2020-11-27 09:45:47

by Qinglang Miao

Subject: [PATCH] drm: rcar-du: fix reference leak in rcar_cmm_enable

pm_runtime_get_sync will increment pm usage counter even it
failed. Forgetting to putting operation will result in a
reference leak here.

A new function pm_runtime_resume_and_get is introduced in
[0] to keep usage counter balanced. So We fix the reference
leak by replacing it with new funtion.

[0] dd8088d5a896 ("PM: runtime: Add pm_runtime_resume_and_get to deal with usage counter")

Fixes: e08e934d6c28 ("drm: rcar-du: Add support for CMM")
Reported-by: Hulk Robot <[email protected]>
Signed-off-by: Qinglang Miao <[email protected]>
---
drivers/gpu/drm/rcar-du/rcar_cmm.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/rcar-du/rcar_cmm.c b/drivers/gpu/drm/rcar-du/rcar_cmm.c
index c578095b0..382d53f8a 100644
--- a/drivers/gpu/drm/rcar-du/rcar_cmm.c
+++ b/drivers/gpu/drm/rcar-du/rcar_cmm.c
@@ -122,7 +122,7 @@ int rcar_cmm_enable(struct platform_device *pdev)
{
int ret;

- ret = pm_runtime_get_sync(&pdev->dev);
+ ret = pm_runtime_resume_and_get(&pdev->dev);
if (ret < 0)
return ret;

--
2.23.0

2020-12-15 11:44:19

by jacopo mondi

Subject: Re: [PATCH] drm: rcar-du: fix reference leak in rcar_cmm_enable

Hello Qinglang,

On Fri, Nov 27, 2020 at 05:44:44PM +0800, Qinglang Miao wrote:
> pm_runtime_get_sync will increment pm usage counter even it
> failed. Forgetting to putting operation will result in a
> reference leak here.
>
> A new function pm_runtime_resume_and_get is introduced in
> [0] to keep usage counter balanced. So We fix the reference
> leak by replacing it with new funtion.
>
> [0] dd8088d5a896 ("PM: runtime: Add pm_runtime_resume_and_get to deal with usage counter")

I -think- you can break this line. Anyway, maintainers can fix when
applying if they feel to.

>
> Fixes: e08e934d6c28 ("drm: rcar-du: Add support for CMM")
> Reported-by: Hulk Robot <[email protected]>
> Signed-off-by: Qinglang Miao <[email protected]>

Seems fair!
Acked-by: Jacopo Mondi <[email protected]>

Thanks
j

> ---
> drivers/gpu/drm/rcar-du/rcar_cmm.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/rcar-du/rcar_cmm.c b/drivers/gpu/drm/rcar-du/rcar_cmm.c
> index c578095b0..382d53f8a 100644
> --- a/drivers/gpu/drm/rcar-du/rcar_cmm.c
> +++ b/drivers/gpu/drm/rcar-du/rcar_cmm.c
> @@ -122,7 +122,7 @@ int rcar_cmm_enable(struct platform_device *pdev)
> {
> int ret;
>
> - ret = pm_runtime_get_sync(&pdev->dev);
> + ret = pm_runtime_resume_and_get(&pdev->dev);
> if (ret < 0)
> return ret;
>
> --
> 2.23.0
>

2020-12-15 18:56:12

by Laurent Pinchart

Subject: Re: [PATCH] drm: rcar-du: fix reference leak in rcar_cmm_enable

Hi Qinglang,

Thank you for the patch.

On Fri, Nov 27, 2020 at 05:44:44PM +0800, Qinglang Miao wrote:
> pm_runtime_get_sync will increment pm usage counter even it
> failed. Forgetting to putting operation will result in a
> reference leak here.
>
> A new function pm_runtime_resume_and_get is introduced in
> [0] to keep usage counter balanced. So We fix the reference
> leak by replacing it with new funtion.
>
> [0] dd8088d5a896 ("PM: runtime: Add pm_runtime_resume_and_get to deal with usage counter")
>
> Fixes: e08e934d6c28 ("drm: rcar-du: Add support for CMM")
> Reported-by: Hulk Robot <[email protected]>
> Signed-off-by: Qinglang Miao <[email protected]>

Reviewed-by: Laurent Pinchart <[email protected]>

And queued for v5.11.

> ---
> drivers/gpu/drm/rcar-du/rcar_cmm.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/rcar-du/rcar_cmm.c b/drivers/gpu/drm/rcar-du/rcar_cmm.c
> index c578095b0..382d53f8a 100644
> --- a/drivers/gpu/drm/rcar-du/rcar_cmm.c
> +++ b/drivers/gpu/drm/rcar-du/rcar_cmm.c
> @@ -122,7 +122,7 @@ int rcar_cmm_enable(struct platform_device *pdev)
> {
> int ret;
>
> - ret = pm_runtime_get_sync(&pdev->dev);
> + ret = pm_runtime_resume_and_get(&pdev->dev);
> if (ret < 0)
> return ret;
>

--
Regards,

Laurent Pinchart