diff options
Diffstat (limited to 'kernel/time/timer.c')
| -rw-r--r-- | kernel/time/timer.c | 20 |
1 files changed, 17 insertions, 3 deletions
diff --git a/kernel/time/timer.c b/kernel/time/timer.c index 3260ffdb368f..3c4e3116cdb1 100644 --- a/kernel/time/timer.c +++ b/kernel/time/timer.c @@ -956,13 +956,27 @@ EXPORT_SYMBOL(add_timer); */ void add_timer_on(struct timer_list *timer, int cpu) { - struct tvec_base *base = per_cpu(tvec_bases, cpu); + struct tvec_base *new_base = per_cpu(tvec_bases, cpu); + struct tvec_base *base; unsigned long flags; timer_stats_timer_set_start_info(timer); BUG_ON(timer_pending(timer) || !timer->function); - spin_lock_irqsave(&base->lock, flags); - timer_set_base(timer, base); + + /* + * If @timer was on a different CPU, it should be migrated with the + * old base locked to prevent other operations proceeding with the + * wrong base locked. See lock_timer_base(). + */ + base = lock_timer_base(timer, &flags); + if (base != new_base) { + timer_set_base(timer, NULL); + spin_unlock(&base->lock); + base = new_base; + spin_lock(&base->lock); + timer_set_base(timer, base); + } + debug_activate(timer, timer->expires); internal_add_timer(base, timer); spin_unlock_irqrestore(&base->lock, flags); |