Re: [PATCH v4 03/13] gpiolib: convert the type of hwnum to unsigned int in gpiochip_get_desc()

Linus Walleij
2020-01-07T10:04:11Z

On Tue, Dec 24, 2019 at 1:07 PM Bartosz Golaszewski <brgl@bgdev.pl> wrote:

> From: Bartosz Golaszewski <bgolaszewski@baylibre.com>
>
> gpiochip_get_desc() takes a u16 hwnum, but it turns out most users don't
> respect that and usually pass an unsigned int. Since implicit casting to
> a smaller type is dangerous - let's change the type of hwnum to unsigned
> int in gpiochip_get_desc() and in gpiochip_request_own_desc() where the
> size of hwnum is not respected either and who's a user of the former.
>
> This is safe as we then check the hwnum against the number of lines
> before proceeding in gpiochip_get_desc().
>
> Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>

Reviewed-by: Linus Walleij <linus.walleij@linaro.org>

Yours,
Linus Walleij