Commit eb44ad4e authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

net: annotate data-races around sk->sk_dst_pending_confirm 



This field can be read or written without socket lock being held.

Add annotations to avoid load-store tearing.

Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 0bb4d124

include/net/sock.h

+3 −3
Original line number Diff line number Diff line
@@ -2182,7 +2182,7 @@ static inline void __dst_negative_advice(struct sock *sk) 
		if (ndst != dst) {

			rcu_assign_pointer(sk->sk_dst_cache, ndst);

			sk_tx_queue_clear(sk);

			sk->sk_dst_pending_confirm = 0;

			WRITE_ONCE(sk->sk_dst_pending_confirm, 0);

		}

	}

}
@@ -2199,7 +2199,7 @@ __sk_dst_set(struct sock *sk, struct dst_entry *dst) 
	struct dst_entry *old_dst;



	sk_tx_queue_clear(sk);

	sk->sk_dst_pending_confirm = 0;

	WRITE_ONCE(sk->sk_dst_pending_confirm, 0);

	old_dst = rcu_dereference_protected(sk->sk_dst_cache,

					    lockdep_sock_is_held(sk));

	rcu_assign_pointer(sk->sk_dst_cache, dst);
@@ -2212,7 +2212,7 @@ sk_dst_set(struct sock *sk, struct dst_entry *dst) 
	struct dst_entry *old_dst;



	sk_tx_queue_clear(sk);

	sk->sk_dst_pending_confirm = 0;

	WRITE_ONCE(sk->sk_dst_pending_confirm, 0);

	old_dst = xchg((__force struct dst_entry **)&sk->sk_dst_cache, dst);

	dst_release(old_dst);

}

net/core/sock.c

+1 −1
Original line number Diff line number Diff line
@@ -600,7 +600,7 @@ struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie) 
	    INDIRECT_CALL_INET(dst->ops->check, ip6_dst_check, ipv4_dst_check,

			       dst, cookie) == NULL) {

		sk_tx_queue_clear(sk);

		sk->sk_dst_pending_confirm = 0;

		WRITE_ONCE(sk->sk_dst_pending_confirm, 0);

		RCU_INIT_POINTER(sk->sk_dst_cache, NULL);

		dst_release(dst);

		return NULL;

net/ipv4/tcp_output.c

+1 −1
Original line number Diff line number Diff line
@@ -1325,7 +1325,7 @@ static int __tcp_transmit_skb(struct sock *sk, struct sk_buff *skb, 
	skb->destructor = skb_is_tcp_pure_ack(skb) ? __sock_wfree : tcp_wfree;

	refcount_add(skb->truesize, &sk->sk_wmem_alloc);



	skb_set_dst_pending_confirm(skb, sk->sk_dst_pending_confirm);

	skb_set_dst_pending_confirm(skb, READ_ONCE(sk->sk_dst_pending_confirm));



	/* Build TCP header and checksum it. */

	th = (struct tcphdr *)skb->data;