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Rollback assumeAligned in MemorySanitizer 

Summary: Rollback of parts of D71213. After digging more into the code I think we should leave 0 when creating the instructions (CreateMemcpy, CreateMaskedStore, CreateMaskedLoad). It's probably fine for MemorySanitizer because Alignement is resolved but I'm having a hard time convincing myself it has no impact at all (although tests are passing).

Reviewers: courbet

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D71332
This commit is contained in:
Guillaume Chatelet 2019-12-11 11:00:32 +01:00
parent 6e9c58946e
commit 3491109587
1 changed files with 22 additions and 18 deletions
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40
llvm/lib/Transforms/Instrumentation/MemorySanitizer.cpp
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@ -1405,10 +1405,9 @@ struct MemorySanitizerVisitor : public InstVisitor<MemorySanitizerVisitor> {
///
/// Shadow = ShadowBase + Offset
/// Origin = (OriginBase + Offset) & ~3ULL
std::pair<Value *, Value *> getShadowOriginPtrUserspace(Value *Addr,
IRBuilder<> &IRB,
Type *ShadowTy,
Align Alignment) {
std::pair<Value *, Value *>
getShadowOriginPtrUserspace(Value *Addr, IRBuilder<> &IRB, Type *ShadowTy,
MaybeAlign Alignment) {
Value *ShadowOffset = getShadowPtrOffset(Addr, IRB);
Value *ShadowLong = ShadowOffset;
uint64_t ShadowBase = MS.MapParams->ShadowBase;
@ -1426,7 +1425,7 @@ struct MemorySanitizerVisitor : public InstVisitor<MemorySanitizerVisitor> {
if (OriginBase != 0)
OriginLong = IRB.CreateAdd(OriginLong,
ConstantInt::get(MS.IntptrTy, OriginBase));
if (Alignment < kMinOriginAlignment) {
if (!Alignment || *Alignment < kMinOriginAlignment) {
uint64_t Mask = kMinOriginAlignment.value() - 1;
OriginLong =
IRB.CreateAnd(OriginLong, ConstantInt::get(MS.IntptrTy, ~Mask));
@ -1465,7 +1464,7 @@ struct MemorySanitizerVisitor : public InstVisitor<MemorySanitizerVisitor> {
std::pair<Value *, Value *> getShadowOriginPtr(Value *Addr, IRBuilder<> &IRB,
Type *ShadowTy,
Align Alignment,
MaybeAlign Alignment,
bool isStore) {
if (MS.CompileKernel)
return getShadowOriginPtrKernel(Addr, IRB, ShadowTy, isStore);
@ -2906,8 +2905,8 @@ struct MemorySanitizerVisitor : public InstVisitor<MemorySanitizerVisitor> {
IRBuilder<> IRB(&I);
Value *V = I.getArgOperand(0);
Value *Addr = I.getArgOperand(1);
const Align Alignment =
assumeAligned(cast<ConstantInt>(I.getArgOperand(2))->getZExtValue());
const MaybeAlign Alignment(
cast<ConstantInt>(I.getArgOperand(2))->getZExtValue());
Value *Mask = I.getArgOperand(3);
Value *Shadow = getShadow(V);
@ -2923,21 +2922,22 @@ struct MemorySanitizerVisitor : public InstVisitor<MemorySanitizerVisitor> {
insertShadowCheck(Mask, &I);
}
IRB.CreateMaskedStore(Shadow, ShadowPtr, Alignment.value(), Mask);
IRB.CreateMaskedStore(Shadow, ShadowPtr, Alignment ? Alignment->value() : 0,
Mask);
if (MS.TrackOrigins) {
auto &DL = F.getParent()->getDataLayout();
paintOrigin(IRB, getOrigin(V), OriginPtr,
DL.getTypeStoreSize(Shadow->getType()),
std::max(Alignment, kMinOriginAlignment));
llvm::max(Alignment, kMinOriginAlignment));
}
}
bool handleMaskedLoad(IntrinsicInst &I) {
IRBuilder<> IRB(&I);
Value *Addr = I.getArgOperand(0);
const Align Alignment =
assumeAligned(cast<ConstantInt>(I.getArgOperand(1))->getZExtValue());
const MaybeAlign Alignment(
cast<ConstantInt>(I.getArgOperand(1))->getZExtValue());
Value *Mask = I.getArgOperand(2);
Value *PassThru = I.getArgOperand(3);
@ -2946,8 +2946,9 @@ struct MemorySanitizerVisitor : public InstVisitor<MemorySanitizerVisitor> {
if (PropagateShadow) {
std::tie(ShadowPtr, OriginPtr) =
getShadowOriginPtr(Addr, IRB, ShadowTy, Alignment, /*isStore*/ false);
setShadow(&I, IRB.CreateMaskedLoad(ShadowPtr, Alignment.value(), Mask,
getShadow(PassThru), "_msmaskedld"));
setShadow(&I, IRB.CreateMaskedLoad(
ShadowPtr, Alignment ? Alignment->value() : 0, Mask,
getShadow(PassThru), "_msmaskedld"));
} else {
setShadow(&I, getCleanShadow(&I));
}
@ -3316,15 +3317,18 @@ struct MemorySanitizerVisitor : public InstVisitor<MemorySanitizerVisitor> {
"ByVal argument is not a pointer!");
Size = DL.getTypeAllocSize(A->getType()->getPointerElementType());
if (ArgOffset + Size > kParamTLSSize) break;
const Align ParamAlignment = assumeAligned(CS.getParamAlignment(i));
const Align Alignment = std::min(ParamAlignment, kShadowTLSAlignment);
const MaybeAlign ParamAlignment(CS.getParamAlignment(i));
MaybeAlign Alignment = llvm::None;
if (ParamAlignment)
Alignment = std::min(*ParamAlignment, kShadowTLSAlignment);
Value *AShadowPtr =
getShadowOriginPtr(A, IRB, IRB.getInt8Ty(), Alignment,
/*isStore*/ false)
.first;
Store = IRB.CreateMemCpy(ArgShadowBase, Alignment.value(), AShadowPtr,
Alignment.value(), Size);
Store = IRB.CreateMemCpy(ArgShadowBase,
Alignment ? Alignment->value() : 0, AShadowPtr,
Alignment ? Alignment->value() : 0, Size);
// TODO(glider): need to copy origins.
} else {
Size = DL.getTypeAllocSize(A->getType());