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 11/11] tcp: annotate data-races around fastopenq.max_qlen
Date: Wed, 19 Jul 2023 21:28:57 +0000 [thread overview]
Message-ID: <20230719212857.3943972-12-edumazet@google.com> (raw)
In-Reply-To: <20230719212857.3943972-1-edumazet@google.com>
This field can be read locklessly.
Fixes: 1536e2857bd3 ("tcp: Add a TCP_FASTOPEN socket option to get a max backlog on its listner")
Signed-off-by: Eric Dumazet <edumazet@google.com>
---
include/linux/tcp.h | 2 +-
net/ipv4/tcp.c | 2 +-
net/ipv4/tcp_fastopen.c | 6 ++++--
3 files changed, 6 insertions(+), 4 deletions(-)
diff --git a/include/linux/tcp.h b/include/linux/tcp.h
index b4c08ac86983568a9511258708724da15d0b999e..91a37c99ba6651c075d1547c5545700be3e5593c 100644
--- a/include/linux/tcp.h
+++ b/include/linux/tcp.h
@@ -513,7 +513,7 @@ static inline void fastopen_queue_tune(struct sock *sk, int backlog)
struct request_sock_queue *queue = &inet_csk(sk)->icsk_accept_queue;
int somaxconn = READ_ONCE(sock_net(sk)->core.sysctl_somaxconn);
- queue->fastopenq.max_qlen = min_t(unsigned int, backlog, somaxconn);
+ WRITE_ONCE(queue->fastopenq.max_qlen, min_t(unsigned int, backlog, somaxconn));
}
static inline void tcp_move_syn(struct tcp_sock *tp,
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 3e137e9a18f552a02d8c74e1af34ba2356e4d8ed..8ed52e1e3c99a334a47964d8fd05c720a8f683f9 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -4145,7 +4145,7 @@ int do_tcp_getsockopt(struct sock *sk, int level,
break;
case TCP_FASTOPEN:
- val = icsk->icsk_accept_queue.fastopenq.max_qlen;
+ val = READ_ONCE(icsk->icsk_accept_queue.fastopenq.max_qlen);
break;
case TCP_FASTOPEN_CONNECT:
diff --git a/net/ipv4/tcp_fastopen.c b/net/ipv4/tcp_fastopen.c
index 45cc7f1ca29618e3ac1066cb49e7d6dc90e1c64d..85e4953f118215ba7100931dccb37ad871c5dfd2 100644
--- a/net/ipv4/tcp_fastopen.c
+++ b/net/ipv4/tcp_fastopen.c
@@ -296,6 +296,7 @@ static struct sock *tcp_fastopen_create_child(struct sock *sk,
static bool tcp_fastopen_queue_check(struct sock *sk)
{
struct fastopen_queue *fastopenq;
+ int max_qlen;
/* Make sure the listener has enabled fastopen, and we don't
* exceed the max # of pending TFO requests allowed before trying
@@ -308,10 +309,11 @@ static bool tcp_fastopen_queue_check(struct sock *sk)
* temporarily vs a server not supporting Fast Open at all.
*/
fastopenq = &inet_csk(sk)->icsk_accept_queue.fastopenq;
- if (fastopenq->max_qlen == 0)
+ max_qlen = READ_ONCE(fastopenq->max_qlen);
+ if (max_qlen == 0)
return false;
- if (fastopenq->qlen >= fastopenq->max_qlen) {
+ if (fastopenq->qlen >= max_qlen) {
struct request_sock *req1;
spin_lock(&fastopenq->lock);
req1 = fastopenq->rskq_rst_head;
--
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 ` [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 ` Eric Dumazet [this message]
2023-07-20 19:50 ` [PATCH net 00/11] tcp: add missing annotations patchwork-bot+netdevbpf
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