1 files changed, 17 insertions, 5 deletions

diff --git a/drivers/char/i8k.c b/drivers/char/i8k.c
index fc8cf7ac7f2b..3bc0eef88717 100644
--- a/drivers/char/i8k.c
+++ b/drivers/char/i8k.c
@@ -23,6 +23,7 @@
 #include <linux/seq_file.h>
 #include <linux/dmi.h>
 #include <linux/capability.h>
+#include <linux/mutex.h>
 #include <asm/uaccess.h>
 #include <asm/io.h>
 
@@ -55,6 +56,7 @@
 
 #define I8K_TEMPERATURE_BUG     1
 
+static DEFINE_MUTEX(i8k_mutex);
 static char bios_version[4];
 
 MODULE_AUTHOR("Massimo Dal Zotto (dz@debian.org)");
@@ -82,8 +84,7 @@ module_param(fan_mult, int, 0);
 MODULE_PARM_DESC(fan_mult, "Factor to multiply fan speed with");
 
 static int i8k_open_fs(struct inode *inode, struct file *file);
-static int i8k_ioctl(struct inode *, struct file *, unsigned int,
-                     unsigned long);
+static long i8k_ioctl(struct file *, unsigned int, unsigned long);
 
 static const struct file_operations i8k_fops = {
         .owner          = THIS_MODULE,
@@ -91,7 +92,7 @@ static const struct file_operations i8k_fops = {
         .read           = seq_read,
         .llseek         = seq_lseek,
         .release        = single_release,
-        .ioctl          = i8k_ioctl,
+        .unlocked_ioctl = i8k_ioctl,
 };
 
 struct smm_regs {
@@ -307,8 +308,8 @@ static int i8k_get_dell_signature(int req_fn)
         return regs.eax == 1145651527 && regs.edx == 1145392204 ? 0 : -1;
 }
 
-static int i8k_ioctl(struct inode *ip, struct file *fp, unsigned int cmd,
-                     unsigned long arg)
+static int
+i8k_ioctl_unlocked(struct file *fp, unsigned int cmd, unsigned long arg)
 {
         int val = 0;
         int speed;
@@ -395,6 +396,17 @@ static int i8k_ioctl(struct inode *ip, struct file *fp, unsigned int cmd,
         return 0;
 }
 
+static long i8k_ioctl(struct file *fp, unsigned int cmd, unsigned long arg)
+{
+        long ret;
+
+        mutex_lock(&i8k_mutex);
+        ret = i8k_ioctl_unlocked(fp, cmd, arg);
+        mutex_unlock(&i8k_mutex);
+
+        return ret;
+}
+
 /*
  * Print the information for /proc/i8k.
  */