The following test:

heapdump/JMapPermCore

fails with exception:

...
Dumping heap to heap.bin ...
Exception in thread "main" java.lang.reflect.InvocationTargetException
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
        at java.lang.reflect.Method.invoke(Method.java:589)
        at sun.tools.jmap.JMap.runTool(JMap.java:177)
        at sun.tools.jmap.JMap.main(JMap.java:109)
Caused by: sun.jvm.hotspot.utilities.AssertionFailure: can not get class data for 0xf7229258
        at sun.jvm.hotspot.utilities.Assert.that(Assert.java:15)
        at sun.jvm.hotspot.utilities.HeapHprofBinWriter.writeInstance(HeapHprofBinWriter.java:706)
        at sun.jvm.hotspot.utilities.AbstractHeapGraphWriter$1.doObj(AbstractHeapGraphWriter.java:77)
        at sun.jvm.hotspot.oops.ObjectHeap.iterateLiveRegions(ObjectHeap.java:411)
        at sun.jvm.hotspot.oops.ObjectHeap.iterate(ObjectHeap.java:226)
        at sun.jvm.hotspot.utilities.AbstractHeapGraphWriter.write(AbstractHeapGraphWriter.java:34)
        at sun.jvm.hotspot.utilities.HeapHprofBinWriter.write(HeapHprofBinWriter.java:399)
        at sun.jvm.hotspot.tools.HeapDumper.run(HeapDumper.java:39)
        at sun.jvm.hotspot.tools.Tool.start(Tool.java:204)
        at sun.jvm.hotspot.tools.HeapDumper.main(HeapDumper.java:60)
        ... 6 more
jmap exited with exit status 1
TEST FAILED

The test fills permanent generation with lots of interned strings, forces core dump and then tries to dump heap using "jmap -dump:format=b". See Comments for details on how to reproduce.