tty: add compat_ioctl

Add compat_ioctl method for tty code to allow processing of 32 bit ioctl
calls on 64 bit systems by tty core, tty drivers, and line disciplines.

Based on patch by Arnd Bergmann:
http://www.uwsg.iu.edu/hypermail/linux/kernel/0511.0/1732.html

[akpm@linux-foundation.org: make things static]
Signed-off-by: Paul Fulghum <paulkf@microgate.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 7 insertions, 0 deletions

diff --git a/include/linux/tty_ldisc.h b/include/linux/tty_ldisc.h
index d75932e27710..6226504d9108 100644
--- a/include/linux/tty_ldisc.h
+++ b/include/linux/tty_ldisc.h
@@ -59,6 +59,11 @@
  *      low-level driver can "grab" an ioctl request before the line
  *      discpline has a chance to see it.
  * 
+ * long (*compat_ioctl)(struct tty_struct * tty, struct file * file,
+ *                      unsigned int cmd, unsigned long arg);
+ *
+ *      Process ioctl calls from 32-bit process on 64-bit system
+ *
  * void (*set_termios)(struct tty_struct *tty, struct ktermios * old);
  *
  *      This function notifies the line discpline that a change has
@@ -118,6 +123,8 @@ struct tty_ldisc {
                          const unsigned char * buf, size_t nr); 
         int     (*ioctl)(struct tty_struct * tty, struct file * file,
                          unsigned int cmd, unsigned long arg);
+        long    (*compat_ioctl)(struct tty_struct * tty, struct file * file,
+                                unsigned int cmd, unsigned long arg);
         void    (*set_termios)(struct tty_struct *tty, struct ktermios * old);
         unsigned int (*poll)(struct tty_struct *, struct file *,
                              struct poll_table_struct *);