianness> 205 struct Elf_Sym_Base<ELFType<TargetEndianness, true>> { 206 LLVM_ELF_IMPORT_TYPES(TargetEndianness, true) 207 Elf_Word st_name; // Symbol name (index into string table) 208 unsigned char st_info; // Symbol's type and binding attributes 209 unsigned char st_other; // Must be zero; reserved 210 Elf_Half st_shndx; // Which section (header table index) it's defined in 211 Elf_Addr st_value; // Value or address associated with the symbol 212 Elf_Xword st_size; // Size of the symbol 213 }; 214 215 template <class ELFT> 216 struct Elf_Sym_Impl : Elf_Sym_Base<ELFT> { 217 using Elf_Sym_Base<ELFT>::st_info; 218 using Elf_Sym_Base<ELFT>::st_shndx; 219 using Elf_Sym_Base<ELFT>::st_other; 220 using Elf_Sym_Base<ELFT>::st_value; 221 222 // These accessors and mutators correspond to the ELF32_ST_BIND, 223 // ELF32_ST_TYPE, and ELF32_ST_INFO macros defined in the ELF specification: 224 unsigned char getBinding() const { return st_info >> 4; } 225 unsigned char getType() const { return st_info & 0x0f; } 226 uint64_t getValue() const { return st_value; } 227 void setBinding(unsigned char b) { setBindingAndType(b, getType()); } 228 void setType(unsigned char t) { setBindingAndType(getBinding(), t); } 229 230 void setBindingAndType(unsigned char b, unsigned char t) { 231 st_info = (b << 4) + (t & 0x0f); 232 } 233 234 /// Access to the STV_xxx flag stored in the first two bits of st_other. 235 /// STV_DEFAULT: 0 236 /// STV_INTERNAL: 1 237 /// STV_HIDDEN: 2 238 /// STV_PROTECTED: 3 239 unsigned char getVisibility() const { return st_other & 0x3; } 240 void setVisibility(unsigned char v) { 241 assert(v < 4 && "Invalid value for visibility"); 242 st_other = (st_other & ~0x3) | v; 243 } 244 245 bool isAbsolute() const { return st_shndx == ELF::SHN_ABS; } 246 247 bool isCommon() const { 248 return getType() == ELF::STT_COMMON || st_shndx == ELF::SHN_COMMON; 249 } 250 251 bool isDefined() const { return !isUndefined(); } 252 253 bool isProcessorSpecific() const { 254 return st_shndx >= ELF::SHN_LOPROC && st_shndx <= ELF::SHN_HIPROC; 255 } 256 257 bool isOSSpecific() const { 258 return st_shndx >= ELF::SHN_LOOS && st_shndx <= ELF::SHN_HIOS; 259 } 260 261 bool isReserved() const { 262 // ELF::SHN_HIRESERVE is 0xffff so st_shndx <= ELF::SHN_HIRESERVE is always 263 // true and some compilers warn about it. 264 return st_shndx >= ELF::SHN_LORESERVE; 265 } 266 267 bool isUndefined() const { return st_shndx == ELF::SHN_UNDEF; } 268 269 bool isExternal() const { 270 return getBinding() != ELF::STB_LOCAL; 271 } 272 273 Expected<StringRef> getName(StringRef StrTab) const; 274 }; 275 276 template <class ELFT> 277 Expected<StringRef> Elf_Sym_Impl<ELFT>::getName(StringRef StrTab) const { 278 uint32_t Offset = this->st_name; 279 if (Offset >= StrTab.size()) 280 return createStringError(object_error::parse_failed, 281 "st_name (0x%" PRIx32 282 ") is past the end of the string table" 283 " of size 0x%zx", 284 Offset, StrTab.size()); 285 return StringRef(StrTab.data() + Offset); 286 } 287 288 /// Elf_Versym: This is the structure of entries in the SHT_GNU_versym section 289 /// (.gnu.version). This structure is identical for ELF32 and ELF64. 290 template <class ELFT> 291 struct Elf_Versym_Impl { 292 LLVM_ELF_IMPORT_TYPES_ELFT(ELFT) 293 Elf_Half vs_index; // Version index with flags (e.g. VERSYM_HIDDEN) 294 }; 295 296 /// Elf_Verdef: This is the structure of entries in the SHT_GNU_verdef section 297 /// (.gnu.version_d). This structure is identical for ELF32 and ELF64. 298 template <class ELFT> 299 struct Elf_Verdef_Impl { 300 LLVM_ELF_IMPORT_TYPES_ELFT(ELFT) 301 Elf_Half vd_version; // Version of this structure (e.g. VER_DEF_CURRENT) 302 Elf_Half vd_flags; // Bitwise flags (VER_DEF_*) 303 Elf_Half vd_ndx; // Version index, used in .gnu.version entries 304 Elf_Half vd_cnt; // Number of Verdaux entries 305 Elf_Word vd_hash; // Hash of name 306 Elf_Word vd_aux; // Offset to the first Verdaux entry (in bytes) 307 Elf_Word vd_next; // Offset to the next Verdef entry (in bytes) 308 309 /// Get the first Verdaux entry for this Verdef. 310 const Elf_Verdaux *getAux() const { 311 return reinterpret_cast<const Elf_Verdaux *>((const char *)this + vd_aux); 312 } 313 }; 314 315 /// Elf_Verdaux: This is the structure of auxiliary data in the SHT_GNU_verdef 316 /// section (.gnu.version_d). This structure is identical for ELF32 and ELF64. 317 template <class ELFT> 318 struct Elf_Verdaux_Impl { 319 LLVM_ELF_IMPORT_TYPES_ELFT(ELFT) 320 Elf_Word vda_name; // Version name (offset in string table) 321 Elf_Word vda_next; // Offset to next Verdaux entry (in bytes) 322 }; 323 324 /// Elf_Verneed: This is the structure of entries in the SHT_GNU_verneed 325 /// section (.gnu.version_r). This structure is identical for ELF32 and ELF64. 326 template <class ELFT> 327 struct Elf_Verneed_Impl { 328 LLVM_ELF_IMPORT_TYPES_ELFT(ELFT) 329 Elf_Half vn_version; // Version of this structure (e.g. VER_NEED_CURRENT) 330 Elf_Half vn_cnt; // Number of associated Vernaux entries 331 Elf_Word vn_file; // Library name (string table offset) 332 Elf_Word vn_aux; // Offset to first Vernaux entry (in bytes) 333 Elf_Word vn_next; // Offset to next Verneed entry (in bytes) 334 }; 335 336 /// Elf_Vernaux: This is the structure of auxiliary data in SHT_GNU_verneed 337 /// section (.gnu.version_r). This structure is identical for ELF32 and ELF64. 338 template <class ELFT> 339 struct Elf_Vernaux_Impl { 340 LLVM_ELF_IMPORT_TYPES_ELFT(ELFT) 341 Elf_Word vna_hash; // Hash of dependency name 342 Elf_Half vna_flags; // Bitwise Flags (VER_FLAG_*) 343 Elf_Half vna_other; // Version index, used in .gnu.version entries 344 Elf_Word vna_name; // Dependency name 345 Elf_Word vna_next; // Offset to next Vernaux entry (in bytes) 346 }; 347 348 /// Elf_Dyn_Base: This structure matches the form of entries in the dynamic 349 /// table section (.dynamic) look like. 350 template <class ELFT> struct Elf_Dyn_Base; 351 352 template <endianness TargetEndianness> 353 struct Elf_Dyn_Base<ELFType<TargetEndianness, false>> { 354 LLVM_ELF_IMPORT_TYPES(TargetEndianness, false) 355 Elf_Sword d_tag; 356 union { 357 Elf_Word d_val; 358 Elf_Addr d_ptr; 359 } d_un; 360 }; 361 362 template <endianness TargetEndianness> 363 struct Elf_Dyn_Base<ELFType<TargetEndianness, true>> { 364 LLVM_ELF_IMPORT_TYPES(TargetEndianness, true) 365 Elf_Sxword d_tag; 366 union { 367 Elf_Xword d_val; 368 Elf_Addr d_ptr; 369 } d_un; 370 }; 371 372 /// Elf_Dyn_Impl: This inherits from Elf_Dyn_Base, adding getters. 373 template <class ELFT> 374 struct Elf_Dyn_Impl : Elf_Dyn_Base<ELFT> { 375 using Elf_Dyn_Base<ELFT>::d_tag; 376 using Elf_Dyn_Base<ELFT>::d_un; 377 using intX_t = std::conditional_t<ELFT::Is64Bits, int64_t, int32_t>; 378 using uintX_t = std::conditional_t<ELFT::Is64Bits, uint64_t, uint32_t>; 379 intX_t getTag() const { return d_tag; } 380 uintX_t getVal() const { return d_un.d_val; } 381 uintX_t getPtr() const { return d_un.d_ptr; } 382 }; 383 384 template <endianness TargetEndianness> 385 struct Elf_Rel_Impl<ELFType<TargetEndianness, false>, false> { 386 LLVM_ELF_IMPORT_TYPES(TargetEndianness, false) 387 static const bool IsRela = false; 388 Elf_Addr r_offset; // Location (file byte offset, or program virtual addr) 389 Elf_Word r_info; // Symbol table index and type of relocation to apply 390 391 uint32_t getRInfo(bool isMips64EL) const { 392 assert(!isMips64EL); 393 return r_info; 394 } 395 void setRInfo(uint32_t R, bool IsMips64EL) { 396 assert(!IsMips64EL); 397 r_info = R; 398 } 399 400 // These accessors and mutators correspond to the ELF32_R_SYM, ELF32_R_TYPE, 401 // and ELF32_R_INFO macros defined in the ELF specification: 402 uint32_t getSymbol(bool isMips64EL) const { 403 return this->getRInfo(isMips64EL) >> 8; 404 } 405 unsigned char getType(bool isMips64EL) const { 406 return (unsigned char)(this->getRInfo(isMips64EL) & 0x0ff); 407 } 408 void setSymbol(uint32_t s, bool IsMips64EL) { 409 setSymbolAndType(s, getType(IsMips64EL), IsMips64EL); 410 } 411 void setType(unsigned char t, bool IsMips64EL) { 412 setSymbolAndType(getSymbol(IsMips64EL), t, IsMips64EL); 413 } 414 void setSymbolAndType(uint32_t s, unsigned char t, bool IsMips64EL) { 415 this->setRInfo((s << 8) + t, IsMips64EL); 416 } 417 }; 418 419 template <endianness TargetEndianness> 420 struct Elf_Rel_Impl<ELFType<TargetEndianness, false>, true> 421 : public Elf_Rel_Impl<ELFType<TargetEndianness, false>, false> { 422 LLVM_ELF_IMPORT_TYPES(TargetEndianness, false) 423 static const bool IsRela = true; 424 Elf_Sword r_addend; // Compute value for relocatable field by adding this 425 }; 426 427 template <endianness TargetEndianness> 428 struct Elf_Rel_Impl<ELFType<TargetEndianness, true>, false> { 429 LLVM_ELF_IMPORT_TYPES(TargetEndianness, true) 430 static const bool IsRela = false; 431 Elf_Addr r_offset; // Location (file byte offset, or program virtual addr) 432 Elf_Xword r_info; // Symbol table index and type of relocation to apply 433 434 uint64_t getRInfo(bool isMips64EL) const { 435 uint64_t t = r_info; 436 if (!isMips64EL) 437 return t; 438 // Mips64 little endian has a "special" encoding of r_info. Instead of one 439 // 64 bit little endian number, it is a little endian 32 bit number followed 440 // by a 32 bit big endian number. 441 return (t << 32) | ((t >> 8) & 0xff000000) | ((t >> 24) & 0x00ff0000) | 442 ((t >> 40) & 0x0000ff00) | ((t >> 56) & 0x000000ff); 443 } 444 445 void setRInfo(uint64_t R, bool IsMips64EL) { 446 if (IsMips64EL) 447 r_info = (R >> 32) | ((R & 0xff000000) << 8) | ((R & 0x00ff0000) << 24) | 448 ((R & 0x0000ff00) << 40) | ((R & 0x000000ff) << 56); 449 else 450 r_info = R; 451 } 452 453 // These accessors and mutators correspond to the ELF64_R_SYM, ELF64_R_TYPE, 454 // and ELF64_R_INFO macros defined in the ELF specification: 455 uint32_t getSymbol(bool isMips64EL) const { 456 return (uint32_t)(this->getRInfo(isMips64EL) >> 32); 457 } 458 uint32_t getType(bool isMips64EL) const { 459 return (uint32_t)(this->getRInfo(isMips64EL) & 0xffffffffL); 460 } 461 void setSymbol(uint32_t s, bool IsMips64EL) { 462 setSymbolAndType(s, getType(IsMips64EL), IsMips64EL); 463 } 464 void setType(uint32_t t, bool IsMips64EL) { 465 setSymbolAndType(getSymbol(IsMips64EL), t, IsMips64EL); 466 } 467 void setSymbolAndType(uint32_t s, uint32_t t, bool IsMips64EL) { 468 this->setRInfo(((uint64_t)s << 32) + (t & 0xffffffffL), IsMips64EL); 469 } 470 }; 471 472 template <endianness TargetEndianness> 473 struct Elf_Rel_Impl<ELFType<TargetEndianness, true>, true> 474 : public Elf_Rel_Impl<ELFType<TargetEndianness, true>, false> { 475 LLVM_ELF_IMPORT_TYPES(TargetEndianness, true) 476 static const bool IsRela = true; 477 Elf_Sxword r_addend; // Compute value for relocatable field by adding this. 478 }; 479 480 template <class ELFT> 481 struct Elf_Ehdr_Impl { 482 LLVM_ELF_IMPORT_TYPES_ELFT(ELFT) 483 unsigned char e_ident[ELF::EI_NIDENT]; // ELF Identification bytes 484 Elf_Half e_type; // Type of file (see ET_*) 485 Elf_Half e_machine; // Required architecture for this file (see EM_*) 486 Elf_Word e_version; // Must be equal to 1 487 Elf_Addr e_entry; // Address to jump to in order to start program 488 Elf_Off e_phoff; // Program header table's file offset, in bytes 489 Elf_Off e_shoff; // Section header table's file offset, in bytes 490 Elf_Word e_flags; // Processor-specific flags 491 Elf_Half e_ehsize; // Size of ELF header, in bytes 492 Elf_Half e_phentsize; // Size of an entry in the program header table 493 Elf_Half e_phnum; // Number of entries in the program header table 494 Elf_Half e_shentsize; // Size of an entry in the section header table 495 Elf_Half e_shnum; // Number of entries in the section header table 496 Elf_Half e_shstrndx; // Section header table index of section name 497 // string table 498 499 bool checkMagic() const { 500 return (memcmp(e_ident, ELF::ElfMagic, strlen(ELF::ElfMagic))) == 0; 501 } 502 503 unsigned char getFileClass() const { return e_ident[ELF::EI_CLASS]; } 504 unsigned char getDataEncoding() const { return e_ident[ELF::EI_DATA]; } 505 }; 506 507 template <endianness TargetEndianness> 508 struct Elf_Phdr_Impl<ELFType<TargetEndianness, false>> { 509 LLVM_ELF_IMPORT_TYPES(TargetEndianness, false) 510 Elf_Word p_type; // Type of segment 511 Elf_Off p_offset; // FileOffset where segment is located, in bytes 512 Elf_Addr p_vaddr; // Virtual Address of beginning of segment 513 Elf_Addr p_paddr; // Physical address of beginning of segment (OS-specific) 514 Elf_Word p_filesz; // Num. of bytes in file image of segment (may be zero) 515 Elf_Word p_memsz; // Num. of bytes in mem image of segment (may be zero) 516 Elf_Word p_flags; // Segment flags 517 Elf_Word p_align; // Segment alignment constraint 518 }; 519 520 template <endianness TargetEndianness> 521 struct Elf_Phdr_Impl<ELFType<TargetEndianness, true>> { 522 LLVM_ELF_IMPORT_TYPES(TargetEndianness, true) 523 Elf_Word p_type; // Type of segment 524 Elf_Word p_flags; // Segment flags 525 Elf_Off p_offset; // FileOffset where segment is located, in bytes 526 Elf_Addr p_vaddr; // Virtual Address of beginning of segment 527 Elf_Addr p_paddr; // Physical address of beginning of segment (OS-specific) 528 Elf_Xword p_filesz; // Num. of bytes in file image of segment (may be zero) 529 Elf_Xword p_memsz; // Num. of bytes in mem image of segment (may be zero) 530 Elf_Xword p_align; // Segment alignment constraint 531 }; 532 533 // ELFT needed for endianness. 534 template <class ELFT> 535 struct Elf_Hash_Impl { 536 LLVM_ELF_IMPORT_TYPES_ELFT(ELFT) 537 Elf_Word nbucket; 538 Elf_Word nchain; 539 540 ArrayRef<Elf_Word> buckets() const { 541 return ArrayRef<Elf_Word>(&nbucket + 2, &nbucket + 2 + nbucket); 542 } 543 544 ArrayRef<Elf_Word> chains() const { 545 return ArrayRef<Elf_Word>(&nbucket + 2 + nbucket, 546 &nbucket + 2 + nbucket + nchain); 547 } 548 }; 549 550 // .gnu.hash section 551 template <class ELFT> 552 struct Elf_GnuHash_Impl { 553 LLVM_ELF_IMPORT_TYPES_ELFT(ELFT) 554 Elf_Word nbuckets; 555 Elf_Word symndx; 556 Elf_Word maskwords; 557 Elf_Word shift2; 558 559 ArrayRef<Elf_Off> filter() const { 560 return ArrayRef<Elf_Off>(reinterpret_cast<const Elf_Off *>(&shift2 + 1), 561 maskwords); 562 } 563 564 ArrayRef<Elf_Word> buckets() const { 565 return ArrayRef<Elf_Word>( 566 reinterpret_cast<const Elf_Word *>(filter().end()), nbuckets); 567 } 568 569 ArrayRef<Elf_Word> values(unsigned DynamicSymCount) const { 570 assert(DynamicSymCount >= symndx); 571 return ArrayRef<Elf_Word>(buckets().end(), DynamicSymCount - symndx); 572 } 573 }; 574 575 // Compressed section headers. 576 // http://www.sco.com/developers/gabi/latest/ch4.sheader.html#compression_header 577 template <endianness TargetEndianness> 578 struct Elf_Chdr_Impl<ELFType<TargetEndianness, false>> { 579 LLVM_ELF_IMPORT_TYPES(TargetEndianness, false) 580 Elf_Word ch_type; 581 Elf_Word ch_size; 582 Elf_Word ch_addralign; 583 }; 584 585 template <endianness TargetEndianness> 586 struct Elf_Chdr_Impl<ELFType<TargetEndianness, true>> { 587 LLVM_ELF_IMPORT_TYPES(TargetEndianness, true) 588 Elf_Word ch_type; 589 Elf_Word ch_reserved; 590 Elf_Xword ch_size; 591 Elf_Xword ch_addralign; 592 }; 593 594 /// Note header 595 template <class ELFT> 596 struct Elf_Nhdr_Impl { 597 LLVM_ELF_IMPORT_TYPES_ELFT(ELFT) 598 Elf_Word n_namesz; 599 Elf_Word n_descsz; 600 Elf_Word n_type; 601 602 /// The alignment of the name and descriptor. 603 /// 604 /// Implementations differ from the specification here: in practice all 605 /// variants align both the name and descriptor to 4-bytes. 606 static const unsigned int Align = 4; 607 608 /// Get the size of the note, including name, descriptor, and padding. 609 size_t getSize() const { 610 return sizeof(*this) + alignTo<Align>(n_namesz) + alignTo<Align>(n_descsz); 611 } 612 }; 613 614 /// An ELF note. 615 /// 616 /// Wraps a note header, providing methods for accessing the name and 617 /// descriptor safely. 618 template <class ELFT> 619 class Elf_Note_Impl { 620 LLVM_ELF_IMPORT_TYPES_ELFT(ELFT) 621 622 const Elf_Nhdr_Impl<ELFT> &Nhdr; 623 624 template <class NoteIteratorELFT> friend class Elf_Note_Iterator_Impl; 625 626 public: 627 Elf_Note_Impl(const Elf_Nhdr_Impl<ELFT> &Nhdr) : Nhdr(Nhdr) {} 628 629 /// Get the note's name, excluding the terminating null byte. 630 StringRef getName() const { 631 if (!Nhdr.n_namesz) 632 return StringRef(); 633 return StringRef(reinterpret_cast<const char *>(&Nhdr) + sizeof(Nhdr), 634 Nhdr.n_namesz - 1); 635 } 636 637 /// Get the note's descriptor. 638 ArrayRef<uint8_t> getDesc() const { 639 if (!Nhdr.n_descsz) 640 return ArrayRef<uint8_t>(); 641 return ArrayRef<uint8_t>( 642 reinterpret_cast<const uint8_t *>(&Nhdr) + sizeof(Nhdr) + 643 alignTo<Elf_Nhdr_Impl<ELFT>::Align>(Nhdr.n_namesz), 644 Nhdr.n_descsz); 645 } 646 647 /// Get the note's descriptor as StringRef 648 StringRef getDescAsStringRef() const { 649 ArrayRef<uint8_t> Desc = getDesc(); 650 return StringRef(reinterpret_cast<const char *>(Desc.data()), Desc.size()); 651 } 652 653 /// Get the note's type. 654 Elf_Word getType() const { return Nhdr.n_type; } 655 }; 656 657 template <class ELFT> class Elf_Note_Iterator_Impl { 658 public: 659 using iterator_category = std::forward_iterator_tag; 660 using value_type = Elf_Note_Impl<ELFT>; 661 using difference_type = std::ptrdiff_t; 662 using pointer = value_type *; 663 using reference = value_type &; 664 665 private: 666 // Nhdr being a nullptr marks the end of iteration. 667 const Elf_Nhdr_Impl<ELFT> *Nhdr = nullptr; 668 size_t RemainingSize = 0u; 669 Error *Err = nullptr; 670 671 template <class ELFFileELFT> friend class ELFFile; 672 673 // Stop iteration and indicate an overflow. 674 void stopWithOverflowError() { 675 Nhdr = nullptr; 676 *Err = make_error<StringError>("ELF note overflows container", 677 object_error::parse_failed); 678 } 679 680 // Advance Nhdr by NoteSize bytes, starting from NhdrPos. 681 // 682 // Assumes NoteSize <= RemainingSize. Ensures Nhdr->getSize() <= RemainingSize 683 // upon returning. Handles stopping iteration when reaching the end of the 684 // container, either cleanly or with an overflow error. 685 void advanceNhdr(const uint8_t *NhdrPos, size_t NoteSize) { 686 RemainingSize -= NoteSize; 687 if (RemainingSize == 0u) { 688 // Ensure that if the iterator walks to the end, the error is checked 689 // afterwards. 690 *Err = Error::success(); 691 Nhdr = nullptr; 692 } else if (sizeof(*Nhdr) > RemainingSize) 693 stopWithOverflowError(); 694 else { 695 Nhdr = reinterpret_cast<const Elf_Nhdr_Impl<ELFT> *>(NhdrPos + NoteSize); 696 if (Nhdr->getSize() > RemainingSize) 697 stopWithOverflowError(); 698 else 699 *Err = Error::success(); 700 } 701 } 702 703 Elf_Note_Iterator_Impl() = default; 704 explicit Elf_Note_Iterator_Impl(Error &Err) : Err(&Err) {} 705 Elf_Note_Iterator_Impl(const uint8_t *Start, size_t Size, Error &Err) 706 : RemainingSize(Size), Err(&Err) { 707 consumeError(std::move(Err)); 708 assert(Start && "ELF note iterator starting at NULL"); 709 advanceNhdr(Start, 0u); 710 } 711 712 public: 713 Elf_Note_Iterator_Impl &operator++() { 714 assert(Nhdr && "incremented ELF note end iterator"); 715 const uint8_t *NhdrPos = reinterpret_cast<const uint8_t *>(Nhdr); 716 size_t NoteSize = Nhdr->getSize(); 717 advanceNhdr(NhdrPos, NoteSize); 718 return *this; 719 } 720 bool operator==(Elf_Note_Iterator_Impl Other) const { 721 if (!Nhdr && Other.Err) 722 (void)(bool)(*Other.Err); 723 if (!Other.Nhdr && Err) 724 (void)(bool)(*Err); 725 return Nhdr == Other.Nhdr; 726 } 727 bool operator!=(Elf_Note_Iterator_Impl Other) const { 728 return !(*this == Other); 729 } 730 Elf_Note_Impl<ELFT> operator*() const { 731 assert(Nhdr && "dereferenced ELF note end iterator"); 732 return Elf_Note_Impl<ELFT>(*Nhdr); 733 } 734 }; 735 736 template <class ELFT> struct Elf_CGProfile_Impl { 737 LLVM_ELF_IMPORT_TYPES_ELFT(ELFT) 738 Elf_Xword cgp_weight; 739 }; 740 741 // MIPS .reginfo section 742 template <class ELFT> 743 struct Elf_Mips_RegInfo; 744 745 template <support::endianness TargetEndianness> 746 struct Elf_Mips_RegInfo<ELFType<TargetEndianness, false>> { 747 LLVM_ELF_IMPORT_TYPES(TargetEndianness, false) 748 Elf_Word ri_gprmask; // bit-mask of used general registers 749 Elf_Word ri_cprmask[4]; // bit-mask of used co-processor registers 750 Elf_Addr ri_gp_value; // gp register value 751 }; 752 753 template <support::endianness TargetEndianness> 754 struct Elf_Mips_RegInfo<ELFType<TargetEndianness, true>> { 755 LLVM_ELF_IMPORT_TYPES(TargetEndianness, true) 756 Elf_Word ri_gprmask; // bit-mask of used general registers 757 Elf_Word ri_pad; // unused padding field 758 Elf_Word ri_cprmask[4]; // bit-mask of used co-processor registers 759 Elf_Addr ri_gp_value; // gp register value 760 }; 761 762 // .MIPS.options section 763 template <class ELFT> struct Elf_Mips_Options { 764 LLVM_ELF_IMPORT_TYPES_ELFT(ELFT) 765 uint8_t kind; // Determines interpretation of variable part of descriptor 766 uint8_t size; // Byte size of descriptor, including this header 767 Elf_Half section; // Section header index of section affected, 768 // or 0 for global options 769 Elf_Word info; // Kind-specific information 770 771 Elf_Mips_RegInfo<ELFT> &getRegInfo() { 772 assert(kind == ELF::ODK_REGINFO); 773 return *reinterpret_cast<Elf_Mips_RegInfo<ELFT> *>( 774 (uint8_t *)this + sizeof(Elf_Mips_Options)); 775 } 776 const Elf_Mips_RegInfo<ELFT> &getRegInfo() const { 777 return const_cast<Elf_Mips_Options *>(this)->getRegInfo(); 778 } 779 }; 780 781 // .MIPS.abiflags section content 782 template <class ELFT> struct Elf_Mips_ABIFlags { 783 LLVM_ELF_IMPORT_TYPES_ELFT(ELFT) 784 Elf_Half version; // Version of the structure 785 uint8_t isa_level; // ISA level: 1-5, 32, and 64 786 uint8_t isa_rev; // ISA revision (0 for MIPS I - MIPS V) 787 uint8_t gpr_size; // General purpose registers size 788 uint8_t cpr1_size; // Co-processor 1 registers size 789 uint8_t cpr2_size; // Co-processor 2 registers size 790 uint8_t fp_abi; // Floating-point ABI flag 791 Elf_Word isa_ext; // Processor-specific extension 792 Elf_Word ases; // ASEs flags 793 Elf_Word flags1; // General flags 794 Elf_Word flags2; // General flags 795 }; 796 797 // Struct representing the BBAddrMap for one function. 798 struct BBAddrMap { 799 uint64_t Addr; // Function address 800 // Struct representing the BBAddrMap information for one basic block. 801 struct BBEntry { 802 uint32_t ID; // Unique ID of this basic block. 803 uint32_t Offset; // Offset of basic block relative to function start. 804 uint32_t Size; // Size of the basic block. 805 806 // The following fields are decoded from the Metadata field. The encoding 807 // happens in AsmPrinter.cpp:getBBAddrMapMetadata. 808 bool HasReturn; // If this block ends with a return (or tail call). 809 bool HasTailCall; // If this block ends with a tail call. 810 bool IsEHPad; // If this is an exception handling block. 811 bool CanFallThrough; // If this block can fall through to its next. 812 813 BBEntry(uint32_t ID, uint32_t Offset, uint32_t Size, uint32_t Metadata) 814 : ID(ID), Offset(Offset), Size(Size), HasReturn(Metadata & 1), 815 HasTailCall(Metadata & (1 << 1)), IsEHPad(Metadata & (1 << 2)), 816 CanFallThrough(Metadata & (1 << 3)){}; 817 818 bool operator==(const BBEntry &Other) const { 819 return ID == Other.ID && Offset == Other.Offset && Size == Other.Size && 820 HasReturn == Other.HasReturn && HasTailCall == Other.HasTailCall && 821 IsEHPad == Other.IsEHPad && CanFallThrough == Other.CanFallThrough; 822 } 823 }; 824 std::vector<BBEntry> BBEntries; // Basic block entries for this function. 825 826 // Equality operator for unit testing. 827 bool operator==(const BBAddrMap &Other) const { 828 return Addr == Other.Addr && std::equal(BBEntries.begin(), BBEntries.end(), 829 Other.BBEntries.begin()); 830 } 831 }; 832 833 } // end namespace object. 834 } // end namespace llvm. 835 836 #endif // LLVM_OBJECT_ELFTYPES_H 837