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SubjectRe: [PATCH RFC V3 2/9] x86/fpu: Refactor arch_set_user_pkey_access() for PKS support
On Tue, Oct 13, 2020 at 10:50:05AM -0700, Dave Hansen wrote:
> On 10/9/20 12:42 PM, ira.weiny@intel.com wrote:
> > +/*
> > + * Update the pk_reg value and return it.
>
> How about:
>
> Replace disable bits for @pkey with values from @flags.

Done.

>
> > + * Kernel users use the same flags as user space:
> > + * PKEY_DISABLE_ACCESS
> > + * PKEY_DISABLE_WRITE
> > + */
> > +u32 update_pkey_val(u32 pk_reg, int pkey, unsigned int flags)
> > +{
> > + int pkey_shift = pkey * PKR_BITS_PER_PKEY;
> > +
> > + pk_reg &= ~(((1 << PKR_BITS_PER_PKEY) - 1) << pkey_shift);
> > +
> > + if (flags & PKEY_DISABLE_ACCESS)
> > + pk_reg |= PKR_AD_BIT << pkey_shift;
> > + if (flags & PKEY_DISABLE_WRITE)
> > + pk_reg |= PKR_WD_BIT << pkey_shift;
>
> I still think this deserves two lines of comments:
>
> /* Mask out old bit values */
>
> /* Or in new values */

Sure, done.
Ira

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