From patchwork Tue Feb 11 23:25:19 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Gustavo A. R. Silva" X-Patchwork-Id: 11377145 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 7B904921 for ; Tue, 11 Feb 2020 23:22:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5A2F920842 for ; Tue, 11 Feb 2020 23:22:47 +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="iqggwRpX" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727791AbgBKXWq (ORCPT ); Tue, 11 Feb 2020 18:22:46 -0500 Received: from gateway21.websitewelcome.com ([192.185.45.175]:25574 "EHLO gateway21.websitewelcome.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727698AbgBKXWq (ORCPT ); Tue, 11 Feb 2020 18:22:46 -0500 Received: from cm12.websitewelcome.com (cm12.websitewelcome.com [100.42.49.8]) by gateway21.websitewelcome.com (Postfix) with ESMTP id DBCD8400CCC9E for ; Tue, 11 Feb 2020 17:22:45 -0600 (CST) Received: from gator4166.hostgator.com ([108.167.133.22]) by cmsmtp with SMTP id 1erdjKQamvBMd1erdje1Fb; Tue, 11 Feb 2020 17:22:45 -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=d45YxL3ZVwmUXRXXaNk1DepB3rRpGpao2lxAWUtx6bM=; b=iqggwRpX32grupnHhcMZ8HGQP6 +vewtQpKtwwjgKiIYlS8OkZgst6U7rTXLHzQpFHADvx0KzIYhXTpTDCwkQYWad6YzUVVBcafCftkF iOJmwV9P/q/LuaYLY+x2Tcxnh1RwvuwaNGFDM4tBRs1oIIdw02z2bvDRfuI3RGO9zn5mbJGcl603K WHQbBwLclwpPQmrwSksRJg08d/+qFP2/WiuGbio5wQyOlqCzVPrIsIb6HbFiGok8KX/kICrdx8qwp McG5drN6KRJXlHhw3PoBJzDhkeey1sYigSbXD1z9xsspkwCRhgE6fzpcMnQvn+eTUTZtTvZua3qX/ h43smIaQ==; Received: from [200.68.140.36] (port=25379 helo=embeddedor) by gator4166.hostgator.com with esmtpa (Exim 4.92) (envelope-from ) id 1j1erc-003arP-Hs; Tue, 11 Feb 2020 17:22:44 -0600 Date: Tue, 11 Feb 2020 17:25:19 -0600 From: "Gustavo A. R. Silva" To: Bin Liu , Greg Kroah-Hartman Cc: linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" Subject: [PATCH] USB: musb: Replace zero-length array with flexible-array member Message-ID: <20200211232519.GA23263@embeddedor> MIME-Version: 1.0 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: 1j1erc-003arP-Hs X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: (embeddedor) [200.68.140.36]:25379 X-Source-Auth: gustavo@embeddedor.com X-Email-Count: 47 X-Source-Cap: Z3V6aWRpbmU7Z3V6aWRpbmU7Z2F0b3I0MTY2Lmhvc3RnYXRvci5jb20= X-Local-Domain: yes Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@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 --- drivers/usb/musb/musb_host.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/usb/musb/musb_host.c b/drivers/usb/musb/musb_host.c index eb308ec35c66..3dab821c1b30 100644 --- a/drivers/usb/musb/musb_host.c +++ b/drivers/usb/musb/musb_host.c @@ -2576,7 +2576,7 @@ static int musb_bus_resume(struct usb_hcd *hcd) struct musb_temp_buffer { void *kmalloc_ptr; void *old_xfer_buffer; - u8 data[0]; + u8 data[]; }; static void musb_free_temp_buffer(struct urb *urb)