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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 39627C433F5 for ; Tue, 12 Apr 2022 13:24:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1355989AbiDLN1A (ORCPT ); Tue, 12 Apr 2022 09:27:00 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39826 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1356194AbiDLN0w (ORCPT ); Tue, 12 Apr 2022 09:26:52 -0400 Received: from cmx-mtlrgo002.bell.net (mta-mtl-002.bell.net [209.71.208.12]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 77BDF32D for ; Tue, 12 Apr 2022 06:20:28 -0700 (PDT) X-RG-CM-BuS: 0 X-RG-CM-SC: 0 X-RG-CM: Clean X-Originating-IP: [70.50.7.94] X-RG-Env-Sender: dave.anglin@bell.net X-RG-Rigid: 624D96FC0091EE18 X-CM-Envelope: MS4xfDxwv0yQynDrdOr2zbG1sdweJ6SndfsUE04p20dSH6xQseBl5oM+VGsedRQpXSYaTKenTVb9B8H9LyHMVIgDYpuNk3kEIER9os5RhXYM2PTBscNL5GwS Kg3P8QgNwidBybx43zvr32LCukqxNR+M+SZI7Z2VXqNtvMwJVYPpkZyuHWP8F2FnzTBDpind25JC681nvb74ZkSJS4BGBG3bRj1xYZHwGEfW6LpAihAZVowK LHnZGQGmSgRUWeeo98kBUbcjj2ikllVNzKswzoKT5Df3J9HNmijCNDKWHE0uMpZv X-CM-Analysis: v=2.4 cv=aKWTFZxm c=1 sm=1 tr=0 ts=62557c93 a=9k1bCY7nR7m1ZFzoCuQ56g==:117 a=9k1bCY7nR7m1ZFzoCuQ56g==:17 a=IkcTkHD0fZMA:10 a=7mOBRU54AAAA:8 a=VwQbUJbxAAAA:8 a=FBHGMhGWAAAA:8 a=Jnis4izeJgldjXVnqSMA:9 a=QEXdDO2ut3YA:10 a=wa9RWnbW_A1YIeRBVszw:22 a=AjGcO6oz07-iQ99wixmX:22 a=9gvnlMMaQFpL9xblJ6ne:22 Received: from [192.168.2.49] (70.50.7.94) by cmx-mtlrgo002.bell.net (5.8.807) (authenticated as dave.anglin@bell.net) id 624D96FC0091EE18; Tue, 12 Apr 2022 09:20:19 -0400 Message-ID: <383d6dfa-bef1-e56f-8f82-dfc0682cdacc@bell.net> Date: Tue, 12 Apr 2022 09:20:20 -0400 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.8.0 Subject: Re: Recurring INEQUIVALENT ALIASES issues and userland corruption/crashes Content-Language: en-US From: John David Anglin To: Sam James Cc: linux-parisc@vger.kernel.org, hppa@gentoo.org References: <63DA313A-FCE1-4535-9BF3-11E36B2DE422@gentoo.org> <94439119-D2B6-4961-B61D-95784E09798D@gentoo.org> In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-parisc@vger.kernel.org On 2022-04-12 8:27 a.m., John David Anglin wrote: > On 2022-04-12 1:18 a.m., Sam James wrote: >>>> Mar 22 04:19:55 muta.hppa.dev.gentoo.org kernel: INEQUIVALENT ALIASES 0x411ee000 and 0x428c9000 in file bash >>>> ``` >>> It seems all these messages result from a single call to flush_dcache_page.  Note the sequential behavior of old_addr >>> and addr, and message times. >> FWIW, from Helge's config on 5.10.108 (config changes on my end: just disabling unneeded devices to speed up build), I have the same >> horrible wall: > This change might help: > https://lore.kernel.org/linux-parisc/YlNw8jzP9OQRKvlV@mx3210.localdomain/T/#u > > It applies on top of Helge's current for-next tree which is based on 5.18.0-rc1+. > > The messages will no longer appear with this patch on c8000/rp34xx. However, the loop corruption > might still occur.  If that happens, I think the stall detector will trigger, or maybe some other crash. > > The loop is changed to flush all mount points on machines with PA8800 or PA8900 processors as I > believe these CPUs don't support equivalent aliases. Thousands of messages aren't useful.  I would suggest adding a BUG_ON statement in the loop that triggers on the first message.  That might help find the circumstances that cause the problem. I think the loop may get corrupted when the mapping code fails to find an address aligned on a 4MB boundary.  Another possibility might be a locking issue.  In both these cases, the messages are just a symptom of a problem elsewhere. Dave -- John David Anglin dave.anglin@bell.net