As HK_TYPE_TIMER cpumask is going to be changeable at run time, use RCU to protect access to the cpumask.
The access of HK_TYPE_TIMER cpumask within hrtimers_cpu_dying() is protected as interrupt is disabled and all the other CPUs are stopped when this function is invoked as part of the CPU tear down process. Signed-off-by: Waiman Long <[email protected]> --- kernel/time/hrtimer.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c index 000fb6ba7d74..85495400a193 100644 --- a/kernel/time/hrtimer.c +++ b/kernel/time/hrtimer.c @@ -242,8 +242,10 @@ static bool hrtimer_suitable_target(struct hrtimer *timer, struct hrtimer_clock_ static inline struct hrtimer_cpu_base *get_target_base(struct hrtimer_cpu_base *base, bool pinned) { if (!hrtimer_base_is_online(base)) { - int cpu = cpumask_any_and(cpu_online_mask, housekeeping_cpumask(HK_TYPE_TIMER)); + int cpu; + guard(rcu)(); + cpu = cpumask_any_and(cpu_online_mask, housekeeping_cpumask(HK_TYPE_TIMER)); return &per_cpu(hrtimer_bases, cpu); } -- 2.53.0
