- fix some cases where we are using uninitialized memory

runtime/vm/native_entry.cc

 // Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/native_entry.h"
 
 #include "include/dart_api.h"
 
 #include "vm/bootstrap.h"
 #include "vm/code_patcher.h"
@@ skipping 81 matching lines @@
   uword entry = reinterpret_cast<uword>(NativeEntry::NativeCallWrapper);
 #if defined(USING_SIMULATOR) && !defined(TARGET_ARCH_DBC)
   // DBC does not use redirections unlike other simulators.
   entry = Simulator::RedirectExternalReference(
       entry, Simulator::kNativeCall, NativeEntry::kNumCallWrapperArguments);
 #endif
   return entry;
 }
 
 
+NO_SANITIZE_MEMORY

[Florian Schneider, 2016/10/04 21:02:02]

Here, it would be nice to figure out why the unpoison that we have is not
enough. I wonder if there is some problem with msan itself?

[siva, 2016/10/05 20:38:07]

Figured out what the problem was, we need to unpoison the contents
of the return value location also (see ArgAt and ReturnValue functions in class
NativeArguments).

I have removed this NO_SANITIZE_MEMORY from here.

 bool NativeEntry::ReturnValueIsError(NativeArguments* arguments) {
   RawObject* retval = arguments->ReturnValue();
   return (retval->IsHeapObject() &&
           RawObject::IsErrorClassId(retval->GetClassId()));
 }
 
 
 void NativeEntry::PropagateErrors(NativeArguments* arguments) {
   Thread* thread = arguments->thread();
   thread->UnwindScopes(thread->top_exit_frame_info());
@@ skipping 184 matching lines @@
     NativeEntry::NativeCallWrapperNoStackCheck(
         args, reinterpret_cast<Dart_NativeFunction>(target_function));
   } else {
     target_function(arguments);
   }
 }
 #endif  // !defined(TARGET_ARCH_DBC)
 
 
 }  // namespace dart