[PATCH net-next 1/2] virtio-net: correctly update XDP_TX counters
From: Jason Wang <hidden>
Date: 2018-07-31 09:43:51
Also in:
lkml
Subsystem:
networking drivers, the rest, virtio net driver · Maintainers:
Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds, "Michael S. Tsirkin", Jason Wang
Commit 5b8f3c8d30a6 ("virtio_net: Add XDP related stats") tries to
count TX XDP stats in virtnet_receive(). This will cause several
issues:
- virtnet_xdp_sq() was called without checking whether or not XDP is
set. This may cause out of bound access when there's no enough txq
for XDP.
- Stats were updated even if there's no XDP/XDP_TX.
Fixing this by reusing virtnet_xdp_xmit() for XDP_TX which can counts
TX XDP counter itself and remove the unnecessary tx stats embedded in
rx stats.
Reported-by: syzbot+604f8271211546f5b3c7@syzkaller.appspotmail.com
Fixes: 5b8f3c8d30a6 ("virtio_net: Add XDP related stats")
Cc: Toshiaki Makita <redacted>
Signed-off-by: Jason Wang <redacted>
---
drivers/net/virtio_net.c | 39 ++++-----------------------------------
1 file changed, 4 insertions(+), 35 deletions(-)
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 1880c86..72d3f68 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c@@ -105,10 +105,6 @@ struct virtnet_rq_stats { struct virtnet_rx_stats { struct virtnet_rq_stat_items rx; - struct { - unsigned int xdp_tx; - unsigned int xdp_tx_drops; - } tx; }; #define VIRTNET_SQ_STAT(m) offsetof(struct virtnet_sq_stats, m)
@@ -485,22 +481,6 @@ static struct send_queue *virtnet_xdp_sq(struct virtnet_info *vi) return &vi->sq[qp]; } -static int __virtnet_xdp_tx_xmit(struct virtnet_info *vi, - struct xdp_frame *xdpf) -{ - struct xdp_frame *xdpf_sent; - struct send_queue *sq; - unsigned int len; - - sq = virtnet_xdp_sq(vi); - - /* Free up any pending old buffers before queueing new ones. */ - while ((xdpf_sent = virtqueue_get_buf(sq->vq, &len)) != NULL) - xdp_return_frame(xdpf_sent); - - return __virtnet_xdp_xmit_one(vi, sq, xdpf); -} - static int virtnet_xdp_xmit(struct net_device *dev, int n, struct xdp_frame **frames, u32 flags) {
@@ -707,10 +687,8 @@ static struct sk_buff *receive_small(struct net_device *dev, xdpf = convert_to_xdp_frame(&xdp); if (unlikely(!xdpf)) goto err_xdp; - stats->tx.xdp_tx++; - err = __virtnet_xdp_tx_xmit(vi, xdpf); - if (unlikely(err)) { - stats->tx.xdp_tx_drops++; + err = virtnet_xdp_xmit(dev, 1, &xdpf, 0); + if (unlikely(err < 0)) { trace_xdp_exception(vi->dev, xdp_prog, act); goto err_xdp; }
@@ -879,10 +857,8 @@ static struct sk_buff *receive_mergeable(struct net_device *dev, xdpf = convert_to_xdp_frame(&xdp); if (unlikely(!xdpf)) goto err_xdp; - stats->tx.xdp_tx++; - err = __virtnet_xdp_tx_xmit(vi, xdpf); - if (unlikely(err)) { - stats->tx.xdp_tx_drops++; + err = virtnet_xdp_xmit(dev, 1, &xdpf, 0); + if (unlikely(err < 0)) { trace_xdp_exception(vi->dev, xdp_prog, act); if (unlikely(xdp_page != page)) put_page(xdp_page);
@@ -1315,7 +1291,6 @@ static int virtnet_receive(struct receive_queue *rq, int budget, { struct virtnet_info *vi = rq->vq->vdev->priv; struct virtnet_rx_stats stats = {}; - struct send_queue *sq; unsigned int len; void *buf; int i;
@@ -1351,12 +1326,6 @@ static int virtnet_receive(struct receive_queue *rq, int budget, } u64_stats_update_end(&rq->stats.syncp); - sq = virtnet_xdp_sq(vi); - u64_stats_update_begin(&sq->stats.syncp); - sq->stats.xdp_tx += stats.tx.xdp_tx; - sq->stats.xdp_tx_drops += stats.tx.xdp_tx_drops; - u64_stats_update_end(&sq->stats.syncp); - return stats.rx.packets; }
--
2.7.4