From 90b6ce9c4066e0b2098dff65e52e6e7df1a51079 Mon Sep 17 00:00:00 2001 From: "pang.xunlei" Date: Tue, 18 Nov 2014 19:15:18 +0800 Subject: [PATCH] time: Provide y2038 safe mktime() replacement As part of addressing "y2038 problem" for in-kernel uses, this patch adds safe mktime64() using time64_t. After this patch, mktime() is deprecated and all its call sites will be fixed using mktime64(), after that it can be removed. Signed-off-by: pang.xunlei Signed-off-by: John Stultz --- include/linux/time.h | 17 ++++++++++++++--- kernel/time/time.c | 20 ++++++++------------ 2 files changed, 22 insertions(+), 15 deletions(-) diff --git a/include/linux/time.h b/include/linux/time.h index 8c42cf8d2444..203c2ad40d71 100644 --- a/include/linux/time.h +++ b/include/linux/time.h @@ -39,9 +39,20 @@ static inline int timeval_compare(const struct timeval *lhs, const struct timeva return lhs->tv_usec - rhs->tv_usec; } -extern unsigned long mktime(const unsigned int year, const unsigned int mon, - const unsigned int day, const unsigned int hour, - const unsigned int min, const unsigned int sec); +extern time64_t mktime64(const unsigned int year, const unsigned int mon, + const unsigned int day, const unsigned int hour, + const unsigned int min, const unsigned int sec); + +/** + * Deprecated. Use mktime64(). + */ +static inline unsigned long mktime(const unsigned int year, + const unsigned int mon, const unsigned int day, + const unsigned int hour, const unsigned int min, + const unsigned int sec) +{ + return mktime64(year, mon, day, hour, min, sec); +} extern void set_normalized_timespec(struct timespec *ts, time_t sec, s64 nsec); diff --git a/kernel/time/time.c b/kernel/time/time.c index a9ae20fb0b11..65015ff2f07c 100644 --- a/kernel/time/time.c +++ b/kernel/time/time.c @@ -304,7 +304,9 @@ struct timespec timespec_trunc(struct timespec t, unsigned gran) } EXPORT_SYMBOL(timespec_trunc); -/* Converts Gregorian date to seconds since 1970-01-01 00:00:00. +/* + * mktime64 - Converts date to seconds. + * Converts Gregorian date to seconds since 1970-01-01 00:00:00. * Assumes input in normal date format, i.e. 1980-12-31 23:59:59 * => year=1980, mon=12, day=31, hour=23, min=59, sec=59. * @@ -314,15 +316,10 @@ EXPORT_SYMBOL(timespec_trunc); * -year/100+year/400 terms, and add 10.] * * This algorithm was first published by Gauss (I think). - * - * WARNING: this function will overflow on 2106-02-07 06:28:16 on - * machines where long is 32-bit! (However, as time_t is signed, we - * will already get problems at other places on 2038-01-19 03:14:08) */ -unsigned long -mktime(const unsigned int year0, const unsigned int mon0, - const unsigned int day, const unsigned int hour, - const unsigned int min, const unsigned int sec) +time64_t mktime64(const unsigned int year0, const unsigned int mon0, + const unsigned int day, const unsigned int hour, + const unsigned int min, const unsigned int sec) { unsigned int mon = mon0, year = year0; @@ -332,15 +329,14 @@ mktime(const unsigned int year0, const unsigned int mon0, year -= 1; } - return ((((unsigned long) + return ((((time64_t) (year/4 - year/100 + year/400 + 367*mon/12 + day) + year*365 - 719499 )*24 + hour /* now have hours */ )*60 + min /* now have minutes */ )*60 + sec; /* finally seconds */ } - -EXPORT_SYMBOL(mktime); +EXPORT_SYMBOL(mktime64); /** * set_normalized_timespec - set timespec sec and nsec parts and normalize