From mboxrd@z Thu Jan 1 00:00:00 1970 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=-13.1 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 E5767C35242 for ; Tue, 11 Feb 2020 20:48:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BB35020714 for ; Tue, 11 Feb 2020 20:48:48 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=embeddedor.com header.i=@embeddedor.com header.b="XdB3q/5U" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731886AbgBKUsr (ORCPT ); Tue, 11 Feb 2020 15:48:47 -0500 Received: from gateway21.websitewelcome.com ([192.185.45.155]:25623 "EHLO gateway21.websitewelcome.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727786AbgBKUsr (ORCPT ); Tue, 11 Feb 2020 15:48:47 -0500 Received: from cm14.websitewelcome.com (cm14.websitewelcome.com [100.42.49.7]) by gateway21.websitewelcome.com (Postfix) with ESMTP id 57018400CECDB for ; Tue, 11 Feb 2020 14:48:46 -0600 (CST) Received: from gator4166.hostgator.com ([108.167.133.22]) by cmsmtp with SMTP id 1cScjIXlfXVkQ1cScjgsOz; Tue, 11 Feb 2020 14:48:46 -0600 X-Authority-Reason: nr=8 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=embeddedor.com; s=default; h=Content-Type:MIME-Version:Message-ID:Subject: Cc:To:From:Date:Sender:Reply-To:Content-Transfer-Encoding:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:In-Reply-To:References:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=pk3jucKkgGeEV6Au0nX+Ttm5YWNvtM3diEI6bWayXng=; b=XdB3q/5U5BVjk2oUsJ6okatoQC 9TUfMCOqfTfbAFjokj2rm0Zih46zq7fY4ULZ4UwK7eCaiC6RH/PtJsnEyX1b4bQUy5H2o/Nt0G3SQ dDEwXHQ1/pQiaS7JelKtB/UwUkMSVtBU3Q3NeUysyCzXWjCHJYbuKrS0NDV/2KsGW2tmgCX2h6yGh c0gJPzRJ+PmPcxUlM+Vnnq6stDFa1mYPp3CX7rWcdBC6pi0WFbGezMG5OnBbpJfYA1bdHl7Nd0NgA fxJHzcPDQtpP7SOqshKFamK7SLzJthk7u56uAqXGf99LV4CfTlnwNmp2mACt51kkozPQzBPJ4hCAG A7i7A+ug==; Received: from [200.68.140.36] (port=6499 helo=embeddedor) by gator4166.hostgator.com with esmtpa (Exim 4.92) (envelope-from ) id 1j1cSa-001vSf-P0; Tue, 11 Feb 2020 14:48:44 -0600 Date: Tue, 11 Feb 2020 14:51:19 -0600 From: "Gustavo A. R. Silva" To: Andrew Morton Cc: linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" Subject: [PATCH] lib/bch: Replace zero-length array with flexible-array member Message-ID: <20200211205119.GA21234@embeddedor> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.9.4 (2018-02-28) X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - gator4166.hostgator.com X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - embeddedor.com X-BWhitelist: no X-Source-IP: 200.68.140.36 X-Source-L: No X-Exim-ID: 1j1cSa-001vSf-P0 X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: (embeddedor) [200.68.140.36]:6499 X-Source-Auth: gustavo@embeddedor.com X-Email-Count: 39 X-Source-Cap: Z3V6aWRpbmU7Z3V6aWRpbmU7Z2F0b3I0MTY2Lmhvc3RnYXRvci5jb20= X-Local-Domain: yes Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The current codebase makes use of the zero-length array language extension to the C90 standard, but the preferred mechanism to declare variable-length types such as these ones is a flexible array member[1][2], introduced in C99: struct foo { int stuff; struct boo array[]; }; By making use of the mechanism above, we will get a compiler warning in case the flexible array does not occur last in the structure, which will help us prevent some kind of undefined behavior bugs from being inadvertenly introduced[3] to the codebase from now on. This issue was found with the help of Coccinelle. [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html [2] https://github.com/KSPP/linux/issues/21 [3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour") Signed-off-by: Gustavo A. R. Silva --- lib/bch.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/lib/bch.c b/lib/bch.c index 5db6d3a4c8a6..052d3fb753a0 100644 --- a/lib/bch.c +++ b/lib/bch.c @@ -102,7 +102,7 @@ */ struct gf_poly { unsigned int deg; /* polynomial degree */ - unsigned int c[0]; /* polynomial terms */ + unsigned int c[]; /* polynomial terms */ }; /* given its degree, compute a polynomial size in bytes */ -- 2.25.0