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=-3.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 9C81FC388F9 for ; Thu, 22 Oct 2020 16:50:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 44C4922267 for ; Thu, 22 Oct 2020 16:50:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2902063AbgJVQuI convert rfc822-to-8bit (ORCPT ); Thu, 22 Oct 2020 12:50:08 -0400 Received: from eu-smtp-delivery-151.mimecast.com ([207.82.80.151]:38652 "EHLO eu-smtp-delivery-151.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2902061AbgJVQuI (ORCPT ); Thu, 22 Oct 2020 12:50:08 -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-194-WOVSzex2MCy7e08hIPnLOQ-1; Thu, 22 Oct 2020 17:50:05 +0100 X-MC-Unique: WOVSzex2MCy7e08hIPnLOQ-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; Thu, 22 Oct 2020 17:50:04 +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; Thu, 22 Oct 2020 17:50:04 +0100 From: David Laight To: 'Matthew Wilcox' CC: 'Christoph Hellwig' , David Hildenbrand , Greg KH , Al Viro , Nick Desaulniers , "kernel-team@android.com" , 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: Buggy commit tracked to: "Re: [PATCH 2/9] iov_iter: move rw_copy_check_uvector() into lib/iov_iter.c" Thread-Topic: Buggy commit tracked to: "Re: [PATCH 2/9] iov_iter: move rw_copy_check_uvector() into lib/iov_iter.c" Thread-Index: AQHWqE5GNDfnH4y9nkGWtfqJueR1KKmjTCJQgAAN4UiAAAD2IIAAQY5tgAAwVkD///XpAIAAEjsw Date: Thu, 22 Oct 2020 16:50:04 +0000 Message-ID: <089031589f0f43a39f9a5a7737443880@AcuMS.aculab.com> References: <80a2e5fa-718a-8433-1ab0-dd5b3e3b5416@redhat.com> <5d2ecb24db1e415b8ff88261435386ec@AcuMS.aculab.com> <20201022090155.GA1483166@kroah.com> <5fd6003b-55a6-2c3c-9a28-8fd3a575ca78@redhat.com> <20201022132342.GB8781@lst.de> <8f1fff0c358b4b669d51cc80098dbba1@AcuMS.aculab.com> <20201022164040.GV20115@casper.infradead.org> In-Reply-To: <20201022164040.GV20115@casper.infradead.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: io-uring@vger.kernel.org From: Matthew Wilcox > Sent: 22 October 2020 17:41 > > On Thu, Oct 22, 2020 at 04:35:17PM +0000, David Laight wrote: > > Wait... > > readv(2) defines: > > ssize_t readv(int fd, const struct iovec *iov, int iovcnt); > > It doesn't really matter what the manpage says. What does the AOSP > libc header say? The only copy I can find is: /usr/include/x86_64-linux-gnu/sys/uio.h:extern ssize_t readv (int __fd, const struct iovec *__iovec, int __count) /usr/include/x86_64-linux-gnu/sys/uio.h- __wur; and not surprisingly agrees. POSIX and/or TOG will (more or less) mandate the prototype. > > But the syscall is defined as: > > > > SYSCALL_DEFINE3(readv, unsigned long, fd, const struct iovec __user *, vec, > > unsigned long, vlen) > > { > > return do_readv(fd, vec, vlen, 0); > > } I wonder when the high bits of 'fd' get zapped? David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)