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-rw-r--r--lib/Transforms/Instrumentation/SanitizerCoverage.cpp157
1 files changed, 125 insertions, 32 deletions
diff --git a/lib/Transforms/Instrumentation/SanitizerCoverage.cpp b/lib/Transforms/Instrumentation/SanitizerCoverage.cpp
index 8c56e87..289675e 100644
--- a/lib/Transforms/Instrumentation/SanitizerCoverage.cpp
+++ b/lib/Transforms/Instrumentation/SanitizerCoverage.cpp
@@ -59,6 +59,7 @@ static const char *const kSanCovWithCheckName = "__sanitizer_cov_with_check";
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;
@@ -72,7 +73,7 @@ static cl::opt<unsigned> ClCoverageBlockThreshold(
"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",
@@ -80,6 +81,22 @@ static cl::opt<bool>
"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:
+// - contention on these counters may cause significant slowdown;
+// - the counter updates are racy and the results may be inaccurate.
+// They are also inaccurate due to 8-bit integer overflow.
+static cl::opt<bool> ClUse8bitCounters("sanitizer-coverage-8bit-counters",
+ cl::desc("Experimental 8-bit counters"),
+ cl::Hidden, cl::init(false));
+
namespace {
class SanitizerCoverageModule : public ModulePass {
@@ -94,26 +111,29 @@ class SanitizerCoverageModule : public ModulePass {
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 SetNoSanitizeMetada(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;
};
@@ -133,12 +153,13 @@ static Function *checkInterfaceFunction(Constant *FuncOrBitcast) {
bool SanitizerCoverageModule::runOnModule(Module &M) {
if (!CoverageLevel) 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),
@@ -152,9 +173,12 @@ bool SanitizerCoverageModule::runOnModule(Module &M) {
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, Int8PtrTy, nullptr));
+ SanCovTraceCmpFunction = checkInterfaceFunction(M.getOrInsertFunction(
+ kSanCovTraceCmp, VoidTy, Int64Ty, Int64Ty, Int64Ty, nullptr));
+
+ SanCovModuleInit = checkInterfaceFunction(M.getOrInsertFunction(
+ kSanCovModuleInitName, Type::getVoidTy(*C), Int32PtrTy, IntptrTy,
+ Int8PtrTy, Int8PtrTy, nullptr));
SanCovModuleInit->setLinkage(Function::ExternalLinkage);
// We insert an empty inline asm after cov callbacks to avoid callback merge.
EmptyAsm = InlineAsm::get(FunctionType::get(IRB.getVoidTy(), false),
@@ -171,26 +195,49 @@ bool SanitizerCoverageModule::runOnModule(Module &M) {
// At this point we create a dummy array of guards because we don't
// know how many elements we will need.
Type *Int32Ty = IRB.getInt32Ty();
+ Type *Int8Ty = IRB.getInt8Ty();
+
GuardArray =
new GlobalVariable(M, Int32Ty, false, GlobalValue::ExternalLinkage,
nullptr, "__sancov_gen_cov_tmp");
+ if (ClUse8bitCounters)
+ 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");
+
// Replace the dummy array with the real one.
GuardArray->replaceAllUsesWith(
IRB.CreatePointerCast(RealGuardArray, Int32PtrTy));
GuardArray->eraseFromParent();
+ GlobalVariable *RealEightBitCounterArray;
+ if (ClUse8bitCounters) {
+ // Make sure the array is 16-aligned.
+ static const int kCounterAlignment = 16;
+ Type *Int8ArrayNTy =
+ ArrayType::get(Int8Ty, RoundUpToAlignment(N, kCounterAlignment));
+ RealEightBitCounterArray = new GlobalVariable(
+ M, Int8ArrayNTy, false, GlobalValue::PrivateLinkage,
+ Constant::getNullValue(Int8ArrayNTy), "__sancov_gen_cov_counter");
+ RealEightBitCounterArray->setAlignment(kCounterAlignment);
+ EightBitCounterArray->replaceAllUsesWith(
+ IRB.CreatePointerCast(RealEightBitCounterArray, Int8PtrTy));
+ EightBitCounterArray->eraseFromParent();
+ }
+
// Create variable for module (compilation unit) name
Constant *ModNameStrConst =
ConstantDataArray::getString(M.getContext(), M.getName(), true);
@@ -200,10 +247,13 @@ bool SanitizerCoverageModule::runOnModule(Module &M) {
// Call __sanitizer_cov_module_init
IRB.SetInsertPoint(CtorFunc->getEntryBlock().getTerminator());
- IRB.CreateCall3(SanCovModuleInit,
- IRB.CreatePointerCast(RealGuardArray, Int32PtrTy),
- ConstantInt::get(IntptrTy, SanCovFunction->getNumUses()),
- IRB.CreatePointerCast(ModuleName, Int8PtrTy));
+ IRB.CreateCall4(
+ SanCovModuleInit, IRB.CreatePointerCast(RealGuardArray, Int32PtrTy),
+ ConstantInt::get(IntptrTy, N),
+ ClUse8bitCounters
+ ? IRB.CreatePointerCast(RealEightBitCounterArray, Int8PtrTy)
+ : Constant::getNullValue(Int8PtrTy),
+ IRB.CreatePointerCast(ModuleName, Int8PtrTy));
return true;
}
@@ -215,23 +265,28 @@ bool SanitizerCoverageModule::runOnFunction(Function &F) {
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 (CoverageLevel >= 4) {
CallSite CS(&Inst);
if (CS && !CS.getCalledFunction())
IndirCalls.push_back(&Inst);
}
+ if (ClExperimentalCMPTracing)
+ if (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) {
+bool SanitizerCoverageModule::InjectCoverage(Function &F,
+ ArrayRef<BasicBlock *> AllBlocks) {
if (!CoverageLevel) return false;
if (CoverageLevel == 1) {
@@ -241,7 +296,6 @@ SanitizerCoverageModule::InjectCoverage(Function &F,
InjectCoverageAtBlock(F, *BB,
ClCoverageBlockThreshold < AllBlocks.size());
}
- InjectCoverageForIndirectCalls(F, IndirCalls);
return true;
}
@@ -273,6 +327,32 @@ void SanitizerCoverageModule::InjectCoverageForIndirectCalls(
}
}
+void SanitizerCoverageModule::InjectTraceForCmp(
+ Function &F, ArrayRef<Instruction *> CmpTraceTargets) {
+ if (!ClExperimentalCMPTracing) return;
+ 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_indir_call((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::SetNoSanitizeMetada(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();
@@ -286,14 +366,15 @@ void SanitizerCoverageModule::InjectCoverageAtBlock(Function &F, BasicBlock &BB,
}
bool IsEntryBB = &BB == &F.getEntryBlock();
- DebugLoc EntryLoc =
- IsEntryBB ? IP->getDebugLoc().getFnDebugLoc(*C) : IP->getDebugLoc();
+ DebugLoc EntryLoc = IsEntryBB && !IP->getDebugLoc().isUnknown()
+ ? IP->getDebugLoc().getFnDebugLoc(*C)
+ : 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) {
@@ -302,8 +383,7 @@ void SanitizerCoverageModule::InjectCoverageAtBlock(Function &F, BasicBlock &BB,
LoadInst *Load = IRB.CreateLoad(GuardP);
Load->setAtomic(Monotonic);
Load->setAlignment(4);
- Load->setMetadata(F.getParent()->getMDKindID("nosanitize"),
- MDNode::get(*C, None));
+ SetNoSanitizeMetada(Load);
Value *Cmp = IRB.CreateICmpSGE(Constant::getNullValue(Load->getType()), Load);
Instruction *Ins = SplitBlockAndInsertIfThen(
Cmp, IP, false, MDBuilder(*C).createBranchWeights(1, 100000));
@@ -314,6 +394,19 @@ void SanitizerCoverageModule::InjectCoverageAtBlock(Function &F, BasicBlock &BB,
IRB.CreateCall(EmptyAsm); // Avoids callback merge.
}
+ if(ClUse8bitCounters) {
+ IRB.SetInsertPoint(IP);
+ Value *P = IRB.CreateAdd(
+ IRB.CreatePointerCast(EightBitCounterArray, IntptrTy),
+ ConstantInt::get(IntptrTy, NumberOfInstrumentedBlocks() - 1));
+ P = IRB.CreateIntToPtr(P, IRB.getInt8PtrTy());
+ LoadInst *LI = IRB.CreateLoad(P);
+ Value *Inc = IRB.CreateAdd(LI, ConstantInt::get(IRB.getInt8Ty(), 1));
+ StoreInst *SI = IRB.CreateStore(Inc, P);
+ SetNoSanitizeMetada(LI);
+ SetNoSanitizeMetada(SI);
+ }
+
if (ClExperimentalTracing) {
// Experimental support for tracing.
// Insert a callback with the same guard variable as used for coverage.
generated by cgit v1.1 at 2024-12-22 11:11:21 +0000