Merge branch 'net-atomic-dev-stats'

Eric Dumazet says:

====================
net: add atomic dev->stats infra

Long standing KCSAN issues are caused by data-race around
some dev->stats changes.

Most performance critical paths already use per-cpu
variables, or per-queue ones.

It is reasonable (and more correct) to use atomic operations
for the slow paths.

First patch adds the infrastructure, then three patches address
the most common paths that syzbot is playing with.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 11 insertions, 11 deletions

diff --git a/net/ipv6/sit.c b/net/ipv6/sit.c
index 5703d3cbea9b..70d81bba5093 100644
--- a/net/ipv6/sit.c
+++ b/net/ipv6/sit.c
@@ -694,7 +694,7 @@ static int ipip6_rcv(struct sk_buff *skb)
 		skb->dev = tunnel->dev;
 
 		if (packet_is_spoofed(skb, iph, tunnel)) {
-			tunnel->dev->stats.rx_errors++;
+			DEV_STATS_INC(tunnel->dev, rx_errors);
 			goto out;
 		}
 
@@ -714,8 +714,8 @@ static int ipip6_rcv(struct sk_buff *skb)
 				net_info_ratelimited("non-ECT from %pI4 with TOS=%#x\n",
 						     &iph->saddr, iph->tos);
 			if (err > 1) {
-				++tunnel->dev->stats.rx_frame_errors;
-				++tunnel->dev->stats.rx_errors;
+				DEV_STATS_INC(tunnel->dev, rx_frame_errors);
+				DEV_STATS_INC(tunnel->dev, rx_errors);
 				goto out;
 			}
 		}
@@ -942,7 +942,7 @@ static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb,
 	if (!rt) {
 		rt = ip_route_output_flow(tunnel->net, &fl4, NULL);
 		if (IS_ERR(rt)) {
-			dev->stats.tx_carrier_errors++;
+			DEV_STATS_INC(dev, tx_carrier_errors);
 			goto tx_error_icmp;
 		}
 		dst_cache_set_ip4(&tunnel->dst_cache, &rt->dst, fl4.saddr);
@@ -950,14 +950,14 @@ static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb,
 
 	if (rt->rt_type != RTN_UNICAST && rt->rt_type != RTN_LOCAL) {
 		ip_rt_put(rt);
-		dev->stats.tx_carrier_errors++;
+		DEV_STATS_INC(dev, tx_carrier_errors);
 		goto tx_error_icmp;
 	}
 	tdev = rt->dst.dev;
 
 	if (tdev == dev) {
 		ip_rt_put(rt);
-		dev->stats.collisions++;
+		DEV_STATS_INC(dev, collisions);
 		goto tx_error;
 	}
 
@@ -970,7 +970,7 @@ static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb,
 		mtu = dst_mtu(&rt->dst) - t_hlen;
 
 		if (mtu < IPV4_MIN_MTU) {
-			dev->stats.collisions++;
+			DEV_STATS_INC(dev, collisions);
 			ip_rt_put(rt);
 			goto tx_error;
 		}
@@ -1009,7 +1009,7 @@ static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb,
 		struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom);
 		if (!new_skb) {
 			ip_rt_put(rt);
-			dev->stats.tx_dropped++;
+			DEV_STATS_INC(dev, tx_dropped);
 			kfree_skb(skb);
 			return NETDEV_TX_OK;
 		}
@@ -1039,7 +1039,7 @@ tx_error_icmp:
 	dst_link_failure(skb);
 tx_error:
 	kfree_skb(skb);
-	dev->stats.tx_errors++;
+	DEV_STATS_INC(dev, tx_errors);
 	return NETDEV_TX_OK;
 }
 
@@ -1058,7 +1058,7 @@ static netdev_tx_t sit_tunnel_xmit__(struct sk_buff *skb,
 	return NETDEV_TX_OK;
 tx_error:
 	kfree_skb(skb);
-	dev->stats.tx_errors++;
+	DEV_STATS_INC(dev, tx_errors);
 	return NETDEV_TX_OK;
 }
 
@@ -1087,7 +1087,7 @@ static netdev_tx_t sit_tunnel_xmit(struct sk_buff *skb,
 	return NETDEV_TX_OK;
 
 tx_err:
-	dev->stats.tx_errors++;
+	DEV_STATS_INC(dev, tx_errors);
 	kfree_skb(skb);
 	return NETDEV_TX_OK;