diff options
| -rw-r--r-- | include/linux/lockdep.h | 3 | ||||
| -rw-r--r-- | kernel/workqueue.c | 14 |
2 files changed, 15 insertions, 2 deletions
diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h index 71c09b26c759..9f19430c7d07 100644 --- a/include/linux/lockdep.h +++ b/include/linux/lockdep.h @@ -522,12 +522,15 @@ static inline void print_irqtrace_events(struct task_struct *curr) #ifdef CONFIG_DEBUG_LOCK_ALLOC # ifdef CONFIG_PROVE_LOCKING # define lock_map_acquire(l) lock_acquire(l, 0, 0, 0, 2, NULL, _THIS_IP_) +# define lock_map_acquire_read(l) lock_acquire(l, 0, 0, 2, 2, NULL, _THIS_IP_) # else # define lock_map_acquire(l) lock_acquire(l, 0, 0, 0, 1, NULL, _THIS_IP_) +# define lock_map_acquire_read(l) lock_acquire(l, 0, 0, 2, 1, NULL, _THIS_IP_) # endif # define lock_map_release(l) lock_release(l, 1, _THIS_IP_) #else # define lock_map_acquire(l) do { } while (0) +# define lock_map_acquire_read(l) do { } while (0) # define lock_map_release(l) do { } while (0) #endif diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 8ee6ec82f88a..930c2390b77e 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -1840,7 +1840,7 @@ __acquires(&gcwq->lock) spin_unlock_irq(&gcwq->lock); work_clear_pending(work); - lock_map_acquire(&cwq->wq->lockdep_map); + lock_map_acquire_read(&cwq->wq->lockdep_map); lock_map_acquire(&lockdep_map); trace_workqueue_execute_start(work); f(work); @@ -2384,8 +2384,18 @@ static bool start_flush_work(struct work_struct *work, struct wq_barrier *barr, insert_wq_barrier(cwq, barr, work, worker); spin_unlock_irq(&gcwq->lock); - lock_map_acquire(&cwq->wq->lockdep_map); + /* + * If @max_active is 1 or rescuer is in use, flushing another work + * item on the same workqueue may lead to deadlock. Make sure the + * flusher is not running on the same workqueue by verifying write + * access. + */ + if (cwq->wq->saved_max_active == 1 || cwq->wq->flags & WQ_RESCUER) + lock_map_acquire(&cwq->wq->lockdep_map); + else + lock_map_acquire_read(&cwq->wq->lockdep_map); lock_map_release(&cwq->wq->lockdep_map); + return true; already_gone: spin_unlock_irq(&gcwq->lock); |