* [PATCH v2] watchdog: tangox_wdt: test clock rate to avoid division by 0
@ 2016-03-03 8:24 Wolfram Sang
2016-03-03 11:44 ` Guenter Roeck
2016-03-06 9:09 ` Wim Van Sebroeck
0 siblings, 2 replies; 3+ messages in thread
From: Wolfram Sang @ 2016-03-03 8:24 UTC (permalink / raw)
To: linux-kernel
Cc: Wolfram Sang, Wim Van Sebroeck, Guenter Roeck, linux-watchdog
From: Wolfram Sang <wsa+renesas@sang-engineering.com>
The clk API may return 0 on clk_get_rate, so we should check the result before
using it as a divisor. For this, refactor the code to use a central
error path.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
---
drivers/watchdog/tangox_wdt.c | 14 ++++++++++----
1 file changed, 10 insertions(+), 4 deletions(-)
diff --git a/drivers/watchdog/tangox_wdt.c b/drivers/watchdog/tangox_wdt.c
index 709c1ed6fd79b9..cfbed7e051b619 100644
--- a/drivers/watchdog/tangox_wdt.c
+++ b/drivers/watchdog/tangox_wdt.c
@@ -139,6 +139,10 @@ static int tangox_wdt_probe(struct platform_device *pdev)
return err;
dev->clk_rate = clk_get_rate(dev->clk);
+ if (!dev->clk_rate) {
+ err = -EINVAL;
+ goto err;
+ }
dev->wdt.parent = &pdev->dev;
dev->wdt.info = &tangox_wdt_info;
@@ -171,10 +175,8 @@ static int tangox_wdt_probe(struct platform_device *pdev)
}
err = watchdog_register_device(&dev->wdt);
- if (err) {
- clk_disable_unprepare(dev->clk);
- return err;
- }
+ if (err)
+ goto err;
platform_set_drvdata(pdev, dev);
@@ -187,6 +189,10 @@ static int tangox_wdt_probe(struct platform_device *pdev)
dev_info(&pdev->dev, "SMP86xx/SMP87xx watchdog registered\n");
return 0;
+
+ err:
+ clk_disable_unprepare(dev->clk);
+ return err;
}
static int tangox_wdt_remove(struct platform_device *pdev)
--
2.7.0
^ permalink raw reply related [flat|nested] 3+ messages in thread* Re: [PATCH v2] watchdog: tangox_wdt: test clock rate to avoid division by 0
2016-03-03 8:24 [PATCH v2] watchdog: tangox_wdt: test clock rate to avoid division by 0 Wolfram Sang
@ 2016-03-03 11:44 ` Guenter Roeck
2016-03-06 9:09 ` Wim Van Sebroeck
1 sibling, 0 replies; 3+ messages in thread
From: Guenter Roeck @ 2016-03-03 11:44 UTC (permalink / raw)
To: Wolfram Sang, linux-kernel; +Cc: Wim Van Sebroeck, linux-watchdog
On 03/03/2016 12:24 AM, Wolfram Sang wrote:
> From: Wolfram Sang <wsa+renesas@sang-engineering.com>
>
> The clk API may return 0 on clk_get_rate, so we should check the result before
> using it as a divisor. For this, refactor the code to use a central
> error path.
>
> Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
> ---
> drivers/watchdog/tangox_wdt.c | 14 ++++++++++----
> 1 file changed, 10 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/watchdog/tangox_wdt.c b/drivers/watchdog/tangox_wdt.c
> index 709c1ed6fd79b9..cfbed7e051b619 100644
> --- a/drivers/watchdog/tangox_wdt.c
> +++ b/drivers/watchdog/tangox_wdt.c
> @@ -139,6 +139,10 @@ static int tangox_wdt_probe(struct platform_device *pdev)
> return err;
>
> dev->clk_rate = clk_get_rate(dev->clk);
> + if (!dev->clk_rate) {
> + err = -EINVAL;
> + goto err;
> + }
>
> dev->wdt.parent = &pdev->dev;
> dev->wdt.info = &tangox_wdt_info;
> @@ -171,10 +175,8 @@ static int tangox_wdt_probe(struct platform_device *pdev)
> }
>
> err = watchdog_register_device(&dev->wdt);
> - if (err) {
> - clk_disable_unprepare(dev->clk);
> - return err;
> - }
> + if (err)
> + goto err;
>
> platform_set_drvdata(pdev, dev);
>
> @@ -187,6 +189,10 @@ static int tangox_wdt_probe(struct platform_device *pdev)
> dev_info(&pdev->dev, "SMP86xx/SMP87xx watchdog registered\n");
>
> return 0;
> +
> + err:
> + clk_disable_unprepare(dev->clk);
> + return err;
> }
>
> static int tangox_wdt_remove(struct platform_device *pdev)
>
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [PATCH v2] watchdog: tangox_wdt: test clock rate to avoid division by 0
2016-03-03 8:24 [PATCH v2] watchdog: tangox_wdt: test clock rate to avoid division by 0 Wolfram Sang
2016-03-03 11:44 ` Guenter Roeck
@ 2016-03-06 9:09 ` Wim Van Sebroeck
1 sibling, 0 replies; 3+ messages in thread
From: Wim Van Sebroeck @ 2016-03-06 9:09 UTC (permalink / raw)
To: Wolfram Sang; +Cc: linux-kernel, Guenter Roeck, linux-watchdog
Hi Wolfram,
> From: Wolfram Sang <wsa+renesas@sang-engineering.com>
>
> The clk API may return 0 on clk_get_rate, so we should check the result before
> using it as a divisor. For this, refactor the code to use a central
> error path.
>
> Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
> ---
> drivers/watchdog/tangox_wdt.c | 14 ++++++++++----
> 1 file changed, 10 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/watchdog/tangox_wdt.c b/drivers/watchdog/tangox_wdt.c
> index 709c1ed6fd79b9..cfbed7e051b619 100644
> --- a/drivers/watchdog/tangox_wdt.c
> +++ b/drivers/watchdog/tangox_wdt.c
> @@ -139,6 +139,10 @@ static int tangox_wdt_probe(struct platform_device *pdev)
> return err;
>
> dev->clk_rate = clk_get_rate(dev->clk);
> + if (!dev->clk_rate) {
> + err = -EINVAL;
> + goto err;
> + }
>
> dev->wdt.parent = &pdev->dev;
> dev->wdt.info = &tangox_wdt_info;
> @@ -171,10 +175,8 @@ static int tangox_wdt_probe(struct platform_device *pdev)
> }
>
> err = watchdog_register_device(&dev->wdt);
> - if (err) {
> - clk_disable_unprepare(dev->clk);
> - return err;
> - }
> + if (err)
> + goto err;
>
> platform_set_drvdata(pdev, dev);
>
> @@ -187,6 +189,10 @@ static int tangox_wdt_probe(struct platform_device *pdev)
> dev_info(&pdev->dev, "SMP86xx/SMP87xx watchdog registered\n");
>
> return 0;
> +
> + err:
> + clk_disable_unprepare(dev->clk);
> + return err;
> }
>
> static int tangox_wdt_remove(struct platform_device *pdev)
> --
> 2.7.0
>
Patch has been added to linux-watchdog-next.
Kind regards,
Wim.
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2016-03-06 9:10 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2016-03-03 8:24 [PATCH v2] watchdog: tangox_wdt: test clock rate to avoid division by 0 Wolfram Sang
2016-03-03 11:44 ` Guenter Roeck
2016-03-06 9:09 ` Wim Van Sebroeck
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox