From 21622939fc452c7fb739464b8e49368c3ceaa0ee Mon Sep 17 00:00:00 2001 From: Peter Hurley Date: Mon, 11 Mar 2013 16:44:21 -0400 Subject: tty: Add diagnostic for halted line discipline Flip buffer work must not be scheduled by the line discipline after the line discipline has been halted; issue warning. Note: drivers can still schedule flip buffer work. Signed-off-by: Peter Hurley Signed-off-by: Greg Kroah-Hartman --- drivers/tty/tty_ldisc.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) (limited to 'drivers/tty/tty_ldisc.c') diff --git a/drivers/tty/tty_ldisc.c b/drivers/tty/tty_ldisc.c index d794087c327e..c641321b9404 100644 --- a/drivers/tty/tty_ldisc.c +++ b/drivers/tty/tty_ldisc.c @@ -375,6 +375,7 @@ static inline void tty_ldisc_put(struct tty_ldisc *ld) void tty_ldisc_enable(struct tty_struct *tty) { + clear_bit(TTY_LDISC_HALTED, &tty->flags); set_bit(TTY_LDISC, &tty->flags); clear_bit(TTY_LDISC_CHANGING, &tty->flags); wake_up(&tty_ldisc_wait); @@ -513,8 +514,11 @@ static void tty_ldisc_restore(struct tty_struct *tty, struct tty_ldisc *old) static int tty_ldisc_halt(struct tty_struct *tty) { + int scheduled; clear_bit(TTY_LDISC, &tty->flags); - return cancel_work_sync(&tty->port->buf.work); + scheduled = cancel_work_sync(&tty->port->buf.work); + set_bit(TTY_LDISC_HALTED, &tty->flags); + return scheduled; } /** @@ -820,6 +824,7 @@ void tty_ldisc_hangup(struct tty_struct *tty) clear_bit(TTY_LDISC, &tty->flags); tty_unlock(tty); cancel_work_sync(&tty->port->buf.work); + set_bit(TTY_LDISC_HALTED, &tty->flags); mutex_unlock(&tty->ldisc_mutex); retry: tty_lock(tty); -- cgit v1.2.1