Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752378AbZA1ATm (ORCPT ); Tue, 27 Jan 2009 19:19:42 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751632AbZA1ATe (ORCPT ); Tue, 27 Jan 2009 19:19:34 -0500 Received: from smtp1.linux-foundation.org ([140.211.169.13]:39537 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751582AbZA1ATd (ORCPT ); Tue, 27 Jan 2009 19:19:33 -0500 Date: Tue, 27 Jan 2009 16:19:13 -0800 (PST) From: Linus Torvalds X-X-Sender: torvalds@localhost.localdomain To: "H. Peter Anvin" cc: Ingo Molnar , Linux Kernel Mailing List , Andrew Morton , Sam Ravnborg , Jaswinder Singh Rajput , "David S. Miller" Subject: Re: [mingo@elte.hu: [git pull] headers_check fixes] In-Reply-To: <497FA2F5.2040806@zytor.com> Message-ID: References: <20090127222825.GA27097@elte.hu> <497F9740.4000505@zytor.com> <497FA2F5.2040806@zytor.com> User-Agent: Alpine 2.00 (LFD 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1469 Lines: 38 On Tue, 27 Jan 2009, H. Peter Anvin wrote: > Linus Torvalds wrote: > > > > Do you think the "fix headers_check" patches spend lots of time analyzing > > things? I bet no. They just try to make the warning go away, so you don't > > actually end up with any more "coverage" anyway. Quite the reverse - instead > > of having a simple rule ("CONFIG_xyz options simply do not exist in user > > space"), you end up having ad-hoc hacks on a per-fix basis. > > > > This is probably true. I think we should add this as one more of the > preprocessing rules which we really should just do, as well as automatic > mangling of integer types. Btw, the really scary thing is that I bet there are programs out there that "know" about kernel internals, and do things like #define CONFIG_SMP 1 #define __KERNEL__ 1 #include in order to get the atomic helpers from the kernel, and using CONFIG_xyz markers to force the exact version they want. And we will inevitably always end up breaking stuff like that. Nothing we can do about it - in the end, users can do infinitely odd things and know about our internals, and whatever changes we do will occasionally break some of the more incestuous code. Linus -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/