From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mails.dpdk.org (mails.dpdk.org [217.70.189.124]) by inbox.dpdk.org (Postfix) with ESMTP id EAAEB46B37; Thu, 10 Jul 2025 10:24:16 +0200 (CEST) Received: from mails.dpdk.org (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id 8E6FB402D8; Thu, 10 Jul 2025 10:24:16 +0200 (CEST) Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) by mails.dpdk.org (Postfix) with ESMTP id 2C275402D1; Thu, 10 Jul 2025 10:24:14 +0200 (CEST) Received: from mail.maildlp.com (unknown [172.18.186.31]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4bd78W2F3bz6L5KG; Thu, 10 Jul 2025 16:20:59 +0800 (CST) Received: from frapeml500006.china.huawei.com (unknown [7.182.85.219]) by mail.maildlp.com (Postfix) with ESMTPS id 0CEA51402F3; Thu, 10 Jul 2025 16:24:14 +0800 (CST) Received: from frapeml500007.china.huawei.com (7.182.85.172) by frapeml500006.china.huawei.com (7.182.85.219) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.1.2507.39; Thu, 10 Jul 2025 10:24:13 +0200 Received: from frapeml500007.china.huawei.com ([7.182.85.172]) by frapeml500007.china.huawei.com ([7.182.85.172]) with mapi id 15.01.2507.039; Thu, 10 Jul 2025 10:24:13 +0200 From: Konstantin Ananyev To: David Marchand , "dev@dpdk.org" CC: "thomas@monjalon.net" , "techboard@dpdk.org" Subject: RE: [PATCH] doc: announce changes in structure alignments for UBSan Thread-Topic: [PATCH] doc: announce changes in structure alignments for UBSan Thread-Index: AQHb8M65Ug/Rgx1shEGQMc2UFWQn7rQrBjpw Date: Thu, 10 Jul 2025 08:24:13 +0000 Message-ID: <70844e94235d40f09a375e10b2d50a35@huawei.com> References: <20250709124022.4105481-1-david.marchand@redhat.com> In-Reply-To: <20250709124022.4105481-1-david.marchand@redhat.com> Accept-Language: en-GB, en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.206.138.73] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org > As part of the effort to limit undefined behaviors in DPDK code, some > structure alignments revealed not to be accurate enough. > At the moment two structures have been identified but others may be > found while running more parts of DPDK with UBSan. >=20 > Though the calling code can explicitly request alignment, > we would prefer to put the alignment constraints as part of the > structure definition itself. >=20 > Such changes are ABI breakages. >=20 > Signed-off-by: David Marchand > --- > doc/guides/rel_notes/deprecation.rst | 4 ++++ > 1 file changed, 4 insertions(+) >=20 > diff --git a/doc/guides/rel_notes/deprecation.rst b/doc/guides/rel_notes/= deprecation.rst > index e2d4125308..4ae561d670 100644 > --- a/doc/guides/rel_notes/deprecation.rst > +++ b/doc/guides/rel_notes/deprecation.rst > @@ -57,6 +57,10 @@ Deprecation Notices > ``__atomic_thread_fence`` must be used for patches that need to be mer= ged in > 20.08 onwards. This change will not introduce any performance degradat= ion. >=20 > +* lib: multiple issues relating to unaligned accesses have been detected= using the UBSan checker. > + As part of resolving those issues, alignment in some structures will b= e updated in 25.11, > + namely (but not exhaustively): ``struct rte_stack_lf_head`` and ``stru= ct rte_mp_msg``. > + > * lib: will fix extending some enum/define breaking the ABI. There are m= ultiple > samples in DPDK that enum/define terminated with a ``.*MAX.*`` value w= hich is > used by iterators, and arrays holding these values are sized with this > -- > 2.50.0 Acked-by: Konstantin Ananyev