| Message ID | 1414667745-7703-2-git-send-email-pang.xunlei@linaro.org |
|---|---|
| State | New |
| Headers | show |
On Thu, 30 Oct 2014, pang.xunlei wrote: Your subject line > time: Add do_settimeofday64() safe version(using timespec64) is confusing at best. time: Provide y2038 safe do_settimeofday() replacement That explains what the patch is doing in a very precice way. > /** > - * 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 > + * Safe version for 2038 safety. I rather put this into the function description above: + * do_settimeofday64 - Sets the time of day. 2038 safe. Way simpler to grep for. > */ > -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 +724,12 @@ 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); > > @@ -741,6 +741,22 @@ int do_settimeofday(const struct timespec *tv) > > return 0; > } > +EXPORT_SYMBOL(do_settimeofday64); EXPORT_SYMBOL_GPL please. > + > +/** > + * do_settimeofday - Sets the time of day > + * @tv: pointer to the timespec variable containing the new time > + * > + * Sets the time of day to the new time and update NTP and notify hrtimers > + * TODO: [2038 safety] should be replaced by do_settimeofday64(). The TODO is not to replace do_settimeofday() by do_settimeofday64(). The TODO is to fix the call sites. So instead of adding this you can simply say: + * do_settimeofday - Sets the time of day. Deprecated. Use do_settimeofday64() We want things like this easy to find and not be burried in some cryptic comment. Thanks, tglx -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
diff --git a/include/linux/timekeeping.h b/include/linux/timekeeping.h index 1caa6b0..afc61c3 100644 --- a/include/linux/timekeeping.h +++ b/include/linux/timekeeping.h @@ -10,6 +10,7 @@ extern int timekeeping_suspended; * Get and set timeofday */ extern void do_gettimeofday(struct timeval *tv); +extern int do_settimeofday64(const struct timespec64 *ts); extern int do_settimeofday(const struct timespec *tv); extern int do_sys_settimeofday(const struct timespec *tv, const struct timezone *tz); diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index ec1791f..f0dcbc0 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -703,18 +703,19 @@ 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 + * Safe version for 2038 safety. */ -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 +724,12 @@ 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); @@ -741,6 +741,22 @@ int do_settimeofday(const struct timespec *tv) return 0; } +EXPORT_SYMBOL(do_settimeofday64); + +/** + * do_settimeofday - Sets the time of day + * @tv: pointer to the timespec variable containing the new time + * + * Sets the time of day to the new time and update NTP and notify hrtimers + * TODO: [2038 safety] should be replaced by do_settimeofday64(). + */ +int do_settimeofday(const struct timespec *tv) +{ + struct timespec64 ts64; + + ts64 = timespec_to_timespec64(*tv); + return do_settimeofday64(&ts64); +} EXPORT_SYMBOL(do_settimeofday); /**
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. We call this "2038 safety" issue. As part of addressing 2038 saftey for in-kernel uses, this patch adds safe do_settimeofday64() using timespec64. After this patch, do_settimeofday() should be replaced by do_settimeofday64() one by one. Eventually, do_settimeofday() will be removed from the kernel when it has no users. Signed-off-by: pang.xunlei <pang.xunlei@linaro.org> --- include/linux/timekeeping.h | 1 + kernel/time/timekeeping.c | 34 +++++++++++++++++++++++++--------- 2 files changed, 26 insertions(+), 9 deletions(-)