2018-02-09 21:58:46

by Alexey Khoroshilov

Subject: [PATCH] watchdog: asm9260_wdt: fix error handling in asm9260_wdt_probe()

If devm_reset_control_get_exclusive() fails, asm9260_wdt_probe()
returns immediately. But clks has been already enabled at that point,
so it is required to disable them.

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Alexey Khoroshilov <[email protected]>
---
drivers/watchdog/asm9260_wdt.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/watchdog/asm9260_wdt.c b/drivers/watchdog/asm9260_wdt.c
index 7dd0da644a7f..de9e538a5fa8 100644
--- a/drivers/watchdog/asm9260_wdt.c
+++ b/drivers/watchdog/asm9260_wdt.c
@@ -297,8 +297,10 @@ static int asm9260_wdt_probe(struct platform_device *pdev)
return ret;

priv->rst = devm_reset_control_get_exclusive(&pdev->dev, "wdt_rst");
- if (IS_ERR(priv->rst))
- return PTR_ERR(priv->rst);
+ if (IS_ERR(priv->rst)) {
+ ret = PTR_ERR(priv->rst);
+ goto clk_off;
+ }

wdd = &priv->wdd;
wdd->info = &asm9260_wdt_ident;
--
2.7.4

2018-02-09 22:33:09

by Guenter Roeck

Subject: Re: [PATCH] watchdog: asm9260_wdt: fix error handling in asm9260_wdt_probe()

On Sat, Feb 10, 2018 at 12:56:29AM +0300, Alexey Khoroshilov wrote:
> If devm_reset_control_get_exclusive() fails, asm9260_wdt_probe()
> returns immediately. But clks has been already enabled at that point,
> so it is required to disable them.
>
> Found by Linux Driver Verification project (linuxtesting.org).
>
> Signed-off-by: Alexey Khoroshilov <[email protected]>
> ---
> drivers/watchdog/asm9260_wdt.c | 6 ++++--
> 1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/watchdog/asm9260_wdt.c b/drivers/watchdog/asm9260_wdt.c
> index 7dd0da644a7f..de9e538a5fa8 100644
> --- a/drivers/watchdog/asm9260_wdt.c
> +++ b/drivers/watchdog/asm9260_wdt.c
> @@ -297,8 +297,10 @@ static int asm9260_wdt_probe(struct platform_device *pdev)
> return ret;
>
> priv->rst = devm_reset_control_get_exclusive(&pdev->dev, "wdt_rst");
> - if (IS_ERR(priv->rst))
> - return PTR_ERR(priv->rst);
> + if (IS_ERR(priv->rst)) {
> + ret = PTR_ERR(priv->rst);
> + goto clk_off;
> + }

Good catch.

I would prefer to move the code around, ie call
devm_reset_control_get_exclusive() first and get the clocks
later.

Thanks,
Guenter

>
> wdd = &priv->wdd;
> wdd->info = &asm9260_wdt_ident;
> --
> 2.7.4
>

2018-02-10 10:22:30

by Alexey Khoroshilov

Subject: [PATCH v2] watchdog: asm9260_wdt: fix error handling in asm9260_wdt_probe()

If devm_reset_control_get_exclusive() fails, asm9260_wdt_probe()
returns immediately. But clks has been already enabled at that point,
so it is required to disable them or to move the code around.

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Alexey Khoroshilov <[email protected]>
---
v2: Move the code around instead of disabling clks as Guenter Roeck suggested.

drivers/watchdog/asm9260_wdt.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/watchdog/asm9260_wdt.c b/drivers/watchdog/asm9260_wdt.c
index 7dd0da644a7f..2cf56b459d84 100644
--- a/drivers/watchdog/asm9260_wdt.c
+++ b/drivers/watchdog/asm9260_wdt.c
@@ -292,14 +292,14 @@ static int asm9260_wdt_probe(struct platform_device *pdev)
if (IS_ERR(priv->iobase))
return PTR_ERR(priv->iobase);

- ret = asm9260_wdt_get_dt_clks(priv);
- if (ret)
- return ret;
-
priv->rst = devm_reset_control_get_exclusive(&pdev->dev, "wdt_rst");
if (IS_ERR(priv->rst))
return PTR_ERR(priv->rst);

+ ret = asm9260_wdt_get_dt_clks(priv);
+ if (ret)
+ return ret;
+
wdd = &priv->wdd;
wdd->info = &asm9260_wdt_ident;
wdd->ops = &asm9260_wdt_ops;
--
2.7.4

2018-02-11 17:47:32

by Guenter Roeck

Subject: Re: [v2] watchdog: asm9260_wdt: fix error handling in asm9260_wdt_probe()

On Sat, Feb 10, 2018 at 01:17:27PM +0300, Alexey Khoroshilov wrote:
> If devm_reset_control_get_exclusive() fails, asm9260_wdt_probe()
> returns immediately. But clks has been already enabled at that point,
> so it is required to disable them or to move the code around.
>
> Found by Linux Driver Verification project (linuxtesting.org).
>
> Signed-off-by: Alexey Khoroshilov <[email protected]>

Reviewed-by: Guenter Roeck <[email protected]>

> ---
> v2: Move the code around instead of disabling clks as Guenter Roeck suggested.
>
> drivers/watchdog/asm9260_wdt.c | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/watchdog/asm9260_wdt.c b/drivers/watchdog/asm9260_wdt.c
> index 7dd0da644a7f..2cf56b459d84 100644
> --- a/drivers/watchdog/asm9260_wdt.c
> +++ b/drivers/watchdog/asm9260_wdt.c
> @@ -292,14 +292,14 @@ static int asm9260_wdt_probe(struct platform_device *pdev)
> if (IS_ERR(priv->iobase))
> return PTR_ERR(priv->iobase);
>
> - ret = asm9260_wdt_get_dt_clks(priv);
> - if (ret)
> - return ret;
> -
> priv->rst = devm_reset_control_get_exclusive(&pdev->dev, "wdt_rst");
> if (IS_ERR(priv->rst))
> return PTR_ERR(priv->rst);
>
> + ret = asm9260_wdt_get_dt_clks(priv);
> + if (ret)
> + return ret;
> +
> wdd = &priv->wdd;
> wdd->info = &asm9260_wdt_ident;
> wdd->ops = &asm9260_wdt_ops;