/* * 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/sched/task_stack.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);