Re: [patch V2 45/52] x86/fpu: Dont restore PKRU in fpregs_restore_userspace()

[Thomas Gleixner]

On Tue, Jun 15 2021 at 17:52, Yu-cheng Yu wrote:
> On 6/14/2021 8:44 AM, Thomas Gleixner wrote:
>> +		 * If PKRU is enabled, then the PKRU value is already
>> +		 * correct because it was either set in switch_to() or in
>> +		 * flush_thread(). So it is excluded because it might be
>> +		 * not up to date in current->thread.fpu.xsave state.
>> +		 */
>> +		__restore_fpregs_from_fpstate(&fpu->state,
>> +					      xfeatures_mask_restore_user());
>
> This needs to be xfeatures_mask_restore_user() | 
> xfeatures_mask_supervisor().

Indeed. Good catch!

Thanks,

        tglx