From patchwork Tue Sep 11 10:10:35 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Heikki Krogerus X-Patchwork-Id: 10595367 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 426BD15E2 for ; Tue, 11 Sep 2018 10:10:51 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 32FEF28F19 for ; Tue, 11 Sep 2018 10:10:51 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 2745829008; Tue, 11 Sep 2018 10:10:51 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id D247728F19 for ; Tue, 11 Sep 2018 10:10:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726739AbeIKPJZ (ORCPT ); Tue, 11 Sep 2018 11:09:25 -0400 Received: from mga18.intel.com ([134.134.136.126]:19099 "EHLO mga18.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726559AbeIKPJZ (ORCPT ); Tue, 11 Sep 2018 11:09:25 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga106.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 11 Sep 2018 03:10:48 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.53,360,1531810800"; d="scan'208";a="88991806" Received: from black.fi.intel.com (HELO black.fi.intel.com.) ([10.237.72.28]) by fmsmga001.fm.intel.com with ESMTP; 11 Sep 2018 03:10:46 -0700 From: Heikki Krogerus To: Hans de Goede , Greg Kroah-Hartman Cc: Andy Shevchenko , Darren Hart , platform-driver-x86@vger.kernel.org, linux-usb@vger.kernel.org, stable@vger.kernel.org Subject: [PATCH v4 01/10] usb: typec: Take care of driver module reference counting Date: Tue, 11 Sep 2018 13:10:35 +0300 Message-Id: <20180911101044.44004-2-heikki.krogerus@linux.intel.com> X-Mailer: git-send-email 2.18.0 In-Reply-To: <20180911101044.44004-1-heikki.krogerus@linux.intel.com> References: <20180911101044.44004-1-heikki.krogerus@linux.intel.com> Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Functions typec_mux_get() and typec_switch_get() already make sure that the mux device reference count is incremented, but the same must be done to the driver module as well to prevent the drivers from being unloaded in the middle of operation. This fixes a potential "BUG: unable to handle kernel paging request at ..." from happening. Fixes: 93dd2112c7b2 ("usb: typec: mux: Get the mux identifier from function parameter") Cc: Signed-off-by: Heikki Krogerus --- drivers/usb/typec/mux.c | 17 +++++++++++++---- 1 file changed, 13 insertions(+), 4 deletions(-) diff --git a/drivers/usb/typec/mux.c b/drivers/usb/typec/mux.c index ddaac63ecf12..d990aa510fab 100644 --- a/drivers/usb/typec/mux.c +++ b/drivers/usb/typec/mux.c @@ -9,6 +9,7 @@ #include #include +#include #include #include @@ -49,8 +50,10 @@ struct typec_switch *typec_switch_get(struct device *dev) mutex_lock(&switch_lock); sw = device_connection_find_match(dev, "typec-switch", NULL, typec_switch_match); - if (!IS_ERR_OR_NULL(sw)) + if (!IS_ERR_OR_NULL(sw)) { + WARN_ON(!try_module_get(sw->dev->driver->owner)); get_device(sw->dev); + } mutex_unlock(&switch_lock); return sw; @@ -65,8 +68,10 @@ EXPORT_SYMBOL_GPL(typec_switch_get); */ void typec_switch_put(struct typec_switch *sw) { - if (!IS_ERR_OR_NULL(sw)) + if (!IS_ERR_OR_NULL(sw)) { + module_put(sw->dev->driver->owner); put_device(sw->dev); + } } EXPORT_SYMBOL_GPL(typec_switch_put); @@ -136,8 +141,10 @@ struct typec_mux *typec_mux_get(struct device *dev, const char *name) mutex_lock(&mux_lock); mux = device_connection_find_match(dev, name, NULL, typec_mux_match); - if (!IS_ERR_OR_NULL(mux)) + if (!IS_ERR_OR_NULL(mux)) { + WARN_ON(!try_module_get(mux->dev->driver->owner)); get_device(mux->dev); + } mutex_unlock(&mux_lock); return mux; @@ -152,8 +159,10 @@ EXPORT_SYMBOL_GPL(typec_mux_get); */ void typec_mux_put(struct typec_mux *mux) { - if (!IS_ERR_OR_NULL(mux)) + if (!IS_ERR_OR_NULL(mux)) { + module_put(mux->dev->driver->owner); put_device(mux->dev); + } } EXPORT_SYMBOL_GPL(typec_mux_put);