diff --git a/include/linux/sched.h b/include/linux/sched.h index 295b7c756ca6107aee29ee4c12e3eb2f486c9f7e..644ffbda17cad0ccfc977386ac81be74ef69cc6b 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -247,6 +247,7 @@ extern void init_idle(struct task_struct *idle, int cpu); extern void init_idle_bootup_task(struct task_struct *idle); extern int runqueue_is_locked(void); +extern void task_rq_unlock_wait(struct task_struct *p); extern cpumask_t nohz_cpu_mask; #if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ) diff --git a/kernel/exit.c b/kernel/exit.c index 80137a5d9467811ba4dab35c6e95790002a5f12a..ae2b92be5faec1efa73beefb63304a22d030fc16 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -141,6 +141,11 @@ static void __exit_signal(struct task_struct *tsk) if (sig) { flush_sigqueue(&sig->shared_pending); taskstats_tgid_free(sig); + /* + * Make sure ->signal can't go away under rq->lock, + * see account_group_exec_runtime(). + */ + task_rq_unlock_wait(tsk); __cleanup_signal(sig); } } diff --git a/kernel/sched.c b/kernel/sched.c index f3149244e324cdf5eae0280e16cf18446295c252..50a21f964679ec42eee299cab7f7f86edc26a408 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -969,6 +969,14 @@ static struct rq *task_rq_lock(struct task_struct *p, unsigned long *flags) } } +void task_rq_unlock_wait(struct task_struct *p) +{ + struct rq *rq = task_rq(p); + + smp_mb(); /* spin-unlock-wait is not a full memory barrier */ + spin_unlock_wait(&rq->lock); +} + static void __task_rq_unlock(struct rq *rq) __releases(rq->lock) {