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,URIBL_BLOCKED, 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 7DC15C35242 for ; Tue, 11 Feb 2020 20:51:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 59DB920659 for ; Tue, 11 Feb 2020 20:51:25 +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="XOgfaAVB" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728921AbgBKUvY (ORCPT ); Tue, 11 Feb 2020 15:51:24 -0500 Received: from gateway33.websitewelcome.com ([192.185.145.23]:45830 "EHLO gateway33.websitewelcome.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727786AbgBKUvX (ORCPT ); Tue, 11 Feb 2020 15:51:23 -0500 Received: from cm14.websitewelcome.com (cm14.websitewelcome.com [100.42.49.7]) by gateway33.websitewelcome.com (Postfix) with ESMTP id C48C299ABDC for ; Tue, 11 Feb 2020 14:51:22 -0600 (CST) Received: from gator4166.hostgator.com ([108.167.133.22]) by cmsmtp with SMTP id 1cV8jIabPXVkQ1cV8jgvDE; Tue, 11 Feb 2020 14:51:22 -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=jrhREslNRp9I3XLIf7+FCkpvJMag3xowhs8nHJz6VDo=; b=XOgfaAVB1vZH+Fel1K2p6eC+T/ 4ML05d0RHpy5WRNdnf33iJCmIezqNFBLDgFr53bZA3eGy2YmlgOXwV//wWRrJVOAUDCsN3+EjBspZ dkBPDBAMkjm/xPAIetWrT1XTSq+Poe9SXYha8HageD/LVW90v0wOzIUfwgPH7+lZgmqI/ZVd2v/Dv 8WmGevfjhOHxYGJ0GL1hKgjjMLzrzDTOmkfhpWn1ENk0/ahaTLdYVvjl7M8Y1JZYfBLRRNkBoAKCf 12VkkIpuiM92RJEXmLQOD+ie3hQorSTmozqGNRry+o58wWzpOnrDihrTu6vE5Vec8FCsPazaFpk9F HJTWEwOw==; Received: from [200.68.140.36] (port=15013 helo=embeddedor) by gator4166.hostgator.com with esmtpa (Exim 4.92) (envelope-from ) id 1j1cV7-001wuz-5G; Tue, 11 Feb 2020 14:51:21 -0600 Date: Tue, 11 Feb 2020 14:53:56 -0600 From: "Gustavo A. R. Silva" To: Jiri Pirko , Andrew Morton Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" Subject: [PATCH] lib: objagg: Replace zero-length arrays with flexible-array member Message-ID: <20200211205356.GA23101@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: 1j1cV7-001wuz-5G X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: (embeddedor) [200.68.140.36]:15013 X-Source-Auth: gustavo@embeddedor.com X-Email-Count: 43 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/objagg.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/lib/objagg.c b/lib/objagg.c index 576be22e86de..668a2c0a88ac 100644 --- a/lib/objagg.c +++ b/lib/objagg.c @@ -28,7 +28,7 @@ struct objagg_hints_node { struct objagg_hints_node *parent; unsigned int root_id; struct objagg_obj_stats_info stats_info; - unsigned long obj[0]; + unsigned long obj[]; }; static struct objagg_hints_node * @@ -66,7 +66,7 @@ struct objagg_obj { * including nested objects */ struct objagg_obj_stats stats; - unsigned long obj[0]; + unsigned long obj[]; }; static unsigned int objagg_obj_ref_inc(struct objagg_obj *objagg_obj) -- 2.25.0