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From: Ira Weiny <ira.weiny@intel.com>
To: Dave Hansen <dave.hansen@intel.com>
Cc: 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>,
	Fenghua Yu <fenghua.yu@intel.com>,
	x86@kernel.org, Dave Hansen <dave.hansen@linux.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 16:56:59 -0700	[thread overview]
Message-ID: <20201013235658.GL2046448@iweiny-DESK2.sc.intel.com> (raw)
In-Reply-To: <7ed91cb5-93e5-67ad-ad35-8489d16d283f@intel.com>

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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WARNING: multiple messages have this Message-ID (diff)
From: Ira Weiny <ira.weiny@intel.com>
To: Dave Hansen <dave.hansen@intel.com>
Cc: 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>,
	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 16:56:59 -0700	[thread overview]
Message-ID: <20201013235658.GL2046448@iweiny-DESK2.sc.intel.com> (raw)
In-Reply-To: <7ed91cb5-93e5-67ad-ad35-8489d16d283f@intel.com>

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


  reply	other threads:[~2020-10-13 23:57 UTC|newest]

Thread overview: 94+ 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 ` ira.weiny
2020-10-09 19:42 ` [PATCH RFC V3 1/9] x86/pkeys: Create pkeys_common.h ira.weiny
2020-10-09 19:42   ` ira.weiny
2020-10-13 17:46   ` Dave Hansen
2020-10-13 17:46     ` Dave Hansen
2020-10-13 19:44     ` Ira Weiny
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
2020-10-09 19:42   ` ira.weiny
2020-10-13 17:50   ` Dave Hansen
2020-10-13 17:50     ` Dave Hansen
2020-10-13 23:56     ` Ira Weiny [this message]
2020-10-13 23:56       ` Ira Weiny
2020-10-16 10:57   ` Peter Zijlstra
2020-10-16 10:57     ` Peter Zijlstra
2020-10-17  3:32     ` Ira Weiny
2020-10-17  3:32       ` Ira Weiny
2020-10-19  9:35       ` Peter Zijlstra
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
2020-10-09 19:42   ` ira.weiny
2020-10-13 18:23   ` Dave Hansen
2020-10-13 18:23     ` Dave Hansen
2020-10-14  2:08     ` Ira Weiny
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
2020-10-09 19:42   ` ira.weiny
2020-10-13 18:31   ` Dave Hansen
2020-10-13 18:31     ` Dave Hansen
2020-10-14 22:36     ` Ira Weiny
2020-10-14 22:36       ` Ira Weiny
2020-10-16 11:12     ` Peter Zijlstra
2020-10-16 11:12       ` Peter Zijlstra
2020-10-17  5:14       ` Ira Weiny
2020-10-17  5:14         ` Ira Weiny
2020-10-19  9:37         ` Peter Zijlstra
2020-10-19  9:37           ` Peter Zijlstra
2020-10-19 18:48           ` Ira Weiny
2020-10-19 18:48             ` Ira Weiny
2020-10-16 11:06   ` Peter Zijlstra
2020-10-16 11:06     ` Peter Zijlstra
2020-10-17  5:37     ` Ira Weiny
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
2020-10-09 19:42   ` ira.weiny
2020-10-13 18:43   ` Dave Hansen
2020-10-13 18:43     ` Dave Hansen
2020-10-15  1:08     ` Ira Weiny
2020-10-15  1:08       ` Ira Weiny
2020-10-16 11:07   ` Peter Zijlstra
2020-10-16 11:07     ` Peter Zijlstra
2020-10-17  5:42     ` Ira Weiny
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
2020-10-09 19:42   ` ira.weiny
2020-10-16 11:45   ` Peter Zijlstra
2020-10-16 11:45     ` Peter Zijlstra
2020-10-16 12:55     ` Thomas Gleixner
2020-10-16 12:55       ` Thomas Gleixner
2020-10-19  5:37       ` Ira Weiny
2020-10-19  5:37         ` Ira Weiny
2020-10-19  9:32         ` Thomas Gleixner
2020-10-19  9:32           ` Thomas Gleixner
2020-10-19 20:26           ` Ira Weiny
2020-10-19 20:26             ` Ira Weiny
2020-10-19 21:12             ` Thomas Gleixner
2020-10-19 21:12               ` Thomas Gleixner
2020-10-20 14:10               ` Ira Weiny
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
2020-10-09 19:42   ` ira.weiny
2020-10-13 18:52   ` Dave Hansen
2020-10-13 18:52     ` Dave Hansen
2020-10-15  3:46     ` Ira Weiny
2020-10-15  3:46       ` Ira Weiny
2020-10-15  4:06       ` Dave Hansen
2020-10-15  4:06         ` Dave Hansen
2020-10-15  4:18         ` Ira Weiny
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
2020-10-09 19:42   ` ira.weiny
2020-10-13 18:56   ` Dave Hansen
2020-10-13 18:56     ` Dave Hansen
2020-10-15  4:13     ` Ira Weiny
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
2020-10-09 19:42   ` ira.weiny
2020-10-13 19:02   ` Dave Hansen
2020-10-13 19:02     ` Dave Hansen
2020-10-15  4:46     ` Ira Weiny
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
2020-10-09 20:18   ` Ira Weiny

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