[asan] instrument cmpxchg and atomicrmw

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@157683 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Transforms/Instrumentation/AddressSanitizer.cpp b/lib/Transforms/Instrumentation/AddressSanitizer.cpp
index 5f03d352d6098d465f5d0d03575bd153a8e24885..a9d08db9c603e256fbf1b91c1273bcbe208b0f3c 100644 (file)
--- a/lib/Transforms/Instrumentation/AddressSanitizer.cpp
+++ b/lib/Transforms/Instrumentation/AddressSanitizer.cpp
@@ -79,6 +79,9 @@ static cl::opt<bool> ClInstrumentReads("asan-instrument-reads",
        cl::desc("instrument read instructions"), cl::Hidden, cl::init(true));
 static cl::opt<bool> ClInstrumentWrites("asan-instrument-writes",
        cl::desc("instrument write instructions"), cl::Hidden, cl::init(true));
+static cl::opt<bool> ClInstrumentAtomics("asan-instrument-atomics",
+       cl::desc("instrument atomic instructions (rmw, cmpxchg)"),
+       cl::Hidden, cl::init(true));
 // This flag may need to be replaced with -f[no]asan-stack.
 static cl::opt<bool> ClStack("asan-stack",
        cl::desc("Handle stack memory"), cl::Hidden, cl::init(true));
@@ -290,16 +293,36 @@ bool AddressSanitizer::instrumentMemIntrinsic(MemIntrinsic *MI) {
   return true;
 }
 
-static Value *getLDSTOperand(Instruction *I) {
+// If I is an interesting memory access, return the PointerOperand
+// and set IsWrite. Otherwise return NULL.
+static Value *isInterestingMemoryAccess(Instruction *I, bool *IsWrite) {
   if (LoadInst *LI = dyn_cast<LoadInst>(I)) {
+    if (!ClInstrumentReads) return NULL;
+    *IsWrite = false;
     return LI->getPointerOperand();
   }
-  return cast<StoreInst>(*I).getPointerOperand();
+  if (StoreInst *SI = dyn_cast<StoreInst>(I)) {
+    if (!ClInstrumentWrites) return NULL;
+    *IsWrite = true;
+    return SI->getPointerOperand();
+  }
+  if (AtomicRMWInst *RMW = dyn_cast<AtomicRMWInst>(I)) {
+    if (!ClInstrumentAtomics) return NULL;
+    *IsWrite = true;
+    return RMW->getPointerOperand();
+  }
+  if (AtomicCmpXchgInst *XCHG = dyn_cast<AtomicCmpXchgInst>(I)) {
+    if (!ClInstrumentAtomics) return NULL;
+    *IsWrite = true;
+    return XCHG->getPointerOperand();
+  }
+  return NULL;
 }
 
 void AddressSanitizer::instrumentMop(Instruction *I) {
-  int IsWrite = isa<StoreInst>(*I);
-  Value *Addr = getLDSTOperand(I);
+  bool IsWrite;
+  Value *Addr = isInterestingMemoryAccess(I, &IsWrite);
+  assert(Addr);
   if (ClOpt && ClOptGlobals && isa<GlobalVariable>(Addr)) {
     // We are accessing a global scalar variable. Nothing to catch here.
     return;
@@ -660,6 +683,7 @@ bool AddressSanitizer::handleFunction(Module &M, Function &F) {
   SmallSet<Value*, 16> TempsToInstrument;
   SmallVector<Instruction*, 16> ToInstrument;
   SmallVector<Instruction*, 8> NoReturnCalls;
+  bool IsWrite;
 
   // Fill the set of memory operations to instrument.
   for (Function::iterator FI = F.begin(), FE = F.end();
@@ -668,9 +692,7 @@ bool AddressSanitizer::handleFunction(Module &M, Function &F) {
     for (BasicBlock::iterator BI = FI->begin(), BE = FI->end();
          BI != BE; ++BI) {
       if (LooksLikeCodeInBug11395(BI)) return false;
-      if ((isa<LoadInst>(BI) && ClInstrumentReads) ||
-          (isa<StoreInst>(BI) && ClInstrumentWrites)) {
-        Value *Addr = getLDSTOperand(BI);
+      if (Value *Addr = isInterestingMemoryAccess(BI, &IsWrite)) {
         if (ClOpt && ClOptSameTemp) {
           if (!TempsToInstrument.insert(Addr))
             continue;  // We've seen this temp in the current BB.
@@ -697,7 +719,7 @@ bool AddressSanitizer::handleFunction(Module &M, Function &F) {
     Instruction *Inst = ToInstrument[i];
     if (ClDebugMin < 0 || ClDebugMax < 0 ||
         (NumInstrumented >= ClDebugMin && NumInstrumented <= ClDebugMax)) {
-      if (isa<StoreInst>(Inst) || isa<LoadInst>(Inst))
+      if (isInterestingMemoryAccess(Inst, &IsWrite))
         instrumentMop(Inst);
       else
         instrumentMemIntrinsic(cast<MemIntrinsic>(Inst));

diff --git a/test/Instrumentation/AddressSanitizer/test64.ll b/test/Instrumentation/AddressSanitizer/test64.ll
index fc27de914dee8d585870213946abc8fece7dd1f4..d544d77b93db9df0a02b833deee9dd85c4ead7f9 100644 (file)
--- a/test/Instrumentation/AddressSanitizer/test64.ll
+++ b/test/Instrumentation/AddressSanitizer/test64.ll
@@ -12,3 +12,25 @@ entry:
 ; Check for ASAN's Offset for 64-bit (2^44)
 ; CHECK-NEXT: 17592186044416
 ; CHECK: ret
+
+define void @example_atomicrmw(i64* %ptr) nounwind uwtable address_safety {
+entry:
+  %0 = atomicrmw add i64* %ptr, i64 1 seq_cst
+  ret void
+}
+
+; CHECK: @example_atomicrmw
+; CHECK: lshr {{.*}} 3
+; CHECK: atomicrmw
+; CHECK: ret
+
+define void @example_cmpxchg(i64* %ptr, i64 %compare_to, i64 %new_value) nounwind uwtable address_safety {
+entry:
+  %0 = cmpxchg i64* %ptr, i64 %compare_to, i64 %new_value seq_cst
+  ret void
+}
+
+; CHECK: @example_cmpxchg
+; CHECK: lshr {{.*}} 3
+; CHECK: cmpxchg
+; CHECK: ret