1 files changed, 20 insertions, 0 deletions
diff --git a/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp b/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
index 6e17801..2646334 100644
--- a/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
+++ b/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
@@ -844,6 +844,7 @@ struct AddressSanitizer {
   bool maybeInsertAsanInitAtFunctionEntry(Function &F);
   bool maybeInsertDynamicShadowAtFunctionEntry(Function &F);
   void markEscapedLocalAllocas(Function &F);
+  void markCatchParametersAsUninteresting(Function &F);
 
 private:
   friend struct FunctionStackPoisoner;
@@ -2997,6 +2998,22 @@ void AddressSanitizer::markEscapedLocalAllocas(Function &F) {
     }
   }
 }
+// Mitigation for https://github.com/google/sanitizers/issues/749
+// We don't instrument Windows catch-block parameters to avoid
+// interfering with exception handling assumptions.
+void AddressSanitizer::markCatchParametersAsUninteresting(Function &F) {
+  for (BasicBlock &BB : F) {
+    for (Instruction &I : BB) {
+      if (auto *CatchPad = dyn_cast<CatchPadInst>(&I)) {
+        // Mark the parameters to a catch-block as uninteresting to avoid
+        // instrumenting them.
+        for (Value *Operand : CatchPad->arg_operands())
+          if (auto *AI = dyn_cast<AllocaInst>(Operand))
+            ProcessedAllocas[AI] = false;
+      }
+    }
+  }
+}
 
 bool AddressSanitizer::suppressInstrumentationSiteForDebug(int &Instrumented) {
   bool ShouldInstrument =
@@ -3041,6 +3058,9 @@ bool AddressSanitizer::instrumentFunction(Function &F,
   // can be passed to that intrinsic.
   markEscapedLocalAllocas(F);
 
+  if (TargetTriple.isOSWindows())
+    markCatchParametersAsUninteresting(F);
+
   // We want to instrument every address only once per basic block (unless there
   // are calls between uses).
   SmallPtrSet<Value *, 16> TempsToInstrument;