Hi,
I tried tracing through sysctl code and it appears that there is no
generic locking for reads and writes to a sysctl node and thus a patch
like below is needed if proc_handler is a bit more complex than simply
storing an integer value.
Am I missing something?
Thanks.
--
Dmitry
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@xxxxxxx>
---
drivers/macintosh/mac_hid.c | 8 ++++++++
1 files changed, 8 insertions(+), 0 deletions(-)
diff --git a/drivers/macintosh/mac_hid.c b/drivers/macintosh/mac_hid.c
index 067f996..6a82388 100644
--- a/drivers/macintosh/mac_hid.c
+++ b/drivers/macintosh/mac_hid.c
@@ -23,6 +23,8 @@ static int mouse_button3_keycode = KEY_RIGHTALT; /* right option key */
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 @@ static int mac_hid_toggle_emumouse(ctl_table *table, int write,
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) {
@@ -202,6 +208,8 @@ static int mac_hid_toggle_emumouse(ctl_table *table, int write,
if (rc)
*valp = old_val;
+ mutex_unlock(&mac_hid_emumouse_mutex);
+
return rc;
}
--
To unsubscribe from this list: send the line "unsubscribe linux-input" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
