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=-12.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 A00DEC433DF for ; Sat, 10 Oct 2020 23:00:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7498F20795 for ; Sat, 10 Oct 2020 23:00:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2391067AbgJJW7t (ORCPT ); Sat, 10 Oct 2020 18:59:49 -0400 Received: from wildebeest.demon.nl ([212.238.236.112]:42970 "EHLO gnu.wildebeest.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732573AbgJJWep (ORCPT ); Sat, 10 Oct 2020 18:34:45 -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 3EEF530D8744; Sun, 11 Oct 2020 00:34:23 +0200 (CEST) Received: by tarox.wildebeest.org (Postfix, from userid 1000) id 2BCC14000C97; Sun, 11 Oct 2020 00:34:23 +0200 (CEST) From: Mark Wielaard To: linux-toolchains@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Peter Zijlstra , Mark Wielaard Subject: [PATCH] Only add -fno-var-tracking-assignments workaround for old GCC versions. Date: Sun, 11 Oct 2020 00:33:50 +0200 Message-Id: <20201010223350.17005-1-mark@klomp.org> X-Mailer: git-send-email 2.18.4 In-Reply-To: <20201010215135.GB2666@wildebeest.org> References: <20201010215135.GB2666@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 --- Makefile | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/Makefile b/Makefile index f84d7e4ca0be..4f4a9416a87a 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