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=unavailable 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 E7AF0C35DEA for ; Tue, 25 Feb 2020 00:17:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B2A9F21927 for ; Tue, 25 Feb 2020 00:17:19 +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="pKNLiHCh" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728356AbgBYART (ORCPT ); Mon, 24 Feb 2020 19:17:19 -0500 Received: from gateway30.websitewelcome.com ([192.185.196.18]:47448 "EHLO gateway30.websitewelcome.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728011AbgBYARS (ORCPT ); Mon, 24 Feb 2020 19:17:18 -0500 Received: from cm14.websitewelcome.com (cm14.websitewelcome.com [100.42.49.7]) by gateway30.websitewelcome.com (Postfix) with ESMTP id 91E5A1133F for ; Mon, 24 Feb 2020 18:15:39 -0600 (CST) Received: from gator4166.hostgator.com ([108.167.133.22]) by cmsmtp with SMTP id 6NsxjOiU1XVkQ6NsxjkK2i; Mon, 24 Feb 2020 18:15:39 -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=LktvCqqFjAA8rDcg5ByaBgBcVMdxrLSTLQa6siIf2JM=; b=pKNLiHChSa57IuH8C+BZVIHDFS aqbfjtyx0N/KX80jSPbfkyRg3Kinl606snDgyjpldW8hmNoGBylzcyC9KOsfjUIKxIefbEGCd9ezj Kl5Idd37G/ZU8bkfgspAK2mDX9BnKt8C5dz5dlb2r8Yd4vYzw9OmQpJ3tU7FpbyShJE4cckTcv8ih nZT1ZJ/IB9WvZukUDk3L2F+yBsQo5FTDiSe8YUPrbtxJ8MJItPPBKITxL5CjXKS1WFyYpIkzk9aA6 B5UpSthtpvXbRx7eD6dDTqAOr+7jL7HsMPuy96HZIctLtVeXLxe39J9IpZThqS7L7H40lsrbg/8wp 06nIXcjg==; Received: from [201.166.191.14] (port=54580 helo=embeddedor) by gator4166.hostgator.com with esmtpa (Exim 4.92) (envelope-from ) id 1j6Nsv-002Rza-GF; Mon, 24 Feb 2020 18:15:38 -0600 Date: Mon, 24 Feb 2020 18:18:26 -0600 From: "Gustavo A. R. Silva" To: Christian Benvenuti , Govindarajulu Varadarajan <_govind@gmx.com>, Parvi Kaustubhi , "David S. Miller" Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" Subject: [PATCH][next] net: cisco: Replace zero-length array with flexible-array member Message-ID: <20200225001826.GA22765@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: 201.166.191.14 X-Source-L: No X-Exim-ID: 1j6Nsv-002Rza-GF X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: (embeddedor) [201.166.191.14]:54580 X-Source-Auth: gustavo@embeddedor.com X-Email-Count: 31 X-Source-Cap: Z3V6aWRpbmU7Z3V6aWRpbmU7Z2F0b3I0MTY2Lmhvc3RnYXRvci5jb20= X-Local-Domain: yes Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@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 inadvertently introduced[3] to the codebase from now on. Also, notice that, dynamic memory allocations won't be affected by this change: "Flexible array members have incomplete type, and so the sizeof operator may not be applied. As a quirk of the original implementation of zero-length arrays, sizeof evaluates to zero."[1] Lastly, fix the following checkpatch warning: CHECK: Prefer kernel type 'u32' over 'u_int32_t' #61: FILE: drivers/net/ethernet/cisco/enic/vnic_devcmd.h:653: + u_int32_t val[]; 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 --- drivers/net/ethernet/cisco/enic/vnic_devcmd.h | 8 ++++---- drivers/net/ethernet/cisco/enic/vnic_vic.h | 2 +- 2 files changed, 5 insertions(+), 5 deletions(-) diff --git a/drivers/net/ethernet/cisco/enic/vnic_devcmd.h b/drivers/net/ethernet/cisco/enic/vnic_devcmd.h index fef5a0a0663d..fcc4a3ccdd94 100644 --- a/drivers/net/ethernet/cisco/enic/vnic_devcmd.h +++ b/drivers/net/ethernet/cisco/enic/vnic_devcmd.h @@ -541,7 +541,7 @@ struct vnic_devcmd_notify { struct vnic_devcmd_provinfo { u8 oui[3]; u8 type; - u8 data[0]; + u8 data[]; }; /* These are used in flags field of different filters to denote @@ -648,9 +648,9 @@ enum { #define FILTER_MAX_BUF_SIZE 100 struct filter_tlv { - u_int32_t type; - u_int32_t length; - u_int32_t val[0]; + u32 type; + u32 length; + u32 val[]; }; enum { diff --git a/drivers/net/ethernet/cisco/enic/vnic_vic.h b/drivers/net/ethernet/cisco/enic/vnic_vic.h index 9ef81f148351..057776908828 100644 --- a/drivers/net/ethernet/cisco/enic/vnic_vic.h +++ b/drivers/net/ethernet/cisco/enic/vnic_vic.h @@ -59,7 +59,7 @@ struct vic_provinfo { u16 type; u16 length; u8 value[0]; - } tlv[0]; + } tlv[]; } __packed; #define VIC_PROVINFO_ADD_TLV(vp, tlvtype, tlvlen, data) \ -- 2.25.0