4.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Alexandre Belloni alexandre.belloni@bootlin.com
[ Upstream commit abfdff44bc38e9e2ef7929f633fb8462632299d4 ]
When using RTC_ALM_SET or RTC_WKALM_SET with rtc_wkalrm.enabled not set, rtc_timer_enqueue() is not called and rtc_set_alarm() may succeed but the subsequent RTC_AIE_ON ioctl will fail. RTC_ALM_READ would also fail in that case.
Ensure rtc_set_alarm() fails when alarms are not supported to avoid letting programs think the alarms are working for a particular RTC when they are not.
Signed-off-by: Alexandre Belloni alexandre.belloni@bootlin.com Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/rtc/interface.c | 5 +++++ 1 file changed, 5 insertions(+)
--- a/drivers/rtc/interface.c +++ b/drivers/rtc/interface.c @@ -349,6 +349,11 @@ int rtc_set_alarm(struct rtc_device *rtc { int err;
+ if (!rtc->ops) + return -ENODEV; + else if (!rtc->ops->set_alarm) + return -EINVAL; + err = rtc_valid_tm(&alarm->time); if (err != 0) return err;