diff --git a/arch/um/drivers/harddog_kern.c b/arch/um/drivers/harddog_kern.c
index d332503..cfcac1f 100644
--- a/arch/um/drivers/harddog_kern.c
+++ b/arch/um/drivers/harddog_kern.c
@@ -124,8 +124,8 @@
 	return 0;
 }
 
-static int harddog_ioctl(struct inode *inode, struct file *file,
-			 unsigned int cmd, unsigned long arg)
+static int harddog_ioctl_unlocked(struct file *file,
+				  unsigned int cmd, unsigned long arg)
 {
 	void __user *argp= (void __user *)arg;
 	static struct watchdog_info ident = {
@@ -148,10 +148,22 @@
 	}
 }
 
+static long harddog_ioctl(struct file *file,
+			  unsigned int cmd, unsigned long arg)
+{
+	long ret;
+
+	lock_kernel();
+	ret = harddog_ioctl_unlocked(file, cmd, arg);
+	unlock_kernel();
+
+	return ret;
+}
+
 static const struct file_operations harddog_fops = {
 	.owner		= THIS_MODULE,
 	.write		= harddog_write,
-	.ioctl		= harddog_ioctl,
+	.unlocked_ioctl	= harddog_ioctl,
 	.open		= harddog_open,
 	.release	= harddog_release,
 };