diff --git a/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp b/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp index 45bcdf87aa49..482ebef2a239 100644 --- a/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp +++ b/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp @@ -230,17 +230,17 @@ static GlobalVariable *createPrivateGlobalForString(Module &M, StringRef Str) { // Returns the ThenBlock's terminator. static BranchInst *splitBlockAndInsertIfThen(Value *Cmp) { Instruction *SplitBefore = cast(Cmp)->getNextNode(); - - // Create three basic blocks, with the middle block empty, by splitting twice. BasicBlock *Head = SplitBefore->getParent(); - BasicBlock *Then = Head->splitBasicBlock(SplitBefore); - BasicBlock *Tail = Then->splitBasicBlock(SplitBefore); - + BasicBlock *Tail = Head->splitBasicBlock(SplitBefore); TerminatorInst *HeadOldTerm = Head->getTerminator(); - IRBuilder<>(HeadOldTerm).CreateCondBr(Cmp, Then, Tail); - HeadOldTerm->eraseFromParent(); + LLVMContext &C = Head->getParent()->getParent()->getContext(); + BasicBlock *ThenBlock = BasicBlock::Create(C, "", Head->getParent()); + BranchInst *HeadNewTerm = + BranchInst::Create(/*ifTrue*/ThenBlock, /*ifFalse*/Tail, Cmp); + ReplaceInstWithInst(HeadOldTerm, HeadNewTerm); - return cast(Then->getTerminator()); + BranchInst *CheckTerm = BranchInst::Create(Tail, ThenBlock); + return CheckTerm; } Value *AddressSanitizer::memToShadow(Value *Shadow, IRBuilder<> &IRB) { @@ -387,28 +387,28 @@ void AddressSanitizer::instrumentAddress(Instruction *OrigIns, Value *Cmp = IRB.CreateICmpNE(ShadowValue, CmpVal); Instruction *CheckTerm = splitBlockAndInsertIfThen(Cmp); - IRB.SetInsertPoint(CheckTerm); + IRBuilder<> IRB2(CheckTerm); size_t Granularity = 1 << MappingScale; if (TypeSize < 8 * Granularity) { // Addr & (Granularity - 1) - Value *LastAccessedByte = IRB.CreateAnd( + Value *LastAccessedByte = IRB2.CreateAnd( AddrLong, ConstantInt::get(IntptrTy, Granularity - 1)); // (Addr & (Granularity - 1)) + size - 1 if (TypeSize / 8 > 1) - LastAccessedByte = IRB.CreateAdd( + LastAccessedByte = IRB2.CreateAdd( LastAccessedByte, ConstantInt::get(IntptrTy, TypeSize / 8 - 1)); // (uint8_t) ((Addr & (Granularity-1)) + size - 1) - LastAccessedByte = IRB.CreateIntCast( + LastAccessedByte = IRB2.CreateIntCast( LastAccessedByte, IRB.getInt8Ty(), false); // ((uint8_t) ((Addr & (Granularity-1)) + size - 1)) >= ShadowValue - Value *Cmp2 = IRB.CreateICmpSGE(LastAccessedByte, ShadowValue); + Value *Cmp2 = IRB2.CreateICmpSGE(LastAccessedByte, ShadowValue); CheckTerm = splitBlockAndInsertIfThen(Cmp2); - IRB.SetInsertPoint(CheckTerm); } - Instruction *Crash = generateCrashCode(IRB, AddrLong, IsWrite, TypeSize); + IRBuilder<> IRB1(CheckTerm); + Instruction *Crash = generateCrashCode(IRB1, AddrLong, IsWrite, TypeSize); Crash->setDebugLoc(OrigIns->getDebugLoc()); ReplaceInstWithInst(CheckTerm, new UnreachableInst(*C)); } diff --git a/llvm/test/Instrumentation/AddressSanitizer/basic.ll b/llvm/test/Instrumentation/AddressSanitizer/basic.ll index 15b51d410ad8..e80cfeef12a7 100644 --- a/llvm/test/Instrumentation/AddressSanitizer/basic.ll +++ b/llvm/test/Instrumentation/AddressSanitizer/basic.ll @@ -16,6 +16,11 @@ define i32 @test_load(i32* %a) address_safety { ; CHECK: icmp ne i8 ; CHECK: br i1 %{{.*}}, label %{{.*}}, label %{{.*}} ; +; The actual load comes next because ASan adds the last instrumentation block +; to the end of the function. +; CHECK: %tmp1 = load i32* %a +; CHECK: ret i32 %tmp1 +; ; First instrumentation block refines the shadow test. ; CHECK: and i64 %[[LOAD_ADDR]], 7 ; CHECK: add i64 %{{.*}}, 3 @@ -23,13 +28,9 @@ define i32 @test_load(i32* %a) address_safety { ; CHECK: icmp sge i8 %{{.*}}, %[[LOAD_SHADOW]] ; CHECK: br i1 %{{.*}}, label %{{.*}}, label %{{.*}} ; -; Second instrumentation block reports the error. +; Final instrumentation block reports the error. ; CHECK: call void @__asan_report_load4(i64 %[[LOAD_ADDR]]) noreturn ; CHECK: unreachable -; -; Finally the instrumented load. -; CHECK: %tmp1 = load i32* %a -; CHECK: ret i32 %tmp1 entry: %tmp1 = load i32* %a @@ -47,6 +48,11 @@ define void @test_store(i32* %a) address_safety { ; CHECK: icmp ne i8 ; CHECK: br i1 %{{.*}}, label %{{.*}}, label %{{.*}} ; +; The actual store comes next because ASan adds the last instrumentation block +; to the end of the function. +; CHECK: store i32 42, i32* %a +; CHECK: ret void +; ; First instrumentation block refines the shadow test. ; CHECK: and i64 %[[STORE_ADDR]], 7 ; CHECK: add i64 %{{.*}}, 3 @@ -54,13 +60,9 @@ define void @test_store(i32* %a) address_safety { ; CHECK: icmp sge i8 %{{.*}}, %[[STORE_SHADOW]] ; CHECK: br i1 %{{.*}}, label %{{.*}}, label %{{.*}} ; -; Second instrumentation block reports the error. +; Final instrumentation block reports the error. ; CHECK: call void @__asan_report_store4(i64 %[[STORE_ADDR]]) noreturn ; CHECK: unreachable -; -; Finally the instrumented store. -; CHECK: store i32 42, i32* %a -; CHECK: ret void entry: store i32 42, i32* %a