forked from rrcarlosr/Jetpack
82 lines
2.0 KiB
C
82 lines
2.0 KiB
C
/*
|
|
* AVR32 specific backtracing code for oprofile
|
|
*
|
|
* Copyright 2008 Weinmann GmbH
|
|
*
|
|
* Author: Nikolaus Voss <n.voss@weinmann.de>
|
|
*
|
|
* Based on i386 oprofile backtrace code by John Levon and David Smith
|
|
*
|
|
* 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/oprofile.h>
|
|
#include <linux/sched.h>
|
|
#include <linux/uaccess.h>
|
|
|
|
/* The first two words of each frame on the stack look like this if we have
|
|
* frame pointers */
|
|
struct frame_head {
|
|
unsigned long lr;
|
|
struct frame_head *fp;
|
|
};
|
|
|
|
/* copied from arch/avr32/kernel/process.c */
|
|
static inline int valid_stack_ptr(struct thread_info *tinfo, unsigned long p)
|
|
{
|
|
return (p > (unsigned long)tinfo)
|
|
&& (p < (unsigned long)tinfo + THREAD_SIZE - 3);
|
|
}
|
|
|
|
/* copied from arch/x86/oprofile/backtrace.c */
|
|
static struct frame_head *dump_user_backtrace(struct frame_head *head)
|
|
{
|
|
struct frame_head bufhead[2];
|
|
|
|
/* Also check accessibility of one struct frame_head beyond */
|
|
if (!access_ok(VERIFY_READ, head, sizeof(bufhead)))
|
|
return NULL;
|
|
if (__copy_from_user_inatomic(bufhead, head, sizeof(bufhead)))
|
|
return NULL;
|
|
|
|
oprofile_add_trace(bufhead[0].lr);
|
|
|
|
/* frame pointers should strictly progress back up the stack
|
|
* (towards higher addresses) */
|
|
if (bufhead[0].fp <= head)
|
|
return NULL;
|
|
|
|
return bufhead[0].fp;
|
|
}
|
|
|
|
void avr32_backtrace(struct pt_regs * const regs, unsigned int depth)
|
|
{
|
|
/* Get first frame pointer */
|
|
struct frame_head *head = (struct frame_head *)(regs->r7);
|
|
|
|
if (!user_mode(regs)) {
|
|
#ifdef CONFIG_FRAME_POINTER
|
|
/*
|
|
* Traverse the kernel stack from frame to frame up to
|
|
* "depth" steps.
|
|
*/
|
|
while (depth-- && valid_stack_ptr(task_thread_info(current),
|
|
(unsigned long)head)) {
|
|
oprofile_add_trace(head->lr);
|
|
if (head->fp <= head)
|
|
break;
|
|
head = head->fp;
|
|
}
|
|
#endif
|
|
} else {
|
|
/* Assume we have frame pointers in user mode process */
|
|
while (depth-- && head)
|
|
head = dump_user_backtrace(head);
|
|
}
|
|
}
|
|
|
|
|