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42eff6a617
It is not allowed to free the memory of an object which is part of a list
which is protected by rcu-read-side-critical sections without making sure
that no other context is accessing the object anymore. This usually happens
by removing the references to this object and then waiting until the rcu
grace period is over and no one (allowedly) accesses it anymore.
But the _now functions ignore this completely. They free the object
directly even when a different context still tries to access it. This has
to be avoided and thus these functions must be removed and all functions
have to use batadv_orig_node_free_ref.
Fixes: 72822225bd ("batman-adv: Fix rcu_barrier() miss due to double call_rcu() in TT code")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Antonio Quartulli <a@unstable.cc>
130 lines
4.3 KiB
C
130 lines
4.3 KiB
C
/* Copyright (C) 2007-2015 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, see <http://www.gnu.org/licenses/>.
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*/
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#ifndef _NET_BATMAN_ADV_ORIGINATOR_H_
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#define _NET_BATMAN_ADV_ORIGINATOR_H_
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#include "main.h"
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#include <linux/atomic.h>
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#include <linux/compiler.h>
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#include <linux/if_ether.h>
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#include <linux/jhash.h>
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#include <linux/rculist.h>
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#include <linux/rcupdate.h>
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#include <linux/stddef.h>
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#include <linux/types.h>
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#include "hash.h"
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struct seq_file;
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int batadv_compare_orig(const struct hlist_node *node, const void *data2);
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int batadv_originator_init(struct batadv_priv *bat_priv);
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void batadv_originator_free(struct batadv_priv *bat_priv);
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void batadv_purge_orig_ref(struct batadv_priv *bat_priv);
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void batadv_orig_node_free_ref(struct batadv_orig_node *orig_node);
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struct batadv_orig_node *batadv_orig_node_new(struct batadv_priv *bat_priv,
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const u8 *addr);
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struct batadv_hardif_neigh_node *
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batadv_hardif_neigh_get(const struct batadv_hard_iface *hard_iface,
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const u8 *neigh_addr);
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void
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batadv_hardif_neigh_free_ref(struct batadv_hardif_neigh_node *hardif_neigh);
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struct batadv_neigh_node *
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batadv_neigh_node_new(struct batadv_orig_node *orig_node,
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struct batadv_hard_iface *hard_iface,
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const u8 *neigh_addr);
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void batadv_neigh_node_free_ref(struct batadv_neigh_node *neigh_node);
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struct batadv_neigh_node *
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batadv_orig_router_get(struct batadv_orig_node *orig_node,
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const struct batadv_hard_iface *if_outgoing);
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struct batadv_neigh_ifinfo *
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batadv_neigh_ifinfo_new(struct batadv_neigh_node *neigh,
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struct batadv_hard_iface *if_outgoing);
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struct batadv_neigh_ifinfo *
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batadv_neigh_ifinfo_get(struct batadv_neigh_node *neigh,
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struct batadv_hard_iface *if_outgoing);
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void batadv_neigh_ifinfo_free_ref(struct batadv_neigh_ifinfo *neigh_ifinfo);
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int batadv_hardif_neigh_seq_print_text(struct seq_file *seq, void *offset);
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struct batadv_orig_ifinfo *
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batadv_orig_ifinfo_get(struct batadv_orig_node *orig_node,
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struct batadv_hard_iface *if_outgoing);
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struct batadv_orig_ifinfo *
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batadv_orig_ifinfo_new(struct batadv_orig_node *orig_node,
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struct batadv_hard_iface *if_outgoing);
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void batadv_orig_ifinfo_free_ref(struct batadv_orig_ifinfo *orig_ifinfo);
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int batadv_orig_seq_print_text(struct seq_file *seq, void *offset);
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int batadv_orig_hardif_seq_print_text(struct seq_file *seq, void *offset);
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int batadv_orig_hash_add_if(struct batadv_hard_iface *hard_iface,
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int max_if_num);
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int batadv_orig_hash_del_if(struct batadv_hard_iface *hard_iface,
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int max_if_num);
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struct batadv_orig_node_vlan *
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batadv_orig_node_vlan_new(struct batadv_orig_node *orig_node,
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unsigned short vid);
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struct batadv_orig_node_vlan *
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batadv_orig_node_vlan_get(struct batadv_orig_node *orig_node,
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unsigned short vid);
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void batadv_orig_node_vlan_free_ref(struct batadv_orig_node_vlan *orig_vlan);
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/* hashfunction to choose an entry in a hash table of given size
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* hash algorithm from http://en.wikipedia.org/wiki/Hash_table
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*/
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static inline u32 batadv_choose_orig(const void *data, u32 size)
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{
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u32 hash = 0;
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hash = jhash(data, ETH_ALEN, hash);
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return hash % size;
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}
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static inline struct batadv_orig_node *
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batadv_orig_hash_find(struct batadv_priv *bat_priv, const void *data)
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{
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struct batadv_hashtable *hash = bat_priv->orig_hash;
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struct hlist_head *head;
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struct batadv_orig_node *orig_node, *orig_node_tmp = NULL;
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int index;
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if (!hash)
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return NULL;
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index = batadv_choose_orig(data, hash->size);
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head = &hash->table[index];
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rcu_read_lock();
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hlist_for_each_entry_rcu(orig_node, head, hash_entry) {
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if (!batadv_compare_eth(orig_node, data))
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continue;
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if (!atomic_inc_not_zero(&orig_node->refcount))
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continue;
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orig_node_tmp = orig_node;
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break;
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}
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rcu_read_unlock();
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return orig_node_tmp;
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}
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#endif /* _NET_BATMAN_ADV_ORIGINATOR_H_ */
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