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_V0); 299 STRINGIFY_ENUM_CASE(ELF, SHT_LLVM_BB_ADDR_MAP); 300 STRINGIFY_ENUM_CASE(ELF, SHT_GNU_ATTRIBUTES); 301 STRINGIFY_ENUM_CASE(ELF, SHT_GNU_HASH); 302 STRINGIFY_ENUM_CASE(ELF, SHT_GNU_verdef); 303 STRINGIFY_ENUM_CASE(ELF, SHT_GNU_verneed); 304 STRINGIFY_ENUM_CASE(ELF, SHT_GNU_versym); 305 default: 306 return "Unknown"; 307 } 308 } 309 310 template <class ELFT> 311 std::vector<typename ELFT::Rel> 312 ELFFile<ELFT>::decode_relrs(Elf_Relr_Range relrs) const { 313 // This function decodes the contents of an SHT_RELR packed relocation 314 // section. 315 // 316 // Proposal for adding SHT_RELR sections to generic-abi is here: 317 // https://groups.google.com/forum/#!topic/generic-abi/bX460iggiKg 318 // 319 // The encoded sequence of Elf64_Relr entries in a SHT_RELR section looks 320 // like [ AAAAAAAA BBBBBBB1 BBBBBBB1 ... AAAAAAAA BBBBBB1 ... ] 321 // 322 // i.e. start with an address, followed by any number of bitmaps. The address 323 // entry encodes 1 relocation. The subsequent bitmap entries encode up to 63 324 // relocations each, at subsequent offsets following the last address entry. 325 // 326 // The bitmap entries must have 1 in the least significant bit. The assumption 327 // here is that an address cannot have 1 in lsb. Odd addresses are not 328 // supported. 329 // 330 // Excluding the least significant bit in the bitmap, each non-zero bit in 331 // the bitmap represents a relocation to be applied to a corresponding machine 332 // word that follows the base address word. The second least significant bit 333 // represents the machine word immediately following the initial address, and 334 // each bit that follows represents the next word, in linear order. As such, 335 // a single bitmap can encode up to 31 relocations in a 32-bit object, and 336 // 63 relocations in a 64-bit object. 337 // 338 // This encoding has a couple of interesting properties: 339 // 1. Looking at any entry, it is clear whether it's an address or a bitmap: 340 // even means address, odd means bitmap. 341 // 2. Just a simple list of addresses is a valid encoding. 342 343 Elf_Rel Rel; 344 Rel.r_info = 0; 345 Rel.setType(getRelativeRelocationType(), false); 346 std::vector<Elf_Rel> Relocs; 347 348 // Word type: uint32_t for Elf32, and uint64_t for Elf64. 349 using Addr = typename ELFT::uint; 350 351 Addr Base = 0; 352 for (Elf_Relr R : relrs) { 353 typename ELFT::uint Entry = R; 354 if ((Entry & 1) == 0) { 355 // Even entry: encodes the offset for next relocation. 356 Rel.r_offset = Entry; 357 Relocs.push_back(Rel); 358 // Set base offset for subsequent bitmap entries. 359 Base = Entry + sizeof(Addr); 360 } else { 361 // Odd entry: encodes bitmap for relocations starting at base. 362 for (Addr Offset = Base; (Entry >>= 1) != 0; Offset += sizeof(Addr)) 363 if ((Entry & 1) != 0) { 364 Rel.r_offset = Offset; 365 Relocs.push_back(Rel); 366 } 367 Base += (CHAR_BIT * sizeof(Entry) - 1) * sizeof(Addr); 368 } 369 } 370 371 return Relocs; 372 } 373 374 template <class ELFT> 375 Expected<std::vector<typename ELFT::Rela>> 376 ELFFile<ELFT>::android_relas(const Elf_Shdr &Sec) const { 377 // This function reads relocations in Android's packed relocation format, 378 // which is based on SLEB128 and delta encoding. 379 Expected<ArrayRef<uint8_t>> ContentsOrErr = getSectionContents(Sec); 380 if (!ContentsOrErr) 381 return ContentsOrErr.takeError(); 382 ArrayRef<uint8_t> Content = *ContentsOrErr; 383 if (Content.size() < 4 || Content[0] != 'A' || Content[1] != 'P' || 384 Content[2] != 'S' || Content[3] != '2') 385 return createError("invalid packed relocation header"); 386 DataExtractor Data(Content, isLE(), ELFT::Is64Bits ? 8 : 4); 387 DataExtractor::Cursor Cur(/*Offset=*/4); 388 389 uint64_t NumRelocs = Data.getSLEB128(Cur); 390 uint64_t Offset = Data.getSLEB128(Cur); 391 uint64_t Addend = 0; 392 393 if (!Cur) 394 return std::move(Cur.takeError()); 395 396 std::vector<Elf_Rela> Relocs; 397 Relocs.reserve(NumRelocs); 398 while (NumRelocs) { 399 uint64_t NumRelocsInGroup = Data.getSLEB128(Cur); 400 if (!Cur) 401 return std::move(Cur.takeError()); 402 if (NumRelocsInGroup > NumRelocs) 403 return createError("relocation group unexpectedly large"); 404 NumRelocs -= NumRelocsInGroup; 405 406 uint64_t GroupFlags = Data.getSLEB128(Cur); 407 bool GroupedByInfo = GroupFlags & ELF::RELOCATION_GROUPED_BY_INFO_FLAG; 408 bool GroupedByOffsetDelta = GroupFlags & ELF::RELOCATION_GROUPED_BY_OFFSET_DELTA_FLAG; 409 bool GroupedByAddend = GroupFlags & ELF::RELOCATION_GROUPED_BY_ADDEND_FLAG; 410 bool GroupHasAddend = GroupFlags & ELF::RELOCATION_GROUP_HAS_ADDEND_FLAG; 411 412 uint64_t GroupOffsetDelta; 413 if (GroupedByOffsetDelta) 414 GroupOffsetDelta = Data.getSLEB128(Cur); 415 416 uint64_t GroupRInfo; 417 if (GroupedByInfo) 418 GroupRInfo = Data.getSLEB128(Cur); 419 420 if (GroupedByAddend && GroupHasAddend) 421 Addend += Data.getSLEB128(Cur); 422 423 if (!GroupHasAddend) 424 Addend = 0; 425 426 for (uint64_t I = 0; Cur && I != NumRelocsInGroup; ++I) { 427 Elf_Rela R; 428 Offset += GroupedByOffsetDelta ? GroupOffsetDelta : Data.getSLEB128(Cur); 429 R.r_offset = Offset; 430 R.r_info = GroupedByInfo ? GroupRInfo : Data.getSLEB128(Cur); 431 if (GroupHasAddend && !GroupedByAddend) 432 Addend += Data.getSLEB128(Cur); 433 R.r_addend = Addend; 434 Relocs.push_back(R); 435 } 436 if (!Cur) 437 return std::move(Cur.takeError()); 438 } 439 440 return Relocs; 441 } 442 443 template <class ELFT> 444 std::string ELFFile<ELFT>::getDynamicTagAsString(unsigned Arch, 445 uint64_t Type) const { 446 #define DYNAMIC_STRINGIFY_ENUM(tag, value) \ 447 case value: \ 448 return #tag; 449 450 #define DYNAMIC_TAG(n, v) 451 switch (Arch) { 452 case ELF::EM_AARCH64: 453 switch (Type) { 454 #define AARCH64_DYNAMIC_TAG(name, value) DYNAMIC_STRINGIFY_ENUM(name, value) 455 #include "llvm/BinaryFormat/DynamicTags.def" 456 #undef AARCH64_DYNAMIC_TAG 457 } 458 break; 459 460 case ELF::EM_HEXAGON: 461 switch (Type) { 462 #define HEXAGON_DYNAMIC_TAG(name, value) DYNAMIC_STRINGIFY_ENUM(name, value) 463 #include "llvm/BinaryFormat/DynamicTags.def" 464 #undef HEXAGON_DYNAMIC_TAG 465 } 466 break; 467 468 case ELF::EM_MIPS: 469 switch (Type) { 470 #define MIPS_DYNAMIC_TAG(name, value) DYNAMIC_STRINGIFY_ENUM(name, value) 471 #include "llvm/BinaryFormat/DynamicTags.def" 472 #undef MIPS_DYNAMIC_TAG 473 } 474 break; 475 476 case ELF::EM_PPC: 477 switch (Type) { 478 #define PPC_DYNAMIC_TAG(name, value) DYNAMIC_STRINGIFY_ENUM(name, value) 479 #include "llvm/BinaryFormat/DynamicTags.def" 480 #undef PPC_DYNAMIC_TAG 481 } 482 break; 483 484 case ELF::EM_PPC64: 485 switch (Type) { 486 #define PPC64_DYNAMIC_TAG(name, value) DYNAMIC_STRINGIFY_ENUM(name, value) 487 #include "llvm/BinaryFormat/DynamicTags.def" 488 #undef PPC64_DYNAMIC_TAG 489 } 490 break; 491 492 case ELF::EM_RISCV: 493 switch (Type) { 494 #define RISCV_DYNAMIC_TAG(name, value) DYNAMIC_STRINGIFY_ENUM(name, value) 495 #include "llvm/BinaryFormat/DynamicTags.def" 496 #undef RISCV_DYNAMIC_TAG 497 } 498 break; 499 } 500 #undef DYNAMIC_TAG 501 switch (Type) { 502 // Now handle all dynamic tags except the architecture specific ones 503 #define AARCH64_DYNAMIC_TAG(name, value) 504 #define MIPS_DYNAMIC_TAG(name, value) 505 #define HEXAGON_DYNAMIC_TAG(name, value) 506 #define PPC_DYNAMIC_TAG(name, value) 507 #define PPC64_DYNAMIC_TAG(name, value) 508 #define RISCV_DYNAMIC_TAG(name, value) 509 // Also ignore marker tags such as DT_HIOS (maps to DT_VERNEEDNUM), etc. 510 #define DYNAMIC_TAG_MARKER(name, value) 511 #define DYNAMIC_TAG(name, value) case value: return #name; 512 #include "llvm/BinaryFormat/DynamicTags.def" 513 #undef DYNAMIC_TAG 514 #undef AARCH64_DYNAMIC_TAG 515 #undef MIPS_DYNAMIC_TAG 516 #undef HEXAGON_DYNAMIC_TAG 517 #undef PPC_DYNAMIC_TAG 518 #undef PPC64_DYNAMIC_TAG 519 #undef RISCV_DYNAMIC_TAG 520 #undef DYNAMIC_TAG_MARKER 521 #undef DYNAMIC_STRINGIFY_ENUM 522 default: 523 return "<unknown:>0x" + utohexstr(Type, true); 524 } 525 } 526 527 template <class ELFT> 528 std::string ELFFile<ELFT>::getDynamicTagAsString(uint64_t Type) const { 529 return getDynamicTagAsString(getHeader().e_machine, Type); 530 } 531 532 template <class ELFT> 533 Expected<typename ELFT::DynRange> ELFFile<ELFT>::dynamicEntries() const { 534 ArrayRef<Elf_Dyn> Dyn; 535 536 auto ProgramHeadersOrError = program_headers(); 537 if (!ProgramHeadersOrError) 538 return ProgramHeadersOrError.takeError(); 539 540 for (const Elf_Phdr &Phdr : *ProgramHeadersOrError) { 541 if (Phdr.p_type == ELF::PT_DYNAMIC) { 542 Dyn = makeArrayRef( 543 reinterpret_cast<const Elf_Dyn *>(base() + Phdr.p_offset), 544 Phdr.p_filesz / sizeof(Elf_Dyn)); 545 break; 546 } 547 } 548 549 // If we can't find the dynamic section in the program headers, we just fall 550 // back on the sections. 551 if (Dyn.empty()) { 552 auto SectionsOrError = sections(); 553 if (!SectionsOrError) 554 return SectionsOrError.takeError(); 555 556 for (const Elf_Shdr &Sec : *SectionsOrError) { 557 if (Sec.sh_type == ELF::SHT_DYNAMIC) { 558 Expected<ArrayRef<Elf_Dyn>> DynOrError = 559 getSectionContentsAsArray<Elf_Dyn>(Sec); 560 if (!DynOrError) 561 return DynOrError.takeError(); 562 Dyn = *DynOrError; 563 break; 564 } 565 } 566 567 if (!Dyn.data()) 568 return ArrayRef<Elf_Dyn>(); 569 } 570 571 if (Dyn.empty()) 572 return createError("invalid empty dynamic section"); 573 574 if (Dyn.back().d_tag != ELF::DT_NULL) 575 return createError("dynamic sections must be DT_NULL terminated"); 576 577 return Dyn; 578 } 579 580 template <class ELFT> 581 Expected<const uint8_t *> 582 ELFFile<ELFT>::toMappedAddr(uint64_t VAddr, WarningHandler WarnHandler) const { 583 auto ProgramHeadersOrError = program_headers(); 584 if (!ProgramHeadersOrError) 585 return ProgramHeadersOrError.takeError(); 586 587 llvm::SmallVector<Elf_Phdr *, 4> LoadSegments; 588 589 for (const Elf_Phdr &Phdr : *ProgramHeadersOrError) 590 if (Phdr.p_type == ELF::PT_LOAD) 591 LoadSegments.push_back(const_cast<Elf_Phdr *>(&Phdr)); 592 593 auto SortPred = [](const Elf_Phdr_Impl<ELFT> *A, 594 const Elf_Phdr_Impl<ELFT> *B) { 595 return A->p_vaddr < B->p_vaddr; 596 }; 597 if (!llvm::is_sorted(LoadSegments, SortPred)) { 598 if (Error E = 599 WarnHandler("loadable segments are unsorted by virtual address")) 600 return std::move(E); 601 llvm::stable_sort(LoadSegments, SortPred); 602 } 603 604 const Elf_Phdr *const *I = llvm::upper_bound( 605 LoadSegments, VAddr, [](uint64_t VAddr, const Elf_Phdr_Impl<ELFT> *Phdr) { 606 return VAddr < Phdr->p_vaddr; 607 }); 608 609 if (I == LoadSegments.begin()) 610 return createError("virtual address is not in any segment: 0x" + 611 Twine::utohexstr(VAddr)); 612 --I; 613 const Elf_Phdr &Phdr = **I; 614 uint64_t Delta = VAddr - Phdr.p_vaddr; 615 if (Delta >= Phdr.p_filesz) 616 return createError("virtual address is not in any segment: 0x" + 617 Twine::utohexstr(VAddr)); 618 619 uint64_t Offset = Phdr.p_offset + Delta; 620 if (Offset >= getBufSize()) 621 return createError("can't map virtual address 0x" + 622 Twine::utohexstr(VAddr) + " to the segment with index " + 623 Twine(&Phdr - (*ProgramHeadersOrError).data() + 1) + 624 ": the segment ends at 0x" + 625 Twine::utohexstr(Phdr.p_offset + Phdr.p_filesz) + 626 ", which is greater than the file size (0x" + 627 Twine::utohexstr(getBufSize()) + ")"); 628 629 return base() + Offset; 630 } 631 632 template <class ELFT> 633 Expected<std::vector<BBAddrMap>> 634 ELFFile<ELFT>::decodeBBAddrMap(const Elf_Shdr &Sec) const { 635 Expected<ArrayRef<uint8_t>> ContentsOrErr = getSectionContents(Sec); 636 if (!ContentsOrErr) 637 return ContentsOrErr.takeError(); 638 ArrayRef<uint8_t> Content = *ContentsOrErr; 639 DataExtractor Data(Content, isLE(), ELFT::Is64Bits ? 8 : 4); 640 std::vector<BBAddrMap> FunctionEntries; 641 642 DataExtractor::Cursor Cur(0); 643 Error ULEBSizeErr = Error::success(); 644 // Helper to extract and decode the next ULEB128 value as uint32_t. 645 // Returns zero and sets ULEBSizeErr if the ULEB128 value exceeds the uint32_t 646 // limit. 647 // Also returns zero if ULEBSizeErr is already in an error state. 648 auto ReadULEB128AsUInt32 = [&Data, &Cur, &ULEBSizeErr]() -> uint32_t { 649 // Bail out and do not extract data if ULEBSizeErr is already set. 650 if (ULEBSizeErr) 651 return 0; 652 uint64_t Offset = Cur.tell(); 653 uint64_t Value = Data.getULEB128(Cur); 654 if (Value > UINT32_MAX) { 655 ULEBSizeErr = createError( 656 "ULEB128 value at offset 0x" + Twine::utohexstr(Offset) + 657 " exceeds UINT32_MAX (0x" + Twine::utohexstr(Value) + ")"); 658 return 0; 659 } 660 return static_cast<uint32_t>(Value); 661 }; 662 663 uint8_t Version = 0; 664 while (!ULEBSizeErr && Cur && Cur.tell() < Content.size()) { 665 if (Sec.sh_type == ELF::SHT_LLVM_BB_ADDR_MAP) { 666 Version = Data.getU8(Cur); 667 if (!Cur) 668 break; 669 if (Version > 1) 670 return createError("unsupported SHT_LLVM_BB_ADDR_MAP version: " + 671 Twine(static_cast<int>(Version))); 672 Data.getU8(Cur); // Feature byte 673 } 674 uintX_t Address = static_cast<uintX_t>(Data.getAddress(Cur)); 675 uint32_t NumBlocks = ReadULEB128AsUInt32(); 676 std::vector<BBAddrMap::BBEntry> BBEntries; 677 uint32_t PrevBBEndOffset = 0; 678 for (uint32_t BlockID = 0; !ULEBSizeErr && Cur && (BlockID < NumBlocks); 679 ++BlockID) { 680 uint32_t Offset = ReadULEB128AsUInt32(); 681 uint32_t Size = ReadULEB128AsUInt32(); 682 uint32_t Metadata = ReadULEB128AsUInt32(); 683 if (Version >= 1) { 684 // Offset is calculated relative to the end of the previous BB. 685 Offset += PrevBBEndOffset; 686 PrevBBEndOffset = Offset + Size; 687 } 688 BBEntries.push_back({Offset, Size, Metadata}); 689 } 690 FunctionEntries.push_back({Address, std::move(BBEntries)}); 691 } 692 // Either Cur is in the error state, or ULEBSizeError is set (not both), but 693 // we join the two errors here to be safe. 694 if (!Cur || ULEBSizeErr) 695 return joinErrors(Cur.takeError(), std::move(ULEBSizeErr)); 696 return FunctionEntries; 697 } 698 699 template class llvm::object::ELFFile<ELF32LE>; 700 template class llvm::object::ELFFile<ELF32BE>; 701 template class llvm::object::ELFFile<ELF64LE>; 702 template class llvm::object::ELFFile<ELF64BE>; 703