On Tue, Sep 29, 2015 at 10:50 AM, Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> wrote: > On Tue, Sep 29, 2015 at 1:35 PM, Andy Lutomirski <luto@xxxxxxxxxxxxxx> wrote: >> >> Does anyone know what happens if you stick a non-accessed segment in >> the GDT, map the GDT RO, and access it? > > You should get a #PF, as you guess, but go ahead and test it if you > want to make sure. > Then I think that, if we do this, the patch series should first make it percpu and fixmapped but RW and then flip it RO as a separate patch in case we need to revert the actual RO bit. I don't want to break Wine or The Witcher 2 because of this, and we might need various fixups. I really hope that no one uses get_thread_area to check whether TLS has been accessed. --Andy -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
