Merge remote-tracking branch 'lsk/v3.10/topic/gator' into linux-linaro-lsk

[firefly-linux-kernel-4.4.55.git] / net / ipv4 / tcp_output.c

diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index d2df17940e07dae96b0644ed652754f188a165b0..56e29f0e230e4a6c06a24d7a5ee08856a644f697 100644 (file)
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -755,6 +755,17 @@ void tcp_release_cb(struct sock *sk)
        if (flags & (1UL << TCP_TSQ_DEFERRED))
                tcp_tsq_handler(sk);
 
+       /* Here begins the tricky part :
+        * We are called from release_sock() with :
+        * 1) BH disabled
+        * 2) sk_lock.slock spinlock held
+        * 3) socket owned by us (sk->sk_lock.owned == 1)
+        *
+        * But following code is meant to be called from BH handlers,
+        * so we should keep BH disabled, but early release socket ownership
+        */
+       sock_release_ownership(sk);
+
        if (flags & (1UL << TCP_WRITE_TIMER_DEFERRED)) {
                tcp_write_timer_handler(sk);
                __sock_put(sk);
@@ -2417,13 +2428,15 @@ int tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb)
                if (!tp->retrans_stamp)
                        tp->retrans_stamp = TCP_SKB_CB(skb)->when;
 
-               tp->undo_retrans += tcp_skb_pcount(skb);
-
                /* snd_nxt is stored to detect loss of retransmitted segment,
                 * see tcp_input.c tcp_sacktag_write_queue().
                 */
                TCP_SKB_CB(skb)->ack_seq = tp->snd_nxt;
        }
+
+       if (tp->undo_retrans < 0)
+               tp->undo_retrans = 0;
+       tp->undo_retrans += tcp_skb_pcount(skb);
        return err;
 }
 
@@ -2892,7 +2905,12 @@ static int tcp_send_syn_data(struct sock *sk, struct sk_buff *syn)
        space = __tcp_mtu_to_mss(sk, inet_csk(sk)->icsk_pmtu_cookie) -
                MAX_TCP_OPTION_SPACE;
 
-       syn_data = skb_copy_expand(syn, skb_headroom(syn), space,
+       space = min_t(size_t, space, fo->size);
+
+       /* limit to order-0 allocations */
+       space = min_t(size_t, space, SKB_MAX_HEAD(MAX_TCP_HEADER));
+
+       syn_data = skb_copy_expand(syn, MAX_TCP_HEADER, space,
                                   sk->sk_allocation);
        if (syn_data == NULL)
                goto fallback;