[PATCH] powerpc/pseries: Fix scv instruction crash with kexec

[Michael Ellerman]

Nicholas Piggin <npiggin at gmail.com> writes:
> kexec on pseries disables AIL (reloc_on_exc), required for scv
> instruction support, before other CPUs have been shut down. This means
> they can execute scv instructions after AIL is disabled, which causes an
> interrupt at an unexpected entry location that crashes the kernel.
>
> Change the kexec sequence to disable AIL after other CPUs have been
> brought down.
>
> As a refresher, the real-mode scv interrupt vector is 0x17000, and the
> fixed-location head code probably couldn't easily deal with implementing
> such high addresses so it was just decided not to support that interrupt
> at all.
>
> Reported-by: Sourabh Jain <sourabhjain at linux.ibm.com>
 
Was this reported publicly? I don't remember it.

cheers