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=-6.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no 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 62A03C48BE5 for ; Wed, 16 Jun 2021 12:44:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 42EDB60FDB for ; Wed, 16 Jun 2021 12:44:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232704AbhFPMqK (ORCPT ); Wed, 16 Jun 2021 08:46:10 -0400 Received: from mail.kernel.org ([198.145.29.99]:52862 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232628AbhFPMqJ (ORCPT ); Wed, 16 Jun 2021 08:46:09 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id B59AF61166; Wed, 16 Jun 2021 12:44:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1623847443; bh=3w2R8A0z9dkpFySB0GblcZy473wM3o3AaZfzRY6cB+A=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=r6IPT15PPQFmwUJYlA2CUFF/MfXwtOLf2RRdJHfYbnk0vztxaLk49sjCkpc5ZKoNP SPW7/TFr57wVvHDYSaGB/k6dratBtb6QSzRKc7xA9ag6Bk7hK+knb/KV3wSMTNfqGA r/wRibtiraLjCJhyRls5tt/KEBgES0UT4Oc1647cFF6R9ZYm/HsAvaMz1Fv+DIYh3I ppG8Lc2M0+OSftbkrmF9Eq9bPYQepSmLXHhGEHAo2dNB/sbtjxnuarH1HRq32X//zP RM6XJ0MMJb8VTPQ0cCulcvEuQdru3eOpWjNF6MQWncztv9Oh4UaG7mdpGkCK/ZQB+O WhA9O0lOC6oJA== Date: Wed, 16 Jun 2021 15:43:59 +0300 From: Leon Romanovsky To: Haakon Bugge Cc: Anand Khoje , OFED mailing list , "linux-kernel@vger.kernel.org" , "dledford@redhat.com" , "jgg@ziepe.ca" Subject: Re: [PATCH v3 3/3] IB/core: Obtain subnet_prefix from cache in IB devices. Message-ID: References: <20210609055534.855-4-anand.a.khoje@oracle.com> <30CD8612-2030-44C1-A879-9A1EC668FC9C@oracle.com> <427FB96F-2550-4106-B8AD-EC589C1FD82B@oracle.com> <76766414-4D50-4E60-B3FC-1989026562D9@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <76766414-4D50-4E60-B3FC-1989026562D9@oracle.com> Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org On Wed, Jun 16, 2021 at 11:20:01AM +0000, Haakon Bugge wrote: > > > > On 15 Jun 2021, at 18:13, Haakon Bugge wrote: > > > > > > > >> On 15 Jun 2021, at 07:08, Leon Romanovsky wrote: > >> > >> On Mon, Jun 14, 2021 at 04:29:09PM +0000, Haakon Bugge wrote: > >>> > >>> > >>>> On 14 Jun 2021, at 09:25, Leon Romanovsky wrote: > >>>> > >>>> On Mon, Jun 14, 2021 at 03:32:39AM +0000, Haakon Bugge wrote: > >>>>> > >>>>> > >>>>>> On 9 Jun 2021, at 12:40, Leon Romanovsky wrote: > >>>>>> > >>>>>> On Wed, Jun 09, 2021 at 09:26:03AM +0000, Anand Khoje wrote: > >>>>>>> Hi Leon, > >>>>>> > >>>>>> Please don't do top-posting. > >>>>>> > >>>>>> > >>>>>>> > >>>>>>> The set_bit()/clear_bit() and enum ib_port_data_flags has been added as a device that can be used for future enhancements. > >>>>>>> Also, usage of set_bit()/clear_bit() ensures the operations on this bit is atomic. > >>>>>> > >>>>>> The bitfield variables are better suit this use case. > >>>>>> Let's don't overcomplicate code without the reason. > >>>>> > >>>>> The problem is always that people tend to build on what's in there. For example, look at the bitfields in rdma_id_private, tos_set, timeout_set, and min_rnr_timer_set. > >>>>> > >>>>> What do you think will happen when, let's say, rdma_set_service_type() and rdma_set_ack_timeout() are called in close proximity in time? There is no locking, and the RMW will fail intermittently. > >>>> > >>>> We are talking about device initialization flow that shouldn't be > >>>> performed in parallel to another initialization of same device, so the > >>>> comparison to rdma-cm is not valid here. > >>> > >>> I can agree to that. And it is probably not worthwhile to fix the bit-fields in rdma_id_private? > >> > >> Before this article [1], I would say no, we don't need to fix. > >> Now, I'm not sure about that. > >> > >> "He also notes that even though the design flaws are difficult to exploit > >> on their own, they can be combined with the other flaws found to make for > >> a much more serious problem." > >> > >> and > >> > >> "In other words, people did notice this vulnerability and a defense was standardized, > >> but in practice the defense was never adopted. This is a good example that security > >> defenses must be adopted before attacks become practical." > > > > Let me send you a commit tomorrow. The last sentence you quoted above is ambiguous as far as I can understand. But the intention is clear though :-) > > Do you prefer for-next or for-rc for this? for-next, please. Thanks > > Thxs, Håkon >