diff --git a/[refs] b/[refs]
index c9aa0d704237..f3558e206a07 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 78dccb46ddc2ff460c8b4d5ec0886964bd4b59e5
+refs/heads/master: bd6859fe836491d20ea6e57fee93e0e08ee69443
diff --git a/trunk/arch/um/drivers/mmapper_kern.c b/trunk/arch/um/drivers/mmapper_kern.c
index 67b2f55a602f..eb240323c40a 100644
--- a/trunk/arch/um/drivers/mmapper_kern.c
+++ b/trunk/arch/um/drivers/mmapper_kern.c
@@ -16,6 +16,7 @@
 #include <linux/miscdevice.h>
 #include <linux/module.h>
 #include <linux/mm.h>
+#include <linux/smp_lock.h>
 #include <asm/uaccess.h>
 #include "mem_user.h"
 
@@ -77,6 +78,7 @@ static int mmapper_mmap(struct file *file, struct vm_area_struct *vma)
 
 static int mmapper_open(struct inode *inode, struct file *file)
 {
+	cycle_kernel_lock();
 	return 0;
 }