From: ebiederm@xmission.com (Eric W. Biederman)
To: Vivek Goyal <vgoyal@in.ibm.com>
Cc: Andrew Morton <akpm@osdl.org>,
Dave Anderson <anderson@redhat.com>, gdb <gdb@sources.redhat.com>,
fastboot <fastboot@lists.osdl.org>,
lkml <linux-kernel@vger.kernel.org>
Subject: Re: [Fastboot] Re: Query: Kdump: Core Image ELF Format
Date: Wed, 09 Mar 2005 14:21:00 -0000 [thread overview]
Message-ID: <m1ll8wlx82.fsf@ebiederm.dsl.xmission.com> (raw)
In-Reply-To: <1110350629.31878.7.camel@wks126478wss.in.ibm.com>
Vivek Goyal <vgoyal@in.ibm.com> writes:
> On Tue, 2005-03-08 at 11:00 -0700, Eric W. Biederman wrote:
> That sounds good. But we loose the advantage of doing limited debugging
> with gdb. Crash (or other analysis tools) will still take considerable
> amount of time before before they are fully ready and tested.
>
> How about giving user the flexibility to choose. What I mean is
> introducing a command line option in kexec-tools to choose between ELF32
> and ELF64 headers. For the users who are not using PAE systems, they can
> very well go with ELF32 headers and do the debugging using gdb.
>
> 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.
But I do agree that it a use case worth solving.
Eric
next prev parent reply other threads:[~2005-03-09 14:21 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <1110286210.4195.27.camel@wks126478wss.in.ibm.com>
[not found] ` <m1br9um313.fsf@ebiederm.dsl.xmission.com>
2005-03-09 6:42 ` Vivek Goyal
2005-03-09 14:21 ` Eric W. Biederman [this message]
2005-03-09 15:06 ` [Fastboot] " Dipankar Sarma
2005-03-10 7:14 ` Eric W. Biederman
2005-03-10 5:01 ` Vivek Goyal
2005-03-10 6:59 ` Eric W. Biederman
2005-03-15 5:48 ` Vivek Goyal
2005-03-10 8:17 ` Itsuro Oda
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