From 288efe8606b62d0753ba6722b36ef241877251fd Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Tue, 5 Nov 2019 14:11:53 -0800 Subject: 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: Eric Dumazet Signed-off-by: David S. Miller --- include/net/sock.h | 6 +++--- net/ipv4/tcp.c | 2 +- net/ipv4/tcp_diag.c | 2 +- net/ipv4/tcp_ipv4.c | 2 +- net/ipv6/tcp_ipv6.c | 2 +- net/sched/em_meta.c | 2 +- net/sctp/diag.c | 2 +- 7 files changed, 9 insertions(+), 9 deletions(-) diff --git a/include/net/sock.h b/include/net/sock.h index f2f853439b65..a126784aa7d9 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -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; } /* diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 1dd25189d83f..68375f7ffdce 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -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; } diff --git a/net/ipv4/tcp_diag.c b/net/ipv4/tcp_diag.c index 549506162dde..edfbab54c46f 100644 --- a/net/ipv4/tcp_diag.c +++ b/net/ipv4/tcp_diag.c @@ -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); diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index 899e100a68e6..92282f98dc82 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -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. diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index 4804b6dc5e65..81f51335e326 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -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. diff --git a/net/sched/em_meta.c b/net/sched/em_meta.c index 3177dcb17316..ebb6e2430861 100644 --- a/net/sched/em_meta.c +++ b/net/sched/em_meta.c @@ -521,7 +521,7 @@ META_COLLECTOR(int_sk_ack_bl) *err = -1; return; } - dst->value = sk->sk_ack_backlog; + dst->value = READ_ONCE(sk->sk_ack_backlog); } META_COLLECTOR(int_sk_max_ack_bl) diff --git a/net/sctp/diag.c b/net/sctp/diag.c index 0851166b9175..f873f15407de 100644 --- a/net/sctp/diag.c +++ b/net/sctp/diag.c @@ -425,7 +425,7 @@ static void sctp_diag_get_info(struct sock *sk, struct inet_diag_msg *r, r->idiag_rqueue = atomic_read(&infox->asoc->rmem_alloc); r->idiag_wqueue = infox->asoc->sndbuf_used; } else { - r->idiag_rqueue = sk->sk_ack_backlog; + r->idiag_rqueue = READ_ONCE(sk->sk_ack_backlog); r->idiag_wqueue = sk->sk_max_ack_backlog; } if (infox->sctpinfo) -- cgit v1.2.3