Index: cfe/trunk/lib/CodeGen/CGClass.cpp
===================================================================
--- cfe/trunk/lib/CodeGen/CGClass.cpp
+++ cfe/trunk/lib/CodeGen/CGClass.cpp
@@ -1577,6 +1577,7 @@
 
  static void EmitSanitizerDtorCallback(CodeGenFunction &CGF, llvm::Value *Ptr,
              CharUnits::QuantityType PoisonSize) {
+   CodeGenFunction::SanitizerScope SanScope(&CGF);
    // Pass in void pointer and size of region as arguments to runtime
    // function
    llvm::Value *Args[] = {CGF.Builder.CreateBitCast(Ptr, CGF.VoidPtrTy),
Index: cfe/trunk/test/CodeGenCXX/sanitize-dtor-callback.cpp
===================================================================
--- cfe/trunk/test/CodeGenCXX/sanitize-dtor-callback.cpp
+++ cfe/trunk/test/CodeGenCXX/sanitize-dtor-callback.cpp
@@ -55,16 +55,19 @@
 // to confirm that all invoked dtors have member poisoning
 // instrumentation inserted.
 // CHECK-LABEL: define {{.*}}SimpleD2Ev
+// CHECK-NOT: store i{{[0-9]+}} 0, {{.*}}@__msan_param_tls
 // CHECK: call void @__sanitizer_dtor_callback
 // CHECK-NOT: call void @__sanitizer_dtor_callback
 // CHECK: ret void
 
 // CHECK-LABEL: define {{.*}}InlinedD2Ev
+// CHECK-NOT: store i{{[0-9]+}} 0, {{.*}}@__msan_param_tls
 // CHECK: call void @__sanitizer_dtor_callback
 // CHECK-NOT: call void @__sanitizer_dtor_callback
 // CHECK: ret void
 
 // CHECK-LABEL: define {{.*}}Defaulted_Non_TrivialD2Ev
+// CHECK-NOT: store i{{[0-9]+}} 0, {{.*}}@__msan_param_tls
 // CHECK: call void @__sanitizer_dtor_callback
 // CHECK-NOT: call void @__sanitizer_dtor_callback
 // CHECK: ret void
Index: llvm/trunk/lib/Transforms/Instrumentation/MemorySanitizer.cpp
===================================================================
--- llvm/trunk/lib/Transforms/Instrumentation/MemorySanitizer.cpp
+++ llvm/trunk/lib/Transforms/Instrumentation/MemorySanitizer.cpp
@@ -2588,6 +2588,7 @@
 
   void visitCallSite(CallSite CS) {
     Instruction &I = *CS.getInstruction();
+    if (I.getMetadata("nosanitize")) return;
     assert((CS.isCall() || CS.isInvoke()) && "Unknown type of CallSite");
     if (CS.isCall()) {
       CallInst *Call = cast<CallInst>(&I);
Index: llvm/trunk/test/Instrumentation/MemorySanitizer/call-nosanitize.ll
===================================================================
--- llvm/trunk/test/Instrumentation/MemorySanitizer/call-nosanitize.ll
+++ llvm/trunk/test/Instrumentation/MemorySanitizer/call-nosanitize.ll
@@ -0,0 +1,16 @@
+; Verify that calls with !nosanitize are not instrumented by MSan.
+; RUN: opt < %s -msan -S | FileCheck %s
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+declare void @bar(i32 %x)
+
+define void @foo() {
+  call void @bar(i32 7), !nosanitize !{}
+  ret void
+}
+
+; CHECK-LABEL: define void @foo
+; CHECK-NOT: store i{{[0-9]+}} 0, {{.*}} @__msan_param_tls
+; CHECK: call void @bar
+; CHECK: ret void