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

[H. Peter Anvin]

On 09/27/2012 07:21 AM, Cyrill Gorcunov wrote:
> On Thu, Sep 27, 2012 at 07:17:49AM -0700, H. Peter Anvin wrote:
> > > While we easily can fetch termios settings and such, there are few bits which
> > > are missed to expord. So this patch provides them to user-space.
> >
> > What bothers me (and the same applies to termios) is that you have
> > NO idea if your particular process is the "owner" of that tty.  tty
> > users use out-of-band protocols, often implicit, to determine which
> > process "owns" the tty state.
> >
> > If you can't guarantee that ALL those processes are stopped and
> > checkpointed/restarted, you have a huge problem.
>
> Well, sure inside our tool before doing checkpoint we stop all
> tasks which are part of dumpee process tree. This unfortunatly
> doesn't apply to these ioctl calls. Peter, any idea how to deal
> with that?

Sorry, no.  I suspect you might be trying to do something that is 
impossible to do in a general fashion without application changes.

	-hpa

--
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel.  I don't speak on their behalf.

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