From 6e2d506dc962873a0e05092bbb034f9a615d1084 Mon Sep 17 00:00:00 2001 From: Kostya Serebryany Date: Wed, 15 Aug 2012 08:58:58 +0000 Subject: [PATCH] [asan] implement --asan-always-slow-path, which is a part of the improvement to handle unaligned partially OOB accesses. See http://code.google.com/p/address-sanitizer/issues/detail?id=100 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@161937 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Transforms/Instrumentation/AddressSanitizer.cpp | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/lib/Transforms/Instrumentation/AddressSanitizer.cpp b/lib/Transforms/Instrumentation/AddressSanitizer.cpp index 3d5424951c1..17b83ceee19 100644 --- a/lib/Transforms/Instrumentation/AddressSanitizer.cpp +++ b/lib/Transforms/Instrumentation/AddressSanitizer.cpp @@ -86,6 +86,9 @@ static cl::opt ClInstrumentWrites("asan-instrument-writes", static cl::opt ClInstrumentAtomics("asan-instrument-atomics", cl::desc("instrument atomic instructions (rmw, cmpxchg)"), cl::Hidden, cl::init(true)); +static cl::opt ClAlwaysSlowPath("asan-always-slow-path", + cl::desc("use instrumentation with slow path for all accesses"), + cl::Hidden, cl::init(false)); // This flag limits the number of instructions to be instrumented // in any given BB. Normally, this should be set to unlimited (INT_MAX), // but due to http://llvm.org/bugs/show_bug.cgi?id=12652 we temporary @@ -416,7 +419,7 @@ Value *AddressSanitizer::createSlowPathCmp(IRBuilder<> &IRB, Value *AddrLong, LastAccessedByte, ConstantInt::get(IntptrTy, TypeSize / 8 - 1)); // (uint8_t) ((Addr & (Granularity-1)) + size - 1) LastAccessedByte = IRB.CreateIntCast( - LastAccessedByte, IRB.getInt8Ty(), false); + LastAccessedByte, ShadowValue->getType(), false); // ((uint8_t) ((Addr & (Granularity-1)) + size - 1)) >= ShadowValue return IRB.CreateICmpSGE(LastAccessedByte, ShadowValue); } @@ -440,7 +443,7 @@ void AddressSanitizer::instrumentAddress(AsanFunctionContext &AFC, size_t Granularity = 1 << MappingScale; TerminatorInst *CrashTerm = 0; - if (TypeSize < 8 * Granularity) { + if (ClAlwaysSlowPath || (TypeSize < 8 * Granularity)) { TerminatorInst *CheckTerm = splitBlockAndInsertIfThen(Cmp, false); assert(dyn_cast(CheckTerm)->isUnconditional()); BasicBlock *NextBB = CheckTerm->getSuccessor(0); -- 2.34.1