MemorySanitizer support.

runtime/vm/stack_frame.cc

 // Copyright (c) 2012, 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/stack_frame.h"
 
+#include "platform/memory_sanitizer.h"
 #include "vm/assembler.h"
 #include "vm/deopt_instructions.h"
 #include "vm/isolate.h"
 #include "vm/object.h"
 #include "vm/object_store.h"
 #include "vm/os.h"
 #include "vm/parser.h"
 #include "vm/raw_object.h"
 #include "vm/reusable_handles.h"
 #include "vm/stub_code.h"
@@ skipping 254 matching lines @@
 
 void StackFrameIterator::SetupNextExitFrameData() {
   uword exit_address = entry_.fp() + (kExitLinkSlotFromEntryFp * kWordSize);
   uword exit_marker = *reinterpret_cast<uword*>(exit_address);
   frames_.fp_ = exit_marker;
   frames_.sp_ = 0;
   frames_.pc_ = 0;
 }
 
 
+// Tell MemorySanitizer that generated code initializes part of the stack.
+// TODO(koda): Limit to frames that are actually written by generated code.
+static void UnpoisonStack(Isolate* isolate) {

[siva, 2014/12/22 17:01:53]

ASSERT(isolate->stack_limit() != ~static_cast<uword>(0));

[koda, 2014/12/22 23:05:52]

Changed to instead take an explicit 'fp' argument, and unpoison the area around
it.

+  __msan_unpoison(reinterpret_cast<void*>(isolate->stack_limit()),
+                  isolate->GetSpecifiedStackSize());
+}
+
+
 StackFrameIterator::StackFrameIterator(bool validate, Isolate* isolate)
     : validate_(validate),
       entry_(isolate),
       exit_(isolate),
       frames_(isolate),
       current_frame_(NULL),
       isolate_(isolate) {
   ASSERT((isolate_ == Isolate::Current()) ||
          OS::AllowStackFrameIteratorFromAnotherThread());
+  UnpoisonStack(isolate);
   SetupLastExitFrameData();  // Setup data for last exit frame.
 }
 
 
 StackFrameIterator::StackFrameIterator(uword last_fp, bool validate,
                                        Isolate* isolate)
     : validate_(validate),
       entry_(isolate),
       exit_(isolate),
       frames_(isolate),
       current_frame_(NULL),
       isolate_(isolate) {
   ASSERT((isolate_ == Isolate::Current()) ||
          OS::AllowStackFrameIteratorFromAnotherThread());
+  UnpoisonStack(isolate);
   frames_.fp_ = last_fp;
   frames_.sp_ = 0;
   frames_.pc_ = 0;
 }
 
 
 StackFrameIterator::StackFrameIterator(uword fp, uword sp, uword pc,
                                        bool validate, Isolate* isolate)
     : validate_(validate),
       entry_(isolate),
       exit_(isolate),
       frames_(isolate),
       current_frame_(NULL),
       isolate_(isolate) {
   ASSERT((isolate_ == Isolate::Current()) ||
          OS::AllowStackFrameIteratorFromAnotherThread());
+  UnpoisonStack(isolate);
   frames_.fp_ = fp;
   frames_.sp_ = sp;
   frames_.pc_ = pc;
 }
 
 
 StackFrame* StackFrameIterator::NextFrame() {
   // When we are at the start of iteration after having created an
   // iterator object, current_frame_ will be NULL as we haven't seen
   // any frames yet (unless we start iterating in the simulator from a given
@@ skipping 149 matching lines @@
     if (deopt_instr->kind() == DeoptInstr::kCallerFp) {
       return (index - num_materializations_);
     }
   }
   UNREACHABLE();
   return 0;
 }
 
 
 }  // namespace dart