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=-0.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,T_DKIMWL_WL_HIGH, URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by aws-us-west-2-korg-lkml-1.web.codeaurora.org (Postfix) with ESMTP id 9144FC5CFF1 for ; Tue, 12 Jun 2018 16:50:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4588F208B0 for ; Tue, 12 Jun 2018 16:50:08 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="gznwjcqI" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4588F208B0 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934943AbeFLQuG (ORCPT ); Tue, 12 Jun 2018 12:50:06 -0400 Received: from mail.kernel.org ([198.145.29.99]:34460 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934951AbeFLQsL (ORCPT ); Tue, 12 Jun 2018 12:48:11 -0400 Received: from localhost (LFbn-1-12247-202.w90-92.abo.wanadoo.fr [90.92.61.202]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 47AB8208B7; Tue, 12 Jun 2018 16:48:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1528822090; bh=M3ks+pkVnOVDKcj1sJRwDklA/o3hqEs2YfAmJfTErFs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=gznwjcqIekOTJxN6Nyu9g3gwj91QQ69uIpUB5dOY+dWKsrdHwmO24wZt3FedlDLs+ 8aMWDSlvjqNjBn6lDUOwxeV63aOoVNLlcs+mgr71DZv7wLeo3fP1JeydFUWbgk6H62 mrPZ6Lk0A6iNkBB1BQfX0a7uVUgxA1U00C0VWzTs= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, kbuild test robot , Josh Poimboeuf , Linus Torvalds , Peter Zijlstra , Thomas Gleixner , Ingo Molnar Subject: [PATCH 4.9 30/31] objtool: Fix gcov check for older versions of GCC Date: Tue, 12 Jun 2018 18:46:33 +0200 Message-Id: <20180612164621.996798847@linuxfoundation.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20180612164620.797338191@linuxfoundation.org> References: <20180612164620.797338191@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Josh Poimboeuf commit 867ac9d737094e46a6c33213f16dd1ec9e8bd5d5 upstream. Objtool tries to silence 'unreachable instruction' warnings when it detects gcov is enabled, because gcov produces a lot of unreachable instructions and they don't really matter. However, the 0-day bot is still reporting some unreachable instruction warnings with CONFIG_GCOV_KERNEL=y on GCC 4.6.4. As it turns out, objtool's gcov detection doesn't work with older versions of GCC because they don't create a bunch of symbols with the 'gcov.' prefix like newer versions of GCC do. Move the gcov check out of objtool and instead just create a new '--no-unreachable' flag which can be passed in by the kernel Makefile when CONFIG_GCOV_KERNEL is defined. Also rename the 'nofp' variable to 'no_fp' for consistency with the new 'no_unreachable' variable. Reported-by: kbuild test robot Signed-off-by: Josh Poimboeuf Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Fixes: 9cfffb116887 ("objtool: Skip all "unreachable instruction" warnings for gcov kernels") Link: http://lkml.kernel.org/r/c243dc78eb2ffdabb6e927844dea39b6033cd395.1500939244.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar [just Makefile.build as the other parts of this patch already applied - gregkh] Signed-off-by: Greg Kroah-Hartman --- scripts/Makefile.build | 3 +++ 1 file changed, 3 insertions(+) --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -253,6 +253,9 @@ objtool_args = check ifndef CONFIG_FRAME_POINTER objtool_args += --no-fp endif +ifdef CONFIG_GCOV_KERNEL +objtool_args += --no-unreachable +endif # 'OBJECT_FILES_NON_STANDARD := y': skip objtool checking for a directory # 'OBJECT_FILES_NON_STANDARD_foo.o := 'y': skip objtool checking for a file