Re: [PATCH RFC] kprobes: Remove MODULES dependency

Kees Cook
2020-07-10T15:52:00Z

On Fri, Jul 10, 2020 at 07:32:57PM +0900, Masami Hiramatsu wrote:
> On Fri, 10 Jul 2020 02:45:19 +0300
> Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> wrote:
> > +#ifdef CONFIG_MODULES
> > /* Lock modules while optimizing kprobes */
> > mutex_lock(&module_mutex);
> > +#endif
>
> Hmm, can you reduce these "#ifdef CONFIG_MODULE"s ?
>
> e.g.
>
> #ifdef CONFIG_MODULES
> static void lock_modules(void)
> {
> mutex_lock(&module_mutex);
> }
> ...
> #else
> #define lock_modules() do { } while (0)
> ...
> #endif

I prefer using "static inline" for no-op functions just because they
will maintain argument type validation by the compiler regardless of the
CONFIG state (though it doesn't really matter here since it's void).

#else
static inline lock_modules(void) { }
#endif

--
Kees Cook