Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

Trivial conflicts in net/can/isotp.c and
tools/testing/selftests/net/mptcp/mptcp_connect.sh

scaled_ppm_to_ppb() was moved from drivers/ptp/ptp_clock.c
to include/linux/ptp_clock_kernel.h in -next so re-apply
the fix there.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 13 insertions, 4 deletions

diff --git a/include/net/sock.h b/include/net/sock.h
index 9b341c2c924f7f..ced2fc965ec7ba 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -1934,7 +1934,8 @@ static inline u32 net_tx_rndhash(void)
 
 static inline void sk_set_txhash(struct sock *sk)
 {
-	sk->sk_txhash = net_tx_rndhash();
+	/* This pairs with READ_ONCE() in skb_set_hash_from_sk() */
+	WRITE_ONCE(sk->sk_txhash, net_tx_rndhash());
 }
 
 static inline bool sk_rethink_txhash(struct sock *sk)
@@ -2206,9 +2207,12 @@ static inline void sock_poll_wait(struct file *filp, struct socket *sock,
 
 static inline void skb_set_hash_from_sk(struct sk_buff *skb, struct sock *sk)
 {
-	if (sk->sk_txhash) {
+	/* This pairs with WRITE_ONCE() in sk_set_txhash() */
+	u32 txhash = READ_ONCE(sk->sk_txhash);
+
+	if (txhash) {
 		skb->l4_hash = 1;
-		skb->hash = sk->sk_txhash;
+		skb->hash = txhash;
 	}
 }
 
@@ -2266,8 +2270,13 @@ struct sk_buff *sock_dequeue_err_skb(struct sock *sk);
 static inline int sock_error(struct sock *sk)
 {
 	int err;
-	if (likely(!sk->sk_err))
+
+	/* Avoid an atomic operation for the common case.
+	 * This is racy since another cpu/thread can change sk_err under us.
+	 */
+	if (likely(data_race(!sk->sk_err)))
 		return 0;
+
 	err = xchg(&sk->sk_err, 0);
 	return -err;
 }