Whitelist serialized objects wrt MSAN.

src/serialize.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/v8.h"
 
 #include "src/accessors.h"
 #include "src/api.h"
 #include "src/base/platform/platform.h"
 #include "src/bootstrapper.h"
@@ skipping 2102 matching lines @@
       // Code age headers are not serializable.
       code->MakeYoung(serializer_->isolate());
       WipeOutRelocations(code);
       // We need to wipe out the header fields *after* wiping out the
       // relocations, because some of these fields are needed for the latter.
       code->WipeOutHeader();
       object_start = code->address();
     }
 
     const char* description = code_object_ ? "Code" : "Byte";
+#ifdef MEMORY_SANITIZER
+    // Object sizes are usually rounded up with uninitialized padding space.
+    MSAN_MEMORY_IS_INITIALIZED(object_start + base, bytes_to_output);
+#endif  // MEMORY_SANITIZER
     sink_->PutRaw(object_start + base, bytes_to_output, description);
     if (code_object_) delete[] object_start;
   }
   if (to_skip != 0 && return_skip == kIgnoringReturn) {
     sink_->Put(kSkip, "Skip");
     sink_->PutInt(to_skip, "SkipDistance");
     to_skip = 0;
   }
   return to_skip;
 }
@@ skipping 508 matching lines @@
   return GetHeaderValue(kNumInternalizedStringsOffset);
 }
 
 Vector<const uint32_t> SerializedCodeData::CodeStubKeys() const {
   int reservations_size = GetHeaderValue(kNumReservationsOffset) * kInt32Size;
   const byte* start = data_ + kHeaderSize + reservations_size;
   return Vector<const uint32_t>(reinterpret_cast<const uint32_t*>(start),
                                 GetHeaderValue(kNumCodeStubKeysOffset));
 }
 } }  // namespace v8::internal