path: root/include/net/sock.h
diff options
authorEric Dumazet <edumazet@google.com>2019-10-09 15:32:35 -0700
committerJakub Kicinski <jakub.kicinski@netronome.com>2019-10-09 21:43:00 -0700
commiteac66402d1c342f07ff38f8d631ff95eb7ad3220 (patch)
treed25d4b62d8f9a01ed18b820307bfb0080a26a28f /include/net/sock.h
parentnet: silence KCSAN warnings around sk_add_backlog() calls (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>
Diffstat (limited to 'include/net/sock.h')
1 files changed, 3 insertions, 1 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.