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 05/11] tcp: annotate data-races around tp->keepalive_probes
Date: Wed, 19 Jul 2023 21:28:51 +0000 [thread overview]
Message-ID: <20230719212857.3943972-6-edumazet@google.com> (raw)
In-Reply-To: <20230719212857.3943972-1-edumazet@google.com>
do_tcp_getsockopt() reads tp->keepalive_probes 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 | 9 +++++++--
net/ipv4/tcp.c | 5 +++--
2 files changed, 10 insertions(+), 4 deletions(-)
diff --git a/include/net/tcp.h b/include/net/tcp.h
index 79af16a4028665d51f6ea5f1a4382265b8163309..855dbe72e431776257037d75e32037b44905453c 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -1531,9 +1531,14 @@ static inline int keepalive_time_when(const struct tcp_sock *tp)
static inline int keepalive_probes(const struct tcp_sock *tp)
{
struct net *net = sock_net((struct sock *)tp);
+ int val;
+
+ /* Paired with WRITE_ONCE() in tcp_sock_set_keepcnt()
+ * and do_tcp_setsockopt().
+ */
+ val = READ_ONCE(tp->keepalive_probes);
- return tp->keepalive_probes ? :
- READ_ONCE(net->ipv4.sysctl_tcp_keepalive_probes);
+ return val ? : READ_ONCE(net->ipv4.sysctl_tcp_keepalive_probes);
}
static inline u32 keepalive_time_elapsed(const struct tcp_sock *tp)
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index d55fe014e7c902859243cdb619d94a230e44f708..574fd0da167339512077c36958578fde2b1181e8 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -3357,7 +3357,8 @@ int tcp_sock_set_keepcnt(struct sock *sk, int val)
return -EINVAL;
lock_sock(sk);
- tcp_sk(sk)->keepalive_probes = val;
+ /* Paired with READ_ONCE() in keepalive_probes() */
+ WRITE_ONCE(tcp_sk(sk)->keepalive_probes, val);
release_sock(sk);
return 0;
}
@@ -3565,7 +3566,7 @@ int do_tcp_setsockopt(struct sock *sk, int level, int optname,
if (val < 1 || val > MAX_TCP_KEEPCNT)
err = -EINVAL;
else
- tp->keepalive_probes = val;
+ WRITE_ONCE(tp->keepalive_probes, val);
break;
case TCP_SYNCNT:
if (val < 1 || val > MAX_TCP_SYNCNT)
--
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 ` [PATCH net 03/11] tcp: annotate data-races around tp->keepalive_time Eric Dumazet
2023-07-19 21:28 ` [PATCH net 04/11] tcp: annotate data-races around tp->keepalive_intvl Eric Dumazet
2023-07-19 21:28 ` Eric Dumazet [this message]
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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