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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 76C42ECAAD8 for ; Wed, 14 Sep 2022 07:57:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230280AbiINH52 (ORCPT ); Wed, 14 Sep 2022 03:57:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59264 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230306AbiINH5H (ORCPT ); Wed, 14 Sep 2022 03:57:07 -0400 Received: from mx07-00178001.pphosted.com (mx07-00178001.pphosted.com [185.132.182.106]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5866C74DDE; Wed, 14 Sep 2022 00:56:04 -0700 (PDT) Received: from pps.filterd (m0241204.ppops.net [127.0.0.1]) by mx07-00178001.pphosted.com (8.17.1.5/8.17.1.5) with ESMTP id 28E4wmj9011529; Wed, 14 Sep 2022 09:55:58 +0200 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=foss.st.com; h=message-id : date : mime-version : subject : to : cc : references : from : in-reply-to : content-type : content-transfer-encoding; s=selector1; bh=TaMxnr1hW83w8IirdV0xmuuDYtv5ukIfg/IXCa7trMY=; b=al78NWzHlanWshtZUb+YQ7PcUPqNYYEoqWrUK1o/JDJ4LS0ObXpgGOazeCrzzIDZhG4V OMlxM+RaSoZvfNXgkUZRLiZe9Rt+8LlvxA8/YeGB6grNWRHtv2z4cmS/iq3pQ83DOCrb RhbOVlruzgdKqm9NnxsiqJCUjjCk2h5+USAAd8xetgYouBhlZXLg1+cBTOx348BQJLUU a8mqH9jMWqNbZ+nlI9C0eJ6KthmAvtrhzlJeM8ZS2WLDiOTM79WEENl1ggsrAnopFtfa 09SD85B4aJPVnphMBlyOObeuoCaa+ho6Dta+SulNQQaUTppNKVwB2qokoOZgSOaBrcdR yg== Received: from beta.dmz-eu.st.com (beta.dmz-eu.st.com [164.129.1.35]) by mx07-00178001.pphosted.com (PPS) with ESMTPS id 3jjy07bcc3-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 14 Sep 2022 09:55:46 +0200 Received: from euls16034.sgp.st.com (euls16034.sgp.st.com [10.75.44.20]) by beta.dmz-eu.st.com (STMicroelectronics) with ESMTP id 204B410002A; Wed, 14 Sep 2022 09:55:37 +0200 (CEST) Received: from Webmail-eu.st.com (eqndag1node5.st.com [10.75.129.134]) by euls16034.sgp.st.com (STMicroelectronics) with ESMTP id 1A7732132C9; Wed, 14 Sep 2022 09:55:37 +0200 (CEST) Received: from [10.201.22.245] (10.75.127.49) by EQNDAG1NODE5.st.com (10.75.129.134) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256) id 15.1.2375.31; Wed, 14 Sep 2022 09:55:36 +0200 Message-ID: <33471742-634b-8fcb-dd56-e396c4e788f5@foss.st.com> Date: Wed, 14 Sep 2022 09:55:35 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.11.0 Subject: Re: [PATCH V3 1/2] rpmsg: glink: Add lock to avoid race when rpmsg device is released Content-Language: en-US To: Deepak Kumar Singh , , , , CC: , , References: <1663002336-11809-1-git-send-email-quic_deesin@quicinc.com> <1663002336-11809-2-git-send-email-quic_deesin@quicinc.com> From: Arnaud POULIQUEN In-Reply-To: <1663002336-11809-2-git-send-email-quic_deesin@quicinc.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.75.127.49] X-ClientProxiedBy: SFHDAG2NODE3.st.com (10.75.127.6) To EQNDAG1NODE5.st.com (10.75.129.134) X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.895,Hydra:6.0.528,FMLib:17.11.122.1 definitions=2022-09-14_02,2022-09-13_01,2022-06-22_01 Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org The commit subject should start with "rpmsg: char:" no glink driver update... Regards, Arnaud On 9/12/22 19:05, Deepak Kumar Singh wrote: > When remote host goes down glink char device channel is freed and > associated rpdev is destroyed through rpmsg_chrdev_eptdev_destroy(), > At the same time user space apps can still try to open/poll rpmsg > char device which will result in calling rpmsg_create_ept()/rpmsg_poll(). > These functions will try to reference rpdev which has already been freed > through rpmsg_chrdev_eptdev_destroy(). > > File operation functions and device removal function must be protected > with lock. This patch adds existing ept lock in remove function as well. > > Signed-off-by: Deepak Kumar Singh > --- > drivers/rpmsg/rpmsg_char.c | 8 ++++++++ > 1 file changed, 8 insertions(+) > > diff --git a/drivers/rpmsg/rpmsg_char.c b/drivers/rpmsg/rpmsg_char.c > index 4f21891..5500dc0 100644 > --- a/drivers/rpmsg/rpmsg_char.c > +++ b/drivers/rpmsg/rpmsg_char.c > @@ -75,6 +75,7 @@ int rpmsg_chrdev_eptdev_destroy(struct device *dev, void *data) > struct rpmsg_eptdev *eptdev = dev_to_eptdev(dev); > > mutex_lock(&eptdev->ept_lock); > + eptdev->rpdev = NULL; > if (eptdev->ept) { > rpmsg_destroy_ept(eptdev->ept); > eptdev->ept = NULL; > @@ -126,6 +127,11 @@ static int rpmsg_eptdev_open(struct inode *inode, struct file *filp) > return -EBUSY; > } > > + if (!eptdev->rpdev) { > + mutex_unlock(&eptdev->ept_lock); > + return -ENETRESET; > + } > + > get_device(dev); > > /* > @@ -277,7 +283,9 @@ static __poll_t rpmsg_eptdev_poll(struct file *filp, poll_table *wait) > if (!skb_queue_empty(&eptdev->queue)) > mask |= EPOLLIN | EPOLLRDNORM; > > + mutex_lock(&eptdev->ept_lock); > mask |= rpmsg_poll(eptdev->ept, filp, wait); > + mutex_unlock(&eptdev->ept_lock); > > return mask; > }