@@ -1519,40 +1519,31 @@ EXPORT_SYMBOL(do_settimeofday64);
*/
static int timekeeping_inject_offset(const struct timespec64 *ts)
{
- struct timekeeper *tk = &tk_core.timekeeper;
- unsigned long flags;
- struct timespec64 tmp;
- int ret = 0;
-
if (ts->tv_nsec < 0 || ts->tv_nsec >= NSEC_PER_SEC)
return -EINVAL;
- raw_spin_lock_irqsave(&tk_core.lock, flags);
- write_seqcount_begin(&tk_core.seq);
-
- timekeeping_forward_now(tk);
-
- /* Make sure the proposed value is valid */
- tmp = timespec64_add(tk_xtime(tk), *ts);
- if (timespec64_compare(&tk->wall_to_monotonic, ts) > 0 ||
- !timespec64_valid_settod(&tmp)) {
- ret = -EINVAL;
- goto error;
- }
+ scoped_guard (raw_spinlock_irqsave, &tk_core.lock) {
+ struct timekeeper *tk = &tk_core.shadow_timekeeper;
+ struct timespec64 tmp;
- tk_xtime_add(tk, ts);
- tk_set_wall_to_mono(tk, timespec64_sub(tk->wall_to_monotonic, *ts));
+ timekeeping_forward_now(tk);
-error: /* even if we error out, we forwarded the time, so call update */
- timekeeping_update(&tk_core, tk, TK_UPDATE_ALL | TK_MIRROR);
+ /* Make sure the proposed value is valid */
+ tmp = timespec64_add(tk_xtime(tk), *ts);
+ if (timespec64_compare(&tk->wall_to_monotonic, ts) > 0 ||
+ !timespec64_valid_settod(&tmp)) {
+ timekeeping_restore_shadow(&tk_core);
+ return -EINVAL;
+ }
- write_seqcount_end(&tk_core.seq);
- raw_spin_unlock_irqrestore(&tk_core.lock, flags);
+ tk_xtime_add(tk, ts);
+ tk_set_wall_to_mono(tk, timespec64_sub(tk->wall_to_monotonic, *ts));
+ timekeeping_update_staged(&tk_core, TK_UPDATE_ALL);
+ }
/* Signal hrtimers about time change */
clock_was_set(CLOCK_SET_WALL);
-
- return ret;
+ return 0;
}
/*
Updates of the timekeeper can be done by operating on the shadow timekeeper and afterwards copying the result into the real timekeeper. This has the advantage, that the sequence count write protected region is kept as small as possible. Convert timekeeping_inject_offset() to use this scheme. That allows to use a scoped_guard() for locking the timekeeper lock as the usage of the shadow timekeeper allows a rollback in the error case instead of the full timekeeper update of the original code. Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de> --- kernel/time/timekeeping.c | 41 ++++++++++++++++------------------------- 1 file changed, 16 insertions(+), 25 deletions(-)