[PATCH v3] x86: treat pkey-0 special

[Dave Hansen]

On 03/15/2018 02:46 AM, Thomas Gleixner wrote:
>> +	if (!pkey || !mm_pkey_is_allocated(mm, pkey))
> Why this extra check? mm_pkey_is_allocated(mm, 0) should not return true
> ever. If it does, then this wants to be fixed.

I was thinking that we _do_ actually want it to seem allocated.  It just
get "allocated" implicitly when an mm is created.  I think that will
simplify the code if we avoid treating it specially in as many places as
possible.