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-rw-r--r--net/vmw_vsock/virtio_transport.c70
1 files changed, 46 insertions, 24 deletions
diff --git a/net/vmw_vsock/virtio_transport.c b/net/vmw_vsock/virtio_transport.c
index 96ab344f17bb..68186419c445 100644
--- a/net/vmw_vsock/virtio_transport.c
+++ b/net/vmw_vsock/virtio_transport.c
@@ -66,19 +66,22 @@ struct virtio_vsock {
u32 guest_cid;
};
-static struct virtio_vsock *virtio_vsock_get(void)
-{
- return the_virtio_vsock;
-}
-
static u32 virtio_transport_get_local_cid(void)
{
- struct virtio_vsock *vsock = virtio_vsock_get();
+ struct virtio_vsock *vsock;
+ u32 ret;
- if (!vsock)
- return VMADDR_CID_ANY;
+ rcu_read_lock();
+ vsock = rcu_dereference(the_virtio_vsock);
+ if (!vsock) {
+ ret = VMADDR_CID_ANY;
+ goto out_rcu;
+ }
- return vsock->guest_cid;
+ ret = vsock->guest_cid;
+out_rcu:
+ rcu_read_unlock();
+ return ret;
}
static void virtio_transport_loopback_work(struct work_struct *work)
@@ -198,14 +201,18 @@ virtio_transport_send_pkt(struct virtio_vsock_pkt *pkt)
struct virtio_vsock *vsock;
int len = pkt->len;
- vsock = virtio_vsock_get();
+ rcu_read_lock();
+ vsock = rcu_dereference(the_virtio_vsock);
if (!vsock) {
virtio_transport_free_pkt(pkt);
- return -ENODEV;
+ len = -ENODEV;
+ goto out_rcu;
}
- if (le64_to_cpu(pkt->hdr.dst_cid) == vsock->guest_cid)
- return virtio_transport_send_pkt_loopback(vsock, pkt);
+ if (le64_to_cpu(pkt->hdr.dst_cid) == vsock->guest_cid) {
+ len = virtio_transport_send_pkt_loopback(vsock, pkt);
+ goto out_rcu;
+ }
if (pkt->reply)
atomic_inc(&vsock->queued_replies);
@@ -215,6 +222,9 @@ virtio_transport_send_pkt(struct virtio_vsock_pkt *pkt)
spin_unlock_bh(&vsock->send_pkt_list_lock);
queue_work(virtio_vsock_workqueue, &vsock->send_pkt_work);
+
+out_rcu:
+ rcu_read_unlock();
return len;
}
@@ -223,12 +233,14 @@ virtio_transport_cancel_pkt(struct vsock_sock *vsk)
{
struct virtio_vsock *vsock;
struct virtio_vsock_pkt *pkt, *n;
- int cnt = 0;
+ int cnt = 0, ret;
LIST_HEAD(freeme);
- vsock = virtio_vsock_get();
+ rcu_read_lock();
+ vsock = rcu_dereference(the_virtio_vsock);
if (!vsock) {
- return -ENODEV;
+ ret = -ENODEV;
+ goto out_rcu;
}
spin_lock_bh(&vsock->send_pkt_list_lock);
@@ -256,7 +268,11 @@ virtio_transport_cancel_pkt(struct vsock_sock *vsk)
queue_work(virtio_vsock_workqueue, &vsock->rx_work);
}
- return 0;
+ ret = 0;
+
+out_rcu:
+ rcu_read_unlock();
+ return ret;
}
static void virtio_vsock_rx_fill(struct virtio_vsock *vsock)
@@ -566,7 +582,8 @@ static int virtio_vsock_probe(struct virtio_device *vdev)
return ret;
/* Only one virtio-vsock device per guest is supported */
- if (the_virtio_vsock) {
+ if (rcu_dereference_protected(the_virtio_vsock,
+ lockdep_is_held(&the_virtio_vsock_mutex))) {
ret = -EBUSY;
goto out;
}
@@ -591,8 +608,6 @@ static int virtio_vsock_probe(struct virtio_device *vdev)
vsock->rx_buf_max_nr = 0;
atomic_set(&vsock->queued_replies, 0);
- vdev->priv = vsock;
- the_virtio_vsock = vsock;
mutex_init(&vsock->tx_lock);
mutex_init(&vsock->rx_lock);
mutex_init(&vsock->event_lock);
@@ -614,6 +629,9 @@ static int virtio_vsock_probe(struct virtio_device *vdev)
virtio_vsock_event_fill(vsock);
mutex_unlock(&vsock->event_lock);
+ vdev->priv = vsock;
+ rcu_assign_pointer(the_virtio_vsock, vsock);
+
mutex_unlock(&the_virtio_vsock_mutex);
return 0;
@@ -628,6 +646,12 @@ static void virtio_vsock_remove(struct virtio_device *vdev)
struct virtio_vsock *vsock = vdev->priv;
struct virtio_vsock_pkt *pkt;
+ mutex_lock(&the_virtio_vsock_mutex);
+
+ vdev->priv = NULL;
+ rcu_assign_pointer(the_virtio_vsock, NULL);
+ synchronize_rcu();
+
flush_work(&vsock->loopback_work);
flush_work(&vsock->rx_work);
flush_work(&vsock->tx_work);
@@ -667,12 +691,10 @@ static void virtio_vsock_remove(struct virtio_device *vdev)
}
spin_unlock_bh(&vsock->loopback_list_lock);
- mutex_lock(&the_virtio_vsock_mutex);
- the_virtio_vsock = NULL;
- mutex_unlock(&the_virtio_vsock_mutex);
-
vdev->config->del_vqs(vdev);
+ mutex_unlock(&the_virtio_vsock_mutex);
+
kfree(vsock);
}