/* *  Copyright (C) 1991, 1992  Linus Torvalds *  Copyright (C) 2000, 2001, 2002 Andi Kleen, SuSE Labs */#include <linux/kallsyms.h>#include <linux/kprobes.h>#include <linux/uaccess.h>#include <linux/hardirq.h>#include <linux/kdebug.h>#include <linux/module.h>#include <linux/ptrace.h>#include <linux/kexec.h>#include <linux/sysfs.h>#include <linux/bug.h>#include <linux/nmi.h> #include <asm/stacktrace.h> static void *is_irq_stack(void *p, void *irq){	if (p < irq || p >= (irq + THREAD_SIZE))		return NULL;	return irq + THREAD_SIZE;}  static void *is_hardirq_stack(unsigned long *stack, int cpu){	void *irq = per_cpu(hardirq_stack, cpu); 	return is_irq_stack(stack, irq);} static void *is_softirq_stack(unsigned long *stack, int cpu){	void *irq = per_cpu(softirq_stack, cpu); 	return is_irq_stack(stack, irq);} void dump_trace(struct task_struct *task, struct pt_regs *regs,		unsigned long *stack, unsigned long bp,		const struct stacktrace_ops *ops, void *data){	const unsigned cpu = get_cpu();	int graph = 0;	u32 *prev_esp; 	if (!task)		task = current; 	if (!stack) {		unsigned long dummy; 		stack = &dummy;		if (task != current)			stack = (unsigned long *)task->thread.sp;	} 	if (!bp)		bp = stack_frame(task, regs); 	for (;;) {		struct thread_info *context;		void *end_stack; 		end_stack = is_hardirq_stack(stack, cpu);		if (!end_stack)			end_stack = is_softirq_stack(stack, cpu); 		context = task_thread_info(task);		bp = ops->walk_stack(context, stack, bp, ops, data,				     end_stack, &graph); 		/* Stop if not on irq stack */		if (!end_stack)			break; 		/* The previous esp is saved on the bottom of the stack */		prev_esp = (u32 *)(end_stack - THREAD_SIZE);		stack = (unsigned long *)*prev_esp;		if (!stack)			break; 		if (ops->stack(data, "IRQ") < 0)			break;		touch_nmi_watchdog();	}	put_cpu();}EXPORT_SYMBOL(dump_trace); voidshow_stack_log_lvl(struct task_struct *task, struct pt_regs *regs,		   unsigned long *sp, unsigned long bp, char *log_lvl){	unsigned long *stack;	int i; 	if (sp == NULL) {		if (task)			sp = (unsigned long *)task->thread.sp;		else			sp = (unsigned long *)&sp;	} 	stack = sp;	for (i = 0; i < kstack_depth_to_print; i++) {		if (kstack_end(stack))			break;		if ((i % STACKSLOTS_PER_LINE) == 0) {			if (i != 0)				pr_cont("\n");			printk("%s %08lx", log_lvl, *stack++);		} else			pr_cont(" %08lx", *stack++);		touch_nmi_watchdog();	}	pr_cont("\n");	show_trace_log_lvl(task, regs, sp, bp, log_lvl);}  void show_regs(struct pt_regs *regs){	int i; 	show_regs_print_info(KERN_EMERG);	__show_regs(regs, !user_mode(regs)); 	/*	 * When in-kernel, we also print out the stack and code at the	 * time of the fault..	 */	if (!user_mode(regs)) {		unsigned int code_prologue = code_bytes * 43 / 64;		unsigned int code_len = code_bytes;		unsigned char c;		u8 *ip; 		pr_emerg("Stack:\n");		show_stack_log_lvl(NULL, regs, &regs->sp, 0, KERN_EMERG); 		pr_emerg("Code:"); 		ip = (u8 *)regs->ip - code_prologue;		if (ip < (u8 *)PAGE_OFFSET || probe_kernel_address(ip, c)) {			/* try starting at IP */			ip = (u8 *)regs->ip;			code_len = code_len - code_prologue + 1;		}		for (i = 0; i < code_len; i++, ip++) {			if (ip < (u8 *)PAGE_OFFSET ||					probe_kernel_address(ip, c)) {				pr_cont("  Bad EIP value.");				break;			}			if (ip == (u8 *)regs->ip)				pr_cont(" <%02x>", c);			else				pr_cont(" %02x", c);		}	}	pr_cont("\n");} int is_valid_bugaddr(unsigned long ip){	unsigned short ud2; 	if (ip < PAGE_OFFSET)		return 0;	if (probe_kernel_address((unsigned short *)ip, ud2))		return 0; 	return ud2 == 0x0b0f;}