Author: kcc Date: Mon Aug 25 21:29:59 2014 New Revision: 216434 URL: http://llvm.org/viewvc/llvm-project?rev=216434&view=rev Log: [clang/asan] call __asan_poison_cxx_array_cookie after operator new[]
Summary: PR19838 When operator new[] is called and an array cookie is created we want asan to detect buffer overflow bugs that touch the cookie. For that we need to a) poison the shadow for the array cookie (call __asan_poison_cxx_array_cookie). b) ignore the legal accesses to the cookie generated by clang (add 'nosanitize' metadata) Reviewers: timurrrr, samsonov, rsmith Reviewed By: rsmith Subscribers: cfe-commits Differential Revision: http://reviews.llvm.org/D4774 Added: cfe/trunk/test/CodeGen/address-sanitizer-and-array-cookie.cpp Modified: cfe/trunk/lib/CodeGen/CodeGenFunction.cpp cfe/trunk/lib/CodeGen/ItaniumCXXABI.cpp cfe/trunk/lib/CodeGen/SanitizerMetadata.cpp cfe/trunk/lib/CodeGen/SanitizerMetadata.h Modified: cfe/trunk/lib/CodeGen/CodeGenFunction.cpp URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CodeGenFunction.cpp?rev=216434&r1=216433&r2=216434&view=diff ============================================================================== --- cfe/trunk/lib/CodeGen/CodeGenFunction.cpp (original) +++ cfe/trunk/lib/CodeGen/CodeGenFunction.cpp Mon Aug 25 21:29:59 2014 @@ -1683,11 +1683,8 @@ void CodeGenFunction::InsertHelper(llvm: llvm::BasicBlock *BB, llvm::BasicBlock::iterator InsertPt) const { LoopStack.InsertHelper(I); - if (IsSanitizerScope) { - I->setMetadata( - CGM.getModule().getMDKindID("nosanitize"), - llvm::MDNode::get(CGM.getLLVMContext(), ArrayRef<llvm::Value *>())); - } + if (IsSanitizerScope) + CGM.getSanitizerMetadata()->disableSanitizerForInstruction(I); } template <bool PreserveNames> Modified: cfe/trunk/lib/CodeGen/ItaniumCXXABI.cpp URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/ItaniumCXXABI.cpp?rev=216434&r1=216433&r2=216434&view=diff ============================================================================== --- cfe/trunk/lib/CodeGen/ItaniumCXXABI.cpp (original) +++ cfe/trunk/lib/CodeGen/ItaniumCXXABI.cpp Mon Aug 25 21:29:59 2014 @@ -1472,10 +1472,19 @@ llvm::Value *ItaniumCXXABI::InitializeAr CookieOffset.getQuantity()); // Write the number of elements into the appropriate slot. - llvm::Value *NumElementsPtr - = CGF.Builder.CreateBitCast(CookiePtr, - CGF.ConvertType(SizeTy)->getPointerTo(AS)); - CGF.Builder.CreateStore(NumElements, NumElementsPtr); + llvm::Type *NumElementsTy = CGF.ConvertType(SizeTy)->getPointerTo(AS); + llvm::Value *NumElementsPtr = + CGF.Builder.CreateBitCast(CookiePtr, NumElementsTy); + llvm::Instruction *SI = CGF.Builder.CreateStore(NumElements, NumElementsPtr); + if (CGM.getLangOpts().Sanitize.Address && + expr->getOperatorNew()->isReplaceableGlobalAllocationFunction()) { + CGM.getSanitizerMetadata()->disableSanitizerForInstruction(SI); + llvm::FunctionType *FTy = + llvm::FunctionType::get(CGM.VoidTy, NumElementsTy, false); + llvm::Constant *F = + CGM.CreateRuntimeFunction(FTy, "__asan_poison_cxx_array_cookie"); + CGF.Builder.CreateCall(F, NumElementsPtr); + } // Finally, compute a pointer to the actual data buffer by skipping // over the cookie completely. @@ -1498,7 +1507,10 @@ llvm::Value *ItaniumCXXABI::readArrayCoo unsigned AS = allocPtr->getType()->getPointerAddressSpace(); numElementsPtr = CGF.Builder.CreateBitCast(numElementsPtr, CGF.SizeTy->getPointerTo(AS)); - return CGF.Builder.CreateLoad(numElementsPtr); + llvm::Instruction *LI = CGF.Builder.CreateLoad(numElementsPtr); + if (CGM.getLangOpts().Sanitize.Address) + CGM.getSanitizerMetadata()->disableSanitizerForInstruction(LI); + return LI; } CharUnits ARMCXXABI::getArrayCookieSizeImpl(QualType elementType) { Modified: cfe/trunk/lib/CodeGen/SanitizerMetadata.cpp URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/SanitizerMetadata.cpp?rev=216434&r1=216433&r2=216434&view=diff ============================================================================== --- cfe/trunk/lib/CodeGen/SanitizerMetadata.cpp (original) +++ cfe/trunk/lib/CodeGen/SanitizerMetadata.cpp Mon Aug 25 21:29:59 2014 @@ -67,6 +67,12 @@ void SanitizerMetadata::disableSanitizer reportGlobalToASan(GV, SourceLocation(), "", false, true); } +void SanitizerMetadata::disableSanitizerForInstruction(llvm::Instruction *I) { + I->setMetadata( + CGM.getModule().getMDKindID("nosanitize"), + llvm::MDNode::get(CGM.getLLVMContext(), ArrayRef<llvm::Value *>())); +} + llvm::MDNode *SanitizerMetadata::getLocationMetadata(SourceLocation Loc) { PresumedLoc PLoc = CGM.getContext().getSourceManager().getPresumedLoc(Loc); if (!PLoc.isValid()) Modified: cfe/trunk/lib/CodeGen/SanitizerMetadata.h URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/SanitizerMetadata.h?rev=216434&r1=216433&r2=216434&view=diff ============================================================================== --- cfe/trunk/lib/CodeGen/SanitizerMetadata.h (original) +++ cfe/trunk/lib/CodeGen/SanitizerMetadata.h Mon Aug 25 21:29:59 2014 @@ -18,6 +18,7 @@ namespace llvm { class GlobalVariable; +class Instruction; class MDNode; } @@ -41,6 +42,7 @@ public: StringRef Name, bool IsDynInit = false, bool IsBlacklisted = false); void disableSanitizerForGlobal(llvm::GlobalVariable *GV); + void disableSanitizerForInstruction(llvm::Instruction *I); private: llvm::MDNode *getLocationMetadata(SourceLocation Loc); }; Added: cfe/trunk/test/CodeGen/address-sanitizer-and-array-cookie.cpp URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGen/address-sanitizer-and-array-cookie.cpp?rev=216434&view=auto ============================================================================== --- cfe/trunk/test/CodeGen/address-sanitizer-and-array-cookie.cpp (added) +++ cfe/trunk/test/CodeGen/address-sanitizer-and-array-cookie.cpp Mon Aug 25 21:29:59 2014 @@ -0,0 +1,54 @@ +// RUN: %clang_cc1 -triple x86_64-gnu-linux -emit-llvm -o - %s | FileCheck %s -check-prefix=PLAIN +// RUN: %clang_cc1 -triple x86_64-gnu-linux -emit-llvm -o - -fsanitize=address %s | FileCheck %s -check-prefix=ASAN + +typedef __typeof__(sizeof(0)) size_t; +namespace std { + struct nothrow_t {}; + std::nothrow_t nothrow; +} +void *operator new[](size_t, const std::nothrow_t &) throw(); +void *operator new[](size_t, char *); + +struct C { + int x; + ~C(); +}; + +C *CallNew() { + return new C[10]; +} +// PLAIN-LABEL: CallNew +// PLAIN-NOT: nosanitize +// PLAIN-NOT: __asan_poison_cxx_array_cookie +// ASAN-LABEL: CallNew +// ASAN: store{{.*}}nosanitize +// ASAN-NOT: nosanitize +// ASAN: call void @__asan_poison_cxx_array_cookie + +C *CallNewNoThrow() { + return new (std::nothrow) C[10]; +} +// PLAIN-LABEL: CallNewNoThrow +// PLAIN-NOT: nosanitize +// PLAIN-NOT: __asan_poison_cxx_array_cookie +// ASAN-LABEL: CallNewNoThrow +// ASAN: store{{.*}}nosanitize +// ASAN-NOT: nosanitize +// ASAN: call void @__asan_poison_cxx_array_cookie + +void CallDelete(C *c) { + delete [] c; +} + +// PLAIN-LABEL: CallDelete +// PLAIN-NOT: nosanitize +// ASAN-LABEL: CallDelete +// ASAN: load{{.*}}!nosanitize +// ASAN-NOT: nosanitize + +char Buffer[20]; +C *CallPlacementNew() { + return new (Buffer) C[20]; +} +// ASAN-LABEL: CallPlacementNew +// ASAN-NOT: __asan_poison_cxx_array_cookie _______________________________________________ cfe-commits mailing list [email protected] http://lists.cs.uiuc.edu/mailman/listinfo/cfe-commits
