1 //===-- RuntimeDyldELF.cpp - Run-time dynamic linker for MC-JIT -*- C++ -*-===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 // 10 // Implementation of ELF support for the MC-JIT runtime dynamic linker. 11 // 12 //===----------------------------------------------------------------------===// 13 14 #include "RuntimeDyldELF.h" 15 #include "RuntimeDyldCheckerImpl.h" 16 #include "Targets/RuntimeDyldELFMips.h" 17 #include "llvm/ADT/IntervalMap.h" 18 #include "llvm/ADT/STLExtras.h" 19 #include "llvm/ADT/StringRef.h" 20 #include "llvm/ADT/Triple.h" 21 #include "llvm/MC/MCStreamer.h" 22 #include "llvm/Object/ELFObjectFile.h" 23 #include "llvm/Object/ObjectFile.h" 24 #include "llvm/Support/ELF.h" 25 #include "llvm/Support/Endian.h" 26 #include "llvm/Support/MemoryBuffer.h" 27 #include "llvm/Support/TargetRegistry.h" 28 29 using namespace llvm; 30 using namespace llvm::object; 31 using namespace llvm::support::endian; 32 33 #define DEBUG_TYPE "dyld" 34 35 static void or32le(void *P, int32_t V) { write32le(P, read32le(P) | V); } 36 37 static void or32AArch64Imm(void *L, uint64_t Imm) { 38 or32le(L, (Imm & 0xFFF) << 10); 39 } 40 41 template <class T> static void write(bool isBE, void *P, T V) { 42 isBE ? write<T, support::big>(P, V) : write<T, support::little>(P, V); 43 } 44 45 static void write32AArch64Addr(void *L, uint64_t Imm) { 46 uint32_t ImmLo = (Imm & 0x3) << 29; 47 uint32_t ImmHi = (Imm & 0x1FFFFC) << 3; 48 uint64_t Mask = (0x3 << 29) | (0x1FFFFC << 3); 49 write32le(L, (read32le(L) & ~Mask) | ImmLo | ImmHi); 50 } 51 52 // Return the bits [Start, End] from Val shifted Start bits. 53 // For instance, getBits(0xF0, 4, 8) returns 0xF. 54 static uint64_t getBits(uint64_t Val, int Start, int End) { 55 uint64_t Mask = ((uint64_t)1 << (End + 1 - Start)) - 1; 56 return (Val >> Start) & Mask; 57 } 58 59 namespace { 60 61 template <class ELFT> class DyldELFObject : public ELFObjectFile<ELFT> { 62 LLVM_ELF_IMPORT_TYPES_ELFT(ELFT) 63 64 typedef Elf_Shdr_Impl<ELFT> Elf_Shdr; 65 typedef Elf_Sym_Impl<ELFT> Elf_Sym; 66 typedef Elf_Rel_Impl<ELFT, false> Elf_Rel; 67 typedef Elf_Rel_Impl<ELFT, true> Elf_Rela; 68 69 typedef Elf_Ehdr_Impl<ELFT> Elf_Ehdr; 70 71 typedef typename ELFDataTypeTypedefHelper<ELFT>::value_type addr_type; 72 73 public: 74 DyldELFObject(MemoryBufferRef Wrapper, std::error_code &ec); 75 76 void updateSectionAddress(const SectionRef &Sec, uint64_t Addr); 77 78 void updateSymbolAddress(const SymbolRef &SymRef, uint64_t Addr); 79 80 // Methods for type inquiry through isa, cast and dyn_cast 81 static inline bool classof(const Binary *v) { 82 return (isa<ELFObjectFile<ELFT>>(v) && 83 classof(cast<ELFObjectFile<ELFT>>(v))); 84 } 85 static inline bool classof(const ELFObjectFile<ELFT> *v) { 86 return v->isDyldType(); 87 } 88 }; 89 90 91 92 // The MemoryBuffer passed into this constructor is just a wrapper around the 93 // actual memory. Ultimately, the Binary parent class will take ownership of 94 // this MemoryBuffer object but not the underlying memory. 95 template <class ELFT> 96 DyldELFObject<ELFT>::DyldELFObject(MemoryBufferRef Wrapper, std::error_code &EC) 97 : ELFObjectFile<ELFT>(Wrapper, EC) { 98 this->isDyldELFObject = true; 99 } 100 101 template <class ELFT> 102 void DyldELFObject<ELFT>::updateSectionAddress(const SectionRef &Sec, 103 uint64_t Addr) { 104 DataRefImpl ShdrRef = Sec.getRawDataRefImpl(); 105 Elf_Shdr *shdr = 106 const_cast<Elf_Shdr *>(reinterpret_cast<const Elf_Shdr *>(ShdrRef.p)); 107 108 // This assumes the address passed in matches the target address bitness 109 // The template-based type cast handles everything else. 110 shdr->sh_addr = static_cast<addr_type>(Addr); 111 } 112 113 template <class ELFT> 114 void DyldELFObject<ELFT>::updateSymbolAddress(const SymbolRef &SymRef, 115 uint64_t Addr) { 116 117 Elf_Sym *sym = const_cast<Elf_Sym *>( 118 ELFObjectFile<ELFT>::getSymbol(SymRef.getRawDataRefImpl())); 119 120 // This assumes the address passed in matches the target address bitness 121 // The template-based type cast handles everything else. 122 sym->st_value = static_cast<addr_type>(Addr); 123 } 124 125 class LoadedELFObjectInfo final 126 : public RuntimeDyld::LoadedObjectInfoHelper<LoadedELFObjectInfo> { 127 public: 128 LoadedELFObjectInfo(RuntimeDyldImpl &RTDyld, ObjSectionToIDMap ObjSecToIDMap) 129 : LoadedObjectInfoHelper(RTDyld, std::move(ObjSecToIDMap)) {} 130 131 OwningBinary<ObjectFile> 132 getObjectForDebug(const ObjectFile &Obj) const override; 133 }; 134 135 template <typename ELFT> 136 std::unique_ptr<DyldELFObject<ELFT>> 137 createRTDyldELFObject(MemoryBufferRef Buffer, 138 const ObjectFile &SourceObject, 139 const LoadedELFObjectInfo &L, 140 std::error_code &ec) { 141 typedef typename ELFFile<ELFT>::Elf_Shdr Elf_Shdr; 142 typedef typename ELFDataTypeTypedefHelper<ELFT>::value_type addr_type; 143 144 std::unique_ptr<DyldELFObject<ELFT>> Obj = 145 llvm::make_unique<DyldELFObject<ELFT>>(Buffer, ec); 146 147 // Iterate over all sections in the object. 148 auto SI = SourceObject.section_begin(); 149 for (const auto &Sec : Obj->sections()) { 150 StringRef SectionName; 151 Sec.getName(SectionName); 152 if (SectionName != "") { 153 DataRefImpl ShdrRef = Sec.getRawDataRefImpl(); 154 Elf_Shdr *shdr = const_cast<Elf_Shdr *>( 155 reinterpret_cast<const Elf_Shdr *>(ShdrRef.p)); 156 157 if (uint64_t SecLoadAddr = L.getSectionLoadAddress(*SI)) { 158 // This assumes that the address passed in matches the target address 159 // bitness. The template-based type cast handles everything else. 160 shdr->sh_addr = static_cast<addr_type>(SecLoadAddr); 161 } 162 } 163 ++SI; 164 } 165 166 return Obj; 167 } 168 169 OwningBinary<ObjectFile> createELFDebugObject(const ObjectFile &Obj, 170 const LoadedELFObjectInfo &L) { 171 assert(Obj.isELF() && "Not an ELF object file."); 172 173 std::unique_ptr<MemoryBuffer> Buffer = 174 MemoryBuffer::getMemBufferCopy(Obj.getData(), Obj.getFileName()); 175 176 std::error_code ec; 177 178 std::unique_ptr<ObjectFile> DebugObj; 179 if (Obj.getBytesInAddress() == 4 && Obj.isLittleEndian()) { 180 typedef ELFType<support::little, false> ELF32LE; 181 DebugObj = createRTDyldELFObject<ELF32LE>(Buffer->getMemBufferRef(), Obj, L, 182 ec); 183 } else if (Obj.getBytesInAddress() == 4 && !Obj.isLittleEndian()) { 184 typedef ELFType<support::big, false> ELF32BE; 185 DebugObj = createRTDyldELFObject<ELF32BE>(Buffer->getMemBufferRef(), Obj, L, 186 ec); 187 } else if (Obj.getBytesInAddress() == 8 && !Obj.isLittleEndian()) { 188 typedef ELFType<support::big, true> ELF64BE; 189 DebugObj = createRTDyldELFObject<ELF64BE>(Buffer->getMemBufferRef(), Obj, L, 190 ec); 191 } else if (Obj.getBytesInAddress() == 8 && Obj.isLittleEndian()) { 192 typedef ELFType<support::little, true> ELF64LE; 193 DebugObj = createRTDyldELFObject<ELF64LE>(Buffer->getMemBufferRef(), Obj, L, 194 ec); 195 } else 196 llvm_unreachable("Unexpected ELF format"); 197 198 assert(!ec && "Could not construct copy ELF object file"); 199 200 return OwningBinary<ObjectFile>(std::move(DebugObj), std::move(Buffer)); 201 } 202 203 OwningBinary<ObjectFile> 204 LoadedELFObjectInfo::getObjectForDebug(const ObjectFile &Obj) const { 205 return createELFDebugObject(Obj, *this); 206 } 207 208 } // anonymous namespace 209 210 namespace llvm { 211 212 RuntimeDyldELF::RuntimeDyldELF(RuntimeDyld::MemoryManager &MemMgr, 213 JITSymbolResolver &Resolver) 214 : RuntimeDyldImpl(MemMgr, Resolver), GOTSectionID(0), CurrentGOTIndex(0) {} 215 RuntimeDyldELF::~RuntimeDyldELF() {} 216 217 void RuntimeDyldELF::registerEHFrames() { 218 for (int i = 0, e = UnregisteredEHFrameSections.size(); i != e; ++i) { 219 SID EHFrameSID = UnregisteredEHFrameSections[i]; 220 uint8_t *EHFrameAddr = Sections[EHFrameSID].getAddress(); 221 uint64_t EHFrameLoadAddr = Sections[EHFrameSID].getLoadAddress(); 222 size_t EHFrameSize = Sections[EHFrameSID].getSize(); 223 MemMgr.registerEHFrames(EHFrameAddr, EHFrameLoadAddr, EHFrameSize); 224 RegisteredEHFrameSections.push_back(EHFrameSID); 225 } 226 UnregisteredEHFrameSections.clear(); 227 } 228 229 void RuntimeDyldELF::deregisterEHFrames() { 230 for (int i = 0, e = RegisteredEHFrameSections.size(); i != e; ++i) { 231 SID EHFrameSID = RegisteredEHFrameSections[i]; 232 uint8_t *EHFrameAddr = Sections[EHFrameSID].getAddress(); 233 uint64_t EHFrameLoadAddr = Sections[EHFrameSID].getLoadAddress(); 234 size_t EHFrameSize = Sections[EHFrameSID].getSize(); 235 MemMgr.deregisterEHFrames(EHFrameAddr, EHFrameLoadAddr, EHFrameSize); 236 } 237 RegisteredEHFrameSections.clear(); 238 } 239 240 std::unique_ptr<RuntimeDyldELF> 241 llvm::RuntimeDyldELF::create(Triple::ArchType Arch, 242 RuntimeDyld::MemoryManager &MemMgr, 243 JITSymbolResolver &Resolver) { 244 switch (Arch) { 245 default: 246 return make_unique<RuntimeDyldELF>(MemMgr, Resolver); 247 case Triple::mips: 248 case Triple::mipsel: 249 case Triple::mips64: 250 case Triple::mips64el: 251 return make_unique<RuntimeDyldELFMips>(MemMgr, Resolver); 252 } 253 } 254 255 std::unique_ptr<RuntimeDyld::LoadedObjectInfo> 256 RuntimeDyldELF::loadObject(const object::ObjectFile &O) { 257 if (auto ObjSectionToIDOrErr = loadObjectImpl(O)) 258 return llvm::make_unique<LoadedELFObjectInfo>(*this, *ObjSectionToIDOrErr); 259 else { 260 HasError = true; 261 raw_string_ostream ErrStream(ErrorStr); 262 logAllUnhandledErrors(ObjSectionToIDOrErr.takeError(), ErrStream, ""); 263 return nullptr; 264 } 265 } 266 267 void RuntimeDyldELF::resolveX86_64Relocation(const SectionEntry &Section, 268 uint64_t Offset, uint64_t Value, 269 uint32_t Type, int64_t Addend, 270 uint64_t SymOffset) { 271 switch (Type) { 272 default: 273 llvm_unreachable("Relocation type not implemented yet!"); 274 break; 275 case ELF::R_X86_64_64: { 276 support::ulittle64_t::ref(Section.getAddressWithOffset(Offset)) = 277 Value + Addend; 278 DEBUG(dbgs() << "Writing " << format("%p", (Value + Addend)) << " at " 279 << format("%p\n", Section.getAddressWithOffset(Offset))); 280 break; 281 } 282 case ELF::R_X86_64_32: 283 case ELF::R_X86_64_32S: { 284 Value += Addend; 285 assert((Type == ELF::R_X86_64_32 && (Value <= UINT32_MAX)) || 286 (Type == ELF::R_X86_64_32S && 287 ((int64_t)Value <= INT32_MAX && (int64_t)Value >= INT32_MIN))); 288 uint32_t TruncatedAddr = (Value & 0xFFFFFFFF); 289 support::ulittle32_t::ref(Section.getAddressWithOffset(Offset)) = 290 TruncatedAddr; 291 DEBUG(dbgs() << "Writing " << format("%p", TruncatedAddr) << " at " 292 << format("%p\n", Section.getAddressWithOffset(Offset))); 293 break; 294 } 295 case ELF::R_X86_64_PC8: { 296 uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset); 297 int64_t RealOffset = Value + Addend - FinalAddress; 298 assert(isInt<8>(RealOffset)); 299 int8_t TruncOffset = (RealOffset & 0xFF); 300 Section.getAddress()[Offset] = TruncOffset; 301 break; 302 } 303 case ELF::R_X86_64_PC32: { 304 uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset); 305 int64_t RealOffset = Value + Addend - FinalAddress; 306 assert(isInt<32>(RealOffset)); 307 int32_t TruncOffset = (RealOffset & 0xFFFFFFFF); 308 support::ulittle32_t::ref(Section.getAddressWithOffset(Offset)) = 309 TruncOffset; 310 break; 311 } 312 case ELF::R_X86_64_PC64: { 313 uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset); 314 int64_t RealOffset = Value + Addend - FinalAddress; 315 support::ulittle64_t::ref(Section.getAddressWithOffset(Offset)) = 316 RealOffset; 317 break; 318 } 319 } 320 } 321 322 void RuntimeDyldELF::resolveX86Relocation(const SectionEntry &Section, 323 uint64_t Offset, uint32_t Value, 324 uint32_t Type, int32_t Addend) { 325 switch (Type) { 326 case ELF::R_386_32: { 327 support::ulittle32_t::ref(Section.getAddressWithOffset(Offset)) = 328 Value + Addend; 329 break; 330 } 331 case ELF::R_386_PC32: { 332 uint32_t FinalAddress = 333 Section.getLoadAddressWithOffset(Offset) & 0xFFFFFFFF; 334 uint32_t RealOffset = Value + Addend - FinalAddress; 335 support::ulittle32_t::ref(Section.getAddressWithOffset(Offset)) = 336 RealOffset; 337 break; 338 } 339 default: 340 // There are other relocation types, but it appears these are the 341 // only ones currently used by the LLVM ELF object writer 342 llvm_unreachable("Relocation type not implemented yet!"); 343 break; 344 } 345 } 346 347 void RuntimeDyldELF::resolveAArch64Relocation(const SectionEntry &Section, 348 uint64_t Offset, uint64_t Value, 349 uint32_t Type, int64_t Addend) { 350 uint32_t *TargetPtr = 351 reinterpret_cast<uint32_t *>(Section.getAddressWithOffset(Offset)); 352 uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset); 353 // Data should use target endian. Code should always use little endian. 354 bool isBE = Arch == Triple::aarch64_be; 355 356 DEBUG(dbgs() << "resolveAArch64Relocation, LocalAddress: 0x" 357 << format("%llx", Section.getAddressWithOffset(Offset)) 358 << " FinalAddress: 0x" << format("%llx", FinalAddress) 359 << " Value: 0x" << format("%llx", Value) << " Type: 0x" 360 << format("%x", Type) << " Addend: 0x" << format("%llx", Addend) 361 << "\n"); 362 363 switch (Type) { 364 default: 365 llvm_unreachable("Relocation type not implemented yet!"); 366 break; 367 case ELF::R_AARCH64_ABS64: 368 write(isBE, TargetPtr, Value + Addend); 369 break; 370 case ELF::R_AARCH64_PREL32: { 371 uint64_t Result = Value + Addend - FinalAddress; 372 assert(static_cast<int64_t>(Result) >= INT32_MIN && 373 static_cast<int64_t>(Result) <= UINT32_MAX); 374 write(isBE, TargetPtr, static_cast<uint32_t>(Result & 0xffffffffU)); 375 break; 376 } 377 case ELF::R_AARCH64_PREL64: 378 write(isBE, TargetPtr, Value + Addend - FinalAddress); 379 break; 380 case ELF::R_AARCH64_CALL26: // fallthrough 381 case ELF::R_AARCH64_JUMP26: { 382 // Operation: S+A-P. Set Call or B immediate value to bits fff_fffc of the 383 // calculation. 384 uint64_t BranchImm = Value + Addend - FinalAddress; 385 386 // "Check that -2^27 <= result < 2^27". 387 assert(isInt<28>(BranchImm)); 388 or32le(TargetPtr, (BranchImm & 0x0FFFFFFC) >> 2); 389 break; 390 } 391 case ELF::R_AARCH64_MOVW_UABS_G3: 392 or32le(TargetPtr, ((Value + Addend) & 0xFFFF000000000000) >> 43); 393 break; 394 case ELF::R_AARCH64_MOVW_UABS_G2_NC: 395 or32le(TargetPtr, ((Value + Addend) & 0xFFFF00000000) >> 27); 396 break; 397 case ELF::R_AARCH64_MOVW_UABS_G1_NC: 398 or32le(TargetPtr, ((Value + Addend) & 0xFFFF0000) >> 11); 399 break; 400 case ELF::R_AARCH64_MOVW_UABS_G0_NC: 401 or32le(TargetPtr, ((Value + Addend) & 0xFFFF) << 5); 402 break; 403 case ELF::R_AARCH64_ADR_PREL_PG_HI21: { 404 // Operation: Page(S+A) - Page(P) 405 uint64_t Result = 406 ((Value + Addend) & ~0xfffULL) - (FinalAddress & ~0xfffULL); 407 408 // Check that -2^32 <= X < 2^32 409 assert(isInt<33>(Result) && "overflow check failed for relocation"); 410 411 // Immediate goes in bits 30:29 + 5:23 of ADRP instruction, taken 412 // from bits 32:12 of X. 413 write32AArch64Addr(TargetPtr, Result >> 12); 414 break; 415 } 416 case ELF::R_AARCH64_ADD_ABS_LO12_NC: 417 // Operation: S + A 418 // Immediate goes in bits 21:10 of LD/ST instruction, taken 419 // from bits 11:0 of X 420 or32AArch64Imm(TargetPtr, Value + Addend); 421 break; 422 case ELF::R_AARCH64_LDST32_ABS_LO12_NC: 423 // Operation: S + A 424 // Immediate goes in bits 21:10 of LD/ST instruction, taken 425 // from bits 11:2 of X 426 or32AArch64Imm(TargetPtr, getBits(Value + Addend, 2, 11)); 427 break; 428 case ELF::R_AARCH64_LDST64_ABS_LO12_NC: 429 // Operation: S + A 430 // Immediate goes in bits 21:10 of LD/ST instruction, taken 431 // from bits 11:3 of X 432 or32AArch64Imm(TargetPtr, getBits(Value + Addend, 3, 11)); 433 break; 434 } 435 } 436 437 void RuntimeDyldELF::resolveARMRelocation(const SectionEntry &Section, 438 uint64_t Offset, uint32_t Value, 439 uint32_t Type, int32_t Addend) { 440 // TODO: Add Thumb relocations. 441 uint32_t *TargetPtr = 442 reinterpret_cast<uint32_t *>(Section.getAddressWithOffset(Offset)); 443 uint32_t FinalAddress = Section.getLoadAddressWithOffset(Offset) & 0xFFFFFFFF; 444 Value += Addend; 445 446 DEBUG(dbgs() << "resolveARMRelocation, LocalAddress: " 447 << Section.getAddressWithOffset(Offset) 448 << " FinalAddress: " << format("%p", FinalAddress) << " Value: " 449 << format("%x", Value) << " Type: " << format("%x", Type) 450 << " Addend: " << format("%x", Addend) << "\n"); 451 452 switch (Type) { 453 default: 454 llvm_unreachable("Not implemented relocation type!"); 455 456 case ELF::R_ARM_NONE: 457 break; 458 // Write a 31bit signed offset 459 case ELF::R_ARM_PREL31: 460 support::ulittle32_t::ref{TargetPtr} = 461 (support::ulittle32_t::ref{TargetPtr} & 0x80000000) | 462 ((Value - FinalAddress) & ~0x80000000); 463 break; 464 case ELF::R_ARM_TARGET1: 465 case ELF::R_ARM_ABS32: 466 support::ulittle32_t::ref{TargetPtr} = Value; 467 break; 468 // Write first 16 bit of 32 bit value to the mov instruction. 469 // Last 4 bit should be shifted. 470 case ELF::R_ARM_MOVW_ABS_NC: 471 case ELF::R_ARM_MOVT_ABS: 472 if (Type == ELF::R_ARM_MOVW_ABS_NC) 473 Value = Value & 0xFFFF; 474 else if (Type == ELF::R_ARM_MOVT_ABS) 475 Value = (Value >> 16) & 0xFFFF; 476 support::ulittle32_t::ref{TargetPtr} = 477 (support::ulittle32_t::ref{TargetPtr} & ~0x000F0FFF) | (Value & 0xFFF) | 478 (((Value >> 12) & 0xF) << 16); 479 break; 480 // Write 24 bit relative value to the branch instruction. 481 case ELF::R_ARM_PC24: // Fall through. 482 case ELF::R_ARM_CALL: // Fall through. 483 case ELF::R_ARM_JUMP24: 484 int32_t RelValue = static_cast<int32_t>(Value - FinalAddress - 8); 485 RelValue = (RelValue & 0x03FFFFFC) >> 2; 486 assert((support::ulittle32_t::ref{TargetPtr} & 0xFFFFFF) == 0xFFFFFE); 487 support::ulittle32_t::ref{TargetPtr} = 488 (support::ulittle32_t::ref{TargetPtr} & 0xFF000000) | RelValue; 489 break; 490 } 491 } 492 493 void RuntimeDyldELF::setMipsABI(const ObjectFile &Obj) { 494 if (Arch == Triple::UnknownArch || 495 !StringRef(Triple::getArchTypePrefix(Arch)).equals("mips")) { 496 IsMipsO32ABI = false; 497 IsMipsN32ABI = false; 498 IsMipsN64ABI = false; 499 return; 500 } 501 unsigned AbiVariant; 502 Obj.getPlatformFlags(AbiVariant); 503 IsMipsO32ABI = AbiVariant & ELF::EF_MIPS_ABI_O32; 504 IsMipsN32ABI = AbiVariant & ELF::EF_MIPS_ABI2; 505 IsMipsN64ABI = Obj.getFileFormatName().equals("ELF64-mips"); 506 } 507 508 // Return the .TOC. section and offset. 509 Error RuntimeDyldELF::findPPC64TOCSection(const ELFObjectFileBase &Obj, 510 ObjSectionToIDMap &LocalSections, 511 RelocationValueRef &Rel) { 512 // Set a default SectionID in case we do not find a TOC section below. 513 // This may happen for references to TOC base base (sym@toc, .odp 514 // relocation) without a .toc directive. In this case just use the 515 // first section (which is usually the .odp) since the code won't 516 // reference the .toc base directly. 517 Rel.SymbolName = nullptr; 518 Rel.SectionID = 0; 519 520 // The TOC consists of sections .got, .toc, .tocbss, .plt in that 521 // order. The TOC starts where the first of these sections starts. 522 for (auto &Section: Obj.sections()) { 523 StringRef SectionName; 524 if (auto EC = Section.getName(SectionName)) 525 return errorCodeToError(EC); 526 527 if (SectionName == ".got" 528 || SectionName == ".toc" 529 || SectionName == ".tocbss" 530 || SectionName == ".plt") { 531 if (auto SectionIDOrErr = 532 findOrEmitSection(Obj, Section, false, LocalSections)) 533 Rel.SectionID = *SectionIDOrErr; 534 else 535 return SectionIDOrErr.takeError(); 536 break; 537 } 538 } 539 540 // Per the ppc64-elf-linux ABI, The TOC base is TOC value plus 0x8000 541 // thus permitting a full 64 Kbytes segment. 542 Rel.Addend = 0x8000; 543 544 return Error::success(); 545 } 546 547 // Returns the sections and offset associated with the ODP entry referenced 548 // by Symbol. 549 Error RuntimeDyldELF::findOPDEntrySection(const ELFObjectFileBase &Obj, 550 ObjSectionToIDMap &LocalSections, 551 RelocationValueRef &Rel) { 552 // Get the ELF symbol value (st_value) to compare with Relocation offset in 553 // .opd entries 554 for (section_iterator si = Obj.section_begin(), se = Obj.section_end(); 555 si != se; ++si) { 556 section_iterator RelSecI = si->getRelocatedSection(); 557 if (RelSecI == Obj.section_end()) 558 continue; 559 560 StringRef RelSectionName; 561 if (auto EC = RelSecI->getName(RelSectionName)) 562 return errorCodeToError(EC); 563 564 if (RelSectionName != ".opd") 565 continue; 566 567 for (elf_relocation_iterator i = si->relocation_begin(), 568 e = si->relocation_end(); 569 i != e;) { 570 // The R_PPC64_ADDR64 relocation indicates the first field 571 // of a .opd entry 572 uint64_t TypeFunc = i->getType(); 573 if (TypeFunc != ELF::R_PPC64_ADDR64) { 574 ++i; 575 continue; 576 } 577 578 uint64_t TargetSymbolOffset = i->getOffset(); 579 symbol_iterator TargetSymbol = i->getSymbol(); 580 int64_t Addend; 581 if (auto AddendOrErr = i->getAddend()) 582 Addend = *AddendOrErr; 583 else 584 return errorCodeToError(AddendOrErr.getError()); 585 586 ++i; 587 if (i == e) 588 break; 589 590 // Just check if following relocation is a R_PPC64_TOC 591 uint64_t TypeTOC = i->getType(); 592 if (TypeTOC != ELF::R_PPC64_TOC) 593 continue; 594 595 // Finally compares the Symbol value and the target symbol offset 596 // to check if this .opd entry refers to the symbol the relocation 597 // points to. 598 if (Rel.Addend != (int64_t)TargetSymbolOffset) 599 continue; 600 601 section_iterator TSI = Obj.section_end(); 602 if (auto TSIOrErr = TargetSymbol->getSection()) 603 TSI = *TSIOrErr; 604 else 605 return TSIOrErr.takeError(); 606 assert(TSI != Obj.section_end() && "TSI should refer to a valid section"); 607 608 bool IsCode = TSI->isText(); 609 if (auto SectionIDOrErr = findOrEmitSection(Obj, *TSI, IsCode, 610 LocalSections)) 611 Rel.SectionID = *SectionIDOrErr; 612 else 613 return SectionIDOrErr.takeError(); 614 Rel.Addend = (intptr_t)Addend; 615 return Error::success(); 616 } 617 } 618 llvm_unreachable("Attempting to get address of ODP entry!"); 619 } 620 621 // Relocation masks following the #lo(value), #hi(value), #ha(value), 622 // #higher(value), #highera(value), #highest(value), and #highesta(value) 623 // macros defined in section 4.5.1. Relocation Types of the PPC-elf64abi 624 // document. 625 626 static inline uint16_t applyPPClo(uint64_t value) { return value & 0xffff; } 627 628 static inline uint16_t applyPPChi(uint64_t value) { 629 return (value >> 16) & 0xffff; 630 } 631 632 static inline uint16_t applyPPCha (uint64_t value) { 633 return ((value + 0x8000) >> 16) & 0xffff; 634 } 635 636 static inline uint16_t applyPPChigher(uint64_t value) { 637 return (value >> 32) & 0xffff; 638 } 639 640 static inline uint16_t applyPPChighera (uint64_t value) { 641 return ((value + 0x8000) >> 32) & 0xffff; 642 } 643 644 static inline uint16_t applyPPChighest(uint64_t value) { 645 return (value >> 48) & 0xffff; 646 } 647 648 static inline uint16_t applyPPChighesta (uint64_t value) { 649 return ((value + 0x8000) >> 48) & 0xffff; 650 } 651 652 void RuntimeDyldELF::resolvePPC32Relocation(const SectionEntry &Section, 653 uint64_t Offset, uint64_t Value, 654 uint32_t Type, int64_t Addend) { 655 uint8_t *LocalAddress = Section.getAddressWithOffset(Offset); 656 switch (Type) { 657 default: 658 llvm_unreachable("Relocation type not implemented yet!"); 659 break; 660 case ELF::R_PPC_ADDR16_LO: 661 writeInt16BE(LocalAddress, applyPPClo(Value + Addend)); 662 break; 663 case ELF::R_PPC_ADDR16_HI: 664 writeInt16BE(LocalAddress, applyPPChi(Value + Addend)); 665 break; 666 case ELF::R_PPC_ADDR16_HA: 667 writeInt16BE(LocalAddress, applyPPCha(Value + Addend)); 668 break; 669 } 670 } 671 672 void RuntimeDyldELF::resolvePPC64Relocation(const SectionEntry &Section, 673 uint64_t Offset, uint64_t Value, 674 uint32_t Type, int64_t Addend) { 675 uint8_t *LocalAddress = Section.getAddressWithOffset(Offset); 676 switch (Type) { 677 default: 678 llvm_unreachable("Relocation type not implemented yet!"); 679 break; 680 case ELF::R_PPC64_ADDR16: 681 writeInt16BE(LocalAddress, applyPPClo(Value + Addend)); 682 break; 683 case ELF::R_PPC64_ADDR16_DS: 684 writeInt16BE(LocalAddress, applyPPClo(Value + Addend) & ~3); 685 break; 686 case ELF::R_PPC64_ADDR16_LO: 687 writeInt16BE(LocalAddress, applyPPClo(Value + Addend)); 688 break; 689 case ELF::R_PPC64_ADDR16_LO_DS: 690 writeInt16BE(LocalAddress, applyPPClo(Value + Addend) & ~3); 691 break; 692 case ELF::R_PPC64_ADDR16_HI: 693 writeInt16BE(LocalAddress, applyPPChi(Value + Addend)); 694 break; 695 case ELF::R_PPC64_ADDR16_HA: 696 writeInt16BE(LocalAddress, applyPPCha(Value + Addend)); 697 break; 698 case ELF::R_PPC64_ADDR16_HIGHER: 699 writeInt16BE(LocalAddress, applyPPChigher(Value + Addend)); 700 break; 701 case ELF::R_PPC64_ADDR16_HIGHERA: 702 writeInt16BE(LocalAddress, applyPPChighera(Value + Addend)); 703 break; 704 case ELF::R_PPC64_ADDR16_HIGHEST: 705 writeInt16BE(LocalAddress, applyPPChighest(Value + Addend)); 706 break; 707 case ELF::R_PPC64_ADDR16_HIGHESTA: 708 writeInt16BE(LocalAddress, applyPPChighesta(Value + Addend)); 709 break; 710 case ELF::R_PPC64_ADDR14: { 711 assert(((Value + Addend) & 3) == 0); 712 // Preserve the AA/LK bits in the branch instruction 713 uint8_t aalk = *(LocalAddress + 3); 714 writeInt16BE(LocalAddress + 2, (aalk & 3) | ((Value + Addend) & 0xfffc)); 715 } break; 716 case ELF::R_PPC64_REL16_LO: { 717 uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset); 718 uint64_t Delta = Value - FinalAddress + Addend; 719 writeInt16BE(LocalAddress, applyPPClo(Delta)); 720 } break; 721 case ELF::R_PPC64_REL16_HI: { 722 uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset); 723 uint64_t Delta = Value - FinalAddress + Addend; 724 writeInt16BE(LocalAddress, applyPPChi(Delta)); 725 } break; 726 case ELF::R_PPC64_REL16_HA: { 727 uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset); 728 uint64_t Delta = Value - FinalAddress + Addend; 729 writeInt16BE(LocalAddress, applyPPCha(Delta)); 730 } break; 731 case ELF::R_PPC64_ADDR32: { 732 int32_t Result = static_cast<int32_t>(Value + Addend); 733 if (SignExtend32<32>(Result) != Result) 734 llvm_unreachable("Relocation R_PPC64_ADDR32 overflow"); 735 writeInt32BE(LocalAddress, Result); 736 } break; 737 case ELF::R_PPC64_REL24: { 738 uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset); 739 int32_t delta = static_cast<int32_t>(Value - FinalAddress + Addend); 740 if (SignExtend32<26>(delta) != delta) 741 llvm_unreachable("Relocation R_PPC64_REL24 overflow"); 742 // Generates a 'bl <address>' instruction 743 writeInt32BE(LocalAddress, 0x48000001 | (delta & 0x03FFFFFC)); 744 } break; 745 case ELF::R_PPC64_REL32: { 746 uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset); 747 int32_t delta = static_cast<int32_t>(Value - FinalAddress + Addend); 748 if (SignExtend32<32>(delta) != delta) 749 llvm_unreachable("Relocation R_PPC64_REL32 overflow"); 750 writeInt32BE(LocalAddress, delta); 751 } break; 752 case ELF::R_PPC64_REL64: { 753 uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset); 754 uint64_t Delta = Value - FinalAddress + Addend; 755 writeInt64BE(LocalAddress, Delta); 756 } break; 757 case ELF::R_PPC64_ADDR64: 758 writeInt64BE(LocalAddress, Value + Addend); 759 break; 760 } 761 } 762 763 void RuntimeDyldELF::resolveSystemZRelocation(const SectionEntry &Section, 764 uint64_t Offset, uint64_t Value, 765 uint32_t Type, int64_t Addend) { 766 uint8_t *LocalAddress = Section.getAddressWithOffset(Offset); 767 switch (Type) { 768 default: 769 llvm_unreachable("Relocation type not implemented yet!"); 770 break; 771 case ELF::R_390_PC16DBL: 772 case ELF::R_390_PLT16DBL: { 773 int64_t Delta = (Value + Addend) - Section.getLoadAddressWithOffset(Offset); 774 assert(int16_t(Delta / 2) * 2 == Delta && "R_390_PC16DBL overflow"); 775 writeInt16BE(LocalAddress, Delta / 2); 776 break; 777 } 778 case ELF::R_390_PC32DBL: 779 case ELF::R_390_PLT32DBL: { 780 int64_t Delta = (Value + Addend) - Section.getLoadAddressWithOffset(Offset); 781 assert(int32_t(Delta / 2) * 2 == Delta && "R_390_PC32DBL overflow"); 782 writeInt32BE(LocalAddress, Delta / 2); 783 break; 784 } 785 case ELF::R_390_PC32: { 786 int64_t Delta = (Value + Addend) - Section.getLoadAddressWithOffset(Offset); 787 assert(int32_t(Delta) == Delta && "R_390_PC32 overflow"); 788 writeInt32BE(LocalAddress, Delta); 789 break; 790 } 791 case ELF::R_390_64: 792 writeInt64BE(LocalAddress, Value + Addend); 793 break; 794 case ELF::R_390_PC64: { 795 int64_t Delta = (Value + Addend) - Section.getLoadAddressWithOffset(Offset); 796 writeInt64BE(LocalAddress, Delta); 797 break; 798 } 799 } 800 } 801 802 // The target location for the relocation is described by RE.SectionID and 803 // RE.Offset. RE.SectionID can be used to find the SectionEntry. Each 804 // SectionEntry has three members describing its location. 805 // SectionEntry::Address is the address at which the section has been loaded 806 // into memory in the current (host) process. SectionEntry::LoadAddress is the 807 // address that the section will have in the target process. 808 // SectionEntry::ObjAddress is the address of the bits for this section in the 809 // original emitted object image (also in the current address space). 810 // 811 // Relocations will be applied as if the section were loaded at 812 // SectionEntry::LoadAddress, but they will be applied at an address based 813 // on SectionEntry::Address. SectionEntry::ObjAddress will be used to refer to 814 // Target memory contents if they are required for value calculations. 815 // 816 // The Value parameter here is the load address of the symbol for the 817 // relocation to be applied. For relocations which refer to symbols in the 818 // current object Value will be the LoadAddress of the section in which 819 // the symbol resides (RE.Addend provides additional information about the 820 // symbol location). For external symbols, Value will be the address of the 821 // symbol in the target address space. 822 void RuntimeDyldELF::resolveRelocation(const RelocationEntry &RE, 823 uint64_t Value) { 824 const SectionEntry &Section = Sections[RE.SectionID]; 825 return resolveRelocation(Section, RE.Offset, Value, RE.RelType, RE.Addend, 826 RE.SymOffset, RE.SectionID); 827 } 828 829 void RuntimeDyldELF::resolveRelocation(const SectionEntry &Section, 830 uint64_t Offset, uint64_t Value, 831 uint32_t Type, int64_t Addend, 832 uint64_t SymOffset, SID SectionID) { 833 switch (Arch) { 834 case Triple::x86_64: 835 resolveX86_64Relocation(Section, Offset, Value, Type, Addend, SymOffset); 836 break; 837 case Triple::x86: 838 resolveX86Relocation(Section, Offset, (uint32_t)(Value & 0xffffffffL), Type, 839 (uint32_t)(Addend & 0xffffffffL)); 840 break; 841 case Triple::aarch64: 842 case Triple::aarch64_be: 843 resolveAArch64Relocation(Section, Offset, Value, Type, Addend); 844 break; 845 case Triple::arm: // Fall through. 846 case Triple::armeb: 847 case Triple::thumb: 848 case Triple::thumbeb: 849 resolveARMRelocation(Section, Offset, (uint32_t)(Value & 0xffffffffL), Type, 850 (uint32_t)(Addend & 0xffffffffL)); 851 break; 852 case Triple::ppc: 853 resolvePPC32Relocation(Section, Offset, Value, Type, Addend); 854 break; 855 case Triple::ppc64: // Fall through. 856 case Triple::ppc64le: 857 resolvePPC64Relocation(Section, Offset, Value, Type, Addend); 858 break; 859 case Triple::systemz: 860 resolveSystemZRelocation(Section, Offset, Value, Type, Addend); 861 break; 862 default: 863 llvm_unreachable("Unsupported CPU type!"); 864 } 865 } 866 867 void *RuntimeDyldELF::computePlaceholderAddress(unsigned SectionID, uint64_t Offset) const { 868 return (void *)(Sections[SectionID].getObjAddress() + Offset); 869 } 870 871 void RuntimeDyldELF::processSimpleRelocation(unsigned SectionID, uint64_t Offset, unsigned RelType, RelocationValueRef Value) { 872 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend, Value.Offset); 873 if (Value.SymbolName) 874 addRelocationForSymbol(RE, Value.SymbolName); 875 else 876 addRelocationForSection(RE, Value.SectionID); 877 } 878 879 uint32_t RuntimeDyldELF::getMatchingLoRelocation(uint32_t RelType, 880 bool IsLocal) const { 881 switch (RelType) { 882 case ELF::R_MICROMIPS_GOT16: 883 if (IsLocal) 884 return ELF::R_MICROMIPS_LO16; 885 break; 886 case ELF::R_MICROMIPS_HI16: 887 return ELF::R_MICROMIPS_LO16; 888 case ELF::R_MIPS_GOT16: 889 if (IsLocal) 890 return ELF::R_MIPS_LO16; 891 break; 892 case ELF::R_MIPS_HI16: 893 return ELF::R_MIPS_LO16; 894 case ELF::R_MIPS_PCHI16: 895 return ELF::R_MIPS_PCLO16; 896 default: 897 break; 898 } 899 return ELF::R_MIPS_NONE; 900 } 901 902 // Sometimes we don't need to create thunk for a branch. 903 // This typically happens when branch target is located 904 // in the same object file. In such case target is either 905 // a weak symbol or symbol in a different executable section. 906 // This function checks if branch target is located in the 907 // same object file and if distance between source and target 908 // fits R_AARCH64_CALL26 relocation. If both conditions are 909 // met, it emits direct jump to the target and returns true. 910 // Otherwise false is returned and thunk is created. 911 bool RuntimeDyldELF::resolveAArch64ShortBranch( 912 unsigned SectionID, relocation_iterator RelI, 913 const RelocationValueRef &Value) { 914 uint64_t Address; 915 if (Value.SymbolName) { 916 auto Loc = GlobalSymbolTable.find(Value.SymbolName); 917 918 // Don't create direct branch for external symbols. 919 if (Loc == GlobalSymbolTable.end()) 920 return false; 921 922 const auto &SymInfo = Loc->second; 923 Address = 924 uint64_t(Sections[SymInfo.getSectionID()].getLoadAddressWithOffset( 925 SymInfo.getOffset())); 926 } else { 927 Address = uint64_t(Sections[Value.SectionID].getLoadAddress()); 928 } 929 uint64_t Offset = RelI->getOffset(); 930 uint64_t SourceAddress = Sections[SectionID].getLoadAddressWithOffset(Offset); 931 932 // R_AARCH64_CALL26 requires immediate to be in range -2^27 <= imm < 2^27 933 // If distance between source and target is out of range then we should 934 // create thunk. 935 if (!isInt<28>(Address + Value.Addend - SourceAddress)) 936 return false; 937 938 resolveRelocation(Sections[SectionID], Offset, Address, RelI->getType(), 939 Value.Addend); 940 941 return true; 942 } 943 944 Expected<relocation_iterator> 945 RuntimeDyldELF::processRelocationRef( 946 unsigned SectionID, relocation_iterator RelI, const ObjectFile &O, 947 ObjSectionToIDMap &ObjSectionToID, StubMap &Stubs) { 948 const auto &Obj = cast<ELFObjectFileBase>(O); 949 uint64_t RelType = RelI->getType(); 950 ErrorOr<int64_t> AddendOrErr = ELFRelocationRef(*RelI).getAddend(); 951 int64_t Addend = AddendOrErr ? *AddendOrErr : 0; 952 elf_symbol_iterator Symbol = RelI->getSymbol(); 953 954 // Obtain the symbol name which is referenced in the relocation 955 StringRef TargetName; 956 if (Symbol != Obj.symbol_end()) { 957 if (auto TargetNameOrErr = Symbol->getName()) 958 TargetName = *TargetNameOrErr; 959 else 960 return TargetNameOrErr.takeError(); 961 } 962 DEBUG(dbgs() << "\t\tRelType: " << RelType << " Addend: " << Addend 963 << " TargetName: " << TargetName << "\n"); 964 RelocationValueRef Value; 965 // First search for the symbol in the local symbol table 966 SymbolRef::Type SymType = SymbolRef::ST_Unknown; 967 968 // Search for the symbol in the global symbol table 969 RTDyldSymbolTable::const_iterator gsi = GlobalSymbolTable.end(); 970 if (Symbol != Obj.symbol_end()) { 971 gsi = GlobalSymbolTable.find(TargetName.data()); 972 Expected<SymbolRef::Type> SymTypeOrErr = Symbol->getType(); 973 if (!SymTypeOrErr) { 974 std::string Buf; 975 raw_string_ostream OS(Buf); 976 logAllUnhandledErrors(SymTypeOrErr.takeError(), OS, ""); 977 OS.flush(); 978 report_fatal_error(Buf); 979 } 980 SymType = *SymTypeOrErr; 981 } 982 if (gsi != GlobalSymbolTable.end()) { 983 const auto &SymInfo = gsi->second; 984 Value.SectionID = SymInfo.getSectionID(); 985 Value.Offset = SymInfo.getOffset(); 986 Value.Addend = SymInfo.getOffset() + Addend; 987 } else { 988 switch (SymType) { 989 case SymbolRef::ST_Debug: { 990 // TODO: Now ELF SymbolRef::ST_Debug = STT_SECTION, it's not obviously 991 // and can be changed by another developers. Maybe best way is add 992 // a new symbol type ST_Section to SymbolRef and use it. 993 auto SectionOrErr = Symbol->getSection(); 994 if (!SectionOrErr) { 995 std::string Buf; 996 raw_string_ostream OS(Buf); 997 logAllUnhandledErrors(SectionOrErr.takeError(), OS, ""); 998 OS.flush(); 999 report_fatal_error(Buf); 1000 } 1001 section_iterator si = *SectionOrErr; 1002 if (si == Obj.section_end()) 1003 llvm_unreachable("Symbol section not found, bad object file format!"); 1004 DEBUG(dbgs() << "\t\tThis is section symbol\n"); 1005 bool isCode = si->isText(); 1006 if (auto SectionIDOrErr = findOrEmitSection(Obj, (*si), isCode, 1007 ObjSectionToID)) 1008 Value.SectionID = *SectionIDOrErr; 1009 else 1010 return SectionIDOrErr.takeError(); 1011 Value.Addend = Addend; 1012 break; 1013 } 1014 case SymbolRef::ST_Data: 1015 case SymbolRef::ST_Function: 1016 case SymbolRef::ST_Unknown: { 1017 Value.SymbolName = TargetName.data(); 1018 Value.Addend = Addend; 1019 1020 // Absolute relocations will have a zero symbol ID (STN_UNDEF), which 1021 // will manifest here as a NULL symbol name. 1022 // We can set this as a valid (but empty) symbol name, and rely 1023 // on addRelocationForSymbol to handle this. 1024 if (!Value.SymbolName) 1025 Value.SymbolName = ""; 1026 break; 1027 } 1028 default: 1029 llvm_unreachable("Unresolved symbol type!"); 1030 break; 1031 } 1032 } 1033 1034 uint64_t Offset = RelI->getOffset(); 1035 1036 DEBUG(dbgs() << "\t\tSectionID: " << SectionID << " Offset: " << Offset 1037 << "\n"); 1038 if ((Arch == Triple::aarch64 || Arch == Triple::aarch64_be) && 1039 (RelType == ELF::R_AARCH64_CALL26 || RelType == ELF::R_AARCH64_JUMP26)) { 1040 // This is an AArch64 branch relocation, need to use a stub function. 1041 DEBUG(dbgs() << "\t\tThis is an AArch64 branch relocation."); 1042 SectionEntry &Section = Sections[SectionID]; 1043 1044 // Look for an existing stub. 1045 StubMap::const_iterator i = Stubs.find(Value); 1046 if (i != Stubs.end()) { 1047 resolveRelocation(Section, Offset, 1048 (uint64_t)Section.getAddressWithOffset(i->second), 1049 RelType, 0); 1050 DEBUG(dbgs() << " Stub function found\n"); 1051 } else if (!resolveAArch64ShortBranch(SectionID, RelI, Value)) { 1052 // Create a new stub function. 1053 DEBUG(dbgs() << " Create a new stub function\n"); 1054 Stubs[Value] = Section.getStubOffset(); 1055 uint8_t *StubTargetAddr = createStubFunction( 1056 Section.getAddressWithOffset(Section.getStubOffset())); 1057 1058 RelocationEntry REmovz_g3(SectionID, 1059 StubTargetAddr - Section.getAddress(), 1060 ELF::R_AARCH64_MOVW_UABS_G3, Value.Addend); 1061 RelocationEntry REmovk_g2(SectionID, StubTargetAddr - 1062 Section.getAddress() + 4, 1063 ELF::R_AARCH64_MOVW_UABS_G2_NC, Value.Addend); 1064 RelocationEntry REmovk_g1(SectionID, StubTargetAddr - 1065 Section.getAddress() + 8, 1066 ELF::R_AARCH64_MOVW_UABS_G1_NC, Value.Addend); 1067 RelocationEntry REmovk_g0(SectionID, StubTargetAddr - 1068 Section.getAddress() + 12, 1069 ELF::R_AARCH64_MOVW_UABS_G0_NC, Value.Addend); 1070 1071 if (Value.SymbolName) { 1072 addRelocationForSymbol(REmovz_g3, Value.SymbolName); 1073 addRelocationForSymbol(REmovk_g2, Value.SymbolName); 1074 addRelocationForSymbol(REmovk_g1, Value.SymbolName); 1075 addRelocationForSymbol(REmovk_g0, Value.SymbolName); 1076 } else { 1077 addRelocationForSection(REmovz_g3, Value.SectionID); 1078 addRelocationForSection(REmovk_g2, Value.SectionID); 1079 addRelocationForSection(REmovk_g1, Value.SectionID); 1080 addRelocationForSection(REmovk_g0, Value.SectionID); 1081 } 1082 resolveRelocation(Section, Offset, 1083 reinterpret_cast<uint64_t>(Section.getAddressWithOffset( 1084 Section.getStubOffset())), 1085 RelType, 0); 1086 Section.advanceStubOffset(getMaxStubSize()); 1087 } 1088 } else if (Arch == Triple::arm) { 1089 if (RelType == ELF::R_ARM_PC24 || RelType == ELF::R_ARM_CALL || 1090 RelType == ELF::R_ARM_JUMP24) { 1091 // This is an ARM branch relocation, need to use a stub function. 1092 DEBUG(dbgs() << "\t\tThis is an ARM branch relocation.\n"); 1093 SectionEntry &Section = Sections[SectionID]; 1094 1095 // Look for an existing stub. 1096 StubMap::const_iterator i = Stubs.find(Value); 1097 if (i != Stubs.end()) { 1098 resolveRelocation( 1099 Section, Offset, 1100 reinterpret_cast<uint64_t>(Section.getAddressWithOffset(i->second)), 1101 RelType, 0); 1102 DEBUG(dbgs() << " Stub function found\n"); 1103 } else { 1104 // Create a new stub function. 1105 DEBUG(dbgs() << " Create a new stub function\n"); 1106 Stubs[Value] = Section.getStubOffset(); 1107 uint8_t *StubTargetAddr = createStubFunction( 1108 Section.getAddressWithOffset(Section.getStubOffset())); 1109 RelocationEntry RE(SectionID, StubTargetAddr - Section.getAddress(), 1110 ELF::R_ARM_ABS32, Value.Addend); 1111 if (Value.SymbolName) 1112 addRelocationForSymbol(RE, Value.SymbolName); 1113 else 1114 addRelocationForSection(RE, Value.SectionID); 1115 1116 resolveRelocation(Section, Offset, reinterpret_cast<uint64_t>( 1117 Section.getAddressWithOffset( 1118 Section.getStubOffset())), 1119 RelType, 0); 1120 Section.advanceStubOffset(getMaxStubSize()); 1121 } 1122 } else { 1123 uint32_t *Placeholder = 1124 reinterpret_cast<uint32_t*>(computePlaceholderAddress(SectionID, Offset)); 1125 if (RelType == ELF::R_ARM_PREL31 || RelType == ELF::R_ARM_TARGET1 || 1126 RelType == ELF::R_ARM_ABS32) { 1127 Value.Addend += *Placeholder; 1128 } else if (RelType == ELF::R_ARM_MOVW_ABS_NC || RelType == ELF::R_ARM_MOVT_ABS) { 1129 // See ELF for ARM documentation 1130 Value.Addend += (int16_t)((*Placeholder & 0xFFF) | (((*Placeholder >> 16) & 0xF) << 12)); 1131 } 1132 processSimpleRelocation(SectionID, Offset, RelType, Value); 1133 } 1134 } else if (IsMipsO32ABI) { 1135 uint8_t *Placeholder = reinterpret_cast<uint8_t *>( 1136 computePlaceholderAddress(SectionID, Offset)); 1137 uint32_t Opcode = readBytesUnaligned(Placeholder, 4); 1138 if (RelType == ELF::R_MIPS_26) { 1139 // This is an Mips branch relocation, need to use a stub function. 1140 DEBUG(dbgs() << "\t\tThis is a Mips branch relocation."); 1141 SectionEntry &Section = Sections[SectionID]; 1142 1143 // Extract the addend from the instruction. 1144 // We shift up by two since the Value will be down shifted again 1145 // when applying the relocation. 1146 uint32_t Addend = (Opcode & 0x03ffffff) << 2; 1147 1148 Value.Addend += Addend; 1149 1150 // Look up for existing stub. 1151 StubMap::const_iterator i = Stubs.find(Value); 1152 if (i != Stubs.end()) { 1153 RelocationEntry RE(SectionID, Offset, RelType, i->second); 1154 addRelocationForSection(RE, SectionID); 1155 DEBUG(dbgs() << " Stub function found\n"); 1156 } else { 1157 // Create a new stub function. 1158 DEBUG(dbgs() << " Create a new stub function\n"); 1159 Stubs[Value] = Section.getStubOffset(); 1160 1161 unsigned AbiVariant; 1162 O.getPlatformFlags(AbiVariant); 1163 1164 uint8_t *StubTargetAddr = createStubFunction( 1165 Section.getAddressWithOffset(Section.getStubOffset()), AbiVariant); 1166 1167 // Creating Hi and Lo relocations for the filled stub instructions. 1168 RelocationEntry REHi(SectionID, StubTargetAddr - Section.getAddress(), 1169 ELF::R_MIPS_HI16, Value.Addend); 1170 RelocationEntry RELo(SectionID, 1171 StubTargetAddr - Section.getAddress() + 4, 1172 ELF::R_MIPS_LO16, Value.Addend); 1173 1174 if (Value.SymbolName) { 1175 addRelocationForSymbol(REHi, Value.SymbolName); 1176 addRelocationForSymbol(RELo, Value.SymbolName); 1177 } 1178 else { 1179 addRelocationForSection(REHi, Value.SectionID); 1180 addRelocationForSection(RELo, Value.SectionID); 1181 } 1182 1183 RelocationEntry RE(SectionID, Offset, RelType, Section.getStubOffset()); 1184 addRelocationForSection(RE, SectionID); 1185 Section.advanceStubOffset(getMaxStubSize()); 1186 } 1187 } else if (RelType == ELF::R_MIPS_HI16 || RelType == ELF::R_MIPS_PCHI16) { 1188 int64_t Addend = (Opcode & 0x0000ffff) << 16; 1189 RelocationEntry RE(SectionID, Offset, RelType, Addend); 1190 PendingRelocs.push_back(std::make_pair(Value, RE)); 1191 } else if (RelType == ELF::R_MIPS_LO16 || RelType == ELF::R_MIPS_PCLO16) { 1192 int64_t Addend = Value.Addend + SignExtend32<16>(Opcode & 0x0000ffff); 1193 for (auto I = PendingRelocs.begin(); I != PendingRelocs.end();) { 1194 const RelocationValueRef &MatchingValue = I->first; 1195 RelocationEntry &Reloc = I->second; 1196 if (MatchingValue == Value && 1197 RelType == getMatchingLoRelocation(Reloc.RelType) && 1198 SectionID == Reloc.SectionID) { 1199 Reloc.Addend += Addend; 1200 if (Value.SymbolName) 1201 addRelocationForSymbol(Reloc, Value.SymbolName); 1202 else 1203 addRelocationForSection(Reloc, Value.SectionID); 1204 I = PendingRelocs.erase(I); 1205 } else 1206 ++I; 1207 } 1208 RelocationEntry RE(SectionID, Offset, RelType, Addend); 1209 if (Value.SymbolName) 1210 addRelocationForSymbol(RE, Value.SymbolName); 1211 else 1212 addRelocationForSection(RE, Value.SectionID); 1213 } else { 1214 if (RelType == ELF::R_MIPS_32) 1215 Value.Addend += Opcode; 1216 else if (RelType == ELF::R_MIPS_PC16) 1217 Value.Addend += SignExtend32<18>((Opcode & 0x0000ffff) << 2); 1218 else if (RelType == ELF::R_MIPS_PC19_S2) 1219 Value.Addend += SignExtend32<21>((Opcode & 0x0007ffff) << 2); 1220 else if (RelType == ELF::R_MIPS_PC21_S2) 1221 Value.Addend += SignExtend32<23>((Opcode & 0x001fffff) << 2); 1222 else if (RelType == ELF::R_MIPS_PC26_S2) 1223 Value.Addend += SignExtend32<28>((Opcode & 0x03ffffff) << 2); 1224 processSimpleRelocation(SectionID, Offset, RelType, Value); 1225 } 1226 } else if (IsMipsN32ABI || IsMipsN64ABI) { 1227 uint32_t r_type = RelType & 0xff; 1228 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend); 1229 if (r_type == ELF::R_MIPS_CALL16 || r_type == ELF::R_MIPS_GOT_PAGE 1230 || r_type == ELF::R_MIPS_GOT_DISP) { 1231 StringMap<uint64_t>::iterator i = GOTSymbolOffsets.find(TargetName); 1232 if (i != GOTSymbolOffsets.end()) 1233 RE.SymOffset = i->second; 1234 else { 1235 RE.SymOffset = allocateGOTEntries(SectionID, 1); 1236 GOTSymbolOffsets[TargetName] = RE.SymOffset; 1237 } 1238 } 1239 if (Value.SymbolName) 1240 addRelocationForSymbol(RE, Value.SymbolName); 1241 else 1242 addRelocationForSection(RE, Value.SectionID); 1243 } else if (Arch == Triple::ppc64 || Arch == Triple::ppc64le) { 1244 if (RelType == ELF::R_PPC64_REL24) { 1245 // Determine ABI variant in use for this object. 1246 unsigned AbiVariant; 1247 Obj.getPlatformFlags(AbiVariant); 1248 AbiVariant &= ELF::EF_PPC64_ABI; 1249 // A PPC branch relocation will need a stub function if the target is 1250 // an external symbol (Symbol::ST_Unknown) or if the target address 1251 // is not within the signed 24-bits branch address. 1252 SectionEntry &Section = Sections[SectionID]; 1253 uint8_t *Target = Section.getAddressWithOffset(Offset); 1254 bool RangeOverflow = false; 1255 if (SymType != SymbolRef::ST_Unknown) { 1256 if (AbiVariant != 2) { 1257 // In the ELFv1 ABI, a function call may point to the .opd entry, 1258 // so the final symbol value is calculated based on the relocation 1259 // values in the .opd section. 1260 if (auto Err = findOPDEntrySection(Obj, ObjSectionToID, Value)) 1261 return std::move(Err); 1262 } else { 1263 // In the ELFv2 ABI, a function symbol may provide a local entry 1264 // point, which must be used for direct calls. 1265 uint8_t SymOther = Symbol->getOther(); 1266 Value.Addend += ELF::decodePPC64LocalEntryOffset(SymOther); 1267 } 1268 uint8_t *RelocTarget = 1269 Sections[Value.SectionID].getAddressWithOffset(Value.Addend); 1270 int32_t delta = static_cast<int32_t>(Target - RelocTarget); 1271 // If it is within 26-bits branch range, just set the branch target 1272 if (SignExtend32<26>(delta) == delta) { 1273 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend); 1274 if (Value.SymbolName) 1275 addRelocationForSymbol(RE, Value.SymbolName); 1276 else 1277 addRelocationForSection(RE, Value.SectionID); 1278 } else { 1279 RangeOverflow = true; 1280 } 1281 } 1282 if (SymType == SymbolRef::ST_Unknown || RangeOverflow) { 1283 // It is an external symbol (SymbolRef::ST_Unknown) or within a range 1284 // larger than 24-bits. 1285 StubMap::const_iterator i = Stubs.find(Value); 1286 if (i != Stubs.end()) { 1287 // Symbol function stub already created, just relocate to it 1288 resolveRelocation(Section, Offset, 1289 reinterpret_cast<uint64_t>( 1290 Section.getAddressWithOffset(i->second)), 1291 RelType, 0); 1292 DEBUG(dbgs() << " Stub function found\n"); 1293 } else { 1294 // Create a new stub function. 1295 DEBUG(dbgs() << " Create a new stub function\n"); 1296 Stubs[Value] = Section.getStubOffset(); 1297 uint8_t *StubTargetAddr = createStubFunction( 1298 Section.getAddressWithOffset(Section.getStubOffset()), 1299 AbiVariant); 1300 RelocationEntry RE(SectionID, StubTargetAddr - Section.getAddress(), 1301 ELF::R_PPC64_ADDR64, Value.Addend); 1302 1303 // Generates the 64-bits address loads as exemplified in section 1304 // 4.5.1 in PPC64 ELF ABI. Note that the relocations need to 1305 // apply to the low part of the instructions, so we have to update 1306 // the offset according to the target endianness. 1307 uint64_t StubRelocOffset = StubTargetAddr - Section.getAddress(); 1308 if (!IsTargetLittleEndian) 1309 StubRelocOffset += 2; 1310 1311 RelocationEntry REhst(SectionID, StubRelocOffset + 0, 1312 ELF::R_PPC64_ADDR16_HIGHEST, Value.Addend); 1313 RelocationEntry REhr(SectionID, StubRelocOffset + 4, 1314 ELF::R_PPC64_ADDR16_HIGHER, Value.Addend); 1315 RelocationEntry REh(SectionID, StubRelocOffset + 12, 1316 ELF::R_PPC64_ADDR16_HI, Value.Addend); 1317 RelocationEntry REl(SectionID, StubRelocOffset + 16, 1318 ELF::R_PPC64_ADDR16_LO, Value.Addend); 1319 1320 if (Value.SymbolName) { 1321 addRelocationForSymbol(REhst, Value.SymbolName); 1322 addRelocationForSymbol(REhr, Value.SymbolName); 1323 addRelocationForSymbol(REh, Value.SymbolName); 1324 addRelocationForSymbol(REl, Value.SymbolName); 1325 } else { 1326 addRelocationForSection(REhst, Value.SectionID); 1327 addRelocationForSection(REhr, Value.SectionID); 1328 addRelocationForSection(REh, Value.SectionID); 1329 addRelocationForSection(REl, Value.SectionID); 1330 } 1331 1332 resolveRelocation(Section, Offset, reinterpret_cast<uint64_t>( 1333 Section.getAddressWithOffset( 1334 Section.getStubOffset())), 1335 RelType, 0); 1336 Section.advanceStubOffset(getMaxStubSize()); 1337 } 1338 if (SymType == SymbolRef::ST_Unknown) { 1339 // Restore the TOC for external calls 1340 if (AbiVariant == 2) 1341 writeInt32BE(Target + 4, 0xE8410018); // ld r2,28(r1) 1342 else 1343 writeInt32BE(Target + 4, 0xE8410028); // ld r2,40(r1) 1344 } 1345 } 1346 } else if (RelType == ELF::R_PPC64_TOC16 || 1347 RelType == ELF::R_PPC64_TOC16_DS || 1348 RelType == ELF::R_PPC64_TOC16_LO || 1349 RelType == ELF::R_PPC64_TOC16_LO_DS || 1350 RelType == ELF::R_PPC64_TOC16_HI || 1351 RelType == ELF::R_PPC64_TOC16_HA) { 1352 // These relocations are supposed to subtract the TOC address from 1353 // the final value. This does not fit cleanly into the RuntimeDyld 1354 // scheme, since there may be *two* sections involved in determining 1355 // the relocation value (the section of the symbol referred to by the 1356 // relocation, and the TOC section associated with the current module). 1357 // 1358 // Fortunately, these relocations are currently only ever generated 1359 // referring to symbols that themselves reside in the TOC, which means 1360 // that the two sections are actually the same. Thus they cancel out 1361 // and we can immediately resolve the relocation right now. 1362 switch (RelType) { 1363 case ELF::R_PPC64_TOC16: RelType = ELF::R_PPC64_ADDR16; break; 1364 case ELF::R_PPC64_TOC16_DS: RelType = ELF::R_PPC64_ADDR16_DS; break; 1365 case ELF::R_PPC64_TOC16_LO: RelType = ELF::R_PPC64_ADDR16_LO; break; 1366 case ELF::R_PPC64_TOC16_LO_DS: RelType = ELF::R_PPC64_ADDR16_LO_DS; break; 1367 case ELF::R_PPC64_TOC16_HI: RelType = ELF::R_PPC64_ADDR16_HI; break; 1368 case ELF::R_PPC64_TOC16_HA: RelType = ELF::R_PPC64_ADDR16_HA; break; 1369 default: llvm_unreachable("Wrong relocation type."); 1370 } 1371 1372 RelocationValueRef TOCValue; 1373 if (auto Err = findPPC64TOCSection(Obj, ObjSectionToID, TOCValue)) 1374 return std::move(Err); 1375 if (Value.SymbolName || Value.SectionID != TOCValue.SectionID) 1376 llvm_unreachable("Unsupported TOC relocation."); 1377 Value.Addend -= TOCValue.Addend; 1378 resolveRelocation(Sections[SectionID], Offset, Value.Addend, RelType, 0); 1379 } else { 1380 // There are two ways to refer to the TOC address directly: either 1381 // via a ELF::R_PPC64_TOC relocation (where both symbol and addend are 1382 // ignored), or via any relocation that refers to the magic ".TOC." 1383 // symbols (in which case the addend is respected). 1384 if (RelType == ELF::R_PPC64_TOC) { 1385 RelType = ELF::R_PPC64_ADDR64; 1386 if (auto Err = findPPC64TOCSection(Obj, ObjSectionToID, Value)) 1387 return std::move(Err); 1388 } else if (TargetName == ".TOC.") { 1389 if (auto Err = findPPC64TOCSection(Obj, ObjSectionToID, Value)) 1390 return std::move(Err); 1391 Value.Addend += Addend; 1392 } 1393 1394 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend); 1395 1396 if (Value.SymbolName) 1397 addRelocationForSymbol(RE, Value.SymbolName); 1398 else 1399 addRelocationForSection(RE, Value.SectionID); 1400 } 1401 } else if (Arch == Triple::systemz && 1402 (RelType == ELF::R_390_PLT32DBL || RelType == ELF::R_390_GOTENT)) { 1403 // Create function stubs for both PLT and GOT references, regardless of 1404 // whether the GOT reference is to data or code. The stub contains the 1405 // full address of the symbol, as needed by GOT references, and the 1406 // executable part only adds an overhead of 8 bytes. 1407 // 1408 // We could try to conserve space by allocating the code and data 1409 // parts of the stub separately. However, as things stand, we allocate 1410 // a stub for every relocation, so using a GOT in JIT code should be 1411 // no less space efficient than using an explicit constant pool. 1412 DEBUG(dbgs() << "\t\tThis is a SystemZ indirect relocation."); 1413 SectionEntry &Section = Sections[SectionID]; 1414 1415 // Look for an existing stub. 1416 StubMap::const_iterator i = Stubs.find(Value); 1417 uintptr_t StubAddress; 1418 if (i != Stubs.end()) { 1419 StubAddress = uintptr_t(Section.getAddressWithOffset(i->second)); 1420 DEBUG(dbgs() << " Stub function found\n"); 1421 } else { 1422 // Create a new stub function. 1423 DEBUG(dbgs() << " Create a new stub function\n"); 1424 1425 uintptr_t BaseAddress = uintptr_t(Section.getAddress()); 1426 uintptr_t StubAlignment = getStubAlignment(); 1427 StubAddress = 1428 (BaseAddress + Section.getStubOffset() + StubAlignment - 1) & 1429 -StubAlignment; 1430 unsigned StubOffset = StubAddress - BaseAddress; 1431 1432 Stubs[Value] = StubOffset; 1433 createStubFunction((uint8_t *)StubAddress); 1434 RelocationEntry RE(SectionID, StubOffset + 8, ELF::R_390_64, 1435 Value.Offset); 1436 if (Value.SymbolName) 1437 addRelocationForSymbol(RE, Value.SymbolName); 1438 else 1439 addRelocationForSection(RE, Value.SectionID); 1440 Section.advanceStubOffset(getMaxStubSize()); 1441 } 1442 1443 if (RelType == ELF::R_390_GOTENT) 1444 resolveRelocation(Section, Offset, StubAddress + 8, ELF::R_390_PC32DBL, 1445 Addend); 1446 else 1447 resolveRelocation(Section, Offset, StubAddress, RelType, Addend); 1448 } else if (Arch == Triple::x86_64) { 1449 if (RelType == ELF::R_X86_64_PLT32) { 1450 // The way the PLT relocations normally work is that the linker allocates 1451 // the 1452 // PLT and this relocation makes a PC-relative call into the PLT. The PLT 1453 // entry will then jump to an address provided by the GOT. On first call, 1454 // the 1455 // GOT address will point back into PLT code that resolves the symbol. After 1456 // the first call, the GOT entry points to the actual function. 1457 // 1458 // For local functions we're ignoring all of that here and just replacing 1459 // the PLT32 relocation type with PC32, which will translate the relocation 1460 // into a PC-relative call directly to the function. For external symbols we 1461 // can't be sure the function will be within 2^32 bytes of the call site, so 1462 // we need to create a stub, which calls into the GOT. This case is 1463 // equivalent to the usual PLT implementation except that we use the stub 1464 // mechanism in RuntimeDyld (which puts stubs at the end of the section) 1465 // rather than allocating a PLT section. 1466 if (Value.SymbolName) { 1467 // This is a call to an external function. 1468 // Look for an existing stub. 1469 SectionEntry &Section = Sections[SectionID]; 1470 StubMap::const_iterator i = Stubs.find(Value); 1471 uintptr_t StubAddress; 1472 if (i != Stubs.end()) { 1473 StubAddress = uintptr_t(Section.getAddress()) + i->second; 1474 DEBUG(dbgs() << " Stub function found\n"); 1475 } else { 1476 // Create a new stub function (equivalent to a PLT entry). 1477 DEBUG(dbgs() << " Create a new stub function\n"); 1478 1479 uintptr_t BaseAddress = uintptr_t(Section.getAddress()); 1480 uintptr_t StubAlignment = getStubAlignment(); 1481 StubAddress = 1482 (BaseAddress + Section.getStubOffset() + StubAlignment - 1) & 1483 -StubAlignment; 1484 unsigned StubOffset = StubAddress - BaseAddress; 1485 Stubs[Value] = StubOffset; 1486 createStubFunction((uint8_t *)StubAddress); 1487 1488 // Bump our stub offset counter 1489 Section.advanceStubOffset(getMaxStubSize()); 1490 1491 // Allocate a GOT Entry 1492 uint64_t GOTOffset = allocateGOTEntries(SectionID, 1); 1493 1494 // The load of the GOT address has an addend of -4 1495 resolveGOTOffsetRelocation(SectionID, StubOffset + 2, GOTOffset - 4); 1496 1497 // Fill in the value of the symbol we're targeting into the GOT 1498 addRelocationForSymbol( 1499 computeGOTOffsetRE(SectionID, GOTOffset, 0, ELF::R_X86_64_64), 1500 Value.SymbolName); 1501 } 1502 1503 // Make the target call a call into the stub table. 1504 resolveRelocation(Section, Offset, StubAddress, ELF::R_X86_64_PC32, 1505 Addend); 1506 } else { 1507 RelocationEntry RE(SectionID, Offset, ELF::R_X86_64_PC32, Value.Addend, 1508 Value.Offset); 1509 addRelocationForSection(RE, Value.SectionID); 1510 } 1511 } else if (RelType == ELF::R_X86_64_GOTPCREL || 1512 RelType == ELF::R_X86_64_GOTPCRELX || 1513 RelType == ELF::R_X86_64_REX_GOTPCRELX) { 1514 uint64_t GOTOffset = allocateGOTEntries(SectionID, 1); 1515 resolveGOTOffsetRelocation(SectionID, Offset, GOTOffset + Addend); 1516 1517 // Fill in the value of the symbol we're targeting into the GOT 1518 RelocationEntry RE = computeGOTOffsetRE(SectionID, GOTOffset, Value.Offset, ELF::R_X86_64_64); 1519 if (Value.SymbolName) 1520 addRelocationForSymbol(RE, Value.SymbolName); 1521 else 1522 addRelocationForSection(RE, Value.SectionID); 1523 } else if (RelType == ELF::R_X86_64_PC32) { 1524 Value.Addend += support::ulittle32_t::ref(computePlaceholderAddress(SectionID, Offset)); 1525 processSimpleRelocation(SectionID, Offset, RelType, Value); 1526 } else if (RelType == ELF::R_X86_64_PC64) { 1527 Value.Addend += support::ulittle64_t::ref(computePlaceholderAddress(SectionID, Offset)); 1528 processSimpleRelocation(SectionID, Offset, RelType, Value); 1529 } else { 1530 processSimpleRelocation(SectionID, Offset, RelType, Value); 1531 } 1532 } else { 1533 if (Arch == Triple::x86) { 1534 Value.Addend += support::ulittle32_t::ref(computePlaceholderAddress(SectionID, Offset)); 1535 } 1536 processSimpleRelocation(SectionID, Offset, RelType, Value); 1537 } 1538 return ++RelI; 1539 } 1540 1541 size_t RuntimeDyldELF::getGOTEntrySize() { 1542 // We don't use the GOT in all of these cases, but it's essentially free 1543 // to put them all here. 1544 size_t Result = 0; 1545 switch (Arch) { 1546 case Triple::x86_64: 1547 case Triple::aarch64: 1548 case Triple::aarch64_be: 1549 case Triple::ppc64: 1550 case Triple::ppc64le: 1551 case Triple::systemz: 1552 Result = sizeof(uint64_t); 1553 break; 1554 case Triple::x86: 1555 case Triple::arm: 1556 case Triple::thumb: 1557 Result = sizeof(uint32_t); 1558 break; 1559 case Triple::mips: 1560 case Triple::mipsel: 1561 case Triple::mips64: 1562 case Triple::mips64el: 1563 if (IsMipsO32ABI || IsMipsN32ABI) 1564 Result = sizeof(uint32_t); 1565 else if (IsMipsN64ABI) 1566 Result = sizeof(uint64_t); 1567 else 1568 llvm_unreachable("Mips ABI not handled"); 1569 break; 1570 default: 1571 llvm_unreachable("Unsupported CPU type!"); 1572 } 1573 return Result; 1574 } 1575 1576 uint64_t RuntimeDyldELF::allocateGOTEntries(unsigned SectionID, unsigned no) 1577 { 1578 (void)SectionID; // The GOT Section is the same for all section in the object file 1579 if (GOTSectionID == 0) { 1580 GOTSectionID = Sections.size(); 1581 // Reserve a section id. We'll allocate the section later 1582 // once we know the total size 1583 Sections.push_back(SectionEntry(".got", nullptr, 0, 0, 0)); 1584 } 1585 uint64_t StartOffset = CurrentGOTIndex * getGOTEntrySize(); 1586 CurrentGOTIndex += no; 1587 return StartOffset; 1588 } 1589 1590 void RuntimeDyldELF::resolveGOTOffsetRelocation(unsigned SectionID, uint64_t Offset, uint64_t GOTOffset) 1591 { 1592 // Fill in the relative address of the GOT Entry into the stub 1593 RelocationEntry GOTRE(SectionID, Offset, ELF::R_X86_64_PC32, GOTOffset); 1594 addRelocationForSection(GOTRE, GOTSectionID); 1595 } 1596 1597 RelocationEntry RuntimeDyldELF::computeGOTOffsetRE(unsigned SectionID, uint64_t GOTOffset, uint64_t SymbolOffset, 1598 uint32_t Type) 1599 { 1600 (void)SectionID; // The GOT Section is the same for all section in the object file 1601 return RelocationEntry(GOTSectionID, GOTOffset, Type, SymbolOffset); 1602 } 1603 1604 Error RuntimeDyldELF::finalizeLoad(const ObjectFile &Obj, 1605 ObjSectionToIDMap &SectionMap) { 1606 if (IsMipsO32ABI) 1607 if (!PendingRelocs.empty()) 1608 return make_error<RuntimeDyldError>("Can't find matching LO16 reloc"); 1609 1610 // If necessary, allocate the global offset table 1611 if (GOTSectionID != 0) { 1612 // Allocate memory for the section 1613 size_t TotalSize = CurrentGOTIndex * getGOTEntrySize(); 1614 uint8_t *Addr = MemMgr.allocateDataSection(TotalSize, getGOTEntrySize(), 1615 GOTSectionID, ".got", false); 1616 if (!Addr) 1617 return make_error<RuntimeDyldError>("Unable to allocate memory for GOT!"); 1618 1619 Sections[GOTSectionID] = 1620 SectionEntry(".got", Addr, TotalSize, TotalSize, 0); 1621 1622 if (Checker) 1623 Checker->registerSection(Obj.getFileName(), GOTSectionID); 1624 1625 // For now, initialize all GOT entries to zero. We'll fill them in as 1626 // needed when GOT-based relocations are applied. 1627 memset(Addr, 0, TotalSize); 1628 if (IsMipsN32ABI || IsMipsN64ABI) { 1629 // To correctly resolve Mips GOT relocations, we need a mapping from 1630 // object's sections to GOTs. 1631 for (section_iterator SI = Obj.section_begin(), SE = Obj.section_end(); 1632 SI != SE; ++SI) { 1633 if (SI->relocation_begin() != SI->relocation_end()) { 1634 section_iterator RelocatedSection = SI->getRelocatedSection(); 1635 ObjSectionToIDMap::iterator i = SectionMap.find(*RelocatedSection); 1636 assert (i != SectionMap.end()); 1637 SectionToGOTMap[i->second] = GOTSectionID; 1638 } 1639 } 1640 GOTSymbolOffsets.clear(); 1641 } 1642 } 1643 1644 // Look for and record the EH frame section. 1645 ObjSectionToIDMap::iterator i, e; 1646 for (i = SectionMap.begin(), e = SectionMap.end(); i != e; ++i) { 1647 const SectionRef &Section = i->first; 1648 StringRef Name; 1649 Section.getName(Name); 1650 if (Name == ".eh_frame") { 1651 UnregisteredEHFrameSections.push_back(i->second); 1652 break; 1653 } 1654 } 1655 1656 GOTSectionID = 0; 1657 CurrentGOTIndex = 0; 1658 1659 return Error::success(); 1660 } 1661 1662 bool RuntimeDyldELF::isCompatibleFile(const object::ObjectFile &Obj) const { 1663 return Obj.isELF(); 1664 } 1665 1666 bool RuntimeDyldELF::relocationNeedsStub(const RelocationRef &R) const { 1667 if (Arch != Triple::x86_64) 1668 return true; // Conservative answer 1669 1670 switch (R.getType()) { 1671 default: 1672 return true; // Conservative answer 1673 1674 1675 case ELF::R_X86_64_GOTPCREL: 1676 case ELF::R_X86_64_GOTPCRELX: 1677 case ELF::R_X86_64_REX_GOTPCRELX: 1678 case ELF::R_X86_64_PC32: 1679 case ELF::R_X86_64_PC64: 1680 case ELF::R_X86_64_64: 1681 // We know that these reloation types won't need a stub function. This list 1682 // can be extended as needed. 1683 return false; 1684 } 1685 } 1686 1687 } // namespace llvm 1688