Input: sparse-keymap - implement safer freeing of the keymap

Allow calling sparse_keymap_free() before unregistering input device
whithout risk of racing with EVIOCGETKEYCODE and EVIOCSETKEYCODE.
This makes life of drivers writers easier.

Acked-by: Yong Wang <yong.y.wang@intel.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

1 files changed, 8 insertions, 1 deletions

diff --git a/drivers/input/input.c b/drivers/input/input.c
index e2aad0a51826..be18fa99fa24 100644
--- a/drivers/input/input.c
+++ b/drivers/input/input.c
@@ -659,7 +659,14 @@ static int input_default_setkeycode(struct input_dev *dev,
 int input_get_keycode(struct input_dev *dev,
                       unsigned int scancode, unsigned int *keycode)
 {
-        return dev->getkeycode(dev, scancode, keycode);
+        unsigned long flags;
+        int retval;
+
+        spin_lock_irqsave(&dev->event_lock, flags);
+        retval = dev->getkeycode(dev, scancode, keycode);
+        spin_unlock_irqrestore(&dev->event_lock, flags);
+
+        return retval;
 }
 EXPORT_SYMBOL(input_get_keycode);