Hi Ilya, On Wed, 2012-12-19 at 23:00 +0400, Ilya Zykov wrote: > When we are opening ptmx, we have closed pts, by description. > Now only if we open and after close all pts' descriptions, pty_close() sets > this bit correctly > > Signed-off-by: Ilya Zykov <ilya@xxxxxxx> > --- > drivers/tty/pty.c | 1 + > 1 files changed, 1 insertions(+), 0 deletions(-) > > diff --git a/drivers/tty/pty.c b/drivers/tty/pty.c > index 1ce1362..7b69307 100644 > --- a/drivers/tty/pty.c > +++ b/drivers/tty/pty.c > @@ -659,6 +659,7 @@ static int ptmx_open(struct inode *inode, struct file *filp) > retval = ptm_driver->ops->open(tty, filp); > if (retval) > goto err_release; > + set_bit(TTY_OTHER_CLOSED, &tty->flags); /* THE SLAVE STILL CLOSED */ I'm not sure this is a good idea. Ideally, if you were only trying to make the logic "more correct", this change would be here, instead: mutex_unlock(&tty_mutex); set_bit(TTY_PTY_LOCK, &tty->flags); /* LOCK THE SLAVE */ + set_bit(TTY_OTHER_CLOSED, &tty->flags); /* THE SLAVE STILL CLOSED */ tty->driver_data = inode; tty_add_file(tty, filp); Of course, that would be a bad idea because then the master pty_open() would fail because of the test in pty_open(). Setting TTY_OTHER_CLOSED after the open() -- as you've done -- appears to leave a race open when this bit is not set but while a slave open() may still be attempted. But as far as I can tell, this change doesn't actually affect any code branches -- that is, doesn't actually do anything -- so no such race exists. Is that correct? Regards, Peter Hurley -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
