Messages in this thread Patch in this message | | | Date | Tue, 17 Apr 2012 16:12:39 -0700 | From | Andrew Morton <> | Subject | Re: [PATCH] leds: ledtrig-timer trigger_data allocation fix |
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On Tue, 17 Apr 2012 17:05:11 -0600 Shuah Khan <shuahkhan@gmail.com> wrote:
> ledtrig-timer doesn't allocate memory for trigger_data and assigns > (void *)1 to save state. Fixed it to allocate int instead. Please > note that non-null trigger_data is used to key off of to do proper > cleanup in deactivation routine and not used during the life of the > trigger itself.
In that case, overloading the value of ->trigger_data in this fashion is inappropriate and a new field should be added to led_classdev for this purpose.
> - led_cdev->trigger_data = (void *)1; > + led_cdev->trigger_data = kzalloc(sizeof(int), GFP_KERNEL);
But that's better than what we have now.
It does require a comment though:
--- a/drivers/leds/ledtrig-timer.c~leds-ledtrig-timer-trigger_data-allocation-fix-fix +++ a/drivers/leds/ledtrig-timer.c @@ -89,6 +89,11 @@ static void timer_trig_activate(struct l led_blink_set(led_cdev, &led_cdev->blink_delay_on, &led_cdev->blink_delay_off); + /* + * Place a dummy allocation at ->trigger_data so that + * timer_trig_deactivate() cleans up correctly. This data is never + * actually used. + */ led_cdev->trigger_data = kzalloc(sizeof(int), GFP_KERNEL); if (!led_cdev->trigger_data) goto err_out_delayoff; _
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