1 files changed, 8 insertions, 6 deletions

diff --git a/arch/um/drivers/harddog_kern.c b/arch/um/drivers/harddog_kern.c
index cfcac1ff4cf2..2d0266d0254d 100644
--- a/arch/um/drivers/harddog_kern.c
+++ b/arch/um/drivers/harddog_kern.c
@@ -42,7 +42,7 @@
 #include <linux/miscdevice.h>
 #include <linux/watchdog.h>
 #include <linux/reboot.h>
-#include <linux/smp_lock.h>
+#include <linux/mutex.h>
 #include <linux/init.h>
 #include <linux/spinlock.h>
 #include <asm/uaccess.h>
@@ -50,6 +50,7 @@
 
 MODULE_LICENSE("GPL");
 
+static DEFINE_MUTEX(harddog_mutex);
 static DEFINE_SPINLOCK(lock);
 static int timer_alive;
 static int harddog_in_fd = -1;
@@ -66,7 +67,7 @@ static int harddog_open(struct inode *inode, struct file *file)
         int err = -EBUSY;
         char *sock = NULL;
 
-        lock_kernel();
+        mutex_lock(&harddog_mutex);
         spin_lock(&lock);
         if(timer_alive)
                 goto err;
@@ -83,11 +84,11 @@ static int harddog_open(struct inode *inode, struct file *file)
 
         timer_alive = 1;
         spin_unlock(&lock);
-        unlock_kernel();
+        mutex_unlock(&harddog_mutex);
         return nonseekable_open(inode, file);
 err:
         spin_unlock(&lock);
-        unlock_kernel();
+        mutex_unlock(&harddog_mutex);
         return err;
 }
 
@@ -153,9 +154,9 @@ static long harddog_ioctl(struct file *file,
 {
         long ret;
 
-        lock_kernel();
+        mutex_lock(&harddog_mutex);
         ret = harddog_ioctl_unlocked(file, cmd, arg);
-        unlock_kernel();
+        mutex_unlock(&harddog_mutex);
 
         return ret;
 }
@@ -166,6 +167,7 @@ static const struct file_operations harddog_fops = {
         .unlocked_ioctl = harddog_ioctl,
         .open           = harddog_open,
         .release        = harddog_release,
+        .llseek         = no_llseek,
 };
 
 static struct miscdevice harddog_miscdev = {