[PATCH 0/6] treewide: test clock rate to avoid division by 0

[PATCH 0/6] treewide: test clock rate to avoid division by 0

[Wolfram Sang]

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

[PATCH 2/6] net: ethernet: renesas: ravb_main: test clock rate to avoid division by 0

[Wolfram Sang]

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/net/ethernet/renesas/ravb_main.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c
index 88656ceb6e2946..ce1954a6a12726 100644
--- a/drivers/net/ethernet/renesas/ravb_main.c
+++ b/drivers/net/ethernet/renesas/ravb_main.c
@@ -1691,6 +1691,9 @@ static int ravb_set_gti(struct net_device *ndev)
 	rate = clk_get_rate(clk);
 	clk_put(clk);
 
+	if (!rate)
+		return -EINVAL;
+
 	inc = 1000000000ULL << 20;
 	do_div(inc, rate);
 
-- 
2.7.0

Re: [PATCH 2/6] net: ethernet: renesas: ravb_main: test clock rate to avoid division by 0

[Sergei Shtylyov]

Hello.

On 3/3/2016 1:33 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.
>
> Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>

Acked-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>

MBR, Sergei

Re: [PATCH 2/6] net: ethernet: renesas: ravb_main: test clock rate to avoid division by 0

[Wolfram Sang]

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On Wed, Mar 02, 2016 at 11:33:33PM +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>

Ping.

> ---
> 
> Should go individually via subsystem tree.
> 
>  drivers/net/ethernet/renesas/ravb_main.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c
> index 88656ceb6e2946..ce1954a6a12726 100644
> --- a/drivers/net/ethernet/renesas/ravb_main.c
> +++ b/drivers/net/ethernet/renesas/ravb_main.c
> @@ -1691,6 +1691,9 @@ static int ravb_set_gti(struct net_device *ndev)
>  	rate = clk_get_rate(clk);
>  	clk_put(clk);
>  
> +	if (!rate)
> +		return -EINVAL;
> +
>  	inc = 1000000000ULL << 20;
>  	do_div(inc, rate);
>  
> -- 
> 2.7.0
> 
> 

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Re: [PATCH 2/6] net: ethernet: renesas: ravb_main: test clock rate to avoid division by 0

[Sergei Shtylyov]

On 04/04/2016 12:36 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.
>>
>> Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
>
> Ping.

    http://patchwork.ozlabs.org/patch/591160/

    I have no idea why it's marked this way... Dave?

MBR, Sergei