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 F0DF9C433E0 for ; Sat, 16 May 2020 15:05:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D07EE20709 for ; Sat, 16 May 2020 15:05:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726912AbgEPPFB convert rfc822-to-8bit (ORCPT ); Sat, 16 May 2020 11:05:01 -0400 Received: from eu-smtp-delivery-151.mimecast.com ([207.82.80.151]:38784 "EHLO eu-smtp-delivery-151.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726294AbgEPPFA (ORCPT ); Sat, 16 May 2020 11:05:00 -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-16-wTkXdC20MN--lnUe8tS_XQ-1; Sat, 16 May 2020 16:04:56 +0100 X-MC-Unique: wTkXdC20MN--lnUe8tS_XQ-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; Sat, 16 May 2020 16:04:55 +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; Sat, 16 May 2020 16:04:55 +0100 From: David Laight To: 'Christoph Hellwig' , "David S. Miller" , Jakub Kicinski , Alexey Kuznetsov , Hideaki YOSHIFUJI CC: "netdev@vger.kernel.org" , open list Subject: RE: move the SIOCDELRT and SIOCADDRT compat_ioctl handlers v2 Thread-Topic: move the SIOCDELRT and SIOCADDRT compat_ioctl handlers v2 Thread-Index: AQHWKruRvQLEg1gZy0+5cm/GoTu+NqiqzzwA Date: Sat, 16 May 2020 15:04:55 +0000 Message-ID: References: <20200515131925.3855053-1-hch@lst.de> In-Reply-To: <20200515131925.3855053-1-hch@lst.de> 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-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Christoph Hellwig > Sent: 15 May 2020 14:19 > > this series moves the compat_ioctl handlers into the protocol handlers, > avoiding the need to override the address space limited as in the current > handler. Is it worth moving the user copies for the main ioctl buffer into the sys_ioctl() entry code? (As is done by the BSD kernels.) This would allow the compat code to adjust the buffers and pass them on. Most ioctls don't have indirect data buffers so wouldn't need to do any further user copies. This would be, of course, require far more changes (and require more external modules be fixed) than the similar change I suggested for [sg]et_sockopt(). David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)