tty: add compat_ioctl callbacks

In order to avoid future diversions between fs/compat_ioctl.c and
drivers/tty/pty.c, define .compat_ioctl callbacks for the relevant
tty_operations structs. Since both pty_unix98_ioctl() and
pty_bsd_ioctl() are compatible between 32-bit and 64-bit userspace no
special translation is required.

Signed-off-by: Aleksa Sarai <[e-mail]>
Reviewed-by: Arnd Bergmann <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/tty/pty.c

···
 	return -ENOIOCTLCMD;
 }
 
+static long pty_bsd_compat_ioctl(struct tty_struct *tty,
+				 unsigned int cmd, unsigned long arg)
+{
+	/*
+	 * PTY ioctls don't require any special translation between 32-bit and
+	 * 64-bit userspace, they are already compatible.
+	 */
+	return pty_bsd_ioctl(tty, cmd, arg);
+}
+
 static int legacy_count = CONFIG_LEGACY_PTY_COUNT;
 /*
  * not really modular, but the easiest way to keep compat with existing
···
 	.chars_in_buffer = pty_chars_in_buffer,
 	.unthrottle = pty_unthrottle,
 	.ioctl = pty_bsd_ioctl,
+	.compat_ioctl = pty_bsd_compat_ioctl,
 	.cleanup = pty_cleanup,
 	.resize = pty_resize,
 	.remove = pty_remove
···
 	return -ENOIOCTLCMD;
 }
 
+static long pty_unix98_compat_ioctl(struct tty_struct *tty,
+				 unsigned int cmd, unsigned long arg)
+{
+	/*
+	 * PTY ioctls don't require any special translation between 32-bit and
+	 * 64-bit userspace, they are already compatible.
+	 */
+	return pty_unix98_ioctl(tty, cmd, arg);
+}
+
 /**
  *	ptm_unix98_lookup	-	find a pty master
  *	@driver: ptm driver
···
 	.chars_in_buffer = pty_chars_in_buffer,
 	.unthrottle = pty_unthrottle,
 	.ioctl = pty_unix98_ioctl,
+	.compat_ioctl = pty_unix98_compat_ioctl,
 	.resize = pty_resize,
 	.cleanup = pty_cleanup
 };

fs/compat_ioctl.c

···
 COMPATIBLE_IOCTL(TIOCCBRK)
 COMPATIBLE_IOCTL(TIOCGSID)
 COMPATIBLE_IOCTL(TIOCGICOUNT)
-COMPATIBLE_IOCTL(TIOCGPKT)
-COMPATIBLE_IOCTL(TIOCGPTLCK)
 COMPATIBLE_IOCTL(TIOCGEXCL)
 /* Little t */
 COMPATIBLE_IOCTL(TIOCGETD)
···
 COMPATIBLE_IOCTL(TIOCMBIC)
 COMPATIBLE_IOCTL(TIOCMBIS)
 COMPATIBLE_IOCTL(TIOCMSET)
-COMPATIBLE_IOCTL(TIOCPKT)
 COMPATIBLE_IOCTL(TIOCNOTTY)
 COMPATIBLE_IOCTL(TIOCSTI)
 COMPATIBLE_IOCTL(TIOCOUTQ)
 COMPATIBLE_IOCTL(TIOCSPGRP)
 COMPATIBLE_IOCTL(TIOCGPGRP)
-COMPATIBLE_IOCTL(TIOCGPTN)
-COMPATIBLE_IOCTL(TIOCSPTLCK)
 COMPATIBLE_IOCTL(TIOCSERGETLSR)
-COMPATIBLE_IOCTL(TIOCSIG)
 #ifdef TIOCSRS485
 COMPATIBLE_IOCTL(TIOCSRS485)
 #endif