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alarmtimer: Fix bug where relative alarm timers were treated as absolute

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Sharvil noticed with the posix timer_settime interface, using the
CLOCK_REALTIME_ALARM or CLOCK_BOOTTIME_ALARM clockid, if the users
tried to specify a relative time timer, it would incorrectly be
treated as absolute regardless of the state of the flags argument.

This patch corrects this, properly checking the absolute/relative flag,
as well as adds further error checking that no invalid flag bits are set.

Reported-by: Sharvil Nanavati <sharvil@google.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Sharvil Nanavati <sharvil@google.com>
Cc: stable <stable@vger.kernel.org> #3.0+
Link: http://lkml.kernel.org/r/1404767171-6902-1-git-send-email-john.stultz@linaro.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This commit is contained in:
John Stultz
2014-07-07 14:06:11 -07:00
committed by Thomas Gleixner
parent e1a08b855f
commit 16927776ae
1 changed files with 18 additions and 2 deletions
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20
kernel/time/alarmtimer.c
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@@ -585,9 +585,14 @@ static int alarm_timer_set(struct k_itimer *timr, int flags,
struct itimerspec *new_setting, struct itimerspec *new_setting,
struct itimerspec *old_setting) struct itimerspec *old_setting)
{ {
ktime_t exp;
if (!rtcdev) if (!rtcdev)
return -ENOTSUPP; return -ENOTSUPP;
if (flags & ~TIMER_ABSTIME)
return -EINVAL;
if (old_setting) if (old_setting)
alarm_timer_get(timr, old_setting); alarm_timer_get(timr, old_setting);
@@ -597,8 +602,16 @@ static int alarm_timer_set(struct k_itimer *timr, int flags,
/* start the timer */ /* start the timer */
timr->it.alarm.interval = timespec_to_ktime(new_setting->it_interval); timr->it.alarm.interval = timespec_to_ktime(new_setting->it_interval);
alarm_start(&timr->it.alarm.alarmtimer, exp = timespec_to_ktime(new_setting->it_value);
timespec_to_ktime(new_setting->it_value)); /* Convert (if necessary) to absolute time */
if (flags != TIMER_ABSTIME) {
ktime_t now;
now = alarm_bases[timr->it.alarm.alarmtimer.type].gettime();
exp = ktime_add(now, exp);
}
alarm_start(&timr->it.alarm.alarmtimer, exp);
return 0; return 0;
} }
@@ -730,6 +743,9 @@ static int alarm_timer_nsleep(const clockid_t which_clock, int flags,
if (!alarmtimer_get_rtcdev()) if (!alarmtimer_get_rtcdev())
return -ENOTSUPP; return -ENOTSUPP;
if (flags & ~TIMER_ABSTIME)
return -EINVAL;
if (!capable(CAP_WAKE_ALARM)) if (!capable(CAP_WAKE_ALARM))
return -EPERM; return -EPERM;