[PATCH 1/2] ACPI: GTDT: Don't corrupt interrupt mappings on watchdow probe failure

[Marc Zyngier]

On Wed, 21 Apr 2021 18:20:56 +0100,
Sudeep Holla <sudeep.holla at arm.com> wrote:
> 
> (with stable email fixed, but may need separate posting anyways)
> 
> On Wed, Apr 21, 2021 at 05:43:16PM +0100, Marc Zyngier wrote:
> > When failing the driver probe because of invalid firmware properties,
> > the GTDT driver unmaps the interrupt that it mapped earlier.
> > 
> > However, it never checks whether the mapping of the interrupt actially
> > succeeded. Even more, should the firmware report an illegal interrupt
> > number that overlaps with the GIC SGI range, this can result in an
> > IPI being unmapped, and subsequent fireworks (as reported by Dann
> > Frazier).
> > 
> > Rework the driver to have a slightly saner behaviour and actually
> > check whether the interrupt has been mapped before unmapping things.
> > 
> > Reported-by: dann frazier <dann.frazier at canonical.com>
> > Fixes: ca9ae5ec4ef0 ("acpi/arm64: Add SBSA Generic Watchdog support in GTDT driver")
> > Signed-off-by: Marc Zyngier <maz at kernel.org>
> > Link: https://lore.kernel.org/r/YH87dtTfwYgavusz@xps13.dannf
> > Cc: stable at vgerlkernel.org
>                 ^^^
> 
> I thought I messed up while replying with my fat fingers, but here is the
> culprit. I got mail delivery failure to my reply, thought I will let you
> know as it may be difficult to notice this when using git send-email.

I'm definitely the one with very fat fingers. I'll fix the patch in my
tree.

Thanks for the heads up,

	M.

-- 
Without deviation from the norm, progress is not possible.