From: Thadeu Lima de Souza Cascardo <cascardo@xxxxxxxxxxxxx> commit f18ddc13af981ce3c7b7f26925f099e7c6929aba upstream. 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 Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- kernel/time/alarmtimer.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/kernel/time/alarmtimer.c +++ b/kernel/time/alarmtimer.c @@ -673,7 +673,7 @@ static int alarm_timer_create(struct k_i enum alarmtimer_type type; if (!alarmtimer_get_rtcdev()) - return -ENOTSUPP; + return -EOPNOTSUPP; if (!capable(CAP_WAKE_ALARM)) return -EPERM; @@ -791,7 +791,7 @@ static int alarm_timer_nsleep(const cloc int ret = 0; if (!alarmtimer_get_rtcdev()) - return -ENOTSUPP; + return -EOPNOTSUPP; if (flags & ~TIMER_ABSTIME) return -EINVAL;