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[msan] Origin tracking with history.

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LLVM part of MSan implementation of advanced origin tracking,
when we record not only creation point, but all locations where
an uninitialized value was stored to memory, too.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204151 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Evgeniy Stepanov
2014-03-18 13:30:56 +00:00
parent c605296342
commit 610469f4c2
3 changed files with 55 additions and 11 deletions
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30
lib/Transforms/Instrumentation/MemorySanitizer.cpp
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@@ -133,9 +133,9 @@ static const unsigned kShadowTLSAlignment = 8;
///
/// Adds a section to MemorySanitizer report that points to the allocation
/// (stack or heap) the uninitialized bits came from originally.
static cl::opt<bool> ClTrackOrigins("msan-track-origins",
static cl::opt<int> ClTrackOrigins("msan-track-origins",
cl::desc("Track origins (allocation sites) of poisoned memory"),
cl::Hidden, cl::init(false));
cl::Hidden, cl::init(0));
static cl::opt<bool> ClKeepGoing("msan-keep-going",
cl::desc("keep going after reporting a UMR"),
cl::Hidden, cl::init(false));
@@ -199,10 +199,10 @@ namespace {
/// uninitialized reads.
class MemorySanitizer : public FunctionPass {
public:
MemorySanitizer(bool TrackOrigins = false,
MemorySanitizer(int TrackOrigins = 0,
StringRef BlacklistFile = StringRef())
: FunctionPass(ID),
TrackOrigins(TrackOrigins || ClTrackOrigins),
TrackOrigins(std::max(TrackOrigins, (int)ClTrackOrigins)),
DL(0),
WarningFn(0),
BlacklistFile(BlacklistFile.empty() ? ClBlacklistFile : BlacklistFile),
@@ -216,7 +216,7 @@ class MemorySanitizer : public FunctionPass {
void initializeCallbacks(Module &M);
/// \brief Track origins (allocation points) of uninitialized values.
bool TrackOrigins;
int TrackOrigins;
const DataLayout *DL;
LLVMContext *C;
@@ -250,6 +250,9 @@ class MemorySanitizer : public FunctionPass {
Value *MsanSetAllocaOrigin4Fn;
/// \brief Run-time helper that poisons stack on function entry.
Value *MsanPoisonStackFn;
/// \brief Run-time helper that records a store (or any event) of an
/// uninitialized value and returns an updated origin id encoding this info.
Value *MsanChainOriginFn;
/// \brief MSan runtime replacements for memmove, memcpy and memset.
Value *MemmoveFn, *MemcpyFn, *MemsetFn;
@@ -286,7 +289,7 @@ INITIALIZE_PASS(MemorySanitizer, "msan",
"MemorySanitizer: detects uninitialized reads.",
false, false)
FunctionPass *llvm::createMemorySanitizerPass(bool TrackOrigins,
FunctionPass *llvm::createMemorySanitizerPass(int TrackOrigins,
StringRef BlacklistFile) {
return new MemorySanitizer(TrackOrigins, BlacklistFile);
}
@@ -323,6 +326,8 @@ void MemorySanitizer::initializeCallbacks(Module &M) {
IRB.getInt8PtrTy(), IntptrTy, NULL);
MsanPoisonStackFn = M.getOrInsertFunction(
"__msan_poison_stack", IRB.getVoidTy(), IRB.getInt8PtrTy(), IntptrTy, NULL);
MsanChainOriginFn = M.getOrInsertFunction(
"__msan_chain_origin", IRB.getInt32Ty(), IRB.getInt32Ty(), NULL);
MemmoveFn = M.getOrInsertFunction(
"__msan_memmove", IRB.getInt8PtrTy(), IRB.getInt8PtrTy(),
IRB.getInt8PtrTy(), IntptrTy, NULL);
@@ -520,6 +525,11 @@ struct MemorySanitizerVisitor : public InstVisitor<MemorySanitizerVisitor> {
<< F.getName() << "'\n");
}
Value *updateOrigin(Value *V, IRBuilder<> &IRB) {
if (MS.TrackOrigins <= 1) return V;
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]);
@@ -544,8 +554,8 @@ struct MemorySanitizerVisitor : public InstVisitor<MemorySanitizerVisitor> {
if (MS.TrackOrigins) {
unsigned Alignment = std::max(kMinOriginAlignment, I.getAlignment());
if (isa<StructType>(Shadow->getType())) {
IRB.CreateAlignedStore(getOrigin(Val), getOriginPtr(Addr, IRB),
Alignment);
IRB.CreateAlignedStore(updateOrigin(getOrigin(Val), IRB),
getOriginPtr(Addr, IRB), Alignment);
} else {
Value *ConvertedShadow = convertToShadowTyNoVec(Shadow, IRB);
@@ -560,8 +570,8 @@ struct MemorySanitizerVisitor : public InstVisitor<MemorySanitizerVisitor> {
Instruction *CheckTerm =
SplitBlockAndInsertIfThen(Cmp, &I, false, MS.OriginStoreWeights);
IRBuilder<> IRBNew(CheckTerm);
IRBNew.CreateAlignedStore(getOrigin(Val), getOriginPtr(Addr, IRBNew),
Alignment);
IRBNew.CreateAlignedStore(updateOrigin(getOrigin(Val), IRBNew),
getOriginPtr(Addr, IRBNew), Alignment);
}
}
}