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 <edumazet@google.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index ac03d74..8746ff9 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -644,13 +644,20 @@
{
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 @@
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 @@
}
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);