2020-12-01 09:30:04

by Qinglang Miao

[permalink] [raw]
Subject: [PATCH 5/8] i2c: omap: fix reference leak when pm_runtime_get_sync fails

The PM reference count is not expected to be incremented on
return in omap_i2c_probe() and omap_i2c_remove().

However, pm_runtime_get_sync will increment the PM reference
count even failed. Forgetting to putting operation will result
in a reference leak here. I Replace it with pm_runtime_resume_and_get
to keep usage counter balanced.

What's more, error path 'err_free_mem' seems not like a proper
name any more. So I change the name to err_disable_pm and move
pm_runtime_disable below, for pm_runtime of 'pdev->dev' should
be disabled when pm_runtime_resume_and_get fails.

Fixes: 3b0fb97c8dc4 ("I2C: OMAP: Handle error check for pm runtime")
Reported-by: Hulk Robot <[email protected]>
Signed-off-by: Qinglang Miao <[email protected]>
---
drivers/i2c/busses/i2c-omap.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
index 12ac4212a..d4f6c6d60 100644
--- a/drivers/i2c/busses/i2c-omap.c
+++ b/drivers/i2c/busses/i2c-omap.c
@@ -1404,9 +1404,9 @@ omap_i2c_probe(struct platform_device *pdev)
pm_runtime_set_autosuspend_delay(omap->dev, OMAP_I2C_PM_TIMEOUT);
pm_runtime_use_autosuspend(omap->dev);

- r = pm_runtime_get_sync(omap->dev);
+ r = pm_runtime_resume_and_get(omap->dev);
if (r < 0)
- goto err_free_mem;
+ goto err_disable_pm;

/*
* Read the Rev hi bit-[15:14] ie scheme this is 1 indicates ver2.
@@ -1513,8 +1513,8 @@ omap_i2c_probe(struct platform_device *pdev)
omap_i2c_write_reg(omap, OMAP_I2C_CON_REG, 0);
pm_runtime_dont_use_autosuspend(omap->dev);
pm_runtime_put_sync(omap->dev);
+err_disable_pm:
pm_runtime_disable(&pdev->dev);
-err_free_mem:

return r;
}
@@ -1525,7 +1525,7 @@ static int omap_i2c_remove(struct platform_device *pdev)
int ret;

i2c_del_adapter(&omap->adapter);
- ret = pm_runtime_get_sync(&pdev->dev);
+ ret = pm_runtime_resume_and_get(&pdev->dev);
if (ret < 0)
return ret;

--
2.23.0


2020-12-01 16:58:40

by Grygorii Strashko

[permalink] [raw]
Subject: Re: [PATCH 5/8] i2c: omap: fix reference leak when pm_runtime_get_sync fails



On 01/12/2020 11:31, Qinglang Miao wrote:
> The PM reference count is not expected to be incremented on
> return in omap_i2c_probe() and omap_i2c_remove().
>
> However, pm_runtime_get_sync will increment the PM reference
> count even failed. Forgetting to putting operation will result
> in a reference leak here. I Replace it with pm_runtime_resume_and_get
> to keep usage counter balanced.
>
> What's more, error path 'err_free_mem' seems not like a proper
> name any more. So I change the name to err_disable_pm and move
> pm_runtime_disable below, for pm_runtime of 'pdev->dev' should
> be disabled when pm_runtime_resume_and_get fails.
>
> Fixes: 3b0fb97c8dc4 ("I2C: OMAP: Handle error check for pm runtime")
> Reported-by: Hulk Robot <[email protected]>
> Signed-off-by: Qinglang Miao <[email protected]>
> ---
> drivers/i2c/busses/i2c-omap.c | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
> index 12ac4212a..d4f6c6d60 100644
> --- a/drivers/i2c/busses/i2c-omap.c
> +++ b/drivers/i2c/busses/i2c-omap.c
> @@ -1404,9 +1404,9 @@ omap_i2c_probe(struct platform_device *pdev)
> pm_runtime_set_autosuspend_delay(omap->dev, OMAP_I2C_PM_TIMEOUT);
> pm_runtime_use_autosuspend(omap->dev);
>
> - r = pm_runtime_get_sync(omap->dev);
> + r = pm_runtime_resume_and_get(omap->dev);
> if (r < 0)
> - goto err_free_mem;
> + goto err_disable_pm;
>
> /*
> * Read the Rev hi bit-[15:14] ie scheme this is 1 indicates ver2.
> @@ -1513,8 +1513,8 @@ omap_i2c_probe(struct platform_device *pdev)
> omap_i2c_write_reg(omap, OMAP_I2C_CON_REG, 0);
> pm_runtime_dont_use_autosuspend(omap->dev);
> pm_runtime_put_sync(omap->dev);
> +err_disable_pm:
> pm_runtime_disable(&pdev->dev);
> -err_free_mem:
>
> return r;
> }
> @@ -1525,7 +1525,7 @@ static int omap_i2c_remove(struct platform_device *pdev)
> int ret;
>
> i2c_del_adapter(&omap->adapter);
> - ret = pm_runtime_get_sync(&pdev->dev);
> + ret = pm_runtime_resume_and_get(&pdev->dev);
> if (ret < 0)
> return ret;
>
>

Reviewed-by: Grygorii Strashko <[email protected]>

--
Best regards,
grygorii

2020-12-02 05:17:58

by Vignesh Raghavendra

[permalink] [raw]
Subject: Re: [PATCH 5/8] i2c: omap: fix reference leak when pm_runtime_get_sync fails



On 12/1/20 3:01 PM, Qinglang Miao wrote:
> The PM reference count is not expected to be incremented on
> return in omap_i2c_probe() and omap_i2c_remove().
>
> However, pm_runtime_get_sync will increment the PM reference
> count even failed. Forgetting to putting operation will result
> in a reference leak here. I Replace it with pm_runtime_resume_and_get
> to keep usage counter balanced.
>
> What's more, error path 'err_free_mem' seems not like a proper
> name any more. So I change the name to err_disable_pm and move
> pm_runtime_disable below, for pm_runtime of 'pdev->dev' should
> be disabled when pm_runtime_resume_and_get fails.
>
> Fixes: 3b0fb97c8dc4 ("I2C: OMAP: Handle error check for pm runtime")
> Reported-by: Hulk Robot <[email protected]>
> Signed-off-by: Qinglang Miao <[email protected]>
> ---

Reviewed-by: Vignesh Raghavendra <[email protected]>

> drivers/i2c/busses/i2c-omap.c | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
> index 12ac4212a..d4f6c6d60 100644
> --- a/drivers/i2c/busses/i2c-omap.c
> +++ b/drivers/i2c/busses/i2c-omap.c
> @@ -1404,9 +1404,9 @@ omap_i2c_probe(struct platform_device *pdev)
> pm_runtime_set_autosuspend_delay(omap->dev, OMAP_I2C_PM_TIMEOUT);
> pm_runtime_use_autosuspend(omap->dev);
>
> - r = pm_runtime_get_sync(omap->dev);
> + r = pm_runtime_resume_and_get(omap->dev);
> if (r < 0)
> - goto err_free_mem;
> + goto err_disable_pm;
>
> /*
> * Read the Rev hi bit-[15:14] ie scheme this is 1 indicates ver2.
> @@ -1513,8 +1513,8 @@ omap_i2c_probe(struct platform_device *pdev)
> omap_i2c_write_reg(omap, OMAP_I2C_CON_REG, 0);
> pm_runtime_dont_use_autosuspend(omap->dev);
> pm_runtime_put_sync(omap->dev);
> +err_disable_pm:
> pm_runtime_disable(&pdev->dev);
> -err_free_mem:
>
> return r;
> }
> @@ -1525,7 +1525,7 @@ static int omap_i2c_remove(struct platform_device *pdev)
> int ret;
>
> i2c_del_adapter(&omap->adapter);
> - ret = pm_runtime_get_sync(&pdev->dev);
> + ret = pm_runtime_resume_and_get(&pdev->dev);
> if (ret < 0)
> return ret;
>
>