/// This file is a part of MemorySanitizer, a detector of uninitialized
/// reads.
///
-/// Status: early prototype.
-///
/// The algorithm of the tool is similar to Memcheck
/// (http://goo.gl/QKbem). We associate a few shadow bits with every
/// byte of the application memory, poison the shadow of the malloc-ed
//===----------------------------------------------------------------------===//
-#define DEBUG_TYPE "msan"
-
#include "llvm/Transforms/Instrumentation.h"
#include "llvm/ADT/DepthFirstIterator.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/SmallVector.h"
+#include "llvm/ADT/StringExtras.h"
#include "llvm/ADT/Triple.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/Function.h"
#include "llvm/Transforms/Utils/BasicBlockUtils.h"
#include "llvm/Transforms/Utils/Local.h"
#include "llvm/Transforms/Utils/ModuleUtils.h"
-#include "llvm/Transforms/Utils/SpecialCaseList.h"
using namespace llvm;
+#define DEBUG_TYPE "msan"
+
static const uint64_t kShadowMask32 = 1ULL << 31;
static const uint64_t kShadowMask64 = 1ULL << 46;
static const uint64_t kOriginOffset32 = 1ULL << 30;
static const unsigned kMinOriginAlignment = 4;
static const unsigned kShadowTLSAlignment = 8;
+// Accesses sizes are powers of two: 1, 2, 4, 8.
+static const size_t kNumberOfAccessSizes = 4;
+
/// \brief Track origins of uninitialized values.
///
/// Adds a section to MemorySanitizer report that points to the allocation
cl::desc("print out instructions with default strict semantics"),
cl::Hidden, cl::init(false));
-static cl::opt<std::string> ClBlacklistFile("msan-blacklist",
- cl::desc("File containing the list of functions where MemorySanitizer "
- "should not report bugs"), cl::Hidden);
+static cl::opt<int> ClInstrumentationWithCallThreshold(
+ "msan-instrumentation-with-call-threshold",
+ cl::desc(
+ "If the function being instrumented requires more than "
+ "this number of checks and origin stores, use callbacks instead of "
+ "inline checks (-1 means never use callbacks)."),
+ cl::Hidden, cl::init(3500));
// Experimental. Wraps all indirect calls in the instrumented code with
// a call to the given function. This is needed to assist the dynamic
/// uninitialized reads.
class MemorySanitizer : public FunctionPass {
public:
- MemorySanitizer(int TrackOrigins = 0,
- StringRef BlacklistFile = StringRef())
+ MemorySanitizer(int TrackOrigins = 0)
: FunctionPass(ID),
TrackOrigins(std::max(TrackOrigins, (int)ClTrackOrigins)),
- DL(0),
- WarningFn(0),
- BlacklistFile(BlacklistFile.empty() ? ClBlacklistFile : BlacklistFile),
+ DL(nullptr),
+ WarningFn(nullptr),
WrapIndirectCalls(!ClWrapIndirectCalls.empty()) {}
const char *getPassName() const override { return "MemorySanitizer"; }
bool runOnFunction(Function &F) override;
/// \brief The run-time callback to print a warning.
Value *WarningFn;
+ // These arrays are indexed by log2(AccessSize).
+ Value *MaybeWarningFn[kNumberOfAccessSizes];
+ Value *MaybeStoreOriginFn[kNumberOfAccessSizes];
+
/// \brief Run-time helper that generates a new origin value for a stack
/// allocation.
Value *MsanSetAllocaOrigin4Fn;
MDNode *ColdCallWeights;
/// \brief Branch weights for origin store.
MDNode *OriginStoreWeights;
- /// \brief Path to blacklist file.
- SmallString<64> BlacklistFile;
- /// \brief The blacklist.
- std::unique_ptr<SpecialCaseList> BL;
/// \brief An empty volatile inline asm that prevents callback merge.
InlineAsm *EmptyAsm;
"MemorySanitizer: detects uninitialized reads.",
false, false)
-FunctionPass *llvm::createMemorySanitizerPass(int TrackOrigins,
- StringRef BlacklistFile) {
- return new MemorySanitizer(TrackOrigins, BlacklistFile);
+FunctionPass *llvm::createMemorySanitizerPass(int TrackOrigins) {
+ return new MemorySanitizer(TrackOrigins);
}
/// \brief Create a non-const global initialized with the given string.
: "__msan_warning_noreturn";
WarningFn = M.getOrInsertFunction(WarningFnName, IRB.getVoidTy(), NULL);
+ for (size_t AccessSizeIndex = 0; AccessSizeIndex < kNumberOfAccessSizes;
+ AccessSizeIndex++) {
+ unsigned AccessSize = 1 << AccessSizeIndex;
+ std::string FunctionName = "__msan_maybe_warning_" + itostr(AccessSize);
+ MaybeWarningFn[AccessSizeIndex] = M.getOrInsertFunction(
+ FunctionName, IRB.getVoidTy(), IRB.getIntNTy(AccessSize * 8),
+ IRB.getInt32Ty(), NULL);
+
+ FunctionName = "__msan_maybe_store_origin_" + itostr(AccessSize);
+ MaybeStoreOriginFn[AccessSizeIndex] = M.getOrInsertFunction(
+ FunctionName, IRB.getVoidTy(), IRB.getIntNTy(AccessSize * 8),
+ IRB.getInt8PtrTy(), IRB.getInt32Ty(), NULL);
+ }
+
MsanSetAllocaOrigin4Fn = M.getOrInsertFunction(
"__msan_set_alloca_origin4", IRB.getVoidTy(), IRB.getInt8PtrTy(), IntptrTy,
IRB.getInt8PtrTy(), IntptrTy, NULL);
// Create globals.
RetvalTLS = new GlobalVariable(
M, ArrayType::get(IRB.getInt64Ty(), 8), false,
- GlobalVariable::ExternalLinkage, 0, "__msan_retval_tls", 0,
+ GlobalVariable::ExternalLinkage, nullptr, "__msan_retval_tls", nullptr,
GlobalVariable::InitialExecTLSModel);
RetvalOriginTLS = new GlobalVariable(
- M, OriginTy, false, GlobalVariable::ExternalLinkage, 0,
- "__msan_retval_origin_tls", 0, GlobalVariable::InitialExecTLSModel);
+ M, OriginTy, false, GlobalVariable::ExternalLinkage, nullptr,
+ "__msan_retval_origin_tls", nullptr, GlobalVariable::InitialExecTLSModel);
ParamTLS = new GlobalVariable(
M, ArrayType::get(IRB.getInt64Ty(), 1000), false,
- GlobalVariable::ExternalLinkage, 0, "__msan_param_tls", 0,
+ GlobalVariable::ExternalLinkage, nullptr, "__msan_param_tls", nullptr,
GlobalVariable::InitialExecTLSModel);
ParamOriginTLS = new GlobalVariable(
M, ArrayType::get(OriginTy, 1000), false, GlobalVariable::ExternalLinkage,
- 0, "__msan_param_origin_tls", 0, GlobalVariable::InitialExecTLSModel);
+ nullptr, "__msan_param_origin_tls", nullptr,
+ GlobalVariable::InitialExecTLSModel);
VAArgTLS = new GlobalVariable(
M, ArrayType::get(IRB.getInt64Ty(), 1000), false,
- GlobalVariable::ExternalLinkage, 0, "__msan_va_arg_tls", 0,
+ GlobalVariable::ExternalLinkage, nullptr, "__msan_va_arg_tls", nullptr,
GlobalVariable::InitialExecTLSModel);
VAArgOverflowSizeTLS = new GlobalVariable(
- M, IRB.getInt64Ty(), false, GlobalVariable::ExternalLinkage, 0,
- "__msan_va_arg_overflow_size_tls", 0,
+ M, IRB.getInt64Ty(), false, GlobalVariable::ExternalLinkage, nullptr,
+ "__msan_va_arg_overflow_size_tls", nullptr,
GlobalVariable::InitialExecTLSModel);
OriginTLS = new GlobalVariable(
- M, IRB.getInt32Ty(), false, GlobalVariable::ExternalLinkage, 0,
- "__msan_origin_tls", 0, GlobalVariable::InitialExecTLSModel);
+ M, IRB.getInt32Ty(), false, GlobalVariable::ExternalLinkage, nullptr,
+ "__msan_origin_tls", nullptr, GlobalVariable::InitialExecTLSModel);
// We insert an empty inline asm after __msan_report* to avoid callback merge.
EmptyAsm = InlineAsm::get(FunctionType::get(IRB.getVoidTy(), false),
ClWrapIndirectCalls, AnyFunctionPtrTy, AnyFunctionPtrTy, NULL);
}
- if (ClWrapIndirectCallsFast) {
+ if (WrapIndirectCalls && ClWrapIndirectCallsFast) {
MsandrModuleStart = new GlobalVariable(
M, IRB.getInt32Ty(), false, GlobalValue::ExternalLinkage,
- 0, "__executable_start");
+ nullptr, "__executable_start");
MsandrModuleStart->setVisibility(GlobalVariable::HiddenVisibility);
MsandrModuleEnd = new GlobalVariable(
M, IRB.getInt32Ty(), false, GlobalValue::ExternalLinkage,
- 0, "_end");
+ nullptr, "_end");
MsandrModuleEnd->setVisibility(GlobalVariable::HiddenVisibility);
}
}
bool MemorySanitizer::doInitialization(Module &M) {
DataLayoutPass *DLP = getAnalysisIfAvailable<DataLayoutPass>();
if (!DLP)
- return false;
+ report_fatal_error("data layout missing");
DL = &DLP->getDataLayout();
- BL.reset(SpecialCaseList::createOrDie(BlacklistFile));
C = &(M.getContext());
unsigned PtrSize = DL->getPointerSizeInBits(/* AddressSpace */0);
switch (PtrSize) {
CreateVarArgHelper(Function &Func, MemorySanitizer &Msan,
MemorySanitizerVisitor &Visitor);
+unsigned TypeSizeToSizeIndex(unsigned TypeSize) {
+ if (TypeSize <= 8) return 0;
+ return Log2_32_Ceil(TypeSize / 8);
+}
+
/// This class does all the work for a given function. Store and Load
/// instructions store and load corresponding shadow and origin
/// values. Most instructions propagate shadow from arguments to their
MemorySanitizerVisitor(Function &F, MemorySanitizer &MS)
: F(F), MS(MS), VAHelper(CreateVarArgHelper(F, MS, *this)) {
- bool SanitizeFunction = !MS.BL->isIn(F) && F.getAttributes().hasAttribute(
- AttributeSet::FunctionIndex,
- Attribute::SanitizeMemory);
+ bool SanitizeFunction = F.getAttributes().hasAttribute(
+ AttributeSet::FunctionIndex, Attribute::SanitizeMemory);
InsertChecks = SanitizeFunction;
LoadShadow = SanitizeFunction;
PoisonStack = SanitizeFunction && ClPoisonStack;
return IRB.CreateCall(MS.MsanChainOriginFn, V);
}
- void materializeStores() {
- for (size_t i = 0, n = StoreList.size(); i < n; i++) {
- StoreInst& I = *dyn_cast<StoreInst>(StoreList[i]);
+ void storeOrigin(IRBuilder<> &IRB, Value *Addr, Value *Shadow, Value *Origin,
+ unsigned Alignment, bool AsCall) {
+ if (isa<StructType>(Shadow->getType())) {
+ IRB.CreateAlignedStore(updateOrigin(Origin, IRB), getOriginPtr(Addr, IRB),
+ Alignment);
+ } else {
+ Value *ConvertedShadow = convertToShadowTyNoVec(Shadow, IRB);
+ // 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 (isa<Constant>(ConvertedShadow)) return;
+ unsigned TypeSizeInBits =
+ MS.DL->getTypeSizeInBits(ConvertedShadow->getType());
+ unsigned SizeIndex = TypeSizeToSizeIndex(TypeSizeInBits);
+ if (AsCall && SizeIndex < kNumberOfAccessSizes) {
+ Value *Fn = MS.MaybeStoreOriginFn[SizeIndex];
+ Value *ConvertedShadow2 = IRB.CreateZExt(
+ ConvertedShadow, IRB.getIntNTy(8 * (1 << SizeIndex)));
+ IRB.CreateCall3(Fn, ConvertedShadow2,
+ IRB.CreatePointerCast(Addr, IRB.getInt8PtrTy()),
+ updateOrigin(Origin, IRB));
+ } else {
+ Value *Cmp = IRB.CreateICmpNE(
+ ConvertedShadow, getCleanShadow(ConvertedShadow), "_mscmp");
+ Instruction *CheckTerm = SplitBlockAndInsertIfThen(
+ Cmp, IRB.GetInsertPoint(), false, MS.OriginStoreWeights);
+ IRBuilder<> IRBNew(CheckTerm);
+ IRBNew.CreateAlignedStore(updateOrigin(Origin, IRBNew),
+ getOriginPtr(Addr, IRBNew), Alignment);
+ }
+ }
+ }
- IRBuilder<> IRB(&I);
- Value *Val = I.getValueOperand();
- Value *Addr = I.getPointerOperand();
- Value *Shadow = I.isAtomic() ? getCleanShadow(Val) : getShadow(Val);
+ void materializeStores(bool InstrumentWithCalls) {
+ for (auto Inst : StoreList) {
+ StoreInst &SI = *dyn_cast<StoreInst>(Inst);
+
+ IRBuilder<> IRB(&SI);
+ Value *Val = SI.getValueOperand();
+ Value *Addr = SI.getPointerOperand();
+ Value *Shadow = SI.isAtomic() ? getCleanShadow(Val) : getShadow(Val);
Value *ShadowPtr = getShadowPtr(Addr, Shadow->getType(), IRB);
StoreInst *NewSI =
- IRB.CreateAlignedStore(Shadow, ShadowPtr, I.getAlignment());
+ IRB.CreateAlignedStore(Shadow, ShadowPtr, SI.getAlignment());
DEBUG(dbgs() << " STORE: " << *NewSI << "\n");
(void)NewSI;
- if (ClCheckAccessAddress)
- insertShadowCheck(Addr, &I);
+ if (ClCheckAccessAddress) insertShadowCheck(Addr, &SI);
- if (I.isAtomic())
- I.setOrdering(addReleaseOrdering(I.getOrdering()));
+ if (SI.isAtomic()) SI.setOrdering(addReleaseOrdering(SI.getOrdering()));
if (MS.TrackOrigins) {
- unsigned Alignment = std::max(kMinOriginAlignment, I.getAlignment());
- if (isa<StructType>(Shadow->getType())) {
- IRB.CreateAlignedStore(updateOrigin(getOrigin(Val), IRB),
- getOriginPtr(Addr, IRB), Alignment);
- } else {
- Value *ConvertedShadow = convertToShadowTyNoVec(Shadow, IRB);
-
- // 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 (isa<Constant>(ConvertedShadow))
- continue;
-
- Value *Cmp = IRB.CreateICmpNE(ConvertedShadow,
- getCleanShadow(ConvertedShadow), "_mscmp");
- Instruction *CheckTerm =
- SplitBlockAndInsertIfThen(Cmp, &I, false, MS.OriginStoreWeights);
- IRBuilder<> IRBNew(CheckTerm);
- IRBNew.CreateAlignedStore(updateOrigin(getOrigin(Val), IRBNew),
- getOriginPtr(Addr, IRBNew), Alignment);
- }
+ unsigned Alignment = std::max(kMinOriginAlignment, SI.getAlignment());
+ storeOrigin(IRB, Addr, Shadow, getOrigin(Val), Alignment,
+ InstrumentWithCalls);
}
}
}
- void materializeChecks() {
- for (size_t i = 0, n = InstrumentationList.size(); i < n; i++) {
- 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;
+ void materializeOneCheck(Instruction *OrigIns, Value *Shadow, Value *Origin,
+ bool AsCall) {
+ 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)) return;
+ unsigned TypeSizeInBits =
+ MS.DL->getTypeSizeInBits(ConvertedShadow->getType());
+ unsigned SizeIndex = TypeSizeToSizeIndex(TypeSizeInBits);
+ if (AsCall && SizeIndex < kNumberOfAccessSizes) {
+ Value *Fn = MS.MaybeWarningFn[SizeIndex];
+ Value *ConvertedShadow2 =
+ IRB.CreateZExt(ConvertedShadow, IRB.getIntNTy(8 * (1 << SizeIndex)));
+ IRB.CreateCall2(Fn, ConvertedShadow2, MS.TrackOrigins && Origin
+ ? Origin
+ : (Value *)IRB.getInt32(0));
+ } else {
Value *Cmp = IRB.CreateICmpNE(ConvertedShadow,
getCleanShadow(ConvertedShadow), "_mscmp");
Instruction *CheckTerm = SplitBlockAndInsertIfThen(
IRB.SetInsertPoint(CheckTerm);
if (MS.TrackOrigins) {
- Value *Origin = InstrumentationList[i].Origin;
- IRB.CreateStore(Origin ? (Value*)Origin : (Value*)IRB.getInt32(0),
+ IRB.CreateStore(Origin ? (Value *)Origin : (Value *)IRB.getInt32(0),
MS.OriginTLS);
}
IRB.CreateCall(MS.WarningFn);
IRB.CreateCall(MS.EmptyAsm);
DEBUG(dbgs() << " CHECK: " << *Cmp << "\n");
}
+ }
+
+ void materializeChecks(bool InstrumentWithCalls) {
+ for (const auto &ShadowData : InstrumentationList) {
+ Instruction *OrigIns = ShadowData.OrigIns;
+ Value *Shadow = ShadowData.Shadow;
+ Value *Origin = ShadowData.Origin;
+ materializeOneCheck(OrigIns, Shadow, Origin, InstrumentWithCalls);
+ }
DEBUG(dbgs() << "DONE:\n" << F);
}
void materializeIndirectCalls() {
- for (size_t i = 0, n = IndirectCallList.size(); i < n; i++) {
- CallSite CS = IndirectCallList[i];
+ for (auto &CS : IndirectCallList) {
Instruction *I = CS.getInstruction();
BasicBlock *B = I->getParent();
IRBuilder<> IRB(I);
// Iterate all BBs in depth-first order and create shadow instructions
// for all instructions (where applicable).
// For PHI nodes we create dummy shadow PHIs which will be finalized later.
- for (df_iterator<BasicBlock*> DI = df_begin(&F.getEntryBlock()),
- DE = df_end(&F.getEntryBlock()); DI != DE; ++DI) {
- BasicBlock *BB = *DI;
+ for (BasicBlock *BB : depth_first(&F.getEntryBlock()))
visit(*BB);
- }
+
// Finalize PHI nodes.
- for (size_t i = 0, n = ShadowPHINodes.size(); i < n; i++) {
- PHINode *PN = ShadowPHINodes[i];
+ for (PHINode *PN : ShadowPHINodes) {
PHINode *PNS = cast<PHINode>(getShadow(PN));
- PHINode *PNO = MS.TrackOrigins ? cast<PHINode>(getOrigin(PN)) : 0;
+ 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));
VAHelper->finalizeInstrumentation();
+ bool InstrumentWithCalls = ClInstrumentationWithCallThreshold >= 0 &&
+ InstrumentationList.size() + StoreList.size() >
+ (unsigned)ClInstrumentationWithCallThreshold;
+
// Delayed instrumentation of StoreInst.
// This may add new checks to be inserted later.
- materializeStores();
+ materializeStores(InstrumentWithCalls);
// Insert shadow value checks.
- materializeChecks();
+ materializeChecks(InstrumentWithCalls);
// Wrap indirect calls.
materializeIndirectCalls();
/// \brief Compute the shadow type that corresponds to a given Type.
Type *getShadowTy(Type *OrigTy) {
if (!OrigTy->isSized()) {
- return 0;
+ return nullptr;
}
// For integer type, shadow is the same as the original type.
// This may return weird-sized types like i1.
/// \brief Compute the origin address for a given function argument.
Value *getOriginPtrForArgument(Value *A, IRBuilder<> &IRB,
int ArgOffset) {
- if (!MS.TrackOrigins) return 0;
+ if (!MS.TrackOrigins) return nullptr;
Value *Base = IRB.CreatePointerCast(MS.ParamOriginTLS, MS.IntptrTy);
Base = IRB.CreateAdd(Base, ConstantInt::get(MS.IntptrTy, ArgOffset));
return IRB.CreateIntToPtr(Base, PointerType::get(MS.OriginTy, 0),
Constant *getCleanShadow(Value *V) {
Type *ShadowTy = getShadowTy(V);
if (!ShadowTy)
- return 0;
+ return nullptr;
return Constant::getNullValue(ShadowTy);
}
Constant *getPoisonedShadow(Value *V) {
Type *ShadowTy = getShadowTy(V);
if (!ShadowTy)
- return 0;
+ return nullptr;
return getPoisonedShadow(ShadowTy);
}
Function *F = A->getParent();
IRBuilder<> EntryIRB(F->getEntryBlock().getFirstNonPHI());
unsigned ArgOffset = 0;
- for (Function::arg_iterator AI = F->arg_begin(), AE = F->arg_end();
- AI != AE; ++AI) {
- if (!AI->getType()->isSized()) {
+ for (auto &FArg : F->args()) {
+ if (!FArg.getType()->isSized()) {
DEBUG(dbgs() << "Arg is not sized\n");
continue;
}
- unsigned Size = AI->hasByValAttr()
- ? MS.DL->getTypeAllocSize(AI->getType()->getPointerElementType())
- : MS.DL->getTypeAllocSize(AI->getType());
- if (A == AI) {
- Value *Base = getShadowPtrForArgument(AI, EntryIRB, ArgOffset);
- if (AI->hasByValAttr()) {
+ unsigned Size = FArg.hasByValAttr()
+ ? MS.DL->getTypeAllocSize(FArg.getType()->getPointerElementType())
+ : MS.DL->getTypeAllocSize(FArg.getType());
+ if (A == &FArg) {
+ Value *Base = getShadowPtrForArgument(&FArg, EntryIRB, ArgOffset);
+ if (FArg.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();
+ unsigned ArgAlign = FArg.getParamAlignment();
if (ArgAlign == 0) {
Type *EltType = A->getType()->getPointerElementType();
ArgAlign = MS.DL->getABITypeAlignment(EltType);
} else {
*ShadowPtr = EntryIRB.CreateAlignedLoad(Base, kShadowTLSAlignment);
}
- DEBUG(dbgs() << " ARG: " << *AI << " ==> " <<
+ DEBUG(dbgs() << " ARG: " << FArg << " ==> " <<
**ShadowPtr << "\n");
if (MS.TrackOrigins) {
- Value* OriginPtr = getOriginPtrForArgument(AI, EntryIRB, ArgOffset);
+ Value *OriginPtr =
+ getOriginPtrForArgument(&FArg, EntryIRB, ArgOffset);
setOrigin(A, EntryIRB.CreateLoad(OriginPtr));
}
}
/// \brief Get the origin for a value.
Value *getOrigin(Value *V) {
- if (!MS.TrackOrigins) return 0;
+ if (!MS.TrackOrigins) return nullptr;
if (isa<Instruction>(V) || isa<Argument>(V)) {
Value *Origin = OriginMap[V];
if (!Origin) {
public:
Combiner(MemorySanitizerVisitor *MSV, IRBuilder<> &IRB) :
- Shadow(0), Origin(0), IRB(IRB), MSV(MSV) {}
+ Shadow(nullptr), Origin(nullptr), IRB(IRB), MSV(MSV) {}
/// \brief Add a pair of shadow and origin values to the mix.
Combiner &Add(Value *OpShadow, Value *OpOrigin) {
if (!Origin) {
Origin = OpOrigin;
} else {
- Value *FlatShadow = MSV->convertToShadowTyNoVec(OpShadow, IRB);
- Value *Cond = IRB.CreateICmpNE(FlatShadow,
- MSV->getCleanShadow(FlatShadow));
- Origin = IRB.CreateSelect(Cond, OpOrigin, Origin);
+ Constant *ConstOrigin = dyn_cast<Constant>(OpOrigin);
+ // No point in adding something that might result in 0 origin value.
+ if (!ConstOrigin || !ConstOrigin->isNullValue()) {
+ Value *FlatShadow = MSV->convertToShadowTyNoVec(OpShadow, IRB);
+ Value *Cond =
+ IRB.CreateICmpNE(FlatShadow, MSV->getCleanShadow(FlatShadow));
+ Origin = IRB.CreateSelect(Cond, OpOrigin, Origin);
+ }
}
}
return *this;
/// \brief Add an application value to the mix.
Combiner &Add(Value *V) {
Value *OpShadow = MSV->getShadow(V);
- Value *OpOrigin = MSV->MS.TrackOrigins ? MSV->getOrigin(V) : 0;
+ Value *OpOrigin = MSV->MS.TrackOrigins ? MSV->getOrigin(V) : nullptr;
return Add(OpShadow, OpOrigin);
}
// TODO: handle struct types.
}
+ /// \brief Cast an application value to the type of its own shadow.
+ Value *CreateAppToShadowCast(IRBuilder<> &IRB, Value *V) {
+ Type *ShadowTy = getShadowTy(V);
+ if (V->getType() == ShadowTy)
+ return V;
+ if (V->getType()->isPtrOrPtrVectorTy())
+ return IRB.CreatePtrToInt(V, ShadowTy);
+ else
+ return IRB.CreateBitCast(V, ShadowTy);
+ }
+
/// \brief Propagate shadow for arbitrary operation.
void handleShadowOr(Instruction &I) {
IRBuilder<> IRB(&I);
SC.Done(&I);
}
+ // \brief Handle multiplication by constant.
+ //
+ // Handle a special case of multiplication by constant that may have one or
+ // more zeros in the lower bits. This makes corresponding number of lower bits
+ // of the result zero as well. We model it by shifting the other operand
+ // shadow left by the required number of bits. Effectively, we transform
+ // (X * (A * 2**B)) to ((X << B) * A) and instrument (X << B) as (Sx << B).
+ // We use multiplication by 2**N instead of shift to cover the case of
+ // multiplication by 0, which may occur in some elements of a vector operand.
+ void handleMulByConstant(BinaryOperator &I, Constant *ConstArg,
+ Value *OtherArg) {
+ Constant *ShadowMul;
+ Type *Ty = ConstArg->getType();
+ if (Ty->isVectorTy()) {
+ unsigned NumElements = Ty->getVectorNumElements();
+ Type *EltTy = Ty->getSequentialElementType();
+ SmallVector<Constant *, 16> Elements;
+ for (unsigned Idx = 0; Idx < NumElements; ++Idx) {
+ ConstantInt *Elt =
+ dyn_cast<ConstantInt>(ConstArg->getAggregateElement(Idx));
+ APInt V = Elt->getValue();
+ APInt V2 = APInt(V.getBitWidth(), 1) << V.countTrailingZeros();
+ Elements.push_back(ConstantInt::get(EltTy, V2));
+ }
+ ShadowMul = ConstantVector::get(Elements);
+ } else {
+ ConstantInt *Elt = dyn_cast<ConstantInt>(ConstArg);
+ APInt V = Elt->getValue();
+ APInt V2 = APInt(V.getBitWidth(), 1) << V.countTrailingZeros();
+ ShadowMul = ConstantInt::get(Elt->getType(), V2);
+ }
+
+ IRBuilder<> IRB(&I);
+ setShadow(&I,
+ IRB.CreateMul(getShadow(OtherArg), ShadowMul, "msprop_mul_cst"));
+ setOrigin(&I, getOrigin(OtherArg));
+ }
+
+ void visitMul(BinaryOperator &I) {
+ Constant *constOp0 = dyn_cast<Constant>(I.getOperand(0));
+ Constant *constOp1 = dyn_cast<Constant>(I.getOperand(1));
+ if (constOp0 && !constOp1)
+ handleMulByConstant(I, constOp0, I.getOperand(1));
+ else if (constOp1 && !constOp0)
+ handleMulByConstant(I, constOp1, I.getOperand(0));
+ else
+ handleShadowOr(I);
+ }
+
void visitFAdd(BinaryOperator &I) { handleShadowOr(I); }
void visitFSub(BinaryOperator &I) { handleShadowOr(I); }
void visitFMul(BinaryOperator &I) { handleShadowOr(I); }
void visitAdd(BinaryOperator &I) { handleShadowOr(I); }
void visitSub(BinaryOperator &I) { handleShadowOr(I); }
void visitXor(BinaryOperator &I) { handleShadowOr(I); }
- void visitMul(BinaryOperator &I) { handleShadowOr(I); }
void handleDiv(Instruction &I) {
IRBuilder<> IRB(&I);
void handleSignedRelationalComparison(ICmpInst &I) {
Constant *constOp0 = dyn_cast<Constant>(I.getOperand(0));
Constant *constOp1 = dyn_cast<Constant>(I.getOperand(1));
- Value* op = NULL;
+ Value* op = nullptr;
CmpInst::Predicate pre = I.getPredicate();
if (constOp0 && constOp0->isNullValue() &&
(pre == CmpInst::ICMP_SGT || pre == CmpInst::ICMP_SLE)) {
break;
case 1:
ConvertOp = I.getArgOperand(0);
- CopyOp = NULL;
+ CopyOp = nullptr;
break;
default:
llvm_unreachable("Cvt intrinsic with unsupported number of arguments.");
// FIXME: consider propagating shadow of ConvertOp, at least in the case of
// int->any conversion.
Value *ConvertShadow = getShadow(ConvertOp);
- Value *AggShadow = 0;
+ Value *AggShadow = nullptr;
if (ConvertOp->getType()->isVectorTy()) {
AggShadow = IRB.CreateExtractElement(
ConvertShadow, ConstantInt::get(IRB.getInt32Ty(), 0));
setOriginForNaryOp(I);
}
+ // \brief Get an X86_MMX-sized vector type.
+ Type *getMMXVectorTy(unsigned EltSizeInBits) {
+ const unsigned X86_MMXSizeInBits = 64;
+ return VectorType::get(IntegerType::get(*MS.C, EltSizeInBits),
+ X86_MMXSizeInBits / EltSizeInBits);
+ }
+
+ // \brief Returns a signed counterpart for an (un)signed-saturate-and-pack
+ // intrinsic.
+ Intrinsic::ID getSignedPackIntrinsic(Intrinsic::ID id) {
+ switch (id) {
+ case llvm::Intrinsic::x86_sse2_packsswb_128:
+ case llvm::Intrinsic::x86_sse2_packuswb_128:
+ return llvm::Intrinsic::x86_sse2_packsswb_128;
+
+ case llvm::Intrinsic::x86_sse2_packssdw_128:
+ case llvm::Intrinsic::x86_sse41_packusdw:
+ return llvm::Intrinsic::x86_sse2_packssdw_128;
+
+ case llvm::Intrinsic::x86_avx2_packsswb:
+ case llvm::Intrinsic::x86_avx2_packuswb:
+ return llvm::Intrinsic::x86_avx2_packsswb;
+
+ case llvm::Intrinsic::x86_avx2_packssdw:
+ case llvm::Intrinsic::x86_avx2_packusdw:
+ return llvm::Intrinsic::x86_avx2_packssdw;
+
+ case llvm::Intrinsic::x86_mmx_packsswb:
+ case llvm::Intrinsic::x86_mmx_packuswb:
+ return llvm::Intrinsic::x86_mmx_packsswb;
+
+ case llvm::Intrinsic::x86_mmx_packssdw:
+ return llvm::Intrinsic::x86_mmx_packssdw;
+ default:
+ llvm_unreachable("unexpected intrinsic id");
+ }
+ }
+
+ // \brief Instrument vector pack instrinsic.
+ //
+ // This function instruments intrinsics like x86_mmx_packsswb, that
+ // packs elements of 2 input vectors into half as many bits with saturation.
+ // Shadow is propagated with the signed variant of the same intrinsic applied
+ // to sext(Sa != zeroinitializer), sext(Sb != zeroinitializer).
+ // EltSizeInBits is used only for x86mmx arguments.
+ void handleVectorPackIntrinsic(IntrinsicInst &I, unsigned EltSizeInBits = 0) {
+ assert(I.getNumArgOperands() == 2);
+ bool isX86_MMX = I.getOperand(0)->getType()->isX86_MMXTy();
+ IRBuilder<> IRB(&I);
+ Value *S1 = getShadow(&I, 0);
+ Value *S2 = getShadow(&I, 1);
+ assert(isX86_MMX || S1->getType()->isVectorTy());
+
+ // SExt and ICmpNE below must apply to individual elements of input vectors.
+ // In case of x86mmx arguments, cast them to appropriate vector types and
+ // back.
+ Type *T = isX86_MMX ? getMMXVectorTy(EltSizeInBits) : S1->getType();
+ if (isX86_MMX) {
+ S1 = IRB.CreateBitCast(S1, T);
+ S2 = IRB.CreateBitCast(S2, T);
+ }
+ Value *S1_ext = IRB.CreateSExt(
+ IRB.CreateICmpNE(S1, llvm::Constant::getNullValue(T)), T);
+ Value *S2_ext = IRB.CreateSExt(
+ IRB.CreateICmpNE(S2, llvm::Constant::getNullValue(T)), T);
+ if (isX86_MMX) {
+ Type *X86_MMXTy = Type::getX86_MMXTy(*MS.C);
+ S1_ext = IRB.CreateBitCast(S1_ext, X86_MMXTy);
+ S2_ext = IRB.CreateBitCast(S2_ext, X86_MMXTy);
+ }
+
+ Function *ShadowFn = Intrinsic::getDeclaration(
+ F.getParent(), getSignedPackIntrinsic(I.getIntrinsicID()));
+
+ Value *S = IRB.CreateCall2(ShadowFn, S1_ext, S2_ext, "_msprop_vector_pack");
+ if (isX86_MMX) S = IRB.CreateBitCast(S, getShadowTy(&I));
+ setShadow(&I, S);
+ setOriginForNaryOp(I);
+ }
+
void visitIntrinsicInst(IntrinsicInst &I) {
switch (I.getIntrinsicID()) {
case llvm::Intrinsic::bswap:
// case llvm::Intrinsic::x86_sse2_psll_dq_bs:
// case llvm::Intrinsic::x86_sse2_psrl_dq_bs:
+ case llvm::Intrinsic::x86_sse2_packsswb_128:
+ case llvm::Intrinsic::x86_sse2_packssdw_128:
+ case llvm::Intrinsic::x86_sse2_packuswb_128:
+ case llvm::Intrinsic::x86_sse41_packusdw:
+ case llvm::Intrinsic::x86_avx2_packsswb:
+ case llvm::Intrinsic::x86_avx2_packssdw:
+ case llvm::Intrinsic::x86_avx2_packuswb:
+ case llvm::Intrinsic::x86_avx2_packusdw:
+ handleVectorPackIntrinsic(I);
+ break;
+
+ case llvm::Intrinsic::x86_mmx_packsswb:
+ case llvm::Intrinsic::x86_mmx_packuswb:
+ handleVectorPackIntrinsic(I, 16);
+ break;
+
+ case llvm::Intrinsic::x86_mmx_packssdw:
+ handleVectorPackIntrinsic(I, 32);
+ break;
+
default:
if (!handleUnknownIntrinsic(I))
visitInstruction(I);
continue;
}
unsigned Size = 0;
- Value *Store = 0;
+ Value *Store = nullptr;
// Compute the Shadow for arg even if it is ByVal, because
// in that case getShadow() will copy the actual arg shadow to
// __msan_param_tls.
IRB.CreateStore(getOrigin(A),
getOriginPtrForArgument(A, IRB, ArgOffset));
(void)Store;
- assert(Size != 0 && Store != 0);
+ assert(Size != 0 && Store != nullptr);
DEBUG(dbgs() << " Param:" << *Store << "\n");
ArgOffset += DataLayout::RoundUpAlignment(Size, 8);
}
// Until we have full dynamic coverage, make sure the retval shadow is 0.
Value *Base = getShadowPtrForRetval(&I, IRBBefore);
IRBBefore.CreateAlignedStore(getCleanShadow(&I), Base, kShadowTLSAlignment);
- Instruction *NextInsn = 0;
+ Instruction *NextInsn = nullptr;
if (CS.isCall()) {
NextInsn = I.getNextNode();
} else {
void visitSelectInst(SelectInst& I) {
IRBuilder<> IRB(&I);
// a = select b, c, d
- Value *S = IRB.CreateSelect(I.getCondition(), getShadow(I.getTrueValue()),
- getShadow(I.getFalseValue()));
+ Value *B = I.getCondition();
+ Value *C = I.getTrueValue();
+ Value *D = I.getFalseValue();
+ Value *Sb = getShadow(B);
+ Value *Sc = getShadow(C);
+ Value *Sd = getShadow(D);
+
+ // Result shadow if condition shadow is 0.
+ Value *Sa0 = IRB.CreateSelect(B, Sc, Sd);
+ Value *Sa1;
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");
+ Sa1 = getPoisonedShadow(getShadowTy(I.getType()));
} else {
- // Sa = (sext Sb) | (select b, Sc, Sd)
- S = IRB.CreateOr(S, CreateShadowCast(IRB, getShadow(I.getCondition()),
- S->getType(), true),
- "_msprop_select");
+ // Sa = select Sb, [ (c^d) | Sc | Sd ], [ b ? Sc : Sd ]
+ // If Sb (condition is poisoned), look for bits in c and d that are equal
+ // and both unpoisoned.
+ // If !Sb (condition is unpoisoned), simply pick one of Sc and Sd.
+
+ // Cast arguments to shadow-compatible type.
+ C = CreateAppToShadowCast(IRB, C);
+ D = CreateAppToShadowCast(IRB, D);
+
+ // Result shadow if condition shadow is 1.
+ Sa1 = IRB.CreateOr(IRB.CreateXor(C, D), IRB.CreateOr(Sc, Sd));
}
- setShadow(&I, S);
+ Value *Sa = IRB.CreateSelect(Sb, Sa1, Sa0, "_msprop_select");
+ setShadow(&I, Sa);
if (MS.TrackOrigins) {
// Origins are always i32, so any vector conditions must be flattened.
// FIXME: consider tracking vector origins for app vectors?
- Value *Cond = I.getCondition();
- Value *CondShadow = getShadow(Cond);
- if (Cond->getType()->isVectorTy()) {
- Type *FlatTy = getShadowTyNoVec(Cond->getType());
- Cond = IRB.CreateICmpNE(IRB.CreateBitCast(Cond, FlatTy),
+ if (B->getType()->isVectorTy()) {
+ Type *FlatTy = getShadowTyNoVec(B->getType());
+ B = IRB.CreateICmpNE(IRB.CreateBitCast(B, FlatTy),
ConstantInt::getNullValue(FlatTy));
- CondShadow = IRB.CreateICmpNE(IRB.CreateBitCast(CondShadow, FlatTy),
+ Sb = IRB.CreateICmpNE(IRB.CreateBitCast(Sb, FlatTy),
ConstantInt::getNullValue(FlatTy));
}
// a = select b, c, d
// Oa = Sb ? Ob : (b ? Oc : Od)
setOrigin(&I, IRB.CreateSelect(
- CondShadow, getOrigin(I.getCondition()),
- IRB.CreateSelect(Cond, getOrigin(I.getTrueValue()),
- getOrigin(I.getFalseValue()))));
+ Sb, getOrigin(I.getCondition()),
+ IRB.CreateSelect(B, getOrigin(C), getOrigin(D))));
}
}
VarArgAMD64Helper(Function &F, MemorySanitizer &MS,
MemorySanitizerVisitor &MSV)
- : F(F), MS(MS), MSV(MSV), VAArgTLSCopy(0), VAArgOverflowSize(0) { }
+ : F(F), MS(MS), MSV(MSV), VAArgTLSCopy(nullptr),
+ VAArgOverflowSize(nullptr) {}
enum ArgKind { AK_GeneralPurpose, AK_FloatingPoint, AK_Memory };
projects / oota-llvm.git / blobdiff