Update Linux to v5.4.148

Sourced from [1]

[1] https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.4.148.tar.gz

Change-Id: Ib3d26c5ba9b022e2e03533005c4fed4d7c30b61b
Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>
diff --git a/include/net/sock.h b/include/net/sock.h
index 718e62f..d3dd89b 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -723,6 +723,11 @@
 	hlist_nulls_add_head_rcu(&sk->sk_nulls_node, list);
 }
 
+static inline void __sk_nulls_add_node_tail_rcu(struct sock *sk, struct hlist_nulls_head *list)
+{
+	hlist_nulls_add_tail_rcu(&sk->sk_nulls_node, list);
+}
+
 static inline void sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list)
 {
 	sock_hold(sk);
@@ -844,6 +849,8 @@
 {
 	return static_branch_unlikely(&memalloc_socks_key);
 }
+
+void __receive_sock(struct file *file);
 #else
 
 static inline int sk_memalloc_socks(void)
@@ -851,6 +858,8 @@
 	return 0;
 }
 
+static inline void __receive_sock(struct file *file)
+{ }
 #endif
 
 static inline gfp_t sk_gfp_mask(const struct sock *sk, gfp_t gfp_mask)
@@ -900,11 +909,11 @@
 	skb_dst_force(skb);
 
 	if (!sk->sk_backlog.tail)
-		sk->sk_backlog.head = skb;
+		WRITE_ONCE(sk->sk_backlog.head, skb);
 	else
 		sk->sk_backlog.tail->next = skb;
 
-	sk->sk_backlog.tail = skb;
+	WRITE_ONCE(sk->sk_backlog.tail, skb);
 	skb->next = NULL;
 }
 
@@ -1798,7 +1807,6 @@
 
 static inline void sk_set_socket(struct sock *sk, struct socket *sock)
 {
-	sk_tx_queue_clear(sk);
 	sk->sk_socket = sock;
 }
 
@@ -1852,7 +1860,8 @@
 
 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 void sk_rethink_txhash(struct sock *sk)
@@ -1940,8 +1949,8 @@
 
 static inline void sk_dst_confirm(struct sock *sk)
 {
-	if (!sk->sk_dst_pending_confirm)
-		sk->sk_dst_pending_confirm = 1;
+	if (!READ_ONCE(sk->sk_dst_pending_confirm))
+		WRITE_ONCE(sk->sk_dst_pending_confirm, 1);
 }
 
 static inline void sock_confirm_neigh(struct sk_buff *skb, struct neighbour *n)
@@ -1951,10 +1960,10 @@
 		unsigned long now = jiffies;
 
 		/* avoid dirtying neighbour */
-		if (n->confirmed != now)
-			n->confirmed = now;
-		if (sk && sk->sk_dst_pending_confirm)
-			sk->sk_dst_pending_confirm = 0;
+		if (READ_ONCE(n->confirmed) != now)
+			WRITE_ONCE(n->confirmed, now);
+		if (sk && READ_ONCE(sk->sk_dst_pending_confirm))
+			WRITE_ONCE(sk->sk_dst_pending_confirm, 0);
 	}
 }
 
@@ -2117,9 +2126,12 @@
 
 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;
 	}
 }
 
@@ -2142,6 +2154,17 @@
 	sk_mem_charge(sk, skb->truesize);
 }
 
+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,
 		    unsigned long expires);
 
@@ -2584,9 +2607,9 @@
  */
 static inline void sk_pacing_shift_update(struct sock *sk, int val)
 {
-	if (!sk || !sk_fullsock(sk) || sk->sk_pacing_shift == val)
+	if (!sk || !sk_fullsock(sk) || READ_ONCE(sk->sk_pacing_shift) == val)
 		return;
-	sk->sk_pacing_shift = val;
+	WRITE_ONCE(sk->sk_pacing_shift, val);
 }
 
 /* if a socket is bound to a device, check that the given device