From patchwork Thu Nov 14 09:57:48 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefano Garzarella X-Patchwork-Id: 11243315 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id D12406C1 for ; Thu, 14 Nov 2019 09:59:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A9B1420723 for ; Thu, 14 Nov 2019 09:59:18 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="AMelJHsx" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727447AbfKNJ7R (ORCPT ); Thu, 14 Nov 2019 04:59:17 -0500 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:42829 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727432AbfKNJ7O (ORCPT ); Thu, 14 Nov 2019 04:59:14 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1573725552; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=QljSnaf1FSPYM6HmLOdL6Z62VLNrQqpYUEnkNfrauXs=; b=AMelJHsxpRJh+Gla2RZoydCBMBd+qxBJLk88m6S0oFJbachwFrFHvfPWIMAsN6SCQmkVEI i6nA8oV4CYANh/xCRUqlj+xnUNBoZyyefk7i3iCxzNSdOyReAm/7nC4Tcma6X7BlH8fDRr vlUHLeLjDlBj/41lBGNR0zOCPOXq3Lg= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-336-8rDX-7Z1MdmAqbsAgWb--A-1; Thu, 14 Nov 2019 04:59:09 -0500 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id A1080593A2; Thu, 14 Nov 2019 09:59:07 +0000 (UTC) Received: from steredhat.redhat.com (ovpn-117-81.ams2.redhat.com [10.36.117.81]) by smtp.corp.redhat.com (Postfix) with ESMTP id 3C7BC19757; Thu, 14 Nov 2019 09:59:04 +0000 (UTC) From: Stefano Garzarella To: netdev@vger.kernel.org Cc: Stephen Hemminger , Arnd Bergmann , Jorgen Hansen , Jason Wang , Greg Kroah-Hartman , linux-kernel@vger.kernel.org, "Michael S. Tsirkin" , Haiyang Zhang , Stefan Hajnoczi , "David S. Miller" , virtualization@lists.linux-foundation.org, kvm@vger.kernel.org, Sasha Levin , "K. Y. Srinivasan" , Dexuan Cui , linux-hyperv@vger.kernel.org Subject: [PATCH net-next v2 13/15] vsock: prevent transport modules unloading Date: Thu, 14 Nov 2019 10:57:48 +0100 Message-Id: <20191114095750.59106-14-sgarzare@redhat.com> In-Reply-To: <20191114095750.59106-1-sgarzare@redhat.com> References: <20191114095750.59106-1-sgarzare@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-MC-Unique: 8rDX-7Z1MdmAqbsAgWb--A-1 X-Mimecast-Spam-Score: 0 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@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. Reviewed-by: Stefan Hajnoczi Reviewed-by: Jorgen Hansen Signed-off-by: Stefano Garzarella --- drivers/vhost/vsock.c | 2 ++ include/net/af_vsock.h | 2 ++ net/vmw_vsock/af_vsock.c | 20 ++++++++++++++++---- net/vmw_vsock/hyperv_transport.c | 2 ++ net/vmw_vsock/virtio_transport.c | 2 ++ net/vmw_vsock/vmci_transport.c | 1 + 6 files changed, 25 insertions(+), 4 deletions(-) diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c index b235f4bbe8ea..fdda9ec625ad 100644 --- a/drivers/vhost/vsock.c +++ b/drivers/vhost/vsock.c @@ -386,6 +386,8 @@ static bool vhost_vsock_more_replies(struct vhost_vsock *vsock) static struct virtio_transport vhost_transport = { .transport = { + .module = THIS_MODULE, + .get_local_cid = vhost_transport_get_local_cid, .init = virtio_transport_do_socket_init, diff --git a/include/net/af_vsock.h b/include/net/af_vsock.h index cf5c3691251b..4206dc6d813f 100644 --- a/include/net/af_vsock.h +++ b/include/net/af_vsock.h @@ -100,6 +100,8 @@ struct vsock_transport_send_notify_data { #define VSOCK_TRANSPORT_F_DGRAM 0x00000004 struct vsock_transport { + struct module *module; + /* Initialize/tear-down socket. */ int (*init)(struct vsock_sock *, struct vsock_sock *); void (*destruct)(struct vsock_sock *); diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c index 5357714b6104..5cb0ae42d916 100644 --- a/net/vmw_vsock/af_vsock.c +++ b/net/vmw_vsock/af_vsock.c @@ -380,6 +380,16 @@ void vsock_enqueue_accept(struct sock *listener, struct sock *connected) } EXPORT_SYMBOL_GPL(vsock_enqueue_accept); +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; +} + /* Assign a transport to a socket and call the .init transport callback. * * Note: for stream socket this must be called when vsk->remote_addr is set @@ -418,10 +428,13 @@ int vsock_assign_transport(struct vsock_sock *vsk, struct vsock_sock *psk) return 0; vsk->transport->release(vsk); - vsk->transport->destruct(vsk); + vsock_deassign_transport(vsk); } - if (!new_transport) + /* We increase the module refcnt to prevent the transport unloading + * while there are open sockets assigned to it. + */ + if (!new_transport || !try_module_get(new_transport->module)) return -ENODEV; vsk->transport = new_transport; @@ -741,8 +754,7 @@ 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. diff --git a/net/vmw_vsock/hyperv_transport.c b/net/vmw_vsock/hyperv_transport.c index 1c9e65d7d94d..3c7d07a99fc5 100644 --- a/net/vmw_vsock/hyperv_transport.c +++ b/net/vmw_vsock/hyperv_transport.c @@ -857,6 +857,8 @@ int hvs_notify_send_post_enqueue(struct vsock_sock *vsk, ssize_t written, } static struct vsock_transport hvs_transport = { + .module = THIS_MODULE, + .get_local_cid = hvs_get_local_cid, .init = hvs_sock_init, diff --git a/net/vmw_vsock/virtio_transport.c b/net/vmw_vsock/virtio_transport.c index 83ad85050384..1458c5c8b64d 100644 --- a/net/vmw_vsock/virtio_transport.c +++ b/net/vmw_vsock/virtio_transport.c @@ -462,6 +462,8 @@ static void virtio_vsock_rx_done(struct virtqueue *vq) static struct virtio_transport virtio_transport = { .transport = { + .module = THIS_MODULE, + .get_local_cid = virtio_transport_get_local_cid, .init = virtio_transport_do_socket_init, diff --git a/net/vmw_vsock/vmci_transport.c b/net/vmw_vsock/vmci_transport.c index d9c9c834ad6f..644d32e43d23 100644 --- a/net/vmw_vsock/vmci_transport.c +++ b/net/vmw_vsock/vmci_transport.c @@ -2020,6 +2020,7 @@ static u32 vmci_transport_get_local_cid(void) } static struct vsock_transport vmci_transport = { + .module = THIS_MODULE, .init = vmci_transport_socket_init, .destruct = vmci_transport_destruct, .release = vmci_transport_release,