diff options
Diffstat (limited to 'gnu/llvm/lib/Transforms/Instrumentation/SanitizerCoverage.cpp')
| -rw-r--r-- | gnu/llvm/lib/Transforms/Instrumentation/SanitizerCoverage.cpp | 868 |
1 files changed, 0 insertions, 868 deletions
diff --git a/gnu/llvm/lib/Transforms/Instrumentation/SanitizerCoverage.cpp b/gnu/llvm/lib/Transforms/Instrumentation/SanitizerCoverage.cpp deleted file mode 100644 index 0ba8d5765e8..00000000000 --- a/gnu/llvm/lib/Transforms/Instrumentation/SanitizerCoverage.cpp +++ /dev/null @@ -1,868 +0,0 @@ -//===-- SanitizerCoverage.cpp - coverage instrumentation for sanitizers ---===// -// -// The LLVM Compiler Infrastructure -// -// This file is distributed under the University of Illinois Open Source -// License. See LICENSE.TXT for details. -// -//===----------------------------------------------------------------------===// -// -// Coverage instrumentation done on LLVM IR level, works with Sanitizers. -// -//===----------------------------------------------------------------------===// - -#include "llvm/ADT/ArrayRef.h" -#include "llvm/ADT/SmallVector.h" -#include "llvm/Analysis/EHPersonalities.h" -#include "llvm/Analysis/PostDominators.h" -#include "llvm/IR/CFG.h" -#include "llvm/IR/CallSite.h" -#include "llvm/IR/Constant.h" -#include "llvm/IR/DataLayout.h" -#include "llvm/IR/DebugInfo.h" -#include "llvm/IR/Dominators.h" -#include "llvm/IR/Function.h" -#include "llvm/IR/GlobalVariable.h" -#include "llvm/IR/IRBuilder.h" -#include "llvm/IR/InlineAsm.h" -#include "llvm/IR/IntrinsicInst.h" -#include "llvm/IR/Intrinsics.h" -#include "llvm/IR/LLVMContext.h" -#include "llvm/IR/MDBuilder.h" -#include "llvm/IR/Mangler.h" -#include "llvm/IR/Module.h" -#include "llvm/IR/Type.h" -#include "llvm/Support/CommandLine.h" -#include "llvm/Support/Debug.h" -#include "llvm/Support/raw_ostream.h" -#include "llvm/Transforms/Instrumentation.h" -#include "llvm/Transforms/Utils/BasicBlockUtils.h" -#include "llvm/Transforms/Utils/ModuleUtils.h" - -using namespace llvm; - -#define DEBUG_TYPE "sancov" - -static const char *const SanCovTracePCIndirName = - "__sanitizer_cov_trace_pc_indir"; -static const char *const SanCovTracePCName = "__sanitizer_cov_trace_pc"; -static const char *const SanCovTraceCmp1 = "__sanitizer_cov_trace_cmp1"; -static const char *const SanCovTraceCmp2 = "__sanitizer_cov_trace_cmp2"; -static const char *const SanCovTraceCmp4 = "__sanitizer_cov_trace_cmp4"; -static const char *const SanCovTraceCmp8 = "__sanitizer_cov_trace_cmp8"; -static const char *const SanCovTraceConstCmp1 = - "__sanitizer_cov_trace_const_cmp1"; -static const char *const SanCovTraceConstCmp2 = - "__sanitizer_cov_trace_const_cmp2"; -static const char *const SanCovTraceConstCmp4 = - "__sanitizer_cov_trace_const_cmp4"; -static const char *const SanCovTraceConstCmp8 = - "__sanitizer_cov_trace_const_cmp8"; -static const char *const SanCovTraceDiv4 = "__sanitizer_cov_trace_div4"; -static const char *const SanCovTraceDiv8 = "__sanitizer_cov_trace_div8"; -static const char *const SanCovTraceGep = "__sanitizer_cov_trace_gep"; -static const char *const SanCovTraceSwitchName = "__sanitizer_cov_trace_switch"; -static const char *const SanCovModuleCtorName = "sancov.module_ctor"; -static const uint64_t SanCtorAndDtorPriority = 2; - -static const char *const SanCovTracePCGuardName = - "__sanitizer_cov_trace_pc_guard"; -static const char *const SanCovTracePCGuardInitName = - "__sanitizer_cov_trace_pc_guard_init"; -static const char *const SanCov8bitCountersInitName = - "__sanitizer_cov_8bit_counters_init"; -static const char *const SanCovPCsInitName = "__sanitizer_cov_pcs_init"; - -static const char *const SanCovGuardsSectionName = "sancov_guards"; -static const char *const SanCovCountersSectionName = "sancov_cntrs"; -static const char *const SanCovPCsSectionName = "sancov_pcs"; - -static const char *const SanCovLowestStackName = "__sancov_lowest_stack"; - -static cl::opt<int> ClCoverageLevel( - "sanitizer-coverage-level", - cl::desc("Sanitizer Coverage. 0: none, 1: entry block, 2: all blocks, " - "3: all blocks and critical edges"), - cl::Hidden, cl::init(0)); - -static cl::opt<bool> ClTracePC("sanitizer-coverage-trace-pc", - cl::desc("Experimental pc tracing"), cl::Hidden, - cl::init(false)); - -static cl::opt<bool> ClTracePCGuard("sanitizer-coverage-trace-pc-guard", - cl::desc("pc tracing with a guard"), - cl::Hidden, cl::init(false)); - -// If true, we create a global variable that contains PCs of all instrumented -// BBs, put this global into a named section, and pass this section's bounds -// to __sanitizer_cov_pcs_init. -// This way the coverage instrumentation does not need to acquire the PCs -// at run-time. Works with trace-pc-guard and inline-8bit-counters. -static cl::opt<bool> ClCreatePCTable("sanitizer-coverage-pc-table", - cl::desc("create a static PC table"), - cl::Hidden, cl::init(false)); - -static cl::opt<bool> - ClInline8bitCounters("sanitizer-coverage-inline-8bit-counters", - cl::desc("increments 8-bit counter for every edge"), - cl::Hidden, cl::init(false)); - -static cl::opt<bool> - ClCMPTracing("sanitizer-coverage-trace-compares", - cl::desc("Tracing of CMP and similar instructions"), - cl::Hidden, cl::init(false)); - -static cl::opt<bool> ClDIVTracing("sanitizer-coverage-trace-divs", - cl::desc("Tracing of DIV instructions"), - cl::Hidden, cl::init(false)); - -static cl::opt<bool> ClGEPTracing("sanitizer-coverage-trace-geps", - cl::desc("Tracing of GEP instructions"), - cl::Hidden, cl::init(false)); - -static cl::opt<bool> - ClPruneBlocks("sanitizer-coverage-prune-blocks", - cl::desc("Reduce the number of instrumented blocks"), - cl::Hidden, cl::init(true)); - -static cl::opt<bool> ClStackDepth("sanitizer-coverage-stack-depth", - cl::desc("max stack depth tracing"), - cl::Hidden, cl::init(false)); - -namespace { - -SanitizerCoverageOptions getOptions(int LegacyCoverageLevel) { - SanitizerCoverageOptions Res; - switch (LegacyCoverageLevel) { - case 0: - Res.CoverageType = SanitizerCoverageOptions::SCK_None; - break; - case 1: - Res.CoverageType = SanitizerCoverageOptions::SCK_Function; - break; - case 2: - Res.CoverageType = SanitizerCoverageOptions::SCK_BB; - break; - case 3: - Res.CoverageType = SanitizerCoverageOptions::SCK_Edge; - break; - case 4: - Res.CoverageType = SanitizerCoverageOptions::SCK_Edge; - Res.IndirectCalls = true; - break; - } - return Res; -} - -SanitizerCoverageOptions OverrideFromCL(SanitizerCoverageOptions Options) { - // Sets CoverageType and IndirectCalls. - SanitizerCoverageOptions CLOpts = getOptions(ClCoverageLevel); - Options.CoverageType = std::max(Options.CoverageType, CLOpts.CoverageType); - Options.IndirectCalls |= CLOpts.IndirectCalls; - Options.TraceCmp |= ClCMPTracing; - Options.TraceDiv |= ClDIVTracing; - Options.TraceGep |= ClGEPTracing; - Options.TracePC |= ClTracePC; - Options.TracePCGuard |= ClTracePCGuard; - Options.Inline8bitCounters |= ClInline8bitCounters; - Options.PCTable |= ClCreatePCTable; - Options.NoPrune |= !ClPruneBlocks; - Options.StackDepth |= ClStackDepth; - if (!Options.TracePCGuard && !Options.TracePC && - !Options.Inline8bitCounters && !Options.StackDepth) - Options.TracePCGuard = true; // TracePCGuard is default. - return Options; -} - -class SanitizerCoverageModule : public ModulePass { -public: - SanitizerCoverageModule( - const SanitizerCoverageOptions &Options = SanitizerCoverageOptions()) - : ModulePass(ID), Options(OverrideFromCL(Options)) { - initializeSanitizerCoverageModulePass(*PassRegistry::getPassRegistry()); - } - bool runOnModule(Module &M) override; - bool runOnFunction(Function &F); - static char ID; // Pass identification, replacement for typeid - StringRef getPassName() const override { return "SanitizerCoverageModule"; } - - void getAnalysisUsage(AnalysisUsage &AU) const override { - AU.addRequired<DominatorTreeWrapperPass>(); - AU.addRequired<PostDominatorTreeWrapperPass>(); - } - -private: - void InjectCoverageForIndirectCalls(Function &F, - ArrayRef<Instruction *> IndirCalls); - void InjectTraceForCmp(Function &F, ArrayRef<Instruction *> CmpTraceTargets); - void InjectTraceForDiv(Function &F, - ArrayRef<BinaryOperator *> DivTraceTargets); - void InjectTraceForGep(Function &F, - ArrayRef<GetElementPtrInst *> GepTraceTargets); - void InjectTraceForSwitch(Function &F, - ArrayRef<Instruction *> SwitchTraceTargets); - bool InjectCoverage(Function &F, ArrayRef<BasicBlock *> AllBlocks, - bool IsLeafFunc = true); - GlobalVariable *CreateFunctionLocalArrayInSection(size_t NumElements, - Function &F, Type *Ty, - const char *Section); - GlobalVariable *CreatePCArray(Function &F, ArrayRef<BasicBlock *> AllBlocks); - void CreateFunctionLocalArrays(Function &F, ArrayRef<BasicBlock *> AllBlocks); - void InjectCoverageAtBlock(Function &F, BasicBlock &BB, size_t Idx, - bool IsLeafFunc = true); - Function *CreateInitCallsForSections(Module &M, const char *InitFunctionName, - Type *Ty, const char *Section); - std::pair<Value *, Value *> CreateSecStartEnd(Module &M, const char *Section, - Type *Ty); - - void SetNoSanitizeMetadata(Instruction *I) { - I->setMetadata(I->getModule()->getMDKindID("nosanitize"), - MDNode::get(*C, None)); - } - - std::string getSectionName(const std::string &Section) const; - std::string getSectionStart(const std::string &Section) const; - std::string getSectionEnd(const std::string &Section) const; - Function *SanCovTracePCIndir; - Function *SanCovTracePC, *SanCovTracePCGuard; - Function *SanCovTraceCmpFunction[4]; - Function *SanCovTraceConstCmpFunction[4]; - Function *SanCovTraceDivFunction[2]; - Function *SanCovTraceGepFunction; - Function *SanCovTraceSwitchFunction; - GlobalVariable *SanCovLowestStack; - InlineAsm *EmptyAsm; - Type *IntptrTy, *IntptrPtrTy, *Int64Ty, *Int64PtrTy, *Int32Ty, *Int32PtrTy, - *Int16Ty, *Int8Ty, *Int8PtrTy; - Module *CurModule; - std::string CurModuleUniqueId; - Triple TargetTriple; - LLVMContext *C; - const DataLayout *DL; - - GlobalVariable *FunctionGuardArray; // for trace-pc-guard. - GlobalVariable *Function8bitCounterArray; // for inline-8bit-counters. - GlobalVariable *FunctionPCsArray; // for pc-table. - SmallVector<GlobalValue *, 20> GlobalsToAppendToUsed; - SmallVector<GlobalValue *, 20> GlobalsToAppendToCompilerUsed; - - SanitizerCoverageOptions Options; -}; - -} // namespace - -std::pair<Value *, Value *> -SanitizerCoverageModule::CreateSecStartEnd(Module &M, const char *Section, - Type *Ty) { - GlobalVariable *SecStart = - new GlobalVariable(M, Ty, false, GlobalVariable::ExternalLinkage, nullptr, - getSectionStart(Section)); - SecStart->setVisibility(GlobalValue::HiddenVisibility); - GlobalVariable *SecEnd = - new GlobalVariable(M, Ty, false, GlobalVariable::ExternalLinkage, - nullptr, getSectionEnd(Section)); - SecEnd->setVisibility(GlobalValue::HiddenVisibility); - IRBuilder<> IRB(M.getContext()); - Value *SecEndPtr = IRB.CreatePointerCast(SecEnd, Ty); - if (!TargetTriple.isOSBinFormatCOFF()) - return std::make_pair(IRB.CreatePointerCast(SecStart, Ty), SecEndPtr); - - // Account for the fact that on windows-msvc __start_* symbols actually - // point to a uint64_t before the start of the array. - auto SecStartI8Ptr = IRB.CreatePointerCast(SecStart, Int8PtrTy); - auto GEP = IRB.CreateGEP(SecStartI8Ptr, - ConstantInt::get(IntptrTy, sizeof(uint64_t))); - return std::make_pair(IRB.CreatePointerCast(GEP, Ty), SecEndPtr); -} - -Function *SanitizerCoverageModule::CreateInitCallsForSections( - Module &M, const char *InitFunctionName, Type *Ty, - const char *Section) { - auto SecStartEnd = CreateSecStartEnd(M, Section, Ty); - auto SecStart = SecStartEnd.first; - auto SecEnd = SecStartEnd.second; - Function *CtorFunc; - std::tie(CtorFunc, std::ignore) = createSanitizerCtorAndInitFunctions( - M, SanCovModuleCtorName, InitFunctionName, {Ty, Ty}, {SecStart, SecEnd}); - - if (TargetTriple.supportsCOMDAT()) { - // Use comdat to dedup CtorFunc. - CtorFunc->setComdat(M.getOrInsertComdat(SanCovModuleCtorName)); - appendToGlobalCtors(M, CtorFunc, SanCtorAndDtorPriority, CtorFunc); - } else { - appendToGlobalCtors(M, CtorFunc, SanCtorAndDtorPriority); - } - - if (TargetTriple.isOSBinFormatCOFF()) { - // In COFF files, if the contructors are set as COMDAT (they are because - // COFF supports COMDAT) and the linker flag /OPT:REF (strip unreferenced - // functions and data) is used, the constructors get stripped. To prevent - // this, give the constructors weak ODR linkage and ensure the linker knows - // to include the sancov constructor. This way the linker can deduplicate - // the constructors but always leave one copy. - CtorFunc->setLinkage(GlobalValue::WeakODRLinkage); - appendToUsed(M, CtorFunc); - } - return CtorFunc; -} - -bool SanitizerCoverageModule::runOnModule(Module &M) { - if (Options.CoverageType == SanitizerCoverageOptions::SCK_None) - return false; - C = &(M.getContext()); - DL = &M.getDataLayout(); - CurModule = &M; - CurModuleUniqueId = getUniqueModuleId(CurModule); - TargetTriple = Triple(M.getTargetTriple()); - FunctionGuardArray = nullptr; - Function8bitCounterArray = nullptr; - FunctionPCsArray = nullptr; - IntptrTy = Type::getIntNTy(*C, DL->getPointerSizeInBits()); - IntptrPtrTy = PointerType::getUnqual(IntptrTy); - Type *VoidTy = Type::getVoidTy(*C); - IRBuilder<> IRB(*C); - Int64PtrTy = PointerType::getUnqual(IRB.getInt64Ty()); - Int32PtrTy = PointerType::getUnqual(IRB.getInt32Ty()); - Int8PtrTy = PointerType::getUnqual(IRB.getInt8Ty()); - Int64Ty = IRB.getInt64Ty(); - Int32Ty = IRB.getInt32Ty(); - Int16Ty = IRB.getInt16Ty(); - Int8Ty = IRB.getInt8Ty(); - - SanCovTracePCIndir = checkSanitizerInterfaceFunction( - M.getOrInsertFunction(SanCovTracePCIndirName, VoidTy, IntptrTy)); - SanCovTraceCmpFunction[0] = - checkSanitizerInterfaceFunction(M.getOrInsertFunction( - SanCovTraceCmp1, VoidTy, IRB.getInt8Ty(), IRB.getInt8Ty())); - SanCovTraceCmpFunction[1] = checkSanitizerInterfaceFunction( - M.getOrInsertFunction(SanCovTraceCmp2, VoidTy, IRB.getInt16Ty(), - IRB.getInt16Ty())); - SanCovTraceCmpFunction[2] = checkSanitizerInterfaceFunction( - M.getOrInsertFunction(SanCovTraceCmp4, VoidTy, IRB.getInt32Ty(), - IRB.getInt32Ty())); - SanCovTraceCmpFunction[3] = - checkSanitizerInterfaceFunction(M.getOrInsertFunction( - SanCovTraceCmp8, VoidTy, Int64Ty, Int64Ty)); - - SanCovTraceConstCmpFunction[0] = - checkSanitizerInterfaceFunction(M.getOrInsertFunction( - SanCovTraceConstCmp1, VoidTy, Int8Ty, Int8Ty)); - SanCovTraceConstCmpFunction[1] = - checkSanitizerInterfaceFunction(M.getOrInsertFunction( - SanCovTraceConstCmp2, VoidTy, Int16Ty, Int16Ty)); - SanCovTraceConstCmpFunction[2] = - checkSanitizerInterfaceFunction(M.getOrInsertFunction( - SanCovTraceConstCmp4, VoidTy, Int32Ty, Int32Ty)); - SanCovTraceConstCmpFunction[3] = - checkSanitizerInterfaceFunction(M.getOrInsertFunction( - SanCovTraceConstCmp8, VoidTy, Int64Ty, Int64Ty)); - - SanCovTraceDivFunction[0] = - checkSanitizerInterfaceFunction(M.getOrInsertFunction( - SanCovTraceDiv4, VoidTy, IRB.getInt32Ty())); - SanCovTraceDivFunction[1] = - checkSanitizerInterfaceFunction(M.getOrInsertFunction( - SanCovTraceDiv8, VoidTy, Int64Ty)); - SanCovTraceGepFunction = - checkSanitizerInterfaceFunction(M.getOrInsertFunction( - SanCovTraceGep, VoidTy, IntptrTy)); - SanCovTraceSwitchFunction = - checkSanitizerInterfaceFunction(M.getOrInsertFunction( - SanCovTraceSwitchName, VoidTy, Int64Ty, Int64PtrTy)); - - Constant *SanCovLowestStackConstant = - M.getOrInsertGlobal(SanCovLowestStackName, IntptrTy); - SanCovLowestStack = cast<GlobalVariable>(SanCovLowestStackConstant); - SanCovLowestStack->setThreadLocalMode( - GlobalValue::ThreadLocalMode::InitialExecTLSModel); - if (Options.StackDepth && !SanCovLowestStack->isDeclaration()) - SanCovLowestStack->setInitializer(Constant::getAllOnesValue(IntptrTy)); - - // Make sure smaller parameters are zero-extended to i64 as required by the - // x86_64 ABI. - if (TargetTriple.getArch() == Triple::x86_64) { - for (int i = 0; i < 3; i++) { - SanCovTraceCmpFunction[i]->addParamAttr(0, Attribute::ZExt); - SanCovTraceCmpFunction[i]->addParamAttr(1, Attribute::ZExt); - SanCovTraceConstCmpFunction[i]->addParamAttr(0, Attribute::ZExt); - SanCovTraceConstCmpFunction[i]->addParamAttr(1, Attribute::ZExt); - } - SanCovTraceDivFunction[0]->addParamAttr(0, Attribute::ZExt); - } - - - // We insert an empty inline asm after cov callbacks to avoid callback merge. - EmptyAsm = InlineAsm::get(FunctionType::get(IRB.getVoidTy(), false), - StringRef(""), StringRef(""), - /*hasSideEffects=*/true); - - SanCovTracePC = checkSanitizerInterfaceFunction( - M.getOrInsertFunction(SanCovTracePCName, VoidTy)); - SanCovTracePCGuard = checkSanitizerInterfaceFunction(M.getOrInsertFunction( - SanCovTracePCGuardName, VoidTy, Int32PtrTy)); - - for (auto &F : M) - runOnFunction(F); - - Function *Ctor = nullptr; - - if (FunctionGuardArray) - Ctor = CreateInitCallsForSections(M, SanCovTracePCGuardInitName, Int32PtrTy, - SanCovGuardsSectionName); - if (Function8bitCounterArray) - Ctor = CreateInitCallsForSections(M, SanCov8bitCountersInitName, Int8PtrTy, - SanCovCountersSectionName); - if (Ctor && Options.PCTable) { - auto SecStartEnd = CreateSecStartEnd(M, SanCovPCsSectionName, IntptrPtrTy); - Function *InitFunction = declareSanitizerInitFunction( - M, SanCovPCsInitName, {IntptrPtrTy, IntptrPtrTy}); - IRBuilder<> IRBCtor(Ctor->getEntryBlock().getTerminator()); - IRBCtor.CreateCall(InitFunction, {SecStartEnd.first, SecStartEnd.second}); - } - // We don't reference these arrays directly in any of our runtime functions, - // so we need to prevent them from being dead stripped. - if (TargetTriple.isOSBinFormatMachO()) - appendToUsed(M, GlobalsToAppendToUsed); - appendToCompilerUsed(M, GlobalsToAppendToCompilerUsed); - return true; -} - -// True if block has successors and it dominates all of them. -static bool isFullDominator(const BasicBlock *BB, const DominatorTree *DT) { - if (succ_begin(BB) == succ_end(BB)) - return false; - - for (const BasicBlock *SUCC : make_range(succ_begin(BB), succ_end(BB))) { - if (!DT->dominates(BB, SUCC)) - return false; - } - - return true; -} - -// True if block has predecessors and it postdominates all of them. -static bool isFullPostDominator(const BasicBlock *BB, - const PostDominatorTree *PDT) { - if (pred_begin(BB) == pred_end(BB)) - return false; - - for (const BasicBlock *PRED : make_range(pred_begin(BB), pred_end(BB))) { - if (!PDT->dominates(BB, PRED)) - return false; - } - - return true; -} - -static bool shouldInstrumentBlock(const Function &F, const BasicBlock *BB, - const DominatorTree *DT, - const PostDominatorTree *PDT, - const SanitizerCoverageOptions &Options) { - // Don't insert coverage for unreachable blocks: we will never call - // __sanitizer_cov() for them, so counting them in - // NumberOfInstrumentedBlocks() might complicate calculation of code coverage - // percentage. Also, unreachable instructions frequently have no debug - // locations. - if (isa<UnreachableInst>(BB->getTerminator())) - return false; - - // Don't insert coverage into blocks without a valid insertion point - // (catchswitch blocks). - if (BB->getFirstInsertionPt() == BB->end()) - return false; - - if (Options.NoPrune || &F.getEntryBlock() == BB) - return true; - - if (Options.CoverageType == SanitizerCoverageOptions::SCK_Function && - &F.getEntryBlock() != BB) - return false; - - // Do not instrument full dominators, or full post-dominators with multiple - // predecessors. - return !isFullDominator(BB, DT) - && !(isFullPostDominator(BB, PDT) && !BB->getSinglePredecessor()); -} - -bool SanitizerCoverageModule::runOnFunction(Function &F) { - if (F.empty()) - return false; - if (F.getName().find(".module_ctor") != std::string::npos) - return false; // Should not instrument sanitizer init functions. - if (F.getName().startswith("__sanitizer_")) - return false; // Don't instrument __sanitizer_* callbacks. - // Don't touch available_externally functions, their actual body is elewhere. - if (F.getLinkage() == GlobalValue::AvailableExternallyLinkage) - return false; - // Don't instrument MSVC CRT configuration helpers. They may run before normal - // initialization. - if (F.getName() == "__local_stdio_printf_options" || - F.getName() == "__local_stdio_scanf_options") - return false; - if (isa<UnreachableInst>(F.getEntryBlock().getTerminator())) - return false; - // Don't instrument functions using SEH for now. Splitting basic blocks like - // we do for coverage breaks WinEHPrepare. - // FIXME: Remove this when SEH no longer uses landingpad pattern matching. - if (F.hasPersonalityFn() && - isAsynchronousEHPersonality(classifyEHPersonality(F.getPersonalityFn()))) - return false; - if (Options.CoverageType >= SanitizerCoverageOptions::SCK_Edge) - SplitAllCriticalEdges(F); - SmallVector<Instruction *, 8> IndirCalls; - SmallVector<BasicBlock *, 16> BlocksToInstrument; - SmallVector<Instruction *, 8> CmpTraceTargets; - SmallVector<Instruction *, 8> SwitchTraceTargets; - SmallVector<BinaryOperator *, 8> DivTraceTargets; - SmallVector<GetElementPtrInst *, 8> GepTraceTargets; - - const DominatorTree *DT = - &getAnalysis<DominatorTreeWrapperPass>(F).getDomTree(); - const PostDominatorTree *PDT = - &getAnalysis<PostDominatorTreeWrapperPass>(F).getPostDomTree(); - bool IsLeafFunc = true; - - for (auto &BB : F) { - if (shouldInstrumentBlock(F, &BB, DT, PDT, Options)) - BlocksToInstrument.push_back(&BB); - for (auto &Inst : BB) { - if (Options.IndirectCalls) { - CallSite CS(&Inst); - if (CS && !CS.getCalledFunction()) - IndirCalls.push_back(&Inst); - } - if (Options.TraceCmp) { - if (isa<ICmpInst>(&Inst)) - CmpTraceTargets.push_back(&Inst); - if (isa<SwitchInst>(&Inst)) - SwitchTraceTargets.push_back(&Inst); - } - if (Options.TraceDiv) - if (BinaryOperator *BO = dyn_cast<BinaryOperator>(&Inst)) - if (BO->getOpcode() == Instruction::SDiv || - BO->getOpcode() == Instruction::UDiv) - DivTraceTargets.push_back(BO); - if (Options.TraceGep) - if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(&Inst)) - GepTraceTargets.push_back(GEP); - if (Options.StackDepth) - if (isa<InvokeInst>(Inst) || - (isa<CallInst>(Inst) && !isa<IntrinsicInst>(Inst))) - IsLeafFunc = false; - } - } - - InjectCoverage(F, BlocksToInstrument, IsLeafFunc); - InjectCoverageForIndirectCalls(F, IndirCalls); - InjectTraceForCmp(F, CmpTraceTargets); - InjectTraceForSwitch(F, SwitchTraceTargets); - InjectTraceForDiv(F, DivTraceTargets); - InjectTraceForGep(F, GepTraceTargets); - return true; -} - -GlobalVariable *SanitizerCoverageModule::CreateFunctionLocalArrayInSection( - size_t NumElements, Function &F, Type *Ty, const char *Section) { - ArrayType *ArrayTy = ArrayType::get(Ty, NumElements); - auto Array = new GlobalVariable( - *CurModule, ArrayTy, false, GlobalVariable::PrivateLinkage, - Constant::getNullValue(ArrayTy), "__sancov_gen_"); - - if (TargetTriple.supportsCOMDAT() && !F.isInterposable()) - if (auto Comdat = - GetOrCreateFunctionComdat(F, TargetTriple, CurModuleUniqueId)) - Array->setComdat(Comdat); - Array->setSection(getSectionName(Section)); - Array->setAlignment(Ty->isPointerTy() ? DL->getPointerSize() - : Ty->getPrimitiveSizeInBits() / 8); - GlobalsToAppendToUsed.push_back(Array); - GlobalsToAppendToCompilerUsed.push_back(Array); - MDNode *MD = MDNode::get(F.getContext(), ValueAsMetadata::get(&F)); - Array->addMetadata(LLVMContext::MD_associated, *MD); - - return Array; -} - -GlobalVariable * -SanitizerCoverageModule::CreatePCArray(Function &F, - ArrayRef<BasicBlock *> AllBlocks) { - size_t N = AllBlocks.size(); - assert(N); - SmallVector<Constant *, 32> PCs; - IRBuilder<> IRB(&*F.getEntryBlock().getFirstInsertionPt()); - for (size_t i = 0; i < N; i++) { - if (&F.getEntryBlock() == AllBlocks[i]) { - PCs.push_back((Constant *)IRB.CreatePointerCast(&F, IntptrPtrTy)); - PCs.push_back((Constant *)IRB.CreateIntToPtr( - ConstantInt::get(IntptrTy, 1), IntptrPtrTy)); - } else { - PCs.push_back((Constant *)IRB.CreatePointerCast( - BlockAddress::get(AllBlocks[i]), IntptrPtrTy)); - PCs.push_back((Constant *)IRB.CreateIntToPtr( - ConstantInt::get(IntptrTy, 0), IntptrPtrTy)); - } - } - auto *PCArray = CreateFunctionLocalArrayInSection(N * 2, F, IntptrPtrTy, - SanCovPCsSectionName); - PCArray->setInitializer( - ConstantArray::get(ArrayType::get(IntptrPtrTy, N * 2), PCs)); - PCArray->setConstant(true); - - return PCArray; -} - -void SanitizerCoverageModule::CreateFunctionLocalArrays( - Function &F, ArrayRef<BasicBlock *> AllBlocks) { - if (Options.TracePCGuard) - FunctionGuardArray = CreateFunctionLocalArrayInSection( - AllBlocks.size(), F, Int32Ty, SanCovGuardsSectionName); - - if (Options.Inline8bitCounters) - Function8bitCounterArray = CreateFunctionLocalArrayInSection( - AllBlocks.size(), F, Int8Ty, SanCovCountersSectionName); - - if (Options.PCTable) - FunctionPCsArray = CreatePCArray(F, AllBlocks); -} - -bool SanitizerCoverageModule::InjectCoverage(Function &F, - ArrayRef<BasicBlock *> AllBlocks, - bool IsLeafFunc) { - if (AllBlocks.empty()) return false; - CreateFunctionLocalArrays(F, AllBlocks); - for (size_t i = 0, N = AllBlocks.size(); i < N; i++) - InjectCoverageAtBlock(F, *AllBlocks[i], i, IsLeafFunc); - return true; -} - -// On every indirect call we call a run-time function -// __sanitizer_cov_indir_call* with two parameters: -// - callee address, -// - global cache array that contains CacheSize pointers (zero-initialized). -// The cache is used to speed up recording the caller-callee pairs. -// The address of the caller is passed implicitly via caller PC. -// CacheSize is encoded in the name of the run-time function. -void SanitizerCoverageModule::InjectCoverageForIndirectCalls( - Function &F, ArrayRef<Instruction *> IndirCalls) { - if (IndirCalls.empty()) - return; - assert(Options.TracePC || Options.TracePCGuard || Options.Inline8bitCounters); - for (auto I : IndirCalls) { - IRBuilder<> IRB(I); - CallSite CS(I); - Value *Callee = CS.getCalledValue(); - if (isa<InlineAsm>(Callee)) - continue; - IRB.CreateCall(SanCovTracePCIndir, IRB.CreatePointerCast(Callee, IntptrTy)); - } -} - -// For every switch statement we insert a call: -// __sanitizer_cov_trace_switch(CondValue, -// {NumCases, ValueSizeInBits, Case0Value, Case1Value, Case2Value, ... }) - -void SanitizerCoverageModule::InjectTraceForSwitch( - Function &, ArrayRef<Instruction *> SwitchTraceTargets) { - for (auto I : SwitchTraceTargets) { - if (SwitchInst *SI = dyn_cast<SwitchInst>(I)) { - IRBuilder<> IRB(I); - SmallVector<Constant *, 16> Initializers; - Value *Cond = SI->getCondition(); - if (Cond->getType()->getScalarSizeInBits() > - Int64Ty->getScalarSizeInBits()) - continue; - Initializers.push_back(ConstantInt::get(Int64Ty, SI->getNumCases())); - Initializers.push_back( - ConstantInt::get(Int64Ty, Cond->getType()->getScalarSizeInBits())); - if (Cond->getType()->getScalarSizeInBits() < - Int64Ty->getScalarSizeInBits()) - Cond = IRB.CreateIntCast(Cond, Int64Ty, false); - for (auto It : SI->cases()) { - Constant *C = It.getCaseValue(); - if (C->getType()->getScalarSizeInBits() < - Int64Ty->getScalarSizeInBits()) - C = ConstantExpr::getCast(CastInst::ZExt, It.getCaseValue(), Int64Ty); - Initializers.push_back(C); - } - llvm::sort(Initializers.begin() + 2, Initializers.end(), - [](const Constant *A, const Constant *B) { - return cast<ConstantInt>(A)->getLimitedValue() < - cast<ConstantInt>(B)->getLimitedValue(); - }); - ArrayType *ArrayOfInt64Ty = ArrayType::get(Int64Ty, Initializers.size()); - GlobalVariable *GV = new GlobalVariable( - *CurModule, ArrayOfInt64Ty, false, GlobalVariable::InternalLinkage, - ConstantArray::get(ArrayOfInt64Ty, Initializers), - "__sancov_gen_cov_switch_values"); - IRB.CreateCall(SanCovTraceSwitchFunction, - {Cond, IRB.CreatePointerCast(GV, Int64PtrTy)}); - } - } -} - -void SanitizerCoverageModule::InjectTraceForDiv( - Function &, ArrayRef<BinaryOperator *> DivTraceTargets) { - for (auto BO : DivTraceTargets) { - IRBuilder<> IRB(BO); - Value *A1 = BO->getOperand(1); - if (isa<ConstantInt>(A1)) continue; - if (!A1->getType()->isIntegerTy()) - continue; - uint64_t TypeSize = DL->getTypeStoreSizeInBits(A1->getType()); - int CallbackIdx = TypeSize == 32 ? 0 : - TypeSize == 64 ? 1 : -1; - if (CallbackIdx < 0) continue; - auto Ty = Type::getIntNTy(*C, TypeSize); - IRB.CreateCall(SanCovTraceDivFunction[CallbackIdx], - {IRB.CreateIntCast(A1, Ty, true)}); - } -} - -void SanitizerCoverageModule::InjectTraceForGep( - Function &, ArrayRef<GetElementPtrInst *> GepTraceTargets) { - for (auto GEP : GepTraceTargets) { - IRBuilder<> IRB(GEP); - for (auto I = GEP->idx_begin(); I != GEP->idx_end(); ++I) - if (!isa<ConstantInt>(*I) && (*I)->getType()->isIntegerTy()) - IRB.CreateCall(SanCovTraceGepFunction, - {IRB.CreateIntCast(*I, IntptrTy, true)}); - } -} - -void SanitizerCoverageModule::InjectTraceForCmp( - Function &, ArrayRef<Instruction *> CmpTraceTargets) { - for (auto I : CmpTraceTargets) { - if (ICmpInst *ICMP = dyn_cast<ICmpInst>(I)) { - IRBuilder<> IRB(ICMP); - Value *A0 = ICMP->getOperand(0); - Value *A1 = ICMP->getOperand(1); - if (!A0->getType()->isIntegerTy()) - continue; - uint64_t TypeSize = DL->getTypeStoreSizeInBits(A0->getType()); - int CallbackIdx = TypeSize == 8 ? 0 : - TypeSize == 16 ? 1 : - TypeSize == 32 ? 2 : - TypeSize == 64 ? 3 : -1; - if (CallbackIdx < 0) continue; - // __sanitizer_cov_trace_cmp((type_size << 32) | predicate, A0, A1); - auto CallbackFunc = SanCovTraceCmpFunction[CallbackIdx]; - bool FirstIsConst = isa<ConstantInt>(A0); - bool SecondIsConst = isa<ConstantInt>(A1); - // If both are const, then we don't need such a comparison. - if (FirstIsConst && SecondIsConst) continue; - // If only one is const, then make it the first callback argument. - if (FirstIsConst || SecondIsConst) { - CallbackFunc = SanCovTraceConstCmpFunction[CallbackIdx]; - if (SecondIsConst) - std::swap(A0, A1); - } - - auto Ty = Type::getIntNTy(*C, TypeSize); - IRB.CreateCall(CallbackFunc, {IRB.CreateIntCast(A0, Ty, true), - IRB.CreateIntCast(A1, Ty, true)}); - } - } -} - -void SanitizerCoverageModule::InjectCoverageAtBlock(Function &F, BasicBlock &BB, - size_t Idx, - bool IsLeafFunc) { - BasicBlock::iterator IP = BB.getFirstInsertionPt(); - bool IsEntryBB = &BB == &F.getEntryBlock(); - DebugLoc EntryLoc; - if (IsEntryBB) { - if (auto SP = F.getSubprogram()) - EntryLoc = DebugLoc::get(SP->getScopeLine(), 0, SP); - // Keep static allocas and llvm.localescape calls in the entry block. Even - // if we aren't splitting the block, it's nice for allocas to be before - // calls. - IP = PrepareToSplitEntryBlock(BB, IP); - } else { - EntryLoc = IP->getDebugLoc(); - } - - IRBuilder<> IRB(&*IP); - IRB.SetCurrentDebugLocation(EntryLoc); - if (Options.TracePC) { - IRB.CreateCall(SanCovTracePC); // gets the PC using GET_CALLER_PC. - IRB.CreateCall(EmptyAsm, {}); // Avoids callback merge. - } - if (Options.TracePCGuard) { - auto GuardPtr = IRB.CreateIntToPtr( - IRB.CreateAdd(IRB.CreatePointerCast(FunctionGuardArray, IntptrTy), - ConstantInt::get(IntptrTy, Idx * 4)), - Int32PtrTy); - IRB.CreateCall(SanCovTracePCGuard, GuardPtr); - IRB.CreateCall(EmptyAsm, {}); // Avoids callback merge. - } - if (Options.Inline8bitCounters) { - auto CounterPtr = IRB.CreateGEP( - Function8bitCounterArray, - {ConstantInt::get(IntptrTy, 0), ConstantInt::get(IntptrTy, Idx)}); - auto Load = IRB.CreateLoad(CounterPtr); - auto Inc = IRB.CreateAdd(Load, ConstantInt::get(Int8Ty, 1)); - auto Store = IRB.CreateStore(Inc, CounterPtr); - SetNoSanitizeMetadata(Load); - SetNoSanitizeMetadata(Store); - } - if (Options.StackDepth && IsEntryBB && !IsLeafFunc) { - // Check stack depth. If it's the deepest so far, record it. - Function *GetFrameAddr = - Intrinsic::getDeclaration(F.getParent(), Intrinsic::frameaddress); - auto FrameAddrPtr = - IRB.CreateCall(GetFrameAddr, {Constant::getNullValue(Int32Ty)}); - auto FrameAddrInt = IRB.CreatePtrToInt(FrameAddrPtr, IntptrTy); - auto LowestStack = IRB.CreateLoad(SanCovLowestStack); - auto IsStackLower = IRB.CreateICmpULT(FrameAddrInt, LowestStack); - auto ThenTerm = SplitBlockAndInsertIfThen(IsStackLower, &*IP, false); - IRBuilder<> ThenIRB(ThenTerm); - auto Store = ThenIRB.CreateStore(FrameAddrInt, SanCovLowestStack); - SetNoSanitizeMetadata(LowestStack); - SetNoSanitizeMetadata(Store); - } -} - -std::string -SanitizerCoverageModule::getSectionName(const std::string &Section) const { - if (TargetTriple.isOSBinFormatCOFF()) { - if (Section == SanCovCountersSectionName) - return ".SCOV$CM"; - if (Section == SanCovPCsSectionName) - return ".SCOVP$M"; - return ".SCOV$GM"; // For SanCovGuardsSectionName. - } - if (TargetTriple.isOSBinFormatMachO()) - return "__DATA,__" + Section; - return "__" + Section; -} - -std::string -SanitizerCoverageModule::getSectionStart(const std::string &Section) const { - if (TargetTriple.isOSBinFormatMachO()) - return "\1section$start$__DATA$__" + Section; - return "__start___" + Section; -} - -std::string -SanitizerCoverageModule::getSectionEnd(const std::string &Section) const { - if (TargetTriple.isOSBinFormatMachO()) - return "\1section$end$__DATA$__" + Section; - return "__stop___" + Section; -} - - -char SanitizerCoverageModule::ID = 0; -INITIALIZE_PASS_BEGIN(SanitizerCoverageModule, "sancov", - "SanitizerCoverage: TODO." - "ModulePass", - false, false) -INITIALIZE_PASS_DEPENDENCY(DominatorTreeWrapperPass) -INITIALIZE_PASS_DEPENDENCY(PostDominatorTreeWrapperPass) -INITIALIZE_PASS_END(SanitizerCoverageModule, "sancov", - "SanitizerCoverage: TODO." - "ModulePass", - false, false) -ModulePass *llvm::createSanitizerCoverageModulePass( - const SanitizerCoverageOptions &Options) { - return new SanitizerCoverageModule(Options); -} |