1 //===---- MachO_arm64.cpp - JIT linker implementation for MachO/arm64 -----===// 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/arm64 jit-link implementation. 10 // 11 //===----------------------------------------------------------------------===// 12 13 #include "llvm/ExecutionEngine/JITLink/MachO_arm64.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_arm64_Edges; 23 24 namespace { 25 26 class MachOLinkGraphBuilder_arm64 : public MachOLinkGraphBuilder { 27 public: 28 MachOLinkGraphBuilder_arm64(const object::MachOObjectFile &Obj) 29 : MachOLinkGraphBuilder(Obj), 30 NumSymbols(Obj.getSymtabLoadCommand().nsyms) { 31 addCustomSectionParser( 32 "__eh_frame", [this](NormalizedSection &EHFrameSection) { 33 if (!EHFrameSection.Data) 34 return make_error<JITLinkError>( 35 "__eh_frame section is marked zero-fill"); 36 return MachOEHFrameBinaryParser( 37 *this, EHFrameSection.Address, 38 StringRef(EHFrameSection.Data, EHFrameSection.Size), 39 *EHFrameSection.GraphSection, 8, 4, NegDelta32, Delta64) 40 .addToGraph(); 41 }); 42 } 43 44 private: 45 static Expected<MachOARM64RelocationKind> 46 getRelocationKind(const MachO::relocation_info &RI) { 47 switch (RI.r_type) { 48 case MachO::ARM64_RELOC_UNSIGNED: 49 if (!RI.r_pcrel) { 50 if (RI.r_length == 3) 51 return RI.r_extern ? Pointer64 : Pointer64Anon; 52 else if (RI.r_length == 2) 53 return Pointer32; 54 } 55 break; 56 case MachO::ARM64_RELOC_SUBTRACTOR: 57 // SUBTRACTOR must be non-pc-rel, extern, with length 2 or 3. 58 // Initially represent SUBTRACTOR relocations with 'Delta<W>'. 59 // They may be turned into NegDelta<W> by parsePairRelocation. 60 if (!RI.r_pcrel && RI.r_extern) { 61 if (RI.r_length == 2) 62 return Delta32; 63 else if (RI.r_length == 3) 64 return Delta64; 65 } 66 break; 67 case MachO::ARM64_RELOC_BRANCH26: 68 if (RI.r_pcrel && RI.r_extern && RI.r_length == 2) 69 return Branch26; 70 break; 71 case MachO::ARM64_RELOC_PAGE21: 72 if (RI.r_pcrel && RI.r_extern && RI.r_length == 2) 73 return Page21; 74 break; 75 case MachO::ARM64_RELOC_PAGEOFF12: 76 if (!RI.r_pcrel && RI.r_extern && RI.r_length == 2) 77 return PageOffset12; 78 break; 79 case MachO::ARM64_RELOC_GOT_LOAD_PAGE21: 80 if (RI.r_pcrel && RI.r_extern && RI.r_length == 2) 81 return GOTPage21; 82 break; 83 case MachO::ARM64_RELOC_GOT_LOAD_PAGEOFF12: 84 if (!RI.r_pcrel && RI.r_extern && RI.r_length == 2) 85 return GOTPageOffset12; 86 break; 87 case MachO::ARM64_RELOC_POINTER_TO_GOT: 88 if (RI.r_pcrel && RI.r_extern && RI.r_length == 2) 89 return PointerToGOT; 90 break; 91 case MachO::ARM64_RELOC_ADDEND: 92 if (!RI.r_pcrel && !RI.r_extern && RI.r_length == 2) 93 return PairedAddend; 94 break; 95 } 96 97 return make_error<JITLinkError>( 98 "Unsupported arm64 relocation: address=" + 99 formatv("{0:x8}", RI.r_address) + 100 ", symbolnum=" + formatv("{0:x6}", RI.r_symbolnum) + 101 ", kind=" + formatv("{0:x1}", RI.r_type) + 102 ", pc_rel=" + (RI.r_pcrel ? "true" : "false") + 103 ", extern=" + (RI.r_extern ? "true" : "false") + 104 ", length=" + formatv("{0:d}", RI.r_length)); 105 } 106 107 MachO::relocation_info 108 getRelocationInfo(const object::relocation_iterator RelItr) { 109 MachO::any_relocation_info ARI = 110 getObject().getRelocation(RelItr->getRawDataRefImpl()); 111 MachO::relocation_info RI; 112 memcpy(&RI, &ARI, sizeof(MachO::relocation_info)); 113 return RI; 114 } 115 116 using PairRelocInfo = 117 std::tuple<MachOARM64RelocationKind, Symbol *, uint64_t>; 118 119 // Parses paired SUBTRACTOR/UNSIGNED relocations and, on success, 120 // returns the edge kind and addend to be used. 121 Expected<PairRelocInfo> 122 parsePairRelocation(Block &BlockToFix, Edge::Kind SubtractorKind, 123 const MachO::relocation_info &SubRI, 124 JITTargetAddress FixupAddress, const char *FixupContent, 125 object::relocation_iterator &UnsignedRelItr, 126 object::relocation_iterator &RelEnd) { 127 using namespace support; 128 129 assert(((SubtractorKind == Delta32 && SubRI.r_length == 2) || 130 (SubtractorKind == Delta64 && SubRI.r_length == 3)) && 131 "Subtractor kind should match length"); 132 assert(SubRI.r_extern && "SUBTRACTOR reloc symbol should be extern"); 133 assert(!SubRI.r_pcrel && "SUBTRACTOR reloc should not be PCRel"); 134 135 if (UnsignedRelItr == RelEnd) 136 return make_error<JITLinkError>("arm64 SUBTRACTOR without paired " 137 "UNSIGNED relocation"); 138 139 auto UnsignedRI = getRelocationInfo(UnsignedRelItr); 140 141 if (SubRI.r_address != UnsignedRI.r_address) 142 return make_error<JITLinkError>("arm64 SUBTRACTOR and paired UNSIGNED " 143 "point to different addresses"); 144 145 if (SubRI.r_length != UnsignedRI.r_length) 146 return make_error<JITLinkError>("length of arm64 SUBTRACTOR and paired " 147 "UNSIGNED reloc must match"); 148 149 Symbol *FromSymbol; 150 if (auto FromSymbolOrErr = findSymbolByIndex(SubRI.r_symbolnum)) 151 FromSymbol = FromSymbolOrErr->GraphSymbol; 152 else 153 return FromSymbolOrErr.takeError(); 154 155 // Read the current fixup value. 156 uint64_t FixupValue = 0; 157 if (SubRI.r_length == 3) 158 FixupValue = *(const little64_t *)FixupContent; 159 else 160 FixupValue = *(const little32_t *)FixupContent; 161 162 // Find 'ToSymbol' using symbol number or address, depending on whether the 163 // paired UNSIGNED relocation is extern. 164 Symbol *ToSymbol = nullptr; 165 if (UnsignedRI.r_extern) { 166 // Find target symbol by symbol index. 167 if (auto ToSymbolOrErr = findSymbolByIndex(UnsignedRI.r_symbolnum)) 168 ToSymbol = ToSymbolOrErr->GraphSymbol; 169 else 170 return ToSymbolOrErr.takeError(); 171 } else { 172 if (auto ToSymbolOrErr = findSymbolByAddress(FixupValue)) 173 ToSymbol = &*ToSymbolOrErr; 174 else 175 return ToSymbolOrErr.takeError(); 176 FixupValue -= ToSymbol->getAddress(); 177 } 178 179 MachOARM64RelocationKind DeltaKind; 180 Symbol *TargetSymbol; 181 uint64_t Addend; 182 if (&BlockToFix == &FromSymbol->getAddressable()) { 183 TargetSymbol = ToSymbol; 184 DeltaKind = (SubRI.r_length == 3) ? Delta64 : Delta32; 185 Addend = FixupValue + (FixupAddress - FromSymbol->getAddress()); 186 // FIXME: handle extern 'from'. 187 } else if (&BlockToFix == &ToSymbol->getAddressable()) { 188 TargetSymbol = &*FromSymbol; 189 DeltaKind = (SubRI.r_length == 3) ? NegDelta64 : NegDelta32; 190 Addend = FixupValue - (FixupAddress - ToSymbol->getAddress()); 191 } else { 192 // BlockToFix was neither FromSymbol nor ToSymbol. 193 return make_error<JITLinkError>("SUBTRACTOR relocation must fix up " 194 "either 'A' or 'B' (or a symbol in one " 195 "of their alt-entry groups)"); 196 } 197 198 return PairRelocInfo(DeltaKind, TargetSymbol, Addend); 199 } 200 201 Error addRelocations() override { 202 using namespace support; 203 auto &Obj = getObject(); 204 205 for (auto &S : Obj.sections()) { 206 207 JITTargetAddress SectionAddress = S.getAddress(); 208 209 for (auto RelItr = S.relocation_begin(), RelEnd = S.relocation_end(); 210 RelItr != RelEnd; ++RelItr) { 211 212 MachO::relocation_info RI = getRelocationInfo(RelItr); 213 214 // Sanity check the relocation kind. 215 auto Kind = getRelocationKind(RI); 216 if (!Kind) 217 return Kind.takeError(); 218 219 // Find the address of the value to fix up. 220 JITTargetAddress FixupAddress = SectionAddress + (uint32_t)RI.r_address; 221 222 LLVM_DEBUG({ 223 dbgs() << "Processing " << getMachOARM64RelocationKindName(*Kind) 224 << " relocation at " << format("0x%016" PRIx64, FixupAddress) 225 << "\n"; 226 }); 227 228 // Find the block that the fixup points to. 229 Block *BlockToFix = nullptr; 230 { 231 auto SymbolToFixOrErr = findSymbolByAddress(FixupAddress); 232 if (!SymbolToFixOrErr) 233 return SymbolToFixOrErr.takeError(); 234 BlockToFix = &SymbolToFixOrErr->getBlock(); 235 } 236 237 if (FixupAddress + static_cast<JITTargetAddress>(1ULL << RI.r_length) > 238 BlockToFix->getAddress() + BlockToFix->getContent().size()) 239 return make_error<JITLinkError>( 240 "Relocation content extends past end of fixup block"); 241 242 // Get a pointer to the fixup content. 243 const char *FixupContent = BlockToFix->getContent().data() + 244 (FixupAddress - BlockToFix->getAddress()); 245 246 // The target symbol and addend will be populated by the switch below. 247 Symbol *TargetSymbol = nullptr; 248 uint64_t Addend = 0; 249 250 if (*Kind == PairedAddend) { 251 // If this is an Addend relocation then process it and move to the 252 // paired reloc. 253 254 Addend = RI.r_symbolnum; 255 256 if (RelItr == RelEnd) 257 return make_error<JITLinkError>("Unpaired Addend reloc at " + 258 formatv("{0:x16}", FixupAddress)); 259 ++RelItr; 260 RI = getRelocationInfo(RelItr); 261 262 Kind = getRelocationKind(RI); 263 if (!Kind) 264 return Kind.takeError(); 265 266 if (*Kind != Branch26 && *Kind != Page21 && *Kind != PageOffset12) 267 return make_error<JITLinkError>( 268 "Invalid relocation pair: Addend + " + 269 getMachOARM64RelocationKindName(*Kind)); 270 else 271 LLVM_DEBUG({ 272 dbgs() << " pair is " << getMachOARM64RelocationKindName(*Kind) 273 << "`\n"; 274 }); 275 276 // Find the address of the value to fix up. 277 JITTargetAddress PairedFixupAddress = 278 SectionAddress + (uint32_t)RI.r_address; 279 if (PairedFixupAddress != FixupAddress) 280 return make_error<JITLinkError>("Paired relocation points at " 281 "different target"); 282 } 283 284 switch (*Kind) { 285 case Branch26: { 286 if (auto TargetSymbolOrErr = findSymbolByIndex(RI.r_symbolnum)) 287 TargetSymbol = TargetSymbolOrErr->GraphSymbol; 288 else 289 return TargetSymbolOrErr.takeError(); 290 uint32_t Instr = *(const ulittle32_t *)FixupContent; 291 if ((Instr & 0x7fffffff) != 0x14000000) 292 return make_error<JITLinkError>("BRANCH26 target is not a B or BL " 293 "instruction with a zero addend"); 294 break; 295 } 296 case Pointer32: 297 if (auto TargetSymbolOrErr = findSymbolByIndex(RI.r_symbolnum)) 298 TargetSymbol = TargetSymbolOrErr->GraphSymbol; 299 else 300 return TargetSymbolOrErr.takeError(); 301 Addend = *(const ulittle32_t *)FixupContent; 302 break; 303 case Pointer64: 304 if (auto TargetSymbolOrErr = findSymbolByIndex(RI.r_symbolnum)) 305 TargetSymbol = TargetSymbolOrErr->GraphSymbol; 306 else 307 return TargetSymbolOrErr.takeError(); 308 Addend = *(const ulittle64_t *)FixupContent; 309 break; 310 case Pointer64Anon: { 311 JITTargetAddress TargetAddress = *(const ulittle64_t *)FixupContent; 312 if (auto TargetSymbolOrErr = findSymbolByAddress(TargetAddress)) 313 TargetSymbol = &*TargetSymbolOrErr; 314 else 315 return TargetSymbolOrErr.takeError(); 316 Addend = TargetAddress - TargetSymbol->getAddress(); 317 break; 318 } 319 case Page21: 320 case GOTPage21: { 321 if (auto TargetSymbolOrErr = findSymbolByIndex(RI.r_symbolnum)) 322 TargetSymbol = TargetSymbolOrErr->GraphSymbol; 323 else 324 return TargetSymbolOrErr.takeError(); 325 uint32_t Instr = *(const ulittle32_t *)FixupContent; 326 if ((Instr & 0xffffffe0) != 0x90000000) 327 return make_error<JITLinkError>("PAGE21/GOTPAGE21 target is not an " 328 "ADRP instruction with a zero " 329 "addend"); 330 break; 331 } 332 case PageOffset12: { 333 if (auto TargetSymbolOrErr = findSymbolByIndex(RI.r_symbolnum)) 334 TargetSymbol = TargetSymbolOrErr->GraphSymbol; 335 else 336 return TargetSymbolOrErr.takeError(); 337 break; 338 } 339 case GOTPageOffset12: { 340 if (auto TargetSymbolOrErr = findSymbolByIndex(RI.r_symbolnum)) 341 TargetSymbol = TargetSymbolOrErr->GraphSymbol; 342 else 343 return TargetSymbolOrErr.takeError(); 344 uint32_t Instr = *(const ulittle32_t *)FixupContent; 345 if ((Instr & 0xfffffc00) != 0xf9400000) 346 return make_error<JITLinkError>("GOTPAGEOFF12 target is not an LDR " 347 "immediate instruction with a zero " 348 "addend"); 349 break; 350 } 351 case PointerToGOT: 352 if (auto TargetSymbolOrErr = findSymbolByIndex(RI.r_symbolnum)) 353 TargetSymbol = TargetSymbolOrErr->GraphSymbol; 354 else 355 return TargetSymbolOrErr.takeError(); 356 break; 357 case Delta32: 358 case Delta64: { 359 // We use Delta32/Delta64 to represent SUBTRACTOR relocations. 360 // parsePairRelocation handles the paired reloc, and returns the 361 // edge kind to be used (either Delta32/Delta64, or 362 // NegDelta32/NegDelta64, depending on the direction of the 363 // subtraction) along with the addend. 364 auto PairInfo = 365 parsePairRelocation(*BlockToFix, *Kind, RI, FixupAddress, 366 FixupContent, ++RelItr, RelEnd); 367 if (!PairInfo) 368 return PairInfo.takeError(); 369 std::tie(*Kind, TargetSymbol, Addend) = *PairInfo; 370 assert(TargetSymbol && "No target symbol from parsePairRelocation?"); 371 break; 372 } 373 default: 374 llvm_unreachable("Special relocation kind should not appear in " 375 "mach-o file"); 376 } 377 378 LLVM_DEBUG({ 379 Edge GE(*Kind, FixupAddress - BlockToFix->getAddress(), *TargetSymbol, 380 Addend); 381 printEdge(dbgs(), *BlockToFix, GE, 382 getMachOARM64RelocationKindName(*Kind)); 383 dbgs() << "\n"; 384 }); 385 BlockToFix->addEdge(*Kind, FixupAddress - BlockToFix->getAddress(), 386 *TargetSymbol, Addend); 387 } 388 } 389 return Error::success(); 390 } 391 392 unsigned NumSymbols = 0; 393 }; 394 395 class MachO_arm64_GOTAndStubsBuilder 396 : public BasicGOTAndStubsBuilder<MachO_arm64_GOTAndStubsBuilder> { 397 public: 398 MachO_arm64_GOTAndStubsBuilder(LinkGraph &G) 399 : BasicGOTAndStubsBuilder<MachO_arm64_GOTAndStubsBuilder>(G) {} 400 401 bool isGOTEdge(Edge &E) const { 402 return E.getKind() == GOTPage21 || E.getKind() == GOTPageOffset12 || 403 E.getKind() == PointerToGOT; 404 } 405 406 Symbol &createGOTEntry(Symbol &Target) { 407 auto &GOTEntryBlock = G.createContentBlock( 408 getGOTSection(), getGOTEntryBlockContent(), 0, 8, 0); 409 GOTEntryBlock.addEdge(Pointer64, 0, Target, 0); 410 return G.addAnonymousSymbol(GOTEntryBlock, 0, 8, false, false); 411 } 412 413 void fixGOTEdge(Edge &E, Symbol &GOTEntry) { 414 if (E.getKind() == GOTPage21 || E.getKind() == GOTPageOffset12) { 415 // Update the target, but leave the edge addend as-is. 416 E.setTarget(GOTEntry); 417 } else if (E.getKind() == PointerToGOT) { 418 E.setTarget(GOTEntry); 419 E.setKind(Delta32); 420 } else 421 llvm_unreachable("Not a GOT edge?"); 422 } 423 424 bool isExternalBranchEdge(Edge &E) { 425 return E.getKind() == Branch26 && !E.getTarget().isDefined(); 426 } 427 428 Symbol &createStub(Symbol &Target) { 429 auto &StubContentBlock = 430 G.createContentBlock(getStubsSection(), getStubBlockContent(), 0, 1, 0); 431 // Re-use GOT entries for stub targets. 432 auto &GOTEntrySymbol = getGOTEntrySymbol(Target); 433 StubContentBlock.addEdge(LDRLiteral19, 0, GOTEntrySymbol, 0); 434 return G.addAnonymousSymbol(StubContentBlock, 0, 8, true, false); 435 } 436 437 void fixExternalBranchEdge(Edge &E, Symbol &Stub) { 438 assert(E.getKind() == Branch26 && "Not a Branch32 edge?"); 439 assert(E.getAddend() == 0 && "Branch32 edge has non-zero addend?"); 440 E.setTarget(Stub); 441 } 442 443 private: 444 Section &getGOTSection() { 445 if (!GOTSection) 446 GOTSection = &G.createSection("$__GOT", sys::Memory::MF_READ); 447 return *GOTSection; 448 } 449 450 Section &getStubsSection() { 451 if (!StubsSection) { 452 auto StubsProt = static_cast<sys::Memory::ProtectionFlags>( 453 sys::Memory::MF_READ | sys::Memory::MF_EXEC); 454 StubsSection = &G.createSection("$__STUBS", StubsProt); 455 } 456 return *StubsSection; 457 } 458 459 StringRef getGOTEntryBlockContent() { 460 return StringRef(reinterpret_cast<const char *>(NullGOTEntryContent), 461 sizeof(NullGOTEntryContent)); 462 } 463 464 StringRef getStubBlockContent() { 465 return StringRef(reinterpret_cast<const char *>(StubContent), 466 sizeof(StubContent)); 467 } 468 469 static const uint8_t NullGOTEntryContent[8]; 470 static const uint8_t StubContent[8]; 471 Section *GOTSection = nullptr; 472 Section *StubsSection = nullptr; 473 }; 474 475 const uint8_t MachO_arm64_GOTAndStubsBuilder::NullGOTEntryContent[8] = { 476 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00}; 477 const uint8_t MachO_arm64_GOTAndStubsBuilder::StubContent[8] = { 478 0x10, 0x00, 0x00, 0x58, // LDR x16, <literal> 479 0x00, 0x02, 0x1f, 0xd6 // BR x16 480 }; 481 482 } // namespace 483 484 namespace llvm { 485 namespace jitlink { 486 487 class MachOJITLinker_arm64 : public JITLinker<MachOJITLinker_arm64> { 488 friend class JITLinker<MachOJITLinker_arm64>; 489 490 public: 491 MachOJITLinker_arm64(std::unique_ptr<JITLinkContext> Ctx, 492 PassConfiguration PassConfig) 493 : JITLinker(std::move(Ctx), std::move(PassConfig)) {} 494 495 private: 496 StringRef getEdgeKindName(Edge::Kind R) const override { 497 return getMachOARM64RelocationKindName(R); 498 } 499 500 Expected<std::unique_ptr<LinkGraph>> 501 buildGraph(MemoryBufferRef ObjBuffer) override { 502 auto MachOObj = object::ObjectFile::createMachOObjectFile(ObjBuffer); 503 if (!MachOObj) 504 return MachOObj.takeError(); 505 return MachOLinkGraphBuilder_arm64(**MachOObj).buildGraph(); 506 } 507 508 static Error targetOutOfRangeError(const Block &B, const Edge &E) { 509 std::string ErrMsg; 510 { 511 raw_string_ostream ErrStream(ErrMsg); 512 ErrStream << "Relocation target out of range: "; 513 printEdge(ErrStream, B, E, getMachOARM64RelocationKindName(E.getKind())); 514 ErrStream << "\n"; 515 } 516 return make_error<JITLinkError>(std::move(ErrMsg)); 517 } 518 519 static unsigned getPageOffset12Shift(uint32_t Instr) { 520 constexpr uint32_t LDRLiteralMask = 0x3ffffc00; 521 522 // Check for a GPR LDR immediate with a zero embedded literal. 523 // If found, the top two bits contain the shift. 524 if ((Instr & LDRLiteralMask) == 0x39400000) 525 return Instr >> 30; 526 527 // Check for a Neon LDR immediate of size 64-bit or less with a zero 528 // embedded literal. If found, the top two bits contain the shift. 529 if ((Instr & LDRLiteralMask) == 0x3d400000) 530 return Instr >> 30; 531 532 // Check for a Neon LDR immediate of size 128-bit with a zero embedded 533 // literal. 534 constexpr uint32_t SizeBitsMask = 0xc0000000; 535 if ((Instr & (LDRLiteralMask | SizeBitsMask)) == 0x3dc00000) 536 return 4; 537 538 return 0; 539 } 540 541 Error applyFixup(Block &B, const Edge &E, char *BlockWorkingMem) const { 542 using namespace support; 543 544 char *FixupPtr = BlockWorkingMem + E.getOffset(); 545 JITTargetAddress FixupAddress = B.getAddress() + E.getOffset(); 546 547 switch (E.getKind()) { 548 case Branch26: { 549 assert((FixupAddress & 0x3) == 0 && "Branch-inst is not 32-bit aligned"); 550 551 int64_t Value = E.getTarget().getAddress() - FixupAddress + E.getAddend(); 552 553 if (static_cast<uint64_t>(Value) & 0x3) 554 return make_error<JITLinkError>("Branch26 target is not 32-bit " 555 "aligned"); 556 557 if (Value < -(1 << 27) || Value > ((1 << 27) - 1)) 558 return targetOutOfRangeError(B, E); 559 560 uint32_t RawInstr = *(little32_t *)FixupPtr; 561 assert((RawInstr & 0x7fffffff) == 0x14000000 && 562 "RawInstr isn't a B or BR immediate instruction"); 563 uint32_t Imm = (static_cast<uint32_t>(Value) & ((1 << 28) - 1)) >> 2; 564 uint32_t FixedInstr = RawInstr | Imm; 565 *(little32_t *)FixupPtr = FixedInstr; 566 break; 567 } 568 case Pointer32: { 569 uint64_t Value = E.getTarget().getAddress() + E.getAddend(); 570 if (Value > std::numeric_limits<uint32_t>::max()) 571 return targetOutOfRangeError(B, E); 572 *(ulittle32_t *)FixupPtr = Value; 573 break; 574 } 575 case Pointer64: { 576 uint64_t Value = E.getTarget().getAddress() + E.getAddend(); 577 *(ulittle64_t *)FixupPtr = Value; 578 break; 579 } 580 case Page21: 581 case GOTPage21: { 582 assert(E.getAddend() == 0 && "PAGE21/GOTPAGE21 with non-zero addend"); 583 uint64_t TargetPage = 584 E.getTarget().getAddress() & ~static_cast<uint64_t>(4096 - 1); 585 uint64_t PCPage = B.getAddress() & ~static_cast<uint64_t>(4096 - 1); 586 587 int64_t PageDelta = TargetPage - PCPage; 588 if (PageDelta < -(1 << 30) || PageDelta > ((1 << 30) - 1)) 589 return targetOutOfRangeError(B, E); 590 591 uint32_t RawInstr = *(ulittle32_t *)FixupPtr; 592 assert((RawInstr & 0xffffffe0) == 0x90000000 && 593 "RawInstr isn't an ADRP instruction"); 594 uint32_t ImmLo = (static_cast<uint64_t>(PageDelta) >> 12) & 0x3; 595 uint32_t ImmHi = (static_cast<uint64_t>(PageDelta) >> 14) & 0x7ffff; 596 uint32_t FixedInstr = RawInstr | (ImmLo << 29) | (ImmHi << 5); 597 *(ulittle32_t *)FixupPtr = FixedInstr; 598 break; 599 } 600 case PageOffset12: { 601 assert(E.getAddend() == 0 && "PAGEOFF12 with non-zero addend"); 602 uint64_t TargetOffset = E.getTarget().getAddress() & 0xfff; 603 604 uint32_t RawInstr = *(ulittle32_t *)FixupPtr; 605 unsigned ImmShift = getPageOffset12Shift(RawInstr); 606 607 if (TargetOffset & ((1 << ImmShift) - 1)) 608 return make_error<JITLinkError>("PAGEOFF12 target is not aligned"); 609 610 uint32_t EncodedImm = (TargetOffset >> ImmShift) << 10; 611 uint32_t FixedInstr = RawInstr | EncodedImm; 612 *(ulittle32_t *)FixupPtr = FixedInstr; 613 break; 614 } 615 case GOTPageOffset12: { 616 assert(E.getAddend() == 0 && "GOTPAGEOF12 with non-zero addend"); 617 618 uint32_t RawInstr = *(ulittle32_t *)FixupPtr; 619 assert((RawInstr & 0xfffffc00) == 0xf9400000 && 620 "RawInstr isn't a 64-bit LDR immediate"); 621 622 uint32_t TargetOffset = E.getTarget().getAddress() & 0xfff; 623 assert((TargetOffset & 0x7) == 0 && "GOT entry is not 8-byte aligned"); 624 uint32_t EncodedImm = (TargetOffset >> 3) << 10; 625 uint32_t FixedInstr = RawInstr | EncodedImm; 626 *(ulittle32_t *)FixupPtr = FixedInstr; 627 break; 628 } 629 case LDRLiteral19: { 630 assert((FixupAddress & 0x3) == 0 && "LDR is not 32-bit aligned"); 631 assert(E.getAddend() == 0 && "LDRLiteral19 with non-zero addend"); 632 uint32_t RawInstr = *(ulittle32_t *)FixupPtr; 633 assert(RawInstr == 0x58000010 && "RawInstr isn't a 64-bit LDR literal"); 634 int64_t Delta = E.getTarget().getAddress() - FixupAddress; 635 if (Delta & 0x3) 636 return make_error<JITLinkError>("LDR literal target is not 32-bit " 637 "aligned"); 638 if (Delta < -(1 << 20) || Delta > ((1 << 20) - 1)) 639 return targetOutOfRangeError(B, E); 640 641 uint32_t EncodedImm = (static_cast<uint32_t>(Delta) >> 2) << 5; 642 uint32_t FixedInstr = RawInstr | EncodedImm; 643 *(ulittle32_t *)FixupPtr = FixedInstr; 644 break; 645 } 646 case Delta32: 647 case Delta64: 648 case NegDelta32: 649 case NegDelta64: { 650 int64_t Value; 651 if (E.getKind() == Delta32 || E.getKind() == Delta64) 652 Value = E.getTarget().getAddress() - FixupAddress + E.getAddend(); 653 else 654 Value = FixupAddress - E.getTarget().getAddress() + E.getAddend(); 655 656 if (E.getKind() == Delta32 || E.getKind() == NegDelta32) { 657 if (Value < std::numeric_limits<int32_t>::min() || 658 Value > std::numeric_limits<int32_t>::max()) 659 return targetOutOfRangeError(B, E); 660 *(little32_t *)FixupPtr = Value; 661 } else 662 *(little64_t *)FixupPtr = Value; 663 break; 664 } 665 default: 666 llvm_unreachable("Unrecognized edge kind"); 667 } 668 669 return Error::success(); 670 } 671 672 uint64_t NullValue = 0; 673 }; 674 675 void jitLink_MachO_arm64(std::unique_ptr<JITLinkContext> Ctx) { 676 PassConfiguration Config; 677 Triple TT("arm64-apple-ios"); 678 679 if (Ctx->shouldAddDefaultTargetPasses(TT)) { 680 // Add a mark-live pass. 681 if (auto MarkLive = Ctx->getMarkLivePass(TT)) 682 Config.PrePrunePasses.push_back(std::move(MarkLive)); 683 else 684 Config.PrePrunePasses.push_back(markAllSymbolsLive); 685 686 // Add an in-place GOT/Stubs pass. 687 Config.PostPrunePasses.push_back([](LinkGraph &G) -> Error { 688 MachO_arm64_GOTAndStubsBuilder(G).run(); 689 return Error::success(); 690 }); 691 } 692 693 if (auto Err = Ctx->modifyPassConfig(TT, Config)) 694 return Ctx->notifyFailed(std::move(Err)); 695 696 // Construct a JITLinker and run the link function. 697 MachOJITLinker_arm64::link(std::move(Ctx), std::move(Config)); 698 } 699 700 StringRef getMachOARM64RelocationKindName(Edge::Kind R) { 701 switch (R) { 702 case Branch26: 703 return "Branch26"; 704 case Pointer64: 705 return "Pointer64"; 706 case Pointer64Anon: 707 return "Pointer64Anon"; 708 case Page21: 709 return "Page21"; 710 case PageOffset12: 711 return "PageOffset12"; 712 case GOTPage21: 713 return "GOTPage21"; 714 case GOTPageOffset12: 715 return "GOTPageOffset12"; 716 case PointerToGOT: 717 return "PointerToGOT"; 718 case PairedAddend: 719 return "PairedAddend"; 720 case LDRLiteral19: 721 return "LDRLiteral19"; 722 case Delta32: 723 return "Delta32"; 724 case Delta64: 725 return "Delta64"; 726 case NegDelta32: 727 return "NegDelta32"; 728 case NegDelta64: 729 return "NegDelta64"; 730 default: 731 return getGenericEdgeKindName(static_cast<Edge::Kind>(R)); 732 } 733 } 734 735 } // end namespace jitlink 736 } // end namespace llvm 737