Messages in this thread Patch in this message | | | From | "pang.xunlei" <> | Subject | [PATCH RFC 04/12] time: Add rtc_tm_to_time() safe version(using time64_t) | Date | Mon, 27 Oct 2014 13:46:34 +0800 |
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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.xunlei@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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