Re: parsecvs and unnamed branches

From: Jon Smirl <jonsmirl@gmail.com>
Date: Jun 17, 2006, 03:31 UTC
Message-ID: <9e4733910606162031o69df27fdje50c88949ed990b5@mail.gmail.com>
In-Reply-To: <1150513943.29738.15.camel@dv>

On 6/16/06, Pavel Roskin <proski@gnu.org> wrote:

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> Hi, Jon!
>
> On Fri, 2006-06-16 at 23:02 -0400, Jon Smirl wrote:
> > My parsecvs job died after 5 hours of CPU time. Does this tell you anything?
> >
> > Pack pack-e28915a5ea09143a9139e84e24534ed888bf1c45 created
> >
> > Error: branch cycle
> > *** glibc detected *** parsecvs: munmap_chunk(): invalid pointer: 0x0a820198 ***
> > *** glibc detected *** parsecvs: corrupted double-linked list: 0x45b1e158 ***
>
> Obviously, memory corruption.  Valgrind is likely to help, but it may
> take 50 hours rather than 5.  It may still be worth it.  Make sure to
> use the latest version of Valgrind and compile parsecvs without
> optimization with full debug information.  If you can get debug info for
> libc, install it (on Fedora: "yum install glibc-debuginfo").
>
> > /lib/libc.so.6(__libc_free+0x179)[0x45a554f0]
> > parsecvs[0x804dec8]
>
> You see, even some libc symbols can be found, but parsecvs is opaque.
> That's why debug information is useful.  Make sure to keep the sources
> around for debugging.

Parsecvs was compiled '-O2 -g' why didn't it decode the addresses to symbols?

The 'Error: branch cycle' message was critical, the app was in the process of doing exit clean up with the link list error was found. If the list is linked in a circle it is likely that the routine freeing it corrupted memory. So the real error is why did I get 'Error: branch cycle'.

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> --
> Regards,
> Pavel Roskin
>
>

-- 
Jon Smirl
jonsmirl@gmail.com