On Wed, Jun 20, 2018 at 04:40:32PM +0100, Catalin Marinas wrote:

On Wed, Jun 20, 2018 at 04:23:47PM +0100, Will Deacon wrote:

quoted

We inspect __kpti_forced early on as part of the cpufeature enable
callback which remaps the swapper page table using non-global entries.

Ensure that __kpti_forced has been updated to reflect the kpti=
command-line option before we start using it.

Reported-by: Wei Xu <xuwei5@hisilicon.com>
Signed-off-by: Will Deacon <redacted>

Does it need a fixes tag?

Fixes: ea1e3de85e94 ("arm64: entry: Add fake CPU feature for unmapping the kernel at EL0")

Perhaps, but really this is just a performance optimisation for the kpti=off
case where we don't actually need to put the nG mappings down.

Will