1 files changed, 10 insertions, 1 deletions
diff --git a/deps/v8/src/heap/heap-write-barrier.cc b/deps/v8/src/heap/heap-write-barrier.cc
index 63949de243..0030615bab 100644
--- a/deps/v8/src/heap/heap-write-barrier.cc
+++ b/deps/v8/src/heap/heap-write-barrier.cc
@@ -68,7 +68,16 @@ void WriteBarrier::MarkingSlow(Heap* heap, DescriptorArray descriptor_array,
 int WriteBarrier::MarkingFromCode(Address raw_host, Address raw_slot) {
   HeapObject host = HeapObject::cast(Object(raw_host));
   MaybeObjectSlot slot(raw_slot);
-  WriteBarrier::Marking(host, slot, *slot);
+  Address value = (*slot).ptr();
+#ifdef V8_MAP_PACKING
+  if (slot.address() == host.address()) {
+    // Clear metadata bits and fix object tag.
+    value = (value & ~Internals::kMapWordMetadataMask &
+             ~Internals::kMapWordXorMask) |
+            (uint64_t)kHeapObjectTag;
+  }
+#endif
+  WriteBarrier::Marking(host, slot, MaybeObject(value));
   // Called by RecordWriteCodeStubAssembler, which doesnt accept void type
   return 0;
 }