misc: cdev lock_kernel() pushdown

misc_open() looks fine, but who knows what all of the misc drivers are
doing in their open() functions?

Signed-off-by: Jonathan Corbet <corbet@lwn.net>

1 files changed, 3 insertions, 0 deletions

diff --git a/drivers/char/misc.c b/drivers/char/misc.c
index eaace0db0ff4..6e1563c3d30a 100644
--- a/drivers/char/misc.c
+++ b/drivers/char/misc.c
@@ -49,6 +49,7 @@
 #include <linux/device.h>
 #include <linux/tty.h>
 #include <linux/kmod.h>
+#include <linux/smp_lock.h>
 
 /*
  * Head entry for the doubly linked miscdevice list
@@ -118,6 +119,7 @@ static int misc_open(struct inode * inode, struct file * file)
         int err = -ENODEV;
         const struct file_operations *old_fops, *new_fops = NULL;
         
+        lock_kernel();
         mutex_lock(&misc_mtx);
         
         list_for_each_entry(c, &misc_list, list) {
@@ -155,6 +157,7 @@ static int misc_open(struct inode * inode, struct file * file)
         fops_put(old_fops);
 fail:
         mutex_unlock(&misc_mtx);
+        unlock_kernel();
         return err;
 }