[PATCH v2 net 10/15] af_unix: Annotate data-races around sk->sk_sndbuf.
From: Kuniyuki Iwashima <hidden>
Date: 2024-06-04 16:56:56
Subsystem:
networking [general], networking [unix sockets], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Kuniyuki Iwashima, Linus Torvalds
sk_setsockopt() changes sk->sk_sndbuf under lock_sock(), but it's
not used in af_unix.c.
Let's use READ_ONCE() to read sk->sk_sndbuf in unix_writable(),
unix_dgram_sendmsg(), and unix_stream_sendmsg().
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Kuniyuki Iwashima <redacted>
---
net/unix/af_unix.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index e7b74207aa3b..de2a5e334a88 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c@@ -533,7 +533,7 @@ static int unix_dgram_peer_wake_me(struct sock *sk, struct sock *other) static int unix_writable(const struct sock *sk, unsigned char state) { return state != TCP_LISTEN && - (refcount_read(&sk->sk_wmem_alloc) << 2) <= sk->sk_sndbuf; + (refcount_read(&sk->sk_wmem_alloc) << 2) <= READ_ONCE(sk->sk_sndbuf); } static void unix_write_space(struct sock *sk)
@@ -1967,7 +1967,7 @@ static int unix_dgram_sendmsg(struct socket *sock, struct msghdr *msg, } err = -EMSGSIZE; - if (len > sk->sk_sndbuf - 32) + if (len > READ_ONCE(sk->sk_sndbuf) - 32) goto out; if (len > SKB_MAX_ALLOC) {
@@ -2247,7 +2247,7 @@ static int unix_stream_sendmsg(struct socket *sock, struct msghdr *msg, &err, 0); } else { /* Keep two messages in the pipe so it schedules better */ - size = min_t(int, size, (sk->sk_sndbuf >> 1) - 64); + size = min_t(int, size, (READ_ONCE(sk->sk_sndbuf) >> 1) - 64); /* allow fallback to order-0 allocations */ size = min_t(int, size, SKB_MAX_HEAD(0) + UNIX_SKB_FRAGS_SZ);
--
2.30.2