From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: David Laight Subject: RE: Buggy commit tracked to: "Re: [PATCH 2/9] iov_iter: move rw_copy_check_uvector() into lib/iov_iter.c" Date: Mon, 2 Nov 2020 09:06:38 +0000 Message-ID: <0ab5ac71f28d459db2f350c2e07b88ca@AcuMS.aculab.com> References: <5fd6003b-55a6-2c3c-9a28-8fd3a575ca78@redhat.com> <20201022104805.GA1503673@kroah.com> <20201022121849.GA1664412@kroah.com> <98d9df88-b7ef-fdfb-7d90-2fa7a9d7bab5@redhat.com> <20201022125759.GA1685526@kroah.com> <20201022135036.GA1787470@kroah.com> <134f162d711d466ebbd88906fae35b33@AcuMS.aculab.com> <935f7168-c2f5-dd14-7124-412b284693a2@redhat.com> <999e2926-9a75-72fd-007a-1de0af341292@redhat.com> <35d0ec90ef4f4a35a75b9df7d791f719@AcuMS.aculab.com> <20201023144718.GA2525489@kroah.com> In-Reply-To: <20201023144718.GA2525489@kroah.com> MIME-Version: 1.0 Content-Language: en-US Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT List-ID: To: 'Greg KH' Cc: 'David Hildenbrand' , Al Viro , Nick Desaulniers , Christoph Hellwig , "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" From: 'Greg KH' > Sent: 23 October 2020 15:47 > > On Fri, Oct 23, 2020 at 02:39:24PM +0000, David Laight wrote: > > From: David Hildenbrand > > > Sent: 23 October 2020 15:33 > > ... > > > I just checked against upstream code generated by clang 10 and it > > > properly discards the upper 32bit via a mov w23 w2. > > > > > > So at least clang 10 indeed properly assumes we could have garbage and > > > masks it off. > > > > > > Maybe the issue is somewhere else, unrelated to nr_pages ... or clang 11 > > > behaves differently. > > > > We'll need the disassembly from a failing kernel image. > > It isn't that big to hand annotate. > > I've worked around the merge at the moment in the android tree, but it > is still quite reproducable, and will try to get a .o file to > disassemble on Monday or so... Did this get properly resolved? David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)