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=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 922A5C10F14 for ; Thu, 3 Oct 2019 16:39:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 667602070B for ; Thu, 3 Oct 2019 16:39:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570120748; bh=L0SmYGtaGcxI3+BLpfscRZ+R1XBFygt6MAgF3wzw8/g=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=G7l2ohel9yDsmNtYa6nc4i8XKqKklGcdJ8bF+yJJ06ckHHt4zsXTALnDjYB/38hJ2 OXXa41Vz1y7eMxbJp8u7gKxvMwDujX2+tBZdrZ1b9948Zq9v2mjTTQN/lHoLWHitnN kLwgSdJuR05lH82R+OA1pEen73PDSaXOTnXYXygM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2404789AbfJCQjH (ORCPT ); Thu, 3 Oct 2019 12:39:07 -0400 Received: from mail.kernel.org ([198.145.29.99]:47728 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2404700AbfJCQiH (ORCPT ); Thu, 3 Oct 2019 12:38:07 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id A50B821783; Thu, 3 Oct 2019 16:38:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570120686; bh=L0SmYGtaGcxI3+BLpfscRZ+R1XBFygt6MAgF3wzw8/g=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Z+1Ta1xKwhsl7y+aFZQnoEMzuLwm2HhuUMa5UWrDXdHLzYoRg6nRq3qcwKL8RCiwd 65vXIHyXP65a2rVQaQpdUGEU2f9Hm/cuap9q/jpTuedS4XhUxfvdSJDOl3IVYxxakY B+bFg8fnSdIwN3OVA4dCpEceKjXq5+mIwB7Im1As= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Pi-Hsun Shih , Enric Balletbo i Serra , Sasha Levin Subject: [PATCH 5.2 313/313] platform/chrome: cros_ec_rpmsg: Fix race with host command when probe failed Date: Thu, 3 Oct 2019 17:54:51 +0200 Message-Id: <20191003154604.030111391@linuxfoundation.org> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20191003154533.590915454@linuxfoundation.org> References: <20191003154533.590915454@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Pi-Hsun Shih [ Upstream commit 71cddb7097e2b0feb855d7fd7d59afd12cbee4bb ] Since the rpmsg_endpoint is created before probe is called, it's possible that a host event is received during cros_ec_register, and there would be some pending work in the host_event_work workqueue while cros_ec_register is called. If cros_ec_register fails, when the leftover work in host_event_work run, the ec_dev from the drvdata of the rpdev could be already set to NULL, causing kernel crash when trying to run cros_ec_get_next_event. Fix this by creating the rpmsg_endpoint by ourself, and when cros_ec_register fails (or on remove), destroy the endpoint first (to make sure there's no more new calls to cros_ec_rpmsg_callback), and then cancel all works in the host_event_work workqueue. Cc: stable@vger.kernel.org Fixes: 2de89fd98958 ("platform/chrome: cros_ec: Add EC host command support using rpmsg") Signed-off-by: Pi-Hsun Shih Signed-off-by: Enric Balletbo i Serra Signed-off-by: Sasha Levin --- drivers/platform/chrome/cros_ec_rpmsg.c | 32 +++++++++++++++++++++---- 1 file changed, 28 insertions(+), 4 deletions(-) diff --git a/drivers/platform/chrome/cros_ec_rpmsg.c b/drivers/platform/chrome/cros_ec_rpmsg.c index 5d3fb2abad1d6..bec19d4814aba 100644 --- a/drivers/platform/chrome/cros_ec_rpmsg.c +++ b/drivers/platform/chrome/cros_ec_rpmsg.c @@ -41,6 +41,7 @@ struct cros_ec_rpmsg { struct rpmsg_device *rpdev; struct completion xfer_ack; struct work_struct host_event_work; + struct rpmsg_endpoint *ept; }; /** @@ -72,7 +73,6 @@ static int cros_ec_pkt_xfer_rpmsg(struct cros_ec_device *ec_dev, struct cros_ec_command *ec_msg) { struct cros_ec_rpmsg *ec_rpmsg = ec_dev->priv; - struct rpmsg_device *rpdev = ec_rpmsg->rpdev; struct ec_host_response *response; unsigned long timeout; int len; @@ -85,7 +85,7 @@ static int cros_ec_pkt_xfer_rpmsg(struct cros_ec_device *ec_dev, dev_dbg(ec_dev->dev, "prepared, len=%d\n", len); reinit_completion(&ec_rpmsg->xfer_ack); - ret = rpmsg_send(rpdev->ept, ec_dev->dout, len); + ret = rpmsg_send(ec_rpmsg->ept, ec_dev->dout, len); if (ret) { dev_err(ec_dev->dev, "rpmsg send failed\n"); return ret; @@ -196,11 +196,24 @@ static int cros_ec_rpmsg_callback(struct rpmsg_device *rpdev, void *data, return 0; } +static struct rpmsg_endpoint * +cros_ec_rpmsg_create_ept(struct rpmsg_device *rpdev) +{ + struct rpmsg_channel_info chinfo = {}; + + strscpy(chinfo.name, rpdev->id.name, RPMSG_NAME_SIZE); + chinfo.src = rpdev->src; + chinfo.dst = RPMSG_ADDR_ANY; + + return rpmsg_create_ept(rpdev, cros_ec_rpmsg_callback, NULL, chinfo); +} + static int cros_ec_rpmsg_probe(struct rpmsg_device *rpdev) { struct device *dev = &rpdev->dev; struct cros_ec_rpmsg *ec_rpmsg; struct cros_ec_device *ec_dev; + int ret; ec_dev = devm_kzalloc(dev, sizeof(*ec_dev), GFP_KERNEL); if (!ec_dev) @@ -225,7 +238,18 @@ static int cros_ec_rpmsg_probe(struct rpmsg_device *rpdev) INIT_WORK(&ec_rpmsg->host_event_work, cros_ec_rpmsg_host_event_function); - return cros_ec_register(ec_dev); + ec_rpmsg->ept = cros_ec_rpmsg_create_ept(rpdev); + if (!ec_rpmsg->ept) + return -ENOMEM; + + ret = cros_ec_register(ec_dev); + if (ret < 0) { + rpmsg_destroy_ept(ec_rpmsg->ept); + cancel_work_sync(&ec_rpmsg->host_event_work); + return ret; + } + + return 0; } static void cros_ec_rpmsg_remove(struct rpmsg_device *rpdev) @@ -233,6 +257,7 @@ static void cros_ec_rpmsg_remove(struct rpmsg_device *rpdev) struct cros_ec_device *ec_dev = dev_get_drvdata(&rpdev->dev); struct cros_ec_rpmsg *ec_rpmsg = ec_dev->priv; + rpmsg_destroy_ept(ec_rpmsg->ept); cancel_work_sync(&ec_rpmsg->host_event_work); } @@ -249,7 +274,6 @@ static struct rpmsg_driver cros_ec_driver_rpmsg = { }, .probe = cros_ec_rpmsg_probe, .remove = cros_ec_rpmsg_remove, - .callback = cros_ec_rpmsg_callback, }; module_rpmsg_driver(cros_ec_driver_rpmsg); -- 2.20.1