Re: [PATCH] media: sti: Fix reference count leaks

From: Krzysztof Kozlowski
Date: Wed Apr 21 2021 - 09:29:42 EST


On Thu, 17 Sept 2020 at 13:45, Hans Verkuil <hverkuil@xxxxxxxxx> wrote:
>
> Hi Jean-Christophe,
>
> I'll take this patch, but while reviewing it I noticed something else:
>
> On 14/06/2020 05:31, wu000273@xxxxxxx wrote:
> > From: Qiushi Wu <wu000273@xxxxxxx>
> >
> > 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@xxxxxxx>
> > ---
> > 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@xxxxxxxxx/

Best regards,
Krzysztof