Re: 2.6-test4 Traditional pty and devfs

From: Christoph Hellwig
Date: Tue Sep 02 2003 - 13:21:34 EST


On Tue, Sep 02, 2003 at 10:21:41AM -0700, Andrew Morton wrote:
> > > Both patches suffer from a problem. The slave is always only RW
> > > root. 2.4 sets the owner of the slave to that of the process opening
> > > the master. I cannot see a way to make this happen with 2.6-test.
> >
> > Well, that's why we have UNIX98 ptys. My preferred fix for this
> > issue would be to just axe traditional ptys, although this would probably
> > make it us incompatible with libc5.
>
> Unless we made an explicit decision to kill off old-style ptys (and we did
> not do that), they should continue to work as in 2.4, yes?

They work as they do in 2.4 and 2.6 (and any previous kernel) without
devfs, remember the pt_chown pain?

There's no point in emulating half of the UNIX98 pty semantics
in devfs when we have UNIX98 ptys that do it right anyway.

> IOW: we broke it. Have you any theory as to which change caused this?

That's the magic use uid/gid of the process calling devfs_Register flag
I killed. With a big HEADSUP and explanation on lkml..

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On Tue, Sep 02, 2003 at 10:21:41AM -0700, Andrew Morton wrote:
> > > Both patches suffer from a problem. The slave is always only RW
> > > root. 2.4 sets the owner of the slave to that of the process opening
> > > the master. I cannot see a way to make this happen with 2.6-test.
> >
> > Well, that's why we have UNIX98 ptys. My preferred fix for this
> > issue would be to just axe traditional ptys, although this would probably
> > make it us incompatible with libc5.
>
> Unless we made an explicit decision to kill off old-style ptys (and we did
> not do that), they should continue to work as in 2.4, yes?

They work as they do in 2.4 and 2.6 (and any previous kernel) without
devfs, remember the pt_chown pain?

There's no point in emulating half of the UNIX98 pty semantics
in devfs when we have UNIX98 ptys that do it right anyway.

> IOW: we broke it. Have you any theory as to which change caused this?

That's the magic use uid/gid of the process calling devfs_Register flag
I killed. With a big HEADSUP and explanation on lkml..

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