linux/arch/avr32/kernel/stacktrace.c

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/*
* Stack trace management functions
*
* Copyright (C) 2007 Atmel Corporation
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/sched.h>
#include <linux/stacktrace.h>
#include <linux/thread_info.h>
#include <linux/module.h>
register unsigned long current_frame_pointer asm("r7");
struct stackframe {
unsigned long lr;
unsigned long fp;
};
/*
* Save stack-backtrace addresses into a stack_trace buffer.
*/
void save_stack_trace(struct stack_trace *trace)
{
unsigned long low, high;
unsigned long fp;
struct stackframe *frame;
int skip = trace->skip;
low = (unsigned long)task_stack_page(current);
high = low + THREAD_SIZE;
fp = current_frame_pointer;
while (fp >= low && fp <= (high - 8)) {
frame = (struct stackframe *)fp;
if (skip) {
skip--;
} else {
trace->entries[trace->nr_entries++] = frame->lr;
if (trace->nr_entries >= trace->max_entries)
break;
}
/*
* The next frame must be at a higher address than the
* current frame.
*/
low = fp + 8;
fp = frame->fp;
}
}
EXPORT_SYMBOL_GPL(save_stack_trace);