From patchwork Sun Nov 4 13:54:31 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sasha Levin X-Patchwork-Id: 150115 Delivered-To: patch@linaro.org Received: by 2002:a2e:299d:0:0:0:0:0 with SMTP id p29-v6csp1539379ljp; Sun, 4 Nov 2018 05:54:49 -0800 (PST) X-Google-Smtp-Source: AJdET5cXdUo9DC4ESe2tQ/NqTWuhnzAfxfwujvUJ3u1TAVRC28o4zA9gWy3MjMvZOL164WPpNp8k X-Received: by 2002:a62:704a:: with SMTP id l71-v6mr3954449pfc.68.1541339689631; Sun, 04 Nov 2018 05:54:49 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1541339689; cv=none; d=google.com; s=arc-20160816; b=CTWofpR8MLba7KWYVLaRjoud7RV5xGjsKEC/yOrFk2xlo9eM/x0wPP5SqhHEl2VOsy nV675VkvaJ5omeQCaWFTntvW6IaO1oPjCcYWtbSiV9WWgZECj0QKZxtjoujXpajJhSj1 XWe9mj8axNlrRMiLxa7u+PB325ZPrkcbh7hf/VQm9Ck0LWFNlwvpaQqrU4mXW4GpDoxN y9ybGs0wZ6OHfRpZF+1eZW3dlibnNlEy0+UXlRqOlJXGsvTLP+9MHbacoSc1/c6GKLHI r4WeOIR9PZvgVwVfBmo9jWo8Cm0ltl6EJ5apAfKiY9vNNNN8NSE3cxFCX2Uq89Pb56SG pzCQ== 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=A+odLfOW1nS4FOf6M1J4/ThfF4jUmluM0KFENv3wUSA=; b=b4hZjd5hZ+b8LFYZu8PT1u3lobLwQvqXGi6SSpiPYn0zvKW3o4Yfk9MIzAto+oFXuw 0QkbPDI8KWkhn9Lj2iubRgSSryQlKvkBXF4ncp4nCl1bAzHCV0Kh84bwMe3BvBs+vRT+ 96czjW0Av4f/cxlqu2xnTg+j6sP1RV0df27ann+qEqlwYN4e6g20r5544F8v7AuYP5ru YCRelBsHAhjq6XRGZsPsmCYOnM5IH0wMqfdcXRqVRU18YlKPz9yXkJ2kP7a8FF+mVC3J oF4xRz2ly/JHmWuodJlnFOmxqbEu2fu551bJxjFQQsVRMtl8JLQUO/vzWZiWwKkFr8be eVnA== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@kernel.org header.s=default header.b=wEUKEFo3; 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 o1-v6si41777279pgf.80.2018.11.04.05.54.49; Sun, 04 Nov 2018 05:54:49 -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=wEUKEFo3; 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 S1731930AbeKDXJv (ORCPT + 15 others); Sun, 4 Nov 2018 18:09:51 -0500 Received: from mail.kernel.org ([198.145.29.99]:50018 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731901AbeKDXJu (ORCPT ); Sun, 4 Nov 2018 18:09:50 -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 9D03D2086B; Sun, 4 Nov 2018 13:54:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1541339686; bh=rwJq4xp8YwFBF2JvgmrEsP9bdlvVq//nsxvjjf0nFF8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=wEUKEFo3NWrTzX3Sqzp3+55ZOh6yq8OSfWo7qnRuEyjZF7fYidP6POn4t35TB5Fed c4Zyn6rbc6ZWsofu8snuZyTYqMwynuG+ybV3GVIQBUQBFRO9pTyOXfK/W9D3iB/FHy CPLeOR0gfpi1n0dIDjcJsJ31wvCBRKAx+XE3aKv0= From: Sasha Levin To: stable@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Joel Stanley , Michael Ellerman , Sasha Levin Subject: [PATCH AUTOSEL 3.18 11/13] powerpc/boot: Ensure _zimage_start is a weak symbol Date: Sun, 4 Nov 2018 08:54:31 -0500 Message-Id: <20181104135433.88734-11-sashal@kernel.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20181104135433.88734-1-sashal@kernel.org> References: <20181104135433.88734-1-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 14de4f8778a7..8539ac93b0de 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: