Re: [PATCH v2 11/17] selftests/x86/ldt_gdt: Prepare for access bit forced

[Thomas Gleixner]

On Thu, 14 Dec 2017, Linus Torvalds wrote:

> On Thu, Dec 14, 2017 at 1:22 PM, Andy Lutomirski <luto@xxxxxxxxxx> wrote:
> >
> > Which kind of kills the whole thing.  There's no way the idea of
> > putting the LDT in a VMA is okay if it's RW.
> 
> Sure there is.
> 
> I really don't understand why you guys think it has to be RO.
> 
> All it has to be is not _user_ accessible. And that's a requirement
> regardless, because no way in hell should users be able to read the
> damn thing.

The user knows the LDT contents because he put it there and it can be read
via modify_ldt(0, ) anyway. Or am I misunderstanding what you are trying to
say?

Thanks,

	tglx