alarmtimer: Return correct remaining time

BugLink: https://bugs.launchpad.net/bugs/1838116
commit 07d7e12091f4ab869cc6a4bb276399057e73b0b3 upstream.

To calculate a remaining time, it's required to subtract the current time
from the expiration time. In alarm_timer_remaining() the arguments of
ktime_sub are swapped.

Fixes: d653d8457c76 ("alarmtimer: Implement remaining callback")
Signed-off-by: Andrei Vagin <avagin@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Mukesh Ojha <mojha@codeaurora.org>
Cc: Stephen Boyd <sboyd@kernel.org>
Cc: John Stultz <john.stultz@linaro.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20190408041542.26338-1-avagin@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>

diff --git a/kernel/time/alarmtimer.c b/kernel/time/alarmtimer.c
index fa5de5e8de61d88d266cd2651dedd2090ad89284..fdeb9bc6affb484398d9d366e358e44c79cd6df2 100644 (file)
--- a/kernel/time/alarmtimer.c
+++ b/kernel/time/alarmtimer.c
@@ -597,7 +597,7 @@ static ktime_t alarm_timer_remaining(struct k_itimer *timr, ktime_t now)
 {
        struct alarm *alarm = &timr->it.alarm.alarmtimer;
 
-       return ktime_sub(now, alarm->node.expires);
+       return ktime_sub(alarm->node.expires, now);
 }
 
 /**