From c4ce5dfe2da865e5e3e81b3638c4c8491d5a6233 Mon Sep 17 00:00:00 2001 From: Kostya Serebryany Date: Mon, 16 Jul 2012 17:12:07 +0000 Subject: [PATCH] [asan] a bit more refactoring, addressed some of the style comments from chandlerc, partially implemented crash callback merging (under flag) llvm-svn: 160290 --- .../Instrumentation/AddressSanitizer.cpp | 56 +++++++++++++------ 1 file changed, 39 insertions(+), 17 deletions(-) diff --git a/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp b/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp index 1fc1871d7124..8d9e85c7eeb8 100644 --- a/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp +++ b/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp @@ -146,10 +146,9 @@ namespace { /// An object of this type is created while instrumenting every function. struct AsanFunctionContext { - AsanFunctionContext() { - memset(this, 0, sizeof(*this)); - } + AsanFunctionContext(Function &Function) : F(Function), CrashBlock() { } + Function &F; // These are initially zero. If we require at least one call to // __asan_report_{read,write}{1,2,4,8,16}, an appropriate BB is created. BasicBlock *CrashBlock[2][kNumberOfAccessSizes]; @@ -166,7 +165,7 @@ struct AddressSanitizer : public ModulePass { Value *createSlowPathCmp(IRBuilder<> &IRB, Value *AddrLong, Value *ShadowValue, uint32_t TypeSize); Instruction *generateCrashCode(BasicBlock *BB, Value *Addr, - bool IsWrite, uint32_t TypeSize); + bool IsWrite, size_t AccessSizeIndex); bool instrumentMemIntrinsic(AsanFunctionContext &AFC, MemIntrinsic *MI); void instrumentMemIntrinsicParam(AsanFunctionContext &AFC, Instruction *OrigIns, Value *Addr, @@ -232,6 +231,12 @@ const char *AddressSanitizer::getPassName() const { return "AddressSanitizer"; } +static size_t TypeSizeToSizeIndex(uint32_t TypeSize) { + size_t Res = CountTrailingZeros_32(TypeSize / 8); + assert(Res < kNumberOfAccessSizes); + return Res; +} + // Create a constant for Str so that we can pass it to the run-time lib. static GlobalVariable *createPrivateGlobalForString(Module &M, StringRef Str) { Constant *StrConst = ConstantDataArray::getString(M.getContext(), Str); @@ -251,14 +256,14 @@ static GlobalVariable *createPrivateGlobalForString(Module &M, StringRef Str) { // Tail // // If ThenBlock is zero, a new block is created and its terminator is returned. -// Otherwize NULL is returned. +// Otherwize 0 is returned. static BranchInst *splitBlockAndInsertIfThen(Value *Cmp, BasicBlock *ThenBlock = 0) { Instruction *SplitBefore = cast(Cmp)->getNextNode(); BasicBlock *Head = SplitBefore->getParent(); BasicBlock *Tail = Head->splitBasicBlock(SplitBefore); TerminatorInst *HeadOldTerm = Head->getTerminator(); - BranchInst *CheckTerm = NULL; + BranchInst *CheckTerm = 0; if (!ThenBlock) { LLVMContext &C = Head->getParent()->getParent()->getContext(); ThenBlock = BasicBlock::Create(C, "", Head->getParent()); @@ -306,7 +311,7 @@ bool AddressSanitizer::instrumentMemIntrinsic(AsanFunctionContext &AFC, MemIntrinsic *MI) { Value *Dst = MI->getDest(); MemTransferInst *MemTran = dyn_cast(MI); - Value *Src = MemTran ? MemTran->getSource() : NULL; + Value *Src = MemTran ? MemTran->getSource() : 0; Value *Length = MI->getLength(); Constant *ConstLength = dyn_cast(Length); @@ -390,17 +395,15 @@ Function *AddressSanitizer::checkInterfaceFunction(Constant *FuncOrBitcast) { } Instruction *AddressSanitizer::generateCrashCode( - BasicBlock *BB, Value *Addr, bool IsWrite, uint32_t TypeSize) { + BasicBlock *BB, Value *Addr, bool IsWrite, size_t AccessSizeIndex) { IRBuilder<> IRB(BB->getFirstNonPHI()); - size_t AccessSizeIndex = CountTrailingZeros_32(TypeSize / 8); - assert(AccessSizeIndex < kNumberOfAccessSizes); CallInst *Call = IRB.CreateCall(AsanErrorCallback[IsWrite][AccessSizeIndex], Addr); Call->setDoesNotReturn(); return Call; } -Value * AddressSanitizer::createSlowPathCmp(IRBuilder<> &IRB, Value *AddrLong, +Value *AddressSanitizer::createSlowPathCmp(IRBuilder<> &IRB, Value *AddrLong, Value *ShadowValue, uint32_t TypeSize) { size_t Granularity = 1 << MappingScale; @@ -434,15 +437,22 @@ void AddressSanitizer::instrumentAddress(AsanFunctionContext &AFC, Value *Cmp = IRB.CreateICmpNE(ShadowValue, CmpVal); - BasicBlock *CrashBlock = NULL; + BasicBlock *CrashBlock = 0; if (ClMergeCallbacks) { - llvm_unreachable("unimplemented yet"); + BasicBlock **Cached = + &AFC.CrashBlock[IsWrite][TypeSizeToSizeIndex(TypeSize)]; + if (!*Cached) { + BasicBlock *BB = BasicBlock::Create(*C, "crash_bb", &AFC.F); + new UnreachableInst(*C, BB); + *Cached = BB; + } + CrashBlock = *Cached; } else { - CrashBlock = BasicBlock::Create(*C, "crash_bb", - OrigIns->getParent()->getParent()); + CrashBlock = BasicBlock::Create(*C, "crash_bb", &AFC.F); new UnreachableInst(*C, CrashBlock); + size_t AccessSizeIndex = TypeSizeToSizeIndex(TypeSize); Instruction *Crash = - generateCrashCode(CrashBlock, AddrLong, IsWrite, TypeSize); + generateCrashCode(CrashBlock, AddrLong, IsWrite, AccessSizeIndex); Crash->setDebugLoc(OrigIns->getDebugLoc()); } @@ -776,7 +786,7 @@ bool AddressSanitizer::handleFunction(Module &M, Function &F) { } } - AsanFunctionContext AFC; + AsanFunctionContext AFC(F); // Instrument. int NumInstrumented = 0; @@ -792,6 +802,18 @@ bool AddressSanitizer::handleFunction(Module &M, Function &F) { NumInstrumented++; } + if (NumInstrumented) { + for (size_t IsWrite = 0; IsWrite <= 1; IsWrite++) { + for (size_t AccessSizeIndex = 0; AccessSizeIndex < kNumberOfAccessSizes; + AccessSizeIndex++) { + BasicBlock *BB = AFC.CrashBlock[IsWrite][AccessSizeIndex]; + if (!BB) continue; + generateCrashCode(BB, ConstantInt::get(IntptrTy, 0), + IsWrite, AccessSizeIndex); + } + } + } + DEBUG(dbgs() << F); bool ChangedStack = poisonStackInFunction(M, F);