1 //===- bolt/Core/BinaryContext.cpp - Low-level context --------------------===// 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 // This file implements the BinaryContext class. 10 // 11 //===----------------------------------------------------------------------===// 12 13 #include "bolt/Core/BinaryContext.h" 14 #include "bolt/Core/BinaryEmitter.h" 15 #include "bolt/Core/BinaryFunction.h" 16 #include "bolt/Utils/CommandLineOpts.h" 17 #include "bolt/Utils/Utils.h" 18 #include "llvm/ADT/STLExtras.h" 19 #include "llvm/ADT/Twine.h" 20 #include "llvm/DebugInfo/DWARF/DWARFCompileUnit.h" 21 #include "llvm/DebugInfo/DWARF/DWARFFormValue.h" 22 #include "llvm/DebugInfo/DWARF/DWARFUnit.h" 23 #include "llvm/MC/MCAsmLayout.h" 24 #include "llvm/MC/MCAssembler.h" 25 #include "llvm/MC/MCContext.h" 26 #include "llvm/MC/MCDisassembler/MCDisassembler.h" 27 #include "llvm/MC/MCInstPrinter.h" 28 #include "llvm/MC/MCObjectStreamer.h" 29 #include "llvm/MC/MCObjectWriter.h" 30 #include "llvm/MC/MCRegisterInfo.h" 31 #include "llvm/MC/MCSectionELF.h" 32 #include "llvm/MC/MCStreamer.h" 33 #include "llvm/MC/MCSubtargetInfo.h" 34 #include "llvm/MC/MCSymbol.h" 35 #include "llvm/Support/CommandLine.h" 36 #include "llvm/Support/Error.h" 37 #include "llvm/Support/Regex.h" 38 #include <algorithm> 39 #include <functional> 40 #include <iterator> 41 #include <unordered_set> 42 43 using namespace llvm; 44 45 #undef DEBUG_TYPE 46 #define DEBUG_TYPE "bolt" 47 48 namespace opts { 49 50 cl::opt<bool> NoHugePages("no-huge-pages", 51 cl::desc("use regular size pages for code alignment"), 52 cl::Hidden, cl::cat(BoltCategory)); 53 54 static cl::opt<bool> 55 PrintDebugInfo("print-debug-info", 56 cl::desc("print debug info when printing functions"), 57 cl::Hidden, 58 cl::ZeroOrMore, 59 cl::cat(BoltCategory)); 60 61 cl::opt<bool> PrintRelocations( 62 "print-relocations", 63 cl::desc("print relocations when printing functions/objects"), cl::Hidden, 64 cl::cat(BoltCategory)); 65 66 static cl::opt<bool> 67 PrintMemData("print-mem-data", 68 cl::desc("print memory data annotations when printing functions"), 69 cl::Hidden, 70 cl::ZeroOrMore, 71 cl::cat(BoltCategory)); 72 73 cl::opt<std::string> CompDirOverride( 74 "comp-dir-override", 75 cl::desc("overrides DW_AT_comp_dir, and provides an alterantive base " 76 "location, which is used with DW_AT_dwo_name to construct a path " 77 "to *.dwo files."), 78 cl::Hidden, cl::init(""), cl::cat(BoltCategory)); 79 } // namespace opts 80 81 namespace llvm { 82 namespace bolt { 83 84 char BOLTError::ID = 0; 85 86 BOLTError::BOLTError(bool IsFatal, const Twine &S) 87 : IsFatal(IsFatal), Msg(S.str()) {} 88 89 void BOLTError::log(raw_ostream &OS) const { 90 if (IsFatal) 91 OS << "FATAL "; 92 StringRef ErrMsg = StringRef(Msg); 93 // Prepend our error prefix if it is missing 94 if (ErrMsg.empty()) { 95 OS << "BOLT-ERROR\n"; 96 } else { 97 if (!ErrMsg.starts_with("BOLT-ERROR")) 98 OS << "BOLT-ERROR: "; 99 OS << ErrMsg << "\n"; 100 } 101 } 102 103 std::error_code BOLTError::convertToErrorCode() const { 104 return inconvertibleErrorCode(); 105 } 106 107 Error createNonFatalBOLTError(const Twine &S) { 108 return make_error<BOLTError>(/*IsFatal*/ false, S); 109 } 110 111 Error createFatalBOLTError(const Twine &S) { 112 return make_error<BOLTError>(/*IsFatal*/ true, S); 113 } 114 115 void BinaryContext::logBOLTErrorsAndQuitOnFatal(Error E) { 116 handleAllErrors(Error(std::move(E)), [&](const BOLTError &E) { 117 if (!E.getMessage().empty()) 118 E.log(this->errs()); 119 if (E.isFatal()) 120 exit(1); 121 }); 122 } 123 124 BinaryContext::BinaryContext(std::unique_ptr<MCContext> Ctx, 125 std::unique_ptr<DWARFContext> DwCtx, 126 std::unique_ptr<Triple> TheTriple, 127 const Target *TheTarget, std::string TripleName, 128 std::unique_ptr<MCCodeEmitter> MCE, 129 std::unique_ptr<MCObjectFileInfo> MOFI, 130 std::unique_ptr<const MCAsmInfo> AsmInfo, 131 std::unique_ptr<const MCInstrInfo> MII, 132 std::unique_ptr<const MCSubtargetInfo> STI, 133 std::unique_ptr<MCInstPrinter> InstPrinter, 134 std::unique_ptr<const MCInstrAnalysis> MIA, 135 std::unique_ptr<MCPlusBuilder> MIB, 136 std::unique_ptr<const MCRegisterInfo> MRI, 137 std::unique_ptr<MCDisassembler> DisAsm, 138 JournalingStreams Logger) 139 : Ctx(std::move(Ctx)), DwCtx(std::move(DwCtx)), 140 TheTriple(std::move(TheTriple)), TheTarget(TheTarget), 141 TripleName(TripleName), MCE(std::move(MCE)), MOFI(std::move(MOFI)), 142 AsmInfo(std::move(AsmInfo)), MII(std::move(MII)), STI(std::move(STI)), 143 InstPrinter(std::move(InstPrinter)), MIA(std::move(MIA)), 144 MIB(std::move(MIB)), MRI(std::move(MRI)), DisAsm(std::move(DisAsm)), 145 Logger(Logger), InitialDynoStats(isAArch64()) { 146 Relocation::Arch = this->TheTriple->getArch(); 147 RegularPageSize = isAArch64() ? RegularPageSizeAArch64 : RegularPageSizeX86; 148 PageAlign = opts::NoHugePages ? RegularPageSize : HugePageSize; 149 } 150 151 BinaryContext::~BinaryContext() { 152 for (BinarySection *Section : Sections) 153 delete Section; 154 for (BinaryFunction *InjectedFunction : InjectedBinaryFunctions) 155 delete InjectedFunction; 156 for (std::pair<const uint64_t, JumpTable *> JTI : JumpTables) 157 delete JTI.second; 158 clearBinaryData(); 159 } 160 161 /// Create BinaryContext for a given architecture \p ArchName and 162 /// triple \p TripleName. 163 Expected<std::unique_ptr<BinaryContext>> BinaryContext::createBinaryContext( 164 Triple TheTriple, StringRef InputFileName, SubtargetFeatures *Features, 165 bool IsPIC, std::unique_ptr<DWARFContext> DwCtx, JournalingStreams Logger) { 166 StringRef ArchName = ""; 167 std::string FeaturesStr = ""; 168 switch (TheTriple.getArch()) { 169 case llvm::Triple::x86_64: 170 if (Features) 171 return createFatalBOLTError( 172 "x86_64 target does not use SubtargetFeatures"); 173 ArchName = "x86-64"; 174 FeaturesStr = "+nopl"; 175 break; 176 case llvm::Triple::aarch64: 177 if (Features) 178 return createFatalBOLTError( 179 "AArch64 target does not use SubtargetFeatures"); 180 ArchName = "aarch64"; 181 FeaturesStr = "+all"; 182 break; 183 case llvm::Triple::riscv64: { 184 ArchName = "riscv64"; 185 if (!Features) 186 return createFatalBOLTError("RISCV target needs SubtargetFeatures"); 187 // We rely on relaxation for some transformations (e.g., promoting all calls 188 // to PseudoCALL and then making JITLink relax them). Since the relax 189 // feature is not stored in the object file, we manually enable it. 190 Features->AddFeature("relax"); 191 FeaturesStr = Features->getString(); 192 break; 193 } 194 default: 195 return createStringError(std::errc::not_supported, 196 "BOLT-ERROR: Unrecognized machine in ELF file"); 197 } 198 199 const std::string TripleName = TheTriple.str(); 200 201 std::string Error; 202 const Target *TheTarget = 203 TargetRegistry::lookupTarget(std::string(ArchName), TheTriple, Error); 204 if (!TheTarget) 205 return createStringError(make_error_code(std::errc::not_supported), 206 Twine("BOLT-ERROR: ", Error)); 207 208 std::unique_ptr<const MCRegisterInfo> MRI( 209 TheTarget->createMCRegInfo(TripleName)); 210 if (!MRI) 211 return createStringError( 212 make_error_code(std::errc::not_supported), 213 Twine("BOLT-ERROR: no register info for target ", TripleName)); 214 215 // Set up disassembler. 216 std::unique_ptr<MCAsmInfo> AsmInfo( 217 TheTarget->createMCAsmInfo(*MRI, TripleName, MCTargetOptions())); 218 if (!AsmInfo) 219 return createStringError( 220 make_error_code(std::errc::not_supported), 221 Twine("BOLT-ERROR: no assembly info for target ", TripleName)); 222 // BOLT creates "func@PLT" symbols for PLT entries. In function assembly dump 223 // we want to emit such names as using @PLT without double quotes to convey 224 // variant kind to the assembler. BOLT doesn't rely on the linker so we can 225 // override the default AsmInfo behavior to emit names the way we want. 226 AsmInfo->setAllowAtInName(true); 227 228 std::unique_ptr<const MCSubtargetInfo> STI( 229 TheTarget->createMCSubtargetInfo(TripleName, "", FeaturesStr)); 230 if (!STI) 231 return createStringError( 232 make_error_code(std::errc::not_supported), 233 Twine("BOLT-ERROR: no subtarget info for target ", TripleName)); 234 235 std::unique_ptr<const MCInstrInfo> MII(TheTarget->createMCInstrInfo()); 236 if (!MII) 237 return createStringError( 238 make_error_code(std::errc::not_supported), 239 Twine("BOLT-ERROR: no instruction info for target ", TripleName)); 240 241 std::unique_ptr<MCContext> Ctx( 242 new MCContext(TheTriple, AsmInfo.get(), MRI.get(), STI.get())); 243 std::unique_ptr<MCObjectFileInfo> MOFI( 244 TheTarget->createMCObjectFileInfo(*Ctx, IsPIC)); 245 Ctx->setObjectFileInfo(MOFI.get()); 246 // We do not support X86 Large code model. Change this in the future. 247 bool Large = false; 248 if (TheTriple.getArch() == llvm::Triple::aarch64) 249 Large = true; 250 unsigned LSDAEncoding = 251 Large ? dwarf::DW_EH_PE_absptr : dwarf::DW_EH_PE_udata4; 252 if (IsPIC) { 253 LSDAEncoding = dwarf::DW_EH_PE_pcrel | 254 (Large ? dwarf::DW_EH_PE_sdata8 : dwarf::DW_EH_PE_sdata4); 255 } 256 257 std::unique_ptr<MCDisassembler> DisAsm( 258 TheTarget->createMCDisassembler(*STI, *Ctx)); 259 260 if (!DisAsm) 261 return createStringError( 262 make_error_code(std::errc::not_supported), 263 Twine("BOLT-ERROR: no disassembler info for target ", TripleName)); 264 265 std::unique_ptr<const MCInstrAnalysis> MIA( 266 TheTarget->createMCInstrAnalysis(MII.get())); 267 if (!MIA) 268 return createStringError( 269 make_error_code(std::errc::not_supported), 270 Twine("BOLT-ERROR: failed to create instruction analysis for target ", 271 TripleName)); 272 273 int AsmPrinterVariant = AsmInfo->getAssemblerDialect(); 274 std::unique_ptr<MCInstPrinter> InstructionPrinter( 275 TheTarget->createMCInstPrinter(TheTriple, AsmPrinterVariant, *AsmInfo, 276 *MII, *MRI)); 277 if (!InstructionPrinter) 278 return createStringError( 279 make_error_code(std::errc::not_supported), 280 Twine("BOLT-ERROR: no instruction printer for target ", TripleName)); 281 InstructionPrinter->setPrintImmHex(true); 282 283 std::unique_ptr<MCCodeEmitter> MCE( 284 TheTarget->createMCCodeEmitter(*MII, *Ctx)); 285 286 auto BC = std::make_unique<BinaryContext>( 287 std::move(Ctx), std::move(DwCtx), std::make_unique<Triple>(TheTriple), 288 TheTarget, std::string(TripleName), std::move(MCE), std::move(MOFI), 289 std::move(AsmInfo), std::move(MII), std::move(STI), 290 std::move(InstructionPrinter), std::move(MIA), nullptr, std::move(MRI), 291 std::move(DisAsm), Logger); 292 293 BC->LSDAEncoding = LSDAEncoding; 294 295 BC->MAB = std::unique_ptr<MCAsmBackend>( 296 BC->TheTarget->createMCAsmBackend(*BC->STI, *BC->MRI, MCTargetOptions())); 297 298 BC->setFilename(InputFileName); 299 300 BC->HasFixedLoadAddress = !IsPIC; 301 302 BC->SymbolicDisAsm = std::unique_ptr<MCDisassembler>( 303 BC->TheTarget->createMCDisassembler(*BC->STI, *BC->Ctx)); 304 305 if (!BC->SymbolicDisAsm) 306 return createStringError( 307 make_error_code(std::errc::not_supported), 308 Twine("BOLT-ERROR: no disassembler info for target ", TripleName)); 309 310 return std::move(BC); 311 } 312 313 bool BinaryContext::forceSymbolRelocations(StringRef SymbolName) const { 314 if (opts::HotText && 315 (SymbolName == "__hot_start" || SymbolName == "__hot_end")) 316 return true; 317 318 if (opts::HotData && 319 (SymbolName == "__hot_data_start" || SymbolName == "__hot_data_end")) 320 return true; 321 322 if (SymbolName == "_end") 323 return true; 324 325 return false; 326 } 327 328 std::unique_ptr<MCObjectWriter> 329 BinaryContext::createObjectWriter(raw_pwrite_stream &OS) { 330 return MAB->createObjectWriter(OS); 331 } 332 333 bool BinaryContext::validateObjectNesting() const { 334 auto Itr = BinaryDataMap.begin(); 335 auto End = BinaryDataMap.end(); 336 bool Valid = true; 337 while (Itr != End) { 338 auto Next = std::next(Itr); 339 while (Next != End && 340 Itr->second->getSection() == Next->second->getSection() && 341 Itr->second->containsRange(Next->second->getAddress(), 342 Next->second->getSize())) { 343 if (Next->second->Parent != Itr->second) { 344 this->errs() << "BOLT-WARNING: object nesting incorrect for:\n" 345 << "BOLT-WARNING: " << *Itr->second << "\n" 346 << "BOLT-WARNING: " << *Next->second << "\n"; 347 Valid = false; 348 } 349 ++Next; 350 } 351 Itr = Next; 352 } 353 return Valid; 354 } 355 356 bool BinaryContext::validateHoles() const { 357 bool Valid = true; 358 for (BinarySection &Section : sections()) { 359 for (const Relocation &Rel : Section.relocations()) { 360 uint64_t RelAddr = Rel.Offset + Section.getAddress(); 361 const BinaryData *BD = getBinaryDataContainingAddress(RelAddr); 362 if (!BD) { 363 this->errs() 364 << "BOLT-WARNING: no BinaryData found for relocation at address" 365 << " 0x" << Twine::utohexstr(RelAddr) << " in " << Section.getName() 366 << "\n"; 367 Valid = false; 368 } else if (!BD->getAtomicRoot()) { 369 this->errs() 370 << "BOLT-WARNING: no atomic BinaryData found for relocation at " 371 << "address 0x" << Twine::utohexstr(RelAddr) << " in " 372 << Section.getName() << "\n"; 373 Valid = false; 374 } 375 } 376 } 377 return Valid; 378 } 379 380 void BinaryContext::updateObjectNesting(BinaryDataMapType::iterator GAI) { 381 const uint64_t Address = GAI->second->getAddress(); 382 const uint64_t Size = GAI->second->getSize(); 383 384 auto fixParents = [&](BinaryDataMapType::iterator Itr, 385 BinaryData *NewParent) { 386 BinaryData *OldParent = Itr->second->Parent; 387 Itr->second->Parent = NewParent; 388 ++Itr; 389 while (Itr != BinaryDataMap.end() && OldParent && 390 Itr->second->Parent == OldParent) { 391 Itr->second->Parent = NewParent; 392 ++Itr; 393 } 394 }; 395 396 // Check if the previous symbol contains the newly added symbol. 397 if (GAI != BinaryDataMap.begin()) { 398 BinaryData *Prev = std::prev(GAI)->second; 399 while (Prev) { 400 if (Prev->getSection() == GAI->second->getSection() && 401 Prev->containsRange(Address, Size)) { 402 fixParents(GAI, Prev); 403 } else { 404 fixParents(GAI, nullptr); 405 } 406 Prev = Prev->Parent; 407 } 408 } 409 410 // Check if the newly added symbol contains any subsequent symbols. 411 if (Size != 0) { 412 BinaryData *BD = GAI->second->Parent ? GAI->second->Parent : GAI->second; 413 auto Itr = std::next(GAI); 414 while ( 415 Itr != BinaryDataMap.end() && 416 BD->containsRange(Itr->second->getAddress(), Itr->second->getSize())) { 417 Itr->second->Parent = BD; 418 ++Itr; 419 } 420 } 421 } 422 423 iterator_range<BinaryContext::binary_data_iterator> 424 BinaryContext::getSubBinaryData(BinaryData *BD) { 425 auto Start = std::next(BinaryDataMap.find(BD->getAddress())); 426 auto End = Start; 427 while (End != BinaryDataMap.end() && BD->isAncestorOf(End->second)) 428 ++End; 429 return make_range(Start, End); 430 } 431 432 std::pair<const MCSymbol *, uint64_t> 433 BinaryContext::handleAddressRef(uint64_t Address, BinaryFunction &BF, 434 bool IsPCRel) { 435 if (isAArch64()) { 436 // Check if this is an access to a constant island and create bookkeeping 437 // to keep track of it and emit it later as part of this function. 438 if (MCSymbol *IslandSym = BF.getOrCreateIslandAccess(Address)) 439 return std::make_pair(IslandSym, 0); 440 441 // Detect custom code written in assembly that refers to arbitrary 442 // constant islands from other functions. Write this reference so we 443 // can pull this constant island and emit it as part of this function 444 // too. 445 auto IslandIter = AddressToConstantIslandMap.lower_bound(Address); 446 447 if (IslandIter != AddressToConstantIslandMap.begin() && 448 (IslandIter == AddressToConstantIslandMap.end() || 449 IslandIter->first > Address)) 450 --IslandIter; 451 452 if (IslandIter != AddressToConstantIslandMap.end()) { 453 // Fall-back to referencing the original constant island in the presence 454 // of dynamic relocs, as we currently do not support cloning them. 455 // Notice: we might fail to link because of this, if the original constant 456 // island we are referring would be emitted too far away. 457 if (IslandIter->second->hasDynamicRelocationAtIsland()) { 458 MCSymbol *IslandSym = 459 IslandIter->second->getOrCreateIslandAccess(Address); 460 if (IslandSym) 461 return std::make_pair(IslandSym, 0); 462 } else if (MCSymbol *IslandSym = 463 IslandIter->second->getOrCreateProxyIslandAccess(Address, 464 BF)) { 465 BF.createIslandDependency(IslandSym, IslandIter->second); 466 return std::make_pair(IslandSym, 0); 467 } 468 } 469 } 470 471 // Note that the address does not necessarily have to reside inside 472 // a section, it could be an absolute address too. 473 ErrorOr<BinarySection &> Section = getSectionForAddress(Address); 474 if (Section && Section->isText()) { 475 if (BF.containsAddress(Address, /*UseMaxSize=*/isAArch64())) { 476 if (Address != BF.getAddress()) { 477 // The address could potentially escape. Mark it as another entry 478 // point into the function. 479 if (opts::Verbosity >= 1) { 480 this->outs() << "BOLT-INFO: potentially escaped address 0x" 481 << Twine::utohexstr(Address) << " in function " << BF 482 << '\n'; 483 } 484 BF.HasInternalLabelReference = true; 485 return std::make_pair( 486 BF.addEntryPointAtOffset(Address - BF.getAddress()), 0); 487 } 488 } else { 489 addInterproceduralReference(&BF, Address); 490 } 491 } 492 493 // With relocations, catch jump table references outside of the basic block 494 // containing the indirect jump. 495 if (HasRelocations) { 496 const MemoryContentsType MemType = analyzeMemoryAt(Address, BF); 497 if (MemType == MemoryContentsType::POSSIBLE_PIC_JUMP_TABLE && IsPCRel) { 498 const MCSymbol *Symbol = 499 getOrCreateJumpTable(BF, Address, JumpTable::JTT_PIC); 500 501 return std::make_pair(Symbol, 0); 502 } 503 } 504 505 if (BinaryData *BD = getBinaryDataContainingAddress(Address)) 506 return std::make_pair(BD->getSymbol(), Address - BD->getAddress()); 507 508 // TODO: use DWARF info to get size/alignment here? 509 MCSymbol *TargetSymbol = getOrCreateGlobalSymbol(Address, "DATAat"); 510 LLVM_DEBUG(dbgs() << "Created symbol " << TargetSymbol->getName() << '\n'); 511 return std::make_pair(TargetSymbol, 0); 512 } 513 514 MemoryContentsType BinaryContext::analyzeMemoryAt(uint64_t Address, 515 BinaryFunction &BF) { 516 if (!isX86()) 517 return MemoryContentsType::UNKNOWN; 518 519 ErrorOr<BinarySection &> Section = getSectionForAddress(Address); 520 if (!Section) { 521 // No section - possibly an absolute address. Since we don't allow 522 // internal function addresses to escape the function scope - we 523 // consider it a tail call. 524 if (opts::Verbosity > 1) { 525 this->errs() << "BOLT-WARNING: no section for address 0x" 526 << Twine::utohexstr(Address) << " referenced from function " 527 << BF << '\n'; 528 } 529 return MemoryContentsType::UNKNOWN; 530 } 531 532 if (Section->isVirtual()) { 533 // The contents are filled at runtime. 534 return MemoryContentsType::UNKNOWN; 535 } 536 537 // No support for jump tables in code yet. 538 if (Section->isText()) 539 return MemoryContentsType::UNKNOWN; 540 541 // Start with checking for PIC jump table. We expect non-PIC jump tables 542 // to have high 32 bits set to 0. 543 if (analyzeJumpTable(Address, JumpTable::JTT_PIC, BF)) 544 return MemoryContentsType::POSSIBLE_PIC_JUMP_TABLE; 545 546 if (analyzeJumpTable(Address, JumpTable::JTT_NORMAL, BF)) 547 return MemoryContentsType::POSSIBLE_JUMP_TABLE; 548 549 return MemoryContentsType::UNKNOWN; 550 } 551 552 bool BinaryContext::analyzeJumpTable(const uint64_t Address, 553 const JumpTable::JumpTableType Type, 554 const BinaryFunction &BF, 555 const uint64_t NextJTAddress, 556 JumpTable::AddressesType *EntriesAsAddress, 557 bool *HasEntryInFragment) const { 558 // Target address of __builtin_unreachable. 559 const uint64_t UnreachableAddress = BF.getAddress() + BF.getSize(); 560 561 // Is one of the targets __builtin_unreachable? 562 bool HasUnreachable = false; 563 564 // Does one of the entries match function start address? 565 bool HasStartAsEntry = false; 566 567 // Number of targets other than __builtin_unreachable. 568 uint64_t NumRealEntries = 0; 569 570 // Size of the jump table without trailing __builtin_unreachable entries. 571 size_t TrimmedSize = 0; 572 573 auto addEntryAddress = [&](uint64_t EntryAddress, bool Unreachable = false) { 574 if (!EntriesAsAddress) 575 return; 576 EntriesAsAddress->emplace_back(EntryAddress); 577 if (!Unreachable) 578 TrimmedSize = EntriesAsAddress->size(); 579 }; 580 581 ErrorOr<const BinarySection &> Section = getSectionForAddress(Address); 582 if (!Section) 583 return false; 584 585 // The upper bound is defined by containing object, section limits, and 586 // the next jump table in memory. 587 uint64_t UpperBound = Section->getEndAddress(); 588 const BinaryData *JumpTableBD = getBinaryDataAtAddress(Address); 589 if (JumpTableBD && JumpTableBD->getSize()) { 590 assert(JumpTableBD->getEndAddress() <= UpperBound && 591 "data object cannot cross a section boundary"); 592 UpperBound = JumpTableBD->getEndAddress(); 593 } 594 if (NextJTAddress) 595 UpperBound = std::min(NextJTAddress, UpperBound); 596 597 LLVM_DEBUG({ 598 using JTT = JumpTable::JumpTableType; 599 dbgs() << formatv("BOLT-DEBUG: analyzeJumpTable @{0:x} in {1}, JTT={2}\n", 600 Address, BF.getPrintName(), 601 Type == JTT::JTT_PIC ? "PIC" : "Normal"); 602 }); 603 const uint64_t EntrySize = getJumpTableEntrySize(Type); 604 for (uint64_t EntryAddress = Address; EntryAddress <= UpperBound - EntrySize; 605 EntryAddress += EntrySize) { 606 LLVM_DEBUG(dbgs() << " * Checking 0x" << Twine::utohexstr(EntryAddress) 607 << " -> "); 608 // Check if there's a proper relocation against the jump table entry. 609 if (HasRelocations) { 610 if (Type == JumpTable::JTT_PIC && 611 !DataPCRelocations.count(EntryAddress)) { 612 LLVM_DEBUG( 613 dbgs() << "FAIL: JTT_PIC table, no relocation for this address\n"); 614 break; 615 } 616 if (Type == JumpTable::JTT_NORMAL && !getRelocationAt(EntryAddress)) { 617 LLVM_DEBUG( 618 dbgs() 619 << "FAIL: JTT_NORMAL table, no relocation for this address\n"); 620 break; 621 } 622 } 623 624 const uint64_t Value = 625 (Type == JumpTable::JTT_PIC) 626 ? Address + *getSignedValueAtAddress(EntryAddress, EntrySize) 627 : *getPointerAtAddress(EntryAddress); 628 629 // __builtin_unreachable() case. 630 if (Value == UnreachableAddress) { 631 addEntryAddress(Value, /*Unreachable*/ true); 632 HasUnreachable = true; 633 LLVM_DEBUG(dbgs() << formatv("OK: {0:x} __builtin_unreachable\n", Value)); 634 continue; 635 } 636 637 // Function start is another special case. It is allowed in the jump table, 638 // but we need at least one another regular entry to distinguish the table 639 // from, e.g. a function pointer array. 640 if (Value == BF.getAddress()) { 641 HasStartAsEntry = true; 642 addEntryAddress(Value); 643 continue; 644 } 645 646 // Function or one of its fragments. 647 const BinaryFunction *TargetBF = getBinaryFunctionContainingAddress(Value); 648 const bool DoesBelongToFunction = 649 BF.containsAddress(Value) || 650 (TargetBF && TargetBF->isParentOrChildOf(BF)); 651 if (!DoesBelongToFunction) { 652 LLVM_DEBUG({ 653 if (!BF.containsAddress(Value)) { 654 dbgs() << "FAIL: function doesn't contain this address\n"; 655 if (TargetBF) { 656 dbgs() << " ! function containing this address: " 657 << TargetBF->getPrintName() << '\n'; 658 if (TargetBF->isFragment()) { 659 dbgs() << " ! is a fragment"; 660 for (BinaryFunction *Parent : TargetBF->ParentFragments) 661 dbgs() << ", parent: " << Parent->getPrintName(); 662 dbgs() << '\n'; 663 } 664 } 665 } 666 }); 667 break; 668 } 669 670 // Check there's an instruction at this offset. 671 if (TargetBF->getState() == BinaryFunction::State::Disassembled && 672 !TargetBF->getInstructionAtOffset(Value - TargetBF->getAddress())) { 673 LLVM_DEBUG(dbgs() << formatv("FAIL: no instruction at {0:x}\n", Value)); 674 break; 675 } 676 677 ++NumRealEntries; 678 LLVM_DEBUG(dbgs() << formatv("OK: {0:x} real entry\n", Value)); 679 680 if (TargetBF != &BF && HasEntryInFragment) 681 *HasEntryInFragment = true; 682 addEntryAddress(Value); 683 } 684 685 // Trim direct/normal jump table to exclude trailing unreachable entries that 686 // can collide with a function address. 687 if (Type == JumpTable::JTT_NORMAL && EntriesAsAddress && 688 TrimmedSize != EntriesAsAddress->size() && 689 getBinaryFunctionAtAddress(UnreachableAddress)) 690 EntriesAsAddress->resize(TrimmedSize); 691 692 // It's a jump table if the number of real entries is more than 1, or there's 693 // one real entry and one or more special targets. If there are only multiple 694 // special targets, then it's not a jump table. 695 return NumRealEntries + (HasUnreachable || HasStartAsEntry) >= 2; 696 } 697 698 void BinaryContext::populateJumpTables() { 699 LLVM_DEBUG(dbgs() << "DataPCRelocations: " << DataPCRelocations.size() 700 << '\n'); 701 for (auto JTI = JumpTables.begin(), JTE = JumpTables.end(); JTI != JTE; 702 ++JTI) { 703 JumpTable *JT = JTI->second; 704 705 bool NonSimpleParent = false; 706 for (BinaryFunction *BF : JT->Parents) 707 NonSimpleParent |= !BF->isSimple(); 708 if (NonSimpleParent) 709 continue; 710 711 uint64_t NextJTAddress = 0; 712 auto NextJTI = std::next(JTI); 713 if (NextJTI != JTE) 714 NextJTAddress = NextJTI->second->getAddress(); 715 716 const bool Success = 717 analyzeJumpTable(JT->getAddress(), JT->Type, *(JT->Parents[0]), 718 NextJTAddress, &JT->EntriesAsAddress, &JT->IsSplit); 719 if (!Success) { 720 LLVM_DEBUG({ 721 dbgs() << "failed to analyze "; 722 JT->print(dbgs()); 723 if (NextJTI != JTE) { 724 dbgs() << "next "; 725 NextJTI->second->print(dbgs()); 726 } 727 }); 728 llvm_unreachable("jump table heuristic failure"); 729 } 730 for (BinaryFunction *Frag : JT->Parents) { 731 if (JT->IsSplit) 732 Frag->setHasIndirectTargetToSplitFragment(true); 733 for (uint64_t EntryAddress : JT->EntriesAsAddress) 734 // if target is builtin_unreachable 735 if (EntryAddress == Frag->getAddress() + Frag->getSize()) { 736 Frag->IgnoredBranches.emplace_back(EntryAddress - Frag->getAddress(), 737 Frag->getSize()); 738 } else if (EntryAddress >= Frag->getAddress() && 739 EntryAddress < Frag->getAddress() + Frag->getSize()) { 740 Frag->registerReferencedOffset(EntryAddress - Frag->getAddress()); 741 } 742 } 743 744 // In strict mode, erase PC-relative relocation record. Later we check that 745 // all such records are erased and thus have been accounted for. 746 if (opts::StrictMode && JT->Type == JumpTable::JTT_PIC) { 747 for (uint64_t Address = JT->getAddress(); 748 Address < JT->getAddress() + JT->getSize(); 749 Address += JT->EntrySize) { 750 DataPCRelocations.erase(DataPCRelocations.find(Address)); 751 } 752 } 753 754 // Mark to skip the function and all its fragments. 755 for (BinaryFunction *Frag : JT->Parents) 756 if (Frag->hasIndirectTargetToSplitFragment()) 757 addFragmentsToSkip(Frag); 758 } 759 760 if (opts::StrictMode && DataPCRelocations.size()) { 761 LLVM_DEBUG({ 762 dbgs() << DataPCRelocations.size() 763 << " unclaimed PC-relative relocations left in data:\n"; 764 for (uint64_t Reloc : DataPCRelocations) 765 dbgs() << Twine::utohexstr(Reloc) << '\n'; 766 }); 767 assert(0 && "unclaimed PC-relative relocations left in data\n"); 768 } 769 clearList(DataPCRelocations); 770 } 771 772 void BinaryContext::skipMarkedFragments() { 773 std::vector<BinaryFunction *> FragmentQueue; 774 // Copy the functions to FragmentQueue. 775 FragmentQueue.assign(FragmentsToSkip.begin(), FragmentsToSkip.end()); 776 auto addToWorklist = [&](BinaryFunction *Function) -> void { 777 if (FragmentsToSkip.count(Function)) 778 return; 779 FragmentQueue.push_back(Function); 780 addFragmentsToSkip(Function); 781 }; 782 // Functions containing split jump tables need to be skipped with all 783 // fragments (transitively). 784 for (size_t I = 0; I != FragmentQueue.size(); I++) { 785 BinaryFunction *BF = FragmentQueue[I]; 786 assert(FragmentsToSkip.count(BF) && 787 "internal error in traversing function fragments"); 788 if (opts::Verbosity >= 1) 789 this->errs() << "BOLT-WARNING: Ignoring " << BF->getPrintName() << '\n'; 790 BF->setSimple(false); 791 BF->setHasIndirectTargetToSplitFragment(true); 792 793 llvm::for_each(BF->Fragments, addToWorklist); 794 llvm::for_each(BF->ParentFragments, addToWorklist); 795 } 796 if (!FragmentsToSkip.empty()) 797 this->errs() << "BOLT-WARNING: skipped " << FragmentsToSkip.size() 798 << " function" << (FragmentsToSkip.size() == 1 ? "" : "s") 799 << " due to cold fragments\n"; 800 } 801 802 MCSymbol *BinaryContext::getOrCreateGlobalSymbol(uint64_t Address, Twine Prefix, 803 uint64_t Size, 804 uint16_t Alignment, 805 unsigned Flags) { 806 auto Itr = BinaryDataMap.find(Address); 807 if (Itr != BinaryDataMap.end()) { 808 assert(Itr->second->getSize() == Size || !Size); 809 return Itr->second->getSymbol(); 810 } 811 812 std::string Name = (Prefix + "0x" + Twine::utohexstr(Address)).str(); 813 assert(!GlobalSymbols.count(Name) && "created name is not unique"); 814 return registerNameAtAddress(Name, Address, Size, Alignment, Flags); 815 } 816 817 MCSymbol *BinaryContext::getOrCreateUndefinedGlobalSymbol(StringRef Name) { 818 return Ctx->getOrCreateSymbol(Name); 819 } 820 821 BinaryFunction *BinaryContext::createBinaryFunction( 822 const std::string &Name, BinarySection &Section, uint64_t Address, 823 uint64_t Size, uint64_t SymbolSize, uint16_t Alignment) { 824 auto Result = BinaryFunctions.emplace( 825 Address, BinaryFunction(Name, Section, Address, Size, *this)); 826 assert(Result.second == true && "unexpected duplicate function"); 827 BinaryFunction *BF = &Result.first->second; 828 registerNameAtAddress(Name, Address, SymbolSize ? SymbolSize : Size, 829 Alignment); 830 setSymbolToFunctionMap(BF->getSymbol(), BF); 831 return BF; 832 } 833 834 const MCSymbol * 835 BinaryContext::getOrCreateJumpTable(BinaryFunction &Function, uint64_t Address, 836 JumpTable::JumpTableType Type) { 837 // Two fragments of same function access same jump table 838 if (JumpTable *JT = getJumpTableContainingAddress(Address)) { 839 assert(JT->Type == Type && "jump table types have to match"); 840 assert(Address == JT->getAddress() && "unexpected non-empty jump table"); 841 842 // Prevent associating a jump table to a specific fragment twice. 843 // This simple check arises from the assumption: no more than 2 fragments. 844 if (JT->Parents.size() == 1 && JT->Parents[0] != &Function) { 845 assert(JT->Parents[0]->isParentOrChildOf(Function) && 846 "cannot re-use jump table of a different function"); 847 // Duplicate the entry for the parent function for easy access 848 JT->Parents.push_back(&Function); 849 if (opts::Verbosity > 2) { 850 this->outs() << "BOLT-INFO: Multiple fragments access same jump table: " 851 << JT->Parents[0]->getPrintName() << "; " 852 << Function.getPrintName() << "\n"; 853 JT->print(this->outs()); 854 } 855 Function.JumpTables.emplace(Address, JT); 856 JT->Parents[0]->setHasIndirectTargetToSplitFragment(true); 857 JT->Parents[1]->setHasIndirectTargetToSplitFragment(true); 858 } 859 860 bool IsJumpTableParent = false; 861 (void)IsJumpTableParent; 862 for (BinaryFunction *Frag : JT->Parents) 863 if (Frag == &Function) 864 IsJumpTableParent = true; 865 assert(IsJumpTableParent && 866 "cannot re-use jump table of a different function"); 867 return JT->getFirstLabel(); 868 } 869 870 // Re-use the existing symbol if possible. 871 MCSymbol *JTLabel = nullptr; 872 if (BinaryData *Object = getBinaryDataAtAddress(Address)) { 873 if (!isInternalSymbolName(Object->getSymbol()->getName())) 874 JTLabel = Object->getSymbol(); 875 } 876 877 const uint64_t EntrySize = getJumpTableEntrySize(Type); 878 if (!JTLabel) { 879 const std::string JumpTableName = generateJumpTableName(Function, Address); 880 JTLabel = registerNameAtAddress(JumpTableName, Address, 0, EntrySize); 881 } 882 883 LLVM_DEBUG(dbgs() << "BOLT-DEBUG: creating jump table " << JTLabel->getName() 884 << " in function " << Function << '\n'); 885 886 JumpTable *JT = new JumpTable(*JTLabel, Address, EntrySize, Type, 887 JumpTable::LabelMapType{{0, JTLabel}}, 888 *getSectionForAddress(Address)); 889 JT->Parents.push_back(&Function); 890 if (opts::Verbosity > 2) 891 JT->print(this->outs()); 892 JumpTables.emplace(Address, JT); 893 894 // Duplicate the entry for the parent function for easy access. 895 Function.JumpTables.emplace(Address, JT); 896 return JTLabel; 897 } 898 899 std::pair<uint64_t, const MCSymbol *> 900 BinaryContext::duplicateJumpTable(BinaryFunction &Function, JumpTable *JT, 901 const MCSymbol *OldLabel) { 902 auto L = scopeLock(); 903 unsigned Offset = 0; 904 bool Found = false; 905 for (std::pair<const unsigned, MCSymbol *> Elmt : JT->Labels) { 906 if (Elmt.second != OldLabel) 907 continue; 908 Offset = Elmt.first; 909 Found = true; 910 break; 911 } 912 assert(Found && "Label not found"); 913 (void)Found; 914 MCSymbol *NewLabel = Ctx->createNamedTempSymbol("duplicatedJT"); 915 JumpTable *NewJT = 916 new JumpTable(*NewLabel, JT->getAddress(), JT->EntrySize, JT->Type, 917 JumpTable::LabelMapType{{Offset, NewLabel}}, 918 *getSectionForAddress(JT->getAddress())); 919 NewJT->Parents = JT->Parents; 920 NewJT->Entries = JT->Entries; 921 NewJT->Counts = JT->Counts; 922 uint64_t JumpTableID = ++DuplicatedJumpTables; 923 // Invert it to differentiate from regular jump tables whose IDs are their 924 // addresses in the input binary memory space 925 JumpTableID = ~JumpTableID; 926 JumpTables.emplace(JumpTableID, NewJT); 927 Function.JumpTables.emplace(JumpTableID, NewJT); 928 return std::make_pair(JumpTableID, NewLabel); 929 } 930 931 std::string BinaryContext::generateJumpTableName(const BinaryFunction &BF, 932 uint64_t Address) { 933 size_t Id; 934 uint64_t Offset = 0; 935 if (const JumpTable *JT = BF.getJumpTableContainingAddress(Address)) { 936 Offset = Address - JT->getAddress(); 937 auto JTLabelsIt = JT->Labels.find(Offset); 938 if (JTLabelsIt != JT->Labels.end()) 939 return std::string(JTLabelsIt->second->getName()); 940 941 auto JTIdsIt = JumpTableIds.find(JT->getAddress()); 942 assert(JTIdsIt != JumpTableIds.end()); 943 Id = JTIdsIt->second; 944 } else { 945 Id = JumpTableIds[Address] = BF.JumpTables.size(); 946 } 947 return ("JUMP_TABLE/" + BF.getOneName().str() + "." + std::to_string(Id) + 948 (Offset ? ("." + std::to_string(Offset)) : "")); 949 } 950 951 bool BinaryContext::hasValidCodePadding(const BinaryFunction &BF) { 952 // FIXME: aarch64 support is missing. 953 if (!isX86()) 954 return true; 955 956 if (BF.getSize() == BF.getMaxSize()) 957 return true; 958 959 ErrorOr<ArrayRef<unsigned char>> FunctionData = BF.getData(); 960 assert(FunctionData && "cannot get function as data"); 961 962 uint64_t Offset = BF.getSize(); 963 MCInst Instr; 964 uint64_t InstrSize = 0; 965 uint64_t InstrAddress = BF.getAddress() + Offset; 966 using std::placeholders::_1; 967 968 // Skip instructions that satisfy the predicate condition. 969 auto skipInstructions = [&](std::function<bool(const MCInst &)> Predicate) { 970 const uint64_t StartOffset = Offset; 971 for (; Offset < BF.getMaxSize(); 972 Offset += InstrSize, InstrAddress += InstrSize) { 973 if (!DisAsm->getInstruction(Instr, InstrSize, FunctionData->slice(Offset), 974 InstrAddress, nulls())) 975 break; 976 if (!Predicate(Instr)) 977 break; 978 } 979 980 return Offset - StartOffset; 981 }; 982 983 // Skip a sequence of zero bytes. 984 auto skipZeros = [&]() { 985 const uint64_t StartOffset = Offset; 986 for (; Offset < BF.getMaxSize(); ++Offset) 987 if ((*FunctionData)[Offset] != 0) 988 break; 989 990 return Offset - StartOffset; 991 }; 992 993 // Accept the whole padding area filled with breakpoints. 994 auto isBreakpoint = std::bind(&MCPlusBuilder::isBreakpoint, MIB.get(), _1); 995 if (skipInstructions(isBreakpoint) && Offset == BF.getMaxSize()) 996 return true; 997 998 auto isNoop = std::bind(&MCPlusBuilder::isNoop, MIB.get(), _1); 999 1000 // Some functions have a jump to the next function or to the padding area 1001 // inserted after the body. 1002 auto isSkipJump = [&](const MCInst &Instr) { 1003 uint64_t TargetAddress = 0; 1004 if (MIB->isUnconditionalBranch(Instr) && 1005 MIB->evaluateBranch(Instr, InstrAddress, InstrSize, TargetAddress)) { 1006 if (TargetAddress >= InstrAddress + InstrSize && 1007 TargetAddress <= BF.getAddress() + BF.getMaxSize()) { 1008 return true; 1009 } 1010 } 1011 return false; 1012 }; 1013 1014 // Skip over nops, jumps, and zero padding. Allow interleaving (this happens). 1015 while (skipInstructions(isNoop) || skipInstructions(isSkipJump) || 1016 skipZeros()) 1017 ; 1018 1019 if (Offset == BF.getMaxSize()) 1020 return true; 1021 1022 if (opts::Verbosity >= 1) { 1023 this->errs() << "BOLT-WARNING: bad padding at address 0x" 1024 << Twine::utohexstr(BF.getAddress() + BF.getSize()) 1025 << " starting at offset " << (Offset - BF.getSize()) 1026 << " in function " << BF << '\n' 1027 << FunctionData->slice(BF.getSize(), 1028 BF.getMaxSize() - BF.getSize()) 1029 << '\n'; 1030 } 1031 1032 return false; 1033 } 1034 1035 void BinaryContext::adjustCodePadding() { 1036 for (auto &BFI : BinaryFunctions) { 1037 BinaryFunction &BF = BFI.second; 1038 if (!shouldEmit(BF)) 1039 continue; 1040 1041 if (!hasValidCodePadding(BF)) { 1042 if (HasRelocations) { 1043 if (opts::Verbosity >= 1) { 1044 this->outs() << "BOLT-INFO: function " << BF 1045 << " has invalid padding. Ignoring the function.\n"; 1046 } 1047 BF.setIgnored(); 1048 } else { 1049 BF.setMaxSize(BF.getSize()); 1050 } 1051 } 1052 } 1053 } 1054 1055 MCSymbol *BinaryContext::registerNameAtAddress(StringRef Name, uint64_t Address, 1056 uint64_t Size, 1057 uint16_t Alignment, 1058 unsigned Flags) { 1059 // Register the name with MCContext. 1060 MCSymbol *Symbol = Ctx->getOrCreateSymbol(Name); 1061 1062 auto GAI = BinaryDataMap.find(Address); 1063 BinaryData *BD; 1064 if (GAI == BinaryDataMap.end()) { 1065 ErrorOr<BinarySection &> SectionOrErr = getSectionForAddress(Address); 1066 BinarySection &Section = 1067 SectionOrErr ? SectionOrErr.get() : absoluteSection(); 1068 BD = new BinaryData(*Symbol, Address, Size, Alignment ? Alignment : 1, 1069 Section, Flags); 1070 GAI = BinaryDataMap.emplace(Address, BD).first; 1071 GlobalSymbols[Name] = BD; 1072 updateObjectNesting(GAI); 1073 } else { 1074 BD = GAI->second; 1075 if (!BD->hasName(Name)) { 1076 GlobalSymbols[Name] = BD; 1077 BD->Symbols.push_back(Symbol); 1078 } 1079 } 1080 1081 return Symbol; 1082 } 1083 1084 const BinaryData * 1085 BinaryContext::getBinaryDataContainingAddressImpl(uint64_t Address) const { 1086 auto NI = BinaryDataMap.lower_bound(Address); 1087 auto End = BinaryDataMap.end(); 1088 if ((NI != End && Address == NI->first) || 1089 ((NI != BinaryDataMap.begin()) && (NI-- != BinaryDataMap.begin()))) { 1090 if (NI->second->containsAddress(Address)) 1091 return NI->second; 1092 1093 // If this is a sub-symbol, see if a parent data contains the address. 1094 const BinaryData *BD = NI->second->getParent(); 1095 while (BD) { 1096 if (BD->containsAddress(Address)) 1097 return BD; 1098 BD = BD->getParent(); 1099 } 1100 } 1101 return nullptr; 1102 } 1103 1104 BinaryData *BinaryContext::getGOTSymbol() { 1105 // First tries to find a global symbol with that name 1106 BinaryData *GOTSymBD = getBinaryDataByName("_GLOBAL_OFFSET_TABLE_"); 1107 if (GOTSymBD) 1108 return GOTSymBD; 1109 1110 // This symbol might be hidden from run-time link, so fetch the local 1111 // definition if available. 1112 GOTSymBD = getBinaryDataByName("_GLOBAL_OFFSET_TABLE_/1"); 1113 if (!GOTSymBD) 1114 return nullptr; 1115 1116 // If the local symbol is not unique, fail 1117 unsigned Index = 2; 1118 SmallString<30> Storage; 1119 while (const BinaryData *BD = 1120 getBinaryDataByName(Twine("_GLOBAL_OFFSET_TABLE_/") 1121 .concat(Twine(Index++)) 1122 .toStringRef(Storage))) 1123 if (BD->getAddress() != GOTSymBD->getAddress()) 1124 return nullptr; 1125 1126 return GOTSymBD; 1127 } 1128 1129 bool BinaryContext::setBinaryDataSize(uint64_t Address, uint64_t Size) { 1130 auto NI = BinaryDataMap.find(Address); 1131 assert(NI != BinaryDataMap.end()); 1132 if (NI == BinaryDataMap.end()) 1133 return false; 1134 // TODO: it's possible that a jump table starts at the same address 1135 // as a larger blob of private data. When we set the size of the 1136 // jump table, it might be smaller than the total blob size. In this 1137 // case we just leave the original size since (currently) it won't really 1138 // affect anything. 1139 assert((!NI->second->Size || NI->second->Size == Size || 1140 (NI->second->isJumpTable() && NI->second->Size > Size)) && 1141 "can't change the size of a symbol that has already had its " 1142 "size set"); 1143 if (!NI->second->Size) { 1144 NI->second->Size = Size; 1145 updateObjectNesting(NI); 1146 return true; 1147 } 1148 return false; 1149 } 1150 1151 void BinaryContext::generateSymbolHashes() { 1152 auto isPadding = [](const BinaryData &BD) { 1153 StringRef Contents = BD.getSection().getContents(); 1154 StringRef SymData = Contents.substr(BD.getOffset(), BD.getSize()); 1155 return (BD.getName().starts_with("HOLEat") || 1156 SymData.find_first_not_of(0) == StringRef::npos); 1157 }; 1158 1159 uint64_t NumCollisions = 0; 1160 for (auto &Entry : BinaryDataMap) { 1161 BinaryData &BD = *Entry.second; 1162 StringRef Name = BD.getName(); 1163 1164 if (!isInternalSymbolName(Name)) 1165 continue; 1166 1167 // First check if a non-anonymous alias exists and move it to the front. 1168 if (BD.getSymbols().size() > 1) { 1169 auto Itr = llvm::find_if(BD.getSymbols(), [&](const MCSymbol *Symbol) { 1170 return !isInternalSymbolName(Symbol->getName()); 1171 }); 1172 if (Itr != BD.getSymbols().end()) { 1173 size_t Idx = std::distance(BD.getSymbols().begin(), Itr); 1174 std::swap(BD.getSymbols()[0], BD.getSymbols()[Idx]); 1175 continue; 1176 } 1177 } 1178 1179 // We have to skip 0 size symbols since they will all collide. 1180 if (BD.getSize() == 0) { 1181 continue; 1182 } 1183 1184 const uint64_t Hash = BD.getSection().hash(BD); 1185 const size_t Idx = Name.find("0x"); 1186 std::string NewName = 1187 (Twine(Name.substr(0, Idx)) + "_" + Twine::utohexstr(Hash)).str(); 1188 if (getBinaryDataByName(NewName)) { 1189 // Ignore collisions for symbols that appear to be padding 1190 // (i.e. all zeros or a "hole") 1191 if (!isPadding(BD)) { 1192 if (opts::Verbosity) { 1193 this->errs() << "BOLT-WARNING: collision detected when hashing " << BD 1194 << " with new name (" << NewName << "), skipping.\n"; 1195 } 1196 ++NumCollisions; 1197 } 1198 continue; 1199 } 1200 BD.Symbols.insert(BD.Symbols.begin(), Ctx->getOrCreateSymbol(NewName)); 1201 GlobalSymbols[NewName] = &BD; 1202 } 1203 if (NumCollisions) { 1204 this->errs() << "BOLT-WARNING: " << NumCollisions 1205 << " collisions detected while hashing binary objects"; 1206 if (!opts::Verbosity) 1207 this->errs() << ". Use -v=1 to see the list."; 1208 this->errs() << '\n'; 1209 } 1210 } 1211 1212 bool BinaryContext::registerFragment(BinaryFunction &TargetFunction, 1213 BinaryFunction &Function) const { 1214 assert(TargetFunction.isFragment() && "TargetFunction must be a fragment"); 1215 if (TargetFunction.isChildOf(Function)) 1216 return true; 1217 TargetFunction.addParentFragment(Function); 1218 Function.addFragment(TargetFunction); 1219 if (!HasRelocations) { 1220 TargetFunction.setSimple(false); 1221 Function.setSimple(false); 1222 } 1223 if (opts::Verbosity >= 1) { 1224 this->outs() << "BOLT-INFO: marking " << TargetFunction 1225 << " as a fragment of " << Function << '\n'; 1226 } 1227 return true; 1228 } 1229 1230 void BinaryContext::addAdrpAddRelocAArch64(BinaryFunction &BF, 1231 MCInst &LoadLowBits, 1232 MCInst &LoadHiBits, 1233 uint64_t Target) { 1234 const MCSymbol *TargetSymbol; 1235 uint64_t Addend = 0; 1236 std::tie(TargetSymbol, Addend) = handleAddressRef(Target, BF, 1237 /*IsPCRel*/ true); 1238 int64_t Val; 1239 MIB->replaceImmWithSymbolRef(LoadHiBits, TargetSymbol, Addend, Ctx.get(), Val, 1240 ELF::R_AARCH64_ADR_PREL_PG_HI21); 1241 MIB->replaceImmWithSymbolRef(LoadLowBits, TargetSymbol, Addend, Ctx.get(), 1242 Val, ELF::R_AARCH64_ADD_ABS_LO12_NC); 1243 } 1244 1245 bool BinaryContext::handleAArch64Veneer(uint64_t Address, bool MatchOnly) { 1246 BinaryFunction *TargetFunction = getBinaryFunctionContainingAddress(Address); 1247 if (TargetFunction) 1248 return false; 1249 1250 ErrorOr<BinarySection &> Section = getSectionForAddress(Address); 1251 assert(Section && "cannot get section for referenced address"); 1252 if (!Section->isText()) 1253 return false; 1254 1255 bool Ret = false; 1256 StringRef SectionContents = Section->getContents(); 1257 uint64_t Offset = Address - Section->getAddress(); 1258 const uint64_t MaxSize = SectionContents.size() - Offset; 1259 const uint8_t *Bytes = 1260 reinterpret_cast<const uint8_t *>(SectionContents.data()); 1261 ArrayRef<uint8_t> Data(Bytes + Offset, MaxSize); 1262 1263 auto matchVeneer = [&](BinaryFunction::InstrMapType &Instructions, 1264 MCInst &Instruction, uint64_t Offset, 1265 uint64_t AbsoluteInstrAddr, 1266 uint64_t TotalSize) -> bool { 1267 MCInst *TargetHiBits, *TargetLowBits; 1268 uint64_t TargetAddress, Count; 1269 Count = MIB->matchLinkerVeneer(Instructions.begin(), Instructions.end(), 1270 AbsoluteInstrAddr, Instruction, TargetHiBits, 1271 TargetLowBits, TargetAddress); 1272 if (!Count) 1273 return false; 1274 1275 if (MatchOnly) 1276 return true; 1277 1278 // NOTE The target symbol was created during disassemble's 1279 // handleExternalReference 1280 const MCSymbol *VeneerSymbol = getOrCreateGlobalSymbol(Address, "FUNCat"); 1281 BinaryFunction *Veneer = createBinaryFunction(VeneerSymbol->getName().str(), 1282 *Section, Address, TotalSize); 1283 addAdrpAddRelocAArch64(*Veneer, *TargetLowBits, *TargetHiBits, 1284 TargetAddress); 1285 MIB->addAnnotation(Instruction, "AArch64Veneer", true); 1286 Veneer->addInstruction(Offset, std::move(Instruction)); 1287 --Count; 1288 for (auto It = Instructions.rbegin(); Count != 0; ++It, --Count) { 1289 MIB->addAnnotation(It->second, "AArch64Veneer", true); 1290 Veneer->addInstruction(It->first, std::move(It->second)); 1291 } 1292 1293 Veneer->getOrCreateLocalLabel(Address); 1294 Veneer->setMaxSize(TotalSize); 1295 Veneer->updateState(BinaryFunction::State::Disassembled); 1296 LLVM_DEBUG(dbgs() << "BOLT-DEBUG: handling veneer function at 0x" << Address 1297 << "\n"); 1298 return true; 1299 }; 1300 1301 uint64_t Size = 0, TotalSize = 0; 1302 BinaryFunction::InstrMapType VeneerInstructions; 1303 for (Offset = 0; Offset < MaxSize; Offset += Size) { 1304 MCInst Instruction; 1305 const uint64_t AbsoluteInstrAddr = Address + Offset; 1306 if (!SymbolicDisAsm->getInstruction(Instruction, Size, Data.slice(Offset), 1307 AbsoluteInstrAddr, nulls())) 1308 break; 1309 1310 TotalSize += Size; 1311 if (MIB->isBranch(Instruction)) { 1312 Ret = matchVeneer(VeneerInstructions, Instruction, Offset, 1313 AbsoluteInstrAddr, TotalSize); 1314 break; 1315 } 1316 1317 VeneerInstructions.emplace(Offset, std::move(Instruction)); 1318 } 1319 1320 return Ret; 1321 } 1322 1323 void BinaryContext::processInterproceduralReferences() { 1324 for (const std::pair<BinaryFunction *, uint64_t> &It : 1325 InterproceduralReferences) { 1326 BinaryFunction &Function = *It.first; 1327 uint64_t Address = It.second; 1328 // Process interprocedural references from ignored functions in BAT mode 1329 // (non-simple in non-relocation mode) to properly register entry points 1330 if (!Address || (Function.isIgnored() && !HasBATSection)) 1331 continue; 1332 1333 BinaryFunction *TargetFunction = 1334 getBinaryFunctionContainingAddress(Address); 1335 if (&Function == TargetFunction) 1336 continue; 1337 1338 if (TargetFunction) { 1339 if (TargetFunction->isFragment() && 1340 !TargetFunction->isChildOf(Function)) { 1341 this->errs() 1342 << "BOLT-WARNING: interprocedural reference between unrelated " 1343 "fragments: " 1344 << Function.getPrintName() << " and " 1345 << TargetFunction->getPrintName() << '\n'; 1346 } 1347 if (uint64_t Offset = Address - TargetFunction->getAddress()) 1348 TargetFunction->addEntryPointAtOffset(Offset); 1349 1350 continue; 1351 } 1352 1353 // Check if address falls in function padding space - this could be 1354 // unmarked data in code. In this case adjust the padding space size. 1355 ErrorOr<BinarySection &> Section = getSectionForAddress(Address); 1356 assert(Section && "cannot get section for referenced address"); 1357 1358 if (!Section->isText()) 1359 continue; 1360 1361 // PLT requires special handling and could be ignored in this context. 1362 StringRef SectionName = Section->getName(); 1363 if (SectionName == ".plt" || SectionName == ".plt.got") 1364 continue; 1365 1366 // Check if it is aarch64 veneer written at Address 1367 if (isAArch64() && handleAArch64Veneer(Address)) 1368 continue; 1369 1370 if (opts::processAllFunctions()) { 1371 this->errs() << "BOLT-ERROR: cannot process binaries with unmarked " 1372 << "object in code at address 0x" 1373 << Twine::utohexstr(Address) << " belonging to section " 1374 << SectionName << " in current mode\n"; 1375 exit(1); 1376 } 1377 1378 TargetFunction = getBinaryFunctionContainingAddress(Address, 1379 /*CheckPastEnd=*/false, 1380 /*UseMaxSize=*/true); 1381 // We are not going to overwrite non-simple functions, but for simple 1382 // ones - adjust the padding size. 1383 if (TargetFunction && TargetFunction->isSimple()) { 1384 this->errs() 1385 << "BOLT-WARNING: function " << *TargetFunction 1386 << " has an object detected in a padding region at address 0x" 1387 << Twine::utohexstr(Address) << '\n'; 1388 TargetFunction->setMaxSize(TargetFunction->getSize()); 1389 } 1390 } 1391 1392 InterproceduralReferences.clear(); 1393 } 1394 1395 void BinaryContext::postProcessSymbolTable() { 1396 fixBinaryDataHoles(); 1397 bool Valid = true; 1398 for (auto &Entry : BinaryDataMap) { 1399 BinaryData *BD = Entry.second; 1400 if ((BD->getName().starts_with("SYMBOLat") || 1401 BD->getName().starts_with("DATAat")) && 1402 !BD->getParent() && !BD->getSize() && !BD->isAbsolute() && 1403 BD->getSection()) { 1404 this->errs() << "BOLT-WARNING: zero-sized top level symbol: " << *BD 1405 << "\n"; 1406 Valid = false; 1407 } 1408 } 1409 assert(Valid); 1410 (void)Valid; 1411 generateSymbolHashes(); 1412 } 1413 1414 void BinaryContext::foldFunction(BinaryFunction &ChildBF, 1415 BinaryFunction &ParentBF) { 1416 assert(!ChildBF.isMultiEntry() && !ParentBF.isMultiEntry() && 1417 "cannot merge functions with multiple entry points"); 1418 1419 std::unique_lock<llvm::sys::RWMutex> WriteCtxLock(CtxMutex, std::defer_lock); 1420 std::unique_lock<llvm::sys::RWMutex> WriteSymbolMapLock( 1421 SymbolToFunctionMapMutex, std::defer_lock); 1422 1423 const StringRef ChildName = ChildBF.getOneName(); 1424 1425 // Move symbols over and update bookkeeping info. 1426 for (MCSymbol *Symbol : ChildBF.getSymbols()) { 1427 ParentBF.getSymbols().push_back(Symbol); 1428 WriteSymbolMapLock.lock(); 1429 SymbolToFunctionMap[Symbol] = &ParentBF; 1430 WriteSymbolMapLock.unlock(); 1431 // NB: there's no need to update BinaryDataMap and GlobalSymbols. 1432 } 1433 ChildBF.getSymbols().clear(); 1434 1435 // Move other names the child function is known under. 1436 llvm::move(ChildBF.Aliases, std::back_inserter(ParentBF.Aliases)); 1437 ChildBF.Aliases.clear(); 1438 1439 if (HasRelocations) { 1440 // Merge execution counts of ChildBF into those of ParentBF. 1441 // Without relocations, we cannot reliably merge profiles as both functions 1442 // continue to exist and either one can be executed. 1443 ChildBF.mergeProfileDataInto(ParentBF); 1444 1445 std::shared_lock<llvm::sys::RWMutex> ReadBfsLock(BinaryFunctionsMutex, 1446 std::defer_lock); 1447 std::unique_lock<llvm::sys::RWMutex> WriteBfsLock(BinaryFunctionsMutex, 1448 std::defer_lock); 1449 // Remove ChildBF from the global set of functions in relocs mode. 1450 ReadBfsLock.lock(); 1451 auto FI = BinaryFunctions.find(ChildBF.getAddress()); 1452 ReadBfsLock.unlock(); 1453 1454 assert(FI != BinaryFunctions.end() && "function not found"); 1455 assert(&ChildBF == &FI->second && "function mismatch"); 1456 1457 WriteBfsLock.lock(); 1458 ChildBF.clearDisasmState(); 1459 FI = BinaryFunctions.erase(FI); 1460 WriteBfsLock.unlock(); 1461 1462 } else { 1463 // In non-relocation mode we keep the function, but rename it. 1464 std::string NewName = "__ICF_" + ChildName.str(); 1465 1466 WriteCtxLock.lock(); 1467 ChildBF.getSymbols().push_back(Ctx->getOrCreateSymbol(NewName)); 1468 WriteCtxLock.unlock(); 1469 1470 ChildBF.setFolded(&ParentBF); 1471 } 1472 1473 ParentBF.setHasFunctionsFoldedInto(); 1474 } 1475 1476 void BinaryContext::fixBinaryDataHoles() { 1477 assert(validateObjectNesting() && "object nesting inconsistency detected"); 1478 1479 for (BinarySection &Section : allocatableSections()) { 1480 std::vector<std::pair<uint64_t, uint64_t>> Holes; 1481 1482 auto isNotHole = [&Section](const binary_data_iterator &Itr) { 1483 BinaryData *BD = Itr->second; 1484 bool isHole = (!BD->getParent() && !BD->getSize() && BD->isObject() && 1485 (BD->getName().starts_with("SYMBOLat0x") || 1486 BD->getName().starts_with("DATAat0x") || 1487 BD->getName().starts_with("ANONYMOUS"))); 1488 return !isHole && BD->getSection() == Section && !BD->getParent(); 1489 }; 1490 1491 auto BDStart = BinaryDataMap.begin(); 1492 auto BDEnd = BinaryDataMap.end(); 1493 auto Itr = FilteredBinaryDataIterator(isNotHole, BDStart, BDEnd); 1494 auto End = FilteredBinaryDataIterator(isNotHole, BDEnd, BDEnd); 1495 1496 uint64_t EndAddress = Section.getAddress(); 1497 1498 while (Itr != End) { 1499 if (Itr->second->getAddress() > EndAddress) { 1500 uint64_t Gap = Itr->second->getAddress() - EndAddress; 1501 Holes.emplace_back(EndAddress, Gap); 1502 } 1503 EndAddress = Itr->second->getEndAddress(); 1504 ++Itr; 1505 } 1506 1507 if (EndAddress < Section.getEndAddress()) 1508 Holes.emplace_back(EndAddress, Section.getEndAddress() - EndAddress); 1509 1510 // If there is already a symbol at the start of the hole, grow that symbol 1511 // to cover the rest. Otherwise, create a new symbol to cover the hole. 1512 for (std::pair<uint64_t, uint64_t> &Hole : Holes) { 1513 BinaryData *BD = getBinaryDataAtAddress(Hole.first); 1514 if (BD) { 1515 // BD->getSection() can be != Section if there are sections that 1516 // overlap. In this case it is probably safe to just skip the holes 1517 // since the overlapping section will not(?) have any symbols in it. 1518 if (BD->getSection() == Section) 1519 setBinaryDataSize(Hole.first, Hole.second); 1520 } else { 1521 getOrCreateGlobalSymbol(Hole.first, "HOLEat", Hole.second, 1); 1522 } 1523 } 1524 } 1525 1526 assert(validateObjectNesting() && "object nesting inconsistency detected"); 1527 assert(validateHoles() && "top level hole detected in object map"); 1528 } 1529 1530 void BinaryContext::printGlobalSymbols(raw_ostream &OS) const { 1531 const BinarySection *CurrentSection = nullptr; 1532 bool FirstSection = true; 1533 1534 for (auto &Entry : BinaryDataMap) { 1535 const BinaryData *BD = Entry.second; 1536 const BinarySection &Section = BD->getSection(); 1537 if (FirstSection || Section != *CurrentSection) { 1538 uint64_t Address, Size; 1539 StringRef Name = Section.getName(); 1540 if (Section) { 1541 Address = Section.getAddress(); 1542 Size = Section.getSize(); 1543 } else { 1544 Address = BD->getAddress(); 1545 Size = BD->getSize(); 1546 } 1547 OS << "BOLT-INFO: Section " << Name << ", " 1548 << "0x" + Twine::utohexstr(Address) << ":" 1549 << "0x" + Twine::utohexstr(Address + Size) << "/" << Size << "\n"; 1550 CurrentSection = &Section; 1551 FirstSection = false; 1552 } 1553 1554 OS << "BOLT-INFO: "; 1555 const BinaryData *P = BD->getParent(); 1556 while (P) { 1557 OS << " "; 1558 P = P->getParent(); 1559 } 1560 OS << *BD << "\n"; 1561 } 1562 } 1563 1564 Expected<unsigned> BinaryContext::getDwarfFile( 1565 StringRef Directory, StringRef FileName, unsigned FileNumber, 1566 std::optional<MD5::MD5Result> Checksum, std::optional<StringRef> Source, 1567 unsigned CUID, unsigned DWARFVersion) { 1568 DwarfLineTable &Table = DwarfLineTablesCUMap[CUID]; 1569 return Table.tryGetFile(Directory, FileName, Checksum, Source, DWARFVersion, 1570 FileNumber); 1571 } 1572 1573 unsigned BinaryContext::addDebugFilenameToUnit(const uint32_t DestCUID, 1574 const uint32_t SrcCUID, 1575 unsigned FileIndex) { 1576 DWARFCompileUnit *SrcUnit = DwCtx->getCompileUnitForOffset(SrcCUID); 1577 const DWARFDebugLine::LineTable *LineTable = 1578 DwCtx->getLineTableForUnit(SrcUnit); 1579 const std::vector<DWARFDebugLine::FileNameEntry> &FileNames = 1580 LineTable->Prologue.FileNames; 1581 // Dir indexes start at 1, as DWARF file numbers, and a dir index 0 1582 // means empty dir. 1583 assert(FileIndex > 0 && FileIndex <= FileNames.size() && 1584 "FileIndex out of range for the compilation unit."); 1585 StringRef Dir = ""; 1586 if (FileNames[FileIndex - 1].DirIdx != 0) { 1587 if (std::optional<const char *> DirName = dwarf::toString( 1588 LineTable->Prologue 1589 .IncludeDirectories[FileNames[FileIndex - 1].DirIdx - 1])) { 1590 Dir = *DirName; 1591 } 1592 } 1593 StringRef FileName = ""; 1594 if (std::optional<const char *> FName = 1595 dwarf::toString(FileNames[FileIndex - 1].Name)) 1596 FileName = *FName; 1597 assert(FileName != ""); 1598 DWARFCompileUnit *DstUnit = DwCtx->getCompileUnitForOffset(DestCUID); 1599 return cantFail(getDwarfFile(Dir, FileName, 0, std::nullopt, std::nullopt, 1600 DestCUID, DstUnit->getVersion())); 1601 } 1602 1603 std::vector<BinaryFunction *> BinaryContext::getSortedFunctions() { 1604 std::vector<BinaryFunction *> SortedFunctions(BinaryFunctions.size()); 1605 llvm::transform(llvm::make_second_range(BinaryFunctions), 1606 SortedFunctions.begin(), 1607 [](BinaryFunction &BF) { return &BF; }); 1608 1609 llvm::stable_sort(SortedFunctions, 1610 [](const BinaryFunction *A, const BinaryFunction *B) { 1611 if (A->hasValidIndex() && B->hasValidIndex()) { 1612 return A->getIndex() < B->getIndex(); 1613 } 1614 return A->hasValidIndex(); 1615 }); 1616 return SortedFunctions; 1617 } 1618 1619 std::vector<BinaryFunction *> BinaryContext::getAllBinaryFunctions() { 1620 std::vector<BinaryFunction *> AllFunctions; 1621 AllFunctions.reserve(BinaryFunctions.size() + InjectedBinaryFunctions.size()); 1622 llvm::transform(llvm::make_second_range(BinaryFunctions), 1623 std::back_inserter(AllFunctions), 1624 [](BinaryFunction &BF) { return &BF; }); 1625 llvm::copy(InjectedBinaryFunctions, std::back_inserter(AllFunctions)); 1626 1627 return AllFunctions; 1628 } 1629 1630 std::optional<DWARFUnit *> BinaryContext::getDWOCU(uint64_t DWOId) { 1631 auto Iter = DWOCUs.find(DWOId); 1632 if (Iter == DWOCUs.end()) 1633 return std::nullopt; 1634 1635 return Iter->second; 1636 } 1637 1638 DWARFContext *BinaryContext::getDWOContext() const { 1639 if (DWOCUs.empty()) 1640 return nullptr; 1641 return &DWOCUs.begin()->second->getContext(); 1642 } 1643 1644 /// Handles DWO sections that can either be in .o, .dwo or .dwp files. 1645 void BinaryContext::preprocessDWODebugInfo() { 1646 for (const std::unique_ptr<DWARFUnit> &CU : DwCtx->compile_units()) { 1647 DWARFUnit *const DwarfUnit = CU.get(); 1648 if (std::optional<uint64_t> DWOId = DwarfUnit->getDWOId()) { 1649 std::string DWOName = dwarf::toString( 1650 DwarfUnit->getUnitDIE().find( 1651 {dwarf::DW_AT_dwo_name, dwarf::DW_AT_GNU_dwo_name}), 1652 ""); 1653 SmallString<16> AbsolutePath; 1654 if (!opts::CompDirOverride.empty()) { 1655 sys::path::append(AbsolutePath, opts::CompDirOverride); 1656 sys::path::append(AbsolutePath, DWOName); 1657 } 1658 DWARFUnit *DWOCU = 1659 DwarfUnit->getNonSkeletonUnitDIE(false, AbsolutePath).getDwarfUnit(); 1660 if (!DWOCU->isDWOUnit()) { 1661 this->outs() 1662 << "BOLT-WARNING: Debug Fission: DWO debug information for " 1663 << DWOName 1664 << " was not retrieved and won't be updated. Please check " 1665 "relative path.\n"; 1666 continue; 1667 } 1668 DWOCUs[*DWOId] = DWOCU; 1669 } 1670 } 1671 if (!DWOCUs.empty()) 1672 this->outs() << "BOLT-INFO: processing split DWARF\n"; 1673 } 1674 1675 void BinaryContext::preprocessDebugInfo() { 1676 struct CURange { 1677 uint64_t LowPC; 1678 uint64_t HighPC; 1679 DWARFUnit *Unit; 1680 1681 bool operator<(const CURange &Other) const { return LowPC < Other.LowPC; } 1682 }; 1683 1684 // Building a map of address ranges to CUs similar to .debug_aranges and use 1685 // it to assign CU to functions. 1686 std::vector<CURange> AllRanges; 1687 AllRanges.reserve(DwCtx->getNumCompileUnits()); 1688 for (const std::unique_ptr<DWARFUnit> &CU : DwCtx->compile_units()) { 1689 Expected<DWARFAddressRangesVector> RangesOrError = 1690 CU->getUnitDIE().getAddressRanges(); 1691 if (!RangesOrError) { 1692 consumeError(RangesOrError.takeError()); 1693 continue; 1694 } 1695 for (DWARFAddressRange &Range : *RangesOrError) { 1696 // Parts of the debug info could be invalidated due to corresponding code 1697 // being removed from the binary by the linker. Hence we check if the 1698 // address is a valid one. 1699 if (containsAddress(Range.LowPC)) 1700 AllRanges.emplace_back(CURange{Range.LowPC, Range.HighPC, CU.get()}); 1701 } 1702 1703 ContainsDwarf5 |= CU->getVersion() >= 5; 1704 ContainsDwarfLegacy |= CU->getVersion() < 5; 1705 } 1706 1707 llvm::sort(AllRanges); 1708 for (auto &KV : BinaryFunctions) { 1709 const uint64_t FunctionAddress = KV.first; 1710 BinaryFunction &Function = KV.second; 1711 1712 auto It = llvm::partition_point( 1713 AllRanges, [=](CURange R) { return R.HighPC <= FunctionAddress; }); 1714 if (It != AllRanges.end() && It->LowPC <= FunctionAddress) 1715 Function.setDWARFUnit(It->Unit); 1716 } 1717 1718 // Discover units with debug info that needs to be updated. 1719 for (const auto &KV : BinaryFunctions) { 1720 const BinaryFunction &BF = KV.second; 1721 if (shouldEmit(BF) && BF.getDWARFUnit()) 1722 ProcessedCUs.insert(BF.getDWARFUnit()); 1723 } 1724 1725 // Clear debug info for functions from units that we are not going to process. 1726 for (auto &KV : BinaryFunctions) { 1727 BinaryFunction &BF = KV.second; 1728 if (BF.getDWARFUnit() && !ProcessedCUs.count(BF.getDWARFUnit())) 1729 BF.setDWARFUnit(nullptr); 1730 } 1731 1732 if (opts::Verbosity >= 1) { 1733 this->outs() << "BOLT-INFO: " << ProcessedCUs.size() << " out of " 1734 << DwCtx->getNumCompileUnits() << " CUs will be updated\n"; 1735 } 1736 1737 preprocessDWODebugInfo(); 1738 1739 // Populate MCContext with DWARF files from all units. 1740 StringRef GlobalPrefix = AsmInfo->getPrivateGlobalPrefix(); 1741 for (const std::unique_ptr<DWARFUnit> &CU : DwCtx->compile_units()) { 1742 const uint64_t CUID = CU->getOffset(); 1743 DwarfLineTable &BinaryLineTable = getDwarfLineTable(CUID); 1744 BinaryLineTable.setLabel(Ctx->getOrCreateSymbol( 1745 GlobalPrefix + "line_table_start" + Twine(CUID))); 1746 1747 if (!ProcessedCUs.count(CU.get())) 1748 continue; 1749 1750 const DWARFDebugLine::LineTable *LineTable = 1751 DwCtx->getLineTableForUnit(CU.get()); 1752 const std::vector<DWARFDebugLine::FileNameEntry> &FileNames = 1753 LineTable->Prologue.FileNames; 1754 1755 uint16_t DwarfVersion = LineTable->Prologue.getVersion(); 1756 if (DwarfVersion >= 5) { 1757 std::optional<MD5::MD5Result> Checksum; 1758 if (LineTable->Prologue.ContentTypes.HasMD5) 1759 Checksum = LineTable->Prologue.FileNames[0].Checksum; 1760 std::optional<const char *> Name = 1761 dwarf::toString(CU->getUnitDIE().find(dwarf::DW_AT_name), nullptr); 1762 if (std::optional<uint64_t> DWOID = CU->getDWOId()) { 1763 auto Iter = DWOCUs.find(*DWOID); 1764 assert(Iter != DWOCUs.end() && "DWO CU was not found."); 1765 Name = dwarf::toString( 1766 Iter->second->getUnitDIE().find(dwarf::DW_AT_name), nullptr); 1767 } 1768 BinaryLineTable.setRootFile(CU->getCompilationDir(), *Name, Checksum, 1769 std::nullopt); 1770 } 1771 1772 BinaryLineTable.setDwarfVersion(DwarfVersion); 1773 1774 // Assign a unique label to every line table, one per CU. 1775 // Make sure empty debug line tables are registered too. 1776 if (FileNames.empty()) { 1777 cantFail(getDwarfFile("", "<unknown>", 0, std::nullopt, std::nullopt, 1778 CUID, DwarfVersion)); 1779 continue; 1780 } 1781 const uint32_t Offset = DwarfVersion < 5 ? 1 : 0; 1782 for (size_t I = 0, Size = FileNames.size(); I != Size; ++I) { 1783 // Dir indexes start at 1, as DWARF file numbers, and a dir index 0 1784 // means empty dir. 1785 StringRef Dir = ""; 1786 if (FileNames[I].DirIdx != 0 || DwarfVersion >= 5) 1787 if (std::optional<const char *> DirName = dwarf::toString( 1788 LineTable->Prologue 1789 .IncludeDirectories[FileNames[I].DirIdx - Offset])) 1790 Dir = *DirName; 1791 StringRef FileName = ""; 1792 if (std::optional<const char *> FName = 1793 dwarf::toString(FileNames[I].Name)) 1794 FileName = *FName; 1795 assert(FileName != ""); 1796 std::optional<MD5::MD5Result> Checksum; 1797 if (DwarfVersion >= 5 && LineTable->Prologue.ContentTypes.HasMD5) 1798 Checksum = LineTable->Prologue.FileNames[I].Checksum; 1799 cantFail(getDwarfFile(Dir, FileName, 0, Checksum, std::nullopt, CUID, 1800 DwarfVersion)); 1801 } 1802 } 1803 } 1804 1805 bool BinaryContext::shouldEmit(const BinaryFunction &Function) const { 1806 if (Function.isPseudo()) 1807 return false; 1808 1809 if (opts::processAllFunctions()) 1810 return true; 1811 1812 if (Function.isIgnored()) 1813 return false; 1814 1815 // In relocation mode we will emit non-simple functions with CFG. 1816 // If the function does not have a CFG it should be marked as ignored. 1817 return HasRelocations || Function.isSimple(); 1818 } 1819 1820 void BinaryContext::dump(const MCInst &Inst) const { 1821 if (LLVM_UNLIKELY(!InstPrinter)) { 1822 dbgs() << "Cannot dump for InstPrinter is not initialized.\n"; 1823 return; 1824 } 1825 InstPrinter->printInst(&Inst, 0, "", *STI, dbgs()); 1826 dbgs() << "\n"; 1827 } 1828 1829 void BinaryContext::printCFI(raw_ostream &OS, const MCCFIInstruction &Inst) { 1830 uint32_t Operation = Inst.getOperation(); 1831 switch (Operation) { 1832 case MCCFIInstruction::OpSameValue: 1833 OS << "OpSameValue Reg" << Inst.getRegister(); 1834 break; 1835 case MCCFIInstruction::OpRememberState: 1836 OS << "OpRememberState"; 1837 break; 1838 case MCCFIInstruction::OpRestoreState: 1839 OS << "OpRestoreState"; 1840 break; 1841 case MCCFIInstruction::OpOffset: 1842 OS << "OpOffset Reg" << Inst.getRegister() << " " << Inst.getOffset(); 1843 break; 1844 case MCCFIInstruction::OpDefCfaRegister: 1845 OS << "OpDefCfaRegister Reg" << Inst.getRegister(); 1846 break; 1847 case MCCFIInstruction::OpDefCfaOffset: 1848 OS << "OpDefCfaOffset " << Inst.getOffset(); 1849 break; 1850 case MCCFIInstruction::OpDefCfa: 1851 OS << "OpDefCfa Reg" << Inst.getRegister() << " " << Inst.getOffset(); 1852 break; 1853 case MCCFIInstruction::OpRelOffset: 1854 OS << "OpRelOffset Reg" << Inst.getRegister() << " " << Inst.getOffset(); 1855 break; 1856 case MCCFIInstruction::OpAdjustCfaOffset: 1857 OS << "OfAdjustCfaOffset " << Inst.getOffset(); 1858 break; 1859 case MCCFIInstruction::OpEscape: 1860 OS << "OpEscape"; 1861 break; 1862 case MCCFIInstruction::OpRestore: 1863 OS << "OpRestore Reg" << Inst.getRegister(); 1864 break; 1865 case MCCFIInstruction::OpUndefined: 1866 OS << "OpUndefined Reg" << Inst.getRegister(); 1867 break; 1868 case MCCFIInstruction::OpRegister: 1869 OS << "OpRegister Reg" << Inst.getRegister() << " Reg" 1870 << Inst.getRegister2(); 1871 break; 1872 case MCCFIInstruction::OpWindowSave: 1873 OS << "OpWindowSave"; 1874 break; 1875 case MCCFIInstruction::OpGnuArgsSize: 1876 OS << "OpGnuArgsSize"; 1877 break; 1878 default: 1879 OS << "Op#" << Operation; 1880 break; 1881 } 1882 } 1883 1884 MarkerSymType BinaryContext::getMarkerType(const SymbolRef &Symbol) const { 1885 // For aarch64 and riscv, the ABI defines mapping symbols so we identify data 1886 // in the code section (see IHI0056B). $x identifies a symbol starting code or 1887 // the end of a data chunk inside code, $d identifies start of data. 1888 if (isX86() || ELFSymbolRef(Symbol).getSize()) 1889 return MarkerSymType::NONE; 1890 1891 Expected<StringRef> NameOrError = Symbol.getName(); 1892 Expected<object::SymbolRef::Type> TypeOrError = Symbol.getType(); 1893 1894 if (!TypeOrError || !NameOrError) 1895 return MarkerSymType::NONE; 1896 1897 if (*TypeOrError != SymbolRef::ST_Unknown) 1898 return MarkerSymType::NONE; 1899 1900 if (*NameOrError == "$x" || NameOrError->starts_with("$x.")) 1901 return MarkerSymType::CODE; 1902 1903 // $x<ISA> 1904 if (isRISCV() && NameOrError->starts_with("$x")) 1905 return MarkerSymType::CODE; 1906 1907 if (*NameOrError == "$d" || NameOrError->starts_with("$d.")) 1908 return MarkerSymType::DATA; 1909 1910 return MarkerSymType::NONE; 1911 } 1912 1913 bool BinaryContext::isMarker(const SymbolRef &Symbol) const { 1914 return getMarkerType(Symbol) != MarkerSymType::NONE; 1915 } 1916 1917 static void printDebugInfo(raw_ostream &OS, const MCInst &Instruction, 1918 const BinaryFunction *Function, 1919 DWARFContext *DwCtx) { 1920 DebugLineTableRowRef RowRef = 1921 DebugLineTableRowRef::fromSMLoc(Instruction.getLoc()); 1922 if (RowRef == DebugLineTableRowRef::NULL_ROW) 1923 return; 1924 1925 const DWARFDebugLine::LineTable *LineTable; 1926 if (Function && Function->getDWARFUnit() && 1927 Function->getDWARFUnit()->getOffset() == RowRef.DwCompileUnitIndex) { 1928 LineTable = Function->getDWARFLineTable(); 1929 } else { 1930 LineTable = DwCtx->getLineTableForUnit( 1931 DwCtx->getCompileUnitForOffset(RowRef.DwCompileUnitIndex)); 1932 } 1933 assert(LineTable && "line table expected for instruction with debug info"); 1934 1935 const DWARFDebugLine::Row &Row = LineTable->Rows[RowRef.RowIndex - 1]; 1936 StringRef FileName = ""; 1937 if (std::optional<const char *> FName = 1938 dwarf::toString(LineTable->Prologue.FileNames[Row.File - 1].Name)) 1939 FileName = *FName; 1940 OS << " # debug line " << FileName << ":" << Row.Line; 1941 if (Row.Column) 1942 OS << ":" << Row.Column; 1943 if (Row.Discriminator) 1944 OS << " discriminator:" << Row.Discriminator; 1945 } 1946 1947 void BinaryContext::printInstruction(raw_ostream &OS, const MCInst &Instruction, 1948 uint64_t Offset, 1949 const BinaryFunction *Function, 1950 bool PrintMCInst, bool PrintMemData, 1951 bool PrintRelocations, 1952 StringRef Endl) const { 1953 OS << format(" %08" PRIx64 ": ", Offset); 1954 if (MIB->isCFI(Instruction)) { 1955 uint32_t Offset = Instruction.getOperand(0).getImm(); 1956 OS << "\t!CFI\t$" << Offset << "\t; "; 1957 if (Function) 1958 printCFI(OS, *Function->getCFIFor(Instruction)); 1959 OS << Endl; 1960 return; 1961 } 1962 if (std::optional<uint32_t> DynamicID = 1963 MIB->getDynamicBranchID(Instruction)) { 1964 OS << "\tjit\t" << MIB->getTargetSymbol(Instruction)->getName() 1965 << " # ID: " << DynamicID; 1966 } else { 1967 InstPrinter->printInst(&Instruction, 0, "", *STI, OS); 1968 } 1969 if (MIB->isCall(Instruction)) { 1970 if (MIB->isTailCall(Instruction)) 1971 OS << " # TAILCALL "; 1972 if (MIB->isInvoke(Instruction)) { 1973 const std::optional<MCPlus::MCLandingPad> EHInfo = 1974 MIB->getEHInfo(Instruction); 1975 OS << " # handler: "; 1976 if (EHInfo->first) 1977 OS << *EHInfo->first; 1978 else 1979 OS << '0'; 1980 OS << "; action: " << EHInfo->second; 1981 const int64_t GnuArgsSize = MIB->getGnuArgsSize(Instruction); 1982 if (GnuArgsSize >= 0) 1983 OS << "; GNU_args_size = " << GnuArgsSize; 1984 } 1985 } else if (MIB->isIndirectBranch(Instruction)) { 1986 if (uint64_t JTAddress = MIB->getJumpTable(Instruction)) { 1987 OS << " # JUMPTABLE @0x" << Twine::utohexstr(JTAddress); 1988 } else { 1989 OS << " # UNKNOWN CONTROL FLOW"; 1990 } 1991 } 1992 if (std::optional<uint32_t> Offset = MIB->getOffset(Instruction)) 1993 OS << " # Offset: " << *Offset; 1994 if (std::optional<uint32_t> Size = MIB->getSize(Instruction)) 1995 OS << " # Size: " << *Size; 1996 if (MCSymbol *Label = MIB->getInstLabel(Instruction)) 1997 OS << " # Label: " << *Label; 1998 1999 MIB->printAnnotations(Instruction, OS); 2000 2001 if (opts::PrintDebugInfo) 2002 printDebugInfo(OS, Instruction, Function, DwCtx.get()); 2003 2004 if ((opts::PrintRelocations || PrintRelocations) && Function) { 2005 const uint64_t Size = computeCodeSize(&Instruction, &Instruction + 1); 2006 Function->printRelocations(OS, Offset, Size); 2007 } 2008 2009 OS << Endl; 2010 2011 if (PrintMCInst) { 2012 Instruction.dump_pretty(OS, InstPrinter.get()); 2013 OS << Endl; 2014 } 2015 } 2016 2017 std::optional<uint64_t> 2018 BinaryContext::getBaseAddressForMapping(uint64_t MMapAddress, 2019 uint64_t FileOffset) const { 2020 // Find a segment with a matching file offset. 2021 for (auto &KV : SegmentMapInfo) { 2022 const SegmentInfo &SegInfo = KV.second; 2023 // FileOffset is got from perf event, 2024 // and it is equal to alignDown(SegInfo.FileOffset, pagesize). 2025 // If the pagesize is not equal to SegInfo.Alignment. 2026 // FileOffset and SegInfo.FileOffset should be aligned first, 2027 // and then judge whether they are equal. 2028 if (alignDown(SegInfo.FileOffset, SegInfo.Alignment) == 2029 alignDown(FileOffset, SegInfo.Alignment)) { 2030 // The function's offset from base address in VAS is aligned by pagesize 2031 // instead of SegInfo.Alignment. Pagesize can't be got from perf events. 2032 // However, The ELF document says that SegInfo.FileOffset should equal 2033 // to SegInfo.Address, modulo the pagesize. 2034 // Reference: https://refspecs.linuxfoundation.org/elf/elf.pdf 2035 2036 // So alignDown(SegInfo.Address, pagesize) can be calculated by: 2037 // alignDown(SegInfo.Address, pagesize) 2038 // = SegInfo.Address - (SegInfo.Address % pagesize) 2039 // = SegInfo.Address - (SegInfo.FileOffset % pagesize) 2040 // = SegInfo.Address - SegInfo.FileOffset + 2041 // alignDown(SegInfo.FileOffset, pagesize) 2042 // = SegInfo.Address - SegInfo.FileOffset + FileOffset 2043 return MMapAddress - (SegInfo.Address - SegInfo.FileOffset + FileOffset); 2044 } 2045 } 2046 2047 return std::nullopt; 2048 } 2049 2050 ErrorOr<BinarySection &> BinaryContext::getSectionForAddress(uint64_t Address) { 2051 auto SI = AddressToSection.upper_bound(Address); 2052 if (SI != AddressToSection.begin()) { 2053 --SI; 2054 uint64_t UpperBound = SI->first + SI->second->getSize(); 2055 if (!SI->second->getSize()) 2056 UpperBound += 1; 2057 if (UpperBound > Address) 2058 return *SI->second; 2059 } 2060 return std::make_error_code(std::errc::bad_address); 2061 } 2062 2063 ErrorOr<StringRef> 2064 BinaryContext::getSectionNameForAddress(uint64_t Address) const { 2065 if (ErrorOr<const BinarySection &> Section = getSectionForAddress(Address)) 2066 return Section->getName(); 2067 return std::make_error_code(std::errc::bad_address); 2068 } 2069 2070 BinarySection &BinaryContext::registerSection(BinarySection *Section) { 2071 auto Res = Sections.insert(Section); 2072 (void)Res; 2073 assert(Res.second && "can't register the same section twice."); 2074 2075 // Only register allocatable sections in the AddressToSection map. 2076 if (Section->isAllocatable() && Section->getAddress()) 2077 AddressToSection.insert(std::make_pair(Section->getAddress(), Section)); 2078 NameToSection.insert( 2079 std::make_pair(std::string(Section->getName()), Section)); 2080 if (Section->hasSectionRef()) 2081 SectionRefToBinarySection.insert( 2082 std::make_pair(Section->getSectionRef(), Section)); 2083 2084 LLVM_DEBUG(dbgs() << "BOLT-DEBUG: registering " << *Section << "\n"); 2085 return *Section; 2086 } 2087 2088 BinarySection &BinaryContext::registerSection(SectionRef Section) { 2089 return registerSection(new BinarySection(*this, Section)); 2090 } 2091 2092 BinarySection & 2093 BinaryContext::registerSection(const Twine &SectionName, 2094 const BinarySection &OriginalSection) { 2095 return registerSection( 2096 new BinarySection(*this, SectionName, OriginalSection)); 2097 } 2098 2099 BinarySection & 2100 BinaryContext::registerOrUpdateSection(const Twine &Name, unsigned ELFType, 2101 unsigned ELFFlags, uint8_t *Data, 2102 uint64_t Size, unsigned Alignment) { 2103 auto NamedSections = getSectionByName(Name); 2104 if (NamedSections.begin() != NamedSections.end()) { 2105 assert(std::next(NamedSections.begin()) == NamedSections.end() && 2106 "can only update unique sections"); 2107 BinarySection *Section = NamedSections.begin()->second; 2108 2109 LLVM_DEBUG(dbgs() << "BOLT-DEBUG: updating " << *Section << " -> "); 2110 const bool Flag = Section->isAllocatable(); 2111 (void)Flag; 2112 Section->update(Data, Size, Alignment, ELFType, ELFFlags); 2113 LLVM_DEBUG(dbgs() << *Section << "\n"); 2114 // FIXME: Fix section flags/attributes for MachO. 2115 if (isELF()) 2116 assert(Flag == Section->isAllocatable() && 2117 "can't change section allocation status"); 2118 return *Section; 2119 } 2120 2121 return registerSection( 2122 new BinarySection(*this, Name, Data, Size, Alignment, ELFType, ELFFlags)); 2123 } 2124 2125 void BinaryContext::deregisterSectionName(const BinarySection &Section) { 2126 auto NameRange = NameToSection.equal_range(Section.getName().str()); 2127 while (NameRange.first != NameRange.second) { 2128 if (NameRange.first->second == &Section) { 2129 NameToSection.erase(NameRange.first); 2130 break; 2131 } 2132 ++NameRange.first; 2133 } 2134 } 2135 2136 void BinaryContext::deregisterUnusedSections() { 2137 ErrorOr<BinarySection &> AbsSection = getUniqueSectionByName("<absolute>"); 2138 for (auto SI = Sections.begin(); SI != Sections.end();) { 2139 BinarySection *Section = *SI; 2140 // We check getOutputData() instead of getOutputSize() because sometimes 2141 // zero-sized .text.cold sections are allocated. 2142 if (Section->hasSectionRef() || Section->getOutputData() || 2143 (AbsSection && Section == &AbsSection.get())) { 2144 ++SI; 2145 continue; 2146 } 2147 2148 LLVM_DEBUG(dbgs() << "LLVM-DEBUG: deregistering " << Section->getName() 2149 << '\n';); 2150 deregisterSectionName(*Section); 2151 SI = Sections.erase(SI); 2152 delete Section; 2153 } 2154 } 2155 2156 bool BinaryContext::deregisterSection(BinarySection &Section) { 2157 BinarySection *SectionPtr = &Section; 2158 auto Itr = Sections.find(SectionPtr); 2159 if (Itr != Sections.end()) { 2160 auto Range = AddressToSection.equal_range(SectionPtr->getAddress()); 2161 while (Range.first != Range.second) { 2162 if (Range.first->second == SectionPtr) { 2163 AddressToSection.erase(Range.first); 2164 break; 2165 } 2166 ++Range.first; 2167 } 2168 2169 deregisterSectionName(*SectionPtr); 2170 Sections.erase(Itr); 2171 delete SectionPtr; 2172 return true; 2173 } 2174 return false; 2175 } 2176 2177 void BinaryContext::renameSection(BinarySection &Section, 2178 const Twine &NewName) { 2179 auto Itr = Sections.find(&Section); 2180 assert(Itr != Sections.end() && "Section must exist to be renamed."); 2181 Sections.erase(Itr); 2182 2183 deregisterSectionName(Section); 2184 2185 Section.Name = NewName.str(); 2186 Section.setOutputName(Section.Name); 2187 2188 NameToSection.insert(std::make_pair(Section.Name, &Section)); 2189 2190 // Reinsert with the new name. 2191 Sections.insert(&Section); 2192 } 2193 2194 void BinaryContext::printSections(raw_ostream &OS) const { 2195 for (BinarySection *const &Section : Sections) 2196 OS << "BOLT-INFO: " << *Section << "\n"; 2197 } 2198 2199 BinarySection &BinaryContext::absoluteSection() { 2200 if (ErrorOr<BinarySection &> Section = getUniqueSectionByName("<absolute>")) 2201 return *Section; 2202 return registerOrUpdateSection("<absolute>", ELF::SHT_NULL, 0u); 2203 } 2204 2205 ErrorOr<uint64_t> BinaryContext::getUnsignedValueAtAddress(uint64_t Address, 2206 size_t Size) const { 2207 const ErrorOr<const BinarySection &> Section = getSectionForAddress(Address); 2208 if (!Section) 2209 return std::make_error_code(std::errc::bad_address); 2210 2211 if (Section->isVirtual()) 2212 return 0; 2213 2214 DataExtractor DE(Section->getContents(), AsmInfo->isLittleEndian(), 2215 AsmInfo->getCodePointerSize()); 2216 auto ValueOffset = static_cast<uint64_t>(Address - Section->getAddress()); 2217 return DE.getUnsigned(&ValueOffset, Size); 2218 } 2219 2220 ErrorOr<int64_t> BinaryContext::getSignedValueAtAddress(uint64_t Address, 2221 size_t Size) const { 2222 const ErrorOr<const BinarySection &> Section = getSectionForAddress(Address); 2223 if (!Section) 2224 return std::make_error_code(std::errc::bad_address); 2225 2226 if (Section->isVirtual()) 2227 return 0; 2228 2229 DataExtractor DE(Section->getContents(), AsmInfo->isLittleEndian(), 2230 AsmInfo->getCodePointerSize()); 2231 auto ValueOffset = static_cast<uint64_t>(Address - Section->getAddress()); 2232 return DE.getSigned(&ValueOffset, Size); 2233 } 2234 2235 void BinaryContext::addRelocation(uint64_t Address, MCSymbol *Symbol, 2236 uint64_t Type, uint64_t Addend, 2237 uint64_t Value) { 2238 ErrorOr<BinarySection &> Section = getSectionForAddress(Address); 2239 assert(Section && "cannot find section for address"); 2240 Section->addRelocation(Address - Section->getAddress(), Symbol, Type, Addend, 2241 Value); 2242 } 2243 2244 void BinaryContext::addDynamicRelocation(uint64_t Address, MCSymbol *Symbol, 2245 uint64_t Type, uint64_t Addend, 2246 uint64_t Value) { 2247 ErrorOr<BinarySection &> Section = getSectionForAddress(Address); 2248 assert(Section && "cannot find section for address"); 2249 Section->addDynamicRelocation(Address - Section->getAddress(), Symbol, Type, 2250 Addend, Value); 2251 } 2252 2253 bool BinaryContext::removeRelocationAt(uint64_t Address) { 2254 ErrorOr<BinarySection &> Section = getSectionForAddress(Address); 2255 assert(Section && "cannot find section for address"); 2256 return Section->removeRelocationAt(Address - Section->getAddress()); 2257 } 2258 2259 const Relocation *BinaryContext::getRelocationAt(uint64_t Address) const { 2260 ErrorOr<const BinarySection &> Section = getSectionForAddress(Address); 2261 if (!Section) 2262 return nullptr; 2263 2264 return Section->getRelocationAt(Address - Section->getAddress()); 2265 } 2266 2267 const Relocation * 2268 BinaryContext::getDynamicRelocationAt(uint64_t Address) const { 2269 ErrorOr<const BinarySection &> Section = getSectionForAddress(Address); 2270 if (!Section) 2271 return nullptr; 2272 2273 return Section->getDynamicRelocationAt(Address - Section->getAddress()); 2274 } 2275 2276 void BinaryContext::markAmbiguousRelocations(BinaryData &BD, 2277 const uint64_t Address) { 2278 auto setImmovable = [&](BinaryData &BD) { 2279 BinaryData *Root = BD.getAtomicRoot(); 2280 LLVM_DEBUG(if (Root->isMoveable()) { 2281 dbgs() << "BOLT-DEBUG: setting " << *Root << " as immovable " 2282 << "due to ambiguous relocation referencing 0x" 2283 << Twine::utohexstr(Address) << '\n'; 2284 }); 2285 Root->setIsMoveable(false); 2286 }; 2287 2288 if (Address == BD.getAddress()) { 2289 setImmovable(BD); 2290 2291 // Set previous symbol as immovable 2292 BinaryData *Prev = getBinaryDataContainingAddress(Address - 1); 2293 if (Prev && Prev->getEndAddress() == BD.getAddress()) 2294 setImmovable(*Prev); 2295 } 2296 2297 if (Address == BD.getEndAddress()) { 2298 setImmovable(BD); 2299 2300 // Set next symbol as immovable 2301 BinaryData *Next = getBinaryDataContainingAddress(BD.getEndAddress()); 2302 if (Next && Next->getAddress() == BD.getEndAddress()) 2303 setImmovable(*Next); 2304 } 2305 } 2306 2307 BinaryFunction *BinaryContext::getFunctionForSymbol(const MCSymbol *Symbol, 2308 uint64_t *EntryDesc) { 2309 std::shared_lock<llvm::sys::RWMutex> Lock(SymbolToFunctionMapMutex); 2310 auto BFI = SymbolToFunctionMap.find(Symbol); 2311 if (BFI == SymbolToFunctionMap.end()) 2312 return nullptr; 2313 2314 BinaryFunction *BF = BFI->second; 2315 if (EntryDesc) 2316 *EntryDesc = BF->getEntryIDForSymbol(Symbol); 2317 2318 return BF; 2319 } 2320 2321 std::string 2322 BinaryContext::generateBugReportMessage(StringRef Message, 2323 const BinaryFunction &Function) const { 2324 std::string Msg; 2325 raw_string_ostream SS(Msg); 2326 SS << "=======================================\n"; 2327 SS << "BOLT is unable to proceed because it couldn't properly understand " 2328 "this function.\n"; 2329 SS << "If you are running the most recent version of BOLT, you may " 2330 "want to " 2331 "report this and paste this dump.\nPlease check that there is no " 2332 "sensitive contents being shared in this dump.\n"; 2333 SS << "\nOffending function: " << Function.getPrintName() << "\n\n"; 2334 ScopedPrinter SP(SS); 2335 SP.printBinaryBlock("Function contents", *Function.getData()); 2336 SS << "\n"; 2337 const_cast<BinaryFunction &>(Function).print(SS, ""); 2338 SS << "ERROR: " << Message; 2339 SS << "\n=======================================\n"; 2340 return Msg; 2341 } 2342 2343 BinaryFunction * 2344 BinaryContext::createInjectedBinaryFunction(const std::string &Name, 2345 bool IsSimple) { 2346 InjectedBinaryFunctions.push_back(new BinaryFunction(Name, *this, IsSimple)); 2347 BinaryFunction *BF = InjectedBinaryFunctions.back(); 2348 setSymbolToFunctionMap(BF->getSymbol(), BF); 2349 BF->CurrentState = BinaryFunction::State::CFG; 2350 return BF; 2351 } 2352 2353 std::pair<size_t, size_t> 2354 BinaryContext::calculateEmittedSize(BinaryFunction &BF, bool FixBranches) { 2355 // Adjust branch instruction to match the current layout. 2356 if (FixBranches) 2357 BF.fixBranches(); 2358 2359 // Create local MC context to isolate the effect of ephemeral code emission. 2360 IndependentCodeEmitter MCEInstance = createIndependentMCCodeEmitter(); 2361 MCContext *LocalCtx = MCEInstance.LocalCtx.get(); 2362 MCAsmBackend *MAB = 2363 TheTarget->createMCAsmBackend(*STI, *MRI, MCTargetOptions()); 2364 2365 SmallString<256> Code; 2366 raw_svector_ostream VecOS(Code); 2367 2368 std::unique_ptr<MCObjectWriter> OW = MAB->createObjectWriter(VecOS); 2369 std::unique_ptr<MCStreamer> Streamer(TheTarget->createMCObjectStreamer( 2370 *TheTriple, *LocalCtx, std::unique_ptr<MCAsmBackend>(MAB), std::move(OW), 2371 std::unique_ptr<MCCodeEmitter>(MCEInstance.MCE.release()), *STI, 2372 /*RelaxAll=*/false, 2373 /*IncrementalLinkerCompatible=*/false, 2374 /*DWARFMustBeAtTheEnd=*/false)); 2375 2376 Streamer->initSections(false, *STI); 2377 2378 MCSection *Section = MCEInstance.LocalMOFI->getTextSection(); 2379 Section->setHasInstructions(true); 2380 2381 // Create symbols in the LocalCtx so that they get destroyed with it. 2382 MCSymbol *StartLabel = LocalCtx->createTempSymbol(); 2383 MCSymbol *EndLabel = LocalCtx->createTempSymbol(); 2384 2385 Streamer->switchSection(Section); 2386 Streamer->emitLabel(StartLabel); 2387 emitFunctionBody(*Streamer, BF, BF.getLayout().getMainFragment(), 2388 /*EmitCodeOnly=*/true); 2389 Streamer->emitLabel(EndLabel); 2390 2391 using LabelRange = std::pair<const MCSymbol *, const MCSymbol *>; 2392 SmallVector<LabelRange> SplitLabels; 2393 for (FunctionFragment &FF : BF.getLayout().getSplitFragments()) { 2394 MCSymbol *const SplitStartLabel = LocalCtx->createTempSymbol(); 2395 MCSymbol *const SplitEndLabel = LocalCtx->createTempSymbol(); 2396 SplitLabels.emplace_back(SplitStartLabel, SplitEndLabel); 2397 2398 MCSectionELF *const SplitSection = LocalCtx->getELFSection( 2399 BF.getCodeSectionName(FF.getFragmentNum()), ELF::SHT_PROGBITS, 2400 ELF::SHF_EXECINSTR | ELF::SHF_ALLOC); 2401 SplitSection->setHasInstructions(true); 2402 Streamer->switchSection(SplitSection); 2403 2404 Streamer->emitLabel(SplitStartLabel); 2405 emitFunctionBody(*Streamer, BF, FF, /*EmitCodeOnly=*/true); 2406 Streamer->emitLabel(SplitEndLabel); 2407 // To avoid calling MCObjectStreamer::flushPendingLabels() which is 2408 // private 2409 Streamer->emitBytes(StringRef("")); 2410 Streamer->switchSection(Section); 2411 } 2412 2413 // To avoid calling MCObjectStreamer::flushPendingLabels() which is private or 2414 // MCStreamer::Finish(), which does more than we want 2415 Streamer->emitBytes(StringRef("")); 2416 2417 MCAssembler &Assembler = 2418 static_cast<MCObjectStreamer *>(Streamer.get())->getAssembler(); 2419 MCAsmLayout Layout(Assembler); 2420 Assembler.layout(Layout); 2421 2422 // Obtain fragment sizes. 2423 std::vector<uint64_t> FragmentSizes; 2424 // Main fragment size. 2425 const uint64_t HotSize = Assembler.getSymbolOffset(*EndLabel) - 2426 Assembler.getSymbolOffset(*StartLabel); 2427 FragmentSizes.push_back(HotSize); 2428 // Split fragment sizes. 2429 uint64_t ColdSize = 0; 2430 for (const auto &Labels : SplitLabels) { 2431 uint64_t Size = Assembler.getSymbolOffset(*Labels.second) - 2432 Assembler.getSymbolOffset(*Labels.first); 2433 FragmentSizes.push_back(Size); 2434 ColdSize += Size; 2435 } 2436 2437 // Populate new start and end offsets of each basic block. 2438 uint64_t FragmentIndex = 0; 2439 for (FunctionFragment &FF : BF.getLayout().fragments()) { 2440 BinaryBasicBlock *PrevBB = nullptr; 2441 for (BinaryBasicBlock *BB : FF) { 2442 const uint64_t BBStartOffset = 2443 Assembler.getSymbolOffset(*(BB->getLabel())); 2444 BB->setOutputStartAddress(BBStartOffset); 2445 if (PrevBB) 2446 PrevBB->setOutputEndAddress(BBStartOffset); 2447 PrevBB = BB; 2448 } 2449 if (PrevBB) 2450 PrevBB->setOutputEndAddress(FragmentSizes[FragmentIndex]); 2451 FragmentIndex++; 2452 } 2453 2454 // Clean-up the effect of the code emission. 2455 for (const MCSymbol &Symbol : Assembler.symbols()) { 2456 MCSymbol *MutableSymbol = const_cast<MCSymbol *>(&Symbol); 2457 MutableSymbol->setUndefined(); 2458 MutableSymbol->setIsRegistered(false); 2459 } 2460 2461 return std::make_pair(HotSize, ColdSize); 2462 } 2463 2464 bool BinaryContext::validateInstructionEncoding( 2465 ArrayRef<uint8_t> InputSequence) const { 2466 MCInst Inst; 2467 uint64_t InstSize; 2468 DisAsm->getInstruction(Inst, InstSize, InputSequence, 0, nulls()); 2469 assert(InstSize == InputSequence.size() && 2470 "Disassembled instruction size does not match the sequence."); 2471 2472 SmallString<256> Code; 2473 SmallVector<MCFixup, 4> Fixups; 2474 2475 MCE->encodeInstruction(Inst, Code, Fixups, *STI); 2476 auto OutputSequence = ArrayRef<uint8_t>((uint8_t *)Code.data(), Code.size()); 2477 if (InputSequence != OutputSequence) { 2478 if (opts::Verbosity > 1) { 2479 this->errs() << "BOLT-WARNING: mismatched encoding detected\n" 2480 << " input: " << InputSequence << '\n' 2481 << " output: " << OutputSequence << '\n'; 2482 } 2483 return false; 2484 } 2485 2486 return true; 2487 } 2488 2489 uint64_t BinaryContext::getHotThreshold() const { 2490 static uint64_t Threshold = 0; 2491 if (Threshold == 0) { 2492 Threshold = std::max( 2493 (uint64_t)opts::ExecutionCountThreshold, 2494 NumProfiledFuncs ? SumExecutionCount / (2 * NumProfiledFuncs) : 1); 2495 } 2496 return Threshold; 2497 } 2498 2499 BinaryFunction *BinaryContext::getBinaryFunctionContainingAddress( 2500 uint64_t Address, bool CheckPastEnd, bool UseMaxSize) { 2501 auto FI = BinaryFunctions.upper_bound(Address); 2502 if (FI == BinaryFunctions.begin()) 2503 return nullptr; 2504 --FI; 2505 2506 const uint64_t UsedSize = 2507 UseMaxSize ? FI->second.getMaxSize() : FI->second.getSize(); 2508 2509 if (Address >= FI->first + UsedSize + (CheckPastEnd ? 1 : 0)) 2510 return nullptr; 2511 2512 return &FI->second; 2513 } 2514 2515 BinaryFunction *BinaryContext::getBinaryFunctionAtAddress(uint64_t Address) { 2516 // First, try to find a function starting at the given address. If the 2517 // function was folded, this will get us the original folded function if it 2518 // wasn't removed from the list, e.g. in non-relocation mode. 2519 auto BFI = BinaryFunctions.find(Address); 2520 if (BFI != BinaryFunctions.end()) 2521 return &BFI->second; 2522 2523 // We might have folded the function matching the object at the given 2524 // address. In such case, we look for a function matching the symbol 2525 // registered at the original address. The new function (the one that the 2526 // original was folded into) will hold the symbol. 2527 if (const BinaryData *BD = getBinaryDataAtAddress(Address)) { 2528 uint64_t EntryID = 0; 2529 BinaryFunction *BF = getFunctionForSymbol(BD->getSymbol(), &EntryID); 2530 if (BF && EntryID == 0) 2531 return BF; 2532 } 2533 return nullptr; 2534 } 2535 2536 DebugAddressRangesVector BinaryContext::translateModuleAddressRanges( 2537 const DWARFAddressRangesVector &InputRanges) const { 2538 DebugAddressRangesVector OutputRanges; 2539 2540 for (const DWARFAddressRange Range : InputRanges) { 2541 auto BFI = BinaryFunctions.lower_bound(Range.LowPC); 2542 while (BFI != BinaryFunctions.end()) { 2543 const BinaryFunction &Function = BFI->second; 2544 if (Function.getAddress() >= Range.HighPC) 2545 break; 2546 const DebugAddressRangesVector FunctionRanges = 2547 Function.getOutputAddressRanges(); 2548 llvm::move(FunctionRanges, std::back_inserter(OutputRanges)); 2549 std::advance(BFI, 1); 2550 } 2551 } 2552 2553 return OutputRanges; 2554 } 2555 2556 } // namespace bolt 2557 } // namespace llvm 2558