Hi!
From: Greg Kroah-Hartman gregkh@linuxfoundation.org
From: Eric Dumazet edumazet@google.com
Dup.
We need to add READ_ONCE() annotations, and also make sure write sides use corresponding WRITE_ONCE() to avoid store-tearing.
@@ -1037,7 +1037,7 @@ new_segment: sk->sk_wmem_queued += copy; sk_mem_charge(sk, copy); skb->ip_summed = CHECKSUM_PARTIAL;
tp->write_seq += copy;
WRITE_ONCE(tp->write_seq, tp->write_seq + copy);
I wonder if this needs to do READ_ONCE, too?
@@ -1391,7 +1391,7 @@ new_segment: if (!copied) TCP_SKB_CB(skb)->tcp_flags &= ~TCPHDR_PSH;
tp->write_seq += copy;
WRITE_ONCE(tp->write_seq, tp->write_seq + copy);
And here.
@@ -2593,9 +2594,12 @@ int tcp_disconnect(struct sock *sk, int sock_reset_flag(sk, SOCK_DONE); tp->srtt_us = 0; tp->rcv_rtt_last_tsecr = 0;
- tp->write_seq += tp->max_window + 2;
- if (tp->write_seq == 0)
tp->write_seq = 1;
- seq = tp->write_seq + tp->max_window + 2;
- if (!seq)
seq = 1;- WRITE_ONCE(tp->write_seq, seq);
And here.
--- a/net/ipv4/tcp_minisocks.c +++ b/net/ipv4/tcp_minisocks.c @@ -510,7 +510,7 @@ struct sock *tcp_create_openreq_child(co newtp->app_limited = ~0U; tcp_init_xmit_timers(newsk);
- newtp->write_seq = newtp->pushed_seq = treq->snt_isn + 1;
- WRITE_ONCE(newtp->write_seq, newtp->pushed_seq = treq->snt_isn + 1);
Would it be better to do assignment to pushed_seq outside of WRITE_ONCE macro? This is ... "interesting".
Best regards, Pavel