diff --git a/[refs] b/[refs]
index d382d18995de..a735b0a433df 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 48b81880519274d2a8b3e9919a47d91d05a1c964
+refs/heads/master: a9c4e8f74ba26f10cf78fed7c5b863ea50988856
diff --git a/trunk/drivers/char/hw_random/core.c b/trunk/drivers/char/hw_random/core.c
index 662d60e44e9a..e5d583c84e4f 100644
--- a/trunk/drivers/char/hw_random/core.c
+++ b/trunk/drivers/char/hw_random/core.c
@@ -37,6 +37,7 @@
 #include <linux/kernel.h>
 #include <linux/fs.h>
 #include <linux/sched.h>
+#include <linux/smp_lock.h>
 #include <linux/init.h>
 #include <linux/miscdevice.h>
 #include <linux/delay.h>
@@ -86,6 +87,7 @@ static int rng_dev_open(struct inode *inode, struct file *filp)
 		return -EINVAL;
 	if (filp->f_mode & FMODE_WRITE)
 		return -EINVAL;
+	cycle_kernel_lock();
 	return 0;
 }