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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT 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 B58A3C3A59F for ; Tue, 27 Aug 2019 01:58:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 93B6F206E0 for ; Tue, 27 Aug 2019 01:58:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728025AbfH0B6O (ORCPT ); Mon, 26 Aug 2019 21:58:14 -0400 Received: from relmlor2.renesas.com ([210.160.252.172]:37472 "EHLO relmlie6.idc.renesas.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727646AbfH0B6O (ORCPT ); Mon, 26 Aug 2019 21:58:14 -0400 X-IronPort-AV: E=Sophos;i="5.64,435,1559487600"; d="scan'208";a="24775755" Received: from unknown (HELO relmlir6.idc.renesas.com) ([10.200.68.152]) by relmlie6.idc.renesas.com with ESMTP; 27 Aug 2019 10:58:11 +0900 Received: from localhost.localdomain (unknown [10.166.17.210]) by relmlir6.idc.renesas.com (Postfix) with ESMTP id 622B44156587; Tue, 27 Aug 2019 10:58:11 +0900 (JST) From: Yoshihiro Shimoda To: gregkh@linuxfoundation.org, stern@rowland.harvard.edu Cc: linux-usb@vger.kernel.org, linux-renesas-soc@vger.kernel.org, Yoshihiro Shimoda Subject: [PATCH v2] usb: host: ohci: fix a race condition between shutdown and irq Date: Tue, 27 Aug 2019 10:56:31 +0900 Message-Id: <1566870991-4870-1-git-send-email-yoshihiro.shimoda.uh@renesas.com> X-Mailer: git-send-email 2.7.4 Sender: linux-renesas-soc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-renesas-soc@vger.kernel.org This patch fixes an issue that the following error is possible to happen when ohci hardware causes an interruption and the system is shutting down at the same time. [ 34.851754] usb 2-1: USB disconnect, device number 2 [ 35.166658] irq 156: nobody cared (try booting with the "irqpoll" option) [ 35.173445] CPU: 0 PID: 22 Comm: kworker/0:1 Not tainted 5.3.0-rc5 #85 [ 35.179964] Hardware name: Renesas Salvator-X 2nd version board based on r8a77965 (DT) [ 35.187886] Workqueue: usb_hub_wq hub_event [ 35.192063] Call trace: [ 35.194509] dump_backtrace+0x0/0x150 [ 35.198165] show_stack+0x14/0x20 [ 35.201475] dump_stack+0xa0/0xc4 [ 35.204785] __report_bad_irq+0x34/0xe8 [ 35.208614] note_interrupt+0x2cc/0x318 [ 35.212446] handle_irq_event_percpu+0x5c/0x88 [ 35.216883] handle_irq_event+0x48/0x78 [ 35.220712] handle_fasteoi_irq+0xb4/0x188 [ 35.224802] generic_handle_irq+0x24/0x38 [ 35.228804] __handle_domain_irq+0x5c/0xb0 [ 35.232893] gic_handle_irq+0x58/0xa8 [ 35.236548] el1_irq+0xb8/0x180 [ 35.239681] __do_softirq+0x94/0x23c [ 35.243253] irq_exit+0xd0/0xd8 [ 35.246387] __handle_domain_irq+0x60/0xb0 [ 35.250475] gic_handle_irq+0x58/0xa8 [ 35.254130] el1_irq+0xb8/0x180 [ 35.257268] kernfs_find_ns+0x5c/0x120 [ 35.261010] kernfs_find_and_get_ns+0x3c/0x60 [ 35.265361] sysfs_unmerge_group+0x20/0x68 [ 35.269454] dpm_sysfs_remove+0x2c/0x68 [ 35.273284] device_del+0x80/0x370 [ 35.276683] hid_destroy_device+0x28/0x60 [ 35.280686] usbhid_disconnect+0x4c/0x80 [ 35.284602] usb_unbind_interface+0x6c/0x268 [ 35.288867] device_release_driver_internal+0xe4/0x1b0 [ 35.293998] device_release_driver+0x14/0x20 [ 35.298261] bus_remove_device+0x110/0x128 [ 35.302350] device_del+0x148/0x370 [ 35.305832] usb_disable_device+0x8c/0x1d0 [ 35.309921] usb_disconnect+0xc8/0x2d0 [ 35.313663] hub_event+0x6e0/0x1128 [ 35.317146] process_one_work+0x1e0/0x320 [ 35.321148] worker_thread+0x40/0x450 [ 35.324805] kthread+0x124/0x128 [ 35.328027] ret_from_fork+0x10/0x18 [ 35.331594] handlers: [ 35.333862] [<0000000079300c1d>] usb_hcd_irq [ 35.338126] [<0000000079300c1d>] usb_hcd_irq [ 35.342389] Disabling IRQ #156 ohci_shutdown() disables all the interrupt and rh_state is set to OHCI_RH_HALTED. In other hand, ohci_irq() is possible to enable OHCI_INTR_SF and OHCI_INTR_MIE on ohci_irq(). Note that OHCI_INTR_SF is possible to be set by start_ed_unlink() which is called: ohci_irq() -> process_done_list() -> takeback_td() -> start_ed_unlink() So, ohci_irq() has the following condition, the issue happens by &ohci->regs->intrenable = OHCI_INTR_MIE | OHCI_INTR_SF and ohci->rh_state = OHCI_RH_HALTED: /* interrupt for some other device? */ if (ints == 0 || unlikely(ohci->rh_state == OHCI_RH_HALTED)) return IRQ_NOTMINE; To fix the issue, ohci_shutdown() holds the spin lock while disabling the interruption and changing the rh_state flag to prevent reenable the OHCI_INTR_MIE unexpectedly. Note that io_watchdog_func() also calls the ohci_shutdown() and it already held the spin lock, so that the patch makes a new function as _ohci_shutdown(). Signed-off-by: Yoshihiro Shimoda --- Changes from v1: - Add more comments in the commit log. https://patchwork.kernel.org/patch/11111459/ drivers/usb/host/ohci-hcd.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) diff --git a/drivers/usb/host/ohci-hcd.c b/drivers/usb/host/ohci-hcd.c index b457fda..1fe3dee 100644 --- a/drivers/usb/host/ohci-hcd.c +++ b/drivers/usb/host/ohci-hcd.c @@ -419,8 +419,7 @@ static void ohci_usb_reset (struct ohci_hcd *ohci) * other cases where the next software may expect clean state from the * "firmware". this is bus-neutral, unlike shutdown() methods. */ -static void -ohci_shutdown (struct usb_hcd *hcd) +static void _ohci_shutdown(struct usb_hcd *hcd) { struct ohci_hcd *ohci; @@ -436,6 +435,16 @@ ohci_shutdown (struct usb_hcd *hcd) ohci->rh_state = OHCI_RH_HALTED; } +static void ohci_shutdown(struct usb_hcd *hcd) +{ + struct ohci_hcd *ohci = hcd_to_ohci(hcd); + unsigned long flags; + + spin_lock_irqsave(&ohci->lock, flags); + _ohci_shutdown(hcd); + spin_unlock_irqrestore(&ohci->lock, flags); +} + /*-------------------------------------------------------------------------* * HC functions *-------------------------------------------------------------------------*/ @@ -760,7 +769,7 @@ static void io_watchdog_func(struct timer_list *t) died: usb_hc_died(ohci_to_hcd(ohci)); ohci_dump(ohci); - ohci_shutdown(ohci_to_hcd(ohci)); + _ohci_shutdown(ohci_to_hcd(ohci)); goto done; } else { /* No write back because the done queue was empty */ -- 2.7.4