From 65afa5e603d507014580ead016ec887b49e1afa6 Mon Sep 17 00:00:00 2001
From: Frederic Weisbecker <fweisbec@gmail.com>
Date: Sun, 23 Nov 2008 18:43:39 +0100
Subject: [PATCH] tracing/function-return-tracer: free the return stack on
 free_task()

Impact: avoid losing some traces when a task is freed

do_exit() is not the last function called when a task finishes.
There are still some functions which are to be called such as
ree_task().  So we delay the freeing of the return stack to the
last moment.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
 kernel/exit.c | 2 --
 kernel/fork.c | 1 +
 2 files changed, 1 insertion(+), 2 deletions(-)

diff --git a/kernel/exit.c b/kernel/exit.c
index ef04d03b3286..e5ae36ebe8af 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -47,7 +47,6 @@
 #include <linux/task_io_accounting_ops.h>
 #include <linux/tracehook.h>
 #include <trace/sched.h>
-#include <linux/ftrace.h>
 
 #include <asm/uaccess.h>
 #include <asm/unistd.h>
@@ -1128,7 +1127,6 @@ NORET_TYPE void do_exit(long code)
 	preempt_disable();
 	/* causes final put_task_struct in finish_task_switch(). */
 	tsk->state = TASK_DEAD;
-	ftrace_retfunc_exit_task(tsk);
 	schedule();
 	BUG();
 	/* Avoid "noreturn function does return".  */
diff --git a/kernel/fork.c b/kernel/fork.c
index fbf4a4c0a628..d6e1a3205f62 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -140,6 +140,7 @@ void free_task(struct task_struct *tsk)
 	prop_local_destroy_single(&tsk->dirties);
 	free_thread_info(tsk->stack);
 	rt_mutex_debug_task_free(tsk);
+	ftrace_retfunc_exit_task(tsk);
 	free_task_struct(tsk);
 }
 EXPORT_SYMBOL(free_task);