[tip: refs/heads/timers/urgent] alarmtimer: Use EOPNOTSUPP instead of ENOTSUPP

[tip-bot2 for Thadeu Lima de Souza Cascardo]

The following commit has been merged into the refs/heads/timers/urgent branch of tip:

Commit-ID:     f18ddc13af981ce3c7b7f26925f099e7c6929aba
Gitweb:        https://git.kernel.org/tip/f18ddc13af981ce3c7b7f26925f099e7c6929aba
Author:        Thadeu Lima de Souza Cascardo <cascardo@xxxxxxxxxxxxx>
AuthorDate:    Tue, 03 Sep 2019 14:18:02 -03:00
Committer:     Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitterDate: Thu, 05 Sep 2019 21:19:26 +02:00

alarmtimer: Use EOPNOTSUPP instead of ENOTSUPP

ENOTSUPP is not supposed to be returned to userspace. This was found on an
OpenPower machine, where the RTC does not support set_alarm.

On that system, a clock_nanosleep(CLOCK_REALTIME_ALARM, ...) results in
"524 Unknown error 524"

Replace it with EOPNOTSUPP which results in the expected "95 Operation not
supported" error.

Fixes: 1c6b39ad3f01 (alarmtimers: Return -ENOTSUPP if no RTC device is present)
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@xxxxxxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Link: https://lkml.kernel.org/r/20190903171802.28314-1-cascardo@xxxxxxxxxxxxx

---
 kernel/time/alarmtimer.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/time/alarmtimer.c b/kernel/time/alarmtimer.c
index 57518ef..b7d75a9 100644
--- a/kernel/time/alarmtimer.c
+++ b/kernel/time/alarmtimer.c
@@ -672,7 +672,7 @@ static int alarm_timer_create(struct k_itimer *new_timer)
 	enum  alarmtimer_type type;
 
 	if (!alarmtimer_get_rtcdev())
-		return -ENOTSUPP;
+		return -EOPNOTSUPP;
 
 	if (!capable(CAP_WAKE_ALARM))
 		return -EPERM;
@@ -790,7 +790,7 @@ static int alarm_timer_nsleep(const clockid_t which_clock, int flags,
 	int ret = 0;
 
 	if (!alarmtimer_get_rtcdev())
-		return -ENOTSUPP;
+		return -EOPNOTSUPP;
 
 	if (flags & ~TIMER_ABSTIME)
 		return -EINVAL;