From patchwork Sun Nov 4 13:54:13 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sasha Levin X-Patchwork-Id: 150113 Delivered-To: patch@linaro.org Received: by 2002:a2e:299d:0:0:0:0:0 with SMTP id p29-v6csp1539168ljp; Sun, 4 Nov 2018 05:54:33 -0800 (PST) X-Google-Smtp-Source: AJdET5eM8l0jCu5IPp9maD4TKmZrCqKHWTPsQmklWf2bynNzs6qkTnrcQszZxLcpZrkhz4XTEXSS X-Received: by 2002:a63:6dc8:: with SMTP id i191mr16443129pgc.215.1541339672879; Sun, 04 Nov 2018 05:54:32 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1541339672; cv=none; d=google.com; s=arc-20160816; b=ToL7Z7IoUWVAh6/WoSJPCTO3w1EVoyL6w8t0jop9qtbq11kZwqWq5hVQmVlTcOUlug UsnZljNFvqerNDRhn90KAHkadTZ+wq7MYOFO59SR8im6TJEerjLhQlSnIMoEkmkOExuR yFT5JG1KWK/KMi59j0xXcLayoYeLhzvJnmlpzLjfhHDci872JNDnLJu22Pq9xZRylD9X 5ehxgAM+aPe+LhBShXrriUQEZNsGtfOeEwL9ZpIRNwu19xpzmrHLb3Pi38xnIz03Sssb SsFgzi5yLjyKv2lTvfUHfsanIUhiWccRfeFBQbA7Gj9D4mVweb/pe3IBsNV+zjRwpJmI ogag== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:references:in-reply-to:message-id:date :subject:cc:to:from:dkim-signature; bh=dCQmcTWLQBWwu8JEKvV7pwmT+DoMB6TOpMfZGztJi3k=; b=W/6yiKhCGo4RU0Uf+ORX30JR98gF+PqHPnlrWVFY2Y2dZP4WxfjsNime6UXjE+caTi tEzZutS3+2OQITqvTWocOvQcBrUqQHXzE5qPDxVezTGi4OCRSPnb81Oz4lr0hP9oaliF FdS2foeAbaXdlDeZgLizR4rbNqDHxedlUx96nYEfavj27jzzh3p0p6TsAqO9SWcUSqnF 8413boZDaTbquOTvBrJZA3Ga5H/81v1Cskm5C2N6x8IvA8EsQSePu7fhUx3ggg9OORPM FKA093snnEgDBH0qRMAOkxIbvOfV6FIrDmQX1ExUMqNc0IPTZlZ2Y5WciVXss/GG/0Hx W70A== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@kernel.org header.s=default header.b=VkqwKiNJ; spf=pass (google.com: best guess record for domain of stable-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=stable-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id t191si17907816pgd.579.2018.11.04.05.54.32; Sun, 04 Nov 2018 05:54:32 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of stable-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=pass header.i=@kernel.org header.s=default header.b=VkqwKiNJ; spf=pass (google.com: best guess record for domain of stable-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=stable-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731776AbeKDXJf (ORCPT + 15 others); Sun, 4 Nov 2018 18:09:35 -0500 Received: from mail.kernel.org ([198.145.29.99]:49436 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731761AbeKDXJe (ORCPT ); Sun, 4 Nov 2018 18:09:34 -0500 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 8018F2087A; Sun, 4 Nov 2018 13:54:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1541339670; bh=TnRIjMVaCIulJyvLRBVq8CVZFdBXdgeLzJn3J/NidgI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=VkqwKiNJlHqvytKaUBiqmnxs3GYEKWOl/uk6/oOLOknqCFsEtclu9YEK97bti3EsT 0WFf7a2haDOdGWvnxP7+6SOjTlcl+4J2l020VGlJbU3E5hjn8qK6FaDhfjsHhIuMRQ BhH+ZjvrJB769lgBPp+hzsUapFWz92s95LNOPsw8= From: Sasha Levin To: stable@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Joel Stanley , Michael Ellerman , Sasha Levin Subject: [PATCH AUTOSEL 4.4 11/15] powerpc/boot: Ensure _zimage_start is a weak symbol Date: Sun, 4 Nov 2018 08:54:13 -0500 Message-Id: <20181104135417.88671-11-sashal@kernel.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20181104135417.88671-1-sashal@kernel.org> References: <20181104135417.88671-1-sashal@kernel.org> Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Joel Stanley [ Upstream commit ee9d21b3b3583712029a0db65a4b7c081d08d3b3 ] When building with clang crt0's _zimage_start is not marked weak, which breaks the build when linking the kernel image: $ objdump -t arch/powerpc/boot/crt0.o |grep _zimage_start$ 0000000000000058 g .text 0000000000000000 _zimage_start ld: arch/powerpc/boot/wrapper.a(crt0.o): in function '_zimage_start': (.text+0x58): multiple definition of '_zimage_start'; arch/powerpc/boot/pseries-head.o:(.text+0x0): first defined here Clang requires the .weak directive to appear after the symbol is declared. The binutils manual says: This directive sets the weak attribute on the comma separated list of symbol names. If the symbols do not already exist, they will be created. So it appears this is different with clang. The only reference I could see for this was an OpenBSD mailing list post[1]. Changing it to be after the declaration fixes building with Clang, and still works with GCC. $ objdump -t arch/powerpc/boot/crt0.o |grep _zimage_start$ 0000000000000058 w .text 0000000000000000 _zimage_start Reported to clang as https://bugs.llvm.org/show_bug.cgi?id=38921 [1] https://groups.google.com/forum/#!topic/fa.openbsd.tech/PAgKKen2YCY Signed-off-by: Joel Stanley Reviewed-by: Nick Desaulniers Signed-off-by: Michael Ellerman Signed-off-by: Sasha Levin --- arch/powerpc/boot/crt0.S | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) -- 2.17.1 diff --git a/arch/powerpc/boot/crt0.S b/arch/powerpc/boot/crt0.S index 12866ccb5694..5c2199857aa8 100644 --- a/arch/powerpc/boot/crt0.S +++ b/arch/powerpc/boot/crt0.S @@ -47,8 +47,10 @@ p_end: .long _end p_pstack: .long _platform_stack_top #endif - .weak _zimage_start .globl _zimage_start + /* Clang appears to require the .weak directive to be after the symbol + * is defined. See https://bugs.llvm.org/show_bug.cgi?id=38921 */ + .weak _zimage_start _zimage_start: .globl _zimage_start_lib _zimage_start_lib: