diff options
| author |   Eric Dumazet <edumazet@google.com> | 2019-10-10 20:17:45 -0700 |
|---|---|---|
| committer |   David S. Miller <davem@davemloft.net> | 2019-10-13 10:13:08 -0700 |
| commit | e292f05e0df73f9fcc93329663936e1ded97a988 (patch) | |
| tree | 441d2a07b24a8dc89e22f14b373ccbcdf6377b34 /net/ipv4 | |
| parent | tcp: annotate sk->sk_rcvbuf lockless reads (diff) | |
| download | linux-dev-e292f05e0df73f9fcc93329663936e1ded97a988.tar.xz linux-dev-e292f05e0df73f9fcc93329663936e1ded97a988.zip | |
tcp: annotate sk->sk_sndbuf lockless reads
For the sake of tcp_poll(), there are few places where we fetch
sk->sk_sndbuf while this field can change from IRQ or other cpu.
We need to add READ_ONCE() annotations, and also make sure write
sides use corresponding WRITE_ONCE() to avoid store-tearing.
Note that other transports probably need similar fixes.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4')
| -rw-r--r-- | net/ipv4/tcp.c | 2 | ||||
| -rw-r--r-- | net/ipv4/tcp_input.c | 3 |
2 files changed, 3 insertions, 2 deletions
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index bc0481aa6633..111853262972 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -450,7 +450,7 @@ void tcp_init_sock(struct sock *sk) icsk->icsk_sync_mss = tcp_sync_mss; - sk->sk_sndbuf = sock_net(sk)->ipv4.sysctl_tcp_wmem[1]; + WRITE_ONCE(sk->sk_sndbuf, sock_net(sk)->ipv4.sysctl_tcp_wmem[1]); WRITE_ONCE(sk->sk_rcvbuf, sock_net(sk)->ipv4.sysctl_tcp_rmem[1]); sk_sockets_allocated_inc(sk); diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 6995df20710a..a2e52ad7cdab 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -359,7 +359,8 @@ static void tcp_sndbuf_expand(struct sock *sk) sndmem *= nr_segs * per_mss; if (sk->sk_sndbuf < sndmem) - sk->sk_sndbuf = min(sndmem, sock_net(sk)->ipv4.sysctl_tcp_wmem[2]); + WRITE_ONCE(sk->sk_sndbuf, + min(sndmem, sock_net(sk)->ipv4.sysctl_tcp_wmem[2])); } /* 2. Tuning advertised window (window_clamp, rcv_ssthresh) |