HID: fix tty<->hid deadlock
hid_compat_load() runs on the default workqueue, it request_module(), it
execs modprobe, it exits, tty flushes default workqueue, it hangs, because
we are still in it.
Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Tested-by: <Valdis.Kletnieks@vt.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
index 18b277a..63c8ce5 100644
--- a/drivers/hid/hid-core.c
+++ b/drivers/hid/hid-core.c
@@ -1657,6 +1657,7 @@
request_module("hid-dummy");
}
static DECLARE_WORK(hid_compat_work, hid_compat_load);
+static struct workqueue_struct *hid_compat_wq;
#endif
static int __init hid_init(void)
@@ -1674,7 +1675,12 @@
goto err_bus;
#ifdef CONFIG_HID_COMPAT
- schedule_work(&hid_compat_work);
+ hid_compat_wq = create_workqueue("hid_compat");
+ if (!hid_compat_wq) {
+ hidraw_exit();
+ goto err;
+ }
+ queue_work(hid_compat_wq, &hid_compat_work);
#endif
return 0;
@@ -1686,6 +1692,9 @@
static void __exit hid_exit(void)
{
+#ifdef CONFIG_HID_COMPAT
+ destroy_workqueue(hid_compat_wq);
+#endif
hidraw_exit();
bus_unregister(&hid_bus_type);
}