Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933659Ab3FFMUT (ORCPT ); Thu, 6 Jun 2013 08:20:19 -0400 Received: from mx1.redhat.com ([209.132.183.28]:52386 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933377Ab3FFMUQ (ORCPT ); Thu, 6 Jun 2013 08:20:16 -0400 Date: Thu, 6 Jun 2013 15:20:39 +0300 From: "Michael S. Tsirkin" To: netdev@vger.kernel.org Cc: Asias He , David Miller , Tommi Rantala , kvm@vger.kernel.org, virtualization@lists.linux-foundation.org, linux-kernel@vger.kernel.org Subject: [PATCH net 1/2] vhost: check owner before we overwrite ubuf_info Message-ID: <1370521145-9723-2-git-send-email-mst@redhat.com> References: <1370521145-9723-1-git-send-email-mst@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1370521145-9723-1-git-send-email-mst@redhat.com> X-Mutt-Fcc: =sent Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2062 Lines: 70 If device has an owner, we shouldn't touch ubuf_info since it might be in use. Signed-off-by: Michael S. Tsirkin --- drivers/vhost/net.c | 4 ++++ drivers/vhost/vhost.c | 8 +++++++- drivers/vhost/vhost.h | 1 + 3 files changed, 12 insertions(+), 1 deletion(-) diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c index 2b51e23..6b00f64 100644 --- a/drivers/vhost/net.c +++ b/drivers/vhost/net.c @@ -1053,6 +1053,10 @@ static long vhost_net_set_owner(struct vhost_net *n) int r; mutex_lock(&n->dev.mutex); + if (vhost_dev_has_owner(&n->dev)) { + r = -EBUSY; + goto out; + } r = vhost_net_set_ubuf_info(n); if (r) goto out; diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index beee7f5..60aa5ad 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -344,13 +344,19 @@ static int vhost_attach_cgroups(struct vhost_dev *dev) } /* Caller should have device mutex */ +bool vhost_dev_has_owner(struct vhost_dev *dev) +{ + return dev->mm; +} + +/* Caller should have device mutex */ long vhost_dev_set_owner(struct vhost_dev *dev) { struct task_struct *worker; int err; /* Is there an owner already? */ - if (dev->mm) { + if (vhost_dev_has_owner(dev)) { err = -EBUSY; goto err_mm; } diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h index a7ad635..64adcf9 100644 --- a/drivers/vhost/vhost.h +++ b/drivers/vhost/vhost.h @@ -133,6 +133,7 @@ struct vhost_dev { long vhost_dev_init(struct vhost_dev *, struct vhost_virtqueue **vqs, int nvqs); long vhost_dev_set_owner(struct vhost_dev *dev); +bool vhost_dev_has_owner(struct vhost_dev *dev); long vhost_dev_check_owner(struct vhost_dev *); struct vhost_memory *vhost_dev_reset_owner_prepare(void); void vhost_dev_reset_owner(struct vhost_dev *, struct vhost_memory *); -- MST -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/