[PATCH v1 4/5] gpio: rockchip: avoid division by zero

Ye Zhang posted 5 patches 1 year, 5 months ago
There is a newer version of this series
[PATCH v1 4/5] gpio: rockchip: avoid division by zero
Posted by Ye Zhang 1 year, 5 months ago
If the clk_get_rate return '0', it will happen division by zero.

Signed-off-by: Ye Zhang <ye.zhang@rock-chips.com>
---
 drivers/gpio/gpio-rockchip.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/gpio/gpio-rockchip.c b/drivers/gpio/gpio-rockchip.c
index 8949324ed816..03e949b0a344 100644
--- a/drivers/gpio/gpio-rockchip.c
+++ b/drivers/gpio/gpio-rockchip.c
@@ -212,8 +212,10 @@ static int rockchip_gpio_set_debounce(struct gpio_chip *gc,
 	if (bank->gpio_type == GPIO_TYPE_V2 && !IS_ERR(bank->db_clk)) {
 		div_debounce_support = true;
 		freq = clk_get_rate(bank->db_clk);
+		if (!freq)
+			return -EINVAL;
 		max_debounce = (GENMASK(23, 0) + 1) * 2 * 1000000 / freq;
-		if (debounce > max_debounce)
+		if ((unsigned long)debounce > max_debounce)
 			return -EINVAL;
 
 		div = debounce * freq;
-- 
2.34.1
Re: [PATCH v1 4/5] gpio: rockchip: avoid division by zero
Posted by Bartosz Golaszewski 1 year, 5 months ago
On Thu, Aug 15, 2024 at 9:17 AM Ye Zhang <ye.zhang@rock-chips.com> wrote:
>
> If the clk_get_rate return '0', it will happen division by zero.
>

This looks like a backportable fix. Please add a Fixes: tag and move
the commit to the first place in the series so that it can be sent for
v6.11 and stable already.

> Signed-off-by: Ye Zhang <ye.zhang@rock-chips.com>
> ---
>  drivers/gpio/gpio-rockchip.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpio/gpio-rockchip.c b/drivers/gpio/gpio-rockchip.c
> index 8949324ed816..03e949b0a344 100644
> --- a/drivers/gpio/gpio-rockchip.c
> +++ b/drivers/gpio/gpio-rockchip.c
> @@ -212,8 +212,10 @@ static int rockchip_gpio_set_debounce(struct gpio_chip *gc,
>         if (bank->gpio_type == GPIO_TYPE_V2 && !IS_ERR(bank->db_clk)) {
>                 div_debounce_support = true;
>                 freq = clk_get_rate(bank->db_clk);
> +               if (!freq)
> +                       return -EINVAL;

Newline here.

>                 max_debounce = (GENMASK(23, 0) + 1) * 2 * 1000000 / freq;
> -               if (debounce > max_debounce)
> +               if ((unsigned long)debounce > max_debounce)

This is a separate change, please put it into a different commit.

Bart

>                         return -EINVAL;
>
>                 div = debounce * freq;
> --
> 2.34.1
>