Jstack - error occurred during stack walking

Question

Trying to use jstack to debug a deadlock on Solaris 8, using jdk/jre 1.5.0-08, I get the following error on stderr:
$ sudo -u apache jstack 17453 > stack
Attaching to process ID 17453, please wait...
Debugger attached successfully.
Client compiler detected.
JVM version is 1.5.0_08-b03
sun.jvm.hotspot.utilities.AssertionFailure: Expected raw sp likely got real sp, value was 0xfffffffe
        at sun.jvm.hotspot.utilities.Assert.that(Assert.java:15)
        at sun.jvm.hotspot.runtime.sparc.SPARCFrame.<init>(SPARCFrame.java:214)
        at sun.jvm.hotspot.runtime.sparc.SPARCFrame.senderWithPCAdjustment(SPARCFrame.java:981)
        at sun.jvm.hotspot.runtime.sparc.SPARCFrame.sender(SPARCFrame.java:484)
        at sun.jvm.hotspot.runtime.Frame.sender(Frame.java:184)
        at sun.jvm.hotspot.runtime.Frame.realSender(Frame.java:189)
        at sun.jvm.hotspot.runtime.VFrame.sender(VFrame.java:102)
        at sun.jvm.hotspot.runtime.VFrame.javaSender(VFrame.java:134)
        at sun.jvm.hotspot.runtime.JavaThread.getLastJavaVFrameDbg(JavaThread.java:231)
        at sun.jvm.hotspot.tools.StackTrace.run(StackTrace.java:50)
        at sun.jvm.hotspot.tools.JStack.run(JStack.java:41)
        at sun.jvm.hotspot.tools.Tool.start(Tool.java:204)
        at sun.jvm.hotspot.tools.JStack.main(JStack.java:58)Any thoughts as to what I am doing wrong are appreciated.

Answer 1

It is not your mistake. Some times the java vm thread
stacks are not in walkable state. So jstack got a bad sp
and hence it asserted.Thanks for the information. However, this seems to be a fairly reproducible error. Even worse, I get a similar error when I run the same program on a AMD64 box.
I am trying to debug a potential deadlock issue, and hoping that jstack will show me why things get hung up. I get the feeling that the stack that cannot be walked has an important relation to my problem.