path: root/net/ipv4
diff options
authorEric Dumazet <edumazet@google.com>2019-10-10 20:17:45 -0700
committerDavid S. Miller <davem@davemloft.net>2019-10-13 10:13:08 -0700
commite292f05e0df73f9fcc93329663936e1ded97a988 (patch)
tree441d2a07b24a8dc89e22f14b373ccbcdf6377b34 /net/ipv4
parenttcp: annotate sk->sk_rcvbuf lockless reads (diff)
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')
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]);
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)