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From: Ira Weiny <ira.weiny@intel.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
	Andy Lutomirski <luto@kernel.org>,
	x86@kernel.org, Dave Hansen <dave.hansen@linux.intel.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	Fenghua Yu <fenghua.yu@intel.com>,
	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 V2 12/17] memremap: Add zone device access protection
Date: Fri, 17 Jul 2020 22:51:03 -0700	[thread overview]
Message-ID: <20200718055103.GU3008823@iweiny-DESK2.sc.intel.com> (raw)
In-Reply-To: <20200717091718.GA10769@hirez.programming.kicks-ass.net>

On Fri, Jul 17, 2020 at 11:17:18AM +0200, Peter Zijlstra wrote:
> On Fri, Jul 17, 2020 at 12:20:51AM -0700, ira.weiny@intel.com wrote:
> > +void dev_access_disable(void)
> > +{
> > +	unsigned long flags;
> > +
> > +	if (!static_branch_unlikely(&dev_protection_static_key))
> > +		return;
> > +
> > +	local_irq_save(flags);
> > +	current->dev_page_access_ref--;
> > +	if (current->dev_page_access_ref == 0)
> 
> 	if (!--current->dev_page_access_ref)

It's not my style but I'm ok with it.

> 
> > +		pks_update_protection(dev_page_pkey, PKEY_DISABLE_ACCESS);
> > +	local_irq_restore(flags);
> > +}
> > +EXPORT_SYMBOL_GPL(dev_access_disable);
> > +
> > +void dev_access_enable(void)
> > +{
> > +	unsigned long flags;
> > +
> > +	if (!static_branch_unlikely(&dev_protection_static_key))
> > +		return;
> > +
> > +	local_irq_save(flags);
> > +	/* 0 clears the PKEY_DISABLE_ACCESS bit, allowing access */
> > +	if (current->dev_page_access_ref == 0)
> > +		pks_update_protection(dev_page_pkey, 0);
> > +	current->dev_page_access_ref++;
> 
> 	if (!current->dev_page_access_ref++)

Sure.

> 
> > +	local_irq_restore(flags);
> > +}
> > +EXPORT_SYMBOL_GPL(dev_access_enable);
> 
> 
> Also, you probably want something like:
> 
> static __always_inline devm_access_disable(void)

Yes that is better.

However, again Dan and I agree devm is not the right prefix here.

I've updated.

Thanks!
Ira

> {
> 	if (static_branch_unlikely(&dev_protection_static_key))
> 		__devm_access_disable();
> }
> 
> static __always_inline devm_access_enable(void)
> {
> 	if (static_branch_unlikely(&dev_protection_static_key))
> 		__devm_access_enable();
> }
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WARNING: multiple messages have this Message-ID (diff)
From: Ira Weiny <ira.weiny@intel.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
	Andy Lutomirski <luto@kernel.org>,
	x86@kernel.org, Dave Hansen <dave.hansen@linux.intel.com>,
	Dan Williams <dan.j.williams@intel.com>,
	Vishal Verma <vishal.l.verma@intel.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	Fenghua Yu <fenghua.yu@intel.com>,
	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 V2 12/17] memremap: Add zone device access protection
Date: Fri, 17 Jul 2020 22:51:03 -0700	[thread overview]
Message-ID: <20200718055103.GU3008823@iweiny-DESK2.sc.intel.com> (raw)
In-Reply-To: <20200717091718.GA10769@hirez.programming.kicks-ass.net>

On Fri, Jul 17, 2020 at 11:17:18AM +0200, Peter Zijlstra wrote:
> On Fri, Jul 17, 2020 at 12:20:51AM -0700, ira.weiny@intel.com wrote:
> > +void dev_access_disable(void)
> > +{
> > +	unsigned long flags;
> > +
> > +	if (!static_branch_unlikely(&dev_protection_static_key))
> > +		return;
> > +
> > +	local_irq_save(flags);
> > +	current->dev_page_access_ref--;
> > +	if (current->dev_page_access_ref == 0)
> 
> 	if (!--current->dev_page_access_ref)

It's not my style but I'm ok with it.

> 
> > +		pks_update_protection(dev_page_pkey, PKEY_DISABLE_ACCESS);
> > +	local_irq_restore(flags);
> > +}
> > +EXPORT_SYMBOL_GPL(dev_access_disable);
> > +
> > +void dev_access_enable(void)
> > +{
> > +	unsigned long flags;
> > +
> > +	if (!static_branch_unlikely(&dev_protection_static_key))
> > +		return;
> > +
> > +	local_irq_save(flags);
> > +	/* 0 clears the PKEY_DISABLE_ACCESS bit, allowing access */
> > +	if (current->dev_page_access_ref == 0)
> > +		pks_update_protection(dev_page_pkey, 0);
> > +	current->dev_page_access_ref++;
> 
> 	if (!current->dev_page_access_ref++)

Sure.

> 
> > +	local_irq_restore(flags);
> > +}
> > +EXPORT_SYMBOL_GPL(dev_access_enable);
> 
> 
> Also, you probably want something like:
> 
> static __always_inline devm_access_disable(void)

Yes that is better.

However, again Dan and I agree devm is not the right prefix here.

I've updated.

Thanks!
Ira

> {
> 	if (static_branch_unlikely(&dev_protection_static_key))
> 		__devm_access_disable();
> }
> 
> static __always_inline devm_access_enable(void)
> {
> 	if (static_branch_unlikely(&dev_protection_static_key))
> 		__devm_access_enable();
> }

  reply	other threads:[~2020-07-18  5:51 UTC|newest]

Thread overview: 157+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-07-17  7:20 [PATCH RFC V2 00/17] PKS: Add Protection Keys Supervisor (PKS) support ira.weiny
2020-07-17  7:20 ` ira.weiny
2020-07-17  7:20 ` [PATCH RFC V2 01/17] x86/pkeys: Create pkeys_internal.h ira.weiny
2020-07-17  7:20   ` ira.weiny
2020-07-17  7:20 ` [PATCH RFC V2 02/17] x86/fpu: Refactor arch_set_user_pkey_access() for PKS support ira.weiny
2020-07-17  7:20   ` ira.weiny
2020-07-17  8:54   ` Peter Zijlstra
2020-07-17  8:54     ` Peter Zijlstra
2020-07-17 20:52     ` Ira Weiny
2020-07-17 20:52       ` Ira Weiny
2020-07-20  9:14       ` Peter Zijlstra
2020-07-20  9:14         ` Peter Zijlstra
2020-07-17 22:36     ` Dave Hansen
2020-07-17 22:36       ` Dave Hansen
2020-07-20  9:13       ` Peter Zijlstra
2020-07-20  9:13         ` Peter Zijlstra
2020-07-17  7:20 ` [PATCH RFC V2 03/17] x86/pks: Enable Protection Keys Supervisor (PKS) ira.weiny
2020-07-17  7:20   ` ira.weiny
2020-07-17  7:20 ` [PATCH RFC V2 04/17] x86/pks: Preserve the PKRS MSR on context switch ira.weiny
2020-07-17  7:20   ` ira.weiny
2020-07-17  8:31   ` Peter Zijlstra
2020-07-17  8:31     ` Peter Zijlstra
2020-07-17 21:39     ` Ira Weiny
2020-07-17 21:39       ` Ira Weiny
2020-07-17  8:59   ` Peter Zijlstra
2020-07-17  8:59     ` Peter Zijlstra
2020-07-17 22:34     ` Ira Weiny
2020-07-17 22:34       ` Ira Weiny
2020-07-20  9:15       ` Peter Zijlstra
2020-07-20  9:15         ` Peter Zijlstra
2020-07-20 18:35         ` Ira Weiny
2020-07-20 18:35           ` Ira Weiny
2020-07-17  7:20 ` [PATCH RFC V2 05/17] x86/pks: Add PKS kernel API ira.weiny
2020-07-17  7:20   ` ira.weiny
2020-07-17  7:20 ` [PATCH RFC V2 06/17] x86/pks: Add a debugfs file for allocated PKS keys ira.weiny
2020-07-17  7:20   ` ira.weiny
2020-07-17  7:20 ` [PATCH RFC V2 07/17] Documentation/pkeys: Update documentation for kernel pkeys ira.weiny
2020-07-17  7:20   ` ira.weiny
2020-07-17  7:20 ` [PATCH RFC V2 08/17] x86/pks: Add PKS Test code ira.weiny
2020-07-17  7:20   ` ira.weiny
2020-07-17  7:20 ` [PATCH RFC V2 09/17] memremap: Convert devmap static branch to {inc,dec} ira.weiny
2020-07-17  7:20   ` ira.weiny
2020-07-17  7:20 ` [PATCH RFC V2 10/17] fs/dax: Remove unused size parameter ira.weiny
2020-07-17  7:20   ` ira.weiny
2020-07-17  7:20 ` [PATCH RFC V2 11/17] drivers/dax: Expand lock scope to cover the use of addresses ira.weiny
2020-07-17  7:20   ` ira.weiny
2020-07-17  7:20 ` [PATCH RFC V2 12/17] memremap: Add zone device access protection ira.weiny
2020-07-17  7:20   ` ira.weiny
2020-07-17  9:10   ` Peter Zijlstra
2020-07-17  9:10     ` Peter Zijlstra
2020-07-18  5:06     ` Ira Weiny
2020-07-18  5:06       ` Ira Weiny
2020-07-20  9:16       ` Peter Zijlstra
2020-07-20  9:16         ` Peter Zijlstra
2020-07-17  9:17   ` Peter Zijlstra
2020-07-17  9:17     ` Peter Zijlstra
2020-07-18  5:51     ` Ira Weiny [this message]
2020-07-18  5:51       ` Ira Weiny
2020-07-17  9:20   ` Peter Zijlstra
2020-07-17  9:20     ` Peter Zijlstra
2020-07-17  7:20 ` [PATCH RFC V2 13/17] kmap: Add stray write protection for device pages ira.weiny
2020-07-17  7:20   ` ira.weiny
2020-07-17  9:21   ` Peter Zijlstra
2020-07-17  9:21     ` Peter Zijlstra
2020-07-19  4:13     ` Ira Weiny
2020-07-19  4:13       ` Ira Weiny
2020-07-20  9:17       ` Peter Zijlstra
2020-07-20  9:17         ` Peter Zijlstra
2020-07-21 16:31         ` Ira Weiny
2020-07-21 16:31           ` Ira Weiny
2020-07-17  7:20 ` [PATCH RFC V2 14/17] dax: Stray write protection for dax_direct_access() ira.weiny
2020-07-17  7:20   ` ira.weiny
2020-07-17  9:22   ` Peter Zijlstra
2020-07-17  9:22     ` Peter Zijlstra
2020-07-19  4:41     ` Ira Weiny
2020-07-19  4:41       ` Ira Weiny
2020-07-17  7:20 ` [PATCH RFC V2 15/17] nvdimm/pmem: Stray write protection for pmem->virt_addr ira.weiny
2020-07-17  7:20   ` ira.weiny
2020-07-17  7:20 ` [PATCH RFC V2 16/17] [dax|pmem]: Enable stray write protection ira.weiny
2020-07-17  7:20   ` ira.weiny
2020-07-17  9:25   ` Peter Zijlstra
2020-07-17  9:25     ` Peter Zijlstra
2020-07-17  7:20 ` [PATCH RFC V2 17/17] x86/entry: Preserve PKRS MSR across exceptions ira.weiny
2020-07-17  7:20   ` ira.weiny
2020-07-17  9:30   ` Peter Zijlstra
2020-07-17  9:30     ` Peter Zijlstra
2020-07-21 18:01     ` Ira Weiny
2020-07-21 18:01       ` Ira Weiny
2020-07-21 19:11       ` Peter Zijlstra
2020-07-21 19:11         ` Peter Zijlstra
2020-07-17  9:34   ` Peter Zijlstra
2020-07-17  9:34     ` Peter Zijlstra
2020-07-17 10:06   ` Peter Zijlstra
2020-07-17 10:06     ` Peter Zijlstra
2020-07-22  5:27     ` Ira Weiny
2020-07-22  5:27       ` Ira Weiny
2020-07-22  9:48       ` Peter Zijlstra
2020-07-22  9:48         ` Peter Zijlstra
2020-07-22 21:24         ` Ira Weiny
2020-07-22 21:24           ` Ira Weiny
2020-07-23 20:08       ` Thomas Gleixner
2020-07-23 20:08         ` Thomas Gleixner
2020-07-23 20:15         ` Thomas Gleixner
2020-07-23 20:15           ` Thomas Gleixner
2020-07-24 17:23           ` Ira Weiny
2020-07-24 17:23             ` Ira Weiny
2020-07-24 17:29             ` Andy Lutomirski
2020-07-24 17:29               ` Andy Lutomirski
2020-07-24 19:43               ` Ira Weiny
2020-07-24 19:43                 ` Ira Weiny
2020-07-22 16:21   ` Andy Lutomirski
2020-07-22 16:21     ` Andy Lutomirski
2020-07-22 16:21     ` Andy Lutomirski
2020-07-23 16:18     ` Fenghua Yu
2020-07-23 16:18       ` Fenghua Yu
2020-07-23 16:18       ` Fenghua Yu
2020-07-23 16:23       ` Dave Hansen
2020-07-23 16:23         ` Dave Hansen
2020-07-23 16:23         ` Dave Hansen
2020-07-23 16:52         ` Fenghua Yu
2020-07-23 16:52           ` Fenghua Yu
2020-07-23 16:52           ` Fenghua Yu
2020-07-23 17:08           ` Andy Lutomirski
2020-07-23 17:08             ` Andy Lutomirski
2020-07-23 17:08             ` Andy Lutomirski
2020-07-23 17:30             ` Dave Hansen
2020-07-23 17:30               ` Dave Hansen
2020-07-23 17:30               ` Dave Hansen
2020-07-23 20:23               ` Thomas Gleixner
2020-07-23 20:23                 ` Thomas Gleixner
2020-07-23 20:23                 ` Thomas Gleixner
2020-07-23 20:22             ` Thomas Gleixner
2020-07-23 20:22               ` Thomas Gleixner
2020-07-23 20:22               ` Thomas Gleixner
2020-07-23 21:30               ` Andy Lutomirski
2020-07-23 21:30                 ` Andy Lutomirski
2020-07-23 21:30                 ` Andy Lutomirski
2020-07-23 22:14                 ` Thomas Gleixner
2020-07-23 22:14                   ` Thomas Gleixner
2020-07-23 22:14                   ` Thomas Gleixner
2020-07-23 19:53   ` Thomas Gleixner
2020-07-23 19:53     ` Thomas Gleixner
2020-07-23 22:04     ` Ira Weiny
2020-07-23 22:04       ` Ira Weiny
2020-07-23 23:41       ` Thomas Gleixner
2020-07-23 23:41         ` Thomas Gleixner
2020-07-24 21:24         ` Thomas Gleixner
2020-07-24 21:24           ` Thomas Gleixner
2020-07-24 21:31           ` Thomas Gleixner
2020-07-24 21:31             ` Thomas Gleixner
2020-07-25  0:09           ` Andy Lutomirski
2020-07-25  0:09             ` Andy Lutomirski
2020-07-25  0:09             ` Andy Lutomirski
2020-07-27 20:59           ` Ira Weiny
2020-07-27 20:59             ` Ira Weiny
2020-07-24 22:19 ` [PATCH RFC V2 00/17] PKS: Add Protection Keys Supervisor (PKS) support Kees Cook
2020-07-24 22:19   ` Kees Cook

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