1 //===- ELF.cpp - ELF object file implementation ---------------------------===// 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 #include "llvm/Object/ELF.h" 10 #include "llvm/BinaryFormat/ELF.h" 11 #include "llvm/Support/DataExtractor.h" 12 13 using namespace llvm; 14 using namespace object; 15 16 #define STRINGIFY_ENUM_CASE(ns, name) \ 17 case ns::name: \ 18 return #name; 19 20 #define ELF_RELOC(name, value) STRINGIFY_ENUM_CASE(ELF, name) 21 22 StringRef llvm::object::getELFRelocationTypeName(uint32_t Machine, 23 uint32_t Type) { 24 switch (Machine) { 25 case ELF::EM_68K: 26 switch (Type) { 27 #include "llvm/BinaryFormat/ELFRelocs/M68k.def" 28 default: 29 break; 30 } 31 break; 32 case ELF::EM_X86_64: 33 switch (Type) { 34 #include "llvm/BinaryFormat/ELFRelocs/x86_64.def" 35 default: 36 break; 37 } 38 break; 39 case ELF::EM_386: 40 case ELF::EM_IAMCU: 41 switch (Type) { 42 #include "llvm/BinaryFormat/ELFRelocs/i386.def" 43 default: 44 break; 45 } 46 break; 47 case ELF::EM_MIPS: 48 switch (Type) { 49 #include "llvm/BinaryFormat/ELFRelocs/Mips.def" 50 default: 51 break; 52 } 53 break; 54 case ELF::EM_AARCH64: 55 switch (Type) { 56 #include "llvm/BinaryFormat/ELFRelocs/AArch64.def" 57 default: 58 break; 59 } 60 break; 61 case ELF::EM_ARM: 62 switch (Type) { 63 #include "llvm/BinaryFormat/ELFRelocs/ARM.def" 64 default: 65 break; 66 } 67 break; 68 case ELF::EM_ARC_COMPACT: 69 case ELF::EM_ARC_COMPACT2: 70 switch (Type) { 71 #include "llvm/BinaryFormat/ELFRelocs/ARC.def" 72 default: 73 break; 74 } 75 break; 76 case ELF::EM_AVR: 77 switch (Type) { 78 #include "llvm/BinaryFormat/ELFRelocs/AVR.def" 79 default: 80 break; 81 } 82 break; 83 case ELF::EM_HEXAGON: 84 switch (Type) { 85 #include "llvm/BinaryFormat/ELFRelocs/Hexagon.def" 86 default: 87 break; 88 } 89 break; 90 case ELF::EM_LANAI: 91 switch (Type) { 92 #include "llvm/BinaryFormat/ELFRelocs/Lanai.def" 93 default: 94 break; 95 } 96 break; 97 case ELF::EM_PPC: 98 switch (Type) { 99 #include "llvm/BinaryFormat/ELFRelocs/PowerPC.def" 100 default: 101 break; 102 } 103 break; 104 case ELF::EM_PPC64: 105 switch (Type) { 106 #include "llvm/BinaryFormat/ELFRelocs/PowerPC64.def" 107 default: 108 break; 109 } 110 break; 111 case ELF::EM_RISCV: 112 switch (Type) { 113 #include "llvm/BinaryFormat/ELFRelocs/RISCV.def" 114 default: 115 break; 116 } 117 break; 118 case ELF::EM_S390: 119 switch (Type) { 120 #include "llvm/BinaryFormat/ELFRelocs/SystemZ.def" 121 default: 122 break; 123 } 124 break; 125 case ELF::EM_SPARC: 126 case ELF::EM_SPARC32PLUS: 127 case ELF::EM_SPARCV9: 128 switch (Type) { 129 #include "llvm/BinaryFormat/ELFRelocs/Sparc.def" 130 default: 131 break; 132 } 133 break; 134 case ELF::EM_AMDGPU: 135 switch (Type) { 136 #include "llvm/BinaryFormat/ELFRelocs/AMDGPU.def" 137 default: 138 break; 139 } 140 break; 141 case ELF::EM_BPF: 142 switch (Type) { 143 #include "llvm/BinaryFormat/ELFRelocs/BPF.def" 144 default: 145 break; 146 } 147 break; 148 case ELF::EM_MSP430: 149 switch (Type) { 150 #include "llvm/BinaryFormat/ELFRelocs/MSP430.def" 151 default: 152 break; 153 } 154 break; 155 case ELF::EM_VE: 156 switch (Type) { 157 #include "llvm/BinaryFormat/ELFRelocs/VE.def" 158 default: 159 break; 160 } 161 break; 162 case ELF::EM_CSKY: 163 switch (Type) { 164 #include "llvm/BinaryFormat/ELFRelocs/CSKY.def" 165 default: 166 break; 167 } 168 break; 169 case ELF::EM_LOONGARCH: 170 switch (Type) { 171 #include "llvm/BinaryFormat/ELFRelocs/LoongArch.def" 172 default: 173 break; 174 } 175 break; 176 default: 177 break; 178 } 179 return "Unknown"; 180 } 181 182 #undef ELF_RELOC 183 184 uint32_t llvm::object::getELFRelativeRelocationType(uint32_t Machine) { 185 switch (Machine) { 186 case ELF::EM_X86_64: 187 return ELF::R_X86_64_RELATIVE; 188 case ELF::EM_386: 189 case ELF::EM_IAMCU: 190 return ELF::R_386_RELATIVE; 191 case ELF::EM_MIPS: 192 break; 193 case ELF::EM_AARCH64: 194 return ELF::R_AARCH64_RELATIVE; 195 case ELF::EM_ARM: 196 return ELF::R_ARM_RELATIVE; 197 case ELF::EM_ARC_COMPACT: 198 case ELF::EM_ARC_COMPACT2: 199 return ELF::R_ARC_RELATIVE; 200 case ELF::EM_AVR: 201 break; 202 case ELF::EM_HEXAGON: 203 return ELF::R_HEX_RELATIVE; 204 case ELF::EM_LANAI: 205 break; 206 case ELF::EM_PPC: 207 break; 208 case ELF::EM_PPC64: 209 return ELF::R_PPC64_RELATIVE; 210 case ELF::EM_RISCV: 211 return ELF::R_RISCV_RELATIVE; 212 case ELF::EM_S390: 213 return ELF::R_390_RELATIVE; 214 case ELF::EM_SPARC: 215 case ELF::EM_SPARC32PLUS: 216 case ELF::EM_SPARCV9: 217 return ELF::R_SPARC_RELATIVE; 218 case ELF::EM_CSKY: 219 return ELF::R_CKCORE_RELATIVE; 220 case ELF::EM_VE: 221 return ELF::R_VE_RELATIVE; 222 case ELF::EM_AMDGPU: 223 break; 224 case ELF::EM_BPF: 225 break; 226 default: 227 break; 228 } 229 return 0; 230 } 231 232 StringRef llvm::object::getELFSectionTypeName(uint32_t Machine, unsigned Type) { 233 switch (Machine) { 234 case ELF::EM_ARM: 235 switch (Type) { 236 STRINGIFY_ENUM_CASE(ELF, SHT_ARM_EXIDX); 237 STRINGIFY_ENUM_CASE(ELF, SHT_ARM_PREEMPTMAP); 238 STRINGIFY_ENUM_CASE(ELF, SHT_ARM_ATTRIBUTES); 239 STRINGIFY_ENUM_CASE(ELF, SHT_ARM_DEBUGOVERLAY); 240 STRINGIFY_ENUM_CASE(ELF, SHT_ARM_OVERLAYSECTION); 241 } 242 break; 243 case ELF::EM_HEXAGON: 244 switch (Type) { STRINGIFY_ENUM_CASE(ELF, SHT_HEX_ORDERED); } 245 break; 246 case ELF::EM_X86_64: 247 switch (Type) { STRINGIFY_ENUM_CASE(ELF, SHT_X86_64_UNWIND); } 248 break; 249 case ELF::EM_MIPS: 250 case ELF::EM_MIPS_RS3_LE: 251 switch (Type) { 252 STRINGIFY_ENUM_CASE(ELF, SHT_MIPS_REGINFO); 253 STRINGIFY_ENUM_CASE(ELF, SHT_MIPS_OPTIONS); 254 STRINGIFY_ENUM_CASE(ELF, SHT_MIPS_DWARF); 255 STRINGIFY_ENUM_CASE(ELF, SHT_MIPS_ABIFLAGS); 256 } 257 break; 258 case ELF::EM_MSP430: 259 switch (Type) { STRINGIFY_ENUM_CASE(ELF, SHT_MSP430_ATTRIBUTES); } 260 break; 261 case ELF::EM_RISCV: 262 switch (Type) { STRINGIFY_ENUM_CASE(ELF, SHT_RISCV_ATTRIBUTES); } 263 break; 264 default: 265 break; 266 } 267 268 switch (Type) { 269 STRINGIFY_ENUM_CASE(ELF, SHT_NULL); 270 STRINGIFY_ENUM_CASE(ELF, SHT_PROGBITS); 271 STRINGIFY_ENUM_CASE(ELF, SHT_SYMTAB); 272 STRINGIFY_ENUM_CASE(ELF, SHT_STRTAB); 273 STRINGIFY_ENUM_CASE(ELF, SHT_RELA); 274 STRINGIFY_ENUM_CASE(ELF, SHT_HASH); 275 STRINGIFY_ENUM_CASE(ELF, SHT_DYNAMIC); 276 STRINGIFY_ENUM_CASE(ELF, SHT_NOTE); 277 STRINGIFY_ENUM_CASE(ELF, SHT_NOBITS); 278 STRINGIFY_ENUM_CASE(ELF, SHT_REL); 279 STRINGIFY_ENUM_CASE(ELF, SHT_SHLIB); 280 STRINGIFY_ENUM_CASE(ELF, SHT_DYNSYM); 281 STRINGIFY_ENUM_CASE(ELF, SHT_INIT_ARRAY); 282 STRINGIFY_ENUM_CASE(ELF, SHT_FINI_ARRAY); 283 STRINGIFY_ENUM_CASE(ELF, SHT_PREINIT_ARRAY); 284 STRINGIFY_ENUM_CASE(ELF, SHT_GROUP); 285 STRINGIFY_ENUM_CASE(ELF, SHT_SYMTAB_SHNDX); 286 STRINGIFY_ENUM_CASE(ELF, SHT_RELR); 287 STRINGIFY_ENUM_CASE(ELF, SHT_ANDROID_REL); 288 STRINGIFY_ENUM_CASE(ELF, SHT_ANDROID_RELA); 289 STRINGIFY_ENUM_CASE(ELF, SHT_ANDROID_RELR); 290 STRINGIFY_ENUM_CASE(ELF, SHT_LLVM_ODRTAB); 291 STRINGIFY_ENUM_CASE(ELF, SHT_LLVM_LINKER_OPTIONS); 292 STRINGIFY_ENUM_CASE(ELF, SHT_LLVM_CALL_GRAPH_PROFILE); 293 STRINGIFY_ENUM_CASE(ELF, SHT_LLVM_ADDRSIG); 294 STRINGIFY_ENUM_CASE(ELF, SHT_LLVM_DEPENDENT_LIBRARIES); 295 STRINGIFY_ENUM_CASE(ELF, SHT_LLVM_SYMPART); 296 STRINGIFY_ENUM_CASE(ELF, SHT_LLVM_PART_EHDR); 297 STRINGIFY_ENUM_CASE(ELF, SHT_LLVM_PART_PHDR); 298 STRINGIFY_ENUM_CASE(ELF, SHT_LLVM_BB_ADDR_MAP); 299 STRINGIFY_ENUM_CASE(ELF, SHT_GNU_ATTRIBUTES); 300 STRINGIFY_ENUM_CASE(ELF, SHT_GNU_HASH); 301 STRINGIFY_ENUM_CASE(ELF, SHT_GNU_verdef); 302 STRINGIFY_ENUM_CASE(ELF, SHT_GNU_verneed); 303 STRINGIFY_ENUM_CASE(ELF, SHT_GNU_versym); 304 default: 305 return "Unknown"; 306 } 307 } 308 309 template <class ELFT> 310 std::vector<typename ELFT::Rel> 311 ELFFile<ELFT>::decode_relrs(Elf_Relr_Range relrs) const { 312 // This function decodes the contents of an SHT_RELR packed relocation 313 // section. 314 // 315 // Proposal for adding SHT_RELR sections to generic-abi is here: 316 // https://groups.google.com/forum/#!topic/generic-abi/bX460iggiKg 317 // 318 // The encoded sequence of Elf64_Relr entries in a SHT_RELR section looks 319 // like [ AAAAAAAA BBBBBBB1 BBBBBBB1 ... AAAAAAAA BBBBBB1 ... ] 320 // 321 // i.e. start with an address, followed by any number of bitmaps. The address 322 // entry encodes 1 relocation. The subsequent bitmap entries encode up to 63 323 // relocations each, at subsequent offsets following the last address entry. 324 // 325 // The bitmap entries must have 1 in the least significant bit. The assumption 326 // here is that an address cannot have 1 in lsb. Odd addresses are not 327 // supported. 328 // 329 // Excluding the least significant bit in the bitmap, each non-zero bit in 330 // the bitmap represents a relocation to be applied to a corresponding machine 331 // word that follows the base address word. The second least significant bit 332 // represents the machine word immediately following the initial address, and 333 // each bit that follows represents the next word, in linear order. As such, 334 // a single bitmap can encode up to 31 relocations in a 32-bit object, and 335 // 63 relocations in a 64-bit object. 336 // 337 // This encoding has a couple of interesting properties: 338 // 1. Looking at any entry, it is clear whether it's an address or a bitmap: 339 // even means address, odd means bitmap. 340 // 2. Just a simple list of addresses is a valid encoding. 341 342 Elf_Rel Rel; 343 Rel.r_info = 0; 344 Rel.setType(getRelativeRelocationType(), false); 345 std::vector<Elf_Rel> Relocs; 346 347 // Word type: uint32_t for Elf32, and uint64_t for Elf64. 348 using Addr = typename ELFT::uint; 349 350 Addr Base = 0; 351 for (Elf_Relr R : relrs) { 352 typename ELFT::uint Entry = R; 353 if ((Entry & 1) == 0) { 354 // Even entry: encodes the offset for next relocation. 355 Rel.r_offset = Entry; 356 Relocs.push_back(Rel); 357 // Set base offset for subsequent bitmap entries. 358 Base = Entry + sizeof(Addr); 359 } else { 360 // Odd entry: encodes bitmap for relocations starting at base. 361 for (Addr Offset = Base; (Entry >>= 1) != 0; Offset += sizeof(Addr)) 362 if ((Entry & 1) != 0) { 363 Rel.r_offset = Offset; 364 Relocs.push_back(Rel); 365 } 366 Base += (CHAR_BIT * sizeof(Entry) - 1) * sizeof(Addr); 367 } 368 } 369 370 return Relocs; 371 } 372 373 template <class ELFT> 374 Expected<std::vector<typename ELFT::Rela>> 375 ELFFile<ELFT>::android_relas(const Elf_Shdr &Sec) const { 376 // This function reads relocations in Android's packed relocation format, 377 // which is based on SLEB128 and delta encoding. 378 Expected<ArrayRef<uint8_t>> ContentsOrErr = getSectionContents(Sec); 379 if (!ContentsOrErr) 380 return ContentsOrErr.takeError(); 381 ArrayRef<uint8_t> Content = *ContentsOrErr; 382 if (Content.size() < 4 || Content[0] != 'A' || Content[1] != 'P' || 383 Content[2] != 'S' || Content[3] != '2') 384 return createError("invalid packed relocation header"); 385 DataExtractor Data(Content, isLE(), ELFT::Is64Bits ? 8 : 4); 386 DataExtractor::Cursor Cur(/*Offset=*/4); 387 388 uint64_t NumRelocs = Data.getSLEB128(Cur); 389 uint64_t Offset = Data.getSLEB128(Cur); 390 uint64_t Addend = 0; 391 392 if (!Cur) 393 return std::move(Cur.takeError()); 394 395 std::vector<Elf_Rela> Relocs; 396 Relocs.reserve(NumRelocs); 397 while (NumRelocs) { 398 uint64_t NumRelocsInGroup = Data.getSLEB128(Cur); 399 if (!Cur) 400 return std::move(Cur.takeError()); 401 if (NumRelocsInGroup > NumRelocs) 402 return createError("relocation group unexpectedly large"); 403 NumRelocs -= NumRelocsInGroup; 404 405 uint64_t GroupFlags = Data.getSLEB128(Cur); 406 bool GroupedByInfo = GroupFlags & ELF::RELOCATION_GROUPED_BY_INFO_FLAG; 407 bool GroupedByOffsetDelta = GroupFlags & ELF::RELOCATION_GROUPED_BY_OFFSET_DELTA_FLAG; 408 bool GroupedByAddend = GroupFlags & ELF::RELOCATION_GROUPED_BY_ADDEND_FLAG; 409 bool GroupHasAddend = GroupFlags & ELF::RELOCATION_GROUP_HAS_ADDEND_FLAG; 410 411 uint64_t GroupOffsetDelta; 412 if (GroupedByOffsetDelta) 413 GroupOffsetDelta = Data.getSLEB128(Cur); 414 415 uint64_t GroupRInfo; 416 if (GroupedByInfo) 417 GroupRInfo = Data.getSLEB128(Cur); 418 419 if (GroupedByAddend && GroupHasAddend) 420 Addend += Data.getSLEB128(Cur); 421 422 if (!GroupHasAddend) 423 Addend = 0; 424 425 for (uint64_t I = 0; Cur && I != NumRelocsInGroup; ++I) { 426 Elf_Rela R; 427 Offset += GroupedByOffsetDelta ? GroupOffsetDelta : Data.getSLEB128(Cur); 428 R.r_offset = Offset; 429 R.r_info = GroupedByInfo ? GroupRInfo : Data.getSLEB128(Cur); 430 if (GroupHasAddend && !GroupedByAddend) 431 Addend += Data.getSLEB128(Cur); 432 R.r_addend = Addend; 433 Relocs.push_back(R); 434 } 435 if (!Cur) 436 return std::move(Cur.takeError()); 437 } 438 439 return Relocs; 440 } 441 442 template <class ELFT> 443 std::string ELFFile<ELFT>::getDynamicTagAsString(unsigned Arch, 444 uint64_t Type) const { 445 #define DYNAMIC_STRINGIFY_ENUM(tag, value) \ 446 case value: \ 447 return #tag; 448 449 #define DYNAMIC_TAG(n, v) 450 switch (Arch) { 451 case ELF::EM_AARCH64: 452 switch (Type) { 453 #define AARCH64_DYNAMIC_TAG(name, value) DYNAMIC_STRINGIFY_ENUM(name, value) 454 #include "llvm/BinaryFormat/DynamicTags.def" 455 #undef AARCH64_DYNAMIC_TAG 456 } 457 break; 458 459 case ELF::EM_HEXAGON: 460 switch (Type) { 461 #define HEXAGON_DYNAMIC_TAG(name, value) DYNAMIC_STRINGIFY_ENUM(name, value) 462 #include "llvm/BinaryFormat/DynamicTags.def" 463 #undef HEXAGON_DYNAMIC_TAG 464 } 465 break; 466 467 case ELF::EM_MIPS: 468 switch (Type) { 469 #define MIPS_DYNAMIC_TAG(name, value) DYNAMIC_STRINGIFY_ENUM(name, value) 470 #include "llvm/BinaryFormat/DynamicTags.def" 471 #undef MIPS_DYNAMIC_TAG 472 } 473 break; 474 475 case ELF::EM_PPC: 476 switch (Type) { 477 #define PPC_DYNAMIC_TAG(name, value) DYNAMIC_STRINGIFY_ENUM(name, value) 478 #include "llvm/BinaryFormat/DynamicTags.def" 479 #undef PPC_DYNAMIC_TAG 480 } 481 break; 482 483 case ELF::EM_PPC64: 484 switch (Type) { 485 #define PPC64_DYNAMIC_TAG(name, value) DYNAMIC_STRINGIFY_ENUM(name, value) 486 #include "llvm/BinaryFormat/DynamicTags.def" 487 #undef PPC64_DYNAMIC_TAG 488 } 489 break; 490 491 case ELF::EM_RISCV: 492 switch (Type) { 493 #define RISCV_DYNAMIC_TAG(name, value) DYNAMIC_STRINGIFY_ENUM(name, value) 494 #include "llvm/BinaryFormat/DynamicTags.def" 495 #undef RISCV_DYNAMIC_TAG 496 } 497 break; 498 } 499 #undef DYNAMIC_TAG 500 switch (Type) { 501 // Now handle all dynamic tags except the architecture specific ones 502 #define AARCH64_DYNAMIC_TAG(name, value) 503 #define MIPS_DYNAMIC_TAG(name, value) 504 #define HEXAGON_DYNAMIC_TAG(name, value) 505 #define PPC_DYNAMIC_TAG(name, value) 506 #define PPC64_DYNAMIC_TAG(name, value) 507 #define RISCV_DYNAMIC_TAG(name, value) 508 // Also ignore marker tags such as DT_HIOS (maps to DT_VERNEEDNUM), etc. 509 #define DYNAMIC_TAG_MARKER(name, value) 510 #define DYNAMIC_TAG(name, value) case value: return #name; 511 #include "llvm/BinaryFormat/DynamicTags.def" 512 #undef DYNAMIC_TAG 513 #undef AARCH64_DYNAMIC_TAG 514 #undef MIPS_DYNAMIC_TAG 515 #undef HEXAGON_DYNAMIC_TAG 516 #undef PPC_DYNAMIC_TAG 517 #undef PPC64_DYNAMIC_TAG 518 #undef RISCV_DYNAMIC_TAG 519 #undef DYNAMIC_TAG_MARKER 520 #undef DYNAMIC_STRINGIFY_ENUM 521 default: 522 return "<unknown:>0x" + utohexstr(Type, true); 523 } 524 } 525 526 template <class ELFT> 527 std::string ELFFile<ELFT>::getDynamicTagAsString(uint64_t Type) const { 528 return getDynamicTagAsString(getHeader().e_machine, Type); 529 } 530 531 template <class ELFT> 532 Expected<typename ELFT::DynRange> ELFFile<ELFT>::dynamicEntries() const { 533 ArrayRef<Elf_Dyn> Dyn; 534 535 auto ProgramHeadersOrError = program_headers(); 536 if (!ProgramHeadersOrError) 537 return ProgramHeadersOrError.takeError(); 538 539 for (const Elf_Phdr &Phdr : *ProgramHeadersOrError) { 540 if (Phdr.p_type == ELF::PT_DYNAMIC) { 541 Dyn = makeArrayRef( 542 reinterpret_cast<const Elf_Dyn *>(base() + Phdr.p_offset), 543 Phdr.p_filesz / sizeof(Elf_Dyn)); 544 break; 545 } 546 } 547 548 // If we can't find the dynamic section in the program headers, we just fall 549 // back on the sections. 550 if (Dyn.empty()) { 551 auto SectionsOrError = sections(); 552 if (!SectionsOrError) 553 return SectionsOrError.takeError(); 554 555 for (const Elf_Shdr &Sec : *SectionsOrError) { 556 if (Sec.sh_type == ELF::SHT_DYNAMIC) { 557 Expected<ArrayRef<Elf_Dyn>> DynOrError = 558 getSectionContentsAsArray<Elf_Dyn>(Sec); 559 if (!DynOrError) 560 return DynOrError.takeError(); 561 Dyn = *DynOrError; 562 break; 563 } 564 } 565 566 if (!Dyn.data()) 567 return ArrayRef<Elf_Dyn>(); 568 } 569 570 if (Dyn.empty()) 571 // TODO: this error is untested. 572 return createError("invalid empty dynamic section"); 573 574 if (Dyn.back().d_tag != ELF::DT_NULL) 575 // TODO: this error is untested. 576 return createError("dynamic sections must be DT_NULL terminated"); 577 578 return Dyn; 579 } 580 581 template <class ELFT> 582 Expected<const uint8_t *> 583 ELFFile<ELFT>::toMappedAddr(uint64_t VAddr, WarningHandler WarnHandler) const { 584 auto ProgramHeadersOrError = program_headers(); 585 if (!ProgramHeadersOrError) 586 return ProgramHeadersOrError.takeError(); 587 588 llvm::SmallVector<Elf_Phdr *, 4> LoadSegments; 589 590 for (const Elf_Phdr &Phdr : *ProgramHeadersOrError) 591 if (Phdr.p_type == ELF::PT_LOAD) 592 LoadSegments.push_back(const_cast<Elf_Phdr *>(&Phdr)); 593 594 auto SortPred = [](const Elf_Phdr_Impl<ELFT> *A, 595 const Elf_Phdr_Impl<ELFT> *B) { 596 return A->p_vaddr < B->p_vaddr; 597 }; 598 if (!llvm::is_sorted(LoadSegments, SortPred)) { 599 if (Error E = 600 WarnHandler("loadable segments are unsorted by virtual address")) 601 return std::move(E); 602 llvm::stable_sort(LoadSegments, SortPred); 603 } 604 605 const Elf_Phdr *const *I = llvm::upper_bound( 606 LoadSegments, VAddr, [](uint64_t VAddr, const Elf_Phdr_Impl<ELFT> *Phdr) { 607 return VAddr < Phdr->p_vaddr; 608 }); 609 610 if (I == LoadSegments.begin()) 611 return createError("virtual address is not in any segment: 0x" + 612 Twine::utohexstr(VAddr)); 613 --I; 614 const Elf_Phdr &Phdr = **I; 615 uint64_t Delta = VAddr - Phdr.p_vaddr; 616 if (Delta >= Phdr.p_filesz) 617 return createError("virtual address is not in any segment: 0x" + 618 Twine::utohexstr(VAddr)); 619 620 uint64_t Offset = Phdr.p_offset + Delta; 621 if (Offset >= getBufSize()) 622 return createError("can't map virtual address 0x" + 623 Twine::utohexstr(VAddr) + " to the segment with index " + 624 Twine(&Phdr - (*ProgramHeadersOrError).data() + 1) + 625 ": the segment ends at 0x" + 626 Twine::utohexstr(Phdr.p_offset + Phdr.p_filesz) + 627 ", which is greater than the file size (0x" + 628 Twine::utohexstr(getBufSize()) + ")"); 629 630 return base() + Offset; 631 } 632 633 template <class ELFT> 634 Expected<std::vector<BBAddrMap>> 635 ELFFile<ELFT>::decodeBBAddrMap(const Elf_Shdr &Sec) const { 636 Expected<ArrayRef<uint8_t>> ContentsOrErr = getSectionContents(Sec); 637 if (!ContentsOrErr) 638 return ContentsOrErr.takeError(); 639 ArrayRef<uint8_t> Content = *ContentsOrErr; 640 DataExtractor Data(Content, isLE(), ELFT::Is64Bits ? 8 : 4); 641 std::vector<BBAddrMap> FunctionEntries; 642 643 DataExtractor::Cursor Cur(0); 644 Error ULEBSizeErr = Error::success(); 645 646 // Helper to extract and decode the next ULEB128 value as uint32_t. 647 // Returns zero and sets ULEBSizeErr if the ULEB128 value exceeds the uint32_t 648 // limit. 649 // Also returns zero if ULEBSizeErr is already in an error state. 650 auto ReadULEB128AsUInt32 = [&Data, &Cur, &ULEBSizeErr]() -> uint32_t { 651 // Bail out and do not extract data if ULEBSizeErr is already set. 652 if (ULEBSizeErr) 653 return 0; 654 uint64_t Offset = Cur.tell(); 655 uint64_t Value = Data.getULEB128(Cur); 656 if (Value > UINT32_MAX) { 657 ULEBSizeErr = createError( 658 "ULEB128 value at offset 0x" + Twine::utohexstr(Offset) + 659 " exceeds UINT32_MAX (0x" + Twine::utohexstr(Value) + ")"); 660 return 0; 661 } 662 return static_cast<uint32_t>(Value); 663 }; 664 665 while (!ULEBSizeErr && Cur && Cur.tell() < Content.size()) { 666 uintX_t Address = static_cast<uintX_t>(Data.getAddress(Cur)); 667 uint32_t NumBlocks = ReadULEB128AsUInt32(); 668 std::vector<BBAddrMap::BBEntry> BBEntries; 669 for (uint32_t BlockID = 0; !ULEBSizeErr && Cur && (BlockID < NumBlocks); 670 ++BlockID) { 671 uint32_t Offset = ReadULEB128AsUInt32(); 672 uint32_t Size = ReadULEB128AsUInt32(); 673 uint32_t Metadata = ReadULEB128AsUInt32(); 674 BBEntries.push_back({Offset, Size, Metadata}); 675 } 676 FunctionEntries.push_back({Address, BBEntries}); 677 } 678 // Either Cur is in the error state, or ULEBSizeError is set (not both), but 679 // we join the two errors here to be safe. 680 if (!Cur || ULEBSizeErr) 681 return joinErrors(Cur.takeError(), std::move(ULEBSizeErr)); 682 return FunctionEntries; 683 } 684 685 template class llvm::object::ELFFile<ELF32LE>; 686 template class llvm::object::ELFFile<ELF32BE>; 687 template class llvm::object::ELFFile<ELF64LE>; 688 template class llvm::object::ELFFile<ELF64BE>; 689