alarmtimer: Use EOPNOTSUPP instead of ENOTSUPP

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@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
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/kernel/time/alarmtimer.c b/kernel/time/alarmtimer.c
index e78480b..70aef32 100644 (file)
--- a/kernel/time/alarmtimer.c
+++ b/kernel/time/alarmtimer.c
@@ -530,7 +530,7 @@ static int alarm_timer_create(struct k_itimer *new_timer)
        struct alarm_base *base;
 
        if (!alarmtimer_get_rtcdev())
-               return -ENOTSUPP;
+               return -EOPNOTSUPP;
 
        if (!capable(CAP_WAKE_ALARM))
                return -EPERM;
@@ -759,7 +759,7 @@ static int alarm_timer_nsleep(const clockid_t which_clock, int flags,
        struct restart_block *restart;
 
        if (!alarmtimer_get_rtcdev())
-               return -ENOTSUPP;
+               return -EOPNOTSUPP;
 
        if (flags & ~TIMER_ABSTIME)
                return -EINVAL;