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 Received: from lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id E7977C4321E for ; Mon, 14 Feb 2022 17:10:44 +0000 (UTC) Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4Jy9hz0Df6z3cFX for ; Tue, 15 Feb 2022 04:10:43 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=aculab.com (client-ip=185.58.86.151; helo=eu-smtp-delivery-151.mimecast.com; envelope-from=david.laight@aculab.com; receiver=) Received: from eu-smtp-delivery-151.mimecast.com (eu-smtp-delivery-151.mimecast.com [185.58.86.151]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4Jy9hS58DLz2xWc for ; Tue, 15 Feb 2022 04:10:15 +1100 (AEDT) Received: from AcuMS.aculab.com (156.67.243.121 [156.67.243.121]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384) id uk-mta-59-4uBsnFPgM72Ml12czhVz_g-1; Mon, 14 Feb 2022 17:10:09 +0000 X-MC-Unique: 4uBsnFPgM72Ml12czhVz_g-1 Received: from AcuMS.Aculab.com (fd9f:af1c:a25b:0:994c:f5c2:35d6:9b65) by AcuMS.aculab.com (fd9f:af1c:a25b:0:994c:f5c2:35d6:9b65) with Microsoft SMTP Server (TLS) id 15.0.1497.28; Mon, 14 Feb 2022 17:10:06 +0000 Received: from AcuMS.Aculab.com ([fe80::994c:f5c2:35d6:9b65]) by AcuMS.aculab.com ([fe80::994c:f5c2:35d6:9b65%12]) with mapi id 15.00.1497.028; Mon, 14 Feb 2022 17:10:06 +0000 From: David Laight To: 'Christoph Hellwig' , Arnd Bergmann Subject: RE: [PATCH 03/14] nds32: fix access_ok() checks in get/put_user Thread-Topic: [PATCH 03/14] nds32: fix access_ok() checks in get/put_user Thread-Index: AQHYIcSLBVNsuZIR/kWyaxa2mA9Gq6yTRsYw Date: Mon, 14 Feb 2022 17:10:05 +0000 Message-ID: <8a6e309687d647e3aef8a88bdb0922af@AcuMS.aculab.com> References: <20220214163452.1568807-1-arnd@kernel.org> <20220214163452.1568807-4-arnd@kernel.org> In-Reply-To: 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: quoted-printable X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: "mark.rutland@arm.com" , "dalias@libc.org" , "linux-ia64@vger.kernel.org" , "linux-sh@vger.kernel.org" , "peterz@infradead.org" , "linux-mips@vger.kernel.org" , "jcmvbkbc@gmail.com" , "guoren@kernel.org" , "sparclinux@vger.kernel.org" , "linux-riscv@lists.infradead.org" , "will@kernel.org" , "ardb@kernel.org" , "linux-arch@vger.kernel.org" , "linux-s390@vger.kernel.org" , "bcain@codeaurora.org" , "linux-hexagon@vger.kernel.org" , "deller@gmx.de" , "x86@kernel.org" , "linux@armlinux.org.uk" , "linux-csky@vger.kernel.org" , Christoph Hellwig , "mingo@redhat.com" , "geert@linux-m68k.org" , "linux-snps-arc@lists.infradead.org" , "linux-xtensa@linux-xtensa.org" , "arnd@arndb.de" , "hca@linux.ibm.com" , "linux-um@lists.infradead.org" , "linuxppc-dev@lists.ozlabs.org" , "richard@nod.at" , "linux-m68k@lists.linux-m68k.org" , "openrisc@lists.librecores.org" , "green.hu@gmail.com" , "shorne@gmail.com" , "linux-arm-kernel@lists.infradead.org" , "monstr@monstr.eu" , "tsbogend@alpha.franken.de" , "nickhu@andestech.com" , "linux-parisc@vger.kernel.org" , "linux-mm@kvack.org" , "linux-api@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "stable@vger.kernel.org" , "dinguyen@kernel.org" , "ebiederm@xmission.com" , "linux-alpha@vger.kernel.org" , "akpm@linux-foundation.org" , Linus Torvalds , "davem@davemloft.net" Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" From: Christoph Hellwig > Sent: 14 February 2022 17:01 >=20 > On Mon, Feb 14, 2022 at 05:34:41PM +0100, Arnd Bergmann wrote: > > From: Arnd Bergmann > > > > The get_user()/put_user() functions are meant to check for > > access_ok(), while the __get_user()/__put_user() functions > > don't. > > > > This broke in 4.19 for nds32, when it gained an extraneous > > check in __get_user(), but lost the check it needs in > > __put_user(). >=20 > Can we follow the lead of MIPS (which this was originally copied > from I think) and kill the pointless __get/put_user_check wrapper > that just obsfucate the code? Is it possible to make all these architectures fall back to a common definition somewhere? Maybe they need to define ACCESS_OK_USER_LIMIT - which can be different from TASK_SIZE. There'll be a few special cases, but most architectures have kernel addresses above userspace ones. =09David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1= PT, UK Registration No: 1397386 (Wales)