1 //===- ELFObjectFile.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 // Part of the ELFObjectFile class implementation. 10 // 11 //===----------------------------------------------------------------------===// 12 13 #include "llvm/Object/ELFObjectFile.h" 14 #include "llvm/ADT/Triple.h" 15 #include "llvm/BinaryFormat/ELF.h" 16 #include "llvm/MC/MCInstrAnalysis.h" 17 #include "llvm/MC/SubtargetFeature.h" 18 #include "llvm/MC/TargetRegistry.h" 19 #include "llvm/Object/ELF.h" 20 #include "llvm/Object/ELFTypes.h" 21 #include "llvm/Object/Error.h" 22 #include "llvm/Support/ARMAttributeParser.h" 23 #include "llvm/Support/ARMBuildAttributes.h" 24 #include "llvm/Support/ErrorHandling.h" 25 #include "llvm/Support/MathExtras.h" 26 #include "llvm/Support/RISCVAttributeParser.h" 27 #include "llvm/Support/RISCVAttributes.h" 28 #include "llvm/Support/RISCVISAInfo.h" 29 #include <algorithm> 30 #include <cstddef> 31 #include <cstdint> 32 #include <memory> 33 #include <optional> 34 #include <string> 35 #include <utility> 36 37 using namespace llvm; 38 using namespace object; 39 40 const EnumEntry<unsigned> llvm::object::ElfSymbolTypes[NumElfSymbolTypes] = { 41 {"None", "NOTYPE", ELF::STT_NOTYPE}, 42 {"Object", "OBJECT", ELF::STT_OBJECT}, 43 {"Function", "FUNC", ELF::STT_FUNC}, 44 {"Section", "SECTION", ELF::STT_SECTION}, 45 {"File", "FILE", ELF::STT_FILE}, 46 {"Common", "COMMON", ELF::STT_COMMON}, 47 {"TLS", "TLS", ELF::STT_TLS}, 48 {"Unknown", "<unknown>: 7", 7}, 49 {"Unknown", "<unknown>: 8", 8}, 50 {"Unknown", "<unknown>: 9", 9}, 51 {"GNU_IFunc", "IFUNC", ELF::STT_GNU_IFUNC}, 52 {"OS Specific", "<OS specific>: 11", 11}, 53 {"OS Specific", "<OS specific>: 12", 12}, 54 {"Proc Specific", "<processor specific>: 13", 13}, 55 {"Proc Specific", "<processor specific>: 14", 14}, 56 {"Proc Specific", "<processor specific>: 15", 15} 57 }; 58 59 ELFObjectFileBase::ELFObjectFileBase(unsigned int Type, MemoryBufferRef Source) 60 : ObjectFile(Type, Source) {} 61 62 template <class ELFT> 63 static Expected<std::unique_ptr<ELFObjectFile<ELFT>>> 64 createPtr(MemoryBufferRef Object, bool InitContent) { 65 auto Ret = ELFObjectFile<ELFT>::create(Object, InitContent); 66 if (Error E = Ret.takeError()) 67 return std::move(E); 68 return std::make_unique<ELFObjectFile<ELFT>>(std::move(*Ret)); 69 } 70 71 Expected<std::unique_ptr<ObjectFile>> 72 ObjectFile::createELFObjectFile(MemoryBufferRef Obj, bool InitContent) { 73 std::pair<unsigned char, unsigned char> Ident = 74 getElfArchType(Obj.getBuffer()); 75 std::size_t MaxAlignment = 76 1ULL << countTrailingZeros( 77 reinterpret_cast<uintptr_t>(Obj.getBufferStart())); 78 79 if (MaxAlignment < 2) 80 return createError("Insufficient alignment"); 81 82 if (Ident.first == ELF::ELFCLASS32) { 83 if (Ident.second == ELF::ELFDATA2LSB) 84 return createPtr<ELF32LE>(Obj, InitContent); 85 else if (Ident.second == ELF::ELFDATA2MSB) 86 return createPtr<ELF32BE>(Obj, InitContent); 87 else 88 return createError("Invalid ELF data"); 89 } else if (Ident.first == ELF::ELFCLASS64) { 90 if (Ident.second == ELF::ELFDATA2LSB) 91 return createPtr<ELF64LE>(Obj, InitContent); 92 else if (Ident.second == ELF::ELFDATA2MSB) 93 return createPtr<ELF64BE>(Obj, InitContent); 94 else 95 return createError("Invalid ELF data"); 96 } 97 return createError("Invalid ELF class"); 98 } 99 100 SubtargetFeatures ELFObjectFileBase::getMIPSFeatures() const { 101 SubtargetFeatures Features; 102 unsigned PlatformFlags = getPlatformFlags(); 103 104 switch (PlatformFlags & ELF::EF_MIPS_ARCH) { 105 case ELF::EF_MIPS_ARCH_1: 106 break; 107 case ELF::EF_MIPS_ARCH_2: 108 Features.AddFeature("mips2"); 109 break; 110 case ELF::EF_MIPS_ARCH_3: 111 Features.AddFeature("mips3"); 112 break; 113 case ELF::EF_MIPS_ARCH_4: 114 Features.AddFeature("mips4"); 115 break; 116 case ELF::EF_MIPS_ARCH_5: 117 Features.AddFeature("mips5"); 118 break; 119 case ELF::EF_MIPS_ARCH_32: 120 Features.AddFeature("mips32"); 121 break; 122 case ELF::EF_MIPS_ARCH_64: 123 Features.AddFeature("mips64"); 124 break; 125 case ELF::EF_MIPS_ARCH_32R2: 126 Features.AddFeature("mips32r2"); 127 break; 128 case ELF::EF_MIPS_ARCH_64R2: 129 Features.AddFeature("mips64r2"); 130 break; 131 case ELF::EF_MIPS_ARCH_32R6: 132 Features.AddFeature("mips32r6"); 133 break; 134 case ELF::EF_MIPS_ARCH_64R6: 135 Features.AddFeature("mips64r6"); 136 break; 137 default: 138 llvm_unreachable("Unknown EF_MIPS_ARCH value"); 139 } 140 141 switch (PlatformFlags & ELF::EF_MIPS_MACH) { 142 case ELF::EF_MIPS_MACH_NONE: 143 // No feature associated with this value. 144 break; 145 case ELF::EF_MIPS_MACH_OCTEON: 146 Features.AddFeature("cnmips"); 147 break; 148 default: 149 llvm_unreachable("Unknown EF_MIPS_ARCH value"); 150 } 151 152 if (PlatformFlags & ELF::EF_MIPS_ARCH_ASE_M16) 153 Features.AddFeature("mips16"); 154 if (PlatformFlags & ELF::EF_MIPS_MICROMIPS) 155 Features.AddFeature("micromips"); 156 157 return Features; 158 } 159 160 SubtargetFeatures ELFObjectFileBase::getARMFeatures() const { 161 SubtargetFeatures Features; 162 ARMAttributeParser Attributes; 163 if (Error E = getBuildAttributes(Attributes)) { 164 consumeError(std::move(E)); 165 return SubtargetFeatures(); 166 } 167 168 // both ARMv7-M and R have to support thumb hardware div 169 bool isV7 = false; 170 std::optional<unsigned> Attr = 171 Attributes.getAttributeValue(ARMBuildAttrs::CPU_arch); 172 if (Attr) 173 isV7 = *Attr == ARMBuildAttrs::v7; 174 175 Attr = Attributes.getAttributeValue(ARMBuildAttrs::CPU_arch_profile); 176 if (Attr) { 177 switch (*Attr) { 178 case ARMBuildAttrs::ApplicationProfile: 179 Features.AddFeature("aclass"); 180 break; 181 case ARMBuildAttrs::RealTimeProfile: 182 Features.AddFeature("rclass"); 183 if (isV7) 184 Features.AddFeature("hwdiv"); 185 break; 186 case ARMBuildAttrs::MicroControllerProfile: 187 Features.AddFeature("mclass"); 188 if (isV7) 189 Features.AddFeature("hwdiv"); 190 break; 191 } 192 } 193 194 Attr = Attributes.getAttributeValue(ARMBuildAttrs::THUMB_ISA_use); 195 if (Attr) { 196 switch (*Attr) { 197 default: 198 break; 199 case ARMBuildAttrs::Not_Allowed: 200 Features.AddFeature("thumb", false); 201 Features.AddFeature("thumb2", false); 202 break; 203 case ARMBuildAttrs::AllowThumb32: 204 Features.AddFeature("thumb2"); 205 break; 206 } 207 } 208 209 Attr = Attributes.getAttributeValue(ARMBuildAttrs::FP_arch); 210 if (Attr) { 211 switch (*Attr) { 212 default: 213 break; 214 case ARMBuildAttrs::Not_Allowed: 215 Features.AddFeature("vfp2sp", false); 216 Features.AddFeature("vfp3d16sp", false); 217 Features.AddFeature("vfp4d16sp", false); 218 break; 219 case ARMBuildAttrs::AllowFPv2: 220 Features.AddFeature("vfp2"); 221 break; 222 case ARMBuildAttrs::AllowFPv3A: 223 case ARMBuildAttrs::AllowFPv3B: 224 Features.AddFeature("vfp3"); 225 break; 226 case ARMBuildAttrs::AllowFPv4A: 227 case ARMBuildAttrs::AllowFPv4B: 228 Features.AddFeature("vfp4"); 229 break; 230 } 231 } 232 233 Attr = Attributes.getAttributeValue(ARMBuildAttrs::Advanced_SIMD_arch); 234 if (Attr) { 235 switch (*Attr) { 236 default: 237 break; 238 case ARMBuildAttrs::Not_Allowed: 239 Features.AddFeature("neon", false); 240 Features.AddFeature("fp16", false); 241 break; 242 case ARMBuildAttrs::AllowNeon: 243 Features.AddFeature("neon"); 244 break; 245 case ARMBuildAttrs::AllowNeon2: 246 Features.AddFeature("neon"); 247 Features.AddFeature("fp16"); 248 break; 249 } 250 } 251 252 Attr = Attributes.getAttributeValue(ARMBuildAttrs::MVE_arch); 253 if (Attr) { 254 switch (*Attr) { 255 default: 256 break; 257 case ARMBuildAttrs::Not_Allowed: 258 Features.AddFeature("mve", false); 259 Features.AddFeature("mve.fp", false); 260 break; 261 case ARMBuildAttrs::AllowMVEInteger: 262 Features.AddFeature("mve.fp", false); 263 Features.AddFeature("mve"); 264 break; 265 case ARMBuildAttrs::AllowMVEIntegerAndFloat: 266 Features.AddFeature("mve.fp"); 267 break; 268 } 269 } 270 271 Attr = Attributes.getAttributeValue(ARMBuildAttrs::DIV_use); 272 if (Attr) { 273 switch (*Attr) { 274 default: 275 break; 276 case ARMBuildAttrs::DisallowDIV: 277 Features.AddFeature("hwdiv", false); 278 Features.AddFeature("hwdiv-arm", false); 279 break; 280 case ARMBuildAttrs::AllowDIVExt: 281 Features.AddFeature("hwdiv"); 282 Features.AddFeature("hwdiv-arm"); 283 break; 284 } 285 } 286 287 return Features; 288 } 289 290 Expected<SubtargetFeatures> ELFObjectFileBase::getRISCVFeatures() const { 291 SubtargetFeatures Features; 292 unsigned PlatformFlags = getPlatformFlags(); 293 294 if (PlatformFlags & ELF::EF_RISCV_RVC) { 295 Features.AddFeature("c"); 296 } 297 298 RISCVAttributeParser Attributes; 299 if (Error E = getBuildAttributes(Attributes)) { 300 return std::move(E); 301 } 302 303 std::optional<StringRef> Attr = 304 Attributes.getAttributeString(RISCVAttrs::ARCH); 305 if (Attr) { 306 // Suppress version checking for experimental extensions to prevent erroring 307 // when getting any unknown version of experimental extension. 308 auto ParseResult = RISCVISAInfo::parseArchString( 309 *Attr, /*EnableExperimentalExtension=*/true, 310 /*ExperimentalExtensionVersionCheck=*/false, 311 /*IgnoreUnknown=*/true); 312 if (!ParseResult) 313 return ParseResult.takeError(); 314 auto &ISAInfo = *ParseResult; 315 316 if (ISAInfo->getXLen() == 32) 317 Features.AddFeature("64bit", false); 318 else if (ISAInfo->getXLen() == 64) 319 Features.AddFeature("64bit"); 320 else 321 llvm_unreachable("XLEN should be 32 or 64."); 322 323 Features.addFeaturesVector(ISAInfo->toFeatureVector()); 324 } 325 326 return Features; 327 } 328 329 SubtargetFeatures ELFObjectFileBase::getLoongArchFeatures() const { 330 SubtargetFeatures Features; 331 332 switch (getPlatformFlags() & ELF::EF_LOONGARCH_ABI_MODIFIER_MASK) { 333 case ELF::EF_LOONGARCH_ABI_SOFT_FLOAT: 334 break; 335 case ELF::EF_LOONGARCH_ABI_DOUBLE_FLOAT: 336 Features.AddFeature("d"); 337 // D implies F according to LoongArch ISA spec. 338 [[fallthrough]]; 339 case ELF::EF_LOONGARCH_ABI_SINGLE_FLOAT: 340 Features.AddFeature("f"); 341 break; 342 } 343 344 return Features; 345 } 346 347 Expected<SubtargetFeatures> ELFObjectFileBase::getFeatures() const { 348 switch (getEMachine()) { 349 case ELF::EM_MIPS: 350 return getMIPSFeatures(); 351 case ELF::EM_ARM: 352 return getARMFeatures(); 353 case ELF::EM_RISCV: 354 return getRISCVFeatures(); 355 case ELF::EM_LOONGARCH: 356 return getLoongArchFeatures(); 357 default: 358 return SubtargetFeatures(); 359 } 360 } 361 362 std::optional<StringRef> ELFObjectFileBase::tryGetCPUName() const { 363 switch (getEMachine()) { 364 case ELF::EM_AMDGPU: 365 return getAMDGPUCPUName(); 366 case ELF::EM_PPC64: 367 return StringRef("future"); 368 default: 369 return std::nullopt; 370 } 371 } 372 373 StringRef ELFObjectFileBase::getAMDGPUCPUName() const { 374 assert(getEMachine() == ELF::EM_AMDGPU); 375 unsigned CPU = getPlatformFlags() & ELF::EF_AMDGPU_MACH; 376 377 switch (CPU) { 378 // Radeon HD 2000/3000 Series (R600). 379 case ELF::EF_AMDGPU_MACH_R600_R600: 380 return "r600"; 381 case ELF::EF_AMDGPU_MACH_R600_R630: 382 return "r630"; 383 case ELF::EF_AMDGPU_MACH_R600_RS880: 384 return "rs880"; 385 case ELF::EF_AMDGPU_MACH_R600_RV670: 386 return "rv670"; 387 388 // Radeon HD 4000 Series (R700). 389 case ELF::EF_AMDGPU_MACH_R600_RV710: 390 return "rv710"; 391 case ELF::EF_AMDGPU_MACH_R600_RV730: 392 return "rv730"; 393 case ELF::EF_AMDGPU_MACH_R600_RV770: 394 return "rv770"; 395 396 // Radeon HD 5000 Series (Evergreen). 397 case ELF::EF_AMDGPU_MACH_R600_CEDAR: 398 return "cedar"; 399 case ELF::EF_AMDGPU_MACH_R600_CYPRESS: 400 return "cypress"; 401 case ELF::EF_AMDGPU_MACH_R600_JUNIPER: 402 return "juniper"; 403 case ELF::EF_AMDGPU_MACH_R600_REDWOOD: 404 return "redwood"; 405 case ELF::EF_AMDGPU_MACH_R600_SUMO: 406 return "sumo"; 407 408 // Radeon HD 6000 Series (Northern Islands). 409 case ELF::EF_AMDGPU_MACH_R600_BARTS: 410 return "barts"; 411 case ELF::EF_AMDGPU_MACH_R600_CAICOS: 412 return "caicos"; 413 case ELF::EF_AMDGPU_MACH_R600_CAYMAN: 414 return "cayman"; 415 case ELF::EF_AMDGPU_MACH_R600_TURKS: 416 return "turks"; 417 418 // AMDGCN GFX6. 419 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX600: 420 return "gfx600"; 421 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX601: 422 return "gfx601"; 423 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX602: 424 return "gfx602"; 425 426 // AMDGCN GFX7. 427 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX700: 428 return "gfx700"; 429 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX701: 430 return "gfx701"; 431 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX702: 432 return "gfx702"; 433 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX703: 434 return "gfx703"; 435 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX704: 436 return "gfx704"; 437 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX705: 438 return "gfx705"; 439 440 // AMDGCN GFX8. 441 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX801: 442 return "gfx801"; 443 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX802: 444 return "gfx802"; 445 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX803: 446 return "gfx803"; 447 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX805: 448 return "gfx805"; 449 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX810: 450 return "gfx810"; 451 452 // AMDGCN GFX9. 453 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX900: 454 return "gfx900"; 455 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX902: 456 return "gfx902"; 457 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX904: 458 return "gfx904"; 459 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX906: 460 return "gfx906"; 461 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX908: 462 return "gfx908"; 463 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX909: 464 return "gfx909"; 465 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX90A: 466 return "gfx90a"; 467 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX90C: 468 return "gfx90c"; 469 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX940: 470 return "gfx940"; 471 472 // AMDGCN GFX10. 473 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX1010: 474 return "gfx1010"; 475 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX1011: 476 return "gfx1011"; 477 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX1012: 478 return "gfx1012"; 479 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX1013: 480 return "gfx1013"; 481 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX1030: 482 return "gfx1030"; 483 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX1031: 484 return "gfx1031"; 485 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX1032: 486 return "gfx1032"; 487 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX1033: 488 return "gfx1033"; 489 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX1034: 490 return "gfx1034"; 491 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX1035: 492 return "gfx1035"; 493 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX1036: 494 return "gfx1036"; 495 496 // AMDGCN GFX11. 497 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX1100: 498 return "gfx1100"; 499 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX1101: 500 return "gfx1101"; 501 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX1102: 502 return "gfx1102"; 503 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX1103: 504 return "gfx1103"; 505 default: 506 llvm_unreachable("Unknown EF_AMDGPU_MACH value"); 507 } 508 } 509 510 // FIXME Encode from a tablegen description or target parser. 511 void ELFObjectFileBase::setARMSubArch(Triple &TheTriple) const { 512 if (TheTriple.getSubArch() != Triple::NoSubArch) 513 return; 514 515 ARMAttributeParser Attributes; 516 if (Error E = getBuildAttributes(Attributes)) { 517 // TODO Propagate Error. 518 consumeError(std::move(E)); 519 return; 520 } 521 522 std::string Triple; 523 // Default to ARM, but use the triple if it's been set. 524 if (TheTriple.isThumb()) 525 Triple = "thumb"; 526 else 527 Triple = "arm"; 528 529 std::optional<unsigned> Attr = 530 Attributes.getAttributeValue(ARMBuildAttrs::CPU_arch); 531 if (Attr) { 532 switch (*Attr) { 533 case ARMBuildAttrs::v4: 534 Triple += "v4"; 535 break; 536 case ARMBuildAttrs::v4T: 537 Triple += "v4t"; 538 break; 539 case ARMBuildAttrs::v5T: 540 Triple += "v5t"; 541 break; 542 case ARMBuildAttrs::v5TE: 543 Triple += "v5te"; 544 break; 545 case ARMBuildAttrs::v5TEJ: 546 Triple += "v5tej"; 547 break; 548 case ARMBuildAttrs::v6: 549 Triple += "v6"; 550 break; 551 case ARMBuildAttrs::v6KZ: 552 Triple += "v6kz"; 553 break; 554 case ARMBuildAttrs::v6T2: 555 Triple += "v6t2"; 556 break; 557 case ARMBuildAttrs::v6K: 558 Triple += "v6k"; 559 break; 560 case ARMBuildAttrs::v7: { 561 std::optional<unsigned> ArchProfileAttr = 562 Attributes.getAttributeValue(ARMBuildAttrs::CPU_arch_profile); 563 if (ArchProfileAttr && 564 *ArchProfileAttr == ARMBuildAttrs::MicroControllerProfile) 565 Triple += "v7m"; 566 else 567 Triple += "v7"; 568 break; 569 } 570 case ARMBuildAttrs::v6_M: 571 Triple += "v6m"; 572 break; 573 case ARMBuildAttrs::v6S_M: 574 Triple += "v6sm"; 575 break; 576 case ARMBuildAttrs::v7E_M: 577 Triple += "v7em"; 578 break; 579 case ARMBuildAttrs::v8_A: 580 Triple += "v8a"; 581 break; 582 case ARMBuildAttrs::v8_R: 583 Triple += "v8r"; 584 break; 585 case ARMBuildAttrs::v8_M_Base: 586 Triple += "v8m.base"; 587 break; 588 case ARMBuildAttrs::v8_M_Main: 589 Triple += "v8m.main"; 590 break; 591 case ARMBuildAttrs::v8_1_M_Main: 592 Triple += "v8.1m.main"; 593 break; 594 case ARMBuildAttrs::v9_A: 595 Triple += "v9a"; 596 break; 597 } 598 } 599 if (!isLittleEndian()) 600 Triple += "eb"; 601 602 TheTriple.setArchName(Triple); 603 } 604 605 std::vector<std::pair<std::optional<DataRefImpl>, uint64_t>> 606 ELFObjectFileBase::getPltAddresses() const { 607 std::string Err; 608 const auto Triple = makeTriple(); 609 const auto *T = TargetRegistry::lookupTarget(Triple.str(), Err); 610 if (!T) 611 return {}; 612 uint64_t JumpSlotReloc = 0; 613 switch (Triple.getArch()) { 614 case Triple::x86: 615 JumpSlotReloc = ELF::R_386_JUMP_SLOT; 616 break; 617 case Triple::x86_64: 618 JumpSlotReloc = ELF::R_X86_64_JUMP_SLOT; 619 break; 620 case Triple::aarch64: 621 case Triple::aarch64_be: 622 JumpSlotReloc = ELF::R_AARCH64_JUMP_SLOT; 623 break; 624 default: 625 return {}; 626 } 627 std::unique_ptr<const MCInstrInfo> MII(T->createMCInstrInfo()); 628 std::unique_ptr<const MCInstrAnalysis> MIA( 629 T->createMCInstrAnalysis(MII.get())); 630 if (!MIA) 631 return {}; 632 std::optional<SectionRef> Plt, RelaPlt, GotPlt; 633 for (const SectionRef &Section : sections()) { 634 Expected<StringRef> NameOrErr = Section.getName(); 635 if (!NameOrErr) { 636 consumeError(NameOrErr.takeError()); 637 continue; 638 } 639 StringRef Name = *NameOrErr; 640 641 if (Name == ".plt") 642 Plt = Section; 643 else if (Name == ".rela.plt" || Name == ".rel.plt") 644 RelaPlt = Section; 645 else if (Name == ".got.plt") 646 GotPlt = Section; 647 } 648 if (!Plt || !RelaPlt || !GotPlt) 649 return {}; 650 Expected<StringRef> PltContents = Plt->getContents(); 651 if (!PltContents) { 652 consumeError(PltContents.takeError()); 653 return {}; 654 } 655 auto PltEntries = MIA->findPltEntries(Plt->getAddress(), 656 arrayRefFromStringRef(*PltContents), 657 GotPlt->getAddress(), Triple); 658 // Build a map from GOT entry virtual address to PLT entry virtual address. 659 DenseMap<uint64_t, uint64_t> GotToPlt; 660 for (const auto &Entry : PltEntries) 661 GotToPlt.insert(std::make_pair(Entry.second, Entry.first)); 662 // Find the relocations in the dynamic relocation table that point to 663 // locations in the GOT for which we know the corresponding PLT entry. 664 std::vector<std::pair<std::optional<DataRefImpl>, uint64_t>> Result; 665 for (const auto &Relocation : RelaPlt->relocations()) { 666 if (Relocation.getType() != JumpSlotReloc) 667 continue; 668 auto PltEntryIter = GotToPlt.find(Relocation.getOffset()); 669 if (PltEntryIter != GotToPlt.end()) { 670 symbol_iterator Sym = Relocation.getSymbol(); 671 if (Sym == symbol_end()) 672 Result.emplace_back(std::nullopt, PltEntryIter->second); 673 else 674 Result.emplace_back(Sym->getRawDataRefImpl(), PltEntryIter->second); 675 } 676 } 677 return Result; 678 } 679 680 template <class ELFT> 681 Expected<std::vector<BBAddrMap>> static readBBAddrMapImpl( 682 const ELFFile<ELFT> &EF, std::optional<unsigned> TextSectionIndex) { 683 using Elf_Shdr = typename ELFT::Shdr; 684 std::vector<BBAddrMap> BBAddrMaps; 685 const auto &Sections = cantFail(EF.sections()); 686 for (const Elf_Shdr &Sec : Sections) { 687 if (Sec.sh_type != ELF::SHT_LLVM_BB_ADDR_MAP && 688 Sec.sh_type != ELF::SHT_LLVM_BB_ADDR_MAP_V0) 689 continue; 690 if (TextSectionIndex) { 691 Expected<const Elf_Shdr *> TextSecOrErr = EF.getSection(Sec.sh_link); 692 if (!TextSecOrErr) 693 return createError("unable to get the linked-to section for " + 694 describe(EF, Sec) + ": " + 695 toString(TextSecOrErr.takeError())); 696 if (*TextSectionIndex != std::distance(Sections.begin(), *TextSecOrErr)) 697 continue; 698 } 699 Expected<std::vector<BBAddrMap>> BBAddrMapOrErr = EF.decodeBBAddrMap(Sec); 700 if (!BBAddrMapOrErr) 701 return createError("unable to read " + describe(EF, Sec) + ": " + 702 toString(BBAddrMapOrErr.takeError())); 703 std::move(BBAddrMapOrErr->begin(), BBAddrMapOrErr->end(), 704 std::back_inserter(BBAddrMaps)); 705 } 706 return BBAddrMaps; 707 } 708 709 template <class ELFT> 710 static Expected<std::vector<VersionEntry>> 711 readDynsymVersionsImpl(const ELFFile<ELFT> &EF, 712 ELFObjectFileBase::elf_symbol_iterator_range Symbols) { 713 using Elf_Shdr = typename ELFT::Shdr; 714 const Elf_Shdr *VerSec = nullptr; 715 const Elf_Shdr *VerNeedSec = nullptr; 716 const Elf_Shdr *VerDefSec = nullptr; 717 // The user should ensure sections() can't fail here. 718 for (const Elf_Shdr &Sec : cantFail(EF.sections())) { 719 if (Sec.sh_type == ELF::SHT_GNU_versym) 720 VerSec = &Sec; 721 else if (Sec.sh_type == ELF::SHT_GNU_verdef) 722 VerDefSec = &Sec; 723 else if (Sec.sh_type == ELF::SHT_GNU_verneed) 724 VerNeedSec = &Sec; 725 } 726 if (!VerSec) 727 return std::vector<VersionEntry>(); 728 729 Expected<SmallVector<std::optional<VersionEntry>, 0>> MapOrErr = 730 EF.loadVersionMap(VerNeedSec, VerDefSec); 731 if (!MapOrErr) 732 return MapOrErr.takeError(); 733 734 std::vector<VersionEntry> Ret; 735 size_t I = 0; 736 for (const ELFSymbolRef &Sym : Symbols) { 737 ++I; 738 Expected<const typename ELFT::Versym *> VerEntryOrErr = 739 EF.template getEntry<typename ELFT::Versym>(*VerSec, I); 740 if (!VerEntryOrErr) 741 return createError("unable to read an entry with index " + Twine(I) + 742 " from " + describe(EF, *VerSec) + ": " + 743 toString(VerEntryOrErr.takeError())); 744 745 Expected<uint32_t> FlagsOrErr = Sym.getFlags(); 746 if (!FlagsOrErr) 747 return createError("unable to read flags for symbol with index " + 748 Twine(I) + ": " + toString(FlagsOrErr.takeError())); 749 750 bool IsDefault; 751 Expected<StringRef> VerOrErr = EF.getSymbolVersionByIndex( 752 (*VerEntryOrErr)->vs_index, IsDefault, *MapOrErr, 753 (*FlagsOrErr) & SymbolRef::SF_Undefined); 754 if (!VerOrErr) 755 return createError("unable to get a version for entry " + Twine(I) + 756 " of " + describe(EF, *VerSec) + ": " + 757 toString(VerOrErr.takeError())); 758 759 Ret.push_back({(*VerOrErr).str(), IsDefault}); 760 } 761 762 return Ret; 763 } 764 765 Expected<std::vector<VersionEntry>> 766 ELFObjectFileBase::readDynsymVersions() const { 767 elf_symbol_iterator_range Symbols = getDynamicSymbolIterators(); 768 if (const auto *Obj = dyn_cast<ELF32LEObjectFile>(this)) 769 return readDynsymVersionsImpl(Obj->getELFFile(), Symbols); 770 if (const auto *Obj = dyn_cast<ELF32BEObjectFile>(this)) 771 return readDynsymVersionsImpl(Obj->getELFFile(), Symbols); 772 if (const auto *Obj = dyn_cast<ELF64LEObjectFile>(this)) 773 return readDynsymVersionsImpl(Obj->getELFFile(), Symbols); 774 return readDynsymVersionsImpl(cast<ELF64BEObjectFile>(this)->getELFFile(), 775 Symbols); 776 } 777 778 Expected<std::vector<BBAddrMap>> ELFObjectFileBase::readBBAddrMap( 779 std::optional<unsigned> TextSectionIndex) const { 780 if (const auto *Obj = dyn_cast<ELF32LEObjectFile>(this)) 781 return readBBAddrMapImpl(Obj->getELFFile(), TextSectionIndex); 782 if (const auto *Obj = dyn_cast<ELF64LEObjectFile>(this)) 783 return readBBAddrMapImpl(Obj->getELFFile(), TextSectionIndex); 784 if (const auto *Obj = dyn_cast<ELF32BEObjectFile>(this)) 785 return readBBAddrMapImpl(Obj->getELFFile(), TextSectionIndex); 786 if (const auto *Obj = cast<ELF64BEObjectFile>(this)) 787 return readBBAddrMapImpl(Obj->getELFFile(), TextSectionIndex); 788 else 789 llvm_unreachable("Unsupported binary format"); 790 } 791