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 EA8FA46B2F; Wed, 9 Jul 2025 14:58:30 +0200 (CEST) Received: from mails.dpdk.org (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id 8FED9402DA; Wed, 9 Jul 2025 14:58:30 +0200 (CEST) Received: from dkmailrelay1.smartsharesystems.com (smartserver.smartsharesystems.com [77.243.40.215]) by mails.dpdk.org (Postfix) with ESMTP id 9D99F402A9; Wed, 9 Jul 2025 14:58:29 +0200 (CEST) Received: from smartserver.smartsharesystems.com (smartserver.smartsharesys.local [192.168.4.10]) by dkmailrelay1.smartsharesystems.com (Postfix) with ESMTP id 66D25204A9; Wed, 9 Jul 2025 14:58:29 +0200 (CEST) Content-class: urn:content-classes:message MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Subject: RE: [PATCH] doc: announce changes in structure alignments for UBSan Content-Transfer-Encoding: quoted-printable X-MimeOLE: Produced By Microsoft Exchange V6.5 Date: Wed, 9 Jul 2025 14:58:27 +0200 Message-ID: <98CBD80474FA8B44BF855DF32C47DC35E9FDA9@smartserver.smartshare.dk> In-Reply-To: <20250709124022.4105481-1-david.marchand@redhat.com> X-MS-Has-Attach: X-MS-TNEF-Correlator: Thread-Topic: [PATCH] doc: announce changes in structure alignments for UBSan Thread-Index: AdvwzrBgDJZ/uSIkRk2QRded6vkRvQAAlaig References: <20250709124022.4105481-1-david.marchand@redhat.com> From: =?iso-8859-1?Q?Morten_Br=F8rup?= To: "David Marchand" , Cc: , 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 > From: David Marchand [mailto:david.marchand@redhat.com] > Sent: Wednesday, 9 July 2025 14.40 >=20 > 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 > merged in > 20.08 onwards. This change will not introduce any performance > degradation. >=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 > be updated in 25.11, > + namely (but not exhaustively): ``struct rte_stack_lf_head`` and > ``struct rte_mp_msg``. > + > * lib: will fix extending some enum/define breaking the ABI. There = are > multiple > samples in DPDK that enum/define terminated with a ``.*MAX.*`` = value > which is > used by iterators, and arrays holding these values are sized with > this > -- > 2.50.0 Yes, please. Acked-by: Morten Br=F8rup