Re: [RFC Patch 1/2][slimdump] Append CRASH_REASON to VMCOREINFO elf-note

["K.Prasad" <prasad@linux.vnet.ibm.com>]

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