Messages in this thread | | | Subject | Re: [PATCH RFC V3 2/9] x86/fpu: Refactor arch_set_user_pkey_access() for PKS support | From | Dave Hansen <> | Date | Tue, 13 Oct 2020 10:50:05 -0700 |
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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.
> + * 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 */
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