ip_tunnel: adapt iptunnel_xmit_stats() to NETDEV_PCPU_STAT_DSTATS

Blamed commits forgot that vxlan/geneve use udp_tunnel[6]_xmit_skb() which
call iptunnel_xmit_stats().

iptunnel_xmit_stats() was assuming tunnels were only using
NETDEV_PCPU_STAT_TSTATS.

@syncp offset in pcpu_sw_netstats and pcpu_dstats is different.

32bit kernels would either have corruptions or freezes if the syncp
sequence was overwritten.

This patch also moves pcpu_stat_type closer to dev->{t,d}stats to avoid
a potential cache line miss since iptunnel_xmit_stats() needs to read it.

Fixes: 6fa6de302246 ("geneve: Handle stats using NETDEV_PCPU_STAT_DSTATS.")
Fixes: be226352e8dc ("vxlan: Handle stats using NETDEV_PCPU_STAT_DSTATS.")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Guillaume Nault <gnault@redhat.com>
Link: https://patch.msgid.link/20260311123110.1471930-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index ae269a2e7f4dd22e4679db7f88b0f6dfedb36115..d7aac6f185bcab8a93a204c349272fc7c1b15ee7 100644 (file)
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -2155,6 +2155,7 @@ struct net_device {
        unsigned long           state;
        unsigned int            flags;
        unsigned short          hard_header_len;
+       enum netdev_stat_type   pcpu_stat_type:8;
        netdev_features_t       features;
        struct inet6_dev __rcu  *ip6_ptr;
        __cacheline_group_end(net_device_read_txrx);
@@ -2404,8 +2405,6 @@ struct net_device {
        void                            *ml_priv;
        enum netdev_ml_priv_type        ml_priv_type;
 
-       enum netdev_stat_type           pcpu_stat_type:8;
-
 #if IS_ENABLED(CONFIG_GARP)
        struct garp_port __rcu  *garp_port;
 #endif

diff --git a/include/net/ip_tunnels.h b/include/net/ip_tunnels.h
index 80662f81208039feb4fc1d3feae401633af2a5c2..1f577a4f8ce9b1ae4223d9cfd903bec8d7d78c04 100644 (file)
--- a/include/net/ip_tunnels.h
+++ b/include/net/ip_tunnels.h
@@ -665,13 +665,29 @@ static inline int iptunnel_pull_offloads(struct sk_buff *skb)
 static inline void iptunnel_xmit_stats(struct net_device *dev, int pkt_len)
 {
        if (pkt_len > 0) {
-               struct pcpu_sw_netstats *tstats = get_cpu_ptr(dev->tstats);
-
-               u64_stats_update_begin(&tstats->syncp);
-               u64_stats_add(&tstats->tx_bytes, pkt_len);
-               u64_stats_inc(&tstats->tx_packets);
-               u64_stats_update_end(&tstats->syncp);
-               put_cpu_ptr(tstats);
+               if (dev->pcpu_stat_type == NETDEV_PCPU_STAT_DSTATS) {
+                       struct pcpu_dstats *dstats = get_cpu_ptr(dev->dstats);
+
+                       u64_stats_update_begin(&dstats->syncp);
+                       u64_stats_add(&dstats->tx_bytes, pkt_len);
+                       u64_stats_inc(&dstats->tx_packets);
+                       u64_stats_update_end(&dstats->syncp);
+                       put_cpu_ptr(dstats);
+                       return;
+               }
+               if (dev->pcpu_stat_type == NETDEV_PCPU_STAT_TSTATS) {
+                       struct pcpu_sw_netstats *tstats = get_cpu_ptr(dev->tstats);
+
+                       u64_stats_update_begin(&tstats->syncp);
+                       u64_stats_add(&tstats->tx_bytes, pkt_len);
+                       u64_stats_inc(&tstats->tx_packets);
+                       u64_stats_update_end(&tstats->syncp);
+                       put_cpu_ptr(tstats);
+                       return;
+               }
+               pr_err_once("iptunnel_xmit_stats pcpu_stat_type=%d\n",
+                           dev->pcpu_stat_type);
+               WARN_ON_ONCE(1);
                return;
        }