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 430E2C35DEC for ; Tue, 25 Feb 2020 00:09:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 113E020732 for ; Tue, 25 Feb 2020 00:09:29 +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="JD/Y/mIS" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728550AbgBYAJ2 (ORCPT ); Mon, 24 Feb 2020 19:09:28 -0500 Received: from gateway33.websitewelcome.com ([192.185.146.195]:38731 "EHLO gateway33.websitewelcome.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728235AbgBYAJ2 (ORCPT ); Mon, 24 Feb 2020 19:09:28 -0500 X-Greylist: delayed 325 seconds by postgrey-1.27 at vger.kernel.org; Mon, 24 Feb 2020 19:09:26 EST Received: from cm11.websitewelcome.com (cm11.websitewelcome.com [100.42.49.5]) by gateway33.websitewelcome.com (Postfix) with ESMTP id ADF6B7175A for ; Mon, 24 Feb 2020 18:09:26 -0600 (CST) Received: from gator4166.hostgator.com ([108.167.133.22]) by cmsmtp with SMTP id 6NmwjJ3AwSl8q6Nmwjy5kU; Mon, 24 Feb 2020 18:09:26 -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=ZwmvXNF0jxPluhfTdIp+OkMhFDGnO6D8vfAw9YlIa3k=; b=JD/Y/mISz9+s6xEcFV8VrUebnA GXp81qYIO0zcoyu28r1UkT83FgP+aju1ycUxK/cvS6CYIVP90cCrNqaK1cFMulvC47GW5P0yscOq/ HU7qUwAULL+2b1mn3E0k6XakzlGx6bfvP6J6w5e4nmLbwrrY17Dq3IDFoR1Y+8AQ9z5VTrYU0p2MS 7YFfFzYQYNKkfmweNOL+uywgNzcLBMr0pBdadbrRYgozPOvTXTklF75Q05Cumo/mCmOfirpAkpSQ2 8Seg1Va6u0aZPU0w5lpNRL3DkoZ3ZrrUNFNViG9JhPXdYVESgL8wDtUg4TxIhcgWEpRxNvl/Yhgg2 IrkC12Zw==; Received: from [201.166.190.60] (port=54458 helo=embeddedor) by gator4166.hostgator.com with esmtpa (Exim 4.92) (envelope-from ) id 1j6Nmu-002OsC-IZ; Mon, 24 Feb 2020 18:09:25 -0600 Date: Mon, 24 Feb 2020 18:12:13 -0600 From: "Gustavo A. R. Silva" To: Mirko Lindner , Stephen Hemminger , "David S. Miller" Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" Subject: [PATCH][next] net: marvell: Replace zero-length array with flexible-array member Message-ID: <20200225001213.GA20527@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: 201.166.190.60 X-Source-L: No X-Exim-ID: 1j6Nmu-002OsC-IZ X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: (embeddedor) [201.166.190.60]:54458 X-Source-Auth: gustavo@embeddedor.com X-Email-Count: 25 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] 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/marvell/skge.h | 2 +- drivers/net/ethernet/marvell/sky2.h | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/net/ethernet/marvell/skge.h b/drivers/net/ethernet/marvell/skge.h index 6fa7b6a34c08..a1313d57e283 100644 --- a/drivers/net/ethernet/marvell/skge.h +++ b/drivers/net/ethernet/marvell/skge.h @@ -2426,7 +2426,7 @@ struct skge_hw { spinlock_t phy_lock; struct tasklet_struct phy_task; - char irq_name[0]; /* skge@pci:000:04:00.0 */ + char irq_name[]; /* skge@pci:000:04:00.0 */ }; enum pause_control { diff --git a/drivers/net/ethernet/marvell/sky2.h b/drivers/net/ethernet/marvell/sky2.h index b02b6523083c..ada1ca60f088 100644 --- a/drivers/net/ethernet/marvell/sky2.h +++ b/drivers/net/ethernet/marvell/sky2.h @@ -2309,7 +2309,7 @@ struct sky2_hw { struct work_struct restart_work; wait_queue_head_t msi_wait; - char irq_name[0]; + char irq_name[]; }; static inline int sky2_is_copper(const struct sky2_hw *hw) -- 2.25.0