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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, 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 AE777C433DF for ; Fri, 15 May 2020 08:14:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 90C6E20657 for ; Fri, 15 May 2020 08:14:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726732AbgEOION convert rfc822-to-8bit (ORCPT ); Fri, 15 May 2020 04:14:13 -0400 Received: from eu-smtp-delivery-151.mimecast.com ([146.101.78.151]:45236 "EHLO eu-smtp-delivery-151.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727896AbgEOION (ORCPT ); Fri, 15 May 2020 04:14:13 -0400 Received: from AcuMS.aculab.com (156.67.243.126 [156.67.243.126]) (Using TLS) by relay.mimecast.com with ESMTP id uk-mta-135-kgvmV9-GP7CT7oWXwAS8yw-1; Fri, 15 May 2020 09:14:08 +0100 X-MC-Unique: kgvmV9-GP7CT7oWXwAS8yw-1 Received: from AcuMS.Aculab.com (fd9f:af1c:a25b:0:43c:695e:880f:8750) by AcuMS.aculab.com (fd9f:af1c:a25b:0:43c:695e:880f:8750) with Microsoft SMTP Server (TLS) id 15.0.1347.2; Fri, 15 May 2020 09:14:07 +0100 Received: from AcuMS.Aculab.com ([fe80::43c:695e:880f:8750]) by AcuMS.aculab.com ([fe80::43c:695e:880f:8750%12]) with mapi id 15.00.1347.000; Fri, 15 May 2020 09:14:07 +0100 From: David Laight To: 'David Miller' CC: "hch@lst.de" , "joe@perches.com" , "kuba@kernel.org" , "edumazet@google.com" , "kuznet@ms2.inr.ac.ru" , "yoshfuji@linux-ipv6.org" , "vyasevich@gmail.com" , "nhorman@tuxdriver.com" , "marcelo.leitner@gmail.com" , "jmaloy@redhat.com" , "ying.xue@windriver.com" , "drbd-dev@lists.linbit.com" , "linux-block@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-rdma@vger.kernel.org" , "linux-nvme@lists.infradead.org" , "target-devel@vger.kernel.org" , "linux-afs@lists.infradead.org" , "linux-cifs@vger.kernel.org" , "cluster-devel@redhat.com" , "ocfs2-devel@oss.oracle.com" , "netdev@vger.kernel.org" , "linux-sctp@vger.kernel.org" , "ceph-devel@vger.kernel.org" , "rds-devel@oss.oracle.com" , "linux-nfs@vger.kernel.org" Subject: RE: remove kernel_setsockopt and kernel_getsockopt Thread-Topic: remove kernel_setsockopt and kernel_getsockopt Thread-Index: AQHWKU15LJmP4mOGDE2/GHhLszFt9KinP7aQgAAO/ACAABIowIAAkWGAgADbQOA= Date: Fri, 15 May 2020 08:14:07 +0000 Message-ID: <29428bc7a5344412be9f632bced8888d@AcuMS.aculab.com> References: <756758e8f0e34e2e97db470609f5fbba@AcuMS.aculab.com> <20200514101838.GA12548@lst.de> <20200514.130357.1683454520750761365.davem@davemloft.net> In-Reply-To: <20200514.130357.1683454520750761365.davem@davemloft.net> Accept-Language: en-GB, en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ms-exchange-transport-fromentityheader: Hosted x-originating-ip: [10.202.205.107] MIME-Version: 1.0 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: aculab.com Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org Looking at __sys_setsockopt() I noticed that the BPF intercept can also cause set_fs(KERNEL_DS) be set in order to pass a modified buffer into the actual setsockopt() code. If that functionality is to be kept then the underlying protocol specific code needs changing to accept a kernel buffer. The 32bit compat code would also be a lot simpler if it could pass an kernel buffer through. At the moment it copies the modified buffer back out onto the user stack. I'm sure there have been suggestions to remove that complete hack. Fixing the compat code would leave a kernel_[sg]et_sockopt() that still worked. David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)