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 <algorithm> 29 #include <cstddef> 30 #include <cstdint> 31 #include <memory> 32 #include <optional> 33 #include <string> 34 #include <utility> 35 36 using namespace llvm; 37 using namespace object; 38 39 const EnumEntry<unsigned> llvm::object::ElfSymbolTypes[NumElfSymbolTypes] = { 40 {"None", "NOTYPE", ELF::STT_NOTYPE}, 41 {"Object", "OBJECT", ELF::STT_OBJECT}, 42 {"Function", "FUNC", ELF::STT_FUNC}, 43 {"Section", "SECTION", ELF::STT_SECTION}, 44 {"File", "FILE", ELF::STT_FILE}, 45 {"Common", "COMMON", ELF::STT_COMMON}, 46 {"TLS", "TLS", ELF::STT_TLS}, 47 {"Unknown", "<unknown>: 7", 7}, 48 {"Unknown", "<unknown>: 8", 8}, 49 {"Unknown", "<unknown>: 9", 9}, 50 {"GNU_IFunc", "IFUNC", ELF::STT_GNU_IFUNC}, 51 {"OS Specific", "<OS specific>: 11", 11}, 52 {"OS Specific", "<OS specific>: 12", 12}, 53 {"Proc Specific", "<processor specific>: 13", 13}, 54 {"Proc Specific", "<processor specific>: 14", 14}, 55 {"Proc Specific", "<processor specific>: 15", 15} 56 }; 57 58 ELFObjectFileBase::ELFObjectFileBase(unsigned int Type, MemoryBufferRef Source) 59 : ObjectFile(Type, Source) {} 60 61 template <class ELFT> 62 static Expected<std::unique_ptr<ELFObjectFile<ELFT>>> 63 createPtr(MemoryBufferRef Object, bool InitContent) { 64 auto Ret = ELFObjectFile<ELFT>::create(Object, InitContent); 65 if (Error E = Ret.takeError()) 66 return std::move(E); 67 return std::make_unique<ELFObjectFile<ELFT>>(std::move(*Ret)); 68 } 69 70 Expected<std::unique_ptr<ObjectFile>> 71 ObjectFile::createELFObjectFile(MemoryBufferRef Obj, bool InitContent) { 72 std::pair<unsigned char, unsigned char> Ident = 73 getElfArchType(Obj.getBuffer()); 74 std::size_t MaxAlignment = 75 1ULL << countTrailingZeros( 76 reinterpret_cast<uintptr_t>(Obj.getBufferStart())); 77 78 if (MaxAlignment < 2) 79 return createError("Insufficient alignment"); 80 81 if (Ident.first == ELF::ELFCLASS32) { 82 if (Ident.second == ELF::ELFDATA2LSB) 83 return createPtr<ELF32LE>(Obj, InitContent); 84 else if (Ident.second == ELF::ELFDATA2MSB) 85 return createPtr<ELF32BE>(Obj, InitContent); 86 else 87 return createError("Invalid ELF data"); 88 } else if (Ident.first == ELF::ELFCLASS64) { 89 if (Ident.second == ELF::ELFDATA2LSB) 90 return createPtr<ELF64LE>(Obj, InitContent); 91 else if (Ident.second == ELF::ELFDATA2MSB) 92 return createPtr<ELF64BE>(Obj, InitContent); 93 else 94 return createError("Invalid ELF data"); 95 } 96 return createError("Invalid ELF class"); 97 } 98 99 SubtargetFeatures ELFObjectFileBase::getMIPSFeatures() const { 100 SubtargetFeatures Features; 101 unsigned PlatformFlags = getPlatformFlags(); 102 103 switch (PlatformFlags & ELF::EF_MIPS_ARCH) { 104 case ELF::EF_MIPS_ARCH_1: 105 break; 106 case ELF::EF_MIPS_ARCH_2: 107 Features.AddFeature("mips2"); 108 break; 109 case ELF::EF_MIPS_ARCH_3: 110 Features.AddFeature("mips3"); 111 break; 112 case ELF::EF_MIPS_ARCH_4: 113 Features.AddFeature("mips4"); 114 break; 115 case ELF::EF_MIPS_ARCH_5: 116 Features.AddFeature("mips5"); 117 break; 118 case ELF::EF_MIPS_ARCH_32: 119 Features.AddFeature("mips32"); 120 break; 121 case ELF::EF_MIPS_ARCH_64: 122 Features.AddFeature("mips64"); 123 break; 124 case ELF::EF_MIPS_ARCH_32R2: 125 Features.AddFeature("mips32r2"); 126 break; 127 case ELF::EF_MIPS_ARCH_64R2: 128 Features.AddFeature("mips64r2"); 129 break; 130 case ELF::EF_MIPS_ARCH_32R6: 131 Features.AddFeature("mips32r6"); 132 break; 133 case ELF::EF_MIPS_ARCH_64R6: 134 Features.AddFeature("mips64r6"); 135 break; 136 default: 137 llvm_unreachable("Unknown EF_MIPS_ARCH value"); 138 } 139 140 switch (PlatformFlags & ELF::EF_MIPS_MACH) { 141 case ELF::EF_MIPS_MACH_NONE: 142 // No feature associated with this value. 143 break; 144 case ELF::EF_MIPS_MACH_OCTEON: 145 Features.AddFeature("cnmips"); 146 break; 147 default: 148 llvm_unreachable("Unknown EF_MIPS_ARCH value"); 149 } 150 151 if (PlatformFlags & ELF::EF_MIPS_ARCH_ASE_M16) 152 Features.AddFeature("mips16"); 153 if (PlatformFlags & ELF::EF_MIPS_MICROMIPS) 154 Features.AddFeature("micromips"); 155 156 return Features; 157 } 158 159 SubtargetFeatures ELFObjectFileBase::getARMFeatures() const { 160 SubtargetFeatures Features; 161 ARMAttributeParser Attributes; 162 if (Error E = getBuildAttributes(Attributes)) { 163 consumeError(std::move(E)); 164 return SubtargetFeatures(); 165 } 166 167 // both ARMv7-M and R have to support thumb hardware div 168 bool isV7 = false; 169 Optional<unsigned> Attr = 170 Attributes.getAttributeValue(ARMBuildAttrs::CPU_arch); 171 if (Attr) 172 isV7 = Attr.value() == ARMBuildAttrs::v7; 173 174 Attr = Attributes.getAttributeValue(ARMBuildAttrs::CPU_arch_profile); 175 if (Attr) { 176 switch (Attr.value()) { 177 case ARMBuildAttrs::ApplicationProfile: 178 Features.AddFeature("aclass"); 179 break; 180 case ARMBuildAttrs::RealTimeProfile: 181 Features.AddFeature("rclass"); 182 if (isV7) 183 Features.AddFeature("hwdiv"); 184 break; 185 case ARMBuildAttrs::MicroControllerProfile: 186 Features.AddFeature("mclass"); 187 if (isV7) 188 Features.AddFeature("hwdiv"); 189 break; 190 } 191 } 192 193 Attr = Attributes.getAttributeValue(ARMBuildAttrs::THUMB_ISA_use); 194 if (Attr) { 195 switch (Attr.value()) { 196 default: 197 break; 198 case ARMBuildAttrs::Not_Allowed: 199 Features.AddFeature("thumb", false); 200 Features.AddFeature("thumb2", false); 201 break; 202 case ARMBuildAttrs::AllowThumb32: 203 Features.AddFeature("thumb2"); 204 break; 205 } 206 } 207 208 Attr = Attributes.getAttributeValue(ARMBuildAttrs::FP_arch); 209 if (Attr) { 210 switch (Attr.value()) { 211 default: 212 break; 213 case ARMBuildAttrs::Not_Allowed: 214 Features.AddFeature("vfp2sp", false); 215 Features.AddFeature("vfp3d16sp", false); 216 Features.AddFeature("vfp4d16sp", false); 217 break; 218 case ARMBuildAttrs::AllowFPv2: 219 Features.AddFeature("vfp2"); 220 break; 221 case ARMBuildAttrs::AllowFPv3A: 222 case ARMBuildAttrs::AllowFPv3B: 223 Features.AddFeature("vfp3"); 224 break; 225 case ARMBuildAttrs::AllowFPv4A: 226 case ARMBuildAttrs::AllowFPv4B: 227 Features.AddFeature("vfp4"); 228 break; 229 } 230 } 231 232 Attr = Attributes.getAttributeValue(ARMBuildAttrs::Advanced_SIMD_arch); 233 if (Attr) { 234 switch (Attr.value()) { 235 default: 236 break; 237 case ARMBuildAttrs::Not_Allowed: 238 Features.AddFeature("neon", false); 239 Features.AddFeature("fp16", false); 240 break; 241 case ARMBuildAttrs::AllowNeon: 242 Features.AddFeature("neon"); 243 break; 244 case ARMBuildAttrs::AllowNeon2: 245 Features.AddFeature("neon"); 246 Features.AddFeature("fp16"); 247 break; 248 } 249 } 250 251 Attr = Attributes.getAttributeValue(ARMBuildAttrs::MVE_arch); 252 if (Attr) { 253 switch (Attr.value()) { 254 default: 255 break; 256 case ARMBuildAttrs::Not_Allowed: 257 Features.AddFeature("mve", false); 258 Features.AddFeature("mve.fp", false); 259 break; 260 case ARMBuildAttrs::AllowMVEInteger: 261 Features.AddFeature("mve.fp", false); 262 Features.AddFeature("mve"); 263 break; 264 case ARMBuildAttrs::AllowMVEIntegerAndFloat: 265 Features.AddFeature("mve.fp"); 266 break; 267 } 268 } 269 270 Attr = Attributes.getAttributeValue(ARMBuildAttrs::DIV_use); 271 if (Attr) { 272 switch (Attr.value()) { 273 default: 274 break; 275 case ARMBuildAttrs::DisallowDIV: 276 Features.AddFeature("hwdiv", false); 277 Features.AddFeature("hwdiv-arm", false); 278 break; 279 case ARMBuildAttrs::AllowDIVExt: 280 Features.AddFeature("hwdiv"); 281 Features.AddFeature("hwdiv-arm"); 282 break; 283 } 284 } 285 286 return Features; 287 } 288 289 SubtargetFeatures ELFObjectFileBase::getRISCVFeatures() const { 290 SubtargetFeatures Features; 291 unsigned PlatformFlags = getPlatformFlags(); 292 293 if (PlatformFlags & ELF::EF_RISCV_RVC) { 294 Features.AddFeature("c"); 295 } 296 297 // Add features according to the ELF attribute section. 298 // If there are any unrecognized features, ignore them. 299 RISCVAttributeParser Attributes; 300 if (Error E = getBuildAttributes(Attributes)) { 301 // TODO Propagate Error. 302 consumeError(std::move(E)); 303 return Features; // Keep "c" feature if there is one in PlatformFlags. 304 } 305 306 Optional<StringRef> Attr = Attributes.getAttributeString(RISCVAttrs::ARCH); 307 if (Attr) { 308 // The Arch pattern is [rv32|rv64][i|e]version(_[m|a|f|d|c]version)* 309 // Version string pattern is (major)p(minor). Major and minor are optional. 310 // For example, a version number could be 2p0, 2, or p92. 311 StringRef Arch = *Attr; 312 if (Arch.consume_front("rv32")) 313 Features.AddFeature("64bit", false); 314 else if (Arch.consume_front("rv64")) 315 Features.AddFeature("64bit"); 316 317 while (!Arch.empty()) { 318 switch (Arch[0]) { 319 default: 320 break; // Ignore unexpected features. 321 case 'i': 322 Features.AddFeature("e", false); 323 break; 324 case 'd': 325 Features.AddFeature("f"); // D-ext will imply F-ext. 326 [[fallthrough]]; 327 case 'e': 328 case 'm': 329 case 'a': 330 case 'f': 331 case 'c': 332 Features.AddFeature(Arch.take_front()); 333 break; 334 } 335 336 // FIXME: Handle version numbers. 337 Arch = Arch.drop_until([](char c) { return c == '_' || c == '\0'; }); 338 Arch = Arch.drop_while([](char c) { return c == '_'; }); 339 } 340 } 341 342 return Features; 343 } 344 345 SubtargetFeatures ELFObjectFileBase::getLoongArchFeatures() const { 346 SubtargetFeatures Features; 347 348 switch (getPlatformFlags() & ELF::EF_LOONGARCH_ABI_MODIFIER_MASK) { 349 case ELF::EF_LOONGARCH_ABI_SOFT_FLOAT: 350 break; 351 case ELF::EF_LOONGARCH_ABI_DOUBLE_FLOAT: 352 Features.AddFeature("d"); 353 // D implies F according to LoongArch ISA spec. 354 [[fallthrough]]; 355 case ELF::EF_LOONGARCH_ABI_SINGLE_FLOAT: 356 Features.AddFeature("f"); 357 break; 358 } 359 360 return Features; 361 } 362 363 SubtargetFeatures ELFObjectFileBase::getFeatures() const { 364 switch (getEMachine()) { 365 case ELF::EM_MIPS: 366 return getMIPSFeatures(); 367 case ELF::EM_ARM: 368 return getARMFeatures(); 369 case ELF::EM_RISCV: 370 return getRISCVFeatures(); 371 case ELF::EM_LOONGARCH: 372 return getLoongArchFeatures(); 373 default: 374 return SubtargetFeatures(); 375 } 376 } 377 378 Optional<StringRef> ELFObjectFileBase::tryGetCPUName() const { 379 switch (getEMachine()) { 380 case ELF::EM_AMDGPU: 381 return getAMDGPUCPUName(); 382 case ELF::EM_PPC64: 383 return StringRef("future"); 384 default: 385 return None; 386 } 387 } 388 389 StringRef ELFObjectFileBase::getAMDGPUCPUName() const { 390 assert(getEMachine() == ELF::EM_AMDGPU); 391 unsigned CPU = getPlatformFlags() & ELF::EF_AMDGPU_MACH; 392 393 switch (CPU) { 394 // Radeon HD 2000/3000 Series (R600). 395 case ELF::EF_AMDGPU_MACH_R600_R600: 396 return "r600"; 397 case ELF::EF_AMDGPU_MACH_R600_R630: 398 return "r630"; 399 case ELF::EF_AMDGPU_MACH_R600_RS880: 400 return "rs880"; 401 case ELF::EF_AMDGPU_MACH_R600_RV670: 402 return "rv670"; 403 404 // Radeon HD 4000 Series (R700). 405 case ELF::EF_AMDGPU_MACH_R600_RV710: 406 return "rv710"; 407 case ELF::EF_AMDGPU_MACH_R600_RV730: 408 return "rv730"; 409 case ELF::EF_AMDGPU_MACH_R600_RV770: 410 return "rv770"; 411 412 // Radeon HD 5000 Series (Evergreen). 413 case ELF::EF_AMDGPU_MACH_R600_CEDAR: 414 return "cedar"; 415 case ELF::EF_AMDGPU_MACH_R600_CYPRESS: 416 return "cypress"; 417 case ELF::EF_AMDGPU_MACH_R600_JUNIPER: 418 return "juniper"; 419 case ELF::EF_AMDGPU_MACH_R600_REDWOOD: 420 return "redwood"; 421 case ELF::EF_AMDGPU_MACH_R600_SUMO: 422 return "sumo"; 423 424 // Radeon HD 6000 Series (Northern Islands). 425 case ELF::EF_AMDGPU_MACH_R600_BARTS: 426 return "barts"; 427 case ELF::EF_AMDGPU_MACH_R600_CAICOS: 428 return "caicos"; 429 case ELF::EF_AMDGPU_MACH_R600_CAYMAN: 430 return "cayman"; 431 case ELF::EF_AMDGPU_MACH_R600_TURKS: 432 return "turks"; 433 434 // AMDGCN GFX6. 435 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX600: 436 return "gfx600"; 437 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX601: 438 return "gfx601"; 439 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX602: 440 return "gfx602"; 441 442 // AMDGCN GFX7. 443 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX700: 444 return "gfx700"; 445 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX701: 446 return "gfx701"; 447 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX702: 448 return "gfx702"; 449 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX703: 450 return "gfx703"; 451 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX704: 452 return "gfx704"; 453 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX705: 454 return "gfx705"; 455 456 // AMDGCN GFX8. 457 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX801: 458 return "gfx801"; 459 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX802: 460 return "gfx802"; 461 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX803: 462 return "gfx803"; 463 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX805: 464 return "gfx805"; 465 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX810: 466 return "gfx810"; 467 468 // AMDGCN GFX9. 469 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX900: 470 return "gfx900"; 471 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX902: 472 return "gfx902"; 473 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX904: 474 return "gfx904"; 475 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX906: 476 return "gfx906"; 477 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX908: 478 return "gfx908"; 479 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX909: 480 return "gfx909"; 481 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX90A: 482 return "gfx90a"; 483 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX90C: 484 return "gfx90c"; 485 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX940: 486 return "gfx940"; 487 488 // AMDGCN GFX10. 489 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX1010: 490 return "gfx1010"; 491 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX1011: 492 return "gfx1011"; 493 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX1012: 494 return "gfx1012"; 495 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX1013: 496 return "gfx1013"; 497 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX1030: 498 return "gfx1030"; 499 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX1031: 500 return "gfx1031"; 501 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX1032: 502 return "gfx1032"; 503 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX1033: 504 return "gfx1033"; 505 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX1034: 506 return "gfx1034"; 507 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX1035: 508 return "gfx1035"; 509 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX1036: 510 return "gfx1036"; 511 512 // AMDGCN GFX11. 513 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX1100: 514 return "gfx1100"; 515 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX1101: 516 return "gfx1101"; 517 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX1102: 518 return "gfx1102"; 519 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX1103: 520 return "gfx1103"; 521 default: 522 llvm_unreachable("Unknown EF_AMDGPU_MACH value"); 523 } 524 } 525 526 // FIXME Encode from a tablegen description or target parser. 527 void ELFObjectFileBase::setARMSubArch(Triple &TheTriple) const { 528 if (TheTriple.getSubArch() != Triple::NoSubArch) 529 return; 530 531 ARMAttributeParser Attributes; 532 if (Error E = getBuildAttributes(Attributes)) { 533 // TODO Propagate Error. 534 consumeError(std::move(E)); 535 return; 536 } 537 538 std::string Triple; 539 // Default to ARM, but use the triple if it's been set. 540 if (TheTriple.isThumb()) 541 Triple = "thumb"; 542 else 543 Triple = "arm"; 544 545 Optional<unsigned> Attr = 546 Attributes.getAttributeValue(ARMBuildAttrs::CPU_arch); 547 if (Attr) { 548 switch (Attr.value()) { 549 case ARMBuildAttrs::v4: 550 Triple += "v4"; 551 break; 552 case ARMBuildAttrs::v4T: 553 Triple += "v4t"; 554 break; 555 case ARMBuildAttrs::v5T: 556 Triple += "v5t"; 557 break; 558 case ARMBuildAttrs::v5TE: 559 Triple += "v5te"; 560 break; 561 case ARMBuildAttrs::v5TEJ: 562 Triple += "v5tej"; 563 break; 564 case ARMBuildAttrs::v6: 565 Triple += "v6"; 566 break; 567 case ARMBuildAttrs::v6KZ: 568 Triple += "v6kz"; 569 break; 570 case ARMBuildAttrs::v6T2: 571 Triple += "v6t2"; 572 break; 573 case ARMBuildAttrs::v6K: 574 Triple += "v6k"; 575 break; 576 case ARMBuildAttrs::v7: { 577 Optional<unsigned> ArchProfileAttr = 578 Attributes.getAttributeValue(ARMBuildAttrs::CPU_arch_profile); 579 if (ArchProfileAttr && 580 ArchProfileAttr.value() == ARMBuildAttrs::MicroControllerProfile) 581 Triple += "v7m"; 582 else 583 Triple += "v7"; 584 break; 585 } 586 case ARMBuildAttrs::v6_M: 587 Triple += "v6m"; 588 break; 589 case ARMBuildAttrs::v6S_M: 590 Triple += "v6sm"; 591 break; 592 case ARMBuildAttrs::v7E_M: 593 Triple += "v7em"; 594 break; 595 case ARMBuildAttrs::v8_A: 596 Triple += "v8a"; 597 break; 598 case ARMBuildAttrs::v8_R: 599 Triple += "v8r"; 600 break; 601 case ARMBuildAttrs::v8_M_Base: 602 Triple += "v8m.base"; 603 break; 604 case ARMBuildAttrs::v8_M_Main: 605 Triple += "v8m.main"; 606 break; 607 case ARMBuildAttrs::v8_1_M_Main: 608 Triple += "v8.1m.main"; 609 break; 610 case ARMBuildAttrs::v9_A: 611 Triple += "v9a"; 612 break; 613 } 614 } 615 if (!isLittleEndian()) 616 Triple += "eb"; 617 618 TheTriple.setArchName(Triple); 619 } 620 621 std::vector<std::pair<Optional<DataRefImpl>, uint64_t>> 622 ELFObjectFileBase::getPltAddresses() const { 623 std::string Err; 624 const auto Triple = makeTriple(); 625 const auto *T = TargetRegistry::lookupTarget(Triple.str(), Err); 626 if (!T) 627 return {}; 628 uint64_t JumpSlotReloc = 0; 629 switch (Triple.getArch()) { 630 case Triple::x86: 631 JumpSlotReloc = ELF::R_386_JUMP_SLOT; 632 break; 633 case Triple::x86_64: 634 JumpSlotReloc = ELF::R_X86_64_JUMP_SLOT; 635 break; 636 case Triple::aarch64: 637 case Triple::aarch64_be: 638 JumpSlotReloc = ELF::R_AARCH64_JUMP_SLOT; 639 break; 640 default: 641 return {}; 642 } 643 std::unique_ptr<const MCInstrInfo> MII(T->createMCInstrInfo()); 644 std::unique_ptr<const MCInstrAnalysis> MIA( 645 T->createMCInstrAnalysis(MII.get())); 646 if (!MIA) 647 return {}; 648 std::optional<SectionRef> Plt, RelaPlt, GotPlt; 649 for (const SectionRef &Section : sections()) { 650 Expected<StringRef> NameOrErr = Section.getName(); 651 if (!NameOrErr) { 652 consumeError(NameOrErr.takeError()); 653 continue; 654 } 655 StringRef Name = *NameOrErr; 656 657 if (Name == ".plt") 658 Plt = Section; 659 else if (Name == ".rela.plt" || Name == ".rel.plt") 660 RelaPlt = Section; 661 else if (Name == ".got.plt") 662 GotPlt = Section; 663 } 664 if (!Plt || !RelaPlt || !GotPlt) 665 return {}; 666 Expected<StringRef> PltContents = Plt->getContents(); 667 if (!PltContents) { 668 consumeError(PltContents.takeError()); 669 return {}; 670 } 671 auto PltEntries = MIA->findPltEntries(Plt->getAddress(), 672 arrayRefFromStringRef(*PltContents), 673 GotPlt->getAddress(), Triple); 674 // Build a map from GOT entry virtual address to PLT entry virtual address. 675 DenseMap<uint64_t, uint64_t> GotToPlt; 676 for (const auto &Entry : PltEntries) 677 GotToPlt.insert(std::make_pair(Entry.second, Entry.first)); 678 // Find the relocations in the dynamic relocation table that point to 679 // locations in the GOT for which we know the corresponding PLT entry. 680 std::vector<std::pair<Optional<DataRefImpl>, uint64_t>> Result; 681 for (const auto &Relocation : RelaPlt->relocations()) { 682 if (Relocation.getType() != JumpSlotReloc) 683 continue; 684 auto PltEntryIter = GotToPlt.find(Relocation.getOffset()); 685 if (PltEntryIter != GotToPlt.end()) { 686 symbol_iterator Sym = Relocation.getSymbol(); 687 if (Sym == symbol_end()) 688 Result.emplace_back(None, PltEntryIter->second); 689 else 690 Result.emplace_back(Sym->getRawDataRefImpl(), PltEntryIter->second); 691 } 692 } 693 return Result; 694 } 695 696 template <class ELFT> 697 Expected<std::vector<BBAddrMap>> static readBBAddrMapImpl( 698 const ELFFile<ELFT> &EF, Optional<unsigned> TextSectionIndex) { 699 using Elf_Shdr = typename ELFT::Shdr; 700 std::vector<BBAddrMap> BBAddrMaps; 701 const auto &Sections = cantFail(EF.sections()); 702 for (const Elf_Shdr &Sec : Sections) { 703 if (Sec.sh_type != ELF::SHT_LLVM_BB_ADDR_MAP && 704 Sec.sh_type != ELF::SHT_LLVM_BB_ADDR_MAP_V0) 705 continue; 706 if (TextSectionIndex) { 707 Expected<const Elf_Shdr *> TextSecOrErr = EF.getSection(Sec.sh_link); 708 if (!TextSecOrErr) 709 return createError("unable to get the linked-to section for " + 710 describe(EF, Sec) + ": " + 711 toString(TextSecOrErr.takeError())); 712 if (*TextSectionIndex != std::distance(Sections.begin(), *TextSecOrErr)) 713 continue; 714 } 715 Expected<std::vector<BBAddrMap>> BBAddrMapOrErr = EF.decodeBBAddrMap(Sec); 716 if (!BBAddrMapOrErr) 717 return createError("unable to read " + describe(EF, Sec) + ": " + 718 toString(BBAddrMapOrErr.takeError())); 719 std::move(BBAddrMapOrErr->begin(), BBAddrMapOrErr->end(), 720 std::back_inserter(BBAddrMaps)); 721 } 722 return BBAddrMaps; 723 } 724 725 template <class ELFT> 726 static Expected<std::vector<VersionEntry>> 727 readDynsymVersionsImpl(const ELFFile<ELFT> &EF, 728 ELFObjectFileBase::elf_symbol_iterator_range Symbols) { 729 using Elf_Shdr = typename ELFT::Shdr; 730 const Elf_Shdr *VerSec = nullptr; 731 const Elf_Shdr *VerNeedSec = nullptr; 732 const Elf_Shdr *VerDefSec = nullptr; 733 // The user should ensure sections() can't fail here. 734 for (const Elf_Shdr &Sec : cantFail(EF.sections())) { 735 if (Sec.sh_type == ELF::SHT_GNU_versym) 736 VerSec = &Sec; 737 else if (Sec.sh_type == ELF::SHT_GNU_verdef) 738 VerDefSec = &Sec; 739 else if (Sec.sh_type == ELF::SHT_GNU_verneed) 740 VerNeedSec = &Sec; 741 } 742 if (!VerSec) 743 return std::vector<VersionEntry>(); 744 745 Expected<SmallVector<Optional<VersionEntry>, 0>> MapOrErr = 746 EF.loadVersionMap(VerNeedSec, VerDefSec); 747 if (!MapOrErr) 748 return MapOrErr.takeError(); 749 750 std::vector<VersionEntry> Ret; 751 size_t I = 0; 752 for (const ELFSymbolRef &Sym : Symbols) { 753 ++I; 754 Expected<const typename ELFT::Versym *> VerEntryOrErr = 755 EF.template getEntry<typename ELFT::Versym>(*VerSec, I); 756 if (!VerEntryOrErr) 757 return createError("unable to read an entry with index " + Twine(I) + 758 " from " + describe(EF, *VerSec) + ": " + 759 toString(VerEntryOrErr.takeError())); 760 761 Expected<uint32_t> FlagsOrErr = Sym.getFlags(); 762 if (!FlagsOrErr) 763 return createError("unable to read flags for symbol with index " + 764 Twine(I) + ": " + toString(FlagsOrErr.takeError())); 765 766 bool IsDefault; 767 Expected<StringRef> VerOrErr = EF.getSymbolVersionByIndex( 768 (*VerEntryOrErr)->vs_index, IsDefault, *MapOrErr, 769 (*FlagsOrErr) & SymbolRef::SF_Undefined); 770 if (!VerOrErr) 771 return createError("unable to get a version for entry " + Twine(I) + 772 " of " + describe(EF, *VerSec) + ": " + 773 toString(VerOrErr.takeError())); 774 775 Ret.push_back({(*VerOrErr).str(), IsDefault}); 776 } 777 778 return Ret; 779 } 780 781 Expected<std::vector<VersionEntry>> 782 ELFObjectFileBase::readDynsymVersions() const { 783 elf_symbol_iterator_range Symbols = getDynamicSymbolIterators(); 784 if (const auto *Obj = dyn_cast<ELF32LEObjectFile>(this)) 785 return readDynsymVersionsImpl(Obj->getELFFile(), Symbols); 786 if (const auto *Obj = dyn_cast<ELF32BEObjectFile>(this)) 787 return readDynsymVersionsImpl(Obj->getELFFile(), Symbols); 788 if (const auto *Obj = dyn_cast<ELF64LEObjectFile>(this)) 789 return readDynsymVersionsImpl(Obj->getELFFile(), Symbols); 790 return readDynsymVersionsImpl(cast<ELF64BEObjectFile>(this)->getELFFile(), 791 Symbols); 792 } 793 794 Expected<std::vector<BBAddrMap>> 795 ELFObjectFileBase::readBBAddrMap(Optional<unsigned> TextSectionIndex) const { 796 if (const auto *Obj = dyn_cast<ELF32LEObjectFile>(this)) 797 return readBBAddrMapImpl(Obj->getELFFile(), TextSectionIndex); 798 if (const auto *Obj = dyn_cast<ELF64LEObjectFile>(this)) 799 return readBBAddrMapImpl(Obj->getELFFile(), TextSectionIndex); 800 if (const auto *Obj = dyn_cast<ELF32BEObjectFile>(this)) 801 return readBBAddrMapImpl(Obj->getELFFile(), TextSectionIndex); 802 if (const auto *Obj = cast<ELF64BEObjectFile>(this)) 803 return readBBAddrMapImpl(Obj->getELFFile(), TextSectionIndex); 804 else 805 llvm_unreachable("Unsupported binary format"); 806 } 807