From patchwork Wed Oct 23 09:55:53 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefano Garzarella X-Patchwork-Id: 11206217 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 C26F41390 for ; Wed, 23 Oct 2019 09:58:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 95FAF20650 for ; Wed, 23 Oct 2019 09:58:45 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="fbegq1n+" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390985AbfJWJ6o (ORCPT ); Wed, 23 Oct 2019 05:58:44 -0400 Received: from us-smtp-1.mimecast.com ([207.211.31.81]:26441 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S2404216AbfJWJ6Y (ORCPT ); Wed, 23 Oct 2019 05:58:24 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1571824703; 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=E6cdvtI+lVBkl+0vlDQhx2DxQdbC47YC/eILjebBwE4=; b=fbegq1n+Z88IJIpEeR5Ga8O/tr8Em6ltPPbnQnMpKGEv5exM95RlwoPSSmM/2aiAh3wY/3 cREk2F0rGj+quF8jF/SPC4d9JfsCMEkHfzK4C5AYF5/XB9rDRXc/8mnCXbxseDBCZLxbwu bq4ByfdYGh5h39VGi5Jl9FXH54G5gzg= 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-259-4Nuw3kesNVi0_lsKblgbMQ-1; Wed, 23 Oct 2019 05:58:21 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id BB84C1005500; Wed, 23 Oct 2019 09:58:19 +0000 (UTC) Received: from steredhat.redhat.com (unknown [10.36.118.164]) by smtp.corp.redhat.com (Postfix) with ESMTP id 58BCB5C1B2; Wed, 23 Oct 2019 09:58:16 +0000 (UTC) From: Stefano Garzarella To: netdev@vger.kernel.org Cc: "Michael S. Tsirkin" , kvm@vger.kernel.org, Greg Kroah-Hartman , Jason Wang , "David S. Miller" , Dexuan Cui , Haiyang Zhang , Jorgen Hansen , Sasha Levin , linux-kernel@vger.kernel.org, Arnd Bergmann , Stefan Hajnoczi , linux-hyperv@vger.kernel.org, "K. Y. Srinivasan" , Stephen Hemminger , virtualization@lists.linux-foundation.org Subject: [PATCH net-next 13/14] vsock: prevent transport modules unloading Date: Wed, 23 Oct 2019 11:55:53 +0200 Message-Id: <20191023095554.11340-14-sgarzare@redhat.com> In-Reply-To: <20191023095554.11340-1-sgarzare@redhat.com> References: <20191023095554.11340-1-sgarzare@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-MC-Unique: 4Nuw3kesNVi0_lsKblgbMQ-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 Signed-off-by: Stefano Garzarella Reviewed-by: Jorgen Hansen --- RFC -> v1: - fixed typo 's/tranport/transport/' in a comment (Stefan) --- 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 27a3463e4892..269e2f034789 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 dddd85d9a147..1f2e707cae66 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 @@ -413,10 +423,13 @@ 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; @@ -737,8 +750,7 @@ 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 0ea66d87af39..d0a349d85414 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 04437f822d82..0cbf023fae11 100644 --- a/net/vmw_vsock/vmci_transport.c +++ b/net/vmw_vsock/vmci_transport.c @@ -2019,6 +2019,7 @@ 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,