From 6460fbbf476ad8d4f4196534c00019975b33e1db Mon Sep 17 00:00:00 2001 From: Peter Hurley Date: Thu, 16 Oct 2014 15:33:22 -0400 Subject: [PATCH 1/1] tty: WARN for attempted set_termios() of pty master The pty master's termios should never be set; currently, all code paths which call the driver's set_termios() method ensure that the pty slave's termios is being set. Signed-off-by: Peter Hurley Reviewed-by: Alan Cox Signed-off-by: Greg Kroah-Hartman --- drivers/tty/pty.c | 2 -- drivers/tty/tty_ioctl.c | 4 ++++ 2 files changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/tty/pty.c b/drivers/tty/pty.c index 4c0218db85ad..6c7602592fe0 100644 --- a/drivers/tty/pty.c +++ b/drivers/tty/pty.c @@ -477,7 +477,6 @@ static const struct tty_operations master_pty_ops_bsd = { .flush_buffer = pty_flush_buffer, .chars_in_buffer = pty_chars_in_buffer, .unthrottle = pty_unthrottle, - .set_termios = pty_set_termios, .ioctl = pty_bsd_ioctl, .cleanup = pty_cleanup, .resize = pty_resize, @@ -654,7 +653,6 @@ static const struct tty_operations ptm_unix98_ops = { .flush_buffer = pty_flush_buffer, .chars_in_buffer = pty_chars_in_buffer, .unthrottle = pty_unthrottle, - .set_termios = pty_set_termios, .ioctl = pty_unix98_ioctl, .resize = pty_resize, .shutdown = pty_unix98_shutdown, diff --git a/drivers/tty/tty_ioctl.c b/drivers/tty/tty_ioctl.c index 62380ccf70fb..ab4562c06af4 100644 --- a/drivers/tty/tty_ioctl.c +++ b/drivers/tty/tty_ioctl.c @@ -528,6 +528,8 @@ EXPORT_SYMBOL(tty_termios_hw_change); * is a bit of layering violation here with n_tty in terms of the * internal knowledge of this function. * + * A master pty's termios should never be set. + * * Locking: termios_rwsem */ @@ -537,6 +539,8 @@ int tty_set_termios(struct tty_struct *tty, struct ktermios *new_termios) struct tty_ldisc *ld; unsigned long flags; + WARN_ON(tty->driver->type == TTY_DRIVER_TYPE_PTY && + tty->driver->subtype == PTY_TYPE_MASTER); /* * Perform the actual termios internal changes under lock. */ -- 2.34.1