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| author | Eric Dumazet <edumazet@google.com> | 2023-08-02 13:14:59 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-08-11 11:45:38 +0200 |
| commit | 0e273d202f84f4fdb2f538f6dcf0dca9a5b0c200 (patch) | |
| tree | 427d8d91826650d741a850b98bd596794ccb9c20 /net | |
| parent | 9267df7f26222c2d5138cf39b4477b4e2669e03c (diff) | |
| download | linux-0e273d202f84f4fdb2f538f6dcf0dca9a5b0c200.tar.gz linux-0e273d202f84f4fdb2f538f6dcf0dca9a5b0c200.tar.bz2 linux-0e273d202f84f4fdb2f538f6dcf0dca9a5b0c200.zip | |
tcp_metrics: annotate data-races around tm->tcpm_net
[ Upstream commit d5d986ce42c71a7562d32c4e21e026b0f87befec ]
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'net')
| -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 fa99481abce8..dfd224979cf6 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; |