Hi Dmitry,
On Jun 30 2024, Dmitry Torokhov wrote:
> 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.
>
> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
> ---
> drivers/input/input.c | 24 ++++++++++++++++++++++++
> 1 file changed, 24 insertions(+)
>
> diff --git a/drivers/input/input.c b/drivers/input/input.c
> index fd4997ba263c..8434348faeac 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) {
Am I missing some upstream commit? I have the following:
in drivers/input/evdev.c:
static struct input_handler evdev_handler = {
.event = evdev_event,
.events = evdev_events,
.connect = evdev_connect,
.disconnect = evdev_disconnect,
.legacy_minors = true,
.minor = EVDEV_MINOR_BASE,
.name = "evdev",
.id_table = evdev_ids,
};
So here count should be 2 and evdev would be rejected?
And in drivers/tty/serial/kgdboc.c:
static struct input_handler kgdboc_reset_handler = {
.connect = kgdboc_reset_connect,
.disconnect = kgdboc_reset_disconnect,
.name = "kgdboc_reset",
.id_table = kgdboc_reset_ids,
};
here count would be 0 and kgdboc would also be rejected.
I agree on the intent of the patch, but these couple of input handlers
should be fixed if they are not already.
Cheers,
Benjamin
> + pr_err("%s: only one event processing method should 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;
> --
> 2.45.2.803.g4e1b14247a-goog
>
