diff --git a/ap/os/linux/linux-3.4.x/kernel/stacktrace.c b/ap/os/linux/linux-3.4.x/kernel/stacktrace.c
new file mode 100644
index 0000000..00fe55c
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/kernel/stacktrace.c
@@ -0,0 +1,43 @@
+/*
+ * kernel/stacktrace.c
+ *
+ * Stack trace management functions
+ *
+ *  Copyright (C) 2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
+ */
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/export.h>
+#include <linux/kallsyms.h>
+#include <linux/stacktrace.h>
+
+void print_stack_trace(struct stack_trace *trace, int spaces)
+{
+	int i;
+
+	if (WARN_ON(!trace->entries))
+		return;
+
+	for (i = 0; i < trace->nr_entries; i++) {
+		printk("%*c", 1 + spaces, ' ');
+		print_ip_sym(trace->entries[i]);
+	}
+}
+EXPORT_SYMBOL_GPL(print_stack_trace);
+
+/*
+ * Architectures that do not implement save_stack_trace_tsk or
+ * save_stack_trace_regs get this weak alias and a once-per-bootup warning
+ * (whenever this facility is utilized - for example by procfs):
+ */
+__weak void
+save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
+{
+	WARN_ONCE(1, KERN_INFO "save_stack_trace_tsk() not implemented yet.\n");
+}
+
+__weak void
+save_stack_trace_regs(struct pt_regs *regs, struct stack_trace *trace)
+{
+	WARN_ONCE(1, KERN_INFO "save_stack_trace_regs() not implemented yet.\n");
+}