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From: Johannes Weiner <hannes@saeurebad.de>
To: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Cc: Andrea Righi <righi.andrea@gmail.com>,
	Dave Jones <davej@redhat.com>, Dave Airlie <airlied@redhat.com>,
	Stefan Richter <stefanr@s5r6.in-berlin.de>
Subject: lockdep splat from ioctl and mmap fops sharing lock
Date: Thu, 23 Oct 2008 15:58:10 +0200	[thread overview]
Message-ID: <87ej27jtvx.fsf@saeurebad.de> (raw)
In-Reply-To: <87ljwgj8p1.fsf@saeurebad.de> (Johannes Weiner's message of "Thu, 23 Oct 2008 05:23:38 +0200")

Johannes Weiner <hannes@saeurebad.de> writes:

> Hi,
>
> fb_mmap() is called under mmap_sem and acquires fb_info->lock.
>
> Since 3e680aae4e53ab "fb: convert lock/unlock_kernel() into local fb
> mutex", fb_ioctl() takes fb_info->lock and does copy_to/from_user()
> under it, which in turn might acquire mmap_sem.

More affected drivers:

agp_ioctl() doing usercopy under agp_fe.agp_mutex
agp_mmap() taking agp_fe.agp_mutex under mmap_sem

dv1394_write() doing usercopy under video->mtx
dv1394_mmap() taking video->mtx under mmap_sem

raw1394_ioctl() doing usercopy under fi->state_mutex
raw1394_mmap() taking fi->state_mutex under mmap_sem

	Hannes

  parent reply	other threads:[~2008-10-23 13:58 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-10-23  3:23 lockdep splat from fbmem Johannes Weiner
2008-10-23 13:10 ` Andrea Righi
2008-10-23 13:58 ` Johannes Weiner [this message]
2008-10-23 15:08   ` lockdep splat from ioctl and mmap fops sharing lock Stefan Richter
2008-10-23 16:32     ` Johannes Weiner
2008-10-25  9:12       ` Stefan Richter
2008-10-28 22:33 ` lockdep splat from fbmem Andrea Righi

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