src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/debugger/DebuggerBase.java

*** 473,10 ***
--- 473,15 ---
    }
  
    protected long readCompKlassAddressValue(long address)
      throws UnmappedAddressException, UnalignedAddressException {
      long value = readCInteger(address, getKlassPtrSize(), true);
+     // Todo: Lilliput: this is a hack. The real problem is the assumption that size
+     //  of a narrow Klass pointer can be expressed in number of bytes (getKlassPtrSize).
+     //  That assumption is present in a number of files here. Better would be
+     //  to change this to getKlassPtrSizeInBits, or to do it some other way.
+     value &= (1 << 22) - 1; // narrow klass pointer size is 22 bits.
      if (value != 0) {
        value = (long)(narrowKlassBase + (long)(value << narrowKlassShift));
      }
      return value;
    }