Re: 2.6.5-rc3-mm1

Andrew Morton
2004-03-31T00:26:39Z

Greg KH <greg@kroah.com> wrote:
>
> On Tue, Mar 30, 2004 at 02:34:37AM -0800, Andrew Morton wrote:
> >
> > ftp://ftp.kernel.org/pub/linux/kernel/people/akpm/patches/2.6/2.6.5-rc3/2.6.5-rc3-mm1/
> >
> > - Dropped the tty locking fix. As predicted, it deadlocked. I also
> > reverted the patch from bk-driver-core.patch which is causing this race to
> > trigger more frequently.
>
> Argh, so the only way I'm going to be able to get my little, tiny,
> simple vc class patch is by fixing all of the tty layer locking code?

Well the good news is that my test box now oopses on about 2-out-of-3 boot
attempts. But that gets tiresome.

> Ugh, that's so mean... :)

Optimistic, too.

I'm thinking that this can be fixed from the other direction: just before
release_dev() calls close (dropping BKL), if tty->count==1, make the
going-away tty ineligible for concurrent lookups. Do that by setting
tty->driver->ttys[idx] to NULL. Maybe.