Message-Id: <11894535912570-git-send-email-vladislav.yasevich@hp.com>
Date:	Mon, 10 Sep 2007 15:46:30 -0400
From:	Vlad Yasevich <vladislav.yasevich@...com>
To:	netdev@...r.kernel.org
Cc:	lksctp-developers@...ts.sourceforge.net,
	Vlad Yasevich <vladislav.yasevich@...com>
Subject: [RFC PATCH 2/2] SCTP: Convert bind_addr_list locking to RCU

Since the sctp_sockaddr_entry is now RCU enabled as part of
the patch to synchronize sctp_localaddr_list, it makes sense to
change all handling of these entries to RCU.  This includes the
sctp_bind_addrs structure and it's list of bound addresses.

This list is currently protected by an external rw_lock and that
looks like an overkill.  There are only 2 writers to the list:
bind()/bindx() calls, and BH processing of ASCONF-ACK chunks.
These are already seriealized via the socket lock, so they will
not step on each other.  These are also relatively rare, so we
should be good with RCU.

The readers are varied and they are easily converted to RCU.

Signed-off-by: Vlad Yasevich <vladislav.yasevich@...com>
---
 include/net/sctp/structs.h |    3 -
 net/sctp/associola.c       |   14 +------
 net/sctp/bind_addr.c       |   59 ++++++++++++++++++----------
 net/sctp/endpointola.c     |   26 ++++---------
 net/sctp/ipv6.c            |   12 ++---
 net/sctp/protocol.c        |   25 +++++-------
 net/sctp/sm_make_chunk.c   |   17 +++-----
 net/sctp/socket.c          |   92 ++++++++++++++------------------------------
 8 files changed, 97 insertions(+), 151 deletions(-)

diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h
index 2591c49..1d46f7d 100644
--- a/include/net/sctp/structs.h
+++ b/include/net/sctp/structs.h
@@ -1222,9 +1222,6 @@ struct sctp_ep_common {
 	 * bind_addr.address_list is our set of local IP addresses.
 	 */
 	struct sctp_bind_addr bind_addr;
-
-	/* Protection during address list comparisons. */
-	rwlock_t   addr_lock;
 };
 
 
diff --git a/net/sctp/associola.c b/net/sctp/associola.c
index 2ad1caf..9bad8ba 100644
--- a/net/sctp/associola.c
+++ b/net/sctp/associola.c
@@ -99,7 +99,6 @@ static struct sctp_association *sctp_association_init(struct sctp_association *a
 
 	/* Initialize the bind addr area.  */
 	sctp_bind_addr_init(&asoc->base.bind_addr, ep->base.bind_addr.port);
-	rwlock_init(&asoc->base.addr_lock);
 
 	asoc->state = SCTP_STATE_CLOSED;
 
@@ -937,8 +936,6 @@ struct sctp_transport *sctp_assoc_is_match(struct sctp_association *asoc,
 {
 	struct sctp_transport *transport;
 
-	sctp_read_lock(&asoc->base.addr_lock);
-
 	if ((htons(asoc->base.bind_addr.port) == laddr->v4.sin_port) &&
 	    (htons(asoc->peer.port) == paddr->v4.sin_port)) {
 		transport = sctp_assoc_lookup_paddr(asoc, paddr);
@@ -952,7 +949,6 @@ struct sctp_transport *sctp_assoc_is_match(struct sctp_association *asoc,
 	transport = NULL;
 
 out:
-	sctp_read_unlock(&asoc->base.addr_lock);
 	return transport;
 }
 
@@ -1376,19 +1372,13 @@ int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association *asoc,
 int sctp_assoc_lookup_laddr(struct sctp_association *asoc,
 			    const union sctp_addr *laddr)
 {
-	int found;
+	int found = 0;
 
-	sctp_read_lock(&asoc->base.addr_lock);
 	if ((asoc->base.bind_addr.port == ntohs(laddr->v4.sin_port)) &&
 	    sctp_bind_addr_match(&asoc->base.bind_addr, laddr,
-				 sctp_sk(asoc->base.sk))) {
+				 sctp_sk(asoc->base.sk)))
 		found = 1;
-		goto out;
-	}
 
-	found = 0;
-out:
-	sctp_read_unlock(&asoc->base.addr_lock);
 	return found;
 }
 
diff --git a/net/sctp/bind_addr.c b/net/sctp/bind_addr.c
index 7fc369f..9c7db1f 100644
--- a/net/sctp/bind_addr.c
+++ b/net/sctp/bind_addr.c
@@ -167,7 +167,10 @@ int sctp_add_bind_addr(struct sctp_bind_addr *bp, union sctp_addr *new,
 
 	INIT_LIST_HEAD(&addr->list);
 	INIT_RCU_HEAD(&addr->rcu);
-	list_add_tail(&addr->list, &bp->address_list);
+
+	rcu_read_lock();
+	list_add_tail_rcu(&addr->list, &bp->address_list);
+	rcu_read_unlock();
 	SCTP_DBG_OBJCNT_INC(addr);
 
 	return 0;
@@ -178,20 +181,23 @@ int sctp_add_bind_addr(struct sctp_bind_addr *bp, union sctp_addr *new,
  */
 int sctp_del_bind_addr(struct sctp_bind_addr *bp, union sctp_addr *del_addr)
 {
-	struct list_head *pos, *temp;
-	struct sctp_sockaddr_entry *addr;
+	struct sctp_sockaddr_entry *addr, *temp;
 
-	list_for_each_safe(pos, temp, &bp->address_list) {
-		addr = list_entry(pos, struct sctp_sockaddr_entry, list);
+	rcu_read_lock_bh();
+	list_for_each_entry_safe(addr, temp, &bp->address_list, list) {
 		if (sctp_cmp_addr_exact(&addr->a, del_addr)) {
 			/* Found the exact match. */
-			list_del(pos);
-			kfree(addr);
-			SCTP_DBG_OBJCNT_DEC(addr);
-
-			return 0;
+			addr->valid = 0;
+			list_del_rcu(&addr->list);
+			break;
 		}
 	}
+	rcu_read_unlock_bh();
+
+	if (addr && !addr->valid) {
+		call_rcu_bh(&addr->rcu, sctp_local_addr_free);
+		SCTP_DBG_OBJCNT_DEC(addr);
+	}
 
 	return -EINVAL;
 }
@@ -302,15 +308,20 @@ int sctp_bind_addr_match(struct sctp_bind_addr *bp,
 			 struct sctp_sock *opt)
 {
 	struct sctp_sockaddr_entry *laddr;
-	struct list_head *pos;
-
-	list_for_each(pos, &bp->address_list) {
-		laddr = list_entry(pos, struct sctp_sockaddr_entry, list);
-		if (opt->pf->cmp_addr(&laddr->a, addr, opt))
-			return 1;
+	int match = 0;
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(laddr, &bp->address_list, list) {
+		if (!laddr->valid)
+			continue;
+		if (opt->pf->cmp_addr(&laddr->a, addr, opt)) {
+			match = 1;
+			break;
+		}
 	}
+	rcu_read_unlock();
 
-	return 0;
+	return match;
 }
 
 /* Find the first address in the bind address list that is not present in
@@ -325,27 +336,31 @@ union sctp_addr *sctp_find_unmatch_addr(struct sctp_bind_addr	*bp,
 	union sctp_addr			*addr;
 	void 				*addr_buf;
 	struct sctp_af			*af;
-	struct list_head		*pos;
 	int				i;
 
-	list_for_each(pos, &bp->address_list) {
-		laddr = list_entry(pos, struct sctp_sockaddr_entry, list);
+	rcu_read_lock();
+	list_for_each_entry_rcu(laddr, &bp->address_list, list) {
+		if (!laddr->valid)
+			continue;
 
 		addr_buf = (union sctp_addr *)addrs;
 		for (i = 0; i < addrcnt; i++) {
 			addr = (union sctp_addr *)addr_buf;
 			af = sctp_get_af_specific(addr->v4.sin_family);
 			if (!af)
-				return NULL;
+				break;
 
 			if (opt->pf->cmp_addr(&laddr->a, addr, opt))
 				break;
 
 			addr_buf += af->sockaddr_len;
 		}
-		if (i == addrcnt)
+		if (i == addrcnt) {
+			rcu_read_unlock();
 			return &laddr->a;
+		}
 	}
+	rcu_read_unlock();
 
 	return NULL;
 }
diff --git a/net/sctp/endpointola.c b/net/sctp/endpointola.c
index 1404a9e..fa10af5 100644
--- a/net/sctp/endpointola.c
+++ b/net/sctp/endpointola.c
@@ -92,7 +92,6 @@ static struct sctp_endpoint *sctp_endpoint_init(struct sctp_endpoint *ep,
 
 	/* Initialize the bind addr area */
 	sctp_bind_addr_init(&ep->base.bind_addr, 0);
-	rwlock_init(&ep->base.addr_lock);
 
 	/* Remember who we are attached to.  */
 	ep->base.sk = sk;
@@ -225,21 +224,14 @@ void sctp_endpoint_put(struct sctp_endpoint *ep)
 struct sctp_endpoint *sctp_endpoint_is_match(struct sctp_endpoint *ep,
 					       const union sctp_addr *laddr)
 {
-	struct sctp_endpoint *retval;
+	struct sctp_endpoint *retval = NULL;
 
-	sctp_read_lock(&ep->base.addr_lock);
 	if (htons(ep->base.bind_addr.port) == laddr->v4.sin_port) {
 		if (sctp_bind_addr_match(&ep->base.bind_addr, laddr,
-					 sctp_sk(ep->base.sk))) {
+					 sctp_sk(ep->base.sk)))
 			retval = ep;
-			goto out;
-		}
 	}
 
-	retval = NULL;
-
-out:
-	sctp_read_unlock(&ep->base.addr_lock);
 	return retval;
 }
 
@@ -261,9 +253,7 @@ static struct sctp_association *__sctp_endpoint_lookup_assoc(
 	list_for_each(pos, &ep->asocs) {
 		asoc = list_entry(pos, struct sctp_association, asocs);
 		if (rport == asoc->peer.port) {
-			sctp_read_lock(&asoc->base.addr_lock);
 			*transport = sctp_assoc_lookup_paddr(asoc, paddr);
-			sctp_read_unlock(&asoc->base.addr_lock);
 
 			if (*transport)
 				return asoc;
@@ -295,20 +285,20 @@ struct sctp_association *sctp_endpoint_lookup_assoc(
 int sctp_endpoint_is_peeled_off(struct sctp_endpoint *ep,
 				const union sctp_addr *paddr)
 {
-	struct list_head *pos;
 	struct sctp_sockaddr_entry *addr;
 	struct sctp_bind_addr *bp;
 
-	sctp_read_lock(&ep->base.addr_lock);
 	bp = &ep->base.bind_addr;
-	list_for_each(pos, &bp->address_list) {
-		addr = list_entry(pos, struct sctp_sockaddr_entry, list);
+	rcu_read_lock();
+	list_for_each_entry_rcu(addr, &bp->address_list, list) {
+		if (!addr->valid)
+			continue;
 		if (sctp_has_association(&addr->a, paddr)) {
-			sctp_read_unlock(&ep->base.addr_lock);
+			rcu_read_unlock();
 			return 1;
 		}
 	}
-	sctp_read_unlock(&ep->base.addr_lock);
+	rcu_read_unlock();
 
 	return 0;
 }
diff --git a/net/sctp/ipv6.c b/net/sctp/ipv6.c
index fc2e4e2..4f6dc55 100644
--- a/net/sctp/ipv6.c
+++ b/net/sctp/ipv6.c
@@ -302,9 +302,7 @@ static void sctp_v6_get_saddr(struct sctp_association *asoc,
 			      union sctp_addr *saddr)
 {
 	struct sctp_bind_addr *bp;
-	rwlock_t *addr_lock;
 	struct sctp_sockaddr_entry *laddr;
-	struct list_head *pos;
 	sctp_scope_t scope;
 	union sctp_addr *baddr = NULL;
 	__u8 matchlen = 0;
@@ -324,14 +322,14 @@ static void sctp_v6_get_saddr(struct sctp_association *asoc,
 	scope = sctp_scope(daddr);
 
 	bp = &asoc->base.bind_addr;
-	addr_lock = &asoc->base.addr_lock;
 
 	/* Go through the bind address list and find the best source address
 	 * that matches the scope of the destination address.
 	 */
-	sctp_read_lock(addr_lock);
-	list_for_each(pos, &bp->address_list) {
-		laddr = list_entry(pos, struct sctp_sockaddr_entry, list);
+	rcu_read_lock();
+	list_for_each_entry_rcu(laddr, &bp->address_list, list) {
+		if (!laddr->valid)
+			continue;
 		if ((laddr->use_as_src) &&
 		    (laddr->a.sa.sa_family == AF_INET6) &&
 		    (scope <= sctp_scope(&laddr->a))) {
@@ -353,7 +351,7 @@ static void sctp_v6_get_saddr(struct sctp_association *asoc,
 		       __FUNCTION__, asoc, NIP6(daddr->v6.sin6_addr));
 	}
 
-	sctp_read_unlock(addr_lock);
+	rcu_read_unlock();
 }
 
 /* Make a copy of all potential local addresses. */
diff --git a/net/sctp/protocol.c b/net/sctp/protocol.c
index ac52f9e..a1030ed 100644
--- a/net/sctp/protocol.c
+++ b/net/sctp/protocol.c
@@ -222,7 +222,7 @@ int sctp_copy_local_addr_list(struct sctp_bind_addr *bp, sctp_scope_t scope,
 			      (copy_flags & SCTP_ADDR6_ALLOWED) &&
 			      (copy_flags & SCTP_ADDR6_PEERSUPP)))) {
 				error = sctp_add_bind_addr(bp, &addr->a, 1,
-							   GFP_ATOMIC);
+						    GFP_ATOMIC);
 				if (error)
 					goto end_copy;
 			}
@@ -426,9 +426,7 @@ static struct dst_entry *sctp_v4_get_dst(struct sctp_association *asoc,
 	struct rtable *rt;
 	struct flowi fl;
 	struct sctp_bind_addr *bp;
-	rwlock_t *addr_lock;
 	struct sctp_sockaddr_entry *laddr;
-	struct list_head *pos;
 	struct dst_entry *dst = NULL;
 	union sctp_addr dst_saddr;
 
@@ -457,23 +455,20 @@ static struct dst_entry *sctp_v4_get_dst(struct sctp_association *asoc,
 		goto out;
 
 	bp = &asoc->base.bind_addr;
-	addr_lock = &asoc->base.addr_lock;
 
 	if (dst) {
 		/* Walk through the bind address list and look for a bind
 		 * address that matches the source address of the returned dst.
 		 */
-		sctp_read_lock(addr_lock);
-		list_for_each(pos, &bp->address_list) {
-			laddr = list_entry(pos, struct sctp_sockaddr_entry,
-					   list);
-			if (!laddr->use_as_src)
+		rcu_read_lock();
+		list_for_each_entry_rcu(laddr, &bp->address_list, list) {
+			if (!laddr->valid || !laddr->use_as_src)
 				continue;
 			sctp_v4_dst_saddr(&dst_saddr, dst, htons(bp->port));
 			if (sctp_v4_cmp_addr(&dst_saddr, &laddr->a))
 				goto out_unlock;
 		}
-		sctp_read_unlock(addr_lock);
+		rcu_read_unlock();
 
 		/* None of the bound addresses match the source address of the
 		 * dst. So release it.
@@ -485,10 +480,10 @@ static struct dst_entry *sctp_v4_get_dst(struct sctp_association *asoc,
 	/* Walk through the bind address list and try to get a dst that
 	 * matches a bind address as the source address.
 	 */
-	sctp_read_lock(addr_lock);
-	list_for_each(pos, &bp->address_list) {
-		laddr = list_entry(pos, struct sctp_sockaddr_entry, list);
-
+	rcu_read_lock();
+	list_for_each_entry_rcu(laddr, &bp->address_list, list) {
+		if (!laddr->valid)
+			continue;
 		if ((laddr->use_as_src) &&
 		    (AF_INET == laddr->a.sa.sa_family)) {
 			fl.fl4_src = laddr->a.v4.sin_addr.s_addr;
@@ -500,7 +495,7 @@ static struct dst_entry *sctp_v4_get_dst(struct sctp_association *asoc,
 	}
 
 out_unlock:
-	sctp_read_unlock(addr_lock);
+	rcu_read_unlock();
 out:
 	if (dst)
 		SCTP_DEBUG_PRINTK("rt_dst:%u.%u.%u.%u, rt_src:%u.%u.%u.%u\n",
diff --git a/net/sctp/sm_make_chunk.c b/net/sctp/sm_make_chunk.c
index 79856c9..caaa29f 100644
--- a/net/sctp/sm_make_chunk.c
+++ b/net/sctp/sm_make_chunk.c
@@ -1531,7 +1531,7 @@ no_hmac:
 	/* Also, add the destination address. */
 	if (list_empty(&retval->base.bind_addr.address_list)) {
 		sctp_add_bind_addr(&retval->base.bind_addr, &chunk->dest, 1,
-				   GFP_ATOMIC);
+				GFP_ATOMIC);
 	}
 
 	retval->next_tsn = retval->c.initial_tsn;
@@ -2613,22 +2613,17 @@ static int sctp_asconf_param_success(struct sctp_association *asoc,
 
 	switch (asconf_param->param_hdr.type) {
 	case SCTP_PARAM_ADD_IP:
-		sctp_local_bh_disable();
-		sctp_write_lock(&asoc->base.addr_lock);
-		list_for_each(pos, &bp->address_list) {
-			saddr = list_entry(pos, struct sctp_sockaddr_entry, list);
+		rcu_read_lock_bh();
+		list_for_each_entry_rcu(saddr, &bp->address_list, list) {
+			if (!saddr->valid)
+				continue;
 			if (sctp_cmp_addr_exact(&saddr->a, &addr))
 				saddr->use_as_src = 1;
 		}
-		sctp_write_unlock(&asoc->base.addr_lock);
-		sctp_local_bh_enable();
+		rcu_read_unlock_bh();
 		break;
 	case SCTP_PARAM_DEL_IP:
-		sctp_local_bh_disable();
-		sctp_write_lock(&asoc->base.addr_lock);
 		retval = sctp_del_bind_addr(bp, &addr);
-		sctp_write_unlock(&asoc->base.addr_lock);
-		sctp_local_bh_enable();
 		list_for_each(pos, &asoc->peer.transport_addr_list) {
 			transport = list_entry(pos, struct sctp_transport,
 						 transports);
diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index a3acf78..35cc30c 100644
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -367,14 +367,10 @@ SCTP_STATIC int sctp_do_bind(struct sock *sk, union sctp_addr *addr, int len)
 	if (!bp->port)
 		bp->port = inet_sk(sk)->num;
 
-	/* Add the address to the bind address list.  */
-	sctp_local_bh_disable();
-	sctp_write_lock(&ep->base.addr_lock);
-
-	/* Use GFP_ATOMIC since BHs are disabled.  */
+	/* Add the address to the bind address list.
+	 * Use GFP_ATOMIC since BHs will be disabled.
+	 */
 	ret = sctp_add_bind_addr(bp, addr, 1, GFP_ATOMIC);
-	sctp_write_unlock(&ep->base.addr_lock);
-	sctp_local_bh_enable();
 
 	/* Copy back into socket for getsockname() use. */
 	if (!ret) {
@@ -497,7 +493,6 @@ static int sctp_send_asconf_add_ip(struct sock		*sk,
 	void				*addr_buf;
 	struct sctp_af			*af;
 	struct list_head		*pos;
-	struct list_head		*p;
 	int 				i;
 	int 				retval = 0;
 
@@ -544,14 +539,15 @@ static int sctp_send_asconf_add_ip(struct sock		*sk,
 		if (i < addrcnt)
 			continue;
 
-		/* Use the first address in bind addr list of association as
-		 * Address Parameter of ASCONF CHUNK.
+		/* Use the first valid address in bind addr list of
+		 * association as Address Parameter of ASCONF CHUNK.
 		 */
-		sctp_read_lock(&asoc->base.addr_lock);
 		bp = &asoc->base.bind_addr;
-		p = bp->address_list.next;
-		laddr = list_entry(p, struct sctp_sockaddr_entry, list);
-		sctp_read_unlock(&asoc->base.addr_lock);
+		rcu_read_lock();
+		list_for_each_entry_rcu(laddr, &bp->address_list, list)
+			if (laddr->valid)
+				break;
+		rcu_read_unlock();
 
 		chunk = sctp_make_asconf_update_ip(asoc, &laddr->a, addrs,
 						   addrcnt, SCTP_PARAM_ADD_IP);
@@ -567,8 +563,6 @@ static int sctp_send_asconf_add_ip(struct sock		*sk,
 		/* Add the new addresses to the bind address list with
 		 * use_as_src set to 0.
 		 */
-		sctp_local_bh_disable();
-		sctp_write_lock(&asoc->base.addr_lock);
 		addr_buf = addrs;
 		for (i = 0; i < addrcnt; i++) {
 			addr = (union sctp_addr *)addr_buf;
@@ -578,8 +572,6 @@ static int sctp_send_asconf_add_ip(struct sock		*sk,
 						    GFP_ATOMIC);
 			addr_buf += af->sockaddr_len;
 		}
-		sctp_write_unlock(&asoc->base.addr_lock);
-		sctp_local_bh_enable();
 	}
 
 out:
@@ -651,14 +643,8 @@ static int sctp_bindx_rem(struct sock *sk, struct sockaddr *addrs, int addrcnt)
 		 * socket routing and failover schemes. Refer to comments in
 		 * sctp_do_bind(). -daisy
 		 */
-		sctp_local_bh_disable();
-		sctp_write_lock(&ep->base.addr_lock);
-
 		retval = sctp_del_bind_addr(bp, sa_addr);
 
-		sctp_write_unlock(&ep->base.addr_lock);
-		sctp_local_bh_enable();
-
 		addr_buf += af->sockaddr_len;
 err_bindx_rem:
 		if (retval < 0) {
@@ -748,11 +734,9 @@ static int sctp_send_asconf_del_ip(struct sock		*sk,
 		 * make sure that we do not delete all the addresses in the
 		 * association.
 		 */
-		sctp_read_lock(&asoc->base.addr_lock);
 		bp = &asoc->base.bind_addr;
 		laddr = sctp_find_unmatch_addr(bp, (union sctp_addr *)addrs,
 					       addrcnt, sp);
-		sctp_read_unlock(&asoc->base.addr_lock);
 		if (!laddr)
 			continue;
 
@@ -766,23 +750,18 @@ static int sctp_send_asconf_del_ip(struct sock		*sk,
 		/* Reset use_as_src flag for the addresses in the bind address
 		 * list that are to be deleted.
 		 */
-		sctp_local_bh_disable();
-		sctp_write_lock(&asoc->base.addr_lock);
 		addr_buf = addrs;
 		for (i = 0; i < addrcnt; i++) {
 			laddr = (union sctp_addr *)addr_buf;
 			af = sctp_get_af_specific(laddr->v4.sin_family);
-			list_for_each(pos1, &bp->address_list) {
-				saddr = list_entry(pos1,
-						   struct sctp_sockaddr_entry,
-						   list);
+			rcu_read_lock();
+			list_for_each_entry_rcu(saddr, &bp->address_list, list) {
 				if (sctp_cmp_addr_exact(&saddr->a, laddr))
 					saddr->use_as_src = 0;
 			}
+			rcu_read_unlock();
 			addr_buf += af->sockaddr_len;
 		}
-		sctp_write_unlock(&asoc->base.addr_lock);
-		sctp_local_bh_enable();
 
 		/* Update the route and saddr entries for all the transports
 		 * as some of the addresses in the bind address list are
@@ -4057,11 +4036,9 @@ static int sctp_getsockopt_local_addrs_num_old(struct sock *sk, int len,
 					       int __user *optlen)
 {
 	sctp_assoc_t id;
-	struct list_head *pos;
 	struct sctp_bind_addr *bp;
 	struct sctp_association *asoc;
 	struct sctp_sockaddr_entry *addr;
-	rwlock_t *addr_lock;
 	int cnt = 0;
 
 	if (len < sizeof(sctp_assoc_t))
@@ -4078,17 +4055,13 @@ static int sctp_getsockopt_local_addrs_num_old(struct sock *sk, int len,
 	 */
 	if (0 == id) {
 		bp = &sctp_sk(sk)->ep->base.bind_addr;
-		addr_lock = &sctp_sk(sk)->ep->base.addr_lock;
 	} else {
 		asoc = sctp_id2assoc(sk, id);
 		if (!asoc)
 			return -EINVAL;
 		bp = &asoc->base.bind_addr;
-		addr_lock = &asoc->base.addr_lock;
 	}
 
-	sctp_read_lock(addr_lock);
-
 	/* If the endpoint is bound to 0.0.0.0 or ::0, count the valid
 	 * addresses from the global local address list.
 	 */
@@ -4115,12 +4088,15 @@ static int sctp_getsockopt_local_addrs_num_old(struct sock *sk, int len,
 		goto done;
 	}
 
-	list_for_each(pos, &bp->address_list) {
+	rcu_read_lock();
+	list_for_each_entry_rcu(addr, &bp->address_list, list) {
+		if (!addr->valid)
+			continue;
 		cnt ++;
 	}
+	rcu_read_unlock();
 
 done:
-	sctp_read_unlock(addr_lock);
 	return cnt;
 }
 
@@ -4204,7 +4180,6 @@ static int sctp_getsockopt_local_addrs_old(struct sock *sk, int len,
 {
 	struct sctp_bind_addr *bp;
 	struct sctp_association *asoc;
-	struct list_head *pos;
 	int cnt = 0;
 	struct sctp_getaddrs_old getaddrs;
 	struct sctp_sockaddr_entry *addr;
@@ -4212,7 +4187,6 @@ static int sctp_getsockopt_local_addrs_old(struct sock *sk, int len,
 	union sctp_addr temp;
 	struct sctp_sock *sp = sctp_sk(sk);
 	int addrlen;
-	rwlock_t *addr_lock;
 	int err = 0;
 	void *addrs;
 	void *buf;
@@ -4234,13 +4208,11 @@ static int sctp_getsockopt_local_addrs_old(struct sock *sk, int len,
 	 */
 	if (0 == getaddrs.assoc_id) {
 		bp = &sctp_sk(sk)->ep->base.bind_addr;
-		addr_lock = &sctp_sk(sk)->ep->base.addr_lock;
 	} else {
 		asoc = sctp_id2assoc(sk, getaddrs.assoc_id);
 		if (!asoc)
 			return -EINVAL;
 		bp = &asoc->base.bind_addr;
-		addr_lock = &asoc->base.addr_lock;
 	}
 
 	to = getaddrs.addrs;
@@ -4254,8 +4226,6 @@ static int sctp_getsockopt_local_addrs_old(struct sock *sk, int len,
 	if (!addrs)
 		return -ENOMEM;
 
-	sctp_read_lock(addr_lock);
-
 	/* If the endpoint is bound to 0.0.0.0 or ::0, get the valid
 	 * addresses from the global local address list.
 	 */
@@ -4271,8 +4241,10 @@ static int sctp_getsockopt_local_addrs_old(struct sock *sk, int len,
 	}
 
 	buf = addrs;
-	list_for_each(pos, &bp->address_list) {
-		addr = list_entry(pos, struct sctp_sockaddr_entry, list);
+	rcu_read_lock();
+	list_for_each_entry_rcu(addr, &bp->address_list, list) {
+		if (!addr->valid)
+			continue;
 		memcpy(&temp, &addr->a, sizeof(temp));
 		sctp_get_pf_specific(sk->sk_family)->addr_v4map(sp, &temp);
 		addrlen = sctp_get_af_specific(temp.sa.sa_family)->sockaddr_len;
@@ -4282,10 +4254,9 @@ static int sctp_getsockopt_local_addrs_old(struct sock *sk, int len,
 		cnt ++;
 		if (cnt >= getaddrs.addr_num) break;
 	}
+	rcu_read_unlock();
 
 copy_getaddrs:
-	sctp_read_unlock(addr_lock);
-
 	/* copy the entire address list into the user provided space */
 	if (copy_to_user(to, addrs, bytes_copied)) {
 		err = -EFAULT;
@@ -4307,7 +4278,6 @@ static int sctp_getsockopt_local_addrs(struct sock *sk, int len,
 {
 	struct sctp_bind_addr *bp;
 	struct sctp_association *asoc;
-	struct list_head *pos;
 	int cnt = 0;
 	struct sctp_getaddrs getaddrs;
 	struct sctp_sockaddr_entry *addr;
@@ -4315,7 +4285,6 @@ static int sctp_getsockopt_local_addrs(struct sock *sk, int len,
 	union sctp_addr temp;
 	struct sctp_sock *sp = sctp_sk(sk);
 	int addrlen;
-	rwlock_t *addr_lock;
 	int err = 0;
 	size_t space_left;
 	int bytes_copied = 0;
@@ -4336,13 +4305,11 @@ static int sctp_getsockopt_local_addrs(struct sock *sk, int len,
 	 */
 	if (0 == getaddrs.assoc_id) {
 		bp = &sctp_sk(sk)->ep->base.bind_addr;
-		addr_lock = &sctp_sk(sk)->ep->base.addr_lock;
 	} else {
 		asoc = sctp_id2assoc(sk, getaddrs.assoc_id);
 		if (!asoc)
 			return -EINVAL;
 		bp = &asoc->base.bind_addr;
-		addr_lock = &asoc->base.addr_lock;
 	}
 
 	to = optval + offsetof(struct sctp_getaddrs,addrs);
@@ -4352,8 +4319,6 @@ static int sctp_getsockopt_local_addrs(struct sock *sk, int len,
 	if (!addrs)
 		return -ENOMEM;
 
-	sctp_read_lock(addr_lock);
-
 	/* If the endpoint is bound to 0.0.0.0 or ::0, get the valid
 	 * addresses from the global local address list.
 	 */
@@ -4372,8 +4337,10 @@ static int sctp_getsockopt_local_addrs(struct sock *sk, int len,
 	}
 
 	buf = addrs;
-	list_for_each(pos, &bp->address_list) {
-		addr = list_entry(pos, struct sctp_sockaddr_entry, list);
+	rcu_read_lock();
+	list_for_each_entry_rcu(addr, &bp->address_list, list) {
+		if (!addr->valid)
+			continue;
 		memcpy(&temp, &addr->a, sizeof(temp));
 		sctp_get_pf_specific(sk->sk_family)->addr_v4map(sp, &temp);
 		addrlen = sctp_get_af_specific(temp.sa.sa_family)->sockaddr_len;
@@ -4387,10 +4354,9 @@ static int sctp_getsockopt_local_addrs(struct sock *sk, int len,
 		cnt ++;
 		space_left -= addrlen;
 	}
+	rcu_read_unlock();
 
 copy_getaddrs:
-	sctp_read_unlock(addr_lock);
-
 	if (copy_to_user(to, addrs, bytes_copied)) {
 		err = -EFAULT;
 		goto out;
@@ -4405,7 +4371,7 @@ copy_getaddrs:
 	goto out;
 
 error_lock:
-	sctp_read_unlock(addr_lock);
+	rcu_read_unlock();
 
 out:
 	kfree(addrs);
-- 
1.5.2.4

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