[mirror_ubuntu-artful-kernel.git] / arch / blackfin / kernel / stacktrace.c

/*
 * Blackfin stacktrace code (mostly copied from avr32)
 *
 * Copyright 2009 Analog Devices Inc.
 * Licensed under the GPL-2 or later.
 */

#include <linux/sched.h>
#include <linux/sched/task_stack.h>
#include <linux/stacktrace.h>
#include <linux/thread_info.h>
#include <linux/module.h>

register unsigned long current_frame_pointer asm("FP");

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);
Commit	Line	Data
c7b412f4 MF	1	/*
	2	* Blackfin stacktrace code (mostly copied from avr32)
	3	*
	4	* Copyright 2009 Analog Devices Inc.
	5	* Licensed under the GPL-2 or later.
	6	*/
	7
	8	#include <linux/sched.h>
68db0cf1	9	#include <linux/sched/task_stack.h>
c7b412f4 MF	10	#include <linux/stacktrace.h>
	11	#include <linux/thread_info.h>
	12	#include <linux/module.h>
	13
	14	register unsigned long current_frame_pointer asm("FP");
	15
	16	struct stackframe {
	17	unsigned long fp;
	18	unsigned long rets;
	19	};
	20
	21	/*
	22	* Save stack-backtrace addresses into a stack_trace buffer.
	23	*/
	24	void save_stack_trace(struct stack_trace *trace)
	25	{
	26	unsigned long low, high;
	27	unsigned long fp;
	28	struct stackframe *frame;
	29	int skip = trace->skip;
	30
	31	low = (unsigned long)task_stack_page(current);
	32	high = low + THREAD_SIZE;
	33	fp = current_frame_pointer;
	34
	35	while (fp >= low && fp <= (high - sizeof(*frame))) {
	36	frame = (struct stackframe *)fp;
	37
	38	if (skip) {
	39	skip--;
	40	} else {
	41	trace->entries[trace->nr_entries++] = frame->rets;
	42	if (trace->nr_entries >= trace->max_entries)
	43	break;
	44	}
	45
	46	/*
	47	* The next frame must be at a higher address than the
	48	* current frame.
	49	*/
	50	low = fp + sizeof(*frame);
	51	fp = frame->fp;
	52	}
	53	}
	54	EXPORT_SYMBOL_GPL(save_stack_trace);