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* [PATCH 0/6] treewide: test clock rate to avoid division by 0
@ 2016-03-02 22:33 Wolfram Sang
  2016-03-02 22:33 ` [PATCH 5/6] watchdog: atlas7_wdt: " Wolfram Sang
  2016-03-02 22:33 ` [PATCH 6/6] watchdog: tangox_wdt: " Wolfram Sang
  0 siblings, 2 replies; 7+ messages in thread
From: Wolfram Sang @ 2016-03-02 22:33 UTC (permalink / raw)
  To: linux-kernel
  Cc: linux-renesas-soc, linux-arm-kernel, linux-ide, linux-pwm,
	linux-watchdog, netdev

Here is the outcome of researching if the result of clk_get_rate() was directly
used as a divisor without checking if it is 0. Inspired by a Coverity report.

Wolfram Sang (6):
  ide: palm_bk3710: test clock rate to avoid division by 0
  net: ethernet: renesas: ravb_main: test clock rate to avoid division
    by 0
  pwm: pwm-img: test clock rate to avoid division by 0
  pwm: pwm-lpc18xx-sct: test clock rate to avoid division by 0
  watchdog: atlas7_wdt: test clock rate to avoid division by 0
  watchdog: tangox_wdt: test clock rate to avoid division by 0

 drivers/ide/palm_bk3710.c                | 2 ++
 drivers/net/ethernet/renesas/ravb_main.c | 3 +++
 drivers/pwm/pwm-img.c                    | 5 +++++
 drivers/pwm/pwm-lpc18xx-sct.c            | 2 ++
 drivers/watchdog/atlas7_wdt.c            | 5 +++++
 drivers/watchdog/tangox_wdt.c            | 2 ++
 6 files changed, 19 insertions(+)

-- 
2.7.0


^ permalink raw reply	[flat|nested] 7+ messages in thread

* [PATCH 5/6] watchdog: atlas7_wdt: test clock rate to avoid division by 0
  2016-03-02 22:33 [PATCH 0/6] treewide: test clock rate to avoid division by 0 Wolfram Sang
@ 2016-03-02 22:33 ` Wolfram Sang
  2016-03-03  4:25   ` Guenter Roeck
  2016-03-06  9:09   ` Wim Van Sebroeck
  2016-03-02 22:33 ` [PATCH 6/6] watchdog: tangox_wdt: " Wolfram Sang
  1 sibling, 2 replies; 7+ messages in thread
From: Wolfram Sang @ 2016-03-02 22:33 UTC (permalink / raw)
  To: linux-kernel
  Cc: linux-renesas-soc, 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.

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

^ permalink raw reply related	[flat|nested] 7+ messages in thread

* [PATCH 6/6] watchdog: tangox_wdt: test clock rate to avoid division by 0
  2016-03-02 22:33 [PATCH 0/6] treewide: test clock rate to avoid division by 0 Wolfram Sang
  2016-03-02 22:33 ` [PATCH 5/6] watchdog: atlas7_wdt: " Wolfram Sang
@ 2016-03-02 22:33 ` Wolfram Sang
  2016-03-03  4:26   ` Guenter Roeck
  1 sibling, 1 reply; 7+ messages in thread
From: Wolfram Sang @ 2016-03-02 22:33 UTC (permalink / raw)
  To: linux-kernel
  Cc: linux-renesas-soc, 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.

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

Should go individually via subsystem tree.

 drivers/watchdog/tangox_wdt.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/watchdog/tangox_wdt.c b/drivers/watchdog/tangox_wdt.c
index 709c1ed6fd79b9..cc702718ae4dbb 100644
--- a/drivers/watchdog/tangox_wdt.c
+++ b/drivers/watchdog/tangox_wdt.c
@@ -139,6 +139,8 @@ static int tangox_wdt_probe(struct platform_device *pdev)
 		return err;
 
 	dev->clk_rate = clk_get_rate(dev->clk);
+	if (!dev->clk_rate)
+		return -EINVAL;
 
 	dev->wdt.parent = &pdev->dev;
 	dev->wdt.info = &tangox_wdt_info;
-- 
2.7.0

^ permalink raw reply related	[flat|nested] 7+ messages in thread

* Re: [PATCH 5/6] watchdog: atlas7_wdt: test clock rate to avoid division by 0
  2016-03-02 22:33 ` [PATCH 5/6] watchdog: atlas7_wdt: " Wolfram Sang
@ 2016-03-03  4:25   ` Guenter Roeck
  2016-03-06  9:09   ` Wim Van Sebroeck
  1 sibling, 0 replies; 7+ messages in thread
From: Guenter Roeck @ 2016-03-03  4:25 UTC (permalink / raw)
  To: Wolfram Sang
  Cc: linux-kernel, linux-renesas-soc, Wim Van Sebroeck, linux-watchdog

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
> 

^ permalink raw reply	[flat|nested] 7+ messages in thread

* Re: [PATCH 6/6] watchdog: tangox_wdt: test clock rate to avoid division by 0
  2016-03-02 22:33 ` [PATCH 6/6] watchdog: tangox_wdt: " Wolfram Sang
@ 2016-03-03  4:26   ` Guenter Roeck
  2016-03-03  8:12     ` Wolfram Sang
  0 siblings, 1 reply; 7+ messages in thread
From: Guenter Roeck @ 2016-03-03  4:26 UTC (permalink / raw)
  To: Wolfram Sang
  Cc: linux-kernel, linux-renesas-soc, Wim Van Sebroeck, linux-watchdog

On Wed, Mar 02, 2016 at 11:33:37PM +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>
> ---
> 
> Should go individually via subsystem tree.
> 
>  drivers/watchdog/tangox_wdt.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/watchdog/tangox_wdt.c b/drivers/watchdog/tangox_wdt.c
> index 709c1ed6fd79b9..cc702718ae4dbb 100644
> --- a/drivers/watchdog/tangox_wdt.c
> +++ b/drivers/watchdog/tangox_wdt.c
> @@ -139,6 +139,8 @@ static int tangox_wdt_probe(struct platform_device *pdev)
>  		return err;
>  
>  	dev->clk_rate = clk_get_rate(dev->clk);
> +	if (!dev->clk_rate)
> +		return -EINVAL;

May be a nitpick, but clk_disable_unprepare() is missing.

Guenter

>  
>  	dev->wdt.parent = &pdev->dev;
>  	dev->wdt.info = &tangox_wdt_info;
> -- 
> 2.7.0
> 

^ permalink raw reply	[flat|nested] 7+ messages in thread

* Re: [PATCH 6/6] watchdog: tangox_wdt: test clock rate to avoid division by 0
  2016-03-03  4:26   ` Guenter Roeck
@ 2016-03-03  8:12     ` Wolfram Sang
  0 siblings, 0 replies; 7+ messages in thread
From: Wolfram Sang @ 2016-03-03  8:12 UTC (permalink / raw)
  To: Guenter Roeck
  Cc: linux-kernel, linux-renesas-soc, Wim Van Sebroeck, linux-watchdog

[-- Attachment #1: Type: text/plain, Size: 183 bytes --]

> > +	if (!dev->clk_rate)
> > +		return -EINVAL;
> 
> May be a nitpick, but clk_disable_unprepare() is missing.

Oh, definately not a nitpick in my book, will resend! Thanks!


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^ permalink raw reply	[flat|nested] 7+ messages in thread

* Re: [PATCH 5/6] watchdog: atlas7_wdt: test clock rate to avoid division by 0
  2016-03-02 22:33 ` [PATCH 5/6] watchdog: atlas7_wdt: " Wolfram Sang
  2016-03-03  4:25   ` Guenter Roeck
@ 2016-03-06  9:09   ` Wim Van Sebroeck
  1 sibling, 0 replies; 7+ messages in thread
From: Wim Van Sebroeck @ 2016-03-06  9:09 UTC (permalink / raw)
  To: Wolfram Sang
  Cc: linux-kernel, linux-renesas-soc, 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.
> 
> 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.


^ permalink raw reply	[flat|nested] 7+ messages in thread

end of thread, other threads:[~2016-03-06  9:09 UTC | newest]

Thread overview: 7+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2016-03-02 22:33 [PATCH 0/6] treewide: test clock rate to avoid division by 0 Wolfram Sang
2016-03-02 22:33 ` [PATCH 5/6] watchdog: atlas7_wdt: " Wolfram Sang
2016-03-03  4:25   ` Guenter Roeck
2016-03-06  9:09   ` Wim Van Sebroeck
2016-03-02 22:33 ` [PATCH 6/6] watchdog: tangox_wdt: " Wolfram Sang
2016-03-03  4:26   ` Guenter Roeck
2016-03-03  8:12     ` Wolfram Sang

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