Input: mac mouse emulation - add locking

We need to add appropriate locking when toggling mac mouse emulation on and off to ensure that input device and handler are in consistent state. Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

Input: mac mouse emulation - add locking
We need to add appropriate locking when toggling mac mouse emulation on and off to ensure that input device and handler are in consistent state. Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Dmitry Torokhov
1 parent a309cdc778
Showing 1 changed file with 8 additions and 0 deletions Side-by-side Diff
drivers/macintosh/mac_hid.c
@@ -23,6 +23,8 @@
  
 static struct input_dev *mac_hid_emumouse_dev;
  
+static DEFINE_MUTEX(mac_hid_emumouse_mutex);
+
 static int mac_hid_create_emumouse(void)
 {
 	static struct lock_class_key mac_hid_emumouse_dev_event_class;
@@ -187,6 +189,10 @@
 	int old_val = *valp;
 	int rc;
  
+	rc = mutex_lock_killable(&mac_hid_emumouse_mutex);
+	if (rc)
+		return rc;
+
 	rc = proc_dointvec(table, write, buffer, lenp, ppos);
  
 	if (rc == 0 && write && *valp != old_val) {
@@ -201,6 +207,8 @@
 	/* Restore the old value in case of error */
 	if (rc)
 		*valp = old_val;
+
+	mutex_unlock(&mac_hid_emumouse_mutex);
  
 	return rc;
 }
...	...	@@ -23,6 +23,8 @@
23	23
24	24	static struct input_dev *mac_hid_emumouse_dev;
25	25
	26	+static DEFINE_MUTEX(mac_hid_emumouse_mutex);
	27	+
26	28	static int mac_hid_create_emumouse(void)
27	29	{
28	30	static struct lock_class_key mac_hid_emumouse_dev_event_class;
...	...	@@ -187,6 +189,10 @@
187	189	int old_val = *valp;
188	190	int rc;
189	191
	192	+ rc = mutex_lock_killable(&mac_hid_emumouse_mutex);
	193	+ if (rc)
	194	+ return rc;
	195	+
190	196	rc = proc_dointvec(table, write, buffer, lenp, ppos);
191	197
192	198	if (rc == 0 && write && *valp != old_val) {
...	...	@@ -201,6 +207,8 @@
201	207	/* Restore the old value in case of error */
202	208	if (rc)
203	209	*valp = old_val;
	210	+
	211	+ mutex_unlock(&mac_hid_emumouse_mutex);
204	212
205	213	return rc;
206	214	}