Re: [PATCH] uio: fix allocating minor id for uio device

["Hans J. Koch" <hjk@hansjkoch.de>]

On Thu, Mar 31, 2011 at 08:38:47PM +0800, Hillf Danton wrote:
> The number of uio devices that could be used should be less than
> UIO_MAX_DEVICES by design, and this work guards any cases in which id
> more than UIO_MAX_DEVICES is utilized.

Looks good.

Thanks for your work,
Hans

> 
> Signed-off-by: Hillf Danton <dhillf@gmail.com>

Signed-off-by: Hans J. Koch <hjk@hansjkoch.de>

> ---
> 
> --- a/drivers/uio/uio.c	2011-01-05 08:50:20.000000000 +0800
> +++ b/drivers/uio/uio.c	2011-03-31 20:43:44.000000000 +0800
> @@ -381,7 +381,13 @@ static int uio_get_minor(struct uio_devi
>  			retval = -ENOMEM;
>  		goto exit;
>  	}
> -	idev->minor = id & MAX_ID_MASK;
> +	if (id < UIO_MAX_DEVICES) {
> +		idev->minor = id;
> +	} else {
> +		dev_err(idev->dev, "too many uio devices\n");
> +		retval = -EINVAL;
> +		idr_remove(&uio_idr, id);
> +	}
>  exit:
>  	mutex_unlock(&minor_lock);
>  	return retval;
>