diff --git a/include/linux/pid_namespace.h b/include/linux/pid_namespace.h
index d82fe82..38d1032 100644
--- a/include/linux/pid_namespace.h
+++ b/include/linux/pid_namespace.h
@@ -79,11 +79,7 @@
 }
 #endif /* CONFIG_PID_NS */
 
-static inline struct pid_namespace *task_active_pid_ns(struct task_struct *tsk)
-{
-	return tsk->nsproxy->pid_ns;
-}
-
+extern struct pid_namespace *task_active_pid_ns(struct task_struct *tsk);
 void pidhash_init(void);
 void pidmap_init(void);
 
diff --git a/kernel/fork.c b/kernel/fork.c
index 7b8f2a7..4018308 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1126,12 +1126,12 @@
 
 	if (pid != &init_struct_pid) {
 		retval = -ENOMEM;
-		pid = alloc_pid(task_active_pid_ns(p));
+		pid = alloc_pid(p->nsproxy->pid_ns);
 		if (!pid)
 			goto bad_fork_cleanup_io;
 
 		if (clone_flags & CLONE_NEWPID) {
-			retval = pid_ns_prepare_proc(task_active_pid_ns(p));
+			retval = pid_ns_prepare_proc(p->nsproxy->pid_ns);
 			if (retval < 0)
 				goto bad_fork_free_pid;
 		}
diff --git a/kernel/pid.c b/kernel/pid.c
index af9224c..1b3586f 100644
--- a/kernel/pid.c
+++ b/kernel/pid.c
@@ -474,6 +474,12 @@
 }
 EXPORT_SYMBOL(task_session_nr_ns);
 
+struct pid_namespace *task_active_pid_ns(struct task_struct *tsk)
+{
+	return ns_of_pid(task_pid(tsk));
+}
+EXPORT_SYMBOL_GPL(task_active_pid_ns);
+
 /*
  * Used by proc to find the first pid that is greater than or equal to nr.
  *