Re: [PATCH v3] leds: Introduce userspace leds driver

[Jacek Anaszewski <j.anaszewski@samsung.com>]

Hi Pavel,

On 09/15/2016 03:35 PM, Pavel Machek wrote:
> Hi!
>
>>>> +	if (copy_from_user(&udev->user_dev, buffer,
>>>> +			   sizeof(struct uleds_user_dev))) {
>>>> +		ret = -EFAULT;
>>>> +		goto out;
>>>> +	}
>>>> +
>>>> +	if (!udev->user_dev.name[0]) {
>>>> +		ret = -EINVAL;
>>>> +		goto out;
>>>> +	}
>>>> +
>>>> +	ret = led_classdev_register(NULL, &udev->led_cdev);
>>>> +	if (ret < 0)
>>>> +		goto out;
>>
>> No sanity checking on the name -> probably a security hole. Do not
>> push this upstream before this is fixed.
>
> And actually... is it possible to have more then one userspace LED
> with this interface? I do have RGB LED connect on /dev/ttyUSB0, and I
> guess userspace driver would be appropriate, but it needs 3
> channels...

Each new successful write to /dev/uleds creates a new LED class device.

See Documentation/leds/uleds.txt.

-- 
Best regards,
Jacek Anaszewski