// The following flags disable parts of MSan instrumentation based on
// blacklist contents and command-line options.
bool InsertChecks;
- bool LoadShadow;
+ bool PropagateShadow;
bool PoisonStack;
bool PoisonUndef;
bool CheckReturnValue;
bool SanitizeFunction = F.getAttributes().hasAttribute(
AttributeSet::FunctionIndex, Attribute::SanitizeMemory);
InsertChecks = SanitizeFunction;
- LoadShadow = SanitizeFunction;
+ PropagateShadow = SanitizeFunction;
PoisonStack = SanitizeFunction && ClPoisonStack;
PoisonUndef = SanitizeFunction && ClPoisonUndef;
// FIXME: Consider using SpecialCaseList to specify a list of functions that
// Finalize PHI nodes.
for (PHINode *PN : ShadowPHINodes) {
+ Value *S = getShadow(PN);
+ if (isa<Constant>(S)) continue;
PHINode *PNS = cast<PHINode>(getShadow(PN));
PHINode *PNO = MS.TrackOrigins ? cast<PHINode>(getOrigin(PN)) : nullptr;
size_t NumValues = PN->getNumIncomingValues();
for (size_t v = 0; v < NumValues; v++) {
PNS->addIncoming(getShadow(PN, v), PN->getIncomingBlock(v));
- if (PNO)
- PNO->addIncoming(getOrigin(PN, v), PN->getIncomingBlock(v));
+ if (PNO) PNO->addIncoming(getOrigin(PN, v), PN->getIncomingBlock(v));
}
}
/// \brief Set SV to be the shadow value for V.
void setShadow(Value *V, Value *SV) {
assert(!ShadowMap.count(V) && "Values may only have one shadow");
- ShadowMap[V] = SV;
+ ShadowMap[V] = PropagateShadow ? SV : getCleanShadow(V);
}
/// \brief Set Origin to be the origin value for V.
/// This function either returns the value set earlier with setShadow,
/// or extracts if from ParamTLS (for function arguments).
Value *getShadow(Value *V) {
+ if (!PropagateShadow) return getCleanShadow(V);
if (Instruction *I = dyn_cast<Instruction>(V)) {
// For instructions the shadow is already stored in the map.
Value *Shadow = ShadowMap[V];
IRBuilder<> IRB(I.getNextNode());
Type *ShadowTy = getShadowTy(&I);
Value *Addr = I.getPointerOperand();
- if (LoadShadow) {
+ if (PropagateShadow) {
Value *ShadowPtr = getShadowPtr(Addr, ShadowTy, IRB);
setShadow(&I,
IRB.CreateAlignedLoad(ShadowPtr, I.getAlignment(), "_msld"));
I.setOrdering(addAcquireOrdering(I.getOrdering()));
if (MS.TrackOrigins) {
- if (LoadShadow) {
+ if (PropagateShadow) {
unsigned Alignment = std::max(kMinOriginAlignment, I.getAlignment());
setOrigin(&I,
IRB.CreateAlignedLoad(getOriginPtr(Addr, IRB), Alignment));
Value *Addr = I.getArgOperand(0);
Type *ShadowTy = getShadowTy(&I);
- if (LoadShadow) {
+ if (PropagateShadow) {
Value *ShadowPtr = getShadowPtr(Addr, ShadowTy, IRB);
// We don't know the pointer alignment (could be unaligned SSE load!).
// Have to assume to worst case.
insertShadowCheck(Addr, &I);
if (MS.TrackOrigins) {
- if (LoadShadow)
+ if (PropagateShadow)
setOrigin(&I, IRB.CreateLoad(getOriginPtr(Addr, IRB)));
else
setOrigin(&I, getCleanOrigin());