From: Jonathan Nieder <jrnieder@gmail.com>
Date: Sun, 1 May 2011 09:29:56 +0000 (-0300)
Subject: cx88: hold device lock during sub-driver initialization
X-Git-Tag: v2.6.39.1~40
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=fa7e5a133b16147d942345d4dd73665a3d8d1bb2;p=pandora-kernel.git

cx88: hold device lock during sub-driver initialization

commit 1d6213ab995c61f7d1d81cf6cf876acf15d6e714 upstream.

cx8802_blackbird_probe makes a device node for the mpeg sub-device
before it has been added to dev->drvlist.  If the device is opened
during that time, the open succeeds but request_acquire cannot be
called, so the reference count remains zero.  Later, when the device
is closed, the reference count becomes negative --- uh oh.

Close the race by holding core->lock during probe and not releasing
until the device is in drvlist and initialization finished.
Previously the BKL prevented this race.

Reported-by: Andreas Huber <hobrom@gmx.at>
Tested-by: Andi Huber <hobrom@gmx.at>
Tested-by: Marlon de Boer <marlon@hyves.nl>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---

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