Commit b071af52 authored Mar 13, 2023 by Eric Dumazet Committed by Jakub Kicinski Mar 15, 2023

neighbour: annotate lockless accesses to n->nud_state



We have many lockless accesses to n->nud_state.

Before adding another one in the following patch,
add annotations to readers and writers.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Reviewed-by: Martin KaFai Lau <martin.lau@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

parent 68a84a12

drivers/net/vxlan/vxlan_core.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -1863,7 +1863,7 @@ static int arp_reduce(struct net_device dev, struct sk_buff skb, __be32 vni)
		struct vxlan_fdb *f;
		struct sk_buff *reply;

		if (!(n->nud_state & NUD_CONNECTED)) {
		if (!(READ_ONCE(n->nud_state) & NUD_CONNECTED)) {
		neigh_release(n);
		goto out;
		}
		@@ -2027,7 +2027,7 @@ static int neigh_reduce(struct net_device dev, struct sk_buff skb, __be32 vni)
		struct vxlan_fdb *f;
		struct sk_buff *reply;

		if (!(n->nud_state & NUD_CONNECTED)) {
		if (!(READ_ONCE(n->nud_state) & NUD_CONNECTED)) {
		neigh_release(n);
		goto out;
		}

include/net/neighbour.h

+1 −1

Original line number	Diff line number	Diff line
		@@ -464,7 +464,7 @@ static __always_inline int neigh_event_send_probe(struct neighbour *neigh,

		if (READ_ONCE(neigh->used) != now)
		WRITE_ONCE(neigh->used, now);
		if (!(neigh->nud_state & (NUD_CONNECTED \| NUD_DELAY \| NUD_PROBE)))
		if (!(READ_ONCE(neigh->nud_state) & (NUD_CONNECTED \| NUD_DELAY \| NUD_PROBE)))
		return __neigh_event_send(neigh, skb, immediate_ok);
		return 0;
		}

net/bridge/br_arp_nd_proxy.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -192,7 +192,7 @@ void br_do_proxy_suppress_arp(struct sk_buff skb, struct net_bridge br,
		if (n) {
		struct net_bridge_fdb_entry *f;

		if (!(n->nud_state & NUD_VALID)) {
		if (!(READ_ONCE(n->nud_state) & NUD_VALID)) {
		neigh_release(n);
		return;
		}
		@@ -452,7 +452,7 @@ void br_do_suppress_nd(struct sk_buff skb, struct net_bridge br,
		if (n) {
		struct net_bridge_fdb_entry *f;

		if (!(n->nud_state & NUD_VALID)) {
		if (!(READ_ONCE(n->nud_state) & NUD_VALID)) {
		neigh_release(n);
		return;
		}

net/bridge/br_netfilter_hooks.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -277,7 +277,8 @@ int br_nf_pre_routing_finish_bridge(struct net net, struct sock sk, struct sk_
		struct nf_bridge_info *nf_bridge = nf_bridge_info_get(skb);
		int ret;

		if ((neigh->nud_state & NUD_CONNECTED) && neigh->hh.hh_len) {
		if ((READ_ONCE(neigh->nud_state) & NUD_CONNECTED) &&
		READ_ONCE(neigh->hh.hh_len)) {
		neigh_hh_bridge(&neigh->hh, skb);
		skb->dev = nf_bridge->physindev;
		ret = br_handle_frame_finish(net, sk, skb);

net/core/filter.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -5871,7 +5871,7 @@ static int bpf_ipv4_fib_lookup(struct net net, struct bpf_fib_lookup params,
		else
		neigh = __ipv6_neigh_lookup_noref_stub(dev, params->ipv6_dst);

		if (!neigh \|\| !(neigh->nud_state & NUD_VALID))
		if (!neigh \|\| !(READ_ONCE(neigh->nud_state) & NUD_VALID))
		return BPF_FIB_LKUP_RET_NO_NEIGH;
		memcpy(params->dmac, neigh->ha, ETH_ALEN);
		memcpy(params->smac, dev->dev_addr, ETH_ALEN);
		@@ -5992,7 +5992,7 @@ static int bpf_ipv6_fib_lookup(struct net net, struct bpf_fib_lookup params,
		* not needed here.
		*/
		neigh = __ipv6_neigh_lookup_noref_stub(dev, dst);
		if (!neigh \|\| !(neigh->nud_state & NUD_VALID))
		if (!neigh \|\| !(READ_ONCE(neigh->nud_state) & NUD_VALID))
		return BPF_FIB_LKUP_RET_NO_NEIGH;
		memcpy(params->dmac, neigh->ha, ETH_ALEN);
		memcpy(params->smac, dev->dev_addr, ETH_ALEN);