1 files changed, 10 insertions, 3 deletions

diff --git a/drivers/sbus/char/jsflash.c b/drivers/sbus/char/jsflash.c
index 4b7079fdc10c..2bec9ccc0293 100644
--- a/drivers/sbus/char/jsflash.c
+++ b/drivers/sbus/char/jsflash.c
@@ -27,6 +27,7 @@
  */
 
 #include <linux/module.h>
+#include <linux/smp_lock.h>
 #include <linux/types.h>
 #include <linux/errno.h>
 #include <linux/miscdevice.h>
@@ -417,11 +418,17 @@ static int jsf_mmap(struct file * file, struct vm_area_struct * vma)
 
 static int jsf_open(struct inode * inode, struct file * filp)
 {
-
-        if (jsf0.base == 0) return -ENXIO;
-        if (test_and_set_bit(0, (void *)&jsf0.busy) != 0)
+        lock_kernel();
+        if (jsf0.base == 0) {
+                unlock_kernel();
+                return -ENXIO;
+        }
+        if (test_and_set_bit(0, (void *)&jsf0.busy) != 0) {
+                unlock_kernel();
                 return -EBUSY;
+        }
 
+        unlock_kernel();
         return 0;       /* XXX What security? */
 }