From: Eric Dumazet <edumazet@google.com>
Date: Tue, 5 Nov 2019 22:11:54 +0000 (-0800)
Subject: net: annotate lockless accesses to sk->sk_max_ack_backlog
X-Git-Tag: v5.5-rc1~174^2~206^2
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=099ecf59f05b;p=linux.git
net: annotate lockless accesses to sk->sk_max_ack_backlog
sk->sk_max_ack_backlog can be read without any lock being held
at least in TCP/DCCP cases.
We need to use READ_ONCE()/WRITE_ONCE() to avoid load/store tearing
and/or potential KCSAN warnings.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
diff --git a/include/net/sock.h b/include/net/sock.h
index a126784aa7d9..d4d3ef5ba049 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -869,7 +869,7 @@ static inline void sk_acceptq_added(struct sock *sk)
static inline bool sk_acceptq_is_full(const struct sock *sk)
{
- return READ_ONCE(sk->sk_ack_backlog) > sk->sk_max_ack_backlog;
+ return READ_ONCE(sk->sk_ack_backlog) > READ_ONCE(sk->sk_max_ack_backlog);
}
/*
diff --git a/net/dccp/proto.c b/net/dccp/proto.c
index 5bad08dc4316..a52e8ba1ced0 100644
--- a/net/dccp/proto.c
+++ b/net/dccp/proto.c
@@ -944,7 +944,7 @@ int inet_dccp_listen(struct socket *sock, int backlog)
if (!((1 << old_state) & (DCCPF_CLOSED | DCCPF_LISTEN)))
goto out;
- sk->sk_max_ack_backlog = backlog;
+ WRITE_ONCE(sk->sk_max_ack_backlog, backlog);
/* Really, if the socket is already in listen state
* we can only allow the backlog to be adjusted.
*/
diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
index 70f92aaca411..53de8e00990e 100644
--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c
@@ -208,7 +208,7 @@ int inet_listen(struct socket *sock, int backlog)
if (!((1 << old_state) & (TCPF_CLOSE | TCPF_LISTEN)))
goto out;
- sk->sk_max_ack_backlog = backlog;
+ WRITE_ONCE(sk->sk_max_ack_backlog, backlog);
/* Really, if the socket is already in listen state
* we can only allow the backlog to be adjusted.
*/
diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c
index eb30fc1770de..e4c6e8b40490 100644
--- a/net/ipv4/inet_connection_sock.c
+++ b/net/ipv4/inet_connection_sock.c
@@ -716,7 +716,7 @@ static void reqsk_timer_handler(struct timer_list *t)
* ones are about to clog our table.
*/
qlen = reqsk_queue_len(queue);
- if ((qlen << 1) > max(8U, sk_listener->sk_max_ack_backlog)) {
+ if ((qlen << 1) > max(8U, READ_ONCE(sk_listener->sk_max_ack_backlog))) {
int young = reqsk_queue_len_young(queue) << 1;
while (thresh > 2) {
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 68375f7ffdce..fb1666440e10 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -3226,7 +3226,7 @@ void tcp_get_info(struct sock *sk, struct tcp_info *info)
* tcpi_sacked -> max backlog
*/
info->tcpi_unacked = READ_ONCE(sk->sk_ack_backlog);
- info->tcpi_sacked = sk->sk_max_ack_backlog;
+ info->tcpi_sacked = READ_ONCE(sk->sk_max_ack_backlog);
return;
}
diff --git a/net/ipv4/tcp_diag.c b/net/ipv4/tcp_diag.c
index edfbab54c46f..0d08f9e2d8d0 100644
--- a/net/ipv4/tcp_diag.c
+++ b/net/ipv4/tcp_diag.c
@@ -22,7 +22,7 @@ static void tcp_diag_get_info(struct sock *sk, struct inet_diag_msg *r,
if (inet_sk_state_load(sk) == TCP_LISTEN) {
r->idiag_rqueue = READ_ONCE(sk->sk_ack_backlog);
- r->idiag_wqueue = sk->sk_max_ack_backlog;
+ r->idiag_wqueue = READ_ONCE(sk->sk_max_ack_backlog);
} else if (sk->sk_type == SOCK_STREAM) {
const struct tcp_sock *tp = tcp_sk(sk);
diff --git a/net/sched/em_meta.c b/net/sched/em_meta.c
index ebb6e2430861..d99966a55c84 100644
--- a/net/sched/em_meta.c
+++ b/net/sched/em_meta.c
@@ -532,7 +532,7 @@ META_COLLECTOR(int_sk_max_ack_bl)
*err = -1;
return;
}
- dst->value = sk->sk_max_ack_backlog;
+ dst->value = READ_ONCE(sk->sk_max_ack_backlog);
}
META_COLLECTOR(int_sk_prio)
diff --git a/net/sctp/diag.c b/net/sctp/diag.c
index f873f15407de..8a15146faaeb 100644
--- a/net/sctp/diag.c
+++ b/net/sctp/diag.c
@@ -426,7 +426,7 @@ static void sctp_diag_get_info(struct sock *sk, struct inet_diag_msg *r,
r->idiag_wqueue = infox->asoc->sndbuf_used;
} else {
r->idiag_rqueue = READ_ONCE(sk->sk_ack_backlog);
- r->idiag_wqueue = sk->sk_max_ack_backlog;
+ r->idiag_wqueue = READ_ONCE(sk->sk_max_ack_backlog);
}
if (infox->sctpinfo)
sctp_get_sctp_info(sk, infox->asoc, infox->sctpinfo);
diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index ffd3262b7a41..53abb97e0061 100644
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -8376,7 +8376,7 @@ static int sctp_listen_start(struct sock *sk, int backlog)
}
}
- sk->sk_max_ack_backlog = backlog;
+ WRITE_ONCE(sk->sk_max_ack_backlog, backlog);
return sctp_hash_endpoint(ep);
}
@@ -8430,7 +8430,7 @@ int sctp_inet_listen(struct socket *sock, int backlog)
/* If we are already listening, just update the backlog */
if (sctp_sstate(sk, LISTENING))
- sk->sk_max_ack_backlog = backlog;
+ WRITE_ONCE(sk->sk_max_ack_backlog, backlog);
else {
err = sctp_listen_start(sk, backlog);
if (err)