Subject: Re: [PATCH v3 1/3] init / kthread: add module_long_probe_init() and module_long_probe_exit()

From: Oleg Nesterov <[email-masked]>
Date: Mon, 18 Aug 2014 14:22:17 +0200

On 08/18, Takashi Iwai wrote:
>
> #define module_long_probe_init(initfn)				\
> 	static int _long_probe_##initfn(void *arg)		\
> 	{							\
> 		module_put_and_exit(initfn());			\
> 		return 0;					\
> 	}							\
> 	static int __init __long_probe_##initfn(void)		\
> 	{							\
> 		struct task_struct *__init_thread =		\
> 			kthread_create(_long_probe_##initfn,	\
> 				       NULL, #initfn);		\
> 		if (IS_ERR(__init_thread))			\
> 			return PTR_ERR(__init_thread);		\
> 		__module_get(THIS_MODULE);			\
> 		wake_up_process(__init_thread);			\
> 		return 0;					\
> 	}							\
> 	module_init(__long_probe_##initfn)
>
> ... and module_exit() remains identical as the normal version.

Aaaah. This is not true, module_exit() should not call exitfn() if initfn()
fails... So _long_probe_##initfn() needs to save the error code which should
be checked by module_exit().

> But, it's really a small difference, and I don't mind much which way
> to take, too.

Agreed.

Oleg.