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>

5 files changed, 38 insertions, 38 deletions

diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
index d8ee5238c395..a4ccef3e6935 100644
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c
@@ -510,7 +510,7 @@ static void gre_fb_xmit(struct sk_buff *skb, struct net_device *dev,
 
 err_free_skb:
 	kfree_skb(skb);
-	dev->stats.tx_dropped++;
+	DEV_STATS_INC(dev, tx_dropped);
 }
 
 static void erspan_fb_xmit(struct sk_buff *skb, struct net_device *dev)
@@ -592,7 +592,7 @@ static void erspan_fb_xmit(struct sk_buff *skb, struct net_device *dev)
 
 err_free_skb:
 	kfree_skb(skb);
-	dev->stats.tx_dropped++;
+	DEV_STATS_INC(dev, tx_dropped);
 }
 
 static int gre_fill_metadata_dst(struct net_device *dev, struct sk_buff *skb)
@@ -663,7 +663,7 @@ static netdev_tx_t ipgre_xmit(struct sk_buff *skb,
 
 free_skb:
 	kfree_skb(skb);
-	dev->stats.tx_dropped++;
+	DEV_STATS_INC(dev, tx_dropped);
 	return NETDEV_TX_OK;
 }
 
@@ -717,7 +717,7 @@ static netdev_tx_t erspan_xmit(struct sk_buff *skb,
 
 free_skb:
 	kfree_skb(skb);
-	dev->stats.tx_dropped++;
+	DEV_STATS_INC(dev, tx_dropped);
 	return NETDEV_TX_OK;
 }
 
@@ -745,7 +745,7 @@ static netdev_tx_t gre_tap_xmit(struct sk_buff *skb,
 
 free_skb:
 	kfree_skb(skb);
-	dev->stats.tx_dropped++;
+	DEV_STATS_INC(dev, tx_dropped);
 	return NETDEV_TX_OK;
 }
 
diff --git a/net/ipv4/ip_tunnel.c b/net/ipv4/ip_tunnel.c
index 019f3b0839c5..de90b09dfe78 100644
--- a/net/ipv4/ip_tunnel.c
+++ b/net/ipv4/ip_tunnel.c
@@ -368,23 +368,23 @@ int ip_tunnel_rcv(struct ip_tunnel *tunnel, struct sk_buff *skb,
 
 #ifdef CONFIG_NET_IPGRE_BROADCAST
 	if (ipv4_is_multicast(iph->daddr)) {
-		tunnel->dev->stats.multicast++;
+		DEV_STATS_INC(tunnel->dev, multicast);
 		skb->pkt_type = PACKET_BROADCAST;
 	}
 #endif
 
 	if ((!(tpi->flags&TUNNEL_CSUM) &&  (tunnel->parms.i_flags&TUNNEL_CSUM)) ||
 	     ((tpi->flags&TUNNEL_CSUM) && !(tunnel->parms.i_flags&TUNNEL_CSUM))) {
-		tunnel->dev->stats.rx_crc_errors++;
-		tunnel->dev->stats.rx_errors++;
+		DEV_STATS_INC(tunnel->dev, rx_crc_errors);
+		DEV_STATS_INC(tunnel->dev, rx_errors);
 		goto drop;
 	}
 
 	if (tunnel->parms.i_flags&TUNNEL_SEQ) {
 		if (!(tpi->flags&TUNNEL_SEQ) ||
 		    (tunnel->i_seqno && (s32)(ntohl(tpi->seq) - tunnel->i_seqno) < 0)) {
-			tunnel->dev->stats.rx_fifo_errors++;
-			tunnel->dev->stats.rx_errors++;
+			DEV_STATS_INC(tunnel->dev, rx_fifo_errors);
+			DEV_STATS_INC(tunnel->dev, rx_errors);
 			goto drop;
 		}
 		tunnel->i_seqno = ntohl(tpi->seq) + 1;
@@ -398,8 +398,8 @@ int ip_tunnel_rcv(struct ip_tunnel *tunnel, 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 drop;
 		}
 	}
@@ -581,7 +581,7 @@ void ip_md_tunnel_xmit(struct sk_buff *skb, struct net_device *dev,
 	if (!rt) {
 		rt = ip_route_output_key(tunnel->net, &fl4);
 		if (IS_ERR(rt)) {
-			dev->stats.tx_carrier_errors++;
+			DEV_STATS_INC(dev, tx_carrier_errors);
 			goto tx_error;
 		}
 		if (use_cache)
@@ -590,7 +590,7 @@ void ip_md_tunnel_xmit(struct sk_buff *skb, struct net_device *dev,
 	}
 	if (rt->dst.dev == dev) {
 		ip_rt_put(rt);
-		dev->stats.collisions++;
+		DEV_STATS_INC(dev, collisions);
 		goto tx_error;
 	}
 
@@ -625,10 +625,10 @@ void ip_md_tunnel_xmit(struct sk_buff *skb, struct net_device *dev,
 		      df, !net_eq(tunnel->net, dev_net(dev)));
 	return;
 tx_error:
-	dev->stats.tx_errors++;
+	DEV_STATS_INC(dev, tx_errors);
 	goto kfree;
 tx_dropped:
-	dev->stats.tx_dropped++;
+	DEV_STATS_INC(dev, tx_dropped);
 kfree:
 	kfree_skb(skb);
 }
@@ -662,7 +662,7 @@ void ip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev,
 		/* NBMA tunnel */
 
 		if (!skb_dst(skb)) {
-			dev->stats.tx_fifo_errors++;
+			DEV_STATS_INC(dev, tx_fifo_errors);
 			goto tx_error;
 		}
 
@@ -749,7 +749,7 @@ void ip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev,
 		rt = ip_route_output_key(tunnel->net, &fl4);
 
 		if (IS_ERR(rt)) {
-			dev->stats.tx_carrier_errors++;
+			DEV_STATS_INC(dev, tx_carrier_errors);
 			goto tx_error;
 		}
 		if (use_cache)
@@ -762,7 +762,7 @@ void ip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev,
 
 	if (rt->dst.dev == dev) {
 		ip_rt_put(rt);
-		dev->stats.collisions++;
+		DEV_STATS_INC(dev, collisions);
 		goto tx_error;
 	}
 
@@ -805,7 +805,7 @@ void ip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev,
 
 	if (skb_cow_head(skb, dev->needed_headroom)) {
 		ip_rt_put(rt);
-		dev->stats.tx_dropped++;
+		DEV_STATS_INC(dev, tx_dropped);
 		kfree_skb(skb);
 		return;
 	}
@@ -819,7 +819,7 @@ tx_error_icmp:
 	dst_link_failure(skb);
 #endif
 tx_error:
-	dev->stats.tx_errors++;
+	DEV_STATS_INC(dev, tx_errors);
 	kfree_skb(skb);
 }
 EXPORT_SYMBOL_GPL(ip_tunnel_xmit);
diff --git a/net/ipv4/ip_vti.c b/net/ipv4/ip_vti.c
index 8c2bd1d9ddce..53bfd8af6920 100644
--- a/net/ipv4/ip_vti.c
+++ b/net/ipv4/ip_vti.c
@@ -107,8 +107,8 @@ static int vti_rcv_cb(struct sk_buff *skb, int err)
 	dev = tunnel->dev;
 
 	if (err) {
-		dev->stats.rx_errors++;
-		dev->stats.rx_dropped++;
+		DEV_STATS_INC(dev, rx_errors);
+		DEV_STATS_INC(dev, rx_dropped);
 
 		return 0;
 	}
@@ -183,7 +183,7 @@ static netdev_tx_t vti_xmit(struct sk_buff *skb, struct net_device *dev,
 			fl->u.ip4.flowi4_flags |= FLOWI_FLAG_ANYSRC;
 			rt = __ip_route_output_key(dev_net(dev), &fl->u.ip4);
 			if (IS_ERR(rt)) {
-				dev->stats.tx_carrier_errors++;
+				DEV_STATS_INC(dev, tx_carrier_errors);
 				goto tx_error_icmp;
 			}
 			dst = &rt->dst;
@@ -198,14 +198,14 @@ static netdev_tx_t vti_xmit(struct sk_buff *skb, struct net_device *dev,
 			if (dst->error) {
 				dst_release(dst);
 				dst = NULL;
-				dev->stats.tx_carrier_errors++;
+				DEV_STATS_INC(dev, tx_carrier_errors);
 				goto tx_error_icmp;
 			}
 			skb_dst_set(skb, dst);
 			break;
 #endif
 		default:
-			dev->stats.tx_carrier_errors++;
+			DEV_STATS_INC(dev, tx_carrier_errors);
 			goto tx_error_icmp;
 		}
 	}
@@ -213,7 +213,7 @@ static netdev_tx_t vti_xmit(struct sk_buff *skb, struct net_device *dev,
 	dst_hold(dst);
 	dst = xfrm_lookup_route(tunnel->net, dst, fl, NULL, 0);
 	if (IS_ERR(dst)) {
-		dev->stats.tx_carrier_errors++;
+		DEV_STATS_INC(dev, tx_carrier_errors);
 		goto tx_error_icmp;
 	}
 
@@ -221,7 +221,7 @@ static netdev_tx_t vti_xmit(struct sk_buff *skb, struct net_device *dev,
 		goto xmit;
 
 	if (!vti_state_check(dst->xfrm, parms->iph.daddr, parms->iph.saddr)) {
-		dev->stats.tx_carrier_errors++;
+		DEV_STATS_INC(dev, tx_carrier_errors);
 		dst_release(dst);
 		goto tx_error_icmp;
 	}
@@ -230,7 +230,7 @@ static netdev_tx_t vti_xmit(struct sk_buff *skb, struct net_device *dev,
 
 	if (tdev == dev) {
 		dst_release(dst);
-		dev->stats.collisions++;
+		DEV_STATS_INC(dev, collisions);
 		goto tx_error;
 	}
 
@@ -267,7 +267,7 @@ xmit:
 tx_error_icmp:
 	dst_link_failure(skb);
 tx_error:
-	dev->stats.tx_errors++;
+	DEV_STATS_INC(dev, tx_errors);
 	kfree_skb(skb);
 	return NETDEV_TX_OK;
 }
@@ -304,7 +304,7 @@ static netdev_tx_t vti_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
 	return vti_xmit(skb, dev, &fl);
 
 tx_err:
-	dev->stats.tx_errors++;
+	DEV_STATS_INC(dev, tx_errors);
 	kfree_skb(skb);
 	return NETDEV_TX_OK;
 }
diff --git a/net/ipv4/ipip.c b/net/ipv4/ipip.c
index 180f9daf5bec..abea77759b7e 100644
--- a/net/ipv4/ipip.c
+++ b/net/ipv4/ipip.c
@@ -310,7 +310,7 @@ static netdev_tx_t ipip_tunnel_xmit(struct sk_buff *skb,
 tx_error:
 	kfree_skb(skb);
 
-	dev->stats.tx_errors++;
+	DEV_STATS_INC(dev, tx_errors);
 	return NETDEV_TX_OK;
 }
 
diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c
index e04544ac4b45..b58df3c1bf7d 100644
--- a/net/ipv4/ipmr.c
+++ b/net/ipv4/ipmr.c
@@ -506,8 +506,8 @@ static netdev_tx_t reg_vif_xmit(struct sk_buff *skb, struct net_device *dev)
 		return err;
 	}
 
-	dev->stats.tx_bytes += skb->len;
-	dev->stats.tx_packets++;
+	DEV_STATS_ADD(dev, tx_bytes, skb->len);
+	DEV_STATS_INC(dev, tx_packets);
 	rcu_read_lock();
 
 	/* Pairs with WRITE_ONCE() in vif_add() and vif_delete() */
@@ -1839,8 +1839,8 @@ static void ipmr_queue_xmit(struct net *net, struct mr_table *mrt,
 	if (vif->flags & VIFF_REGISTER) {
 		WRITE_ONCE(vif->pkt_out, vif->pkt_out + 1);
 		WRITE_ONCE(vif->bytes_out, vif->bytes_out + skb->len);
-		vif_dev->stats.tx_bytes += skb->len;
-		vif_dev->stats.tx_packets++;
+		DEV_STATS_ADD(vif_dev, tx_bytes, skb->len);
+		DEV_STATS_INC(vif_dev, tx_packets);
 		ipmr_cache_report(mrt, skb, vifi, IGMPMSG_WHOLEPKT);
 		goto out_free;
 	}
@@ -1898,8 +1898,8 @@ static void ipmr_queue_xmit(struct net *net, struct mr_table *mrt,
 	if (vif->flags & VIFF_TUNNEL) {
 		ip_encap(net, skb, vif->local, vif->remote);
 		/* FIXME: extra output firewall step used to be here. --RR */
-		vif_dev->stats.tx_packets++;
-		vif_dev->stats.tx_bytes += skb->len;
+		DEV_STATS_INC(vif_dev, tx_packets);
+		DEV_STATS_ADD(vif_dev, tx_bytes, skb->len);
 	}
 
 	IPCB(skb)->flags |= IPSKB_FORWARDED;