Serge Hallyn [serge@xxxxxxxxxx] wrote: | Quoting Al Viro (viro@xxxxxxxxxxxxxxxxxx): | > On Mon, Jan 23, 2012 at 04:41:25PM -0800, Linus Torvalds wrote: | > | > > Right. I think the opportunity for problems should be pretty small. | > > | > > And it's not like the pty itself wouldn't continue to work - it's just | > > that programs like /usr/bin/tty wouldn't be able to *find* it. | > > | > > Although who knows - maybe there is some other subtle interaction. | > | > FWIW, the subtle and nasty part in all that is that you can mknod /dev/ptmx | > and it *will* work, refering to the "initial" instance. That's what | > concerns me about the chroot scenarios - | > mknod /jail/dev/ptmx c 5 2 | > mkdir /jail/dev/pts | > mount -t devpts /jail/dev/pts | > chroot /jail | > works fine right now, but with that change behaviour will be all wrong - | > opening /dev/ptmx inside of jail will grab you a pts, all right, but | > it will *not* show up in (jail) /dev/pts/* as it does with the current | > kernel. | > | > Note that if you replace that mknod with symlink pts/ptmx /jail/dev/ptmx | > the things will keep working. However, that will _only_ work for kernels | > with DEVPTS_MULTIPLE_INSTANCES - without it you won't get ptmx inside | > devpts (which is arguably wrong, BTW) | | Should /dev/pts/ptmx be created for DEVPTS_MULTIPLE_INSTANCES=n? With DEVPTS_MULTIPLE_INSTANCES=n, there is only _one_ (global) instance right ? Why would we need a 'pts/ptmx' node ? To keep the symlink (i.e user space scripts) valid for both single and multiple instance cases ? Sukadev _______________________________________________ Containers mailing list Containers@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/containers
