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=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 99D8AC433DB for ; Fri, 8 Jan 2021 11:49:34 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id F13EE238EA for ; Fri, 8 Jan 2021 11:49:33 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F13EE238EA Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=ACULAB.COM Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 242428D017B; Fri, 8 Jan 2021 06:49:33 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 226C78D0156; Fri, 8 Jan 2021 06:49:33 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 043628D017C; Fri, 8 Jan 2021 06:49:33 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0029.hostedemail.com [216.40.44.29]) by kanga.kvack.org (Postfix) with ESMTP id DEC8F8D017B for ; Fri, 8 Jan 2021 06:49:32 -0500 (EST) Received: from smtpin23.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id A361D2496 for ; Fri, 8 Jan 2021 11:49:32 +0000 (UTC) X-FDA: 77682437784.23.arm42_2103bca274f2 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin23.hostedemail.com (Postfix) with ESMTP id 8761837608 for ; Fri, 8 Jan 2021 11:49:32 +0000 (UTC) X-HE-Tag: arm42_2103bca274f2 X-Filterd-Recvd-Size: 5197 Received: from eu-smtp-delivery-151.mimecast.com (eu-smtp-delivery-151.mimecast.com [185.58.86.151]) by imf04.hostedemail.com (Postfix) with ESMTP for ; Fri, 8 Jan 2021 11:49:31 +0000 (UTC) Received: from AcuMS.aculab.com (156.67.243.126 [156.67.243.126]) (Using TLS) by relay.mimecast.com with ESMTP id uk-mta-227-JrkSGbMLN9-FUY2lxHNdvQ-1; Fri, 08 Jan 2021 11:49:28 +0000 X-MC-Unique: JrkSGbMLN9-FUY2lxHNdvQ-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, 8 Jan 2021 11:49:27 +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; Fri, 8 Jan 2021 11:49:27 +0000 From: David Laight To: 'Christoph Hellwig' , Alexander Viro CC: Andrew Morton , Jens Axboe , Arnd Bergmann , David Howells , "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" , "linux-mips@vger.kernel.org" , "linux-parisc@vger.kernel.org" , "linuxppc-dev@lists.ozlabs.org" , "linux-s390@vger.kernel.org" , "sparclinux@vger.kernel.org" , "linux-block@vger.kernel.org" , "linux-scsi@vger.kernel.org" , "linux-fsdevel@vger.kernel.org" , "linux-aio@kvack.org" , "io-uring@vger.kernel.org" , "linux-arch@vger.kernel.org" , "linux-mm@kvack.org" , "netdev@vger.kernel.org" , "keyrings@vger.kernel.org" , "linux-security-module@vger.kernel.org" Subject: RE: [PATCH 05/11] iov_iter: merge the compat case into rw_copy_check_uvector Thread-Topic: [PATCH 05/11] iov_iter: merge the compat case into rw_copy_check_uvector Thread-Index: AQHWkCRUvpDO9SBAlU68E+WeFLSma6oeR04A Date: Fri, 8 Jan 2021 11:49:27 +0000 Message-ID: <7167a94511a84f30b18733d56007a7a5@AcuMS.aculab.com> References: <20200921143434.707844-1-hch@lst.de> <20200921143434.707844-6-hch@lst.de> In-Reply-To: <20200921143434.707844-6-hch@lst.de> 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-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: From: Christoph Hellwig > Sent: 21 September 2020 15:34 >=20 > Stop duplicating the iovec verify code, and instead add add a > __import_iovec helper that does the whole verify and import, but takes > a bool compat to decided on the native or compat layout. This also > ends up massively simplifying the calling conventions. >=20 > Signed-off-by: Christoph Hellwig > --- > lib/iov_iter.c | 195 ++++++++++++++++++------------------------------- > 1 file changed, 70 insertions(+), 125 deletions(-) >=20 > diff --git a/lib/iov_iter.c b/lib/iov_iter.c > index a64867501a7483..8bfa47b63d39aa 100644 > --- a/lib/iov_iter.c > +++ b/lib/iov_iter.c > @@ -10,6 +10,7 @@ > #include > #include > #include > +#include >=20 > #define PIPE_PARANOIA /* for now */ >=20 > @@ -1650,43 +1651,76 @@ const void *dup_iter(struct iov_iter *new, struct= iov_iter *old, gfp_t flags) > } > EXPORT_SYMBOL(dup_iter); >=20 > -static ssize_t rw_copy_check_uvector(int type, > -=09=09const struct iovec __user *uvector, unsigned long nr_segs, > -=09=09unsigned long fast_segs, struct iovec *fast_pointer, > -=09=09struct iovec **ret_pointer) > +static int compat_copy_iovecs_from_user(struct iovec *iov, > +=09=09const struct iovec __user *uvector, unsigned long nr_segs) > +{ > +=09const struct compat_iovec __user *uiov =3D > +=09=09(const struct compat_iovec __user *)uvector; > +=09unsigned long i; > +=09int ret =3D -EFAULT; > + > +=09if (!user_access_begin(uvector, nr_segs * sizeof(*uvector))) > +=09=09return -EFAULT; I little bit late, but the above isn't quite right. It should be sizeof(*iouv) - the length is double what it should be. Not that access_ok() can fail for compat addresses and the extra length won't matter for architectures that need the address/length to open an address hole into userspace. =09David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1= PT, UK Registration No: 1397386 (Wales)