diff options
| author |   Eric Dumazet <edumazet@google.com> | 2019-10-10 20:17:44 -0700 |
|---|---|---|
| committer |   David S. Miller <davem@davemloft.net> | 2019-10-13 10:13:08 -0700 |
| commit | ebb3b78db7bf842270a46fd4fe7cc45c78fa5ed6 (patch) | |
| tree | 9a0ecbc667473f785c77851f2db6c31f1fa3d2a4 /include | |
| parent | tcp: annotate tp->urg_seq lockless reads (diff) | |
| download | linux-dev-ebb3b78db7bf842270a46fd4fe7cc45c78fa5ed6.tar.xz linux-dev-ebb3b78db7bf842270a46fd4fe7cc45c78fa5ed6.zip | |
tcp: annotate sk->sk_rcvbuf lockless reads
For the sake of tcp_poll(), there are few places where we fetch
sk->sk_rcvbuf 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 'include')
| -rw-r--r-- | include/net/tcp.h | 4 | ||||
| -rw-r--r-- | include/trace/events/sock.h | 2 |
2 files changed, 3 insertions, 3 deletions
diff --git a/include/net/tcp.h b/include/net/tcp.h index e1d08f69fd39..ab4eb5eb5d07 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -1380,14 +1380,14 @@ static inline int tcp_win_from_space(const struct sock *sk, int space) /* Note: caller must be prepared to deal with negative returns */ static inline int tcp_space(const struct sock *sk) { - return tcp_win_from_space(sk, sk->sk_rcvbuf - + return tcp_win_from_space(sk, READ_ONCE(sk->sk_rcvbuf) - READ_ONCE(sk->sk_backlog.len) - atomic_read(&sk->sk_rmem_alloc)); } static inline int tcp_full_space(const struct sock *sk) { - return tcp_win_from_space(sk, sk->sk_rcvbuf); + return tcp_win_from_space(sk, READ_ONCE(sk->sk_rcvbuf)); } extern void tcp_openreq_init_rwin(struct request_sock *req, diff --git a/include/trace/events/sock.h b/include/trace/events/sock.h index a0c4b8a30966..f720c32e7dfd 100644 --- a/include/trace/events/sock.h +++ b/include/trace/events/sock.h @@ -82,7 +82,7 @@ TRACE_EVENT(sock_rcvqueue_full, TP_fast_assign( __entry->rmem_alloc = atomic_read(&sk->sk_rmem_alloc); __entry->truesize = skb->truesize; - __entry->sk_rcvbuf = sk->sk_rcvbuf; + __entry->sk_rcvbuf = READ_ONCE(sk->sk_rcvbuf); ), TP_printk("rmem_alloc=%d truesize=%u sk_rcvbuf=%d", |