From patchwork Wed Apr 22 09:56:59 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 227343 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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 5C5A4C55186 for ; Wed, 22 Apr 2020 10:02:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 36C842076C for ; Wed, 22 Apr 2020 10:02:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587549753; bh=aS6rCUp0LQwVhHJsV5uUa9qCEMgITqc2OzijRDMUb+0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=X10bVdMtrICV8/ktB/QBZb7RmXLiuQx1aTfYfUw6RMTD+lV67fihtCU7Hb9kgavo5 1HzD96GxQhfukjkmVILHqBBpQKOULQGYY3EZxH9RO73ab6xfAfDy0pGofmz0Vfx8Cn oF6VD0/svvrLa3X/y+HGLyBis688PMx+R8ShCnHI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727005AbgDVKCc (ORCPT ); Wed, 22 Apr 2020 06:02:32 -0400 Received: from mail.kernel.org ([198.145.29.99]:51510 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726995AbgDVKC1 (ORCPT ); Wed, 22 Apr 2020 06:02:27 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id AD98820735; Wed, 22 Apr 2020 10:02:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587549747; bh=aS6rCUp0LQwVhHJsV5uUa9qCEMgITqc2OzijRDMUb+0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=AL7TBk1NbBo081jAlILAgVrA9CaKCJlKcQjuUqFGdDx2eA3v5TiT/lF2TVjqdCpwt xfbw5UUNOBDJXkHlHIg2Yon8rx2Xt2cNm+3FPa2qOcuqtBtmyalzJMWNPiS0Hnj4El gWvDYeweegsQrQuszMSJBymGA4SHOkdsMSQS/0EA= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Vegard Nossum , Andrew Morton , Masahiro Yamada , Daniel Santos , Rasmus Villemoes , Ian Abbott , Joe Perches , Linus Torvalds , Sasha Levin Subject: [PATCH 4.4 089/100] compiler.h: fix error in BUILD_BUG_ON() reporting Date: Wed, 22 Apr 2020 11:56:59 +0200 Message-Id: <20200422095039.026259456@linuxfoundation.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200422095022.476101261@linuxfoundation.org> References: <20200422095022.476101261@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Vegard Nossum [ Upstream commit af9c5d2e3b355854ff0e4acfbfbfadcd5198a349 ] compiletime_assert() uses __LINE__ to create a unique function name. This means that if you have more than one BUILD_BUG_ON() in the same source line (which can happen if they appear e.g. in a macro), then the error message from the compiler might output the wrong condition. For this source file: #include #define macro() \ BUILD_BUG_ON(1); \ BUILD_BUG_ON(0); void foo() { macro(); } gcc would output: ./include/linux/compiler.h:350:38: error: call to `__compiletime_assert_9' declared with attribute error: BUILD_BUG_ON failed: 0 _compiletime_assert(condition, msg, __compiletime_assert_, __LINE__) However, it was not the BUILD_BUG_ON(0) that failed, so it should say 1 instead of 0. With this patch, we use __COUNTER__ instead of __LINE__, so each BUILD_BUG_ON() gets a different function name and the correct condition is printed: ./include/linux/compiler.h:350:38: error: call to `__compiletime_assert_0' declared with attribute error: BUILD_BUG_ON failed: 1 _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__) Signed-off-by: Vegard Nossum Signed-off-by: Andrew Morton Reviewed-by: Masahiro Yamada Reviewed-by: Daniel Santos Cc: Rasmus Villemoes Cc: Ian Abbott Cc: Joe Perches Link: http://lkml.kernel.org/r/20200331112637.25047-1-vegard.nossum@oracle.com Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin --- include/linux/compiler.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/linux/compiler.h b/include/linux/compiler.h index 5508011cc0c79..5f8749440c6af 100644 --- a/include/linux/compiler.h +++ b/include/linux/compiler.h @@ -502,7 +502,7 @@ static __always_inline void __write_once_size(volatile void *p, void *res, int s * compiler has support to do so. */ #define compiletime_assert(condition, msg) \ - _compiletime_assert(condition, msg, __compiletime_assert_, __LINE__) + _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__) #define compiletime_assert_atomic_type(t) \ compiletime_assert(__native_word(t), \