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,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,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 C8F5EC4742C for ; Mon, 2 Nov 2020 13:51:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8438E223BD for ; Mon, 2 Nov 2020 13:51:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604325072; bh=9qIUbE3lwH4ZvgtTC9bbV3+9hXUEaYm6WiiqQ4WE/Co=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=N/avytYBGjshP8FHoQV0yS61Fnq6CwCqJsn86xAjOpwuRjEhFreRSQQxz78sCV8J2 yRjzVMnR2ssvgd+UEZOyRPLpOhacQhopHWpDWG2ddfflz9M5o32IX2jw441uBd9YrD nSISglJDA5x7jpRcmqr1cNqss1qyEgLq4qpwajMg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725835AbgKBNvM (ORCPT ); Mon, 2 Nov 2020 08:51:12 -0500 Received: from mail.kernel.org ([198.145.29.99]:47994 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725797AbgKBNvK (ORCPT ); Mon, 2 Nov 2020 08:51:10 -0500 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 8C0442231B; Mon, 2 Nov 2020 13:51:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604325067; bh=9qIUbE3lwH4ZvgtTC9bbV3+9hXUEaYm6WiiqQ4WE/Co=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=rpbg/1lEiVgNn9Ysvs/9LknHZYACC7zXQOCGCw264IRu8ax1gLK6WH9zSjr+uRe43 j5PkmmIzKYvzuR6uPdj0UxdnGNyDn2tiAsnr4m+Rc6wtDwZreVMVedmDOCqs8DpK24 uLH4O6s20Bi63bMTeguJmmwdpc+o+rm+otUlIokQ= Date: Mon, 2 Nov 2020 14:52:02 +0100 From: 'Greg KH' To: David Laight 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" Subject: Re: Buggy commit tracked to: "Re: [PATCH 2/9] iov_iter: move rw_copy_check_uvector() into lib/iov_iter.c" Message-ID: <20201102135202.GA1016272@kroah.com> References: <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> <0ab5ac71f28d459db2f350c2e07b88ca@AcuMS.aculab.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <0ab5ac71f28d459db2f350c2e07b88ca@AcuMS.aculab.com> Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org On Mon, Nov 02, 2020 at 09:06:38AM +0000, David Laight wrote: > 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? For some reason, 5.10-rc2 fixed all of this up. I backed out all of the patches I had to revert to get 5.10-rc1 to work properly, and then did the merge and all is well. It must have been something to do with the compat changes in this same area that went in after 5.10-rc1, and something got reorganized in the files somehow. I really do not know, and at the moment, don't have the time to track it down anymore. So for now, I'd say it's all good, sorry for the noise. greg k-h