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=-3.8 required=3.0 tests=BAYES_00, 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 5DB9BC2D0E4 for ; Tue, 24 Nov 2020 16:20:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 19734206C0 for ; Tue, 24 Nov 2020 16:20:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390332AbgKXQTx convert rfc822-to-8bit (ORCPT ); Tue, 24 Nov 2020 11:19:53 -0500 Received: from eu-smtp-delivery-151.mimecast.com ([207.82.80.151]:39951 "EHLO eu-smtp-delivery-151.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390289AbgKXQTw (ORCPT ); Tue, 24 Nov 2020 11:19:52 -0500 Received: from AcuMS.aculab.com (156.67.243.126 [156.67.243.126]) (Using TLS) by relay.mimecast.com with ESMTP id uk-mta-240--1M7RfZEPdaZjSdutV-hqw-1; Tue, 24 Nov 2020 16:19:48 +0000 X-MC-Unique: -1M7RfZEPdaZjSdutV-hqw-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; Tue, 24 Nov 2020 16:19:47 +0000 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; Tue, 24 Nov 2020 16:19:47 +0000 From: David Laight To: 'Arnd Bergmann' , "netdev@vger.kernel.org" CC: Arnd Bergmann , Christoph Hellwig Subject: RE: [PATCH v4 1/4] ethtool: improve compat ioctl handling Thread-Topic: [PATCH v4 1/4] ethtool: improve compat ioctl handling Thread-Index: AQHWwnVihBpZpY3N3UWbfisKlTppO6nXdVHA Date: Tue, 24 Nov 2020 16:19:47 +0000 Message-ID: <4d1a587e7a9e4b65ac3a0c20554abdd3@AcuMS.aculab.com> References: <20201124151828.169152-1-arnd@kernel.org> <20201124151828.169152-2-arnd@kernel.org> In-Reply-To: <20201124151828.169152-2-arnd@kernel.org> Accept-Language: en-GB, 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 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=C51A453 smtp.mailfrom=david.laight@aculab.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: aculab.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Arnd Bergmann > Sent: 24 November 2020 15:18 > > The ethtool compat ioctl handling is hidden away in net/socket.c, > which introduces a couple of minor oddities: > ... > + > +static int ethtool_rxnfc_copy_from_compat(struct ethtool_rxnfc *rxnfc, > + const struct compat_ethtool_rxnfc __user *useraddr, > + size_t size) > +{ I think this (and possibly others) want a 'noinline_for_stack'. So that both the normal and compat structures aren't both on the stack when the real code is called. David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)