Re: [PATCH] early init: open /dev/console with O_LARGEFILE

[Arvind Sankar]

On Wed, Jan 01, 2020 at 03:01:12PM -0800, Linus Torvalds wrote:
> On Wed, Jan 1, 2020 at 2:50 PM Arvind Sankar <nivedita@xxxxxxxxxxxx> wrote:
> >
> > Shouldn't that only affect init though? The getty's it spawns should be
> > in their own sessions.
> 
> They *should* be in their own sessions, and clearly this problem
> doesn't seem to really affect much anybody else.
> 
> But I think youling has some limited and/or odd init userspace, and I
> think it gets confused.
> 
> So my theory is that because of the file descriptor leak, that "forget
> the old controlling tty" doesn't happen, and then subsequent tty opens
> don't do the right thing.
> 
> Maybe.
> 
> But it's the only real semantic change I can see in that whole patch.
> 
>                  Linus

Ok. If you do end up going with this rather than the revert, one minor
nit with the patch -- if somehow the filp_open succeeds but one of the
f_dupfd's fails, you still need to do an fput to avoid leaking the
reference.