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Re: Kernel Oops



On Wed, Apr 18, 2001 at 03:05:48PM -0700, Walt wrote:
> >> Are there any patches being worked on or available
> to
> >> get memory core dumps?
> 
> >It's already there, you just have to switch it on:
> 
> >limit coredumpsize unlimited (for csh/tcsh)
> >ulimit -c unlimited (for bash)
> 
> Thanks for the response. Did some reading on mcore at
> missioncriticallinux.com. I checked the kernel
> documentation section and because of the dynamic
> nature of modules they can be a real pain to debug.

Check out http://oss.sgi.com/. SGI hosts kdb and kgdb, and also has a
dump-kernel-core-to-swap patch.

> Very much so if lacking exported symbols, the docs
> pertaining to module debugging did not mention core
> files that I can remember. Are using gdb with the core
> file (or another code utility) efficient in this case?

You can use gdb read-only on a running kernel using /proc/kcore . Or
use kdb or kgdb.

> It appears to be the logical next step if the oops
> does not shed light on the problem and you are lacking
> module source to insert exports and soforth. 

Lacking module source? Well, there is only a single advice with respect
to binary-only modules: complain to the vendor, or drop it completely.
Don't try to debug an optimised piece of assembly, it's a waste of
time.

And be sure to check the license: most software licenses don't allow
you to disassemble the code (though local laws might give you that
right explicitly). IANAL, so check a lawyer to be sure.


Erik

-- 
J.A.K. (Erik) Mouw, Information and Communication Theory Group, Department
of Electrical Engineering, Faculty of Information Technology and Systems,
Delft University of Technology, PO BOX 5031,  2600 GA Delft, The Netherlands
Phone: +31-15-2783635  Fax: +31-15-2781843  Email: J.A.K.Mouw@its.tudelft.nl
WWW: http://www-ict.its.tudelft.nl/~erik/
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