diff --git a/kernel/ksu.c b/kernel/ksu.c
index 7424e1e7..56ea85f8 100644
--- a/kernel/ksu.c
+++ b/kernel/ksu.c
@@ -115,11 +115,6 @@ static bool become_manager(char *pkg)
 		return false;
 	}
 
-	if (ksu_is_manager_uid_valid()) {
-		pr_info("manager already exist: %d\n", ksu_manager_uid);
-		return is_manager();
-	}
-
 	buf = (char *)kmalloc(PATH_MAX, GFP_ATOMIC);
 	if (!buf) {
 		pr_err("kalloc path failed.\n");
@@ -195,6 +190,18 @@ int ksu_handle_prctl(int option, unsigned long arg2, unsigned long arg3,
 	pr_info("option: 0x%x, cmd: %ld\n", option, arg2);
 
 	if (arg2 == CMD_BECOME_MANAGER) {
+		// quick check
+		if (is_manager()) {
+			if (copy_to_user(result, &reply_ok, sizeof(reply_ok))) {
+				pr_err("become_manager: prctl reply error\n");
+			}
+			return 0;
+		}
+		if (ksu_is_manager_uid_valid()) {
+			pr_info("manager already exist: %d\n", ksu_manager_uid);
+			return 0;
+		}
+
 		// someone wants to be root manager, just check it!
 		// arg3 should be `/data/data/<manager_package_name>`
 		char param[128];
diff --git a/kernel/ksu.h b/kernel/ksu.h
index b472a110..269c5533 100644
--- a/kernel/ksu.h
+++ b/kernel/ksu.h
@@ -24,7 +24,11 @@ extern uid_t ksu_manager_uid;
 
 static inline bool ksu_is_manager_uid_valid()
 {
+#ifndef CONFIG_KSU_DEBUG
 	return ksu_manager_uid != INVALID_UID;
+#else
+	return false; // always allow in debug mode
+#endif
 }
 
 static inline uid_t ksu_get_manager_uid()