From patchwork Wed Jan 26 19:04:46 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Deepak Kumar Singh X-Patchwork-Id: 12725633 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 2E611C63682 for ; Wed, 26 Jan 2022 19:05:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244359AbiAZTFf (ORCPT ); Wed, 26 Jan 2022 14:05:35 -0500 Received: from alexa-out-sd-01.qualcomm.com ([199.106.114.38]:42425 "EHLO alexa-out-sd-01.qualcomm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244338AbiAZTFb (ORCPT ); Wed, 26 Jan 2022 14:05:31 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=quicinc.com; i=@quicinc.com; q=dns/txt; s=qcdkim; t=1643223931; x=1674759931; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version; bh=LFRE4HwPeuPzOCaR80UUEjsVA+y4mxNn65JRwX9K7fY=; b=vd7evSiHlLgyzx8/iS9pn3kEXxYWcMdqr5DtYK3TX17CmNTAlYsooMbv v/+9d1Qu5l4nRJojFziOdU4y2tAJHWXQev8HlrBDvx4isWgcaU9mysyZk OVlWV6R+gV80LidOqjTv6nO/0Ptcp5uPxgnqn7cFqYTAFTMnh22ZtPOmf o=; Received: from unknown (HELO ironmsg05-sd.qualcomm.com) ([10.53.140.145]) by alexa-out-sd-01.qualcomm.com with ESMTP; 26 Jan 2022 11:05:31 -0800 X-QCInternal: smtphost Received: from nasanex01c.na.qualcomm.com ([10.47.97.222]) by ironmsg05-sd.qualcomm.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 26 Jan 2022 11:05:30 -0800 Received: from nalasex01a.na.qualcomm.com (10.47.209.196) by nasanex01c.na.qualcomm.com (10.47.97.222) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.922.19; Wed, 26 Jan 2022 11:05:30 -0800 Received: from deesin-linux.qualcomm.com (10.80.80.8) by nalasex01a.na.qualcomm.com (10.47.209.196) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.922.19; Wed, 26 Jan 2022 11:05:27 -0800 From: Deepak Kumar Singh To: , , , CC: , , , Deepak Kumar Singh , Ohad Ben-Cohen Subject: [PATCH V1 3/3] rpmsg: glink: Add lock for ctrl device Date: Thu, 27 Jan 2022 00:34:46 +0530 Message-ID: <1643223886-28170-4-git-send-email-quic_deesin@quicinc.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1643223886-28170-1-git-send-email-quic_deesin@quicinc.com> References: <1643223886-28170-1-git-send-email-quic_deesin@quicinc.com> MIME-Version: 1.0 X-Originating-IP: [10.80.80.8] X-ClientProxiedBy: nasanex01b.na.qualcomm.com (10.46.141.250) To nalasex01a.na.qualcomm.com (10.47.209.196) Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org Race between rpmsg_eptdev_create and rpmsg_chrdev_remove can sometime casue crash while accessing rpdev while new endpoint is being created. Using lock ensure no new eptdev is created after rpmsg_chrdev_remove has been completed. --- drivers/rpmsg/rpmsg_char.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/drivers/rpmsg/rpmsg_char.c b/drivers/rpmsg/rpmsg_char.c index 2108ef8..3e5b85d 100644 --- a/drivers/rpmsg/rpmsg_char.c +++ b/drivers/rpmsg/rpmsg_char.c @@ -27,6 +27,7 @@ static dev_t rpmsg_major; static struct class *rpmsg_class; +struct mutex ctrl_lock; static DEFINE_IDA(rpmsg_ctrl_ida); static DEFINE_IDA(rpmsg_ept_ida); @@ -396,9 +397,12 @@ static int rpmsg_eptdev_create(struct rpmsg_ctrldev *ctrldev, struct device *dev; int ret; + mutex_lock(&ctrl_lock); eptdev = kzalloc(sizeof(*eptdev), GFP_KERNEL); - if (!eptdev) + if (!eptdev) { + mutex_unlock(&ctrl_lock); return -ENOMEM; + } dev = &eptdev->dev; eptdev->rpdev = rpdev; @@ -443,6 +447,7 @@ static int rpmsg_eptdev_create(struct rpmsg_ctrldev *ctrldev, put_device(dev); } + mutex_unlock(&ctrl_lock); return ret; free_ept_ida: @@ -453,6 +458,7 @@ static int rpmsg_eptdev_create(struct rpmsg_ctrldev *ctrldev, put_device(dev); kfree(eptdev); + mutex_unlock(&ctrl_lock); return ret; } @@ -525,6 +531,7 @@ static int rpmsg_chrdev_probe(struct rpmsg_device *rpdev) if (!ctrldev) return -ENOMEM; + mutex_init(&ctrl_lock); ctrldev->rpdev = rpdev; dev = &ctrldev->dev; @@ -581,12 +588,14 @@ static void rpmsg_chrdev_remove(struct rpmsg_device *rpdev) int ret; /* Destroy all endpoints */ + mutex_lock(&ctrl_lock); ret = device_for_each_child(&ctrldev->dev, NULL, rpmsg_eptdev_destroy); if (ret) dev_warn(&rpdev->dev, "failed to nuke endpoints: %d\n", ret); device_del(&ctrldev->dev); put_device(&ctrldev->dev); + mutex_unlock(&ctrl_lock); } static struct rpmsg_driver rpmsg_chrdev_driver = {