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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 6C3D9C7618F for ; Tue, 16 Jul 2019 16:20:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4B1B6205ED for ; Tue, 16 Jul 2019 16:20:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732614AbfGPQUS (ORCPT ); Tue, 16 Jul 2019 12:20:18 -0400 Received: from mx1.redhat.com ([209.132.183.28]:55570 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727796AbfGPQUR (ORCPT ); Tue, 16 Jul 2019 12:20:17 -0400 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 328AB308FBAF; Tue, 16 Jul 2019 16:20:17 +0000 (UTC) Received: from treble (ovpn-123-204.rdu2.redhat.com [10.10.123.204]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 6181260A9F; Tue, 16 Jul 2019 16:20:16 +0000 (UTC) Date: Tue, 16 Jul 2019 11:20:14 -0500 From: Josh Poimboeuf To: Seth Forshee Cc: Masahiro Yamada , kbuild-all@01.org, Linux Kbuild mailing list , Linux Kernel Mailing List , kbuild test robot Subject: Re: [kbuild:kbuild 5/19] drivers/atm/eni.o: warning: objtool: eni_init_one()+0xe42: indirect call found in RETPOLINE build Message-ID: <20190716162014.iu47g6o7ralxhcf5@treble> References: <201907160706.9xUSQ36X%lkp@intel.com> <20190716124249.GP5418@ubuntu-xps13> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20190716124249.GP5418@ubuntu-xps13> User-Agent: NeoMutt/20180716 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.43]); Tue, 16 Jul 2019 16:20:17 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jul 16, 2019 at 07:42:49AM -0500, Seth Forshee wrote: > On Tue, Jul 16, 2019 at 03:57:24PM +0900, Masahiro Yamada wrote: > > (+ Josh Poimboeuf) > > > > On Tue, Jul 16, 2019 at 8:44 AM kbuild test robot wrote: > > > > > > tree: https://kernel.googlesource.com/pub/scm/linux/kernel/git/masahiroy/linux-kbuild.git kbuild > > > head: 0ff0c3753e06c0420c80dac1b0187a442b372acb > > > commit: 2eaf4e87ba258cc3f27e486cdf32d5ba76303c6f [5/19] kbuild: add -fcf-protection=none to retpoline flags > > > config: x86_64-randconfig-s2-07160214 (attached as .config) > > > compiler: gcc-4.9 (Debian 4.9.4-2) 4.9.4 > > > reproduce: > > > git checkout 2eaf4e87ba258cc3f27e486cdf32d5ba76303c6f > > > # save the attached .config to linux build tree > > > make ARCH=x86_64 > > > > 0-day bot reports objtool warnings with the following applied: > > https://patchwork.kernel.org/patch/11037379/ > > > > I have no idea about objtool. > > > > Is it better to drop this patch for now? > > I'm surprised that the change would have any impact on a build with > gcc-4.9, since -fcf-protection seems to have been introduced in gcc-8. I > guess there's no full build log that would let us see the actual flags > passed to the compiler. > > I'll try to reproduce this result. If you think the patch should be > dropped in the meantime, that's fine. The problem with this patch is that it's breaking the following check in arch/x86/Makefile. GCC 4.9 doesn't support retpolines, so it's supposed to fail with the below error. ifdef CONFIG_RETPOLINE ifeq ($(RETPOLINE_CFLAGS),) @echo "You are building kernel with non-retpoline compiler." >&2 @echo "Please update your compiler." >&2 @false endif endif Maybe the flags should be placed in another variable other than RETPOLINE_CFLAGS. -- Josh