From patchwork Tue Jun 13 23:08:53 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthias Kaehlcke X-Patchwork-Id: 9784915 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id D95F16038E for ; Tue, 13 Jun 2017 23:10:12 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id CBE6F2858D for ; Tue, 13 Jun 2017 23:10:12 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id C038C285A3; Tue, 13 Jun 2017 23:10:12 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 400312858D for ; Tue, 13 Jun 2017 23:10:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753825AbdFMXKD (ORCPT ); Tue, 13 Jun 2017 19:10:03 -0400 Received: from mail-pf0-f181.google.com ([209.85.192.181]:36264 "EHLO mail-pf0-f181.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753858AbdFMXKA (ORCPT ); Tue, 13 Jun 2017 19:10:00 -0400 Received: by mail-pf0-f181.google.com with SMTP id x63so74453083pff.3 for ; Tue, 13 Jun 2017 16:10:00 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=y4PTSLqgTXFRR8Ox0gf3sEL3Gpp5KmRvRa0O9Rcs4sA=; b=K9D81KZTs5CGnLQ8j2Z8w4E7JCPPno4nt6rcw3dAsCof9g0CCT3NyZH7DLwI47qw3y 7RhQGrJhSJ7hXlBgyXgg7eGcbI75516kirxOvmi3ZHbV92+5KGQrWxcx3Xgd94X2Mv97 EO063d54HL12Sik1gOov4UC5FRZ5+5BHvG05R2560GVVmGnOS6r1tgPmBXmi+h308lVG PeXq3nRjYIW2rmZnIID340/yDsfNcfcriMnIFdpK+d1rLbvNtIUV8DWLskkXdU2xF5pe JmvpGhZTfnJaKwnIMgiWZcTgem9wch5y6aaTlj2aqJUBABM0TyfTja10lmvy+WrbB1Pc gEbA== X-Gm-Message-State: AKS2vOww7oZ+9GZQlBVOBuYOdRexaOBkC1KJICvQGOGscm5kBbP6HjI3 vtBqpIJajO5hiMYf X-Received: by 10.84.131.36 with SMTP id 33mr1774765pld.234.1497395399971; Tue, 13 Jun 2017 16:09:59 -0700 (PDT) Received: from mka.mtv.corp.google.com ([172.22.64.162]) by smtp.gmail.com with ESMTPSA id e18sm29179939pfk.118.2017.06.13.16.09.58 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Tue, 13 Jun 2017 16:09:59 -0700 (PDT) From: Matthias Kaehlcke To: Thomas Gleixner , Ingo Molnar , "H . Peter Anvin" , "H . J . Lu" , David Woodhouse , Masahiro Yamada , Michal Marek Cc: x86@kernel.org, linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org, Michael Davidson , Greg Hackmann , Nick Desaulniers , Stephen Hines , Kees Cook , Arnd Bergmann , Bernhard.Rosenkranzer@linaro.org, Peter Foley , Behan Webster , Douglas Anderson , Matthias Kaehlcke Subject: [PATCH v2 3/4] x86/build: Use cc-option-raw for boot code compiler options Date: Tue, 13 Jun 2017 16:08:53 -0700 Message-Id: <20170613230854.112282-4-mka@chromium.org> X-Mailer: git-send-email 2.13.1.518.g3df882009-goog In-Reply-To: <20170613230854.112282-1-mka@chromium.org> References: <20170613230854.112282-1-mka@chromium.org> Sender: linux-kbuild-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kbuild@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP cc-option uses KBUILD_CFLAGS and KBUILD_CPPFLAGS when checking if a compiler option is available. These flags aren't used to build the boot code, in consequence cc-option can yield wrong results. For example -mpreferred-stack-boundary=2 is never set with a 64 bit compiler, since the setting is only valid for 16 and 32 bit binaries. This is also the case for 32 bit kernel builds, because the option -m32 is added to KBUILD_CFLAGS after the assignment of REALMODE_CFLAGS. Use cc-option-raw instead of cc-option for the boot mode options. The macro receives the compiler options as parameter instead of using KBUILD_C*FLAGS. For the boot code we pass REALMODE_CFLAGS. Also use separate statements for the cc-option-raw checks instead of performing them in the initial assignment of REALMODE_CFLAGS since the variable is an input of the macro. Signed-off-by: Matthias Kaehlcke --- Changes in v2: - Adapted to use kbuild macro cc-option-raw instead of cc-option-no-kbuild arch/x86/Makefile | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/arch/x86/Makefile b/arch/x86/Makefile index bf240b920473..6d3ae4b20a5b 100644 --- a/arch/x86/Makefile +++ b/arch/x86/Makefile @@ -24,10 +24,11 @@ REALMODE_CFLAGS := $(M16_CFLAGS) -g -Os -D__KERNEL__ \ -DDISABLE_BRANCH_PROFILING \ -Wall -Wstrict-prototypes -march=i386 -mregparm=3 \ -fno-strict-aliasing -fomit-frame-pointer -fno-pic \ - -mno-mmx -mno-sse \ - $(call cc-option, -ffreestanding) \ - $(call cc-option, -fno-stack-protector) \ - $(call cc-option, -mpreferred-stack-boundary=2) + -mno-mmx -mno-sse + +REALMODE_CFLAGS += $(call cc-option-raw, $(CC), $(REALMODE_CFLAGS), -ffreestanding) +REALMODE_CFLAGS += $(call cc-option-raw, $(CC), $(REALMODE_CFLAGS), -fno-stack-protector) +REALMODE_CFLAGS += $(call cc-option-raw, $(CC), $(REALMODE_CFLAGS), -mpreferred-stack-boundary=2) export REALMODE_CFLAGS # BITS is used as extension for files which are available in a 32 bit