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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 | */ | |
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> | |
10 | #include <linux/module.h> | |
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 | ||
6fcbede3 | 19 | |
b8030906 IM |
20 | #define N_EXCEPTION_STACKS_END \ |
21 | (N_EXCEPTION_STACKS + DEBUG_STKSZ/EXCEPTION_STKSZ - 2) | |
0406ca6d FW |
22 | |
23 | static char x86_stack_ids[][8] = { | |
b8030906 IM |
24 | [ DEBUG_STACK-1 ] = "#DB", |
25 | [ NMI_STACK-1 ] = "NMI", | |
26 | [ DOUBLEFAULT_STACK-1 ] = "#DF", | |
b8030906 | 27 | [ MCE_STACK-1 ] = "#MC", |
6fcbede3 | 28 | #if DEBUG_STKSZ > EXCEPTION_STKSZ |
b8030906 IM |
29 | [ N_EXCEPTION_STACKS ... |
30 | N_EXCEPTION_STACKS_END ] = "#DB[?]" | |
6fcbede3 | 31 | #endif |
b8030906 | 32 | }; |
0406ca6d | 33 | |
0406ca6d | 34 | static unsigned long *in_exception_stack(unsigned cpu, unsigned long stack, |
b8030906 | 35 | unsigned *usedp, char **idp) |
0406ca6d | 36 | { |
6fcbede3 AH |
37 | unsigned k; |
38 | ||
39 | /* | |
40 | * Iterate over all exception stacks, and figure out whether | |
41 | * 'stack' is in one of them: | |
42 | */ | |
43 | for (k = 0; k < N_EXCEPTION_STACKS; k++) { | |
44 | unsigned long end = per_cpu(orig_ist, cpu).ist[k]; | |
45 | /* | |
46 | * Is 'stack' above this exception frame's end? | |
47 | * If yes then skip to the next frame. | |
48 | */ | |
49 | if (stack >= end) | |
50 | continue; | |
51 | /* | |
52 | * Is 'stack' above this exception frame's start address? | |
53 | * If yes then we found the right frame. | |
54 | */ | |
55 | if (stack >= end - EXCEPTION_STKSZ) { | |
56 | /* | |
57 | * Make sure we only iterate through an exception | |
58 | * stack once. If it comes up for the second time | |
59 | * then there's something wrong going on - just | |
60 | * break out and return NULL: | |
61 | */ | |
62 | if (*usedp & (1U << k)) | |
63 | break; | |
64 | *usedp |= 1U << k; | |
0406ca6d | 65 | *idp = x86_stack_ids[k]; |
6fcbede3 AH |
66 | return (unsigned long *)end; |
67 | } | |
68 | /* | |
69 | * If this is a debug stack, and if it has a larger size than | |
70 | * the usual exception stacks, then 'stack' might still | |
71 | * be within the lower portion of the debug stack: | |
72 | */ | |
73 | #if DEBUG_STKSZ > EXCEPTION_STKSZ | |
74 | if (k == DEBUG_STACK - 1 && stack >= end - DEBUG_STKSZ) { | |
75 | unsigned j = N_EXCEPTION_STACKS - 1; | |
76 | ||
77 | /* | |
78 | * Black magic. A large debug stack is composed of | |
79 | * multiple exception stack entries, which we | |
80 | * iterate through now. Dont look: | |
81 | */ | |
82 | do { | |
83 | ++j; | |
84 | end -= EXCEPTION_STKSZ; | |
0406ca6d FW |
85 | x86_stack_ids[j][4] = '1' + |
86 | (j - N_EXCEPTION_STACKS); | |
6fcbede3 AH |
87 | } while (stack < end - EXCEPTION_STKSZ); |
88 | if (*usedp & (1U << j)) | |
89 | break; | |
90 | *usedp |= 1U << j; | |
0406ca6d | 91 | *idp = x86_stack_ids[j]; |
6fcbede3 AH |
92 | return (unsigned long *)end; |
93 | } | |
94 | #endif | |
95 | } | |
96 | return NULL; | |
97 | } | |
98 | ||
af2d8289 FW |
99 | static inline int |
100 | in_irq_stack(unsigned long *stack, unsigned long *irq_stack, | |
101 | unsigned long *irq_stack_end) | |
102 | { | |
103 | return (stack >= irq_stack && stack < irq_stack_end); | |
104 | } | |
105 | ||
2223f6f6 SR |
106 | static const unsigned long irq_stack_size = |
107 | (IRQ_STACK_SIZE - 64) / sizeof(unsigned long); | |
108 | ||
109 | enum stack_type { | |
110 | STACK_IS_UNKNOWN, | |
111 | STACK_IS_NORMAL, | |
112 | STACK_IS_EXCEPTION, | |
113 | STACK_IS_IRQ, | |
114 | }; | |
115 | ||
116 | static enum stack_type | |
1aabc599 | 117 | analyze_stack(int cpu, struct task_struct *task, unsigned long *stack, |
63c95654 SRRH |
118 | unsigned long **stack_end, unsigned long *irq_stack, |
119 | unsigned *used, char **id) | |
2223f6f6 | 120 | { |
2223f6f6 | 121 | unsigned long addr; |
2223f6f6 SR |
122 | |
123 | addr = ((unsigned long)stack & (~(THREAD_SIZE - 1))); | |
124 | if ((unsigned long)task_stack_page(task) == addr) | |
125 | return STACK_IS_NORMAL; | |
126 | ||
127 | *stack_end = in_exception_stack(cpu, (unsigned long)stack, | |
1aabc599 | 128 | used, id); |
2223f6f6 SR |
129 | if (*stack_end) |
130 | return STACK_IS_EXCEPTION; | |
131 | ||
63c95654 SRRH |
132 | if (!irq_stack) |
133 | return STACK_IS_NORMAL; | |
2223f6f6 | 134 | |
63c95654 SRRH |
135 | *stack_end = irq_stack; |
136 | irq_stack = irq_stack - irq_stack_size; | |
2223f6f6 SR |
137 | |
138 | if (in_irq_stack(stack, irq_stack, *stack_end)) | |
139 | return STACK_IS_IRQ; | |
140 | ||
141 | return STACK_IS_UNKNOWN; | |
142 | } | |
143 | ||
6fcbede3 AH |
144 | /* |
145 | * x86-64 can have up to three kernel stacks: | |
146 | * process stack | |
147 | * interrupt stack | |
148 | * severe exception (double fault, nmi, stack fault, debug, mce) hardware stack | |
149 | */ | |
150 | ||
e8e999cf NK |
151 | void dump_trace(struct task_struct *task, struct pt_regs *regs, |
152 | unsigned long *stack, unsigned long bp, | |
6fcbede3 AH |
153 | const struct stacktrace_ops *ops, void *data) |
154 | { | |
155 | const unsigned cpu = get_cpu(); | |
6fcbede3 | 156 | struct thread_info *tinfo; |
63c95654 | 157 | unsigned long *irq_stack = (unsigned long *)per_cpu(irq_stack_ptr, cpu); |
2e5aa682 | 158 | unsigned long dummy; |
1aabc599 | 159 | unsigned used = 0; |
2223f6f6 SR |
160 | int graph = 0; |
161 | int done = 0; | |
6fcbede3 AH |
162 | |
163 | if (!task) | |
164 | task = current; | |
165 | ||
166 | if (!stack) { | |
47ce11a2 FW |
167 | if (regs) |
168 | stack = (unsigned long *)regs->sp; | |
d0caf292 | 169 | else if (task != current) |
6fcbede3 | 170 | stack = (unsigned long *)task->thread.sp; |
47ce11a2 FW |
171 | else |
172 | stack = &dummy; | |
6fcbede3 AH |
173 | } |
174 | ||
e8e999cf NK |
175 | if (!bp) |
176 | bp = stack_frame(task, regs); | |
6fcbede3 AH |
177 | /* |
178 | * Print function call entries in all stacks, starting at the | |
179 | * current stack address. If the stacks consist of nested | |
180 | * exceptions | |
181 | */ | |
182 | tinfo = task_thread_info(task); | |
2223f6f6 SR |
183 | while (!done) { |
184 | unsigned long *stack_end; | |
185 | enum stack_type stype; | |
6fcbede3 | 186 | char *id; |
6fcbede3 | 187 | |
63c95654 SRRH |
188 | stype = analyze_stack(cpu, task, stack, &stack_end, |
189 | irq_stack, &used, &id); | |
2223f6f6 SR |
190 | |
191 | /* Default finish unless specified to continue */ | |
192 | done = 1; | |
193 | ||
194 | switch (stype) { | |
195 | ||
196 | /* Break out early if we are on the thread stack */ | |
197 | case STACK_IS_NORMAL: | |
198 | break; | |
199 | ||
200 | case STACK_IS_EXCEPTION: | |
201 | ||
6fcbede3 AH |
202 | if (ops->stack(data, id) < 0) |
203 | break; | |
204 | ||
61c1917f | 205 | bp = ops->walk_stack(tinfo, stack, bp, ops, |
2223f6f6 | 206 | data, stack_end, &graph); |
6fcbede3 AH |
207 | ops->stack(data, "<EOE>"); |
208 | /* | |
209 | * We link to the next stack via the | |
210 | * second-to-last pointer (index -2 to end) in the | |
211 | * exception stack: | |
212 | */ | |
2223f6f6 SR |
213 | stack = (unsigned long *) stack_end[-2]; |
214 | done = 0; | |
215 | break; | |
216 | ||
217 | case STACK_IS_IRQ: | |
218 | ||
219 | if (ops->stack(data, "IRQ") < 0) | |
220 | break; | |
221 | bp = ops->walk_stack(tinfo, stack, bp, | |
222 | ops, data, stack_end, &graph); | |
223 | /* | |
224 | * We link to the next stack (which would be | |
225 | * the process stack normally) the last | |
226 | * pointer (index -1 to end) in the IRQ stack: | |
227 | */ | |
228 | stack = (unsigned long *) (stack_end[-1]); | |
63c95654 | 229 | irq_stack = NULL; |
2223f6f6 SR |
230 | ops->stack(data, "EOI"); |
231 | done = 0; | |
232 | break; | |
233 | ||
234 | case STACK_IS_UNKNOWN: | |
235 | ops->stack(data, "UNK"); | |
236 | break; | |
6fcbede3 | 237 | } |
6fcbede3 AH |
238 | } |
239 | ||
240 | /* | |
241 | * This handles the process stack: | |
242 | */ | |
61e67fb9 | 243 | bp = ops->walk_stack(tinfo, stack, bp, ops, data, NULL, &graph); |
6fcbede3 AH |
244 | put_cpu(); |
245 | } | |
246 | EXPORT_SYMBOL(dump_trace); | |
247 | ||
878719e8 | 248 | void |
6fcbede3 | 249 | show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs, |
e8e999cf | 250 | unsigned long *sp, unsigned long bp, char *log_lvl) |
6fcbede3 | 251 | { |
67f2de0b IM |
252 | unsigned long *irq_stack_end; |
253 | unsigned long *irq_stack; | |
6fcbede3 | 254 | unsigned long *stack; |
67f2de0b | 255 | int cpu; |
6fcbede3 | 256 | int i; |
67f2de0b IM |
257 | |
258 | preempt_disable(); | |
259 | cpu = smp_processor_id(); | |
260 | ||
261 | irq_stack_end = (unsigned long *)(per_cpu(irq_stack_ptr, cpu)); | |
262 | irq_stack = (unsigned long *)(per_cpu(irq_stack_ptr, cpu) - IRQ_STACK_SIZE); | |
6fcbede3 AH |
263 | |
264 | /* | |
67f2de0b IM |
265 | * Debugging aid: "show_stack(NULL, NULL);" prints the |
266 | * back trace for this cpu: | |
6fcbede3 | 267 | */ |
6fcbede3 AH |
268 | if (sp == NULL) { |
269 | if (task) | |
270 | sp = (unsigned long *)task->thread.sp; | |
271 | else | |
272 | sp = (unsigned long *)&sp; | |
273 | } | |
274 | ||
275 | stack = sp; | |
276 | for (i = 0; i < kstack_depth_to_print; i++) { | |
26f80bd6 BG |
277 | if (stack >= irq_stack && stack <= irq_stack_end) { |
278 | if (stack == irq_stack_end) { | |
279 | stack = (unsigned long *) (irq_stack_end[-1]); | |
c767a54b | 280 | pr_cont(" <EOI> "); |
6fcbede3 AH |
281 | } |
282 | } else { | |
04769ae3 | 283 | if (kstack_end(stack)) |
6fcbede3 AH |
284 | break; |
285 | } | |
1fc7f61c AS |
286 | if ((i % STACKSLOTS_PER_LINE) == 0) { |
287 | if (i != 0) | |
288 | pr_cont("\n"); | |
289 | printk("%s %016lx", log_lvl, *stack++); | |
290 | } else | |
291 | pr_cont(" %016lx", *stack++); | |
6fcbede3 AH |
292 | touch_nmi_watchdog(); |
293 | } | |
67f2de0b IM |
294 | preempt_enable(); |
295 | ||
c767a54b | 296 | pr_cont("\n"); |
e8e999cf | 297 | show_trace_log_lvl(task, regs, sp, bp, log_lvl); |
6fcbede3 AH |
298 | } |
299 | ||
57da8b96 | 300 | void show_regs(struct pt_regs *regs) |
6fcbede3 AH |
301 | { |
302 | int i; | |
303 | unsigned long sp; | |
6fcbede3 AH |
304 | |
305 | sp = regs->sp; | |
a43cb95d | 306 | show_regs_print_info(KERN_DEFAULT); |
6fcbede3 | 307 | __show_regs(regs, 1); |
6fcbede3 AH |
308 | |
309 | /* | |
310 | * When in-kernel, we also print out the stack and code at the | |
311 | * time of the fault.. | |
312 | */ | |
313 | if (!user_mode(regs)) { | |
314 | unsigned int code_prologue = code_bytes * 43 / 64; | |
315 | unsigned int code_len = code_bytes; | |
316 | unsigned char c; | |
317 | u8 *ip; | |
318 | ||
b0f4c4b3 | 319 | printk(KERN_DEFAULT "Stack:\n"); |
6fcbede3 | 320 | show_stack_log_lvl(NULL, regs, (unsigned long *)sp, |
b0f4c4b3 | 321 | 0, KERN_DEFAULT); |
6fcbede3 | 322 | |
b0f4c4b3 | 323 | printk(KERN_DEFAULT "Code: "); |
6fcbede3 AH |
324 | |
325 | ip = (u8 *)regs->ip - code_prologue; | |
326 | if (ip < (u8 *)PAGE_OFFSET || probe_kernel_address(ip, c)) { | |
8a541665 | 327 | /* try starting at IP */ |
6fcbede3 AH |
328 | ip = (u8 *)regs->ip; |
329 | code_len = code_len - code_prologue + 1; | |
330 | } | |
331 | for (i = 0; i < code_len; i++, ip++) { | |
332 | if (ip < (u8 *)PAGE_OFFSET || | |
333 | probe_kernel_address(ip, c)) { | |
c767a54b | 334 | pr_cont(" Bad RIP value."); |
6fcbede3 AH |
335 | break; |
336 | } | |
337 | if (ip == (u8 *)regs->ip) | |
c767a54b | 338 | pr_cont("<%02x> ", c); |
6fcbede3 | 339 | else |
c767a54b | 340 | pr_cont("%02x ", c); |
6fcbede3 AH |
341 | } |
342 | } | |
c767a54b | 343 | pr_cont("\n"); |
6fcbede3 AH |
344 | } |
345 | ||
346 | int is_valid_bugaddr(unsigned long ip) | |
347 | { | |
348 | unsigned short ud2; | |
349 | ||
350 | if (__copy_from_user(&ud2, (const void __user *) ip, sizeof(ud2))) | |
351 | return 0; | |
352 | ||
353 | return ud2 == 0x0b0f; | |
354 | } |