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 824BCC00A89 for ; Mon, 2 Nov 2020 13:51:11 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id E8BF7223BD for ; Mon, 2 Nov 2020 13:51:10 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="rpbg/1lE" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E8BF7223BD Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id EBC2F6B006E; Mon, 2 Nov 2020 08:51:09 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id E3FA06B0071; Mon, 2 Nov 2020 08:51:09 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id C94AE6B0073; Mon, 2 Nov 2020 08:51:09 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0196.hostedemail.com [216.40.44.196]) by kanga.kvack.org (Postfix) with ESMTP id 8C4786B006E for ; Mon, 2 Nov 2020 08:51:09 -0500 (EST) Received: from smtpin10.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 1A454181AEF09 for ; Mon, 2 Nov 2020 13:51:09 +0000 (UTC) X-FDA: 77439614658.10.beef66_3b03e1f272b0 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin10.hostedemail.com (Postfix) with ESMTP id E54F416A4A5; Mon, 2 Nov 2020 13:51:08 +0000 (UTC) X-HE-Tag: beef66_3b03e1f272b0 X-Filterd-Recvd-Size: 4660 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf36.hostedemail.com (Postfix) with ESMTP; Mon, 2 Nov 2020 13:51:08 +0000 (UTC) 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> 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: 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