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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 1991, 1992 Linus Torvalds
4 * Copyright (C) 2000, 2001, 2002 Andi Kleen, SuSE Labs
5 */
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>
18
19#include <asm/stacktrace.h>
20
21const char *stack_type_name(enum stack_type type)
22{
23 if (type == STACK_TYPE_IRQ)
24 return "IRQ";
25
26 if (type == STACK_TYPE_SOFTIRQ)
27 return "SOFTIRQ";
28
29 if (type == STACK_TYPE_ENTRY)
30 return "ENTRY_TRAMPOLINE";
31
32 return NULL;
33}
34
35static bool in_hardirq_stack(unsigned long *stack, struct stack_info *info)
36{
37 unsigned long *begin = (unsigned long *)this_cpu_read(hardirq_stack_ptr);
38 unsigned long *end = begin + (THREAD_SIZE / sizeof(long));
39
40 /*
41 * This is a software stack, so 'end' can be a valid stack pointer.
42 * It just means the stack is empty.
43 */
44 if (stack < begin || stack > end)
45 return false;
46
47 info->type = STACK_TYPE_IRQ;
48 info->begin = begin;
49 info->end = end;
50
51 /*
52 * See irq_32.c -- the next stack pointer is stored at the beginning of
53 * the stack.
54 */
55 info->next_sp = (unsigned long *)*begin;
56
57 return true;
58}
59
60static bool in_softirq_stack(unsigned long *stack, struct stack_info *info)
61{
62 unsigned long *begin = (unsigned long *)this_cpu_read(softirq_stack_ptr);
63 unsigned long *end = begin + (THREAD_SIZE / sizeof(long));
64
65 /*
66 * This is a software stack, so 'end' can be a valid stack pointer.
67 * It just means the stack is empty.
68 */
69 if (stack < begin || stack > end)
70 return false;
71
72 info->type = STACK_TYPE_SOFTIRQ;
73 info->begin = begin;
74 info->end = end;
75
76 /*
77 * The next stack pointer is stored at the beginning of the stack.
78 * See irq_32.c.
79 */
80 info->next_sp = (unsigned long *)*begin;
81
82 return true;
83}
84
85int get_stack_info(unsigned long *stack, struct task_struct *task,
86 struct stack_info *info, unsigned long *visit_mask)
87{
88 if (!stack)
89 goto unknown;
90
91 task = task ? : current;
92
93 if (in_task_stack(stack, task, info))
94 goto recursion_check;
95
96 if (task != current)
97 goto unknown;
98
99 if (in_entry_stack(stack, info))
100 goto recursion_check;
101
102 if (in_hardirq_stack(stack, info))
103 goto recursion_check;
104
105 if (in_softirq_stack(stack, info))
106 goto recursion_check;
107
108 goto unknown;
109
110recursion_check:
111 /*
112 * Make sure we don't iterate through any given stack more than once.
113 * If it comes up a second time then there's something wrong going on:
114 * just break out and report an unknown stack type.
115 */
116 if (visit_mask) {
117 if (*visit_mask & (1UL << info->type)) {
118 printk_deferred_once(KERN_WARNING "WARNING: stack recursion on stack type %d\n", info->type);
119 goto unknown;
120 }
121 *visit_mask |= 1UL << info->type;
122 }
123
124 return 0;
125
126unknown:
127 info->type = STACK_TYPE_UNKNOWN;
128 return -EINVAL;
129}
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 1991, 1992 Linus Torvalds
4 * Copyright (C) 2000, 2001, 2002 Andi Kleen, SuSE Labs
5 */
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>
18
19#include <asm/stacktrace.h>
20
21const char *stack_type_name(enum stack_type type)
22{
23 if (type == STACK_TYPE_IRQ)
24 return "IRQ";
25
26 if (type == STACK_TYPE_SOFTIRQ)
27 return "SOFTIRQ";
28
29 if (type == STACK_TYPE_ENTRY)
30 return "ENTRY_TRAMPOLINE";
31
32 return NULL;
33}
34
35static bool in_hardirq_stack(unsigned long *stack, struct stack_info *info)
36{
37 unsigned long *begin = (unsigned long *)this_cpu_read(hardirq_stack);
38 unsigned long *end = begin + (THREAD_SIZE / sizeof(long));
39
40 /*
41 * This is a software stack, so 'end' can be a valid stack pointer.
42 * It just means the stack is empty.
43 */
44 if (stack <= begin || stack > end)
45 return false;
46
47 info->type = STACK_TYPE_IRQ;
48 info->begin = begin;
49 info->end = end;
50
51 /*
52 * See irq_32.c -- the next stack pointer is stored at the beginning of
53 * the stack.
54 */
55 info->next_sp = (unsigned long *)*begin;
56
57 return true;
58}
59
60static bool in_softirq_stack(unsigned long *stack, struct stack_info *info)
61{
62 unsigned long *begin = (unsigned long *)this_cpu_read(softirq_stack);
63 unsigned long *end = begin + (THREAD_SIZE / sizeof(long));
64
65 /*
66 * This is a software stack, so 'end' can be a valid stack pointer.
67 * It just means the stack is empty.
68 */
69 if (stack <= begin || stack > end)
70 return false;
71
72 info->type = STACK_TYPE_SOFTIRQ;
73 info->begin = begin;
74 info->end = end;
75
76 /*
77 * The next stack pointer is stored at the beginning of the stack.
78 * See irq_32.c.
79 */
80 info->next_sp = (unsigned long *)*begin;
81
82 return true;
83}
84
85int get_stack_info(unsigned long *stack, struct task_struct *task,
86 struct stack_info *info, unsigned long *visit_mask)
87{
88 if (!stack)
89 goto unknown;
90
91 task = task ? : current;
92
93 if (in_task_stack(stack, task, info))
94 goto recursion_check;
95
96 if (task != current)
97 goto unknown;
98
99 if (in_entry_stack(stack, info))
100 goto recursion_check;
101
102 if (in_hardirq_stack(stack, info))
103 goto recursion_check;
104
105 if (in_softirq_stack(stack, info))
106 goto recursion_check;
107
108 goto unknown;
109
110recursion_check:
111 /*
112 * Make sure we don't iterate through any given stack more than once.
113 * If it comes up a second time then there's something wrong going on:
114 * just break out and report an unknown stack type.
115 */
116 if (visit_mask) {
117 if (*visit_mask & (1UL << info->type)) {
118 printk_deferred_once(KERN_WARNING "WARNING: stack recursion on stack type %d\n", info->type);
119 goto unknown;
120 }
121 *visit_mask |= 1UL << info->type;
122 }
123
124 return 0;
125
126unknown:
127 info->type = STACK_TYPE_UNKNOWN;
128 return -EINVAL;
129}