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 "MachOLinkGraphBuilder.h" 16 #include "PerGraphGOTAndPLTStubsBuilder.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, Triple("arm64-apple-darwin"), 30 getMachOARM64RelocationKindName), 31 NumSymbols(Obj.getSymtabLoadCommand().nsyms) {} 32 33 private: 34 static Expected<MachOARM64RelocationKind> 35 getRelocationKind(const MachO::relocation_info &RI) { 36 switch (RI.r_type) { 37 case MachO::ARM64_RELOC_UNSIGNED: 38 if (!RI.r_pcrel) { 39 if (RI.r_length == 3) 40 return RI.r_extern ? Pointer64 : Pointer64Anon; 41 else if (RI.r_length == 2) 42 return Pointer32; 43 } 44 break; 45 case MachO::ARM64_RELOC_SUBTRACTOR: 46 // SUBTRACTOR must be non-pc-rel, extern, with length 2 or 3. 47 // Initially represent SUBTRACTOR relocations with 'Delta<W>'. 48 // They may be turned into NegDelta<W> by parsePairRelocation. 49 if (!RI.r_pcrel && RI.r_extern) { 50 if (RI.r_length == 2) 51 return Delta32; 52 else if (RI.r_length == 3) 53 return Delta64; 54 } 55 break; 56 case MachO::ARM64_RELOC_BRANCH26: 57 if (RI.r_pcrel && RI.r_extern && RI.r_length == 2) 58 return Branch26; 59 break; 60 case MachO::ARM64_RELOC_PAGE21: 61 if (RI.r_pcrel && RI.r_extern && RI.r_length == 2) 62 return Page21; 63 break; 64 case MachO::ARM64_RELOC_PAGEOFF12: 65 if (!RI.r_pcrel && RI.r_extern && RI.r_length == 2) 66 return PageOffset12; 67 break; 68 case MachO::ARM64_RELOC_GOT_LOAD_PAGE21: 69 if (RI.r_pcrel && RI.r_extern && RI.r_length == 2) 70 return GOTPage21; 71 break; 72 case MachO::ARM64_RELOC_GOT_LOAD_PAGEOFF12: 73 if (!RI.r_pcrel && RI.r_extern && RI.r_length == 2) 74 return GOTPageOffset12; 75 break; 76 case MachO::ARM64_RELOC_POINTER_TO_GOT: 77 if (RI.r_pcrel && RI.r_extern && RI.r_length == 2) 78 return PointerToGOT; 79 break; 80 case MachO::ARM64_RELOC_ADDEND: 81 if (!RI.r_pcrel && !RI.r_extern && RI.r_length == 2) 82 return PairedAddend; 83 break; 84 case MachO::ARM64_RELOC_TLVP_LOAD_PAGE21: 85 if (RI.r_pcrel && RI.r_extern && RI.r_length == 2) 86 return TLVPage21; 87 break; 88 case MachO::ARM64_RELOC_TLVP_LOAD_PAGEOFF12: 89 if (!RI.r_pcrel && RI.r_extern && RI.r_length == 2) 90 return TLVPageOffset12; 91 break; 92 } 93 94 return make_error<JITLinkError>( 95 "Unsupported arm64 relocation: address=" + 96 formatv("{0:x8}", RI.r_address) + 97 ", symbolnum=" + formatv("{0:x6}", RI.r_symbolnum) + 98 ", kind=" + formatv("{0:x1}", RI.r_type) + 99 ", pc_rel=" + (RI.r_pcrel ? "true" : "false") + 100 ", extern=" + (RI.r_extern ? "true" : "false") + 101 ", length=" + formatv("{0:d}", RI.r_length)); 102 } 103 104 using PairRelocInfo = 105 std::tuple<MachOARM64RelocationKind, Symbol *, uint64_t>; 106 107 // Parses paired SUBTRACTOR/UNSIGNED relocations and, on success, 108 // returns the edge kind and addend to be used. 109 Expected<PairRelocInfo> 110 parsePairRelocation(Block &BlockToFix, Edge::Kind SubtractorKind, 111 const MachO::relocation_info &SubRI, 112 JITTargetAddress FixupAddress, const char *FixupContent, 113 object::relocation_iterator &UnsignedRelItr, 114 object::relocation_iterator &RelEnd) { 115 using namespace support; 116 117 assert(((SubtractorKind == Delta32 && SubRI.r_length == 2) || 118 (SubtractorKind == Delta64 && SubRI.r_length == 3)) && 119 "Subtractor kind should match length"); 120 assert(SubRI.r_extern && "SUBTRACTOR reloc symbol should be extern"); 121 assert(!SubRI.r_pcrel && "SUBTRACTOR reloc should not be PCRel"); 122 123 if (UnsignedRelItr == RelEnd) 124 return make_error<JITLinkError>("arm64 SUBTRACTOR without paired " 125 "UNSIGNED relocation"); 126 127 auto UnsignedRI = getRelocationInfo(UnsignedRelItr); 128 129 if (SubRI.r_address != UnsignedRI.r_address) 130 return make_error<JITLinkError>("arm64 SUBTRACTOR and paired UNSIGNED " 131 "point to different addresses"); 132 133 if (SubRI.r_length != UnsignedRI.r_length) 134 return make_error<JITLinkError>("length of arm64 SUBTRACTOR and paired " 135 "UNSIGNED reloc must match"); 136 137 Symbol *FromSymbol; 138 if (auto FromSymbolOrErr = findSymbolByIndex(SubRI.r_symbolnum)) 139 FromSymbol = FromSymbolOrErr->GraphSymbol; 140 else 141 return FromSymbolOrErr.takeError(); 142 143 // Read the current fixup value. 144 uint64_t FixupValue = 0; 145 if (SubRI.r_length == 3) 146 FixupValue = *(const little64_t *)FixupContent; 147 else 148 FixupValue = *(const little32_t *)FixupContent; 149 150 // Find 'ToSymbol' using symbol number or address, depending on whether the 151 // paired UNSIGNED relocation is extern. 152 Symbol *ToSymbol = nullptr; 153 if (UnsignedRI.r_extern) { 154 // Find target symbol by symbol index. 155 if (auto ToSymbolOrErr = findSymbolByIndex(UnsignedRI.r_symbolnum)) 156 ToSymbol = ToSymbolOrErr->GraphSymbol; 157 else 158 return ToSymbolOrErr.takeError(); 159 } else { 160 auto ToSymbolSec = findSectionByIndex(UnsignedRI.r_symbolnum - 1); 161 if (!ToSymbolSec) 162 return ToSymbolSec.takeError(); 163 ToSymbol = getSymbolByAddress(ToSymbolSec->Address); 164 assert(ToSymbol && "No symbol for section"); 165 FixupValue -= ToSymbol->getAddress(); 166 } 167 168 MachOARM64RelocationKind DeltaKind; 169 Symbol *TargetSymbol; 170 uint64_t Addend; 171 if (&BlockToFix == &FromSymbol->getAddressable()) { 172 TargetSymbol = ToSymbol; 173 DeltaKind = (SubRI.r_length == 3) ? Delta64 : Delta32; 174 Addend = FixupValue + (FixupAddress - FromSymbol->getAddress()); 175 // FIXME: handle extern 'from'. 176 } else if (&BlockToFix == &ToSymbol->getAddressable()) { 177 TargetSymbol = &*FromSymbol; 178 DeltaKind = (SubRI.r_length == 3) ? NegDelta64 : NegDelta32; 179 Addend = FixupValue - (FixupAddress - ToSymbol->getAddress()); 180 } else { 181 // BlockToFix was neither FromSymbol nor ToSymbol. 182 return make_error<JITLinkError>("SUBTRACTOR relocation must fix up " 183 "either 'A' or 'B' (or a symbol in one " 184 "of their alt-entry groups)"); 185 } 186 187 return PairRelocInfo(DeltaKind, TargetSymbol, Addend); 188 } 189 190 Error addRelocations() override { 191 using namespace support; 192 auto &Obj = getObject(); 193 194 LLVM_DEBUG(dbgs() << "Processing relocations:\n"); 195 196 for (auto &S : Obj.sections()) { 197 198 JITTargetAddress SectionAddress = S.getAddress(); 199 200 // Skip relocations virtual sections. 201 if (S.isVirtual()) { 202 if (S.relocation_begin() != S.relocation_end()) 203 return make_error<JITLinkError>("Virtual section contains " 204 "relocations"); 205 continue; 206 } 207 208 // Skip relocations for debug symbols. 209 { 210 auto &NSec = 211 getSectionByIndex(Obj.getSectionIndex(S.getRawDataRefImpl())); 212 if (!NSec.GraphSection) { 213 LLVM_DEBUG({ 214 dbgs() << " Skipping relocations for MachO section " 215 << NSec.SegName << "/" << NSec.SectName 216 << " which has no associated graph section\n"; 217 }); 218 continue; 219 } 220 } 221 222 for (auto RelItr = S.relocation_begin(), RelEnd = S.relocation_end(); 223 RelItr != RelEnd; ++RelItr) { 224 225 MachO::relocation_info RI = getRelocationInfo(RelItr); 226 227 // Sanity check the relocation kind. 228 auto Kind = getRelocationKind(RI); 229 if (!Kind) 230 return Kind.takeError(); 231 232 // Find the address of the value to fix up. 233 JITTargetAddress FixupAddress = SectionAddress + (uint32_t)RI.r_address; 234 235 LLVM_DEBUG({ 236 auto &NSec = 237 getSectionByIndex(Obj.getSectionIndex(S.getRawDataRefImpl())); 238 dbgs() << " " << NSec.SectName << " + " 239 << formatv("{0:x8}", RI.r_address) << ":\n"; 240 }); 241 242 // Find the block that the fixup points to. 243 Block *BlockToFix = nullptr; 244 { 245 auto SymbolToFixOrErr = findSymbolByAddress(FixupAddress); 246 if (!SymbolToFixOrErr) 247 return SymbolToFixOrErr.takeError(); 248 BlockToFix = &SymbolToFixOrErr->getBlock(); 249 } 250 251 if (FixupAddress + static_cast<JITTargetAddress>(1ULL << RI.r_length) > 252 BlockToFix->getAddress() + BlockToFix->getContent().size()) 253 return make_error<JITLinkError>( 254 "Relocation content extends past end of fixup block"); 255 256 // Get a pointer to the fixup content. 257 const char *FixupContent = BlockToFix->getContent().data() + 258 (FixupAddress - BlockToFix->getAddress()); 259 260 // The target symbol and addend will be populated by the switch below. 261 Symbol *TargetSymbol = nullptr; 262 uint64_t Addend = 0; 263 264 if (*Kind == PairedAddend) { 265 // If this is an Addend relocation then process it and move to the 266 // paired reloc. 267 268 Addend = SignExtend64(RI.r_symbolnum, 24); 269 270 if (RelItr == RelEnd) 271 return make_error<JITLinkError>("Unpaired Addend reloc at " + 272 formatv("{0:x16}", FixupAddress)); 273 ++RelItr; 274 RI = getRelocationInfo(RelItr); 275 276 Kind = getRelocationKind(RI); 277 if (!Kind) 278 return Kind.takeError(); 279 280 if (*Kind != Branch26 && *Kind != Page21 && *Kind != PageOffset12) 281 return make_error<JITLinkError>( 282 "Invalid relocation pair: Addend + " + 283 StringRef(getMachOARM64RelocationKindName(*Kind))); 284 285 LLVM_DEBUG({ 286 dbgs() << " Addend: value = " << formatv("{0:x6}", Addend) 287 << ", pair is " << getMachOARM64RelocationKindName(*Kind) 288 << "\n"; 289 }); 290 291 // Find the address of the value to fix up. 292 JITTargetAddress PairedFixupAddress = 293 SectionAddress + (uint32_t)RI.r_address; 294 if (PairedFixupAddress != FixupAddress) 295 return make_error<JITLinkError>("Paired relocation points at " 296 "different target"); 297 } 298 299 switch (*Kind) { 300 case Branch26: { 301 if (auto TargetSymbolOrErr = findSymbolByIndex(RI.r_symbolnum)) 302 TargetSymbol = TargetSymbolOrErr->GraphSymbol; 303 else 304 return TargetSymbolOrErr.takeError(); 305 uint32_t Instr = *(const ulittle32_t *)FixupContent; 306 if ((Instr & 0x7fffffff) != 0x14000000) 307 return make_error<JITLinkError>("BRANCH26 target is not a B or BL " 308 "instruction with a zero addend"); 309 break; 310 } 311 case Pointer32: 312 if (auto TargetSymbolOrErr = findSymbolByIndex(RI.r_symbolnum)) 313 TargetSymbol = TargetSymbolOrErr->GraphSymbol; 314 else 315 return TargetSymbolOrErr.takeError(); 316 Addend = *(const ulittle32_t *)FixupContent; 317 break; 318 case Pointer64: 319 if (auto TargetSymbolOrErr = findSymbolByIndex(RI.r_symbolnum)) 320 TargetSymbol = TargetSymbolOrErr->GraphSymbol; 321 else 322 return TargetSymbolOrErr.takeError(); 323 Addend = *(const ulittle64_t *)FixupContent; 324 break; 325 case Pointer64Anon: { 326 JITTargetAddress TargetAddress = *(const ulittle64_t *)FixupContent; 327 if (auto TargetSymbolOrErr = findSymbolByAddress(TargetAddress)) 328 TargetSymbol = &*TargetSymbolOrErr; 329 else 330 return TargetSymbolOrErr.takeError(); 331 Addend = TargetAddress - TargetSymbol->getAddress(); 332 break; 333 } 334 case Page21: 335 case TLVPage21: 336 case GOTPage21: { 337 if (auto TargetSymbolOrErr = findSymbolByIndex(RI.r_symbolnum)) 338 TargetSymbol = TargetSymbolOrErr->GraphSymbol; 339 else 340 return TargetSymbolOrErr.takeError(); 341 uint32_t Instr = *(const ulittle32_t *)FixupContent; 342 if ((Instr & 0xffffffe0) != 0x90000000) 343 return make_error<JITLinkError>("PAGE21/GOTPAGE21 target is not an " 344 "ADRP instruction with a zero " 345 "addend"); 346 break; 347 } 348 case PageOffset12: { 349 if (auto TargetSymbolOrErr = findSymbolByIndex(RI.r_symbolnum)) 350 TargetSymbol = TargetSymbolOrErr->GraphSymbol; 351 else 352 return TargetSymbolOrErr.takeError(); 353 uint32_t Instr = *(const ulittle32_t *)FixupContent; 354 uint32_t EncodedAddend = (Instr & 0x003FFC00) >> 10; 355 if (EncodedAddend != 0) 356 return make_error<JITLinkError>("GOTPAGEOFF12 target has non-zero " 357 "encoded addend"); 358 break; 359 } 360 case TLVPageOffset12: 361 case GOTPageOffset12: { 362 if (auto TargetSymbolOrErr = findSymbolByIndex(RI.r_symbolnum)) 363 TargetSymbol = TargetSymbolOrErr->GraphSymbol; 364 else 365 return TargetSymbolOrErr.takeError(); 366 uint32_t Instr = *(const ulittle32_t *)FixupContent; 367 if ((Instr & 0xfffffc00) != 0xf9400000) 368 return make_error<JITLinkError>("GOTPAGEOFF12 target is not an LDR " 369 "immediate instruction with a zero " 370 "addend"); 371 break; 372 } 373 case PointerToGOT: 374 if (auto TargetSymbolOrErr = findSymbolByIndex(RI.r_symbolnum)) 375 TargetSymbol = TargetSymbolOrErr->GraphSymbol; 376 else 377 return TargetSymbolOrErr.takeError(); 378 break; 379 case Delta32: 380 case Delta64: { 381 // We use Delta32/Delta64 to represent SUBTRACTOR relocations. 382 // parsePairRelocation handles the paired reloc, and returns the 383 // edge kind to be used (either Delta32/Delta64, or 384 // NegDelta32/NegDelta64, depending on the direction of the 385 // subtraction) along with the addend. 386 auto PairInfo = 387 parsePairRelocation(*BlockToFix, *Kind, RI, FixupAddress, 388 FixupContent, ++RelItr, RelEnd); 389 if (!PairInfo) 390 return PairInfo.takeError(); 391 std::tie(*Kind, TargetSymbol, Addend) = *PairInfo; 392 assert(TargetSymbol && "No target symbol from parsePairRelocation?"); 393 break; 394 } 395 default: 396 llvm_unreachable("Special relocation kind should not appear in " 397 "mach-o file"); 398 } 399 400 LLVM_DEBUG({ 401 dbgs() << " "; 402 Edge GE(*Kind, FixupAddress - BlockToFix->getAddress(), *TargetSymbol, 403 Addend); 404 printEdge(dbgs(), *BlockToFix, GE, 405 getMachOARM64RelocationKindName(*Kind)); 406 dbgs() << "\n"; 407 }); 408 BlockToFix->addEdge(*Kind, FixupAddress - BlockToFix->getAddress(), 409 *TargetSymbol, Addend); 410 } 411 } 412 return Error::success(); 413 } 414 415 unsigned NumSymbols = 0; 416 }; 417 418 class PerGraphGOTAndPLTStubsBuilder_MachO_arm64 419 : public PerGraphGOTAndPLTStubsBuilder< 420 PerGraphGOTAndPLTStubsBuilder_MachO_arm64> { 421 public: 422 using PerGraphGOTAndPLTStubsBuilder< 423 PerGraphGOTAndPLTStubsBuilder_MachO_arm64>::PerGraphGOTAndPLTStubsBuilder; 424 425 bool isGOTEdgeToFix(Edge &E) const { 426 return E.getKind() == GOTPage21 || E.getKind() == GOTPageOffset12 || 427 E.getKind() == TLVPage21 || E.getKind() == TLVPageOffset12 || 428 E.getKind() == PointerToGOT; 429 } 430 431 Symbol &createGOTEntry(Symbol &Target) { 432 auto &GOTEntryBlock = G.createContentBlock( 433 getGOTSection(), getGOTEntryBlockContent(), 0, 8, 0); 434 GOTEntryBlock.addEdge(Pointer64, 0, Target, 0); 435 return G.addAnonymousSymbol(GOTEntryBlock, 0, 8, false, false); 436 } 437 438 void fixGOTEdge(Edge &E, Symbol &GOTEntry) { 439 if (E.getKind() == GOTPage21 || E.getKind() == GOTPageOffset12 || 440 E.getKind() == TLVPage21 || E.getKind() == TLVPageOffset12) { 441 // Update the target, but leave the edge addend as-is. 442 E.setTarget(GOTEntry); 443 } else if (E.getKind() == PointerToGOT) { 444 E.setTarget(GOTEntry); 445 E.setKind(Delta32); 446 } else 447 llvm_unreachable("Not a GOT edge?"); 448 } 449 450 bool isExternalBranchEdge(Edge &E) { 451 return E.getKind() == Branch26 && !E.getTarget().isDefined(); 452 } 453 454 Symbol &createPLTStub(Symbol &Target) { 455 auto &StubContentBlock = 456 G.createContentBlock(getStubsSection(), getStubBlockContent(), 0, 1, 0); 457 // Re-use GOT entries for stub targets. 458 auto &GOTEntrySymbol = getGOTEntry(Target); 459 StubContentBlock.addEdge(LDRLiteral19, 0, GOTEntrySymbol, 0); 460 return G.addAnonymousSymbol(StubContentBlock, 0, 8, true, false); 461 } 462 463 void fixPLTEdge(Edge &E, Symbol &Stub) { 464 assert(E.getKind() == Branch26 && "Not a Branch32 edge?"); 465 assert(E.getAddend() == 0 && "Branch32 edge has non-zero addend?"); 466 E.setTarget(Stub); 467 } 468 469 private: 470 Section &getGOTSection() { 471 if (!GOTSection) 472 GOTSection = &G.createSection("$__GOT", MemProt::Read); 473 return *GOTSection; 474 } 475 476 Section &getStubsSection() { 477 if (!StubsSection) 478 StubsSection = 479 &G.createSection("$__STUBS", MemProt::Read | MemProt::Exec); 480 return *StubsSection; 481 } 482 483 ArrayRef<char> getGOTEntryBlockContent() { 484 return {reinterpret_cast<const char *>(NullGOTEntryContent), 485 sizeof(NullGOTEntryContent)}; 486 } 487 488 ArrayRef<char> getStubBlockContent() { 489 return {reinterpret_cast<const char *>(StubContent), sizeof(StubContent)}; 490 } 491 492 static const uint8_t NullGOTEntryContent[8]; 493 static const uint8_t StubContent[8]; 494 Section *GOTSection = nullptr; 495 Section *StubsSection = nullptr; 496 }; 497 498 const uint8_t 499 PerGraphGOTAndPLTStubsBuilder_MachO_arm64::NullGOTEntryContent[8] = { 500 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00}; 501 const uint8_t PerGraphGOTAndPLTStubsBuilder_MachO_arm64::StubContent[8] = { 502 0x10, 0x00, 0x00, 0x58, // LDR x16, <literal> 503 0x00, 0x02, 0x1f, 0xd6 // BR x16 504 }; 505 506 } // namespace 507 508 namespace llvm { 509 namespace jitlink { 510 511 class MachOJITLinker_arm64 : public JITLinker<MachOJITLinker_arm64> { 512 friend class JITLinker<MachOJITLinker_arm64>; 513 514 public: 515 MachOJITLinker_arm64(std::unique_ptr<JITLinkContext> Ctx, 516 std::unique_ptr<LinkGraph> G, 517 PassConfiguration PassConfig) 518 : JITLinker(std::move(Ctx), std::move(G), std::move(PassConfig)) {} 519 520 private: 521 522 static unsigned getPageOffset12Shift(uint32_t Instr) { 523 constexpr uint32_t LoadStoreImm12Mask = 0x3b000000; 524 constexpr uint32_t Vec128Mask = 0x04800000; 525 526 if ((Instr & LoadStoreImm12Mask) == 0x39000000) { 527 uint32_t ImplicitShift = Instr >> 30; 528 if (ImplicitShift == 0) 529 if ((Instr & Vec128Mask) == Vec128Mask) 530 ImplicitShift = 4; 531 532 return ImplicitShift; 533 } 534 535 return 0; 536 } 537 538 Error applyFixup(LinkGraph &G, Block &B, const Edge &E) const { 539 using namespace support; 540 541 char *BlockWorkingMem = B.getAlreadyMutableContent().data(); 542 char *FixupPtr = BlockWorkingMem + E.getOffset(); 543 JITTargetAddress FixupAddress = B.getAddress() + E.getOffset(); 544 545 switch (E.getKind()) { 546 case Branch26: { 547 assert((FixupAddress & 0x3) == 0 && "Branch-inst is not 32-bit aligned"); 548 549 int64_t Value = E.getTarget().getAddress() - FixupAddress + E.getAddend(); 550 551 if (static_cast<uint64_t>(Value) & 0x3) 552 return make_error<JITLinkError>("Branch26 target is not 32-bit " 553 "aligned"); 554 555 if (Value < -(1 << 27) || Value > ((1 << 27) - 1)) 556 return makeTargetOutOfRangeError(G, B, E); 557 558 uint32_t RawInstr = *(little32_t *)FixupPtr; 559 assert((RawInstr & 0x7fffffff) == 0x14000000 && 560 "RawInstr isn't a B or BR immediate instruction"); 561 uint32_t Imm = (static_cast<uint32_t>(Value) & ((1 << 28) - 1)) >> 2; 562 uint32_t FixedInstr = RawInstr | Imm; 563 *(little32_t *)FixupPtr = FixedInstr; 564 break; 565 } 566 case Pointer32: { 567 uint64_t Value = E.getTarget().getAddress() + E.getAddend(); 568 if (Value > std::numeric_limits<uint32_t>::max()) 569 return makeTargetOutOfRangeError(G, B, E); 570 *(ulittle32_t *)FixupPtr = Value; 571 break; 572 } 573 case Pointer64: 574 case Pointer64Anon: { 575 uint64_t Value = E.getTarget().getAddress() + E.getAddend(); 576 *(ulittle64_t *)FixupPtr = Value; 577 break; 578 } 579 case Page21: 580 case TLVPage21: 581 case GOTPage21: { 582 assert((E.getKind() != GOTPage21 || E.getAddend() == 0) && 583 "GOTPAGE21 with non-zero addend"); 584 uint64_t TargetPage = 585 (E.getTarget().getAddress() + E.getAddend()) & 586 ~static_cast<uint64_t>(4096 - 1); 587 uint64_t PCPage = FixupAddress & ~static_cast<uint64_t>(4096 - 1); 588 589 int64_t PageDelta = TargetPage - PCPage; 590 if (PageDelta < -(1 << 30) || PageDelta > ((1 << 30) - 1)) 591 return makeTargetOutOfRangeError(G, 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 uint64_t TargetOffset = 604 (E.getTarget().getAddress() + E.getAddend()) & 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 TLVPageOffset12: 618 case GOTPageOffset12: { 619 assert(E.getAddend() == 0 && "GOTPAGEOF12 with non-zero addend"); 620 621 uint32_t RawInstr = *(ulittle32_t *)FixupPtr; 622 assert((RawInstr & 0xfffffc00) == 0xf9400000 && 623 "RawInstr isn't a 64-bit LDR immediate"); 624 625 uint32_t TargetOffset = E.getTarget().getAddress() & 0xfff; 626 assert((TargetOffset & 0x7) == 0 && "GOT entry is not 8-byte aligned"); 627 uint32_t EncodedImm = (TargetOffset >> 3) << 10; 628 uint32_t FixedInstr = RawInstr | EncodedImm; 629 *(ulittle32_t *)FixupPtr = FixedInstr; 630 break; 631 } 632 case LDRLiteral19: { 633 assert((FixupAddress & 0x3) == 0 && "LDR is not 32-bit aligned"); 634 assert(E.getAddend() == 0 && "LDRLiteral19 with non-zero addend"); 635 uint32_t RawInstr = *(ulittle32_t *)FixupPtr; 636 assert(RawInstr == 0x58000010 && "RawInstr isn't a 64-bit LDR literal"); 637 int64_t Delta = E.getTarget().getAddress() - FixupAddress; 638 if (Delta & 0x3) 639 return make_error<JITLinkError>("LDR literal target is not 32-bit " 640 "aligned"); 641 if (Delta < -(1 << 20) || Delta > ((1 << 20) - 1)) 642 return makeTargetOutOfRangeError(G, B, E); 643 644 uint32_t EncodedImm = 645 ((static_cast<uint32_t>(Delta) >> 2) & 0x7ffff) << 5; 646 uint32_t FixedInstr = RawInstr | EncodedImm; 647 *(ulittle32_t *)FixupPtr = FixedInstr; 648 break; 649 } 650 case Delta32: 651 case Delta64: 652 case NegDelta32: 653 case NegDelta64: { 654 int64_t Value; 655 if (E.getKind() == Delta32 || E.getKind() == Delta64) 656 Value = E.getTarget().getAddress() - FixupAddress + E.getAddend(); 657 else 658 Value = FixupAddress - E.getTarget().getAddress() + E.getAddend(); 659 660 if (E.getKind() == Delta32 || E.getKind() == NegDelta32) { 661 if (Value < std::numeric_limits<int32_t>::min() || 662 Value > std::numeric_limits<int32_t>::max()) 663 return makeTargetOutOfRangeError(G, B, E); 664 *(little32_t *)FixupPtr = Value; 665 } else 666 *(little64_t *)FixupPtr = Value; 667 break; 668 } 669 default: 670 llvm_unreachable("Unrecognized edge kind"); 671 } 672 673 return Error::success(); 674 } 675 676 uint64_t NullValue = 0; 677 }; 678 679 Expected<std::unique_ptr<LinkGraph>> 680 createLinkGraphFromMachOObject_arm64(MemoryBufferRef ObjectBuffer) { 681 auto MachOObj = object::ObjectFile::createMachOObjectFile(ObjectBuffer); 682 if (!MachOObj) 683 return MachOObj.takeError(); 684 return MachOLinkGraphBuilder_arm64(**MachOObj).buildGraph(); 685 } 686 687 void link_MachO_arm64(std::unique_ptr<LinkGraph> G, 688 std::unique_ptr<JITLinkContext> Ctx) { 689 690 PassConfiguration Config; 691 692 if (Ctx->shouldAddDefaultTargetPasses(G->getTargetTriple())) { 693 // Add a mark-live pass. 694 if (auto MarkLive = Ctx->getMarkLivePass(G->getTargetTriple())) 695 Config.PrePrunePasses.push_back(std::move(MarkLive)); 696 else 697 Config.PrePrunePasses.push_back(markAllSymbolsLive); 698 699 // Add compact unwind splitter pass. 700 Config.PrePrunePasses.push_back( 701 CompactUnwindSplitter("__LD,__compact_unwind")); 702 703 // Add an in-place GOT/Stubs pass. 704 Config.PostPrunePasses.push_back( 705 PerGraphGOTAndPLTStubsBuilder_MachO_arm64::asPass); 706 } 707 708 if (auto Err = Ctx->modifyPassConfig(*G, Config)) 709 return Ctx->notifyFailed(std::move(Err)); 710 711 // Construct a JITLinker and run the link function. 712 MachOJITLinker_arm64::link(std::move(Ctx), std::move(G), std::move(Config)); 713 } 714 715 const char *getMachOARM64RelocationKindName(Edge::Kind R) { 716 switch (R) { 717 case Branch26: 718 return "Branch26"; 719 case Pointer64: 720 return "Pointer64"; 721 case Pointer64Anon: 722 return "Pointer64Anon"; 723 case Page21: 724 return "Page21"; 725 case PageOffset12: 726 return "PageOffset12"; 727 case GOTPage21: 728 return "GOTPage21"; 729 case GOTPageOffset12: 730 return "GOTPageOffset12"; 731 case TLVPage21: 732 return "TLVPage21"; 733 case TLVPageOffset12: 734 return "TLVPageOffset12"; 735 case PointerToGOT: 736 return "PointerToGOT"; 737 case PairedAddend: 738 return "PairedAddend"; 739 case LDRLiteral19: 740 return "LDRLiteral19"; 741 case Delta32: 742 return "Delta32"; 743 case Delta64: 744 return "Delta64"; 745 case NegDelta32: 746 return "NegDelta32"; 747 case NegDelta64: 748 return "NegDelta64"; 749 default: 750 return getGenericEdgeKindName(static_cast<Edge::Kind>(R)); 751 } 752 } 753 754 } // end namespace jitlink 755 } // end namespace llvm 756