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=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 85A42C43381 for ; Mon, 25 Mar 2019 11:48:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 56D8D20850 for ; Mon, 25 Mar 2019 11:48:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730967AbfCYLs5 (ORCPT ); Mon, 25 Mar 2019 07:48:57 -0400 Received: from mx1.redhat.com ([209.132.183.28]:40478 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729831AbfCYLs4 (ORCPT ); Mon, 25 Mar 2019 07:48:56 -0400 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id B197C3099FD1; Mon, 25 Mar 2019 11:48:56 +0000 (UTC) Received: from maximlenovopc.usersys.redhat.com (unknown [10.35.206.72]) by smtp.corp.redhat.com (Postfix) with ESMTP id 1D55576F62; Mon, 25 Mar 2019 11:48:52 +0000 (UTC) Message-ID: Subject: Re: [PATCH 1/8] vfio/mdev: Fix to not do put_device on device_register failure From: Maxim Levitsky To: Parav Pandit , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, kwankhede@nvidia.com, alex.williamson@redhat.com Date: Mon, 25 Mar 2019 13:48:51 +0200 In-Reply-To: <1553296835-37522-2-git-send-email-parav@mellanox.com> References: <1553296835-37522-1-git-send-email-parav@mellanox.com> <1553296835-37522-2-git-send-email-parav@mellanox.com> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.41]); Mon, 25 Mar 2019 11:48:56 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 2019-03-22 at 18:20 -0500, Parav Pandit wrote: > device_register() performs put_device() if device_add() fails. > This balances with device_initialize(). > > mdev core performing put_device() when device_register() fails, > is an error that puts already released device again. > Therefore, don't put the device on error. > > Fixes: 7b96953bc640 ("vfio: Mediated device Core driver") > Signed-off-by: Parav Pandit > --- > drivers/vfio/mdev/mdev_core.c | 4 +--- > 1 file changed, 1 insertion(+), 3 deletions(-) > > diff --git a/drivers/vfio/mdev/mdev_core.c b/drivers/vfio/mdev/mdev_core.c > index 0212f0e..3e5880a 100644 > --- a/drivers/vfio/mdev/mdev_core.c > +++ b/drivers/vfio/mdev/mdev_core.c > @@ -318,10 +318,8 @@ int mdev_device_create(struct kobject *kobj, struct > device *dev, uuid_le uuid) > dev_set_name(&mdev->dev, "%pUl", uuid.b); > > ret = device_register(&mdev->dev); > - if (ret) { > - put_device(&mdev->dev); > + if (ret) > goto mdev_fail; > - } > > ret = mdev_device_create_ops(kobj, mdev); > if (ret) Very good catch! Thanks! Reviewed-by: Maxim Levitsky Best regards, Maxim Levitsky