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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=ham 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 62AF6C282C8 for ; Mon, 28 Jan 2019 14:05:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 303C920989 for ; Mon, 28 Jan 2019 14:05:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726683AbfA1OFc (ORCPT ); Mon, 28 Jan 2019 09:05:32 -0500 Received: from szxga07-in.huawei.com ([45.249.212.35]:45482 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726682AbfA1OFc (ORCPT ); Mon, 28 Jan 2019 09:05:32 -0500 Received: from DGGEMS409-HUB.china.huawei.com (unknown [172.30.72.58]) by Forcepoint Email with ESMTP id EA66D45085AD96A1B998; Mon, 28 Jan 2019 22:05:29 +0800 (CST) Received: from [127.0.0.1] (10.63.141.25) by DGGEMS409-HUB.china.huawei.com (10.3.19.209) with Microsoft SMTP Server id 14.3.408.0; Mon, 28 Jan 2019 22:05:21 +0800 Subject: Re: [PATCH] PCI/ERR: Fix run error recovery callbacks for all affected devices To: Sinan Kaya , Keith Busch References: <1548337810-69892-1-git-send-email-liudongdong3@huawei.com> <20190124213701.GA9882@localhost.localdomain> <5d58ea17-115f-139d-93db-fe6e9ce573cb@huawei.com> <7b515af9-b119-bf33-f774-3e091ca30483@kernel.org> CC: "helgaas@kernel.org" , "linux-pci@vger.kernel.org" , "linuxarm@huawei.com" , Bjorn Helgaas , tanxiaofei From: Dongdong Liu Message-ID: <2871dbbe-fb99-ef33-3787-79a96b274b50@huawei.com> Date: Mon, 28 Jan 2019 22:05:21 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.4.0 MIME-Version: 1.0 In-Reply-To: <7b515af9-b119-bf33-f774-3e091ca30483@kernel.org> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 8bit X-Originating-IP: [10.63.141.25] X-CFilter-Loop: Reflected Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org Hi Sinan 在 2019/1/26 1:09, Sinan Kaya 写道: > On 1/25/2019 9:28 AM, Dongdong Liu wrote: >> I want to fix 2 points by the patch. >> >> 1. For EP devices (such as multi-function EP device) under the same bus, >> when one of the EP devices met non-fatal error, should report non-fatal >> error only to the error endpoint device, no need to broadcast all of them. >> That is the patch (PCI/AER: Report non-fatal errors only to the affected endpoint #4.15) >> have done, but current code PATCH [1] broken this. >> >> 2. We found a NULL pointer dereference issue for 74:02.0 device >> when the device met a non-fatal error (firmware-first) after 4.19. >> The topology is as below. > > Is it possible to split the patches into two to address these two different > issues? Good suggestion, will do. > > I can understand the first one but second one seems some mystery that needs > to be explored in detail. > +-[0000:74]-+-02.0 Huawei Technologies Co., Ltd. HiSilicon SAS 3.0 HBA | \-03.0 Huawei Technologies Co., Ltd. HiSilicon AHCI HBA 74:02.0 is a RCiEP, but do not under a root port. Current code have the issue as the below code, see [DD]. aer_recover_work_func() pcie_do_recovery() { /* * Error recovery runs on all subordinates of the first downstream port. * If the downstream port detected the error, it is cleared at the end. */ if (!(pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT || pci_pcie_type(dev) == PCI_EXP_TYPE_DOWNSTREAM)) dev = dev->bus->self; //[DD]: Here dev will be NULL pointer for 74:02.0（RCiEP）as it does not have a root port. bus = dev->subordinate; } We do not have the NULL pointer dereference issue before the patch [1] PCI/ERR: Run error recovery callbacks for all affected devices #4.20 . Thanks, Dongdong > . >