android/android_kernel_asus_sm8350
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Merge branch 'tipc-next'

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Ying Xue says:

====================
tipc: fix two corner issues

The patch set aims at resolving the following two critical issues:

Patch #1: Resolve a deadlock which happens while all links are reset
Patch #2: Correct a mistake usage of RCU lock which is used to protect
          node list
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
David S. Miller 2015-03-29 12:40:37 -07:00
commit ae7633c841
7 changed files with 87 additions and 62 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

28
net/tipc/bcast.c
View File

@ -62,21 +62,8 @@ static void tipc_bclink_lock(struct net *net)
static void tipc_bclink_unlock(struct net *net)
{
struct tipc_net *tn = net_generic(net, tipc_net_id);
struct tipc_node *node = NULL;
if (likely(!tn->bclink->flags)) {
spin_unlock_bh(&tn->bclink->lock);
return;
}
if (tn->bclink->flags & TIPC_BCLINK_RESET) {
tn->bclink->flags &= ~TIPC_BCLINK_RESET;
node = tipc_bclink_retransmit_to(net);
}
spin_unlock_bh(&tn->bclink->lock);
if (node)
tipc_link_reset_all(node);
}
void tipc_bclink_input(struct net *net)
@ -91,13 +78,6 @@ uint tipc_bclink_get_mtu(void)
return MAX_PKT_DEFAULT_MCAST;
}
void tipc_bclink_set_flags(struct net *net, unsigned int flags)
{
struct tipc_net *tn = net_generic(net, tipc_net_id);
tn->bclink->flags |= flags;
}
static u32 bcbuf_acks(struct sk_buff *buf)
{
return (u32)(unsigned long)TIPC_SKB_CB(buf)->handle;
@ -156,7 +136,6 @@ static void bclink_update_last_sent(struct tipc_node *node, u32 seqno)
seqno : node->bclink.last_sent;
}
/**
* tipc_bclink_retransmit_to - get most recent node to request retransmission
*
@ -350,13 +329,12 @@ static void bclink_peek_nack(struct net *net, struct tipc_msg *msg)
return;
tipc_node_lock(n_ptr);
if (n_ptr->bclink.recv_permitted &&
(n_ptr->bclink.last_in != n_ptr->bclink.last_sent) &&
(n_ptr->bclink.last_in == msg_bcgap_after(msg)))
n_ptr->bclink.oos_state = 2;
tipc_node_unlock(n_ptr);
tipc_node_put(n_ptr);
}
/* tipc_bclink_xmit - deliver buffer chain to all nodes in cluster
@ -476,17 +454,18 @@ void tipc_bclink_rcv(struct net *net, struct sk_buff *buf)
goto unlock;
if (msg_destnode(msg) == tn->own_addr) {
tipc_bclink_acknowledge(node, msg_bcast_ack(msg));
tipc_node_unlock(node);
tipc_bclink_lock(net);
bcl->stats.recv_nacks++;
tn->bclink->retransmit_to = node;
bclink_retransmit_pkt(tn, msg_bcgap_after(msg),
msg_bcgap_to(msg));
tipc_bclink_unlock(net);
tipc_node_unlock(node);
} else {
tipc_node_unlock(node);
bclink_peek_nack(net, msg);
}
tipc_node_put(node);
goto exit;
}
@ -591,6 +570,7 @@ void tipc_bclink_rcv(struct net *net, struct sk_buff *buf)
unlock:
tipc_node_unlock(node);
tipc_node_put(node);
exit:
kfree_skb(buf);
}

4
net/tipc/bcast.h
View File

@ -55,7 +55,6 @@ struct tipc_bcbearer_pair {
struct tipc_bearer *secondary;
};
#define TIPC_BCLINK_RESET 1
#define BCBEARER MAX_BEARERS
/**
@ -86,7 +85,6 @@ struct tipc_bcbearer {
* @lock: spinlock governing access to structure
* @link: (non-standard) broadcast link structure
* @node: (non-standard) node structure representing b'cast link's peer node
* @flags: represent bclink states
* @bcast_nodes: map of broadcast-capable nodes
* @retransmit_to: node that most recently requested a retransmit
*
@ -96,7 +94,6 @@ struct tipc_bclink {
spinlock_t lock;
struct tipc_link link;
struct tipc_node node;
unsigned int flags;
struct sk_buff_head arrvq;
struct sk_buff_head inputq;
struct tipc_node_map bcast_nodes;
@ -117,7 +114,6 @@ static inline int tipc_nmap_equal(struct tipc_node_map *nm_a,
int tipc_bclink_init(struct net *net);
void tipc_bclink_stop(struct net *net);
void tipc_bclink_set_flags(struct net *tn, unsigned int flags);
void tipc_bclink_add_node(struct net *net, u32 addr);
void tipc_bclink_remove_node(struct net *net, u32 addr);
struct tipc_node *tipc_bclink_retransmit_to(struct net *tn);

1
net/tipc/discover.c
View File

@ -260,6 +260,7 @@ void tipc_disc_rcv(struct net *net, struct sk_buff *buf,
}
}
tipc_node_unlock(node);
tipc_node_put(node);
}
/**

12
net/tipc/link.c
View File

@ -854,6 +854,7 @@ int tipc_link_xmit(struct net *net, struct sk_buff_head *list, u32 dnode,
if (link)
rc = __tipc_link_xmit(net, link, list);
tipc_node_unlock(node);
tipc_node_put(node);
}
if (link)
return rc;
@ -980,7 +981,6 @@ static void link_retransmit_failure(struct tipc_link *l_ptr,
(unsigned long) TIPC_SKB_CB(buf)->handle);
n_ptr = tipc_bclink_retransmit_to(net);
tipc_node_lock(n_ptr);
tipc_addr_string_fill(addr_string, n_ptr->addr);
pr_info("Broadcast link info for %s\n", addr_string);
@ -992,9 +992,7 @@ static void link_retransmit_failure(struct tipc_link *l_ptr,
n_ptr->bclink.oos_state,
n_ptr->bclink.last_sent);
tipc_node_unlock(n_ptr);
tipc_bclink_set_flags(net, TIPC_BCLINK_RESET);
n_ptr->action_flags |= TIPC_BCAST_RESET;
l_ptr->stale_count = 0;
}
}
@ -1119,8 +1117,8 @@ void tipc_rcv(struct net *net, struct sk_buff *skb, struct tipc_bearer *b_ptr)
n_ptr = tipc_node_find(net, msg_prevnode(msg));
if (unlikely(!n_ptr))
goto discard;
tipc_node_lock(n_ptr);
tipc_node_lock(n_ptr);
/* Locate unicast link endpoint that should handle message */
l_ptr = n_ptr->links[b_ptr->identity];
if (unlikely(!l_ptr))
@ -1208,6 +1206,7 @@ void tipc_rcv(struct net *net, struct sk_buff *skb, struct tipc_bearer *b_ptr)
skb = NULL;
unlock:
tipc_node_unlock(n_ptr);
tipc_node_put(n_ptr);
discard:
if (unlikely(skb))
kfree_skb(skb);
@ -2239,7 +2238,6 @@ int tipc_nl_link_dump(struct sk_buff *skb, struct netlink_callback *cb)
msg.seq = cb->nlh->nlmsg_seq;
rcu_read_lock();
if (prev_node) {
node = tipc_node_find(net, prev_node);
if (!node) {
@ -2252,6 +2250,7 @@ int tipc_nl_link_dump(struct sk_buff *skb, struct netlink_callback *cb)
cb->prev_seq = 1;
goto out;
}
tipc_node_put(node);
list_for_each_entry_continue_rcu(node, &tn->node_list,
list) {
@ -2259,6 +2258,7 @@ int tipc_nl_link_dump(struct sk_buff *skb, struct netlink_callback *cb)
err = __tipc_nl_add_node_links(net, &msg, node,
&prev_link);
tipc_node_unlock(node);
tipc_node_put(node);
if (err)
goto out;

2
net/tipc/name_distr.c
View File

@ -244,6 +244,7 @@ static void tipc_publ_subscribe(struct net *net, struct publication *publ,
tipc_node_lock(node);
list_add_tail(&publ->nodesub_list, &node->publ_list);
tipc_node_unlock(node);
tipc_node_put(node);
}
static void tipc_publ_unsubscribe(struct net *net, struct publication *publ,
@ -258,6 +259,7 @@ static void tipc_publ_unsubscribe(struct net *net, struct publication *publ,
tipc_node_lock(node);
list_del_init(&publ->nodesub_list);
tipc_node_unlock(node);
tipc_node_put(node);
}
/**

90
net/tipc/node.c
View File

@ -42,6 +42,7 @@
static void node_lost_contact(struct tipc_node *n_ptr);
static void node_established_contact(struct tipc_node *n_ptr);
static void tipc_node_delete(struct tipc_node *node);
struct tipc_sock_conn {
u32 port;
@ -67,6 +68,23 @@ static unsigned int tipc_hashfn(u32 addr)
return addr & (NODE_HTABLE_SIZE - 1);
}
static void tipc_node_kref_release(struct kref *kref)
{
struct tipc_node *node = container_of(kref, struct tipc_node, kref);
tipc_node_delete(node);
}
void tipc_node_put(struct tipc_node *node)
{
kref_put(&node->kref, tipc_node_kref_release);
}
static void tipc_node_get(struct tipc_node *node)
{
kref_get(&node->kref);
}
/*
* tipc_node_find - locate specified node object, if it exists
*/
@ -82,6 +100,7 @@ struct tipc_node *tipc_node_find(struct net *net, u32 addr)
hlist_for_each_entry_rcu(node, &tn->node_htable[tipc_hashfn(addr)],
hash) {
if (node->addr == addr) {
tipc_node_get(node);
rcu_read_unlock();
return node;
}
@ -106,6 +125,7 @@ struct tipc_node *tipc_node_create(struct net *net, u32 addr)
}
n_ptr->addr = addr;
n_ptr->net = net;
kref_init(&n_ptr->kref);
spin_lock_init(&n_ptr->lock);
INIT_HLIST_NODE(&n_ptr->hash);
INIT_LIST_HEAD(&n_ptr->list);
@ -120,16 +140,17 @@ struct tipc_node *tipc_node_create(struct net *net, u32 addr)
list_add_tail_rcu(&n_ptr->list, &temp_node->list);
n_ptr->action_flags = TIPC_WAIT_PEER_LINKS_DOWN;
n_ptr->signature = INVALID_NODE_SIG;
tipc_node_get(n_ptr);
exit:
spin_unlock_bh(&tn->node_list_lock);
return n_ptr;
}
static void tipc_node_delete(struct tipc_net *tn, struct tipc_node *n_ptr)
static void tipc_node_delete(struct tipc_node *node)
{
list_del_rcu(&n_ptr->list);
hlist_del_rcu(&n_ptr->hash);
kfree_rcu(n_ptr, rcu);
list_del_rcu(&node->list);
hlist_del_rcu(&node->hash);
kfree_rcu(node, rcu);
}
void tipc_node_stop(struct net *net)
@ -139,7 +160,7 @@ void tipc_node_stop(struct net *net)
spin_lock_bh(&tn->node_list_lock);
list_for_each_entry_safe(node, t_node, &tn->node_list, list)
tipc_node_delete(tn, node);
tipc_node_put(node);
spin_unlock_bh(&tn->node_list_lock);
}
@ -147,6 +168,7 @@ int tipc_node_add_conn(struct net *net, u32 dnode, u32 port, u32 peer_port)
{
struct tipc_node *node;
struct tipc_sock_conn *conn;
int err = 0;
if (in_own_node(net, dnode))
return 0;
@ -157,8 +179,10 @@ int tipc_node_add_conn(struct net *net, u32 dnode, u32 port, u32 peer_port)
return -EHOSTUNREACH;
}
conn = kmalloc(sizeof(*conn), GFP_ATOMIC);
if (!conn)
return -EHOSTUNREACH;
if (!conn) {
err = -EHOSTUNREACH;
goto exit;
}
conn->peer_node = dnode;
conn->port = port;
conn->peer_port = peer_port;
@ -166,7 +190,9 @@ int tipc_node_add_conn(struct net *net, u32 dnode, u32 port, u32 peer_port)
tipc_node_lock(node);
list_add_tail(&conn->list, &node->conn_sks);
tipc_node_unlock(node);
return 0;
exit:
tipc_node_put(node);
return err;
}
void tipc_node_remove_conn(struct net *net, u32 dnode, u32 port)
@ -189,6 +215,7 @@ void tipc_node_remove_conn(struct net *net, u32 dnode, u32 port)
kfree(conn);
}
tipc_node_unlock(node);
tipc_node_put(node);
}
/**
@ -417,19 +444,25 @@ int tipc_node_get_linkname(struct net *net, u32 bearer_id, u32 addr,
char *linkname, size_t len)
{
struct tipc_link *link;
int err = -EINVAL;
struct tipc_node *node = tipc_node_find(net, addr);
if ((bearer_id >= MAX_BEARERS) || !node)
return -EINVAL;
if (!node)
return err;
if (bearer_id >= MAX_BEARERS)
goto exit;
tipc_node_lock(node);
link = node->links[bearer_id];
if (link) {
strncpy(linkname, link->name, len);
tipc_node_unlock(node);
return 0;
err = 0;
}
exit:
tipc_node_unlock(node);
return -EINVAL;
tipc_node_put(node);
return err;
}
void tipc_node_unlock(struct tipc_node *node)
@ -459,7 +492,7 @@ void tipc_node_unlock(struct tipc_node *node)
TIPC_NOTIFY_NODE_DOWN | TIPC_NOTIFY_NODE_UP |
TIPC_NOTIFY_LINK_DOWN | TIPC_NOTIFY_LINK_UP |
TIPC_WAKEUP_BCAST_USERS | TIPC_BCAST_MSG_EVT |
TIPC_NAMED_MSG_EVT);
TIPC_NAMED_MSG_EVT | TIPC_BCAST_RESET);
spin_unlock_bh(&node->lock);
@ -488,6 +521,9 @@ void tipc_node_unlock(struct tipc_node *node)
if (flags & TIPC_BCAST_MSG_EVT)
tipc_bclink_input(net);
if (flags & TIPC_BCAST_RESET)
tipc_link_reset_all(node);
}
/* Caller should hold node lock for the passed node */
@ -542,17 +578,21 @@ int tipc_nl_node_dump(struct sk_buff *skb, struct netlink_callback *cb)
msg.seq = cb->nlh->nlmsg_seq;
rcu_read_lock();
if (last_addr && !tipc_node_find(net, last_addr)) {
rcu_read_unlock();
/* We never set seq or call nl_dump_check_consistent() this
* means that setting prev_seq here will cause the consistence
* check to fail in the netlink callback handler. Resulting in
* the NLMSG_DONE message having the NLM_F_DUMP_INTR flag set if
* the node state changed while we released the lock.
*/
cb->prev_seq = 1;
return -EPIPE;
if (last_addr) {
node = tipc_node_find(net, last_addr);
if (!node) {
rcu_read_unlock();
/* We never set seq or call nl_dump_check_consistent()
* this means that setting prev_seq here will cause the
* consistence check to fail in the netlink callback
* handler. Resulting in the NLMSG_DONE message having
* the NLM_F_DUMP_INTR flag set if the node state
* changed while we released the lock.
*/
cb->prev_seq = 1;
return -EPIPE;
}
tipc_node_put(node);
}
list_for_each_entry_rcu(node, &tn->node_list, list) {

12
net/tipc/node.h
View File

@ -64,7 +64,8 @@ enum {
TIPC_NOTIFY_LINK_UP = (1 << 6),
TIPC_NOTIFY_LINK_DOWN = (1 << 7),
TIPC_NAMED_MSG_EVT = (1 << 8),
TIPC_BCAST_MSG_EVT = (1 << 9)
TIPC_BCAST_MSG_EVT = (1 << 9),
TIPC_BCAST_RESET = (1 << 10)
};
/**
@ -93,6 +94,7 @@ struct tipc_node_bclink {
/**
* struct tipc_node - TIPC node structure
* @addr: network address of node
* @ref: reference counter to node object
* @lock: spinlock governing access to structure
* @net: the applicable net namespace
* @hash: links to adjacent nodes in unsorted hash chain
@ -114,6 +116,7 @@ struct tipc_node_bclink {
*/
struct tipc_node {
u32 addr;
struct kref kref;
spinlock_t lock;
struct net *net;
struct hlist_node hash;
@ -136,6 +139,7 @@ struct tipc_node {
};
struct tipc_node *tipc_node_find(struct net *net, u32 addr);
void tipc_node_put(struct tipc_node *node);
struct tipc_node *tipc_node_create(struct net *net, u32 addr);
void tipc_node_stop(struct net *net);
void tipc_node_attach_link(struct tipc_node *n_ptr, struct tipc_link *l_ptr);
@ -170,10 +174,12 @@ static inline uint tipc_node_get_mtu(struct net *net, u32 addr, u32 selector)
node = tipc_node_find(net, addr);
if (likely(node))
if (likely(node)) {
mtu = node->act_mtus[selector & 1];
else
tipc_node_put(node);
} else {
mtu = MAX_MSG_SIZE;
}
return mtu;
}