On Tue, May 29, 2018 at 01:56:29PM +1000, Michael Neuling wrote: > Clear the PCR (Processor Compatibility Register) on boot to ensure we > are not running in a compatibility 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@xxxxxxxxxxx> > Cc: stable@xxxxxxxxxxxxxxx # v4.9 > Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx> > -- > > Greg, This is a backport for v4.9 only since the original patch didn't > apply. > > Commit faf37c44a105f3608115785f17cbbf3500f8bc71 upstream. Thanks for this, and the 4.4 backport, both now queued up. greg k-h
