diff options
Diffstat (limited to 'net/qrtr/ns.c')
| -rw-r--r-- | net/qrtr/ns.c | 27 |
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); |