diff options
| author | Eric Dumazet | 2023-07-19 21:28:55 +0000 |
|---|---|---|
| committer | Jakub Kicinski | 2023-07-20 12:34:18 -0700 |
| commit | 1aeb87bc1440c5447a7fa2d6e3c2cca52cbd206b (patch) | |
| tree | da6989426c0f6a60fc3af24da6df5ebb71cd4ae1 | |
| parent | ae488c74422fb1dcd807c0201804b3b5e8a322a3 (diff) | |
tcp: annotate data-races around tp->notsent_lowat
tp->notsent_lowat can be read locklessly from do_tcp_getsockopt()
and tcp_poll().
Fixes: c9bee3b7fdec ("tcp: TCP_NOTSENT_LOWAT socket option")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20230719212857.3943972-10-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| -rw-r--r-- | include/net/tcp.h | 6 | ||||
| -rw-r--r-- | net/ipv4/tcp.c | 4 |
2 files changed, 7 insertions, 3 deletions
diff --git a/include/net/tcp.h b/include/net/tcp.h index a8b93b2875ea..0ca972ebd3dd 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -2061,7 +2061,11 @@ void __tcp_v4_send_check(struct sk_buff *skb, __be32 saddr, __be32 daddr); static inline u32 tcp_notsent_lowat(const struct tcp_sock *tp) { struct net *net = sock_net((struct sock *)tp); - return tp->notsent_lowat ?: READ_ONCE(net->ipv4.sysctl_tcp_notsent_lowat); + u32 val; + + val = READ_ONCE(tp->notsent_lowat); + + return val ?: READ_ONCE(net->ipv4.sysctl_tcp_notsent_lowat); } bool tcp_stream_memory_free(const struct sock *sk, int wake); diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 5beec71a5c41..2b2241e9b492 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -3664,7 +3664,7 @@ int do_tcp_setsockopt(struct sock *sk, int level, int optname, err = tcp_repair_set_window(tp, optval, optlen); break; case TCP_NOTSENT_LOWAT: - tp->notsent_lowat = val; + WRITE_ONCE(tp->notsent_lowat, val); sk->sk_write_space(sk); break; case TCP_INQ: @@ -4164,7 +4164,7 @@ int do_tcp_getsockopt(struct sock *sk, int level, val = tcp_time_stamp_raw() + READ_ONCE(tp->tsoffset); break; case TCP_NOTSENT_LOWAT: - val = tp->notsent_lowat; + val = READ_ONCE(tp->notsent_lowat); break; case TCP_INQ: val = tp->recvmsg_inq; |