// SPDX-License-Identifier: GPL-2.0/* *  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> const char *stack_type_name(enum stack_type type){	if (type == STACK_TYPE_IRQ)		return "IRQ"; 	if (type == STACK_TYPE_SOFTIRQ)		return "SOFTIRQ"; 	if (type == STACK_TYPE_ENTRY)		return "ENTRY_TRAMPOLINE"; 	if (type == STACK_TYPE_EXCEPTION)		return "#DF"; 	return NULL;} static bool in_hardirq_stack(unsigned long *stack, struct stack_info *info){	unsigned long *begin = (unsigned long *)this_cpu_read(hardirq_stack_ptr);	unsigned long *end   = begin + (THREAD_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; 	/*	 * See irq_32.c -- the next stack pointer is stored at the beginning of	 * the stack.	 */	info->next_sp	= (unsigned long *)*begin; 	return true;} static bool in_softirq_stack(unsigned long *stack, struct stack_info *info){	unsigned long *begin = (unsigned long *)this_cpu_read(softirq_stack_ptr);	unsigned long *end   = begin + (THREAD_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_SOFTIRQ;	info->begin	= begin;	info->end	= end; 	/*	 * The next stack pointer is stored at the beginning of the stack.	 * See irq_32.c.	 */	info->next_sp	= (unsigned long *)*begin; 	return true;} static bool in_doublefault_stack(unsigned long *stack, struct stack_info *info){	struct cpu_entry_area *cea = get_cpu_entry_area(raw_smp_processor_id());	struct doublefault_stack *ss = &cea->doublefault_stack; 	void *begin = ss->stack;	void *end = begin + sizeof(ss->stack); 	if ((void *)stack < begin || (void *)stack >= end)		return false; 	info->type	= STACK_TYPE_EXCEPTION;	info->begin	= begin;	info->end	= end;	info->next_sp	= (unsigned long *)this_cpu_read(cpu_tss_rw.x86_tss.sp); 	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_entry_stack(stack, info))		goto recursion_check; 	if (in_hardirq_stack(stack, info))		goto recursion_check; 	if (in_softirq_stack(stack, info))		goto recursion_check; 	if (in_doublefault_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;}