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=-11.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS 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 ABFCDC3F68F for ; Wed, 12 Feb 2020 22:19:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8CDF92082F for ; Wed, 12 Feb 2020 22:19:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729176AbgBLWTx convert rfc822-to-8bit (ORCPT ); Wed, 12 Feb 2020 17:19:53 -0500 Received: from mga14.intel.com ([192.55.52.115]:28120 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728603AbgBLWTw (ORCPT ); Wed, 12 Feb 2020 17:19:52 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga006.jf.intel.com ([10.7.209.51]) by fmsmga103.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 12 Feb 2020 14:19:52 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.70,434,1574150400"; d="scan'208";a="237849203" Received: from fmsmsx106.amr.corp.intel.com ([10.18.124.204]) by orsmga006.jf.intel.com with ESMTP; 12 Feb 2020 14:19:51 -0800 Received: from lcsmsx602.ger.corp.intel.com (10.109.210.11) by FMSMSX106.amr.corp.intel.com (10.18.124.204) with Microsoft SMTP Server (TLS) id 14.3.439.0; Wed, 12 Feb 2020 14:19:51 -0800 Received: from hasmsx602.ger.corp.intel.com (10.184.107.142) by LCSMSX602.ger.corp.intel.com (10.109.210.11) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1713.5; Thu, 13 Feb 2020 00:19:49 +0200 Received: from hasmsx602.ger.corp.intel.com ([10.184.107.142]) by HASMSX602.ger.corp.intel.com ([10.184.107.142]) with mapi id 15.01.1713.004; Thu, 13 Feb 2020 00:19:48 +0200 From: "Winkler, Tomas" To: "Gustavo A. R. Silva" , Arnd Bergmann , Greg Kroah-Hartman CC: "linux-kernel@vger.kernel.org" , "Usyskin, Alexander" , "Lubart, Vitaly" Subject: RE: [PATCH] mei: bus: replace zero-length array with flexible-array member Thread-Topic: [PATCH] mei: bus: replace zero-length array with flexible-array member Thread-Index: AQHV4R8PZ6+DToj5cUCD4Y1TT5B8IKgYIqMQ Date: Wed, 12 Feb 2020 22:19:48 +0000 Message-ID: <71cd2c9eba7f4ac68de55148edb08e19@intel.com> References: <20200211210822.GA31368@embeddedor> In-Reply-To: <20200211210822.GA31368@embeddedor> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: dlp-product: dlpe-windows dlp-reaction: no-action dlp-version: 11.2.0.6 x-originating-ip: [10.184.70.1] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > -----Original Message----- > From: Gustavo A. R. Silva > Sent: Tuesday, February 11, 2020 23:08 > To: Winkler, Tomas ; Arnd Bergmann > ; Greg Kroah-Hartman > Cc: linux-kernel@vger.kernel.org; Gustavo A. R. Silva > > Subject: [PATCH] mei: bus: replace zero-length array with flexible-array member > > 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 Ack. > --- > drivers/misc/mei/bus-fixup.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/misc/mei/bus-fixup.c b/drivers/misc/mei/bus-fixup.c index > 5fcac02233af..aa3648d59a8a 100644 > --- a/drivers/misc/mei/bus-fixup.c > +++ b/drivers/misc/mei/bus-fixup.c > @@ -107,7 +107,7 @@ struct mkhi_rule_id { struct mkhi_fwcaps { > struct mkhi_rule_id id; > u8 len; > - u8 data[0]; > + u8 data[]; > } __packed; > > struct mkhi_fw_ver_block { > @@ -135,7 +135,7 @@ struct mkhi_msg_hdr { > > struct mkhi_msg { > struct mkhi_msg_hdr hdr; > - u8 data[0]; > + u8 data[]; > } __packed; > > #define MKHI_OSVER_BUF_LEN (sizeof(struct mkhi_msg_hdr) + \ > -- > 2.25.0