linux-sg2042/arch/hexagon/kernel/stacktrace.c

67 lines
1.7 KiB
C

/*
* Stacktrace support for Hexagon
*
* Copyright (c) 2010-2011, The Linux Foundation. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 and
* only version 2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301, USA.
*/
#include <linux/sched.h>
#include <linux/stacktrace.h>
#include <linux/thread_info.h>
#include <linux/module.h>
register unsigned long current_frame_pointer asm("r30");
struct stackframe {
unsigned long fp;
unsigned long rets;
};
/*
* 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 - sizeof(*frame))) {
frame = (struct stackframe *)fp;
if (skip) {
skip--;
} else {
trace->entries[trace->nr_entries++] = frame->rets;
if (trace->nr_entries >= trace->max_entries)
break;
}
/*
* The next frame must be at a higher address than the
* current frame.
*/
low = fp + sizeof(*frame);
fp = frame->fp;
}
}
EXPORT_SYMBOL_GPL(save_stack_trace);