From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752286AbaBOWyr (ORCPT ); Sat, 15 Feb 2014 17:54:47 -0500 Received: from mx1.redhat.com ([209.132.183.28]:46464 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751197AbaBOWyq (ORCPT ); Sat, 15 Feb 2014 17:54:46 -0500 Organization: Red Hat UK Ltd. Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 From: David Howells In-Reply-To: <1392326938-14405-1-git-send-email-paul.gortmaker@windriver.com> References: <1392326938-14405-1-git-send-email-paul.gortmaker@windriver.com> To: Paul Gortmaker Cc: dhowells@redhat.com, linux-kernel@vger.kernel.org, Michal Marek Subject: Re: [PATCH] kbuild: unconditionally clobber include/linux/version.h on distclean Date: Sat, 15 Feb 2014 22:54:41 +0000 Message-ID: <16324.1392504881@warthog.procyon.org.uk> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Paul Gortmaker wrote: > As of v3.7, the UAPI changes relocated headers around such that the > kernel version header lived in a new place. > > If a person is bisecting and if you go back to pre-UAPI days, > you will create an include/linux/version.h -- then if you checkout a > post-UAPI kernel, and even run "make distclean" it still won't delete > that old version file. So you get a situation like this: > > $ grep -R LINUX_VERSION_CODE include/ > include/generated/uapi/linux/version.h:#define LINUX_VERSION_CODE 200192 > include/linux/version.h:#define LINUX_VERSION_CODE 132646 > > The value in that second line is representative of a v2.6.38 version. > And it will be sourced/used, hence leading to strange behaviours, such > as drivers/staging content (which typically hasn't been purged of version > ifdefs) failing to build. > > Since it is a subtle mode of failure, lets always clobber the old > file when doing a distclean. > > Cc: Michal Marek > Cc: David Howells > Signed-off-by: Paul Gortmaker Acked-by: David Howells