On Fri, 2017-09-22 at 03:32:21 UTC, Michael Neuling wrote:

On POWER9 DD2.1 and below, it's possible for a paste instruction to
cause a Machine Check Exception (MCE) where only DSISR bit 33 is
set. This will result in the MCE handler seeing an unknown event,
which triggers linux to crash.

We change this by detecting unknown events caused by load/stores in
the MCE handler and marking them as handled so that we no longer
crash.

An MCE that occurs like this is spurious, so we don't need to do
anything in terms of servicing it. If there is something that needs to
be serviced, the CPU will raise the MCE again with the correct DSISR
so that it can be serviced properly.

Signed-off-by: Michael Neuling <redacted>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com
Acked-by: Balbir SIngh <bsingharora@gmail.com>

Applied to powerpc fixes, thanks.

https://git.kernel.org/powerpc/c/d8bd9f3f0925d22726de159531bfe3

cheers