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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org,
        Thadeu Lima de Souza Cascardo <cascardo@canonical.com>,
        Thomas Gleixner <tglx@linutronix.de>
Subject: [PATCH 4.19 179/211] alarmtimer: Use EOPNOTSUPP instead of ENOTSUPP
Date:   Thu,  3 Oct 2019 17:54:05 +0200
Message-Id: <20191003154527.198767687@linuxfoundation.org>
In-Reply-To: <20191003154447.010950442@linuxfoundation.org>
References: <20191003154447.010950442@linuxfoundation.org>
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From: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>

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>

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

--- a/kernel/time/alarmtimer.c
+++ b/kernel/time/alarmtimer.c
@@ -676,7 +676,7 @@ 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;
@@ -794,7 +794,7 @@ static int alarm_timer_nsleep(const cloc
 	int ret = 0;
 
 	if (!alarmtimer_get_rtcdev())
-		return -ENOTSUPP;
+		return -EOPNOTSUPP;
 
 	if (flags & ~TIMER_ABSTIME)
 		return -EINVAL;