Commit 288efe86 authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

net: annotate lockless accesses to sk->sk_ack_backlog 



sk->sk_ack_backlog can be read without any lock being held.
We need to use READ_ONCE()/WRITE_ONCE() to avoid load/store tearing
and/or potential KCSAN warnings.

Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 7976a11b

include/net/sock.h

+3 −3
Original line number Diff line number Diff line
@@ -859,17 +859,17 @@ static inline gfp_t sk_gfp_mask(const struct sock *sk, gfp_t gfp_mask) 


static inline void sk_acceptq_removed(struct sock *sk)

{

	sk->sk_ack_backlog--;

	WRITE_ONCE(sk->sk_ack_backlog, sk->sk_ack_backlog - 1);

}



static inline void sk_acceptq_added(struct sock *sk)

{

	sk->sk_ack_backlog++;

	WRITE_ONCE(sk->sk_ack_backlog, sk->sk_ack_backlog + 1);

}



static inline bool sk_acceptq_is_full(const struct sock *sk)

{

	return sk->sk_ack_backlog > sk->sk_max_ack_backlog;

	return READ_ONCE(sk->sk_ack_backlog) > sk->sk_max_ack_backlog;

}



/*

net/ipv4/tcp.c

+1 −1
Original line number Diff line number Diff line
@@ -3225,7 +3225,7 @@ void tcp_get_info(struct sock *sk, struct tcp_info *info) 
		 * tcpi_unacked -> Number of children ready for accept()

		 * tcpi_sacked  -> max backlog

		 */

		info->tcpi_unacked = sk->sk_ack_backlog;

		info->tcpi_unacked = READ_ONCE(sk->sk_ack_backlog);

		info->tcpi_sacked = sk->sk_max_ack_backlog;

		return;

	}

net/ipv4/tcp_diag.c

+1 −1
Original line number Diff line number Diff line
@@ -21,7 +21,7 @@ static void tcp_diag_get_info(struct sock *sk, struct inet_diag_msg *r, 
	struct tcp_info *info = _info;



	if (inet_sk_state_load(sk) == TCP_LISTEN) {

		r->idiag_rqueue = sk->sk_ack_backlog;

		r->idiag_rqueue = READ_ONCE(sk->sk_ack_backlog);

		r->idiag_wqueue = sk->sk_max_ack_backlog;

	} else if (sk->sk_type == SOCK_STREAM) {

		const struct tcp_sock *tp = tcp_sk(sk);

net/ipv4/tcp_ipv4.c

+1 −1
Original line number Diff line number Diff line
@@ -2451,7 +2451,7 @@ static void get_tcp4_sock(struct sock *sk, struct seq_file *f, int i) 


	state = inet_sk_state_load(sk);

	if (state == TCP_LISTEN)

		rx_queue = sk->sk_ack_backlog;

		rx_queue = READ_ONCE(sk->sk_ack_backlog);

	else

		/* Because we don't lock the socket,

		 * we might find a transient negative value.

net/ipv6/tcp_ipv6.c

+1 −1
Original line number Diff line number Diff line
@@ -1891,7 +1891,7 @@ static void get_tcp6_sock(struct seq_file *seq, struct sock *sp, int i) 


	state = inet_sk_state_load(sp);

	if (state == TCP_LISTEN)

		rx_queue = sp->sk_ack_backlog;

		rx_queue = READ_ONCE(sp->sk_ack_backlog);

	else

		/* Because we don't lock the socket,

		 * we might find a transient negative value.