From ce355e209feb030945dae4c358c02f29a84f3f8b Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Wed, 9 Jul 2014 15:14:06 +0200 Subject: netfilter: nf_tables: 64bit stats need some extra synchronization Use generic u64_stats_sync infrastructure to get proper 64bit stats, even on 32bit arches, at no extra cost for 64bit arches. Without this fix, 32bit arches can have some wrong counters at the time the carry is propagated into upper word. Signed-off-by: Eric Dumazet Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nf_tables_api.c | 15 +++++++++++---- net/netfilter/nf_tables_core.c | 10 ++++++---- 2 files changed, 17 insertions(+), 8 deletions(-) (limited to 'net') diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index ac03d748360e..8746ff9a8357 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -644,13 +644,20 @@ static int nft_dump_stats(struct sk_buff *skb, struct nft_stats __percpu *stats) { struct nft_stats *cpu_stats, total; struct nlattr *nest; + unsigned int seq; + u64 pkts, bytes; int cpu; memset(&total, 0, sizeof(total)); for_each_possible_cpu(cpu) { cpu_stats = per_cpu_ptr(stats, cpu); - total.pkts += cpu_stats->pkts; - total.bytes += cpu_stats->bytes; + do { + seq = u64_stats_fetch_begin_irq(&cpu_stats->syncp); + pkts = cpu_stats->pkts; + bytes = cpu_stats->bytes; + } while (u64_stats_fetch_retry_irq(&cpu_stats->syncp, seq)); + total.pkts += pkts; + total.bytes += bytes; } nest = nla_nest_start(skb, NFTA_CHAIN_COUNTERS); if (nest == NULL) @@ -875,7 +882,7 @@ static struct nft_stats __percpu *nft_stats_alloc(const struct nlattr *attr) if (!tb[NFTA_COUNTER_BYTES] || !tb[NFTA_COUNTER_PACKETS]) return ERR_PTR(-EINVAL); - newstats = alloc_percpu(struct nft_stats); + newstats = netdev_alloc_pcpu_stats(struct nft_stats); if (newstats == NULL) return ERR_PTR(-ENOMEM); @@ -1091,7 +1098,7 @@ static int nf_tables_newchain(struct sock *nlsk, struct sk_buff *skb, } basechain->stats = stats; } else { - stats = alloc_percpu(struct nft_stats); + stats = netdev_alloc_pcpu_stats(struct nft_stats); if (IS_ERR(stats)) { module_put(type->owner); kfree(basechain); diff --git a/net/netfilter/nf_tables_core.c b/net/netfilter/nf_tables_core.c index 345acfb1720b..3b90eb2b2c55 100644 --- a/net/netfilter/nf_tables_core.c +++ b/net/netfilter/nf_tables_core.c @@ -109,7 +109,7 @@ nft_do_chain(struct nft_pktinfo *pkt, const struct nf_hook_ops *ops) struct nft_data data[NFT_REG_MAX + 1]; unsigned int stackptr = 0; struct nft_jumpstack jumpstack[NFT_JUMP_STACK_SIZE]; - struct nft_stats __percpu *stats; + struct nft_stats *stats; int rulenum; /* * Cache cursor to avoid problems in case that the cursor is updated @@ -205,9 +205,11 @@ next_rule: nft_trace_packet(pkt, basechain, -1, NFT_TRACE_POLICY); rcu_read_lock_bh(); - stats = rcu_dereference(nft_base_chain(basechain)->stats); - __this_cpu_inc(stats->pkts); - __this_cpu_add(stats->bytes, pkt->skb->len); + stats = this_cpu_ptr(rcu_dereference(nft_base_chain(basechain)->stats)); + u64_stats_update_begin(&stats->syncp); + stats->pkts++; + stats->bytes += pkt->skb->len; + u64_stats_update_end(&stats->syncp); rcu_read_unlock_bh(); return nft_base_chain(basechain)->policy; -- cgit v1.2.3