1 //===-- SanitizerCoverage.cpp - coverage instrumentation for sanitizers ---===// 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 // Coverage instrumentation done on LLVM IR level, works with Sanitizers. 10 // 11 //===----------------------------------------------------------------------===// 12 13 #include "llvm/Transforms/Instrumentation/SanitizerCoverage.h" 14 #include "llvm/ADT/ArrayRef.h" 15 #include "llvm/ADT/SmallVector.h" 16 #include "llvm/Analysis/EHPersonalities.h" 17 #include "llvm/Analysis/PostDominators.h" 18 #include "llvm/IR/CFG.h" 19 #include "llvm/IR/CallSite.h" 20 #include "llvm/IR/Constant.h" 21 #include "llvm/IR/DataLayout.h" 22 #include "llvm/IR/DebugInfo.h" 23 #include "llvm/IR/Dominators.h" 24 #include "llvm/IR/Function.h" 25 #include "llvm/IR/GlobalVariable.h" 26 #include "llvm/IR/IRBuilder.h" 27 #include "llvm/IR/InlineAsm.h" 28 #include "llvm/IR/IntrinsicInst.h" 29 #include "llvm/IR/Intrinsics.h" 30 #include "llvm/IR/LLVMContext.h" 31 #include "llvm/IR/MDBuilder.h" 32 #include "llvm/IR/Mangler.h" 33 #include "llvm/IR/Module.h" 34 #include "llvm/IR/Type.h" 35 #include "llvm/Support/CommandLine.h" 36 #include "llvm/Support/Debug.h" 37 #include "llvm/Support/raw_ostream.h" 38 #include "llvm/Transforms/Instrumentation.h" 39 #include "llvm/Transforms/Utils/BasicBlockUtils.h" 40 #include "llvm/Transforms/Utils/ModuleUtils.h" 41 42 using namespace llvm; 43 44 #define DEBUG_TYPE "sancov" 45 46 static const char *const SanCovTracePCIndirName = 47 "__sanitizer_cov_trace_pc_indir"; 48 static const char *const SanCovTracePCName = "__sanitizer_cov_trace_pc"; 49 static const char *const SanCovTraceCmp1 = "__sanitizer_cov_trace_cmp1"; 50 static const char *const SanCovTraceCmp2 = "__sanitizer_cov_trace_cmp2"; 51 static const char *const SanCovTraceCmp4 = "__sanitizer_cov_trace_cmp4"; 52 static const char *const SanCovTraceCmp8 = "__sanitizer_cov_trace_cmp8"; 53 static const char *const SanCovTraceConstCmp1 = 54 "__sanitizer_cov_trace_const_cmp1"; 55 static const char *const SanCovTraceConstCmp2 = 56 "__sanitizer_cov_trace_const_cmp2"; 57 static const char *const SanCovTraceConstCmp4 = 58 "__sanitizer_cov_trace_const_cmp4"; 59 static const char *const SanCovTraceConstCmp8 = 60 "__sanitizer_cov_trace_const_cmp8"; 61 static const char *const SanCovTraceDiv4 = "__sanitizer_cov_trace_div4"; 62 static const char *const SanCovTraceDiv8 = "__sanitizer_cov_trace_div8"; 63 static const char *const SanCovTraceGep = "__sanitizer_cov_trace_gep"; 64 static const char *const SanCovTraceSwitchName = "__sanitizer_cov_trace_switch"; 65 static const char *const SanCovModuleCtorTracePcGuardName = 66 "sancov.module_ctor_trace_pc_guard"; 67 static const char *const SanCovModuleCtor8bitCountersName = 68 "sancov.module_ctor_8bit_counters"; 69 static const uint64_t SanCtorAndDtorPriority = 2; 70 71 static const char *const SanCovTracePCGuardName = 72 "__sanitizer_cov_trace_pc_guard"; 73 static const char *const SanCovTracePCGuardInitName = 74 "__sanitizer_cov_trace_pc_guard_init"; 75 static const char *const SanCov8bitCountersInitName = 76 "__sanitizer_cov_8bit_counters_init"; 77 static const char *const SanCovPCsInitName = "__sanitizer_cov_pcs_init"; 78 79 static const char *const SanCovGuardsSectionName = "sancov_guards"; 80 static const char *const SanCovCountersSectionName = "sancov_cntrs"; 81 static const char *const SanCovPCsSectionName = "sancov_pcs"; 82 83 static const char *const SanCovLowestStackName = "__sancov_lowest_stack"; 84 85 static cl::opt<int> ClCoverageLevel( 86 "sanitizer-coverage-level", 87 cl::desc("Sanitizer Coverage. 0: none, 1: entry block, 2: all blocks, " 88 "3: all blocks and critical edges"), 89 cl::Hidden, cl::init(0)); 90 91 static cl::opt<bool> ClTracePC("sanitizer-coverage-trace-pc", 92 cl::desc("Experimental pc tracing"), cl::Hidden, 93 cl::init(false)); 94 95 static cl::opt<bool> ClTracePCGuard("sanitizer-coverage-trace-pc-guard", 96 cl::desc("pc tracing with a guard"), 97 cl::Hidden, cl::init(false)); 98 99 // If true, we create a global variable that contains PCs of all instrumented 100 // BBs, put this global into a named section, and pass this section's bounds 101 // to __sanitizer_cov_pcs_init. 102 // This way the coverage instrumentation does not need to acquire the PCs 103 // at run-time. Works with trace-pc-guard and inline-8bit-counters. 104 static cl::opt<bool> ClCreatePCTable("sanitizer-coverage-pc-table", 105 cl::desc("create a static PC table"), 106 cl::Hidden, cl::init(false)); 107 108 static cl::opt<bool> 109 ClInline8bitCounters("sanitizer-coverage-inline-8bit-counters", 110 cl::desc("increments 8-bit counter for every edge"), 111 cl::Hidden, cl::init(false)); 112 113 static cl::opt<bool> 114 ClCMPTracing("sanitizer-coverage-trace-compares", 115 cl::desc("Tracing of CMP and similar instructions"), 116 cl::Hidden, cl::init(false)); 117 118 static cl::opt<bool> ClDIVTracing("sanitizer-coverage-trace-divs", 119 cl::desc("Tracing of DIV instructions"), 120 cl::Hidden, cl::init(false)); 121 122 static cl::opt<bool> ClGEPTracing("sanitizer-coverage-trace-geps", 123 cl::desc("Tracing of GEP instructions"), 124 cl::Hidden, cl::init(false)); 125 126 static cl::opt<bool> 127 ClPruneBlocks("sanitizer-coverage-prune-blocks", 128 cl::desc("Reduce the number of instrumented blocks"), 129 cl::Hidden, cl::init(true)); 130 131 static cl::opt<bool> ClStackDepth("sanitizer-coverage-stack-depth", 132 cl::desc("max stack depth tracing"), 133 cl::Hidden, cl::init(false)); 134 135 namespace { 136 137 SanitizerCoverageOptions getOptions(int LegacyCoverageLevel) { 138 SanitizerCoverageOptions Res; 139 switch (LegacyCoverageLevel) { 140 case 0: 141 Res.CoverageType = SanitizerCoverageOptions::SCK_None; 142 break; 143 case 1: 144 Res.CoverageType = SanitizerCoverageOptions::SCK_Function; 145 break; 146 case 2: 147 Res.CoverageType = SanitizerCoverageOptions::SCK_BB; 148 break; 149 case 3: 150 Res.CoverageType = SanitizerCoverageOptions::SCK_Edge; 151 break; 152 case 4: 153 Res.CoverageType = SanitizerCoverageOptions::SCK_Edge; 154 Res.IndirectCalls = true; 155 break; 156 } 157 return Res; 158 } 159 160 SanitizerCoverageOptions OverrideFromCL(SanitizerCoverageOptions Options) { 161 // Sets CoverageType and IndirectCalls. 162 SanitizerCoverageOptions CLOpts = getOptions(ClCoverageLevel); 163 Options.CoverageType = std::max(Options.CoverageType, CLOpts.CoverageType); 164 Options.IndirectCalls |= CLOpts.IndirectCalls; 165 Options.TraceCmp |= ClCMPTracing; 166 Options.TraceDiv |= ClDIVTracing; 167 Options.TraceGep |= ClGEPTracing; 168 Options.TracePC |= ClTracePC; 169 Options.TracePCGuard |= ClTracePCGuard; 170 Options.Inline8bitCounters |= ClInline8bitCounters; 171 Options.PCTable |= ClCreatePCTable; 172 Options.NoPrune |= !ClPruneBlocks; 173 Options.StackDepth |= ClStackDepth; 174 if (!Options.TracePCGuard && !Options.TracePC && 175 !Options.Inline8bitCounters && !Options.StackDepth) 176 Options.TracePCGuard = true; // TracePCGuard is default. 177 return Options; 178 } 179 180 bool canInstrumentWithSancov(const Function &F) { 181 if (F.empty()) 182 return false; 183 if (F.getName().find(".module_ctor") != std::string::npos) 184 return false; // Should not instrument sanitizer init functions. 185 if (F.getName().startswith("__sanitizer_")) 186 return false; // Don't instrument __sanitizer_* callbacks. 187 // Don't touch available_externally functions, their actual body is elewhere. 188 if (F.getLinkage() == GlobalValue::AvailableExternallyLinkage) 189 return false; 190 // Don't instrument MSVC CRT configuration helpers. They may run before normal 191 // initialization. 192 if (F.getName() == "__local_stdio_printf_options" || 193 F.getName() == "__local_stdio_scanf_options") 194 return false; 195 if (isa<UnreachableInst>(F.getEntryBlock().getTerminator())) 196 return false; 197 // Don't instrument functions using SEH for now. Splitting basic blocks like 198 // we do for coverage breaks WinEHPrepare. 199 // FIXME: Remove this when SEH no longer uses landingpad pattern matching. 200 if (F.hasPersonalityFn() && 201 isAsynchronousEHPersonality(classifyEHPersonality(F.getPersonalityFn()))) 202 return false; 203 return true; 204 } 205 206 /// This is a class for instrumenting the module to add calls to initializing 207 /// the trace PC guards and 8bit counter globals. This should only be done 208 /// though if there is at least one function that can be instrumented with 209 /// Sancov. 210 class ModuleSanitizerCoverage { 211 public: 212 ModuleSanitizerCoverage(const SanitizerCoverageOptions &Options) 213 : Options(OverrideFromCL(Options)) {} 214 215 bool instrumentModule(Module &M) { 216 if (Options.CoverageType == SanitizerCoverageOptions::SCK_None) 217 return false; 218 219 Function *Ctor = nullptr; 220 LLVMContext *C = &(M.getContext()); 221 const DataLayout *DL = &M.getDataLayout(); 222 TargetTriple = Triple(M.getTargetTriple()); 223 IntptrTy = Type::getIntNTy(*C, DL->getPointerSizeInBits()); 224 Type *IntptrPtrTy = PointerType::getUnqual(IntptrTy); 225 IRBuilder<> IRB(*C); 226 Type *Int32PtrTy = PointerType::getUnqual(IRB.getInt32Ty()); 227 Int8PtrTy = PointerType::getUnqual(IRB.getInt8Ty()); 228 Int8Ty = IRB.getInt8Ty(); 229 230 // Check that the __sancov_lowest_stack marker does not already exist. 231 Constant *SanCovLowestStackConstant = 232 M.getOrInsertGlobal(SanCovLowestStackName, IntptrTy); 233 GlobalVariable *SanCovLowestStack = 234 dyn_cast<GlobalVariable>(SanCovLowestStackConstant); 235 if (!SanCovLowestStack) { 236 C->emitError(StringRef("'") + SanCovLowestStackName + 237 "' should not be declared by the user"); 238 return true; 239 } 240 241 // We want to emit guard init calls if the module contains a function that 242 // we can instrument with SanitizerCoverage. We ignore any functions that 243 // were inserted by SanitizerCoverage and get the result from the analysis 244 // that checks for a valid function that the analysis may have run over. 245 if (!llvm::any_of( 246 M, [](const Function &F) { return canInstrumentWithSancov(F); })) 247 return false; 248 249 // Emit the init calls. 250 if (Options.TracePCGuard) 251 Ctor = CreateInitCallsForSections(M, SanCovModuleCtorTracePcGuardName, 252 SanCovTracePCGuardInitName, Int32PtrTy, 253 SanCovGuardsSectionName); 254 if (Options.Inline8bitCounters) 255 Ctor = CreateInitCallsForSections(M, SanCovModuleCtor8bitCountersName, 256 SanCov8bitCountersInitName, Int8PtrTy, 257 SanCovCountersSectionName); 258 if (Ctor && Options.PCTable) { 259 auto SecStartEnd = 260 CreateSecStartEnd(M, SanCovPCsSectionName, IntptrPtrTy); 261 FunctionCallee InitFunction = declareSanitizerInitFunction( 262 M, SanCovPCsInitName, {IntptrPtrTy, IntptrPtrTy}); 263 IRBuilder<> IRBCtor(Ctor->getEntryBlock().getTerminator()); 264 IRBCtor.CreateCall(InitFunction, {SecStartEnd.first, SecStartEnd.second}); 265 } 266 return Ctor; 267 } 268 269 private: 270 Function *CreateInitCallsForSections(Module &M, const char *CtorName, 271 const char *InitFunctionName, Type *Ty, 272 const char *Section); 273 std::pair<Value *, Value *> CreateSecStartEnd(Module &M, const char *Section, 274 Type *Ty); 275 std::string getSectionStart(const std::string &Section) const { 276 if (TargetTriple.isOSBinFormatMachO()) 277 return "\1section$start$__DATA$__" + Section; 278 return "__start___" + Section; 279 } 280 std::string getSectionEnd(const std::string &Section) const { 281 if (TargetTriple.isOSBinFormatMachO()) 282 return "\1section$end$__DATA$__" + Section; 283 return "__stop___" + Section; 284 } 285 286 SanitizerCoverageOptions Options; 287 Triple TargetTriple; 288 Type *IntptrTy, *Int8PtrTy, *Int8Ty; 289 }; 290 291 class ModuleSanitizerCoverageLegacyPass : public ModulePass { 292 public: 293 static char ID; 294 295 ModuleSanitizerCoverageLegacyPass( 296 SanitizerCoverageOptions Options = SanitizerCoverageOptions()) 297 : ModulePass(ID), Options(Options) { 298 initializeModuleSanitizerCoverageLegacyPassPass( 299 *PassRegistry::getPassRegistry()); 300 } 301 302 bool runOnModule(Module &M) override { 303 ModuleSanitizerCoverage ModuleSancov(Options); 304 return ModuleSancov.instrumentModule(M); 305 }; 306 307 StringRef getPassName() const override { 308 return "ModuleSanitizerCoverageLegacyPass"; 309 } 310 311 private: 312 SanitizerCoverageOptions Options; 313 }; 314 315 char ModuleSanitizerCoverageLegacyPass::ID = 0; 316 317 class SanitizerCoverage { 318 public: 319 SanitizerCoverage(Function &F, const SanitizerCoverageOptions &Options) 320 : CurModule(F.getParent()), Options(OverrideFromCL(Options)) { 321 initializeModule(*F.getParent()); 322 } 323 324 ~SanitizerCoverage() { finalizeModule(*CurModule); } 325 326 bool instrumentFunction(Function &F, const DominatorTree *DT, 327 const PostDominatorTree *PDT); 328 329 private: 330 void initializeModule(Module &M); 331 void finalizeModule(Module &M); 332 void InjectCoverageForIndirectCalls(Function &F, 333 ArrayRef<Instruction *> IndirCalls); 334 void InjectTraceForCmp(Function &F, ArrayRef<Instruction *> CmpTraceTargets); 335 void InjectTraceForDiv(Function &F, 336 ArrayRef<BinaryOperator *> DivTraceTargets); 337 void InjectTraceForGep(Function &F, 338 ArrayRef<GetElementPtrInst *> GepTraceTargets); 339 void InjectTraceForSwitch(Function &F, 340 ArrayRef<Instruction *> SwitchTraceTargets); 341 bool InjectCoverage(Function &F, ArrayRef<BasicBlock *> AllBlocks, 342 bool IsLeafFunc = true); 343 GlobalVariable *CreateFunctionLocalArrayInSection(size_t NumElements, 344 Function &F, Type *Ty, 345 const char *Section); 346 GlobalVariable *CreatePCArray(Function &F, ArrayRef<BasicBlock *> AllBlocks); 347 void CreateFunctionLocalArrays(Function &F, ArrayRef<BasicBlock *> AllBlocks); 348 void InjectCoverageAtBlock(Function &F, BasicBlock &BB, size_t Idx, 349 bool IsLeafFunc = true); 350 351 void SetNoSanitizeMetadata(Instruction *I) { 352 I->setMetadata(I->getModule()->getMDKindID("nosanitize"), 353 MDNode::get(*C, None)); 354 } 355 356 std::string getSectionName(const std::string &Section) const; 357 FunctionCallee SanCovTracePCIndir; 358 FunctionCallee SanCovTracePC, SanCovTracePCGuard; 359 FunctionCallee SanCovTraceCmpFunction[4]; 360 FunctionCallee SanCovTraceConstCmpFunction[4]; 361 FunctionCallee SanCovTraceDivFunction[2]; 362 FunctionCallee SanCovTraceGepFunction; 363 FunctionCallee SanCovTraceSwitchFunction; 364 GlobalVariable *SanCovLowestStack; 365 InlineAsm *EmptyAsm; 366 Type *IntptrTy, *IntptrPtrTy, *Int64Ty, *Int64PtrTy, *Int32Ty, *Int32PtrTy, 367 *Int16Ty, *Int8Ty, *Int8PtrTy; 368 Module *CurModule; 369 std::string CurModuleUniqueId; 370 Triple TargetTriple; 371 LLVMContext *C; 372 const DataLayout *DL; 373 374 GlobalVariable *FunctionGuardArray; // for trace-pc-guard. 375 GlobalVariable *Function8bitCounterArray; // for inline-8bit-counters. 376 GlobalVariable *FunctionPCsArray; // for pc-table. 377 SmallVector<GlobalValue *, 20> GlobalsToAppendToUsed; 378 SmallVector<GlobalValue *, 20> GlobalsToAppendToCompilerUsed; 379 380 SanitizerCoverageOptions Options; 381 }; 382 383 class SanitizerCoverageLegacyPass : public FunctionPass { 384 public: 385 static char ID; // Pass identification, replacement for typeid 386 387 SanitizerCoverageLegacyPass( 388 SanitizerCoverageOptions Options = SanitizerCoverageOptions()) 389 : FunctionPass(ID), Options(Options) { 390 initializeSanitizerCoverageLegacyPassPass(*PassRegistry::getPassRegistry()); 391 } 392 393 bool runOnFunction(Function &F) override { 394 const DominatorTree *DT = 395 &getAnalysis<DominatorTreeWrapperPass>().getDomTree(); 396 const PostDominatorTree *PDT = 397 &getAnalysis<PostDominatorTreeWrapperPass>().getPostDomTree(); 398 SanitizerCoverage Sancov(F, Options); 399 return Sancov.instrumentFunction(F, DT, PDT); 400 } 401 402 StringRef getPassName() const override { 403 return "SanitizerCoverageLegacyPass"; 404 } 405 406 void getAnalysisUsage(AnalysisUsage &AU) const override { 407 // Make the module sancov pass required by this pass so that it runs when 408 // -sancov is passed. 409 AU.addRequired<ModuleSanitizerCoverageLegacyPass>(); 410 AU.addRequired<DominatorTreeWrapperPass>(); 411 AU.addRequired<PostDominatorTreeWrapperPass>(); 412 } 413 414 private: 415 SanitizerCoverageOptions Options; 416 }; 417 418 } // namespace 419 420 PreservedAnalyses SanitizerCoveragePass::run(Function &F, 421 FunctionAnalysisManager &AM) { 422 const DominatorTree *DT = &AM.getResult<DominatorTreeAnalysis>(F); 423 const PostDominatorTree *PDT = &AM.getResult<PostDominatorTreeAnalysis>(F); 424 SanitizerCoverage Sancov(F, Options); 425 if (Sancov.instrumentFunction(F, DT, PDT)) 426 return PreservedAnalyses::none(); 427 return PreservedAnalyses::all(); 428 } 429 430 PreservedAnalyses ModuleSanitizerCoveragePass::run(Module &M, 431 ModuleAnalysisManager &AM) { 432 ModuleSanitizerCoverage ModuleSancov(Options); 433 if (ModuleSancov.instrumentModule(M)) 434 return PreservedAnalyses::none(); 435 return PreservedAnalyses::all(); 436 } 437 438 std::pair<Value *, Value *> 439 ModuleSanitizerCoverage::CreateSecStartEnd(Module &M, const char *Section, 440 Type *Ty) { 441 GlobalVariable *SecStart = 442 new GlobalVariable(M, Ty, false, GlobalVariable::ExternalLinkage, nullptr, 443 getSectionStart(Section)); 444 SecStart->setVisibility(GlobalValue::HiddenVisibility); 445 GlobalVariable *SecEnd = 446 new GlobalVariable(M, Ty, false, GlobalVariable::ExternalLinkage, 447 nullptr, getSectionEnd(Section)); 448 SecEnd->setVisibility(GlobalValue::HiddenVisibility); 449 450 IRBuilder<> IRB(M.getContext()); 451 Value *SecEndPtr = IRB.CreatePointerCast(SecEnd, Ty); 452 if (!TargetTriple.isOSBinFormatCOFF()) 453 return std::make_pair(IRB.CreatePointerCast(SecStart, Ty), SecEndPtr); 454 455 // Account for the fact that on windows-msvc __start_* symbols actually 456 // point to a uint64_t before the start of the array. 457 auto SecStartI8Ptr = IRB.CreatePointerCast(SecStart, Int8PtrTy); 458 auto GEP = IRB.CreateGEP(Int8Ty, SecStartI8Ptr, 459 ConstantInt::get(IntptrTy, sizeof(uint64_t))); 460 return std::make_pair(IRB.CreatePointerCast(GEP, Ty), SecEndPtr); 461 } 462 463 Function *ModuleSanitizerCoverage::CreateInitCallsForSections( 464 Module &M, const char *CtorName, const char *InitFunctionName, Type *Ty, 465 const char *Section) { 466 auto SecStartEnd = CreateSecStartEnd(M, Section, Ty); 467 auto SecStart = SecStartEnd.first; 468 auto SecEnd = SecStartEnd.second; 469 Function *CtorFunc; 470 std::tie(CtorFunc, std::ignore) = createSanitizerCtorAndInitFunctions( 471 M, CtorName, InitFunctionName, {Ty, Ty}, {SecStart, SecEnd}); 472 assert(CtorFunc->getName() == CtorName); 473 474 if (TargetTriple.supportsCOMDAT()) { 475 // Use comdat to dedup CtorFunc. 476 CtorFunc->setComdat(M.getOrInsertComdat(CtorName)); 477 appendToGlobalCtors(M, CtorFunc, SanCtorAndDtorPriority, CtorFunc); 478 } else { 479 appendToGlobalCtors(M, CtorFunc, SanCtorAndDtorPriority); 480 } 481 482 if (TargetTriple.isOSBinFormatCOFF()) { 483 // In COFF files, if the contructors are set as COMDAT (they are because 484 // COFF supports COMDAT) and the linker flag /OPT:REF (strip unreferenced 485 // functions and data) is used, the constructors get stripped. To prevent 486 // this, give the constructors weak ODR linkage and ensure the linker knows 487 // to include the sancov constructor. This way the linker can deduplicate 488 // the constructors but always leave one copy. 489 CtorFunc->setLinkage(GlobalValue::WeakODRLinkage); 490 appendToUsed(M, CtorFunc); 491 } 492 return CtorFunc; 493 } 494 495 void SanitizerCoverage::initializeModule(Module &M) { 496 if (Options.CoverageType == SanitizerCoverageOptions::SCK_None) 497 return; 498 C = &(M.getContext()); 499 DL = &M.getDataLayout(); 500 CurModuleUniqueId = getUniqueModuleId(CurModule); 501 TargetTriple = Triple(M.getTargetTriple()); 502 FunctionGuardArray = nullptr; 503 Function8bitCounterArray = nullptr; 504 FunctionPCsArray = nullptr; 505 IntptrTy = Type::getIntNTy(*C, DL->getPointerSizeInBits()); 506 IntptrPtrTy = PointerType::getUnqual(IntptrTy); 507 Type *VoidTy = Type::getVoidTy(*C); 508 IRBuilder<> IRB(*C); 509 Int64PtrTy = PointerType::getUnqual(IRB.getInt64Ty()); 510 Int32PtrTy = PointerType::getUnqual(IRB.getInt32Ty()); 511 Int8PtrTy = PointerType::getUnqual(IRB.getInt8Ty()); 512 Int64Ty = IRB.getInt64Ty(); 513 Int32Ty = IRB.getInt32Ty(); 514 Int16Ty = IRB.getInt16Ty(); 515 Int8Ty = IRB.getInt8Ty(); 516 517 SanCovTracePCIndir = 518 M.getOrInsertFunction(SanCovTracePCIndirName, VoidTy, IntptrTy); 519 // Make sure smaller parameters are zero-extended to i64 as required by the 520 // x86_64 ABI. 521 AttributeList SanCovTraceCmpZeroExtAL; 522 if (TargetTriple.getArch() == Triple::x86_64) { 523 SanCovTraceCmpZeroExtAL = 524 SanCovTraceCmpZeroExtAL.addParamAttribute(*C, 0, Attribute::ZExt); 525 SanCovTraceCmpZeroExtAL = 526 SanCovTraceCmpZeroExtAL.addParamAttribute(*C, 1, Attribute::ZExt); 527 } 528 529 SanCovTraceCmpFunction[0] = 530 M.getOrInsertFunction(SanCovTraceCmp1, SanCovTraceCmpZeroExtAL, VoidTy, 531 IRB.getInt8Ty(), IRB.getInt8Ty()); 532 SanCovTraceCmpFunction[1] = 533 M.getOrInsertFunction(SanCovTraceCmp2, SanCovTraceCmpZeroExtAL, VoidTy, 534 IRB.getInt16Ty(), IRB.getInt16Ty()); 535 SanCovTraceCmpFunction[2] = 536 M.getOrInsertFunction(SanCovTraceCmp4, SanCovTraceCmpZeroExtAL, VoidTy, 537 IRB.getInt32Ty(), IRB.getInt32Ty()); 538 SanCovTraceCmpFunction[3] = 539 M.getOrInsertFunction(SanCovTraceCmp8, VoidTy, Int64Ty, Int64Ty); 540 541 SanCovTraceConstCmpFunction[0] = M.getOrInsertFunction( 542 SanCovTraceConstCmp1, SanCovTraceCmpZeroExtAL, VoidTy, Int8Ty, Int8Ty); 543 SanCovTraceConstCmpFunction[1] = M.getOrInsertFunction( 544 SanCovTraceConstCmp2, SanCovTraceCmpZeroExtAL, VoidTy, Int16Ty, Int16Ty); 545 SanCovTraceConstCmpFunction[2] = M.getOrInsertFunction( 546 SanCovTraceConstCmp4, SanCovTraceCmpZeroExtAL, VoidTy, Int32Ty, Int32Ty); 547 SanCovTraceConstCmpFunction[3] = 548 M.getOrInsertFunction(SanCovTraceConstCmp8, VoidTy, Int64Ty, Int64Ty); 549 550 { 551 AttributeList AL; 552 if (TargetTriple.getArch() == Triple::x86_64) 553 AL = AL.addParamAttribute(*C, 0, Attribute::ZExt); 554 SanCovTraceDivFunction[0] = 555 M.getOrInsertFunction(SanCovTraceDiv4, AL, VoidTy, IRB.getInt32Ty()); 556 } 557 SanCovTraceDivFunction[1] = 558 M.getOrInsertFunction(SanCovTraceDiv8, VoidTy, Int64Ty); 559 SanCovTraceGepFunction = 560 M.getOrInsertFunction(SanCovTraceGep, VoidTy, IntptrTy); 561 SanCovTraceSwitchFunction = 562 M.getOrInsertFunction(SanCovTraceSwitchName, VoidTy, Int64Ty, Int64PtrTy); 563 564 Constant *SanCovLowestStackConstant = 565 M.getOrInsertGlobal(SanCovLowestStackName, IntptrTy); 566 SanCovLowestStack = dyn_cast<GlobalVariable>(SanCovLowestStackConstant); 567 SanCovLowestStack->setThreadLocalMode( 568 GlobalValue::ThreadLocalMode::InitialExecTLSModel); 569 if (Options.StackDepth && !SanCovLowestStack->isDeclaration()) 570 SanCovLowestStack->setInitializer(Constant::getAllOnesValue(IntptrTy)); 571 572 // We insert an empty inline asm after cov callbacks to avoid callback merge. 573 EmptyAsm = InlineAsm::get(FunctionType::get(IRB.getVoidTy(), false), 574 StringRef(""), StringRef(""), 575 /*hasSideEffects=*/true); 576 577 SanCovTracePC = M.getOrInsertFunction(SanCovTracePCName, VoidTy); 578 SanCovTracePCGuard = 579 M.getOrInsertFunction(SanCovTracePCGuardName, VoidTy, Int32PtrTy); 580 } 581 582 void SanitizerCoverage::finalizeModule(Module &M) { 583 // We don't reference these arrays directly in any of our runtime functions, 584 // so we need to prevent them from being dead stripped. 585 if (TargetTriple.isOSBinFormatMachO()) 586 appendToUsed(M, GlobalsToAppendToUsed); 587 appendToCompilerUsed(M, GlobalsToAppendToCompilerUsed); 588 } 589 590 // True if block has successors and it dominates all of them. 591 static bool isFullDominator(const BasicBlock *BB, const DominatorTree *DT) { 592 if (succ_begin(BB) == succ_end(BB)) 593 return false; 594 595 for (const BasicBlock *SUCC : make_range(succ_begin(BB), succ_end(BB))) { 596 if (!DT->dominates(BB, SUCC)) 597 return false; 598 } 599 600 return true; 601 } 602 603 // True if block has predecessors and it postdominates all of them. 604 static bool isFullPostDominator(const BasicBlock *BB, 605 const PostDominatorTree *PDT) { 606 if (pred_begin(BB) == pred_end(BB)) 607 return false; 608 609 for (const BasicBlock *PRED : make_range(pred_begin(BB), pred_end(BB))) { 610 if (!PDT->dominates(BB, PRED)) 611 return false; 612 } 613 614 return true; 615 } 616 617 static bool shouldInstrumentBlock(const Function &F, const BasicBlock *BB, 618 const DominatorTree *DT, 619 const PostDominatorTree *PDT, 620 const SanitizerCoverageOptions &Options) { 621 // Don't insert coverage for blocks containing nothing but unreachable: we 622 // will never call __sanitizer_cov() for them, so counting them in 623 // NumberOfInstrumentedBlocks() might complicate calculation of code coverage 624 // percentage. Also, unreachable instructions frequently have no debug 625 // locations. 626 if (isa<UnreachableInst>(BB->getFirstNonPHIOrDbgOrLifetime())) 627 return false; 628 629 // Don't insert coverage into blocks without a valid insertion point 630 // (catchswitch blocks). 631 if (BB->getFirstInsertionPt() == BB->end()) 632 return false; 633 634 if (Options.NoPrune || &F.getEntryBlock() == BB) 635 return true; 636 637 if (Options.CoverageType == SanitizerCoverageOptions::SCK_Function && 638 &F.getEntryBlock() != BB) 639 return false; 640 641 // Do not instrument full dominators, or full post-dominators with multiple 642 // predecessors. 643 return !isFullDominator(BB, DT) 644 && !(isFullPostDominator(BB, PDT) && !BB->getSinglePredecessor()); 645 } 646 647 648 // Returns true iff From->To is a backedge. 649 // A twist here is that we treat From->To as a backedge if 650 // * To dominates From or 651 // * To->UniqueSuccessor dominates From 652 static bool IsBackEdge(BasicBlock *From, BasicBlock *To, 653 const DominatorTree *DT) { 654 if (DT->dominates(To, From)) 655 return true; 656 if (auto Next = To->getUniqueSuccessor()) 657 if (DT->dominates(Next, From)) 658 return true; 659 return false; 660 } 661 662 // Prunes uninteresting Cmp instrumentation: 663 // * CMP instructions that feed into loop backedge branch. 664 // 665 // Note that Cmp pruning is controlled by the same flag as the 666 // BB pruning. 667 static bool IsInterestingCmp(ICmpInst *CMP, const DominatorTree *DT, 668 const SanitizerCoverageOptions &Options) { 669 if (!Options.NoPrune) 670 if (CMP->hasOneUse()) 671 if (auto BR = dyn_cast<BranchInst>(CMP->user_back())) 672 for (BasicBlock *B : BR->successors()) 673 if (IsBackEdge(BR->getParent(), B, DT)) 674 return false; 675 return true; 676 } 677 678 bool SanitizerCoverage::instrumentFunction(Function &F, const DominatorTree *DT, 679 const PostDominatorTree *PDT) { 680 if (Options.CoverageType == SanitizerCoverageOptions::SCK_None) 681 return false; 682 if (!canInstrumentWithSancov(F)) 683 return false; 684 if (Options.CoverageType >= SanitizerCoverageOptions::SCK_Edge) 685 SplitAllCriticalEdges(F, CriticalEdgeSplittingOptions().setIgnoreUnreachableDests()); 686 SmallVector<Instruction *, 8> IndirCalls; 687 SmallVector<BasicBlock *, 16> BlocksToInstrument; 688 SmallVector<Instruction *, 8> CmpTraceTargets; 689 SmallVector<Instruction *, 8> SwitchTraceTargets; 690 SmallVector<BinaryOperator *, 8> DivTraceTargets; 691 SmallVector<GetElementPtrInst *, 8> GepTraceTargets; 692 693 bool IsLeafFunc = true; 694 695 for (auto &BB : F) { 696 if (shouldInstrumentBlock(F, &BB, DT, PDT, Options)) 697 BlocksToInstrument.push_back(&BB); 698 for (auto &Inst : BB) { 699 if (Options.IndirectCalls) { 700 CallSite CS(&Inst); 701 if (CS && !CS.getCalledFunction()) 702 IndirCalls.push_back(&Inst); 703 } 704 if (Options.TraceCmp) { 705 if (ICmpInst *CMP = dyn_cast<ICmpInst>(&Inst)) 706 if (IsInterestingCmp(CMP, DT, Options)) 707 CmpTraceTargets.push_back(&Inst); 708 if (isa<SwitchInst>(&Inst)) 709 SwitchTraceTargets.push_back(&Inst); 710 } 711 if (Options.TraceDiv) 712 if (BinaryOperator *BO = dyn_cast<BinaryOperator>(&Inst)) 713 if (BO->getOpcode() == Instruction::SDiv || 714 BO->getOpcode() == Instruction::UDiv) 715 DivTraceTargets.push_back(BO); 716 if (Options.TraceGep) 717 if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(&Inst)) 718 GepTraceTargets.push_back(GEP); 719 if (Options.StackDepth) 720 if (isa<InvokeInst>(Inst) || 721 (isa<CallInst>(Inst) && !isa<IntrinsicInst>(Inst))) 722 IsLeafFunc = false; 723 } 724 } 725 726 InjectCoverage(F, BlocksToInstrument, IsLeafFunc); 727 InjectCoverageForIndirectCalls(F, IndirCalls); 728 InjectTraceForCmp(F, CmpTraceTargets); 729 InjectTraceForSwitch(F, SwitchTraceTargets); 730 InjectTraceForDiv(F, DivTraceTargets); 731 InjectTraceForGep(F, GepTraceTargets); 732 return true; 733 } 734 735 GlobalVariable *SanitizerCoverage::CreateFunctionLocalArrayInSection( 736 size_t NumElements, Function &F, Type *Ty, const char *Section) { 737 ArrayType *ArrayTy = ArrayType::get(Ty, NumElements); 738 auto Array = new GlobalVariable( 739 *CurModule, ArrayTy, false, GlobalVariable::PrivateLinkage, 740 Constant::getNullValue(ArrayTy), "__sancov_gen_"); 741 742 if (TargetTriple.supportsCOMDAT() && !F.isInterposable()) 743 if (auto Comdat = 744 GetOrCreateFunctionComdat(F, TargetTriple, CurModuleUniqueId)) 745 Array->setComdat(Comdat); 746 Array->setSection(getSectionName(Section)); 747 Array->setAlignment(Ty->isPointerTy() ? DL->getPointerSize() 748 : Ty->getPrimitiveSizeInBits() / 8); 749 GlobalsToAppendToUsed.push_back(Array); 750 GlobalsToAppendToCompilerUsed.push_back(Array); 751 MDNode *MD = MDNode::get(F.getContext(), ValueAsMetadata::get(&F)); 752 Array->addMetadata(LLVMContext::MD_associated, *MD); 753 754 return Array; 755 } 756 757 GlobalVariable * 758 SanitizerCoverage::CreatePCArray(Function &F, 759 ArrayRef<BasicBlock *> AllBlocks) { 760 size_t N = AllBlocks.size(); 761 assert(N); 762 SmallVector<Constant *, 32> PCs; 763 IRBuilder<> IRB(&*F.getEntryBlock().getFirstInsertionPt()); 764 for (size_t i = 0; i < N; i++) { 765 if (&F.getEntryBlock() == AllBlocks[i]) { 766 PCs.push_back((Constant *)IRB.CreatePointerCast(&F, IntptrPtrTy)); 767 PCs.push_back((Constant *)IRB.CreateIntToPtr( 768 ConstantInt::get(IntptrTy, 1), IntptrPtrTy)); 769 } else { 770 PCs.push_back((Constant *)IRB.CreatePointerCast( 771 BlockAddress::get(AllBlocks[i]), IntptrPtrTy)); 772 PCs.push_back((Constant *)IRB.CreateIntToPtr( 773 ConstantInt::get(IntptrTy, 0), IntptrPtrTy)); 774 } 775 } 776 auto *PCArray = CreateFunctionLocalArrayInSection(N * 2, F, IntptrPtrTy, 777 SanCovPCsSectionName); 778 PCArray->setInitializer( 779 ConstantArray::get(ArrayType::get(IntptrPtrTy, N * 2), PCs)); 780 PCArray->setConstant(true); 781 782 return PCArray; 783 } 784 785 void SanitizerCoverage::CreateFunctionLocalArrays( 786 Function &F, ArrayRef<BasicBlock *> AllBlocks) { 787 if (Options.TracePCGuard) 788 FunctionGuardArray = CreateFunctionLocalArrayInSection( 789 AllBlocks.size(), F, Int32Ty, SanCovGuardsSectionName); 790 791 if (Options.Inline8bitCounters) 792 Function8bitCounterArray = CreateFunctionLocalArrayInSection( 793 AllBlocks.size(), F, Int8Ty, SanCovCountersSectionName); 794 795 if (Options.PCTable) 796 FunctionPCsArray = CreatePCArray(F, AllBlocks); 797 } 798 799 bool SanitizerCoverage::InjectCoverage(Function &F, 800 ArrayRef<BasicBlock *> AllBlocks, 801 bool IsLeafFunc) { 802 if (AllBlocks.empty()) return false; 803 CreateFunctionLocalArrays(F, AllBlocks); 804 for (size_t i = 0, N = AllBlocks.size(); i < N; i++) 805 InjectCoverageAtBlock(F, *AllBlocks[i], i, IsLeafFunc); 806 return true; 807 } 808 809 // On every indirect call we call a run-time function 810 // __sanitizer_cov_indir_call* with two parameters: 811 // - callee address, 812 // - global cache array that contains CacheSize pointers (zero-initialized). 813 // The cache is used to speed up recording the caller-callee pairs. 814 // The address of the caller is passed implicitly via caller PC. 815 // CacheSize is encoded in the name of the run-time function. 816 void SanitizerCoverage::InjectCoverageForIndirectCalls( 817 Function &F, ArrayRef<Instruction *> IndirCalls) { 818 if (IndirCalls.empty()) 819 return; 820 assert(Options.TracePC || Options.TracePCGuard || Options.Inline8bitCounters); 821 for (auto I : IndirCalls) { 822 IRBuilder<> IRB(I); 823 CallSite CS(I); 824 Value *Callee = CS.getCalledValue(); 825 if (isa<InlineAsm>(Callee)) 826 continue; 827 IRB.CreateCall(SanCovTracePCIndir, IRB.CreatePointerCast(Callee, IntptrTy)); 828 } 829 } 830 831 // For every switch statement we insert a call: 832 // __sanitizer_cov_trace_switch(CondValue, 833 // {NumCases, ValueSizeInBits, Case0Value, Case1Value, Case2Value, ... }) 834 835 void SanitizerCoverage::InjectTraceForSwitch( 836 Function &, ArrayRef<Instruction *> SwitchTraceTargets) { 837 for (auto I : SwitchTraceTargets) { 838 if (SwitchInst *SI = dyn_cast<SwitchInst>(I)) { 839 IRBuilder<> IRB(I); 840 SmallVector<Constant *, 16> Initializers; 841 Value *Cond = SI->getCondition(); 842 if (Cond->getType()->getScalarSizeInBits() > 843 Int64Ty->getScalarSizeInBits()) 844 continue; 845 Initializers.push_back(ConstantInt::get(Int64Ty, SI->getNumCases())); 846 Initializers.push_back( 847 ConstantInt::get(Int64Ty, Cond->getType()->getScalarSizeInBits())); 848 if (Cond->getType()->getScalarSizeInBits() < 849 Int64Ty->getScalarSizeInBits()) 850 Cond = IRB.CreateIntCast(Cond, Int64Ty, false); 851 for (auto It : SI->cases()) { 852 Constant *C = It.getCaseValue(); 853 if (C->getType()->getScalarSizeInBits() < 854 Int64Ty->getScalarSizeInBits()) 855 C = ConstantExpr::getCast(CastInst::ZExt, It.getCaseValue(), Int64Ty); 856 Initializers.push_back(C); 857 } 858 llvm::sort(Initializers.begin() + 2, Initializers.end(), 859 [](const Constant *A, const Constant *B) { 860 return cast<ConstantInt>(A)->getLimitedValue() < 861 cast<ConstantInt>(B)->getLimitedValue(); 862 }); 863 ArrayType *ArrayOfInt64Ty = ArrayType::get(Int64Ty, Initializers.size()); 864 GlobalVariable *GV = new GlobalVariable( 865 *CurModule, ArrayOfInt64Ty, false, GlobalVariable::InternalLinkage, 866 ConstantArray::get(ArrayOfInt64Ty, Initializers), 867 "__sancov_gen_cov_switch_values"); 868 IRB.CreateCall(SanCovTraceSwitchFunction, 869 {Cond, IRB.CreatePointerCast(GV, Int64PtrTy)}); 870 } 871 } 872 } 873 874 void SanitizerCoverage::InjectTraceForDiv( 875 Function &, ArrayRef<BinaryOperator *> DivTraceTargets) { 876 for (auto BO : DivTraceTargets) { 877 IRBuilder<> IRB(BO); 878 Value *A1 = BO->getOperand(1); 879 if (isa<ConstantInt>(A1)) continue; 880 if (!A1->getType()->isIntegerTy()) 881 continue; 882 uint64_t TypeSize = DL->getTypeStoreSizeInBits(A1->getType()); 883 int CallbackIdx = TypeSize == 32 ? 0 : 884 TypeSize == 64 ? 1 : -1; 885 if (CallbackIdx < 0) continue; 886 auto Ty = Type::getIntNTy(*C, TypeSize); 887 IRB.CreateCall(SanCovTraceDivFunction[CallbackIdx], 888 {IRB.CreateIntCast(A1, Ty, true)}); 889 } 890 } 891 892 void SanitizerCoverage::InjectTraceForGep( 893 Function &, ArrayRef<GetElementPtrInst *> GepTraceTargets) { 894 for (auto GEP : GepTraceTargets) { 895 IRBuilder<> IRB(GEP); 896 for (auto I = GEP->idx_begin(); I != GEP->idx_end(); ++I) 897 if (!isa<ConstantInt>(*I) && (*I)->getType()->isIntegerTy()) 898 IRB.CreateCall(SanCovTraceGepFunction, 899 {IRB.CreateIntCast(*I, IntptrTy, true)}); 900 } 901 } 902 903 void SanitizerCoverage::InjectTraceForCmp( 904 Function &, ArrayRef<Instruction *> CmpTraceTargets) { 905 for (auto I : CmpTraceTargets) { 906 if (ICmpInst *ICMP = dyn_cast<ICmpInst>(I)) { 907 IRBuilder<> IRB(ICMP); 908 Value *A0 = ICMP->getOperand(0); 909 Value *A1 = ICMP->getOperand(1); 910 if (!A0->getType()->isIntegerTy()) 911 continue; 912 uint64_t TypeSize = DL->getTypeStoreSizeInBits(A0->getType()); 913 int CallbackIdx = TypeSize == 8 ? 0 : 914 TypeSize == 16 ? 1 : 915 TypeSize == 32 ? 2 : 916 TypeSize == 64 ? 3 : -1; 917 if (CallbackIdx < 0) continue; 918 // __sanitizer_cov_trace_cmp((type_size << 32) | predicate, A0, A1); 919 auto CallbackFunc = SanCovTraceCmpFunction[CallbackIdx]; 920 bool FirstIsConst = isa<ConstantInt>(A0); 921 bool SecondIsConst = isa<ConstantInt>(A1); 922 // If both are const, then we don't need such a comparison. 923 if (FirstIsConst && SecondIsConst) continue; 924 // If only one is const, then make it the first callback argument. 925 if (FirstIsConst || SecondIsConst) { 926 CallbackFunc = SanCovTraceConstCmpFunction[CallbackIdx]; 927 if (SecondIsConst) 928 std::swap(A0, A1); 929 } 930 931 auto Ty = Type::getIntNTy(*C, TypeSize); 932 IRB.CreateCall(CallbackFunc, {IRB.CreateIntCast(A0, Ty, true), 933 IRB.CreateIntCast(A1, Ty, true)}); 934 } 935 } 936 } 937 938 void SanitizerCoverage::InjectCoverageAtBlock(Function &F, BasicBlock &BB, 939 size_t Idx, bool IsLeafFunc) { 940 BasicBlock::iterator IP = BB.getFirstInsertionPt(); 941 bool IsEntryBB = &BB == &F.getEntryBlock(); 942 DebugLoc EntryLoc; 943 if (IsEntryBB) { 944 if (auto SP = F.getSubprogram()) 945 EntryLoc = DebugLoc::get(SP->getScopeLine(), 0, SP); 946 // Keep static allocas and llvm.localescape calls in the entry block. Even 947 // if we aren't splitting the block, it's nice for allocas to be before 948 // calls. 949 IP = PrepareToSplitEntryBlock(BB, IP); 950 } else { 951 EntryLoc = IP->getDebugLoc(); 952 } 953 954 IRBuilder<> IRB(&*IP); 955 IRB.SetCurrentDebugLocation(EntryLoc); 956 if (Options.TracePC) { 957 IRB.CreateCall(SanCovTracePC); // gets the PC using GET_CALLER_PC. 958 IRB.CreateCall(EmptyAsm, {}); // Avoids callback merge. 959 } 960 if (Options.TracePCGuard) { 961 auto GuardPtr = IRB.CreateIntToPtr( 962 IRB.CreateAdd(IRB.CreatePointerCast(FunctionGuardArray, IntptrTy), 963 ConstantInt::get(IntptrTy, Idx * 4)), 964 Int32PtrTy); 965 IRB.CreateCall(SanCovTracePCGuard, GuardPtr); 966 IRB.CreateCall(EmptyAsm, {}); // Avoids callback merge. 967 } 968 if (Options.Inline8bitCounters) { 969 auto CounterPtr = IRB.CreateGEP( 970 Function8bitCounterArray->getValueType(), Function8bitCounterArray, 971 {ConstantInt::get(IntptrTy, 0), ConstantInt::get(IntptrTy, Idx)}); 972 auto Load = IRB.CreateLoad(Int8Ty, CounterPtr); 973 auto Inc = IRB.CreateAdd(Load, ConstantInt::get(Int8Ty, 1)); 974 auto Store = IRB.CreateStore(Inc, CounterPtr); 975 SetNoSanitizeMetadata(Load); 976 SetNoSanitizeMetadata(Store); 977 } 978 if (Options.StackDepth && IsEntryBB && !IsLeafFunc) { 979 // Check stack depth. If it's the deepest so far, record it. 980 Function *GetFrameAddr = 981 Intrinsic::getDeclaration(F.getParent(), Intrinsic::frameaddress); 982 auto FrameAddrPtr = 983 IRB.CreateCall(GetFrameAddr, {Constant::getNullValue(Int32Ty)}); 984 auto FrameAddrInt = IRB.CreatePtrToInt(FrameAddrPtr, IntptrTy); 985 auto LowestStack = IRB.CreateLoad(IntptrTy, SanCovLowestStack); 986 auto IsStackLower = IRB.CreateICmpULT(FrameAddrInt, LowestStack); 987 auto ThenTerm = SplitBlockAndInsertIfThen(IsStackLower, &*IP, false); 988 IRBuilder<> ThenIRB(ThenTerm); 989 auto Store = ThenIRB.CreateStore(FrameAddrInt, SanCovLowestStack); 990 SetNoSanitizeMetadata(LowestStack); 991 SetNoSanitizeMetadata(Store); 992 } 993 } 994 995 std::string 996 SanitizerCoverage::getSectionName(const std::string &Section) const { 997 if (TargetTriple.isOSBinFormatCOFF()) { 998 if (Section == SanCovCountersSectionName) 999 return ".SCOV$CM"; 1000 if (Section == SanCovPCsSectionName) 1001 return ".SCOVP$M"; 1002 return ".SCOV$GM"; // For SanCovGuardsSectionName. 1003 } 1004 if (TargetTriple.isOSBinFormatMachO()) 1005 return "__DATA,__" + Section; 1006 return "__" + Section; 1007 } 1008 1009 INITIALIZE_PASS(ModuleSanitizerCoverageLegacyPass, "module-sancov", 1010 "Pass for inserting sancov top-level initialization calls", 1011 false, false) 1012 1013 char SanitizerCoverageLegacyPass::ID = 0; 1014 INITIALIZE_PASS_BEGIN(SanitizerCoverageLegacyPass, "sancov", 1015 "Pass for instrumenting coverage on functions", false, 1016 false) 1017 INITIALIZE_PASS_DEPENDENCY(ModuleSanitizerCoverageLegacyPass) 1018 INITIALIZE_PASS_DEPENDENCY(DominatorTreeWrapperPass) 1019 INITIALIZE_PASS_DEPENDENCY(PostDominatorTreeWrapperPass) 1020 INITIALIZE_PASS_END(SanitizerCoverageLegacyPass, "sancov", 1021 "Pass for instrumenting coverage on functions", false, 1022 false) 1023 FunctionPass *llvm::createSanitizerCoverageLegacyPassPass( 1024 const SanitizerCoverageOptions &Options) { 1025 return new SanitizerCoverageLegacyPass(Options); 1026 } 1027 ModulePass *llvm::createModuleSanitizerCoverageLegacyPassPass( 1028 const SanitizerCoverageOptions &Options) { 1029 return new ModuleSanitizerCoverageLegacyPass(Options); 1030 } 1031