ipv6: remove daddr temp buffer in __ip6_make_skb

ipv6_push_nfrag_opts() doesn't change passed daddr, and so
__ip6_make_skb() doesn't actually need to keep an on-stack copy of
fl6->daddr. Set initially final_dst to fl6->daddr,
ipv6_push_nfrag_opts() will override it if needed, and get rid of extra
copies.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index 14d607c..4acd577 100644 (file)
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -1843,7 +1843,7 @@ struct sk_buff *__ip6_make_skb(struct sock *sk,
 {
        struct sk_buff *skb, *tmp_skb;
        struct sk_buff **tail_skb;
-       struct in6_addr final_dst_buf, *final_dst = &final_dst_buf;
+       struct in6_addr *final_dst;
        struct ipv6_pinfo *np = inet6_sk(sk);
        struct net *net = sock_net(sk);
        struct ipv6hdr *hdr;
@@ -1873,9 +1873,9 @@ struct sk_buff *__ip6_make_skb(struct sock *sk,
 
        /* Allow local fragmentation. */
        skb->ignore_df = ip6_sk_ignore_df(sk);
-
-       *final_dst = fl6->daddr;
        __skb_pull(skb, skb_network_header_len(skb));
+
+       final_dst = &fl6->daddr;
        if (opt && opt->opt_flen)
                ipv6_push_frag_opts(skb, opt, &proto);
        if (opt && opt->opt_nflen)
@@ -1895,7 +1895,6 @@ struct sk_buff *__ip6_make_skb(struct sock *sk,
 
        skb->priority = sk->sk_priority;
        skb->mark = cork->base.mark;
-
        skb->tstamp = cork->base.transmit_time;
 
        ip6_cork_steal_dst(skb, cork);