/*
* net/tipc/bcast.h: Include file for TIPC broadcast code
*
* Copyright (c) 2003-2006, 2014-2015, Ericsson AB
* Copyright (c) 2005, 2010-2011, 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_BCAST_H
#define _TIPC_BCAST_H
#include "core.h"
struct tipc_node;
struct tipc_msg;
struct tipc_nl_msg;
struct tipc_nlist;
struct tipc_nitem;
extern const char tipc_bclink_name[];
#define TIPC_METHOD_EXPIRE msecs_to_jiffies(5000)
struct tipc_nlist {
struct list_head list;
u32 self;
u16 remote;
bool local;
};
void tipc_nlist_init(struct tipc_nlist *nl, u32 self);
void tipc_nlist_purge(struct tipc_nlist *nl);
void tipc_nlist_add(struct tipc_nlist *nl, u32 node);
void tipc_nlist_del(struct tipc_nlist *nl, u32 node);
/* Cookie to be used between socket and broadcast layer
* @rcast: replicast (instead of broadcast) was used at previous xmit
* @mandatory: broadcast/replicast indication was set by user
* @expires: re-evaluate non-mandatory transmit method if we are past this
*/
struct tipc_mc_method {
bool rcast;
bool mandatory;
unsigned long expires;
};
int tipc_bcast_init(struct net *net);
void tipc_bcast_stop(struct net *net);
void tipc_bcast_add_peer(struct net *net, struct tipc_link *l,
struct sk_buff_head *xmitq);
void tipc_bcast_remove_peer(struct net *net, struct tipc_link *rcv_bcl);
void tipc_bcast_inc_bearer_dst_cnt(struct net *net, int bearer_id);
void tipc_bcast_dec_bearer_dst_cnt(struct net *net, int bearer_id);
int tipc_bcast_get_mtu(struct net *net);
void tipc_bcast_disable_rcast(struct net *net);
int tipc_mcast_xmit(struct net *net, struct sk_buff_head *pkts,
struct tipc_mc_method *method, struct tipc_nlist *dests,
u16 *cong_link_cnt);
int tipc_bcast_rcv(struct net *net, struct tipc_link *l, struct sk_buff *skb);
void tipc_bcast_ack_rcv(struct net *net, struct tipc_link *l,
struct tipc_msg *hdr);
int tipc_bcast_sync_rcv(struct net *net, struct tipc_link *l,
struct tipc_msg *hdr);
int tipc_nl_add_bc_link(struct net *net, struct tipc_nl_msg *msg);
int tipc_nl_bc_link_set(struct net *net, struct nlattr *attrs[]);
int tipc_bclink_reset_stats(struct net *net);
static inline void tipc_bcast_lock(struct net *net)
{
spin_lock_bh(&tipc_net(net)->bclock);
}
static inline void tipc_bcast_unlock(struct net *net)
{
spin_unlock_bh(&tipc_net(net)->bclock);
}
static inline struct tipc_link *tipc_bc_sndlink(struct net *net)
{
return tipc_net(net)->bcl;
}
#endif
tion value='30'>30
The static bug finder EBA (http://www.iagoabal.eu/eba/) reported the
following double-lock bug:
Double lock:
1. spin_lock_irqsave(pch->lock, flags) at pl330_free_chan_resources:2236;
2. call to function `pl330_release_channel' immediately after;
3. call to function `dma_pl330_rqcb' in line 1753;
4. spin_lock_irqsave(pch->lock, flags) at dma_pl330_rqcb:1505.
I have fixed it as suggested by Marek Szyprowski.
First, I have replaced `pch->lock' with `pl330->lock' in functions
`pl330_alloc_chan_resources' and `pl330_free_chan_resources'. This avoids
the double-lock by acquiring a different lock than `dma_pl330_rqcb'.
NOTE that, as a result, `pl330_free_chan_resources' executes
`list_splice_tail_init' on `pch->work_list' under lock `pl330->lock',
whereas in the rest of the code `pch->work_list' is protected by
`pch->lock'. I don't know if this may cause race conditions. Similarly
`pch->cyclic' is written by `pl330_alloc_chan_resources' under
`pl330->lock' but read by `pl330_tx_submit' under `pch->lock'.
Second, I have removed locking from `pl330_request_channel' and
`pl330_release_channel' functions. Function `pl330_request_channel' is
only called from `pl330_alloc_chan_resources', so the lock is already
held. Function `pl330_release_channel' is called from
`pl330_free_chan_resources', which already holds the lock, and from
`pl330_del'. Function `pl330_del' is called in an error path of
`pl330_probe' and at the end of `pl330_remove', but I assume that there
cannot be concurrent accesses to the protected data at those points.
Signed-off-by: Iago Abal <mail@iagoabal.eu>
Reviewed-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>