From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_NEOMUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E8CB1C43387 for ; Mon, 17 Dec 2018 17:49:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BA5732086C for ; Mon, 17 Dec 2018 17:49:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388060AbeLQRtl (ORCPT ); Mon, 17 Dec 2018 12:49:41 -0500 Received: from mx1.redhat.com ([209.132.183.28]:43552 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726660AbeLQRtl (ORCPT ); Mon, 17 Dec 2018 12:49:41 -0500 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 04E055D61D; Mon, 17 Dec 2018 17:49:41 +0000 (UTC) Received: from treble (ovpn-120-179.rdu2.redhat.com [10.10.120.179]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 0DDDF3DA7; Mon, 17 Dec 2018 17:49:38 +0000 (UTC) Date: Mon, 17 Dec 2018 11:49:36 -0600 From: Josh Poimboeuf To: Qian Cai Cc: yamada.masahiro@socionext.com, michal.lkml@markovi.net, mingo@kernel.org, bp@alien8.de, linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org, Paul Gortmaker Subject: Re: [PATCH] kbuild: error for CONFIG_ORC_UNWINDER is too much Message-ID: <20181217174936.ouhelssdkshclrr6@treble> References: <869bc700-1d6d-b950-76c7-5d0fc589152c@lca.pw> <20181217161728.6875-1-cai@lca.pw> <20181217170305.chni6e5vmev7hp4r@treble> <1545066839.18411.17.camel@lca.pw> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <1545066839.18411.17.camel@lca.pw> User-Agent: NeoMutt/20180716 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.39]); Mon, 17 Dec 2018 17:49:41 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Dec 17, 2018 at 12:13:59PM -0500, Qian Cai wrote: > On Mon, 2018-12-17 at 11:03 -0600, Josh Poimboeuf wrote: > > On Mon, Dec 17, 2018 at 11:17:28AM -0500, Qian Cai wrote: > > > Since ifdef will be evaluated immediately in the first phrase of the > > > Makefile read-in, there is no guarantee that the value for > > > CONFIG_ORC_UNWINDER will be up-to-date until in the second phrase that > > > this recipe is ran. > > > > > > include/config/%.conf: $(KCONFIG_CONFIG) include/config/auto.conf.cmd > > > $(Q)$(MAKE) -f $(srctree)/Makefile syncconfig > > > > > > Hence, change error to warning as this is essentially a best guess. The > > > original bug can be reproduced this way, > > > > But this still doesn't fix the root of the problem, that the check > > relies on a stale auto.conf. > > > > Yes, but it at least let people to be able to continue compiling kernel without > prematurely being terminated incorrectly. The good thing is that that check will > be triggered again to print out the right message once auto.conf has been synced > up. > > # make > Makefile:966: "Cannot generate ORC metadata for CONFIG_UNWINDER_ORC=y, please > install libelf-dev, libelf-devel or elfutils-libelf-devel" >   HOSTCC  scripts/kconfig/conf.o >   HOSTLD  scripts/kconfig/conf > scripts/kconfig/conf  --syncconfig Kconfig > Makefile:968: "Cannot use CONFIG_STACK_VALIDATION=y, please install libelf-dev, > libelf-devel or elfutils-libelf-devel" Instead of giving false (or silent) warnings, why not just fix the real problem? Also the error exists for a reason: if the user misses the warning then the ORC unwinder is broken and oops stack dumps are much less useful. -- Josh