bluetooth: rfcomm_init bug fix

rfcomm tty may be used before rfcomm_tty_driver initilized,
The problem is that now socket layer init before tty layer, if userspace
program do socket callback right here then oops will happen.

reporting in:
http://marc.info/?l=linux-bluetooth&m=124404919324542&w=2

make 3 changes:
1. remove #ifdef in rfcomm/core.c,
make it blank function when rfcomm tty not selected in rfcomm.h

2. tune the rfcomm_init error patch to ensure
tty driver initilized before rfcomm socket usage.

3. remove __exit for rfcomm_cleanup_sockets
because above change need call it in a __init function.

Reported-by: Oliver Hartkopp <oliver@hartkopp.net>
Tested-by: Oliver Hartkopp <oliver@hartkopp.net>
Signed-off-by: Dave Young <hidave.darkstar@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 20 insertions, 9 deletions

diff --git a/net/bluetooth/rfcomm/core.c b/net/bluetooth/rfcomm/core.c
index e50566ebf9f9..94b3388c188b 100644
--- a/net/bluetooth/rfcomm/core.c
+++ b/net/bluetooth/rfcomm/core.c
@@ -2080,28 +2080,41 @@ static CLASS_ATTR(rfcomm_dlc, S_IRUGO, rfcomm_dlc_sysfs_show, NULL);
 /* ---- Initialization ---- */
 static int __init rfcomm_init(void)
 {
+        int ret;
+
         l2cap_load();
 
         hci_register_cb(&rfcomm_cb);
 
         rfcomm_thread = kthread_run(rfcomm_run, NULL, "krfcommd");
         if (IS_ERR(rfcomm_thread)) {
-                hci_unregister_cb(&rfcomm_cb);
-                return PTR_ERR(rfcomm_thread);
+                ret = PTR_ERR(rfcomm_thread);
+                goto out_thread;
         }
 
         if (class_create_file(bt_class, &class_attr_rfcomm_dlc) < 0)
                 BT_ERR("Failed to create RFCOMM info file");
 
-        rfcomm_init_sockets();
+        ret = rfcomm_init_ttys();
+        if (ret)
+                goto out_tty;
 
-#ifdef CONFIG_BT_RFCOMM_TTY
-        rfcomm_init_ttys();
-#endif
+        ret = rfcomm_init_sockets();
+        if (ret)
+                goto out_sock;
 
         BT_INFO("RFCOMM ver %s", VERSION);
 
         return 0;
+
+out_sock:
+        rfcomm_cleanup_ttys();
+out_tty:
+        kthread_stop(rfcomm_thread);
+out_thread:
+        hci_unregister_cb(&rfcomm_cb);
+
+        return ret;
 }
 
 static void __exit rfcomm_exit(void)
@@ -2112,9 +2125,7 @@ static void __exit rfcomm_exit(void)
 
         kthread_stop(rfcomm_thread);
 
-#ifdef CONFIG_BT_RFCOMM_TTY
         rfcomm_cleanup_ttys();
-#endif
 
         rfcomm_cleanup_sockets();
 }
diff --git a/net/bluetooth/rfcomm/sock.c b/net/bluetooth/rfcomm/sock.c
index 7f482784e9f7..0b85e8116859 100644
--- a/net/bluetooth/rfcomm/sock.c
+++ b/net/bluetooth/rfcomm/sock.c
@@ -1132,7 +1132,7 @@ error:
         return err;
 }
 
-void __exit rfcomm_cleanup_sockets(void)
+void rfcomm_cleanup_sockets(void)
 {
         class_remove_file(bt_class, &class_attr_rfcomm);