On Thu, 13 Sep 2012 16:54:01 +0400 Cyrill Gorcunov <gorcu...@openvz.org> wrote:
> On Thu, Sep 13, 2012 at 01:51:31PM +0100, Alan Cox wrote: > > > +static int pty_get_lock(struct tty_struct *tty, int __user *arg) > > > +{ > > > + int locked = test_bit(TTY_PTY_LOCK, &tty->flags); > > > + if (put_user(locked, arg)) > > > + return -EFAULT; > > > > Now explain exactly how this doesn't race with another thread chanigng > > the lock setting ? > > It's the same as to set/clear this bit, isn't it? Please correct me > if I'm wrong. So by the time you've finished the test bit and returned it to user space the answer may have changed ? > > The other comment I have is that it might be better put these in now > > there are sysfs patches for the tty layer bouncing about to provide the > > needed infrastructure ? > > Alan, could you please point me where these patches are living, so I would > take a look and check them out linux-serial or check tty-next as I think Greg has now merged the test patch. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/