diff --git a/kernel/fork.c b/kernel/fork.c
index 4014be1..0b9688d 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -58,6 +58,7 @@
 #include <linux/tsacct_kern.h>
 #include <linux/cn_proc.h>
 #include <linux/freezer.h>
+#include <linux/kaiser.h>
 #include <linux/delayacct.h>
 #include <linux/taskstats_kern.h>
 #include <linux/random.h>
@@ -472,7 +473,6 @@
 	*stackend = STACK_END_MAGIC;	/* for overflow detection */
 }
 
-extern void kaiser_add_mapping(unsigned long addr, unsigned long size, unsigned long flags);
 static struct task_struct *dup_task_struct(struct task_struct *orig, int node)
 {
 	struct task_struct *tsk;
@@ -500,9 +500,10 @@
 	 * functions again.
 	 */
 	tsk->stack = stack;
-#ifdef CONFIG_KAISER
-	kaiser_add_mapping((unsigned long)tsk->stack, THREAD_SIZE, __PAGE_KERNEL);
-#endif
+
+	err= kaiser_add_mapping((unsigned long)tsk->stack, THREAD_SIZE, __PAGE_KERNEL);
+	if (err)
+		goto free_stack;
 #ifdef CONFIG_VMAP_STACK
 	tsk->stack_vm_area = stack_vm_area;
 #endif