diff --git a/include/linux/sched.h b/include/linux/sched.h
index 722dd31..49df878 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1519,17 +1519,23 @@
  *
  * see also pid_nr() etc in include/linux/pid.h
  */
+pid_t __task_pid_nr_ns(struct task_struct *task, enum pid_type type,
+			struct pid_namespace *ns);
 
 static inline pid_t task_pid_nr(struct task_struct *tsk)
 {
 	return tsk->pid;
 }
 
-pid_t task_pid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns);
+static inline pid_t task_pid_nr_ns(struct task_struct *tsk,
+					struct pid_namespace *ns)
+{
+	return __task_pid_nr_ns(tsk, PIDTYPE_PID, ns);
+}
 
 static inline pid_t task_pid_vnr(struct task_struct *tsk)
 {
-	return pid_vnr(task_pid(tsk));
+	return __task_pid_nr_ns(tsk, PIDTYPE_PID, NULL);
 }
 
 
@@ -1551,11 +1557,15 @@
 	return tsk->signal->__pgrp;
 }
 
-pid_t task_pgrp_nr_ns(struct task_struct *tsk, struct pid_namespace *ns);
+static inline pid_t task_pgrp_nr_ns(struct task_struct *tsk,
+					struct pid_namespace *ns)
+{
+	return __task_pid_nr_ns(tsk, PIDTYPE_PGID, ns);
+}
 
 static inline pid_t task_pgrp_vnr(struct task_struct *tsk)
 {
-	return pid_vnr(task_pgrp(tsk));
+	return __task_pid_nr_ns(tsk, PIDTYPE_PGID, NULL);
 }
 
 
@@ -1564,14 +1574,17 @@
 	return tsk->signal->__session;
 }
 
-pid_t task_session_nr_ns(struct task_struct *tsk, struct pid_namespace *ns);
+static inline pid_t task_session_nr_ns(struct task_struct *tsk,
+					struct pid_namespace *ns)
+{
+	return __task_pid_nr_ns(tsk, PIDTYPE_SID, ns);
+}
 
 static inline pid_t task_session_vnr(struct task_struct *tsk)
 {
-	return pid_vnr(task_session(tsk));
+	return __task_pid_nr_ns(tsk, PIDTYPE_SID, NULL);
 }
 
-
 /**
  * pid_alive - check that a task structure is not stale
  * @p: Task structure to be checked.
diff --git a/kernel/pid.c b/kernel/pid.c
index 6628abc..b2e5f78 100644
--- a/kernel/pid.c
+++ b/kernel/pid.c
@@ -452,11 +452,24 @@
 }
 EXPORT_SYMBOL_GPL(pid_vnr);
 
-pid_t task_pid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
+pid_t __task_pid_nr_ns(struct task_struct *task, enum pid_type type,
+			struct pid_namespace *ns)
 {
-	return pid_nr_ns(task_pid(tsk), ns);
+	pid_t nr = 0;
+
+	rcu_read_lock();
+	if (!ns)
+		ns = current->nsproxy->pid_ns;
+	if (likely(pid_alive(task))) {
+		if (type != PIDTYPE_PID)
+			task = task->group_leader;
+		nr = pid_nr_ns(task->pids[type].pid, ns);
+	}
+	rcu_read_unlock();
+
+	return nr;
 }
-EXPORT_SYMBOL(task_pid_nr_ns);
+EXPORT_SYMBOL(__task_pid_nr_ns);
 
 pid_t task_tgid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
 {
@@ -464,18 +477,6 @@
 }
 EXPORT_SYMBOL(task_tgid_nr_ns);
 
-pid_t task_pgrp_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
-{
-	return pid_nr_ns(task_pgrp(tsk), ns);
-}
-EXPORT_SYMBOL(task_pgrp_nr_ns);
-
-pid_t task_session_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
-{
-	return pid_nr_ns(task_session(tsk), ns);
-}
-EXPORT_SYMBOL(task_session_nr_ns);
-
 struct pid_namespace *task_active_pid_ns(struct task_struct *tsk)
 {
 	return ns_of_pid(task_pid(tsk));