From patchwork Sun Nov 4 13:53:49 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sasha Levin X-Patchwork-Id: 150116 Delivered-To: patch@linaro.org Received: by 2002:a2e:299d:0:0:0:0:0 with SMTP id p29-v6csp1541422ljp; Sun, 4 Nov 2018 05:57:41 -0800 (PST) X-Google-Smtp-Source: AJdET5dXuIsfGuh9KiqRj+rWbPvmqdy08k6xOoHAVpNJ3m4FeIuZJhkKKxcISA/Bt9oB7DpOAG9k X-Received: by 2002:a62:6981:: with SMTP id e123-v6mr3475322pfc.104.1541339860871; Sun, 04 Nov 2018 05:57:40 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1541339860; cv=none; d=google.com; s=arc-20160816; b=keNKT2pk8b/3S8eRhLcZUesVIn7fQmPNW4w7eUflZ5ln2/It2cCRNfyAo8B/3zRmFM DX1mT9JWHtzoVtAC9HDdkXMm1vCApOwLl4xbL2XINdtFhq26M8/aHn6cBsE5ffnxmb/A ZtfhLU2fj/pUz4G0k7qwq+2NQOWaAfsFRCvXUCQbj4uzNA4R1Q/HO86W8ypTG5j80Ytu t7RhxAY+DtX2NFsfnFjCjhQw8KSO0f0KNCakdQ9NLtpOETqXSmgDBTpoVBVS6YtmKpcU J8a6R6r9NIiERMZaJxgpELemkVX1aHvGVnPIibx4vGJxGP0eafIqnWfUCZeUtSofvNxB EC+A== 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=psJ7myUCkZjhaB7ffRtyV7Kx2+xz/73IJjmM1vFfeTIfWoZ4VF1s8S8A9ecomsgyGI RQzfkXSk+kDFXY0WljS/ILIn6739lIS4OBpRPWDj6AAATgu3IKXG8K6XCseXa3p4DZ+n uxB9qhi9mFVjToDGrAoG7iwgmuErIzFwGQfeYzGv5TEi4sEjYpuwygWmnof4wfpRl9J6 m1YVXmwS8OgFLepAEpJbj8rGODHfDGhLenJofJLFO6kish84/TjgzoBEwODNTn7ooFon g7K3MBVIj1qyN0mfbuREHjzqikTrMhEgUOBVYHDEbDbBD4Vpy27v2t96D0tXAWe+Hx5Z z35Q== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@kernel.org header.s=default header.b=I0HTopOD; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-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 n3-v6si36305044pld.137.2018.11.04.05.57.40; Sun, 04 Nov 2018 05:57:40 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-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=I0HTopOD; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-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 S1731706AbeKDXMo (ORCPT + 32 others); Sun, 4 Nov 2018 18:12:44 -0500 Received: from mail.kernel.org ([198.145.29.99]:48862 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731603AbeKDXJQ (ORCPT ); Sun, 4 Nov 2018 18:09:16 -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 5131620866; Sun, 4 Nov 2018 13:54:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1541339651; bh=TnRIjMVaCIulJyvLRBVq8CVZFdBXdgeLzJn3J/NidgI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=I0HTopOD1Mq/VdLAAAbBv4EKyoNgJ6HgiY1Zw92oI9dt8OA0n8y+3NckP9uXy42pk ETdnAIV6YjRfi7xBmYfu+Tpj2HYDfAypun0fLjCSnkMXmoN8QhEsmjI4ZgkgRrerwY 3QmE/3XI7bCnz3IIFctqe3ydjG4u45mYcHxf5OLI= From: Sasha Levin To: stable@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Joel Stanley , Michael Ellerman , Sasha Levin Subject: [PATCH AUTOSEL 4.9 15/21] powerpc/boot: Ensure _zimage_start is a weak symbol Date: Sun, 4 Nov 2018 08:53:49 -0500 Message-Id: <20181104135355.88602-15-sashal@kernel.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20181104135355.88602-1-sashal@kernel.org> References: <20181104135355.88602-1-sashal@kernel.org> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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: