Re: [PATCH v3 0/6] allow ramoops to collect all kmesg_dump events

Kees Cook
2020-05-13T07:47:13Z

On Wed, May 13, 2020 at 09:34:49AM +0200, Petr Mladek wrote:
> On Tue 2020-05-12 11:45:54, Kees Cook wrote:
> > Here are the problems I see being solved by this:
> >
> > - lifting kmsg dump reason filtering out of the individual pstore
> > backends and making it part of the "infrastructure", so that
> > there is a central place to set expectations. Right now there
> > is a mix of explicit and implicit kmsg dump handling:
> >
> > - arch/powerpc/kernel/nvram_64.c has a hard-coded list
>
> It handles restart, halt, poweroff the same way. I wonder if anyone
> would want to distinguish them.
>
> > - drivers/firmware/efi/efi-pstore.c doesn't expect anything but
> > OOPS and PANIC.
> > - drivers/mtd/mtdoops.c tries to filter using its own dump_oops
> > and doesn't expect anything but OOPS and PANIC.
> > - fs/pstore/ram.c: has a hard-coded list and uses its own
> > dump_oops.
> > - drivers/mtd/mtdpstore.c (under development[3]) expected only
> > OOPS and PANIC and had its own dump_oops.
>
> The others handle only panic or oops.
>
> What about splitting the reason into two variables? One for severity
> and other for shutdown behavior. I mean:
>
> + reason: panic, oops, emergency, shutdown (ordered by severity)
> + handling: restart, halt, poweroff
>
> Or we might just replace KMSG_DUMP_RESTART, KMSG_DUMP_HALT,
> KMSG_DUMP_POWEROFF with a single KMSG_DUMP_SHUTDOWN.
>
> Then the max reason variable would make sense.

That would work for me, yeah. Pavel, is that enough granularity for you?

--
Kees Cook