1 files changed, 11 insertions, 1 deletions

diff --git a/drivers/rtc/rtc-sysfs.c b/drivers/rtc/rtc-sysfs.c
index 4d27ccc4fc06..2531ce4c9db0 100644
--- a/drivers/rtc/rtc-sysfs.c
+++ b/drivers/rtc/rtc-sysfs.c
@@ -145,6 +145,8 @@ rtc_sysfs_set_wakealarm(struct device *dev, struct device_attribute *attr,
         unsigned long now, alarm;
         struct rtc_wkalrm alm;
         struct rtc_device *rtc = to_rtc_device(dev);
+        char *buf_ptr;
+        int adjust = 0;
 
         /* Only request alarms that trigger in the future.  Disable them
          * by writing another time, e.g. 0 meaning Jan 1 1970 UTC.
@@ -154,7 +156,15 @@ rtc_sysfs_set_wakealarm(struct device *dev, struct device_attribute *attr,
                 return retval;
         rtc_tm_to_time(&alm.time, &now);
 
-        alarm = simple_strtoul(buf, NULL, 0);
+        buf_ptr = (char *)buf;
+        if (*buf_ptr == '+') {
+                buf_ptr++;
+                adjust = 1;
+        }
+        alarm = simple_strtoul(buf_ptr, NULL, 0);
+        if (adjust) {
+                alarm += now;
+        }
         if (alarm > now) {
                 /* Avoid accidentally clobbering active alarms; we can't
                  * entirely prevent that here, without even the minimal