diff -r ec59f88eb330 -r 5dd5c4dd4b7d hotspot/src/share/vm/prims/jvmtiEnv.cpp
--- a/hotspot/src/share/vm/prims/jvmtiEnv.cpp	Wed Dec 21 18:22:14 2011 -0800
+++ b/hotspot/src/share/vm/prims/jvmtiEnv.cpp	Thu Dec 22 12:50:42 2011 -0800
@@ -267,7 +267,10 @@
 
     instanceKlassHandle ikh(current_thread, k_oop);
     if (ikh->get_cached_class_file_bytes() == NULL) {
-      // not cached, we need to reconstitute the class file from VM representation
+      // Not cached, we need to reconstitute the class file from the
+      // VM representation. We don't attach the reconstituted class
+      // bytes to the instanceKlass here because they have not been
+      // validated and we're not at a safepoint.
       constantPoolHandle  constants(current_thread, ikh->constants());
       ObjectLocker ol(constants, current_thread);    // lock constant pool while we query it