rtc: test before subtraction on unsigned

new_alarm is unsigned so test before the subtraction.

[akpm@linux-foundation.org: time-wrapping fix]
Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Cc: David Brownell <david-b@pacbell.net>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Roel Kluin 2009-03-31 15:25:00 -07:00 committed by Linus Torvalds
parent c08cf9daf6
commit fa7af8b1bb

View file

@ -222,16 +222,16 @@ static int ds1374_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
rtc_tm_to_time(&alarm->time, &new_alarm);
rtc_tm_to_time(&now, &itime);
new_alarm -= itime;
/* This can happen due to races, in addition to dates that are
* truly in the past. To avoid requiring the caller to check for
* races, dates in the past are assumed to be in the recent past
* (i.e. not something that we'd rather the caller know about via
* an error), and the alarm is set to go off as soon as possible.
*/
if (new_alarm <= 0)
if (time_before_eq(new_alarm, itime))
new_alarm = 1;
else
new_alarm -= itime;
mutex_lock(&ds1374->mutex);