1 files changed, 2 insertions, 0 deletions

diff --git a/drivers/char/hw_random/core.c b/drivers/char/hw_random/core.c
index 662d60e44e9a..e5d583c84e4f 100644
--- a/drivers/char/hw_random/core.c
+++ b/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;
 }