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@canonical.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20190903171802.28314-1-cascardo@canonical.com

diff --git a/kernel/time/alarmtimer.c b/kernel/time/alarmtimer.c
index 57518efc3810037e571ecb130a47866e492f4737..b7d75a9e8ccf17c7b616b649e8d76bd5522561b4 100644 (file)
--- 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;