Subject: Re: [Cbe-oss-dev] [RFC] cell: saving spus information for kexec crash

From: Benjamin Herrenschmidt <[email-masked]>
Date: Mon, 14 May 2007 08:14:01 +1000

On Fri, 2007-05-11 at 12:22 -0500, Anton Blanchard wrote:
> Hi,
> 
> > This patch adds support for investigating spus information after a
> > kernel crash event, through kdump vmcore file.
> > Implementation is based on xmon code, but the new functionality was
> > kept independent.
> 
> This brings up a point: it looks like kdump doesnt capture the FP and
> altivec regs. Could be important for some bugs.
> 
> This brings up yet another point, it looks like our userspace core dumps
> dont capture altivec or SPU state.

That's interesting: We do have a dump_task_altivec() but it looks like
its never called ... ouch. Maybe we can use the XFPREGS stuff or should
we add our own hook in binfmt_elf.c for that ?

As for SPU state, there's code to dump the SPEs in a separate section,
though I don't know if it's been merged yet (no up to date git tree
at hand right now). It uses different macros off binfmt_elf.

Ben.