Commit 8431c602 authored by Eric Dumazet's avatar Eric Dumazet Committed by Jakub Kicinski
Browse files

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: 6fa6de30 ("geneve: Handle stats using NETDEV_PCPU_STAT_DSTATS.")
Fixes: be226352 ("vxlan: Handle stats using NETDEV_PCPU_STAT_DSTATS.")
Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Reviewed-by: default avatarGuillaume Nault <gnault@redhat.com>
Link: https://patch.msgid.link/20260311123110.1471930-1-edumazet@google.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent e1f0a18c

include/linux/netdevice.h

+1 −2
Original line number Diff line number Diff line
@@ -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

include/net/ip_tunnels.h

+23 −7
Original line number Diff line number Diff line
@@ -665,6 +665,17 @@ 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) {

		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);
@@ -674,6 +685,11 @@ static inline void iptunnel_xmit_stats(struct net_device *dev, int pkt_len) 
			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;

	}



	if (pkt_len < 0) {

		DEV_STATS_INC(dev, tx_errors);