diff options
| author | Paul E. McKenney <paulmck@kernel.org> | 2026-09-18 17:14:28 -0700 |
|---|---|---|
| committer | Thomas Gleixner <tglx@kernel.org> | 2026-09-29 21:02:52 +0200 |
| commit | 5dffe33bfdafcc768d090c55479f515585509ffa (patch) | |
| tree | e584ca01d50683e667539f901f24688d268a0f4d /kernel/time | |
| parent | ad80926d780340ab08799cdb38be010e0dce8ec0 (diff) | |
hrtimer: Apply READ_ONCE() to lockless base->running loads
Updates to base->running are protected by the hrtimer base lock, but some
loads are lockless. Therefore, prevent compiler mischief by applying
READ_ONCE() to the lockless loads.
KCSAN located this issue.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Link: https://patch.msgid.link/20260919001428.3133388-12-paulmck@kernel.org
Diffstat (limited to 'kernel/time')
| -rw-r--r-- | kernel/time/hrtimer.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c index 205406460993..17dd38a6cee7 100644 --- a/kernel/time/hrtimer.c +++ b/kernel/time/hrtimer.c @@ -2004,7 +2004,7 @@ bool hrtimer_active(const struct hrtimer *timer) base = READ_ONCE(timer->base); seq = raw_read_seqcount_begin(&base->seq); - if (timer->is_queued || base->running == timer) + if (timer->is_queued || READ_ONCE(base->running) == timer) return true; } while (read_seqcount_retry(&base->seq, seq) || base != READ_ONCE(timer->base)); @@ -2041,7 +2041,7 @@ static void __run_hrtimer(struct hrtimer_cpu_base *cpu_base, struct hrtimer_cloc lockdep_assert_held(&cpu_base->lock); debug_hrtimer_deactivate(timer); - base->running = timer; + WRITE_ONCE(base->running, timer); /* * Separate the ->running assignment from the ->is_queued assignment. @@ -2100,7 +2100,7 @@ static void __run_hrtimer(struct hrtimer_cpu_base *cpu_base, struct hrtimer_cloc raw_write_seqcount_barrier(&base->seq); WARN_ON_ONCE(base->running != timer); - base->running = NULL; + WRITE_ONCE(base->running, NULL); } static void __hrtimer_run_queues(struct hrtimer_cpu_base *cpu_base, ktime_t now, |