Re: [Fastboot] Re: Query: Kdump: Core Image ELF Format

Dipankar Sarma
2005-03-09T15:06:12Z

On Wed, Mar 09, 2005 at 07:17:49AM -0700, Eric W. Biederman wrote:
> Vivek Goyal <vgoyal@in.ibm.com> writes:
>
> > On Tue, 2005-03-08 at 11:00 -0700, Eric W. Biederman wrote:
> >
> > This also requires, setting the kernel virtual addresses while preparing
> > the headers. KVA for linearly mapped region is known in advance and can
> > be filled at header creation time and gdb can directly operate upon this
> > region.
>
> I have no problems decorating the ELF header you are generating
> in user space with virtual addresses assuming we can reliably
> get that information. And before a kernel crashes looks like a reasonable
> time to ask that question. I don't currently see where you could
> derive that information.
>
> Beyond that I prefer a little command line tool that will do the
> ELF64 to ELF32 conversion and possibly add in the kva mapping to
> make the core dump usable with gdb. Doing it in a separate tool
> means it is the developer who is doing the analysis who cares
> not the user who is capturing the system core dump.

Well, as a kernel developer, I am both :) For me, having to install
half-a-dozen different command line tools to get and analyze a crash dump
is a PITA, not to mention potential version mismatches. As someone
who would like very much to use crash dump for debugging, I would
much rather be able to force a dump and then use gdb for
a quick debug. I agree that a customer would see a different
situation. It would be nice if we can cater to both the kinds.

Thanks
Dipankar