Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933160Ab3GOPk4 (ORCPT ); Mon, 15 Jul 2013 11:40:56 -0400 Received: from aserp1040.oracle.com ([141.146.126.69]:37025 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932646Ab3GOPkz (ORCPT ); Mon, 15 Jul 2013 11:40:55 -0400 Date: Mon, 15 Jul 2013 11:40:50 -0400 From: Konrad Rzeszutek Wilk To: Linus Torvalds , linux-kernel@vger.kernel.org Subject: CONFIG_* used by user-space to figure out whether a feature is on/off Message-ID: <20130715154050.GA5941@phenom.dumpdata.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.21 (2010-09-15) X-Source-IP: ucsinet22.oracle.com [156.151.31.94] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1174 Lines: 28 Hey Linus, I am hoping you can help me draw an understanding and a line in sand whether: a) Tools should not depend on /proc/config.gz to figure out whether a kernel has some CONFIG_X=y feature. b) If they are OK to do so, what do we do when certain CONFIG_X options get reworked/removed. Would they be considered regressions? Aka is this similar to 'you shall not break user-space'? Irrespective of that, do you have any ideas of how a user-space program (say GRUB) can figure out whether the configuration stanze it generates is supported by the kernel. If you don't want to answer this question - since this might open a can of worms you prefer not to deal with - that is absolutly OK. Folks have been tossing ideas such as: - Let the user deal with it and if it does not boot - oh well. - readelf or objdump. - use /boot/config-- as most (all?) distros stick that in there. Thanks! -- 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/