--- old/src/hotspot/share/memory/allocation.hpp	2018-01-15 16:24:04.888444153 -0800
+++ new/src/hotspot/share/memory/allocation.hpp	2018-01-15 16:24:04.472428394 -0800
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1997, 2017, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2018, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -227,9 +227,17 @@
 class MetaspaceClosure;
 
 class MetaspaceObj {
+  friend class MetaspaceShared;
+  static void*   _shared_metaspace_base;
+  static void*   _shared_metaspace_top;
+
  public:
   bool is_metaspace_object() const;
-  bool is_shared() const;
+  bool is_shared() const {
+    // If no shared metaspace regions are mapped, _shared_metaspace_{base,top} will
+    // both be NULL and all values of p will be rejected quickly.
+    return (((void*)this) < _shared_metaspace_top && ((void*)this) >= _shared_metaspace_base);
+  }
   void print_address_on(outputStream* st) const;  // nonvirtual address printing
 
 #define METASPACE_OBJ_TYPES_DO(f) \