1 //===-- RuntimeDyldELF.cpp - Run-time dynamic linker for MC-JIT -*- 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 // Implementation of ELF support for the MC-JIT runtime dynamic linker. 10 // 11 //===----------------------------------------------------------------------===// 12 13 #include "RuntimeDyldELF.h" 14 #include "Targets/RuntimeDyldELFMips.h" 15 #include "llvm/ADT/StringRef.h" 16 #include "llvm/BinaryFormat/ELF.h" 17 #include "llvm/ExecutionEngine/Orc/SymbolStringPool.h" 18 #include "llvm/Object/ELFObjectFile.h" 19 #include "llvm/Object/ObjectFile.h" 20 #include "llvm/Support/Endian.h" 21 #include "llvm/Support/MemoryBuffer.h" 22 #include "llvm/TargetParser/Triple.h" 23 24 using namespace llvm; 25 using namespace llvm::object; 26 using namespace llvm::support::endian; 27 28 #define DEBUG_TYPE "dyld" 29 30 static void or32le(void *P, int32_t V) { write32le(P, read32le(P) | V); } 31 32 static void or32AArch64Imm(void *L, uint64_t Imm) { 33 or32le(L, (Imm & 0xFFF) << 10); 34 } 35 36 template <class T> static void write(bool isBE, void *P, T V) { 37 isBE ? write<T, llvm::endianness::big>(P, V) 38 : write<T, llvm::endianness::little>(P, V); 39 } 40 41 static void write32AArch64Addr(void *L, uint64_t Imm) { 42 uint32_t ImmLo = (Imm & 0x3) << 29; 43 uint32_t ImmHi = (Imm & 0x1FFFFC) << 3; 44 uint64_t Mask = (0x3 << 29) | (0x1FFFFC << 3); 45 write32le(L, (read32le(L) & ~Mask) | ImmLo | ImmHi); 46 } 47 48 // Return the bits [Start, End] from Val shifted Start bits. 49 // For instance, getBits(0xF0, 4, 8) returns 0xF. 50 static uint64_t getBits(uint64_t Val, int Start, int End) { 51 uint64_t Mask = ((uint64_t)1 << (End + 1 - Start)) - 1; 52 return (Val >> Start) & Mask; 53 } 54 55 namespace { 56 57 template <class ELFT> class DyldELFObject : public ELFObjectFile<ELFT> { 58 LLVM_ELF_IMPORT_TYPES_ELFT(ELFT) 59 60 typedef typename ELFT::uint addr_type; 61 62 DyldELFObject(ELFObjectFile<ELFT> &&Obj); 63 64 public: 65 static Expected<std::unique_ptr<DyldELFObject>> 66 create(MemoryBufferRef Wrapper); 67 68 void updateSectionAddress(const SectionRef &Sec, uint64_t Addr); 69 70 void updateSymbolAddress(const SymbolRef &SymRef, uint64_t Addr); 71 72 // Methods for type inquiry through isa, cast and dyn_cast 73 static bool classof(const Binary *v) { 74 return (isa<ELFObjectFile<ELFT>>(v) && 75 classof(cast<ELFObjectFile<ELFT>>(v))); 76 } 77 static bool classof(const ELFObjectFile<ELFT> *v) { 78 return v->isDyldType(); 79 } 80 }; 81 82 83 84 // The MemoryBuffer passed into this constructor is just a wrapper around the 85 // actual memory. Ultimately, the Binary parent class will take ownership of 86 // this MemoryBuffer object but not the underlying memory. 87 template <class ELFT> 88 DyldELFObject<ELFT>::DyldELFObject(ELFObjectFile<ELFT> &&Obj) 89 : ELFObjectFile<ELFT>(std::move(Obj)) { 90 this->isDyldELFObject = true; 91 } 92 93 template <class ELFT> 94 Expected<std::unique_ptr<DyldELFObject<ELFT>>> 95 DyldELFObject<ELFT>::create(MemoryBufferRef Wrapper) { 96 auto Obj = ELFObjectFile<ELFT>::create(Wrapper); 97 if (auto E = Obj.takeError()) 98 return std::move(E); 99 std::unique_ptr<DyldELFObject<ELFT>> Ret( 100 new DyldELFObject<ELFT>(std::move(*Obj))); 101 return std::move(Ret); 102 } 103 104 template <class ELFT> 105 void DyldELFObject<ELFT>::updateSectionAddress(const SectionRef &Sec, 106 uint64_t Addr) { 107 DataRefImpl ShdrRef = Sec.getRawDataRefImpl(); 108 Elf_Shdr *shdr = 109 const_cast<Elf_Shdr *>(reinterpret_cast<const Elf_Shdr *>(ShdrRef.p)); 110 111 // This assumes the address passed in matches the target address bitness 112 // The template-based type cast handles everything else. 113 shdr->sh_addr = static_cast<addr_type>(Addr); 114 } 115 116 template <class ELFT> 117 void DyldELFObject<ELFT>::updateSymbolAddress(const SymbolRef &SymRef, 118 uint64_t Addr) { 119 120 Elf_Sym *sym = const_cast<Elf_Sym *>( 121 ELFObjectFile<ELFT>::getSymbol(SymRef.getRawDataRefImpl())); 122 123 // This assumes the address passed in matches the target address bitness 124 // The template-based type cast handles everything else. 125 sym->st_value = static_cast<addr_type>(Addr); 126 } 127 128 class LoadedELFObjectInfo final 129 : public LoadedObjectInfoHelper<LoadedELFObjectInfo, 130 RuntimeDyld::LoadedObjectInfo> { 131 public: 132 LoadedELFObjectInfo(RuntimeDyldImpl &RTDyld, ObjSectionToIDMap ObjSecToIDMap) 133 : LoadedObjectInfoHelper(RTDyld, std::move(ObjSecToIDMap)) {} 134 135 OwningBinary<ObjectFile> 136 getObjectForDebug(const ObjectFile &Obj) const override; 137 }; 138 139 template <typename ELFT> 140 static Expected<std::unique_ptr<DyldELFObject<ELFT>>> 141 createRTDyldELFObject(MemoryBufferRef Buffer, const ObjectFile &SourceObject, 142 const LoadedELFObjectInfo &L) { 143 typedef typename ELFT::Shdr Elf_Shdr; 144 typedef typename ELFT::uint addr_type; 145 146 Expected<std::unique_ptr<DyldELFObject<ELFT>>> ObjOrErr = 147 DyldELFObject<ELFT>::create(Buffer); 148 if (Error E = ObjOrErr.takeError()) 149 return std::move(E); 150 151 std::unique_ptr<DyldELFObject<ELFT>> Obj = std::move(*ObjOrErr); 152 153 // Iterate over all sections in the object. 154 auto SI = SourceObject.section_begin(); 155 for (const auto &Sec : Obj->sections()) { 156 Expected<StringRef> NameOrErr = Sec.getName(); 157 if (!NameOrErr) { 158 consumeError(NameOrErr.takeError()); 159 continue; 160 } 161 162 if (*NameOrErr != "") { 163 DataRefImpl ShdrRef = Sec.getRawDataRefImpl(); 164 Elf_Shdr *shdr = const_cast<Elf_Shdr *>( 165 reinterpret_cast<const Elf_Shdr *>(ShdrRef.p)); 166 167 if (uint64_t SecLoadAddr = L.getSectionLoadAddress(*SI)) { 168 // This assumes that the address passed in matches the target address 169 // bitness. The template-based type cast handles everything else. 170 shdr->sh_addr = static_cast<addr_type>(SecLoadAddr); 171 } 172 } 173 ++SI; 174 } 175 176 return std::move(Obj); 177 } 178 179 static OwningBinary<ObjectFile> 180 createELFDebugObject(const ObjectFile &Obj, const LoadedELFObjectInfo &L) { 181 assert(Obj.isELF() && "Not an ELF object file."); 182 183 std::unique_ptr<MemoryBuffer> Buffer = 184 MemoryBuffer::getMemBufferCopy(Obj.getData(), Obj.getFileName()); 185 186 Expected<std::unique_ptr<ObjectFile>> DebugObj(nullptr); 187 handleAllErrors(DebugObj.takeError()); 188 if (Obj.getBytesInAddress() == 4 && Obj.isLittleEndian()) 189 DebugObj = 190 createRTDyldELFObject<ELF32LE>(Buffer->getMemBufferRef(), Obj, L); 191 else if (Obj.getBytesInAddress() == 4 && !Obj.isLittleEndian()) 192 DebugObj = 193 createRTDyldELFObject<ELF32BE>(Buffer->getMemBufferRef(), Obj, L); 194 else if (Obj.getBytesInAddress() == 8 && !Obj.isLittleEndian()) 195 DebugObj = 196 createRTDyldELFObject<ELF64BE>(Buffer->getMemBufferRef(), Obj, L); 197 else if (Obj.getBytesInAddress() == 8 && Obj.isLittleEndian()) 198 DebugObj = 199 createRTDyldELFObject<ELF64LE>(Buffer->getMemBufferRef(), Obj, L); 200 else 201 llvm_unreachable("Unexpected ELF format"); 202 203 handleAllErrors(DebugObj.takeError()); 204 return OwningBinary<ObjectFile>(std::move(*DebugObj), std::move(Buffer)); 205 } 206 207 OwningBinary<ObjectFile> 208 LoadedELFObjectInfo::getObjectForDebug(const ObjectFile &Obj) const { 209 return createELFDebugObject(Obj, *this); 210 } 211 212 } // anonymous namespace 213 214 namespace llvm { 215 216 RuntimeDyldELF::RuntimeDyldELF(RuntimeDyld::MemoryManager &MemMgr, 217 JITSymbolResolver &Resolver) 218 : RuntimeDyldImpl(MemMgr, Resolver), GOTSectionID(0), CurrentGOTIndex(0) {} 219 RuntimeDyldELF::~RuntimeDyldELF() = default; 220 221 void RuntimeDyldELF::registerEHFrames() { 222 for (SID EHFrameSID : UnregisteredEHFrameSections) { 223 uint8_t *EHFrameAddr = Sections[EHFrameSID].getAddress(); 224 uint64_t EHFrameLoadAddr = Sections[EHFrameSID].getLoadAddress(); 225 size_t EHFrameSize = Sections[EHFrameSID].getSize(); 226 MemMgr.registerEHFrames(EHFrameAddr, EHFrameLoadAddr, EHFrameSize); 227 } 228 UnregisteredEHFrameSections.clear(); 229 } 230 231 std::unique_ptr<RuntimeDyldELF> 232 llvm::RuntimeDyldELF::create(Triple::ArchType Arch, 233 RuntimeDyld::MemoryManager &MemMgr, 234 JITSymbolResolver &Resolver) { 235 switch (Arch) { 236 default: 237 return std::make_unique<RuntimeDyldELF>(MemMgr, Resolver); 238 case Triple::mips: 239 case Triple::mipsel: 240 case Triple::mips64: 241 case Triple::mips64el: 242 return std::make_unique<RuntimeDyldELFMips>(MemMgr, Resolver); 243 } 244 } 245 246 std::unique_ptr<RuntimeDyld::LoadedObjectInfo> 247 RuntimeDyldELF::loadObject(const object::ObjectFile &O) { 248 if (auto ObjSectionToIDOrErr = loadObjectImpl(O)) 249 return std::make_unique<LoadedELFObjectInfo>(*this, *ObjSectionToIDOrErr); 250 else { 251 HasError = true; 252 raw_string_ostream ErrStream(ErrorStr); 253 logAllUnhandledErrors(ObjSectionToIDOrErr.takeError(), ErrStream); 254 return nullptr; 255 } 256 } 257 258 void RuntimeDyldELF::resolveX86_64Relocation(const SectionEntry &Section, 259 uint64_t Offset, uint64_t Value, 260 uint32_t Type, int64_t Addend, 261 uint64_t SymOffset) { 262 switch (Type) { 263 default: 264 report_fatal_error("Relocation type not implemented yet!"); 265 break; 266 case ELF::R_X86_64_NONE: 267 break; 268 case ELF::R_X86_64_8: { 269 Value += Addend; 270 assert((int64_t)Value <= INT8_MAX && (int64_t)Value >= INT8_MIN); 271 uint8_t TruncatedAddr = (Value & 0xFF); 272 *Section.getAddressWithOffset(Offset) = TruncatedAddr; 273 LLVM_DEBUG(dbgs() << "Writing " << format("%p", TruncatedAddr) << " at " 274 << format("%p\n", Section.getAddressWithOffset(Offset))); 275 break; 276 } 277 case ELF::R_X86_64_16: { 278 Value += Addend; 279 assert((int64_t)Value <= INT16_MAX && (int64_t)Value >= INT16_MIN); 280 uint16_t TruncatedAddr = (Value & 0xFFFF); 281 support::ulittle16_t::ref(Section.getAddressWithOffset(Offset)) = 282 TruncatedAddr; 283 LLVM_DEBUG(dbgs() << "Writing " << format("%p", TruncatedAddr) << " at " 284 << format("%p\n", Section.getAddressWithOffset(Offset))); 285 break; 286 } 287 case ELF::R_X86_64_64: { 288 support::ulittle64_t::ref(Section.getAddressWithOffset(Offset)) = 289 Value + Addend; 290 LLVM_DEBUG(dbgs() << "Writing " << format("%p", (Value + Addend)) << " at " 291 << format("%p\n", Section.getAddressWithOffset(Offset))); 292 break; 293 } 294 case ELF::R_X86_64_32: 295 case ELF::R_X86_64_32S: { 296 Value += Addend; 297 assert((Type == ELF::R_X86_64_32 && (Value <= UINT32_MAX)) || 298 (Type == ELF::R_X86_64_32S && 299 ((int64_t)Value <= INT32_MAX && (int64_t)Value >= INT32_MIN))); 300 uint32_t TruncatedAddr = (Value & 0xFFFFFFFF); 301 support::ulittle32_t::ref(Section.getAddressWithOffset(Offset)) = 302 TruncatedAddr; 303 LLVM_DEBUG(dbgs() << "Writing " << format("%p", TruncatedAddr) << " at " 304 << format("%p\n", Section.getAddressWithOffset(Offset))); 305 break; 306 } 307 case ELF::R_X86_64_PC8: { 308 uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset); 309 int64_t RealOffset = Value + Addend - FinalAddress; 310 assert(isInt<8>(RealOffset)); 311 int8_t TruncOffset = (RealOffset & 0xFF); 312 Section.getAddress()[Offset] = TruncOffset; 313 break; 314 } 315 case ELF::R_X86_64_PC32: { 316 uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset); 317 int64_t RealOffset = Value + Addend - FinalAddress; 318 assert(isInt<32>(RealOffset)); 319 int32_t TruncOffset = (RealOffset & 0xFFFFFFFF); 320 support::ulittle32_t::ref(Section.getAddressWithOffset(Offset)) = 321 TruncOffset; 322 break; 323 } 324 case ELF::R_X86_64_PC64: { 325 uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset); 326 int64_t RealOffset = Value + Addend - FinalAddress; 327 support::ulittle64_t::ref(Section.getAddressWithOffset(Offset)) = 328 RealOffset; 329 LLVM_DEBUG(dbgs() << "Writing " << format("%p", RealOffset) << " at " 330 << format("%p\n", FinalAddress)); 331 break; 332 } 333 case ELF::R_X86_64_GOTOFF64: { 334 // Compute Value - GOTBase. 335 uint64_t GOTBase = 0; 336 for (const auto &Section : Sections) { 337 if (Section.getName() == ".got") { 338 GOTBase = Section.getLoadAddressWithOffset(0); 339 break; 340 } 341 } 342 assert(GOTBase != 0 && "missing GOT"); 343 int64_t GOTOffset = Value - GOTBase + Addend; 344 support::ulittle64_t::ref(Section.getAddressWithOffset(Offset)) = GOTOffset; 345 break; 346 } 347 case ELF::R_X86_64_DTPMOD64: { 348 // We only have one DSO, so the module id is always 1. 349 support::ulittle64_t::ref(Section.getAddressWithOffset(Offset)) = 1; 350 break; 351 } 352 case ELF::R_X86_64_DTPOFF64: 353 case ELF::R_X86_64_TPOFF64: { 354 // DTPOFF64 should resolve to the offset in the TLS block, TPOFF64 to the 355 // offset in the *initial* TLS block. Since we are statically linking, all 356 // TLS blocks already exist in the initial block, so resolve both 357 // relocations equally. 358 support::ulittle64_t::ref(Section.getAddressWithOffset(Offset)) = 359 Value + Addend; 360 break; 361 } 362 case ELF::R_X86_64_DTPOFF32: 363 case ELF::R_X86_64_TPOFF32: { 364 // As for the (D)TPOFF64 relocations above, both DTPOFF32 and TPOFF32 can 365 // be resolved equally. 366 int64_t RealValue = Value + Addend; 367 assert(RealValue >= INT32_MIN && RealValue <= INT32_MAX); 368 int32_t TruncValue = RealValue; 369 support::ulittle32_t::ref(Section.getAddressWithOffset(Offset)) = 370 TruncValue; 371 break; 372 } 373 } 374 } 375 376 void RuntimeDyldELF::resolveX86Relocation(const SectionEntry &Section, 377 uint64_t Offset, uint32_t Value, 378 uint32_t Type, int32_t Addend) { 379 switch (Type) { 380 case ELF::R_386_32: { 381 support::ulittle32_t::ref(Section.getAddressWithOffset(Offset)) = 382 Value + Addend; 383 break; 384 } 385 // Handle R_386_PLT32 like R_386_PC32 since it should be able to 386 // reach any 32 bit address. 387 case ELF::R_386_PLT32: 388 case ELF::R_386_PC32: { 389 uint32_t FinalAddress = 390 Section.getLoadAddressWithOffset(Offset) & 0xFFFFFFFF; 391 uint32_t RealOffset = Value + Addend - FinalAddress; 392 support::ulittle32_t::ref(Section.getAddressWithOffset(Offset)) = 393 RealOffset; 394 break; 395 } 396 default: 397 // There are other relocation types, but it appears these are the 398 // only ones currently used by the LLVM ELF object writer 399 report_fatal_error("Relocation type not implemented yet!"); 400 break; 401 } 402 } 403 404 void RuntimeDyldELF::resolveAArch64Relocation(const SectionEntry &Section, 405 uint64_t Offset, uint64_t Value, 406 uint32_t Type, int64_t Addend) { 407 uint32_t *TargetPtr = 408 reinterpret_cast<uint32_t *>(Section.getAddressWithOffset(Offset)); 409 uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset); 410 // Data should use target endian. Code should always use little endian. 411 bool isBE = Arch == Triple::aarch64_be; 412 413 LLVM_DEBUG(dbgs() << "resolveAArch64Relocation, LocalAddress: 0x" 414 << format("%llx", Section.getAddressWithOffset(Offset)) 415 << " FinalAddress: 0x" << format("%llx", FinalAddress) 416 << " Value: 0x" << format("%llx", Value) << " Type: 0x" 417 << format("%x", Type) << " Addend: 0x" 418 << format("%llx", Addend) << "\n"); 419 420 switch (Type) { 421 default: 422 report_fatal_error("Relocation type not implemented yet!"); 423 break; 424 case ELF::R_AARCH64_NONE: 425 break; 426 case ELF::R_AARCH64_ABS16: { 427 uint64_t Result = Value + Addend; 428 assert(Result == static_cast<uint64_t>(llvm::SignExtend64(Result, 16)) || 429 (Result >> 16) == 0); 430 write(isBE, TargetPtr, static_cast<uint16_t>(Result & 0xffffU)); 431 break; 432 } 433 case ELF::R_AARCH64_ABS32: { 434 uint64_t Result = Value + Addend; 435 assert(Result == static_cast<uint64_t>(llvm::SignExtend64(Result, 32)) || 436 (Result >> 32) == 0); 437 write(isBE, TargetPtr, static_cast<uint32_t>(Result & 0xffffffffU)); 438 break; 439 } 440 case ELF::R_AARCH64_ABS64: 441 write(isBE, TargetPtr, Value + Addend); 442 break; 443 case ELF::R_AARCH64_PLT32: { 444 uint64_t Result = Value + Addend - FinalAddress; 445 assert(static_cast<int64_t>(Result) >= INT32_MIN && 446 static_cast<int64_t>(Result) <= INT32_MAX); 447 write(isBE, TargetPtr, static_cast<uint32_t>(Result)); 448 break; 449 } 450 case ELF::R_AARCH64_PREL16: { 451 uint64_t Result = Value + Addend - FinalAddress; 452 assert(static_cast<int64_t>(Result) >= INT16_MIN && 453 static_cast<int64_t>(Result) <= UINT16_MAX); 454 write(isBE, TargetPtr, static_cast<uint16_t>(Result & 0xffffU)); 455 break; 456 } 457 case ELF::R_AARCH64_PREL32: { 458 uint64_t Result = Value + Addend - FinalAddress; 459 assert(static_cast<int64_t>(Result) >= INT32_MIN && 460 static_cast<int64_t>(Result) <= UINT32_MAX); 461 write(isBE, TargetPtr, static_cast<uint32_t>(Result & 0xffffffffU)); 462 break; 463 } 464 case ELF::R_AARCH64_PREL64: 465 write(isBE, TargetPtr, Value + Addend - FinalAddress); 466 break; 467 case ELF::R_AARCH64_CONDBR19: { 468 uint64_t BranchImm = Value + Addend - FinalAddress; 469 470 assert(isInt<21>(BranchImm)); 471 *TargetPtr &= 0xff00001fU; 472 // Immediate:20:2 goes in bits 23:5 of Bcc, CBZ, CBNZ 473 or32le(TargetPtr, (BranchImm & 0x001FFFFC) << 3); 474 break; 475 } 476 case ELF::R_AARCH64_TSTBR14: { 477 uint64_t BranchImm = Value + Addend - FinalAddress; 478 479 assert(isInt<16>(BranchImm)); 480 481 uint32_t RawInstr = *(support::little32_t *)TargetPtr; 482 *(support::little32_t *)TargetPtr = RawInstr & 0xfff8001fU; 483 484 // Immediate:15:2 goes in bits 18:5 of TBZ, TBNZ 485 or32le(TargetPtr, (BranchImm & 0x0000FFFC) << 3); 486 break; 487 } 488 case ELF::R_AARCH64_CALL26: // fallthrough 489 case ELF::R_AARCH64_JUMP26: { 490 // Operation: S+A-P. Set Call or B immediate value to bits fff_fffc of the 491 // calculation. 492 uint64_t BranchImm = Value + Addend - FinalAddress; 493 494 // "Check that -2^27 <= result < 2^27". 495 assert(isInt<28>(BranchImm)); 496 or32le(TargetPtr, (BranchImm & 0x0FFFFFFC) >> 2); 497 break; 498 } 499 case ELF::R_AARCH64_MOVW_UABS_G3: 500 or32le(TargetPtr, ((Value + Addend) & 0xFFFF000000000000) >> 43); 501 break; 502 case ELF::R_AARCH64_MOVW_UABS_G2_NC: 503 or32le(TargetPtr, ((Value + Addend) & 0xFFFF00000000) >> 27); 504 break; 505 case ELF::R_AARCH64_MOVW_UABS_G1_NC: 506 or32le(TargetPtr, ((Value + Addend) & 0xFFFF0000) >> 11); 507 break; 508 case ELF::R_AARCH64_MOVW_UABS_G0_NC: 509 or32le(TargetPtr, ((Value + Addend) & 0xFFFF) << 5); 510 break; 511 case ELF::R_AARCH64_ADR_PREL_PG_HI21: { 512 // Operation: Page(S+A) - Page(P) 513 uint64_t Result = 514 ((Value + Addend) & ~0xfffULL) - (FinalAddress & ~0xfffULL); 515 516 // Check that -2^32 <= X < 2^32 517 assert(isInt<33>(Result) && "overflow check failed for relocation"); 518 519 // Immediate goes in bits 30:29 + 5:23 of ADRP instruction, taken 520 // from bits 32:12 of X. 521 write32AArch64Addr(TargetPtr, Result >> 12); 522 break; 523 } 524 case ELF::R_AARCH64_ADD_ABS_LO12_NC: 525 // Operation: S + A 526 // Immediate goes in bits 21:10 of LD/ST instruction, taken 527 // from bits 11:0 of X 528 or32AArch64Imm(TargetPtr, Value + Addend); 529 break; 530 case ELF::R_AARCH64_LDST8_ABS_LO12_NC: 531 // Operation: S + A 532 // Immediate goes in bits 21:10 of LD/ST instruction, taken 533 // from bits 11:0 of X 534 or32AArch64Imm(TargetPtr, getBits(Value + Addend, 0, 11)); 535 break; 536 case ELF::R_AARCH64_LDST16_ABS_LO12_NC: 537 // Operation: S + A 538 // Immediate goes in bits 21:10 of LD/ST instruction, taken 539 // from bits 11:1 of X 540 or32AArch64Imm(TargetPtr, getBits(Value + Addend, 1, 11)); 541 break; 542 case ELF::R_AARCH64_LDST32_ABS_LO12_NC: 543 // Operation: S + A 544 // Immediate goes in bits 21:10 of LD/ST instruction, taken 545 // from bits 11:2 of X 546 or32AArch64Imm(TargetPtr, getBits(Value + Addend, 2, 11)); 547 break; 548 case ELF::R_AARCH64_LDST64_ABS_LO12_NC: 549 // Operation: S + A 550 // Immediate goes in bits 21:10 of LD/ST instruction, taken 551 // from bits 11:3 of X 552 or32AArch64Imm(TargetPtr, getBits(Value + Addend, 3, 11)); 553 break; 554 case ELF::R_AARCH64_LDST128_ABS_LO12_NC: 555 // Operation: S + A 556 // Immediate goes in bits 21:10 of LD/ST instruction, taken 557 // from bits 11:4 of X 558 or32AArch64Imm(TargetPtr, getBits(Value + Addend, 4, 11)); 559 break; 560 case ELF::R_AARCH64_LD_PREL_LO19: { 561 // Operation: S + A - P 562 uint64_t Result = Value + Addend - FinalAddress; 563 564 // "Check that -2^20 <= result < 2^20". 565 assert(isInt<21>(Result)); 566 567 *TargetPtr &= 0xff00001fU; 568 // Immediate goes in bits 23:5 of LD imm instruction, taken 569 // from bits 20:2 of X 570 *TargetPtr |= ((Result & 0xffc) << (5 - 2)); 571 break; 572 } 573 case ELF::R_AARCH64_ADR_PREL_LO21: { 574 // Operation: S + A - P 575 uint64_t Result = Value + Addend - FinalAddress; 576 577 // "Check that -2^20 <= result < 2^20". 578 assert(isInt<21>(Result)); 579 580 *TargetPtr &= 0x9f00001fU; 581 // Immediate goes in bits 23:5, 30:29 of ADR imm instruction, taken 582 // from bits 20:0 of X 583 *TargetPtr |= ((Result & 0xffc) << (5 - 2)); 584 *TargetPtr |= (Result & 0x3) << 29; 585 break; 586 } 587 } 588 } 589 590 void RuntimeDyldELF::resolveARMRelocation(const SectionEntry &Section, 591 uint64_t Offset, uint32_t Value, 592 uint32_t Type, int32_t Addend) { 593 // TODO: Add Thumb relocations. 594 uint32_t *TargetPtr = 595 reinterpret_cast<uint32_t *>(Section.getAddressWithOffset(Offset)); 596 uint32_t FinalAddress = Section.getLoadAddressWithOffset(Offset) & 0xFFFFFFFF; 597 Value += Addend; 598 599 LLVM_DEBUG(dbgs() << "resolveARMRelocation, LocalAddress: " 600 << Section.getAddressWithOffset(Offset) 601 << " FinalAddress: " << format("%p", FinalAddress) 602 << " Value: " << format("%x", Value) 603 << " Type: " << format("%x", Type) 604 << " Addend: " << format("%x", Addend) << "\n"); 605 606 switch (Type) { 607 default: 608 llvm_unreachable("Not implemented relocation type!"); 609 610 case ELF::R_ARM_NONE: 611 break; 612 // Write a 31bit signed offset 613 case ELF::R_ARM_PREL31: 614 support::ulittle32_t::ref{TargetPtr} = 615 (support::ulittle32_t::ref{TargetPtr} & 0x80000000) | 616 ((Value - FinalAddress) & ~0x80000000); 617 break; 618 case ELF::R_ARM_TARGET1: 619 case ELF::R_ARM_ABS32: 620 support::ulittle32_t::ref{TargetPtr} = Value; 621 break; 622 // Write first 16 bit of 32 bit value to the mov instruction. 623 // Last 4 bit should be shifted. 624 case ELF::R_ARM_MOVW_ABS_NC: 625 case ELF::R_ARM_MOVT_ABS: 626 if (Type == ELF::R_ARM_MOVW_ABS_NC) 627 Value = Value & 0xFFFF; 628 else if (Type == ELF::R_ARM_MOVT_ABS) 629 Value = (Value >> 16) & 0xFFFF; 630 support::ulittle32_t::ref{TargetPtr} = 631 (support::ulittle32_t::ref{TargetPtr} & ~0x000F0FFF) | (Value & 0xFFF) | 632 (((Value >> 12) & 0xF) << 16); 633 break; 634 // Write 24 bit relative value to the branch instruction. 635 case ELF::R_ARM_PC24: // Fall through. 636 case ELF::R_ARM_CALL: // Fall through. 637 case ELF::R_ARM_JUMP24: 638 int32_t RelValue = static_cast<int32_t>(Value - FinalAddress - 8); 639 RelValue = (RelValue & 0x03FFFFFC) >> 2; 640 assert((support::ulittle32_t::ref{TargetPtr} & 0xFFFFFF) == 0xFFFFFE); 641 support::ulittle32_t::ref{TargetPtr} = 642 (support::ulittle32_t::ref{TargetPtr} & 0xFF000000) | RelValue; 643 break; 644 } 645 } 646 647 bool RuntimeDyldELF::resolveLoongArch64ShortBranch( 648 unsigned SectionID, relocation_iterator RelI, 649 const RelocationValueRef &Value) { 650 uint64_t Address; 651 if (Value.SymbolName) { 652 auto Loc = GlobalSymbolTable.find(Value.SymbolName); 653 // Don't create direct branch for external symbols. 654 if (Loc == GlobalSymbolTable.end()) 655 return false; 656 const auto &SymInfo = Loc->second; 657 Address = 658 uint64_t(Sections[SymInfo.getSectionID()].getLoadAddressWithOffset( 659 SymInfo.getOffset())); 660 } else { 661 Address = uint64_t(Sections[Value.SectionID].getLoadAddress()); 662 } 663 uint64_t Offset = RelI->getOffset(); 664 uint64_t SourceAddress = Sections[SectionID].getLoadAddressWithOffset(Offset); 665 uint64_t Delta = Address + Value.Addend - SourceAddress; 666 // Normal call 667 if (RelI->getType() == ELF::R_LARCH_B26) { 668 if (!isInt<28>(Delta)) 669 return false; 670 resolveRelocation(Sections[SectionID], Offset, Address, RelI->getType(), 671 Value.Addend); 672 return true; 673 } 674 // Medium call: R_LARCH_CALL36 675 // Range: [-128G - 0x20000, +128G - 0x20000) 676 if (((int64_t)Delta + 0x20000) != llvm::SignExtend64(Delta + 0x20000, 38)) 677 return false; 678 resolveRelocation(Sections[SectionID], Offset, Address, RelI->getType(), 679 Value.Addend); 680 return true; 681 } 682 683 void RuntimeDyldELF::resolveLoongArch64Branch(unsigned SectionID, 684 const RelocationValueRef &Value, 685 relocation_iterator RelI, 686 StubMap &Stubs) { 687 LLVM_DEBUG(dbgs() << "\t\tThis is an LoongArch64 branch relocation.\n"); 688 689 if (resolveLoongArch64ShortBranch(SectionID, RelI, Value)) 690 return; 691 692 SectionEntry &Section = Sections[SectionID]; 693 uint64_t Offset = RelI->getOffset(); 694 unsigned RelType = RelI->getType(); 695 // Look for an existing stub. 696 auto [It, Inserted] = Stubs.try_emplace(Value); 697 if (!Inserted) { 698 resolveRelocation(Section, Offset, 699 (uint64_t)Section.getAddressWithOffset(It->second), 700 RelType, 0); 701 LLVM_DEBUG(dbgs() << " Stub function found\n"); 702 return; 703 } 704 // Create a new stub function. 705 LLVM_DEBUG(dbgs() << " Create a new stub function\n"); 706 It->second = Section.getStubOffset(); 707 uint8_t *StubTargetAddr = 708 createStubFunction(Section.getAddressWithOffset(Section.getStubOffset())); 709 RelocationEntry LU12I_W(SectionID, StubTargetAddr - Section.getAddress(), 710 ELF::R_LARCH_ABS_HI20, Value.Addend); 711 RelocationEntry ORI(SectionID, StubTargetAddr - Section.getAddress() + 4, 712 ELF::R_LARCH_ABS_LO12, Value.Addend); 713 RelocationEntry LU32I_D(SectionID, StubTargetAddr - Section.getAddress() + 8, 714 ELF::R_LARCH_ABS64_LO20, Value.Addend); 715 RelocationEntry LU52I_D(SectionID, StubTargetAddr - Section.getAddress() + 12, 716 ELF::R_LARCH_ABS64_HI12, Value.Addend); 717 if (Value.SymbolName) { 718 addRelocationForSymbol(LU12I_W, Value.SymbolName); 719 addRelocationForSymbol(ORI, Value.SymbolName); 720 addRelocationForSymbol(LU32I_D, Value.SymbolName); 721 addRelocationForSymbol(LU52I_D, Value.SymbolName); 722 } else { 723 addRelocationForSection(LU12I_W, Value.SectionID); 724 addRelocationForSection(ORI, Value.SectionID); 725 addRelocationForSection(LU32I_D, Value.SectionID); 726 727 addRelocationForSection(LU52I_D, Value.SectionID); 728 } 729 resolveRelocation(Section, Offset, 730 reinterpret_cast<uint64_t>( 731 Section.getAddressWithOffset(Section.getStubOffset())), 732 RelType, 0); 733 Section.advanceStubOffset(getMaxStubSize()); 734 } 735 736 // Returns extract bits Val[Hi:Lo]. 737 static inline uint32_t extractBits(uint64_t Val, uint32_t Hi, uint32_t Lo) { 738 return Hi == 63 ? Val >> Lo : (Val & (((1ULL << (Hi + 1)) - 1))) >> Lo; 739 } 740 741 void RuntimeDyldELF::resolveLoongArch64Relocation(const SectionEntry &Section, 742 uint64_t Offset, 743 uint64_t Value, uint32_t Type, 744 int64_t Addend) { 745 auto *TargetPtr = Section.getAddressWithOffset(Offset); 746 uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset); 747 748 LLVM_DEBUG(dbgs() << "resolveLoongArch64Relocation, LocalAddress: 0x" 749 << format("%llx", Section.getAddressWithOffset(Offset)) 750 << " FinalAddress: 0x" << format("%llx", FinalAddress) 751 << " Value: 0x" << format("%llx", Value) << " Type: 0x" 752 << format("%x", Type) << " Addend: 0x" 753 << format("%llx", Addend) << "\n"); 754 755 switch (Type) { 756 default: 757 report_fatal_error("Relocation type not implemented yet!"); 758 break; 759 case ELF::R_LARCH_32: 760 support::ulittle32_t::ref{TargetPtr} = 761 static_cast<uint32_t>(Value + Addend); 762 break; 763 case ELF::R_LARCH_64: 764 support::ulittle64_t::ref{TargetPtr} = Value + Addend; 765 break; 766 case ELF::R_LARCH_32_PCREL: 767 support::ulittle32_t::ref{TargetPtr} = 768 static_cast<uint32_t>(Value + Addend - FinalAddress); 769 break; 770 case ELF::R_LARCH_B26: { 771 uint64_t B26 = (Value + Addend - FinalAddress) >> 2; 772 auto Instr = support::ulittle32_t::ref(TargetPtr); 773 uint32_t Imm15_0 = extractBits(B26, /*Hi=*/15, /*Lo=*/0) << 10; 774 uint32_t Imm25_16 = extractBits(B26, /*Hi=*/25, /*Lo=*/16); 775 Instr = (Instr & 0xfc000000) | Imm15_0 | Imm25_16; 776 break; 777 } 778 case ELF::R_LARCH_CALL36: { 779 uint64_t Call36 = (Value + Addend - FinalAddress) >> 2; 780 auto Pcaddu18i = support::ulittle32_t::ref(TargetPtr); 781 uint32_t Imm35_16 = 782 extractBits((Call36 + (1UL << 15)), /*Hi=*/35, /*Lo=*/16) << 5; 783 Pcaddu18i = (Pcaddu18i & 0xfe00001f) | Imm35_16; 784 auto Jirl = support::ulittle32_t::ref(TargetPtr + 4); 785 uint32_t Imm15_0 = extractBits(Call36, /*Hi=*/15, /*Lo=*/0) << 10; 786 Jirl = (Jirl & 0xfc0003ff) | Imm15_0; 787 break; 788 } 789 case ELF::R_LARCH_GOT_PC_HI20: 790 case ELF::R_LARCH_PCALA_HI20: { 791 uint64_t Target = Value + Addend; 792 uint64_t TargetPage = 793 (Target + (Target & 0x800)) & ~static_cast<uint64_t>(0xfff); 794 uint64_t PCPage = FinalAddress & ~static_cast<uint64_t>(0xfff); 795 int64_t PageDelta = TargetPage - PCPage; 796 auto Instr = support::ulittle32_t::ref(TargetPtr); 797 uint32_t Imm31_12 = extractBits(PageDelta, /*Hi=*/31, /*Lo=*/12) << 5; 798 Instr = (Instr & 0xfe00001f) | Imm31_12; 799 break; 800 } 801 case ELF::R_LARCH_GOT_PC_LO12: 802 case ELF::R_LARCH_PCALA_LO12: { 803 uint64_t TargetOffset = (Value + Addend) & 0xfff; 804 auto Instr = support::ulittle32_t::ref(TargetPtr); 805 uint32_t Imm11_0 = TargetOffset << 10; 806 Instr = (Instr & 0xffc003ff) | Imm11_0; 807 break; 808 } 809 case ELF::R_LARCH_ABS_HI20: { 810 uint64_t Target = Value + Addend; 811 auto Instr = support::ulittle32_t::ref(TargetPtr); 812 uint32_t Imm31_12 = extractBits(Target, /*Hi=*/31, /*Lo=*/12) << 5; 813 Instr = (Instr & 0xfe00001f) | Imm31_12; 814 break; 815 } 816 case ELF::R_LARCH_ABS_LO12: { 817 uint64_t Target = Value + Addend; 818 auto Instr = support::ulittle32_t::ref(TargetPtr); 819 uint32_t Imm11_0 = extractBits(Target, /*Hi=*/11, /*Lo=*/0) << 10; 820 Instr = (Instr & 0xffc003ff) | Imm11_0; 821 break; 822 } 823 case ELF::R_LARCH_ABS64_LO20: { 824 uint64_t Target = Value + Addend; 825 auto Instr = support::ulittle32_t::ref(TargetPtr); 826 uint32_t Imm51_32 = extractBits(Target, /*Hi=*/51, /*Lo=*/32) << 5; 827 Instr = (Instr & 0xfe00001f) | Imm51_32; 828 break; 829 } 830 case ELF::R_LARCH_ABS64_HI12: { 831 uint64_t Target = Value + Addend; 832 auto Instr = support::ulittle32_t::ref(TargetPtr); 833 uint32_t Imm63_52 = extractBits(Target, /*Hi=*/63, /*Lo=*/52) << 10; 834 Instr = (Instr & 0xffc003ff) | Imm63_52; 835 break; 836 } 837 case ELF::R_LARCH_ADD32: 838 support::ulittle32_t::ref{TargetPtr} = 839 (support::ulittle32_t::ref{TargetPtr} + 840 static_cast<uint32_t>(Value + Addend)); 841 break; 842 case ELF::R_LARCH_SUB32: 843 support::ulittle32_t::ref{TargetPtr} = 844 (support::ulittle32_t::ref{TargetPtr} - 845 static_cast<uint32_t>(Value + Addend)); 846 break; 847 case ELF::R_LARCH_ADD64: 848 support::ulittle64_t::ref{TargetPtr} = 849 (support::ulittle64_t::ref{TargetPtr} + Value + Addend); 850 break; 851 case ELF::R_LARCH_SUB64: 852 support::ulittle64_t::ref{TargetPtr} = 853 (support::ulittle64_t::ref{TargetPtr} - Value - Addend); 854 break; 855 } 856 } 857 858 void RuntimeDyldELF::setMipsABI(const ObjectFile &Obj) { 859 if (Arch == Triple::UnknownArch || 860 Triple::getArchTypePrefix(Arch) != "mips") { 861 IsMipsO32ABI = false; 862 IsMipsN32ABI = false; 863 IsMipsN64ABI = false; 864 return; 865 } 866 if (auto *E = dyn_cast<ELFObjectFileBase>(&Obj)) { 867 unsigned AbiVariant = E->getPlatformFlags(); 868 IsMipsO32ABI = AbiVariant & ELF::EF_MIPS_ABI_O32; 869 IsMipsN32ABI = AbiVariant & ELF::EF_MIPS_ABI2; 870 } 871 IsMipsN64ABI = Obj.getFileFormatName() == "elf64-mips"; 872 } 873 874 // Return the .TOC. section and offset. 875 Error RuntimeDyldELF::findPPC64TOCSection(const ELFObjectFileBase &Obj, 876 ObjSectionToIDMap &LocalSections, 877 RelocationValueRef &Rel) { 878 // Set a default SectionID in case we do not find a TOC section below. 879 // This may happen for references to TOC base base (sym@toc, .odp 880 // relocation) without a .toc directive. In this case just use the 881 // first section (which is usually the .odp) since the code won't 882 // reference the .toc base directly. 883 Rel.SymbolName = nullptr; 884 Rel.SectionID = 0; 885 886 // The TOC consists of sections .got, .toc, .tocbss, .plt in that 887 // order. The TOC starts where the first of these sections starts. 888 for (auto &Section : Obj.sections()) { 889 Expected<StringRef> NameOrErr = Section.getName(); 890 if (!NameOrErr) 891 return NameOrErr.takeError(); 892 StringRef SectionName = *NameOrErr; 893 894 if (SectionName == ".got" 895 || SectionName == ".toc" 896 || SectionName == ".tocbss" 897 || SectionName == ".plt") { 898 if (auto SectionIDOrErr = 899 findOrEmitSection(Obj, Section, false, LocalSections)) 900 Rel.SectionID = *SectionIDOrErr; 901 else 902 return SectionIDOrErr.takeError(); 903 break; 904 } 905 } 906 907 // Per the ppc64-elf-linux ABI, The TOC base is TOC value plus 0x8000 908 // thus permitting a full 64 Kbytes segment. 909 Rel.Addend = 0x8000; 910 911 return Error::success(); 912 } 913 914 // Returns the sections and offset associated with the ODP entry referenced 915 // by Symbol. 916 Error RuntimeDyldELF::findOPDEntrySection(const ELFObjectFileBase &Obj, 917 ObjSectionToIDMap &LocalSections, 918 RelocationValueRef &Rel) { 919 // Get the ELF symbol value (st_value) to compare with Relocation offset in 920 // .opd entries 921 for (section_iterator si = Obj.section_begin(), se = Obj.section_end(); 922 si != se; ++si) { 923 924 Expected<section_iterator> RelSecOrErr = si->getRelocatedSection(); 925 if (!RelSecOrErr) 926 report_fatal_error(Twine(toString(RelSecOrErr.takeError()))); 927 928 section_iterator RelSecI = *RelSecOrErr; 929 if (RelSecI == Obj.section_end()) 930 continue; 931 932 Expected<StringRef> NameOrErr = RelSecI->getName(); 933 if (!NameOrErr) 934 return NameOrErr.takeError(); 935 StringRef RelSectionName = *NameOrErr; 936 937 if (RelSectionName != ".opd") 938 continue; 939 940 for (elf_relocation_iterator i = si->relocation_begin(), 941 e = si->relocation_end(); 942 i != e;) { 943 // The R_PPC64_ADDR64 relocation indicates the first field 944 // of a .opd entry 945 uint64_t TypeFunc = i->getType(); 946 if (TypeFunc != ELF::R_PPC64_ADDR64) { 947 ++i; 948 continue; 949 } 950 951 uint64_t TargetSymbolOffset = i->getOffset(); 952 symbol_iterator TargetSymbol = i->getSymbol(); 953 int64_t Addend; 954 if (auto AddendOrErr = i->getAddend()) 955 Addend = *AddendOrErr; 956 else 957 return AddendOrErr.takeError(); 958 959 ++i; 960 if (i == e) 961 break; 962 963 // Just check if following relocation is a R_PPC64_TOC 964 uint64_t TypeTOC = i->getType(); 965 if (TypeTOC != ELF::R_PPC64_TOC) 966 continue; 967 968 // Finally compares the Symbol value and the target symbol offset 969 // to check if this .opd entry refers to the symbol the relocation 970 // points to. 971 if (Rel.Addend != (int64_t)TargetSymbolOffset) 972 continue; 973 974 section_iterator TSI = Obj.section_end(); 975 if (auto TSIOrErr = TargetSymbol->getSection()) 976 TSI = *TSIOrErr; 977 else 978 return TSIOrErr.takeError(); 979 assert(TSI != Obj.section_end() && "TSI should refer to a valid section"); 980 981 bool IsCode = TSI->isText(); 982 if (auto SectionIDOrErr = findOrEmitSection(Obj, *TSI, IsCode, 983 LocalSections)) 984 Rel.SectionID = *SectionIDOrErr; 985 else 986 return SectionIDOrErr.takeError(); 987 Rel.Addend = (intptr_t)Addend; 988 return Error::success(); 989 } 990 } 991 llvm_unreachable("Attempting to get address of ODP entry!"); 992 } 993 994 // Relocation masks following the #lo(value), #hi(value), #ha(value), 995 // #higher(value), #highera(value), #highest(value), and #highesta(value) 996 // macros defined in section 4.5.1. Relocation Types of the PPC-elf64abi 997 // document. 998 999 static inline uint16_t applyPPClo(uint64_t value) { return value & 0xffff; } 1000 1001 static inline uint16_t applyPPChi(uint64_t value) { 1002 return (value >> 16) & 0xffff; 1003 } 1004 1005 static inline uint16_t applyPPCha (uint64_t value) { 1006 return ((value + 0x8000) >> 16) & 0xffff; 1007 } 1008 1009 static inline uint16_t applyPPChigher(uint64_t value) { 1010 return (value >> 32) & 0xffff; 1011 } 1012 1013 static inline uint16_t applyPPChighera (uint64_t value) { 1014 return ((value + 0x8000) >> 32) & 0xffff; 1015 } 1016 1017 static inline uint16_t applyPPChighest(uint64_t value) { 1018 return (value >> 48) & 0xffff; 1019 } 1020 1021 static inline uint16_t applyPPChighesta (uint64_t value) { 1022 return ((value + 0x8000) >> 48) & 0xffff; 1023 } 1024 1025 void RuntimeDyldELF::resolvePPC32Relocation(const SectionEntry &Section, 1026 uint64_t Offset, uint64_t Value, 1027 uint32_t Type, int64_t Addend) { 1028 uint8_t *LocalAddress = Section.getAddressWithOffset(Offset); 1029 switch (Type) { 1030 default: 1031 report_fatal_error("Relocation type not implemented yet!"); 1032 break; 1033 case ELF::R_PPC_ADDR16_LO: 1034 writeInt16BE(LocalAddress, applyPPClo(Value + Addend)); 1035 break; 1036 case ELF::R_PPC_ADDR16_HI: 1037 writeInt16BE(LocalAddress, applyPPChi(Value + Addend)); 1038 break; 1039 case ELF::R_PPC_ADDR16_HA: 1040 writeInt16BE(LocalAddress, applyPPCha(Value + Addend)); 1041 break; 1042 } 1043 } 1044 1045 void RuntimeDyldELF::resolvePPC64Relocation(const SectionEntry &Section, 1046 uint64_t Offset, uint64_t Value, 1047 uint32_t Type, int64_t Addend) { 1048 uint8_t *LocalAddress = Section.getAddressWithOffset(Offset); 1049 switch (Type) { 1050 default: 1051 report_fatal_error("Relocation type not implemented yet!"); 1052 break; 1053 case ELF::R_PPC64_ADDR16: 1054 writeInt16BE(LocalAddress, applyPPClo(Value + Addend)); 1055 break; 1056 case ELF::R_PPC64_ADDR16_DS: 1057 writeInt16BE(LocalAddress, applyPPClo(Value + Addend) & ~3); 1058 break; 1059 case ELF::R_PPC64_ADDR16_LO: 1060 writeInt16BE(LocalAddress, applyPPClo(Value + Addend)); 1061 break; 1062 case ELF::R_PPC64_ADDR16_LO_DS: 1063 writeInt16BE(LocalAddress, applyPPClo(Value + Addend) & ~3); 1064 break; 1065 case ELF::R_PPC64_ADDR16_HI: 1066 case ELF::R_PPC64_ADDR16_HIGH: 1067 writeInt16BE(LocalAddress, applyPPChi(Value + Addend)); 1068 break; 1069 case ELF::R_PPC64_ADDR16_HA: 1070 case ELF::R_PPC64_ADDR16_HIGHA: 1071 writeInt16BE(LocalAddress, applyPPCha(Value + Addend)); 1072 break; 1073 case ELF::R_PPC64_ADDR16_HIGHER: 1074 writeInt16BE(LocalAddress, applyPPChigher(Value + Addend)); 1075 break; 1076 case ELF::R_PPC64_ADDR16_HIGHERA: 1077 writeInt16BE(LocalAddress, applyPPChighera(Value + Addend)); 1078 break; 1079 case ELF::R_PPC64_ADDR16_HIGHEST: 1080 writeInt16BE(LocalAddress, applyPPChighest(Value + Addend)); 1081 break; 1082 case ELF::R_PPC64_ADDR16_HIGHESTA: 1083 writeInt16BE(LocalAddress, applyPPChighesta(Value + Addend)); 1084 break; 1085 case ELF::R_PPC64_ADDR14: { 1086 assert(((Value + Addend) & 3) == 0); 1087 // Preserve the AA/LK bits in the branch instruction 1088 uint8_t aalk = *(LocalAddress + 3); 1089 writeInt16BE(LocalAddress + 2, (aalk & 3) | ((Value + Addend) & 0xfffc)); 1090 } break; 1091 case ELF::R_PPC64_REL16_LO: { 1092 uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset); 1093 uint64_t Delta = Value - FinalAddress + Addend; 1094 writeInt16BE(LocalAddress, applyPPClo(Delta)); 1095 } break; 1096 case ELF::R_PPC64_REL16_HI: { 1097 uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset); 1098 uint64_t Delta = Value - FinalAddress + Addend; 1099 writeInt16BE(LocalAddress, applyPPChi(Delta)); 1100 } break; 1101 case ELF::R_PPC64_REL16_HA: { 1102 uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset); 1103 uint64_t Delta = Value - FinalAddress + Addend; 1104 writeInt16BE(LocalAddress, applyPPCha(Delta)); 1105 } break; 1106 case ELF::R_PPC64_ADDR32: { 1107 int64_t Result = static_cast<int64_t>(Value + Addend); 1108 if (SignExtend64<32>(Result) != Result) 1109 llvm_unreachable("Relocation R_PPC64_ADDR32 overflow"); 1110 writeInt32BE(LocalAddress, Result); 1111 } break; 1112 case ELF::R_PPC64_REL24: { 1113 uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset); 1114 int64_t delta = static_cast<int64_t>(Value - FinalAddress + Addend); 1115 if (SignExtend64<26>(delta) != delta) 1116 llvm_unreachable("Relocation R_PPC64_REL24 overflow"); 1117 // We preserve bits other than LI field, i.e. PO and AA/LK fields. 1118 uint32_t Inst = readBytesUnaligned(LocalAddress, 4); 1119 writeInt32BE(LocalAddress, (Inst & 0xFC000003) | (delta & 0x03FFFFFC)); 1120 } break; 1121 case ELF::R_PPC64_REL32: { 1122 uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset); 1123 int64_t delta = static_cast<int64_t>(Value - FinalAddress + Addend); 1124 if (SignExtend64<32>(delta) != delta) 1125 llvm_unreachable("Relocation R_PPC64_REL32 overflow"); 1126 writeInt32BE(LocalAddress, delta); 1127 } break; 1128 case ELF::R_PPC64_REL64: { 1129 uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset); 1130 uint64_t Delta = Value - FinalAddress + Addend; 1131 writeInt64BE(LocalAddress, Delta); 1132 } break; 1133 case ELF::R_PPC64_ADDR64: 1134 writeInt64BE(LocalAddress, Value + Addend); 1135 break; 1136 } 1137 } 1138 1139 void RuntimeDyldELF::resolveSystemZRelocation(const SectionEntry &Section, 1140 uint64_t Offset, uint64_t Value, 1141 uint32_t Type, int64_t Addend) { 1142 uint8_t *LocalAddress = Section.getAddressWithOffset(Offset); 1143 switch (Type) { 1144 default: 1145 report_fatal_error("Relocation type not implemented yet!"); 1146 break; 1147 case ELF::R_390_PC16DBL: 1148 case ELF::R_390_PLT16DBL: { 1149 int64_t Delta = (Value + Addend) - Section.getLoadAddressWithOffset(Offset); 1150 assert(int16_t(Delta / 2) * 2 == Delta && "R_390_PC16DBL overflow"); 1151 writeInt16BE(LocalAddress, Delta / 2); 1152 break; 1153 } 1154 case ELF::R_390_PC32DBL: 1155 case ELF::R_390_PLT32DBL: { 1156 int64_t Delta = (Value + Addend) - Section.getLoadAddressWithOffset(Offset); 1157 assert(int32_t(Delta / 2) * 2 == Delta && "R_390_PC32DBL overflow"); 1158 writeInt32BE(LocalAddress, Delta / 2); 1159 break; 1160 } 1161 case ELF::R_390_PC16: { 1162 int64_t Delta = (Value + Addend) - Section.getLoadAddressWithOffset(Offset); 1163 assert(int16_t(Delta) == Delta && "R_390_PC16 overflow"); 1164 writeInt16BE(LocalAddress, Delta); 1165 break; 1166 } 1167 case ELF::R_390_PC32: { 1168 int64_t Delta = (Value + Addend) - Section.getLoadAddressWithOffset(Offset); 1169 assert(int32_t(Delta) == Delta && "R_390_PC32 overflow"); 1170 writeInt32BE(LocalAddress, Delta); 1171 break; 1172 } 1173 case ELF::R_390_PC64: { 1174 int64_t Delta = (Value + Addend) - Section.getLoadAddressWithOffset(Offset); 1175 writeInt64BE(LocalAddress, Delta); 1176 break; 1177 } 1178 case ELF::R_390_8: 1179 *LocalAddress = (uint8_t)(Value + Addend); 1180 break; 1181 case ELF::R_390_16: 1182 writeInt16BE(LocalAddress, Value + Addend); 1183 break; 1184 case ELF::R_390_32: 1185 writeInt32BE(LocalAddress, Value + Addend); 1186 break; 1187 case ELF::R_390_64: 1188 writeInt64BE(LocalAddress, Value + Addend); 1189 break; 1190 } 1191 } 1192 1193 void RuntimeDyldELF::resolveBPFRelocation(const SectionEntry &Section, 1194 uint64_t Offset, uint64_t Value, 1195 uint32_t Type, int64_t Addend) { 1196 bool isBE = Arch == Triple::bpfeb; 1197 1198 switch (Type) { 1199 default: 1200 report_fatal_error("Relocation type not implemented yet!"); 1201 break; 1202 case ELF::R_BPF_NONE: 1203 case ELF::R_BPF_64_64: 1204 case ELF::R_BPF_64_32: 1205 case ELF::R_BPF_64_NODYLD32: 1206 break; 1207 case ELF::R_BPF_64_ABS64: { 1208 write(isBE, Section.getAddressWithOffset(Offset), Value + Addend); 1209 LLVM_DEBUG(dbgs() << "Writing " << format("%p", (Value + Addend)) << " at " 1210 << format("%p\n", Section.getAddressWithOffset(Offset))); 1211 break; 1212 } 1213 case ELF::R_BPF_64_ABS32: { 1214 Value += Addend; 1215 assert(Value <= UINT32_MAX); 1216 write(isBE, Section.getAddressWithOffset(Offset), static_cast<uint32_t>(Value)); 1217 LLVM_DEBUG(dbgs() << "Writing " << format("%p", Value) << " at " 1218 << format("%p\n", Section.getAddressWithOffset(Offset))); 1219 break; 1220 } 1221 } 1222 } 1223 1224 static void applyUTypeImmRISCV(uint8_t *InstrAddr, uint32_t Imm) { 1225 uint32_t UpperImm = (Imm + 0x800) & 0xfffff000; 1226 auto Instr = support::ulittle32_t::ref(InstrAddr); 1227 Instr = (Instr & 0xfff) | UpperImm; 1228 } 1229 1230 static void applyITypeImmRISCV(uint8_t *InstrAddr, uint32_t Imm) { 1231 uint32_t LowerImm = Imm & 0xfff; 1232 auto Instr = support::ulittle32_t::ref(InstrAddr); 1233 Instr = (Instr & 0xfffff) | (LowerImm << 20); 1234 } 1235 1236 void RuntimeDyldELF::resolveRISCVRelocation(const SectionEntry &Section, 1237 uint64_t Offset, uint64_t Value, 1238 uint32_t Type, int64_t Addend, 1239 SID SectionID) { 1240 switch (Type) { 1241 default: { 1242 std::string Err = "Unimplemented reloc type: " + std::to_string(Type); 1243 llvm::report_fatal_error(Err.c_str()); 1244 } 1245 // 32-bit PC-relative function call, macros call, tail (PIC) 1246 // Write first 20 bits of 32 bit value to the auipc instruction 1247 // Last 12 bits to the jalr instruction 1248 case ELF::R_RISCV_CALL: 1249 case ELF::R_RISCV_CALL_PLT: { 1250 uint64_t P = Section.getLoadAddressWithOffset(Offset); 1251 uint64_t PCOffset = Value + Addend - P; 1252 applyUTypeImmRISCV(Section.getAddressWithOffset(Offset), PCOffset); 1253 applyITypeImmRISCV(Section.getAddressWithOffset(Offset + 4), PCOffset); 1254 break; 1255 } 1256 // High 20 bits of 32-bit absolute address, %hi(symbol) 1257 case ELF::R_RISCV_HI20: { 1258 uint64_t PCOffset = Value + Addend; 1259 applyUTypeImmRISCV(Section.getAddressWithOffset(Offset), PCOffset); 1260 break; 1261 } 1262 // Low 12 bits of 32-bit absolute address, %lo(symbol) 1263 case ELF::R_RISCV_LO12_I: { 1264 uint64_t PCOffset = Value + Addend; 1265 applyITypeImmRISCV(Section.getAddressWithOffset(Offset), PCOffset); 1266 break; 1267 } 1268 // High 20 bits of 32-bit PC-relative reference, %pcrel_hi(symbol) 1269 case ELF::R_RISCV_GOT_HI20: 1270 case ELF::R_RISCV_PCREL_HI20: { 1271 uint64_t P = Section.getLoadAddressWithOffset(Offset); 1272 uint64_t PCOffset = Value + Addend - P; 1273 applyUTypeImmRISCV(Section.getAddressWithOffset(Offset), PCOffset); 1274 break; 1275 } 1276 1277 // label: 1278 // auipc a0, %pcrel_hi(symbol) // R_RISCV_PCREL_HI20 1279 // addi a0, a0, %pcrel_lo(label) // R_RISCV_PCREL_LO12_I 1280 // 1281 // The low 12 bits of relative address between pc and symbol. 1282 // The symbol is related to the high part instruction which is marked by 1283 // label. 1284 case ELF::R_RISCV_PCREL_LO12_I: { 1285 for (auto &&PendingReloc : PendingRelocs) { 1286 const RelocationValueRef &MatchingValue = PendingReloc.first; 1287 RelocationEntry &Reloc = PendingReloc.second; 1288 uint64_t HIRelocPC = 1289 getSectionLoadAddress(Reloc.SectionID) + Reloc.Offset; 1290 if (Value + Addend == HIRelocPC) { 1291 uint64_t Symbol = getSectionLoadAddress(MatchingValue.SectionID) + 1292 MatchingValue.Addend; 1293 auto PCOffset = Symbol - HIRelocPC; 1294 applyITypeImmRISCV(Section.getAddressWithOffset(Offset), PCOffset); 1295 return; 1296 } 1297 } 1298 1299 llvm::report_fatal_error( 1300 "R_RISCV_PCREL_LO12_I without matching R_RISCV_PCREL_HI20"); 1301 } 1302 case ELF::R_RISCV_32_PCREL: { 1303 uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset); 1304 int64_t RealOffset = Value + Addend - FinalAddress; 1305 int32_t TruncOffset = Lo_32(RealOffset); 1306 support::ulittle32_t::ref(Section.getAddressWithOffset(Offset)) = 1307 TruncOffset; 1308 break; 1309 } 1310 case ELF::R_RISCV_32: { 1311 auto Ref = support::ulittle32_t::ref(Section.getAddressWithOffset(Offset)); 1312 Ref = Value + Addend; 1313 break; 1314 } 1315 case ELF::R_RISCV_64: { 1316 auto Ref = support::ulittle64_t::ref(Section.getAddressWithOffset(Offset)); 1317 Ref = Value + Addend; 1318 break; 1319 } 1320 case ELF::R_RISCV_ADD8: { 1321 auto Ref = support::ulittle8_t::ref(Section.getAddressWithOffset(Offset)); 1322 Ref = Ref + Value + Addend; 1323 break; 1324 } 1325 case ELF::R_RISCV_ADD16: { 1326 auto Ref = support::ulittle16_t::ref(Section.getAddressWithOffset(Offset)); 1327 Ref = Ref + Value + Addend; 1328 break; 1329 } 1330 case ELF::R_RISCV_ADD32: { 1331 auto Ref = support::ulittle32_t::ref(Section.getAddressWithOffset(Offset)); 1332 Ref = Ref + Value + Addend; 1333 break; 1334 } 1335 case ELF::R_RISCV_ADD64: { 1336 auto Ref = support::ulittle64_t::ref(Section.getAddressWithOffset(Offset)); 1337 Ref = Ref + Value + Addend; 1338 break; 1339 } 1340 case ELF::R_RISCV_SUB8: { 1341 auto Ref = support::ulittle8_t::ref(Section.getAddressWithOffset(Offset)); 1342 Ref = Ref - Value - Addend; 1343 break; 1344 } 1345 case ELF::R_RISCV_SUB16: { 1346 auto Ref = support::ulittle16_t::ref(Section.getAddressWithOffset(Offset)); 1347 Ref = Ref - Value - Addend; 1348 break; 1349 } 1350 case ELF::R_RISCV_SUB32: { 1351 auto Ref = support::ulittle32_t::ref(Section.getAddressWithOffset(Offset)); 1352 Ref = Ref - Value - Addend; 1353 break; 1354 } 1355 case ELF::R_RISCV_SUB64: { 1356 auto Ref = support::ulittle64_t::ref(Section.getAddressWithOffset(Offset)); 1357 Ref = Ref - Value - Addend; 1358 break; 1359 } 1360 case ELF::R_RISCV_SET8: { 1361 auto Ref = support::ulittle8_t::ref(Section.getAddressWithOffset(Offset)); 1362 Ref = Value + Addend; 1363 break; 1364 } 1365 case ELF::R_RISCV_SET16: { 1366 auto Ref = support::ulittle16_t::ref(Section.getAddressWithOffset(Offset)); 1367 Ref = Value + Addend; 1368 break; 1369 } 1370 case ELF::R_RISCV_SET32: { 1371 auto Ref = support::ulittle32_t::ref(Section.getAddressWithOffset(Offset)); 1372 Ref = Value + Addend; 1373 break; 1374 } 1375 } 1376 } 1377 1378 // The target location for the relocation is described by RE.SectionID and 1379 // RE.Offset. RE.SectionID can be used to find the SectionEntry. Each 1380 // SectionEntry has three members describing its location. 1381 // SectionEntry::Address is the address at which the section has been loaded 1382 // into memory in the current (host) process. SectionEntry::LoadAddress is the 1383 // address that the section will have in the target process. 1384 // SectionEntry::ObjAddress is the address of the bits for this section in the 1385 // original emitted object image (also in the current address space). 1386 // 1387 // Relocations will be applied as if the section were loaded at 1388 // SectionEntry::LoadAddress, but they will be applied at an address based 1389 // on SectionEntry::Address. SectionEntry::ObjAddress will be used to refer to 1390 // Target memory contents if they are required for value calculations. 1391 // 1392 // The Value parameter here is the load address of the symbol for the 1393 // relocation to be applied. For relocations which refer to symbols in the 1394 // current object Value will be the LoadAddress of the section in which 1395 // the symbol resides (RE.Addend provides additional information about the 1396 // symbol location). For external symbols, Value will be the address of the 1397 // symbol in the target address space. 1398 void RuntimeDyldELF::resolveRelocation(const RelocationEntry &RE, 1399 uint64_t Value) { 1400 const SectionEntry &Section = Sections[RE.SectionID]; 1401 return resolveRelocation(Section, RE.Offset, Value, RE.RelType, RE.Addend, 1402 RE.SymOffset, RE.SectionID); 1403 } 1404 1405 void RuntimeDyldELF::resolveRelocation(const SectionEntry &Section, 1406 uint64_t Offset, uint64_t Value, 1407 uint32_t Type, int64_t Addend, 1408 uint64_t SymOffset, SID SectionID) { 1409 switch (Arch) { 1410 case Triple::x86_64: 1411 resolveX86_64Relocation(Section, Offset, Value, Type, Addend, SymOffset); 1412 break; 1413 case Triple::x86: 1414 resolveX86Relocation(Section, Offset, (uint32_t)(Value & 0xffffffffL), Type, 1415 (uint32_t)(Addend & 0xffffffffL)); 1416 break; 1417 case Triple::aarch64: 1418 case Triple::aarch64_be: 1419 resolveAArch64Relocation(Section, Offset, Value, Type, Addend); 1420 break; 1421 case Triple::arm: // Fall through. 1422 case Triple::armeb: 1423 case Triple::thumb: 1424 case Triple::thumbeb: 1425 resolveARMRelocation(Section, Offset, (uint32_t)(Value & 0xffffffffL), Type, 1426 (uint32_t)(Addend & 0xffffffffL)); 1427 break; 1428 case Triple::loongarch64: 1429 resolveLoongArch64Relocation(Section, Offset, Value, Type, Addend); 1430 break; 1431 case Triple::ppc: // Fall through. 1432 case Triple::ppcle: 1433 resolvePPC32Relocation(Section, Offset, Value, Type, Addend); 1434 break; 1435 case Triple::ppc64: // Fall through. 1436 case Triple::ppc64le: 1437 resolvePPC64Relocation(Section, Offset, Value, Type, Addend); 1438 break; 1439 case Triple::systemz: 1440 resolveSystemZRelocation(Section, Offset, Value, Type, Addend); 1441 break; 1442 case Triple::bpfel: 1443 case Triple::bpfeb: 1444 resolveBPFRelocation(Section, Offset, Value, Type, Addend); 1445 break; 1446 case Triple::riscv32: // Fall through. 1447 case Triple::riscv64: 1448 resolveRISCVRelocation(Section, Offset, Value, Type, Addend, SectionID); 1449 break; 1450 default: 1451 llvm_unreachable("Unsupported CPU type!"); 1452 } 1453 } 1454 1455 void *RuntimeDyldELF::computePlaceholderAddress(unsigned SectionID, 1456 uint64_t Offset) const { 1457 return (void *)(Sections[SectionID].getObjAddress() + Offset); 1458 } 1459 1460 void RuntimeDyldELF::processSimpleRelocation(unsigned SectionID, uint64_t Offset, unsigned RelType, RelocationValueRef Value) { 1461 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend, Value.Offset); 1462 if (Value.SymbolName) 1463 addRelocationForSymbol(RE, Value.SymbolName); 1464 else 1465 addRelocationForSection(RE, Value.SectionID); 1466 } 1467 1468 uint32_t RuntimeDyldELF::getMatchingLoRelocation(uint32_t RelType, 1469 bool IsLocal) const { 1470 switch (RelType) { 1471 case ELF::R_MICROMIPS_GOT16: 1472 if (IsLocal) 1473 return ELF::R_MICROMIPS_LO16; 1474 break; 1475 case ELF::R_MICROMIPS_HI16: 1476 return ELF::R_MICROMIPS_LO16; 1477 case ELF::R_MIPS_GOT16: 1478 if (IsLocal) 1479 return ELF::R_MIPS_LO16; 1480 break; 1481 case ELF::R_MIPS_HI16: 1482 return ELF::R_MIPS_LO16; 1483 case ELF::R_MIPS_PCHI16: 1484 return ELF::R_MIPS_PCLO16; 1485 default: 1486 break; 1487 } 1488 return ELF::R_MIPS_NONE; 1489 } 1490 1491 // Sometimes we don't need to create thunk for a branch. 1492 // This typically happens when branch target is located 1493 // in the same object file. In such case target is either 1494 // a weak symbol or symbol in a different executable section. 1495 // This function checks if branch target is located in the 1496 // same object file and if distance between source and target 1497 // fits R_AARCH64_CALL26 relocation. If both conditions are 1498 // met, it emits direct jump to the target and returns true. 1499 // Otherwise false is returned and thunk is created. 1500 bool RuntimeDyldELF::resolveAArch64ShortBranch( 1501 unsigned SectionID, relocation_iterator RelI, 1502 const RelocationValueRef &Value) { 1503 uint64_t TargetOffset; 1504 unsigned TargetSectionID; 1505 if (Value.SymbolName) { 1506 auto Loc = GlobalSymbolTable.find(Value.SymbolName); 1507 1508 // Don't create direct branch for external symbols. 1509 if (Loc == GlobalSymbolTable.end()) 1510 return false; 1511 1512 const auto &SymInfo = Loc->second; 1513 1514 TargetSectionID = SymInfo.getSectionID(); 1515 TargetOffset = SymInfo.getOffset(); 1516 } else { 1517 TargetSectionID = Value.SectionID; 1518 TargetOffset = 0; 1519 } 1520 1521 // We don't actually know the load addresses at this point, so if the 1522 // branch is cross-section, we don't know exactly how far away it is. 1523 if (TargetSectionID != SectionID) 1524 return false; 1525 1526 uint64_t SourceOffset = RelI->getOffset(); 1527 1528 // R_AARCH64_CALL26 requires immediate to be in range -2^27 <= imm < 2^27 1529 // If distance between source and target is out of range then we should 1530 // create thunk. 1531 if (!isInt<28>(TargetOffset + Value.Addend - SourceOffset)) 1532 return false; 1533 1534 RelocationEntry RE(SectionID, SourceOffset, RelI->getType(), Value.Addend); 1535 if (Value.SymbolName) 1536 addRelocationForSymbol(RE, Value.SymbolName); 1537 else 1538 addRelocationForSection(RE, Value.SectionID); 1539 1540 return true; 1541 } 1542 1543 void RuntimeDyldELF::resolveAArch64Branch(unsigned SectionID, 1544 const RelocationValueRef &Value, 1545 relocation_iterator RelI, 1546 StubMap &Stubs) { 1547 1548 LLVM_DEBUG(dbgs() << "\t\tThis is an AArch64 branch relocation."); 1549 SectionEntry &Section = Sections[SectionID]; 1550 1551 uint64_t Offset = RelI->getOffset(); 1552 unsigned RelType = RelI->getType(); 1553 // Look for an existing stub. 1554 StubMap::const_iterator i = Stubs.find(Value); 1555 if (i != Stubs.end()) { 1556 resolveRelocation(Section, Offset, 1557 Section.getLoadAddressWithOffset(i->second), RelType, 0); 1558 LLVM_DEBUG(dbgs() << " Stub function found\n"); 1559 } else if (!resolveAArch64ShortBranch(SectionID, RelI, Value)) { 1560 // Create a new stub function. 1561 LLVM_DEBUG(dbgs() << " Create a new stub function\n"); 1562 Stubs[Value] = Section.getStubOffset(); 1563 uint8_t *StubTargetAddr = createStubFunction( 1564 Section.getAddressWithOffset(Section.getStubOffset())); 1565 1566 RelocationEntry REmovz_g3(SectionID, StubTargetAddr - Section.getAddress(), 1567 ELF::R_AARCH64_MOVW_UABS_G3, Value.Addend); 1568 RelocationEntry REmovk_g2(SectionID, 1569 StubTargetAddr - Section.getAddress() + 4, 1570 ELF::R_AARCH64_MOVW_UABS_G2_NC, Value.Addend); 1571 RelocationEntry REmovk_g1(SectionID, 1572 StubTargetAddr - Section.getAddress() + 8, 1573 ELF::R_AARCH64_MOVW_UABS_G1_NC, Value.Addend); 1574 RelocationEntry REmovk_g0(SectionID, 1575 StubTargetAddr - Section.getAddress() + 12, 1576 ELF::R_AARCH64_MOVW_UABS_G0_NC, Value.Addend); 1577 1578 if (Value.SymbolName) { 1579 addRelocationForSymbol(REmovz_g3, Value.SymbolName); 1580 addRelocationForSymbol(REmovk_g2, Value.SymbolName); 1581 addRelocationForSymbol(REmovk_g1, Value.SymbolName); 1582 addRelocationForSymbol(REmovk_g0, Value.SymbolName); 1583 } else { 1584 addRelocationForSection(REmovz_g3, Value.SectionID); 1585 addRelocationForSection(REmovk_g2, Value.SectionID); 1586 addRelocationForSection(REmovk_g1, Value.SectionID); 1587 addRelocationForSection(REmovk_g0, Value.SectionID); 1588 } 1589 resolveRelocation(Section, Offset, 1590 Section.getLoadAddressWithOffset(Section.getStubOffset()), 1591 RelType, 0); 1592 Section.advanceStubOffset(getMaxStubSize()); 1593 } 1594 } 1595 1596 Expected<relocation_iterator> 1597 RuntimeDyldELF::processRelocationRef( 1598 unsigned SectionID, relocation_iterator RelI, const ObjectFile &O, 1599 ObjSectionToIDMap &ObjSectionToID, StubMap &Stubs) { 1600 const auto &Obj = cast<ELFObjectFileBase>(O); 1601 uint64_t RelType = RelI->getType(); 1602 int64_t Addend = 0; 1603 if (Expected<int64_t> AddendOrErr = ELFRelocationRef(*RelI).getAddend()) 1604 Addend = *AddendOrErr; 1605 else 1606 consumeError(AddendOrErr.takeError()); 1607 elf_symbol_iterator Symbol = RelI->getSymbol(); 1608 1609 // Obtain the symbol name which is referenced in the relocation 1610 StringRef TargetName; 1611 if (Symbol != Obj.symbol_end()) { 1612 if (auto TargetNameOrErr = Symbol->getName()) 1613 TargetName = *TargetNameOrErr; 1614 else 1615 return TargetNameOrErr.takeError(); 1616 } 1617 LLVM_DEBUG(dbgs() << "\t\tRelType: " << RelType << " Addend: " << Addend 1618 << " TargetName: " << TargetName << "\n"); 1619 RelocationValueRef Value; 1620 // First search for the symbol in the local symbol table 1621 SymbolRef::Type SymType = SymbolRef::ST_Unknown; 1622 1623 // Search for the symbol in the global symbol table 1624 RTDyldSymbolTable::const_iterator gsi = GlobalSymbolTable.end(); 1625 if (Symbol != Obj.symbol_end()) { 1626 gsi = GlobalSymbolTable.find(TargetName.data()); 1627 Expected<SymbolRef::Type> SymTypeOrErr = Symbol->getType(); 1628 if (!SymTypeOrErr) { 1629 std::string Buf; 1630 raw_string_ostream OS(Buf); 1631 logAllUnhandledErrors(SymTypeOrErr.takeError(), OS); 1632 report_fatal_error(Twine(Buf)); 1633 } 1634 SymType = *SymTypeOrErr; 1635 } 1636 if (gsi != GlobalSymbolTable.end()) { 1637 const auto &SymInfo = gsi->second; 1638 Value.SectionID = SymInfo.getSectionID(); 1639 Value.Offset = SymInfo.getOffset(); 1640 Value.Addend = SymInfo.getOffset() + Addend; 1641 } else { 1642 switch (SymType) { 1643 case SymbolRef::ST_Debug: { 1644 // TODO: Now ELF SymbolRef::ST_Debug = STT_SECTION, it's not obviously 1645 // and can be changed by another developers. Maybe best way is add 1646 // a new symbol type ST_Section to SymbolRef and use it. 1647 auto SectionOrErr = Symbol->getSection(); 1648 if (!SectionOrErr) { 1649 std::string Buf; 1650 raw_string_ostream OS(Buf); 1651 logAllUnhandledErrors(SectionOrErr.takeError(), OS); 1652 report_fatal_error(Twine(Buf)); 1653 } 1654 section_iterator si = *SectionOrErr; 1655 if (si == Obj.section_end()) 1656 llvm_unreachable("Symbol section not found, bad object file format!"); 1657 LLVM_DEBUG(dbgs() << "\t\tThis is section symbol\n"); 1658 bool isCode = si->isText(); 1659 if (auto SectionIDOrErr = findOrEmitSection(Obj, (*si), isCode, 1660 ObjSectionToID)) 1661 Value.SectionID = *SectionIDOrErr; 1662 else 1663 return SectionIDOrErr.takeError(); 1664 Value.Addend = Addend; 1665 break; 1666 } 1667 case SymbolRef::ST_Data: 1668 case SymbolRef::ST_Function: 1669 case SymbolRef::ST_Other: 1670 case SymbolRef::ST_Unknown: { 1671 Value.SymbolName = TargetName.data(); 1672 Value.Addend = Addend; 1673 1674 // Absolute relocations will have a zero symbol ID (STN_UNDEF), which 1675 // will manifest here as a NULL symbol name. 1676 // We can set this as a valid (but empty) symbol name, and rely 1677 // on addRelocationForSymbol to handle this. 1678 if (!Value.SymbolName) 1679 Value.SymbolName = ""; 1680 break; 1681 } 1682 default: 1683 llvm_unreachable("Unresolved symbol type!"); 1684 break; 1685 } 1686 } 1687 1688 uint64_t Offset = RelI->getOffset(); 1689 1690 LLVM_DEBUG(dbgs() << "\t\tSectionID: " << SectionID << " Offset: " << Offset 1691 << "\n"); 1692 if ((Arch == Triple::aarch64 || Arch == Triple::aarch64_be)) { 1693 if ((RelType == ELF::R_AARCH64_CALL26 || 1694 RelType == ELF::R_AARCH64_JUMP26) && 1695 MemMgr.allowStubAllocation()) { 1696 resolveAArch64Branch(SectionID, Value, RelI, Stubs); 1697 } else if (RelType == ELF::R_AARCH64_ADR_GOT_PAGE) { 1698 // Create new GOT entry or find existing one. If GOT entry is 1699 // to be created, then we also emit ABS64 relocation for it. 1700 uint64_t GOTOffset = findOrAllocGOTEntry(Value, ELF::R_AARCH64_ABS64); 1701 resolveGOTOffsetRelocation(SectionID, Offset, GOTOffset + Addend, 1702 ELF::R_AARCH64_ADR_PREL_PG_HI21); 1703 1704 } else if (RelType == ELF::R_AARCH64_LD64_GOT_LO12_NC) { 1705 uint64_t GOTOffset = findOrAllocGOTEntry(Value, ELF::R_AARCH64_ABS64); 1706 resolveGOTOffsetRelocation(SectionID, Offset, GOTOffset + Addend, 1707 ELF::R_AARCH64_LDST64_ABS_LO12_NC); 1708 } else { 1709 processSimpleRelocation(SectionID, Offset, RelType, Value); 1710 } 1711 } else if (Arch == Triple::arm) { 1712 if (RelType == ELF::R_ARM_PC24 || RelType == ELF::R_ARM_CALL || 1713 RelType == ELF::R_ARM_JUMP24) { 1714 // This is an ARM branch relocation, need to use a stub function. 1715 LLVM_DEBUG(dbgs() << "\t\tThis is an ARM branch relocation.\n"); 1716 SectionEntry &Section = Sections[SectionID]; 1717 1718 // Look for an existing stub. 1719 auto [It, Inserted] = Stubs.try_emplace(Value); 1720 if (!Inserted) { 1721 resolveRelocation(Section, Offset, 1722 Section.getLoadAddressWithOffset(It->second), RelType, 1723 0); 1724 LLVM_DEBUG(dbgs() << " Stub function found\n"); 1725 } else { 1726 // Create a new stub function. 1727 LLVM_DEBUG(dbgs() << " Create a new stub function\n"); 1728 It->second = Section.getStubOffset(); 1729 uint8_t *StubTargetAddr = createStubFunction( 1730 Section.getAddressWithOffset(Section.getStubOffset())); 1731 RelocationEntry RE(SectionID, StubTargetAddr - Section.getAddress(), 1732 ELF::R_ARM_ABS32, Value.Addend); 1733 if (Value.SymbolName) 1734 addRelocationForSymbol(RE, Value.SymbolName); 1735 else 1736 addRelocationForSection(RE, Value.SectionID); 1737 1738 resolveRelocation( 1739 Section, Offset, 1740 Section.getLoadAddressWithOffset(Section.getStubOffset()), RelType, 1741 0); 1742 Section.advanceStubOffset(getMaxStubSize()); 1743 } 1744 } else { 1745 uint32_t *Placeholder = 1746 reinterpret_cast<uint32_t*>(computePlaceholderAddress(SectionID, Offset)); 1747 if (RelType == ELF::R_ARM_PREL31 || RelType == ELF::R_ARM_TARGET1 || 1748 RelType == ELF::R_ARM_ABS32) { 1749 Value.Addend += *Placeholder; 1750 } else if (RelType == ELF::R_ARM_MOVW_ABS_NC || RelType == ELF::R_ARM_MOVT_ABS) { 1751 // See ELF for ARM documentation 1752 Value.Addend += (int16_t)((*Placeholder & 0xFFF) | (((*Placeholder >> 16) & 0xF) << 12)); 1753 } 1754 processSimpleRelocation(SectionID, Offset, RelType, Value); 1755 } 1756 } else if (Arch == Triple::loongarch64) { 1757 if ((RelType == ELF::R_LARCH_B26 || RelType == ELF::R_LARCH_CALL36) && 1758 MemMgr.allowStubAllocation()) { 1759 resolveLoongArch64Branch(SectionID, Value, RelI, Stubs); 1760 } else if (RelType == ELF::R_LARCH_GOT_PC_HI20 || 1761 RelType == ELF::R_LARCH_GOT_PC_LO12) { 1762 uint64_t GOTOffset = findOrAllocGOTEntry(Value, ELF::R_LARCH_64); 1763 resolveGOTOffsetRelocation(SectionID, Offset, GOTOffset + Addend, 1764 RelType); 1765 } else { 1766 processSimpleRelocation(SectionID, Offset, RelType, Value); 1767 } 1768 } else if (IsMipsO32ABI) { 1769 uint8_t *Placeholder = reinterpret_cast<uint8_t *>( 1770 computePlaceholderAddress(SectionID, Offset)); 1771 uint32_t Opcode = readBytesUnaligned(Placeholder, 4); 1772 if (RelType == ELF::R_MIPS_26) { 1773 // This is an Mips branch relocation, need to use a stub function. 1774 LLVM_DEBUG(dbgs() << "\t\tThis is a Mips branch relocation."); 1775 SectionEntry &Section = Sections[SectionID]; 1776 1777 // Extract the addend from the instruction. 1778 // We shift up by two since the Value will be down shifted again 1779 // when applying the relocation. 1780 uint32_t Addend = (Opcode & 0x03ffffff) << 2; 1781 1782 Value.Addend += Addend; 1783 1784 // Look up for existing stub. 1785 auto [It, Inserted] = Stubs.try_emplace(Value); 1786 if (!Inserted) { 1787 RelocationEntry RE(SectionID, Offset, RelType, It->second); 1788 addRelocationForSection(RE, SectionID); 1789 LLVM_DEBUG(dbgs() << " Stub function found\n"); 1790 } else { 1791 // Create a new stub function. 1792 LLVM_DEBUG(dbgs() << " Create a new stub function\n"); 1793 It->second = Section.getStubOffset(); 1794 1795 unsigned AbiVariant = Obj.getPlatformFlags(); 1796 1797 uint8_t *StubTargetAddr = createStubFunction( 1798 Section.getAddressWithOffset(Section.getStubOffset()), AbiVariant); 1799 1800 // Creating Hi and Lo relocations for the filled stub instructions. 1801 RelocationEntry REHi(SectionID, StubTargetAddr - Section.getAddress(), 1802 ELF::R_MIPS_HI16, Value.Addend); 1803 RelocationEntry RELo(SectionID, 1804 StubTargetAddr - Section.getAddress() + 4, 1805 ELF::R_MIPS_LO16, Value.Addend); 1806 1807 if (Value.SymbolName) { 1808 addRelocationForSymbol(REHi, Value.SymbolName); 1809 addRelocationForSymbol(RELo, Value.SymbolName); 1810 } else { 1811 addRelocationForSection(REHi, Value.SectionID); 1812 addRelocationForSection(RELo, Value.SectionID); 1813 } 1814 1815 RelocationEntry RE(SectionID, Offset, RelType, Section.getStubOffset()); 1816 addRelocationForSection(RE, SectionID); 1817 Section.advanceStubOffset(getMaxStubSize()); 1818 } 1819 } else if (RelType == ELF::R_MIPS_HI16 || RelType == ELF::R_MIPS_PCHI16) { 1820 int64_t Addend = (Opcode & 0x0000ffff) << 16; 1821 RelocationEntry RE(SectionID, Offset, RelType, Addend); 1822 PendingRelocs.push_back(std::make_pair(Value, RE)); 1823 } else if (RelType == ELF::R_MIPS_LO16 || RelType == ELF::R_MIPS_PCLO16) { 1824 int64_t Addend = Value.Addend + SignExtend32<16>(Opcode & 0x0000ffff); 1825 for (auto I = PendingRelocs.begin(); I != PendingRelocs.end();) { 1826 const RelocationValueRef &MatchingValue = I->first; 1827 RelocationEntry &Reloc = I->second; 1828 if (MatchingValue == Value && 1829 RelType == getMatchingLoRelocation(Reloc.RelType) && 1830 SectionID == Reloc.SectionID) { 1831 Reloc.Addend += Addend; 1832 if (Value.SymbolName) 1833 addRelocationForSymbol(Reloc, Value.SymbolName); 1834 else 1835 addRelocationForSection(Reloc, Value.SectionID); 1836 I = PendingRelocs.erase(I); 1837 } else 1838 ++I; 1839 } 1840 RelocationEntry RE(SectionID, Offset, RelType, Addend); 1841 if (Value.SymbolName) 1842 addRelocationForSymbol(RE, Value.SymbolName); 1843 else 1844 addRelocationForSection(RE, Value.SectionID); 1845 } else { 1846 if (RelType == ELF::R_MIPS_32) 1847 Value.Addend += Opcode; 1848 else if (RelType == ELF::R_MIPS_PC16) 1849 Value.Addend += SignExtend32<18>((Opcode & 0x0000ffff) << 2); 1850 else if (RelType == ELF::R_MIPS_PC19_S2) 1851 Value.Addend += SignExtend32<21>((Opcode & 0x0007ffff) << 2); 1852 else if (RelType == ELF::R_MIPS_PC21_S2) 1853 Value.Addend += SignExtend32<23>((Opcode & 0x001fffff) << 2); 1854 else if (RelType == ELF::R_MIPS_PC26_S2) 1855 Value.Addend += SignExtend32<28>((Opcode & 0x03ffffff) << 2); 1856 processSimpleRelocation(SectionID, Offset, RelType, Value); 1857 } 1858 } else if (IsMipsN32ABI || IsMipsN64ABI) { 1859 uint32_t r_type = RelType & 0xff; 1860 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend); 1861 if (r_type == ELF::R_MIPS_CALL16 || r_type == ELF::R_MIPS_GOT_PAGE 1862 || r_type == ELF::R_MIPS_GOT_DISP) { 1863 auto [I, Inserted] = GOTSymbolOffsets.try_emplace(TargetName); 1864 if (Inserted) 1865 I->second = allocateGOTEntries(1); 1866 RE.SymOffset = I->second; 1867 if (Value.SymbolName) 1868 addRelocationForSymbol(RE, Value.SymbolName); 1869 else 1870 addRelocationForSection(RE, Value.SectionID); 1871 } else if (RelType == ELF::R_MIPS_26) { 1872 // This is an Mips branch relocation, need to use a stub function. 1873 LLVM_DEBUG(dbgs() << "\t\tThis is a Mips branch relocation."); 1874 SectionEntry &Section = Sections[SectionID]; 1875 1876 // Look up for existing stub. 1877 StubMap::const_iterator i = Stubs.find(Value); 1878 if (i != Stubs.end()) { 1879 RelocationEntry RE(SectionID, Offset, RelType, i->second); 1880 addRelocationForSection(RE, SectionID); 1881 LLVM_DEBUG(dbgs() << " Stub function found\n"); 1882 } else { 1883 // Create a new stub function. 1884 LLVM_DEBUG(dbgs() << " Create a new stub function\n"); 1885 Stubs[Value] = Section.getStubOffset(); 1886 1887 unsigned AbiVariant = Obj.getPlatformFlags(); 1888 1889 uint8_t *StubTargetAddr = createStubFunction( 1890 Section.getAddressWithOffset(Section.getStubOffset()), AbiVariant); 1891 1892 if (IsMipsN32ABI) { 1893 // Creating Hi and Lo relocations for the filled stub instructions. 1894 RelocationEntry REHi(SectionID, StubTargetAddr - Section.getAddress(), 1895 ELF::R_MIPS_HI16, Value.Addend); 1896 RelocationEntry RELo(SectionID, 1897 StubTargetAddr - Section.getAddress() + 4, 1898 ELF::R_MIPS_LO16, Value.Addend); 1899 if (Value.SymbolName) { 1900 addRelocationForSymbol(REHi, Value.SymbolName); 1901 addRelocationForSymbol(RELo, Value.SymbolName); 1902 } else { 1903 addRelocationForSection(REHi, Value.SectionID); 1904 addRelocationForSection(RELo, Value.SectionID); 1905 } 1906 } else { 1907 // Creating Highest, Higher, Hi and Lo relocations for the filled stub 1908 // instructions. 1909 RelocationEntry REHighest(SectionID, 1910 StubTargetAddr - Section.getAddress(), 1911 ELF::R_MIPS_HIGHEST, Value.Addend); 1912 RelocationEntry REHigher(SectionID, 1913 StubTargetAddr - Section.getAddress() + 4, 1914 ELF::R_MIPS_HIGHER, Value.Addend); 1915 RelocationEntry REHi(SectionID, 1916 StubTargetAddr - Section.getAddress() + 12, 1917 ELF::R_MIPS_HI16, Value.Addend); 1918 RelocationEntry RELo(SectionID, 1919 StubTargetAddr - Section.getAddress() + 20, 1920 ELF::R_MIPS_LO16, Value.Addend); 1921 if (Value.SymbolName) { 1922 addRelocationForSymbol(REHighest, Value.SymbolName); 1923 addRelocationForSymbol(REHigher, Value.SymbolName); 1924 addRelocationForSymbol(REHi, Value.SymbolName); 1925 addRelocationForSymbol(RELo, Value.SymbolName); 1926 } else { 1927 addRelocationForSection(REHighest, Value.SectionID); 1928 addRelocationForSection(REHigher, Value.SectionID); 1929 addRelocationForSection(REHi, Value.SectionID); 1930 addRelocationForSection(RELo, Value.SectionID); 1931 } 1932 } 1933 RelocationEntry RE(SectionID, Offset, RelType, Section.getStubOffset()); 1934 addRelocationForSection(RE, SectionID); 1935 Section.advanceStubOffset(getMaxStubSize()); 1936 } 1937 } else { 1938 processSimpleRelocation(SectionID, Offset, RelType, Value); 1939 } 1940 1941 } else if (Arch == Triple::ppc64 || Arch == Triple::ppc64le) { 1942 if (RelType == ELF::R_PPC64_REL24) { 1943 // Determine ABI variant in use for this object. 1944 unsigned AbiVariant = Obj.getPlatformFlags(); 1945 AbiVariant &= ELF::EF_PPC64_ABI; 1946 // A PPC branch relocation will need a stub function if the target is 1947 // an external symbol (either Value.SymbolName is set, or SymType is 1948 // Symbol::ST_Unknown) or if the target address is not within the 1949 // signed 24-bits branch address. 1950 SectionEntry &Section = Sections[SectionID]; 1951 uint8_t *Target = Section.getAddressWithOffset(Offset); 1952 bool RangeOverflow = false; 1953 bool IsExtern = Value.SymbolName || SymType == SymbolRef::ST_Unknown; 1954 if (!IsExtern) { 1955 if (AbiVariant != 2) { 1956 // In the ELFv1 ABI, a function call may point to the .opd entry, 1957 // so the final symbol value is calculated based on the relocation 1958 // values in the .opd section. 1959 if (auto Err = findOPDEntrySection(Obj, ObjSectionToID, Value)) 1960 return std::move(Err); 1961 } else { 1962 // In the ELFv2 ABI, a function symbol may provide a local entry 1963 // point, which must be used for direct calls. 1964 if (Value.SectionID == SectionID){ 1965 uint8_t SymOther = Symbol->getOther(); 1966 Value.Addend += ELF::decodePPC64LocalEntryOffset(SymOther); 1967 } 1968 } 1969 uint8_t *RelocTarget = 1970 Sections[Value.SectionID].getAddressWithOffset(Value.Addend); 1971 int64_t delta = static_cast<int64_t>(Target - RelocTarget); 1972 // If it is within 26-bits branch range, just set the branch target 1973 if (SignExtend64<26>(delta) != delta) { 1974 RangeOverflow = true; 1975 } else if ((AbiVariant != 2) || 1976 (AbiVariant == 2 && Value.SectionID == SectionID)) { 1977 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend); 1978 addRelocationForSection(RE, Value.SectionID); 1979 } 1980 } 1981 if (IsExtern || (AbiVariant == 2 && Value.SectionID != SectionID) || 1982 RangeOverflow) { 1983 // It is an external symbol (either Value.SymbolName is set, or 1984 // SymType is SymbolRef::ST_Unknown) or out of range. 1985 auto [It, Inserted] = Stubs.try_emplace(Value); 1986 if (!Inserted) { 1987 // Symbol function stub already created, just relocate to it 1988 resolveRelocation(Section, Offset, 1989 Section.getLoadAddressWithOffset(It->second), 1990 RelType, 0); 1991 LLVM_DEBUG(dbgs() << " Stub function found\n"); 1992 } else { 1993 // Create a new stub function. 1994 LLVM_DEBUG(dbgs() << " Create a new stub function\n"); 1995 It->second = Section.getStubOffset(); 1996 uint8_t *StubTargetAddr = createStubFunction( 1997 Section.getAddressWithOffset(Section.getStubOffset()), 1998 AbiVariant); 1999 RelocationEntry RE(SectionID, StubTargetAddr - Section.getAddress(), 2000 ELF::R_PPC64_ADDR64, Value.Addend); 2001 2002 // Generates the 64-bits address loads as exemplified in section 2003 // 4.5.1 in PPC64 ELF ABI. Note that the relocations need to 2004 // apply to the low part of the instructions, so we have to update 2005 // the offset according to the target endianness. 2006 uint64_t StubRelocOffset = StubTargetAddr - Section.getAddress(); 2007 if (!IsTargetLittleEndian) 2008 StubRelocOffset += 2; 2009 2010 RelocationEntry REhst(SectionID, StubRelocOffset + 0, 2011 ELF::R_PPC64_ADDR16_HIGHEST, Value.Addend); 2012 RelocationEntry REhr(SectionID, StubRelocOffset + 4, 2013 ELF::R_PPC64_ADDR16_HIGHER, Value.Addend); 2014 RelocationEntry REh(SectionID, StubRelocOffset + 12, 2015 ELF::R_PPC64_ADDR16_HI, Value.Addend); 2016 RelocationEntry REl(SectionID, StubRelocOffset + 16, 2017 ELF::R_PPC64_ADDR16_LO, Value.Addend); 2018 2019 if (Value.SymbolName) { 2020 addRelocationForSymbol(REhst, Value.SymbolName); 2021 addRelocationForSymbol(REhr, Value.SymbolName); 2022 addRelocationForSymbol(REh, Value.SymbolName); 2023 addRelocationForSymbol(REl, Value.SymbolName); 2024 } else { 2025 addRelocationForSection(REhst, Value.SectionID); 2026 addRelocationForSection(REhr, Value.SectionID); 2027 addRelocationForSection(REh, Value.SectionID); 2028 addRelocationForSection(REl, Value.SectionID); 2029 } 2030 2031 resolveRelocation( 2032 Section, Offset, 2033 Section.getLoadAddressWithOffset(Section.getStubOffset()), 2034 RelType, 0); 2035 Section.advanceStubOffset(getMaxStubSize()); 2036 } 2037 if (IsExtern || (AbiVariant == 2 && Value.SectionID != SectionID)) { 2038 // Restore the TOC for external calls 2039 if (AbiVariant == 2) 2040 writeInt32BE(Target + 4, 0xE8410018); // ld r2,24(r1) 2041 else 2042 writeInt32BE(Target + 4, 0xE8410028); // ld r2,40(r1) 2043 } 2044 } 2045 } else if (RelType == ELF::R_PPC64_TOC16 || 2046 RelType == ELF::R_PPC64_TOC16_DS || 2047 RelType == ELF::R_PPC64_TOC16_LO || 2048 RelType == ELF::R_PPC64_TOC16_LO_DS || 2049 RelType == ELF::R_PPC64_TOC16_HI || 2050 RelType == ELF::R_PPC64_TOC16_HA) { 2051 // These relocations are supposed to subtract the TOC address from 2052 // the final value. This does not fit cleanly into the RuntimeDyld 2053 // scheme, since there may be *two* sections involved in determining 2054 // the relocation value (the section of the symbol referred to by the 2055 // relocation, and the TOC section associated with the current module). 2056 // 2057 // Fortunately, these relocations are currently only ever generated 2058 // referring to symbols that themselves reside in the TOC, which means 2059 // that the two sections are actually the same. Thus they cancel out 2060 // and we can immediately resolve the relocation right now. 2061 switch (RelType) { 2062 case ELF::R_PPC64_TOC16: RelType = ELF::R_PPC64_ADDR16; break; 2063 case ELF::R_PPC64_TOC16_DS: RelType = ELF::R_PPC64_ADDR16_DS; break; 2064 case ELF::R_PPC64_TOC16_LO: RelType = ELF::R_PPC64_ADDR16_LO; break; 2065 case ELF::R_PPC64_TOC16_LO_DS: RelType = ELF::R_PPC64_ADDR16_LO_DS; break; 2066 case ELF::R_PPC64_TOC16_HI: RelType = ELF::R_PPC64_ADDR16_HI; break; 2067 case ELF::R_PPC64_TOC16_HA: RelType = ELF::R_PPC64_ADDR16_HA; break; 2068 default: llvm_unreachable("Wrong relocation type."); 2069 } 2070 2071 RelocationValueRef TOCValue; 2072 if (auto Err = findPPC64TOCSection(Obj, ObjSectionToID, TOCValue)) 2073 return std::move(Err); 2074 if (Value.SymbolName || Value.SectionID != TOCValue.SectionID) 2075 llvm_unreachable("Unsupported TOC relocation."); 2076 Value.Addend -= TOCValue.Addend; 2077 resolveRelocation(Sections[SectionID], Offset, Value.Addend, RelType, 0); 2078 } else { 2079 // There are two ways to refer to the TOC address directly: either 2080 // via a ELF::R_PPC64_TOC relocation (where both symbol and addend are 2081 // ignored), or via any relocation that refers to the magic ".TOC." 2082 // symbols (in which case the addend is respected). 2083 if (RelType == ELF::R_PPC64_TOC) { 2084 RelType = ELF::R_PPC64_ADDR64; 2085 if (auto Err = findPPC64TOCSection(Obj, ObjSectionToID, Value)) 2086 return std::move(Err); 2087 } else if (TargetName == ".TOC.") { 2088 if (auto Err = findPPC64TOCSection(Obj, ObjSectionToID, Value)) 2089 return std::move(Err); 2090 Value.Addend += Addend; 2091 } 2092 2093 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend); 2094 2095 if (Value.SymbolName) 2096 addRelocationForSymbol(RE, Value.SymbolName); 2097 else 2098 addRelocationForSection(RE, Value.SectionID); 2099 } 2100 } else if (Arch == Triple::systemz && 2101 (RelType == ELF::R_390_PLT32DBL || RelType == ELF::R_390_GOTENT)) { 2102 // Create function stubs for both PLT and GOT references, regardless of 2103 // whether the GOT reference is to data or code. The stub contains the 2104 // full address of the symbol, as needed by GOT references, and the 2105 // executable part only adds an overhead of 8 bytes. 2106 // 2107 // We could try to conserve space by allocating the code and data 2108 // parts of the stub separately. However, as things stand, we allocate 2109 // a stub for every relocation, so using a GOT in JIT code should be 2110 // no less space efficient than using an explicit constant pool. 2111 LLVM_DEBUG(dbgs() << "\t\tThis is a SystemZ indirect relocation."); 2112 SectionEntry &Section = Sections[SectionID]; 2113 2114 // Look for an existing stub. 2115 StubMap::const_iterator i = Stubs.find(Value); 2116 uintptr_t StubAddress; 2117 if (i != Stubs.end()) { 2118 StubAddress = uintptr_t(Section.getAddressWithOffset(i->second)); 2119 LLVM_DEBUG(dbgs() << " Stub function found\n"); 2120 } else { 2121 // Create a new stub function. 2122 LLVM_DEBUG(dbgs() << " Create a new stub function\n"); 2123 2124 uintptr_t BaseAddress = uintptr_t(Section.getAddress()); 2125 StubAddress = 2126 alignTo(BaseAddress + Section.getStubOffset(), getStubAlignment()); 2127 unsigned StubOffset = StubAddress - BaseAddress; 2128 2129 Stubs[Value] = StubOffset; 2130 createStubFunction((uint8_t *)StubAddress); 2131 RelocationEntry RE(SectionID, StubOffset + 8, ELF::R_390_64, 2132 Value.Offset); 2133 if (Value.SymbolName) 2134 addRelocationForSymbol(RE, Value.SymbolName); 2135 else 2136 addRelocationForSection(RE, Value.SectionID); 2137 Section.advanceStubOffset(getMaxStubSize()); 2138 } 2139 2140 if (RelType == ELF::R_390_GOTENT) 2141 resolveRelocation(Section, Offset, StubAddress + 8, ELF::R_390_PC32DBL, 2142 Addend); 2143 else 2144 resolveRelocation(Section, Offset, StubAddress, RelType, Addend); 2145 } else if (Arch == Triple::x86_64) { 2146 if (RelType == ELF::R_X86_64_PLT32) { 2147 // The way the PLT relocations normally work is that the linker allocates 2148 // the 2149 // PLT and this relocation makes a PC-relative call into the PLT. The PLT 2150 // entry will then jump to an address provided by the GOT. On first call, 2151 // the 2152 // GOT address will point back into PLT code that resolves the symbol. After 2153 // the first call, the GOT entry points to the actual function. 2154 // 2155 // For local functions we're ignoring all of that here and just replacing 2156 // the PLT32 relocation type with PC32, which will translate the relocation 2157 // into a PC-relative call directly to the function. For external symbols we 2158 // can't be sure the function will be within 2^32 bytes of the call site, so 2159 // we need to create a stub, which calls into the GOT. This case is 2160 // equivalent to the usual PLT implementation except that we use the stub 2161 // mechanism in RuntimeDyld (which puts stubs at the end of the section) 2162 // rather than allocating a PLT section. 2163 if (Value.SymbolName && MemMgr.allowStubAllocation()) { 2164 // This is a call to an external function. 2165 // Look for an existing stub. 2166 SectionEntry *Section = &Sections[SectionID]; 2167 auto [It, Inserted] = Stubs.try_emplace(Value); 2168 uintptr_t StubAddress; 2169 if (!Inserted) { 2170 StubAddress = uintptr_t(Section->getAddress()) + It->second; 2171 LLVM_DEBUG(dbgs() << " Stub function found\n"); 2172 } else { 2173 // Create a new stub function (equivalent to a PLT entry). 2174 LLVM_DEBUG(dbgs() << " Create a new stub function\n"); 2175 2176 uintptr_t BaseAddress = uintptr_t(Section->getAddress()); 2177 StubAddress = alignTo(BaseAddress + Section->getStubOffset(), 2178 getStubAlignment()); 2179 unsigned StubOffset = StubAddress - BaseAddress; 2180 It->second = StubOffset; 2181 createStubFunction((uint8_t *)StubAddress); 2182 2183 // Bump our stub offset counter 2184 Section->advanceStubOffset(getMaxStubSize()); 2185 2186 // Allocate a GOT Entry 2187 uint64_t GOTOffset = allocateGOTEntries(1); 2188 // This potentially creates a new Section which potentially 2189 // invalidates the Section pointer, so reload it. 2190 Section = &Sections[SectionID]; 2191 2192 // The load of the GOT address has an addend of -4 2193 resolveGOTOffsetRelocation(SectionID, StubOffset + 2, GOTOffset - 4, 2194 ELF::R_X86_64_PC32); 2195 2196 // Fill in the value of the symbol we're targeting into the GOT 2197 addRelocationForSymbol( 2198 computeGOTOffsetRE(GOTOffset, 0, ELF::R_X86_64_64), 2199 Value.SymbolName); 2200 } 2201 2202 // Make the target call a call into the stub table. 2203 resolveRelocation(*Section, Offset, StubAddress, ELF::R_X86_64_PC32, 2204 Addend); 2205 } else { 2206 Value.Addend += support::ulittle32_t::ref( 2207 computePlaceholderAddress(SectionID, Offset)); 2208 processSimpleRelocation(SectionID, Offset, ELF::R_X86_64_PC32, Value); 2209 } 2210 } else if (RelType == ELF::R_X86_64_GOTPCREL || 2211 RelType == ELF::R_X86_64_GOTPCRELX || 2212 RelType == ELF::R_X86_64_REX_GOTPCRELX) { 2213 uint64_t GOTOffset = allocateGOTEntries(1); 2214 resolveGOTOffsetRelocation(SectionID, Offset, GOTOffset + Addend, 2215 ELF::R_X86_64_PC32); 2216 2217 // Fill in the value of the symbol we're targeting into the GOT 2218 RelocationEntry RE = 2219 computeGOTOffsetRE(GOTOffset, Value.Offset, ELF::R_X86_64_64); 2220 if (Value.SymbolName) 2221 addRelocationForSymbol(RE, Value.SymbolName); 2222 else 2223 addRelocationForSection(RE, Value.SectionID); 2224 } else if (RelType == ELF::R_X86_64_GOT64) { 2225 // Fill in a 64-bit GOT offset. 2226 uint64_t GOTOffset = allocateGOTEntries(1); 2227 resolveRelocation(Sections[SectionID], Offset, GOTOffset, 2228 ELF::R_X86_64_64, 0); 2229 2230 // Fill in the value of the symbol we're targeting into the GOT 2231 RelocationEntry RE = 2232 computeGOTOffsetRE(GOTOffset, Value.Offset, ELF::R_X86_64_64); 2233 if (Value.SymbolName) 2234 addRelocationForSymbol(RE, Value.SymbolName); 2235 else 2236 addRelocationForSection(RE, Value.SectionID); 2237 } else if (RelType == ELF::R_X86_64_GOTPC32) { 2238 // Materialize the address of the base of the GOT relative to the PC. 2239 // This doesn't create a GOT entry, but it does mean we need a GOT 2240 // section. 2241 (void)allocateGOTEntries(0); 2242 resolveGOTOffsetRelocation(SectionID, Offset, Addend, ELF::R_X86_64_PC32); 2243 } else if (RelType == ELF::R_X86_64_GOTPC64) { 2244 (void)allocateGOTEntries(0); 2245 resolveGOTOffsetRelocation(SectionID, Offset, Addend, ELF::R_X86_64_PC64); 2246 } else if (RelType == ELF::R_X86_64_GOTOFF64) { 2247 // GOTOFF relocations ultimately require a section difference relocation. 2248 (void)allocateGOTEntries(0); 2249 processSimpleRelocation(SectionID, Offset, RelType, Value); 2250 } else if (RelType == ELF::R_X86_64_PC32) { 2251 Value.Addend += support::ulittle32_t::ref(computePlaceholderAddress(SectionID, Offset)); 2252 processSimpleRelocation(SectionID, Offset, RelType, Value); 2253 } else if (RelType == ELF::R_X86_64_PC64) { 2254 Value.Addend += support::ulittle64_t::ref( 2255 computePlaceholderAddress(SectionID, Offset)); 2256 processSimpleRelocation(SectionID, Offset, RelType, Value); 2257 } else if (RelType == ELF::R_X86_64_GOTTPOFF) { 2258 processX86_64GOTTPOFFRelocation(SectionID, Offset, Value, Addend); 2259 } else if (RelType == ELF::R_X86_64_TLSGD || 2260 RelType == ELF::R_X86_64_TLSLD) { 2261 // The next relocation must be the relocation for __tls_get_addr. 2262 ++RelI; 2263 auto &GetAddrRelocation = *RelI; 2264 processX86_64TLSRelocation(SectionID, Offset, RelType, Value, Addend, 2265 GetAddrRelocation); 2266 } else { 2267 processSimpleRelocation(SectionID, Offset, RelType, Value); 2268 } 2269 } else if (Arch == Triple::riscv32 || Arch == Triple::riscv64) { 2270 // *_LO12 relocation receive information about a symbol from the 2271 // corresponding *_HI20 relocation, so we have to collect this information 2272 // before resolving 2273 if (RelType == ELF::R_RISCV_GOT_HI20 || 2274 RelType == ELF::R_RISCV_PCREL_HI20 || 2275 RelType == ELF::R_RISCV_TPREL_HI20 || 2276 RelType == ELF::R_RISCV_TLS_GD_HI20 || 2277 RelType == ELF::R_RISCV_TLS_GOT_HI20) { 2278 RelocationEntry RE(SectionID, Offset, RelType, Addend); 2279 PendingRelocs.push_back({Value, RE}); 2280 } 2281 processSimpleRelocation(SectionID, Offset, RelType, Value); 2282 } else { 2283 if (Arch == Triple::x86) { 2284 Value.Addend += support::ulittle32_t::ref( 2285 computePlaceholderAddress(SectionID, Offset)); 2286 } 2287 processSimpleRelocation(SectionID, Offset, RelType, Value); 2288 } 2289 return ++RelI; 2290 } 2291 2292 void RuntimeDyldELF::processX86_64GOTTPOFFRelocation(unsigned SectionID, 2293 uint64_t Offset, 2294 RelocationValueRef Value, 2295 int64_t Addend) { 2296 // Use the approach from "x86-64 Linker Optimizations" from the TLS spec 2297 // to replace the GOTTPOFF relocation with a TPOFF relocation. The spec 2298 // only mentions one optimization even though there are two different 2299 // code sequences for the Initial Exec TLS Model. We match the code to 2300 // find out which one was used. 2301 2302 // A possible TLS code sequence and its replacement 2303 struct CodeSequence { 2304 // The expected code sequence 2305 ArrayRef<uint8_t> ExpectedCodeSequence; 2306 // The negative offset of the GOTTPOFF relocation to the beginning of 2307 // the sequence 2308 uint64_t TLSSequenceOffset; 2309 // The new code sequence 2310 ArrayRef<uint8_t> NewCodeSequence; 2311 // The offset of the new TPOFF relocation 2312 uint64_t TpoffRelocationOffset; 2313 }; 2314 2315 std::array<CodeSequence, 2> CodeSequences; 2316 2317 // Initial Exec Code Model Sequence 2318 { 2319 static const std::initializer_list<uint8_t> ExpectedCodeSequenceList = { 2320 0x64, 0x48, 0x8b, 0x04, 0x25, 0x00, 0x00, 0x00, 2321 0x00, // mov %fs:0, %rax 2322 0x48, 0x03, 0x05, 0x00, 0x00, 0x00, 0x00 // add x@gotpoff(%rip), 2323 // %rax 2324 }; 2325 CodeSequences[0].ExpectedCodeSequence = 2326 ArrayRef<uint8_t>(ExpectedCodeSequenceList); 2327 CodeSequences[0].TLSSequenceOffset = 12; 2328 2329 static const std::initializer_list<uint8_t> NewCodeSequenceList = { 2330 0x64, 0x48, 0x8b, 0x04, 0x25, 0x00, 0x00, 0x00, 0x00, // mov %fs:0, %rax 2331 0x48, 0x8d, 0x80, 0x00, 0x00, 0x00, 0x00 // lea x@tpoff(%rax), %rax 2332 }; 2333 CodeSequences[0].NewCodeSequence = ArrayRef<uint8_t>(NewCodeSequenceList); 2334 CodeSequences[0].TpoffRelocationOffset = 12; 2335 } 2336 2337 // Initial Exec Code Model Sequence, II 2338 { 2339 static const std::initializer_list<uint8_t> ExpectedCodeSequenceList = { 2340 0x48, 0x8b, 0x05, 0x00, 0x00, 0x00, 0x00, // mov x@gotpoff(%rip), %rax 2341 0x64, 0x48, 0x8b, 0x00, 0x00, 0x00, 0x00 // mov %fs:(%rax), %rax 2342 }; 2343 CodeSequences[1].ExpectedCodeSequence = 2344 ArrayRef<uint8_t>(ExpectedCodeSequenceList); 2345 CodeSequences[1].TLSSequenceOffset = 3; 2346 2347 static const std::initializer_list<uint8_t> NewCodeSequenceList = { 2348 0x66, 0x0f, 0x1f, 0x44, 0x00, 0x00, // 6 byte nop 2349 0x64, 0x8b, 0x04, 0x25, 0x00, 0x00, 0x00, 0x00, // mov %fs:x@tpoff, %rax 2350 }; 2351 CodeSequences[1].NewCodeSequence = ArrayRef<uint8_t>(NewCodeSequenceList); 2352 CodeSequences[1].TpoffRelocationOffset = 10; 2353 } 2354 2355 bool Resolved = false; 2356 auto &Section = Sections[SectionID]; 2357 for (const auto &C : CodeSequences) { 2358 assert(C.ExpectedCodeSequence.size() == C.NewCodeSequence.size() && 2359 "Old and new code sequences must have the same size"); 2360 2361 if (Offset < C.TLSSequenceOffset || 2362 (Offset - C.TLSSequenceOffset + C.NewCodeSequence.size()) > 2363 Section.getSize()) { 2364 // This can't be a matching sequence as it doesn't fit in the current 2365 // section 2366 continue; 2367 } 2368 2369 auto TLSSequenceStartOffset = Offset - C.TLSSequenceOffset; 2370 auto *TLSSequence = Section.getAddressWithOffset(TLSSequenceStartOffset); 2371 if (ArrayRef<uint8_t>(TLSSequence, C.ExpectedCodeSequence.size()) != 2372 C.ExpectedCodeSequence) { 2373 continue; 2374 } 2375 2376 memcpy(TLSSequence, C.NewCodeSequence.data(), C.NewCodeSequence.size()); 2377 2378 // The original GOTTPOFF relocation has an addend as it is PC relative, 2379 // so it needs to be corrected. The TPOFF32 relocation is used as an 2380 // absolute value (which is an offset from %fs:0), so remove the addend 2381 // again. 2382 RelocationEntry RE(SectionID, 2383 TLSSequenceStartOffset + C.TpoffRelocationOffset, 2384 ELF::R_X86_64_TPOFF32, Value.Addend - Addend); 2385 2386 if (Value.SymbolName) 2387 addRelocationForSymbol(RE, Value.SymbolName); 2388 else 2389 addRelocationForSection(RE, Value.SectionID); 2390 2391 Resolved = true; 2392 break; 2393 } 2394 2395 if (!Resolved) { 2396 // The GOTTPOFF relocation was not used in one of the sequences 2397 // described in the spec, so we can't optimize it to a TPOFF 2398 // relocation. 2399 uint64_t GOTOffset = allocateGOTEntries(1); 2400 resolveGOTOffsetRelocation(SectionID, Offset, GOTOffset + Addend, 2401 ELF::R_X86_64_PC32); 2402 RelocationEntry RE = 2403 computeGOTOffsetRE(GOTOffset, Value.Offset, ELF::R_X86_64_TPOFF64); 2404 if (Value.SymbolName) 2405 addRelocationForSymbol(RE, Value.SymbolName); 2406 else 2407 addRelocationForSection(RE, Value.SectionID); 2408 } 2409 } 2410 2411 void RuntimeDyldELF::processX86_64TLSRelocation( 2412 unsigned SectionID, uint64_t Offset, uint64_t RelType, 2413 RelocationValueRef Value, int64_t Addend, 2414 const RelocationRef &GetAddrRelocation) { 2415 // Since we are statically linking and have no additional DSOs, we can resolve 2416 // the relocation directly without using __tls_get_addr. 2417 // Use the approach from "x86-64 Linker Optimizations" from the TLS spec 2418 // to replace it with the Local Exec relocation variant. 2419 2420 // Find out whether the code was compiled with the large or small memory 2421 // model. For this we look at the next relocation which is the relocation 2422 // for the __tls_get_addr function. If it's a 32 bit relocation, it's the 2423 // small code model, with a 64 bit relocation it's the large code model. 2424 bool IsSmallCodeModel; 2425 // Is the relocation for the __tls_get_addr a PC-relative GOT relocation? 2426 bool IsGOTPCRel = false; 2427 2428 switch (GetAddrRelocation.getType()) { 2429 case ELF::R_X86_64_GOTPCREL: 2430 case ELF::R_X86_64_REX_GOTPCRELX: 2431 case ELF::R_X86_64_GOTPCRELX: 2432 IsGOTPCRel = true; 2433 [[fallthrough]]; 2434 case ELF::R_X86_64_PLT32: 2435 IsSmallCodeModel = true; 2436 break; 2437 case ELF::R_X86_64_PLTOFF64: 2438 IsSmallCodeModel = false; 2439 break; 2440 default: 2441 report_fatal_error( 2442 "invalid TLS relocations for General/Local Dynamic TLS Model: " 2443 "expected PLT or GOT relocation for __tls_get_addr function"); 2444 } 2445 2446 // The negative offset to the start of the TLS code sequence relative to 2447 // the offset of the TLSGD/TLSLD relocation 2448 uint64_t TLSSequenceOffset; 2449 // The expected start of the code sequence 2450 ArrayRef<uint8_t> ExpectedCodeSequence; 2451 // The new TLS code sequence that will replace the existing code 2452 ArrayRef<uint8_t> NewCodeSequence; 2453 2454 if (RelType == ELF::R_X86_64_TLSGD) { 2455 // The offset of the new TPOFF32 relocation (offset starting from the 2456 // beginning of the whole TLS sequence) 2457 uint64_t TpoffRelocOffset; 2458 2459 if (IsSmallCodeModel) { 2460 if (!IsGOTPCRel) { 2461 static const std::initializer_list<uint8_t> CodeSequence = { 2462 0x66, // data16 (no-op prefix) 2463 0x48, 0x8d, 0x3d, 0x00, 0x00, 2464 0x00, 0x00, // lea <disp32>(%rip), %rdi 2465 0x66, 0x66, // two data16 prefixes 2466 0x48, // rex64 (no-op prefix) 2467 0xe8, 0x00, 0x00, 0x00, 0x00 // call __tls_get_addr@plt 2468 }; 2469 ExpectedCodeSequence = ArrayRef<uint8_t>(CodeSequence); 2470 TLSSequenceOffset = 4; 2471 } else { 2472 // This code sequence is not described in the TLS spec but gcc 2473 // generates it sometimes. 2474 static const std::initializer_list<uint8_t> CodeSequence = { 2475 0x66, // data16 (no-op prefix) 2476 0x48, 0x8d, 0x3d, 0x00, 0x00, 2477 0x00, 0x00, // lea <disp32>(%rip), %rdi 2478 0x66, // data16 prefix (no-op prefix) 2479 0x48, // rex64 (no-op prefix) 2480 0xff, 0x15, 0x00, 0x00, 0x00, 2481 0x00 // call *__tls_get_addr@gotpcrel(%rip) 2482 }; 2483 ExpectedCodeSequence = ArrayRef<uint8_t>(CodeSequence); 2484 TLSSequenceOffset = 4; 2485 } 2486 2487 // The replacement code for the small code model. It's the same for 2488 // both sequences. 2489 static const std::initializer_list<uint8_t> SmallSequence = { 2490 0x64, 0x48, 0x8b, 0x04, 0x25, 0x00, 0x00, 0x00, 2491 0x00, // mov %fs:0, %rax 2492 0x48, 0x8d, 0x80, 0x00, 0x00, 0x00, 0x00 // lea x@tpoff(%rax), 2493 // %rax 2494 }; 2495 NewCodeSequence = ArrayRef<uint8_t>(SmallSequence); 2496 TpoffRelocOffset = 12; 2497 } else { 2498 static const std::initializer_list<uint8_t> CodeSequence = { 2499 0x48, 0x8d, 0x3d, 0x00, 0x00, 0x00, 0x00, // lea <disp32>(%rip), 2500 // %rdi 2501 0x48, 0xb8, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 2502 0x00, // movabs $__tls_get_addr@pltoff, %rax 2503 0x48, 0x01, 0xd8, // add %rbx, %rax 2504 0xff, 0xd0 // call *%rax 2505 }; 2506 ExpectedCodeSequence = ArrayRef<uint8_t>(CodeSequence); 2507 TLSSequenceOffset = 3; 2508 2509 // The replacement code for the large code model 2510 static const std::initializer_list<uint8_t> LargeSequence = { 2511 0x64, 0x48, 0x8b, 0x04, 0x25, 0x00, 0x00, 0x00, 2512 0x00, // mov %fs:0, %rax 2513 0x48, 0x8d, 0x80, 0x00, 0x00, 0x00, 0x00, // lea x@tpoff(%rax), 2514 // %rax 2515 0x66, 0x0f, 0x1f, 0x44, 0x00, 0x00 // nopw 0x0(%rax,%rax,1) 2516 }; 2517 NewCodeSequence = ArrayRef<uint8_t>(LargeSequence); 2518 TpoffRelocOffset = 12; 2519 } 2520 2521 // The TLSGD/TLSLD relocations are PC-relative, so they have an addend. 2522 // The new TPOFF32 relocations is used as an absolute offset from 2523 // %fs:0, so remove the TLSGD/TLSLD addend again. 2524 RelocationEntry RE(SectionID, Offset - TLSSequenceOffset + TpoffRelocOffset, 2525 ELF::R_X86_64_TPOFF32, Value.Addend - Addend); 2526 if (Value.SymbolName) 2527 addRelocationForSymbol(RE, Value.SymbolName); 2528 else 2529 addRelocationForSection(RE, Value.SectionID); 2530 } else if (RelType == ELF::R_X86_64_TLSLD) { 2531 if (IsSmallCodeModel) { 2532 if (!IsGOTPCRel) { 2533 static const std::initializer_list<uint8_t> CodeSequence = { 2534 0x48, 0x8d, 0x3d, 0x00, 0x00, 0x00, // leaq <disp32>(%rip), %rdi 2535 0x00, 0xe8, 0x00, 0x00, 0x00, 0x00 // call __tls_get_addr@plt 2536 }; 2537 ExpectedCodeSequence = ArrayRef<uint8_t>(CodeSequence); 2538 TLSSequenceOffset = 3; 2539 2540 // The replacement code for the small code model 2541 static const std::initializer_list<uint8_t> SmallSequence = { 2542 0x66, 0x66, 0x66, // three data16 prefixes (no-op) 2543 0x64, 0x48, 0x8b, 0x04, 0x25, 2544 0x00, 0x00, 0x00, 0x00 // mov %fs:0, %rax 2545 }; 2546 NewCodeSequence = ArrayRef<uint8_t>(SmallSequence); 2547 } else { 2548 // This code sequence is not described in the TLS spec but gcc 2549 // generates it sometimes. 2550 static const std::initializer_list<uint8_t> CodeSequence = { 2551 0x48, 0x8d, 0x3d, 0x00, 2552 0x00, 0x00, 0x00, // leaq <disp32>(%rip), %rdi 2553 0xff, 0x15, 0x00, 0x00, 2554 0x00, 0x00 // call 2555 // *__tls_get_addr@gotpcrel(%rip) 2556 }; 2557 ExpectedCodeSequence = ArrayRef<uint8_t>(CodeSequence); 2558 TLSSequenceOffset = 3; 2559 2560 // The replacement is code is just like above but it needs to be 2561 // one byte longer. 2562 static const std::initializer_list<uint8_t> SmallSequence = { 2563 0x0f, 0x1f, 0x40, 0x00, // 4 byte nop 2564 0x64, 0x48, 0x8b, 0x04, 0x25, 2565 0x00, 0x00, 0x00, 0x00 // mov %fs:0, %rax 2566 }; 2567 NewCodeSequence = ArrayRef<uint8_t>(SmallSequence); 2568 } 2569 } else { 2570 // This is the same sequence as for the TLSGD sequence with the large 2571 // memory model above 2572 static const std::initializer_list<uint8_t> CodeSequence = { 2573 0x48, 0x8d, 0x3d, 0x00, 0x00, 0x00, 0x00, // lea <disp32>(%rip), 2574 // %rdi 2575 0x48, 0xb8, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 2576 0x48, // movabs $__tls_get_addr@pltoff, %rax 2577 0x01, 0xd8, // add %rbx, %rax 2578 0xff, 0xd0 // call *%rax 2579 }; 2580 ExpectedCodeSequence = ArrayRef<uint8_t>(CodeSequence); 2581 TLSSequenceOffset = 3; 2582 2583 // The replacement code for the large code model 2584 static const std::initializer_list<uint8_t> LargeSequence = { 2585 0x66, 0x66, 0x66, // three data16 prefixes (no-op) 2586 0x66, 0x66, 0x0f, 0x1f, 0x84, 0x00, 0x00, 0x00, 0x00, 2587 0x00, // 10 byte nop 2588 0x64, 0x48, 0x8b, 0x04, 0x25, 0x00, 0x00, 0x00, 0x00 // mov %fs:0,%rax 2589 }; 2590 NewCodeSequence = ArrayRef<uint8_t>(LargeSequence); 2591 } 2592 } else { 2593 llvm_unreachable("both TLS relocations handled above"); 2594 } 2595 2596 assert(ExpectedCodeSequence.size() == NewCodeSequence.size() && 2597 "Old and new code sequences must have the same size"); 2598 2599 auto &Section = Sections[SectionID]; 2600 if (Offset < TLSSequenceOffset || 2601 (Offset - TLSSequenceOffset + NewCodeSequence.size()) > 2602 Section.getSize()) { 2603 report_fatal_error("unexpected end of section in TLS sequence"); 2604 } 2605 2606 auto *TLSSequence = Section.getAddressWithOffset(Offset - TLSSequenceOffset); 2607 if (ArrayRef<uint8_t>(TLSSequence, ExpectedCodeSequence.size()) != 2608 ExpectedCodeSequence) { 2609 report_fatal_error( 2610 "invalid TLS sequence for Global/Local Dynamic TLS Model"); 2611 } 2612 2613 memcpy(TLSSequence, NewCodeSequence.data(), NewCodeSequence.size()); 2614 } 2615 2616 size_t RuntimeDyldELF::getGOTEntrySize() { 2617 // We don't use the GOT in all of these cases, but it's essentially free 2618 // to put them all here. 2619 size_t Result = 0; 2620 switch (Arch) { 2621 case Triple::x86_64: 2622 case Triple::aarch64: 2623 case Triple::aarch64_be: 2624 case Triple::loongarch64: 2625 case Triple::ppc64: 2626 case Triple::ppc64le: 2627 case Triple::systemz: 2628 Result = sizeof(uint64_t); 2629 break; 2630 case Triple::x86: 2631 case Triple::arm: 2632 case Triple::thumb: 2633 Result = sizeof(uint32_t); 2634 break; 2635 case Triple::mips: 2636 case Triple::mipsel: 2637 case Triple::mips64: 2638 case Triple::mips64el: 2639 if (IsMipsO32ABI || IsMipsN32ABI) 2640 Result = sizeof(uint32_t); 2641 else if (IsMipsN64ABI) 2642 Result = sizeof(uint64_t); 2643 else 2644 llvm_unreachable("Mips ABI not handled"); 2645 break; 2646 default: 2647 llvm_unreachable("Unsupported CPU type!"); 2648 } 2649 return Result; 2650 } 2651 2652 uint64_t RuntimeDyldELF::allocateGOTEntries(unsigned no) { 2653 if (GOTSectionID == 0) { 2654 GOTSectionID = Sections.size(); 2655 // Reserve a section id. We'll allocate the section later 2656 // once we know the total size 2657 Sections.push_back(SectionEntry(".got", nullptr, 0, 0, 0)); 2658 } 2659 uint64_t StartOffset = CurrentGOTIndex * getGOTEntrySize(); 2660 CurrentGOTIndex += no; 2661 return StartOffset; 2662 } 2663 2664 uint64_t RuntimeDyldELF::findOrAllocGOTEntry(const RelocationValueRef &Value, 2665 unsigned GOTRelType) { 2666 auto E = GOTOffsetMap.insert({Value, 0}); 2667 if (E.second) { 2668 uint64_t GOTOffset = allocateGOTEntries(1); 2669 2670 // Create relocation for newly created GOT entry 2671 RelocationEntry RE = 2672 computeGOTOffsetRE(GOTOffset, Value.Offset, GOTRelType); 2673 if (Value.SymbolName) 2674 addRelocationForSymbol(RE, Value.SymbolName); 2675 else 2676 addRelocationForSection(RE, Value.SectionID); 2677 2678 E.first->second = GOTOffset; 2679 } 2680 2681 return E.first->second; 2682 } 2683 2684 void RuntimeDyldELF::resolveGOTOffsetRelocation(unsigned SectionID, 2685 uint64_t Offset, 2686 uint64_t GOTOffset, 2687 uint32_t Type) { 2688 // Fill in the relative address of the GOT Entry into the stub 2689 RelocationEntry GOTRE(SectionID, Offset, Type, GOTOffset); 2690 addRelocationForSection(GOTRE, GOTSectionID); 2691 } 2692 2693 RelocationEntry RuntimeDyldELF::computeGOTOffsetRE(uint64_t GOTOffset, 2694 uint64_t SymbolOffset, 2695 uint32_t Type) { 2696 return RelocationEntry(GOTSectionID, GOTOffset, Type, SymbolOffset); 2697 } 2698 2699 void RuntimeDyldELF::processNewSymbol(const SymbolRef &ObjSymbol, SymbolTableEntry& Symbol) { 2700 // This should never return an error as `processNewSymbol` wouldn't have been 2701 // called if getFlags() returned an error before. 2702 auto ObjSymbolFlags = cantFail(ObjSymbol.getFlags()); 2703 2704 if (ObjSymbolFlags & SymbolRef::SF_Indirect) { 2705 if (IFuncStubSectionID == 0) { 2706 // Create a dummy section for the ifunc stubs. It will be actually 2707 // allocated in finalizeLoad() below. 2708 IFuncStubSectionID = Sections.size(); 2709 Sections.push_back( 2710 SectionEntry(".text.__llvm_IFuncStubs", nullptr, 0, 0, 0)); 2711 // First 64B are reserverd for the IFunc resolver 2712 IFuncStubOffset = 64; 2713 } 2714 2715 IFuncStubs.push_back(IFuncStub{IFuncStubOffset, Symbol}); 2716 // Modify the symbol so that it points to the ifunc stub instead of to the 2717 // resolver function. 2718 Symbol = SymbolTableEntry(IFuncStubSectionID, IFuncStubOffset, 2719 Symbol.getFlags()); 2720 IFuncStubOffset += getMaxIFuncStubSize(); 2721 } 2722 } 2723 2724 Error RuntimeDyldELF::finalizeLoad(const ObjectFile &Obj, 2725 ObjSectionToIDMap &SectionMap) { 2726 if (IsMipsO32ABI) 2727 if (!PendingRelocs.empty()) 2728 return make_error<RuntimeDyldError>("Can't find matching LO16 reloc"); 2729 2730 // Create the IFunc stubs if necessary. This must be done before processing 2731 // the GOT entries, as the IFunc stubs may create some. 2732 if (IFuncStubSectionID != 0) { 2733 uint8_t *IFuncStubsAddr = MemMgr.allocateCodeSection( 2734 IFuncStubOffset, 1, IFuncStubSectionID, ".text.__llvm_IFuncStubs"); 2735 if (!IFuncStubsAddr) 2736 return make_error<RuntimeDyldError>( 2737 "Unable to allocate memory for IFunc stubs!"); 2738 Sections[IFuncStubSectionID] = 2739 SectionEntry(".text.__llvm_IFuncStubs", IFuncStubsAddr, IFuncStubOffset, 2740 IFuncStubOffset, 0); 2741 2742 createIFuncResolver(IFuncStubsAddr); 2743 2744 LLVM_DEBUG(dbgs() << "Creating IFunc stubs SectionID: " 2745 << IFuncStubSectionID << " Addr: " 2746 << Sections[IFuncStubSectionID].getAddress() << '\n'); 2747 for (auto &IFuncStub : IFuncStubs) { 2748 auto &Symbol = IFuncStub.OriginalSymbol; 2749 LLVM_DEBUG(dbgs() << "\tSectionID: " << Symbol.getSectionID() 2750 << " Offset: " << format("%p", Symbol.getOffset()) 2751 << " IFuncStubOffset: " 2752 << format("%p\n", IFuncStub.StubOffset)); 2753 createIFuncStub(IFuncStubSectionID, 0, IFuncStub.StubOffset, 2754 Symbol.getSectionID(), Symbol.getOffset()); 2755 } 2756 2757 IFuncStubSectionID = 0; 2758 IFuncStubOffset = 0; 2759 IFuncStubs.clear(); 2760 } 2761 2762 // If necessary, allocate the global offset table 2763 if (GOTSectionID != 0) { 2764 // Allocate memory for the section 2765 size_t TotalSize = CurrentGOTIndex * getGOTEntrySize(); 2766 uint8_t *Addr = MemMgr.allocateDataSection(TotalSize, getGOTEntrySize(), 2767 GOTSectionID, ".got", false); 2768 if (!Addr) 2769 return make_error<RuntimeDyldError>("Unable to allocate memory for GOT!"); 2770 2771 Sections[GOTSectionID] = 2772 SectionEntry(".got", Addr, TotalSize, TotalSize, 0); 2773 2774 // For now, initialize all GOT entries to zero. We'll fill them in as 2775 // needed when GOT-based relocations are applied. 2776 memset(Addr, 0, TotalSize); 2777 if (IsMipsN32ABI || IsMipsN64ABI) { 2778 // To correctly resolve Mips GOT relocations, we need a mapping from 2779 // object's sections to GOTs. 2780 for (section_iterator SI = Obj.section_begin(), SE = Obj.section_end(); 2781 SI != SE; ++SI) { 2782 if (SI->relocation_begin() != SI->relocation_end()) { 2783 Expected<section_iterator> RelSecOrErr = SI->getRelocatedSection(); 2784 if (!RelSecOrErr) 2785 return make_error<RuntimeDyldError>( 2786 toString(RelSecOrErr.takeError())); 2787 2788 section_iterator RelocatedSection = *RelSecOrErr; 2789 ObjSectionToIDMap::iterator i = SectionMap.find(*RelocatedSection); 2790 assert(i != SectionMap.end()); 2791 SectionToGOTMap[i->second] = GOTSectionID; 2792 } 2793 } 2794 GOTSymbolOffsets.clear(); 2795 } 2796 } 2797 2798 // Look for and record the EH frame section. 2799 ObjSectionToIDMap::iterator i, e; 2800 for (i = SectionMap.begin(), e = SectionMap.end(); i != e; ++i) { 2801 const SectionRef &Section = i->first; 2802 2803 StringRef Name; 2804 Expected<StringRef> NameOrErr = Section.getName(); 2805 if (NameOrErr) 2806 Name = *NameOrErr; 2807 else 2808 consumeError(NameOrErr.takeError()); 2809 2810 if (Name == ".eh_frame") { 2811 UnregisteredEHFrameSections.push_back(i->second); 2812 break; 2813 } 2814 } 2815 2816 GOTOffsetMap.clear(); 2817 GOTSectionID = 0; 2818 CurrentGOTIndex = 0; 2819 2820 return Error::success(); 2821 } 2822 2823 bool RuntimeDyldELF::isCompatibleFile(const object::ObjectFile &Obj) const { 2824 return Obj.isELF(); 2825 } 2826 2827 void RuntimeDyldELF::createIFuncResolver(uint8_t *Addr) const { 2828 if (Arch == Triple::x86_64) { 2829 // The adddres of the GOT1 entry is in %r11, the GOT2 entry is in %r11+8 2830 // (see createIFuncStub() for details) 2831 // The following code first saves all registers that contain the original 2832 // function arguments as those registers are not saved by the resolver 2833 // function. %r11 is saved as well so that the GOT2 entry can be updated 2834 // afterwards. Then it calls the actual IFunc resolver function whose 2835 // address is stored in GOT2. After the resolver function returns, all 2836 // saved registers are restored and the return value is written to GOT1. 2837 // Finally, jump to the now resolved function. 2838 // clang-format off 2839 const uint8_t StubCode[] = { 2840 0x57, // push %rdi 2841 0x56, // push %rsi 2842 0x52, // push %rdx 2843 0x51, // push %rcx 2844 0x41, 0x50, // push %r8 2845 0x41, 0x51, // push %r9 2846 0x41, 0x53, // push %r11 2847 0x41, 0xff, 0x53, 0x08, // call *0x8(%r11) 2848 0x41, 0x5b, // pop %r11 2849 0x41, 0x59, // pop %r9 2850 0x41, 0x58, // pop %r8 2851 0x59, // pop %rcx 2852 0x5a, // pop %rdx 2853 0x5e, // pop %rsi 2854 0x5f, // pop %rdi 2855 0x49, 0x89, 0x03, // mov %rax,(%r11) 2856 0xff, 0xe0 // jmp *%rax 2857 }; 2858 // clang-format on 2859 static_assert(sizeof(StubCode) <= 64, 2860 "maximum size of the IFunc resolver is 64B"); 2861 memcpy(Addr, StubCode, sizeof(StubCode)); 2862 } else { 2863 report_fatal_error( 2864 "IFunc resolver is not supported for target architecture"); 2865 } 2866 } 2867 2868 void RuntimeDyldELF::createIFuncStub(unsigned IFuncStubSectionID, 2869 uint64_t IFuncResolverOffset, 2870 uint64_t IFuncStubOffset, 2871 unsigned IFuncSectionID, 2872 uint64_t IFuncOffset) { 2873 auto &IFuncStubSection = Sections[IFuncStubSectionID]; 2874 auto *Addr = IFuncStubSection.getAddressWithOffset(IFuncStubOffset); 2875 2876 if (Arch == Triple::x86_64) { 2877 // The first instruction loads a PC-relative address into %r11 which is a 2878 // GOT entry for this stub. This initially contains the address to the 2879 // IFunc resolver. We can use %r11 here as it's caller saved but not used 2880 // to pass any arguments. In fact, x86_64 ABI even suggests using %r11 for 2881 // code in the PLT. The IFunc resolver will use %r11 to update the GOT 2882 // entry. 2883 // 2884 // The next instruction just jumps to the address contained in the GOT 2885 // entry. As mentioned above, we do this two-step jump by first setting 2886 // %r11 so that the IFunc resolver has access to it. 2887 // 2888 // The IFunc resolver of course also needs to know the actual address of 2889 // the actual IFunc resolver function. This will be stored in a GOT entry 2890 // right next to the first one for this stub. So, the IFunc resolver will 2891 // be able to call it with %r11+8. 2892 // 2893 // In total, two adjacent GOT entries (+relocation) and one additional 2894 // relocation are required: 2895 // GOT1: Address of the IFunc resolver. 2896 // GOT2: Address of the IFunc resolver function. 2897 // IFuncStubOffset+3: 32-bit PC-relative address of GOT1. 2898 uint64_t GOT1 = allocateGOTEntries(2); 2899 uint64_t GOT2 = GOT1 + getGOTEntrySize(); 2900 2901 RelocationEntry RE1(GOTSectionID, GOT1, ELF::R_X86_64_64, 2902 IFuncResolverOffset, {}); 2903 addRelocationForSection(RE1, IFuncStubSectionID); 2904 RelocationEntry RE2(GOTSectionID, GOT2, ELF::R_X86_64_64, IFuncOffset, {}); 2905 addRelocationForSection(RE2, IFuncSectionID); 2906 2907 const uint8_t StubCode[] = { 2908 0x4c, 0x8d, 0x1d, 0x00, 0x00, 0x00, 0x00, // leaq 0x0(%rip),%r11 2909 0x41, 0xff, 0x23 // jmpq *(%r11) 2910 }; 2911 assert(sizeof(StubCode) <= getMaxIFuncStubSize() && 2912 "IFunc stub size must not exceed getMaxIFuncStubSize()"); 2913 memcpy(Addr, StubCode, sizeof(StubCode)); 2914 2915 // The PC-relative value starts 4 bytes from the end of the leaq 2916 // instruction, so the addend is -4. 2917 resolveGOTOffsetRelocation(IFuncStubSectionID, IFuncStubOffset + 3, 2918 GOT1 - 4, ELF::R_X86_64_PC32); 2919 } else { 2920 report_fatal_error("IFunc stub is not supported for target architecture"); 2921 } 2922 } 2923 2924 unsigned RuntimeDyldELF::getMaxIFuncStubSize() const { 2925 if (Arch == Triple::x86_64) { 2926 return 10; 2927 } 2928 return 0; 2929 } 2930 2931 bool RuntimeDyldELF::relocationNeedsGot(const RelocationRef &R) const { 2932 unsigned RelTy = R.getType(); 2933 if (Arch == Triple::aarch64 || Arch == Triple::aarch64_be) 2934 return RelTy == ELF::R_AARCH64_ADR_GOT_PAGE || 2935 RelTy == ELF::R_AARCH64_LD64_GOT_LO12_NC; 2936 2937 if (Arch == Triple::loongarch64) 2938 return RelTy == ELF::R_LARCH_GOT_PC_HI20 || 2939 RelTy == ELF::R_LARCH_GOT_PC_LO12; 2940 2941 if (Arch == Triple::x86_64) 2942 return RelTy == ELF::R_X86_64_GOTPCREL || 2943 RelTy == ELF::R_X86_64_GOTPCRELX || 2944 RelTy == ELF::R_X86_64_GOT64 || 2945 RelTy == ELF::R_X86_64_REX_GOTPCRELX; 2946 return false; 2947 } 2948 2949 bool RuntimeDyldELF::relocationNeedsStub(const RelocationRef &R) const { 2950 if (Arch != Triple::x86_64) 2951 return true; // Conservative answer 2952 2953 switch (R.getType()) { 2954 default: 2955 return true; // Conservative answer 2956 2957 2958 case ELF::R_X86_64_GOTPCREL: 2959 case ELF::R_X86_64_GOTPCRELX: 2960 case ELF::R_X86_64_REX_GOTPCRELX: 2961 case ELF::R_X86_64_GOTPC64: 2962 case ELF::R_X86_64_GOT64: 2963 case ELF::R_X86_64_GOTOFF64: 2964 case ELF::R_X86_64_PC32: 2965 case ELF::R_X86_64_PC64: 2966 case ELF::R_X86_64_64: 2967 // We know that these reloation types won't need a stub function. This list 2968 // can be extended as needed. 2969 return false; 2970 } 2971 } 2972 2973 } // namespace llvm 2974