drivers/rtc: Provide y2038 safe rtc_class_ops.set_mmss() replacement

Currently the rtc_class_op's set_mmss() function takes a 32-bit
second value (on 32-bit systems), which is problematic for dates
past y2038.

This patch provides a safe version named set_mmss64() using
y2038 safe time64_t.

After this patch, set_mmss() is deprecated and all its users
will be fixed to use set_mmss64(), it can be removed when having
no users.

Signed-off-by: Xunlei Pang <pang.xunlei@linaro.org>
[jstultz: Add whitespace fix for checkpatch]
Signed-off-by: John Stultz <john.stultz@linaro.org>
Acked-by: Alessandro Zummo <a.zummo@towertech.it>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1427945681-29972-8-git-send-email-john.stultz@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/drivers/rtc/interface.c b/drivers/rtc/interface.c
index 37215cf..d43ee40 100644 (file)
--- a/drivers/rtc/interface.c
+++ b/drivers/rtc/interface.c
@@ -72,7 +72,11 @@ int rtc_set_time(struct rtc_device *rtc, struct rtc_time *tm)
                err = -ENODEV;
        else if (rtc->ops->set_time)
                err = rtc->ops->set_time(rtc->dev.parent, tm);
-       else if (rtc->ops->set_mmss) {
+       else if (rtc->ops->set_mmss64) {
+               time64_t secs64 = rtc_tm_to_time64(tm);
+
+               err = rtc->ops->set_mmss64(rtc->dev.parent, secs64);
+       } else if (rtc->ops->set_mmss) {
                time64_t secs64 = rtc_tm_to_time64(tm);
                err = rtc->ops->set_mmss(rtc->dev.parent, secs64);
        } else
@@ -96,6 +100,8 @@ int rtc_set_mmss(struct rtc_device *rtc, unsigned long secs)
 
        if (!rtc->ops)
                err = -ENODEV;
+       else if (rtc->ops->set_mmss64)
+               err = rtc->ops->set_mmss64(rtc->dev.parent, secs);
        else if (rtc->ops->set_mmss)
                err = rtc->ops->set_mmss(rtc->dev.parent, secs);
        else if (rtc->ops->read_time && rtc->ops->set_time) {

diff --git a/drivers/rtc/systohc.c b/drivers/rtc/systohc.c
index ef3c07a..7728d5e 100644 (file)
--- a/drivers/rtc/systohc.c
+++ b/drivers/rtc/systohc.c
@@ -35,7 +35,10 @@ int rtc_set_ntp_time(struct timespec64 now)
        if (rtc) {
                /* rtc_hctosys exclusively uses UTC, so we call set_time here,
                 * not set_mmss. */
-               if (rtc->ops && (rtc->ops->set_time || rtc->ops->set_mmss))
+               if (rtc->ops &&
+                   (rtc->ops->set_time ||
+                    rtc->ops->set_mmss64 ||
+                    rtc->ops->set_mmss))
                        err = rtc_set_time(rtc, &tm);
                rtc_class_close(rtc);
        }

diff --git a/include/linux/rtc.h b/include/linux/rtc.h
index dcad7ee..8dcf682 100644 (file)
--- a/include/linux/rtc.h
+++ b/include/linux/rtc.h
@@ -77,6 +77,7 @@ struct rtc_class_ops {
        int (*read_alarm)(struct device *, struct rtc_wkalrm *);
        int (*set_alarm)(struct device *, struct rtc_wkalrm *);
        int (*proc)(struct device *, struct seq_file *);
+       int (*set_mmss64)(struct device *, time64_t secs);
        int (*set_mmss)(struct device *, unsigned long secs);
        int (*read_callback)(struct device *, int data);
        int (*alarm_irq_enable)(struct device *, unsigned int enabled);