From: Dave Hansen <dave.hansen@intel.com>
To: ira.weiny@intel.com, Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
Andy Lutomirski <luto@kernel.org>,
Peter Zijlstra <peterz@infradead.org>
Cc: Fenghua Yu <fenghua.yu@intel.com>,
x86@kernel.org, Dave Hansen <dave.hansen@linux.intel.com>,
Dan Williams <dan.j.williams@intel.com>,
Andrew Morton <akpm@linux-foundation.org>,
linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-nvdimm@lists.01.org, linux-fsdevel@vger.kernel.org,
linux-mm@kvack.org, linux-kselftest@vger.kernel.org
Subject: Re: [PATCH RFC V3 2/9] x86/fpu: Refactor arch_set_user_pkey_access() for PKS support
Date: Tue, 13 Oct 2020 10:50:05 -0700 [thread overview]
Message-ID: <7ed91cb5-93e5-67ad-ad35-8489d16d283f@intel.com> (raw)
In-Reply-To: <20201009194258.3207172-3-ira.weiny@intel.com>
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 */
next prev parent reply other threads:[~2020-10-13 17:50 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-09 19:42 [PATCH RFC V3 0/9] PKS: Add Protection Keys Supervisor (PKS) support RFC v3 ira.weiny
2020-10-09 19:42 ` [PATCH RFC V3 1/9] x86/pkeys: Create pkeys_common.h ira.weiny
2020-10-13 17:46 ` Dave Hansen
2020-10-13 19:44 ` Ira Weiny
2020-10-09 19:42 ` [PATCH RFC V3 2/9] x86/fpu: Refactor arch_set_user_pkey_access() for PKS support ira.weiny
2020-10-13 17:50 ` Dave Hansen [this message]
2020-10-13 23:56 ` Ira Weiny
2020-10-16 10:57 ` Peter Zijlstra
2020-10-17 3:32 ` Ira Weiny
2020-10-19 9:35 ` Peter Zijlstra
2020-10-09 19:42 ` [PATCH RFC V3 3/9] x86/pks: Enable Protection Keys Supervisor (PKS) ira.weiny
2020-10-13 18:23 ` Dave Hansen
2020-10-14 2:08 ` Ira Weiny
2020-10-09 19:42 ` [PATCH RFC V3 4/9] x86/pks: Preserve the PKRS MSR on context switch ira.weiny
2020-10-13 18:31 ` Dave Hansen
2020-10-14 22:36 ` Ira Weiny
2020-10-16 11:12 ` Peter Zijlstra
2020-10-17 5:14 ` Ira Weiny
2020-10-19 9:37 ` Peter Zijlstra
2020-10-19 18:48 ` Ira Weiny
2020-10-16 11:06 ` Peter Zijlstra
2020-10-17 5:37 ` Ira Weiny
2020-10-09 19:42 ` [PATCH RFC V3 5/9] x86/pks: Add PKS kernel API ira.weiny
2020-10-13 18:43 ` Dave Hansen
2020-10-15 1:08 ` Ira Weiny
2020-10-16 11:07 ` Peter Zijlstra
2020-10-17 5:42 ` Ira Weiny
2020-10-09 19:42 ` [PATCH RFC V3 6/9] x86/entry: Pass irqentry_state_t by reference ira.weiny
2020-10-16 11:45 ` Peter Zijlstra
2020-10-16 12:55 ` Thomas Gleixner
2020-10-19 5:37 ` Ira Weiny
2020-10-19 9:32 ` Thomas Gleixner
2020-10-19 20:26 ` Ira Weiny
2020-10-19 21:12 ` Thomas Gleixner
2020-10-20 14:10 ` Ira Weiny
2020-10-09 19:42 ` [PATCH RFC V3 7/9] x86/entry: Preserve PKRS MSR across exceptions ira.weiny
2020-10-13 18:52 ` Dave Hansen
2020-10-15 3:46 ` Ira Weiny
2020-10-15 4:06 ` Dave Hansen
2020-10-15 4:18 ` Ira Weiny
2020-10-09 19:42 ` [PATCH RFC V3 8/9] x86/fault: Report the PKRS state on fault ira.weiny
2020-10-13 18:56 ` Dave Hansen
2020-10-15 4:13 ` Ira Weiny
2020-10-09 19:42 ` [PATCH RFC V3 9/9] x86/pks: Add PKS test code ira.weiny
2020-10-13 19:02 ` Dave Hansen
2020-10-15 4:46 ` Ira Weiny
2020-10-09 20:18 ` [PATCH RFC V3 0/9] PKS: Add Protection Keys Supervisor (PKS) support RFC v3 Ira Weiny
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