Merge branch 'inet-more-data-race-fixes'

Eric Dumazet says:

====================
inet: more data-race fixes

This series fixes some existing data-races on inet fields:

inet->mc_ttl, inet->pmtudisc, inet->tos, inet->uc_index,
inet->mc_index and inet->mc_addr.

While fixing them, we convert eight socket options
to lockless implementation.

v2: addressed David Ahern feedback on ("inet: implement lockless IP_TOS")
    Added David Reviewed-by: tag on other patches.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 11 insertions, 9 deletions

diff --git a/include/net/ip.h b/include/net/ip.h
index 3489a1cca5e7..6fbc0dcf4b97 100644
--- a/include/net/ip.h
+++ b/include/net/ip.h
@@ -258,7 +258,7 @@ static inline u8 ip_sendmsg_scope(const struct inet_sock *inet,
 
 static inline __u8 get_rttos(struct ipcm_cookie* ipc, struct inet_sock *inet)
 {
-	return (ipc->tos != -1) ? RT_TOS(ipc->tos) : RT_TOS(inet->tos);
+	return (ipc->tos != -1) ? RT_TOS(ipc->tos) : RT_TOS(READ_ONCE(inet->tos));
 }
 
 /* datagram.c */
@@ -434,19 +434,22 @@ int ip_dont_fragment(const struct sock *sk, const struct dst_entry *dst)
 
 static inline bool ip_sk_accept_pmtu(const struct sock *sk)
 {
-	return inet_sk(sk)->pmtudisc != IP_PMTUDISC_INTERFACE &&
-	       inet_sk(sk)->pmtudisc != IP_PMTUDISC_OMIT;
+	u8 pmtudisc = READ_ONCE(inet_sk(sk)->pmtudisc);
+
+	return pmtudisc != IP_PMTUDISC_INTERFACE &&
+	       pmtudisc != IP_PMTUDISC_OMIT;
 }
 
 static inline bool ip_sk_use_pmtu(const struct sock *sk)
 {
-	return inet_sk(sk)->pmtudisc < IP_PMTUDISC_PROBE;
+	return READ_ONCE(inet_sk(sk)->pmtudisc) < IP_PMTUDISC_PROBE;
 }
 
 static inline bool ip_sk_ignore_df(const struct sock *sk)
 {
-	return inet_sk(sk)->pmtudisc < IP_PMTUDISC_DO ||
-	       inet_sk(sk)->pmtudisc == IP_PMTUDISC_OMIT;
+	u8 pmtudisc = READ_ONCE(inet_sk(sk)->pmtudisc);
+
+	return pmtudisc < IP_PMTUDISC_DO || pmtudisc == IP_PMTUDISC_OMIT;
 }
 
 static inline unsigned int ip_dst_mtu_maybe_forward(const struct dst_entry *dst,
@@ -807,6 +810,5 @@ int ip_sock_set_mtu_discover(struct sock *sk, int val);
 void ip_sock_set_pktinfo(struct sock *sk);
 void ip_sock_set_recverr(struct sock *sk);
 void ip_sock_set_tos(struct sock *sk, int val);
-void  __ip_sock_set_tos(struct sock *sk, int val);
 
 #endif	/* _IP_H */
diff --git a/include/net/route.h b/include/net/route.h
index 51a45b1887b5..5c248a8e3d0e 100644
--- a/include/net/route.h
+++ b/include/net/route.h
@@ -37,7 +37,7 @@
 
 #define RTO_ONLINK	0x01
 
-#define RT_CONN_FLAGS(sk)   (RT_TOS(inet_sk(sk)->tos) | sock_flag(sk, SOCK_LOCALROUTE))
+#define RT_CONN_FLAGS(sk)   (RT_TOS(READ_ONCE(inet_sk(sk)->tos)) | sock_flag(sk, SOCK_LOCALROUTE))
 #define RT_CONN_FLAGS_TOS(sk,tos)   (RT_TOS(tos) | sock_flag(sk, SOCK_LOCALROUTE))
 
 static inline __u8 ip_sock_rt_scope(const struct sock *sk)
@@ -50,7 +50,7 @@ static inline __u8 ip_sock_rt_scope(const struct sock *sk)
 
 static inline __u8 ip_sock_rt_tos(const struct sock *sk)
 {
-	return RT_TOS(inet_sk(sk)->tos);
+	return RT_TOS(READ_ONCE(inet_sk(sk)->tos));
 }
 
 struct ip_tunnel_info;