From 21f7eca555ad14e7c7b2cb59a6c6252e74ee5c8b Mon Sep 17 00:00:00 2001 From: "pang.xunlei" Date: Tue, 18 Nov 2014 19:15:16 +0800 Subject: [PATCH] time: Provide y2038 safe do_settimeofday() replacement The kernel uses 32-bit signed value(time_t) for seconds elapsed 1970-01-01:00:00:00, thus it will overflow at 2038-01-19 03:14:08 on 32-bit systems. This is widely known as the y2038 problem. As part of addressing "y2038 problem" for in-kernel uses, this patch adds safe do_settimeofday64() using timespec64. After this patch, do_settimeofday() is deprecated and all its call sites will be fixed using do_settimeofday64(), after that it can be removed. Signed-off-by: pang.xunlei Signed-off-by: John Stultz --- include/linux/timekeeping.h | 21 ++++++++++++++++++++- kernel/time/timekeeping.c | 19 +++++++++---------- 2 files changed, 29 insertions(+), 11 deletions(-) diff --git a/include/linux/timekeeping.h b/include/linux/timekeeping.h index 1caa6b04fdc5..071ad7e0c981 100644 --- a/include/linux/timekeeping.h +++ b/include/linux/timekeeping.h @@ -10,7 +10,7 @@ extern int timekeeping_suspended; * Get and set timeofday */ extern void do_gettimeofday(struct timeval *tv); -extern int do_settimeofday(const struct timespec *tv); +extern int do_settimeofday64(const struct timespec64 *ts); extern int do_sys_settimeofday(const struct timespec *tv, const struct timezone *tz); @@ -33,6 +33,14 @@ extern int __getnstimeofday64(struct timespec64 *tv); extern void getnstimeofday64(struct timespec64 *tv); #if BITS_PER_LONG == 64 +/** + * Deprecated. Use do_settimeofday64(). + */ +static inline int do_settimeofday(const struct timespec *ts) +{ + return do_settimeofday64(ts); +} + static inline int __getnstimeofday(struct timespec *ts) { return __getnstimeofday64(ts); @@ -54,6 +62,17 @@ static inline void ktime_get_real_ts(struct timespec *ts) } #else +/** + * Deprecated. Use do_settimeofday64(). + */ +static inline int do_settimeofday(const struct timespec *ts) +{ + struct timespec64 ts64; + + ts64 = timespec_to_timespec64(*ts); + return do_settimeofday64(&ts64); +} + static inline int __getnstimeofday(struct timespec *ts) { struct timespec64 ts64; diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index 41fcbe19ccfe..10140dae71c6 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -703,18 +703,18 @@ void do_gettimeofday(struct timeval *tv) EXPORT_SYMBOL(do_gettimeofday); /** - * do_settimeofday - Sets the time of day - * @tv: pointer to the timespec variable containing the new time + * do_settimeofday64 - Sets the time of day. + * @ts: pointer to the timespec64 variable containing the new time * * Sets the time of day to the new time and update NTP and notify hrtimers */ -int do_settimeofday(const struct timespec *tv) +int do_settimeofday64(const struct timespec64 *ts) { struct timekeeper *tk = &tk_core.timekeeper; - struct timespec64 ts_delta, xt, tmp; + struct timespec64 ts_delta, xt; unsigned long flags; - if (!timespec_valid_strict(tv)) + if (!timespec64_valid_strict(ts)) return -EINVAL; raw_spin_lock_irqsave(&timekeeper_lock, flags); @@ -723,13 +723,12 @@ int do_settimeofday(const struct timespec *tv) timekeeping_forward_now(tk); xt = tk_xtime(tk); - ts_delta.tv_sec = tv->tv_sec - xt.tv_sec; - ts_delta.tv_nsec = tv->tv_nsec - xt.tv_nsec; + ts_delta.tv_sec = ts->tv_sec - xt.tv_sec; + ts_delta.tv_nsec = ts->tv_nsec - xt.tv_nsec; tk_set_wall_to_mono(tk, timespec64_sub(tk->wall_to_monotonic, ts_delta)); - tmp = timespec_to_timespec64(*tv); - tk_set_xtime(tk, &tmp); + tk_set_xtime(tk, ts); timekeeping_update(tk, TK_CLEAR_NTP | TK_MIRROR | TK_CLOCK_WAS_SET); @@ -741,7 +740,7 @@ int do_settimeofday(const struct timespec *tv) return 0; } -EXPORT_SYMBOL(do_settimeofday); +EXPORT_SYMBOL(do_settimeofday64); /** * timekeeping_inject_offset - Adds or subtracts from the current time. -- 2.30.2