/* *  Copyright (C) 1991, 1992  Linus Torvalds *  Copyright (C) 2000, 2001, 2002 Andi Kleen, SuSE Labs */#include <linux/sched/debug.h>#include <linux/kallsyms.h>#include <linux/kprobes.h>#include <linux/uaccess.h>#include <linux/hardirq.h>#include <linux/kdebug.h>#include <linux/export.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 char *exception_stack_names[N_EXCEPTION_STACKS] = {		[ DOUBLEFAULT_STACK-1	]	= "#DF",		[ NMI_STACK-1		]	= "NMI",		[ DEBUG_STACK-1		]	= "#DB",		[ MCE_STACK-1		]	= "#MC",}; static unsigned long exception_stack_sizes[N_EXCEPTION_STACKS] = {	[0 ... N_EXCEPTION_STACKS - 1]		= EXCEPTION_STKSZ,	[DEBUG_STACK - 1]			= DEBUG_STKSZ}; const char *stack_type_name(enum stack_type type){	BUILD_BUG_ON(N_EXCEPTION_STACKS != 4); 	if (type == STACK_TYPE_IRQ)		return "IRQ"; 	if (type >= STACK_TYPE_EXCEPTION && type <= STACK_TYPE_EXCEPTION_LAST)		return exception_stack_names[type - STACK_TYPE_EXCEPTION]; 	return NULL;} static bool in_exception_stack(unsigned long *stack, struct stack_info *info){	unsigned long *begin, *end;	struct pt_regs *regs;	unsigned k; 	BUILD_BUG_ON(N_EXCEPTION_STACKS != 4); 	for (k = 0; k < N_EXCEPTION_STACKS; k++) {		end   = (unsigned long *)raw_cpu_ptr(&orig_ist)->ist[k];		begin = end - (exception_stack_sizes[k] / sizeof(long));		regs  = (struct pt_regs *)end - 1; 		if (stack < begin || stack >= end)			continue; 		info->type	= STACK_TYPE_EXCEPTION + k;		info->begin	= begin;		info->end	= end;		info->next_sp	= (unsigned long *)regs->sp; 		return true;	} 	return false;} static bool in_irq_stack(unsigned long *stack, struct stack_info *info){	unsigned long *end   = (unsigned long *)this_cpu_read(irq_stack_ptr);	unsigned long *begin = end - (IRQ_STACK_SIZE / sizeof(long)); 	/*	 * This is a software stack, so 'end' can be a valid stack pointer.	 * It just means the stack is empty.	 */	if (stack < begin || stack > end)		return false; 	info->type	= STACK_TYPE_IRQ;	info->begin	= begin;	info->end	= end; 	/*	 * The next stack pointer is the first thing pushed by the entry code	 * after switching to the irq stack.	 */	info->next_sp = (unsigned long *)*(end - 1); 	return true;} int get_stack_info(unsigned long *stack, struct task_struct *task,		   struct stack_info *info, unsigned long *visit_mask){	if (!stack)		goto unknown; 	task = task ? : current; 	if (in_task_stack(stack, task, info))		goto recursion_check; 	if (task != current)		goto unknown; 	if (in_exception_stack(stack, info))		goto recursion_check; 	if (in_irq_stack(stack, info))		goto recursion_check; 	goto unknown; recursion_check:	/*	 * Make sure we don't iterate through any given stack more than once.	 * If it comes up a second time then there's something wrong going on:	 * just break out and report an unknown stack type.	 */	if (visit_mask) {		if (*visit_mask & (1UL << info->type)) {			printk_deferred_once(KERN_WARNING "WARNING: stack recursion on stack type %d\n", info->type);			goto unknown;		}		*visit_mask |= 1UL << info->type;	} 	return 0; unknown:	info->type = STACK_TYPE_UNKNOWN;	return -EINVAL;} void show_regs(struct pt_regs *regs){	int i; 	show_regs_print_info(KERN_DEFAULT);	__show_regs(regs, 1); 	/*	 * 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; 		show_trace_log_lvl(current, regs, NULL, KERN_DEFAULT); 		printk(KERN_DEFAULT "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 RIP value.");				break;			}			if (ip == (u8 *)regs->ip)				pr_cont("<%02x> ", c);			else				pr_cont("%02x ", c);		}	}	pr_cont("\n");}