sctp: Add RCU protection to assoc->transport_addr_list
peer.transport_addr_list is currently only protected by sk_sock
which is inpractical to acquire for procfs dumping purposes.
This patch adds RCU protection allowing for the procfs readers to
enter RCU read-side critical sections.
Modification of the list continues to be serialized via sk_lock.
V2: Use list_del_rcu() in sctp_association_free() to be safe
Skip transports marked dead when dumping for procfs
Cc: Vlad Yasevich <vyasevich@gmail.com>
Cc: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Acked-by: Vlad Yasevich <vyasevich@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/sctp/proc.c b/net/sctp/proc.c
index 06b05ee..8c19e97 100644
--- a/net/sctp/proc.c
+++ b/net/sctp/proc.c
@@ -162,15 +162,20 @@
struct sctp_af *af;
primary = &assoc->peer.primary_addr;
- list_for_each_entry(transport, &assoc->peer.transport_addr_list,
+ rcu_read_lock();
+ list_for_each_entry_rcu(transport, &assoc->peer.transport_addr_list,
transports) {
addr = &transport->ipaddr;
+ if (transport->dead)
+ continue;
+
af = sctp_get_af_specific(addr->sa.sa_family);
if (af->cmp_addr(addr, primary)) {
seq_printf(seq, "*");
}
af->seq_dump_addr(seq, addr);
}
+ rcu_read_unlock();
}
static void * sctp_eps_seq_start(struct seq_file *seq, loff_t *pos)
@@ -441,12 +446,16 @@
head = &sctp_assoc_hashtable[hash];
sctp_local_bh_disable();
read_lock(&head->lock);
+ rcu_read_lock();
sctp_for_each_hentry(epb, node, &head->chain) {
if (!net_eq(sock_net(epb->sk), seq_file_net(seq)))
continue;
assoc = sctp_assoc(epb);
- list_for_each_entry(tsp, &assoc->peer.transport_addr_list,
+ list_for_each_entry_rcu(tsp, &assoc->peer.transport_addr_list,
transports) {
+ if (tsp->dead)
+ continue;
+
/*
* The remote address (ADDR)
*/
@@ -492,6 +501,7 @@
}
}
+ rcu_read_unlock();
read_unlock(&head->lock);
sctp_local_bh_enable();