Re: [PATCH stable 4.9] arm64: kpti: Whitelist Cortex-A CPUs that don't implement the CSV3 field

On Fri, Jan 24, 2020 at 12:08:20PM -0800, Florian Fainelli wrote:

From: Will Deacon will.deacon@arm.com

commit 2a355ec25729053bb9a1a89b6c1d1cdd6c3b3fb1 upstream.

While the CSV3 field of the ID_AA64_PFR0 CPU ID register can be checked to see if a CPU is susceptible to Meltdown and therefore requires kpti to be enabled, existing CPUs do not implement this field.

We therefore whitelist all unaffected Cortex-A CPUs that do not implement the CSV3 field.

Signed-off-by: Will Deacon will.deacon@arm.com [florian: adjust whilelist location and table to stable-4.9.y] Signed-off-by: Florian Fainelli f.fainelli@gmail.com

Thanks for the backport, now applied.

greg k-h