[PATCH 2/6] serio: possible race between port removal and kseriod

[Dmitry Torokhov <dtor_core@ameritech.net>]

Input: There is a possibility that serio might get deleted while there
       are outstanding events involving that serio waiting for kseriod
       to process them. Invalidate them so kseriod thread will just
       drop dead events.


 serio.c |   18 ++++++++++++++++--
 1 files changed, 16 insertions(+), 2 deletions(-)

===================================================================

diff -Nru a/drivers/input/serio/serio.c b/drivers/input/serio/serio.c
--- a/drivers/input/serio/serio.c	Tue Sep 30 01:07:17 2003
+++ b/drivers/input/serio/serio.c	Tue Sep 30 01:07:17 2003
@@ -87,6 +87,15 @@
 static DECLARE_WAIT_QUEUE_HEAD(serio_wait);
 static DECLARE_COMPLETION(serio_exited);
 
+static void serio_invalidate_pending_events(struct serio *serio)
+{
+	struct serio_event *event;
+	
+	list_for_each_entry(event, &serio_event_list, node)
+		if (event->serio == serio)
+			event->serio = NULL;
+}
+
 void serio_handle_events(void)
 {
 	struct list_head *node, *next;
@@ -95,17 +104,21 @@
 	list_for_each_safe(node, next, &serio_event_list) {
 		event = container_of(node, struct serio_event, node);	
 
+		down(&serio_sem);
+		if (event->serio == NULL)
+			goto event_done;
+		
 		switch (event->type) {
 			case SERIO_RESCAN :
-				down(&serio_sem);
 				if (event->serio->dev && event->serio->dev->disconnect)
 					event->serio->dev->disconnect(event->serio);
 				serio_find_dev(event->serio);
-				up(&serio_sem);
 				break;
 			default:
 				break;
 		}
+event_done:
+		up(&serio_sem);
 		list_del_init(node);
 		kfree(event);
 	}
@@ -192,6 +205,7 @@
  */
 void __serio_unregister_port(struct serio *serio)
 {
+	serio_invalidate_pending_events(serio);
 	list_del_init(&serio->node);
 	if (serio->dev && serio->dev->disconnect)
 		serio->dev->disconnect(serio);