diff options
| -rw-r--r-- | drivers/input/input.c | 41 | ||||
| -rw-r--r-- | include/linux/input.h | 8 |
2 files changed, 42 insertions, 7 deletions
diff --git a/drivers/input/input.c b/drivers/input/input.c index 6c161e220868..7080a9d4b840 100644 --- a/drivers/input/input.c +++ b/drivers/input/input.c @@ -86,12 +86,14 @@ static int input_defuzz_abs_event(int value, int old_val, int fuzz) } /* - * Pass event through all open handles. This function is called with + * Pass event first through all filters and then, if event has not been + * filtered out, through all open handles. This function is called with * dev->event_lock held and interrupts disabled. */ static void input_pass_event(struct input_dev *dev, unsigned int type, unsigned int code, int value) { + struct input_handler *handler; struct input_handle *handle; rcu_read_lock(); @@ -99,11 +101,25 @@ static void input_pass_event(struct input_dev *dev, handle = rcu_dereference(dev->grab); if (handle) handle->handler->event(handle, type, code, value); - else - list_for_each_entry_rcu(handle, &dev->h_list, d_node) - if (handle->open) - handle->handler->event(handle, - type, code, value); + else { + bool filtered = false; + + list_for_each_entry_rcu(handle, &dev->h_list, d_node) { + if (!handle->open) + continue; + + handler = handle->handler; + if (!handler->filter) { + if (filtered) + break; + + handler->event(handle, type, code, value); + + } else if (handler->filter(handle, type, code, value)) + filtered = true; + } + } + rcu_read_unlock(); } @@ -990,6 +1006,8 @@ static int input_handlers_seq_show(struct seq_file *seq, void *v) union input_seq_state *state = (union input_seq_state *)&seq->private; seq_printf(seq, "N: Number=%u Name=%s", state->pos, handler->name); + if (handler->filter) + seq_puts(seq, " (filter)"); if (handler->fops) seq_printf(seq, " Minor=%d", handler->minor); seq_putc(seq, '\n'); @@ -1803,7 +1821,16 @@ int input_register_handle(struct input_handle *handle) error = mutex_lock_interruptible(&dev->mutex); if (error) return error; - list_add_tail_rcu(&handle->d_node, &dev->h_list); + + /* + * Filters go to the head of the list, normal handlers + * to the tail. + */ + if (handler->filter) + list_add_rcu(&handle->d_node, &dev->h_list); + else + list_add_tail_rcu(&handle->d_node, &dev->h_list); + mutex_unlock(&dev->mutex); /* diff --git a/include/linux/input.h b/include/linux/input.h index 7be8a6537b57..6c9d3d49fa91 100644 --- a/include/linux/input.h +++ b/include/linux/input.h @@ -1198,6 +1198,8 @@ struct input_handle; * @event: event handler. This method is being called by input core with * interrupts disabled and dev->event_lock spinlock held and so * it may not sleep + * @filter: similar to @event; separates normal event handlers from + * "filters". * @connect: called when attaching a handler to an input device * @disconnect: disconnects a handler from input device * @start: starts handler for given handle. This function is called by @@ -1219,6 +1221,11 @@ struct input_handle; * same time. All of them will get their copy of input event generated by * the device. * + * The very same structure is used to implement input filters. Input core + * allows filters to run first and will not pass event to regular handlers + * if any of the filters indicate that the event should be filtered (by + * returning %true from their filter() method). + * * Note that input core serializes calls to connect() and disconnect() * methods. */ @@ -1227,6 +1234,7 @@ struct input_handler { void *private; void (*event)(struct input_handle *handle, unsigned int type, unsigned int code, int value); + bool (*filter)(struct input_handle *handle, unsigned int type, unsigned int code, int value); int (*connect)(struct input_handler *handler, struct input_dev *dev, const struct input_device_id *id); void (*disconnect)(struct input_handle *handle); void (*start)(struct input_handle *handle); |