"Number of optimized accesses to global vars");
namespace {
+/// Frontend-provided metadata for source location.
+struct LocationMetadata {
+ StringRef Filename;
+ int LineNo;
+ int ColumnNo;
+
+ LocationMetadata() : Filename(), LineNo(0), ColumnNo(0) {}
+
+ bool empty() const { return Filename.empty(); }
+
+ void parse(MDNode *MDN) {
+ assert(MDN->getNumOperands() == 3);
+ MDString *MDFilename = cast<MDString>(MDN->getOperand(0));
+ Filename = MDFilename->getString();
+ LineNo = cast<ConstantInt>(MDN->getOperand(1))->getLimitedValue();
+ ColumnNo = cast<ConstantInt>(MDN->getOperand(2))->getLimitedValue();
+ }
+};
+
/// Frontend-provided metadata for global variables.
class GlobalsMetadata {
public:
+ struct Entry {
+ Entry()
+ : SourceLoc(), Name(), IsDynInit(false),
+ IsBlacklisted(false) {}
+ LocationMetadata SourceLoc;
+ StringRef Name;
+ bool IsDynInit;
+ bool IsBlacklisted;
+ };
+
GlobalsMetadata() : inited_(false) {}
+
void init(Module& M) {
assert(!inited_);
inited_ = true;
if (!Globals)
return;
for (auto MDN : Globals->operands()) {
- // Format of the metadata node for the global:
- // {
- // global,
- // source_location,
- // i1 is_dynamically_initialized,
- // i1 is_blacklisted
- // }
- assert(MDN->getNumOperands() == 4);
+ // Metadata node contains the global and the fields of "Entry".
+ assert(MDN->getNumOperands() == 5);
Value *V = MDN->getOperand(0);
// The optimizer may optimize away a global entirely.
if (!V)
continue;
GlobalVariable *GV = cast<GlobalVariable>(V);
- if (Value *Loc = MDN->getOperand(1)) {
- GlobalVariable *GVLoc = cast<GlobalVariable>(Loc);
- // We may already know the source location for GV, if it was merged
- // with another global.
- if (SourceLocation.insert(std::make_pair(GV, GVLoc)).second)
- addSourceLocationGlobal(GVLoc);
+ // We can already have an entry for GV if it was merged with another
+ // global.
+ Entry &E = Entries[GV];
+ if (Value *Loc = MDN->getOperand(1))
+ E.SourceLoc.parse(cast<MDNode>(Loc));
+ if (Value *Name = MDN->getOperand(2)) {
+ MDString *MDName = cast<MDString>(Name);
+ E.Name = MDName->getString();
}
- ConstantInt *IsDynInit = cast<ConstantInt>(MDN->getOperand(2));
- if (IsDynInit->isOne())
- DynInitGlobals.insert(GV);
- ConstantInt *IsBlacklisted = cast<ConstantInt>(MDN->getOperand(3));
- if (IsBlacklisted->isOne())
- BlacklistedGlobals.insert(GV);
+ ConstantInt *IsDynInit = cast<ConstantInt>(MDN->getOperand(3));
+ E.IsDynInit |= IsDynInit->isOne();
+ ConstantInt *IsBlacklisted = cast<ConstantInt>(MDN->getOperand(4));
+ E.IsBlacklisted |= IsBlacklisted->isOne();
}
}
- GlobalVariable *getSourceLocation(GlobalVariable *G) const {
- auto Pos = SourceLocation.find(G);
- return (Pos != SourceLocation.end()) ? Pos->second : nullptr;
- }
-
- /// Check if the global is dynamically initialized.
- bool isDynInit(GlobalVariable *G) const {
- return DynInitGlobals.count(G);
- }
-
- /// Check if the global was blacklisted.
- bool isBlacklisted(GlobalVariable *G) const {
- return BlacklistedGlobals.count(G);
- }
-
- /// Check if the global was generated to describe source location of another
- /// global (we don't want to instrument them).
- bool isSourceLocationGlobal(GlobalVariable *G) const {
- return LocationGlobals.count(G);
+ /// Returns metadata entry for a given global.
+ Entry get(GlobalVariable *G) const {
+ auto Pos = Entries.find(G);
+ return (Pos != Entries.end()) ? Pos->second : Entry();
}
private:
bool inited_;
- DenseMap<GlobalVariable*, GlobalVariable*> SourceLocation;
- DenseSet<GlobalVariable*> DynInitGlobals;
- DenseSet<GlobalVariable*> BlacklistedGlobals;
- DenseSet<GlobalVariable*> LocationGlobals;
-
- void addSourceLocationGlobal(GlobalVariable *SourceLocGV) {
- // Source location global is a struct with layout:
- // {
- // filename,
- // i32 line_number,
- // i32 column_number,
- // }
- LocationGlobals.insert(SourceLocGV);
- ConstantStruct *Contents =
- cast<ConstantStruct>(SourceLocGV->getInitializer());
- GlobalVariable *FilenameGV = cast<GlobalVariable>(Contents->getOperand(0));
- LocationGlobals.insert(FilenameGV);
- }
+ DenseMap<GlobalVariable*, Entry> Entries;
};
/// This struct defines the shadow mapping using the rule:
bool LooksLikeCodeInBug11395(Instruction *I);
bool GlobalIsLinkerInitialized(GlobalVariable *G);
- bool InjectCoverage(Function &F, const ArrayRef<BasicBlock*> AllBlocks);
+ bool InjectCoverage(Function &F, ArrayRef<BasicBlock*> AllBlocks);
void InjectCoverageAtBlock(Function &F, BasicBlock &BB);
LLVMContext *C;
}
/// Finds alloca where the value comes from.
AllocaInst *findAllocaForValue(Value *V);
- void poisonRedZones(const ArrayRef<uint8_t> ShadowBytes, IRBuilder<> &IRB,
+ void poisonRedZones(ArrayRef<uint8_t> ShadowBytes, IRBuilder<> &IRB,
Value *ShadowBase, bool DoPoison);
void poisonAlloca(Value *V, uint64_t Size, IRBuilder<> &IRB, bool DoPoison);
return GV;
}
+/// \brief Create a global describing a source location.
+static GlobalVariable *createPrivateGlobalForSourceLoc(Module &M,
+ LocationMetadata MD) {
+ Constant *LocData[] = {
+ createPrivateGlobalForString(M, MD.Filename, true),
+ ConstantInt::get(Type::getInt32Ty(M.getContext()), MD.LineNo),
+ ConstantInt::get(Type::getInt32Ty(M.getContext()), MD.ColumnNo),
+ };
+ auto LocStruct = ConstantStruct::getAnon(LocData);
+ auto GV = new GlobalVariable(M, LocStruct->getType(), true,
+ GlobalValue::PrivateLinkage, LocStruct,
+ kAsanGenPrefix);
+ GV->setUnnamedAddr(true);
+ return GV;
+}
+
static bool GlobalWasGeneratedByAsan(GlobalVariable *G) {
return G->getName().find(kAsanGenPrefix) == 0;
}
// and set IsWrite/Alignment. Otherwise return NULL.
static Value *isInterestingMemoryAccess(Instruction *I, bool *IsWrite,
unsigned *Alignment) {
+ // Skip memory accesses inserted by another instrumentation.
+ if (I->getMetadata("nosanitize"))
+ return nullptr;
if (LoadInst *LI = dyn_cast<LoadInst>(I)) {
if (!ClInstrumentReads) return nullptr;
*IsWrite = false;
// If a global variable does not have dynamic initialization we don't
// have to instrument it. However, if a global does not have initializer
// at all, we assume it has dynamic initializer (in other TU).
- return G->hasInitializer() && !GlobalsMD.isDynInit(G);
+ return G->hasInitializer() && !GlobalsMD.get(G).IsDynInit;
}
void
TerminatorInst *CrashTerm = nullptr;
if (ClAlwaysSlowPath || (TypeSize < 8 * Granularity)) {
+ // We use branch weights for the slow path check, to indicate that the slow
+ // path is rarely taken. This seems to be the case for SPEC benchmarks.
TerminatorInst *CheckTerm =
- SplitBlockAndInsertIfThen(Cmp, InsertBefore, false);
+ SplitBlockAndInsertIfThen(Cmp, InsertBefore, false,
+ MDBuilder(*C).createBranchWeights(1, 100000));
assert(dyn_cast<BranchInst>(CheckTerm)->isUnconditional());
BasicBlock *NextBB = CheckTerm->getSuccessor(0);
IRB.SetInsertPoint(CheckTerm);
Type *Ty = cast<PointerType>(G->getType())->getElementType();
DEBUG(dbgs() << "GLOBAL: " << *G << "\n");
- if (GlobalsMD.isBlacklisted(G)) return false;
- if (GlobalsMD.isSourceLocationGlobal(G)) return false;
+ if (GlobalsMD.get(G).IsBlacklisted) return false;
if (!Ty->isSized()) return false;
if (!G->hasInitializer()) return false;
if (GlobalWasGeneratedByAsan(G)) return false; // Our own global.
// Touch only those globals that will not be defined in other modules.
- // Don't handle ODR type linkages since other modules may be built w/o asan.
+ // Don't handle ODR linkage types and COMDATs since other modules may be built
+ // without ASan.
if (G->getLinkage() != GlobalVariable::ExternalLinkage &&
G->getLinkage() != GlobalVariable::PrivateLinkage &&
G->getLinkage() != GlobalVariable::InternalLinkage)
return false;
+ if (G->hasComdat())
+ return false;
// Two problems with thread-locals:
// - The address of the main thread's copy can't be computed at link-time.
// - Need to poison all copies, not just the main thread's one.
return false;
}
- // Don't instrument private COMDAT globals on Windows until PR20244 (linkage
- // of vftables with RTTI) is properly fixed.
- llvm::Triple TargetTriple(G->getParent()->getTargetTriple());
- if (G->hasComdat() && G->getLinkage() == GlobalVariable::PrivateLinkage &&
- TargetTriple.isWindowsMSVCEnvironment())
- return false;
-
if (G->hasSection()) {
StringRef Section(G->getSection());
// Ignore the globals from the __OBJC section. The ObjC runtime assumes
for (size_t i = 0; i < n; i++) {
static const uint64_t kMaxGlobalRedzone = 1 << 18;
GlobalVariable *G = GlobalsToChange[i];
+
+ auto MD = GlobalsMD.get(G);
+ // Create string holding the global name (use global name from metadata
+ // if it's available, otherwise just write the name of global variable).
+ GlobalVariable *Name = createPrivateGlobalForString(
+ M, MD.Name.empty() ? G->getName() : MD.Name,
+ /*AllowMerging*/ true);
+
PointerType *PtrTy = cast<PointerType>(G->getType());
Type *Ty = PtrTy->getElementType();
uint64_t SizeInBytes = DL->getTypeAllocSize(Ty);
NewTy, G->getInitializer(),
Constant::getNullValue(RightRedZoneTy), NULL);
- GlobalVariable *Name =
- createPrivateGlobalForString(M, G->getName(), /*AllowMerging*/true);
-
// Create a new global variable with enough space for a redzone.
GlobalValue::LinkageTypes Linkage = G->getLinkage();
if (G->isConstant() && Linkage == GlobalValue::PrivateLinkage)
NewGlobal->takeName(G);
G->eraseFromParent();
- bool GlobalHasDynamicInitializer = GlobalsMD.isDynInit(G);
- GlobalVariable *SourceLoc = GlobalsMD.getSourceLocation(G);
+ Constant *SourceLoc;
+ if (!MD.SourceLoc.empty()) {
+ auto SourceLocGlobal = createPrivateGlobalForSourceLoc(M, MD.SourceLoc);
+ SourceLoc = ConstantExpr::getPointerCast(SourceLocGlobal, IntptrTy);
+ } else {
+ SourceLoc = ConstantInt::get(IntptrTy, 0);
+ }
Initializers[i] = ConstantStruct::get(
GlobalStructTy, ConstantExpr::getPointerCast(NewGlobal, IntptrTy),
ConstantInt::get(IntptrTy, SizeInBytes + RightRedzoneSize),
ConstantExpr::getPointerCast(Name, IntptrTy),
ConstantExpr::getPointerCast(ModuleName, IntptrTy),
- ConstantInt::get(IntptrTy, GlobalHasDynamicInitializer),
- SourceLoc ? ConstantExpr::getPointerCast(SourceLoc, IntptrTy)
- : ConstantInt::get(IntptrTy, 0),
- NULL);
+ ConstantInt::get(IntptrTy, MD.IsDynInit), SourceLoc, NULL);
- if (ClInitializers && GlobalHasDynamicInitializer)
+ if (ClInitializers && MD.IsDynInit)
HasDynamicallyInitializedGlobals = true;
DEBUG(dbgs() << "NEW GLOBAL: " << *NewGlobal << "\n");
Cmp, IP, false, MDBuilder(*C).createBranchWeights(1, 100000));
IRB.SetInsertPoint(Ins);
IRB.SetCurrentDebugLocation(EntryLoc);
- // We pass &F to __sanitizer_cov. We could avoid this and rely on
- // GET_CALLER_PC, but having the PC of the first instruction is just nice.
+ // __sanitizer_cov gets the PC of the instruction using GET_CALLER_PC.
IRB.CreateCall(AsanCovFunction);
StoreInst *Store = IRB.CreateStore(ConstantInt::get(Int8Ty, 1), Guard);
Store->setAtomic(Monotonic);
// as the function and inject this code into the entry block (-asan-coverage=1)
// or all blocks (-asan-coverage=2):
// if (*Guard) {
-// __sanitizer_cov(&F);
+// __sanitizer_cov();
// *Guard = 1;
// }
// The accesses to Guard are atomic. The rest of the logic is
// a) get the functionality to users earlier and
// b) collect usage statistics to help improve Clang coverage design.
bool AddressSanitizer::InjectCoverage(Function &F,
- const ArrayRef<BasicBlock *> AllBlocks) {
+ ArrayRef<BasicBlock *> AllBlocks) {
if (!ClCoverage) return false;
if (ClCoverage == 1 ||
}
void
-FunctionStackPoisoner::poisonRedZones(const ArrayRef<uint8_t> ShadowBytes,
+FunctionStackPoisoner::poisonRedZones(ArrayRef<uint8_t> ShadowBytes,
IRBuilder<> &IRB, Value *ShadowBase,
bool DoPoison) {
size_t n = ShadowBytes.size();
projects / oota-llvm.git / blobdiff