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-rw-r--r--net/qrtr/ns.c27
1 files changed, 27 insertions, 0 deletions
diff --git a/net/qrtr/ns.c b/net/qrtr/ns.c
index abb0c70ffc..654a3cc0d3 100644
--- a/net/qrtr/ns.c
+++ b/net/qrtr/ns.c
@@ -725,6 +725,24 @@ int qrtr_ns_init(void)
if (ret < 0)
goto err_wq;
+ /* As the qrtr ns socket owner and creator is the same module, we have
+ * to decrease the qrtr module reference count to guarantee that it
+ * remains zero after the ns socket is created, otherwise, executing
+ * "rmmod" command is unable to make the qrtr module deleted after the
+ * qrtr module is inserted successfully.
+ *
+ * However, the reference count is increased twice in
+ * sock_create_kern(): one is to increase the reference count of owner
+ * of qrtr socket's proto_ops struct; another is to increment the
+ * reference count of owner of qrtr proto struct. Therefore, we must
+ * decrement the module reference count twice to ensure that it keeps
+ * zero after server's listening socket is created. Of course, we
+ * must bump the module reference count twice as well before the socket
+ * is closed.
+ */
+ module_put(qrtr_ns.sock->ops->owner);
+ module_put(qrtr_ns.sock->sk->sk_prot_creator->owner);
+
return 0;
err_wq:
@@ -739,6 +757,15 @@ void qrtr_ns_remove(void)
{
cancel_work_sync(&qrtr_ns.work);
destroy_workqueue(qrtr_ns.workqueue);
+
+ /* sock_release() expects the two references that were put during
+ * qrtr_ns_init(). This function is only called during module remove,
+ * so try_stop_module() has already set the refcnt to 0. Use
+ * __module_get() instead of try_module_get() to successfully take two
+ * references.
+ */
+ __module_get(qrtr_ns.sock->ops->owner);
+ __module_get(qrtr_ns.sock->sk->sk_prot_creator->owner);
sock_release(qrtr_ns.sock);
}
EXPORT_SYMBOL_GPL(qrtr_ns_remove);