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=-3.6 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 19121C4727F for ; Tue, 29 Sep 2020 02:35:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CE80D2145D for ; Tue, 29 Sep 2020 02:35:31 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="jlGtjwrZ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727294AbgI2Cfa (ORCPT ); Mon, 28 Sep 2020 22:35:30 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39260 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725272AbgI2Cfa (ORCPT ); Mon, 28 Sep 2020 22:35:30 -0400 Received: from mail-ej1-x643.google.com (mail-ej1-x643.google.com [IPv6:2a00:1450:4864:20::643]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 834E6C061755; Mon, 28 Sep 2020 19:35:29 -0700 (PDT) Received: by mail-ej1-x643.google.com with SMTP id u21so12746637eja.2; Mon, 28 Sep 2020 19:35:28 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=fispIEpvKzQ4yK99Q5GZdxzrqvs5hFT355gL1BD8Ux8=; b=jlGtjwrZx/9uMiv9ZibPYP2cdAQGnAgA0Qn2ynTyFmxLUeLsZ0iQbZGioWKVQPTnDO iAO1vT2ozPJoSLm+2um+GmrvOWUr6GqO+jFuDeWlMNYdUdFH4rFAPNDkyCPgj05+tZYx sTeauxfwsTmf8TNF3IDalgItv0rvdhD8Khg5pksHiCGqIBpmXW8VVIyNgL83sZ0jcCFH IZLCwd8opRhQceH027gyW1kz17FPywXI4tnf1AF4wSNwuAG7nCrpoy3Wj6tU724RCPrD wUwpKqU8arpZjZIAox7JPhAfs8XTIEeSVgUqvZ0rClUpSQtuCRsP+9U+AOkyT9VDUwBt i7cg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=fispIEpvKzQ4yK99Q5GZdxzrqvs5hFT355gL1BD8Ux8=; b=B57Lgrh7zCXMJU6vo9LRIKiEEIim93LgXPu39nbvdxEGJvHm4kBQgD3wFzJaBOfx2R Z0OFgltGcydy4tONDzQEXuHXiZahSSKIlsA/5UVb78bG1iFd6VOE986wK0xOTuYx+bt5 gi8gB1933fHZp9FtMjnhJFK4y1DmUpJ3567EMayGJSopmrIcVACU6qk/yvk2R6b3bPEI JxvFZDCEm0jpC7wvoJcDyUul9GpziD1YP1AkkjJypukGJPv8oktKeHdN53J8kKtFBTtR hGXc5yPosnZHbF4F2N21ql6gYdUc/8zre8gpqd9jFToYLL0t6eihpusLfwWoP9mjiYq6 e8mQ== X-Gm-Message-State: AOAM532rDVdk3fgjp4lTpdtiM2yfefrBpJewB+Bg/H/JlK6OX0L7MfyV 8nyhhld417KrbdVOthNpAWoGSTMirIsNXAaoTH8= X-Google-Smtp-Source: ABdhPJyu6D8OayMr5IUYnr9YLRD1yDfO7Yj1MvWlAS6jspKb6UKU6joWizLvFp7R9Sl6zWrNw4rgtN3kGbJd9AmSE2I= X-Received: by 2002:a17:906:4956:: with SMTP id f22mr1629762ejt.62.1601346926062; Mon, 28 Sep 2020 19:35:26 -0700 (PDT) MIME-Version: 1.0 References: <20200925023423.42675-1-haifeng.zhao@intel.com> <20200925023423.42675-4-haifeng.zhao@intel.com> <20200925123515.GF3956970@smile.fi.intel.com> In-Reply-To: <20200925123515.GF3956970@smile.fi.intel.com> From: Ethan Zhao Date: Tue, 29 Sep 2020 10:35:14 +0800 Message-ID: Subject: Re: [PATCH 3/5] PCI/ERR: get device before call device driver to avoid null pointer reference To: Andy Shevchenko Cc: Ethan Zhao , Bjorn Helgaas , Oliver , ruscur@russell.cc, Lukas Wunner , Stuart Hayes , Alexandru Gagniuc , Mika Westerberg , linux-pci , Linux Kernel Mailing List , "Jia, Pei P" Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Preferred style, there will be cleared comment in v6. Thanks, Ethan On Sat, Sep 26, 2020 at 12:42 AM Andy Shevchenko wrote: > > On Thu, Sep 24, 2020 at 10:34:21PM -0400, Ethan Zhao wrote: > > During DPC error injection test we found there is race condition between > > pciehp and DPC driver, null pointer reference caused panic as following > > null -> NULL > > > > > # setpci -s 64:02.0 0x196.w=000a > > // 64:02.0 is rootport has DPC capability > > # setpci -s 65:00.0 0x04.w=0544 > > // 65:00.0 is NVMe SSD populated in above port > > # mount /dev/nvme0n1p1 nvme > > > > (tested on stable 5.8 & ICX platform) > > > > Buffer I/O error on dev nvme0n1p1, logical block 468843328, > > async page read > > BUG: kernel NULL pointer dereference, address: 0000000000000050 > > #PF: supervisor read access in kernel mode > > #PF: error_code(0x0000) - not-present page > > Same comment about Oops. > > -- > With Best Regards, > Andy Shevchenko > >