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 <pang.xunlei@linaro.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>
This commit is contained in:
pang.xunlei 2014-11-18 19:15:18 +08:00 committed by John Stultz
parent 04d9089086
commit 90b6ce9c40
2 changed files with 22 additions and 15 deletions

View File

@ -39,10 +39,21 @@ 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,
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);
/*

View File

@ -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.
*
@ -314,13 +316,8 @@ 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,
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)
{
@ -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