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

[Kees Cook]

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