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 orc::ExecutorAddr 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, ToSymbolSec->Address); 164 assert(ToSymbol && "No symbol for section"); 165 FixupValue -= ToSymbol->getAddress().getValue(); 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 orc::ExecutorAddr 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 auto NSec = 209 findSectionByIndex(Obj.getSectionIndex(S.getRawDataRefImpl())); 210 if (!NSec) 211 return NSec.takeError(); 212 213 // Skip relocations for MachO sections without corresponding graph 214 // sections. 215 { 216 if (!NSec->GraphSection) { 217 LLVM_DEBUG({ 218 dbgs() << " Skipping relocations for MachO section " 219 << NSec->SegName << "/" << NSec->SectName 220 << " which has no associated graph section\n"; 221 }); 222 continue; 223 } 224 } 225 226 for (auto RelItr = S.relocation_begin(), RelEnd = S.relocation_end(); 227 RelItr != RelEnd; ++RelItr) { 228 229 MachO::relocation_info RI = getRelocationInfo(RelItr); 230 231 // Validate the relocation kind. 232 auto Kind = getRelocationKind(RI); 233 if (!Kind) 234 return Kind.takeError(); 235 236 // Find the address of the value to fix up. 237 orc::ExecutorAddr FixupAddress = 238 SectionAddress + (uint32_t)RI.r_address; 239 LLVM_DEBUG({ 240 dbgs() << " " << NSec->SectName << " + " 241 << formatv("{0:x8}", RI.r_address) << ":\n"; 242 }); 243 244 // Find the block that the fixup points to. 245 Block *BlockToFix = nullptr; 246 { 247 auto SymbolToFixOrErr = findSymbolByAddress(*NSec, FixupAddress); 248 if (!SymbolToFixOrErr) 249 return SymbolToFixOrErr.takeError(); 250 BlockToFix = &SymbolToFixOrErr->getBlock(); 251 } 252 253 if (FixupAddress + orc::ExecutorAddrDiff(1ULL << RI.r_length) > 254 BlockToFix->getAddress() + BlockToFix->getContent().size()) 255 return make_error<JITLinkError>( 256 "Relocation content extends past end of fixup block"); 257 258 // Get a pointer to the fixup content. 259 const char *FixupContent = BlockToFix->getContent().data() + 260 (FixupAddress - BlockToFix->getAddress()); 261 262 // The target symbol and addend will be populated by the switch below. 263 Symbol *TargetSymbol = nullptr; 264 uint64_t Addend = 0; 265 266 if (*Kind == PairedAddend) { 267 // If this is an Addend relocation then process it and move to the 268 // paired reloc. 269 270 Addend = SignExtend64(RI.r_symbolnum, 24); 271 272 if (RelItr == RelEnd) 273 return make_error<JITLinkError>("Unpaired Addend reloc at " + 274 formatv("{0:x16}", FixupAddress)); 275 ++RelItr; 276 RI = getRelocationInfo(RelItr); 277 278 Kind = getRelocationKind(RI); 279 if (!Kind) 280 return Kind.takeError(); 281 282 if (*Kind != Branch26 && *Kind != Page21 && *Kind != PageOffset12) 283 return make_error<JITLinkError>( 284 "Invalid relocation pair: Addend + " + 285 StringRef(getMachOARM64RelocationKindName(*Kind))); 286 287 LLVM_DEBUG({ 288 dbgs() << " Addend: value = " << formatv("{0:x6}", Addend) 289 << ", pair is " << getMachOARM64RelocationKindName(*Kind) 290 << "\n"; 291 }); 292 293 // Find the address of the value to fix up. 294 orc::ExecutorAddr PairedFixupAddress = 295 SectionAddress + (uint32_t)RI.r_address; 296 if (PairedFixupAddress != FixupAddress) 297 return make_error<JITLinkError>("Paired relocation points at " 298 "different target"); 299 } 300 301 switch (*Kind) { 302 case Branch26: { 303 if (auto TargetSymbolOrErr = findSymbolByIndex(RI.r_symbolnum)) 304 TargetSymbol = TargetSymbolOrErr->GraphSymbol; 305 else 306 return TargetSymbolOrErr.takeError(); 307 uint32_t Instr = *(const ulittle32_t *)FixupContent; 308 if ((Instr & 0x7fffffff) != 0x14000000) 309 return make_error<JITLinkError>("BRANCH26 target is not a B or BL " 310 "instruction with a zero addend"); 311 break; 312 } 313 case Pointer32: 314 if (auto TargetSymbolOrErr = findSymbolByIndex(RI.r_symbolnum)) 315 TargetSymbol = TargetSymbolOrErr->GraphSymbol; 316 else 317 return TargetSymbolOrErr.takeError(); 318 Addend = *(const ulittle32_t *)FixupContent; 319 break; 320 case Pointer64: 321 if (auto TargetSymbolOrErr = findSymbolByIndex(RI.r_symbolnum)) 322 TargetSymbol = TargetSymbolOrErr->GraphSymbol; 323 else 324 return TargetSymbolOrErr.takeError(); 325 Addend = *(const ulittle64_t *)FixupContent; 326 break; 327 case Pointer64Anon: { 328 orc::ExecutorAddr TargetAddress(*(const ulittle64_t *)FixupContent); 329 auto TargetNSec = findSectionByIndex(RI.r_symbolnum - 1); 330 if (!TargetNSec) 331 return TargetNSec.takeError(); 332 if (auto TargetSymbolOrErr = 333 findSymbolByAddress(*TargetNSec, TargetAddress)) 334 TargetSymbol = &*TargetSymbolOrErr; 335 else 336 return TargetSymbolOrErr.takeError(); 337 Addend = TargetAddress - TargetSymbol->getAddress(); 338 break; 339 } 340 case Page21: 341 case TLVPage21: 342 case GOTPage21: { 343 if (auto TargetSymbolOrErr = findSymbolByIndex(RI.r_symbolnum)) 344 TargetSymbol = TargetSymbolOrErr->GraphSymbol; 345 else 346 return TargetSymbolOrErr.takeError(); 347 uint32_t Instr = *(const ulittle32_t *)FixupContent; 348 if ((Instr & 0xffffffe0) != 0x90000000) 349 return make_error<JITLinkError>("PAGE21/GOTPAGE21 target is not an " 350 "ADRP instruction with a zero " 351 "addend"); 352 break; 353 } 354 case PageOffset12: { 355 if (auto TargetSymbolOrErr = findSymbolByIndex(RI.r_symbolnum)) 356 TargetSymbol = TargetSymbolOrErr->GraphSymbol; 357 else 358 return TargetSymbolOrErr.takeError(); 359 uint32_t Instr = *(const ulittle32_t *)FixupContent; 360 uint32_t EncodedAddend = (Instr & 0x003FFC00) >> 10; 361 if (EncodedAddend != 0) 362 return make_error<JITLinkError>("GOTPAGEOFF12 target has non-zero " 363 "encoded addend"); 364 break; 365 } 366 case TLVPageOffset12: 367 case GOTPageOffset12: { 368 if (auto TargetSymbolOrErr = findSymbolByIndex(RI.r_symbolnum)) 369 TargetSymbol = TargetSymbolOrErr->GraphSymbol; 370 else 371 return TargetSymbolOrErr.takeError(); 372 uint32_t Instr = *(const ulittle32_t *)FixupContent; 373 if ((Instr & 0xfffffc00) != 0xf9400000) 374 return make_error<JITLinkError>("GOTPAGEOFF12 target is not an LDR " 375 "immediate instruction with a zero " 376 "addend"); 377 break; 378 } 379 case PointerToGOT: 380 if (auto TargetSymbolOrErr = findSymbolByIndex(RI.r_symbolnum)) 381 TargetSymbol = TargetSymbolOrErr->GraphSymbol; 382 else 383 return TargetSymbolOrErr.takeError(); 384 break; 385 case Delta32: 386 case Delta64: { 387 // We use Delta32/Delta64 to represent SUBTRACTOR relocations. 388 // parsePairRelocation handles the paired reloc, and returns the 389 // edge kind to be used (either Delta32/Delta64, or 390 // NegDelta32/NegDelta64, depending on the direction of the 391 // subtraction) along with the addend. 392 auto PairInfo = 393 parsePairRelocation(*BlockToFix, *Kind, RI, FixupAddress, 394 FixupContent, ++RelItr, RelEnd); 395 if (!PairInfo) 396 return PairInfo.takeError(); 397 std::tie(*Kind, TargetSymbol, Addend) = *PairInfo; 398 assert(TargetSymbol && "No target symbol from parsePairRelocation?"); 399 break; 400 } 401 default: 402 llvm_unreachable("Special relocation kind should not appear in " 403 "mach-o file"); 404 } 405 406 LLVM_DEBUG({ 407 dbgs() << " "; 408 Edge GE(*Kind, FixupAddress - BlockToFix->getAddress(), *TargetSymbol, 409 Addend); 410 printEdge(dbgs(), *BlockToFix, GE, 411 getMachOARM64RelocationKindName(*Kind)); 412 dbgs() << "\n"; 413 }); 414 BlockToFix->addEdge(*Kind, FixupAddress - BlockToFix->getAddress(), 415 *TargetSymbol, Addend); 416 } 417 } 418 return Error::success(); 419 } 420 421 unsigned NumSymbols = 0; 422 }; 423 424 class PerGraphGOTAndPLTStubsBuilder_MachO_arm64 425 : public PerGraphGOTAndPLTStubsBuilder< 426 PerGraphGOTAndPLTStubsBuilder_MachO_arm64> { 427 public: 428 using PerGraphGOTAndPLTStubsBuilder< 429 PerGraphGOTAndPLTStubsBuilder_MachO_arm64>::PerGraphGOTAndPLTStubsBuilder; 430 431 bool isGOTEdgeToFix(Edge &E) const { 432 return E.getKind() == GOTPage21 || E.getKind() == GOTPageOffset12 || 433 E.getKind() == TLVPage21 || E.getKind() == TLVPageOffset12 || 434 E.getKind() == PointerToGOT; 435 } 436 437 Symbol &createGOTEntry(Symbol &Target) { 438 auto &GOTEntryBlock = G.createContentBlock( 439 getGOTSection(), getGOTEntryBlockContent(), orc::ExecutorAddr(), 8, 0); 440 GOTEntryBlock.addEdge(Pointer64, 0, Target, 0); 441 return G.addAnonymousSymbol(GOTEntryBlock, 0, 8, false, false); 442 } 443 444 void fixGOTEdge(Edge &E, Symbol &GOTEntry) { 445 if (E.getKind() == GOTPage21 || E.getKind() == GOTPageOffset12 || 446 E.getKind() == TLVPage21 || E.getKind() == TLVPageOffset12) { 447 // Update the target, but leave the edge addend as-is. 448 E.setTarget(GOTEntry); 449 } else if (E.getKind() == PointerToGOT) { 450 E.setTarget(GOTEntry); 451 E.setKind(Delta32); 452 } else 453 llvm_unreachable("Not a GOT edge?"); 454 } 455 456 bool isExternalBranchEdge(Edge &E) { 457 return E.getKind() == Branch26 && !E.getTarget().isDefined(); 458 } 459 460 Symbol &createPLTStub(Symbol &Target) { 461 auto &StubContentBlock = G.createContentBlock( 462 getStubsSection(), getStubBlockContent(), orc::ExecutorAddr(), 1, 0); 463 // Re-use GOT entries for stub targets. 464 auto &GOTEntrySymbol = getGOTEntry(Target); 465 StubContentBlock.addEdge(LDRLiteral19, 0, GOTEntrySymbol, 0); 466 return G.addAnonymousSymbol(StubContentBlock, 0, 8, true, false); 467 } 468 469 void fixPLTEdge(Edge &E, Symbol &Stub) { 470 assert(E.getKind() == Branch26 && "Not a Branch32 edge?"); 471 assert(E.getAddend() == 0 && "Branch32 edge has non-zero addend?"); 472 E.setTarget(Stub); 473 } 474 475 private: 476 Section &getGOTSection() { 477 if (!GOTSection) 478 GOTSection = &G.createSection("$__GOT", MemProt::Read | MemProt::Exec); 479 return *GOTSection; 480 } 481 482 Section &getStubsSection() { 483 if (!StubsSection) 484 StubsSection = 485 &G.createSection("$__STUBS", MemProt::Read | MemProt::Exec); 486 return *StubsSection; 487 } 488 489 ArrayRef<char> getGOTEntryBlockContent() { 490 return {reinterpret_cast<const char *>(NullGOTEntryContent), 491 sizeof(NullGOTEntryContent)}; 492 } 493 494 ArrayRef<char> getStubBlockContent() { 495 return {reinterpret_cast<const char *>(StubContent), sizeof(StubContent)}; 496 } 497 498 static const uint8_t NullGOTEntryContent[8]; 499 static const uint8_t StubContent[8]; 500 Section *GOTSection = nullptr; 501 Section *StubsSection = nullptr; 502 }; 503 504 const uint8_t 505 PerGraphGOTAndPLTStubsBuilder_MachO_arm64::NullGOTEntryContent[8] = { 506 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00}; 507 const uint8_t PerGraphGOTAndPLTStubsBuilder_MachO_arm64::StubContent[8] = { 508 0x10, 0x00, 0x00, 0x58, // LDR x16, <literal> 509 0x00, 0x02, 0x1f, 0xd6 // BR x16 510 }; 511 512 } // namespace 513 514 namespace llvm { 515 namespace jitlink { 516 517 class MachOJITLinker_arm64 : public JITLinker<MachOJITLinker_arm64> { 518 friend class JITLinker<MachOJITLinker_arm64>; 519 520 public: 521 MachOJITLinker_arm64(std::unique_ptr<JITLinkContext> Ctx, 522 std::unique_ptr<LinkGraph> G, 523 PassConfiguration PassConfig) 524 : JITLinker(std::move(Ctx), std::move(G), std::move(PassConfig)) {} 525 526 private: 527 528 static unsigned getPageOffset12Shift(uint32_t Instr) { 529 constexpr uint32_t LoadStoreImm12Mask = 0x3b000000; 530 constexpr uint32_t Vec128Mask = 0x04800000; 531 532 if ((Instr & LoadStoreImm12Mask) == 0x39000000) { 533 uint32_t ImplicitShift = Instr >> 30; 534 if (ImplicitShift == 0) 535 if ((Instr & Vec128Mask) == Vec128Mask) 536 ImplicitShift = 4; 537 538 return ImplicitShift; 539 } 540 541 return 0; 542 } 543 544 Error applyFixup(LinkGraph &G, Block &B, const Edge &E) const { 545 using namespace support; 546 547 char *BlockWorkingMem = B.getAlreadyMutableContent().data(); 548 char *FixupPtr = BlockWorkingMem + E.getOffset(); 549 orc::ExecutorAddr FixupAddress = B.getAddress() + E.getOffset(); 550 551 switch (E.getKind()) { 552 case Branch26: { 553 assert((FixupAddress.getValue() & 0x3) == 0 && 554 "Branch-inst is not 32-bit aligned"); 555 556 int64_t Value = E.getTarget().getAddress() - FixupAddress + E.getAddend(); 557 558 if (static_cast<uint64_t>(Value) & 0x3) 559 return make_error<JITLinkError>("Branch26 target is not 32-bit " 560 "aligned"); 561 562 if (Value < -(1 << 27) || Value > ((1 << 27) - 1)) 563 return makeTargetOutOfRangeError(G, B, E); 564 565 uint32_t RawInstr = *(little32_t *)FixupPtr; 566 assert((RawInstr & 0x7fffffff) == 0x14000000 && 567 "RawInstr isn't a B or BR immediate instruction"); 568 uint32_t Imm = (static_cast<uint32_t>(Value) & ((1 << 28) - 1)) >> 2; 569 uint32_t FixedInstr = RawInstr | Imm; 570 *(little32_t *)FixupPtr = FixedInstr; 571 break; 572 } 573 case Pointer32: { 574 uint64_t Value = E.getTarget().getAddress().getValue() + E.getAddend(); 575 if (Value > std::numeric_limits<uint32_t>::max()) 576 return makeTargetOutOfRangeError(G, B, E); 577 *(ulittle32_t *)FixupPtr = Value; 578 break; 579 } 580 case Pointer64: 581 case Pointer64Anon: { 582 uint64_t Value = E.getTarget().getAddress().getValue() + E.getAddend(); 583 *(ulittle64_t *)FixupPtr = Value; 584 break; 585 } 586 case Page21: 587 case TLVPage21: 588 case GOTPage21: { 589 assert((E.getKind() != GOTPage21 || E.getAddend() == 0) && 590 "GOTPAGE21 with non-zero addend"); 591 uint64_t TargetPage = 592 (E.getTarget().getAddress().getValue() + E.getAddend()) & 593 ~static_cast<uint64_t>(4096 - 1); 594 uint64_t PCPage = 595 FixupAddress.getValue() & ~static_cast<uint64_t>(4096 - 1); 596 597 int64_t PageDelta = TargetPage - PCPage; 598 if (PageDelta < -(1 << 30) || PageDelta > ((1 << 30) - 1)) 599 return makeTargetOutOfRangeError(G, B, E); 600 601 uint32_t RawInstr = *(ulittle32_t *)FixupPtr; 602 assert((RawInstr & 0xffffffe0) == 0x90000000 && 603 "RawInstr isn't an ADRP instruction"); 604 uint32_t ImmLo = (static_cast<uint64_t>(PageDelta) >> 12) & 0x3; 605 uint32_t ImmHi = (static_cast<uint64_t>(PageDelta) >> 14) & 0x7ffff; 606 uint32_t FixedInstr = RawInstr | (ImmLo << 29) | (ImmHi << 5); 607 *(ulittle32_t *)FixupPtr = FixedInstr; 608 break; 609 } 610 case PageOffset12: { 611 uint64_t TargetOffset = 612 (E.getTarget().getAddress() + E.getAddend()).getValue() & 0xfff; 613 614 uint32_t RawInstr = *(ulittle32_t *)FixupPtr; 615 unsigned ImmShift = getPageOffset12Shift(RawInstr); 616 617 if (TargetOffset & ((1 << ImmShift) - 1)) 618 return make_error<JITLinkError>("PAGEOFF12 target is not aligned"); 619 620 uint32_t EncodedImm = (TargetOffset >> ImmShift) << 10; 621 uint32_t FixedInstr = RawInstr | EncodedImm; 622 *(ulittle32_t *)FixupPtr = FixedInstr; 623 break; 624 } 625 case TLVPageOffset12: 626 case GOTPageOffset12: { 627 assert(E.getAddend() == 0 && "GOTPAGEOF12 with non-zero addend"); 628 629 uint32_t RawInstr = *(ulittle32_t *)FixupPtr; 630 assert((RawInstr & 0xfffffc00) == 0xf9400000 && 631 "RawInstr isn't a 64-bit LDR immediate"); 632 633 uint32_t TargetOffset = E.getTarget().getAddress().getValue() & 0xfff; 634 assert((TargetOffset & 0x7) == 0 && "GOT entry is not 8-byte aligned"); 635 uint32_t EncodedImm = (TargetOffset >> 3) << 10; 636 uint32_t FixedInstr = RawInstr | EncodedImm; 637 *(ulittle32_t *)FixupPtr = FixedInstr; 638 break; 639 } 640 case LDRLiteral19: { 641 assert((FixupAddress.getValue() & 0x3) == 0 && 642 "LDR is not 32-bit aligned"); 643 assert(E.getAddend() == 0 && "LDRLiteral19 with non-zero addend"); 644 uint32_t RawInstr = *(ulittle32_t *)FixupPtr; 645 assert(RawInstr == 0x58000010 && "RawInstr isn't a 64-bit LDR literal"); 646 int64_t Delta = E.getTarget().getAddress() - FixupAddress; 647 if (Delta & 0x3) 648 return make_error<JITLinkError>("LDR literal target is not 32-bit " 649 "aligned"); 650 if (Delta < -(1 << 20) || Delta > ((1 << 20) - 1)) 651 return makeTargetOutOfRangeError(G, B, E); 652 653 uint32_t EncodedImm = 654 ((static_cast<uint32_t>(Delta) >> 2) & 0x7ffff) << 5; 655 uint32_t FixedInstr = RawInstr | EncodedImm; 656 *(ulittle32_t *)FixupPtr = FixedInstr; 657 break; 658 } 659 case Delta32: 660 case Delta64: 661 case NegDelta32: 662 case NegDelta64: { 663 int64_t Value; 664 if (E.getKind() == Delta32 || E.getKind() == Delta64) 665 Value = E.getTarget().getAddress() - FixupAddress + E.getAddend(); 666 else 667 Value = FixupAddress - E.getTarget().getAddress() + E.getAddend(); 668 669 if (E.getKind() == Delta32 || E.getKind() == NegDelta32) { 670 if (Value < std::numeric_limits<int32_t>::min() || 671 Value > std::numeric_limits<int32_t>::max()) 672 return makeTargetOutOfRangeError(G, B, E); 673 *(little32_t *)FixupPtr = Value; 674 } else 675 *(little64_t *)FixupPtr = Value; 676 break; 677 } 678 default: 679 llvm_unreachable("Unrecognized edge kind"); 680 } 681 682 return Error::success(); 683 } 684 685 uint64_t NullValue = 0; 686 }; 687 688 Expected<std::unique_ptr<LinkGraph>> 689 createLinkGraphFromMachOObject_arm64(MemoryBufferRef ObjectBuffer) { 690 auto MachOObj = object::ObjectFile::createMachOObjectFile(ObjectBuffer); 691 if (!MachOObj) 692 return MachOObj.takeError(); 693 return MachOLinkGraphBuilder_arm64(**MachOObj).buildGraph(); 694 } 695 696 void link_MachO_arm64(std::unique_ptr<LinkGraph> G, 697 std::unique_ptr<JITLinkContext> Ctx) { 698 699 PassConfiguration Config; 700 701 if (Ctx->shouldAddDefaultTargetPasses(G->getTargetTriple())) { 702 // Add a mark-live pass. 703 if (auto MarkLive = Ctx->getMarkLivePass(G->getTargetTriple())) 704 Config.PrePrunePasses.push_back(std::move(MarkLive)); 705 else 706 Config.PrePrunePasses.push_back(markAllSymbolsLive); 707 708 // Add compact unwind splitter pass. 709 Config.PrePrunePasses.push_back( 710 CompactUnwindSplitter("__LD,__compact_unwind")); 711 712 // Add eh-frame passses. 713 // FIXME: Prune eh-frames for which compact-unwind is available once 714 // we support compact-unwind registration with libunwind. 715 Config.PrePrunePasses.push_back(EHFrameSplitter("__TEXT,__eh_frame")); 716 Config.PrePrunePasses.push_back( 717 EHFrameEdgeFixer("__TEXT,__eh_frame", 8, Delta64, Delta32, NegDelta32)); 718 719 // Add an in-place GOT/Stubs pass. 720 Config.PostPrunePasses.push_back( 721 PerGraphGOTAndPLTStubsBuilder_MachO_arm64::asPass); 722 } 723 724 if (auto Err = Ctx->modifyPassConfig(*G, Config)) 725 return Ctx->notifyFailed(std::move(Err)); 726 727 // Construct a JITLinker and run the link function. 728 MachOJITLinker_arm64::link(std::move(Ctx), std::move(G), std::move(Config)); 729 } 730 731 const char *getMachOARM64RelocationKindName(Edge::Kind R) { 732 switch (R) { 733 case Branch26: 734 return "Branch26"; 735 case Pointer64: 736 return "Pointer64"; 737 case Pointer64Anon: 738 return "Pointer64Anon"; 739 case Page21: 740 return "Page21"; 741 case PageOffset12: 742 return "PageOffset12"; 743 case GOTPage21: 744 return "GOTPage21"; 745 case GOTPageOffset12: 746 return "GOTPageOffset12"; 747 case TLVPage21: 748 return "TLVPage21"; 749 case TLVPageOffset12: 750 return "TLVPageOffset12"; 751 case PointerToGOT: 752 return "PointerToGOT"; 753 case PairedAddend: 754 return "PairedAddend"; 755 case LDRLiteral19: 756 return "LDRLiteral19"; 757 case Delta32: 758 return "Delta32"; 759 case Delta64: 760 return "Delta64"; 761 case NegDelta32: 762 return "NegDelta32"; 763 case NegDelta64: 764 return "NegDelta64"; 765 default: 766 return getGenericEdgeKindName(static_cast<Edge::Kind>(R)); 767 } 768 } 769 770 } // end namespace jitlink 771 } // end namespace llvm 772