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=-10.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,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 A475AC3F2D1 for ; Fri, 6 Mar 2020 01:49:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 820452073B for ; Fri, 6 Mar 2020 01:49:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726875AbgCFBtV (ORCPT ); Thu, 5 Mar 2020 20:49:21 -0500 Received: from helcar.hmeau.com ([216.24.177.18]:46030 "EHLO fornost.hmeau.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726162AbgCFBtV (ORCPT ); Thu, 5 Mar 2020 20:49:21 -0500 Received: from gwarestrin.me.apana.org.au ([192.168.0.7] helo=gwarestrin.arnor.me.apana.org.au) by fornost.hmeau.com with smtp (Exim 4.89 #2 (Debian)) id 1jA26R-0005j2-Mp; Fri, 06 Mar 2020 12:48:40 +1100 Received: by gwarestrin.arnor.me.apana.org.au (sSMTP sendmail emulation); Fri, 06 Mar 2020 12:48:39 +1100 Date: Fri, 6 Mar 2020 12:48:39 +1100 From: Herbert Xu To: "Gustavo A. R. Silva" Cc: Horia =?utf-8?Q?Geant=C4=83?= , Aymen Sghaier , "David S. Miller" , Atul Gupta , Matthias Brugger , Breno =?iso-8859-1?Q?Leit=E3o?= , Nayna Jain , Paulo Flabiano Smorigo , Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org, linuxppc-dev@lists.ozlabs.org Subject: Re: [PATCH] crypto: Replace zero-length array with flexible-array member Message-ID: <20200306014839.GC30653@gondor.apana.org.au> References: <20200224162100.GA25697@embeddedor> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200224162100.GA25697@embeddedor> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Feb 24, 2020 at 10:21:00AM -0600, Gustavo A. R. Silva wrote: > 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/crypto/caam/caamalg.c | 2 +- > drivers/crypto/caam/caamalg_qi.c | 4 ++-- > drivers/crypto/caam/caamalg_qi2.h | 6 +++--- > drivers/crypto/caam/caamhash.c | 2 +- > drivers/crypto/cavium/nitrox/nitrox_main.c | 2 +- > drivers/crypto/chelsio/chcr_core.h | 2 +- > drivers/crypto/mediatek/mtk-sha.c | 2 +- > drivers/crypto/nx/nx.h | 2 +- > drivers/crypto/omap-sham.c | 4 ++-- > include/crypto/if_alg.h | 2 +- > 10 files changed, 14 insertions(+), 14 deletions(-) Patch applied. Thanks. -- Email: Herbert Xu Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt