kernel-fxtec-pro1x/net/tipc/port.h
Ying Xue 84602761ca 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A deadlock might occur if name table is withdrawn in socket release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>
2013-12-29 22:24:07 -05:00

201 lines
7 KiB
C

/*
* net/tipc/port.h: Include file for TIPC port code
*
* Copyright (c) 1994-2007, Ericsson AB
* Copyright (c) 2004-2007, 2010-2013, Wind River Systems
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the names of the copyright holders nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* Alternatively, this software may be distributed under the terms of the
* GNU General Public License ("GPL") version 2 as published by the Free
* Software Foundation.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef _TIPC_PORT_H
#define _TIPC_PORT_H
#include "ref.h"
#include "net.h"
#include "msg.h"
#include "node_subscr.h"
#define TIPC_FLOW_CONTROL_WIN 512
#define CONN_OVERLOAD_LIMIT ((TIPC_FLOW_CONTROL_WIN * 2 + 1) * \
SKB_TRUESIZE(TIPC_MAX_USER_MSG_SIZE))
/**
* struct tipc_port - TIPC port structure
* @sk: pointer to socket handle
* @lock: pointer to spinlock for controlling access to port
* @connected: non-zero if port is currently connected to a peer port
* @conn_type: TIPC type used when connection was established
* @conn_instance: TIPC instance used when connection was established
* @conn_unacked: number of unacknowledged messages received from peer port
* @published: non-zero if port has one or more associated names
* @congested: non-zero if cannot send because of link or port congestion
* @max_pkt: maximum packet size "hint" used when building messages sent by port
* @ref: unique reference to port in TIPC object registry
* @phdr: preformatted message header used when sending messages
* @port_list: adjacent ports in TIPC's global list of ports
* @dispatcher: ptr to routine which handles received messages
* @wakeup: ptr to routine to call when port is no longer congested
* @wait_list: adjacent ports in list of ports waiting on link congestion
* @waiting_pkts:
* @sent: # of non-empty messages sent by port
* @acked: # of non-empty message acknowledgements from connected port's peer
* @publications: list of publications for port
* @pub_count: total # of publications port has made during its lifetime
* @probing_state:
* @probing_interval:
* @timer_ref:
* @subscription: "node down" subscription used to terminate failed connections
*/
struct tipc_port {
struct sock *sk;
spinlock_t *lock;
int connected;
u32 conn_type;
u32 conn_instance;
u32 conn_unacked;
int published;
u32 congested;
u32 max_pkt;
u32 ref;
struct tipc_msg phdr;
struct list_head port_list;
u32 (*dispatcher)(struct tipc_port *, struct sk_buff *);
void (*wakeup)(struct tipc_port *);
struct list_head wait_list;
u32 waiting_pkts;
u32 sent;
u32 acked;
struct list_head publications;
u32 pub_count;
u32 probing_state;
u32 probing_interval;
struct timer_list timer;
struct tipc_node_subscr subscription;
};
extern spinlock_t tipc_port_list_lock;
struct tipc_port_list;
/*
* TIPC port manipulation routines
*/
struct tipc_port *tipc_createport(struct sock *sk,
u32 (*dispatcher)(struct tipc_port *,
struct sk_buff *),
void (*wakeup)(struct tipc_port *),
const u32 importance);
int tipc_reject_msg(struct sk_buff *buf, u32 err);
void tipc_acknowledge(u32 port_ref, u32 ack);
int tipc_deleteport(struct tipc_port *p_ptr);
int tipc_portimportance(u32 portref, unsigned int *importance);
int tipc_set_portimportance(u32 portref, unsigned int importance);
int tipc_portunreliable(u32 portref, unsigned int *isunreliable);
int tipc_set_portunreliable(u32 portref, unsigned int isunreliable);
int tipc_portunreturnable(u32 portref, unsigned int *isunreturnable);
int tipc_set_portunreturnable(u32 portref, unsigned int isunreturnable);
int tipc_publish(struct tipc_port *p_ptr, unsigned int scope,
struct tipc_name_seq const *name_seq);
int tipc_withdraw(struct tipc_port *p_ptr, unsigned int scope,
struct tipc_name_seq const *name_seq);
int tipc_connect(u32 portref, struct tipc_portid const *port);
int tipc_disconnect(u32 portref);
int tipc_shutdown(u32 ref);
/*
* The following routines require that the port be locked on entry
*/
int __tipc_disconnect(struct tipc_port *tp_ptr);
int __tipc_connect(u32 ref, struct tipc_port *p_ptr,
struct tipc_portid const *peer);
int tipc_port_peer_msg(struct tipc_port *p_ptr, struct tipc_msg *msg);
/*
* TIPC messaging routines
*/
int tipc_port_recv_msg(struct sk_buff *buf);
int tipc_send(u32 portref, struct iovec const *msg_sect, unsigned int len);
int tipc_send2name(u32 portref, struct tipc_name const *name, u32 domain,
struct iovec const *msg_sect, unsigned int len);
int tipc_send2port(u32 portref, struct tipc_portid const *dest,
struct iovec const *msg_sect, unsigned int len);
int tipc_multicast(u32 portref, struct tipc_name_seq const *seq,
struct iovec const *msg, unsigned int len);
int tipc_port_reject_sections(struct tipc_port *p_ptr, struct tipc_msg *hdr,
struct iovec const *msg_sect, unsigned int len,
int err);
struct sk_buff *tipc_port_get_ports(void);
void tipc_port_recv_proto_msg(struct sk_buff *buf);
void tipc_port_recv_mcast(struct sk_buff *buf, struct tipc_port_list *dp);
void tipc_port_reinit(void);
/**
* tipc_port_lock - lock port instance referred to and return its pointer
*/
static inline struct tipc_port *tipc_port_lock(u32 ref)
{
return (struct tipc_port *)tipc_ref_lock(ref);
}
/**
* tipc_port_unlock - unlock a port instance
*
* Can use pointer instead of tipc_ref_unlock() since port is already locked.
*/
static inline void tipc_port_unlock(struct tipc_port *p_ptr)
{
spin_unlock_bh(p_ptr->lock);
}
static inline struct tipc_port *tipc_port_deref(u32 ref)
{
return (struct tipc_port *)tipc_ref_deref(ref);
}
static inline int tipc_port_congested(struct tipc_port *p_ptr)
{
return (p_ptr->sent - p_ptr->acked) >= (TIPC_FLOW_CONTROL_WIN * 2);
}
#endif