Re: [PATCH v2 2/7] Input: make sure input handlers define only one processing method

From
Jeff LaBundy <hidden>
Date
2024-07-07 19:53:55
Also in
lkml
Reply to
Dmitry Torokhov, 2024-07-03
Hi Dmitry,

On Wed, Jul 03, 2024 at 02:37:49PM -0700, 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@gmail.com>
Reviewed-by: Jeff LaBundy <redacted>
quoted hunk ↗ jump to hunk
---
 drivers/input/input.c | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)
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;
-- 
2.45.2.803.g4e1b14247a-goog
Kind regards,
Jeff LaBundy
Thread (16 messages) 16 messages, 3 authors, last reply 2024-07-07
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