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_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 ED352C04AB5 for ; Tue, 4 Jun 2019 03:25:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CCC5B25F63 for ; Tue, 4 Jun 2019 03:25:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726136AbfFDDZT (ORCPT ); Mon, 3 Jun 2019 23:25:19 -0400 Received: from szxga01-in.huawei.com ([45.249.212.187]:6931 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726076AbfFDDZS (ORCPT ); Mon, 3 Jun 2019 23:25:18 -0400 Received: from DGGEMM405-HUB.china.huawei.com (unknown [172.30.72.56]) by Forcepoint Email with ESMTP id BE94997D671FA07ECE05; Tue, 4 Jun 2019 11:25:16 +0800 (CST) Received: from dggeme758-chm.china.huawei.com (10.3.19.104) by DGGEMM405-HUB.china.huawei.com (10.3.20.213) with Microsoft SMTP Server (TLS) id 14.3.439.0; Tue, 4 Jun 2019 11:25:16 +0800 Received: from [127.0.0.1] (10.40.49.11) by dggeme758-chm.china.huawei.com (10.3.19.104) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1591.10; Tue, 4 Jun 2019 11:25:16 +0800 To: CC: Bjorn Helgaas , "Rafael J. Wysocki" From: "Fangjian (Turing)" Subject: Bug report: AER driver deadlock Message-ID: Date: Tue, 4 Jun 2019 11:25:44 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.5.2 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.40.49.11] X-ClientProxiedBy: dggeme710-chm.china.huawei.com (10.1.199.106) To dggeme758-chm.china.huawei.com (10.3.19.104) X-CFilter-Loop: Reflected Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org Hi, We met a deadlock triggered by a NONFATAL AER event during a sysfs "sriov_numvfs" operation. Any suggestion to fix such deadlock ? enable one VF # echo 1 > /sys/devices/pci0000:74/0000:74:00.0/0000:75:00.0/sriov_numvfs The sysfs "sriov_numvfs" side is: sriov_numvfs_store device_lock # hold the device_lock ... pci_enable_sriov sriov_enable ... pci_device_add down_write(&pci_bus_sem) # wait for up_read(&pci_bus_sem) The AER side is: pcie_do_recovery pci_walk_bus down_read(&pci_bus_sem) # hold the rw_semaphore report_resume device_lock # wait for device_unlock() The calltrace is as below: [ 258.411464] INFO: task kworker/0:1:13 blocked for more than 120 seconds. [ 258.418139] Tainted: G C O 5.1.0-rc1-ge2e3ca0 #1 [ 258.424379] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 258.432172] kworker/0:1 D 0 13 2 0x00000028 [ 258.437640] Workqueue: events aer_recover_work_func [ 258.442496] Call trace: [ 258.444933] __switch_to+0xb4/0x1b8 [ 258.448409] __schedule+0x1ec/0x720 [ 258.451884] schedule+0x38/0x90 [ 258.455012] schedule_preempt_disabled+0x20/0x38 [ 258.459610] __mutex_lock.isra.1+0x150/0x518 [ 258.463861] __mutex_lock_slowpath+0x10/0x18 [ 258.468112] mutex_lock+0x34/0x40 [ 258.471413] report_resume+0x1c/0x78 [ 258.474973] pci_walk_bus+0x58/0xb0 [ 258.478451] pcie_do_recovery+0x18c/0x248 [ 258.482445] aer_recover_work_func+0xe0/0x118 [ 258.486783] process_one_work+0x1e4/0x468 [ 258.490776] worker_thread+0x40/0x450 [ 258.494424] kthread+0x128/0x130 [ 258.497639] ret_from_fork+0x10/0x1c [ 258.501329] INFO: task flr.sh:4534 blocked for more than 120 seconds. [ 258.507742] Tainted: G C O 5.1.0-rc1-ge2e3ca0 #1 [ 258.513980] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 258.521774] flr.sh D 0 4534 4504 0x00000000 [ 258.527235] Call trace: [ 258.529671] __switch_to+0xb4/0x1b8 [ 258.533146] __schedule+0x1ec/0x720 [ 258.536619] schedule+0x38/0x90 [ 258.539749] rwsem_down_write_failed+0x14c/0x210 [ 258.544347] down_write+0x48/0x60 [ 258.547648] pci_device_add+0x1a0/0x290 [ 258.551469] pci_iov_add_virtfn+0x190/0x358 [ 258.555633] sriov_enable+0x24c/0x480 [ 258.559279] pci_enable_sriov+0x14/0x28 [ 258.563101] hisi_zip_sriov_configure+0x64/0x100 [hisi_zip] [ 258.568649] sriov_numvfs_store+0xc4/0x190 [ 258.572728] dev_attr_store+0x18/0x28 [ 258.576375] sysfs_kf_write+0x3c/0x50 [ 258.580024] kernfs_fop_write+0x114/0x1d8 [ 258.584018] __vfs_write+0x18/0x38 [ 258.587404] vfs_write+0xa4/0x1b0 [ 258.590705] ksys_write+0x60/0xd8 [ 258.594007] __arm64_sys_write+0x18/0x20 [ 258.597914] el0_svc_common+0x5c/0x100 [ 258.601646] el0_svc_handler+0x2c/0x80 [ 258.605381] el0_svc+0x8/0xc [ 379.243461] INFO: task kworker/0:1:13 blocked for more than 241 seconds. [ 379.250134] Tainted: G C O 5.1.0-rc1-ge2e3ca0 #1 [ 379.256373] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. Thank you, Jay