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authorYing Xue <ying.xue@windriver.com>2013-12-27 03:18:28 +0100
committerDavid S. Miller <davem@davemloft.net>2013-12-30 04:24:07 +0100
commit84602761ca4495dd409be936dfa93ed20c946684 (patch)
tree5936e501cc24cc66cf298a8e6713cbb04b4427b0 /net/tipc/port.c
parentMerge tag 'batman-adv-fix-for-davem' of git://git.open-mesh.org/linux-merge (diff)
downloadlinux-84602761ca4495dd409be936dfa93ed20c946684.tar.xz
linux-84602761ca4495dd409be936dfa93ed20c946684.zip
tipc: fix deadlock during socket release
A deadlock might occur if name table is withdrawn in socket release routine, and while packets are still being received from bearer. CPU0 CPU1 T0: recv_msg() release() T1: tipc_recv_msg() tipc_withdraw() T2: [grab node lock] [grab port lock] T3: tipc_link_wakeup_ports() tipc_nametbl_withdraw() T4: [grab port lock]* named_cluster_distribute() T5: wakeupdispatch() tipc_link_send() T6: [grab node lock]* The opposite order of holding port lock and node lock on above two different paths may result in a deadlock. If socket lock instead of port lock is used to protect port instance in tipc_withdraw(), the reverse order of holding port lock and node lock will be eliminated, as a result, the deadlock is killed as well. Reported-by: Lars Everbrand <lars.everbrand@ericsson.com> Reviewed-by: Erik Hugne <erik.hugne@ericsson.com> Signed-off-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/tipc/port.c')
-rw-r--r--net/tipc/port.c45
1 files changed, 15 insertions, 30 deletions
diff --git a/net/tipc/port.c b/net/tipc/port.c
index c081a7632302..d43f3182b1d4 100644
--- a/net/tipc/port.c
+++ b/net/tipc/port.c
@@ -251,18 +251,15 @@ struct tipc_port *tipc_createport(struct sock *sk,
return p_ptr;
}
-int tipc_deleteport(u32 ref)
+int tipc_deleteport(struct tipc_port *p_ptr)
{
- struct tipc_port *p_ptr;
struct sk_buff *buf = NULL;
- tipc_withdraw(ref, 0, NULL);
- p_ptr = tipc_port_lock(ref);
- if (!p_ptr)
- return -EINVAL;
+ tipc_withdraw(p_ptr, 0, NULL);
- tipc_ref_discard(ref);
- tipc_port_unlock(p_ptr);
+ spin_lock_bh(p_ptr->lock);
+ tipc_ref_discard(p_ptr->ref);
+ spin_unlock_bh(p_ptr->lock);
k_cancel_timer(&p_ptr->timer);
if (p_ptr->connected) {
@@ -704,47 +701,36 @@ int tipc_set_portimportance(u32 ref, unsigned int imp)
}
-int tipc_publish(u32 ref, unsigned int scope, struct tipc_name_seq const *seq)
+int tipc_publish(struct tipc_port *p_ptr, unsigned int scope,
+ struct tipc_name_seq const *seq)
{
- struct tipc_port *p_ptr;
struct publication *publ;
u32 key;
- int res = -EINVAL;
- p_ptr = tipc_port_lock(ref);
- if (!p_ptr)
+ if (p_ptr->connected)
return -EINVAL;
+ key = p_ptr->ref + p_ptr->pub_count + 1;
+ if (key == p_ptr->ref)
+ return -EADDRINUSE;
- if (p_ptr->connected)
- goto exit;
- key = ref + p_ptr->pub_count + 1;
- if (key == ref) {
- res = -EADDRINUSE;
- goto exit;
- }
publ = tipc_nametbl_publish(seq->type, seq->lower, seq->upper,
scope, p_ptr->ref, key);
if (publ) {
list_add(&publ->pport_list, &p_ptr->publications);
p_ptr->pub_count++;
p_ptr->published = 1;
- res = 0;
+ return 0;
}
-exit:
- tipc_port_unlock(p_ptr);
- return res;
+ return -EINVAL;
}
-int tipc_withdraw(u32 ref, unsigned int scope, struct tipc_name_seq const *seq)
+int tipc_withdraw(struct tipc_port *p_ptr, unsigned int scope,
+ struct tipc_name_seq const *seq)
{
- struct tipc_port *p_ptr;
struct publication *publ;
struct publication *tpubl;
int res = -EINVAL;
- p_ptr = tipc_port_lock(ref);
- if (!p_ptr)
- return -EINVAL;
if (!seq) {
list_for_each_entry_safe(publ, tpubl,
&p_ptr->publications, pport_list) {
@@ -771,7 +757,6 @@ int tipc_withdraw(u32 ref, unsigned int scope, struct tipc_name_seq const *seq)
}
if (list_empty(&p_ptr->publications))
p_ptr->published = 0;
- tipc_port_unlock(p_ptr);
return res;
}