/*
* net/tipc/monitor.h
*
* Copyright (c) 2015, Ericsson AB
* 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_MONITOR_H
#define _TIPC_MONITOR_H
#include "netlink.h"
/* struct tipc_mon_state: link instance's cache of monitor list and domain state
* @list_gen: current generation of this node's monitor list
* @gen: current generation of this node's local domain
* @peer_gen: most recent domain generation received from peer
* @acked_gen: most recent generation of self's domain acked by peer
* @monitoring: this peer endpoint should continuously monitored
* @probing: peer endpoint should be temporarily probed for potential loss
* @synched: domain record's generation has been synched with peer after reset
*/
struct tipc_mon_state {
u16 list_gen;
u16 peer_gen;
u16 acked_gen;
bool monitoring :1;
bool probing :1;
bool reset :1;
bool synched :1;
};
int tipc_mon_create(struct net *net, int bearer_id);
void tipc_mon_delete(struct net *net, int bearer_id);
void tipc_mon_peer_up(struct net *net, u32 addr, int bearer_id);
void tipc_mon_peer_down(struct net *net, u32 addr, int bearer_id);
void tipc_mon_prep(struct net *net, void *data, int *dlen,
struct tipc_mon_state *state, int bearer_id);
void tipc_mon_rcv(struct net *net, void *data, u16 dlen, u32 addr,
struct tipc_mon_state *state, int bearer_id);
void tipc_mon_get_state(struct net *net, u32 addr,
struct tipc_mon_state *state,
int bearer_id);
void tipc_mon_remove_peer(struct net *net, u32 addr, int bearer_id);
int tipc_nl_monitor_set_threshold(struct net *net, u32 cluster_size);
int tipc_nl_monitor_get_threshold(struct net *net);
int __tipc_nl_add_monitor(struct net *net, struct tipc_nl_msg *msg,
u32 bearer_id);
int tipc_nl_add_monitor_peer(struct net *net, struct tipc_nl_msg *msg,
u32 bearer_id, u32 *prev_node);
extern const int tipc_max_domain_size;
#endif
5d6'>psc.h
pid: fix lockdep deadlock warning due to ucount_lock
=========================================================
[ INFO: possible irq lock inversion dependency detected ]
4.10.0-rc2-00024-g4aecec9-dirty #118 Tainted: G W
---------------------------------------------------------
swapper/1/0 just changed the state of lock:
(&(&sighand->siglock)->rlock){-.....}, at: [<ffffffffbd0a1bc6>] __lock_task_sighand+0xb6/0x2c0
but this lock took another, HARDIRQ-unsafe lock in the past:
(ucounts_lock){+.+...}
and interrupts could create inverse lock ordering between them.
other info that might help us debug this:
Chain exists of: &(&sighand->siglock)->rlock --> &(&tty->ctrl_lock)->rlock --> ucounts_lock
Possible interrupt unsafe locking scenario:
CPU0 CPU1
---- ----
lock(ucounts_lock);
local_irq_disable();
lock(&(&sighand->siglock)->rlock);
lock(&(&tty->ctrl_lock)->rlock);
<Interrupt>
lock(&(&sighand->siglock)->rlock);
*** DEADLOCK ***
This patch removes a dependency between rlock and ucount_lock.
Fixes: f333c700c610 ("pidns: Add a limit on the number of pid namespaces")
Cc: stable@vger.kernel.org
Signed-off-by: Andrei Vagin <avagin@openvz.org>
Acked-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>