Re: [RFC] tty: Add get- ioctls to fetch tty status

From: Cyrill Gorcunov
Date: Thu Sep 13 2012 - 08:54:04 EST

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.

> 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.

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