/* * arch/sh/kernel/return_address.c * * Copyright (C) 2009  Matt Fleming * Copyright (C) 2009  Paul Mundt * * This file is subject to the terms and conditions of the GNU General Public * License.  See the file "COPYING" in the main directory of this archive * for more details. */#include <linux/kernel.h>#include <linux/module.h>#include <asm/dwarf.h> #ifdef CONFIG_DWARF_UNWINDER void *return_address(unsigned int depth){	struct dwarf_frame *frame;	unsigned long ra;	int i; 	for (i = 0, frame = NULL, ra = 0; i <= depth; i++) {		struct dwarf_frame *tmp; 		tmp = dwarf_unwind_stack(ra, frame);		if (!tmp)			return NULL; 		if (frame)			dwarf_free_frame(frame); 		frame = tmp; 		if (!frame || !frame->return_addr)			break; 		ra = frame->return_addr;	} 	/* Failed to unwind the stack to the specified depth. */	WARN_ON(i != depth + 1); 	if (frame)		dwarf_free_frame(frame); 	return (void *)ra;} #else void *return_address(unsigned int depth){	return NULL;} #endif EXPORT_SYMBOL_GPL(return_address);