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| author | John Stultz <johnstul@us.ibm.com> | 2010-07-13 17:56:19 -0700 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2010-07-27 12:40:53 +0200 |
| commit | ce3bf7ab22527183634a76512d9854a38615e4d5 (patch) | |
| tree | 79e48c7c84618d968664bd660c75e03fc98e7d11 | |
| parent | 8c73626ab28527b7eb7f3061c027fbfe530c488c (diff) | |
| download | op-kernel-dev-ce3bf7ab22527183634a76512d9854a38615e4d5.zip op-kernel-dev-ce3bf7ab22527183634a76512d9854a38615e4d5.tar.gz | |
time: Implement timespec_add
After accidentally misusing timespec_add_safe, I wanted to make sure
we don't accidently trip over that issue again, so I created a simple
timespec_add() function which we can use to replace the instances
of timespec_add_safe() that don't want the overflow detection.
Signed-off-by: John Stultz <johnstul@us.ibm.com>
LKML-Reference: <1279068988-21864-3-git-send-email-johnstul@us.ibm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| -rw-r--r-- | include/linux/time.h | 16 | ||||
| -rw-r--r-- | kernel/time/timekeeping.c | 6 |
2 files changed, 19 insertions, 3 deletions
diff --git a/include/linux/time.h b/include/linux/time.h index ea3559f0..9072df8 100644 --- a/include/linux/time.h +++ b/include/linux/time.h @@ -76,9 +76,25 @@ extern unsigned long mktime(const unsigned int year, const unsigned int mon, const unsigned int min, const unsigned int sec); extern void set_normalized_timespec(struct timespec *ts, time_t sec, s64 nsec); + +/* + * timespec_add_safe assumes both values are positive and checks + * for overflow. It will return TIME_T_MAX if the reutrn would be + * smaller then either of the arguments. + */ extern struct timespec timespec_add_safe(const struct timespec lhs, const struct timespec rhs); + +static inline struct timespec timespec_add(struct timespec lhs, + struct timespec rhs) +{ + struct timespec ts_delta; + set_normalized_timespec(&ts_delta, lhs.tv_sec + rhs.tv_sec, + lhs.tv_nsec + rhs.tv_nsec); + return ts_delta; +} + /* * sub = lhs - rhs, in normalized form */ diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index caf8d4d..623fe3d 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -579,9 +579,9 @@ static int timekeeping_resume(struct sys_device *dev) if (timespec_compare(&ts, &timekeeping_suspend_time) > 0) { ts = timespec_sub(ts, timekeeping_suspend_time); - xtime = timespec_add_safe(xtime, ts); + xtime = timespec_add(xtime, ts); wall_to_monotonic = timespec_sub(wall_to_monotonic, ts); - total_sleep_time = timespec_add_safe(total_sleep_time, ts); + total_sleep_time = timespec_add(total_sleep_time, ts); } /* re-base the last cycle value */ timekeeper.clock->cycle_last = timekeeper.clock->read(timekeeper.clock); @@ -887,7 +887,7 @@ EXPORT_SYMBOL_GPL(getboottime); */ void monotonic_to_bootbased(struct timespec *ts) { - *ts = timespec_add_safe(*ts, total_sleep_time); + *ts = timespec_add(*ts, total_sleep_time); } EXPORT_SYMBOL_GPL(monotonic_to_bootbased); |
