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_Nhdr = typename ELFT::Nhdr; \ 129 using Elf_Note = typename ELFT::Note; \ 130 using Elf_Note_Iterator = typename ELFT::NoteIterator; \ 131 using Elf_CGProfile = typename ELFT::CGProfile; \ 132 using Elf_Dyn_Range = typename ELFT::DynRange; \ 133 using Elf_Shdr_Range = typename ELFT::ShdrRange; \ 134 using Elf_Sym_Range = typename ELFT::SymRange; \ 135 using Elf_Rel_Range = typename ELFT::RelRange; \ 136 using Elf_Rela_Range = typename ELFT::RelaRange; \ 137 using Elf_Relr_Range = typename ELFT::RelrRange; \ 138 using Elf_Phdr_Range = typename ELFT::PhdrRange; 139 140 #define LLVM_ELF_COMMA , 141 #define LLVM_ELF_IMPORT_TYPES(E, W) \ 142 LLVM_ELF_IMPORT_TYPES_ELFT(ELFType<E LLVM_ELF_COMMA W>) 143 144 // Section header. 145 template <class ELFT> struct Elf_Shdr_Base; 146 147 template <endianness TargetEndianness> 148 struct Elf_Shdr_Base<ELFType<TargetEndianness, false>> { 149 LLVM_ELF_IMPORT_TYPES(TargetEndianness, false) 150 Elf_Word sh_name; // Section name (index into string table) 151 Elf_Word sh_type; // Section type (SHT_*) 152 Elf_Word sh_flags; // Section flags (SHF_*) 153 Elf_Addr sh_addr; // Address where section is to be loaded 154 Elf_Off sh_offset; // File offset of section data, in bytes 155 Elf_Word sh_size; // Size of section, in bytes 156 Elf_Word sh_link; // Section type-specific header table index link 157 Elf_Word sh_info; // Section type-specific extra information 158 Elf_Word sh_addralign; // Section address alignment 159 Elf_Word sh_entsize; // Size of records contained within the section 160 }; 161 162 template <endianness TargetEndianness> 163 struct Elf_Shdr_Base<ELFType<TargetEndianness, true>> { 164 LLVM_ELF_IMPORT_TYPES(TargetEndianness, true) 165 Elf_Word sh_name; // Section name (index into string table) 166 Elf_Word sh_type; // Section type (SHT_*) 167 Elf_Xword sh_flags; // Section flags (SHF_*) 168 Elf_Addr sh_addr; // Address where section is to be loaded 169 Elf_Off sh_offset; // File offset of section data, in bytes 170 Elf_Xword sh_size; // Size of section, in bytes 171 Elf_Word sh_link; // Section type-specific header table index link 172 Elf_Word sh_info; // Section type-specific extra information 173 Elf_Xword sh_addralign; // Section address alignment 174 Elf_Xword sh_entsize; // Size of records contained within the section 175 }; 176 177 template <class ELFT> 178 struct Elf_Shdr_Impl : Elf_Shdr_Base<ELFT> { 179 using Elf_Shdr_Base<ELFT>::sh_entsize; 180 using Elf_Shdr_Base<ELFT>::sh_size; 181 182 /// Get the number of entities this section contains if it has any. 183 unsigned getEntityCount() const { 184 if (sh_entsize == 0) 185 return 0; 186 return sh_size / sh_entsize; 187 } 188 }; 189 190 template <class ELFT> struct Elf_Sym_Base; 191 192 template <endianness TargetEndianness> 193 struct Elf_Sym_Base<ELFType<TargetEndianness, false>> { 194 LLVM_ELF_IMPORT_TYPES(TargetEndianness, false) 195 Elf_Word st_name; // Symbol name (index into string table) 196 Elf_Addr st_value; // Value or address associated with the symbol 197 Elf_Word st_size; // Size of the symbol 198 unsigned char st_info; // Symbol's type and binding attributes 199 unsigned char st_other; // Must be zero; reserved 200 Elf_Half st_shndx; // Which section (header table index) it's defined in 201 }; 202 203 template <endianness TargetEndianness> 204 struct Elf_Sym_Base<ELFType<TargetEndianness, true>> { 205 LLVM_ELF_IMPORT_TYPES(TargetEndianness, true) 206 Elf_Word st_name; // Symbol name (index into string table) 207 unsigned char st_info; // Symbol's type and binding attributes 208 unsigned char st_other; // Must be zero; reserved 209 Elf_Half st_shndx; // Which section (header table index) it's defined in 210 Elf_Addr st_value; // Value or address associated with the symbol 211 Elf_Xword st_size; // Size of the symbol 212 }; 213 214 template <class ELFT> 215 struct Elf_Sym_Impl : Elf_Sym_Base<ELFT> { 216 using Elf_Sym_Base<ELFT>::st_info; 217 using Elf_Sym_Base<ELFT>::st_shndx; 218 using Elf_Sym_Base<ELFT>::st_other; 219 using Elf_Sym_Base<ELFT>::st_value; 220 221 // These accessors and mutators correspond to the ELF32_ST_BIND, 222 // ELF32_ST_TYPE, and ELF32_ST_INFO macros defined in the ELF specification: 223 unsigned char getBinding() const { return st_info >> 4; } 224 unsigned char getType() const { return st_info & 0x0f; } 225 uint64_t getValue() const { return st_value; } 226 void setBinding(unsigned char b) { setBindingAndType(b, getType()); } 227 void setType(unsigned char t) { setBindingAndType(getBinding(), t); } 228 229 void setBindingAndType(unsigned char b, unsigned char t) { 230 st_info = (b << 4) + (t & 0x0f); 231 } 232 233 /// Access to the STV_xxx flag stored in the first two bits of st_other. 234 /// STV_DEFAULT: 0 235 /// STV_INTERNAL: 1 236 /// STV_HIDDEN: 2 237 /// STV_PROTECTED: 3 238 unsigned char getVisibility() const { return st_other & 0x3; } 239 void setVisibility(unsigned char v) { 240 assert(v < 4 && "Invalid value for visibility"); 241 st_other = (st_other & ~0x3) | v; 242 } 243 244 bool isAbsolute() const { return st_shndx == ELF::SHN_ABS; } 245 246 bool isCommon() const { 247 return getType() == ELF::STT_COMMON || st_shndx == ELF::SHN_COMMON; 248 } 249 250 bool isDefined() const { return !isUndefined(); } 251 252 bool isProcessorSpecific() const { 253 return st_shndx >= ELF::SHN_LOPROC && st_shndx <= ELF::SHN_HIPROC; 254 } 255 256 bool isOSSpecific() const { 257 return st_shndx >= ELF::SHN_LOOS && st_shndx <= ELF::SHN_HIOS; 258 } 259 260 bool isReserved() const { 261 // ELF::SHN_HIRESERVE is 0xffff so st_shndx <= ELF::SHN_HIRESERVE is always 262 // true and some compilers warn about it. 263 return st_shndx >= ELF::SHN_LORESERVE; 264 } 265 266 bool isUndefined() const { return st_shndx == ELF::SHN_UNDEF; } 267 268 bool isExternal() const { 269 return getBinding() != ELF::STB_LOCAL; 270 } 271 272 Expected<StringRef> getName(StringRef StrTab) const; 273 }; 274 275 template <class ELFT> 276 Expected<StringRef> Elf_Sym_Impl<ELFT>::getName(StringRef StrTab) const { 277 uint32_t Offset = this->st_name; 278 if (Offset >= StrTab.size()) 279 return createStringError(object_error::parse_failed, 280 "st_name (0x%" PRIx32 281 ") is past the end of the string table" 282 " of size 0x%zx", 283 Offset, StrTab.size()); 284 return StringRef(StrTab.data() + Offset); 285 } 286 287 /// Elf_Versym: This is the structure of entries in the SHT_GNU_versym section 288 /// (.gnu.version). This structure is identical for ELF32 and ELF64. 289 template <class ELFT> 290 struct Elf_Versym_Impl { 291 LLVM_ELF_IMPORT_TYPES_ELFT(ELFT) 292 Elf_Half vs_index; // Version index with flags (e.g. VERSYM_HIDDEN) 293 }; 294 295 /// Elf_Verdef: This is the structure of entries in the SHT_GNU_verdef section 296 /// (.gnu.version_d). This structure is identical for ELF32 and ELF64. 297 template <class ELFT> 298 struct Elf_Verdef_Impl { 299 LLVM_ELF_IMPORT_TYPES_ELFT(ELFT) 300 Elf_Half vd_version; // Version of this structure (e.g. VER_DEF_CURRENT) 301 Elf_Half vd_flags; // Bitwise flags (VER_DEF_*) 302 Elf_Half vd_ndx; // Version index, used in .gnu.version entries 303 Elf_Half vd_cnt; // Number of Verdaux entries 304 Elf_Word vd_hash; // Hash of name 305 Elf_Word vd_aux; // Offset to the first Verdaux entry (in bytes) 306 Elf_Word vd_next; // Offset to the next Verdef entry (in bytes) 307 308 /// Get the first Verdaux entry for this Verdef. 309 const Elf_Verdaux *getAux() const { 310 return reinterpret_cast<const Elf_Verdaux *>((const char *)this + vd_aux); 311 } 312 }; 313 314 /// Elf_Verdaux: This is the structure of auxiliary data in the SHT_GNU_verdef 315 /// section (.gnu.version_d). This structure is identical for ELF32 and ELF64. 316 template <class ELFT> 317 struct Elf_Verdaux_Impl { 318 LLVM_ELF_IMPORT_TYPES_ELFT(ELFT) 319 Elf_Word vda_name; // Version name (offset in string table) 320 Elf_Word vda_next; // Offset to next Verdaux entry (in bytes) 321 }; 322 323 /// Elf_Verneed: This is the structure of entries in the SHT_GNU_verneed 324 /// section (.gnu.version_r). This structure is identical for ELF32 and ELF64. 325 template <class ELFT> 326 struct Elf_Verneed_Impl { 327 LLVM_ELF_IMPORT_TYPES_ELFT(ELFT) 328 Elf_Half vn_version; // Version of this structure (e.g. VER_NEED_CURRENT) 329 Elf_Half vn_cnt; // Number of associated Vernaux entries 330 Elf_Word vn_file; // Library name (string table offset) 331 Elf_Word vn_aux; // Offset to first Vernaux entry (in bytes) 332 Elf_Word vn_next; // Offset to next Verneed entry (in bytes) 333 }; 334 335 /// Elf_Vernaux: This is the structure of auxiliary data in SHT_GNU_verneed 336 /// section (.gnu.version_r). This structure is identical for ELF32 and ELF64. 337 template <class ELFT> 338 struct Elf_Vernaux_Impl { 339 LLVM_ELF_IMPORT_TYPES_ELFT(ELFT) 340 Elf_Word vna_hash; // Hash of dependency name 341 Elf_Half vna_flags; // Bitwise Flags (VER_FLAG_*) 342 Elf_Half vna_other; // Version index, used in .gnu.version entries 343 Elf_Word vna_name; // Dependency name 344 Elf_Word vna_next; // Offset to next Vernaux entry (in bytes) 345 }; 346 347 /// Elf_Dyn_Base: This structure matches the form of entries in the dynamic 348 /// table section (.dynamic) look like. 349 template <class ELFT> struct Elf_Dyn_Base; 350 351 template <endianness TargetEndianness> 352 struct Elf_Dyn_Base<ELFType<TargetEndianness, false>> { 353 LLVM_ELF_IMPORT_TYPES(TargetEndianness, false) 354 Elf_Sword d_tag; 355 union { 356 Elf_Word d_val; 357 Elf_Addr d_ptr; 358 } d_un; 359 }; 360 361 template <endianness TargetEndianness> 362 struct Elf_Dyn_Base<ELFType<TargetEndianness, true>> { 363 LLVM_ELF_IMPORT_TYPES(TargetEndianness, true) 364 Elf_Sxword d_tag; 365 union { 366 Elf_Xword d_val; 367 Elf_Addr d_ptr; 368 } d_un; 369 }; 370 371 /// Elf_Dyn_Impl: This inherits from Elf_Dyn_Base, adding getters. 372 template <class ELFT> 373 struct Elf_Dyn_Impl : Elf_Dyn_Base<ELFT> { 374 using Elf_Dyn_Base<ELFT>::d_tag; 375 using Elf_Dyn_Base<ELFT>::d_un; 376 using intX_t = std::conditional_t<ELFT::Is64Bits, int64_t, int32_t>; 377 using uintX_t = std::conditional_t<ELFT::Is64Bits, uint64_t, uint32_t>; 378 intX_t getTag() const { return d_tag; } 379 uintX_t getVal() const { return d_un.d_val; } 380 uintX_t getPtr() const { return d_un.d_ptr; } 381 }; 382 383 template <endianness TargetEndianness> 384 struct Elf_Rel_Impl<ELFType<TargetEndianness, false>, false> { 385 LLVM_ELF_IMPORT_TYPES(TargetEndianness, false) 386 static const bool IsRela = false; 387 Elf_Addr r_offset; // Location (file byte offset, or program virtual addr) 388 Elf_Word r_info; // Symbol table index and type of relocation to apply 389 390 uint32_t getRInfo(bool isMips64EL) const { 391 assert(!isMips64EL); 392 return r_info; 393 } 394 void setRInfo(uint32_t R, bool IsMips64EL) { 395 assert(!IsMips64EL); 396 r_info = R; 397 } 398 399 // These accessors and mutators correspond to the ELF32_R_SYM, ELF32_R_TYPE, 400 // and ELF32_R_INFO macros defined in the ELF specification: 401 uint32_t getSymbol(bool isMips64EL) const { 402 return this->getRInfo(isMips64EL) >> 8; 403 } 404 unsigned char getType(bool isMips64EL) const { 405 return (unsigned char)(this->getRInfo(isMips64EL) & 0x0ff); 406 } 407 void setSymbol(uint32_t s, bool IsMips64EL) { 408 setSymbolAndType(s, getType(IsMips64EL), IsMips64EL); 409 } 410 void setType(unsigned char t, bool IsMips64EL) { 411 setSymbolAndType(getSymbol(IsMips64EL), t, IsMips64EL); 412 } 413 void setSymbolAndType(uint32_t s, unsigned char t, bool IsMips64EL) { 414 this->setRInfo((s << 8) + t, IsMips64EL); 415 } 416 }; 417 418 template <endianness TargetEndianness> 419 struct Elf_Rel_Impl<ELFType<TargetEndianness, false>, true> 420 : public Elf_Rel_Impl<ELFType<TargetEndianness, false>, false> { 421 LLVM_ELF_IMPORT_TYPES(TargetEndianness, false) 422 static const bool IsRela = true; 423 Elf_Sword r_addend; // Compute value for relocatable field by adding this 424 }; 425 426 template <endianness TargetEndianness> 427 struct Elf_Rel_Impl<ELFType<TargetEndianness, true>, false> { 428 LLVM_ELF_IMPORT_TYPES(TargetEndianness, true) 429 static const bool IsRela = false; 430 Elf_Addr r_offset; // Location (file byte offset, or program virtual addr) 431 Elf_Xword r_info; // Symbol table index and type of relocation to apply 432 433 uint64_t getRInfo(bool isMips64EL) const { 434 uint64_t t = r_info; 435 if (!isMips64EL) 436 return t; 437 // Mips64 little endian has a "special" encoding of r_info. Instead of one 438 // 64 bit little endian number, it is a little endian 32 bit number followed 439 // by a 32 bit big endian number. 440 return (t << 32) | ((t >> 8) & 0xff000000) | ((t >> 24) & 0x00ff0000) | 441 ((t >> 40) & 0x0000ff00) | ((t >> 56) & 0x000000ff); 442 } 443 444 void setRInfo(uint64_t R, bool IsMips64EL) { 445 if (IsMips64EL) 446 r_info = (R >> 32) | ((R & 0xff000000) << 8) | ((R & 0x00ff0000) << 24) | 447 ((R & 0x0000ff00) << 40) | ((R & 0x000000ff) << 56); 448 else 449 r_info = R; 450 } 451 452 // These accessors and mutators correspond to the ELF64_R_SYM, ELF64_R_TYPE, 453 // and ELF64_R_INFO macros defined in the ELF specification: 454 uint32_t getSymbol(bool isMips64EL) const { 455 return (uint32_t)(this->getRInfo(isMips64EL) >> 32); 456 } 457 uint32_t getType(bool isMips64EL) const { 458 return (uint32_t)(this->getRInfo(isMips64EL) & 0xffffffffL); 459 } 460 void setSymbol(uint32_t s, bool IsMips64EL) { 461 setSymbolAndType(s, getType(IsMips64EL), IsMips64EL); 462 } 463 void setType(uint32_t t, bool IsMips64EL) { 464 setSymbolAndType(getSymbol(IsMips64EL), t, IsMips64EL); 465 } 466 void setSymbolAndType(uint32_t s, uint32_t t, bool IsMips64EL) { 467 this->setRInfo(((uint64_t)s << 32) + (t & 0xffffffffL), IsMips64EL); 468 } 469 }; 470 471 template <endianness TargetEndianness> 472 struct Elf_Rel_Impl<ELFType<TargetEndianness, true>, true> 473 : public Elf_Rel_Impl<ELFType<TargetEndianness, true>, false> { 474 LLVM_ELF_IMPORT_TYPES(TargetEndianness, true) 475 static const bool IsRela = true; 476 Elf_Sxword r_addend; // Compute value for relocatable field by adding this. 477 }; 478 479 template <class ELFT> 480 struct Elf_Ehdr_Impl { 481 LLVM_ELF_IMPORT_TYPES_ELFT(ELFT) 482 unsigned char e_ident[ELF::EI_NIDENT]; // ELF Identification bytes 483 Elf_Half e_type; // Type of file (see ET_*) 484 Elf_Half e_machine; // Required architecture for this file (see EM_*) 485 Elf_Word e_version; // Must be equal to 1 486 Elf_Addr e_entry; // Address to jump to in order to start program 487 Elf_Off e_phoff; // Program header table's file offset, in bytes 488 Elf_Off e_shoff; // Section header table's file offset, in bytes 489 Elf_Word e_flags; // Processor-specific flags 490 Elf_Half e_ehsize; // Size of ELF header, in bytes 491 Elf_Half e_phentsize; // Size of an entry in the program header table 492 Elf_Half e_phnum; // Number of entries in the program header table 493 Elf_Half e_shentsize; // Size of an entry in the section header table 494 Elf_Half e_shnum; // Number of entries in the section header table 495 Elf_Half e_shstrndx; // Section header table index of section name 496 // string table 497 498 bool checkMagic() const { 499 return (memcmp(e_ident, ELF::ElfMagic, strlen(ELF::ElfMagic))) == 0; 500 } 501 502 unsigned char getFileClass() const { return e_ident[ELF::EI_CLASS]; } 503 unsigned char getDataEncoding() const { return e_ident[ELF::EI_DATA]; } 504 }; 505 506 template <endianness TargetEndianness> 507 struct Elf_Phdr_Impl<ELFType<TargetEndianness, false>> { 508 LLVM_ELF_IMPORT_TYPES(TargetEndianness, false) 509 Elf_Word p_type; // Type of segment 510 Elf_Off p_offset; // FileOffset where segment is located, in bytes 511 Elf_Addr p_vaddr; // Virtual Address of beginning of segment 512 Elf_Addr p_paddr; // Physical address of beginning of segment (OS-specific) 513 Elf_Word p_filesz; // Num. of bytes in file image of segment (may be zero) 514 Elf_Word p_memsz; // Num. of bytes in mem image of segment (may be zero) 515 Elf_Word p_flags; // Segment flags 516 Elf_Word p_align; // Segment alignment constraint 517 }; 518 519 template <endianness TargetEndianness> 520 struct Elf_Phdr_Impl<ELFType<TargetEndianness, true>> { 521 LLVM_ELF_IMPORT_TYPES(TargetEndianness, true) 522 Elf_Word p_type; // Type of segment 523 Elf_Word p_flags; // Segment flags 524 Elf_Off p_offset; // FileOffset where segment is located, in bytes 525 Elf_Addr p_vaddr; // Virtual Address of beginning of segment 526 Elf_Addr p_paddr; // Physical address of beginning of segment (OS-specific) 527 Elf_Xword p_filesz; // Num. of bytes in file image of segment (may be zero) 528 Elf_Xword p_memsz; // Num. of bytes in mem image of segment (may be zero) 529 Elf_Xword p_align; // Segment alignment constraint 530 }; 531 532 // ELFT needed for endianness. 533 template <class ELFT> 534 struct Elf_Hash_Impl { 535 LLVM_ELF_IMPORT_TYPES_ELFT(ELFT) 536 Elf_Word nbucket; 537 Elf_Word nchain; 538 539 ArrayRef<Elf_Word> buckets() const { 540 return ArrayRef<Elf_Word>(&nbucket + 2, &nbucket + 2 + nbucket); 541 } 542 543 ArrayRef<Elf_Word> chains() const { 544 return ArrayRef<Elf_Word>(&nbucket + 2 + nbucket, 545 &nbucket + 2 + nbucket + nchain); 546 } 547 }; 548 549 // .gnu.hash section 550 template <class ELFT> 551 struct Elf_GnuHash_Impl { 552 LLVM_ELF_IMPORT_TYPES_ELFT(ELFT) 553 Elf_Word nbuckets; 554 Elf_Word symndx; 555 Elf_Word maskwords; 556 Elf_Word shift2; 557 558 ArrayRef<Elf_Off> filter() const { 559 return ArrayRef<Elf_Off>(reinterpret_cast<const Elf_Off *>(&shift2 + 1), 560 maskwords); 561 } 562 563 ArrayRef<Elf_Word> buckets() const { 564 return ArrayRef<Elf_Word>( 565 reinterpret_cast<const Elf_Word *>(filter().end()), nbuckets); 566 } 567 568 ArrayRef<Elf_Word> values(unsigned DynamicSymCount) const { 569 assert(DynamicSymCount >= symndx); 570 return ArrayRef<Elf_Word>(buckets().end(), DynamicSymCount - symndx); 571 } 572 }; 573 574 // Compressed section headers. 575 // http://www.sco.com/developers/gabi/latest/ch4.sheader.html#compression_header 576 template <endianness TargetEndianness> 577 struct Elf_Chdr_Impl<ELFType<TargetEndianness, false>> { 578 LLVM_ELF_IMPORT_TYPES(TargetEndianness, false) 579 Elf_Word ch_type; 580 Elf_Word ch_size; 581 Elf_Word ch_addralign; 582 }; 583 584 template <endianness TargetEndianness> 585 struct Elf_Chdr_Impl<ELFType<TargetEndianness, true>> { 586 LLVM_ELF_IMPORT_TYPES(TargetEndianness, true) 587 Elf_Word ch_type; 588 Elf_Word ch_reserved; 589 Elf_Xword ch_size; 590 Elf_Xword ch_addralign; 591 }; 592 593 /// Note header 594 template <class ELFT> 595 struct Elf_Nhdr_Impl { 596 LLVM_ELF_IMPORT_TYPES_ELFT(ELFT) 597 Elf_Word n_namesz; 598 Elf_Word n_descsz; 599 Elf_Word n_type; 600 601 /// The alignment of the name and descriptor. 602 /// 603 /// Implementations differ from the specification here: in practice all 604 /// variants align both the name and descriptor to 4-bytes. 605 static const unsigned int Align = 4; 606 607 /// Get the size of the note, including name, descriptor, and padding. 608 size_t getSize() const { 609 return sizeof(*this) + alignTo<Align>(n_namesz) + alignTo<Align>(n_descsz); 610 } 611 }; 612 613 /// An ELF note. 614 /// 615 /// Wraps a note header, providing methods for accessing the name and 616 /// descriptor safely. 617 template <class ELFT> 618 class Elf_Note_Impl { 619 LLVM_ELF_IMPORT_TYPES_ELFT(ELFT) 620 621 const Elf_Nhdr_Impl<ELFT> &Nhdr; 622 623 template <class NoteIteratorELFT> friend class Elf_Note_Iterator_Impl; 624 625 public: 626 Elf_Note_Impl(const Elf_Nhdr_Impl<ELFT> &Nhdr) : Nhdr(Nhdr) {} 627 628 /// Get the note's name, excluding the terminating null byte. 629 StringRef getName() const { 630 if (!Nhdr.n_namesz) 631 return StringRef(); 632 return StringRef(reinterpret_cast<const char *>(&Nhdr) + sizeof(Nhdr), 633 Nhdr.n_namesz - 1); 634 } 635 636 /// Get the note's descriptor. 637 ArrayRef<uint8_t> getDesc() const { 638 if (!Nhdr.n_descsz) 639 return ArrayRef<uint8_t>(); 640 return ArrayRef<uint8_t>( 641 reinterpret_cast<const uint8_t *>(&Nhdr) + sizeof(Nhdr) + 642 alignTo<Elf_Nhdr_Impl<ELFT>::Align>(Nhdr.n_namesz), 643 Nhdr.n_descsz); 644 } 645 646 /// Get the note's descriptor as StringRef 647 StringRef getDescAsStringRef() const { 648 ArrayRef<uint8_t> Desc = getDesc(); 649 return StringRef(reinterpret_cast<const char *>(Desc.data()), Desc.size()); 650 } 651 652 /// Get the note's type. 653 Elf_Word getType() const { return Nhdr.n_type; } 654 }; 655 656 template <class ELFT> class Elf_Note_Iterator_Impl { 657 public: 658 using iterator_category = std::forward_iterator_tag; 659 using value_type = Elf_Note_Impl<ELFT>; 660 using difference_type = std::ptrdiff_t; 661 using pointer = value_type *; 662 using reference = value_type &; 663 664 private: 665 // Nhdr being a nullptr marks the end of iteration. 666 const Elf_Nhdr_Impl<ELFT> *Nhdr = nullptr; 667 size_t RemainingSize = 0u; 668 Error *Err = nullptr; 669 670 template <class ELFFileELFT> friend class ELFFile; 671 672 // Stop iteration and indicate an overflow. 673 void stopWithOverflowError() { 674 Nhdr = nullptr; 675 *Err = make_error<StringError>("ELF note overflows container", 676 object_error::parse_failed); 677 } 678 679 // Advance Nhdr by NoteSize bytes, starting from NhdrPos. 680 // 681 // Assumes NoteSize <= RemainingSize. Ensures Nhdr->getSize() <= RemainingSize 682 // upon returning. Handles stopping iteration when reaching the end of the 683 // container, either cleanly or with an overflow error. 684 void advanceNhdr(const uint8_t *NhdrPos, size_t NoteSize) { 685 RemainingSize -= NoteSize; 686 if (RemainingSize == 0u) { 687 // Ensure that if the iterator walks to the end, the error is checked 688 // afterwards. 689 *Err = Error::success(); 690 Nhdr = nullptr; 691 } else if (sizeof(*Nhdr) > RemainingSize) 692 stopWithOverflowError(); 693 else { 694 Nhdr = reinterpret_cast<const Elf_Nhdr_Impl<ELFT> *>(NhdrPos + NoteSize); 695 if (Nhdr->getSize() > RemainingSize) 696 stopWithOverflowError(); 697 else 698 *Err = Error::success(); 699 } 700 } 701 702 Elf_Note_Iterator_Impl() = default; 703 explicit Elf_Note_Iterator_Impl(Error &Err) : Err(&Err) {} 704 Elf_Note_Iterator_Impl(const uint8_t *Start, size_t Size, Error &Err) 705 : RemainingSize(Size), Err(&Err) { 706 consumeError(std::move(Err)); 707 assert(Start && "ELF note iterator starting at NULL"); 708 advanceNhdr(Start, 0u); 709 } 710 711 public: 712 Elf_Note_Iterator_Impl &operator++() { 713 assert(Nhdr && "incremented ELF note end iterator"); 714 const uint8_t *NhdrPos = reinterpret_cast<const uint8_t *>(Nhdr); 715 size_t NoteSize = Nhdr->getSize(); 716 advanceNhdr(NhdrPos, NoteSize); 717 return *this; 718 } 719 bool operator==(Elf_Note_Iterator_Impl Other) const { 720 if (!Nhdr && Other.Err) 721 (void)(bool)(*Other.Err); 722 if (!Other.Nhdr && Err) 723 (void)(bool)(*Err); 724 return Nhdr == Other.Nhdr; 725 } 726 bool operator!=(Elf_Note_Iterator_Impl Other) const { 727 return !(*this == Other); 728 } 729 Elf_Note_Impl<ELFT> operator*() const { 730 assert(Nhdr && "dereferenced ELF note end iterator"); 731 return Elf_Note_Impl<ELFT>(*Nhdr); 732 } 733 }; 734 735 template <class ELFT> struct Elf_CGProfile_Impl { 736 LLVM_ELF_IMPORT_TYPES_ELFT(ELFT) 737 Elf_Xword cgp_weight; 738 }; 739 740 // MIPS .reginfo section 741 template <class ELFT> 742 struct Elf_Mips_RegInfo; 743 744 template <support::endianness TargetEndianness> 745 struct Elf_Mips_RegInfo<ELFType<TargetEndianness, false>> { 746 LLVM_ELF_IMPORT_TYPES(TargetEndianness, false) 747 Elf_Word ri_gprmask; // bit-mask of used general registers 748 Elf_Word ri_cprmask[4]; // bit-mask of used co-processor registers 749 Elf_Addr ri_gp_value; // gp register value 750 }; 751 752 template <support::endianness TargetEndianness> 753 struct Elf_Mips_RegInfo<ELFType<TargetEndianness, true>> { 754 LLVM_ELF_IMPORT_TYPES(TargetEndianness, true) 755 Elf_Word ri_gprmask; // bit-mask of used general registers 756 Elf_Word ri_pad; // unused padding field 757 Elf_Word ri_cprmask[4]; // bit-mask of used co-processor registers 758 Elf_Addr ri_gp_value; // gp register value 759 }; 760 761 // .MIPS.options section 762 template <class ELFT> struct Elf_Mips_Options { 763 LLVM_ELF_IMPORT_TYPES_ELFT(ELFT) 764 uint8_t kind; // Determines interpretation of variable part of descriptor 765 uint8_t size; // Byte size of descriptor, including this header 766 Elf_Half section; // Section header index of section affected, 767 // or 0 for global options 768 Elf_Word info; // Kind-specific information 769 770 Elf_Mips_RegInfo<ELFT> &getRegInfo() { 771 assert(kind == ELF::ODK_REGINFO); 772 return *reinterpret_cast<Elf_Mips_RegInfo<ELFT> *>( 773 (uint8_t *)this + sizeof(Elf_Mips_Options)); 774 } 775 const Elf_Mips_RegInfo<ELFT> &getRegInfo() const { 776 return const_cast<Elf_Mips_Options *>(this)->getRegInfo(); 777 } 778 }; 779 780 // .MIPS.abiflags section content 781 template <class ELFT> struct Elf_Mips_ABIFlags { 782 LLVM_ELF_IMPORT_TYPES_ELFT(ELFT) 783 Elf_Half version; // Version of the structure 784 uint8_t isa_level; // ISA level: 1-5, 32, and 64 785 uint8_t isa_rev; // ISA revision (0 for MIPS I - MIPS V) 786 uint8_t gpr_size; // General purpose registers size 787 uint8_t cpr1_size; // Co-processor 1 registers size 788 uint8_t cpr2_size; // Co-processor 2 registers size 789 uint8_t fp_abi; // Floating-point ABI flag 790 Elf_Word isa_ext; // Processor-specific extension 791 Elf_Word ases; // ASEs flags 792 Elf_Word flags1; // General flags 793 Elf_Word flags2; // General flags 794 }; 795 796 // Struct representing the BBAddrMap for one function. 797 struct BBAddrMap { 798 uint64_t Addr; // Function address 799 // Struct representing the BBAddrMap information for one basic block. 800 struct BBEntry { 801 uint32_t Offset; // Offset of basic block relative to function start. 802 uint32_t Size; // Size of the basic block. 803 804 // The following fields are decoded from the Metadata field. The encoding 805 // happens in AsmPrinter.cpp:getBBAddrMapMetadata. 806 bool HasReturn; // If this block ends with a return (or tail call). 807 bool HasTailCall; // If this block ends with a tail call. 808 bool IsEHPad; // If this is an exception handling block. 809 bool CanFallThrough; // If this block can fall through to its next. 810 811 BBEntry(uint32_t Offset, uint32_t Size, uint32_t Metadata) 812 : Offset(Offset), Size(Size), HasReturn(Metadata & 1), 813 HasTailCall(Metadata & (1 << 1)), IsEHPad(Metadata & (1 << 2)), 814 CanFallThrough(Metadata & (1 << 3)){}; 815 816 bool operator==(const BBEntry &Other) const { 817 return Offset == Other.Offset && Size == Other.Size && 818 HasReturn == Other.HasReturn && HasTailCall == Other.HasTailCall && 819 IsEHPad == Other.IsEHPad && CanFallThrough == Other.CanFallThrough; 820 } 821 }; 822 std::vector<BBEntry> BBEntries; // Basic block entries for this function. 823 824 // Equality operator for unit testing. 825 bool operator==(const BBAddrMap &Other) const { 826 return Addr == Other.Addr && std::equal(BBEntries.begin(), BBEntries.end(), 827 Other.BBEntries.begin()); 828 } 829 }; 830 831 } // end namespace object. 832 } // end namespace llvm. 833 834 #endif // LLVM_OBJECT_ELFTYPES_H 835