Merge remote-tracking branch 'torvalds/master' into perf/core

To pick up the fixes in perf/urgent that were just merged into upstream.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

4 files changed, 65 insertions, 42 deletions

diff --git a/net/core/dev.c b/net/core/dev.c
index 74fd402d26dd..7ee9fecd3aff 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -6923,12 +6923,16 @@ EXPORT_SYMBOL(napi_disable);
  */
 void napi_enable(struct napi_struct *n)
 {
-	BUG_ON(!test_bit(NAPI_STATE_SCHED, &n->state));
-	smp_mb__before_atomic();
-	clear_bit(NAPI_STATE_SCHED, &n->state);
-	clear_bit(NAPI_STATE_NPSVC, &n->state);
-	if (n->dev->threaded && n->thread)
-		set_bit(NAPI_STATE_THREADED, &n->state);
+	unsigned long val, new;
+
+	do {
+		val = READ_ONCE(n->state);
+		BUG_ON(!test_bit(NAPI_STATE_SCHED, &val));
+
+		new = val & ~(NAPIF_STATE_SCHED | NAPIF_STATE_NPSVC);
+		if (n->dev->threaded && n->thread)
+			new |= NAPIF_STATE_THREADED;
+	} while (cmpxchg(&n->state, val, new) != val);
 }
 EXPORT_SYMBOL(napi_enable);
 
diff --git a/net/core/dev_addr_lists.c b/net/core/dev_addr_lists.c
index 8c39283c26ae..f0cb38344126 100644
--- a/net/core/dev_addr_lists.c
+++ b/net/core/dev_addr_lists.c
@@ -50,6 +50,11 @@ static int __hw_addr_add_ex(struct netdev_hw_addr_list *list,
 	if (addr_len > MAX_ADDR_LEN)
 		return -EINVAL;
 
+	ha = list_first_entry(&list->list, struct netdev_hw_addr, list);
+	if (ha && !memcmp(addr, ha->addr, addr_len) &&
+	    (!addr_type || addr_type == ha->type))
+		goto found_it;
+
 	while (*ins_point) {
 		int diff;
 
@@ -64,6 +69,7 @@ static int __hw_addr_add_ex(struct netdev_hw_addr_list *list,
 		} else if (diff > 0) {
 			ins_point = &parent->rb_right;
 		} else {
+found_it:
 			if (exclusive)
 				return -EEXIST;
 			if (global) {
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 972c8cb303a5..8ccce85562a1 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -5262,7 +5262,7 @@ nla_put_failure:
 static size_t if_nlmsg_stats_size(const struct net_device *dev,
 				  u32 filter_mask)
 {
-	size_t size = 0;
+	size_t size = NLMSG_ALIGN(sizeof(struct if_stats_msg));
 
 	if (stats_attr_valid(filter_mask, IFLA_STATS_LINK_64, 0))
 		size += nla_total_size_64bit(sizeof(struct rtnl_link_stats64));
diff --git a/net/core/sock.c b/net/core/sock.c
index 62627e868e03..c1601f75ec4b 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -1376,6 +1376,16 @@ set_sndbuf:
 }
 EXPORT_SYMBOL(sock_setsockopt);
 
+static const struct cred *sk_get_peer_cred(struct sock *sk)
+{
+	const struct cred *cred;
+
+	spin_lock(&sk->sk_peer_lock);
+	cred = get_cred(sk->sk_peer_cred);
+	spin_unlock(&sk->sk_peer_lock);
+
+	return cred;
+}
 
 static void cred_to_ucred(struct pid *pid, const struct cred *cred,
 			  struct ucred *ucred)
@@ -1552,7 +1562,11 @@ int sock_getsockopt(struct socket *sock, int level, int optname,
 		struct ucred peercred;
 		if (len > sizeof(peercred))
 			len = sizeof(peercred);
+
+		spin_lock(&sk->sk_peer_lock);
 		cred_to_ucred(sk->sk_peer_pid, sk->sk_peer_cred, &peercred);
+		spin_unlock(&sk->sk_peer_lock);
+
 		if (copy_to_user(optval, &peercred, len))
 			return -EFAULT;
 		goto lenout;
@@ -1560,20 +1574,23 @@ int sock_getsockopt(struct socket *sock, int level, int optname,
 
 	case SO_PEERGROUPS:
 	{
+		const struct cred *cred;
 		int ret, n;
 
-		if (!sk->sk_peer_cred)
+		cred = sk_get_peer_cred(sk);
+		if (!cred)
 			return -ENODATA;
 
-		n = sk->sk_peer_cred->group_info->ngroups;
+		n = cred->group_info->ngroups;
 		if (len < n * sizeof(gid_t)) {
 			len = n * sizeof(gid_t);
+			put_cred(cred);
 			return put_user(len, optlen) ? -EFAULT : -ERANGE;
 		}
 		len = n * sizeof(gid_t);
 
-		ret = groups_to_user((gid_t __user *)optval,
-				     sk->sk_peer_cred->group_info);
+		ret = groups_to_user((gid_t __user *)optval, cred->group_info);
+		put_cred(cred);
 		if (ret)
 			return ret;
 		goto lenout;
@@ -1935,9 +1952,10 @@ static void __sk_destruct(struct rcu_head *head)
 		sk->sk_frag.page = NULL;
 	}
 
-	if (sk->sk_peer_cred)
-		put_cred(sk->sk_peer_cred);
+	/* We do not need to acquire sk->sk_peer_lock, we are the last user. */
+	put_cred(sk->sk_peer_cred);
 	put_pid(sk->sk_peer_pid);
+
 	if (likely(sk->sk_net_refcnt))
 		put_net(sock_net(sk));
 	sk_prot_free(sk->sk_prot_creator, sk);
@@ -3145,6 +3163,8 @@ void sock_init_data(struct socket *sock, struct sock *sk)
 
 	sk->sk_peer_pid 	=	NULL;
 	sk->sk_peer_cred	=	NULL;
+	spin_lock_init(&sk->sk_peer_lock);
+
 	sk->sk_write_pending	=	0;
 	sk->sk_rcvlowat		=	1;
 	sk->sk_rcvtimeo		=	MAX_SCHEDULE_TIMEOUT;
@@ -3179,17 +3199,15 @@ EXPORT_SYMBOL(sock_init_data);
 
 void lock_sock_nested(struct sock *sk, int subclass)
 {
+	/* The sk_lock has mutex_lock() semantics here. */
+	mutex_acquire(&sk->sk_lock.dep_map, subclass, 0, _RET_IP_);
+
 	might_sleep();
 	spin_lock_bh(&sk->sk_lock.slock);
 	if (sk->sk_lock.owned)
 		__lock_sock(sk);
 	sk->sk_lock.owned = 1;
-	spin_unlock(&sk->sk_lock.slock);
-	/*
-	 * The sk_lock has mutex_lock() semantics here:
-	 */
-	mutex_acquire(&sk->sk_lock.dep_map, subclass, 0, _RET_IP_);
-	local_bh_enable();
+	spin_unlock_bh(&sk->sk_lock.slock);
 }
 EXPORT_SYMBOL(lock_sock_nested);
 
@@ -3212,42 +3230,37 @@ void release_sock(struct sock *sk)
 }
 EXPORT_SYMBOL(release_sock);
 
-/**
- * lock_sock_fast - fast version of lock_sock
- * @sk: socket
- *
- * This version should be used for very small section, where process wont block
- * return false if fast path is taken:
- *
- *   sk_lock.slock locked, owned = 0, BH disabled
- *
- * return true if slow path is taken:
- *
- *   sk_lock.slock unlocked, owned = 1, BH enabled
- */
-bool lock_sock_fast(struct sock *sk) __acquires(&sk->sk_lock.slock)
+bool __lock_sock_fast(struct sock *sk) __acquires(&sk->sk_lock.slock)
 {
 	might_sleep();
 	spin_lock_bh(&sk->sk_lock.slock);
 
-	if (!sk->sk_lock.owned)
+	if (!sk->sk_lock.owned) {
 		/*
-		 * Note : We must disable BH
+		 * Fast path return with bottom halves disabled and
+		 * sock::sk_lock.slock held.
+		 *
+		 * The 'mutex' is not contended and holding
+		 * sock::sk_lock.slock prevents all other lockers to
+		 * proceed so the corresponding unlock_sock_fast() can
+		 * avoid the slow path of release_sock() completely and
+		 * just release slock.
+		 *
+		 * From a semantical POV this is equivalent to 'acquiring'
+		 * the 'mutex', hence the corresponding lockdep
+		 * mutex_release() has to happen in the fast path of
+		 * unlock_sock_fast().
 		 */
 		return false;
+	}
 
 	__lock_sock(sk);
 	sk->sk_lock.owned = 1;
-	spin_unlock(&sk->sk_lock.slock);
-	/*
-	 * The sk_lock has mutex_lock() semantics here:
-	 */
-	mutex_acquire(&sk->sk_lock.dep_map, 0, 0, _RET_IP_);
 	__acquire(&sk->sk_lock.slock);
-	local_bh_enable();
+	spin_unlock_bh(&sk->sk_lock.slock);
 	return true;
 }
-EXPORT_SYMBOL(lock_sock_fast);
+EXPORT_SYMBOL(__lock_sock_fast);
 
 int sock_gettstamp(struct socket *sock, void __user *userstamp,
 		   bool timeval, bool time32)