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-rw-r--r--drivers/vhost/vhost.c17
1 files changed, 13 insertions, 4 deletions
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index de110363a..8ed9c9b63 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -2513,9 +2513,19 @@ bool vhost_vq_avail_empty(struct vhost_dev *dev, struct vhost_virtqueue *vq)
r = vhost_get_avail_idx(vq, &avail_idx);
if (unlikely(r))
return false;
+
vq->avail_idx = vhost16_to_cpu(vq, avail_idx);
+ if (vq->avail_idx != vq->last_avail_idx) {
+ /* Since we have updated avail_idx, the following
+ * call to vhost_get_vq_desc() will read available
+ * ring entries. Make sure that read happens after
+ * the avail_idx read.
+ */
+ smp_rmb();
+ return false;
+ }
- return vq->avail_idx == vq->last_avail_idx;
+ return true;
}
EXPORT_SYMBOL_GPL(vhost_vq_avail_empty);
@@ -2577,12 +2587,11 @@ EXPORT_SYMBOL_GPL(vhost_disable_notify);
/* Create a new message. */
struct vhost_msg_node *vhost_new_msg(struct vhost_virtqueue *vq, int type)
{
- struct vhost_msg_node *node = kmalloc(sizeof *node, GFP_KERNEL);
+ /* Make sure all padding within the structure is initialized. */
+ struct vhost_msg_node *node = kzalloc(sizeof(*node), GFP_KERNEL);
if (!node)
return NULL;
- /* Make sure all padding within the structure is initialized. */
- memset(&node->msg, 0, sizeof node->msg);
node->vq = vq;
node->msg.type = type;
return node;