// and potentially with other Sanitizers.
//
// We create a Guard variable with the same linkage
-// as the function and inject this code into the entry block (CoverageLevel=1)
-// or all blocks (CoverageLevel>=2):
+// as the function and inject this code into the entry block (SCK_Function)
+// or all blocks (SCK_BB):
// if (Guard < 0) {
// __sanitizer_cov(&Guard);
// }
// The accesses to Guard are atomic. The rest of the logic is
// in __sanitizer_cov (it's fine to call it more than once).
//
-// With CoverageLevel>=3 we also split critical edges this effectively
+// With SCK_Edge we also split critical edges this effectively
// instrumenting all edges.
//
-// CoverageLevel>=4 add indirect call profiling implented as a function call.
-//
// This coverage implementation provides very limited data:
// it only tells if a given function (block) was ever executed. No counters.
// But for many use cases this is what we need and the added slowdown small.
static const char *const kSanCovIndirCallName = "__sanitizer_cov_indir_call16";
static const char *const kSanCovTraceEnter = "__sanitizer_cov_trace_func_enter";
static const char *const kSanCovTraceBB = "__sanitizer_cov_trace_basic_block";
+static const char *const kSanCovTraceCmp = "__sanitizer_cov_trace_cmp";
static const char *const kSanCovModuleCtorName = "sancov.module_ctor";
static const uint64_t kSanCtorAndDtorPriority = 2;
"sanitizer-coverage-block-threshold",
cl::desc("Use a callback with a guard check inside it if there are"
" more than this number of blocks."),
- cl::Hidden, cl::init(1000));
+ cl::Hidden, cl::init(500));
static cl::opt<bool>
ClExperimentalTracing("sanitizer-coverage-experimental-tracing",
"callbacks at every basic block"),
cl::Hidden, cl::init(false));
+static cl::opt<bool>
+ ClExperimentalCMPTracing("sanitizer-coverage-experimental-trace-compares",
+ cl::desc("Experimental tracing of CMP and similar "
+ "instructions"),
+ cl::Hidden, cl::init(false));
+
// Experimental 8-bit counters used as an additional search heuristic during
// coverage-guided fuzzing.
// The counters are not thread-friendly:
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.TraceBB |= ClExperimentalTracing;
+ Options.TraceCmp |= ClExperimentalCMPTracing;
+ Options.Use8bitCounters |= ClUse8bitCounters;
+ return Options;
+}
+
class SanitizerCoverageModule : public ModulePass {
public:
- SanitizerCoverageModule(int CoverageLevel = 0)
- : ModulePass(ID),
- CoverageLevel(std::max(CoverageLevel, (int)ClCoverageLevel)) {}
+ SanitizerCoverageModule(
+ const SanitizerCoverageOptions &Options = SanitizerCoverageOptions())
+ : ModulePass(ID), Options(OverrideFromCL(Options)) {}
bool runOnModule(Module &M) override;
bool runOnFunction(Function &F);
static char ID; // Pass identification, replacement for typeid
return "SanitizerCoverageModule";
}
- void getAnalysisUsage(AnalysisUsage &AU) const override {
- AU.addRequired<DataLayoutPass>();
- }
-
private:
void InjectCoverageForIndirectCalls(Function &F,
ArrayRef<Instruction *> IndirCalls);
- bool InjectCoverage(Function &F, ArrayRef<BasicBlock *> AllBlocks,
- ArrayRef<Instruction *> IndirCalls);
+ void InjectTraceForCmp(Function &F, ArrayRef<Instruction *> CmpTraceTargets);
+ bool InjectCoverage(Function &F, ArrayRef<BasicBlock *> AllBlocks);
+ void SetNoSanitizeMetadata(Instruction *I);
void InjectCoverageAtBlock(Function &F, BasicBlock &BB, bool UseCalls);
+ unsigned NumberOfInstrumentedBlocks() {
+ return SanCovFunction->getNumUses() + SanCovWithCheckFunction->getNumUses();
+ }
Function *SanCovFunction;
Function *SanCovWithCheckFunction;
Function *SanCovIndirCallFunction;
Function *SanCovModuleInit;
Function *SanCovTraceEnter, *SanCovTraceBB;
+ Function *SanCovTraceCmpFunction;
InlineAsm *EmptyAsm;
- Type *IntptrTy;
+ Type *IntptrTy, *Int64Ty;
LLVMContext *C;
+ const DataLayout *DL;
GlobalVariable *GuardArray;
GlobalVariable *EightBitCounterArray;
- int CoverageLevel;
+ SanitizerCoverageOptions Options;
};
} // namespace
-static Function *checkInterfaceFunction(Constant *FuncOrBitcast) {
- if (Function *F = dyn_cast<Function>(FuncOrBitcast))
- return F;
- std::string Err;
- raw_string_ostream Stream(Err);
- Stream << "SanitizerCoverage interface function redefined: "
- << *FuncOrBitcast;
- report_fatal_error(Err);
-}
-
bool SanitizerCoverageModule::runOnModule(Module &M) {
- if (!CoverageLevel) return false;
+ if (Options.CoverageType == SanitizerCoverageOptions::SCK_None)
+ return false;
C = &(M.getContext());
- DataLayoutPass *DLP = &getAnalysis<DataLayoutPass>();
- IntptrTy = Type::getIntNTy(*C, DLP->getDataLayout().getPointerSizeInBits());
+ DL = &M.getDataLayout();
+ IntptrTy = Type::getIntNTy(*C, DL->getPointerSizeInBits());
Type *VoidTy = Type::getVoidTy(*C);
IRBuilder<> IRB(*C);
Type *Int8PtrTy = PointerType::getUnqual(IRB.getInt8Ty());
Type *Int32PtrTy = PointerType::getUnqual(IRB.getInt32Ty());
+ Int64Ty = IRB.getInt64Ty();
Function *CtorFunc =
Function::Create(FunctionType::get(VoidTy, false),
ReturnInst::Create(*C, BasicBlock::Create(*C, "", CtorFunc));
appendToGlobalCtors(M, CtorFunc, kSanCtorAndDtorPriority);
- SanCovFunction = checkInterfaceFunction(
+ SanCovFunction = checkSanitizerInterfaceFunction(
M.getOrInsertFunction(kSanCovName, VoidTy, Int32PtrTy, nullptr));
- SanCovWithCheckFunction = checkInterfaceFunction(
+ SanCovWithCheckFunction = checkSanitizerInterfaceFunction(
M.getOrInsertFunction(kSanCovWithCheckName, VoidTy, Int32PtrTy, nullptr));
- SanCovIndirCallFunction = checkInterfaceFunction(M.getOrInsertFunction(
- kSanCovIndirCallName, VoidTy, IntptrTy, IntptrTy, nullptr));
- SanCovModuleInit = checkInterfaceFunction(M.getOrInsertFunction(
- kSanCovModuleInitName, Type::getVoidTy(*C), Int32PtrTy, IntptrTy,
+ SanCovIndirCallFunction =
+ checkSanitizerInterfaceFunction(M.getOrInsertFunction(
+ kSanCovIndirCallName, VoidTy, IntptrTy, IntptrTy, nullptr));
+ SanCovTraceCmpFunction =
+ checkSanitizerInterfaceFunction(M.getOrInsertFunction(
+ kSanCovTraceCmp, VoidTy, Int64Ty, Int64Ty, Int64Ty, nullptr));
+
+ SanCovModuleInit = checkSanitizerInterfaceFunction(M.getOrInsertFunction(
+ kSanCovModuleInitName, VoidTy, Int32PtrTy, IntptrTy,
Int8PtrTy, Int8PtrTy, nullptr));
SanCovModuleInit->setLinkage(Function::ExternalLinkage);
// We insert an empty inline asm after cov callbacks to avoid callback merge.
StringRef(""), StringRef(""),
/*hasSideEffects=*/true);
- if (ClExperimentalTracing) {
- SanCovTraceEnter = checkInterfaceFunction(
+ if (Options.TraceBB) {
+ SanCovTraceEnter = checkSanitizerInterfaceFunction(
M.getOrInsertFunction(kSanCovTraceEnter, VoidTy, Int32PtrTy, nullptr));
- SanCovTraceBB = checkInterfaceFunction(
+ SanCovTraceBB = checkSanitizerInterfaceFunction(
M.getOrInsertFunction(kSanCovTraceBB, VoidTy, Int32PtrTy, nullptr));
}
GuardArray =
new GlobalVariable(M, Int32Ty, false, GlobalValue::ExternalLinkage,
nullptr, "__sancov_gen_cov_tmp");
- if (ClUse8bitCounters)
+ if (Options.Use8bitCounters)
EightBitCounterArray =
new GlobalVariable(M, Int8Ty, false, GlobalVariable::ExternalLinkage,
nullptr, "__sancov_gen_cov_tmp");
for (auto &F : M)
runOnFunction(F);
+ auto N = NumberOfInstrumentedBlocks();
+
// Now we know how many elements we need. Create an array of guards
// with one extra element at the beginning for the size.
- Type *Int32ArrayNTy =
- ArrayType::get(Int32Ty, SanCovFunction->getNumUses() + 1);
+ Type *Int32ArrayNTy = ArrayType::get(Int32Ty, N + 1);
GlobalVariable *RealGuardArray = new GlobalVariable(
M, Int32ArrayNTy, false, GlobalValue::PrivateLinkage,
Constant::getNullValue(Int32ArrayNTy), "__sancov_gen_cov");
GuardArray->eraseFromParent();
GlobalVariable *RealEightBitCounterArray;
- if (ClUse8bitCounters) {
+ if (Options.Use8bitCounters) {
// Make sure the array is 16-aligned.
static const int kCounterAlignment = 16;
Type *Int8ArrayNTy =
- ArrayType::get(Int8Ty, RoundUpToAlignment(SanCovFunction->getNumUses(),
- kCounterAlignment));
+ ArrayType::get(Int8Ty, RoundUpToAlignment(N, kCounterAlignment));
RealEightBitCounterArray = new GlobalVariable(
M, Int8ArrayNTy, false, GlobalValue::PrivateLinkage,
Constant::getNullValue(Int8ArrayNTy), "__sancov_gen_cov_counter");
IRB.SetInsertPoint(CtorFunc->getEntryBlock().getTerminator());
IRB.CreateCall4(
SanCovModuleInit, IRB.CreatePointerCast(RealGuardArray, Int32PtrTy),
- ConstantInt::get(IntptrTy, SanCovFunction->getNumUses()),
- ClUse8bitCounters
+ ConstantInt::get(IntptrTy, N),
+ Options.Use8bitCounters
? IRB.CreatePointerCast(RealEightBitCounterArray, Int8PtrTy)
: Constant::getNullValue(Int8PtrTy),
IRB.CreatePointerCast(ModuleName, Int8PtrTy));
if (F.empty()) return false;
if (F.getName().find(".module_ctor") != std::string::npos)
return false; // Should not instrument sanitizer init functions.
- if (CoverageLevel >= 3)
+ if (Options.CoverageType >= SanitizerCoverageOptions::SCK_Edge)
SplitAllCriticalEdges(F);
SmallVector<Instruction*, 8> IndirCalls;
SmallVector<BasicBlock*, 16> AllBlocks;
+ SmallVector<Instruction*, 8> CmpTraceTargets;
for (auto &BB : F) {
AllBlocks.push_back(&BB);
- if (CoverageLevel >= 4)
- for (auto &Inst : BB) {
+ for (auto &Inst : BB) {
+ if (Options.IndirectCalls) {
CallSite CS(&Inst);
if (CS && !CS.getCalledFunction())
IndirCalls.push_back(&Inst);
}
+ if (Options.TraceCmp && isa<ICmpInst>(&Inst))
+ CmpTraceTargets.push_back(&Inst);
+ }
}
- InjectCoverage(F, AllBlocks, IndirCalls);
+ InjectCoverage(F, AllBlocks);
+ InjectCoverageForIndirectCalls(F, IndirCalls);
+ InjectTraceForCmp(F, CmpTraceTargets);
return true;
}
-bool
-SanitizerCoverageModule::InjectCoverage(Function &F,
- ArrayRef<BasicBlock *> AllBlocks,
- ArrayRef<Instruction *> IndirCalls) {
- if (!CoverageLevel) return false;
-
- if (CoverageLevel == 1) {
+bool SanitizerCoverageModule::InjectCoverage(Function &F,
+ ArrayRef<BasicBlock *> AllBlocks) {
+ switch (Options.CoverageType) {
+ case SanitizerCoverageOptions::SCK_None:
+ return false;
+ case SanitizerCoverageOptions::SCK_Function:
InjectCoverageAtBlock(F, F.getEntryBlock(), false);
- } else {
+ return true;
+ default: {
+ bool UseCalls = ClCoverageBlockThreshold < AllBlocks.size();
for (auto BB : AllBlocks)
- InjectCoverageAtBlock(F, *BB,
- ClCoverageBlockThreshold < AllBlocks.size());
+ InjectCoverageAtBlock(F, *BB, UseCalls);
+ return true;
+ }
}
- InjectCoverageForIndirectCalls(F, IndirCalls);
- return true;
}
// On every indirect call we call a run-time function
IRBuilder<> IRB(I);
CallSite CS(I);
Value *Callee = CS.getCalledValue();
- if (dyn_cast<InlineAsm>(Callee)) continue;
+ if (isa<InlineAsm>(Callee)) continue;
GlobalVariable *CalleeCache = new GlobalVariable(
*F.getParent(), Ty, false, GlobalValue::PrivateLinkage,
Constant::getNullValue(Ty), "__sancov_gen_callee_cache");
}
}
+void SanitizerCoverageModule::InjectTraceForCmp(
+ Function &F, 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());
+ // __sanitizer_cov_trace_cmp((type_size << 32) | predicate, A0, A1);
+ IRB.CreateCall3(
+ SanCovTraceCmpFunction,
+ ConstantInt::get(Int64Ty, (TypeSize << 32) | ICMP->getPredicate()),
+ IRB.CreateIntCast(A0, Int64Ty, true),
+ IRB.CreateIntCast(A1, Int64Ty, true));
+ }
+ }
+}
+
+void SanitizerCoverageModule::SetNoSanitizeMetadata(Instruction *I) {
+ I->setMetadata(
+ I->getParent()->getParent()->getParent()->getMDKindID("nosanitize"),
+ MDNode::get(*C, None));
+}
+
void SanitizerCoverageModule::InjectCoverageAtBlock(Function &F, BasicBlock &BB,
bool UseCalls) {
BasicBlock::iterator IP = BB.getFirstInsertionPt(), BE = BB.end();
}
bool IsEntryBB = &BB == &F.getEntryBlock();
- DebugLoc EntryLoc =
- IsEntryBB ? IP->getDebugLoc().getFnDebugLoc(*C) : IP->getDebugLoc();
+ DebugLoc EntryLoc = IsEntryBB && IP->getDebugLoc()
+ ? IP->getDebugLoc().getFnDebugLoc()
+ : IP->getDebugLoc();
IRBuilder<> IRB(IP);
IRB.SetCurrentDebugLocation(EntryLoc);
SmallVector<Value *, 1> Indices;
Value *GuardP = IRB.CreateAdd(
IRB.CreatePointerCast(GuardArray, IntptrTy),
- ConstantInt::get(IntptrTy, (1 + SanCovFunction->getNumUses()) * 4));
+ ConstantInt::get(IntptrTy, (1 + NumberOfInstrumentedBlocks()) * 4));
Type *Int32PtrTy = PointerType::getUnqual(IRB.getInt32Ty());
GuardP = IRB.CreateIntToPtr(GuardP, Int32PtrTy);
if (UseCalls) {
LoadInst *Load = IRB.CreateLoad(GuardP);
Load->setAtomic(Monotonic);
Load->setAlignment(4);
- Load->setMetadata(F.getParent()->getMDKindID("nosanitize"),
- MDNode::get(*C, None));
+ SetNoSanitizeMetadata(Load);
Value *Cmp = IRB.CreateICmpSGE(Constant::getNullValue(Load->getType()), Load);
Instruction *Ins = SplitBlockAndInsertIfThen(
Cmp, IP, false, MDBuilder(*C).createBranchWeights(1, 100000));
IRB.CreateCall(EmptyAsm); // Avoids callback merge.
}
- if(ClUse8bitCounters) {
+ if (Options.Use8bitCounters) {
IRB.SetInsertPoint(IP);
Value *P = IRB.CreateAdd(
IRB.CreatePointerCast(EightBitCounterArray, IntptrTy),
- ConstantInt::get(IntptrTy, SanCovFunction->getNumUses() - 1));
+ ConstantInt::get(IntptrTy, NumberOfInstrumentedBlocks() - 1));
P = IRB.CreateIntToPtr(P, IRB.getInt8PtrTy());
- Value *LI = IRB.CreateLoad(P);
+ LoadInst *LI = IRB.CreateLoad(P);
Value *Inc = IRB.CreateAdd(LI, ConstantInt::get(IRB.getInt8Ty(), 1));
- IRB.CreateStore(Inc, P);
+ StoreInst *SI = IRB.CreateStore(Inc, P);
+ SetNoSanitizeMetadata(LI);
+ SetNoSanitizeMetadata(SI);
}
- if (ClExperimentalTracing) {
+ if (Options.TraceBB) {
// Experimental support for tracing.
// Insert a callback with the same guard variable as used for coverage.
IRB.SetInsertPoint(IP);
"SanitizerCoverage: TODO."
"ModulePass", false, false)
ModulePass *llvm::createSanitizerCoverageModulePass(int CoverageLevel) {
- return new SanitizerCoverageModule(CoverageLevel);
+ return createSanitizerCoverageModulePass(getOptions(CoverageLevel));
+}
+ModulePass *llvm::createSanitizerCoverageModulePass(
+ const SanitizerCoverageOptions &Options) {
+ return new SanitizerCoverageModule(Options);
}
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