Re: [PATCH 2/4] lib: Make test_sysctl initialized as module

[Kees Cook <keescook@chromium.org>]

On Thu, May 28, 2020 at 11:52:16PM +0900, Masami Hiramatsu wrote:
> test_sysctl.c is expected to be used as a module, but since
> it does not use module_init(), it never be registered as
> a module and not appeared under /sys/module/.
> In the result, the selftests/sysctl/sysctl.sh always fails
> to find the test module and is skipped.
> 
> This makes test_sysctl.c initialized as a module by module_init()
> and allow sysctl.sh to find the test module is loaded.
> 
> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
> ---
>  lib/test_sysctl.c |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/lib/test_sysctl.c b/lib/test_sysctl.c
> index 566dad3f4196..ec4d0f03475d 100644
> --- a/lib/test_sysctl.c
> +++ b/lib/test_sysctl.c
> @@ -149,7 +149,7 @@ static int __init test_sysctl_init(void)
>  	}
>  	return 0;
>  }
> -late_initcall(test_sysctl_init);
> +module_init(test_sysctl_init);

This is the only part I think we need to double check. As a non-module,
module_init() becomes device_initcall() not late_initcall().

I don't see any notes in the commit log for the original driver that
mention why this needs to be late_initcall(), though, so I *think* it's
safe. Luis?

-- 
Kees Cook