From 7c61c3d8f44d5d822f758754287af644307b4af9 Mon Sep 17 00:00:00 2001 From: Peter Hurley Date: Thu, 13 Jun 2013 15:56:37 -0400 Subject: tty: Fix transient pty write() EIO Commit 699390354da6c258b65bf8fa79cfd5feaede50b6 ('pty: Ignore slave pty close() if never successfully opened') introduced a bug with ptys whereby a write() in parallel with an open() on an existing pty could mistakenly indicate an I/O error. Only indicate an I/O error if the condition on open() actually exists. Reported-by: Markus Trippelsdorf Signed-off-by: Peter Hurley Tested-by: Mikael Pettersson Cc: stable # 3.9 Signed-off-by: Greg Kroah-Hartman --- drivers/tty/pty.c | 13 +++++-------- 1 file changed, 5 insertions(+), 8 deletions(-) (limited to 'drivers/tty') diff --git a/drivers/tty/pty.c b/drivers/tty/pty.c index 59bfaecc4e14..abfd99089781 100644 --- a/drivers/tty/pty.c +++ b/drivers/tty/pty.c @@ -244,14 +244,9 @@ static void pty_flush_buffer(struct tty_struct *tty) static int pty_open(struct tty_struct *tty, struct file *filp) { - int retval = -ENODEV; - if (!tty || !tty->link) - goto out; - - set_bit(TTY_IO_ERROR, &tty->flags); + return -ENODEV; - retval = -EIO; if (test_bit(TTY_OTHER_CLOSED, &tty->flags)) goto out; if (test_bit(TTY_PTY_LOCK, &tty->link->flags)) @@ -262,9 +257,11 @@ static int pty_open(struct tty_struct *tty, struct file *filp) clear_bit(TTY_IO_ERROR, &tty->flags); clear_bit(TTY_OTHER_CLOSED, &tty->link->flags); set_bit(TTY_THROTTLED, &tty->flags); - retval = 0; + return 0; + out: - return retval; + set_bit(TTY_IO_ERROR, &tty->flags); + return -EIO; } static void pty_set_termios(struct tty_struct *tty, -- cgit v1.2.3