* Hanna Linder (hannal@us.ibm.com) wrote:
> +		ppp_class = class_simple_create(THIS_MODULE, "ppp");
> +		class_simple_device_add(ppp_class, MKDEV(PPP_MAJOR, 0), NULL, "ppp");

What happens if that class_simple_create() fails?  Actually,
class_simple_device_add could fail too, but doesn't seem anybody is
checking for that.

>  		err = devfs_mk_cdev(MKDEV(PPP_MAJOR, 0),
>  				S_IFCHR|S_IRUSR|S_IWUSR, "ppp");
> -		if (err)
> +		if (err) {
>  			unregister_chrdev(PPP_MAJOR, "ppp");
> +			class_simple_device_remove(MKDEV(PPP_MAJOR,0));
> +		}

need to destroy the class on error path to avoid leak.

> @@ -2540,6 +2547,7 @@ static void __exit ppp_cleanup(void)
>  	if (unregister_chrdev(PPP_MAJOR, "ppp") != 0)
>  		printk(KERN_ERR "PPP: failed to unregister PPP device\n");
>  	devfs_remove("ppp");
> +	class_simple_device_remove(MKDEV(PPP_MAJOR, 0));

ditto.  this will leak and would cause oops on reload of module.

something like below.