The kernel uses 32-bit signed value(time_t) for seconds since
1970-01-01:00:00:00, thus 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 adds the safe
rtc_tm_to_time()
using time64_t. After this patch, rtc_tm_to_time_unsafe() should be replaced by
rtc_tm_to_time()
one by one.
Eventually, rtc_tm_to_time_unsafe() will be removed from the kernel when it has
no users.
Signed-off-by: pang.xunlei <pang.xun...@linaro.org>
---
drivers/rtc/rtc-lib.c | 9 +++++++++
include/linux/rtc.h | 1 +
2 files changed, 10 insertions(+)
diff --git a/drivers/rtc/rtc-lib.c b/drivers/rtc/rtc-lib.c
index 168d2a2..829eef8 100644
--- a/drivers/rtc/rtc-lib.c
+++ b/drivers/rtc/rtc-lib.c
@@ -111,6 +111,15 @@ EXPORT_SYMBOL(rtc_valid_tm);
/*
* Convert Gregorian date to seconds since 01-01-1970 00:00:00.
*/
+int rtc_tm_to_time(struct rtc_time *tm, time64_t *time)
+{
+ *time = mktime(tm->tm_year + 1900, tm->tm_mon + 1, tm->tm_mday,
+ tm->tm_hour, tm->tm_min, tm->tm_sec);
+ return 0;
+}
+EXPORT_SYMBOL(rtc_tm_to_time);
+
+/* TODO: [2038 safety] unsafe for legacy, and should be replaced by
rtc_tm_to_time() */
int rtc_tm_to_time_unsafe(struct rtc_time *tm, unsigned long *time)
{
*time = (unsigned long) mktime(tm->tm_year + 1900, tm->tm_mon + 1,
tm->tm_mday,
diff --git a/include/linux/rtc.h b/include/linux/rtc.h
index 97bbb6f..ffd22e9 100644
--- a/include/linux/rtc.h
+++ b/include/linux/rtc.h
@@ -19,6 +19,7 @@
extern int rtc_month_days(unsigned int month, unsigned int year);
extern int rtc_year_days(unsigned int day, unsigned int month, unsigned int
year);
extern int rtc_valid_tm(struct rtc_time *tm);
+extern int rtc_tm_to_time(struct rtc_time *tm, time64_t *time);
extern int rtc_tm_to_time_unsafe(struct rtc_time *tm, unsigned long *time);
extern void rtc_time_to_tm(unsigned long time, struct rtc_time *tm);
ktime_t rtc_tm_to_ktime(struct rtc_time tm);
--
1.7.9.5
--
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