mbcs: cdev lock_kernel() pushdown

This driver would appear to have no internal locking at all.

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

1 files changed, 5 insertions, 0 deletions

diff --git a/drivers/char/mbcs.c b/drivers/char/mbcs.c
index f4716ad7348a..acd8e9ed474a 100644
--- a/drivers/char/mbcs.c
+++ b/drivers/char/mbcs.c
@@ -24,6 +24,7 @@
 #include <linux/mm.h>
 #include <linux/uio.h>
 #include <linux/mutex.h>
+#include <linux/smp_lock.h>
 #include <asm/io.h>
 #include <asm/uaccess.h>
 #include <asm/system.h>
@@ -382,15 +383,19 @@ static int mbcs_open(struct inode *ip, struct file *fp)
         struct mbcs_soft *soft;
         int minor;
 
+        lock_kernel();
         minor = iminor(ip);
 
+        /* Nothing protects access to this list... */
         list_for_each_entry(soft, &soft_list, list) {
                 if (soft->nasid == minor) {
                         fp->private_data = soft->cxdev;
+                        unlock_kernel();
                         return 0;
                 }
         }
 
+        unlock_kernel();
         return -ENODEV;
 }