diff --git a/drivers/input/input.c b/drivers/input/input.c index fd4997ba263c..7e4f8824f4fd 100644 --- a/drivers/input/input.c +++ b/drivers/input/input.c @@ -2517,6 +2517,26 @@ void input_unregister_device(struct input_dev *dev) } EXPORT_SYMBOL(input_unregister_device); +static int input_handler_check_methods(const struct input_handler *handler) +{ + int count = 0; + + if (handler->filter) + count++; + if (handler->events) + count++; + if (handler->event) + count++; + + if (count > 1) { + pr_err("%s: only one event processing method can be defined (%s)\n", + __func__, handler->name); + return -EINVAL; + } + + return 0; +} + /** * input_register_handler - register a new input handler * @handler: handler to be registered @@ -2530,6 +2550,10 @@ int input_register_handler(struct input_handler *handler) struct input_dev *dev; int error; + error = input_handler_check_methods(handler); + if (error) + return error; + error = mutex_lock_interruptible(&input_mutex); if (error) return error;