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/Constant.h" 20 #include "llvm/IR/DataLayout.h" 21 #include "llvm/IR/DebugInfo.h" 22 #include "llvm/IR/Dominators.h" 23 #include "llvm/IR/Function.h" 24 #include "llvm/IR/GlobalVariable.h" 25 #include "llvm/IR/IRBuilder.h" 26 #include "llvm/IR/InlineAsm.h" 27 #include "llvm/IR/IntrinsicInst.h" 28 #include "llvm/IR/Intrinsics.h" 29 #include "llvm/IR/LLVMContext.h" 30 #include "llvm/IR/MDBuilder.h" 31 #include "llvm/IR/Mangler.h" 32 #include "llvm/IR/Module.h" 33 #include "llvm/IR/Type.h" 34 #include "llvm/InitializePasses.h" 35 #include "llvm/Support/CommandLine.h" 36 #include "llvm/Support/Debug.h" 37 #include "llvm/Support/SpecialCaseList.h" 38 #include "llvm/Support/VirtualFileSystem.h" 39 #include "llvm/Support/raw_ostream.h" 40 #include "llvm/Transforms/Instrumentation.h" 41 #include "llvm/Transforms/Utils/BasicBlockUtils.h" 42 #include "llvm/Transforms/Utils/ModuleUtils.h" 43 44 using namespace llvm; 45 46 #define DEBUG_TYPE "sancov" 47 48 const char SanCovTracePCIndirName[] = "__sanitizer_cov_trace_pc_indir"; 49 const char SanCovTracePCName[] = "__sanitizer_cov_trace_pc"; 50 const char SanCovTraceCmp1[] = "__sanitizer_cov_trace_cmp1"; 51 const char SanCovTraceCmp2[] = "__sanitizer_cov_trace_cmp2"; 52 const char SanCovTraceCmp4[] = "__sanitizer_cov_trace_cmp4"; 53 const char SanCovTraceCmp8[] = "__sanitizer_cov_trace_cmp8"; 54 const char SanCovTraceConstCmp1[] = "__sanitizer_cov_trace_const_cmp1"; 55 const char SanCovTraceConstCmp2[] = "__sanitizer_cov_trace_const_cmp2"; 56 const char SanCovTraceConstCmp4[] = "__sanitizer_cov_trace_const_cmp4"; 57 const char SanCovTraceConstCmp8[] = "__sanitizer_cov_trace_const_cmp8"; 58 const char SanCovTraceDiv4[] = "__sanitizer_cov_trace_div4"; 59 const char SanCovTraceDiv8[] = "__sanitizer_cov_trace_div8"; 60 const char SanCovTraceGep[] = "__sanitizer_cov_trace_gep"; 61 const char SanCovTraceSwitchName[] = "__sanitizer_cov_trace_switch"; 62 const char SanCovModuleCtorTracePcGuardName[] = 63 "sancov.module_ctor_trace_pc_guard"; 64 const char SanCovModuleCtor8bitCountersName[] = 65 "sancov.module_ctor_8bit_counters"; 66 const char SanCovModuleCtorBoolFlagName[] = "sancov.module_ctor_bool_flag"; 67 static const uint64_t SanCtorAndDtorPriority = 2; 68 69 const char SanCovTracePCGuardName[] = "__sanitizer_cov_trace_pc_guard"; 70 const char SanCovTracePCGuardInitName[] = "__sanitizer_cov_trace_pc_guard_init"; 71 const char SanCov8bitCountersInitName[] = "__sanitizer_cov_8bit_counters_init"; 72 const char SanCovBoolFlagInitName[] = "__sanitizer_cov_bool_flag_init"; 73 const char SanCovPCsInitName[] = "__sanitizer_cov_pcs_init"; 74 75 const char SanCovGuardsSectionName[] = "sancov_guards"; 76 const char SanCovCountersSectionName[] = "sancov_cntrs"; 77 const char SanCovBoolFlagSectionName[] = "sancov_bools"; 78 const char SanCovPCsSectionName[] = "sancov_pcs"; 79 80 const char SanCovLowestStackName[] = "__sancov_lowest_stack"; 81 82 static cl::opt<int> ClCoverageLevel( 83 "sanitizer-coverage-level", 84 cl::desc("Sanitizer Coverage. 0: none, 1: entry block, 2: all blocks, " 85 "3: all blocks and critical edges"), 86 cl::Hidden, cl::init(0)); 87 88 static cl::opt<bool> ClTracePC("sanitizer-coverage-trace-pc", 89 cl::desc("Experimental pc tracing"), cl::Hidden, 90 cl::init(false)); 91 92 static cl::opt<bool> ClTracePCGuard("sanitizer-coverage-trace-pc-guard", 93 cl::desc("pc tracing with a guard"), 94 cl::Hidden, cl::init(false)); 95 96 // If true, we create a global variable that contains PCs of all instrumented 97 // BBs, put this global into a named section, and pass this section's bounds 98 // to __sanitizer_cov_pcs_init. 99 // This way the coverage instrumentation does not need to acquire the PCs 100 // at run-time. Works with trace-pc-guard, inline-8bit-counters, and 101 // inline-bool-flag. 102 static cl::opt<bool> ClCreatePCTable("sanitizer-coverage-pc-table", 103 cl::desc("create a static PC table"), 104 cl::Hidden, cl::init(false)); 105 106 static cl::opt<bool> 107 ClInline8bitCounters("sanitizer-coverage-inline-8bit-counters", 108 cl::desc("increments 8-bit counter for every edge"), 109 cl::Hidden, cl::init(false)); 110 111 static cl::opt<bool> 112 ClInlineBoolFlag("sanitizer-coverage-inline-bool-flag", 113 cl::desc("sets a boolean flag for every edge"), cl::Hidden, 114 cl::init(false)); 115 116 static cl::opt<bool> 117 ClCMPTracing("sanitizer-coverage-trace-compares", 118 cl::desc("Tracing of CMP and similar instructions"), 119 cl::Hidden, cl::init(false)); 120 121 static cl::opt<bool> ClDIVTracing("sanitizer-coverage-trace-divs", 122 cl::desc("Tracing of DIV instructions"), 123 cl::Hidden, cl::init(false)); 124 125 static cl::opt<bool> ClGEPTracing("sanitizer-coverage-trace-geps", 126 cl::desc("Tracing of GEP instructions"), 127 cl::Hidden, cl::init(false)); 128 129 static cl::opt<bool> 130 ClPruneBlocks("sanitizer-coverage-prune-blocks", 131 cl::desc("Reduce the number of instrumented blocks"), 132 cl::Hidden, cl::init(true)); 133 134 static cl::opt<bool> ClStackDepth("sanitizer-coverage-stack-depth", 135 cl::desc("max stack depth tracing"), 136 cl::Hidden, cl::init(false)); 137 138 namespace { 139 140 SanitizerCoverageOptions getOptions(int LegacyCoverageLevel) { 141 SanitizerCoverageOptions Res; 142 switch (LegacyCoverageLevel) { 143 case 0: 144 Res.CoverageType = SanitizerCoverageOptions::SCK_None; 145 break; 146 case 1: 147 Res.CoverageType = SanitizerCoverageOptions::SCK_Function; 148 break; 149 case 2: 150 Res.CoverageType = SanitizerCoverageOptions::SCK_BB; 151 break; 152 case 3: 153 Res.CoverageType = SanitizerCoverageOptions::SCK_Edge; 154 break; 155 case 4: 156 Res.CoverageType = SanitizerCoverageOptions::SCK_Edge; 157 Res.IndirectCalls = true; 158 break; 159 } 160 return Res; 161 } 162 163 SanitizerCoverageOptions OverrideFromCL(SanitizerCoverageOptions Options) { 164 // Sets CoverageType and IndirectCalls. 165 SanitizerCoverageOptions CLOpts = getOptions(ClCoverageLevel); 166 Options.CoverageType = std::max(Options.CoverageType, CLOpts.CoverageType); 167 Options.IndirectCalls |= CLOpts.IndirectCalls; 168 Options.TraceCmp |= ClCMPTracing; 169 Options.TraceDiv |= ClDIVTracing; 170 Options.TraceGep |= ClGEPTracing; 171 Options.TracePC |= ClTracePC; 172 Options.TracePCGuard |= ClTracePCGuard; 173 Options.Inline8bitCounters |= ClInline8bitCounters; 174 Options.InlineBoolFlag |= ClInlineBoolFlag; 175 Options.PCTable |= ClCreatePCTable; 176 Options.NoPrune |= !ClPruneBlocks; 177 Options.StackDepth |= ClStackDepth; 178 if (!Options.TracePCGuard && !Options.TracePC && 179 !Options.Inline8bitCounters && !Options.StackDepth && 180 !Options.InlineBoolFlag) 181 Options.TracePCGuard = true; // TracePCGuard is default. 182 return Options; 183 } 184 185 using DomTreeCallback = function_ref<const DominatorTree *(Function &F)>; 186 using PostDomTreeCallback = 187 function_ref<const PostDominatorTree *(Function &F)>; 188 189 class ModuleSanitizerCoverage { 190 public: 191 ModuleSanitizerCoverage( 192 const SanitizerCoverageOptions &Options = SanitizerCoverageOptions(), 193 const SpecialCaseList *Allowlist = nullptr, 194 const SpecialCaseList *Blocklist = nullptr) 195 : Options(OverrideFromCL(Options)), Allowlist(Allowlist), 196 Blocklist(Blocklist) {} 197 bool instrumentModule(Module &M, DomTreeCallback DTCallback, 198 PostDomTreeCallback PDTCallback); 199 200 private: 201 void instrumentFunction(Function &F, DomTreeCallback DTCallback, 202 PostDomTreeCallback PDTCallback); 203 void InjectCoverageForIndirectCalls(Function &F, 204 ArrayRef<Instruction *> IndirCalls); 205 void InjectTraceForCmp(Function &F, ArrayRef<Instruction *> CmpTraceTargets); 206 void InjectTraceForDiv(Function &F, 207 ArrayRef<BinaryOperator *> DivTraceTargets); 208 void InjectTraceForGep(Function &F, 209 ArrayRef<GetElementPtrInst *> GepTraceTargets); 210 void InjectTraceForSwitch(Function &F, 211 ArrayRef<Instruction *> SwitchTraceTargets); 212 bool InjectCoverage(Function &F, ArrayRef<BasicBlock *> AllBlocks, 213 bool IsLeafFunc = true); 214 GlobalVariable *CreateFunctionLocalArrayInSection(size_t NumElements, 215 Function &F, Type *Ty, 216 const char *Section); 217 GlobalVariable *CreatePCArray(Function &F, ArrayRef<BasicBlock *> AllBlocks); 218 void CreateFunctionLocalArrays(Function &F, ArrayRef<BasicBlock *> AllBlocks); 219 void InjectCoverageAtBlock(Function &F, BasicBlock &BB, size_t Idx, 220 bool IsLeafFunc = true); 221 Function *CreateInitCallsForSections(Module &M, const char *CtorName, 222 const char *InitFunctionName, Type *Ty, 223 const char *Section); 224 std::pair<Value *, Value *> CreateSecStartEnd(Module &M, const char *Section, 225 Type *Ty); 226 227 void SetNoSanitizeMetadata(Instruction *I) { 228 I->setMetadata(I->getModule()->getMDKindID("nosanitize"), 229 MDNode::get(*C, None)); 230 } 231 232 std::string getSectionName(const std::string &Section) const; 233 std::string getSectionStart(const std::string &Section) const; 234 std::string getSectionEnd(const std::string &Section) const; 235 FunctionCallee SanCovTracePCIndir; 236 FunctionCallee SanCovTracePC, SanCovTracePCGuard; 237 FunctionCallee SanCovTraceCmpFunction[4]; 238 FunctionCallee SanCovTraceConstCmpFunction[4]; 239 FunctionCallee SanCovTraceDivFunction[2]; 240 FunctionCallee SanCovTraceGepFunction; 241 FunctionCallee SanCovTraceSwitchFunction; 242 GlobalVariable *SanCovLowestStack; 243 Type *IntptrTy, *IntptrPtrTy, *Int64Ty, *Int64PtrTy, *Int32Ty, *Int32PtrTy, 244 *Int16Ty, *Int8Ty, *Int8PtrTy, *Int1Ty, *Int1PtrTy; 245 Module *CurModule; 246 std::string CurModuleUniqueId; 247 Triple TargetTriple; 248 LLVMContext *C; 249 const DataLayout *DL; 250 251 GlobalVariable *FunctionGuardArray; // for trace-pc-guard. 252 GlobalVariable *Function8bitCounterArray; // for inline-8bit-counters. 253 GlobalVariable *FunctionBoolArray; // for inline-bool-flag. 254 GlobalVariable *FunctionPCsArray; // for pc-table. 255 SmallVector<GlobalValue *, 20> GlobalsToAppendToUsed; 256 SmallVector<GlobalValue *, 20> GlobalsToAppendToCompilerUsed; 257 258 SanitizerCoverageOptions Options; 259 260 const SpecialCaseList *Allowlist; 261 const SpecialCaseList *Blocklist; 262 }; 263 264 class ModuleSanitizerCoverageLegacyPass : public ModulePass { 265 public: 266 ModuleSanitizerCoverageLegacyPass( 267 const SanitizerCoverageOptions &Options = SanitizerCoverageOptions(), 268 const std::vector<std::string> &AllowlistFiles = 269 std::vector<std::string>(), 270 const std::vector<std::string> &BlocklistFiles = 271 std::vector<std::string>()) 272 : ModulePass(ID), Options(Options) { 273 if (AllowlistFiles.size() > 0) 274 Allowlist = SpecialCaseList::createOrDie(AllowlistFiles, 275 *vfs::getRealFileSystem()); 276 if (BlocklistFiles.size() > 0) 277 Blocklist = SpecialCaseList::createOrDie(BlocklistFiles, 278 *vfs::getRealFileSystem()); 279 initializeModuleSanitizerCoverageLegacyPassPass( 280 *PassRegistry::getPassRegistry()); 281 } 282 bool runOnModule(Module &M) override { 283 ModuleSanitizerCoverage ModuleSancov(Options, Allowlist.get(), 284 Blocklist.get()); 285 auto DTCallback = [this](Function &F) -> const DominatorTree * { 286 return &this->getAnalysis<DominatorTreeWrapperPass>(F).getDomTree(); 287 }; 288 auto PDTCallback = [this](Function &F) -> const PostDominatorTree * { 289 return &this->getAnalysis<PostDominatorTreeWrapperPass>(F) 290 .getPostDomTree(); 291 }; 292 return ModuleSancov.instrumentModule(M, DTCallback, PDTCallback); 293 } 294 295 static char ID; // Pass identification, replacement for typeid 296 StringRef getPassName() const override { return "ModuleSanitizerCoverage"; } 297 298 void getAnalysisUsage(AnalysisUsage &AU) const override { 299 AU.addRequired<DominatorTreeWrapperPass>(); 300 AU.addRequired<PostDominatorTreeWrapperPass>(); 301 } 302 303 private: 304 SanitizerCoverageOptions Options; 305 306 std::unique_ptr<SpecialCaseList> Allowlist; 307 std::unique_ptr<SpecialCaseList> Blocklist; 308 }; 309 310 } // namespace 311 312 PreservedAnalyses ModuleSanitizerCoveragePass::run(Module &M, 313 ModuleAnalysisManager &MAM) { 314 ModuleSanitizerCoverage ModuleSancov(Options, Allowlist.get(), 315 Blocklist.get()); 316 auto &FAM = MAM.getResult<FunctionAnalysisManagerModuleProxy>(M).getManager(); 317 auto DTCallback = [&FAM](Function &F) -> const DominatorTree * { 318 return &FAM.getResult<DominatorTreeAnalysis>(F); 319 }; 320 auto PDTCallback = [&FAM](Function &F) -> const PostDominatorTree * { 321 return &FAM.getResult<PostDominatorTreeAnalysis>(F); 322 }; 323 if (ModuleSancov.instrumentModule(M, DTCallback, PDTCallback)) 324 return PreservedAnalyses::none(); 325 return PreservedAnalyses::all(); 326 } 327 328 std::pair<Value *, Value *> 329 ModuleSanitizerCoverage::CreateSecStartEnd(Module &M, const char *Section, 330 Type *Ty) { 331 // Use ExternalWeak so that if all sections are discarded due to section 332 // garbage collection, the linker will not report undefined symbol errors. 333 GlobalVariable *SecStart = new GlobalVariable( 334 M, Ty->getPointerElementType(), false, 335 GlobalVariable::ExternalWeakLinkage, nullptr, getSectionStart(Section)); 336 SecStart->setVisibility(GlobalValue::HiddenVisibility); 337 GlobalVariable *SecEnd = new GlobalVariable( 338 M, Ty->getPointerElementType(), false, 339 GlobalVariable::ExternalWeakLinkage, nullptr, getSectionEnd(Section)); 340 SecEnd->setVisibility(GlobalValue::HiddenVisibility); 341 IRBuilder<> IRB(M.getContext()); 342 if (!TargetTriple.isOSBinFormatCOFF()) 343 return std::make_pair(SecStart, SecEnd); 344 345 // Account for the fact that on windows-msvc __start_* symbols actually 346 // point to a uint64_t before the start of the array. 347 auto SecStartI8Ptr = IRB.CreatePointerCast(SecStart, Int8PtrTy); 348 auto GEP = IRB.CreateGEP(Int8Ty, SecStartI8Ptr, 349 ConstantInt::get(IntptrTy, sizeof(uint64_t))); 350 return std::make_pair(IRB.CreatePointerCast(GEP, Ty), SecEnd); 351 } 352 353 Function *ModuleSanitizerCoverage::CreateInitCallsForSections( 354 Module &M, const char *CtorName, const char *InitFunctionName, Type *Ty, 355 const char *Section) { 356 auto SecStartEnd = CreateSecStartEnd(M, Section, Ty); 357 auto SecStart = SecStartEnd.first; 358 auto SecEnd = SecStartEnd.second; 359 Function *CtorFunc; 360 std::tie(CtorFunc, std::ignore) = createSanitizerCtorAndInitFunctions( 361 M, CtorName, InitFunctionName, {Ty, Ty}, {SecStart, SecEnd}); 362 assert(CtorFunc->getName() == CtorName); 363 364 if (TargetTriple.supportsCOMDAT()) { 365 // Use comdat to dedup CtorFunc. 366 CtorFunc->setComdat(M.getOrInsertComdat(CtorName)); 367 appendToGlobalCtors(M, CtorFunc, SanCtorAndDtorPriority, CtorFunc); 368 } else { 369 appendToGlobalCtors(M, CtorFunc, SanCtorAndDtorPriority); 370 } 371 372 if (TargetTriple.isOSBinFormatCOFF()) { 373 // In COFF files, if the contructors are set as COMDAT (they are because 374 // COFF supports COMDAT) and the linker flag /OPT:REF (strip unreferenced 375 // functions and data) is used, the constructors get stripped. To prevent 376 // this, give the constructors weak ODR linkage and ensure the linker knows 377 // to include the sancov constructor. This way the linker can deduplicate 378 // the constructors but always leave one copy. 379 CtorFunc->setLinkage(GlobalValue::WeakODRLinkage); 380 appendToUsed(M, CtorFunc); 381 } 382 return CtorFunc; 383 } 384 385 bool ModuleSanitizerCoverage::instrumentModule( 386 Module &M, DomTreeCallback DTCallback, PostDomTreeCallback PDTCallback) { 387 if (Options.CoverageType == SanitizerCoverageOptions::SCK_None) 388 return false; 389 if (Allowlist && 390 !Allowlist->inSection("coverage", "src", M.getSourceFileName())) 391 return false; 392 if (Blocklist && 393 Blocklist->inSection("coverage", "src", M.getSourceFileName())) 394 return false; 395 C = &(M.getContext()); 396 DL = &M.getDataLayout(); 397 CurModule = &M; 398 CurModuleUniqueId = getUniqueModuleId(CurModule); 399 TargetTriple = Triple(M.getTargetTriple()); 400 FunctionGuardArray = nullptr; 401 Function8bitCounterArray = nullptr; 402 FunctionBoolArray = nullptr; 403 FunctionPCsArray = nullptr; 404 IntptrTy = Type::getIntNTy(*C, DL->getPointerSizeInBits()); 405 IntptrPtrTy = PointerType::getUnqual(IntptrTy); 406 Type *VoidTy = Type::getVoidTy(*C); 407 IRBuilder<> IRB(*C); 408 Int64PtrTy = PointerType::getUnqual(IRB.getInt64Ty()); 409 Int32PtrTy = PointerType::getUnqual(IRB.getInt32Ty()); 410 Int8PtrTy = PointerType::getUnqual(IRB.getInt8Ty()); 411 Int1PtrTy = PointerType::getUnqual(IRB.getInt1Ty()); 412 Int64Ty = IRB.getInt64Ty(); 413 Int32Ty = IRB.getInt32Ty(); 414 Int16Ty = IRB.getInt16Ty(); 415 Int8Ty = IRB.getInt8Ty(); 416 Int1Ty = IRB.getInt1Ty(); 417 418 SanCovTracePCIndir = 419 M.getOrInsertFunction(SanCovTracePCIndirName, VoidTy, IntptrTy); 420 // Make sure smaller parameters are zero-extended to i64 if required by the 421 // target ABI. 422 AttributeList SanCovTraceCmpZeroExtAL; 423 SanCovTraceCmpZeroExtAL = 424 SanCovTraceCmpZeroExtAL.addParamAttribute(*C, 0, Attribute::ZExt); 425 SanCovTraceCmpZeroExtAL = 426 SanCovTraceCmpZeroExtAL.addParamAttribute(*C, 1, Attribute::ZExt); 427 428 SanCovTraceCmpFunction[0] = 429 M.getOrInsertFunction(SanCovTraceCmp1, SanCovTraceCmpZeroExtAL, VoidTy, 430 IRB.getInt8Ty(), IRB.getInt8Ty()); 431 SanCovTraceCmpFunction[1] = 432 M.getOrInsertFunction(SanCovTraceCmp2, SanCovTraceCmpZeroExtAL, VoidTy, 433 IRB.getInt16Ty(), IRB.getInt16Ty()); 434 SanCovTraceCmpFunction[2] = 435 M.getOrInsertFunction(SanCovTraceCmp4, SanCovTraceCmpZeroExtAL, VoidTy, 436 IRB.getInt32Ty(), IRB.getInt32Ty()); 437 SanCovTraceCmpFunction[3] = 438 M.getOrInsertFunction(SanCovTraceCmp8, VoidTy, Int64Ty, Int64Ty); 439 440 SanCovTraceConstCmpFunction[0] = M.getOrInsertFunction( 441 SanCovTraceConstCmp1, SanCovTraceCmpZeroExtAL, VoidTy, Int8Ty, Int8Ty); 442 SanCovTraceConstCmpFunction[1] = M.getOrInsertFunction( 443 SanCovTraceConstCmp2, SanCovTraceCmpZeroExtAL, VoidTy, Int16Ty, Int16Ty); 444 SanCovTraceConstCmpFunction[2] = M.getOrInsertFunction( 445 SanCovTraceConstCmp4, SanCovTraceCmpZeroExtAL, VoidTy, Int32Ty, Int32Ty); 446 SanCovTraceConstCmpFunction[3] = 447 M.getOrInsertFunction(SanCovTraceConstCmp8, VoidTy, Int64Ty, Int64Ty); 448 449 { 450 AttributeList AL; 451 AL = AL.addParamAttribute(*C, 0, Attribute::ZExt); 452 SanCovTraceDivFunction[0] = 453 M.getOrInsertFunction(SanCovTraceDiv4, AL, VoidTy, IRB.getInt32Ty()); 454 } 455 SanCovTraceDivFunction[1] = 456 M.getOrInsertFunction(SanCovTraceDiv8, VoidTy, Int64Ty); 457 SanCovTraceGepFunction = 458 M.getOrInsertFunction(SanCovTraceGep, VoidTy, IntptrTy); 459 SanCovTraceSwitchFunction = 460 M.getOrInsertFunction(SanCovTraceSwitchName, VoidTy, Int64Ty, Int64PtrTy); 461 462 Constant *SanCovLowestStackConstant = 463 M.getOrInsertGlobal(SanCovLowestStackName, IntptrTy); 464 SanCovLowestStack = dyn_cast<GlobalVariable>(SanCovLowestStackConstant); 465 if (!SanCovLowestStack) { 466 C->emitError(StringRef("'") + SanCovLowestStackName + 467 "' should not be declared by the user"); 468 return true; 469 } 470 SanCovLowestStack->setThreadLocalMode( 471 GlobalValue::ThreadLocalMode::InitialExecTLSModel); 472 if (Options.StackDepth && !SanCovLowestStack->isDeclaration()) 473 SanCovLowestStack->setInitializer(Constant::getAllOnesValue(IntptrTy)); 474 475 SanCovTracePC = M.getOrInsertFunction(SanCovTracePCName, VoidTy); 476 SanCovTracePCGuard = 477 M.getOrInsertFunction(SanCovTracePCGuardName, VoidTy, Int32PtrTy); 478 479 for (auto &F : M) 480 instrumentFunction(F, DTCallback, PDTCallback); 481 482 Function *Ctor = nullptr; 483 484 if (FunctionGuardArray) 485 Ctor = CreateInitCallsForSections(M, SanCovModuleCtorTracePcGuardName, 486 SanCovTracePCGuardInitName, Int32PtrTy, 487 SanCovGuardsSectionName); 488 if (Function8bitCounterArray) 489 Ctor = CreateInitCallsForSections(M, SanCovModuleCtor8bitCountersName, 490 SanCov8bitCountersInitName, Int8PtrTy, 491 SanCovCountersSectionName); 492 if (FunctionBoolArray) { 493 Ctor = CreateInitCallsForSections(M, SanCovModuleCtorBoolFlagName, 494 SanCovBoolFlagInitName, Int1PtrTy, 495 SanCovBoolFlagSectionName); 496 } 497 if (Ctor && Options.PCTable) { 498 auto SecStartEnd = CreateSecStartEnd(M, SanCovPCsSectionName, IntptrPtrTy); 499 FunctionCallee InitFunction = declareSanitizerInitFunction( 500 M, SanCovPCsInitName, {IntptrPtrTy, IntptrPtrTy}); 501 IRBuilder<> IRBCtor(Ctor->getEntryBlock().getTerminator()); 502 IRBCtor.CreateCall(InitFunction, {SecStartEnd.first, SecStartEnd.second}); 503 } 504 appendToUsed(M, GlobalsToAppendToUsed); 505 appendToCompilerUsed(M, GlobalsToAppendToCompilerUsed); 506 return true; 507 } 508 509 // True if block has successors and it dominates all of them. 510 static bool isFullDominator(const BasicBlock *BB, const DominatorTree *DT) { 511 if (succ_empty(BB)) 512 return false; 513 514 return llvm::all_of(successors(BB), [&](const BasicBlock *SUCC) { 515 return DT->dominates(BB, SUCC); 516 }); 517 } 518 519 // True if block has predecessors and it postdominates all of them. 520 static bool isFullPostDominator(const BasicBlock *BB, 521 const PostDominatorTree *PDT) { 522 if (pred_empty(BB)) 523 return false; 524 525 return llvm::all_of(predecessors(BB), [&](const BasicBlock *PRED) { 526 return PDT->dominates(BB, PRED); 527 }); 528 } 529 530 static bool shouldInstrumentBlock(const Function &F, const BasicBlock *BB, 531 const DominatorTree *DT, 532 const PostDominatorTree *PDT, 533 const SanitizerCoverageOptions &Options) { 534 // Don't insert coverage for blocks containing nothing but unreachable: we 535 // will never call __sanitizer_cov() for them, so counting them in 536 // NumberOfInstrumentedBlocks() might complicate calculation of code coverage 537 // percentage. Also, unreachable instructions frequently have no debug 538 // locations. 539 if (isa<UnreachableInst>(BB->getFirstNonPHIOrDbgOrLifetime())) 540 return false; 541 542 // Don't insert coverage into blocks without a valid insertion point 543 // (catchswitch blocks). 544 if (BB->getFirstInsertionPt() == BB->end()) 545 return false; 546 547 if (Options.NoPrune || &F.getEntryBlock() == BB) 548 return true; 549 550 if (Options.CoverageType == SanitizerCoverageOptions::SCK_Function && 551 &F.getEntryBlock() != BB) 552 return false; 553 554 // Do not instrument full dominators, or full post-dominators with multiple 555 // predecessors. 556 return !isFullDominator(BB, DT) 557 && !(isFullPostDominator(BB, PDT) && !BB->getSinglePredecessor()); 558 } 559 560 561 // Returns true iff From->To is a backedge. 562 // A twist here is that we treat From->To as a backedge if 563 // * To dominates From or 564 // * To->UniqueSuccessor dominates From 565 static bool IsBackEdge(BasicBlock *From, BasicBlock *To, 566 const DominatorTree *DT) { 567 if (DT->dominates(To, From)) 568 return true; 569 if (auto Next = To->getUniqueSuccessor()) 570 if (DT->dominates(Next, From)) 571 return true; 572 return false; 573 } 574 575 // Prunes uninteresting Cmp instrumentation: 576 // * CMP instructions that feed into loop backedge branch. 577 // 578 // Note that Cmp pruning is controlled by the same flag as the 579 // BB pruning. 580 static bool IsInterestingCmp(ICmpInst *CMP, const DominatorTree *DT, 581 const SanitizerCoverageOptions &Options) { 582 if (!Options.NoPrune) 583 if (CMP->hasOneUse()) 584 if (auto BR = dyn_cast<BranchInst>(CMP->user_back())) 585 for (BasicBlock *B : BR->successors()) 586 if (IsBackEdge(BR->getParent(), B, DT)) 587 return false; 588 return true; 589 } 590 591 void ModuleSanitizerCoverage::instrumentFunction( 592 Function &F, DomTreeCallback DTCallback, PostDomTreeCallback PDTCallback) { 593 if (F.empty()) 594 return; 595 if (F.getName().find(".module_ctor") != std::string::npos) 596 return; // Should not instrument sanitizer init functions. 597 if (F.getName().startswith("__sanitizer_")) 598 return; // Don't instrument __sanitizer_* callbacks. 599 // Don't touch available_externally functions, their actual body is elewhere. 600 if (F.getLinkage() == GlobalValue::AvailableExternallyLinkage) 601 return; 602 // Don't instrument MSVC CRT configuration helpers. They may run before normal 603 // initialization. 604 if (F.getName() == "__local_stdio_printf_options" || 605 F.getName() == "__local_stdio_scanf_options") 606 return; 607 if (isa<UnreachableInst>(F.getEntryBlock().getTerminator())) 608 return; 609 // Don't instrument functions using SEH for now. Splitting basic blocks like 610 // we do for coverage breaks WinEHPrepare. 611 // FIXME: Remove this when SEH no longer uses landingpad pattern matching. 612 if (F.hasPersonalityFn() && 613 isAsynchronousEHPersonality(classifyEHPersonality(F.getPersonalityFn()))) 614 return; 615 if (Allowlist && !Allowlist->inSection("coverage", "fun", F.getName())) 616 return; 617 if (Blocklist && Blocklist->inSection("coverage", "fun", F.getName())) 618 return; 619 if (Options.CoverageType >= SanitizerCoverageOptions::SCK_Edge) 620 SplitAllCriticalEdges(F, CriticalEdgeSplittingOptions().setIgnoreUnreachableDests()); 621 SmallVector<Instruction *, 8> IndirCalls; 622 SmallVector<BasicBlock *, 16> BlocksToInstrument; 623 SmallVector<Instruction *, 8> CmpTraceTargets; 624 SmallVector<Instruction *, 8> SwitchTraceTargets; 625 SmallVector<BinaryOperator *, 8> DivTraceTargets; 626 SmallVector<GetElementPtrInst *, 8> GepTraceTargets; 627 628 const DominatorTree *DT = DTCallback(F); 629 const PostDominatorTree *PDT = PDTCallback(F); 630 bool IsLeafFunc = true; 631 632 for (auto &BB : F) { 633 if (shouldInstrumentBlock(F, &BB, DT, PDT, Options)) 634 BlocksToInstrument.push_back(&BB); 635 for (auto &Inst : BB) { 636 if (Options.IndirectCalls) { 637 CallBase *CB = dyn_cast<CallBase>(&Inst); 638 if (CB && !CB->getCalledFunction()) 639 IndirCalls.push_back(&Inst); 640 } 641 if (Options.TraceCmp) { 642 if (ICmpInst *CMP = dyn_cast<ICmpInst>(&Inst)) 643 if (IsInterestingCmp(CMP, DT, Options)) 644 CmpTraceTargets.push_back(&Inst); 645 if (isa<SwitchInst>(&Inst)) 646 SwitchTraceTargets.push_back(&Inst); 647 } 648 if (Options.TraceDiv) 649 if (BinaryOperator *BO = dyn_cast<BinaryOperator>(&Inst)) 650 if (BO->getOpcode() == Instruction::SDiv || 651 BO->getOpcode() == Instruction::UDiv) 652 DivTraceTargets.push_back(BO); 653 if (Options.TraceGep) 654 if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(&Inst)) 655 GepTraceTargets.push_back(GEP); 656 if (Options.StackDepth) 657 if (isa<InvokeInst>(Inst) || 658 (isa<CallInst>(Inst) && !isa<IntrinsicInst>(Inst))) 659 IsLeafFunc = false; 660 } 661 } 662 663 InjectCoverage(F, BlocksToInstrument, IsLeafFunc); 664 InjectCoverageForIndirectCalls(F, IndirCalls); 665 InjectTraceForCmp(F, CmpTraceTargets); 666 InjectTraceForSwitch(F, SwitchTraceTargets); 667 InjectTraceForDiv(F, DivTraceTargets); 668 InjectTraceForGep(F, GepTraceTargets); 669 } 670 671 GlobalVariable *ModuleSanitizerCoverage::CreateFunctionLocalArrayInSection( 672 size_t NumElements, Function &F, Type *Ty, const char *Section) { 673 ArrayType *ArrayTy = ArrayType::get(Ty, NumElements); 674 auto Array = new GlobalVariable( 675 *CurModule, ArrayTy, false, GlobalVariable::PrivateLinkage, 676 Constant::getNullValue(ArrayTy), "__sancov_gen_"); 677 678 if (TargetTriple.supportsCOMDAT() && 679 (TargetTriple.isOSBinFormatELF() || !F.isInterposable())) 680 if (auto Comdat = getOrCreateFunctionComdat(F, TargetTriple)) 681 Array->setComdat(Comdat); 682 Array->setSection(getSectionName(Section)); 683 Array->setAlignment(Align(DL->getTypeStoreSize(Ty).getFixedSize())); 684 685 // sancov_pcs parallels the other metadata section(s). Optimizers (e.g. 686 // GlobalOpt/ConstantMerge) may not discard sancov_pcs and the other 687 // section(s) as a unit, so we conservatively retain all unconditionally in 688 // the compiler. 689 // 690 // With comdat (COFF/ELF), the linker can guarantee the associated sections 691 // will be retained or discarded as a unit, so llvm.compiler.used is 692 // sufficient. Otherwise, conservatively make all of them retained by the 693 // linker. 694 if (Array->hasComdat()) 695 GlobalsToAppendToCompilerUsed.push_back(Array); 696 else 697 GlobalsToAppendToUsed.push_back(Array); 698 699 return Array; 700 } 701 702 GlobalVariable * 703 ModuleSanitizerCoverage::CreatePCArray(Function &F, 704 ArrayRef<BasicBlock *> AllBlocks) { 705 size_t N = AllBlocks.size(); 706 assert(N); 707 SmallVector<Constant *, 32> PCs; 708 IRBuilder<> IRB(&*F.getEntryBlock().getFirstInsertionPt()); 709 for (size_t i = 0; i < N; i++) { 710 if (&F.getEntryBlock() == AllBlocks[i]) { 711 PCs.push_back((Constant *)IRB.CreatePointerCast(&F, IntptrPtrTy)); 712 PCs.push_back((Constant *)IRB.CreateIntToPtr( 713 ConstantInt::get(IntptrTy, 1), IntptrPtrTy)); 714 } else { 715 PCs.push_back((Constant *)IRB.CreatePointerCast( 716 BlockAddress::get(AllBlocks[i]), IntptrPtrTy)); 717 PCs.push_back((Constant *)IRB.CreateIntToPtr( 718 ConstantInt::get(IntptrTy, 0), IntptrPtrTy)); 719 } 720 } 721 auto *PCArray = CreateFunctionLocalArrayInSection(N * 2, F, IntptrPtrTy, 722 SanCovPCsSectionName); 723 PCArray->setInitializer( 724 ConstantArray::get(ArrayType::get(IntptrPtrTy, N * 2), PCs)); 725 PCArray->setConstant(true); 726 727 return PCArray; 728 } 729 730 void ModuleSanitizerCoverage::CreateFunctionLocalArrays( 731 Function &F, ArrayRef<BasicBlock *> AllBlocks) { 732 if (Options.TracePCGuard) 733 FunctionGuardArray = CreateFunctionLocalArrayInSection( 734 AllBlocks.size(), F, Int32Ty, SanCovGuardsSectionName); 735 736 if (Options.Inline8bitCounters) 737 Function8bitCounterArray = CreateFunctionLocalArrayInSection( 738 AllBlocks.size(), F, Int8Ty, SanCovCountersSectionName); 739 if (Options.InlineBoolFlag) 740 FunctionBoolArray = CreateFunctionLocalArrayInSection( 741 AllBlocks.size(), F, Int1Ty, SanCovBoolFlagSectionName); 742 743 if (Options.PCTable) 744 FunctionPCsArray = CreatePCArray(F, AllBlocks); 745 } 746 747 bool ModuleSanitizerCoverage::InjectCoverage(Function &F, 748 ArrayRef<BasicBlock *> AllBlocks, 749 bool IsLeafFunc) { 750 if (AllBlocks.empty()) return false; 751 CreateFunctionLocalArrays(F, AllBlocks); 752 for (size_t i = 0, N = AllBlocks.size(); i < N; i++) 753 InjectCoverageAtBlock(F, *AllBlocks[i], i, IsLeafFunc); 754 return true; 755 } 756 757 // On every indirect call we call a run-time function 758 // __sanitizer_cov_indir_call* with two parameters: 759 // - callee address, 760 // - global cache array that contains CacheSize pointers (zero-initialized). 761 // The cache is used to speed up recording the caller-callee pairs. 762 // The address of the caller is passed implicitly via caller PC. 763 // CacheSize is encoded in the name of the run-time function. 764 void ModuleSanitizerCoverage::InjectCoverageForIndirectCalls( 765 Function &F, ArrayRef<Instruction *> IndirCalls) { 766 if (IndirCalls.empty()) 767 return; 768 assert(Options.TracePC || Options.TracePCGuard || 769 Options.Inline8bitCounters || Options.InlineBoolFlag); 770 for (auto I : IndirCalls) { 771 IRBuilder<> IRB(I); 772 CallBase &CB = cast<CallBase>(*I); 773 Value *Callee = CB.getCalledOperand(); 774 if (isa<InlineAsm>(Callee)) 775 continue; 776 IRB.CreateCall(SanCovTracePCIndir, IRB.CreatePointerCast(Callee, IntptrTy)); 777 } 778 } 779 780 // For every switch statement we insert a call: 781 // __sanitizer_cov_trace_switch(CondValue, 782 // {NumCases, ValueSizeInBits, Case0Value, Case1Value, Case2Value, ... }) 783 784 void ModuleSanitizerCoverage::InjectTraceForSwitch( 785 Function &, ArrayRef<Instruction *> SwitchTraceTargets) { 786 for (auto I : SwitchTraceTargets) { 787 if (SwitchInst *SI = dyn_cast<SwitchInst>(I)) { 788 IRBuilder<> IRB(I); 789 SmallVector<Constant *, 16> Initializers; 790 Value *Cond = SI->getCondition(); 791 if (Cond->getType()->getScalarSizeInBits() > 792 Int64Ty->getScalarSizeInBits()) 793 continue; 794 Initializers.push_back(ConstantInt::get(Int64Ty, SI->getNumCases())); 795 Initializers.push_back( 796 ConstantInt::get(Int64Ty, Cond->getType()->getScalarSizeInBits())); 797 if (Cond->getType()->getScalarSizeInBits() < 798 Int64Ty->getScalarSizeInBits()) 799 Cond = IRB.CreateIntCast(Cond, Int64Ty, false); 800 for (auto It : SI->cases()) { 801 Constant *C = It.getCaseValue(); 802 if (C->getType()->getScalarSizeInBits() < 803 Int64Ty->getScalarSizeInBits()) 804 C = ConstantExpr::getCast(CastInst::ZExt, It.getCaseValue(), Int64Ty); 805 Initializers.push_back(C); 806 } 807 llvm::sort(drop_begin(Initializers, 2), 808 [](const Constant *A, const Constant *B) { 809 return cast<ConstantInt>(A)->getLimitedValue() < 810 cast<ConstantInt>(B)->getLimitedValue(); 811 }); 812 ArrayType *ArrayOfInt64Ty = ArrayType::get(Int64Ty, Initializers.size()); 813 GlobalVariable *GV = new GlobalVariable( 814 *CurModule, ArrayOfInt64Ty, false, GlobalVariable::InternalLinkage, 815 ConstantArray::get(ArrayOfInt64Ty, Initializers), 816 "__sancov_gen_cov_switch_values"); 817 IRB.CreateCall(SanCovTraceSwitchFunction, 818 {Cond, IRB.CreatePointerCast(GV, Int64PtrTy)}); 819 } 820 } 821 } 822 823 void ModuleSanitizerCoverage::InjectTraceForDiv( 824 Function &, ArrayRef<BinaryOperator *> DivTraceTargets) { 825 for (auto BO : DivTraceTargets) { 826 IRBuilder<> IRB(BO); 827 Value *A1 = BO->getOperand(1); 828 if (isa<ConstantInt>(A1)) continue; 829 if (!A1->getType()->isIntegerTy()) 830 continue; 831 uint64_t TypeSize = DL->getTypeStoreSizeInBits(A1->getType()); 832 int CallbackIdx = TypeSize == 32 ? 0 : 833 TypeSize == 64 ? 1 : -1; 834 if (CallbackIdx < 0) continue; 835 auto Ty = Type::getIntNTy(*C, TypeSize); 836 IRB.CreateCall(SanCovTraceDivFunction[CallbackIdx], 837 {IRB.CreateIntCast(A1, Ty, true)}); 838 } 839 } 840 841 void ModuleSanitizerCoverage::InjectTraceForGep( 842 Function &, ArrayRef<GetElementPtrInst *> GepTraceTargets) { 843 for (auto GEP : GepTraceTargets) { 844 IRBuilder<> IRB(GEP); 845 for (Use &Idx : GEP->indices()) 846 if (!isa<ConstantInt>(Idx) && Idx->getType()->isIntegerTy()) 847 IRB.CreateCall(SanCovTraceGepFunction, 848 {IRB.CreateIntCast(Idx, IntptrTy, true)}); 849 } 850 } 851 852 void ModuleSanitizerCoverage::InjectTraceForCmp( 853 Function &, ArrayRef<Instruction *> CmpTraceTargets) { 854 for (auto I : CmpTraceTargets) { 855 if (ICmpInst *ICMP = dyn_cast<ICmpInst>(I)) { 856 IRBuilder<> IRB(ICMP); 857 Value *A0 = ICMP->getOperand(0); 858 Value *A1 = ICMP->getOperand(1); 859 if (!A0->getType()->isIntegerTy()) 860 continue; 861 uint64_t TypeSize = DL->getTypeStoreSizeInBits(A0->getType()); 862 int CallbackIdx = TypeSize == 8 ? 0 : 863 TypeSize == 16 ? 1 : 864 TypeSize == 32 ? 2 : 865 TypeSize == 64 ? 3 : -1; 866 if (CallbackIdx < 0) continue; 867 // __sanitizer_cov_trace_cmp((type_size << 32) | predicate, A0, A1); 868 auto CallbackFunc = SanCovTraceCmpFunction[CallbackIdx]; 869 bool FirstIsConst = isa<ConstantInt>(A0); 870 bool SecondIsConst = isa<ConstantInt>(A1); 871 // If both are const, then we don't need such a comparison. 872 if (FirstIsConst && SecondIsConst) continue; 873 // If only one is const, then make it the first callback argument. 874 if (FirstIsConst || SecondIsConst) { 875 CallbackFunc = SanCovTraceConstCmpFunction[CallbackIdx]; 876 if (SecondIsConst) 877 std::swap(A0, A1); 878 } 879 880 auto Ty = Type::getIntNTy(*C, TypeSize); 881 IRB.CreateCall(CallbackFunc, {IRB.CreateIntCast(A0, Ty, true), 882 IRB.CreateIntCast(A1, Ty, true)}); 883 } 884 } 885 } 886 887 void ModuleSanitizerCoverage::InjectCoverageAtBlock(Function &F, BasicBlock &BB, 888 size_t Idx, 889 bool IsLeafFunc) { 890 BasicBlock::iterator IP = BB.getFirstInsertionPt(); 891 bool IsEntryBB = &BB == &F.getEntryBlock(); 892 DebugLoc EntryLoc; 893 if (IsEntryBB) { 894 if (auto SP = F.getSubprogram()) 895 EntryLoc = DILocation::get(SP->getContext(), SP->getScopeLine(), 0, SP); 896 // Keep static allocas and llvm.localescape calls in the entry block. Even 897 // if we aren't splitting the block, it's nice for allocas to be before 898 // calls. 899 IP = PrepareToSplitEntryBlock(BB, IP); 900 } else { 901 EntryLoc = IP->getDebugLoc(); 902 } 903 904 IRBuilder<> IRB(&*IP); 905 IRB.SetCurrentDebugLocation(EntryLoc); 906 if (Options.TracePC) { 907 IRB.CreateCall(SanCovTracePC) 908 ->setCannotMerge(); // gets the PC using GET_CALLER_PC. 909 } 910 if (Options.TracePCGuard) { 911 auto GuardPtr = IRB.CreateIntToPtr( 912 IRB.CreateAdd(IRB.CreatePointerCast(FunctionGuardArray, IntptrTy), 913 ConstantInt::get(IntptrTy, Idx * 4)), 914 Int32PtrTy); 915 IRB.CreateCall(SanCovTracePCGuard, GuardPtr)->setCannotMerge(); 916 } 917 if (Options.Inline8bitCounters) { 918 auto CounterPtr = IRB.CreateGEP( 919 Function8bitCounterArray->getValueType(), Function8bitCounterArray, 920 {ConstantInt::get(IntptrTy, 0), ConstantInt::get(IntptrTy, Idx)}); 921 auto Load = IRB.CreateLoad(Int8Ty, CounterPtr); 922 auto Inc = IRB.CreateAdd(Load, ConstantInt::get(Int8Ty, 1)); 923 auto Store = IRB.CreateStore(Inc, CounterPtr); 924 SetNoSanitizeMetadata(Load); 925 SetNoSanitizeMetadata(Store); 926 } 927 if (Options.InlineBoolFlag) { 928 auto FlagPtr = IRB.CreateGEP( 929 FunctionBoolArray->getValueType(), FunctionBoolArray, 930 {ConstantInt::get(IntptrTy, 0), ConstantInt::get(IntptrTy, Idx)}); 931 auto Load = IRB.CreateLoad(Int1Ty, FlagPtr); 932 auto ThenTerm = 933 SplitBlockAndInsertIfThen(IRB.CreateIsNull(Load), &*IP, false); 934 IRBuilder<> ThenIRB(ThenTerm); 935 auto Store = ThenIRB.CreateStore(ConstantInt::getTrue(Int1Ty), FlagPtr); 936 SetNoSanitizeMetadata(Load); 937 SetNoSanitizeMetadata(Store); 938 } 939 if (Options.StackDepth && IsEntryBB && !IsLeafFunc) { 940 // Check stack depth. If it's the deepest so far, record it. 941 Module *M = F.getParent(); 942 Function *GetFrameAddr = Intrinsic::getDeclaration( 943 M, Intrinsic::frameaddress, 944 IRB.getInt8PtrTy(M->getDataLayout().getAllocaAddrSpace())); 945 auto FrameAddrPtr = 946 IRB.CreateCall(GetFrameAddr, {Constant::getNullValue(Int32Ty)}); 947 auto FrameAddrInt = IRB.CreatePtrToInt(FrameAddrPtr, IntptrTy); 948 auto LowestStack = IRB.CreateLoad(IntptrTy, SanCovLowestStack); 949 auto IsStackLower = IRB.CreateICmpULT(FrameAddrInt, LowestStack); 950 auto ThenTerm = SplitBlockAndInsertIfThen(IsStackLower, &*IP, false); 951 IRBuilder<> ThenIRB(ThenTerm); 952 auto Store = ThenIRB.CreateStore(FrameAddrInt, SanCovLowestStack); 953 SetNoSanitizeMetadata(LowestStack); 954 SetNoSanitizeMetadata(Store); 955 } 956 } 957 958 std::string 959 ModuleSanitizerCoverage::getSectionName(const std::string &Section) const { 960 if (TargetTriple.isOSBinFormatCOFF()) { 961 if (Section == SanCovCountersSectionName) 962 return ".SCOV$CM"; 963 if (Section == SanCovBoolFlagSectionName) 964 return ".SCOV$BM"; 965 if (Section == SanCovPCsSectionName) 966 return ".SCOVP$M"; 967 return ".SCOV$GM"; // For SanCovGuardsSectionName. 968 } 969 if (TargetTriple.isOSBinFormatMachO()) 970 return "__DATA,__" + Section; 971 return "__" + Section; 972 } 973 974 std::string 975 ModuleSanitizerCoverage::getSectionStart(const std::string &Section) const { 976 if (TargetTriple.isOSBinFormatMachO()) 977 return "\1section$start$__DATA$__" + Section; 978 return "__start___" + Section; 979 } 980 981 std::string 982 ModuleSanitizerCoverage::getSectionEnd(const std::string &Section) const { 983 if (TargetTriple.isOSBinFormatMachO()) 984 return "\1section$end$__DATA$__" + Section; 985 return "__stop___" + Section; 986 } 987 988 char ModuleSanitizerCoverageLegacyPass::ID = 0; 989 INITIALIZE_PASS_BEGIN(ModuleSanitizerCoverageLegacyPass, "sancov", 990 "Pass for instrumenting coverage on functions", false, 991 false) 992 INITIALIZE_PASS_DEPENDENCY(DominatorTreeWrapperPass) 993 INITIALIZE_PASS_DEPENDENCY(PostDominatorTreeWrapperPass) 994 INITIALIZE_PASS_END(ModuleSanitizerCoverageLegacyPass, "sancov", 995 "Pass for instrumenting coverage on functions", false, 996 false) 997 ModulePass *llvm::createModuleSanitizerCoverageLegacyPassPass( 998 const SanitizerCoverageOptions &Options, 999 const std::vector<std::string> &AllowlistFiles, 1000 const std::vector<std::string> &BlocklistFiles) { 1001 return new ModuleSanitizerCoverageLegacyPass(Options, AllowlistFiles, 1002 BlocklistFiles); 1003 } 1004