3 files changed, 8 insertions, 0 deletions

diff --git a/arch/um/drivers/harddog_kern.c b/arch/um/drivers/harddog_kern.c
index a9ad4bd6d953..d332503fa1be 100644
--- a/arch/um/drivers/harddog_kern.c
+++ b/arch/um/drivers/harddog_kern.c
@@ -66,6 +66,7 @@ static int harddog_open(struct inode *inode, struct file *file)
         int err = -EBUSY;
         char *sock = NULL;
 
+        lock_kernel();
         spin_lock(&lock);
         if(timer_alive)
                 goto err;
@@ -82,9 +83,11 @@ static int harddog_open(struct inode *inode, struct file *file)
 
         timer_alive = 1;
         spin_unlock(&lock);
+        unlock_kernel();
         return nonseekable_open(inode, file);
 err:
         spin_unlock(&lock);
+        unlock_kernel();
         return err;
 }
 
diff --git a/arch/um/drivers/mmapper_kern.c b/arch/um/drivers/mmapper_kern.c
index 67b2f55a602f..eb240323c40a 100644
--- a/arch/um/drivers/mmapper_kern.c
+++ b/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 @@ out:
 
 static int mmapper_open(struct inode *inode, struct file *file)
 {
+        cycle_kernel_lock();
         return 0;
 }
 
diff --git a/arch/um/drivers/random.c b/arch/um/drivers/random.c
index 4949044773ba..6eabb7022a2d 100644
--- a/arch/um/drivers/random.c
+++ b/arch/um/drivers/random.c
@@ -7,6 +7,7 @@
  * of the GNU General Public License, incorporated herein by reference.
  */
 #include <linux/sched.h>
+#include <linux/smp_lock.h>
 #include <linux/module.h>
 #include <linux/fs.h>
 #include <linux/interrupt.h>
@@ -33,6 +34,8 @@ static DECLARE_WAIT_QUEUE_HEAD(host_read_wait);
 
 static int rng_dev_open (struct inode *inode, struct file *filp)
 {
+        cycle_kernel_lock();
+
         /* enforce read-only access to this chrdev */
         if ((filp->f_mode & FMODE_READ) == 0)
                 return -EINVAL;