diff options
| author | Eric Dumazet <edumazet@google.com> | 2019-10-09 15:32:35 -0700 |
|---|---|---|
| committer | Jakub Kicinski <jakub.kicinski@netronome.com> | 2019-10-09 21:43:00 -0700 |
| commit | eac66402d1c342f07ff38f8d631ff95eb7ad3220 (patch) | |
| tree | d25d4b62d8f9a01ed18b820307bfb0080a26a28f | |
| parent | 8265792bf8871acc2d00fd03883d830e2249d395 (diff) | |
net: annotate sk->sk_rcvlowat lockless reads
sock_rcvlowat() or int_sk_rcvlowat() might be called without the socket
lock for example from tcp_poll().
Use READ_ONCE() to document the fact that other cpus might change
sk->sk_rcvlowat under us and avoid KCSAN splats.
Use WRITE_ONCE() on write sides too.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
| -rw-r--r-- | include/net/sock.h | 4 | ||||
| -rw-r--r-- | net/core/filter.c | 2 | ||||
| -rw-r--r-- | net/core/sock.c | 2 | ||||
| -rw-r--r-- | net/ipv4/tcp.c | 2 | ||||
| -rw-r--r-- | net/sched/em_meta.c | 2 |
5 files changed, 7 insertions, 5 deletions
diff --git a/include/net/sock.h b/include/net/sock.h index 2c53f1a1d905..79f54e1f8827 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -2271,7 +2271,9 @@ static inline long sock_sndtimeo(const struct sock *sk, bool noblock) static inline int sock_rcvlowat(const struct sock *sk, int waitall, int len) { - return (waitall ? len : min_t(int, sk->sk_rcvlowat, len)) ? : 1; + int v = waitall ? len : min_t(int, READ_ONCE(sk->sk_rcvlowat), len); + + return v ?: 1; } /* Alas, with timeout socket operations are not restartable. diff --git a/net/core/filter.c b/net/core/filter.c index ed6563622ce3..a50c0b6846f2 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -4274,7 +4274,7 @@ BPF_CALL_5(bpf_setsockopt, struct bpf_sock_ops_kern *, bpf_sock, case SO_RCVLOWAT: if (val < 0) val = INT_MAX; - sk->sk_rcvlowat = val ? : 1; + WRITE_ONCE(sk->sk_rcvlowat, val ? : 1); break; case SO_MARK: if (sk->sk_mark != val) { diff --git a/net/core/sock.c b/net/core/sock.c index 1cf06934da50..b7c5c6ea51ba 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -974,7 +974,7 @@ set_rcvbuf: if (sock->ops->set_rcvlowat) ret = sock->ops->set_rcvlowat(sk, val); else - sk->sk_rcvlowat = val ? : 1; + WRITE_ONCE(sk->sk_rcvlowat, val ? : 1); break; case SO_RCVTIMEO_OLD: diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 888c92b63f5a..8781a92ea4b6 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -1699,7 +1699,7 @@ int tcp_set_rcvlowat(struct sock *sk, int val) else cap = sock_net(sk)->ipv4.sysctl_tcp_rmem[2] >> 1; val = min(val, cap); - sk->sk_rcvlowat = val ? : 1; + WRITE_ONCE(sk->sk_rcvlowat, val ? : 1); /* Check if we need to signal EPOLLIN right now */ tcp_data_ready(sk); diff --git a/net/sched/em_meta.c b/net/sched/em_meta.c index 82bd14e7ac93..4c9122fc35c9 100644 --- a/net/sched/em_meta.c +++ b/net/sched/em_meta.c @@ -554,7 +554,7 @@ META_COLLECTOR(int_sk_rcvlowat) *err = -1; return; } - dst->value = sk->sk_rcvlowat; + dst->value = READ_ONCE(sk->sk_rcvlowat); } META_COLLECTOR(int_sk_rcvtimeo) |