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=-13.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, 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 2AB96C433F7 for ; Mon, 20 Jul 2020 16:21:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 01DE52070A for ; Mon, 20 Jul 2020 16:21:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1595262066; bh=IQtVVwASIV9iN5LpAQ0FqLnEWWJ0Umn2MdHysulL3lQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=KRLiKiPNH42OQQTOQ3zRuPJ1oTE48QEALN1r7i353sCam7ZWX3O6hXf9CtiVeu9GV tE9PCZYsJkKv9TD1M0M2T8htJ41ZEI8Zo4VjlyEGEk9MZCl9LjgX/BaWiCc5HD9bIo 9FHdKFLYygwfDelyuSr1Gbd2HiqrZuACzibhoQUc= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387480AbgGTQJE (ORCPT ); Mon, 20 Jul 2020 12:09:04 -0400 Received: from mail.kernel.org ([198.145.29.99]:46770 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387461AbgGTQJD (ORCPT ); Mon, 20 Jul 2020 12:09:03 -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 3AF662065E; Mon, 20 Jul 2020 16:09:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1595261342; bh=IQtVVwASIV9iN5LpAQ0FqLnEWWJ0Umn2MdHysulL3lQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=mHD3ayACkiLDf7WleGsT0v+SYipGmn3ekMY91anz0UErKePkE5Yina2YMRVx03p8q 7ED9aGZp8BNqlmUXslqKCGfA1n30fjf0ki/BEL5p93fEYy4mS9ytEigIzoIgZTn7AZ rZIwri1aW4v4mmIOlgZZdtmSnAIbGZdRoYgLltqs= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Nikhil Rao , Dave Jiang , Vinod Koul , Sasha Levin Subject: [PATCH 5.7 082/244] dmaengine: idxd: fix cdev locking for open and release Date: Mon, 20 Jul 2020 17:35:53 +0200 Message-Id: <20200720152829.742328308@linuxfoundation.org> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200720152825.863040590@linuxfoundation.org> References: <20200720152825.863040590@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Nikhil Rao [ Upstream commit 66983bc18fad17d10766650b3685045f6f092d73 ] add the wq lock in cdev open and release call. This fixes race conditions observed in the open and close routines. Fixes: 42d279f9137a ("dmaengine: idxd: add char driver to expose submission portal to userland") Signed-off-by: Nikhil Rao Signed-off-by: Dave Jiang Link: https://lore.kernel.org/r/159285824892.64944.2905413694915141834.stgit@djiang5-desk3.ch.intel.com Signed-off-by: Vinod Koul Signed-off-by: Sasha Levin --- drivers/dma/idxd/cdev.c | 19 ++++++++++++++++--- 1 file changed, 16 insertions(+), 3 deletions(-) diff --git a/drivers/dma/idxd/cdev.c b/drivers/dma/idxd/cdev.c index ff49847e37a86..cb376cf6a2d2c 100644 --- a/drivers/dma/idxd/cdev.c +++ b/drivers/dma/idxd/cdev.c @@ -74,6 +74,7 @@ static int idxd_cdev_open(struct inode *inode, struct file *filp) struct idxd_device *idxd; struct idxd_wq *wq; struct device *dev; + int rc = 0; wq = inode_wq(inode); idxd = wq->idxd; @@ -81,17 +82,27 @@ static int idxd_cdev_open(struct inode *inode, struct file *filp) dev_dbg(dev, "%s called: %d\n", __func__, idxd_wq_refcount(wq)); - if (idxd_wq_refcount(wq) > 0 && wq_dedicated(wq)) - return -EBUSY; - ctx = kzalloc(sizeof(*ctx), GFP_KERNEL); if (!ctx) return -ENOMEM; + mutex_lock(&wq->wq_lock); + + if (idxd_wq_refcount(wq) > 0 && wq_dedicated(wq)) { + rc = -EBUSY; + goto failed; + } + ctx->wq = wq; filp->private_data = ctx; idxd_wq_get(wq); + mutex_unlock(&wq->wq_lock); return 0; + + failed: + mutex_unlock(&wq->wq_lock); + kfree(ctx); + return rc; } static int idxd_cdev_release(struct inode *node, struct file *filep) @@ -105,7 +116,9 @@ static int idxd_cdev_release(struct inode *node, struct file *filep) filep->private_data = NULL; kfree(ctx); + mutex_lock(&wq->wq_lock); idxd_wq_put(wq); + mutex_unlock(&wq->wq_lock); return 0; } -- 2.25.1