From: Alan Cox <alan@lxorguk.ukuu.org.uk>
To: Dave Airlie <airlied@linux.ie>,
dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org
Subject: Locking question for DRM
Date: Fri, 23 Apr 2010 11:22:22 +0100 [thread overview]
Message-ID: <20100423112222.67cfcbb2@lxorguk.ukuu.org.uk> (raw)
Various bits of the DRM deal with minor->master:
In the case of the open helper its protected by the struct mutex.
In the release path it's protected on some paths, but not this one ...
/* if the master has gone away we can't do anything with the lock */
if (file_priv->minor->master)
drm_master_release(dev, filp);
and I can't see what makes this safe if the drm_release for the master
and a client occur at the same time ?
The setmaster/dropmaster ioctl seems similar - the various conditional
checks are not protected from parallel changes occuring during their
execution.
Is this a bug or is something clever afoot ?
Alan
next reply other threads:[~2010-04-23 10:17 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-04-23 10:22 Alan Cox [this message]
2010-04-23 10:24 ` Dave Airlie
2010-04-23 10:37 ` Alan Cox
2010-04-23 10:44 ` Dave Airlie
2010-04-23 11:00 ` Alan Cox
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