Re: [PATCH v2 2/3] module: Use the same logic for setting and unsetting RO/NX

Rusty Russell
2015-11-08T22:50:42Z

Josh Poimboeuf <jpoimboe@redhat.com> writes:
> When setting a module's RO and NX permissions, set_section_ro_nx() is
> used, but when clearing them, unset_module_{init,core}_ro_nx() are used.
> The unset functions don't have the same checks the set function has for
> partial page protections. It's probably harmless, but it's still
> confusingly asymmetrical.
>
> Instead, use the same logic to do both. Also add some new
> set_module_{init,core}_ro_nx() helper functions for more symmetry with
> the unset functions.

Yes, this seems sensible.

One nit to pick:

> + unsigned long total_size,
> + int (*set_ro)(unsigned long start, int num_pages),
> + int (*set_nx)(unsigned long start, int num_pages))

...
> + set_section_ro_nx(mod->module_core, mod->core_text_size,
> + mod->core_ro_size, mod->core_size,
> + set_memory_rw, set_memory_x);

set_ro == set_memory_rw here. That's just confusing.

I think we have to avoid the word "set" in the function parameters
since it may unset instead.

Suggest "alter_ro" or "frob_ro" instead?

Thanks,
Rusty.