| From 7c61c3d8f44d5d822f758754287af644307b4af9 Mon Sep 17 00:00:00 2001 |
| From: Peter Hurley <peter@hurleysoftware.com> |
| Date: Thu, 13 Jun 2013 15:56:37 -0400 |
| Subject: tty: Fix transient pty write() EIO |
| |
| From: Peter Hurley <peter@hurleysoftware.com> |
| |
| commit 7c61c3d8f44d5d822f758754287af644307b4af9 upstream. |
| |
| 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 <markus@trippelsdorf.de> |
| Signed-off-by: Peter Hurley <peter@hurleysoftware.com> |
| Tested-by: Mikael Pettersson <mikpe@it.uu.se> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| drivers/tty/pty.c | 13 +++++-------- |
| 1 file changed, 5 insertions(+), 8 deletions(-) |
| |
| --- a/drivers/tty/pty.c |
| +++ b/drivers/tty/pty.c |
| @@ -244,14 +244,9 @@ static void pty_flush_buffer(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 *t |
| 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, |
