+
+ friend struct FunctionStackPoisoner;
+};
+
+class AddressSanitizerModule : public ModulePass {
+ public:
+ AddressSanitizerModule(bool CheckInitOrder = true,
+ StringRef BlacklistFile = StringRef())
+ : ModulePass(ID),
+ CheckInitOrder(CheckInitOrder || ClInitializers),
+ BlacklistFile(BlacklistFile.empty() ? ClBlacklistFile
+ : BlacklistFile) {}
+ bool runOnModule(Module &M);
+ static char ID; // Pass identification, replacement for typeid
+ virtual const char *getPassName() const {
+ return "AddressSanitizerModule";
+ }
+
+ private:
+ void initializeCallbacks(Module &M);
+
+ bool ShouldInstrumentGlobal(GlobalVariable *G);
+ void createInitializerPoisonCalls(Module &M, GlobalValue *ModuleName);
+ size_t MinRedzoneSizeForGlobal() const {
+ return RedzoneSizeForScale(Mapping.Scale);
+ }
+
+ bool CheckInitOrder;
+ SmallString<64> BlacklistFile;
+
+ OwningPtr<SpecialCaseList> BL;
+ SetOfDynamicallyInitializedGlobals DynamicallyInitializedGlobals;
+ Type *IntptrTy;
+ LLVMContext *C;
+ DataLayout *TD;
+ ShadowMapping Mapping;
+ Function *AsanPoisonGlobals;
+ Function *AsanUnpoisonGlobals;
+ Function *AsanRegisterGlobals;
+ Function *AsanUnregisterGlobals;
+};
+
+// Stack poisoning does not play well with exception handling.
+// When an exception is thrown, we essentially bypass the code
+// that unpoisones the stack. This is why the run-time library has
+// to intercept __cxa_throw (as well as longjmp, etc) and unpoison the entire
+// stack in the interceptor. This however does not work inside the
+// actual function which catches the exception. Most likely because the
+// compiler hoists the load of the shadow value somewhere too high.
+// This causes asan to report a non-existing bug on 453.povray.
+// It sounds like an LLVM bug.
+struct FunctionStackPoisoner : public InstVisitor<FunctionStackPoisoner> {
+ Function &F;
+ AddressSanitizer &ASan;
+ DIBuilder DIB;
+ LLVMContext *C;
+ Type *IntptrTy;
+ Type *IntptrPtrTy;
+ ShadowMapping Mapping;
+
+ SmallVector<AllocaInst*, 16> AllocaVec;
+ SmallVector<Instruction*, 8> RetVec;
+ unsigned StackAlignment;
+
+ Function *AsanStackMallocFunc[kMaxAsanStackMallocSizeClass + 1],
+ *AsanStackFreeFunc[kMaxAsanStackMallocSizeClass + 1];
+ Function *AsanPoisonStackMemoryFunc, *AsanUnpoisonStackMemoryFunc;
+
+ // Stores a place and arguments of poisoning/unpoisoning call for alloca.
+ struct AllocaPoisonCall {
+ IntrinsicInst *InsBefore;
+ AllocaInst *AI;
+ uint64_t Size;
+ bool DoPoison;
+ };
+ SmallVector<AllocaPoisonCall, 8> AllocaPoisonCallVec;
+
+ // Maps Value to an AllocaInst from which the Value is originated.
+ typedef DenseMap<Value*, AllocaInst*> AllocaForValueMapTy;
+ AllocaForValueMapTy AllocaForValue;
+
+ FunctionStackPoisoner(Function &F, AddressSanitizer &ASan)
+ : F(F), ASan(ASan), DIB(*F.getParent()), C(ASan.C),
+ IntptrTy(ASan.IntptrTy), IntptrPtrTy(PointerType::get(IntptrTy, 0)),
+ Mapping(ASan.Mapping),
+ StackAlignment(1 << Mapping.Scale) {}
+
+ bool runOnFunction() {
+ if (!ClStack) return false;
+ // Collect alloca, ret, lifetime instructions etc.
+ for (df_iterator<BasicBlock*> DI = df_begin(&F.getEntryBlock()),
+ DE = df_end(&F.getEntryBlock()); DI != DE; ++DI) {
+ BasicBlock *BB = *DI;
+ visit(*BB);
+ }
+ if (AllocaVec.empty()) return false;
+
+ initializeCallbacks(*F.getParent());
+
+ poisonStack();
+
+ if (ClDebugStack) {
+ DEBUG(dbgs() << F);
+ }
+ return true;
+ }
+
+ // Finds all static Alloca instructions and puts
+ // poisoned red zones around all of them.
+ // Then unpoison everything back before the function returns.
+ void poisonStack();
+
+ // ----------------------- Visitors.
+ /// \brief Collect all Ret instructions.
+ void visitReturnInst(ReturnInst &RI) {
+ RetVec.push_back(&RI);
+ }
+
+ /// \brief Collect Alloca instructions we want (and can) handle.
+ void visitAllocaInst(AllocaInst &AI) {
+ if (!isInterestingAlloca(AI)) return;
+
+ StackAlignment = std::max(StackAlignment, AI.getAlignment());
+ AllocaVec.push_back(&AI);
+ }
+
+ /// \brief Collect lifetime intrinsic calls to check for use-after-scope
+ /// errors.
+ void visitIntrinsicInst(IntrinsicInst &II) {
+ if (!ASan.CheckLifetime) return;
+ Intrinsic::ID ID = II.getIntrinsicID();
+ if (ID != Intrinsic::lifetime_start &&
+ ID != Intrinsic::lifetime_end)
+ return;
+ // Found lifetime intrinsic, add ASan instrumentation if necessary.
+ ConstantInt *Size = dyn_cast<ConstantInt>(II.getArgOperand(0));
+ // If size argument is undefined, don't do anything.
+ if (Size->isMinusOne()) return;
+ // Check that size doesn't saturate uint64_t and can
+ // be stored in IntptrTy.
+ const uint64_t SizeValue = Size->getValue().getLimitedValue();
+ if (SizeValue == ~0ULL ||
+ !ConstantInt::isValueValidForType(IntptrTy, SizeValue))
+ return;
+ // Find alloca instruction that corresponds to llvm.lifetime argument.
+ AllocaInst *AI = findAllocaForValue(II.getArgOperand(1));
+ if (!AI) return;
+ bool DoPoison = (ID == Intrinsic::lifetime_end);
+ AllocaPoisonCall APC = {&II, AI, SizeValue, DoPoison};
+ AllocaPoisonCallVec.push_back(APC);
+ }
+
+ // ---------------------- Helpers.
+ void initializeCallbacks(Module &M);
+
+ // Check if we want (and can) handle this alloca.
+ bool isInterestingAlloca(AllocaInst &AI) const {
+ return (!AI.isArrayAllocation() && AI.isStaticAlloca() &&
+ AI.getAllocatedType()->isSized() &&
+ // alloca() may be called with 0 size, ignore it.
+ getAllocaSizeInBytes(&AI) > 0);
+ }
+
+ uint64_t getAllocaSizeInBytes(AllocaInst *AI) const {
+ Type *Ty = AI->getAllocatedType();
+ uint64_t SizeInBytes = ASan.TD->getTypeAllocSize(Ty);
+ return SizeInBytes;
+ }
+ /// Finds alloca where the value comes from.
+ AllocaInst *findAllocaForValue(Value *V);
+ void poisonRedZones(const ArrayRef<uint8_t> ShadowBytes, IRBuilder<> &IRB,
+ Value *ShadowBase, bool DoPoison);
+ void poisonAlloca(Value *V, uint64_t Size, IRBuilder<> &IRB, bool DoPoison);
+
+ void SetShadowToStackAfterReturnInlined(IRBuilder<> &IRB, Value *ShadowBase,
+ int Size);