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=-7.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 105F3C2D0E4 for ; Fri, 20 Nov 2020 21:13:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 624CF22253 for ; Fri, 20 Nov 2020 21:13:27 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="sKDdd9J8" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727907AbgKTVN0 (ORCPT ); Fri, 20 Nov 2020 16:13:26 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38776 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727814AbgKTVN0 (ORCPT ); Fri, 20 Nov 2020 16:13:26 -0500 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7AE0CC0613CF for ; Fri, 20 Nov 2020 13:13:26 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=Content-Transfer-Encoding:Content-Type: In-Reply-To:MIME-Version:Date:Message-ID:From:References:Cc:To:Subject:Sender :Reply-To:Content-ID:Content-Description; bh=YFyZ12L9XZV5/bG8xWEunlZ6fJwvZBT9afefbuSo1tQ=; b=sKDdd9J8rGaVUdeY0+FLm2VlNW dPmuVpZ68mxRj8S58YVKQE1uuj6JerRpyMk8/expyqsqDSlt9DLP0D4hgx/D0x3DcfVALQEjgy7eF WQzK1Diucumfz1d9Uo1fc0KfnN3fA3Ik8G4+uEhVTKJtICiJns4FoCMFDNLnydMyTak4SLto5uFBK oBrd1kUY1RkHAcs0zelSwrqB0tHDgPbDqQeSBp/O9jMqZmhr83ne6gMuSXOJ+xojrp27CJnL5Sx9x cIcCEGBfL74tEhfBEaH8Q9UeFlh+9gCW8FFdhuk6uhgoOxtECxzn/iAqhGk/sof1U4iUs4KlczvBY 7TU5d5Bg==; Received: from [2601:1c0:6280:3f0::bcc4] by casper.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1kgDie-0000X4-Hj; Fri, 20 Nov 2020 21:13:24 +0000 Subject: Re: BUG triggers running lsof To: "K.R. Foley" , Jeff Moyer Cc: linux-fsdevel@vger.kernel.org References: <4cc7a530-41ed-81f4-82cd-6a3a93661dce@infradead.org> <5310969ec0c67c25ae2eff16f1e904d5@cybsft.com> From: Randy Dunlap Message-ID: Date: Fri, 20 Nov 2020 13:13:22 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.12.0 MIME-Version: 1.0 In-Reply-To: <5310969ec0c67c25ae2eff16f1e904d5@cybsft.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On 11/20/20 12:59 PM, K.R. Foley wrote: > > > > On 2020-11-20 13:51, Jeff Moyer wrote: >> Randy Dunlap writes: >> >>> On 11/20/20 11:16 AM, K.R. Foley wrote: >>>> I have found an issue that triggers by running lsof. The problem is >>>> reproducible, but not consistently. I have seen this issue occur on >>>> multiple versions of the kernel (5.0.10, 5.2.8 and now 5.4.77). It >>>> looks like it could be a race condition or the file pointer is being >>>> corrupted. Any pointers on how to track this down? What additional >>>> information can I provide? >>> >>> Hi, >>> >>> 2 things in general: >>> >>> a) Can you test with a more recent kernel? >>> >>> b) Can you reproduce this without loading the proprietary & out-of-tree >>> kernel modules?  They should never have been loaded after bootup. >>> I.e., don't just unload them -- that could leave something bad behind. >> >> Heh, the EIP contains part of the name of one of the modules: >> >>> >>>> [ 8057.297159] BUG: unable to handle page fault for address: 31376f63 >>                                                                 ^^^^^^^^ Thanks for noticing that, Jeff. I should have seen it. >>>> [ 8057.297219] Modules linked in: ITXico7100Module(O) >>                                          ^^^^ > > Perhaps this is a dumb question, but how could this happen? We don't know what is in that loadable kernel module, so we can't give a definitive answer to your question, other than it's buggy. Or maybe it was just written for an older kernel version. Or a kernel with different build options/settings. Have you contacted IT support? It would (will) be interesting to see if you can reproduce the problem without these modules being loaded... I kind of doubt it, but if it does still fail, it will give us something to look at. -- ~Randy