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Asked: 2011-10-01 11:10:35 +0800 CST

How do I view CoreDump file?

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When reporting a bug from a crash, the bug is made private and a file called CoreDump.gz. The Bug Triage documentation says the following:

If the crash still has a CoreDump.gz attachment, then it was not possible to automatically get a fully symbolic stack trace and check for duplicates.

Stacktrace.txt seems readable by a human. How can I understand the meaning of a stack trace. CoreDump withing CoreDump.gz does not seem human readable. What is a "fully symbolic stack trace"? What is the difference between a "fully symbolic stack trace" How do I view the contents of a CoreDump file? (tried 'cat', but it's not clean)

bug-reporting

1 Answers

  1. Best Answer

    Coredump.gz is the (compressed) memory accessible by the program that crashed. It is a binary file. Coredumps are a treasure trove, with all sorts of private data to be mined.

    Coredumps can be viewed by running 'gdb': 

    gdb --core=mycoredump

    Of course, you will still need the debug packages associated with this core.

    You can, then, generate a stacktrace by:

    (gdb) bt

    to generate a stacktrace of the current thread -- without parameter resolution --, or

    (gdb) thread apply all bt full

    to generate a stacktrace of all threads in the coredump, with parameter resolution.

    stacktrace and full stacktraces show the control flow within a program. For Python, the top of the stacktrace shows the oldest call, with the most recent at the bottom; for pretty much everything else, the top is the most recent call, and the bottom the oldest.

    A full stacktrace will not only show the flow, but also the parameter's values. This is where we usually find private data -- for example, say you see a function called "validatePassword" with a parameter called "Password", and a value of "MySecretPassword"...

    Stacktraces are usually only helpful if the debug packages are installed (so that the stack frames can be resolved into something we can easily read). Analysis of a stacktrace will require one to have the sources that were used to build this specific program instance.

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