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Diffstat (limited to 'net/core/net_namespace.c')
-rw-r--r--net/core/net_namespace.c35
1 files changed, 32 insertions, 3 deletions
diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c
index 197283072cc8..1c1af2756f38 100644
--- a/net/core/net_namespace.c
+++ b/net/core/net_namespace.c
@@ -6,6 +6,8 @@
#include <linux/delay.h>
#include <linux/sched.h>
#include <linux/idr.h>
+#include <linux/rculist.h>
+#include <linux/nsproxy.h>
#include <net/net_namespace.h>
#include <net/netns/generic.h>
@@ -127,7 +129,7 @@ static struct net *net_create(void)
rv = setup_net(net);
if (rv == 0) {
rtnl_lock();
- list_add_tail(&net->list, &net_namespace_list);
+ list_add_tail_rcu(&net->list, &net_namespace_list);
rtnl_unlock();
}
mutex_unlock(&net_mutex);
@@ -156,9 +158,16 @@ static void cleanup_net(struct work_struct *work)
/* Don't let anyone else find us. */
rtnl_lock();
- list_del(&net->list);
+ list_del_rcu(&net->list);
rtnl_unlock();
+ /*
+ * Another CPU might be rcu-iterating the list, wait for it.
+ * This needs to be before calling the exit() notifiers, so
+ * the rcu_barrier() below isn't sufficient alone.
+ */
+ synchronize_rcu();
+
/* Run all of the network namespace exit methods */
list_for_each_entry_reverse(ops, &pernet_list, list) {
if (ops->exit)
@@ -193,6 +202,26 @@ struct net *copy_net_ns(unsigned long flags, struct net *old_net)
}
#endif
+struct net *get_net_ns_by_pid(pid_t pid)
+{
+ struct task_struct *tsk;
+ struct net *net;
+
+ /* Lookup the network namespace */
+ net = ERR_PTR(-ESRCH);
+ rcu_read_lock();
+ tsk = find_task_by_vpid(pid);
+ if (tsk) {
+ struct nsproxy *nsproxy;
+ nsproxy = task_nsproxy(tsk);
+ if (nsproxy)
+ net = get_net(nsproxy->net_ns);
+ }
+ rcu_read_unlock();
+ return net;
+}
+EXPORT_SYMBOL_GPL(get_net_ns_by_pid);
+
static int __init net_ns_init(void)
{
struct net_generic *ng;
@@ -219,7 +248,7 @@ static int __init net_ns_init(void)
panic("Could not setup the initial network namespace");
rtnl_lock();
- list_add_tail(&init_net.list, &net_namespace_list);
+ list_add_tail_rcu(&init_net.list, &net_namespace_list);
rtnl_unlock();
mutex_unlock(&net_mutex);