lkml.org 
[lkml]   [2018]   [Aug]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 4.9 020/144] rtc: ensure rtc_set_alarm fails when alarms are not supported
Date
4.9-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
@@ -359,6 +359,11 @@ 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;

\
 
 \ /
  Last update: 2018-08-01 19:44    [W:0.433 / U:0.148 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site