From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761829AbXGQTpE (ORCPT ); Tue, 17 Jul 2007 15:45:04 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1760608AbXGQTog (ORCPT ); Tue, 17 Jul 2007 15:44:36 -0400 Received: from kukmak.uni-mb.si ([164.8.100.3]:56340 "EHLO kukmak.uni-mb.si" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758578AbXGQTof (ORCPT ); Tue, 17 Jul 2007 15:44:35 -0400 Date: Tue, 17 Jul 2007 21:44:32 +0200 From: Domen Puncer To: Takashi Iwai Cc: Sam Ravnborg , linux-kernel@vger.kernel.org Subject: Re: [PATCH] introduce __init_exit function annotation Message-ID: <20070717194432.GO2400@nd47.coderock.org> References: <20070717080248.GK4375@moe.telargo.com> <20070717130230.GB24780@uranus.ravnborg.org> <20070717151432.GA25939@uranus.ravnborg.org> <20070717153236.GB25939@uranus.ravnborg.org> <20070717164846.GB26953@uranus.ravnborg.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.4.2.2i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On 17/07/07 19:02 +0200, Takashi Iwai wrote: > At Tue, 17 Jul 2007 18:48:46 +0200, > Sam Ravnborg wrote: > > > > On Tue, Jul 17, 2007 at 05:40:15PM +0200, Takashi Iwai wrote: > > > At Tue, 17 Jul 2007 17:32:36 +0200, > > > Sam Ravnborg wrote: > > > > > > > > On Tue, Jul 17, 2007 at 05:16:13PM +0200, Takashi Iwai wrote: > > > > > At Tue, 17 Jul 2007 17:14:32 +0200, > > > > > Sam Ravnborg wrote: > > > > > > > > > > > > On Tue, Jul 17, 2007 at 04:52:12PM +0200, Takashi Iwai wrote: > > > > > > > At Tue, 17 Jul 2007 15:02:30 +0200, > > > > > > > Sam Ravnborg wrote: > > > > > > > > > > > > > > > > On Tue, Jul 17, 2007 at 10:02:48AM +0200, Domen Puncer wrote: > > > > > > > > > Introduce __init_exit, which is useful ie. for drivers that call > > > > > > > > > cleanup functions when they fail in __init functions. > > > > > > > > > > > > > > > > This is wrong. > > > > > > > > On arm (just one example of several) the __exit section are discarded > > > > > > > > at buildtime so any reference from __init to __exit will cause the > > > > > > > > linker to error out. > > > > > > > > > > > > > > Hmm, from what I see, it adds __init to the function. There is no > > > > > > > reference to __exit. > > > > > > > > > > > > The cleanup functions are marked __exit in the referenced case. > > > > > > > > > > My understanding is that it's the very purpose of this patch -- > > > > > change the mark from __exit to __init_exit for such clean-up > > > > > functions. > > > > > > > > And that is wrong. > > > > > > You misunderstood. What I meant is the case like this: > > > > > > static void __init_exit cleanup() > > > { > > > ... > > > } > > > > > > static void __init foo_init() > > > { > > > if (error) > > > cleanup(); > > > } > > > > > > static void __exit foo_exit() > > > { > > > cleanup(); > > > } > > > > > > Currently, there is no proper way to mark cleanup(). Neither __init, > > > __exit, __devinit nor __devexit can be used there. > > > > Then you get the annotation sorted out so cleanup() get discarded in the > > built-in case. But you leave no room for automated tools to detect this. > > > > If this is really necessary (and I daught) then a specific section should be > > dedicated for this usage. > > > > We have lot of issues with current __init/__exit, __devinit/__devexit, __cpuint/__cpuexit > > and introducing more of the kind does not help it. > > So even if it saves a few bytes in some odd cases the added complaxity is IMHO not worth it. > > Well, I don't think it's a few bytes and not so odd, but I agree that > this solution isn't the best way. And, I now remember that this won't > work anyway, too. Calling __init from __exit also causes error... I made this patch because I saw __init calling __exit in yet another driver (gianfar). Guess I'll just send the old way fix, and remove __exit. As for calling __init_exit from __exit: 1 - in kernel, there's no __exit => no problem 2 - module, __init_exit is a no-op => no problem the code in question again: > #ifdef MODULE > #define __exit __attribute__ ((__section__(".exit.text"))) > +#define __init_exit > #else > #define __exit __attribute_used__ __attribute__ ((__section__(".exit.text"))) > +#define __init_exit __init > #endif Or maybe it's the name that is confuzing, but it makes sense to me: __init_exit - you can call it from __init or __exit. __init_or_exit? Domen