Adding module support for __ro_after_init

[Kees Cook]

Hi Rusty,

I'd love to get your thoughts on the best way to support
__ro_after_init markings for modules. Are the r/o markings done after
module __init runs? If so, this should make things easy, and then we
just need to move .data..ro_after_init into .rodata at link time. If
not, then we'd need to explicitly make this section read-only after
_init.

Thanks!

-Kees

-- 
Kees Cook
Chrome OS & Brillo Security