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Date: Wed, 23 Nov 2011 23:09:31 +0530
From: "K.Prasad" <prasad@linux.vnet.ibm.com>
To: Dave Anderson <anderson@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>, Borislav Petkov <bp@alien8.de>,
        Tony Luck <tony.luck@intel.com>,
        "Eric W. Biederman" <ebiederm@xmission.com>,
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        Valdis Kletnieks <Valdis.Kletnieks@vt.edu>,
        Nick Bowler <nbowler@elliptictech.com>, linux-kernel@vger.kernel.org
Subject: Re: [RFC Patch 1/2][slimdump] Append CRASH_REASON to VMCOREINFO
 elf-note
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On Mon, Nov 21, 2011 at 10:19:31AM -0500, Dave Anderson wrote:
> 
> 
> ----- Original Message -----
> > Allow various crash paths to append the reason of crash into the
> > VMCOREINFO elf-note through the field CRASH_REASON. We also make the
> > fatal machine check exceptions append "PANIC_MCE" as the crash
> > reason.  This string will be recognised by upstream tools like makedumpfile and
> > crash to generate slimdump.
> 
> I don't understand -- how could "various paths" append a reason?
> The patch below seems to return "PANIC_MCE" for every x86 crash.
> What am I missing?
> 
> Dave
> 

Yes, presently it can only be "PANIC_MCE" for MCE crashes in x86 (not
for every crash though).

With increased usage, we should move this code to a generic location and
let each of these crash paths return a string to be appended. In fact it
doesn't have to be a string for CRASH_REASON but just an encoding of the
various crash types into numbers. User-space tools could then do a lookup
for getting the right crash string.

Thanks,
K.Prasad