Commit | Line | Data |
---|---|---|
6fcbede3 AH |
1 | /* |
2 | * Copyright (C) 1991, 1992 Linus Torvalds | |
3 | * Copyright (C) 2000, 2001, 2002 Andi Kleen, SuSE Labs | |
4 | */ | |
5 | #include <linux/kallsyms.h> | |
6 | #include <linux/kprobes.h> | |
7 | #include <linux/uaccess.h> | |
6fcbede3 AH |
8 | #include <linux/hardirq.h> |
9 | #include <linux/kdebug.h> | |
186f4360 | 10 | #include <linux/export.h> |
6fcbede3 AH |
11 | #include <linux/ptrace.h> |
12 | #include <linux/kexec.h> | |
b8030906 | 13 | #include <linux/sysfs.h> |
6fcbede3 AH |
14 | #include <linux/bug.h> |
15 | #include <linux/nmi.h> | |
16 | ||
17 | #include <asm/stacktrace.h> | |
18 | ||
9c003907 JP |
19 | static char *exception_stack_names[N_EXCEPTION_STACKS] = { |
20 | [ DOUBLEFAULT_STACK-1 ] = "#DF", | |
21 | [ NMI_STACK-1 ] = "NMI", | |
22 | [ DEBUG_STACK-1 ] = "#DB", | |
23 | [ MCE_STACK-1 ] = "#MC", | |
24 | }; | |
6fcbede3 | 25 | |
9c003907 JP |
26 | static unsigned long exception_stack_sizes[N_EXCEPTION_STACKS] = { |
27 | [0 ... N_EXCEPTION_STACKS - 1] = EXCEPTION_STKSZ, | |
28 | [DEBUG_STACK - 1] = DEBUG_STKSZ | |
b8030906 | 29 | }; |
0406ca6d | 30 | |
3d02a9c4 | 31 | const char *stack_type_name(enum stack_type type) |
0406ca6d | 32 | { |
cb76c939 JP |
33 | BUILD_BUG_ON(N_EXCEPTION_STACKS != 4); |
34 | ||
3d02a9c4 JP |
35 | if (type == STACK_TYPE_IRQ) |
36 | return "IRQ"; | |
37 | ||
38 | if (type >= STACK_TYPE_EXCEPTION && type <= STACK_TYPE_EXCEPTION_LAST) | |
39 | return exception_stack_names[type - STACK_TYPE_EXCEPTION]; | |
40 | ||
41 | return NULL; | |
cb76c939 JP |
42 | } |
43 | ||
fcd709ef | 44 | static bool in_exception_stack(unsigned long *stack, struct stack_info *info) |
cb76c939 JP |
45 | { |
46 | unsigned long *begin, *end; | |
47 | struct pt_regs *regs; | |
6fcbede3 AH |
48 | unsigned k; |
49 | ||
9c003907 JP |
50 | BUILD_BUG_ON(N_EXCEPTION_STACKS != 4); |
51 | ||
6fcbede3 | 52 | for (k = 0; k < N_EXCEPTION_STACKS; k++) { |
cb76c939 JP |
53 | end = (unsigned long *)raw_cpu_ptr(&orig_ist)->ist[k]; |
54 | begin = end - (exception_stack_sizes[k] / sizeof(long)); | |
55 | regs = (struct pt_regs *)end - 1; | |
9c003907 JP |
56 | |
57 | if (stack < begin || stack >= end) | |
6fcbede3 | 58 | continue; |
9c003907 | 59 | |
cb76c939 JP |
60 | info->type = STACK_TYPE_EXCEPTION + k; |
61 | info->begin = begin; | |
62 | info->end = end; | |
63 | info->next_sp = (unsigned long *)regs->sp; | |
64 | ||
65 | return true; | |
6fcbede3 | 66 | } |
9c003907 | 67 | |
cb76c939 | 68 | return false; |
6fcbede3 AH |
69 | } |
70 | ||
cb76c939 | 71 | static bool in_irq_stack(unsigned long *stack, struct stack_info *info) |
af2d8289 | 72 | { |
cb76c939 JP |
73 | unsigned long *end = (unsigned long *)this_cpu_read(irq_stack_ptr); |
74 | unsigned long *begin = end - (IRQ_STACK_SIZE / sizeof(long)); | |
af2d8289 | 75 | |
5fe599e0 JP |
76 | /* |
77 | * This is a software stack, so 'end' can be a valid stack pointer. | |
78 | * It just means the stack is empty. | |
79 | */ | |
80 | if (stack < begin || stack > end) | |
cb76c939 | 81 | return false; |
2223f6f6 | 82 | |
cb76c939 JP |
83 | info->type = STACK_TYPE_IRQ; |
84 | info->begin = begin; | |
85 | info->end = end; | |
86 | ||
87 | /* | |
88 | * The next stack pointer is the first thing pushed by the entry code | |
89 | * after switching to the irq stack. | |
90 | */ | |
91 | info->next_sp = (unsigned long *)*(end - 1); | |
92 | ||
93 | return true; | |
94 | } | |
95 | ||
96 | int get_stack_info(unsigned long *stack, struct task_struct *task, | |
97 | struct stack_info *info, unsigned long *visit_mask) | |
2223f6f6 | 98 | { |
cb76c939 JP |
99 | if (!stack) |
100 | goto unknown; | |
101 | ||
102 | task = task ? : current; | |
2223f6f6 | 103 | |
cb76c939 | 104 | if (in_task_stack(stack, task, info)) |
fcd709ef | 105 | goto recursion_check; |
2223f6f6 | 106 | |
cb76c939 JP |
107 | if (task != current) |
108 | goto unknown; | |
2223f6f6 | 109 | |
fcd709ef JP |
110 | if (in_exception_stack(stack, info)) |
111 | goto recursion_check; | |
2223f6f6 | 112 | |
cb76c939 | 113 | if (in_irq_stack(stack, info)) |
fcd709ef JP |
114 | goto recursion_check; |
115 | ||
116 | goto unknown; | |
117 | ||
118 | recursion_check: | |
119 | /* | |
120 | * Make sure we don't iterate through any given stack more than once. | |
121 | * If it comes up a second time then there's something wrong going on: | |
122 | * just break out and report an unknown stack type. | |
123 | */ | |
124 | if (visit_mask) { | |
0d2b8579 JP |
125 | if (*visit_mask & (1UL << info->type)) { |
126 | printk_deferred_once(KERN_WARNING "WARNING: stack recursion on stack type %d\n", info->type); | |
fcd709ef | 127 | goto unknown; |
0d2b8579 | 128 | } |
fcd709ef JP |
129 | *visit_mask |= 1UL << info->type; |
130 | } | |
2223f6f6 | 131 | |
cb76c939 | 132 | return 0; |
2223f6f6 | 133 | |
cb76c939 JP |
134 | unknown: |
135 | info->type = STACK_TYPE_UNKNOWN; | |
136 | return -EINVAL; | |
2223f6f6 SR |
137 | } |
138 | ||
57da8b96 | 139 | void show_regs(struct pt_regs *regs) |
6fcbede3 AH |
140 | { |
141 | int i; | |
6fcbede3 | 142 | |
a43cb95d | 143 | show_regs_print_info(KERN_DEFAULT); |
6fcbede3 | 144 | __show_regs(regs, 1); |
6fcbede3 AH |
145 | |
146 | /* | |
147 | * When in-kernel, we also print out the stack and code at the | |
148 | * time of the fault.. | |
149 | */ | |
150 | if (!user_mode(regs)) { | |
151 | unsigned int code_prologue = code_bytes * 43 / 64; | |
152 | unsigned int code_len = code_bytes; | |
153 | unsigned char c; | |
154 | u8 *ip; | |
155 | ||
0ee1dd9f | 156 | show_trace_log_lvl(current, regs, NULL, KERN_DEFAULT); |
6fcbede3 | 157 | |
b0f4c4b3 | 158 | printk(KERN_DEFAULT "Code: "); |
6fcbede3 AH |
159 | |
160 | ip = (u8 *)regs->ip - code_prologue; | |
161 | if (ip < (u8 *)PAGE_OFFSET || probe_kernel_address(ip, c)) { | |
8a541665 | 162 | /* try starting at IP */ |
6fcbede3 AH |
163 | ip = (u8 *)regs->ip; |
164 | code_len = code_len - code_prologue + 1; | |
165 | } | |
166 | for (i = 0; i < code_len; i++, ip++) { | |
167 | if (ip < (u8 *)PAGE_OFFSET || | |
168 | probe_kernel_address(ip, c)) { | |
c767a54b | 169 | pr_cont(" Bad RIP value."); |
6fcbede3 AH |
170 | break; |
171 | } | |
172 | if (ip == (u8 *)regs->ip) | |
c767a54b | 173 | pr_cont("<%02x> ", c); |
6fcbede3 | 174 | else |
c767a54b | 175 | pr_cont("%02x ", c); |
6fcbede3 AH |
176 | } |
177 | } | |
c767a54b | 178 | pr_cont("\n"); |
6fcbede3 AH |
179 | } |
180 | ||
181 | int is_valid_bugaddr(unsigned long ip) | |
182 | { | |
183 | unsigned short ud2; | |
184 | ||
185 | if (__copy_from_user(&ud2, (const void __user *) ip, sizeof(ud2))) | |
186 | return 0; | |
187 | ||
188 | return ud2 == 0x0b0f; | |
189 | } |