ed75ccbe26
It might be possible that 2 threads access the same data in the same rcu grace period. The first thread calls call_rcu() to decrement the refcount and free the data while the second thread increases the refcount to use the data. To avoid this race condition all refcount operations have to be atomic. Reported-by: Sven Eckelmann <sven@narfation.org> Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
48 lines
1.6 KiB
C
48 lines
1.6 KiB
C
/*
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* Copyright (C) 2007-2011 B.A.T.M.A.N. contributors:
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*
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* Marek Lindner, Simon Wunderlich
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of version 2 of the GNU General Public
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* License as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
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* 02110-1301, USA
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*
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*/
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#ifndef _NET_BATMAN_ADV_HARD_INTERFACE_H_
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#define _NET_BATMAN_ADV_HARD_INTERFACE_H_
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#define IF_NOT_IN_USE 0
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#define IF_TO_BE_REMOVED 1
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#define IF_INACTIVE 2
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#define IF_ACTIVE 3
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#define IF_TO_BE_ACTIVATED 4
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#define IF_I_WANT_YOU 5
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extern struct notifier_block hard_if_notifier;
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struct batman_if *get_batman_if_by_netdev(struct net_device *net_dev);
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int hardif_enable_interface(struct batman_if *batman_if, char *iface_name);
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void hardif_disable_interface(struct batman_if *batman_if);
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void hardif_remove_interfaces(void);
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int hardif_min_mtu(struct net_device *soft_iface);
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void update_min_mtu(struct net_device *soft_iface);
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void hardif_free_rcu(struct rcu_head *rcu);
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static inline void hardif_free_ref(struct batman_if *batman_if)
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{
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if (atomic_dec_and_test(&batman_if->refcount))
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call_rcu(&batman_if->rcu, hardif_free_rcu);
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}
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#endif /* _NET_BATMAN_ADV_HARD_INTERFACE_H_ */
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