Re: [PATCH] drivers: char: scx200_gpio: check return value of cdev_add()

[Greg Kroah-Hartman]

On Mon, Apr 07, 2025 at 05:56:14PM +0100, Salah Triki wrote:
> Check return value of cdev_add() and in case of error unregister the
> range of device numbers.
> 
> Signed-off-by: Salah Triki <salah.triki@xxxxxxxxx>
> ---
>  drivers/char/scx200_gpio.c | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/char/scx200_gpio.c b/drivers/char/scx200_gpio.c
> index 700e6affea6f..36efcc828e8e 100644
> --- a/drivers/char/scx200_gpio.c
> +++ b/drivers/char/scx200_gpio.c
> @@ -107,10 +107,14 @@ static int __init scx200_gpio_init(void)
>  	}
>  
>  	cdev_init(&scx200_gpio_cdev, &scx200_gpio_fileops);
> -	cdev_add(&scx200_gpio_cdev, devid, MAX_PINS);
> +	rc = cdev_add(&scx200_gpio_cdev, devid, MAX_PINS);
> +	if (rc)
> +		goto unregister_chrdev_region;
>  
>  	return 0; /* succeed */
>  
> +unregister_chrdev_region:
> +	unregister_chrdev_region(devid, MAX_PINS);
>  undo_platform_device_add:
>  	platform_device_del(pdev);
>  undo_malloc:
> -- 
> 2.43.0
> 

How was this tested?

thanks,

greg k-h