From patchwork Fri Jun 30 20:48:01 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sergey Shtylyov X-Patchwork-Id: 13298742 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9F476EB64DA for ; Fri, 30 Jun 2023 20:48:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232598AbjF3UsN (ORCPT ); Fri, 30 Jun 2023 16:48:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54598 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232614AbjF3UsM (ORCPT ); Fri, 30 Jun 2023 16:48:12 -0400 Received: from mx01.omp.ru (mx01.omp.ru [90.154.21.10]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E556E3A81 for ; Fri, 30 Jun 2023 13:48:10 -0700 (PDT) Received: from [192.168.1.103] (178.176.76.44) by msexch01.omp.ru (10.188.4.12) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384) id 15.2.986.14; Fri, 30 Jun 2023 23:48:02 +0300 From: Sergey Shtylyov Subject: [PATCH v2] usb: host: xhci-plat: fix possible kernel oops while resuming To: Mathias Nyman , Greg Kroah-Hartman , CC: Florian Fainelli Organization: Open Mobile Platform Message-ID: <7c560c92-40a7-944a-f46d-28503ce8583c@omp.ru> Date: Fri, 30 Jun 2023 23:48:01 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.10.1 MIME-Version: 1.0 Content-Language: en-US X-Originating-IP: [178.176.76.44] X-ClientProxiedBy: msexch01.omp.ru (10.188.4.12) To msexch01.omp.ru (10.188.4.12) X-KSE-ServerInfo: msexch01.omp.ru, 9 X-KSE-AntiSpam-Interceptor-Info: scan successful X-KSE-AntiSpam-Version: 5.9.59, Database issued on: 06/30/2023 20:31:01 X-KSE-AntiSpam-Status: KAS_STATUS_NOT_DETECTED X-KSE-AntiSpam-Method: none X-KSE-AntiSpam-Rate: 59 X-KSE-AntiSpam-Info: Lua profiles 178380 [Jun 30 2023] X-KSE-AntiSpam-Info: Version: 5.9.59.0 X-KSE-AntiSpam-Info: Envelope from: s.shtylyov@omp.ru X-KSE-AntiSpam-Info: LuaCore: 517 517 b0056c19d8e10afbb16cb7aad7258dedb0179a79 X-KSE-AntiSpam-Info: {rep_avail} X-KSE-AntiSpam-Info: {Tracking_from_domain_doesnt_match_to} X-KSE-AntiSpam-Info: {relay has no DNS name} X-KSE-AntiSpam-Info: {SMTP from is not routable} X-KSE-AntiSpam-Info: {Found in DNSBL: 178.176.76.44 in (user) b.barracudacentral.org} X-KSE-AntiSpam-Info: 178.176.76.44:7.1.2;omp.ru:7.1.1;d41d8cd98f00b204e9800998ecf8427e.com:7.1.1;127.0.0.199:7.1.2 X-KSE-AntiSpam-Info: ApMailHostAddress: 178.176.76.44 X-KSE-AntiSpam-Info: {DNS response errors} X-KSE-AntiSpam-Info: Rate: 59 X-KSE-AntiSpam-Info: Status: not_detected X-KSE-AntiSpam-Info: Method: none X-KSE-AntiSpam-Info: Auth:dmarc=temperror header.from=omp.ru;spf=temperror smtp.mailfrom=omp.ru;dkim=none X-KSE-Antiphishing-Info: Clean X-KSE-Antiphishing-ScanningType: Heuristic X-KSE-Antiphishing-Method: None X-KSE-Antiphishing-Bases: 06/30/2023 20:37:00 X-KSE-Antivirus-Interceptor-Info: scan successful X-KSE-Antivirus-Info: Clean, bases: 6/30/2023 5:36:00 PM X-KSE-Attachment-Filter-Triggered-Rules: Clean X-KSE-Attachment-Filter-Triggered-Filters: Clean X-KSE-BulkMessagesFiltering-Scan-Result: InTheLimit Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org If this driver enables the xHC clocks while resuming from sleep, it calls clk_prepare_enable() without checking for errors and blithely goes on to read/write the xHC's registers -- which, with the xHC not being clocked, at least on ARM32 usually causes an imprecise external abort exceptions which cause kernel oops. Currently, the chips for which the driver does the clock dance on suspend/resume seem to be the Broadcom STB SoCs, based on ARM32 CPUs, as it seems... Found by Linux Verification Center (linuxtesting.org) with the Svace static analysis tool. Fixes: 8bd954c56197 ("usb: host: xhci-plat: suspend and resume clocks") Signed-off-by: Sergey Shtylyov --- This patch is against the 'usb-linus' branch of Greg KH's 'usb.git' repo... Changes in version 2: - fixed up the error path for clk_prepare_enable() calls in xhci_plat_resume(). drivers/usb/host/xhci-plat.c | 21 +++++++++++++++++---- 1 file changed, 17 insertions(+), 4 deletions(-) Index: usb/drivers/usb/host/xhci-plat.c =================================================================== --- usb.orig/drivers/usb/host/xhci-plat.c +++ usb/drivers/usb/host/xhci-plat.c @@ -470,23 +470,36 @@ static int __maybe_unused xhci_plat_resu int ret; if (!device_may_wakeup(dev) && (xhci->quirks & XHCI_SUSPEND_RESUME_CLKS)) { - clk_prepare_enable(xhci->clk); - clk_prepare_enable(xhci->reg_clk); + ret = clk_prepare_enable(xhci->clk); + if (ret) + return ret; + + ret = clk_prepare_enable(xhci->reg_clk); + if (ret) + goto disable_clk; } ret = xhci_priv_resume_quirk(hcd); if (ret) - return ret; + goto disable_reg_clk; ret = xhci_resume(xhci, 0); if (ret) - return ret; + goto disable_reg_clk; pm_runtime_disable(dev); pm_runtime_set_active(dev); pm_runtime_enable(dev); return 0; + +disable_reg_clk: + clk_disable_unprepare(xhci->reg_clk); + +disable_clk: + clk_disable_unprepare(xhci->clk); + + return ret; } static int __maybe_unused xhci_plat_runtime_suspend(struct device *dev)