From 21f7eca555ad14e7c7b2cb59a6c6252e74ee5c8b Mon Sep 17 00:00:00 2001 From: "pang.xunlei" Date: Tue, 18 Nov 2014 19:15:16 +0800 Subject: 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 --- kernel/time/timekeeping.c | 19 +++++++++---------- 1 file changed, 9 insertions(+), 10 deletions(-) (limited to 'kernel/time') 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. -- cgit v1.2.3-58-ga151