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=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS 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 C4956C4360C for ; Fri, 27 Sep 2019 11:28:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9C7EE217D9 for ; Fri, 27 Sep 2019 11:28:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727912AbfI0L2p (ORCPT ); Fri, 27 Sep 2019 07:28:45 -0400 Received: from mx1.redhat.com ([209.132.183.28]:40128 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727128AbfI0L2i (ORCPT ); Fri, 27 Sep 2019 07:28:38 -0400 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id ED482A44AE4; Fri, 27 Sep 2019 11:28:37 +0000 (UTC) Received: from steredhat.redhat.com (ovpn-117-249.ams2.redhat.com [10.36.117.249]) by smtp.corp.redhat.com (Postfix) with ESMTP id E8BDA5D9C3; Fri, 27 Sep 2019 11:28:34 +0000 (UTC) From: Stefano Garzarella To: netdev@vger.kernel.org Cc: linux-hyperv@vger.kernel.org, "K. Y. Srinivasan" , Stefan Hajnoczi , Sasha Levin , linux-kernel@vger.kernel.org, kvm@vger.kernel.org, "David S. Miller" , virtualization@lists.linux-foundation.org, Stephen Hemminger , Jason Wang , "Michael S. Tsirkin" , Haiyang Zhang , Dexuan Cui , Jorgen Hansen Subject: [RFC PATCH 12/13] vsock: prevent transport modules unloading Date: Fri, 27 Sep 2019 13:27:02 +0200 Message-Id: <20190927112703.17745-13-sgarzare@redhat.com> In-Reply-To: <20190927112703.17745-1-sgarzare@redhat.com> References: <20190927112703.17745-1-sgarzare@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.6.2 (mx1.redhat.com [10.5.110.68]); Fri, 27 Sep 2019 11:28:38 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This patch adds 'module' member in the 'struct vsock_transport' in order to get/put the transport module. This prevents the module unloading while sockets are assigned to it. We increase the module refcnt when a socket is assigned to a transport, and we decrease the module refcnt when the socket is destructed. Signed-off-by: Stefano Garzarella --- drivers/vhost/vsock.c | 1 + include/net/af_vsock.h | 1 + net/vmw_vsock/af_vsock.c | 23 +++++++++++++++++------ net/vmw_vsock/hyperv_transport.c | 1 + net/vmw_vsock/virtio_transport.c | 1 + net/vmw_vsock/vmci_transport.c | 1 + 6 files changed, 22 insertions(+), 6 deletions(-) diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c index 375af01a5b64..6d7a8fc9eb63 100644 --- a/drivers/vhost/vsock.c +++ b/drivers/vhost/vsock.c @@ -387,6 +387,7 @@ static bool vhost_vsock_more_replies(struct vhost_vsock *vsock) static struct virtio_transport vhost_transport = { .transport = { .features = VSOCK_TRANSPORT_F_H2G, + .module = THIS_MODULE, .get_local_cid = vhost_transport_get_local_cid, diff --git a/include/net/af_vsock.h b/include/net/af_vsock.h index 2a081d19e20d..f10fa918bf23 100644 --- a/include/net/af_vsock.h +++ b/include/net/af_vsock.h @@ -100,6 +100,7 @@ struct vsock_transport_send_notify_data { struct vsock_transport { uint64_t features; + struct module *module; /* Initialize/tear-down socket. */ int (*init)(struct vsock_sock *, struct vsock_sock *); diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c index c5f46b8242ce..750b62711b01 100644 --- a/net/vmw_vsock/af_vsock.c +++ b/net/vmw_vsock/af_vsock.c @@ -416,13 +416,28 @@ int vsock_assign_transport(struct vsock_sock *vsk, struct vsock_sock *psk) return -ESOCKTNOSUPPORT; } - if (!vsk->transport) + /* We increase the module refcnt to prevent the tranport unloading + * while there are open sockets assigned to it. + */ + if (!vsk->transport || !try_module_get(vsk->transport->module)) { + vsk->transport = NULL; return -ENODEV; + } return vsk->transport->init(vsk, psk); } EXPORT_SYMBOL_GPL(vsock_assign_transport); +static void vsock_deassign_transport(struct vsock_sock *vsk) +{ + if (!vsk->transport) + return; + + vsk->transport->destruct(vsk); + module_put(vsk->transport->module); + vsk->transport = NULL; +} + static bool vsock_find_cid(unsigned int cid) { if (transport_g2h && cid == transport_g2h->get_local_cid()) @@ -728,8 +743,7 @@ static void vsock_sk_destruct(struct sock *sk) { struct vsock_sock *vsk = vsock_sk(sk); - if (vsk->transport) - vsk->transport->destruct(vsk); + vsock_deassign_transport(vsk); /* When clearing these addresses, there's no need to set the family and * possibly register the address family with the kernel. @@ -2161,9 +2175,6 @@ void vsock_core_unregister(const struct vsock_transport *t) { mutex_lock(&vsock_register_mutex); - /* RFC-TODO: maybe we should check if there are open sockets - * assigned to that transport and avoid the unregistration - */ if (transport_h2g == t) transport_h2g = NULL; diff --git a/net/vmw_vsock/hyperv_transport.c b/net/vmw_vsock/hyperv_transport.c index 94e6fc905a77..bd4f3c222904 100644 --- a/net/vmw_vsock/hyperv_transport.c +++ b/net/vmw_vsock/hyperv_transport.c @@ -857,6 +857,7 @@ int hvs_notify_send_post_enqueue(struct vsock_sock *vsk, ssize_t written, static struct vsock_transport hvs_transport = { .features = VSOCK_TRANSPORT_F_G2H, + .module = THIS_MODULE, .get_local_cid = hvs_get_local_cid, diff --git a/net/vmw_vsock/virtio_transport.c b/net/vmw_vsock/virtio_transport.c index 0ff037ef7f8e..439fe01e6691 100644 --- a/net/vmw_vsock/virtio_transport.c +++ b/net/vmw_vsock/virtio_transport.c @@ -463,6 +463,7 @@ static void virtio_vsock_rx_done(struct virtqueue *vq) static struct virtio_transport virtio_transport = { .transport = { .features = VSOCK_TRANSPORT_F_G2H, + .module = THIS_MODULE, .get_local_cid = virtio_transport_get_local_cid, diff --git a/net/vmw_vsock/vmci_transport.c b/net/vmw_vsock/vmci_transport.c index 52e63952d0d4..900392686c03 100644 --- a/net/vmw_vsock/vmci_transport.c +++ b/net/vmw_vsock/vmci_transport.c @@ -2021,6 +2021,7 @@ static u32 vmci_transport_get_local_cid(void) static struct vsock_transport vmci_transport = { .features = VSOCK_TRANSPORT_F_DGRAM | VSOCK_TRANSPORT_F_H2G, + .module = THIS_MODULE, .init = vmci_transport_socket_init, .destruct = vmci_transport_destruct, .release = vmci_transport_release, -- 2.21.0