From 0b068c714ca9479d2783cc333fff5bc2d4a6d45c Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Thu, 21 Sep 2023 08:52:16 +0000 Subject: [PATCH 1/3] net: add DEV_STATS_READ() helper Companion of DEV_STATS_INC() & DEV_STATS_ADD(). This is going to be used in the series. Use it in macsec_get_stats64(). Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- drivers/net/macsec.c | 6 +++--- include/linux/netdevice.h | 1 + 2 files changed, 4 insertions(+), 3 deletions(-) diff --git a/drivers/net/macsec.c b/drivers/net/macsec.c index b7e151439c48..7a44e1cbe305 100644 --- a/drivers/net/macsec.c +++ b/drivers/net/macsec.c @@ -3655,9 +3655,9 @@ static void macsec_get_stats64(struct net_device *dev, dev_fetch_sw_netstats(s, dev->tstats); - s->rx_dropped = atomic_long_read(&dev->stats.__rx_dropped); - s->tx_dropped = atomic_long_read(&dev->stats.__tx_dropped); - s->rx_errors = atomic_long_read(&dev->stats.__rx_errors); + s->rx_dropped = DEV_STATS_READ(dev, rx_dropped); + s->tx_dropped = DEV_STATS_READ(dev, tx_dropped); + s->rx_errors = DEV_STATS_READ(dev, rx_errors); } static int macsec_get_iflink(const struct net_device *dev) diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 7e520c14eb8c..e070a4540fba 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -5236,5 +5236,6 @@ extern struct net_device *blackhole_netdev; #define DEV_STATS_INC(DEV, FIELD) atomic_long_inc(&(DEV)->stats.__##FIELD) #define DEV_STATS_ADD(DEV, FIELD, VAL) \ atomic_long_add((VAL), &(DEV)->stats.__##FIELD) +#define DEV_STATS_READ(DEV, FIELD) atomic_long_read(&(DEV)->stats.__##FIELD) #endif /* _LINUX_NETDEVICE_H */ From d12a26b74fb77434b73fe39022266c4b00907219 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Thu, 21 Sep 2023 08:52:17 +0000 Subject: [PATCH 2/3] virtio_net: avoid data-races on dev->stats fields Use DEV_STATS_INC() and DEV_STATS_READ() which provide atomicity on paths that can be used concurrently. Reported-by: syzbot Signed-off-by: Eric Dumazet Reviewed-by: Xuan Zhuo Cc: "Michael S. Tsirkin" Cc: Jason Wang Signed-off-by: David S. Miller --- drivers/net/virtio_net.c | 30 +++++++++++++++--------------- 1 file changed, 15 insertions(+), 15 deletions(-) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index fe7f314d65c9..1ed6bcc4cbb1 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -1258,7 +1258,7 @@ static struct sk_buff *receive_small(struct net_device *dev, if (unlikely(len > GOOD_PACKET_LEN)) { pr_debug("%s: rx error: len %u exceeds max size %d\n", dev->name, len, GOOD_PACKET_LEN); - dev->stats.rx_length_errors++; + DEV_STATS_INC(dev, rx_length_errors); goto err; } @@ -1323,7 +1323,7 @@ static void mergeable_buf_free(struct receive_queue *rq, int num_buf, if (unlikely(!buf)) { pr_debug("%s: rx error: %d buffers missing\n", dev->name, num_buf); - dev->stats.rx_length_errors++; + DEV_STATS_INC(dev, rx_length_errors); break; } stats->bytes += len; @@ -1432,7 +1432,7 @@ static int virtnet_build_xdp_buff_mrg(struct net_device *dev, pr_debug("%s: rx error: %d buffers out of %d missing\n", dev->name, *num_buf, virtio16_to_cpu(vi->vdev, hdr->num_buffers)); - dev->stats.rx_length_errors++; + DEV_STATS_INC(dev, rx_length_errors); goto err; } @@ -1451,7 +1451,7 @@ static int virtnet_build_xdp_buff_mrg(struct net_device *dev, put_page(page); pr_debug("%s: rx error: len %u exceeds truesize %lu\n", dev->name, len, (unsigned long)(truesize - room)); - dev->stats.rx_length_errors++; + DEV_STATS_INC(dev, rx_length_errors); goto err; } @@ -1630,7 +1630,7 @@ static struct sk_buff *receive_mergeable(struct net_device *dev, if (unlikely(len > truesize - room)) { pr_debug("%s: rx error: len %u exceeds truesize %lu\n", dev->name, len, (unsigned long)(truesize - room)); - dev->stats.rx_length_errors++; + DEV_STATS_INC(dev, rx_length_errors); goto err_skb; } @@ -1662,7 +1662,7 @@ static struct sk_buff *receive_mergeable(struct net_device *dev, dev->name, num_buf, virtio16_to_cpu(vi->vdev, hdr->num_buffers)); - dev->stats.rx_length_errors++; + DEV_STATS_INC(dev, rx_length_errors); goto err_buf; } @@ -1676,7 +1676,7 @@ static struct sk_buff *receive_mergeable(struct net_device *dev, if (unlikely(len > truesize - room)) { pr_debug("%s: rx error: len %u exceeds truesize %lu\n", dev->name, len, (unsigned long)(truesize - room)); - dev->stats.rx_length_errors++; + DEV_STATS_INC(dev, rx_length_errors); goto err_skb; } @@ -1763,7 +1763,7 @@ static void receive_buf(struct virtnet_info *vi, struct receive_queue *rq, if (unlikely(len < vi->hdr_len + ETH_HLEN)) { pr_debug("%s: short packet %i\n", dev->name, len); - dev->stats.rx_length_errors++; + DEV_STATS_INC(dev, rx_length_errors); virtnet_rq_free_unused_buf(rq->vq, buf); return; } @@ -1803,7 +1803,7 @@ static void receive_buf(struct virtnet_info *vi, struct receive_queue *rq, return; frame_err: - dev->stats.rx_frame_errors++; + DEV_STATS_INC(dev, rx_frame_errors); dev_kfree_skb(skb); } @@ -2349,12 +2349,12 @@ static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev) /* This should not happen! */ if (unlikely(err)) { - dev->stats.tx_fifo_errors++; + DEV_STATS_INC(dev, tx_fifo_errors); if (net_ratelimit()) dev_warn(&dev->dev, "Unexpected TXQ (%d) queue failure: %d\n", qnum, err); - dev->stats.tx_dropped++; + DEV_STATS_INC(dev, tx_dropped); dev_kfree_skb_any(skb); return NETDEV_TX_OK; } @@ -2573,10 +2573,10 @@ static void virtnet_stats(struct net_device *dev, tot->tx_errors += terrors; } - tot->tx_dropped = dev->stats.tx_dropped; - tot->tx_fifo_errors = dev->stats.tx_fifo_errors; - tot->rx_length_errors = dev->stats.rx_length_errors; - tot->rx_frame_errors = dev->stats.rx_frame_errors; + tot->tx_dropped = DEV_STATS_READ(dev, tx_dropped); + tot->tx_fifo_errors = DEV_STATS_READ(dev, tx_fifo_errors); + tot->rx_length_errors = DEV_STATS_READ(dev, rx_length_errors); + tot->rx_frame_errors = DEV_STATS_READ(dev, rx_frame_errors); } static void virtnet_ack_link_announce(struct virtnet_info *vi) From a56d9390bd6045e8c37bcfd0586ff5f65ef22997 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Thu, 21 Sep 2023 08:52:18 +0000 Subject: [PATCH 3/3] net: l2tp_eth: use generic dev->stats fields Core networking has opt-in atomic variant of dev->stats, simply use DEV_STATS_INC(), DEV_STATS_ADD() and DEV_STATS_READ(). v2: removed @priv local var in l2tp_eth_dev_recv() (Simon) Signed-off-by: Eric Dumazet Cc: Simon Horman Signed-off-by: David S. Miller --- net/l2tp/l2tp_eth.c | 34 ++++++++++++---------------------- 1 file changed, 12 insertions(+), 22 deletions(-) diff --git a/net/l2tp/l2tp_eth.c b/net/l2tp/l2tp_eth.c index f2ae03c40473..25ca89f80414 100644 --- a/net/l2tp/l2tp_eth.c +++ b/net/l2tp/l2tp_eth.c @@ -37,12 +37,6 @@ /* via netdev_priv() */ struct l2tp_eth { struct l2tp_session *session; - atomic_long_t tx_bytes; - atomic_long_t tx_packets; - atomic_long_t tx_dropped; - atomic_long_t rx_bytes; - atomic_long_t rx_packets; - atomic_long_t rx_errors; }; /* via l2tp_session_priv() */ @@ -79,10 +73,10 @@ static netdev_tx_t l2tp_eth_dev_xmit(struct sk_buff *skb, struct net_device *dev int ret = l2tp_xmit_skb(session, skb); if (likely(ret == NET_XMIT_SUCCESS)) { - atomic_long_add(len, &priv->tx_bytes); - atomic_long_inc(&priv->tx_packets); + DEV_STATS_ADD(dev, tx_bytes, len); + DEV_STATS_INC(dev, tx_packets); } else { - atomic_long_inc(&priv->tx_dropped); + DEV_STATS_INC(dev, tx_dropped); } return NETDEV_TX_OK; } @@ -90,14 +84,12 @@ static netdev_tx_t l2tp_eth_dev_xmit(struct sk_buff *skb, struct net_device *dev static void l2tp_eth_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats) { - struct l2tp_eth *priv = netdev_priv(dev); - - stats->tx_bytes = (unsigned long)atomic_long_read(&priv->tx_bytes); - stats->tx_packets = (unsigned long)atomic_long_read(&priv->tx_packets); - stats->tx_dropped = (unsigned long)atomic_long_read(&priv->tx_dropped); - stats->rx_bytes = (unsigned long)atomic_long_read(&priv->rx_bytes); - stats->rx_packets = (unsigned long)atomic_long_read(&priv->rx_packets); - stats->rx_errors = (unsigned long)atomic_long_read(&priv->rx_errors); + stats->tx_bytes = DEV_STATS_READ(dev, tx_bytes); + stats->tx_packets = DEV_STATS_READ(dev, tx_packets); + stats->tx_dropped = DEV_STATS_READ(dev, tx_dropped); + stats->rx_bytes = DEV_STATS_READ(dev, rx_bytes); + stats->rx_packets = DEV_STATS_READ(dev, rx_packets); + stats->rx_errors = DEV_STATS_READ(dev, rx_errors); } static const struct net_device_ops l2tp_eth_netdev_ops = { @@ -126,7 +118,6 @@ static void l2tp_eth_dev_recv(struct l2tp_session *session, struct sk_buff *skb, { struct l2tp_eth_sess *spriv = l2tp_session_priv(session); struct net_device *dev; - struct l2tp_eth *priv; if (!pskb_may_pull(skb, ETH_HLEN)) goto error; @@ -144,12 +135,11 @@ static void l2tp_eth_dev_recv(struct l2tp_session *session, struct sk_buff *skb, if (!dev) goto error_rcu; - priv = netdev_priv(dev); if (dev_forward_skb(dev, skb) == NET_RX_SUCCESS) { - atomic_long_inc(&priv->rx_packets); - atomic_long_add(data_len, &priv->rx_bytes); + DEV_STATS_INC(dev, rx_packets); + DEV_STATS_ADD(dev, rx_bytes, data_len); } else { - atomic_long_inc(&priv->rx_errors); + DEV_STATS_INC(dev, rx_errors); } rcu_read_unlock();