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

[Jacek Anaszewski]

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