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Commit | Line | Data |
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6fcbede3 AH |
1 | /* |
2 | * Copyright (C) 1991, 1992 Linus Torvalds | |
3 | * Copyright (C) 2000, 2001, 2002 Andi Kleen, SuSE Labs | |
4 | */ | |
b17b0153 | 5 | #include <linux/sched/debug.h> |
6fcbede3 AH |
6 | #include <linux/kallsyms.h> |
7 | #include <linux/kprobes.h> | |
8 | #include <linux/uaccess.h> | |
6fcbede3 AH |
9 | #include <linux/hardirq.h> |
10 | #include <linux/kdebug.h> | |
186f4360 | 11 | #include <linux/export.h> |
6fcbede3 AH |
12 | #include <linux/ptrace.h> |
13 | #include <linux/kexec.h> | |
b8030906 | 14 | #include <linux/sysfs.h> |
6fcbede3 AH |
15 | #include <linux/bug.h> |
16 | #include <linux/nmi.h> | |
17 | ||
18 | #include <asm/stacktrace.h> | |
19 | ||
9c003907 JP |
20 | static char *exception_stack_names[N_EXCEPTION_STACKS] = { |
21 | [ DOUBLEFAULT_STACK-1 ] = "#DF", | |
22 | [ NMI_STACK-1 ] = "NMI", | |
23 | [ DEBUG_STACK-1 ] = "#DB", | |
24 | [ MCE_STACK-1 ] = "#MC", | |
25 | }; | |
6fcbede3 | 26 | |
9c003907 JP |
27 | static unsigned long exception_stack_sizes[N_EXCEPTION_STACKS] = { |
28 | [0 ... N_EXCEPTION_STACKS - 1] = EXCEPTION_STKSZ, | |
29 | [DEBUG_STACK - 1] = DEBUG_STKSZ | |
b8030906 | 30 | }; |
0406ca6d | 31 | |
3d02a9c4 | 32 | const char *stack_type_name(enum stack_type type) |
0406ca6d | 33 | { |
cb76c939 JP |
34 | BUILD_BUG_ON(N_EXCEPTION_STACKS != 4); |
35 | ||
3d02a9c4 JP |
36 | if (type == STACK_TYPE_IRQ) |
37 | return "IRQ"; | |
38 | ||
e0437c47 DH |
39 | if (type == STACK_TYPE_ENTRY) { |
40 | /* | |
41 | * On 64-bit, we have a generic entry stack that we | |
42 | * use for all the kernel entry points, including | |
43 | * SYSENTER. | |
44 | */ | |
45 | return "ENTRY_TRAMPOLINE"; | |
46 | } | |
72e90cc5 | 47 | |
3d02a9c4 JP |
48 | if (type >= STACK_TYPE_EXCEPTION && type <= STACK_TYPE_EXCEPTION_LAST) |
49 | return exception_stack_names[type - STACK_TYPE_EXCEPTION]; | |
50 | ||
51 | return NULL; | |
cb76c939 JP |
52 | } |
53 | ||
fcd709ef | 54 | static bool in_exception_stack(unsigned long *stack, struct stack_info *info) |
cb76c939 JP |
55 | { |
56 | unsigned long *begin, *end; | |
57 | struct pt_regs *regs; | |
6fcbede3 AH |
58 | unsigned k; |
59 | ||
9c003907 JP |
60 | BUILD_BUG_ON(N_EXCEPTION_STACKS != 4); |
61 | ||
6fcbede3 | 62 | for (k = 0; k < N_EXCEPTION_STACKS; k++) { |
cb76c939 JP |
63 | end = (unsigned long *)raw_cpu_ptr(&orig_ist)->ist[k]; |
64 | begin = end - (exception_stack_sizes[k] / sizeof(long)); | |
65 | regs = (struct pt_regs *)end - 1; | |
9c003907 JP |
66 | |
67 | if (stack < begin || stack >= end) | |
6fcbede3 | 68 | continue; |
9c003907 | 69 | |
cb76c939 JP |
70 | info->type = STACK_TYPE_EXCEPTION + k; |
71 | info->begin = begin; | |
72 | info->end = end; | |
73 | info->next_sp = (unsigned long *)regs->sp; | |
74 | ||
75 | return true; | |
6fcbede3 | 76 | } |
9c003907 | 77 | |
cb76c939 | 78 | return false; |
6fcbede3 AH |
79 | } |
80 | ||
cb76c939 | 81 | static bool in_irq_stack(unsigned long *stack, struct stack_info *info) |
af2d8289 | 82 | { |
cb76c939 JP |
83 | unsigned long *end = (unsigned long *)this_cpu_read(irq_stack_ptr); |
84 | unsigned long *begin = end - (IRQ_STACK_SIZE / sizeof(long)); | |
af2d8289 | 85 | |
5fe599e0 JP |
86 | /* |
87 | * This is a software stack, so 'end' can be a valid stack pointer. | |
88 | * It just means the stack is empty. | |
89 | */ | |
90 | if (stack < begin || stack > end) | |
cb76c939 | 91 | return false; |
2223f6f6 | 92 | |
cb76c939 JP |
93 | info->type = STACK_TYPE_IRQ; |
94 | info->begin = begin; | |
95 | info->end = end; | |
96 | ||
97 | /* | |
98 | * The next stack pointer is the first thing pushed by the entry code | |
99 | * after switching to the irq stack. | |
100 | */ | |
101 | info->next_sp = (unsigned long *)*(end - 1); | |
102 | ||
103 | return true; | |
104 | } | |
105 | ||
106 | int get_stack_info(unsigned long *stack, struct task_struct *task, | |
107 | struct stack_info *info, unsigned long *visit_mask) | |
2223f6f6 | 108 | { |
cb76c939 JP |
109 | if (!stack) |
110 | goto unknown; | |
111 | ||
112 | task = task ? : current; | |
2223f6f6 | 113 | |
cb76c939 | 114 | if (in_task_stack(stack, task, info)) |
fcd709ef | 115 | goto recursion_check; |
2223f6f6 | 116 | |
cb76c939 JP |
117 | if (task != current) |
118 | goto unknown; | |
2223f6f6 | 119 | |
fcd709ef JP |
120 | if (in_exception_stack(stack, info)) |
121 | goto recursion_check; | |
2223f6f6 | 122 | |
cb76c939 | 123 | if (in_irq_stack(stack, info)) |
fcd709ef JP |
124 | goto recursion_check; |
125 | ||
e0437c47 | 126 | if (in_entry_stack(stack, info)) |
72e90cc5 AL |
127 | goto recursion_check; |
128 | ||
fcd709ef JP |
129 | goto unknown; |
130 | ||
131 | recursion_check: | |
132 | /* | |
133 | * Make sure we don't iterate through any given stack more than once. | |
134 | * If it comes up a second time then there's something wrong going on: | |
135 | * just break out and report an unknown stack type. | |
136 | */ | |
137 | if (visit_mask) { | |
0d2b8579 JP |
138 | if (*visit_mask & (1UL << info->type)) { |
139 | printk_deferred_once(KERN_WARNING "WARNING: stack recursion on stack type %d\n", info->type); | |
fcd709ef | 140 | goto unknown; |
0d2b8579 | 141 | } |
fcd709ef JP |
142 | *visit_mask |= 1UL << info->type; |
143 | } | |
2223f6f6 | 144 | |
cb76c939 | 145 | return 0; |
2223f6f6 | 146 | |
cb76c939 JP |
147 | unknown: |
148 | info->type = STACK_TYPE_UNKNOWN; | |
149 | return -EINVAL; | |
2223f6f6 SR |
150 | } |
151 | ||
57da8b96 | 152 | void show_regs(struct pt_regs *regs) |
6fcbede3 AH |
153 | { |
154 | int i; | |
6fcbede3 | 155 | |
a43cb95d | 156 | show_regs_print_info(KERN_DEFAULT); |
6fcbede3 | 157 | __show_regs(regs, 1); |
6fcbede3 AH |
158 | |
159 | /* | |
160 | * When in-kernel, we also print out the stack and code at the | |
161 | * time of the fault.. | |
162 | */ | |
163 | if (!user_mode(regs)) { | |
164 | unsigned int code_prologue = code_bytes * 43 / 64; | |
165 | unsigned int code_len = code_bytes; | |
166 | unsigned char c; | |
167 | u8 *ip; | |
168 | ||
0ee1dd9f | 169 | show_trace_log_lvl(current, regs, NULL, KERN_DEFAULT); |
6fcbede3 | 170 | |
b0f4c4b3 | 171 | printk(KERN_DEFAULT "Code: "); |
6fcbede3 AH |
172 | |
173 | ip = (u8 *)regs->ip - code_prologue; | |
174 | if (ip < (u8 *)PAGE_OFFSET || probe_kernel_address(ip, c)) { | |
8a541665 | 175 | /* try starting at IP */ |
6fcbede3 AH |
176 | ip = (u8 *)regs->ip; |
177 | code_len = code_len - code_prologue + 1; | |
178 | } | |
179 | for (i = 0; i < code_len; i++, ip++) { | |
180 | if (ip < (u8 *)PAGE_OFFSET || | |
181 | probe_kernel_address(ip, c)) { | |
c767a54b | 182 | pr_cont(" Bad RIP value."); |
6fcbede3 AH |
183 | break; |
184 | } | |
185 | if (ip == (u8 *)regs->ip) | |
c767a54b | 186 | pr_cont("<%02x> ", c); |
6fcbede3 | 187 | else |
c767a54b | 188 | pr_cont("%02x ", c); |
6fcbede3 AH |
189 | } |
190 | } | |
c767a54b | 191 | pr_cont("\n"); |
6fcbede3 | 192 | } |