From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Alexandre Belloni , Sasha Levin Subject: [PATCH 4.4 015/124] rtc: ensure rtc_set_alarm fails when alarms are not supported Date: Sat, 4 Aug 2018 11:00:04 +0200 Message-Id: <20180804082703.022594979@linuxfoundation.org> In-Reply-To: <20180804082702.434482435@linuxfoundation.org> References: <20180804082702.434482435@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Alexandre Belloni [ 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 Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- 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;