ipv6: use inet->cork.fl.u.ip6 and np->final in ip6_datagram_dst_update()

Get rid of @fl6 and &final variables in ip6_datagram_dst_update().

Use instead inet->cork.fl.u.ip6 and np->final so that a stack canary
is no longer needed.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20260206173426.1638518-4-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/net/ipv6/datagram.c b/net/ipv6/datagram.c
index 83e03176819ce940b3a84b2dd91f273490fcc017..c564b68a056268c7cbc81b5f29f60289ea9e09eb 100644 (file)
--- a/net/ipv6/datagram.c
+++ b/net/ipv6/datagram.c
@@ -72,12 +72,12 @@ static void ip6_datagram_flow_key_init(struct flowi6 *fl6,
 int ip6_datagram_dst_update(struct sock *sk, bool fix_sk_saddr)
 {
        struct ip6_flowlabel *flowlabel = NULL;
-       struct in6_addr *final_p, final;
-       struct ipv6_txoptions *opt;
-       struct dst_entry *dst;
        struct inet_sock *inet = inet_sk(sk);
        struct ipv6_pinfo *np = inet6_sk(sk);
-       struct flowi6 fl6;
+       struct ipv6_txoptions *opt;
+       struct in6_addr *final_p;
+       struct dst_entry *dst;
+       struct flowi6 *fl6;
        int err = 0;
 
        if (inet6_test_bit(SNDFLOW, sk) &&
@@ -86,14 +86,15 @@ int ip6_datagram_dst_update(struct sock *sk, bool fix_sk_saddr)
                if (IS_ERR(flowlabel))
                        return -EINVAL;
        }
-       ip6_datagram_flow_key_init(&fl6, sk);
+       fl6 = &inet_sk(sk)->cork.fl.u.ip6;
+       ip6_datagram_flow_key_init(fl6, sk);
 
        rcu_read_lock();
        opt = flowlabel ? flowlabel->opt : rcu_dereference(np->opt);
-       final_p = fl6_update_dst(&fl6, opt, &final);
+       final_p = fl6_update_dst(fl6, opt, &np->final);
        rcu_read_unlock();
 
-       dst = ip6_dst_lookup_flow(sock_net(sk), sk, &fl6, final_p);
+       dst = ip6_dst_lookup_flow(sock_net(sk), sk, fl6, final_p);
        if (IS_ERR(dst)) {
                err = PTR_ERR(dst);
                goto out;
@@ -101,17 +102,17 @@ int ip6_datagram_dst_update(struct sock *sk, bool fix_sk_saddr)
 
        if (fix_sk_saddr) {
                if (ipv6_addr_any(&np->saddr))
-                       np->saddr = fl6.saddr;
+                       np->saddr = fl6->saddr;
 
                if (ipv6_addr_any(&sk->sk_v6_rcv_saddr)) {
-                       sk->sk_v6_rcv_saddr = fl6.saddr;
+                       sk->sk_v6_rcv_saddr = fl6->saddr;
                        inet->inet_rcv_saddr = LOOPBACK4_IPV6;
                        if (sk->sk_prot->rehash)
                                sk->sk_prot->rehash(sk);
                }
        }
 
-       ip6_sk_dst_store_flow(sk, dst, &fl6);
+       ip6_sk_dst_store_flow(sk, dst, fl6);
 
 out:
        fl6_sock_release(flowlabel);