From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756318Ab0LHArv (ORCPT ); Tue, 7 Dec 2010 19:47:51 -0500 Received: from kroah.org ([198.145.64.141]:58516 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756286Ab0LHArr (ORCPT ); Tue, 7 Dec 2010 19:47:47 -0500 X-Mailbox-Line: From gregkh@clark.site Tue Dec 7 16:44:32 2010 Message-Id: <20101208004432.817309284@clark.site> User-Agent: quilt/0.48-11.2 Date: Tue, 07 Dec 2010 16:44:31 -0800 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: stable-review@kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, =?ISO-8859-15?q?Uwe=20Kleine-K=C3=B6nig?= , Richard Purdie Subject: [085/127] backlight: grab ops_lock before testing bd->ops In-Reply-To: <20101208004456.GA23578@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.32-stable review patch. If anyone has any objections, please let us know. ------------------ From: =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= commit d1d73578e053b981c3611e5a211534290d24a5eb upstream. According to the comment describing ops_lock in the definition of struct backlight_device and when comparing with other functions in backlight.c the mutex must be hold when checking ops to be non-NULL. Fixes a problem added by c835ee7f4154992e6 ("backlight: Add suspend/resume support to the backlight core") in Jan 2009. Signed-off-by: Uwe Kleine-König Acked-by: Richard Purdie Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- drivers/video/backlight/backlight.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) --- a/drivers/video/backlight/backlight.c +++ b/drivers/video/backlight/backlight.c @@ -196,12 +196,12 @@ static int backlight_suspend(struct devi { struct backlight_device *bd = to_backlight_device(dev); - if (bd->ops->options & BL_CORE_SUSPENDRESUME) { - mutex_lock(&bd->ops_lock); + mutex_lock(&bd->ops_lock); + if (bd->ops && bd->ops->options & BL_CORE_SUSPENDRESUME) { bd->props.state |= BL_CORE_SUSPENDED; backlight_update_status(bd); - mutex_unlock(&bd->ops_lock); } + mutex_unlock(&bd->ops_lock); return 0; } @@ -210,12 +210,12 @@ static int backlight_resume(struct devic { struct backlight_device *bd = to_backlight_device(dev); - if (bd->ops->options & BL_CORE_SUSPENDRESUME) { - mutex_lock(&bd->ops_lock); + mutex_lock(&bd->ops_lock); + if (bd->ops && bd->ops->options & BL_CORE_SUSPENDRESUME) { bd->props.state &= ~BL_CORE_SUSPENDED; backlight_update_status(bd); - mutex_unlock(&bd->ops_lock); } + mutex_unlock(&bd->ops_lock); return 0; }