* [PATCH] backlight: grab ops_lock before testing bd->ops
@ 2010-11-22 9:43 Uwe Kleine-König
2010-11-22 9:59 ` Richard Purdie
0 siblings, 1 reply; 5+ messages in thread
From: Uwe Kleine-König @ 2010-11-22 9:43 UTC (permalink / raw)
To: Richard Purdie; +Cc: linux-kernel, kernel
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.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
---
drivers/video/backlight/backlight.c | 12 ++++++------
1 files changed, 6 insertions(+), 6 deletions(-)
diff --git a/drivers/video/backlight/backlight.c b/drivers/video/backlight/backlight.c
index e207810..0870329 100644
--- a/drivers/video/backlight/backlight.c
+++ b/drivers/video/backlight/backlight.c
@@ -197,12 +197,12 @@ static int backlight_suspend(struct device *dev, pm_message_t state)
{
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;
}
@@ -211,12 +211,12 @@ static int backlight_resume(struct device *dev)
{
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;
}
--
1.7.2.3
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH] backlight: grab ops_lock before testing bd->ops
2010-11-22 9:43 [PATCH] backlight: grab ops_lock before testing bd->ops Uwe Kleine-König
@ 2010-11-22 9:59 ` Richard Purdie
2010-11-22 10:05 ` Uwe Kleine-König
0 siblings, 1 reply; 5+ messages in thread
From: Richard Purdie @ 2010-11-22 9:59 UTC (permalink / raw)
To: Uwe Kleine-König, akpm; +Cc: linux-kernel, kernel
On Mon, 2010-11-22 at 10:43 +0100, Uwe Kleine-König wrote:
> 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.
>
> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Richard Purdie <rpurdie@linux.intel.com>
> ---
> drivers/video/backlight/backlight.c | 12 ++++++------
> 1 files changed, 6 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/video/backlight/backlight.c b/drivers/video/backlight/backlight.c
> index e207810..0870329 100644
> --- a/drivers/video/backlight/backlight.c
> +++ b/drivers/video/backlight/backlight.c
> @@ -197,12 +197,12 @@ static int backlight_suspend(struct device *dev, pm_message_t state)
> {
> 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;
> }
> @@ -211,12 +211,12 @@ static int backlight_resume(struct device *dev)
> {
> 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;
> }
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] backlight: grab ops_lock before testing bd->ops
2010-11-22 9:59 ` Richard Purdie
@ 2010-11-22 10:05 ` Uwe Kleine-König
2010-11-22 17:53 ` [stable] " Greg KH
0 siblings, 1 reply; 5+ messages in thread
From: Uwe Kleine-König @ 2010-11-22 10:05 UTC (permalink / raw)
To: Richard Purdie; +Cc: akpm, linux-kernel, kernel, stable
Hello,
On Mon, Nov 22, 2010 at 09:59:07AM +0000, Richard Purdie wrote:
> On Mon, 2010-11-22 at 10:43 +0100, Uwe Kleine-König wrote:
> > 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.
> >
> > Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
>
> Acked-by: Richard Purdie <rpurdie@linux.intel.com>
The problem was introduced by c835ee7f4154992e6cf0674d7ee136f5d36247a4
(that is in 2.6.29-rc1). Is this relevant for stable?
Best regards
Uwe
> > ---
> > drivers/video/backlight/backlight.c | 12 ++++++------
> > 1 files changed, 6 insertions(+), 6 deletions(-)
> >
> > diff --git a/drivers/video/backlight/backlight.c b/drivers/video/backlight/backlight.c
> > index e207810..0870329 100644
> > --- a/drivers/video/backlight/backlight.c
> > +++ b/drivers/video/backlight/backlight.c
> > @@ -197,12 +197,12 @@ static int backlight_suspend(struct device *dev, pm_message_t state)
> > {
> > 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;
> > }
> > @@ -211,12 +211,12 @@ static int backlight_resume(struct device *dev)
> > {
> > 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;
> > }
>
>
>
--
Pengutronix e.K. | Uwe Kleine-König |
Industrial Linux Solutions | http://www.pengutronix.de/ |
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [stable] [PATCH] backlight: grab ops_lock before testing bd->ops
2010-11-22 10:05 ` Uwe Kleine-König
@ 2010-11-22 17:53 ` Greg KH
2010-11-23 8:56 ` Uwe Kleine-König
0 siblings, 1 reply; 5+ messages in thread
From: Greg KH @ 2010-11-22 17:53 UTC (permalink / raw)
To: Uwe Kleine-König; +Cc: Richard Purdie, akpm, linux-kernel, kernel, stable
On Mon, Nov 22, 2010 at 11:05:32AM +0100, Uwe Kleine-König wrote:
> Hello,
>
> On Mon, Nov 22, 2010 at 09:59:07AM +0000, Richard Purdie wrote:
> > On Mon, 2010-11-22 at 10:43 +0100, Uwe Kleine-König wrote:
> > > 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.
> > >
> > > Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
> >
> > Acked-by: Richard Purdie <rpurdie@linux.intel.com>
> The problem was introduced by c835ee7f4154992e6cf0674d7ee136f5d36247a4
> (that is in 2.6.29-rc1). Is this relevant for stable?
Yes.
What is the git commit id of the fix in Linus's tree?
thanks,
greg k-h
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [stable] [PATCH] backlight: grab ops_lock before testing bd->ops
2010-11-22 17:53 ` [stable] " Greg KH
@ 2010-11-23 8:56 ` Uwe Kleine-König
0 siblings, 0 replies; 5+ messages in thread
From: Uwe Kleine-König @ 2010-11-23 8:56 UTC (permalink / raw)
To: Greg KH; +Cc: Richard Purdie, akpm, linux-kernel, kernel, stable
Hi Greg,
On Mon, Nov 22, 2010 at 09:53:32AM -0800, Greg KH wrote:
> On Mon, Nov 22, 2010 at 11:05:32AM +0100, Uwe Kleine-König wrote:
> > Hello,
> >
> > On Mon, Nov 22, 2010 at 09:59:07AM +0000, Richard Purdie wrote:
> > > On Mon, 2010-11-22 at 10:43 +0100, Uwe Kleine-König wrote:
> > > > 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.
> > > >
> > > > Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
> > >
> > > Acked-by: Richard Purdie <rpurdie@linux.intel.com>
> > The problem was introduced by c835ee7f4154992e6cf0674d7ee136f5d36247a4
> > (that is in 2.6.29-rc1). Is this relevant for stable?
>
> Yes.
>
> What is the git commit id of the fix in Linus's tree?
I'll let you know when it hits his tree.
Best regards
Uwe
--
Pengutronix e.K. | Uwe Kleine-König |
Industrial Linux Solutions | http://www.pengutronix.de/ |
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2010-11-23 8:56 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
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2010-11-22 9:43 [PATCH] backlight: grab ops_lock before testing bd->ops Uwe Kleine-König
2010-11-22 9:59 ` Richard Purdie
2010-11-22 10:05 ` Uwe Kleine-König
2010-11-22 17:53 ` [stable] " Greg KH
2010-11-23 8:56 ` Uwe Kleine-König
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