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 32 private: 33 static Expected<MachOARM64RelocationKind> 34 getRelocationKind(const MachO::relocation_info &RI) { 35 switch (RI.r_type) { 36 case MachO::ARM64_RELOC_UNSIGNED: 37 if (!RI.r_pcrel) { 38 if (RI.r_length == 3) 39 return RI.r_extern ? Pointer64 : Pointer64Anon; 40 else if (RI.r_length == 2) 41 return Pointer32; 42 } 43 break; 44 case MachO::ARM64_RELOC_SUBTRACTOR: 45 // SUBTRACTOR must be non-pc-rel, extern, with length 2 or 3. 46 // Initially represent SUBTRACTOR relocations with 'Delta<W>'. 47 // They may be turned into NegDelta<W> by parsePairRelocation. 48 if (!RI.r_pcrel && RI.r_extern) { 49 if (RI.r_length == 2) 50 return Delta32; 51 else if (RI.r_length == 3) 52 return Delta64; 53 } 54 break; 55 case MachO::ARM64_RELOC_BRANCH26: 56 if (RI.r_pcrel && RI.r_extern && RI.r_length == 2) 57 return Branch26; 58 break; 59 case MachO::ARM64_RELOC_PAGE21: 60 if (RI.r_pcrel && RI.r_extern && RI.r_length == 2) 61 return Page21; 62 break; 63 case MachO::ARM64_RELOC_PAGEOFF12: 64 if (!RI.r_pcrel && RI.r_extern && RI.r_length == 2) 65 return PageOffset12; 66 break; 67 case MachO::ARM64_RELOC_GOT_LOAD_PAGE21: 68 if (RI.r_pcrel && RI.r_extern && RI.r_length == 2) 69 return GOTPage21; 70 break; 71 case MachO::ARM64_RELOC_GOT_LOAD_PAGEOFF12: 72 if (!RI.r_pcrel && RI.r_extern && RI.r_length == 2) 73 return GOTPageOffset12; 74 break; 75 case MachO::ARM64_RELOC_POINTER_TO_GOT: 76 if (RI.r_pcrel && RI.r_extern && RI.r_length == 2) 77 return PointerToGOT; 78 break; 79 case MachO::ARM64_RELOC_ADDEND: 80 if (!RI.r_pcrel && !RI.r_extern && RI.r_length == 2) 81 return PairedAddend; 82 break; 83 } 84 85 return make_error<JITLinkError>( 86 "Unsupported arm64 relocation: address=" + 87 formatv("{0:x8}", RI.r_address) + 88 ", symbolnum=" + formatv("{0:x6}", RI.r_symbolnum) + 89 ", kind=" + formatv("{0:x1}", RI.r_type) + 90 ", pc_rel=" + (RI.r_pcrel ? "true" : "false") + 91 ", extern=" + (RI.r_extern ? "true" : "false") + 92 ", length=" + formatv("{0:d}", RI.r_length)); 93 } 94 95 using PairRelocInfo = 96 std::tuple<MachOARM64RelocationKind, Symbol *, uint64_t>; 97 98 // Parses paired SUBTRACTOR/UNSIGNED relocations and, on success, 99 // returns the edge kind and addend to be used. 100 Expected<PairRelocInfo> 101 parsePairRelocation(Block &BlockToFix, Edge::Kind SubtractorKind, 102 const MachO::relocation_info &SubRI, 103 JITTargetAddress FixupAddress, const char *FixupContent, 104 object::relocation_iterator &UnsignedRelItr, 105 object::relocation_iterator &RelEnd) { 106 using namespace support; 107 108 assert(((SubtractorKind == Delta32 && SubRI.r_length == 2) || 109 (SubtractorKind == Delta64 && SubRI.r_length == 3)) && 110 "Subtractor kind should match length"); 111 assert(SubRI.r_extern && "SUBTRACTOR reloc symbol should be extern"); 112 assert(!SubRI.r_pcrel && "SUBTRACTOR reloc should not be PCRel"); 113 114 if (UnsignedRelItr == RelEnd) 115 return make_error<JITLinkError>("arm64 SUBTRACTOR without paired " 116 "UNSIGNED relocation"); 117 118 auto UnsignedRI = getRelocationInfo(UnsignedRelItr); 119 120 if (SubRI.r_address != UnsignedRI.r_address) 121 return make_error<JITLinkError>("arm64 SUBTRACTOR and paired UNSIGNED " 122 "point to different addresses"); 123 124 if (SubRI.r_length != UnsignedRI.r_length) 125 return make_error<JITLinkError>("length of arm64 SUBTRACTOR and paired " 126 "UNSIGNED reloc must match"); 127 128 Symbol *FromSymbol; 129 if (auto FromSymbolOrErr = findSymbolByIndex(SubRI.r_symbolnum)) 130 FromSymbol = FromSymbolOrErr->GraphSymbol; 131 else 132 return FromSymbolOrErr.takeError(); 133 134 // Read the current fixup value. 135 uint64_t FixupValue = 0; 136 if (SubRI.r_length == 3) 137 FixupValue = *(const little64_t *)FixupContent; 138 else 139 FixupValue = *(const little32_t *)FixupContent; 140 141 // Find 'ToSymbol' using symbol number or address, depending on whether the 142 // paired UNSIGNED relocation is extern. 143 Symbol *ToSymbol = nullptr; 144 if (UnsignedRI.r_extern) { 145 // Find target symbol by symbol index. 146 if (auto ToSymbolOrErr = findSymbolByIndex(UnsignedRI.r_symbolnum)) 147 ToSymbol = ToSymbolOrErr->GraphSymbol; 148 else 149 return ToSymbolOrErr.takeError(); 150 } else { 151 if (auto ToSymbolOrErr = findSymbolByAddress(FixupValue)) 152 ToSymbol = &*ToSymbolOrErr; 153 else 154 return ToSymbolOrErr.takeError(); 155 FixupValue -= ToSymbol->getAddress(); 156 } 157 158 MachOARM64RelocationKind DeltaKind; 159 Symbol *TargetSymbol; 160 uint64_t Addend; 161 if (&BlockToFix == &FromSymbol->getAddressable()) { 162 TargetSymbol = ToSymbol; 163 DeltaKind = (SubRI.r_length == 3) ? Delta64 : Delta32; 164 Addend = FixupValue + (FixupAddress - FromSymbol->getAddress()); 165 // FIXME: handle extern 'from'. 166 } else if (&BlockToFix == &ToSymbol->getAddressable()) { 167 TargetSymbol = &*FromSymbol; 168 DeltaKind = (SubRI.r_length == 3) ? NegDelta64 : NegDelta32; 169 Addend = FixupValue - (FixupAddress - ToSymbol->getAddress()); 170 } else { 171 // BlockToFix was neither FromSymbol nor ToSymbol. 172 return make_error<JITLinkError>("SUBTRACTOR relocation must fix up " 173 "either 'A' or 'B' (or a symbol in one " 174 "of their alt-entry groups)"); 175 } 176 177 return PairRelocInfo(DeltaKind, TargetSymbol, Addend); 178 } 179 180 Error addRelocations() override { 181 using namespace support; 182 auto &Obj = getObject(); 183 184 for (auto &S : Obj.sections()) { 185 186 JITTargetAddress SectionAddress = S.getAddress(); 187 188 // Skip relocations virtual sections. 189 if (S.isVirtual()) { 190 if (S.relocation_begin() != S.relocation_end()) 191 return make_error<JITLinkError>("Virtual section contains " 192 "relocations"); 193 continue; 194 } 195 196 // Skip relocations for debug symbols. 197 { 198 auto &NSec = 199 getSectionByIndex(Obj.getSectionIndex(S.getRawDataRefImpl())); 200 if (!NSec.GraphSection) { 201 LLVM_DEBUG({ 202 dbgs() << "Skipping relocations for MachO section " << NSec.SegName 203 << "/" << NSec.SectName 204 << " which has no associated graph section\n"; 205 }); 206 continue; 207 } 208 } 209 210 for (auto RelItr = S.relocation_begin(), RelEnd = S.relocation_end(); 211 RelItr != RelEnd; ++RelItr) { 212 213 MachO::relocation_info RI = getRelocationInfo(RelItr); 214 215 // Sanity check the relocation kind. 216 auto Kind = getRelocationKind(RI); 217 if (!Kind) 218 return Kind.takeError(); 219 220 // Find the address of the value to fix up. 221 JITTargetAddress FixupAddress = SectionAddress + (uint32_t)RI.r_address; 222 223 LLVM_DEBUG({ 224 dbgs() << "Processing " << getMachOARM64RelocationKindName(*Kind) 225 << " relocation at " << format("0x%016" PRIx64, FixupAddress) 226 << "\n"; 227 }); 228 229 // Find the block that the fixup points to. 230 Block *BlockToFix = nullptr; 231 { 232 auto SymbolToFixOrErr = findSymbolByAddress(FixupAddress); 233 if (!SymbolToFixOrErr) 234 return SymbolToFixOrErr.takeError(); 235 BlockToFix = &SymbolToFixOrErr->getBlock(); 236 } 237 238 if (FixupAddress + static_cast<JITTargetAddress>(1ULL << RI.r_length) > 239 BlockToFix->getAddress() + BlockToFix->getContent().size()) 240 return make_error<JITLinkError>( 241 "Relocation content extends past end of fixup block"); 242 243 // Get a pointer to the fixup content. 244 const char *FixupContent = BlockToFix->getContent().data() + 245 (FixupAddress - BlockToFix->getAddress()); 246 247 // The target symbol and addend will be populated by the switch below. 248 Symbol *TargetSymbol = nullptr; 249 uint64_t Addend = 0; 250 251 if (*Kind == PairedAddend) { 252 // If this is an Addend relocation then process it and move to the 253 // paired reloc. 254 255 Addend = RI.r_symbolnum; 256 257 if (RelItr == RelEnd) 258 return make_error<JITLinkError>("Unpaired Addend reloc at " + 259 formatv("{0:x16}", FixupAddress)); 260 ++RelItr; 261 RI = getRelocationInfo(RelItr); 262 263 Kind = getRelocationKind(RI); 264 if (!Kind) 265 return Kind.takeError(); 266 267 if (*Kind != Branch26 && *Kind != Page21 && *Kind != PageOffset12) 268 return make_error<JITLinkError>( 269 "Invalid relocation pair: Addend + " + 270 getMachOARM64RelocationKindName(*Kind)); 271 else 272 LLVM_DEBUG({ 273 dbgs() << " pair is " << getMachOARM64RelocationKindName(*Kind) 274 << "`\n"; 275 }); 276 277 // Find the address of the value to fix up. 278 JITTargetAddress PairedFixupAddress = 279 SectionAddress + (uint32_t)RI.r_address; 280 if (PairedFixupAddress != FixupAddress) 281 return make_error<JITLinkError>("Paired relocation points at " 282 "different target"); 283 } 284 285 switch (*Kind) { 286 case Branch26: { 287 if (auto TargetSymbolOrErr = findSymbolByIndex(RI.r_symbolnum)) 288 TargetSymbol = TargetSymbolOrErr->GraphSymbol; 289 else 290 return TargetSymbolOrErr.takeError(); 291 uint32_t Instr = *(const ulittle32_t *)FixupContent; 292 if ((Instr & 0x7fffffff) != 0x14000000) 293 return make_error<JITLinkError>("BRANCH26 target is not a B or BL " 294 "instruction with a zero addend"); 295 break; 296 } 297 case Pointer32: 298 if (auto TargetSymbolOrErr = findSymbolByIndex(RI.r_symbolnum)) 299 TargetSymbol = TargetSymbolOrErr->GraphSymbol; 300 else 301 return TargetSymbolOrErr.takeError(); 302 Addend = *(const ulittle32_t *)FixupContent; 303 break; 304 case Pointer64: 305 if (auto TargetSymbolOrErr = findSymbolByIndex(RI.r_symbolnum)) 306 TargetSymbol = TargetSymbolOrErr->GraphSymbol; 307 else 308 return TargetSymbolOrErr.takeError(); 309 Addend = *(const ulittle64_t *)FixupContent; 310 break; 311 case Pointer64Anon: { 312 JITTargetAddress TargetAddress = *(const ulittle64_t *)FixupContent; 313 if (auto TargetSymbolOrErr = findSymbolByAddress(TargetAddress)) 314 TargetSymbol = &*TargetSymbolOrErr; 315 else 316 return TargetSymbolOrErr.takeError(); 317 Addend = TargetAddress - TargetSymbol->getAddress(); 318 break; 319 } 320 case Page21: 321 case GOTPage21: { 322 if (auto TargetSymbolOrErr = findSymbolByIndex(RI.r_symbolnum)) 323 TargetSymbol = TargetSymbolOrErr->GraphSymbol; 324 else 325 return TargetSymbolOrErr.takeError(); 326 uint32_t Instr = *(const ulittle32_t *)FixupContent; 327 if ((Instr & 0xffffffe0) != 0x90000000) 328 return make_error<JITLinkError>("PAGE21/GOTPAGE21 target is not an " 329 "ADRP instruction with a zero " 330 "addend"); 331 break; 332 } 333 case PageOffset12: { 334 if (auto TargetSymbolOrErr = findSymbolByIndex(RI.r_symbolnum)) 335 TargetSymbol = TargetSymbolOrErr->GraphSymbol; 336 else 337 return TargetSymbolOrErr.takeError(); 338 break; 339 } 340 case GOTPageOffset12: { 341 if (auto TargetSymbolOrErr = findSymbolByIndex(RI.r_symbolnum)) 342 TargetSymbol = TargetSymbolOrErr->GraphSymbol; 343 else 344 return TargetSymbolOrErr.takeError(); 345 uint32_t Instr = *(const ulittle32_t *)FixupContent; 346 if ((Instr & 0xfffffc00) != 0xf9400000) 347 return make_error<JITLinkError>("GOTPAGEOFF12 target is not an LDR " 348 "immediate instruction with a zero " 349 "addend"); 350 break; 351 } 352 case PointerToGOT: 353 if (auto TargetSymbolOrErr = findSymbolByIndex(RI.r_symbolnum)) 354 TargetSymbol = TargetSymbolOrErr->GraphSymbol; 355 else 356 return TargetSymbolOrErr.takeError(); 357 break; 358 case Delta32: 359 case Delta64: { 360 // We use Delta32/Delta64 to represent SUBTRACTOR relocations. 361 // parsePairRelocation handles the paired reloc, and returns the 362 // edge kind to be used (either Delta32/Delta64, or 363 // NegDelta32/NegDelta64, depending on the direction of the 364 // subtraction) along with the addend. 365 auto PairInfo = 366 parsePairRelocation(*BlockToFix, *Kind, RI, FixupAddress, 367 FixupContent, ++RelItr, RelEnd); 368 if (!PairInfo) 369 return PairInfo.takeError(); 370 std::tie(*Kind, TargetSymbol, Addend) = *PairInfo; 371 assert(TargetSymbol && "No target symbol from parsePairRelocation?"); 372 break; 373 } 374 default: 375 llvm_unreachable("Special relocation kind should not appear in " 376 "mach-o file"); 377 } 378 379 LLVM_DEBUG({ 380 Edge GE(*Kind, FixupAddress - BlockToFix->getAddress(), *TargetSymbol, 381 Addend); 382 printEdge(dbgs(), *BlockToFix, GE, 383 getMachOARM64RelocationKindName(*Kind)); 384 dbgs() << "\n"; 385 }); 386 BlockToFix->addEdge(*Kind, FixupAddress - BlockToFix->getAddress(), 387 *TargetSymbol, Addend); 388 } 389 } 390 return Error::success(); 391 } 392 393 unsigned NumSymbols = 0; 394 }; 395 396 class MachO_arm64_GOTAndStubsBuilder 397 : public BasicGOTAndStubsBuilder<MachO_arm64_GOTAndStubsBuilder> { 398 public: 399 MachO_arm64_GOTAndStubsBuilder(LinkGraph &G) 400 : BasicGOTAndStubsBuilder<MachO_arm64_GOTAndStubsBuilder>(G) {} 401 402 bool isGOTEdge(Edge &E) const { 403 return E.getKind() == GOTPage21 || E.getKind() == GOTPageOffset12 || 404 E.getKind() == PointerToGOT; 405 } 406 407 Symbol &createGOTEntry(Symbol &Target) { 408 auto &GOTEntryBlock = G.createContentBlock( 409 getGOTSection(), getGOTEntryBlockContent(), 0, 8, 0); 410 GOTEntryBlock.addEdge(Pointer64, 0, Target, 0); 411 return G.addAnonymousSymbol(GOTEntryBlock, 0, 8, false, false); 412 } 413 414 void fixGOTEdge(Edge &E, Symbol &GOTEntry) { 415 if (E.getKind() == GOTPage21 || E.getKind() == GOTPageOffset12) { 416 // Update the target, but leave the edge addend as-is. 417 E.setTarget(GOTEntry); 418 } else if (E.getKind() == PointerToGOT) { 419 E.setTarget(GOTEntry); 420 E.setKind(Delta32); 421 } else 422 llvm_unreachable("Not a GOT edge?"); 423 } 424 425 bool isExternalBranchEdge(Edge &E) { 426 return E.getKind() == Branch26 && !E.getTarget().isDefined(); 427 } 428 429 Symbol &createStub(Symbol &Target) { 430 auto &StubContentBlock = 431 G.createContentBlock(getStubsSection(), getStubBlockContent(), 0, 1, 0); 432 // Re-use GOT entries for stub targets. 433 auto &GOTEntrySymbol = getGOTEntrySymbol(Target); 434 StubContentBlock.addEdge(LDRLiteral19, 0, GOTEntrySymbol, 0); 435 return G.addAnonymousSymbol(StubContentBlock, 0, 8, true, false); 436 } 437 438 void fixExternalBranchEdge(Edge &E, Symbol &Stub) { 439 assert(E.getKind() == Branch26 && "Not a Branch32 edge?"); 440 assert(E.getAddend() == 0 && "Branch32 edge has non-zero addend?"); 441 E.setTarget(Stub); 442 } 443 444 private: 445 Section &getGOTSection() { 446 if (!GOTSection) 447 GOTSection = &G.createSection("$__GOT", sys::Memory::MF_READ); 448 return *GOTSection; 449 } 450 451 Section &getStubsSection() { 452 if (!StubsSection) { 453 auto StubsProt = static_cast<sys::Memory::ProtectionFlags>( 454 sys::Memory::MF_READ | sys::Memory::MF_EXEC); 455 StubsSection = &G.createSection("$__STUBS", StubsProt); 456 } 457 return *StubsSection; 458 } 459 460 StringRef getGOTEntryBlockContent() { 461 return StringRef(reinterpret_cast<const char *>(NullGOTEntryContent), 462 sizeof(NullGOTEntryContent)); 463 } 464 465 StringRef getStubBlockContent() { 466 return StringRef(reinterpret_cast<const char *>(StubContent), 467 sizeof(StubContent)); 468 } 469 470 static const uint8_t NullGOTEntryContent[8]; 471 static const uint8_t StubContent[8]; 472 Section *GOTSection = nullptr; 473 Section *StubsSection = nullptr; 474 }; 475 476 const uint8_t MachO_arm64_GOTAndStubsBuilder::NullGOTEntryContent[8] = { 477 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00}; 478 const uint8_t MachO_arm64_GOTAndStubsBuilder::StubContent[8] = { 479 0x10, 0x00, 0x00, 0x58, // LDR x16, <literal> 480 0x00, 0x02, 0x1f, 0xd6 // BR x16 481 }; 482 483 } // namespace 484 485 namespace llvm { 486 namespace jitlink { 487 488 class MachOJITLinker_arm64 : public JITLinker<MachOJITLinker_arm64> { 489 friend class JITLinker<MachOJITLinker_arm64>; 490 491 public: 492 MachOJITLinker_arm64(std::unique_ptr<JITLinkContext> Ctx, 493 PassConfiguration PassConfig) 494 : JITLinker(std::move(Ctx), std::move(PassConfig)) {} 495 496 private: 497 StringRef getEdgeKindName(Edge::Kind R) const override { 498 return getMachOARM64RelocationKindName(R); 499 } 500 501 Expected<std::unique_ptr<LinkGraph>> 502 buildGraph(MemoryBufferRef ObjBuffer) override { 503 auto MachOObj = object::ObjectFile::createMachOObjectFile(ObjBuffer); 504 if (!MachOObj) 505 return MachOObj.takeError(); 506 return MachOLinkGraphBuilder_arm64(**MachOObj).buildGraph(); 507 } 508 509 static Error targetOutOfRangeError(const Block &B, const Edge &E) { 510 std::string ErrMsg; 511 { 512 raw_string_ostream ErrStream(ErrMsg); 513 ErrStream << "Relocation target out of range: "; 514 printEdge(ErrStream, B, E, getMachOARM64RelocationKindName(E.getKind())); 515 ErrStream << "\n"; 516 } 517 return make_error<JITLinkError>(std::move(ErrMsg)); 518 } 519 520 static unsigned getPageOffset12Shift(uint32_t Instr) { 521 constexpr uint32_t LDRLiteralMask = 0x3ffffc00; 522 523 // Check for a GPR LDR immediate with a zero embedded literal. 524 // If found, the top two bits contain the shift. 525 if ((Instr & LDRLiteralMask) == 0x39400000) 526 return Instr >> 30; 527 528 // Check for a Neon LDR immediate of size 64-bit or less with a zero 529 // embedded literal. If found, the top two bits contain the shift. 530 if ((Instr & LDRLiteralMask) == 0x3d400000) 531 return Instr >> 30; 532 533 // Check for a Neon LDR immediate of size 128-bit with a zero embedded 534 // literal. 535 constexpr uint32_t SizeBitsMask = 0xc0000000; 536 if ((Instr & (LDRLiteralMask | SizeBitsMask)) == 0x3dc00000) 537 return 4; 538 539 return 0; 540 } 541 542 Error applyFixup(Block &B, const Edge &E, char *BlockWorkingMem) const { 543 using namespace support; 544 545 char *FixupPtr = BlockWorkingMem + E.getOffset(); 546 JITTargetAddress FixupAddress = B.getAddress() + E.getOffset(); 547 548 switch (E.getKind()) { 549 case Branch26: { 550 assert((FixupAddress & 0x3) == 0 && "Branch-inst is not 32-bit aligned"); 551 552 int64_t Value = E.getTarget().getAddress() - FixupAddress + E.getAddend(); 553 554 if (static_cast<uint64_t>(Value) & 0x3) 555 return make_error<JITLinkError>("Branch26 target is not 32-bit " 556 "aligned"); 557 558 if (Value < -(1 << 27) || Value > ((1 << 27) - 1)) 559 return targetOutOfRangeError(B, E); 560 561 uint32_t RawInstr = *(little32_t *)FixupPtr; 562 assert((RawInstr & 0x7fffffff) == 0x14000000 && 563 "RawInstr isn't a B or BR immediate instruction"); 564 uint32_t Imm = (static_cast<uint32_t>(Value) & ((1 << 28) - 1)) >> 2; 565 uint32_t FixedInstr = RawInstr | Imm; 566 *(little32_t *)FixupPtr = FixedInstr; 567 break; 568 } 569 case Pointer32: { 570 uint64_t Value = E.getTarget().getAddress() + E.getAddend(); 571 if (Value > std::numeric_limits<uint32_t>::max()) 572 return targetOutOfRangeError(B, E); 573 *(ulittle32_t *)FixupPtr = Value; 574 break; 575 } 576 case Pointer64: 577 case Pointer64Anon: { 578 uint64_t Value = E.getTarget().getAddress() + E.getAddend(); 579 *(ulittle64_t *)FixupPtr = Value; 580 break; 581 } 582 case Page21: 583 case GOTPage21: { 584 assert(E.getAddend() == 0 && "PAGE21/GOTPAGE21 with non-zero addend"); 585 uint64_t TargetPage = 586 E.getTarget().getAddress() & ~static_cast<uint64_t>(4096 - 1); 587 uint64_t PCPage = B.getAddress() & ~static_cast<uint64_t>(4096 - 1); 588 589 int64_t PageDelta = TargetPage - PCPage; 590 if (PageDelta < -(1 << 30) || PageDelta > ((1 << 30) - 1)) 591 return targetOutOfRangeError(B, E); 592 593 uint32_t RawInstr = *(ulittle32_t *)FixupPtr; 594 assert((RawInstr & 0xffffffe0) == 0x90000000 && 595 "RawInstr isn't an ADRP instruction"); 596 uint32_t ImmLo = (static_cast<uint64_t>(PageDelta) >> 12) & 0x3; 597 uint32_t ImmHi = (static_cast<uint64_t>(PageDelta) >> 14) & 0x7ffff; 598 uint32_t FixedInstr = RawInstr | (ImmLo << 29) | (ImmHi << 5); 599 *(ulittle32_t *)FixupPtr = FixedInstr; 600 break; 601 } 602 case PageOffset12: { 603 assert(E.getAddend() == 0 && "PAGEOFF12 with non-zero addend"); 604 uint64_t TargetOffset = E.getTarget().getAddress() & 0xfff; 605 606 uint32_t RawInstr = *(ulittle32_t *)FixupPtr; 607 unsigned ImmShift = getPageOffset12Shift(RawInstr); 608 609 if (TargetOffset & ((1 << ImmShift) - 1)) 610 return make_error<JITLinkError>("PAGEOFF12 target is not aligned"); 611 612 uint32_t EncodedImm = (TargetOffset >> ImmShift) << 10; 613 uint32_t FixedInstr = RawInstr | EncodedImm; 614 *(ulittle32_t *)FixupPtr = FixedInstr; 615 break; 616 } 617 case GOTPageOffset12: { 618 assert(E.getAddend() == 0 && "GOTPAGEOF12 with non-zero addend"); 619 620 uint32_t RawInstr = *(ulittle32_t *)FixupPtr; 621 assert((RawInstr & 0xfffffc00) == 0xf9400000 && 622 "RawInstr isn't a 64-bit LDR immediate"); 623 624 uint32_t TargetOffset = E.getTarget().getAddress() & 0xfff; 625 assert((TargetOffset & 0x7) == 0 && "GOT entry is not 8-byte aligned"); 626 uint32_t EncodedImm = (TargetOffset >> 3) << 10; 627 uint32_t FixedInstr = RawInstr | EncodedImm; 628 *(ulittle32_t *)FixupPtr = FixedInstr; 629 break; 630 } 631 case LDRLiteral19: { 632 assert((FixupAddress & 0x3) == 0 && "LDR is not 32-bit aligned"); 633 assert(E.getAddend() == 0 && "LDRLiteral19 with non-zero addend"); 634 uint32_t RawInstr = *(ulittle32_t *)FixupPtr; 635 assert(RawInstr == 0x58000010 && "RawInstr isn't a 64-bit LDR literal"); 636 int64_t Delta = E.getTarget().getAddress() - FixupAddress; 637 if (Delta & 0x3) 638 return make_error<JITLinkError>("LDR literal target is not 32-bit " 639 "aligned"); 640 if (Delta < -(1 << 20) || Delta > ((1 << 20) - 1)) 641 return targetOutOfRangeError(B, E); 642 643 uint32_t EncodedImm = (static_cast<uint32_t>(Delta) >> 2) << 5; 644 uint32_t FixedInstr = RawInstr | EncodedImm; 645 *(ulittle32_t *)FixupPtr = FixedInstr; 646 break; 647 } 648 case Delta32: 649 case Delta64: 650 case NegDelta32: 651 case NegDelta64: { 652 int64_t Value; 653 if (E.getKind() == Delta32 || E.getKind() == Delta64) 654 Value = E.getTarget().getAddress() - FixupAddress + E.getAddend(); 655 else 656 Value = FixupAddress - E.getTarget().getAddress() + E.getAddend(); 657 658 if (E.getKind() == Delta32 || E.getKind() == NegDelta32) { 659 if (Value < std::numeric_limits<int32_t>::min() || 660 Value > std::numeric_limits<int32_t>::max()) 661 return targetOutOfRangeError(B, E); 662 *(little32_t *)FixupPtr = Value; 663 } else 664 *(little64_t *)FixupPtr = Value; 665 break; 666 } 667 default: 668 llvm_unreachable("Unrecognized edge kind"); 669 } 670 671 return Error::success(); 672 } 673 674 uint64_t NullValue = 0; 675 }; 676 677 void jitLink_MachO_arm64(std::unique_ptr<JITLinkContext> Ctx) { 678 PassConfiguration Config; 679 Triple TT("arm64-apple-ios"); 680 681 if (Ctx->shouldAddDefaultTargetPasses(TT)) { 682 // Add a mark-live pass. 683 if (auto MarkLive = Ctx->getMarkLivePass(TT)) 684 Config.PrePrunePasses.push_back(std::move(MarkLive)); 685 else 686 Config.PrePrunePasses.push_back(markAllSymbolsLive); 687 688 // Add an in-place GOT/Stubs pass. 689 Config.PostPrunePasses.push_back([](LinkGraph &G) -> Error { 690 MachO_arm64_GOTAndStubsBuilder(G).run(); 691 return Error::success(); 692 }); 693 } 694 695 if (auto Err = Ctx->modifyPassConfig(TT, Config)) 696 return Ctx->notifyFailed(std::move(Err)); 697 698 // Construct a JITLinker and run the link function. 699 MachOJITLinker_arm64::link(std::move(Ctx), std::move(Config)); 700 } 701 702 StringRef getMachOARM64RelocationKindName(Edge::Kind R) { 703 switch (R) { 704 case Branch26: 705 return "Branch26"; 706 case Pointer64: 707 return "Pointer64"; 708 case Pointer64Anon: 709 return "Pointer64Anon"; 710 case Page21: 711 return "Page21"; 712 case PageOffset12: 713 return "PageOffset12"; 714 case GOTPage21: 715 return "GOTPage21"; 716 case GOTPageOffset12: 717 return "GOTPageOffset12"; 718 case PointerToGOT: 719 return "PointerToGOT"; 720 case PairedAddend: 721 return "PairedAddend"; 722 case LDRLiteral19: 723 return "LDRLiteral19"; 724 case Delta32: 725 return "Delta32"; 726 case Delta64: 727 return "Delta64"; 728 case NegDelta32: 729 return "NegDelta32"; 730 case NegDelta64: 731 return "NegDelta64"; 732 default: 733 return getGenericEdgeKindName(static_cast<Edge::Kind>(R)); 734 } 735 } 736 737 } // end namespace jitlink 738 } // end namespace llvm 739