From b071af523579df7341cabf0f16fc661125e9a13f Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Mon, 13 Mar 2023 20:17:31 +0000 Subject: 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 Reviewed-by: David Ahern Reviewed-by: Martin KaFai Lau Signed-off-by: Jakub Kicinski --- net/bridge/br_arp_nd_proxy.c | 4 ++-- net/bridge/br_netfilter_hooks.c | 3 ++- net/core/filter.c | 4 ++-- net/core/neighbour.c | 28 ++++++++++++++-------------- net/ipv4/arp.c | 8 ++++---- net/ipv4/fib_semantics.c | 4 ++-- net/ipv4/nexthop.c | 4 ++-- net/ipv4/route.c | 2 +- net/ipv6/ip6_output.c | 2 +- net/ipv6/ndisc.c | 4 ++-- net/ipv6/route.c | 2 +- 11 files changed, 33 insertions(+), 32 deletions(-) (limited to 'net') diff --git a/net/bridge/br_arp_nd_proxy.c b/net/bridge/br_arp_nd_proxy.c index e5e48c6e35d7..b45c00c01dea 100644 --- a/net/bridge/br_arp_nd_proxy.c +++ b/net/bridge/br_arp_nd_proxy.c @@ -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; } diff --git a/net/bridge/br_netfilter_hooks.c b/net/bridge/br_netfilter_hooks.c index 638a4d5359db..3e3065bc0465 100644 --- a/net/bridge/br_netfilter_hooks.c +++ b/net/bridge/br_netfilter_hooks.c @@ -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); diff --git a/net/core/filter.c b/net/core/filter.c index 50f649f1b4a9..d052fac28d02 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -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); diff --git a/net/core/neighbour.c b/net/core/neighbour.c index 0116b0ff91a7..90d399b3f980 100644 --- a/net/core/neighbour.c +++ b/net/core/neighbour.c @@ -1093,13 +1093,13 @@ static void neigh_timer_handler(struct timer_list *t) neigh->used + NEIGH_VAR(neigh->parms, DELAY_PROBE_TIME))) { neigh_dbg(2, "neigh %p is delayed\n", neigh); - neigh->nud_state = NUD_DELAY; + WRITE_ONCE(neigh->nud_state, NUD_DELAY); neigh->updated = jiffies; neigh_suspect(neigh); next = now + NEIGH_VAR(neigh->parms, DELAY_PROBE_TIME); } else { neigh_dbg(2, "neigh %p is suspected\n", neigh); - neigh->nud_state = NUD_STALE; + WRITE_ONCE(neigh->nud_state, NUD_STALE); neigh->updated = jiffies; neigh_suspect(neigh); notify = 1; @@ -1109,14 +1109,14 @@ static void neigh_timer_handler(struct timer_list *t) neigh->confirmed + NEIGH_VAR(neigh->parms, DELAY_PROBE_TIME))) { neigh_dbg(2, "neigh %p is now reachable\n", neigh); - neigh->nud_state = NUD_REACHABLE; + WRITE_ONCE(neigh->nud_state, NUD_REACHABLE); neigh->updated = jiffies; neigh_connect(neigh); notify = 1; next = neigh->confirmed + neigh->parms->reachable_time; } else { neigh_dbg(2, "neigh %p is probed\n", neigh); - neigh->nud_state = NUD_PROBE; + WRITE_ONCE(neigh->nud_state, NUD_PROBE); neigh->updated = jiffies; atomic_set(&neigh->probes, 0); notify = 1; @@ -1130,7 +1130,7 @@ static void neigh_timer_handler(struct timer_list *t) if ((neigh->nud_state & (NUD_INCOMPLETE | NUD_PROBE)) && atomic_read(&neigh->probes) >= neigh_max_probes(neigh)) { - neigh->nud_state = NUD_FAILED; + WRITE_ONCE(neigh->nud_state, NUD_FAILED); notify = 1; neigh_invalidate(neigh); goto out; @@ -1179,7 +1179,7 @@ int __neigh_event_send(struct neighbour *neigh, struct sk_buff *skb, atomic_set(&neigh->probes, NEIGH_VAR(neigh->parms, UCAST_PROBES)); neigh_del_timer(neigh); - neigh->nud_state = NUD_INCOMPLETE; + WRITE_ONCE(neigh->nud_state, NUD_INCOMPLETE); neigh->updated = now; if (!immediate_ok) { next = now + 1; @@ -1191,7 +1191,7 @@ int __neigh_event_send(struct neighbour *neigh, struct sk_buff *skb, } neigh_add_timer(neigh, next); } else { - neigh->nud_state = NUD_FAILED; + WRITE_ONCE(neigh->nud_state, NUD_FAILED); neigh->updated = jiffies; write_unlock_bh(&neigh->lock); @@ -1201,7 +1201,7 @@ int __neigh_event_send(struct neighbour *neigh, struct sk_buff *skb, } else if (neigh->nud_state & NUD_STALE) { neigh_dbg(2, "neigh %p is delayed\n", neigh); neigh_del_timer(neigh); - neigh->nud_state = NUD_DELAY; + WRITE_ONCE(neigh->nud_state, NUD_DELAY); neigh->updated = jiffies; neigh_add_timer(neigh, jiffies + NEIGH_VAR(neigh->parms, DELAY_PROBE_TIME)); @@ -1313,7 +1313,7 @@ static int __neigh_update(struct neighbour *neigh, const u8 *lladdr, neigh_update_flags(neigh, flags, ¬ify, &gc_update, &managed_update); if (flags & (NEIGH_UPDATE_F_USE | NEIGH_UPDATE_F_MANAGED)) { new = old & ~NUD_PERMANENT; - neigh->nud_state = new; + WRITE_ONCE(neigh->nud_state, new); err = 0; goto out; } @@ -1322,7 +1322,7 @@ static int __neigh_update(struct neighbour *neigh, const u8 *lladdr, neigh_del_timer(neigh); if (old & NUD_CONNECTED) neigh_suspect(neigh); - neigh->nud_state = new; + WRITE_ONCE(neigh->nud_state, new); err = 0; notify = old & NUD_VALID; if ((old & (NUD_INCOMPLETE | NUD_PROBE)) && @@ -1401,7 +1401,7 @@ static int __neigh_update(struct neighbour *neigh, const u8 *lladdr, ((new & NUD_REACHABLE) ? neigh->parms->reachable_time : 0))); - neigh->nud_state = new; + WRITE_ONCE(neigh->nud_state, new); notify = 1; } @@ -1488,7 +1488,7 @@ void __neigh_set_probe_once(struct neighbour *neigh) neigh->updated = jiffies; if (!(neigh->nud_state & NUD_FAILED)) return; - neigh->nud_state = NUD_INCOMPLETE; + WRITE_ONCE(neigh->nud_state, NUD_INCOMPLETE); atomic_set(&neigh->probes, neigh_max_probes(neigh)); neigh_add_timer(neigh, jiffies + max(NEIGH_VAR(neigh->parms, RETRANS_TIME), @@ -3198,7 +3198,7 @@ static struct neighbour *neigh_get_first(struct seq_file *seq) } if (!(state->flags & NEIGH_SEQ_SKIP_NOARP)) break; - if (n->nud_state & ~NUD_NOARP) + if (READ_ONCE(n->nud_state) & ~NUD_NOARP) break; next: n = rcu_dereference_bh(n->next); @@ -3240,7 +3240,7 @@ static struct neighbour *neigh_get_next(struct seq_file *seq, if (!(state->flags & NEIGH_SEQ_SKIP_NOARP)) break; - if (n->nud_state & ~NUD_NOARP) + if (READ_ONCE(n->nud_state) & ~NUD_NOARP) break; next: n = rcu_dereference_bh(n->next); diff --git a/net/ipv4/arp.c b/net/ipv4/arp.c index 4f7237661afb..9456f5bb35e5 100644 --- a/net/ipv4/arp.c +++ b/net/ipv4/arp.c @@ -375,7 +375,7 @@ static void arp_solicit(struct neighbour *neigh, struct sk_buff *skb) probes -= NEIGH_VAR(neigh->parms, UCAST_PROBES); if (probes < 0) { - if (!(neigh->nud_state & NUD_VALID)) + if (!(READ_ONCE(neigh->nud_state) & NUD_VALID)) pr_debug("trying to ucast probe in NUD_INVALID\n"); neigh_ha_snapshot(dst_ha, neigh, dev); dst_hw = dst_ha; @@ -1123,7 +1123,7 @@ static int arp_req_get(struct arpreq *r, struct net_device *dev) neigh = neigh_lookup(&arp_tbl, &ip, dev); if (neigh) { - if (!(neigh->nud_state & NUD_NOARP)) { + if (!(READ_ONCE(neigh->nud_state) & NUD_NOARP)) { read_lock_bh(&neigh->lock); memcpy(r->arp_ha.sa_data, neigh->ha, dev->addr_len); r->arp_flags = arp_state_to_flags(neigh); @@ -1144,12 +1144,12 @@ int arp_invalidate(struct net_device *dev, __be32 ip, bool force) struct neigh_table *tbl = &arp_tbl; if (neigh) { - if ((neigh->nud_state & NUD_VALID) && !force) { + if ((READ_ONCE(neigh->nud_state) & NUD_VALID) && !force) { neigh_release(neigh); return 0; } - if (neigh->nud_state & ~NUD_NOARP) + if (READ_ONCE(neigh->nud_state) & ~NUD_NOARP) err = neigh_update(neigh, NULL, NUD_FAILED, NEIGH_UPDATE_F_OVERRIDE| NEIGH_UPDATE_F_ADMIN, 0); diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c index 3bb890a40ed7..574ff450c4d2 100644 --- a/net/ipv4/fib_semantics.c +++ b/net/ipv4/fib_semantics.c @@ -563,7 +563,7 @@ static int fib_detect_death(struct fib_info *fi, int order, n = NULL; if (n) { - state = n->nud_state; + state = READ_ONCE(n->nud_state); neigh_release(n); } else { return 0; @@ -2202,7 +2202,7 @@ static bool fib_good_nh(const struct fib_nh *nh) else n = NULL; if (n) - state = n->nud_state; + state = READ_ONCE(n->nud_state); rcu_read_unlock_bh(); } diff --git a/net/ipv4/nexthop.c b/net/ipv4/nexthop.c index d8ef05347fd9..e28a99f1996b 100644 --- a/net/ipv4/nexthop.c +++ b/net/ipv4/nexthop.c @@ -1128,7 +1128,7 @@ static bool ipv6_good_nh(const struct fib6_nh *nh) n = __ipv6_neigh_lookup_noref_stub(nh->fib_nh_dev, &nh->fib_nh_gw6); if (n) - state = n->nud_state; + state = READ_ONCE(n->nud_state); rcu_read_unlock_bh(); @@ -1145,7 +1145,7 @@ static bool ipv4_good_nh(const struct fib_nh *nh) n = __ipv4_neigh_lookup_noref(nh->fib_nh_dev, (__force u32)nh->fib_nh_gw4); if (n) - state = n->nud_state; + state = READ_ONCE(n->nud_state); rcu_read_unlock_bh(); diff --git a/net/ipv4/route.c b/net/ipv4/route.c index de6e3515ab4f..232009d216c4 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -784,7 +784,7 @@ static void __ip_do_redirect(struct rtable *rt, struct sk_buff *skb, struct flow if (!n) n = neigh_create(&arp_tbl, &new_gw, rt->dst.dev); if (!IS_ERR(n)) { - if (!(n->nud_state & NUD_VALID)) { + if (!(READ_ONCE(n->nud_state) & NUD_VALID)) { neigh_event_send(n, NULL); } else { if (fib_lookup(net, fl4, &res, 0) == 0) { diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c index 4ce3f9d3bc8a..e5ed39a3c65f 100644 --- a/net/ipv6/ip6_output.c +++ b/net/ipv6/ip6_output.c @@ -1153,7 +1153,7 @@ static int ip6_dst_lookup_tail(struct net *net, const struct sock *sk, rcu_read_lock_bh(); n = __ipv6_neigh_lookup_noref(rt->dst.dev, rt6_nexthop(rt, &fl6->daddr)); - err = n && !(n->nud_state & NUD_VALID) ? -EINVAL : 0; + err = n && !(READ_ONCE(n->nud_state) & NUD_VALID) ? -EINVAL : 0; rcu_read_unlock_bh(); if (err) { diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c index c4be62c99f73..18634ebd20a4 100644 --- a/net/ipv6/ndisc.c +++ b/net/ipv6/ndisc.c @@ -745,7 +745,7 @@ static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb) saddr = &ipv6_hdr(skb)->saddr; probes -= NEIGH_VAR(neigh->parms, UCAST_PROBES); if (probes < 0) { - if (!(neigh->nud_state & NUD_VALID)) { + if (!(READ_ONCE(neigh->nud_state) & NUD_VALID)) { ND_PRINTK(1, dbg, "%s: trying to ucast probe in NUD_INVALID: %pI6\n", __func__, target); @@ -1090,7 +1090,7 @@ static enum skb_drop_reason ndisc_recv_na(struct sk_buff *skb) u8 old_flags = neigh->flags; struct net *net = dev_net(dev); - if (neigh->nud_state & NUD_FAILED) + if (READ_ONCE(neigh->nud_state) & NUD_FAILED) goto out; /* diff --git a/net/ipv6/route.c b/net/ipv6/route.c index 0fdb03df2287..25c00c6f5131 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -638,7 +638,7 @@ static void rt6_probe(struct fib6_nh *fib6_nh) idev = __in6_dev_get(dev); neigh = __ipv6_neigh_lookup_noref(dev, nh_gw); if (neigh) { - if (neigh->nud_state & NUD_VALID) + if (READ_ONCE(neigh->nud_state) & NUD_VALID) goto out; write_lock(&neigh->lock); -- cgit