3 files changed, 21 insertions, 0 deletions

diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
index 150e4f747c7d..4ca4bcd28ff7 100644
--- a/drivers/tty/tty_io.c
+++ b/drivers/tty/tty_io.c
@@ -2717,6 +2717,8 @@ static long tty_compat_ioctl(struct file *file, unsigned int cmd,
         ld = tty_ldisc_ref_wait(tty);
         if (ld->ops->compat_ioctl)
                 retval = ld->ops->compat_ioctl(tty, file, cmd, arg);
+        else
+                retval = n_tty_compat_ioctl_helper(tty, file, cmd, arg);
         tty_ldisc_deref(ld);
 
         return retval;
diff --git a/drivers/tty/tty_ioctl.c b/drivers/tty/tty_ioctl.c
index 53f2442c6099..9314d93c1a20 100644
--- a/drivers/tty/tty_ioctl.c
+++ b/drivers/tty/tty_ioctl.c
@@ -19,6 +19,7 @@
 #include <linux/module.h>
 #include <linux/bitops.h>
 #include <linux/mutex.h>
+#include <linux/compat.h>
 
 #include <asm/io.h>
 #include <asm/uaccess.h>
@@ -1179,3 +1180,19 @@ int n_tty_ioctl_helper(struct tty_struct *tty, struct file *file,
         }
 }
 EXPORT_SYMBOL(n_tty_ioctl_helper);
+
+#ifdef CONFIG_COMPAT
+long n_tty_compat_ioctl_helper(struct tty_struct *tty, struct file *file,
+                                        unsigned int cmd, unsigned long arg)
+{
+        switch (cmd) {
+        case TIOCGLCKTRMIOS:
+        case TIOCSLCKTRMIOS:
+                return tty_mode_ioctl(tty, file, cmd, (unsigned long) compat_ptr(arg));
+        default:
+                return -ENOIOCTLCMD;
+        }
+}
+EXPORT_SYMBOL(n_tty_compat_ioctl_helper);
+#endif
+
diff --git a/include/linux/tty.h b/include/linux/tty.h
index 0ad68889fc1a..64c12a3e65f0 100644
--- a/include/linux/tty.h
+++ b/include/linux/tty.h
@@ -579,6 +579,8 @@ extern int __init tty_init(void);
 /* tty_ioctl.c */
 extern int n_tty_ioctl_helper(struct tty_struct *tty, struct file *file,
                        unsigned int cmd, unsigned long arg);
+extern long n_tty_compat_ioctl_helper(struct tty_struct *tty, struct file *file,
+                       unsigned int cmd, unsigned long arg);
 
 /* serial.c */