From: Eric Dumazet <edumazet@google.com>
To: "David S . Miller" <davem@davemloft.net>,
Jakub Kicinski <kuba@kernel.org>,
Paolo Abeni <pabeni@redhat.com>
Cc: netdev@vger.kernel.org, eric.dumazet@gmail.com,
Eric Dumazet <edumazet@google.com>
Subject: [PATCH net 03/11] tcp: annotate data-races around tp->keepalive_time
Date: Wed, 19 Jul 2023 21:28:49 +0000 [thread overview]
Message-ID: <20230719212857.3943972-4-edumazet@google.com> (raw)
In-Reply-To: <20230719212857.3943972-1-edumazet@google.com>
do_tcp_getsockopt() reads tp->keepalive_time while another cpu
might change its value.
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Eric Dumazet <edumazet@google.com>
---
include/net/tcp.h | 7 +++++--
net/ipv4/tcp.c | 3 ++-
2 files changed, 7 insertions(+), 3 deletions(-)
diff --git a/include/net/tcp.h b/include/net/tcp.h
index efaed11e691d52db0fcece85d966954763d3cfcf..ff7372410472246d372402dfdfd6391544be8259 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -1515,9 +1515,12 @@ static inline int keepalive_intvl_when(const struct tcp_sock *tp)
static inline int keepalive_time_when(const struct tcp_sock *tp)
{
struct net *net = sock_net((struct sock *)tp);
+ int val;
- return tp->keepalive_time ? :
- READ_ONCE(net->ipv4.sysctl_tcp_keepalive_time);
+ /* Paired with WRITE_ONCE() in tcp_sock_set_keepidle_locked() */
+ val = READ_ONCE(tp->keepalive_time);
+
+ return val ? : READ_ONCE(net->ipv4.sysctl_tcp_keepalive_time);
}
static inline int keepalive_probes(const struct tcp_sock *tp)
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 03ae6554c78d1e42894a8e511cef362134660aac..b4f7856dfb1611f02073699ee24d48f1a6fe7b87 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -3312,7 +3312,8 @@ int tcp_sock_set_keepidle_locked(struct sock *sk, int val)
if (val < 1 || val > MAX_TCP_KEEPIDLE)
return -EINVAL;
- tp->keepalive_time = val * HZ;
+ /* Paired with WRITE_ONCE() in keepalive_time_when() */
+ WRITE_ONCE(tp->keepalive_time, val * HZ);
if (sock_flag(sk, SOCK_KEEPOPEN) &&
!((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) {
u32 elapsed = keepalive_time_elapsed(tp);
--
2.41.0.255.g8b1d071c50-goog
next prev parent reply other threads:[~2023-07-19 21:29 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-07-19 21:28 [PATCH net 00/11] tcp: add missing annotations Eric Dumazet
2023-07-19 21:28 ` [PATCH net 01/11] tcp: annotate data-races around tp->tcp_tx_delay Eric Dumazet
2023-07-19 21:28 ` [PATCH net 02/11] tcp: annotate data-races around tp->tsoffset Eric Dumazet
2023-07-19 21:28 ` Eric Dumazet [this message]
2023-07-19 21:28 ` [PATCH net 04/11] tcp: annotate data-races around tp->keepalive_intvl Eric Dumazet
2023-07-19 21:28 ` [PATCH net 05/11] tcp: annotate data-races around tp->keepalive_probes Eric Dumazet
2023-07-19 21:28 ` [PATCH net 06/11] tcp: annotate data-races around icsk->icsk_syn_retries Eric Dumazet
2023-07-19 21:28 ` [PATCH net 07/11] tcp: annotate data-races around tp->linger2 Eric Dumazet
2023-07-19 21:28 ` [PATCH net 08/11] tcp: annotate data-races around rskq_defer_accept Eric Dumazet
2023-07-19 21:28 ` [PATCH net 09/11] tcp: annotate data-races around tp->notsent_lowat Eric Dumazet
2023-07-19 21:28 ` [PATCH net 10/11] tcp: annotate data-races around icsk->icsk_user_timeout Eric Dumazet
2023-07-19 21:28 ` [PATCH net 11/11] tcp: annotate data-races around fastopenq.max_qlen Eric Dumazet
2023-07-20 19:50 ` [PATCH net 00/11] tcp: add missing annotations patchwork-bot+netdevbpf
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