More checks for patterns? was: Fix pattern handling optimalization

From: Pavel Machek
Date: Thu Oct 25 2018 - 17:24:36 EST



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




--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

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