Input: remove BKL, fix input_open_file() locking
Holding the BKL in input_open_file seems pointless because it does not
protect against updates of input_table, and all open functions from the
underlying drivers have proper mutex locking.
This makes input_open_file take the input_mutex when accessing
the table and no lock when calling into the lower function.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Thadeu Lima de Souza Cascardo <cascardo@holoscopio.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
diff --git a/drivers/input/input.c b/drivers/input/input.c
index e2dd885..e2aad0a 100644
--- a/drivers/input/input.c
+++ b/drivers/input/input.c
@@ -1879,35 +1879,37 @@
const struct file_operations *old_fops, *new_fops = NULL;
int err;
- lock_kernel();
+ err = mutex_lock_interruptible(&input_mutex);
+ if (err)
+ return err;
+
/* No load-on-demand here? */
handler = input_table[iminor(inode) >> 5];
- if (!handler || !(new_fops = fops_get(handler->fops))) {
- err = -ENODEV;
- goto out;
- }
+ if (handler)
+ new_fops = fops_get(handler->fops);
+
+ mutex_unlock(&input_mutex);
/*
* That's _really_ odd. Usually NULL ->open means "nothing special",
* not "no device". Oh, well...
*/
- if (!new_fops->open) {
+ if (!new_fops || !new_fops->open) {
fops_put(new_fops);
err = -ENODEV;
goto out;
}
+
old_fops = file->f_op;
file->f_op = new_fops;
err = new_fops->open(inode, file);
-
if (err) {
fops_put(file->f_op);
file->f_op = fops_get(old_fops);
}
fops_put(old_fops);
out:
- unlock_kernel();
return err;
}