/* * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) * Copyright (C) 2013 Richard Weinberger <richard@nod.at> * Copyright (C) 2014 Google Inc., Author: Daniel Walter <dwalter@google.com> * * 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/kallsyms.h>#include <linux/kernel.h>#include <linux/sched.h>#include <linux/stacktrace.h>#include <linux/module.h>#include <linux/uaccess.h>#include <asm/stacktrace.h> void dump_trace(struct task_struct *tsk,		const struct stacktrace_ops *ops,		void *data){	int reliable = 0;	unsigned long *sp, bp, addr;	struct pt_regs *segv_regs = tsk->thread.segv_regs;	struct stack_frame *frame; 	bp = get_frame_pointer(tsk, segv_regs);	sp = get_stack_pointer(tsk, segv_regs); 	frame = (struct stack_frame *)bp;	while (((long) sp & (THREAD_SIZE-1)) != 0) {		addr = *sp;		if (__kernel_text_address(addr)) {			reliable = 0;			if ((unsigned long) sp == bp + sizeof(long)) {				frame = frame ? frame->next_frame : NULL;				bp = (unsigned long)frame;				reliable = 1;			}			ops->address(data, addr, reliable);		}		sp++;	}} static void save_addr(void *data, unsigned long address, int reliable){	struct stack_trace *trace = data; 	if (!reliable)		return;	if (trace->nr_entries >= trace->max_entries)		return; 	trace->entries[trace->nr_entries++] = address;} static const struct stacktrace_ops dump_ops = {	.address = save_addr}; static void __save_stack_trace(struct task_struct *tsk, struct stack_trace *trace){	dump_trace(tsk, &dump_ops, trace);	if (trace->nr_entries < trace->max_entries)		trace->entries[trace->nr_entries++] = ULONG_MAX;} void save_stack_trace(struct stack_trace *trace){	__save_stack_trace(current, trace);}EXPORT_SYMBOL_GPL(save_stack_trace); void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace){	__save_stack_trace(tsk, trace);}EXPORT_SYMBOL_GPL(save_stack_trace_tsk);