Received: by 2002:a05:6a10:6744:0:0:0:0 with SMTP id w4csp600499pxu; Wed, 14 Oct 2020 09:01:48 -0700 (PDT) X-Google-Smtp-Source: ABdhPJyB4p+9ASbAePfCwzwu/mXdpIgqzs6OQdF08Dp84Kg+f/xLcFhF82EmmIMqujD6+MR4/M0f X-Received: by 2002:ac2:52b2:: with SMTP id r18mr7849lfm.498.1602691307815; Wed, 14 Oct 2020 09:01:47 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1602691307; cv=none; d=google.com; s=arc-20160816; b=X0o6axHutYWJn3Z4tD6icAN5cyiqEFOGhitl6QSGkn6of1pvdyWCkY+bQp1VwuJ0vY EOO1neDusAJQPm36VwEYoPaBqNR+2iHtU6hLWVCueMDYxB+HYDtELZFn9XTGlbZ5KZ2N 24x3jl2j4+D44+mbzj4OywDc9cC80UIrp2bE72z08pUy37WyQns+lGCD9mu9KCaVyCWa JDEzdw3GNJRx3ZOMeRKPpNwICB8kDyJMCWeZRliwbqOrQhMYaaYOAG8Qv/JD2EvlSbei T28GEdWE10Y6lgBZO2LC7gdfqjmFjkFy07+XFs5SKel6kdPjul27ZyPSHCGgAjwakNGY Dknw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:references:in-reply-to:message-id:date:subject :cc:to:from; bh=NuCMcmWyuDn10d3mSLAmLqqVyp7pIjBxk5U9YXVsJzE=; b=WFbHEYz+SXbOVWvH+t+ydaW9Vb3kOMHNr+NQya5CJ1tbHhzjhNn+PEGC1dJcdf/29p 9b50E2hG+gzM+PqDDaU7MQwaR/CP0BpYM0xrprQGpG7DBlE8HeVgSyeXSop9dnfd7Www hpiv+RRL6VOpsaPbw53wsbBXkWaQeHmay54YhhKWfexJplvRZSafCJK2vjterCNJ/KBG uVCe1Ju2oniz1K3fSOFfJOcITG2BhQIoqMPWYU0G/TOX2tUGfVmbZcbaGd5iuMQAv6MO MqguZHmclpGMEJVvtrWmExXiSUPC1Hs7wyyrtt4pqAS8A/XL3WQwnPSOqdPeWVFWUoaQ m1FQ== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [23.128.96.18]) by mx.google.com with ESMTP id j24si66522ejb.48.2020.10.14.09.01.19; Wed, 14 Oct 2020 09:01:47 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730252AbgJNLCj (ORCPT + 99 others); Wed, 14 Oct 2020 07:02:39 -0400 Received: from wildebeest.demon.nl ([212.238.236.112]:49604 "EHLO gnu.wildebeest.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728925AbgJNLCj (ORCPT ); Wed, 14 Oct 2020 07:02:39 -0400 Received: from tarox.wildebeest.org (tarox.wildebeest.org [172.31.17.39]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by gnu.wildebeest.org (Postfix) with ESMTPSA id 2F12D30291AC; Wed, 14 Oct 2020 13:02:35 +0200 (CEST) Received: by tarox.wildebeest.org (Postfix, from userid 1000) id D9CC74000C5F; Wed, 14 Oct 2020 13:02:35 +0200 (CEST) From: Mark Wielaard To: linux-kernel@vger.kernel.org, Masahiro Yamada , Michal Marek , linux-kbuild@vger.kernel.org Cc: Ian Rogers , Mark Wielaard , linux-toolchains@vger.kernel.org, Andi Kleen , Nick Desaulniers , Segher Boessenkool , Florian Weimer Subject: [PATCH] Only add -fno-var-tracking-assignments workaround for old GCC versions. Date: Wed, 14 Oct 2020 13:01:32 +0200 Message-Id: <20201014110132.2680-1-mark@klomp.org> X-Mailer: git-send-email 2.18.4 In-Reply-To: References: X-Spam-Flag: NO X-Spam-Status: No, score=-2.9 required=5.0 tests=ALL_TRUSTED,BAYES_00 autolearn=ham autolearn_force=no version=3.4.0 X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on gnu.wildebeest.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Some old GCC versions between 4.5.0 and 4.9.1 might miscompile code with -fvar-tracking-assingments (which is enabled by default with -g -O2). commit 2062afb4f added -fno-var-tracking-assignments unconditionally to work around this. But newer versions of GCC no longer have this bug, so only add it for versions of GCC before 5.0. Signed-off-by: Mark Wielaard Acked-by: Ian Rogers Cc: linux-toolchains@vger.kernel.org Cc: Andi Kleen Cc: Nick Desaulniers Cc: Segher Boessenkool Cc: Florian Weimer --- Makefile | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/Makefile b/Makefile index 51540b291738..8477fee5f309 100644 --- a/Makefile +++ b/Makefile @@ -813,7 +813,9 @@ KBUILD_CFLAGS += -ftrivial-auto-var-init=zero KBUILD_CFLAGS += -enable-trivial-auto-var-init-zero-knowing-it-will-be-removed-from-clang endif -DEBUG_CFLAGS := $(call cc-option, -fno-var-tracking-assignments) +# Workaround https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61801 +# for old versions of GCC. +DEBUG_CFLAGS := $(call cc-ifversion, -lt, 0500, $(call cc-option, -fno-var-tracking-assignments)) ifdef CONFIG_DEBUG_INFO ifdef CONFIG_DEBUG_INFO_SPLIT -- 2.18.4