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 auto ToSymbolSec = findSectionByIndex(UnsignedRI.r_symbolnum - 1); 152 if (!ToSymbolSec) 153 return ToSymbolSec.takeError(); 154 ToSymbol = getSymbolByAddress(ToSymbolSec->Address); 155 assert(ToSymbol && "No symbol for section"); 156 FixupValue -= ToSymbol->getAddress(); 157 } 158 159 MachOARM64RelocationKind DeltaKind; 160 Symbol *TargetSymbol; 161 uint64_t Addend; 162 if (&BlockToFix == &FromSymbol->getAddressable()) { 163 TargetSymbol = ToSymbol; 164 DeltaKind = (SubRI.r_length == 3) ? Delta64 : Delta32; 165 Addend = FixupValue + (FixupAddress - FromSymbol->getAddress()); 166 // FIXME: handle extern 'from'. 167 } else if (&BlockToFix == &ToSymbol->getAddressable()) { 168 TargetSymbol = &*FromSymbol; 169 DeltaKind = (SubRI.r_length == 3) ? NegDelta64 : NegDelta32; 170 Addend = FixupValue - (FixupAddress - ToSymbol->getAddress()); 171 } else { 172 // BlockToFix was neither FromSymbol nor ToSymbol. 173 return make_error<JITLinkError>("SUBTRACTOR relocation must fix up " 174 "either 'A' or 'B' (or a symbol in one " 175 "of their alt-entry groups)"); 176 } 177 178 return PairRelocInfo(DeltaKind, TargetSymbol, Addend); 179 } 180 181 Error addRelocations() override { 182 using namespace support; 183 auto &Obj = getObject(); 184 185 LLVM_DEBUG(dbgs() << "Processing relocations:\n"); 186 187 for (auto &S : Obj.sections()) { 188 189 JITTargetAddress SectionAddress = S.getAddress(); 190 191 // Skip relocations virtual sections. 192 if (S.isVirtual()) { 193 if (S.relocation_begin() != S.relocation_end()) 194 return make_error<JITLinkError>("Virtual section contains " 195 "relocations"); 196 continue; 197 } 198 199 // Skip relocations for debug symbols. 200 { 201 auto &NSec = 202 getSectionByIndex(Obj.getSectionIndex(S.getRawDataRefImpl())); 203 if (!NSec.GraphSection) { 204 LLVM_DEBUG({ 205 dbgs() << " Skipping relocations for MachO section " 206 << NSec.SegName << "/" << NSec.SectName 207 << " which has no associated graph section\n"; 208 }); 209 continue; 210 } 211 } 212 213 for (auto RelItr = S.relocation_begin(), RelEnd = S.relocation_end(); 214 RelItr != RelEnd; ++RelItr) { 215 216 MachO::relocation_info RI = getRelocationInfo(RelItr); 217 218 // Sanity check the relocation kind. 219 auto Kind = getRelocationKind(RI); 220 if (!Kind) 221 return Kind.takeError(); 222 223 // Find the address of the value to fix up. 224 JITTargetAddress FixupAddress = SectionAddress + (uint32_t)RI.r_address; 225 226 LLVM_DEBUG({ 227 auto &NSec = 228 getSectionByIndex(Obj.getSectionIndex(S.getRawDataRefImpl())); 229 dbgs() << " " << NSec.SectName << " + " 230 << formatv("{0:x8}", RI.r_address) << ":\n"; 231 }); 232 233 // Find the block that the fixup points to. 234 Block *BlockToFix = nullptr; 235 { 236 auto SymbolToFixOrErr = findSymbolByAddress(FixupAddress); 237 if (!SymbolToFixOrErr) 238 return SymbolToFixOrErr.takeError(); 239 BlockToFix = &SymbolToFixOrErr->getBlock(); 240 } 241 242 if (FixupAddress + static_cast<JITTargetAddress>(1ULL << RI.r_length) > 243 BlockToFix->getAddress() + BlockToFix->getContent().size()) 244 return make_error<JITLinkError>( 245 "Relocation content extends past end of fixup block"); 246 247 // Get a pointer to the fixup content. 248 const char *FixupContent = BlockToFix->getContent().data() + 249 (FixupAddress - BlockToFix->getAddress()); 250 251 // The target symbol and addend will be populated by the switch below. 252 Symbol *TargetSymbol = nullptr; 253 uint64_t Addend = 0; 254 255 if (*Kind == PairedAddend) { 256 // If this is an Addend relocation then process it and move to the 257 // paired reloc. 258 259 Addend = RI.r_symbolnum; 260 261 if (RelItr == RelEnd) 262 return make_error<JITLinkError>("Unpaired Addend reloc at " + 263 formatv("{0:x16}", FixupAddress)); 264 ++RelItr; 265 RI = getRelocationInfo(RelItr); 266 267 Kind = getRelocationKind(RI); 268 if (!Kind) 269 return Kind.takeError(); 270 271 if (*Kind != Branch26 && *Kind != Page21 && *Kind != PageOffset12) 272 return make_error<JITLinkError>( 273 "Invalid relocation pair: Addend + " + 274 getMachOARM64RelocationKindName(*Kind)); 275 else 276 LLVM_DEBUG({ 277 dbgs() << " pair is " << getMachOARM64RelocationKindName(*Kind) 278 << "`\n"; 279 }); 280 281 // Find the address of the value to fix up. 282 JITTargetAddress PairedFixupAddress = 283 SectionAddress + (uint32_t)RI.r_address; 284 if (PairedFixupAddress != FixupAddress) 285 return make_error<JITLinkError>("Paired relocation points at " 286 "different target"); 287 } 288 289 switch (*Kind) { 290 case Branch26: { 291 if (auto TargetSymbolOrErr = findSymbolByIndex(RI.r_symbolnum)) 292 TargetSymbol = TargetSymbolOrErr->GraphSymbol; 293 else 294 return TargetSymbolOrErr.takeError(); 295 uint32_t Instr = *(const ulittle32_t *)FixupContent; 296 if ((Instr & 0x7fffffff) != 0x14000000) 297 return make_error<JITLinkError>("BRANCH26 target is not a B or BL " 298 "instruction with a zero addend"); 299 break; 300 } 301 case Pointer32: 302 if (auto TargetSymbolOrErr = findSymbolByIndex(RI.r_symbolnum)) 303 TargetSymbol = TargetSymbolOrErr->GraphSymbol; 304 else 305 return TargetSymbolOrErr.takeError(); 306 Addend = *(const ulittle32_t *)FixupContent; 307 break; 308 case Pointer64: 309 if (auto TargetSymbolOrErr = findSymbolByIndex(RI.r_symbolnum)) 310 TargetSymbol = TargetSymbolOrErr->GraphSymbol; 311 else 312 return TargetSymbolOrErr.takeError(); 313 Addend = *(const ulittle64_t *)FixupContent; 314 break; 315 case Pointer64Anon: { 316 JITTargetAddress TargetAddress = *(const ulittle64_t *)FixupContent; 317 if (auto TargetSymbolOrErr = findSymbolByAddress(TargetAddress)) 318 TargetSymbol = &*TargetSymbolOrErr; 319 else 320 return TargetSymbolOrErr.takeError(); 321 Addend = TargetAddress - TargetSymbol->getAddress(); 322 break; 323 } 324 case Page21: 325 case GOTPage21: { 326 if (auto TargetSymbolOrErr = findSymbolByIndex(RI.r_symbolnum)) 327 TargetSymbol = TargetSymbolOrErr->GraphSymbol; 328 else 329 return TargetSymbolOrErr.takeError(); 330 uint32_t Instr = *(const ulittle32_t *)FixupContent; 331 if ((Instr & 0xffffffe0) != 0x90000000) 332 return make_error<JITLinkError>("PAGE21/GOTPAGE21 target is not an " 333 "ADRP instruction with a zero " 334 "addend"); 335 break; 336 } 337 case PageOffset12: { 338 if (auto TargetSymbolOrErr = findSymbolByIndex(RI.r_symbolnum)) 339 TargetSymbol = TargetSymbolOrErr->GraphSymbol; 340 else 341 return TargetSymbolOrErr.takeError(); 342 break; 343 } 344 case GOTPageOffset12: { 345 if (auto TargetSymbolOrErr = findSymbolByIndex(RI.r_symbolnum)) 346 TargetSymbol = TargetSymbolOrErr->GraphSymbol; 347 else 348 return TargetSymbolOrErr.takeError(); 349 uint32_t Instr = *(const ulittle32_t *)FixupContent; 350 if ((Instr & 0xfffffc00) != 0xf9400000) 351 return make_error<JITLinkError>("GOTPAGEOFF12 target is not an LDR " 352 "immediate instruction with a zero " 353 "addend"); 354 break; 355 } 356 case PointerToGOT: 357 if (auto TargetSymbolOrErr = findSymbolByIndex(RI.r_symbolnum)) 358 TargetSymbol = TargetSymbolOrErr->GraphSymbol; 359 else 360 return TargetSymbolOrErr.takeError(); 361 break; 362 case Delta32: 363 case Delta64: { 364 // We use Delta32/Delta64 to represent SUBTRACTOR relocations. 365 // parsePairRelocation handles the paired reloc, and returns the 366 // edge kind to be used (either Delta32/Delta64, or 367 // NegDelta32/NegDelta64, depending on the direction of the 368 // subtraction) along with the addend. 369 auto PairInfo = 370 parsePairRelocation(*BlockToFix, *Kind, RI, FixupAddress, 371 FixupContent, ++RelItr, RelEnd); 372 if (!PairInfo) 373 return PairInfo.takeError(); 374 std::tie(*Kind, TargetSymbol, Addend) = *PairInfo; 375 assert(TargetSymbol && "No target symbol from parsePairRelocation?"); 376 break; 377 } 378 default: 379 llvm_unreachable("Special relocation kind should not appear in " 380 "mach-o file"); 381 } 382 383 LLVM_DEBUG({ 384 dbgs() << " "; 385 Edge GE(*Kind, FixupAddress - BlockToFix->getAddress(), *TargetSymbol, 386 Addend); 387 printEdge(dbgs(), *BlockToFix, GE, 388 getMachOARM64RelocationKindName(*Kind)); 389 dbgs() << "\n"; 390 }); 391 BlockToFix->addEdge(*Kind, FixupAddress - BlockToFix->getAddress(), 392 *TargetSymbol, Addend); 393 } 394 } 395 return Error::success(); 396 } 397 398 unsigned NumSymbols = 0; 399 }; 400 401 class MachO_arm64_GOTAndStubsBuilder 402 : public BasicGOTAndStubsBuilder<MachO_arm64_GOTAndStubsBuilder> { 403 public: 404 MachO_arm64_GOTAndStubsBuilder(LinkGraph &G) 405 : BasicGOTAndStubsBuilder<MachO_arm64_GOTAndStubsBuilder>(G) {} 406 407 bool isGOTEdge(Edge &E) const { 408 return E.getKind() == GOTPage21 || E.getKind() == GOTPageOffset12 || 409 E.getKind() == PointerToGOT; 410 } 411 412 Symbol &createGOTEntry(Symbol &Target) { 413 auto &GOTEntryBlock = G.createContentBlock( 414 getGOTSection(), getGOTEntryBlockContent(), 0, 8, 0); 415 GOTEntryBlock.addEdge(Pointer64, 0, Target, 0); 416 return G.addAnonymousSymbol(GOTEntryBlock, 0, 8, false, false); 417 } 418 419 void fixGOTEdge(Edge &E, Symbol &GOTEntry) { 420 if (E.getKind() == GOTPage21 || E.getKind() == GOTPageOffset12) { 421 // Update the target, but leave the edge addend as-is. 422 E.setTarget(GOTEntry); 423 } else if (E.getKind() == PointerToGOT) { 424 E.setTarget(GOTEntry); 425 E.setKind(Delta32); 426 } else 427 llvm_unreachable("Not a GOT edge?"); 428 } 429 430 bool isExternalBranchEdge(Edge &E) { 431 return E.getKind() == Branch26 && !E.getTarget().isDefined(); 432 } 433 434 Symbol &createStub(Symbol &Target) { 435 auto &StubContentBlock = 436 G.createContentBlock(getStubsSection(), getStubBlockContent(), 0, 1, 0); 437 // Re-use GOT entries for stub targets. 438 auto &GOTEntrySymbol = getGOTEntrySymbol(Target); 439 StubContentBlock.addEdge(LDRLiteral19, 0, GOTEntrySymbol, 0); 440 return G.addAnonymousSymbol(StubContentBlock, 0, 8, true, false); 441 } 442 443 void fixExternalBranchEdge(Edge &E, Symbol &Stub) { 444 assert(E.getKind() == Branch26 && "Not a Branch32 edge?"); 445 assert(E.getAddend() == 0 && "Branch32 edge has non-zero addend?"); 446 E.setTarget(Stub); 447 } 448 449 private: 450 Section &getGOTSection() { 451 if (!GOTSection) 452 GOTSection = &G.createSection("$__GOT", sys::Memory::MF_READ); 453 return *GOTSection; 454 } 455 456 Section &getStubsSection() { 457 if (!StubsSection) { 458 auto StubsProt = static_cast<sys::Memory::ProtectionFlags>( 459 sys::Memory::MF_READ | sys::Memory::MF_EXEC); 460 StubsSection = &G.createSection("$__STUBS", StubsProt); 461 } 462 return *StubsSection; 463 } 464 465 StringRef getGOTEntryBlockContent() { 466 return StringRef(reinterpret_cast<const char *>(NullGOTEntryContent), 467 sizeof(NullGOTEntryContent)); 468 } 469 470 StringRef getStubBlockContent() { 471 return StringRef(reinterpret_cast<const char *>(StubContent), 472 sizeof(StubContent)); 473 } 474 475 static const uint8_t NullGOTEntryContent[8]; 476 static const uint8_t StubContent[8]; 477 Section *GOTSection = nullptr; 478 Section *StubsSection = nullptr; 479 }; 480 481 const uint8_t MachO_arm64_GOTAndStubsBuilder::NullGOTEntryContent[8] = { 482 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00}; 483 const uint8_t MachO_arm64_GOTAndStubsBuilder::StubContent[8] = { 484 0x10, 0x00, 0x00, 0x58, // LDR x16, <literal> 485 0x00, 0x02, 0x1f, 0xd6 // BR x16 486 }; 487 488 } // namespace 489 490 namespace llvm { 491 namespace jitlink { 492 493 class MachOJITLinker_arm64 : public JITLinker<MachOJITLinker_arm64> { 494 friend class JITLinker<MachOJITLinker_arm64>; 495 496 public: 497 MachOJITLinker_arm64(std::unique_ptr<JITLinkContext> Ctx, 498 PassConfiguration PassConfig) 499 : JITLinker(std::move(Ctx), std::move(PassConfig)) {} 500 501 private: 502 StringRef getEdgeKindName(Edge::Kind R) const override { 503 return getMachOARM64RelocationKindName(R); 504 } 505 506 Expected<std::unique_ptr<LinkGraph>> 507 buildGraph(MemoryBufferRef ObjBuffer) override { 508 auto MachOObj = object::ObjectFile::createMachOObjectFile(ObjBuffer); 509 if (!MachOObj) 510 return MachOObj.takeError(); 511 return MachOLinkGraphBuilder_arm64(**MachOObj).buildGraph(); 512 } 513 514 static Error targetOutOfRangeError(const Block &B, const Edge &E) { 515 std::string ErrMsg; 516 { 517 raw_string_ostream ErrStream(ErrMsg); 518 ErrStream << "Relocation target out of range: "; 519 printEdge(ErrStream, B, E, getMachOARM64RelocationKindName(E.getKind())); 520 ErrStream << "\n"; 521 } 522 return make_error<JITLinkError>(std::move(ErrMsg)); 523 } 524 525 static unsigned getPageOffset12Shift(uint32_t Instr) { 526 constexpr uint32_t LDRLiteralMask = 0x3ffffc00; 527 528 // Check for a GPR LDR immediate with a zero embedded literal. 529 // If found, the top two bits contain the shift. 530 if ((Instr & LDRLiteralMask) == 0x39400000) 531 return Instr >> 30; 532 533 // Check for a Neon LDR immediate of size 64-bit or less with a zero 534 // embedded literal. If found, the top two bits contain the shift. 535 if ((Instr & LDRLiteralMask) == 0x3d400000) 536 return Instr >> 30; 537 538 // Check for a Neon LDR immediate of size 128-bit with a zero embedded 539 // literal. 540 constexpr uint32_t SizeBitsMask = 0xc0000000; 541 if ((Instr & (LDRLiteralMask | SizeBitsMask)) == 0x3dc00000) 542 return 4; 543 544 return 0; 545 } 546 547 Error applyFixup(Block &B, const Edge &E, char *BlockWorkingMem) const { 548 using namespace support; 549 550 char *FixupPtr = BlockWorkingMem + E.getOffset(); 551 JITTargetAddress FixupAddress = B.getAddress() + E.getOffset(); 552 553 switch (E.getKind()) { 554 case Branch26: { 555 assert((FixupAddress & 0x3) == 0 && "Branch-inst is not 32-bit aligned"); 556 557 int64_t Value = E.getTarget().getAddress() - FixupAddress + E.getAddend(); 558 559 if (static_cast<uint64_t>(Value) & 0x3) 560 return make_error<JITLinkError>("Branch26 target is not 32-bit " 561 "aligned"); 562 563 if (Value < -(1 << 27) || Value > ((1 << 27) - 1)) 564 return targetOutOfRangeError(B, E); 565 566 uint32_t RawInstr = *(little32_t *)FixupPtr; 567 assert((RawInstr & 0x7fffffff) == 0x14000000 && 568 "RawInstr isn't a B or BR immediate instruction"); 569 uint32_t Imm = (static_cast<uint32_t>(Value) & ((1 << 28) - 1)) >> 2; 570 uint32_t FixedInstr = RawInstr | Imm; 571 *(little32_t *)FixupPtr = FixedInstr; 572 break; 573 } 574 case Pointer32: { 575 uint64_t Value = E.getTarget().getAddress() + E.getAddend(); 576 if (Value > std::numeric_limits<uint32_t>::max()) 577 return targetOutOfRangeError(B, E); 578 *(ulittle32_t *)FixupPtr = Value; 579 break; 580 } 581 case Pointer64: 582 case Pointer64Anon: { 583 uint64_t Value = E.getTarget().getAddress() + E.getAddend(); 584 *(ulittle64_t *)FixupPtr = Value; 585 break; 586 } 587 case Page21: 588 case GOTPage21: { 589 assert(E.getAddend() == 0 && "PAGE21/GOTPAGE21 with non-zero addend"); 590 uint64_t TargetPage = 591 E.getTarget().getAddress() & ~static_cast<uint64_t>(4096 - 1); 592 uint64_t PCPage = B.getAddress() & ~static_cast<uint64_t>(4096 - 1); 593 594 int64_t PageDelta = TargetPage - PCPage; 595 if (PageDelta < -(1 << 30) || PageDelta > ((1 << 30) - 1)) 596 return targetOutOfRangeError(B, E); 597 598 uint32_t RawInstr = *(ulittle32_t *)FixupPtr; 599 assert((RawInstr & 0xffffffe0) == 0x90000000 && 600 "RawInstr isn't an ADRP instruction"); 601 uint32_t ImmLo = (static_cast<uint64_t>(PageDelta) >> 12) & 0x3; 602 uint32_t ImmHi = (static_cast<uint64_t>(PageDelta) >> 14) & 0x7ffff; 603 uint32_t FixedInstr = RawInstr | (ImmLo << 29) | (ImmHi << 5); 604 *(ulittle32_t *)FixupPtr = FixedInstr; 605 break; 606 } 607 case PageOffset12: { 608 assert(E.getAddend() == 0 && "PAGEOFF12 with non-zero addend"); 609 uint64_t TargetOffset = E.getTarget().getAddress() & 0xfff; 610 611 uint32_t RawInstr = *(ulittle32_t *)FixupPtr; 612 unsigned ImmShift = getPageOffset12Shift(RawInstr); 613 614 if (TargetOffset & ((1 << ImmShift) - 1)) 615 return make_error<JITLinkError>("PAGEOFF12 target is not aligned"); 616 617 uint32_t EncodedImm = (TargetOffset >> ImmShift) << 10; 618 uint32_t FixedInstr = RawInstr | EncodedImm; 619 *(ulittle32_t *)FixupPtr = FixedInstr; 620 break; 621 } 622 case GOTPageOffset12: { 623 assert(E.getAddend() == 0 && "GOTPAGEOF12 with non-zero addend"); 624 625 uint32_t RawInstr = *(ulittle32_t *)FixupPtr; 626 assert((RawInstr & 0xfffffc00) == 0xf9400000 && 627 "RawInstr isn't a 64-bit LDR immediate"); 628 629 uint32_t TargetOffset = E.getTarget().getAddress() & 0xfff; 630 assert((TargetOffset & 0x7) == 0 && "GOT entry is not 8-byte aligned"); 631 uint32_t EncodedImm = (TargetOffset >> 3) << 10; 632 uint32_t FixedInstr = RawInstr | EncodedImm; 633 *(ulittle32_t *)FixupPtr = FixedInstr; 634 break; 635 } 636 case LDRLiteral19: { 637 assert((FixupAddress & 0x3) == 0 && "LDR is not 32-bit aligned"); 638 assert(E.getAddend() == 0 && "LDRLiteral19 with non-zero addend"); 639 uint32_t RawInstr = *(ulittle32_t *)FixupPtr; 640 assert(RawInstr == 0x58000010 && "RawInstr isn't a 64-bit LDR literal"); 641 int64_t Delta = E.getTarget().getAddress() - FixupAddress; 642 if (Delta & 0x3) 643 return make_error<JITLinkError>("LDR literal target is not 32-bit " 644 "aligned"); 645 if (Delta < -(1 << 20) || Delta > ((1 << 20) - 1)) 646 return targetOutOfRangeError(B, E); 647 648 uint32_t EncodedImm = (static_cast<uint32_t>(Delta) >> 2) << 5; 649 uint32_t FixedInstr = RawInstr | EncodedImm; 650 *(ulittle32_t *)FixupPtr = FixedInstr; 651 break; 652 } 653 case Delta32: 654 case Delta64: 655 case NegDelta32: 656 case NegDelta64: { 657 int64_t Value; 658 if (E.getKind() == Delta32 || E.getKind() == Delta64) 659 Value = E.getTarget().getAddress() - FixupAddress + E.getAddend(); 660 else 661 Value = FixupAddress - E.getTarget().getAddress() + E.getAddend(); 662 663 if (E.getKind() == Delta32 || E.getKind() == NegDelta32) { 664 if (Value < std::numeric_limits<int32_t>::min() || 665 Value > std::numeric_limits<int32_t>::max()) 666 return targetOutOfRangeError(B, E); 667 *(little32_t *)FixupPtr = Value; 668 } else 669 *(little64_t *)FixupPtr = Value; 670 break; 671 } 672 default: 673 llvm_unreachable("Unrecognized edge kind"); 674 } 675 676 return Error::success(); 677 } 678 679 uint64_t NullValue = 0; 680 }; 681 682 void jitLink_MachO_arm64(std::unique_ptr<JITLinkContext> Ctx) { 683 PassConfiguration Config; 684 Triple TT("arm64-apple-ios"); 685 686 if (Ctx->shouldAddDefaultTargetPasses(TT)) { 687 // Add a mark-live pass. 688 if (auto MarkLive = Ctx->getMarkLivePass(TT)) 689 Config.PrePrunePasses.push_back(std::move(MarkLive)); 690 else 691 Config.PrePrunePasses.push_back(markAllSymbolsLive); 692 693 // Add an in-place GOT/Stubs pass. 694 Config.PostPrunePasses.push_back([](LinkGraph &G) -> Error { 695 MachO_arm64_GOTAndStubsBuilder(G).run(); 696 return Error::success(); 697 }); 698 } 699 700 if (auto Err = Ctx->modifyPassConfig(TT, Config)) 701 return Ctx->notifyFailed(std::move(Err)); 702 703 // Construct a JITLinker and run the link function. 704 MachOJITLinker_arm64::link(std::move(Ctx), std::move(Config)); 705 } 706 707 StringRef getMachOARM64RelocationKindName(Edge::Kind R) { 708 switch (R) { 709 case Branch26: 710 return "Branch26"; 711 case Pointer64: 712 return "Pointer64"; 713 case Pointer64Anon: 714 return "Pointer64Anon"; 715 case Page21: 716 return "Page21"; 717 case PageOffset12: 718 return "PageOffset12"; 719 case GOTPage21: 720 return "GOTPage21"; 721 case GOTPageOffset12: 722 return "GOTPageOffset12"; 723 case PointerToGOT: 724 return "PointerToGOT"; 725 case PairedAddend: 726 return "PairedAddend"; 727 case LDRLiteral19: 728 return "LDRLiteral19"; 729 case Delta32: 730 return "Delta32"; 731 case Delta64: 732 return "Delta64"; 733 case NegDelta32: 734 return "NegDelta32"; 735 case NegDelta64: 736 return "NegDelta64"; 737 default: 738 return getGenericEdgeKindName(static_cast<Edge::Kind>(R)); 739 } 740 } 741 742 } // end namespace jitlink 743 } // end namespace llvm 744