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[5/6] watchdog: atlas7_wdt: test clock rate to avoid division by 0

Message ID 1456958018-7849-6-git-send-email-wsa@the-dreams.de (mailing list archive)
State Awaiting Upstream
Delegated to: Simon Horman
Headers show

Commit Message

Wolfram Sang March 2, 2016, 10:33 p.m. UTC 
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.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
---

Should go individually via subsystem tree.

 drivers/watchdog/atlas7_wdt.c | 5 +++++
 1 file changed, 5 insertions(+)

Comments

Guenter Roeck March 3, 2016, 4:25 a.m. UTC | #1 
On Wed, Mar 02, 2016 at 11:33:36PM +0100, 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.
> 
> Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>

Reviewed-by: Guenter Roeck <linux@roeck-us.net>

> ---
> 
> Should go individually via subsystem tree.
> 
>  drivers/watchdog/atlas7_wdt.c | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/drivers/watchdog/atlas7_wdt.c b/drivers/watchdog/atlas7_wdt.c
> index df6d9242a31958..ed80734befae16 100644
> --- a/drivers/watchdog/atlas7_wdt.c
> +++ b/drivers/watchdog/atlas7_wdt.c
> @@ -154,6 +154,11 @@ static int atlas7_wdt_probe(struct platform_device *pdev)
>  	writel(0, wdt->base + ATLAS7_WDT_CNT_CTRL);
>  
>  	wdt->tick_rate = clk_get_rate(clk);
> +	if (!wdt->tick_rate) {
> +		ret = -EINVAL;
> +		goto err1;
> +	}
> +
>  	wdt->clk = clk;
>  	atlas7_wdd.min_timeout = 1;
>  	atlas7_wdd.max_timeout = UINT_MAX / wdt->tick_rate;
> -- 
> 2.7.0
>
Wim Van Sebroeck March 6, 2016, 9:09 a.m. UTC | #2 
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.
> 
> Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
> ---
> 
> Should go individually via subsystem tree.
> 
>  drivers/watchdog/atlas7_wdt.c | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/drivers/watchdog/atlas7_wdt.c b/drivers/watchdog/atlas7_wdt.c
> index df6d9242a31958..ed80734befae16 100644
> --- a/drivers/watchdog/atlas7_wdt.c
> +++ b/drivers/watchdog/atlas7_wdt.c
> @@ -154,6 +154,11 @@ static int atlas7_wdt_probe(struct platform_device *pdev)
>  	writel(0, wdt->base + ATLAS7_WDT_CNT_CTRL);
>  
>  	wdt->tick_rate = clk_get_rate(clk);
> +	if (!wdt->tick_rate) {
> +		ret = -EINVAL;
> +		goto err1;
> +	}
> +
>  	wdt->clk = clk;
>  	atlas7_wdd.min_timeout = 1;
>  	atlas7_wdd.max_timeout = UINT_MAX / wdt->tick_rate;
> -- 
> 2.7.0
> 

Patch has been added to linux-watchdog-next.

Kind regards,
Wim.
diff mbox

Patch

diff --git a/drivers/watchdog/atlas7_wdt.c b/drivers/watchdog/atlas7_wdt.c
index df6d9242a31958..ed80734befae16 100644
--- a/drivers/watchdog/atlas7_wdt.c
+++ b/drivers/watchdog/atlas7_wdt.c
@@ -154,6 +154,11 @@  static int atlas7_wdt_probe(struct platform_device *pdev)
 	writel(0, wdt->base + ATLAS7_WDT_CNT_CTRL);
 
 	wdt->tick_rate = clk_get_rate(clk);
+	if (!wdt->tick_rate) {
+		ret = -EINVAL;
+		goto err1;
+	}
+
 	wdt->clk = clk;
 	atlas7_wdd.min_timeout = 1;
 	atlas7_wdd.max_timeout = UINT_MAX / wdt->tick_rate;