[PATCH RFC 04/25] net: Move mutex_unlock() in cleanup_net() up

Kirill Tkhai
2017-11-17T18:27:58Z

net_sem protects from pernet_list changing, while
ops_free_list() makes simple kfree(), and it can't
race with other pernet_operations callbacks.

So we may release net_mutex earlier then it was.

Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
---
net/core/net_namespace.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c
index 2254b1639209..a8ea580885d9 100644
--- a/net/core/net_namespace.c
+++ b/net/core/net_namespace.c
@@ -489,11 +489,12 @@ static void cleanup_net(struct work_struct *work)
list_for_each_entry_reverse(ops, &pernet_list, list)
ops_exit_list(ops, &net_exit_list);

+ mutex_unlock(&net_mutex);
+
/* Free the net generic variables */
list_for_each_entry_reverse(ops, &pernet_list, list)
ops_free_list(ops, &net_exit_list);

- mutex_unlock(&net_mutex);
up_read(&net_sem);

/* Ensure there are no outstanding rcu callbacks using this