From a184cf98b1d4397fe7eca881da596059fea36a18 Mon Sep 17 00:00:00 2001 From: Dmitry Torokhov Date: Wed, 3 Jul 2024 14:37:49 -0700 Subject: Input: make sure input handlers define only one processing method Input core expects input handlers to be either filters, or regular handlers, but not both. Additionally, for regular handlers it does not make sense to define both single event method and batch method. Refuse registering handler if it defines more than one method. Reviewed-by: Jeff LaBundy Reviewed-by: Benjamin Tissoires Link: https://lore.kernel.org/r/20240703213756.3375978-3-dmitry.torokhov@gmail.com Signed-off-by: Dmitry Torokhov --- drivers/input/input.c | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) (limited to 'drivers/input') 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; -- cgit v1.2.3