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, uword fp) {
+  ASSERT(fp != 0);
+  uword size = isolate->GetSpecifiedStackSize();
+  MSAN_UNPOISON(reinterpret_cast<void*>(fp - size), 2 * size);
+}
+
+
 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());
   SetupLastExitFrameData();  // Setup data for last exit frame.
@@ skipping 42 matching lines @@
   // top_exit_frame_info will be 0 and so we would return NULL.
 
   // current_frame_ will also be NULL, when we are at the end of having
   // iterated through all the frames. If NextFrame is called at this
   // point, we will try and set up the next exit frame, but since we are
   // at the end of the iteration, fp_ will be 0 and we would return NULL.
   if (current_frame_ == NULL) {
     if (!HasNextFrame()) {
       return NULL;
     }
+    UnpoisonStack(isolate_, frames_.fp_);
     if (frames_.pc_ == 0) {
       // Iteration starts from an exit frame given by its fp.
       current_frame_ = NextExitFrame();
     } else if (*(reinterpret_cast<uword*>(
         frames_.fp_ + (kSavedCallerFpSlotFromFp * kWordSize))) == 0) {
       // Iteration starts from an entry frame given by its fp, sp, and pc.
       current_frame_ = NextEntryFrame();
     } else {
       // Iteration starts from a Dart or stub frame given by its fp, sp, and pc.
       current_frame_ = frames_.NextFrame(validate_);
@@ skipping 126 matching lines @@
     if (deopt_instr->kind() == DeoptInstr::kCallerFp) {
       return (index - num_materializations_);
     }
   }
   UNREACHABLE();
   return 0;
 }
 
 
 }  // namespace dart