[PATCH net-next 10/10] inet: add READ_ONCE(sk->sk_bound_dev_if) in INET_MATCH()

[Eric Dumazet <eric.dumazet@gmail.com>]

From: Eric Dumazet <edumazet@google.com>

INET_MATCH() runs without holding a lock on the socket.

We probably need to annotate most reads.

This patch makes INET_MATCH() an inline function
to ease our changes. This also allows us
to add some __always_unused qualifiers.

Signed-off-by: Eric Dumazet <edumazet@google.com>
---
 include/net/inet_hashtables.h | 52 +++++++++++++++++++++++++----------
 1 file changed, 38 insertions(+), 14 deletions(-)

diff --git a/include/net/inet_hashtables.h b/include/net/inet_hashtables.h
index 98e1ec1a14f0382d1f4f8e85fe5ac2a056d2d6bc..5d3fa071d754601149c9ad0dd559f074ac58deaa 100644
--- a/include/net/inet_hashtables.h
+++ b/include/net/inet_hashtables.h
@@ -307,23 +307,47 @@ static inline struct sock *inet_lookup_listener(struct net *net,
 				   (((__force __u64)(__be32)(__daddr)) << 32) | \
 				   ((__force __u64)(__be32)(__saddr)))
 #endif /* __BIG_ENDIAN */
-#define INET_MATCH(__sk, __net, __cookie, __saddr, __daddr, __ports, __dif, __sdif) \
-	(((__sk)->sk_portpair == (__ports))			&&	\
-	 ((__sk)->sk_addrpair == (__cookie))			&&	\
-	 (((__sk)->sk_bound_dev_if == (__dif))			||	\
-	  ((__sk)->sk_bound_dev_if == (__sdif)))		&&	\
-	 net_eq(sock_net(__sk), (__net)))
+static inline bool INET_MATCH(const struct sock *sk, struct net *net,
+			      const __addrpair cookie,
+			      const __be32 __always_unused saddr,
+			      const __be32 __always_unused daddr,
+			      const __portpair ports,
+			      const int dif,
+			      const int sdif)
+{
+	int bound_dev_if;
+
+	if (!net_eq(sock_net(sk), net) ||
+	    sk->sk_portpair != ports ||
+	    sk->sk_addrpair != cookie)
+		return false;
+
+	bound_dev_if = READ_ONCE(sk->sk_bound_dev_if);
+	return bound_dev_if == dif || bound_dev_if == sdif;
+}
 #else /* 32-bit arch */
 #define INET_ADDR_COOKIE(__name, __saddr, __daddr) \
-	const int __name __deprecated __attribute__((unused))
+	const int __name __deprecated __always_unused
 
-#define INET_MATCH(__sk, __net, __cookie, __saddr, __daddr, __ports, __dif, __sdif) \
-	(((__sk)->sk_portpair == (__ports))		&&		\
-	 ((__sk)->sk_daddr	== (__saddr))		&&		\
-	 ((__sk)->sk_rcv_saddr	== (__daddr))		&&		\
-	 (((__sk)->sk_bound_dev_if == (__dif))		||		\
-	  ((__sk)->sk_bound_dev_if == (__sdif)))	&&		\
-	 net_eq(sock_net(__sk), (__net)))
+static inline bool INET_MATCH(const struct sock *sk, struct net *net,
+			      const __addrpair __always_unused cookie,
+			      const __be32 saddr,
+			      const __be32 daddr,
+			      const __portpair ports,
+			      const int dif,
+			      const int sdif)
+{
+	int bound_dev_if;
+
+	if (!net_eq(sock_net(sk), net) ||
+	    sk->sk_portpair != ports ||
+	    sk->sk_daddr != saddr ||
+	    sk->sk_rcv_saddr != daddr)
+		return false;
+
+	bound_dev_if = READ_ONCE(sk->sk_bound_dev_if);
+	return bound_dev_if == dif || bound_dev_if == sdif;
+}
 #endif /* 64-bit arch */
 
 /* Sockets in TCP_CLOSE state are _always_ taken out of the hash, so we need
-- 
2.36.0.512.ge40c2bad7a-goog