diff mbox series

[v2] hwrng: exynos - fix reference leak in exynos_trng_probe

Message ID 20201130130118.51339-1-miaoqinglang@huawei.com
State New
Headers show
Series [v2] hwrng: exynos - fix reference leak in exynos_trng_probe | expand

Commit Message

'Qinglang Miao Nov. 30, 2020, 1:01 p.m. UTC
pm_runtime_get_sync will increment pm usage counter even
failed. Forgetting to putting operation will result in a
reference leak here.

Replace it with pm_runtime_resume_and_get to keep usage
counter balanced. I remove err_clock label at the same.

Fixes: 6cd225cc5d8a ("hwrng: exynos - add Samsung Exynos True RNG driver")
Reported-by: Hulk Robot <hulkci@huawei.com>
Suggested-by: Lukasz Stelmach <l.stelmach@samsung.com>
Signed-off-by: Qinglang Miao <miaoqinglang@huawei.com>
---
 v2: remobe useless label as Lukasz suggested.

 drivers/char/hw_random/exynos-trng.c | 9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

Comments

Lukasz Stelmach Dec. 2, 2020, 10:14 a.m. UTC | #1
It was <2020-11-30 pon 21:01>, when Qinglang Miao wrote:
> pm_runtime_get_sync will increment pm usage counter even

> failed. Forgetting to putting operation will result in a

> reference leak here.

>

> Replace it with pm_runtime_resume_and_get to keep usage

> counter balanced. I remove err_clock label at the same.

>

> Fixes: 6cd225cc5d8a ("hwrng: exynos - add Samsung Exynos True RNG driver")

> Reported-by: Hulk Robot <hulkci@huawei.com>

> Suggested-by: Lukasz Stelmach <l.stelmach@samsung.com>

> Signed-off-by: Qinglang Miao <miaoqinglang@huawei.com>

> ---

>  v2: remobe useless label as Lukasz suggested.


That is good too, but I meant using pm_runtime_resume_and_get() in
exynos_trng_resume() too. Please take a look at that function.

>

>  drivers/char/hw_random/exynos-trng.c | 9 +++------

>  1 file changed, 3 insertions(+), 6 deletions(-)

>

> diff --git a/drivers/char/hw_random/exynos-trng.c b/drivers/char/hw_random/exynos-trng.c

> index 8e1fe3f8d..ffebb72e4 100644

> --- a/drivers/char/hw_random/exynos-trng.c

> +++ b/drivers/char/hw_random/exynos-trng.c

> @@ -132,7 +132,7 @@ static int exynos_trng_probe(struct platform_device *pdev)

>  		return PTR_ERR(trng->mem);

>  

>  	pm_runtime_enable(&pdev->dev);

> -	ret = pm_runtime_get_sync(&pdev->dev);

> +	ret = pm_runtime_resume_and_get(&pdev->dev);

>  	if (ret < 0) {

>  		dev_err(&pdev->dev, "Could not get runtime PM.\n");

>  		goto err_pm_get;

> @@ -142,13 +142,13 @@ static int exynos_trng_probe(struct platform_device *pdev)

>  	if (IS_ERR(trng->clk)) {

>  		ret = PTR_ERR(trng->clk);

>  		dev_err(&pdev->dev, "Could not get clock.\n");

> -		goto err_clock;

> +		goto err_pm_get;

>  	}

>  

>  	ret = clk_prepare_enable(trng->clk);

>  	if (ret) {

>  		dev_err(&pdev->dev, "Could not enable the clk.\n");

> -		goto err_clock;

> +		goto err_pm_get;

>  	}

>  

>  	ret = devm_hwrng_register(&pdev->dev, &trng->rng);

> @@ -164,9 +164,6 @@ static int exynos_trng_probe(struct platform_device *pdev)

>  err_register:

>  	clk_disable_unprepare(trng->clk);

>  

> -err_clock:

> -	pm_runtime_put_sync(&pdev->dev);

> -

>  err_pm_get:

>  	pm_runtime_disable(&pdev->dev);


-- 
Ɓukasz Stelmach
Samsung R&D Institute Poland
Samsung Electronics
diff mbox series

Patch

diff --git a/drivers/char/hw_random/exynos-trng.c b/drivers/char/hw_random/exynos-trng.c
index 8e1fe3f8d..ffebb72e4 100644
--- a/drivers/char/hw_random/exynos-trng.c
+++ b/drivers/char/hw_random/exynos-trng.c
@@ -132,7 +132,7 @@  static int exynos_trng_probe(struct platform_device *pdev)
 		return PTR_ERR(trng->mem);
 
 	pm_runtime_enable(&pdev->dev);
-	ret = pm_runtime_get_sync(&pdev->dev);
+	ret = pm_runtime_resume_and_get(&pdev->dev);
 	if (ret < 0) {
 		dev_err(&pdev->dev, "Could not get runtime PM.\n");
 		goto err_pm_get;
@@ -142,13 +142,13 @@  static int exynos_trng_probe(struct platform_device *pdev)
 	if (IS_ERR(trng->clk)) {
 		ret = PTR_ERR(trng->clk);
 		dev_err(&pdev->dev, "Could not get clock.\n");
-		goto err_clock;
+		goto err_pm_get;
 	}
 
 	ret = clk_prepare_enable(trng->clk);
 	if (ret) {
 		dev_err(&pdev->dev, "Could not enable the clk.\n");
-		goto err_clock;
+		goto err_pm_get;
 	}
 
 	ret = devm_hwrng_register(&pdev->dev, &trng->rng);
@@ -164,9 +164,6 @@  static int exynos_trng_probe(struct platform_device *pdev)
 err_register:
 	clk_disable_unprepare(trng->clk);
 
-err_clock:
-	pm_runtime_put_sync(&pdev->dev);
-
 err_pm_get:
 	pm_runtime_disable(&pdev->dev);