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-rw-r--r--contrib/llvm/lib/Transforms/Instrumentation/MemorySanitizer.cpp537
1 files changed, 451 insertions, 86 deletions
diff --git a/contrib/llvm/lib/Transforms/Instrumentation/MemorySanitizer.cpp b/contrib/llvm/lib/Transforms/Instrumentation/MemorySanitizer.cpp
index 4e75904..d547adc 100644
--- a/contrib/llvm/lib/Transforms/Instrumentation/MemorySanitizer.cpp
+++ b/contrib/llvm/lib/Transforms/Instrumentation/MemorySanitizer.cpp
@@ -66,6 +66,31 @@
/// avoids storing origin to memory when a fully initialized value is stored.
/// This way it avoids needless overwritting origin of the 4-byte region on
/// a short (i.e. 1 byte) clean store, and it is also good for performance.
+///
+/// Atomic handling.
+///
+/// Ideally, every atomic store of application value should update the
+/// corresponding shadow location in an atomic way. Unfortunately, atomic store
+/// of two disjoint locations can not be done without severe slowdown.
+///
+/// Therefore, we implement an approximation that may err on the safe side.
+/// In this implementation, every atomically accessed location in the program
+/// may only change from (partially) uninitialized to fully initialized, but
+/// not the other way around. We load the shadow _after_ the application load,
+/// and we store the shadow _before_ the app store. Also, we always store clean
+/// shadow (if the application store is atomic). This way, if the store-load
+/// pair constitutes a happens-before arc, shadow store and load are correctly
+/// ordered such that the load will get either the value that was stored, or
+/// some later value (which is always clean).
+///
+/// This does not work very well with Compare-And-Swap (CAS) and
+/// Read-Modify-Write (RMW) operations. To follow the above logic, CAS and RMW
+/// must store the new shadow before the app operation, and load the shadow
+/// after the app operation. Computers don't work this way. Current
+/// implementation ignores the load aspect of CAS/RMW, always returning a clean
+/// value. It implements the store part as a simple atomic store by storing a
+/// clean shadow.
+
//===----------------------------------------------------------------------===//
#define DEBUG_TYPE "msan"
@@ -74,6 +99,7 @@
#include "llvm/ADT/DepthFirstIterator.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/SmallVector.h"
+#include "llvm/ADT/Triple.h"
#include "llvm/ADT/ValueMap.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/Function.h"
@@ -90,9 +116,9 @@
#include "llvm/Support/Debug.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Transforms/Utils/BasicBlockUtils.h"
-#include "llvm/Transforms/Utils/BlackList.h"
#include "llvm/Transforms/Utils/Local.h"
#include "llvm/Transforms/Utils/ModuleUtils.h"
+#include "llvm/Transforms/Utils/SpecialCaseList.h"
using namespace llvm;
@@ -156,6 +182,18 @@ static cl::opt<std::string> ClBlacklistFile("msan-blacklist",
cl::desc("File containing the list of functions where MemorySanitizer "
"should not report bugs"), cl::Hidden);
+// Experimental. Wraps all indirect calls in the instrumented code with
+// a call to the given function. This is needed to assist the dynamic
+// helper tool (MSanDR) to regain control on transition between instrumented and
+// non-instrumented code.
+static cl::opt<std::string> ClWrapIndirectCalls("msan-wrap-indirect-calls",
+ cl::desc("Wrap indirect calls with a given function"),
+ cl::Hidden);
+
+static cl::opt<bool> ClWrapIndirectCallsFast("msan-wrap-indirect-calls-fast",
+ cl::desc("Do not wrap indirect calls with target in the same module"),
+ cl::Hidden, cl::init(true));
+
namespace {
/// \brief An instrumentation pass implementing detection of uninitialized
@@ -167,12 +205,12 @@ class MemorySanitizer : public FunctionPass {
public:
MemorySanitizer(bool TrackOrigins = false,
StringRef BlacklistFile = StringRef())
- : FunctionPass(ID),
- TrackOrigins(TrackOrigins || ClTrackOrigins),
- TD(0),
- WarningFn(0),
- BlacklistFile(BlacklistFile.empty() ? ClBlacklistFile
- : BlacklistFile) { }
+ : FunctionPass(ID),
+ TrackOrigins(TrackOrigins || ClTrackOrigins),
+ TD(0),
+ WarningFn(0),
+ BlacklistFile(BlacklistFile.empty() ? ClBlacklistFile : BlacklistFile),
+ WrapIndirectCalls(!ClWrapIndirectCalls.empty()) {}
const char *getPassName() const { return "MemorySanitizer"; }
bool runOnFunction(Function &F);
bool doInitialization(Module &M);
@@ -206,13 +244,16 @@ class MemorySanitizer : public FunctionPass {
/// function.
GlobalVariable *OriginTLS;
+ GlobalVariable *MsandrModuleStart;
+ GlobalVariable *MsandrModuleEnd;
+
/// \brief The run-time callback to print a warning.
Value *WarningFn;
/// \brief Run-time helper that copies origin info for a memory range.
Value *MsanCopyOriginFn;
/// \brief Run-time helper that generates a new origin value for a stack
/// allocation.
- Value *MsanSetAllocaOriginFn;
+ Value *MsanSetAllocaOrigin4Fn;
/// \brief Run-time helper that poisons stack on function entry.
Value *MsanPoisonStackFn;
/// \brief MSan runtime replacements for memmove, memcpy and memset.
@@ -228,13 +269,19 @@ class MemorySanitizer : public FunctionPass {
MDNode *ColdCallWeights;
/// \brief Branch weights for origin store.
MDNode *OriginStoreWeights;
- /// \bried Path to blacklist file.
+ /// \brief Path to blacklist file.
SmallString<64> BlacklistFile;
/// \brief The blacklist.
- OwningPtr<BlackList> BL;
+ OwningPtr<SpecialCaseList> BL;
/// \brief An empty volatile inline asm that prevents callback merge.
InlineAsm *EmptyAsm;
+ bool WrapIndirectCalls;
+ /// \brief Run-time wrapper for indirect calls.
+ Value *IndirectCallWrapperFn;
+ // Argument and return type of IndirectCallWrapperFn: void (*f)(void).
+ Type *AnyFunctionPtrTy;
+
friend struct MemorySanitizerVisitor;
friend struct VarArgAMD64Helper;
};
@@ -280,9 +327,9 @@ void MemorySanitizer::initializeCallbacks(Module &M) {
MsanCopyOriginFn = M.getOrInsertFunction(
"__msan_copy_origin", IRB.getVoidTy(), IRB.getInt8PtrTy(),
IRB.getInt8PtrTy(), IntptrTy, NULL);
- MsanSetAllocaOriginFn = M.getOrInsertFunction(
- "__msan_set_alloca_origin", IRB.getVoidTy(), IRB.getInt8PtrTy(), IntptrTy,
- IRB.getInt8PtrTy(), NULL);
+ MsanSetAllocaOrigin4Fn = M.getOrInsertFunction(
+ "__msan_set_alloca_origin4", IRB.getVoidTy(), IRB.getInt8PtrTy(), IntptrTy,
+ IRB.getInt8PtrTy(), IntptrTy, NULL);
MsanPoisonStackFn = M.getOrInsertFunction(
"__msan_poison_stack", IRB.getVoidTy(), IRB.getInt8PtrTy(), IntptrTy, NULL);
MemmoveFn = M.getOrInsertFunction(
@@ -299,35 +346,53 @@ void MemorySanitizer::initializeCallbacks(Module &M) {
RetvalTLS = new GlobalVariable(
M, ArrayType::get(IRB.getInt64Ty(), 8), false,
GlobalVariable::ExternalLinkage, 0, "__msan_retval_tls", 0,
- GlobalVariable::GeneralDynamicTLSModel);
+ GlobalVariable::InitialExecTLSModel);
RetvalOriginTLS = new GlobalVariable(
M, OriginTy, false, GlobalVariable::ExternalLinkage, 0,
- "__msan_retval_origin_tls", 0, GlobalVariable::GeneralDynamicTLSModel);
+ "__msan_retval_origin_tls", 0, GlobalVariable::InitialExecTLSModel);
ParamTLS = new GlobalVariable(
M, ArrayType::get(IRB.getInt64Ty(), 1000), false,
GlobalVariable::ExternalLinkage, 0, "__msan_param_tls", 0,
- GlobalVariable::GeneralDynamicTLSModel);
+ GlobalVariable::InitialExecTLSModel);
ParamOriginTLS = new GlobalVariable(
M, ArrayType::get(OriginTy, 1000), false, GlobalVariable::ExternalLinkage,
- 0, "__msan_param_origin_tls", 0, GlobalVariable::GeneralDynamicTLSModel);
+ 0, "__msan_param_origin_tls", 0, GlobalVariable::InitialExecTLSModel);
VAArgTLS = new GlobalVariable(
M, ArrayType::get(IRB.getInt64Ty(), 1000), false,
GlobalVariable::ExternalLinkage, 0, "__msan_va_arg_tls", 0,
- GlobalVariable::GeneralDynamicTLSModel);
+ GlobalVariable::InitialExecTLSModel);
VAArgOverflowSizeTLS = new GlobalVariable(
M, IRB.getInt64Ty(), false, GlobalVariable::ExternalLinkage, 0,
"__msan_va_arg_overflow_size_tls", 0,
- GlobalVariable::GeneralDynamicTLSModel);
+ GlobalVariable::InitialExecTLSModel);
OriginTLS = new GlobalVariable(
M, IRB.getInt32Ty(), false, GlobalVariable::ExternalLinkage, 0,
- "__msan_origin_tls", 0, GlobalVariable::GeneralDynamicTLSModel);
+ "__msan_origin_tls", 0, GlobalVariable::InitialExecTLSModel);
// We insert an empty inline asm after __msan_report* to avoid callback merge.
EmptyAsm = InlineAsm::get(FunctionType::get(IRB.getVoidTy(), false),
StringRef(""), StringRef(""),
/*hasSideEffects=*/true);
+
+ if (WrapIndirectCalls) {
+ AnyFunctionPtrTy =
+ PointerType::getUnqual(FunctionType::get(IRB.getVoidTy(), false));
+ IndirectCallWrapperFn = M.getOrInsertFunction(
+ ClWrapIndirectCalls, AnyFunctionPtrTy, AnyFunctionPtrTy, NULL);
+ }
+
+ if (ClWrapIndirectCallsFast) {
+ MsandrModuleStart = new GlobalVariable(
+ M, IRB.getInt32Ty(), false, GlobalValue::ExternalLinkage,
+ 0, "__executable_start");
+ MsandrModuleStart->setVisibility(GlobalVariable::HiddenVisibility);
+ MsandrModuleEnd = new GlobalVariable(
+ M, IRB.getInt32Ty(), false, GlobalValue::ExternalLinkage,
+ 0, "_end");
+ MsandrModuleEnd->setVisibility(GlobalVariable::HiddenVisibility);
+ }
}
/// \brief Module-level initialization.
@@ -337,7 +402,7 @@ bool MemorySanitizer::doInitialization(Module &M) {
TD = getAnalysisIfAvailable<DataLayout>();
if (!TD)
return false;
- BL.reset(new BlackList(BlacklistFile));
+ BL.reset(SpecialCaseList::createOrDie(BlacklistFile));
C = &(M.getContext());
unsigned PtrSize = TD->getPointerSizeInBits(/* AddressSpace */0);
switch (PtrSize) {
@@ -365,11 +430,13 @@ bool MemorySanitizer::doInitialization(Module &M) {
appendToGlobalCtors(M, cast<Function>(M.getOrInsertFunction(
"__msan_init", IRB.getVoidTy(), NULL)), 0);
- new GlobalVariable(M, IRB.getInt32Ty(), true, GlobalValue::WeakODRLinkage,
- IRB.getInt32(TrackOrigins), "__msan_track_origins");
+ if (TrackOrigins)
+ new GlobalVariable(M, IRB.getInt32Ty(), true, GlobalValue::WeakODRLinkage,
+ IRB.getInt32(TrackOrigins), "__msan_track_origins");
- new GlobalVariable(M, IRB.getInt32Ty(), true, GlobalValue::WeakODRLinkage,
- IRB.getInt32(ClKeepGoing), "__msan_keep_going");
+ if (ClKeepGoing)
+ new GlobalVariable(M, IRB.getInt32Ty(), true, GlobalValue::WeakODRLinkage,
+ IRB.getInt32(ClKeepGoing), "__msan_keep_going");
return true;
}
@@ -420,27 +487,40 @@ struct MemorySanitizerVisitor : public InstVisitor<MemorySanitizerVisitor> {
MemorySanitizer &MS;
SmallVector<PHINode *, 16> ShadowPHINodes, OriginPHINodes;
ValueMap<Value*, Value*> ShadowMap, OriginMap;
+ OwningPtr<VarArgHelper> VAHelper;
+
+ // The following flags disable parts of MSan instrumentation based on
+ // blacklist contents and command-line options.
bool InsertChecks;
bool LoadShadow;
- OwningPtr<VarArgHelper> VAHelper;
+ bool PoisonStack;
+ bool PoisonUndef;
+ bool CheckReturnValue;
struct ShadowOriginAndInsertPoint {
- Instruction *Shadow;
- Instruction *Origin;
+ Value *Shadow;
+ Value *Origin;
Instruction *OrigIns;
- ShadowOriginAndInsertPoint(Instruction *S, Instruction *O, Instruction *I)
+ ShadowOriginAndInsertPoint(Value *S, Value *O, Instruction *I)
: Shadow(S), Origin(O), OrigIns(I) { }
ShadowOriginAndInsertPoint() : Shadow(0), Origin(0), OrigIns(0) { }
};
SmallVector<ShadowOriginAndInsertPoint, 16> InstrumentationList;
SmallVector<Instruction*, 16> StoreList;
+ SmallVector<CallSite, 16> IndirectCallList;
MemorySanitizerVisitor(Function &F, MemorySanitizer &MS)
: F(F), MS(MS), VAHelper(CreateVarArgHelper(F, MS, *this)) {
- LoadShadow = InsertChecks =
- !MS.BL->isIn(F) &&
- F.getAttributes().hasAttribute(AttributeSet::FunctionIndex,
- Attribute::SanitizeMemory);
+ bool SanitizeFunction = !MS.BL->isIn(F) && F.getAttributes().hasAttribute(
+ AttributeSet::FunctionIndex,
+ Attribute::SanitizeMemory);
+ InsertChecks = SanitizeFunction;
+ LoadShadow = SanitizeFunction;
+ PoisonStack = SanitizeFunction && ClPoisonStack;
+ PoisonUndef = SanitizeFunction && ClPoisonUndef;
+ // FIXME: Consider using SpecialCaseList to specify a list of functions that
+ // must always return fully initialized values. For now, we hardcode "main".
+ CheckReturnValue = SanitizeFunction && (F.getName() == "main");
DEBUG(if (!InsertChecks)
dbgs() << "MemorySanitizer is not inserting checks into '"
@@ -454,7 +534,7 @@ struct MemorySanitizerVisitor : public InstVisitor<MemorySanitizerVisitor> {
IRBuilder<> IRB(&I);
Value *Val = I.getValueOperand();
Value *Addr = I.getPointerOperand();
- Value *Shadow = getShadow(Val);
+ Value *Shadow = I.isAtomic() ? getCleanShadow(Val) : getShadow(Val);
Value *ShadowPtr = getShadowPtr(Addr, Shadow->getType(), IRB);
StoreInst *NewSI =
@@ -463,7 +543,10 @@ struct MemorySanitizerVisitor : public InstVisitor<MemorySanitizerVisitor> {
(void)NewSI;
if (ClCheckAccessAddress)
- insertCheck(Addr, &I);
+ insertShadowCheck(Addr, &I);
+
+ if (I.isAtomic())
+ I.setOrdering(addReleaseOrdering(I.getOrdering()));
if (MS.TrackOrigins) {
unsigned Alignment = std::max(kMinOriginAlignment, I.getAlignment());
@@ -473,11 +556,10 @@ struct MemorySanitizerVisitor : public InstVisitor<MemorySanitizerVisitor> {
} else {
Value *ConvertedShadow = convertToShadowTyNoVec(Shadow, IRB);
- Constant *Cst = dyn_cast_or_null<Constant>(ConvertedShadow);
// TODO(eugenis): handle non-zero constant shadow by inserting an
// unconditional check (can not simply fail compilation as this could
// be in the dead code).
- if (Cst)
+ if (isa<Constant>(ConvertedShadow))
continue;
Value *Cmp = IRB.CreateICmpNE(ConvertedShadow,
@@ -495,12 +577,15 @@ struct MemorySanitizerVisitor : public InstVisitor<MemorySanitizerVisitor> {
void materializeChecks() {
for (size_t i = 0, n = InstrumentationList.size(); i < n; i++) {
- Instruction *Shadow = InstrumentationList[i].Shadow;
+ Value *Shadow = InstrumentationList[i].Shadow;
Instruction *OrigIns = InstrumentationList[i].OrigIns;
IRBuilder<> IRB(OrigIns);
DEBUG(dbgs() << " SHAD0 : " << *Shadow << "\n");
Value *ConvertedShadow = convertToShadowTyNoVec(Shadow, IRB);
DEBUG(dbgs() << " SHAD1 : " << *ConvertedShadow << "\n");
+ // See the comment in materializeStores().
+ if (isa<Constant>(ConvertedShadow))
+ continue;
Value *Cmp = IRB.CreateICmpNE(ConvertedShadow,
getCleanShadow(ConvertedShadow), "_mscmp");
Instruction *CheckTerm =
@@ -510,7 +595,7 @@ struct MemorySanitizerVisitor : public InstVisitor<MemorySanitizerVisitor> {
IRB.SetInsertPoint(CheckTerm);
if (MS.TrackOrigins) {
- Instruction *Origin = InstrumentationList[i].Origin;
+ Value *Origin = InstrumentationList[i].Origin;
IRB.CreateStore(Origin ? (Value*)Origin : (Value*)IRB.getInt32(0),
MS.OriginTLS);
}
@@ -522,6 +607,48 @@ struct MemorySanitizerVisitor : public InstVisitor<MemorySanitizerVisitor> {
DEBUG(dbgs() << "DONE:\n" << F);
}
+ void materializeIndirectCalls() {
+ for (size_t i = 0, n = IndirectCallList.size(); i < n; i++) {
+ CallSite CS = IndirectCallList[i];
+ Instruction *I = CS.getInstruction();
+ BasicBlock *B = I->getParent();
+ IRBuilder<> IRB(I);
+ Value *Fn0 = CS.getCalledValue();
+ Value *Fn = IRB.CreateBitCast(Fn0, MS.AnyFunctionPtrTy);
+
+ if (ClWrapIndirectCallsFast) {
+ // Check that call target is inside this module limits.
+ Value *Start =
+ IRB.CreateBitCast(MS.MsandrModuleStart, MS.AnyFunctionPtrTy);
+ Value *End = IRB.CreateBitCast(MS.MsandrModuleEnd, MS.AnyFunctionPtrTy);
+
+ Value *NotInThisModule = IRB.CreateOr(IRB.CreateICmpULT(Fn, Start),
+ IRB.CreateICmpUGE(Fn, End));
+
+ PHINode *NewFnPhi =
+ IRB.CreatePHI(Fn0->getType(), 2, "msandr.indirect_target");
+
+ Instruction *CheckTerm = SplitBlockAndInsertIfThen(
+ cast<Instruction>(NotInThisModule),
+ /* Unreachable */ false, MS.ColdCallWeights);
+
+ IRB.SetInsertPoint(CheckTerm);
+ // Slow path: call wrapper function to possibly transform the call
+ // target.
+ Value *NewFn = IRB.CreateBitCast(
+ IRB.CreateCall(MS.IndirectCallWrapperFn, Fn), Fn0->getType());
+
+ NewFnPhi->addIncoming(Fn0, B);
+ NewFnPhi->addIncoming(NewFn, dyn_cast<Instruction>(NewFn)->getParent());
+ CS.setCalledFunction(NewFnPhi);
+ } else {
+ Value *NewFn = IRB.CreateBitCast(
+ IRB.CreateCall(MS.IndirectCallWrapperFn, Fn), Fn0->getType());
+ CS.setCalledFunction(NewFn);
+ }
+ }
+ }
+
/// \brief Add MemorySanitizer instrumentation to a function.
bool runOnFunction() {
MS.initializeCallbacks(*F.getParent());
@@ -564,6 +691,9 @@ struct MemorySanitizerVisitor : public InstVisitor<MemorySanitizerVisitor> {
// Insert shadow value checks.
materializeChecks();
+ // Wrap indirect calls.
+ materializeIndirectCalls();
+
return true;
}
@@ -741,7 +871,7 @@ struct MemorySanitizerVisitor : public InstVisitor<MemorySanitizerVisitor> {
return Shadow;
}
if (UndefValue *U = dyn_cast<UndefValue>(V)) {
- Value *AllOnes = ClPoisonUndef ? getPoisonedShadow(V) : getCleanShadow(V);
+ Value *AllOnes = PoisonUndef ? getPoisonedShadow(V) : getCleanShadow(V);
DEBUG(dbgs() << "Undef: " << *U << " ==> " << *AllOnes << "\n");
(void)U;
return AllOnes;
@@ -768,14 +898,21 @@ struct MemorySanitizerVisitor : public InstVisitor<MemorySanitizerVisitor> {
if (AI->hasByValAttr()) {
// ByVal pointer itself has clean shadow. We copy the actual
// argument shadow to the underlying memory.
+ // Figure out maximal valid memcpy alignment.
+ unsigned ArgAlign = AI->getParamAlignment();
+ if (ArgAlign == 0) {
+ Type *EltType = A->getType()->getPointerElementType();
+ ArgAlign = MS.TD->getABITypeAlignment(EltType);
+ }
+ unsigned CopyAlign = std::min(ArgAlign, kShadowTLSAlignment);
Value *Cpy = EntryIRB.CreateMemCpy(
- getShadowPtr(V, EntryIRB.getInt8Ty(), EntryIRB),
- Base, Size, AI->getParamAlignment());
+ getShadowPtr(V, EntryIRB.getInt8Ty(), EntryIRB), Base, Size,
+ CopyAlign);
DEBUG(dbgs() << " ByValCpy: " << *Cpy << "\n");
(void)Cpy;
*ShadowPtr = getCleanShadow(V);
} else {
- *ShadowPtr = EntryIRB.CreateLoad(Base);
+ *ShadowPtr = EntryIRB.CreateAlignedLoad(Base, kShadowTLSAlignment);
}
DEBUG(dbgs() << " ARG: " << *AI << " ==> " <<
**ShadowPtr << "\n");
@@ -784,7 +921,7 @@ struct MemorySanitizerVisitor : public InstVisitor<MemorySanitizerVisitor> {
setOrigin(A, EntryIRB.CreateLoad(OriginPtr));
}
}
- ArgOffset += DataLayout::RoundUpAlignment(Size, 8);
+ ArgOffset += DataLayout::RoundUpAlignment(Size, kShadowTLSAlignment);
}
assert(*ShadowPtr && "Could not find shadow for an argument");
return *ShadowPtr;
@@ -820,20 +957,63 @@ struct MemorySanitizerVisitor : public InstVisitor<MemorySanitizerVisitor> {
/// \brief Remember the place where a shadow check should be inserted.
///
/// This location will be later instrumented with a check that will print a
- /// UMR warning in runtime if the value is not fully defined.
- void insertCheck(Value *Val, Instruction *OrigIns) {
- assert(Val);
+ /// UMR warning in runtime if the shadow value is not 0.
+ void insertShadowCheck(Value *Shadow, Value *Origin, Instruction *OrigIns) {
+ assert(Shadow);
if (!InsertChecks) return;
- Instruction *Shadow = dyn_cast_or_null<Instruction>(getShadow(Val));
- if (!Shadow) return;
#ifndef NDEBUG
Type *ShadowTy = Shadow->getType();
assert((isa<IntegerType>(ShadowTy) || isa<VectorType>(ShadowTy)) &&
"Can only insert checks for integer and vector shadow types");
#endif
- Instruction *Origin = dyn_cast_or_null<Instruction>(getOrigin(Val));
InstrumentationList.push_back(
- ShadowOriginAndInsertPoint(Shadow, Origin, OrigIns));
+ ShadowOriginAndInsertPoint(Shadow, Origin, OrigIns));
+ }
+
+ /// \brief Remember the place where a shadow check should be inserted.
+ ///
+ /// This location will be later instrumented with a check that will print a
+ /// UMR warning in runtime if the value is not fully defined.
+ void insertShadowCheck(Value *Val, Instruction *OrigIns) {
+ assert(Val);
+ Instruction *Shadow = dyn_cast_or_null<Instruction>(getShadow(Val));
+ if (!Shadow) return;
+ Instruction *Origin = dyn_cast_or_null<Instruction>(getOrigin(Val));
+ insertShadowCheck(Shadow, Origin, OrigIns);
+ }
+
+ AtomicOrdering addReleaseOrdering(AtomicOrdering a) {
+ switch (a) {
+ case NotAtomic:
+ return NotAtomic;
+ case Unordered:
+ case Monotonic:
+ case Release:
+ return Release;
+ case Acquire:
+ case AcquireRelease:
+ return AcquireRelease;
+ case SequentiallyConsistent:
+ return SequentiallyConsistent;
+ }
+ llvm_unreachable("Unknown ordering");
+ }
+
+ AtomicOrdering addAcquireOrdering(AtomicOrdering a) {
+ switch (a) {
+ case NotAtomic:
+ return NotAtomic;
+ case Unordered:
+ case Monotonic:
+ case Acquire:
+ return Acquire;
+ case Release:
+ case AcquireRelease:
+ return AcquireRelease;
+ case SequentiallyConsistent:
+ return SequentiallyConsistent;
+ }
+ llvm_unreachable("Unknown ordering");
}
// ------------------- Visitors.
@@ -844,7 +1024,7 @@ struct MemorySanitizerVisitor : public InstVisitor<MemorySanitizerVisitor> {
/// Optionally, checks that the load address is fully defined.
void visitLoadInst(LoadInst &I) {
assert(I.getType()->isSized() && "Load type must have size");
- IRBuilder<> IRB(&I);
+ IRBuilder<> IRB(I.getNextNode());
Type *ShadowTy = getShadowTy(&I);
Value *Addr = I.getPointerOperand();
if (LoadShadow) {
@@ -856,7 +1036,10 @@ struct MemorySanitizerVisitor : public InstVisitor<MemorySanitizerVisitor> {
}
if (ClCheckAccessAddress)
- insertCheck(I.getPointerOperand(), &I);
+ insertShadowCheck(I.getPointerOperand(), &I);
+
+ if (I.isAtomic())
+ I.setOrdering(addAcquireOrdering(I.getOrdering()));
if (MS.TrackOrigins) {
if (LoadShadow) {
@@ -877,9 +1060,40 @@ struct MemorySanitizerVisitor : public InstVisitor<MemorySanitizerVisitor> {
StoreList.push_back(&I);
}
+ void handleCASOrRMW(Instruction &I) {
+ assert(isa<AtomicRMWInst>(I) || isa<AtomicCmpXchgInst>(I));
+
+ IRBuilder<> IRB(&I);
+ Value *Addr = I.getOperand(0);
+ Value *ShadowPtr = getShadowPtr(Addr, I.getType(), IRB);
+
+ if (ClCheckAccessAddress)
+ insertShadowCheck(Addr, &I);
+
+ // Only test the conditional argument of cmpxchg instruction.
+ // The other argument can potentially be uninitialized, but we can not
+ // detect this situation reliably without possible false positives.
+ if (isa<AtomicCmpXchgInst>(I))
+ insertShadowCheck(I.getOperand(1), &I);
+
+ IRB.CreateStore(getCleanShadow(&I), ShadowPtr);
+
+ setShadow(&I, getCleanShadow(&I));
+ }
+
+ void visitAtomicRMWInst(AtomicRMWInst &I) {
+ handleCASOrRMW(I);
+ I.setOrdering(addReleaseOrdering(I.getOrdering()));
+ }
+
+ void visitAtomicCmpXchgInst(AtomicCmpXchgInst &I) {
+ handleCASOrRMW(I);
+ I.setOrdering(addReleaseOrdering(I.getOrdering()));
+ }
+
// Vector manipulation.
void visitExtractElementInst(ExtractElementInst &I) {
- insertCheck(I.getOperand(1), &I);
+ insertShadowCheck(I.getOperand(1), &I);
IRBuilder<> IRB(&I);
setShadow(&I, IRB.CreateExtractElement(getShadow(&I, 0), I.getOperand(1),
"_msprop"));
@@ -887,7 +1101,7 @@ struct MemorySanitizerVisitor : public InstVisitor<MemorySanitizerVisitor> {
}
void visitInsertElementInst(InsertElementInst &I) {
- insertCheck(I.getOperand(2), &I);
+ insertShadowCheck(I.getOperand(2), &I);
IRBuilder<> IRB(&I);
setShadow(&I, IRB.CreateInsertElement(getShadow(&I, 0), getShadow(&I, 1),
I.getOperand(2), "_msprop"));
@@ -895,7 +1109,7 @@ struct MemorySanitizerVisitor : public InstVisitor<MemorySanitizerVisitor> {
}
void visitShuffleVectorInst(ShuffleVectorInst &I) {
- insertCheck(I.getOperand(2), &I);
+ insertShadowCheck(I.getOperand(2), &I);
IRBuilder<> IRB(&I);
setShadow(&I, IRB.CreateShuffleVector(getShadow(&I, 0), getShadow(&I, 1),
I.getOperand(2), "_msprop"));
@@ -1094,18 +1308,19 @@ struct MemorySanitizerVisitor : public InstVisitor<MemorySanitizerVisitor> {
/// \brief Cast between two shadow types, extending or truncating as
/// necessary.
- Value *CreateShadowCast(IRBuilder<> &IRB, Value *V, Type *dstTy) {
+ Value *CreateShadowCast(IRBuilder<> &IRB, Value *V, Type *dstTy,
+ bool Signed = false) {
Type *srcTy = V->getType();
if (dstTy->isIntegerTy() && srcTy->isIntegerTy())
- return IRB.CreateIntCast(V, dstTy, false);
+ return IRB.CreateIntCast(V, dstTy, Signed);
if (dstTy->isVectorTy() && srcTy->isVectorTy() &&
dstTy->getVectorNumElements() == srcTy->getVectorNumElements())
- return IRB.CreateIntCast(V, dstTy, false);
+ return IRB.CreateIntCast(V, dstTy, Signed);
size_t srcSizeInBits = VectorOrPrimitiveTypeSizeInBits(srcTy);
size_t dstSizeInBits = VectorOrPrimitiveTypeSizeInBits(dstTy);
Value *V1 = IRB.CreateBitCast(V, Type::getIntNTy(*MS.C, srcSizeInBits));
Value *V2 =
- IRB.CreateIntCast(V1, Type::getIntNTy(*MS.C, dstSizeInBits), false);
+ IRB.CreateIntCast(V1, Type::getIntNTy(*MS.C, dstSizeInBits), Signed);
return IRB.CreateBitCast(V2, dstTy);
// TODO: handle struct types.
}
@@ -1130,7 +1345,7 @@ struct MemorySanitizerVisitor : public InstVisitor<MemorySanitizerVisitor> {
void handleDiv(Instruction &I) {
IRBuilder<> IRB(&I);
// Strict on the second argument.
- insertCheck(I.getOperand(1), &I);
+ insertShadowCheck(I.getOperand(1), &I);
setShadow(&I, getShadow(&I, 0));
setOrigin(&I, getOrigin(&I, 0));
}
@@ -1413,7 +1628,7 @@ struct MemorySanitizerVisitor : public InstVisitor<MemorySanitizerVisitor> {
IRB.CreateAlignedStore(Shadow, ShadowPtr, 1);
if (ClCheckAccessAddress)
- insertCheck(Addr, &I);
+ insertShadowCheck(Addr, &I);
// FIXME: use ClStoreCleanOrigin
// FIXME: factor out common code from materializeStores
@@ -1440,9 +1655,8 @@ struct MemorySanitizerVisitor : public InstVisitor<MemorySanitizerVisitor> {
setShadow(&I, getCleanShadow(&I));
}
-
if (ClCheckAccessAddress)
- insertCheck(Addr, &I);
+ insertShadowCheck(Addr, &I);
if (MS.TrackOrigins) {
if (LoadShadow)
@@ -1539,11 +1753,119 @@ struct MemorySanitizerVisitor : public InstVisitor<MemorySanitizerVisitor> {
setOrigin(&I, getOrigin(Op));
}
+ // \brief Instrument vector convert instrinsic.
+ //
+ // This function instruments intrinsics like cvtsi2ss:
+ // %Out = int_xxx_cvtyyy(%ConvertOp)
+ // or
+ // %Out = int_xxx_cvtyyy(%CopyOp, %ConvertOp)
+ // Intrinsic converts \p NumUsedElements elements of \p ConvertOp to the same
+ // number \p Out elements, and (if has 2 arguments) copies the rest of the
+ // elements from \p CopyOp.
+ // In most cases conversion involves floating-point value which may trigger a
+ // hardware exception when not fully initialized. For this reason we require
+ // \p ConvertOp[0:NumUsedElements] to be fully initialized and trap otherwise.
+ // We copy the shadow of \p CopyOp[NumUsedElements:] to \p
+ // Out[NumUsedElements:]. This means that intrinsics without \p CopyOp always
+ // return a fully initialized value.
+ void handleVectorConvertIntrinsic(IntrinsicInst &I, int NumUsedElements) {
+ IRBuilder<> IRB(&I);
+ Value *CopyOp, *ConvertOp;
+
+ switch (I.getNumArgOperands()) {
+ case 2:
+ CopyOp = I.getArgOperand(0);
+ ConvertOp = I.getArgOperand(1);
+ break;
+ case 1:
+ ConvertOp = I.getArgOperand(0);
+ CopyOp = NULL;
+ break;
+ default:
+ llvm_unreachable("Cvt intrinsic with unsupported number of arguments.");
+ }
+
+ // The first *NumUsedElements* elements of ConvertOp are converted to the
+ // same number of output elements. The rest of the output is copied from
+ // CopyOp, or (if not available) filled with zeroes.
+ // Combine shadow for elements of ConvertOp that are used in this operation,
+ // and insert a check.
+ // FIXME: consider propagating shadow of ConvertOp, at least in the case of
+ // int->any conversion.
+ Value *ConvertShadow = getShadow(ConvertOp);
+ Value *AggShadow = 0;
+ if (ConvertOp->getType()->isVectorTy()) {
+ AggShadow = IRB.CreateExtractElement(
+ ConvertShadow, ConstantInt::get(IRB.getInt32Ty(), 0));
+ for (int i = 1; i < NumUsedElements; ++i) {
+ Value *MoreShadow = IRB.CreateExtractElement(
+ ConvertShadow, ConstantInt::get(IRB.getInt32Ty(), i));
+ AggShadow = IRB.CreateOr(AggShadow, MoreShadow);
+ }
+ } else {
+ AggShadow = ConvertShadow;
+ }
+ assert(AggShadow->getType()->isIntegerTy());
+ insertShadowCheck(AggShadow, getOrigin(ConvertOp), &I);
+
+ // Build result shadow by zero-filling parts of CopyOp shadow that come from
+ // ConvertOp.
+ if (CopyOp) {
+ assert(CopyOp->getType() == I.getType());
+ assert(CopyOp->getType()->isVectorTy());
+ Value *ResultShadow = getShadow(CopyOp);
+ Type *EltTy = ResultShadow->getType()->getVectorElementType();
+ for (int i = 0; i < NumUsedElements; ++i) {
+ ResultShadow = IRB.CreateInsertElement(
+ ResultShadow, ConstantInt::getNullValue(EltTy),
+ ConstantInt::get(IRB.getInt32Ty(), i));
+ }
+ setShadow(&I, ResultShadow);
+ setOrigin(&I, getOrigin(CopyOp));
+ } else {
+ setShadow(&I, getCleanShadow(&I));
+ }
+ }
+
void visitIntrinsicInst(IntrinsicInst &I) {
switch (I.getIntrinsicID()) {
case llvm::Intrinsic::bswap:
handleBswap(I);
break;
+ case llvm::Intrinsic::x86_avx512_cvtsd2usi64:
+ case llvm::Intrinsic::x86_avx512_cvtsd2usi:
+ case llvm::Intrinsic::x86_avx512_cvtss2usi64:
+ case llvm::Intrinsic::x86_avx512_cvtss2usi:
+ case llvm::Intrinsic::x86_avx512_cvttss2usi64:
+ case llvm::Intrinsic::x86_avx512_cvttss2usi:
+ case llvm::Intrinsic::x86_avx512_cvttsd2usi64:
+ case llvm::Intrinsic::x86_avx512_cvttsd2usi:
+ case llvm::Intrinsic::x86_avx512_cvtusi2sd:
+ case llvm::Intrinsic::x86_avx512_cvtusi2ss:
+ case llvm::Intrinsic::x86_avx512_cvtusi642sd:
+ case llvm::Intrinsic::x86_avx512_cvtusi642ss:
+ case llvm::Intrinsic::x86_sse2_cvtsd2si64:
+ case llvm::Intrinsic::x86_sse2_cvtsd2si:
+ case llvm::Intrinsic::x86_sse2_cvtsd2ss:
+ case llvm::Intrinsic::x86_sse2_cvtsi2sd:
+ case llvm::Intrinsic::x86_sse2_cvtsi642sd:
+ case llvm::Intrinsic::x86_sse2_cvtss2sd:
+ case llvm::Intrinsic::x86_sse2_cvttsd2si64:
+ case llvm::Intrinsic::x86_sse2_cvttsd2si:
+ case llvm::Intrinsic::x86_sse_cvtsi2ss:
+ case llvm::Intrinsic::x86_sse_cvtsi642ss:
+ case llvm::Intrinsic::x86_sse_cvtss2si64:
+ case llvm::Intrinsic::x86_sse_cvtss2si:
+ case llvm::Intrinsic::x86_sse_cvttss2si64:
+ case llvm::Intrinsic::x86_sse_cvttss2si:
+ handleVectorConvertIntrinsic(I, 1);
+ break;
+ case llvm::Intrinsic::x86_sse2_cvtdq2pd:
+ case llvm::Intrinsic::x86_sse2_cvtps2pd:
+ case llvm::Intrinsic::x86_sse_cvtps2pi:
+ case llvm::Intrinsic::x86_sse_cvttps2pi:
+ handleVectorConvertIntrinsic(I, 2);
+ break;
default:
if (!handleUnknownIntrinsic(I))
visitInstruction(I);
@@ -1589,6 +1911,10 @@ struct MemorySanitizerVisitor : public InstVisitor<MemorySanitizerVisitor> {
}
}
IRBuilder<> IRB(&I);
+
+ if (MS.WrapIndirectCalls && !CS.getCalledFunction())
+ IndirectCallList.push_back(CS);
+
unsigned ArgOffset = 0;
DEBUG(dbgs() << " CallSite: " << I << "\n");
for (CallSite::arg_iterator ArgIt = CS.arg_begin(), End = CS.arg_end();
@@ -1632,7 +1958,7 @@ struct MemorySanitizerVisitor : public InstVisitor<MemorySanitizerVisitor> {
DEBUG(dbgs() << " done with call args\n");
FunctionType *FT =
- cast<FunctionType>(CS.getCalledValue()->getType()-> getContainedType(0));
+ cast<FunctionType>(CS.getCalledValue()->getType()->getContainedType(0));
if (FT->isVarArg()) {
VAHelper->visitCallSite(CS, IRB);
}
@@ -1671,12 +1997,17 @@ struct MemorySanitizerVisitor : public InstVisitor<MemorySanitizerVisitor> {
void visitReturnInst(ReturnInst &I) {
IRBuilder<> IRB(&I);
- if (Value *RetVal = I.getReturnValue()) {
- // Set the shadow for the RetVal.
+ Value *RetVal = I.getReturnValue();
+ if (!RetVal) return;
+ Value *ShadowPtr = getShadowPtrForRetval(RetVal, IRB);
+ if (CheckReturnValue) {
+ insertShadowCheck(RetVal, &I);
+ Value *Shadow = getCleanShadow(RetVal);
+ IRB.CreateAlignedStore(Shadow, ShadowPtr, kShadowTLSAlignment);
+ } else {
Value *Shadow = getShadow(RetVal);
- Value *ShadowPtr = getShadowPtrForRetval(RetVal, IRB);
- DEBUG(dbgs() << "Return: " << *Shadow << "\n" << *ShadowPtr << "\n");
IRB.CreateAlignedStore(Shadow, ShadowPtr, kShadowTLSAlignment);
+ // FIXME: make it conditional if ClStoreCleanOrigin==0
if (MS.TrackOrigins)
IRB.CreateStore(getOrigin(RetVal), getOriginPtrForRetval(IRB));
}
@@ -1694,20 +2025,19 @@ struct MemorySanitizerVisitor : public InstVisitor<MemorySanitizerVisitor> {
void visitAllocaInst(AllocaInst &I) {
setShadow(&I, getCleanShadow(&I));
- if (!ClPoisonStack) return;
IRBuilder<> IRB(I.getNextNode());
uint64_t Size = MS.TD->getTypeAllocSize(I.getAllocatedType());
- if (ClPoisonStackWithCall) {
+ if (PoisonStack && ClPoisonStackWithCall) {
IRB.CreateCall2(MS.MsanPoisonStackFn,
IRB.CreatePointerCast(&I, IRB.getInt8PtrTy()),
ConstantInt::get(MS.IntptrTy, Size));
} else {
Value *ShadowBase = getShadowPtr(&I, Type::getInt8PtrTy(*MS.C), IRB);
- IRB.CreateMemSet(ShadowBase, IRB.getInt8(ClPoisonStackPattern),
- Size, I.getAlignment());
+ Value *PoisonValue = IRB.getInt8(PoisonStack ? ClPoisonStackPattern : 0);
+ IRB.CreateMemSet(ShadowBase, PoisonValue, Size, I.getAlignment());
}
- if (MS.TrackOrigins) {
+ if (PoisonStack && MS.TrackOrigins) {
setOrigin(&I, getCleanOrigin());
SmallString<2048> StackDescriptionStorage;
raw_svector_ostream StackDescription(StackDescriptionStorage);
@@ -1720,18 +2050,34 @@ struct MemorySanitizerVisitor : public InstVisitor<MemorySanitizerVisitor> {
Value *Descr =
createPrivateNonConstGlobalForString(*F.getParent(),
StackDescription.str());
- IRB.CreateCall3(MS.MsanSetAllocaOriginFn,
+
+ IRB.CreateCall4(MS.MsanSetAllocaOrigin4Fn,
IRB.CreatePointerCast(&I, IRB.getInt8PtrTy()),
ConstantInt::get(MS.IntptrTy, Size),
- IRB.CreatePointerCast(Descr, IRB.getInt8PtrTy()));
+ IRB.CreatePointerCast(Descr, IRB.getInt8PtrTy()),
+ IRB.CreatePointerCast(&F, MS.IntptrTy));
}
}
void visitSelectInst(SelectInst& I) {
IRBuilder<> IRB(&I);
- setShadow(&I, IRB.CreateSelect(I.getCondition(),
- getShadow(I.getTrueValue()), getShadow(I.getFalseValue()),
- "_msprop"));
+ // a = select b, c, d
+ Value *S = IRB.CreateSelect(I.getCondition(), getShadow(I.getTrueValue()),
+ getShadow(I.getFalseValue()));
+ if (I.getType()->isAggregateType()) {
+ // To avoid "sign extending" i1 to an arbitrary aggregate type, we just do
+ // an extra "select". This results in much more compact IR.
+ // Sa = select Sb, poisoned, (select b, Sc, Sd)
+ S = IRB.CreateSelect(getShadow(I.getCondition()),
+ getPoisonedShadow(getShadowTy(I.getType())), S,
+ "_msprop_select_agg");
+ } else {
+ // Sa = (sext Sb) | (select b, Sc, Sd)
+ S = IRB.CreateOr(S, CreateShadowCast(IRB, getShadow(I.getCondition()),
+ S->getType(), true),
+ "_msprop_select");
+ }
+ setShadow(&I, S);
if (MS.TrackOrigins) {
// Origins are always i32, so any vector conditions must be flattened.
// FIXME: consider tracking vector origins for app vectors?
@@ -1766,7 +2112,7 @@ struct MemorySanitizerVisitor : public InstVisitor<MemorySanitizerVisitor> {
Value *ResShadow = IRB.CreateExtractValue(AggShadow, I.getIndices());
DEBUG(dbgs() << " ResShadow: " << *ResShadow << "\n");
setShadow(&I, ResShadow);
- setOrigin(&I, getCleanOrigin());
+ setOriginForNaryOp(I);
}
void visitInsertValueInst(InsertValueInst &I) {
@@ -1779,7 +2125,7 @@ struct MemorySanitizerVisitor : public InstVisitor<MemorySanitizerVisitor> {
Value *Res = IRB.CreateInsertValue(AggShadow, InsShadow, I.getIndices());
DEBUG(dbgs() << " Res: " << *Res << "\n");
setShadow(&I, Res);
- setOrigin(&I, getCleanOrigin());
+ setOriginForNaryOp(I);
}
void dumpInst(Instruction &I) {
@@ -1802,7 +2148,7 @@ struct MemorySanitizerVisitor : public InstVisitor<MemorySanitizerVisitor> {
dumpInst(I);
DEBUG(dbgs() << "DEFAULT: " << I << "\n");
for (size_t i = 0, n = I.getNumOperands(); i < n; i++)
- insertCheck(I.getOperand(i), &I);
+ insertShadowCheck(I.getOperand(i), &I);
setShadow(&I, getCleanShadow(&I));
setOrigin(&I, getCleanOrigin());
}
@@ -1956,16 +2302,35 @@ struct VarArgAMD64Helper : public VarArgHelper {
Value *OverflowArgAreaPtr = IRB.CreateLoad(OverflowArgAreaPtrPtr);
Value *OverflowArgAreaShadowPtr =
MSV.getShadowPtr(OverflowArgAreaPtr, IRB.getInt8Ty(), IRB);
- Value *SrcPtr =
- getShadowPtrForVAArgument(VAArgTLSCopy, IRB, AMD64FpEndOffset);
+ Value *SrcPtr = IRB.CreateConstGEP1_32(VAArgTLSCopy, AMD64FpEndOffset);
IRB.CreateMemCpy(OverflowArgAreaShadowPtr, SrcPtr, VAArgOverflowSize, 16);
}
}
};
-VarArgHelper* CreateVarArgHelper(Function &Func, MemorySanitizer &Msan,
+/// \brief A no-op implementation of VarArgHelper.
+struct VarArgNoOpHelper : public VarArgHelper {
+ VarArgNoOpHelper(Function &F, MemorySanitizer &MS,
+ MemorySanitizerVisitor &MSV) {}
+
+ void visitCallSite(CallSite &CS, IRBuilder<> &IRB) {}
+
+ void visitVAStartInst(VAStartInst &I) {}
+
+ void visitVACopyInst(VACopyInst &I) {}
+
+ void finalizeInstrumentation() {}
+};
+
+VarArgHelper *CreateVarArgHelper(Function &Func, MemorySanitizer &Msan,
MemorySanitizerVisitor &Visitor) {
- return new VarArgAMD64Helper(Func, Msan, Visitor);
+ // VarArg handling is only implemented on AMD64. False positives are possible
+ // on other platforms.
+ llvm::Triple TargetTriple(Func.getParent()->getTargetTriple());
+ if (TargetTriple.getArch() == llvm::Triple::x86_64)
+ return new VarArgAMD64Helper(Func, Msan, Visitor);
+ else
+ return new VarArgNoOpHelper(Func, Msan, Visitor);
}
} // namespace
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