Re: [PATCH] gpio: sim: Remove intermediate pointer variable and harden function

[Bartosz Golaszewski]

On Fri, Apr 24, 2026 at 12:32 AM Maxwell Doose <m32285159@xxxxxxxxx> wrote:
>
> Remove the *pdev intermediate variable and directly dereference the
> pointer. While at it, replace sprintf() calls with sysfs_emit() to
> harden the driver.
>
> Signed-off-by: Maxwell Doose <m32285159@xxxxxxxxx>
> ---
>  drivers/gpio/gpio-sim.c | 8 +++-----
>  1 file changed, 3 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/gpio/gpio-sim.c b/drivers/gpio/gpio-sim.c
> index 13b87c8e6d0c..3c230f94eea2 100644
> --- a/drivers/gpio/gpio-sim.c
> +++ b/drivers/gpio/gpio-sim.c
> @@ -691,15 +691,13 @@ static ssize_t gpio_sim_device_config_dev_name_show(struct config_item *item,
>                                                     char *page)
>  {
>         struct gpio_sim_device *dev = to_gpio_sim_device(item);
> -       struct platform_device *pdev;
>
>         guard(mutex)(&dev->lock);
>
> -       pdev = dev->probe_data.pdev;
> -       if (pdev)
> -               return sprintf(page, "%s\n", dev_name(&pdev->dev));
> +       if (dev->probe_data.pdev)
> +               return sysfs_emit(page, "%s\n", dev_name(&dev->probe_data.pdev->dev));

Do you believe the code looks better with more layered dereferences?

>
> -       return sprintf(page, "gpio-sim.%d\n", dev->id);
> +       return sysfs_emit(page, "gpio-sim.%d\n", dev->id);

sprintf() is safe here as we cannot possibly exceed PAGE_SIZE with
this format but if you really want to do this, than please send a
separate patch converting all configfs show callbacks in the driver.

Bart

>  }
>
>  CONFIGFS_ATTR_RO(gpio_sim_device_config_, dev_name);
> --
> 2.53.0
>