From patchwork Tue May 28 10:56:20 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefano Garzarella X-Patchwork-Id: 1106255 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=redhat.com Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 45CrPl5Zczz9sB3 for ; Tue, 28 May 2019 20:56:43 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726806AbfE1K4j (ORCPT ); Tue, 28 May 2019 06:56:39 -0400 Received: from mx1.redhat.com ([209.132.183.28]:60092 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726282AbfE1K4j (ORCPT ); Tue, 28 May 2019 06:56:39 -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 E2B8B3079B8F; Tue, 28 May 2019 10:56:38 +0000 (UTC) Received: from steredhat.redhat.com (ovpn-117-13.ams2.redhat.com [10.36.117.13]) by smtp.corp.redhat.com (Postfix) with ESMTP id 2E37560BE2; Tue, 28 May 2019 10:56:36 +0000 (UTC) From: Stefano Garzarella To: netdev@vger.kernel.org Cc: linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org, kvm@vger.kernel.org, Stefan Hajnoczi , "David S. Miller" , "Michael S . Tsirkin" Subject: [PATCH 1/4] vsock/virtio: fix locking around 'the_virtio_vsock' Date: Tue, 28 May 2019 12:56:20 +0200 Message-Id: <20190528105623.27983-2-sgarzare@redhat.com> In-Reply-To: <20190528105623.27983-1-sgarzare@redhat.com> References: <20190528105623.27983-1-sgarzare@redhat.com> MIME-Version: 1.0 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]); Tue, 28 May 2019 10:56:39 +0000 (UTC) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org This patch protects the reading of 'the_virtio_vsock' taking the mutex used when it is set. We also move the 'the_virtio_vsock' assignment at the end of the .probe(), when we finished all the initialization, and at the beginning of .remove(), before to release resources, taking the lock until the end of the function. Signed-off-by: Stefano Garzarella --- net/vmw_vsock/virtio_transport.c | 19 +++++++++++++------ 1 file changed, 13 insertions(+), 6 deletions(-) diff --git a/net/vmw_vsock/virtio_transport.c b/net/vmw_vsock/virtio_transport.c index 96ab344f17bb..d3ba7747aa73 100644 --- a/net/vmw_vsock/virtio_transport.c +++ b/net/vmw_vsock/virtio_transport.c @@ -68,7 +68,13 @@ struct virtio_vsock { static struct virtio_vsock *virtio_vsock_get(void) { - return the_virtio_vsock; + struct virtio_vsock *vsock; + + mutex_lock(&the_virtio_vsock_mutex); + vsock = the_virtio_vsock; + mutex_unlock(&the_virtio_vsock_mutex); + + return vsock; } static u32 virtio_transport_get_local_cid(void) @@ -592,7 +598,6 @@ static int virtio_vsock_probe(struct virtio_device *vdev) atomic_set(&vsock->queued_replies, 0); vdev->priv = vsock; - the_virtio_vsock = vsock; mutex_init(&vsock->tx_lock); mutex_init(&vsock->rx_lock); mutex_init(&vsock->event_lock); @@ -614,6 +619,8 @@ static int virtio_vsock_probe(struct virtio_device *vdev) virtio_vsock_event_fill(vsock); mutex_unlock(&vsock->event_lock); + the_virtio_vsock = vsock; + mutex_unlock(&the_virtio_vsock_mutex); return 0; @@ -628,6 +635,9 @@ static void virtio_vsock_remove(struct virtio_device *vdev) struct virtio_vsock *vsock = vdev->priv; struct virtio_vsock_pkt *pkt; + mutex_lock(&the_virtio_vsock_mutex); + the_virtio_vsock = NULL; + flush_work(&vsock->loopback_work); flush_work(&vsock->rx_work); flush_work(&vsock->tx_work); @@ -667,13 +677,10 @@ static void virtio_vsock_remove(struct virtio_device *vdev) } spin_unlock_bh(&vsock->loopback_list_lock); - mutex_lock(&the_virtio_vsock_mutex); - the_virtio_vsock = NULL; - mutex_unlock(&the_virtio_vsock_mutex); - vdev->config->del_vqs(vdev); kfree(vsock); + mutex_unlock(&the_virtio_vsock_mutex); } static struct virtio_device_id id_table[] = {