diff --git a/kernel/workqueue.c b/kernel/workqueue.c index f5f5a3dcb91b..59bd5f0686d6 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -2551,6 +2551,7 @@ __acquires(&pool->lock) struct pool_workqueue *pwq = get_work_pwq(work); struct worker_pool *pool = worker->pool; unsigned long work_data; + int lockdep_start_depth, rcu_start_depth; #ifdef CONFIG_LOCKDEP /* * It is permissible to free the struct work_struct from @@ -2613,6 +2614,8 @@ __acquires(&pool->lock) pwq->stats[PWQ_STAT_STARTED]++; raw_spin_unlock_irq(&pool->lock); + rcu_start_depth = rcu_preempt_depth(); + lockdep_start_depth = lockdep_depth(current); lock_map_acquire(&pwq->wq->lockdep_map); lock_map_acquire(&lockdep_map); /* @@ -2648,12 +2651,15 @@ __acquires(&pool->lock) lock_map_release(&lockdep_map); lock_map_release(&pwq->wq->lockdep_map); - if (unlikely(in_atomic() || lockdep_depth(current) > 0 || - rcu_preempt_depth() > 0)) { - pr_err("BUG: workqueue leaked lock or atomic: %s/0x%08x/%d/%d\n" - " last function: %ps\n", - current->comm, preempt_count(), rcu_preempt_depth(), - task_pid_nr(current), worker->current_func); + if (unlikely((worker->task && in_atomic()) || + lockdep_depth(current) != lockdep_start_depth || + rcu_preempt_depth() != rcu_start_depth)) { + pr_err("BUG: workqueue leaked atomic, lock or RCU: %s[%d]\n" + " preempt=0x%08x lock=%d->%d RCU=%d->%d workfn=%ps\n", + current->comm, task_pid_nr(current), preempt_count(), + lockdep_start_depth, lockdep_depth(current), + rcu_start_depth, rcu_preempt_depth(), + worker->current_func); debug_show_held_locks(current); dump_stack(); } @@ -3133,6 +3139,19 @@ static bool flush_workqueue_prep_pwqs(struct workqueue_struct *wq, return wait; } +static void touch_wq_lockdep_map(struct workqueue_struct *wq) +{ + lock_map_acquire(&wq->lockdep_map); + lock_map_release(&wq->lockdep_map); +} + +static void touch_work_lockdep_map(struct work_struct *work, + struct workqueue_struct *wq) +{ + lock_map_acquire(&work->lockdep_map); + lock_map_release(&work->lockdep_map); +} + /** * __flush_workqueue - ensure that any scheduled work has run to completion. * @wq: workqueue to flush @@ -3152,8 +3171,7 @@ void __flush_workqueue(struct workqueue_struct *wq) if (WARN_ON(!wq_online)) return; - lock_map_acquire(&wq->lockdep_map); - lock_map_release(&wq->lockdep_map); + touch_wq_lockdep_map(wq); mutex_lock(&wq->mutex); @@ -3352,6 +3370,7 @@ static bool start_flush_work(struct work_struct *work, struct wq_barrier *barr, struct worker *worker = NULL; struct worker_pool *pool; struct pool_workqueue *pwq; + struct workqueue_struct *wq; might_sleep(); @@ -3375,11 +3394,14 @@ static bool start_flush_work(struct work_struct *work, struct wq_barrier *barr, pwq = worker->current_pwq; } - check_flush_dependency(pwq->wq, work); + wq = pwq->wq; + check_flush_dependency(wq, work); insert_wq_barrier(pwq, barr, work, worker); raw_spin_unlock_irq(&pool->lock); + touch_work_lockdep_map(work, wq); + /* * Force a lock recursion deadlock when using flush_work() inside a * single-threaded or rescuer equipped workqueue. @@ -3389,11 +3411,9 @@ static bool start_flush_work(struct work_struct *work, struct wq_barrier *barr, * workqueues the deadlock happens when the rescuer stalls, blocking * forward progress. */ - if (!from_cancel && - (pwq->wq->saved_max_active == 1 || pwq->wq->rescuer)) { - lock_map_acquire(&pwq->wq->lockdep_map); - lock_map_release(&pwq->wq->lockdep_map); - } + if (!from_cancel && (wq->saved_max_active == 1 || wq->rescuer)) + touch_wq_lockdep_map(wq); + rcu_read_unlock(); return true; already_gone: @@ -3412,9 +3432,6 @@ static bool __flush_work(struct work_struct *work, bool from_cancel) if (WARN_ON(!work->func)) return false; - lock_map_acquire(&work->lockdep_map); - lock_map_release(&work->lockdep_map); - if (start_flush_work(work, &barr, from_cancel)) { wait_for_completion(&barr.done); destroy_work_on_stack(&barr.work);