drivers/rtc/interface.c: check the error after __rtc_read_time()

In __rtc_set_alarm(), the error after __rtc_read_time() is not checked.
If rtc device fail to read time, we cannot guarantee the following
process.

Add the verification code for returned __rtc_read_time() error.

Signed-off-by: Hyogi Gim <hyogi.gim@lge.com>
Acked-by: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 2 insertions, 0 deletions

diff --git a/drivers/rtc/interface.c b/drivers/rtc/interface.c
index 5813fa52c3d4..5b2717f5dafa 100644
--- a/drivers/rtc/interface.c
+++ b/drivers/rtc/interface.c
@@ -348,6 +348,8 @@ static int __rtc_set_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
 
         /* Make sure we're not setting alarms in the past */
         err = __rtc_read_time(rtc, &tm);
+        if (err)
+                return err;
         rtc_tm_to_time(&tm, &now);
         if (scheduled <= now)
                 return -ETIME;