/*
   * 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%pS
  ", 1 + spaces, ' ', (void *)trace->entries[i]);

  }

  EXPORT_SYMBOL_GPL(print_stack_trace);

  int snprint_stack_trace(char *buf, size_t size,
  			struct stack_trace *trace, int spaces)
  {
  	int i;

  	int generated;
  	int total = 0;
  
  	if (WARN_ON(!trace->entries))
  		return 0;
  
  	for (i = 0; i < trace->nr_entries; i++) {

  		generated = snprintf(buf, size, "%*c%pS
  ", 1 + spaces, ' ',
  				     (void *)trace->entries[i]);

  
  		total += generated;
  
  		/* Assume that generated isn't a negative number */
  		if (generated >= size) {
  			buf += size;
  			size = 0;
  		} else {
  			buf += generated;
  			size -= generated;
  		}
  	}
  
  	return total;
  }
  EXPORT_SYMBOL_GPL(snprint_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.
  ");
  }

  
  __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.
  ");
  }