1 //===---- MachO_x86_64.cpp -JIT linker implementation for MachO/x86-64 ----===// 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 // MachO/x86-64 jit-link implementation. 10 // 11 //===----------------------------------------------------------------------===// 12 13 #include "llvm/ExecutionEngine/JITLink/MachO_x86_64.h" 14 15 #include "BasicGOTAndStubsBuilder.h" 16 #include "MachOLinkGraphBuilder.h" 17 18 #define DEBUG_TYPE "jitlink" 19 20 using namespace llvm; 21 using namespace llvm::jitlink; 22 using namespace llvm::jitlink::MachO_x86_64_Edges; 23 24 namespace { 25 26 class MachOLinkGraphBuilder_x86_64 : public MachOLinkGraphBuilder { 27 public: 28 MachOLinkGraphBuilder_x86_64(const object::MachOObjectFile &Obj) 29 : MachOLinkGraphBuilder(Obj) {} 30 31 private: 32 static Expected<MachOX86RelocationKind> 33 getRelocationKind(const MachO::relocation_info &RI) { 34 switch (RI.r_type) { 35 case MachO::X86_64_RELOC_UNSIGNED: 36 if (!RI.r_pcrel) { 37 if (RI.r_length == 3) 38 return RI.r_extern ? Pointer64 : Pointer64Anon; 39 else if (RI.r_extern && RI.r_length == 2) 40 return Pointer32; 41 } 42 break; 43 case MachO::X86_64_RELOC_SIGNED: 44 if (RI.r_pcrel && RI.r_length == 2) 45 return RI.r_extern ? PCRel32 : PCRel32Anon; 46 break; 47 case MachO::X86_64_RELOC_BRANCH: 48 if (RI.r_pcrel && RI.r_extern && RI.r_length == 2) 49 return Branch32; 50 break; 51 case MachO::X86_64_RELOC_GOT_LOAD: 52 if (RI.r_pcrel && RI.r_extern && RI.r_length == 2) 53 return PCRel32GOTLoad; 54 break; 55 case MachO::X86_64_RELOC_GOT: 56 if (RI.r_pcrel && RI.r_extern && RI.r_length == 2) 57 return PCRel32GOT; 58 break; 59 case MachO::X86_64_RELOC_SUBTRACTOR: 60 // SUBTRACTOR must be non-pc-rel, extern, with length 2 or 3. 61 // Initially represent SUBTRACTOR relocations with 'Delta<W>'. They may 62 // be turned into NegDelta<W> by parsePairRelocation. 63 if (!RI.r_pcrel && RI.r_extern) { 64 if (RI.r_length == 2) 65 return Delta32; 66 else if (RI.r_length == 3) 67 return Delta64; 68 } 69 break; 70 case MachO::X86_64_RELOC_SIGNED_1: 71 if (RI.r_pcrel && RI.r_length == 2) 72 return RI.r_extern ? PCRel32Minus1 : PCRel32Minus1Anon; 73 break; 74 case MachO::X86_64_RELOC_SIGNED_2: 75 if (RI.r_pcrel && RI.r_length == 2) 76 return RI.r_extern ? PCRel32Minus2 : PCRel32Minus2Anon; 77 break; 78 case MachO::X86_64_RELOC_SIGNED_4: 79 if (RI.r_pcrel && RI.r_length == 2) 80 return RI.r_extern ? PCRel32Minus4 : PCRel32Minus4Anon; 81 break; 82 case MachO::X86_64_RELOC_TLV: 83 if (RI.r_pcrel && RI.r_extern && RI.r_length == 2) 84 return PCRel32TLV; 85 break; 86 } 87 88 return make_error<JITLinkError>( 89 "Unsupported x86-64 relocation: address=" + 90 formatv("{0:x8}", RI.r_address) + 91 ", symbolnum=" + formatv("{0:x6}", RI.r_symbolnum) + 92 ", kind=" + formatv("{0:x1}", RI.r_type) + 93 ", pc_rel=" + (RI.r_pcrel ? "true" : "false") + 94 ", extern=" + (RI.r_extern ? "true" : "false") + 95 ", length=" + formatv("{0:d}", RI.r_length)); 96 } 97 98 using PairRelocInfo = std::tuple<MachOX86RelocationKind, Symbol *, uint64_t>; 99 100 // Parses paired SUBTRACTOR/UNSIGNED relocations and, on success, 101 // returns the edge kind and addend to be used. 102 Expected<PairRelocInfo> 103 parsePairRelocation(Block &BlockToFix, Edge::Kind SubtractorKind, 104 const MachO::relocation_info &SubRI, 105 JITTargetAddress FixupAddress, const char *FixupContent, 106 object::relocation_iterator &UnsignedRelItr, 107 object::relocation_iterator &RelEnd) { 108 using namespace support; 109 110 assert(((SubtractorKind == Delta32 && SubRI.r_length == 2) || 111 (SubtractorKind == Delta64 && SubRI.r_length == 3)) && 112 "Subtractor kind should match length"); 113 assert(SubRI.r_extern && "SUBTRACTOR reloc symbol should be extern"); 114 assert(!SubRI.r_pcrel && "SUBTRACTOR reloc should not be PCRel"); 115 116 if (UnsignedRelItr == RelEnd) 117 return make_error<JITLinkError>("x86_64 SUBTRACTOR without paired " 118 "UNSIGNED relocation"); 119 120 auto UnsignedRI = getRelocationInfo(UnsignedRelItr); 121 122 if (SubRI.r_address != UnsignedRI.r_address) 123 return make_error<JITLinkError>("x86_64 SUBTRACTOR and paired UNSIGNED " 124 "point to different addresses"); 125 126 if (SubRI.r_length != UnsignedRI.r_length) 127 return make_error<JITLinkError>("length of x86_64 SUBTRACTOR and paired " 128 "UNSIGNED reloc must match"); 129 130 Symbol *FromSymbol; 131 if (auto FromSymbolOrErr = findSymbolByIndex(SubRI.r_symbolnum)) 132 FromSymbol = FromSymbolOrErr->GraphSymbol; 133 else 134 return FromSymbolOrErr.takeError(); 135 136 // Read the current fixup value. 137 uint64_t FixupValue = 0; 138 if (SubRI.r_length == 3) 139 FixupValue = *(const little64_t *)FixupContent; 140 else 141 FixupValue = *(const little32_t *)FixupContent; 142 143 // Find 'ToSymbol' using symbol number or address, depending on whether the 144 // paired UNSIGNED relocation is extern. 145 Symbol *ToSymbol = nullptr; 146 if (UnsignedRI.r_extern) { 147 // Find target symbol by symbol index. 148 if (auto ToSymbolOrErr = findSymbolByIndex(UnsignedRI.r_symbolnum)) 149 ToSymbol = ToSymbolOrErr->GraphSymbol; 150 else 151 return ToSymbolOrErr.takeError(); 152 } else { 153 if (auto ToSymbolOrErr = findSymbolByAddress(FixupValue)) 154 ToSymbol = &*ToSymbolOrErr; 155 else 156 return ToSymbolOrErr.takeError(); 157 FixupValue -= ToSymbol->getAddress(); 158 } 159 160 MachOX86RelocationKind DeltaKind; 161 Symbol *TargetSymbol; 162 uint64_t Addend; 163 if (&BlockToFix == &FromSymbol->getAddressable()) { 164 TargetSymbol = ToSymbol; 165 DeltaKind = (SubRI.r_length == 3) ? Delta64 : Delta32; 166 Addend = FixupValue + (FixupAddress - FromSymbol->getAddress()); 167 // FIXME: handle extern 'from'. 168 } else if (&BlockToFix == &ToSymbol->getAddressable()) { 169 TargetSymbol = FromSymbol; 170 DeltaKind = (SubRI.r_length == 3) ? NegDelta64 : NegDelta32; 171 Addend = FixupValue - (FixupAddress - ToSymbol->getAddress()); 172 } else { 173 // BlockToFix was neither FromSymbol nor ToSymbol. 174 return make_error<JITLinkError>("SUBTRACTOR relocation must fix up " 175 "either 'A' or 'B' (or a symbol in one " 176 "of their alt-entry chains)"); 177 } 178 179 return PairRelocInfo(DeltaKind, TargetSymbol, Addend); 180 } 181 182 Error addRelocations() override { 183 using namespace support; 184 auto &Obj = getObject(); 185 186 for (auto &S : Obj.sections()) { 187 188 JITTargetAddress SectionAddress = S.getAddress(); 189 190 if (S.isVirtual()) { 191 if (S.relocation_begin() != S.relocation_end()) 192 return make_error<JITLinkError>("Virtual section contains " 193 "relocations"); 194 continue; 195 } 196 197 for (auto RelItr = S.relocation_begin(), RelEnd = S.relocation_end(); 198 RelItr != RelEnd; ++RelItr) { 199 200 MachO::relocation_info RI = getRelocationInfo(RelItr); 201 202 // Sanity check the relocation kind. 203 auto Kind = getRelocationKind(RI); 204 if (!Kind) 205 return Kind.takeError(); 206 207 // Find the address of the value to fix up. 208 JITTargetAddress FixupAddress = SectionAddress + (uint32_t)RI.r_address; 209 210 LLVM_DEBUG({ 211 dbgs() << "Processing relocation at " 212 << format("0x%016" PRIx64, FixupAddress) << "\n"; 213 }); 214 215 // Find the block that the fixup points to. 216 Block *BlockToFix = nullptr; 217 { 218 auto SymbolToFixOrErr = findSymbolByAddress(FixupAddress); 219 if (!SymbolToFixOrErr) 220 return SymbolToFixOrErr.takeError(); 221 BlockToFix = &SymbolToFixOrErr->getBlock(); 222 } 223 224 if (FixupAddress + static_cast<JITTargetAddress>(1ULL << RI.r_length) > 225 BlockToFix->getAddress() + BlockToFix->getContent().size()) 226 return make_error<JITLinkError>( 227 "Relocation extends past end of fixup block"); 228 229 // Get a pointer to the fixup content. 230 const char *FixupContent = BlockToFix->getContent().data() + 231 (FixupAddress - BlockToFix->getAddress()); 232 233 // The target symbol and addend will be populated by the switch below. 234 Symbol *TargetSymbol = nullptr; 235 uint64_t Addend = 0; 236 237 switch (*Kind) { 238 case Branch32: 239 case PCRel32: 240 case PCRel32GOTLoad: 241 case PCRel32GOT: 242 if (auto TargetSymbolOrErr = findSymbolByIndex(RI.r_symbolnum)) 243 TargetSymbol = TargetSymbolOrErr->GraphSymbol; 244 else 245 return TargetSymbolOrErr.takeError(); 246 Addend = *(const little32_t *)FixupContent; 247 break; 248 case Pointer32: 249 if (auto TargetSymbolOrErr = findSymbolByIndex(RI.r_symbolnum)) 250 TargetSymbol = TargetSymbolOrErr->GraphSymbol; 251 else 252 return TargetSymbolOrErr.takeError(); 253 Addend = *(const ulittle32_t *)FixupContent; 254 break; 255 case Pointer64: 256 if (auto TargetSymbolOrErr = findSymbolByIndex(RI.r_symbolnum)) 257 TargetSymbol = TargetSymbolOrErr->GraphSymbol; 258 else 259 return TargetSymbolOrErr.takeError(); 260 Addend = *(const ulittle64_t *)FixupContent; 261 break; 262 case Pointer64Anon: { 263 JITTargetAddress TargetAddress = *(const ulittle64_t *)FixupContent; 264 if (auto TargetSymbolOrErr = findSymbolByAddress(TargetAddress)) 265 TargetSymbol = &*TargetSymbolOrErr; 266 else 267 return TargetSymbolOrErr.takeError(); 268 Addend = TargetAddress - TargetSymbol->getAddress(); 269 break; 270 } 271 case PCRel32Minus1: 272 case PCRel32Minus2: 273 case PCRel32Minus4: 274 if (auto TargetSymbolOrErr = findSymbolByIndex(RI.r_symbolnum)) 275 TargetSymbol = TargetSymbolOrErr->GraphSymbol; 276 else 277 return TargetSymbolOrErr.takeError(); 278 Addend = *(const little32_t *)FixupContent + 279 (1 << (*Kind - PCRel32Minus1)); 280 break; 281 case PCRel32Anon: { 282 JITTargetAddress TargetAddress = 283 FixupAddress + 4 + *(const little32_t *)FixupContent; 284 if (auto TargetSymbolOrErr = findSymbolByAddress(TargetAddress)) 285 TargetSymbol = &*TargetSymbolOrErr; 286 else 287 return TargetSymbolOrErr.takeError(); 288 Addend = TargetAddress - TargetSymbol->getAddress(); 289 break; 290 } 291 case PCRel32Minus1Anon: 292 case PCRel32Minus2Anon: 293 case PCRel32Minus4Anon: { 294 JITTargetAddress Delta = 295 static_cast<JITTargetAddress>(1ULL << (*Kind - PCRel32Minus1Anon)); 296 JITTargetAddress TargetAddress = 297 FixupAddress + 4 + Delta + *(const little32_t *)FixupContent; 298 if (auto TargetSymbolOrErr = findSymbolByAddress(TargetAddress)) 299 TargetSymbol = &*TargetSymbolOrErr; 300 else 301 return TargetSymbolOrErr.takeError(); 302 Addend = TargetAddress - TargetSymbol->getAddress(); 303 break; 304 } 305 case Delta32: 306 case Delta64: { 307 // We use Delta32/Delta64 to represent SUBTRACTOR relocations. 308 // parsePairRelocation handles the paired reloc, and returns the 309 // edge kind to be used (either Delta32/Delta64, or 310 // NegDelta32/NegDelta64, depending on the direction of the 311 // subtraction) along with the addend. 312 auto PairInfo = 313 parsePairRelocation(*BlockToFix, *Kind, RI, FixupAddress, 314 FixupContent, ++RelItr, RelEnd); 315 if (!PairInfo) 316 return PairInfo.takeError(); 317 std::tie(*Kind, TargetSymbol, Addend) = *PairInfo; 318 assert(TargetSymbol && "No target symbol from parsePairRelocation?"); 319 break; 320 } 321 default: 322 llvm_unreachable("Special relocation kind should not appear in " 323 "mach-o file"); 324 } 325 326 LLVM_DEBUG({ 327 Edge GE(*Kind, FixupAddress - BlockToFix->getAddress(), *TargetSymbol, 328 Addend); 329 printEdge(dbgs(), *BlockToFix, GE, 330 getMachOX86RelocationKindName(*Kind)); 331 dbgs() << "\n"; 332 }); 333 BlockToFix->addEdge(*Kind, FixupAddress - BlockToFix->getAddress(), 334 *TargetSymbol, Addend); 335 } 336 } 337 return Error::success(); 338 } 339 }; 340 341 class MachO_x86_64_GOTAndStubsBuilder 342 : public BasicGOTAndStubsBuilder<MachO_x86_64_GOTAndStubsBuilder> { 343 public: 344 static const uint8_t NullGOTEntryContent[8]; 345 static const uint8_t StubContent[6]; 346 347 MachO_x86_64_GOTAndStubsBuilder(LinkGraph &G) 348 : BasicGOTAndStubsBuilder<MachO_x86_64_GOTAndStubsBuilder>(G) {} 349 350 bool isGOTEdge(Edge &E) const { 351 return E.getKind() == PCRel32GOT || E.getKind() == PCRel32GOTLoad; 352 } 353 354 Symbol &createGOTEntry(Symbol &Target) { 355 auto &GOTEntryBlock = G.createContentBlock( 356 getGOTSection(), getGOTEntryBlockContent(), 0, 8, 0); 357 GOTEntryBlock.addEdge(Pointer64, 0, Target, 0); 358 return G.addAnonymousSymbol(GOTEntryBlock, 0, 8, false, false); 359 } 360 361 void fixGOTEdge(Edge &E, Symbol &GOTEntry) { 362 assert((E.getKind() == PCRel32GOT || E.getKind() == PCRel32GOTLoad) && 363 "Not a GOT edge?"); 364 // If this is a PCRel32GOT then change it to an ordinary PCRel32. If it is 365 // a PCRel32GOTLoad then leave it as-is for now. We will use the kind to 366 // check for GOT optimization opportunities in the 367 // optimizeMachO_x86_64_GOTAndStubs pass below. 368 if (E.getKind() == PCRel32GOT) 369 E.setKind(PCRel32); 370 371 E.setTarget(GOTEntry); 372 // Leave the edge addend as-is. 373 } 374 375 bool isExternalBranchEdge(Edge &E) { 376 return E.getKind() == Branch32 && !E.getTarget().isDefined(); 377 } 378 379 Symbol &createStub(Symbol &Target) { 380 auto &StubContentBlock = 381 G.createContentBlock(getStubsSection(), getStubBlockContent(), 0, 1, 0); 382 // Re-use GOT entries for stub targets. 383 auto &GOTEntrySymbol = getGOTEntrySymbol(Target); 384 StubContentBlock.addEdge(PCRel32, 2, GOTEntrySymbol, 0); 385 return G.addAnonymousSymbol(StubContentBlock, 0, 6, true, false); 386 } 387 388 void fixExternalBranchEdge(Edge &E, Symbol &Stub) { 389 assert(E.getKind() == Branch32 && "Not a Branch32 edge?"); 390 assert(E.getAddend() == 0 && "Branch32 edge has non-zero addend?"); 391 392 // Set the edge kind to Branch32ToStub. We will use this to check for stub 393 // optimization opportunities in the optimizeMachO_x86_64_GOTAndStubs pass 394 // below. 395 E.setKind(Branch32ToStub); 396 E.setTarget(Stub); 397 } 398 399 private: 400 Section &getGOTSection() { 401 if (!GOTSection) 402 GOTSection = &G.createSection("$__GOT", sys::Memory::MF_READ); 403 return *GOTSection; 404 } 405 406 Section &getStubsSection() { 407 if (!StubsSection) { 408 auto StubsProt = static_cast<sys::Memory::ProtectionFlags>( 409 sys::Memory::MF_READ | sys::Memory::MF_EXEC); 410 StubsSection = &G.createSection("$__STUBS", StubsProt); 411 } 412 return *StubsSection; 413 } 414 415 StringRef getGOTEntryBlockContent() { 416 return StringRef(reinterpret_cast<const char *>(NullGOTEntryContent), 417 sizeof(NullGOTEntryContent)); 418 } 419 420 StringRef getStubBlockContent() { 421 return StringRef(reinterpret_cast<const char *>(StubContent), 422 sizeof(StubContent)); 423 } 424 425 Section *GOTSection = nullptr; 426 Section *StubsSection = nullptr; 427 }; 428 429 const uint8_t MachO_x86_64_GOTAndStubsBuilder::NullGOTEntryContent[8] = { 430 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00}; 431 const uint8_t MachO_x86_64_GOTAndStubsBuilder::StubContent[6] = { 432 0xFF, 0x25, 0x00, 0x00, 0x00, 0x00}; 433 } // namespace 434 435 static Error optimizeMachO_x86_64_GOTAndStubs(LinkGraph &G) { 436 LLVM_DEBUG(dbgs() << "Optimizing GOT entries and stubs:\n"); 437 438 for (auto *B : G.blocks()) 439 for (auto &E : B->edges()) 440 if (E.getKind() == PCRel32GOTLoad) { 441 assert(E.getOffset() >= 3 && "GOT edge occurs too early in block"); 442 443 // Switch the edge kind to PCRel32: Whether we change the edge target 444 // or not this will be the desired kind. 445 E.setKind(PCRel32); 446 447 // Optimize GOT references. 448 auto &GOTBlock = E.getTarget().getBlock(); 449 assert(GOTBlock.getSize() == G.getPointerSize() && 450 "GOT entry block should be pointer sized"); 451 assert(GOTBlock.edges_size() == 1 && 452 "GOT entry should only have one outgoing edge"); 453 454 auto &GOTTarget = GOTBlock.edges().begin()->getTarget(); 455 JITTargetAddress EdgeAddr = B->getAddress() + E.getOffset(); 456 JITTargetAddress TargetAddr = GOTTarget.getAddress(); 457 458 // Check that this is a recognized MOV instruction. 459 // FIXME: Can we assume this? 460 constexpr uint8_t MOVQRIPRel[] = {0x48, 0x8b}; 461 if (strncmp(B->getContent().data() + E.getOffset() - 3, 462 reinterpret_cast<const char *>(MOVQRIPRel), 2) != 0) 463 continue; 464 465 int64_t Displacement = TargetAddr - EdgeAddr + 4; 466 if (Displacement >= std::numeric_limits<int32_t>::min() && 467 Displacement <= std::numeric_limits<int32_t>::max()) { 468 E.setTarget(GOTTarget); 469 auto *BlockData = reinterpret_cast<uint8_t *>( 470 const_cast<char *>(B->getContent().data())); 471 BlockData[E.getOffset() - 2] = 0x8d; 472 LLVM_DEBUG({ 473 dbgs() << " Replaced GOT load wih LEA:\n "; 474 printEdge(dbgs(), *B, E, 475 getMachOX86RelocationKindName(E.getKind())); 476 dbgs() << "\n"; 477 }); 478 } 479 } else if (E.getKind() == Branch32ToStub) { 480 481 // Switch the edge kind to PCRel32: Whether we change the edge target 482 // or not this will be the desired kind. 483 E.setKind(Branch32); 484 485 auto &StubBlock = E.getTarget().getBlock(); 486 assert(StubBlock.getSize() == 487 sizeof(MachO_x86_64_GOTAndStubsBuilder::StubContent) && 488 "Stub block should be stub sized"); 489 assert(StubBlock.edges_size() == 1 && 490 "Stub block should only have one outgoing edge"); 491 492 auto &GOTBlock = StubBlock.edges().begin()->getTarget().getBlock(); 493 assert(GOTBlock.getSize() == G.getPointerSize() && 494 "GOT block should be pointer sized"); 495 assert(GOTBlock.edges_size() == 1 && 496 "GOT block should only have one outgoing edge"); 497 498 auto &GOTTarget = GOTBlock.edges().begin()->getTarget(); 499 JITTargetAddress EdgeAddr = B->getAddress() + E.getOffset(); 500 JITTargetAddress TargetAddr = GOTTarget.getAddress(); 501 502 int64_t Displacement = TargetAddr - EdgeAddr + 4; 503 if (Displacement >= std::numeric_limits<int32_t>::min() && 504 Displacement <= std::numeric_limits<int32_t>::max()) { 505 E.setTarget(GOTTarget); 506 LLVM_DEBUG({ 507 dbgs() << " Replaced stub branch with direct branch:\n "; 508 printEdge(dbgs(), *B, E, 509 getMachOX86RelocationKindName(E.getKind())); 510 dbgs() << "\n"; 511 }); 512 } 513 } 514 515 return Error::success(); 516 } 517 518 namespace llvm { 519 namespace jitlink { 520 521 class MachOJITLinker_x86_64 : public JITLinker<MachOJITLinker_x86_64> { 522 friend class JITLinker<MachOJITLinker_x86_64>; 523 524 public: 525 MachOJITLinker_x86_64(std::unique_ptr<JITLinkContext> Ctx, 526 PassConfiguration PassConfig) 527 : JITLinker(std::move(Ctx), std::move(PassConfig)) {} 528 529 private: 530 StringRef getEdgeKindName(Edge::Kind R) const override { 531 return getMachOX86RelocationKindName(R); 532 } 533 534 Expected<std::unique_ptr<LinkGraph>> 535 buildGraph(MemoryBufferRef ObjBuffer) override { 536 auto MachOObj = object::ObjectFile::createMachOObjectFile(ObjBuffer); 537 if (!MachOObj) 538 return MachOObj.takeError(); 539 return MachOLinkGraphBuilder_x86_64(**MachOObj).buildGraph(); 540 } 541 542 static Error targetOutOfRangeError(const Block &B, const Edge &E) { 543 std::string ErrMsg; 544 { 545 raw_string_ostream ErrStream(ErrMsg); 546 ErrStream << "Relocation target out of range: "; 547 printEdge(ErrStream, B, E, getMachOX86RelocationKindName(E.getKind())); 548 ErrStream << "\n"; 549 } 550 return make_error<JITLinkError>(std::move(ErrMsg)); 551 } 552 553 Error applyFixup(Block &B, const Edge &E, char *BlockWorkingMem) const { 554 555 using namespace support; 556 557 char *FixupPtr = BlockWorkingMem + E.getOffset(); 558 JITTargetAddress FixupAddress = B.getAddress() + E.getOffset(); 559 560 switch (E.getKind()) { 561 case Branch32: 562 case PCRel32: 563 case PCRel32Anon: { 564 int64_t Value = 565 E.getTarget().getAddress() - (FixupAddress + 4) + E.getAddend(); 566 if (Value < std::numeric_limits<int32_t>::min() || 567 Value > std::numeric_limits<int32_t>::max()) 568 return targetOutOfRangeError(B, E); 569 *(little32_t *)FixupPtr = Value; 570 break; 571 } 572 case Pointer64: 573 case Pointer64Anon: { 574 uint64_t Value = E.getTarget().getAddress() + E.getAddend(); 575 *(ulittle64_t *)FixupPtr = Value; 576 break; 577 } 578 case PCRel32Minus1: 579 case PCRel32Minus2: 580 case PCRel32Minus4: { 581 int Delta = 4 + (1 << (E.getKind() - PCRel32Minus1)); 582 int64_t Value = 583 E.getTarget().getAddress() - (FixupAddress + Delta) + E.getAddend(); 584 if (Value < std::numeric_limits<int32_t>::min() || 585 Value > std::numeric_limits<int32_t>::max()) 586 return targetOutOfRangeError(B, E); 587 *(little32_t *)FixupPtr = Value; 588 break; 589 } 590 case PCRel32Minus1Anon: 591 case PCRel32Minus2Anon: 592 case PCRel32Minus4Anon: { 593 int Delta = 4 + (1 << (E.getKind() - PCRel32Minus1Anon)); 594 int64_t Value = 595 E.getTarget().getAddress() - (FixupAddress + Delta) + E.getAddend(); 596 if (Value < std::numeric_limits<int32_t>::min() || 597 Value > std::numeric_limits<int32_t>::max()) 598 return targetOutOfRangeError(B, E); 599 *(little32_t *)FixupPtr = Value; 600 break; 601 } 602 case Delta32: 603 case Delta64: 604 case NegDelta32: 605 case NegDelta64: { 606 int64_t Value; 607 if (E.getKind() == Delta32 || E.getKind() == Delta64) 608 Value = E.getTarget().getAddress() - FixupAddress + E.getAddend(); 609 else 610 Value = FixupAddress - E.getTarget().getAddress() + E.getAddend(); 611 612 if (E.getKind() == Delta32 || E.getKind() == NegDelta32) { 613 if (Value < std::numeric_limits<int32_t>::min() || 614 Value > std::numeric_limits<int32_t>::max()) 615 return targetOutOfRangeError(B, E); 616 *(little32_t *)FixupPtr = Value; 617 } else 618 *(little64_t *)FixupPtr = Value; 619 break; 620 } 621 case Pointer32: { 622 uint64_t Value = E.getTarget().getAddress() + E.getAddend(); 623 if (Value > std::numeric_limits<uint32_t>::max()) 624 return targetOutOfRangeError(B, E); 625 *(ulittle32_t *)FixupPtr = Value; 626 break; 627 } 628 default: 629 llvm_unreachable("Unrecognized edge kind"); 630 } 631 632 return Error::success(); 633 } 634 635 uint64_t NullValue = 0; 636 }; 637 638 void jitLink_MachO_x86_64(std::unique_ptr<JITLinkContext> Ctx) { 639 PassConfiguration Config; 640 Triple TT("x86_64-apple-macosx"); 641 642 if (Ctx->shouldAddDefaultTargetPasses(TT)) { 643 // Add eh-frame passses. 644 Config.PrePrunePasses.push_back(EHFrameSplitter("__eh_frame")); 645 Config.PrePrunePasses.push_back( 646 EHFrameEdgeFixer("__eh_frame", NegDelta32, Delta64, Delta64)); 647 648 // Add a mark-live pass. 649 if (auto MarkLive = Ctx->getMarkLivePass(TT)) 650 Config.PrePrunePasses.push_back(std::move(MarkLive)); 651 else 652 Config.PrePrunePasses.push_back(markAllSymbolsLive); 653 654 // Add an in-place GOT/Stubs pass. 655 Config.PostPrunePasses.push_back([](LinkGraph &G) -> Error { 656 MachO_x86_64_GOTAndStubsBuilder(G).run(); 657 return Error::success(); 658 }); 659 660 // Add GOT/Stubs optimizer pass. 661 Config.PostAllocationPasses.push_back(optimizeMachO_x86_64_GOTAndStubs); 662 } 663 664 if (auto Err = Ctx->modifyPassConfig(TT, Config)) 665 return Ctx->notifyFailed(std::move(Err)); 666 667 // Construct a JITLinker and run the link function. 668 MachOJITLinker_x86_64::link(std::move(Ctx), std::move(Config)); 669 } 670 671 StringRef getMachOX86RelocationKindName(Edge::Kind R) { 672 switch (R) { 673 case Branch32: 674 return "Branch32"; 675 case Branch32ToStub: 676 return "Branch32ToStub"; 677 case Pointer32: 678 return "Pointer32"; 679 case Pointer64: 680 return "Pointer64"; 681 case Pointer64Anon: 682 return "Pointer64Anon"; 683 case PCRel32: 684 return "PCRel32"; 685 case PCRel32Minus1: 686 return "PCRel32Minus1"; 687 case PCRel32Minus2: 688 return "PCRel32Minus2"; 689 case PCRel32Minus4: 690 return "PCRel32Minus4"; 691 case PCRel32Anon: 692 return "PCRel32Anon"; 693 case PCRel32Minus1Anon: 694 return "PCRel32Minus1Anon"; 695 case PCRel32Minus2Anon: 696 return "PCRel32Minus2Anon"; 697 case PCRel32Minus4Anon: 698 return "PCRel32Minus4Anon"; 699 case PCRel32GOTLoad: 700 return "PCRel32GOTLoad"; 701 case PCRel32GOT: 702 return "PCRel32GOT"; 703 case PCRel32TLV: 704 return "PCRel32TLV"; 705 case Delta32: 706 return "Delta32"; 707 case Delta64: 708 return "Delta64"; 709 case NegDelta32: 710 return "NegDelta32"; 711 case NegDelta64: 712 return "NegDelta64"; 713 default: 714 return getGenericEdgeKindName(static_cast<Edge::Kind>(R)); 715 } 716 } 717 718 } // end namespace jitlink 719 } // end namespace llvm 720