Re: [PATCH v5 0/2] provide check for ro_after_init memory sections

[Andrew Morton <akpm@linux-foundation.org>]

On Fri, 7 Apr 2017 15:15:36 -0700 Kees Cook <keescook@chromium.org> wrote:

> On Fri, Apr 7, 2017 at 3:12 PM, Andrew Morton <akpm@linux-foundation.org> wrote:
> > On Fri, 7 Apr 2017 14:53:23 -0700 Kees Cook <keescook@chromium.org> wrote:
> >
> >> > Eddie Kovsky (2):
> >> >   module: verify address is read-only
> >> >   extable: verify address is read-only
> >> >
> >> >  include/linux/kernel.h |  2 ++
> >> >  include/linux/module.h | 12 ++++++++++++
> >> >  kernel/extable.c       | 29 +++++++++++++++++++++++++++
> >> >  kernel/module.c        | 53 ++++++++++++++++++++++++++++++++++++++++++++++++++
> >> >  4 files changed, 96 insertions(+)
> >>
> >> Andrew, do you have these in your mailbox (it went to lkml), or should
> >> I resend them directly to you? Since they depend on the
> >> __start_ro_after_init naming fixes in -mm, it seemed like it'd be best
> >> to carry these two patches there. If so, please consider them both:
> >>
> >> Acked-by: Kees Cook <keescook@chromium.org>
> >>
> >> (And, from the thread on the module patch, Jessica has Acked that one too.)
> >
> > Well I grabbed them, but the patches don't actually do anything - they
> > add interfaces with no users.  What's the plan here?
> 
> I'd like to have a way for interfaces (especially the various
> *_register()) to be able to check that a structure is either const or
> __ro_after_init. My expectation is to add those and similar
> sanity-checks now that we can do so.

OK.  But I'd rather sit on the patches until we have working, tested,
reviewed callers which are agreed to be useful.