powepc: Clear PCR on boot

[Michael Ellerman]

On Fri, 2018-05-18 at 01:37:42 UTC, Michael Neuling wrote:
> Clear the PCR on boot to ensure we are not running in a compat mode.
> 
> We've seen this cause problems when a crash (and kdump) occurs while
> running compat mode guests. The kdump kernel then runs with the PCR
> set and causes problems. The symptom in the kdump kernel (also seen in
> petitboot after fast-reboot) is early userspace programs taking
> sigills on newer instructions (seen in libc).
> 
> Signed-off-by: Michael Neuling <mikey at neuling.org>
> Cc: <stable at vger.kernel.org>

Applied to powerpc fixes, thanks.

https://git.kernel.org/powerpc/c/faf37c44a105f3608115785f17cbbf

cheers