From patchwork Sat May 21 03:35:05 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Shengjiu Wang X-Patchwork-Id: 12857683 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 3750FC433F5 for ; Sat, 21 May 2022 03:47:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235592AbiEUDrv (ORCPT ); Fri, 20 May 2022 23:47:51 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52424 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229773AbiEUDrt (ORCPT ); Fri, 20 May 2022 23:47:49 -0400 Received: from inva020.nxp.com (inva020.nxp.com [92.121.34.13]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7D3D8187DB4; Fri, 20 May 2022 20:47:48 -0700 (PDT) Received: from inva020.nxp.com (localhost [127.0.0.1]) by inva020.eu-rdc02.nxp.com (Postfix) with ESMTP id D4DAD1A0740; Sat, 21 May 2022 05:47:46 +0200 (CEST) Received: from aprdc01srsp001v.ap-rdc01.nxp.com (aprdc01srsp001v.ap-rdc01.nxp.com [165.114.16.16]) by inva020.eu-rdc02.nxp.com (Postfix) with ESMTP id 9F16F1A02E1; Sat, 21 May 2022 05:47:46 +0200 (CEST) Received: from localhost.localdomain (shlinux2.ap.freescale.net [10.192.224.44]) by aprdc01srsp001v.ap-rdc01.nxp.com (Postfix) with ESMTP id 7CD7D180031E; Sat, 21 May 2022 11:47:45 +0800 (+08) From: Shengjiu Wang To: bjorn.andersson@linaro.org, mathieu.poirier@linaro.org, arnaud.pouliquen@foss.st.com Cc: linux-remoteproc@vger.kernel.org, linux-kernel@vger.kernel.org, shengjiu.wang@gmail.com Subject: [RESEND PATCH] rpmsg: char: Add mutex protection for rpmsg_eptdev_open() Date: Sat, 21 May 2022 11:35:05 +0800 Message-Id: <1653104105-16779-1-git-send-email-shengjiu.wang@nxp.com> X-Mailer: git-send-email 2.7.4 X-Virus-Scanned: ClamAV using ClamSMTP Precedence: bulk List-ID: X-Mailing-List: linux-remoteproc@vger.kernel.org There is no mutex protection for rpmsg_eptdev_open(), especially for eptdev->ept read and write operation. It may cause issues when multiple instances call rpmsg_eptdev_open() in parallel,the return state may be success or EBUGY. Fixes: 964e8bedd5a1 ("rpmsg: char: Return an error if device already open") Signed-off-by: Shengjiu Wang --- changes in resend: - add fixes tag drivers/rpmsg/rpmsg_char.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/rpmsg/rpmsg_char.c b/drivers/rpmsg/rpmsg_char.c index b6183d4f62a2..4f2189111494 100644 --- a/drivers/rpmsg/rpmsg_char.c +++ b/drivers/rpmsg/rpmsg_char.c @@ -120,8 +120,11 @@ static int rpmsg_eptdev_open(struct inode *inode, struct file *filp) struct rpmsg_device *rpdev = eptdev->rpdev; struct device *dev = &eptdev->dev; - if (eptdev->ept) + mutex_lock(&eptdev->ept_lock); + if (eptdev->ept) { + mutex_unlock(&eptdev->ept_lock); return -EBUSY; + } get_device(dev); @@ -137,11 +140,13 @@ static int rpmsg_eptdev_open(struct inode *inode, struct file *filp) if (!ept) { dev_err(dev, "failed to open %s\n", eptdev->chinfo.name); put_device(dev); + mutex_unlock(&eptdev->ept_lock); return -EINVAL; } eptdev->ept = ept; filp->private_data = eptdev; + mutex_unlock(&eptdev->ept_lock); return 0; }