5.4-stable review patch. If anyone has any objections, please let me know.
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From: Eric Dumazet edumazet@google.com
[ Upstream commit eb44ad4e635132754bfbcb18103f1dcb7058aedd ]
This field can be read or written without socket lock being held.
Add annotations to avoid load-store tearing.
Signed-off-by: Eric Dumazet edumazet@google.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- include/net/sock.h | 6 +++--- net/core/sock.c | 2 +- net/ipv4/tcp_output.c | 2 +- 3 files changed, 5 insertions(+), 5 deletions(-)
diff --git a/include/net/sock.h b/include/net/sock.h index b021c8912e2cf..5293f2b65fb55 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -1941,7 +1941,7 @@ 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); } } } @@ -1952,7 +1952,7 @@ __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); @@ -1965,7 +1965,7 @@ 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); } diff --git a/net/core/sock.c b/net/core/sock.c index 9979cd602dfac..2c3c5df139345 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -545,7 +545,7 @@ struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie)
if (dst && dst->obsolete && dst->ops->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; diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index 0107436860171..1dce05bfa3005 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -1103,7 +1103,7 @@ static int __tcp_transmit_skb(struct sock *sk, struct sk_buff *skb, skb_set_hash_from_sk(skb, sk); 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;