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=-13.0 required=3.0 tests=BAYES_00,HK_RANDOM_FROM, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, URIBL_BLOCKED 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 98956C433E0 for ; Thu, 14 Jan 2021 14:44:19 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 0AFE023A5E for ; Thu, 14 Jan 2021 14:44:19 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0AFE023A5E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=bu.edu Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:40216 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1l03rG-0007HZ-8G for qemu-devel@archiver.kernel.org; Thu, 14 Jan 2021 09:44:18 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:40604) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1l03qX-0006q4-Ab for qemu-devel@nongnu.org; Thu, 14 Jan 2021 09:43:33 -0500 Received: from relay64.bu.edu ([128.197.228.104]:52991) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1l03qV-0000d4-FV for qemu-devel@nongnu.org; Thu, 14 Jan 2021 09:43:32 -0500 X-Envelope-From: alxndr@bu.edu X-BU-AUTH: mozz.bu.edu [128.197.127.33] Received: from BU-AUTH (localhost.localdomain [127.0.0.1]) (authenticated bits=0) by relay64.bu.edu (8.14.3/8.14.3) with ESMTP id 10EEgHmk016831 (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256 verify=NO); Thu, 14 Jan 2021 09:42:20 -0500 Date: Thu, 14 Jan 2021 09:42:17 -0500 From: Alexander Bulekov To: Miroslav Rezanina Subject: Re: [PATCH v3 1/2] Fix net.c warning on GCC 11 Message-ID: <20210114144217.7kjo6h7luxcbxxml@mozz.bu.edu> References: <4fd8d2a3-e665-4422-79e0-4e2a7337e4fc@redhat.com> <20210114141920.qjsnlt3cmkauggtw@mozz.bu.edu> <20210114143803.vow3l6r5nlugz6sc@lws.brq.redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20210114143803.vow3l6r5nlugz6sc@lws.brq.redhat.com> Received-SPF: pass client-ip=128.197.228.104; envelope-from=alxndr@bu.edu; helo=relay64.bu.edu X-Spam_score_int: -15 X-Spam_score: -1.6 X-Spam_bar: - X-Spam_report: (-1.6 / 5.0 requ) BAYES_00=-1.9, HK_RANDOM_ENVFROM=0.001, HK_RANDOM_FROM=0.998, RCVD_IN_DNSWL_LOW=-0.7, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=no autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Jason Wang , Dmitry Fleytman , Philippe =?utf-8?Q?Mathieu-Daud=C3=A9?= , qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 210114 1538, Miroslav Rezanina wrote: > On Thu, Jan 14, 2021 at 09:19:20AM -0500, Alexander Bulekov wrote: > > On 210114 1415, Philippe Mathieu-Daudé wrote: > > > +Jason +Dmitry > > > > > > On 1/14/21 8:07 AM, Miroslav Rezanina wrote: > > > > When building qemu with GCC 11, compiling eth.c file produce following warning: > > > > > > > > warning: array subscript 'struct ip6_ext_hdr_routing[0]' is partly outside array bounds of 'struct ip6_ext_hdr[1]' [-Warray-bounds] > > > > > > > > This is caused by retyping from ip6_ext_hdr to ip6_ext_hdr_routing that has more > > > > attributes. > > > > > > > > As this usage is expected, suppress the warning temporarily through the function > > > > using this retyping. > > > > > > This is not expected, this is a bug... > > > > > > > Seems related: https://bugs.launchpad.net/qemu/+bug/1879531 > > -Alex > > > > Yes, it is caused by the issue triggering the warning. Do you know > whether the patch mentioned in bug was already sent? > > Mirek I don't think so.. -Alex > > > > > > > > Signed-off-by: Miroslav Rezanina > > > > --- > > > > net/eth.c | 3 +++ > > > > 1 file changed, 3 insertions(+) > > > > > > > > diff --git a/net/eth.c b/net/eth.c > > > > index 1e0821c5f8..b9bdd0435c 100644 > > > > --- a/net/eth.c > > > > +++ b/net/eth.c > > > > @@ -405,6 +405,8 @@ _eth_get_rss_ex_dst_addr(const struct iovec *pkt, int pkt_frags, > > > > struct ip6_ext_hdr *ext_hdr, > > > > struct in6_address *dst_addr) > > > > { > > > > +#pragma GCC diagnostic push > > > > +#pragma GCC diagnostic ignored "-Warray-bounds" > > > > struct ip6_ext_hdr_routing *rthdr = (struct ip6_ext_hdr_routing *) ext_hdr; > > > > > > eth_parse_ipv6_hdr() called iov_to_buf() to fill the 2 bytes of ext_hdr. > > > > > > > if ((rthdr->rtype == 2) && > > > > > > Here we access after the 2 bytes filled... rthdr->rtype is somewhere on > > > eth_parse_ipv6_hdr's stack, its content is unknown. > > > > > > > @@ -426,6 +428,7 @@ _eth_get_rss_ex_dst_addr(const struct iovec *pkt, int pkt_frags, > > > > } > > > > > > > > return false; > > > > +#pragma GCC diagnostic pop > > > > > > Nacked-by: Philippe Mathieu-Daudé > > > > > > > > >