kernel: init/exit umount feature

kernel/core_hook.c

@@ -1627,6 +1627,9 @@ void __init ksu_core_init(void)
         pr_err("ksu_kprobe_init failed: %d\n", rc);
     }
 #endif
+    if (ksu_register_feature_handler(&kernel_umount_handler)) {
+        pr_err("Failed to register umount feature handler\n");
+    }
 }
 
 void ksu_core_exit(void)
@@ -1641,4 +1644,5 @@ void ksu_core_exit(void)
     pr_info("ksu_core_kprobe_exit\n");
     ksu_kprobe_exit();
 #endif
+    ksu_unregister_feature_handler(KSU_FEATURE_KERNEL_UMOUNT);
 }