> You could do that by adding: > > if (!(pteflags & (_PAGE_USER | _PAGE_RW))) > rflags |= (1 << 1) | (1 << 63); > > Dbl check that the resulting mapping isn't accessible to user space though. Make these 1UL << x, and a proper patch would have to also test that the CPU supports the 3rd PP bit. We probably need to add a CPU feature bit for that. Ben.