From patchwork Thu May 20 09:16:40 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 444547 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=-19.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, 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 065B8C43460 for ; Thu, 20 May 2021 09:39:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E0EFA6191C for ; Thu, 20 May 2021 09:39:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232550AbhETJk6 (ORCPT ); Thu, 20 May 2021 05:40:58 -0400 Received: from mail.kernel.org ([198.145.29.99]:35510 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233126AbhETJhk (ORCPT ); Thu, 20 May 2021 05:37:40 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 9568F6140F; Thu, 20 May 2021 09:30:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1621503020; bh=DTWH8NVoZWx4rVhmqGlYuLjfmdZbDkg5InMe1IXTpgU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=19XbSLlQ6+DzaOBSDUaRw75fDILkRLStLulpoMxqNkn6i2k+8lraHwUI71Dx8/Kce phRAFxEEcqqQkl+WH0MxsxP5IyBwawOnNnpf+lGQ4Ze/n3WgvKHLHbEzhTE4L2ytss P/poJC2U1UFu0D8OGeHrfxUhEkv796GYy9Sk9U5A= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, John Millikin , Nathan Chancellor , Borislav Petkov , Ard Biesheuvel , Sedat Dilek , Sasha Levin Subject: [PATCH 4.19 031/425] x86/build: Propagate $(CLANG_FLAGS) to $(REALMODE_FLAGS) Date: Thu, 20 May 2021 11:16:40 +0200 Message-Id: <20210520092132.428514112@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210520092131.308959589@linuxfoundation.org> References: <20210520092131.308959589@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: John Millikin [ Upstream commit 8abe7fc26ad8f28bfdf78adbed56acd1fa93f82d ] When cross-compiling with Clang, the `$(CLANG_FLAGS)' variable contains additional flags needed to build C and assembly sources for the target platform. Normally this variable is automatically included in `$(KBUILD_CFLAGS)' via the top-level Makefile. The x86 real-mode makefile builds `$(REALMODE_CFLAGS)' from a plain assignment and therefore drops the Clang flags. This causes Clang to not recognize x86-specific assembler directives:   arch/x86/realmode/rm/header.S:36:1: error: unknown directive   .type real_mode_header STT_OBJECT ; .size real_mode_header, .-real_mode_header   ^ Explicit propagation of `$(CLANG_FLAGS)' to `$(REALMODE_CFLAGS)', which is inherited by real-mode make rules, fixes cross-compilation with Clang for x86 targets. Relevant flags: * `--target' sets the target architecture when cross-compiling. This   flag must be set for both compilation and assembly (`KBUILD_AFLAGS')   to support architecture-specific assembler directives. * `-no-integrated-as' tells clang to assemble with GNU Assembler   instead of its built-in LLVM assembler. This flag is set by default   unless `LLVM_IAS=1' is set, because the LLVM assembler can't yet   parse certain GNU extensions. Signed-off-by: John Millikin Signed-off-by: Nathan Chancellor Signed-off-by: Borislav Petkov Acked-by: Ard Biesheuvel Tested-by: Sedat Dilek Link: https://lkml.kernel.org/r/20210326000435.4785-2-nathan@kernel.org Signed-off-by: Sasha Levin --- arch/x86/Makefile | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/x86/Makefile b/arch/x86/Makefile index 6ebdbad21fb2..65a8722e784c 100644 --- a/arch/x86/Makefile +++ b/arch/x86/Makefile @@ -40,6 +40,7 @@ REALMODE_CFLAGS += $(call __cc-option, $(CC), $(REALMODE_CFLAGS), -ffreestanding REALMODE_CFLAGS += $(call __cc-option, $(CC), $(REALMODE_CFLAGS), -fno-stack-protector) REALMODE_CFLAGS += $(call __cc-option, $(CC), $(REALMODE_CFLAGS), -Wno-address-of-packed-member) REALMODE_CFLAGS += $(call __cc-option, $(CC), $(REALMODE_CFLAGS), $(cc_stack_align4)) +REALMODE_CFLAGS += $(CLANG_FLAGS) export REALMODE_CFLAGS # BITS is used as extension for files which are available in a 32 bit