tcp: add RETPOLINE mitigation to sk_backlog_rcv

Use INDIRECT_CALL_INET() to avoid an indirect call
when/if CONFIG_RETPOLINE=y

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/net/sock.h b/include/net/sock.h
index cb97c44..2d40fe4 100644 (file)
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -1018,12 +1018,18 @@ static inline __must_check int sk_add_backlog(struct sock *sk, struct sk_buff *s
 
 int __sk_backlog_rcv(struct sock *sk, struct sk_buff *skb);
 
+INDIRECT_CALLABLE_DECLARE(int tcp_v4_do_rcv(struct sock *sk, struct sk_buff *skb));
+INDIRECT_CALLABLE_DECLARE(int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb));
+
 static inline int sk_backlog_rcv(struct sock *sk, struct sk_buff *skb)
 {
        if (sk_memalloc_socks() && skb_pfmemalloc(skb))
                return __sk_backlog_rcv(sk, skb);
 
-       return sk->sk_backlog_rcv(sk, skb);
+       return INDIRECT_CALL_INET(sk->sk_backlog_rcv,
+                                 tcp_v6_do_rcv,
+                                 tcp_v4_do_rcv,
+                                 sk, skb);
 }
 
 static inline void sk_incoming_cpu_update(struct sock *sk)

diff --git a/net/core/sock.c b/net/core/sock.c
index 99738e1..c57d988 100644 (file)
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -327,7 +327,10 @@ int __sk_backlog_rcv(struct sock *sk, struct sk_buff *skb)
        BUG_ON(!sock_flag(sk, SOCK_MEMALLOC));
 
        noreclaim_flag = memalloc_noreclaim_save();
-       ret = sk->sk_backlog_rcv(sk, skb);
+       ret = INDIRECT_CALL_INET(sk->sk_backlog_rcv,
+                                tcp_v6_do_rcv,
+                                tcp_v4_do_rcv,
+                                sk, skb);
        memalloc_noreclaim_restore(noreclaim_flag);
 
        return ret;

diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 1f1a89f..f41f14b 100644 (file)
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -72,7 +72,7 @@ static void   tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb);
 static void    tcp_v6_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb,
                                      struct request_sock *req);
 
-static int     tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb);
+INDIRECT_CALLABLE_SCOPE int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb);
 
 static const struct inet_connection_sock_af_ops ipv6_mapped;
 const struct inet_connection_sock_af_ops ipv6_specific;
@@ -1466,7 +1466,8 @@ INDIRECT_CALLABLE_DECLARE(struct dst_entry *ipv4_dst_check(struct dst_entry *,
  * This is because we cannot sleep with the original spinlock
  * held.
  */
-static int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
+INDIRECT_CALLABLE_SCOPE
+int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
 {
        struct ipv6_pinfo *np = tcp_inet6_sk(sk);
        struct sk_buff *opt_skb = NULL;