On 07/12/16 08:32, Dave Hansen wrote:
> On 07/09/2016 02:27 PM, Andy Lutomirski wrote:
>> is_prefetch in arch/x86/mm/fault.c can be called on a user address
>> that's not readable due to PKRU. This could break it. You might need
>> to add a get_user_exec or similar.
>
> Thanks for the heads-up. I think I'll just need a version that does
> something along the lines of stac/clac, but with PKRU.
>
> I think I can do it with an "_exec" variant of probe_kernel_address(),
> but it's a bit messy.
>
Can this particular codepath even be executed on a PKRU-equipped
machine? I thought it was a bug fix for a specific AMD CPU line.
-hpa
