Merge x86/urgent into x86/fpu

Pick up dependent changes which either went mainline (x86/urgent is
based on -rc7 and that contains them) as urgent fixes and the current
x86/urgent branch which contains two more urgent fixes, so that the
bigger FPU rework can base off ontop.

Signed-off-by: Borislav Petkov <bp@suse.de>

1 files changed, 16 insertions, 5 deletions

diff --git a/include/net/sock.h b/include/net/sock.h
index 42bc5e1a627f..7a7058f4f265 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;
 	}
 }
 
@@ -2231,13 +2235,15 @@ static inline void skb_set_owner_r(struct sk_buff *skb, struct sock *sk)
 	sk_mem_charge(sk, skb->truesize);
 }
 
-static inline void skb_set_owner_sk_safe(struct sk_buff *skb, struct sock *sk)
+static inline __must_check bool skb_set_owner_sk_safe(struct sk_buff *skb, struct sock *sk)
 {
 	if (sk && refcount_inc_not_zero(&sk->sk_refcnt)) {
 		skb_orphan(skb);
 		skb->destructor = sock_efree;
 		skb->sk = sk;
+		return true;
 	}
+	return false;
 }
 
 void sk_reset_timer(struct sock *sk, struct timer_list *timer,
@@ -2264,8 +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;
 }