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Commit | Line | Data |
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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
2bc5f927 AH |
2 | /* |
3 | * Copyright (C) 1991, 1992 Linus Torvalds | |
4 | * Copyright (C) 2000, 2001, 2002 Andi Kleen, SuSE Labs | |
5 | */ | |
b17b0153 | 6 | #include <linux/sched/debug.h> |
2bc5f927 AH |
7 | #include <linux/kallsyms.h> |
8 | #include <linux/kprobes.h> | |
9 | #include <linux/uaccess.h> | |
2bc5f927 AH |
10 | #include <linux/hardirq.h> |
11 | #include <linux/kdebug.h> | |
186f4360 | 12 | #include <linux/export.h> |
2bc5f927 AH |
13 | #include <linux/ptrace.h> |
14 | #include <linux/kexec.h> | |
b8030906 | 15 | #include <linux/sysfs.h> |
2bc5f927 AH |
16 | #include <linux/bug.h> |
17 | #include <linux/nmi.h> | |
18 | ||
19 | #include <asm/stacktrace.h> | |
20 | ||
3d02a9c4 | 21 | const char *stack_type_name(enum stack_type type) |
198d208d | 22 | { |
3d02a9c4 JP |
23 | if (type == STACK_TYPE_IRQ) |
24 | return "IRQ"; | |
25 | ||
26 | if (type == STACK_TYPE_SOFTIRQ) | |
27 | return "SOFTIRQ"; | |
28 | ||
4fe2d8b1 DH |
29 | if (type == STACK_TYPE_ENTRY) |
30 | return "ENTRY_TRAMPOLINE"; | |
33a2f1a6 | 31 | |
3d02a9c4 | 32 | return NULL; |
198d208d SR |
33 | } |
34 | ||
cb76c939 JP |
35 | static bool in_hardirq_stack(unsigned long *stack, struct stack_info *info) |
36 | { | |
a754fe2b | 37 | unsigned long *begin = (unsigned long *)this_cpu_read(hardirq_stack_ptr); |
cb76c939 JP |
38 | unsigned long *end = begin + (THREAD_SIZE / sizeof(long)); |
39 | ||
5fe599e0 JP |
40 | /* |
41 | * This is a software stack, so 'end' can be a valid stack pointer. | |
42 | * It just means the stack is empty. | |
43 | */ | |
fa332154 | 44 | if (stack < begin || stack > end) |
cb76c939 JP |
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; | |
198d208d | 56 | |
cb76c939 JP |
57 | return true; |
58 | } | |
59 | ||
60 | static bool in_softirq_stack(unsigned long *stack, struct stack_info *info) | |
198d208d | 61 | { |
a754fe2b | 62 | unsigned long *begin = (unsigned long *)this_cpu_read(softirq_stack_ptr); |
cb76c939 JP |
63 | unsigned long *end = begin + (THREAD_SIZE / sizeof(long)); |
64 | ||
5fe599e0 JP |
65 | /* |
66 | * This is a software stack, so 'end' can be a valid stack pointer. | |
67 | * It just means the stack is empty. | |
68 | */ | |
fa332154 | 69 | if (stack < begin || stack > end) |
cb76c939 JP |
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; | |
198d208d | 81 | |
cb76c939 | 82 | return true; |
198d208d SR |
83 | } |
84 | ||
cb76c939 JP |
85 | int get_stack_info(unsigned long *stack, struct task_struct *task, |
86 | struct stack_info *info, unsigned long *visit_mask) | |
198d208d | 87 | { |
cb76c939 JP |
88 | if (!stack) |
89 | goto unknown; | |
198d208d | 90 | |
cb76c939 JP |
91 | task = task ? : current; |
92 | ||
93 | if (in_task_stack(stack, task, info)) | |
fcd709ef | 94 | goto recursion_check; |
cb76c939 JP |
95 | |
96 | if (task != current) | |
97 | goto unknown; | |
98 | ||
4fe2d8b1 | 99 | if (in_entry_stack(stack, info)) |
33a2f1a6 AL |
100 | goto recursion_check; |
101 | ||
cb76c939 | 102 | if (in_hardirq_stack(stack, info)) |
fcd709ef | 103 | goto recursion_check; |
cb76c939 JP |
104 | |
105 | if (in_softirq_stack(stack, info)) | |
fcd709ef JP |
106 | goto recursion_check; |
107 | ||
108 | goto unknown; | |
109 | ||
110 | recursion_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) { | |
0d2b8579 JP |
117 | if (*visit_mask & (1UL << info->type)) { |
118 | printk_deferred_once(KERN_WARNING "WARNING: stack recursion on stack type %d\n", info->type); | |
fcd709ef | 119 | goto unknown; |
0d2b8579 | 120 | } |
fcd709ef JP |
121 | *visit_mask |= 1UL << info->type; |
122 | } | |
123 | ||
124 | return 0; | |
cb76c939 JP |
125 | |
126 | unknown: | |
127 | info->type = STACK_TYPE_UNKNOWN; | |
128 | return -EINVAL; | |
198d208d | 129 | } |