diff options
| author |   Eric Dumazet <edumazet@google.com> | 2023-08-02 13:14:59 +0000 |
|---|---|---|
| committer |   Jakub Kicinski <kuba@kernel.org> | 2023-08-03 10:58:24 -0700 |
| commit | d5d986ce42c71a7562d32c4e21e026b0f87befec (patch) | |
| tree | 9b4b6d9d2684efe9d5298e8b18d2958ca83d8613 | |
| parent | tcp_metrics: annotate data-races around tm->tcpm_vals[] (diff) | |
| download | linux-d5d986ce42c71a7562d32c4e21e026b0f87befec.tar.xz linux-d5d986ce42c71a7562d32c4e21e026b0f87befec.zip | |
tcp_metrics: annotate data-races around tm->tcpm_net
tm->tcpm_net can be read or written locklessly.
Instead of changing write_pnet() and read_pnet() and potentially
hurt performance, add the needed READ_ONCE()/WRITE_ONCE()
in tm_net() and tcpm_new().
Fixes: 849e8a0ca8d5 ("tcp_metrics: Add a field tcpm_net and verify it matches on lookup")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://lore.kernel.org/r/20230802131500.1478140-6-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| -rw-r--r-- | net/ipv4/tcp_metrics.c | 11 |
1 files changed, 7 insertions, 4 deletions
diff --git a/net/ipv4/tcp_metrics.c b/net/ipv4/tcp_metrics.c index fd4ab7a51cef..4fd274836a48 100644 --- a/net/ipv4/tcp_metrics.c +++ b/net/ipv4/tcp_metrics.c @@ -40,7 +40,7 @@ struct tcp_fastopen_metrics { struct tcp_metrics_block { struct tcp_metrics_block __rcu *tcpm_next; - possible_net_t tcpm_net; + struct net *tcpm_net; struct inetpeer_addr tcpm_saddr; struct inetpeer_addr tcpm_daddr; unsigned long tcpm_stamp; @@ -51,9 +51,10 @@ struct tcp_metrics_block { struct rcu_head rcu_head; }; -static inline struct net *tm_net(struct tcp_metrics_block *tm) +static inline struct net *tm_net(const struct tcp_metrics_block *tm) { - return read_pnet(&tm->tcpm_net); + /* Paired with the WRITE_ONCE() in tcpm_new() */ + return READ_ONCE(tm->tcpm_net); } static bool tcp_metric_locked(struct tcp_metrics_block *tm, @@ -197,7 +198,9 @@ static struct tcp_metrics_block *tcpm_new(struct dst_entry *dst, if (!tm) goto out_unlock; } - write_pnet(&tm->tcpm_net, net); + /* Paired with the READ_ONCE() in tm_net() */ + WRITE_ONCE(tm->tcpm_net, net); + tm->tcpm_saddr = *saddr; tm->tcpm_daddr = *daddr; |