diff options
| -rw-r--r-- | include/linux/time.h | 1 | ||||
| -rw-r--r-- | kernel/time/timekeeping.c | 36 |
2 files changed, 37 insertions, 0 deletions
diff --git a/include/linux/time.h b/include/linux/time.h index 7c44e7778033..379b9037b5b4 100644 --- a/include/linux/time.h +++ b/include/linux/time.h @@ -166,6 +166,7 @@ extern struct timespec timespec_trunc(struct timespec t, unsigned gran); extern int timekeeping_valid_for_hres(void); extern u64 timekeeping_max_deferment(void); extern void timekeeping_leap_insert(int leapsecond); +extern int timekeeping_inject_offset(struct timespec *ts); struct tms; extern void do_sys_times(struct tms *); diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index 4f9f65b91323..6262c1d18397 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -387,6 +387,42 @@ int do_settimeofday(const struct timespec *tv) EXPORT_SYMBOL(do_settimeofday); + +/** + * timekeeping_inject_offset - Adds or subtracts from the current time. + * @tv: pointer to the timespec variable containing the offset + * + * Adds or subtracts an offset value from the current time. + */ +int timekeeping_inject_offset(struct timespec *ts) +{ + unsigned long flags; + + if ((unsigned long)ts->tv_nsec >= NSEC_PER_SEC) + return -EINVAL; + + write_seqlock_irqsave(&xtime_lock, flags); + + timekeeping_forward_now(); + + xtime = timespec_add(xtime, *ts); + wall_to_monotonic = timespec_sub(wall_to_monotonic, *ts); + + timekeeper.ntp_error = 0; + ntp_clear(); + + update_vsyscall(&xtime, &wall_to_monotonic, timekeeper.clock, + timekeeper.mult); + + write_sequnlock_irqrestore(&xtime_lock, flags); + + /* signal hrtimers about time change */ + clock_was_set(); + + return 0; +} +EXPORT_SYMBOL(timekeeping_inject_offset); + /** * change_clocksource - Swaps clocksources if a new one is available * |