#include "llvm/ADT/StringExtras.h"
#include "llvm/Analysis/ValueTracking.h"
#include "llvm/IR/Dominators.h"
+#include "llvm/IR/DebugInfo.h"
#include "llvm/IR/IRBuilder.h"
#include "llvm/IR/InlineAsm.h"
#include "llvm/IR/InstVisitor.h"
std::unique_ptr<SpecialCaseList> SCL;
public:
- DFSanABIList(SpecialCaseList *SCL) : SCL(SCL) {}
+ DFSanABIList(std::unique_ptr<SpecialCaseList> SCL) : SCL(std::move(SCL)) {}
/// Returns whether either this function or its source file are listed in the
/// given category.
- bool isIn(const Function &F, const StringRef Category) const {
+ bool isIn(const Function &F, StringRef Category) const {
return isIn(*F.getParent(), Category) ||
SCL->inSection("fun", F.getName(), Category);
}
///
/// If GA aliases a function, the alias's name is matched as a function name
/// would be. Similarly, aliases of globals are matched like globals.
- bool isIn(const GlobalAlias &GA, const StringRef Category) const {
+ bool isIn(const GlobalAlias &GA, StringRef Category) const {
if (isIn(*GA.getParent(), Category))
return true;
}
/// Returns whether this module is listed in the given category.
- bool isIn(const Module &M, const StringRef Category) const {
+ bool isIn(const Module &M, StringRef Category) const {
return SCL->inSection("src", M.getModuleIdentifier(), Category);
}
};
FunctionType *DFSanUnimplementedFnTy;
FunctionType *DFSanSetLabelFnTy;
FunctionType *DFSanNonzeroLabelFnTy;
+ FunctionType *DFSanVarargWrapperFnTy;
Constant *DFSanUnionFn;
+ Constant *DFSanCheckedUnionFn;
Constant *DFSanUnionLoadFn;
Constant *DFSanUnimplementedFn;
Constant *DFSanSetLabelFn;
Constant *DFSanNonzeroLabelFn;
+ Constant *DFSanVarargWrapperFn;
MDNode *ColdCallWeights;
DFSanABIList ABIList;
DenseMap<Value *, Function *> UnwrappedFnMap;
AttributeSet ReadOnlyNoneAttrs;
+ DenseMap<const Function *, DISubprogram> FunctionDIs;
Value *getShadowAddress(Value *Addr, Instruction *Pos);
bool isInstrumented(const Function *F);
DenseMap<AllocaInst *, AllocaInst *> AllocaShadowMap;
std::vector<std::pair<PHINode *, PHINode *> > PHIFixups;
DenseSet<Instruction *> SkipInsts;
- DenseSet<Value *> NonZeroChecks;
+ std::vector<Value *> NonZeroChecks;
+ bool AvoidNewBlocks;
struct CachedCombinedShadow {
BasicBlock *Block;
IsNativeABI(IsNativeABI), ArgTLSPtr(nullptr), RetvalTLSPtr(nullptr),
LabelReturnAlloca(nullptr) {
DT.recalculate(*F);
+ // FIXME: Need to track down the register allocator issue which causes poor
+ // performance in pathological cases with large numbers of basic blocks.
+ AvoidNewBlocks = F->size() > 1000;
}
Value *getArgTLSPtr();
Value *getArgTLS(unsigned Index, Instruction *Pos);
}
FunctionType *DataFlowSanitizer::getCustomFunctionType(FunctionType *T) {
- assert(!T->isVarArg());
llvm::SmallVector<Type *, 4> ArgTypes;
for (FunctionType::param_iterator i = T->param_begin(), e = T->param_end();
i != e; ++i) {
}
for (unsigned i = 0, e = T->getNumParams(); i != e; ++i)
ArgTypes.push_back(ShadowTy);
+ if (T->isVarArg())
+ ArgTypes.push_back(ShadowPtrTy);
Type *RetType = T->getReturnType();
if (!RetType->isVoidTy())
ArgTypes.push_back(ShadowPtrTy);
- return FunctionType::get(T->getReturnType(), ArgTypes, false);
+ return FunctionType::get(T->getReturnType(), ArgTypes, T->isVarArg());
}
bool DataFlowSanitizer::doInitialization(Module &M) {
DFSanSetLabelFnTy = FunctionType::get(Type::getVoidTy(*Ctx),
DFSanSetLabelArgs, /*isVarArg=*/false);
DFSanNonzeroLabelFnTy = FunctionType::get(
- Type::getVoidTy(*Ctx), ArrayRef<Type *>(), /*isVarArg=*/false);
+ Type::getVoidTy(*Ctx), None, /*isVarArg=*/false);
+ DFSanVarargWrapperFnTy = FunctionType::get(
+ Type::getVoidTy(*Ctx), Type::getInt8PtrTy(*Ctx), /*isVarArg=*/false);
if (GetArgTLSPtr) {
Type *ArgTLSTy = ArrayType::get(ShadowTy, 64);
AttributeSet::ReturnIndex));
BasicBlock *BB = BasicBlock::Create(*Ctx, "entry", NewF);
- std::vector<Value *> Args;
- unsigned n = FT->getNumParams();
- for (Function::arg_iterator ai = NewF->arg_begin(); n != 0; ++ai, --n)
- Args.push_back(&*ai);
- CallInst *CI = CallInst::Create(F, Args, "", BB);
- if (FT->getReturnType()->isVoidTy())
- ReturnInst::Create(*Ctx, BB);
- else
- ReturnInst::Create(*Ctx, CI, BB);
+ if (F->isVarArg()) {
+ NewF->removeAttributes(
+ AttributeSet::FunctionIndex,
+ AttributeSet().addAttribute(*Ctx, AttributeSet::FunctionIndex,
+ "split-stack"));
+ CallInst::Create(DFSanVarargWrapperFn,
+ IRBuilder<>(BB).CreateGlobalStringPtr(F->getName()), "",
+ BB);
+ new UnreachableInst(*Ctx, BB);
+ } else {
+ std::vector<Value *> Args;
+ unsigned n = FT->getNumParams();
+ for (Function::arg_iterator ai = NewF->arg_begin(); n != 0; ++ai, --n)
+ Args.push_back(&*ai);
+ CallInst *CI = CallInst::Create(F, Args, "", BB);
+ if (FT->getReturnType()->isVoidTy())
+ ReturnInst::Create(*Ctx, BB);
+ else
+ ReturnInst::Create(*Ctx, CI, BB);
+ }
return NewF;
}
if (ABIList.isIn(M, "skip"))
return false;
+ FunctionDIs = makeSubprogramMap(M);
+
if (!GetArgTLSPtr) {
Type *ArgTLSTy = ArrayType::get(ShadowTy, 64);
ArgTLS = Mod->getOrInsertGlobal("__dfsan_arg_tls", ArgTLSTy);
DFSanUnionFn = Mod->getOrInsertFunction("__dfsan_union", DFSanUnionFnTy);
if (Function *F = dyn_cast<Function>(DFSanUnionFn)) {
+ F->addAttribute(AttributeSet::FunctionIndex, Attribute::NoUnwind);
+ F->addAttribute(AttributeSet::FunctionIndex, Attribute::ReadNone);
+ F->addAttribute(AttributeSet::ReturnIndex, Attribute::ZExt);
+ F->addAttribute(1, Attribute::ZExt);
+ F->addAttribute(2, Attribute::ZExt);
+ }
+ DFSanCheckedUnionFn = Mod->getOrInsertFunction("dfsan_union", DFSanUnionFnTy);
+ if (Function *F = dyn_cast<Function>(DFSanCheckedUnionFn)) {
+ F->addAttribute(AttributeSet::FunctionIndex, Attribute::NoUnwind);
F->addAttribute(AttributeSet::FunctionIndex, Attribute::ReadNone);
F->addAttribute(AttributeSet::ReturnIndex, Attribute::ZExt);
F->addAttribute(1, Attribute::ZExt);
DFSanUnionLoadFn =
Mod->getOrInsertFunction("__dfsan_union_load", DFSanUnionLoadFnTy);
if (Function *F = dyn_cast<Function>(DFSanUnionLoadFn)) {
+ F->addAttribute(AttributeSet::FunctionIndex, Attribute::NoUnwind);
F->addAttribute(AttributeSet::FunctionIndex, Attribute::ReadOnly);
F->addAttribute(AttributeSet::ReturnIndex, Attribute::ZExt);
}
}
DFSanNonzeroLabelFn =
Mod->getOrInsertFunction("__dfsan_nonzero_label", DFSanNonzeroLabelFnTy);
+ DFSanVarargWrapperFn = Mod->getOrInsertFunction("__dfsan_vararg_wrapper",
+ DFSanVarargWrapperFnTy);
std::vector<Function *> FnsToInstrument;
llvm::SmallPtrSet<Function *, 2> FnsWithNativeABI;
for (Module::iterator i = M.begin(), e = M.end(); i != e; ++i) {
if (!i->isIntrinsic() &&
i != DFSanUnionFn &&
+ i != DFSanCheckedUnionFn &&
i != DFSanUnionLoadFn &&
i != DFSanUnimplementedFn &&
i != DFSanSetLabelFn &&
- i != DFSanNonzeroLabelFn)
+ i != DFSanNonzeroLabelFn &&
+ i != DFSanVarargWrapperFn)
FnsToInstrument.push_back(&*i);
}
} else {
addGlobalNamePrefix(&F);
}
- // Hopefully, nobody will try to indirectly call a vararg
- // function... yet.
- } else if (FT->isVarArg()) {
- UnwrappedFnMap[&F] = &F;
- *i = nullptr;
} else if (!IsZeroArgsVoidRet || getWrapperKind(&F) == WK_Custom) {
// Build a wrapper function for F. The wrapper simply calls F, and is
// added to FnsToInstrument so that any instrumentation according to its
Value *WrappedFnCst =
ConstantExpr::getBitCast(NewF, PointerType::getUnqual(FT));
F.replaceAllUsesWith(WrappedFnCst);
+
+ // Patch the pointer to LLVM function in debug info descriptor.
+ auto DI = FunctionDIs.find(&F);
+ if (DI != FunctionDIs.end())
+ DI->second.replaceFunction(&F);
+
UnwrappedFnMap[WrappedFnCst] = &F;
*i = NewF;
i = FnsToInstrument.begin() + N;
e = FnsToInstrument.begin() + Count;
}
+ // Hopefully, nobody will try to indirectly call a vararg
+ // function... yet.
+ } else if (FT->isVarArg()) {
+ UnwrappedFnMap[&F] = &F;
+ *i = nullptr;
}
}
// yet). To make our life easier, do this work in a pass after the main
// instrumentation.
if (ClDebugNonzeroLabels) {
- for (DenseSet<Value *>::iterator i = DFSF.NonZeroChecks.begin(),
- e = DFSF.NonZeroChecks.end();
- i != e; ++i) {
+ for (Value *V : DFSF.NonZeroChecks) {
Instruction *Pos;
- if (Instruction *I = dyn_cast<Instruction>(*i))
+ if (Instruction *I = dyn_cast<Instruction>(V))
Pos = I->getNextNode();
else
Pos = DFSF.F->getEntryBlock().begin();
while (isa<PHINode>(Pos) || isa<AllocaInst>(Pos))
Pos = Pos->getNextNode();
IRBuilder<> IRB(Pos);
- Value *Ne = IRB.CreateICmpNE(*i, DFSF.DFS.ZeroShadow);
+ Value *Ne = IRB.CreateICmpNE(V, DFSF.DFS.ZeroShadow);
BranchInst *BI = cast<BranchInst>(SplitBlockAndInsertIfThen(
Ne, Pos, /*Unreachable=*/false, ColdCallWeights));
IRBuilder<> ThenIRB(BI);
break;
}
}
- NonZeroChecks.insert(Shadow);
+ NonZeroChecks.push_back(Shadow);
} else {
Shadow = DFS.ZeroShadow;
}
return CCS.Shadow;
IRBuilder<> IRB(Pos);
- BasicBlock *Head = Pos->getParent();
- Value *Ne = IRB.CreateICmpNE(V1, V2);
- BranchInst *BI = cast<BranchInst>(SplitBlockAndInsertIfThen(
- Ne, Pos, /*Unreachable=*/false, DFS.ColdCallWeights, &DT));
- IRBuilder<> ThenIRB(BI);
- CallInst *Call = ThenIRB.CreateCall2(DFS.DFSanUnionFn, V1, V2);
- Call->addAttribute(AttributeSet::ReturnIndex, Attribute::ZExt);
- Call->addAttribute(1, Attribute::ZExt);
- Call->addAttribute(2, Attribute::ZExt);
-
- BasicBlock *Tail = BI->getSuccessor(0);
- PHINode *Phi = PHINode::Create(DFS.ShadowTy, 2, "", Tail->begin());
- Phi->addIncoming(Call, Call->getParent());
- Phi->addIncoming(V1, Head);
-
- CCS.Block = Tail;
- CCS.Shadow = Phi;
+ if (AvoidNewBlocks) {
+ CallInst *Call = IRB.CreateCall2(DFS.DFSanCheckedUnionFn, V1, V2);
+ Call->addAttribute(AttributeSet::ReturnIndex, Attribute::ZExt);
+ Call->addAttribute(1, Attribute::ZExt);
+ Call->addAttribute(2, Attribute::ZExt);
+
+ CCS.Block = Pos->getParent();
+ CCS.Shadow = Call;
+ } else {
+ BasicBlock *Head = Pos->getParent();
+ Value *Ne = IRB.CreateICmpNE(V1, V2);
+ BranchInst *BI = cast<BranchInst>(SplitBlockAndInsertIfThen(
+ Ne, Pos, /*Unreachable=*/false, DFS.ColdCallWeights, &DT));
+ IRBuilder<> ThenIRB(BI);
+ CallInst *Call = ThenIRB.CreateCall2(DFS.DFSanUnionFn, V1, V2);
+ Call->addAttribute(AttributeSet::ReturnIndex, Attribute::ZExt);
+ Call->addAttribute(1, Attribute::ZExt);
+ Call->addAttribute(2, Attribute::ZExt);
+
+ BasicBlock *Tail = BI->getSuccessor(0);
+ PHINode *Phi = PHINode::Create(DFS.ShadowTy, 2, "", Tail->begin());
+ Phi->addIncoming(Call, Call->getParent());
+ Phi->addIncoming(V1, Head);
+
+ CCS.Block = Tail;
+ CCS.Shadow = Phi;
+ }
std::set<Value *> UnionElems;
if (V1Elems != ShadowElements.end()) {
} else {
UnionElems.insert(V2);
}
- ShadowElements[Phi] = std::move(UnionElems);
+ ShadowElements[CCS.Shadow] = std::move(UnionElems);
- return Phi;
+ return CCS.Shadow;
}
// A convenience function which folds the shadows of each of the operands
IRB.CreateAlignedLoad(ShadowAddr1, ShadowAlign), Pos);
}
}
- if (Size % (64 / DFS.ShadowWidth) == 0) {
+ if (!AvoidNewBlocks && Size % (64 / DFS.ShadowWidth) == 0) {
// Fast path for the common case where each byte has identical shadow: load
// shadow 64 bits at a time, fall out to a __dfsan_union_load call if any
// shadow is non-equal.
Shadow = DFSF.combineShadows(Shadow, PtrShadow, &LI);
}
if (Shadow != DFSF.DFS.ZeroShadow)
- DFSF.NonZeroChecks.insert(Shadow);
+ DFSF.NonZeroChecks.push_back(Shadow);
DFSF.setShadow(&LI, Shadow);
}
return;
}
+ // Calls to this function are synthesized in wrappers, and we shouldn't
+ // instrument them.
+ if (F == DFSF.DFS.DFSanVarargWrapperFn)
+ return;
+
+ assert(!(cast<FunctionType>(
+ CS.getCalledValue()->getType()->getPointerElementType())->isVarArg() &&
+ dyn_cast<InvokeInst>(CS.getInstruction())));
+
IRBuilder<> IRB(CS.getInstruction());
DenseMap<Value *, Function *>::iterator i =
for (unsigned n = FT->getNumParams(); n != 0; ++i, --n)
Args.push_back(DFSF.getShadow(*i));
+ if (FT->isVarArg()) {
+ auto LabelVAAlloca =
+ new AllocaInst(ArrayType::get(DFSF.DFS.ShadowTy,
+ CS.arg_size() - FT->getNumParams()),
+ "labelva", DFSF.F->getEntryBlock().begin());
+
+ for (unsigned n = 0; i != CS.arg_end(); ++i, ++n) {
+ auto LabelVAPtr = IRB.CreateStructGEP(LabelVAAlloca, n);
+ IRB.CreateStore(DFSF.getShadow(*i), LabelVAPtr);
+ }
+
+ Args.push_back(IRB.CreateStructGEP(LabelVAAlloca, 0));
+ }
+
if (!FT->getReturnType()->isVoidTy()) {
if (!DFSF.LabelReturnAlloca) {
DFSF.LabelReturnAlloca =
Args.push_back(DFSF.LabelReturnAlloca);
}
+ for (i = CS.arg_begin() + FT->getNumParams(); i != CS.arg_end(); ++i)
+ Args.push_back(*i);
+
CallInst *CustomCI = IRB.CreateCall(CustomF, Args);
CustomCI->setCallingConv(CI->getCallingConv());
CustomCI->setAttributes(CI->getAttributes());
LoadInst *LI = NextIRB.CreateLoad(DFSF.getRetvalTLS());
DFSF.SkipInsts.insert(LI);
DFSF.setShadow(CS.getInstruction(), LI);
- DFSF.NonZeroChecks.insert(LI);
+ DFSF.NonZeroChecks.push_back(LI);
}
}
ExtractValueInst::Create(NewCS.getInstruction(), 1, "", Next);
DFSF.SkipInsts.insert(ExShadow);
DFSF.setShadow(ExVal, ExShadow);
- DFSF.NonZeroChecks.insert(ExShadow);
+ DFSF.NonZeroChecks.push_back(ExShadow);
CS.getInstruction()->replaceAllUsesWith(ExVal);
}