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From: Arnd Bergmann <arnd@arndb.de>
To: Johannes Berg <johannes@sipsolutions.net>
Cc: Dan Carpenter <error27@gmail.com>,
	Jaroslav Kysela <perex@perex.cz>, Takashi Iwai <tiwai@suse.de>,
	alsa-devel@alsa-project.org, kernel-janitors@vger.kernel.org,
	linux-sparse@vger.kernel.org, Josh Triplett <josh@kernel.org>
Subject: Re: [patch 1/2] OSS: soundcard: locking bug in sound_ioctl()
Date: Mon, 11 Oct 2010 12:50:16 +0200	[thread overview]
Message-ID: <201010111250.16299.arnd@arndb.de> (raw)
In-Reply-To: <1286787000.3634.1.camel@jlt3.sipsolutions.net>

On Monday 11 October 2010, Johannes Berg wrote:
> On Mon, 2010-10-11 at 10:13 +0200, Arnd Bergmann wrote:
> 
> > Hmm, actually sparse does not warn about sound_ioctl returning in
> > different lock contexts. Sparse developers: is there a known limitation
> > in sparse for this? I expected to see context warnings because
> > sound_ioctl normally releases soundcard_mutex (previously lock_kernel)
> > in some cases returns while holding the lock.
> 
> Arnd, mutexes aren't annotated in the kernel source to make use of
> sparse's context checking.

D'oh. I never realized this was only done for some types of locks.
Is there a reason why we don't want mutexes to be annotated or do
we just need someone to do it?

	Arnd

WARNING: multiple messages have this Message-ID (diff)
From: Arnd Bergmann <arnd@arndb.de>
To: Johannes Berg <johannes@sipsolutions.net>
Cc: Dan Carpenter <error27@gmail.com>,
	Jaroslav Kysela <perex@perex.cz>, Takashi Iwai <tiwai@suse.de>,
	alsa-devel@alsa-project.org, kernel-janitors@vger.kernel.org,
	linux-sparse@vger.kernel.org, Josh Triplett <josh@kernel.org>
Subject: Re: [patch 1/2] OSS: soundcard: locking bug in sound_ioctl()
Date: Mon, 11 Oct 2010 10:50:16 +0000	[thread overview]
Message-ID: <201010111250.16299.arnd@arndb.de> (raw)
In-Reply-To: <1286787000.3634.1.camel@jlt3.sipsolutions.net>

On Monday 11 October 2010, Johannes Berg wrote:
> On Mon, 2010-10-11 at 10:13 +0200, Arnd Bergmann wrote:
> 
> > Hmm, actually sparse does not warn about sound_ioctl returning in
> > different lock contexts. Sparse developers: is there a known limitation
> > in sparse for this? I expected to see context warnings because
> > sound_ioctl normally releases soundcard_mutex (previously lock_kernel)
> > in some cases returns while holding the lock.
> 
> Arnd, mutexes aren't annotated in the kernel source to make use of
> sparse's context checking.

D'oh. I never realized this was only done for some types of locks.
Is there a reason why we don't want mutexes to be annotated or do
we just need someone to do it?

	Arnd

  reply	other threads:[~2010-10-11 10:50 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-10-10 17:33 [patch 1/2] OSS: soundcard: locking bug in sound_ioctl() Dan Carpenter
2010-10-10 17:33 ` Dan Carpenter
2010-10-10 18:39 ` Arnd Bergmann
2010-10-10 18:39   ` Arnd Bergmann
2010-10-11  8:13   ` Arnd Bergmann
2010-10-11  8:13     ` Arnd Bergmann
2010-10-11  8:50     ` Johannes Berg
2010-10-11  8:50       ` Johannes Berg
2010-10-11 10:50       ` Arnd Bergmann [this message]
2010-10-11 10:50         ` Arnd Bergmann
2010-10-11 10:52         ` Johannes Berg
2010-10-11 10:52           ` Johannes Berg
2010-10-11 18:54           ` Josh Triplett
2010-10-11 18:54             ` Josh Triplett
2010-10-11 20:42             ` Arnd Bergmann
2010-10-11 20:42               ` Arnd Bergmann
2010-10-11 22:23               ` Josh Triplett
2010-10-11 22:23                 ` Josh Triplett
2010-10-12  6:39                 ` Arnd Bergmann
2010-10-12  6:39                   ` Arnd Bergmann
2010-10-12  6:43                   ` Josh Triplett
2010-10-12  6:43                     ` Josh Triplett
2010-10-11 11:59 ` Takashi Iwai
2010-10-11 11:59   ` Takashi Iwai

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