Re: [PATCH v4 2/3] x86/ldt: Make modify_ldt optional

[Willy Tarreau <w@1wt.eu>]

On Fri, Jul 24, 2015 at 11:44:52PM -0700, Andy Lutomirski wrote:
> I'm all for it, but I think it should be hard-disablable in config,
> too, for the -tiny people.

I totally agree.

> If we add a runtime disable, let's do a
> separate patch, and you and Kees can fight over how general it should
> be.

Initially I was thinking about changing it for a 3-state option but
that would prevent X86_16BIT from being hard-disablable, so I'll do
something completely separate.

> > That's why here I think we should do the same, and possibly even
> > emit a warning once to report the first user of modify_ldt if that
> > can help.
> >
> > What do you think ?
> 
> I'm generally in favor.

OK.

> On the other hand, the current series is already written, might even
> be compatible with Xen, and patch 1 at least fixes a real bug.  Maybe
> several real bugs.

That's my guess as well given how hard it seems for everyone in this
long thread to imagine all possible bugs we can face :-/

Thanks,
Willy