Re: cpufreq: mediatek: allow modular build

From: Viresh Kumar
Date: Fri Sep 11 2015 - 06:19:44 EST


On 11-09-15, 11:13, Russell King - ARM Linux wrote:
> Yes, but it's not that simple.
>
> A module with no module_init() and no module_exit() is what's called a
> library module, which can be inserted, and later removed provided no
> other module depends on anything the library module exports.
>
> A module with a module_init() but no module_exit() is one which can be
> inserted, but never removed.
>
> A module with a module_init() and a module_exit() can be inserted, and
> later removed in much the same way as the library module mentioned above.
>
> See kernel/module.c:
>
> /* If it has an init func, it must have an exit func to unload */
> if (mod->init && !mod->exit) {
> forced = try_force_unload(flags);
> if (!forced) {
> /* This module can't be removed */
> ret = -EBUSY;
> goto out;
> }
> }
>
> and
>
> if (mod->init != NULL && mod->exit == NULL) {
> printed_something = 1;
> seq_puts(m, "[permanent],");
> }

Thanks for that, really appreciate it.

And now I realize that Arnd was correct to start with :)

--
viresh
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/