[PATCH RFC 05/12] time: Convert rtc_tm_to_time_unsafe() to rtc_tm_to_time() in rtc_hctosys()

["pang.xunlei" <pang.xunlei@linaro.org>]

The kernel uses 32-bit signed value(time_t) for seconds since 1970-01-01:00:00:00, so it
will overflow at 2038-01-19 03:14:08 on 32-bit systems. We call this "2038 safety" issue.

As part of addressing 2038 saftey for in-kernel uses, this patch creates no functional change
in existing users, and converts rtc_tm_to_time_unsafe() to rtc_tm_to_time() in rtc_hctosys().

Signed-off-by: pang.xunlei <pang.xunlei@linaro.org>
---
 drivers/rtc/hctosys.c |   12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/drivers/rtc/hctosys.c b/drivers/rtc/hctosys.c
index 4e9a5c6..c80723f 100644
--- a/drivers/rtc/hctosys.c
+++ b/drivers/rtc/hctosys.c
@@ -26,9 +26,10 @@ static int __init rtc_hctosys(void)
 {
 	int err = -ENODEV;
 	struct rtc_time tm;
-	struct timespec tv = {
+	struct timespec64 tv = {
 		.tv_nsec = NSEC_PER_SEC >> 1,
 	};
+	struct timespec ts32;
 	struct rtc_device *rtc = rtc_class_open(CONFIG_RTC_HCTOSYS_DEVICE);
 
 	if (rtc == NULL) {
@@ -52,16 +53,17 @@ static int __init rtc_hctosys(void)
 		goto err_invalid;
 	}
 
-	rtc_tm_to_time_unsafe(&tm, &tv.tv_sec);
+	rtc_tm_to_time(&tm, &tv.tv_sec);
 
-	err = do_settimeofday(&tv);
+	ts32 = timespec64_to_timespec(tv);
+	err = do_settimeofday(&ts32);
 
 	dev_info(rtc->dev.parent,
 		"setting system clock to "
-		"%d-%02d-%02d %02d:%02d:%02d UTC (%u)\n",
+		"%d-%02d-%02d %02d:%02d:%02d UTC (%llu)\n",
 		tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
 		tm.tm_hour, tm.tm_min, tm.tm_sec,
-		(unsigned int) tv.tv_sec);
+		(unsigned long long) tv.tv_sec);
 
 err_invalid:
 err_read:
-- 
1.7.9.5