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From: Jens Axboe <jens.axboe@oracle.com>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>,
	Ingo Molnar <mingo@elte.hu>, Tejun Heo <htejun@gmail.com>,
	Arjan van de Ven <arjan@infradead.org>,
	Hugh Dickins <hugh@veritas.com>,
	linux-kernel@vger.kernel.org, akpm@linux-foundation.org
Subject: Re: [PATCH] Fix kunmap() argument in sg_miter_stop
Date: Mon, 17 Nov 2008 19:26:50 +0100	[thread overview]
Message-ID: <20081117182650.GY26778@kernel.dk> (raw)
In-Reply-To: <alpine.LFD.2.00.0811171015070.3468@nehalem.linux-foundation.org>

On Mon, Nov 17 2008, Linus Torvalds wrote:
> 
> 
> On Mon, 17 Nov 2008, Jens Axboe wrote:
> > 
> > Any opinions on the kunmap/kunmap_atomic pointer checking? It's a bit
> > ugly that we have to enforce a void * rule for kunmap_atomic(),
> 
> I don't think that's a "bit ugly". I think it's unacceptable.
> 
> Making sure we pass in "struct page" to kunmap() sounds good, but the 
> kunmap_atomic() part just sounds insane.

It's been the primary source of bugs that I have seen. The xen and sg
iter bug were kunmap() variants though, but otherwise I've mostly seen
the opposite. But it is ugly, no doubt about it. I can't think of a
better way to attempt to warn about it though, so if you really dislike
it I'll just drop the _atomic() bits.

-- 
Jens Axboe


  reply	other threads:[~2008-11-17 18:28 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-11-15 19:27 [PATCH] Fix kunmap() argument in sg_miter_stop Arjan van de Ven
2008-11-15 20:15 ` Hugh Dickins
2008-11-15 20:27   ` Arjan van de Ven
2008-11-15 20:39   ` Arjan van de Ven
2008-11-16  5:16     ` Tejun Heo
2008-11-17  8:11       ` Jens Axboe
2008-11-17  8:22         ` Ingo Molnar
2008-11-17  8:30           ` Jens Axboe
2008-11-17  8:50             ` Ingo Molnar
2008-11-17  8:58               ` Jens Axboe
2008-11-17  9:34                 ` Jens Axboe
2008-11-17  9:41                   ` Ingo Molnar
2008-11-17  9:45                     ` Jens Axboe
2008-11-17 11:13                       ` Jens Axboe
2008-11-17 17:08                         ` Jeremy Fitzhardinge
2008-11-17 17:10                           ` Ingo Molnar
2008-11-17 17:15                             ` Jeremy Fitzhardinge
2008-11-17 17:25                               ` Linus Torvalds
2008-11-17 17:35                                 ` Jeremy Fitzhardinge
2008-11-17 18:14                                   ` [PATCH] xen: fix scrub_page() Ingo Molnar
2008-11-17 18:07                                 ` [PATCH] Fix kunmap() argument in sg_miter_stop Jens Axboe
2008-11-17 18:16                                   ` Linus Torvalds
2008-11-17 18:26                                     ` Jens Axboe [this message]
2008-11-18  8:27                                       ` Ingo Molnar

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