Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull hrtimer fixlet from Thomas Gleixner:
 "A single commit annotating the lockcless access to timer->base with
  READ_ONCE() and adding the WRITE_ONCE() counterparts for completeness"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  hrtimer: Annotate lockless access to timer->base
This commit is contained in:
Linus Torvalds 2019-10-20 06:25:12 -04:00
commit 188768f3c0

View File

@ -164,7 +164,7 @@ struct hrtimer_clock_base *lock_hrtimer_base(const struct hrtimer *timer,
struct hrtimer_clock_base *base;
for (;;) {
base = timer->base;
base = READ_ONCE(timer->base);
if (likely(base != &migration_base)) {
raw_spin_lock_irqsave(&base->cpu_base->lock, *flags);
if (likely(base == timer->base))
@ -244,7 +244,7 @@ again:
return base;
/* See the comment in lock_hrtimer_base() */
timer->base = &migration_base;
WRITE_ONCE(timer->base, &migration_base);
raw_spin_unlock(&base->cpu_base->lock);
raw_spin_lock(&new_base->cpu_base->lock);
@ -253,10 +253,10 @@ again:
raw_spin_unlock(&new_base->cpu_base->lock);
raw_spin_lock(&base->cpu_base->lock);
new_cpu_base = this_cpu_base;
timer->base = base;
WRITE_ONCE(timer->base, base);
goto again;
}
timer->base = new_base;
WRITE_ONCE(timer->base, new_base);
} else {
if (new_cpu_base != this_cpu_base &&
hrtimer_check_target(timer, new_base)) {