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authorMichael S. Tsirkin <mst@redhat.com>2013-06-06 15:20:39 +0300
committerDavid S. Miller <davem@davemloft.net>2013-06-11 02:46:21 -0700
commit05c05351943cc03bf5c77e86953b24ae6fb21368 (patch)
tree51274c86eeca2cd5040979d1fdebd81fe0518a19
parentc2020be3c35ab230b4ee046c262ddab3e0d3aab4 (diff)
vhost: check owner before we overwrite ubuf_info
If device has an owner, we shouldn't touch ubuf_info since it might be in use. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--drivers/vhost/net.c4
-rw-r--r--drivers/vhost/vhost.c8
-rw-r--r--drivers/vhost/vhost.h1
3 files changed, 12 insertions, 1 deletions
diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index b07d96b8c0d1..8cf5aece8c84 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -1054,6 +1054,10 @@ 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 beee7f5787e6..60aa5ad09a2f 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 a7ad63592987..64adcf99ff33 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 *);