linux-kernel - Re: [PATCH v2 3/7] kmod: split call to call_usermodehelper

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Message-ID: <20130309202329.GC16399@redhat.com>
Date:	Sat, 9 Mar 2013 21:23:29 +0100
From:	Oleg Nesterov <oleg@...hat.com>
To:	Lucas De Marchi <lucas.demarchi@...fusion.mobi>
Cc:	lucas.de.marchi@...il.com, David Howells <dhowells@...hat.com>,
	James Morris <james.l.morris@...cle.com>,
	Andrew Morton <akpm@...ux-foundation.org>,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2 3/7] kmod: split call to call_usermodehelper_fns()

On 03/08, Lucas De Marchi wrote:
>
> Use call_usermodehelper_setup() + call_usermodehelper_exec() instead of
> calling call_usermodehelper_fns(). In case the latter returns -ENOMEM
> the cleanup function may had not been called - in this case we would
> not free argv and module_name.
>
> Signed-off-by: Lucas De Marchi <lucas.demarchi@...fusion.mobi>

Thanks!

looks correct, but...

> @@ -98,8 +100,17 @@ static int call_modprobe(char *module_name, int wait)
>  	argv[3] = module_name;	/* check free_modprobe_argv() */
>  	argv[4] = NULL;
>
> -	return call_usermodehelper_fns(modprobe_path, argv, envp,
> -		wait | UMH_KILLABLE, NULL, free_modprobe_argv, NULL);
> +	gfp_mask = (wait == UMH_NO_WAIT) ? GFP_ATOMIC : GFP_KERNEL;

Why? it is never called with UMH_NO_WAIT,

> +	info = call_usermodehelper_setup(modprobe_path, argv, envp,
> +					 gfp_mask, NULL, free_modprobe_argv,

can't we simply use GFP_KERNEL?

Oleg.

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