diff mbox series

media: sti: Fix reference count leaks

Message ID 20200614033106.426-1-wu000273@umn.edu
State Accepted
Commit 6f4432bae9f2d12fc1815b5e26cc07e69bcad0df
Headers show
Series media: sti: Fix reference count leaks | expand

Commit Message

wu000273@umn.edu June 14, 2020, 3:31 a.m. UTC
From: Qiushi Wu <wu000273@umn.edu>

pm_runtime_get_sync() increments the runtime PM usage counter even
when it returns an error code, causing incorrect ref count if
pm_runtime_put_noidle() is not called in error handling paths.
Thus call pm_runtime_put_noidle() if pm_runtime_get_sync() fails.

Signed-off-by: Qiushi Wu <wu000273@umn.edu>
---
 drivers/media/platform/sti/hva/hva-hw.c | 2 ++
 1 file changed, 2 insertions(+)

Comments

Hans Verkuil Sept. 17, 2020, 11:40 a.m. UTC | #1
Hi Jean-Christophe,

I'll take this patch, but while reviewing it I noticed something else:

On 14/06/2020 05:31, wu000273@umn.edu wrote:
> From: Qiushi Wu <wu000273@umn.edu>

> 

> pm_runtime_get_sync() increments the runtime PM usage counter even

> when it returns an error code, causing incorrect ref count if

> pm_runtime_put_noidle() is not called in error handling paths.

> Thus call pm_runtime_put_noidle() if pm_runtime_get_sync() fails.

> 

> Signed-off-by: Qiushi Wu <wu000273@umn.edu>

> ---

>  drivers/media/platform/sti/hva/hva-hw.c | 2 ++

>  1 file changed, 2 insertions(+)

> 

> diff --git a/drivers/media/platform/sti/hva/hva-hw.c b/drivers/media/platform/sti/hva/hva-hw.c

> index 401aaafa1710..bb13348be083 100644

> --- a/drivers/media/platform/sti/hva/hva-hw.c

> +++ b/drivers/media/platform/sti/hva/hva-hw.c

> @@ -272,6 +272,7 @@ static unsigned long int hva_hw_get_ip_version(struct hva_dev *hva)

>  

>  	if (pm_runtime_get_sync(dev) < 0) {

>  		dev_err(dev, "%s     failed to get pm_runtime\n", HVA_PREFIX);

> +		pm_runtime_put_noidle(dev);

>  		mutex_unlock(&hva->protect_mutex);


This appears to be a spurious mutex_unlock() since I don't see a corresponding mutex_lock.

Jean-Christophe, can you check this and, if I am right, post a patch fixing this?

Regards,

	Hans

>  		return -EFAULT;

>  	}

> @@ -553,6 +554,7 @@ void hva_hw_dump_regs(struct hva_dev *hva, struct seq_file *s)

>  

>  	if (pm_runtime_get_sync(dev) < 0) {

>  		seq_puts(s, "Cannot wake up IP\n");

> +		pm_runtime_put_noidle(dev);

>  		mutex_unlock(&hva->protect_mutex);

>  		return;

>  	}

>
Krzysztof Kozlowski April 21, 2021, 1:29 p.m. UTC | #2
On Thu, 17 Sept 2020 at 13:45, Hans Verkuil <hverkuil@xs4all.nl> wrote:
>

> Hi Jean-Christophe,

>

> I'll take this patch, but while reviewing it I noticed something else:

>

> On 14/06/2020 05:31, wu000273@umn.edu wrote:

> > From: Qiushi Wu <wu000273@umn.edu>

> >

> > pm_runtime_get_sync() increments the runtime PM usage counter even

> > when it returns an error code, causing incorrect ref count if

> > pm_runtime_put_noidle() is not called in error handling paths.

> > Thus call pm_runtime_put_noidle() if pm_runtime_get_sync() fails.

> >

> > Signed-off-by: Qiushi Wu <wu000273@umn.edu>

> > ---

> >  drivers/media/platform/sti/hva/hva-hw.c | 2 ++

> >  1 file changed, 2 insertions(+)

> >

> > diff --git a/drivers/media/platform/sti/hva/hva-hw.c b/drivers/media/platform/sti/hva/hva-hw.c

> > index 401aaafa1710..bb13348be083 100644

> > --- a/drivers/media/platform/sti/hva/hva-hw.c

> > +++ b/drivers/media/platform/sti/hva/hva-hw.c

> > @@ -272,6 +272,7 @@ static unsigned long int hva_hw_get_ip_version(struct hva_dev *hva)

> >

> >       if (pm_runtime_get_sync(dev) < 0) {

> >               dev_err(dev, "%s     failed to get pm_runtime\n", HVA_PREFIX);

> > +             pm_runtime_put_noidle(dev);

> >               mutex_unlock(&hva->protect_mutex);

>

> This appears to be a spurious mutex_unlock() since I don't see a corresponding mutex_lock.

>

> Jean-Christophe, can you check this and, if I am right, post a patch fixing this?


Probably patch should be skipped due to uncertain intentions:
https://lore.kernel.org/linux-nfs/YH+7ZydHv4+Y1hlx@kroah.com/

Best regards,
Krzysztof
diff mbox series

Patch

diff --git a/drivers/media/platform/sti/hva/hva-hw.c b/drivers/media/platform/sti/hva/hva-hw.c
index 401aaafa1710..bb13348be083 100644
--- a/drivers/media/platform/sti/hva/hva-hw.c
+++ b/drivers/media/platform/sti/hva/hva-hw.c
@@ -272,6 +272,7 @@  static unsigned long int hva_hw_get_ip_version(struct hva_dev *hva)
 
 	if (pm_runtime_get_sync(dev) < 0) {
 		dev_err(dev, "%s     failed to get pm_runtime\n", HVA_PREFIX);
+		pm_runtime_put_noidle(dev);
 		mutex_unlock(&hva->protect_mutex);
 		return -EFAULT;
 	}
@@ -553,6 +554,7 @@  void hva_hw_dump_regs(struct hva_dev *hva, struct seq_file *s)
 
 	if (pm_runtime_get_sync(dev) < 0) {
 		seq_puts(s, "Cannot wake up IP\n");
+		pm_runtime_put_noidle(dev);
 		mutex_unlock(&hva->protect_mutex);
 		return;
 	}