1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright (C) 1991, 1992 Linus Torvalds
4 * Copyright (C) 2000, 2001, 2002 Andi Kleen, SuSE Labs
6 #include <linux/sched/debug.h>
7 #include <linux/kallsyms.h>
8 #include <linux/kprobes.h>
9 #include <linux/uaccess.h>
10 #include <linux/hardirq.h>
11 #include <linux/kdebug.h>
12 #include <linux/export.h>
13 #include <linux/ptrace.h>
14 #include <linux/kexec.h>
15 #include <linux/sysfs.h>
16 #include <linux/bug.h>
17 #include <linux/nmi.h>
19 #include <asm/stacktrace.h>
21 const char *stack_type_name(enum stack_type type)
23 if (type == STACK_TYPE_IRQ)
26 if (type == STACK_TYPE_SOFTIRQ)
29 if (type == STACK_TYPE_ENTRY)
30 return "ENTRY_TRAMPOLINE";
32 if (type == STACK_TYPE_EXCEPTION)
38 static bool in_hardirq_stack(unsigned long *stack, struct stack_info *info)
40 unsigned long *begin = (unsigned long *)this_cpu_read(hardirq_stack_ptr);
41 unsigned long *end = begin + (THREAD_SIZE / sizeof(long));
44 * This is a software stack, so 'end' can be a valid stack pointer.
45 * It just means the stack is empty.
47 if (stack < begin || stack > end)
50 info->type = STACK_TYPE_IRQ;
55 * See irq_32.c -- the next stack pointer is stored at the beginning of
58 info->next_sp = (unsigned long *)*begin;
63 static bool in_softirq_stack(unsigned long *stack, struct stack_info *info)
65 unsigned long *begin = (unsigned long *)this_cpu_read(softirq_stack_ptr);
66 unsigned long *end = begin + (THREAD_SIZE / sizeof(long));
69 * This is a software stack, so 'end' can be a valid stack pointer.
70 * It just means the stack is empty.
72 if (stack < begin || stack > end)
75 info->type = STACK_TYPE_SOFTIRQ;
80 * The next stack pointer is stored at the beginning of the stack.
83 info->next_sp = (unsigned long *)*begin;
88 static bool in_doublefault_stack(unsigned long *stack, struct stack_info *info)
90 #ifdef CONFIG_DOUBLEFAULT
91 struct cpu_entry_area *cea = get_cpu_entry_area(raw_smp_processor_id());
92 struct doublefault_stack *ss = &cea->doublefault_stack;
94 void *begin = ss->stack;
95 void *end = begin + sizeof(ss->stack);
97 if ((void *)stack < begin || (void *)stack >= end)
100 info->type = STACK_TYPE_EXCEPTION;
103 info->next_sp = (unsigned long *)this_cpu_read(cpu_tss_rw.x86_tss.sp);
112 int get_stack_info(unsigned long *stack, struct task_struct *task,
113 struct stack_info *info, unsigned long *visit_mask)
118 task = task ? : current;
120 if (in_task_stack(stack, task, info))
121 goto recursion_check;
126 if (in_entry_stack(stack, info))
127 goto recursion_check;
129 if (in_hardirq_stack(stack, info))
130 goto recursion_check;
132 if (in_softirq_stack(stack, info))
133 goto recursion_check;
135 if (in_doublefault_stack(stack, info))
136 goto recursion_check;
142 * Make sure we don't iterate through any given stack more than once.
143 * If it comes up a second time then there's something wrong going on:
144 * just break out and report an unknown stack type.
147 if (*visit_mask & (1UL << info->type)) {
148 printk_deferred_once(KERN_WARNING "WARNING: stack recursion on stack type %d\n", info->type);
151 *visit_mask |= 1UL << info->type;
157 info->type = STACK_TYPE_UNKNOWN;