rtnetlink.c (9cbbd694a58bdf24def2462276514c90cab7cf80) rtnetlink.c (0b5c21bbc01e92745ca1ca4f6fd87d878fa3ea5e)
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * INET An implementation of the TCP/IP protocol suite for the LINUX
4 * operating system. INET is implemented using the BSD Socket
5 * interface as the means of communication with the user level.
6 *
7 * Routing netlink socket interface: protocol independent part.
8 *

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90EXPORT_SYMBOL(rtnl_kfree_skbs);
91
92void __rtnl_unlock(void)
93{
94 struct sk_buff *head = defer_kfree_skb_list;
95
96 defer_kfree_skb_list = NULL;
97
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * INET An implementation of the TCP/IP protocol suite for the LINUX
4 * operating system. INET is implemented using the BSD Socket
5 * interface as the means of communication with the user level.
6 *
7 * Routing netlink socket interface: protocol independent part.
8 *

--- 81 unchanged lines hidden (view full) ---

90EXPORT_SYMBOL(rtnl_kfree_skbs);
91
92void __rtnl_unlock(void)
93{
94 struct sk_buff *head = defer_kfree_skb_list;
95
96 defer_kfree_skb_list = NULL;
97
98 /* Ensure that we didn't actually add any TODO item when __rtnl_unlock()
99 * is used. In some places, e.g. in cfg80211, we have code that will do
100 * something like
101 * rtnl_lock()
102 * wiphy_lock()
103 * ...
104 * rtnl_unlock()
105 *
106 * and because netdev_run_todo() acquires the RTNL for items on the list
107 * we could cause a situation such as this:
108 * Thread 1 Thread 2
109 * rtnl_lock()
110 * unregister_netdevice()
111 * __rtnl_unlock()
112 * rtnl_lock()
113 * wiphy_lock()
114 * rtnl_unlock()
115 * netdev_run_todo()
116 * __rtnl_unlock()
117 *
118 * // list not empty now
119 * // because of thread 2
120 * rtnl_lock()
121 * while (!list_empty(...))
122 * rtnl_lock()
123 * wiphy_lock()
124 * **** DEADLOCK ****
125 *
126 * However, usage of __rtnl_unlock() is rare, and so we can ensure that
127 * it's not used in cases where something is added to do the list.
128 */
129 WARN_ON(!list_empty(&net_todo_list));
130
98 mutex_unlock(&rtnl_mutex);
99
100 while (head) {
101 struct sk_buff *next = head->next;
102
103 kfree_skb(head);
104 cond_resched();
105 head = next;

--- 6010 unchanged lines hidden --- 		131 mutex_unlock(&rtnl_mutex);
132
133 while (head) {
134 struct sk_buff *next = head->next;
135
136 kfree_skb(head);
137 cond_resched();
138 head = next;

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