Re: Removing Mandatory Locks

Kees Cook
2021-08-20T16:30:35Z

On Thu, Aug 19, 2021 at 12:15:08PM -0700, Linus Torvalds wrote:
> On Thu, Aug 19, 2021 at 11:39 AM Jeff Layton <jlayton@kernel.org> wrote:
> >
> > I'm all for ripping it out too. It's an insane interface anyway.
> >
> > I've not heard a single complaint about this being turned off in
> > fedora/rhel or any other distro that has this disabled.
>
> I'd love to remove it, we could absolutely test it. The fact that
> several major distros have it disabled makes me think it's fine.

FWIW, it is now disabled in Ubuntu too:

https://git.launchpad.net/~ubuntu-kernel/ubuntu/+source/linux/+git/impish/commit/?h=master-next&id=f3aac5e47789cbeb3177a14d3d2a06575249e14b

> But as always, it would be good to check Android.

It looks like it's enabled (checking the Pixel 4 kernel image), but it's
not specifically mentioned in any of the build configs that are used to
construct the image, so I think this is just catching the "default y". I
expect it'd be fine to turn this off.

I will ask around to see if it's actually used.

--
Kees Cook