Re: More checks for patterns? was: Fix pattern handling optimalization

From: Jacek Anaszewski
Date: Fri Oct 26 2018 - 15:57:31 EST


On 10/25/2018 11:24 PM, Pavel Machek wrote:
>
> We don't want brightness < 0, but this may not be best way to do
> this. We also don't want brightness > max_brightness, but I'm not sure
> this check is effective.
>
> We probably also don't want pattern where all the delta_t s are zero.
>
> I came up with this so far....
> Pavel
>
>
>
> diff --git a/drivers/leds/trigger/ledtrig-pattern.c b/drivers/leds/trigger/ledtrig-pattern.c
> index ce7acd1..bc5f495 100644
> --- a/drivers/leds/trigger/ledtrig-pattern.c
> +++ b/drivers/leds/trigger/ledtrig-pattern.c
> @@ -250,9 +251,16 @@ static ssize_t pattern_trig_store_patterns(struct led_classdev *led_cdev,
>
> while (offset < count - 1 && data->npatterns < MAX_PATTERNS) {
> cr = 0;
> - ccount = sscanf(buf + offset, "%d %u %n",
> + ccount = sscanf(buf + offset, "%u %u %n",
> &data->patterns[data->npatterns].brightness,
> &data->patterns[data->npatterns].delta_t, &cr);
> +
> + if (data->patterns[data->npatterns].brightness > data->led_cdev->max_brightness) {
> + data->npatterns = 0;
> + err = -EINVAL;

We don't fail on attempt of setting brightness > max_brightness, but
only truncate it. In this case we could do the same for consistency.

> + goto out;
> + }
> +
> if (ccount != 2) {
> data->npatterns = 0;
> err = -EINVAL;
>
>
>
>

--
Best regards,
Jacek Anaszewski