From patchwork Wed Oct 4 20:47:03 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sergey Shtylyov X-Patchwork-Id: 13409456 Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id AF23A2110B for ; Wed, 4 Oct 2023 20:47:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=none Received: from mx01.omp.ru (mx01.omp.ru [90.154.21.10]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D71B5B8 for ; Wed, 4 Oct 2023 13:47:06 -0700 (PDT) Received: from [192.168.1.103] (31.173.82.102) 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; Wed, 4 Oct 2023 23:47:03 +0300 From: Sergey Shtylyov Subject: [PATCH v5] 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: Date: Wed, 4 Oct 2023 23:47:03 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.10.1 Precedence: bulk X-Mailing-List: linux-usb@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Language: en-US X-Originating-IP: [31.173.82.102] 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: 6.0.0, Database issued on: 10/04/2023 20:24:56 X-KSE-AntiSpam-Status: KAS_STATUS_NOT_DETECTED X-KSE-AntiSpam-Method: none X-KSE-AntiSpam-Rate: 59 X-KSE-AntiSpam-Info: Lua profiles 180363 [Oct 04 2023] X-KSE-AntiSpam-Info: Version: 6.0.0.2 X-KSE-AntiSpam-Info: Envelope from: s.shtylyov@omp.ru X-KSE-AntiSpam-Info: LuaCore: 535 535 da804c0ea8918f802fc60e7a20ba49783d957ba2 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: 31.173.82.102 in (user) b.barracudacentral.org} X-KSE-AntiSpam-Info: 31.173.82.102:7.7.3,7.4.1;d41d8cd98f00b204e9800998ecf8427e.com:7.1.1;omp.ru:7.1.1;127.0.0.199:7.1.2 X-KSE-AntiSpam-Info: {cloud_iprep_silent} X-KSE-AntiSpam-Info: FromAlignment: s X-KSE-AntiSpam-Info: {rdns complete} X-KSE-AntiSpam-Info: {fromrtbl complete} X-KSE-AntiSpam-Info: ApMailHostAddress: 31.173.82.102 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=none header.from=omp.ru;spf=none 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: 10/04/2023 20:29:00 X-KSE-Antivirus-Interceptor-Info: scan successful X-KSE-Antivirus-Info: Clean, bases: 10/4/2023 5:06:00 PM X-KSE-Attachment-Filter-Triggered-Rules: Clean X-KSE-Attachment-Filter-Triggered-Filters: Clean X-KSE-BulkMessagesFiltering-Scan-Result: InTheLimit X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00,SPF_HELO_NONE, SPF_PASS autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net 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-next' branch of Greg KH's 'usb.git' repo... Changes in version 5: - got rid of xhci_plat_disable_clocks() helper; - removed the passage on what's done by the patch from the patch description; - rebased the patch against the 'usb-next' branch. Changes in version 4: - resolved reject in xhci_plat_resume() due to the changed xhci_resume() call; - added the __maybe_unused attribute to xhci_plat_disable_clocks(). Changes in version 3: - sanitized the clock enabling error paths in xhci_plat_resume() WRT the applicability checks; - factored out the common clock disabling code from the suspend() and resume() driver PM methods; - added to the patch sescriptiun a passage describing the change being done. Changes in version 2: - fixed up the error path for clk_prepare_enable() calls in xhci_plat_resume(). drivers/usb/host/xhci-plat.c | 23 +++++++++++++++++++---- 1 file changed, 19 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 @@ -458,23 +458,38 @@ 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) { + clk_disable_unprepare(xhci->clk); + return ret; + } } ret = xhci_priv_resume_quirk(hcd); if (ret) - return ret; + goto disable_clks; ret = xhci_resume(xhci, PMSG_RESUME); if (ret) - return ret; + goto disable_clks; pm_runtime_disable(dev); pm_runtime_set_active(dev); pm_runtime_enable(dev); return 0; + +disable_clks: + if (!device_may_wakeup(dev) && (xhci->quirks & XHCI_SUSPEND_RESUME_CLKS)) { + clk_disable_unprepare(xhci->clk); + clk_disable_unprepare(xhci->reg_clk); + } + + return ret; } static int __maybe_unused xhci_plat_runtime_suspend(struct device *dev)