Messages in this thread | | | From | Thomas Gleixner <> | Subject | Re: [PATCH V7 02/18] x86/fpu: Refactor arch_set_user_pkey_access() | Date | Thu, 25 Nov 2021 15:23:26 +0100 |
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On Tue, Aug 03 2021 at 21:32, ira weiny wrote: > +/* > + * 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)
pkey_.... please.
> +{ > + int pkey_shift = pkey * PKR_BITS_PER_PKEY; > + > + /* Mask out old bit values */ > + pk_reg &= ~(((1 << PKR_BITS_PER_PKEY) - 1) << pkey_shift); > + > + /* Or in new values */ > + if (flags & PKEY_DISABLE_ACCESS) > + pk_reg |= PKR_AD_BIT << pkey_shift; > + if (flags & PKEY_DISABLE_WRITE) > + pk_reg |= PKR_WD_BIT << pkey_shift; > + > + return pk_reg;
Also this code is silly.
#define PKEY_ACCESS_MASK (PKEY_DISABLE_ACCESS | PKEY_DISABLE_WRITE)
u32 pkey_update_pkval(u32 pkval, int pkey, u32 accessbits) { int shift = pkey * PKR_BITS_PER_PKEY;
if (WARN_ON_ONCE(accessbits & ~PKEY_ACCESS_MASK)) accessbits &= PKEY_ACCESS_MASK;
pkval &= ~(PKEY_ACCESS_MASK << shift); return pkval | accessbit << pkey_shift; }
See? It does not even need comments because it's self explaining and uses sensible argument names matching the function name.
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