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", | |
27 | [ STACKFAULT_STACK-1 ] = "#SS", | |
28 | [ MCE_STACK-1 ] = "#MC", | |
6fcbede3 | 29 | #if DEBUG_STKSZ > EXCEPTION_STKSZ |
b8030906 IM |
30 | [ N_EXCEPTION_STACKS ... |
31 | N_EXCEPTION_STACKS_END ] = "#DB[?]" | |
6fcbede3 | 32 | #endif |
b8030906 | 33 | }; |
0406ca6d | 34 | |
0406ca6d | 35 | static unsigned long *in_exception_stack(unsigned cpu, unsigned long stack, |
b8030906 | 36 | unsigned *usedp, char **idp) |
0406ca6d | 37 | { |
6fcbede3 AH |
38 | unsigned k; |
39 | ||
40 | /* | |
41 | * Iterate over all exception stacks, and figure out whether | |
42 | * 'stack' is in one of them: | |
43 | */ | |
44 | for (k = 0; k < N_EXCEPTION_STACKS; k++) { | |
45 | unsigned long end = per_cpu(orig_ist, cpu).ist[k]; | |
46 | /* | |
47 | * Is 'stack' above this exception frame's end? | |
48 | * If yes then skip to the next frame. | |
49 | */ | |
50 | if (stack >= end) | |
51 | continue; | |
52 | /* | |
53 | * Is 'stack' above this exception frame's start address? | |
54 | * If yes then we found the right frame. | |
55 | */ | |
56 | if (stack >= end - EXCEPTION_STKSZ) { | |
57 | /* | |
58 | * Make sure we only iterate through an exception | |
59 | * stack once. If it comes up for the second time | |
60 | * then there's something wrong going on - just | |
61 | * break out and return NULL: | |
62 | */ | |
63 | if (*usedp & (1U << k)) | |
64 | break; | |
65 | *usedp |= 1U << k; | |
0406ca6d | 66 | *idp = x86_stack_ids[k]; |
6fcbede3 AH |
67 | return (unsigned long *)end; |
68 | } | |
69 | /* | |
70 | * If this is a debug stack, and if it has a larger size than | |
71 | * the usual exception stacks, then 'stack' might still | |
72 | * be within the lower portion of the debug stack: | |
73 | */ | |
74 | #if DEBUG_STKSZ > EXCEPTION_STKSZ | |
75 | if (k == DEBUG_STACK - 1 && stack >= end - DEBUG_STKSZ) { | |
76 | unsigned j = N_EXCEPTION_STACKS - 1; | |
77 | ||
78 | /* | |
79 | * Black magic. A large debug stack is composed of | |
80 | * multiple exception stack entries, which we | |
81 | * iterate through now. Dont look: | |
82 | */ | |
83 | do { | |
84 | ++j; | |
85 | end -= EXCEPTION_STKSZ; | |
0406ca6d FW |
86 | x86_stack_ids[j][4] = '1' + |
87 | (j - N_EXCEPTION_STACKS); | |
6fcbede3 AH |
88 | } while (stack < end - EXCEPTION_STKSZ); |
89 | if (*usedp & (1U << j)) | |
90 | break; | |
91 | *usedp |= 1U << j; | |
0406ca6d | 92 | *idp = x86_stack_ids[j]; |
6fcbede3 AH |
93 | return (unsigned long *)end; |
94 | } | |
95 | #endif | |
96 | } | |
97 | return NULL; | |
98 | } | |
99 | ||
af2d8289 FW |
100 | static inline int |
101 | in_irq_stack(unsigned long *stack, unsigned long *irq_stack, | |
102 | unsigned long *irq_stack_end) | |
103 | { | |
104 | return (stack >= irq_stack && stack < irq_stack_end); | |
105 | } | |
106 | ||
107 | /* | |
108 | * We are returning from the irq stack and go to the previous one. | |
109 | * If the previous stack is also in the irq stack, then bp in the first | |
110 | * frame of the irq stack points to the previous, interrupted one. | |
111 | * Otherwise we have another level of indirection: We first save | |
112 | * the bp of the previous stack, then we switch the stack to the irq one | |
113 | * and save a new bp that links to the previous one. | |
114 | * (See save_args()) | |
115 | */ | |
116 | static inline unsigned long | |
117 | fixup_bp_irq_link(unsigned long bp, unsigned long *stack, | |
118 | unsigned long *irq_stack, unsigned long *irq_stack_end) | |
119 | { | |
120 | #ifdef CONFIG_FRAME_POINTER | |
121 | struct stack_frame *frame = (struct stack_frame *)bp; | |
29044ad1 | 122 | unsigned long next; |
af2d8289 | 123 | |
29044ad1 FW |
124 | if (!in_irq_stack(stack, irq_stack, irq_stack_end)) { |
125 | if (!probe_kernel_address(&frame->next_frame, next)) | |
126 | return next; | |
127 | else | |
128 | WARN_ONCE(1, "Perf: bad frame pointer = %p in " | |
129 | "callchain\n", &frame->next_frame); | |
130 | } | |
af2d8289 FW |
131 | #endif |
132 | return bp; | |
133 | } | |
134 | ||
6fcbede3 AH |
135 | /* |
136 | * x86-64 can have up to three kernel stacks: | |
137 | * process stack | |
138 | * interrupt stack | |
139 | * severe exception (double fault, nmi, stack fault, debug, mce) hardware stack | |
140 | */ | |
141 | ||
e8e999cf NK |
142 | void dump_trace(struct task_struct *task, struct pt_regs *regs, |
143 | unsigned long *stack, unsigned long bp, | |
6fcbede3 AH |
144 | const struct stacktrace_ops *ops, void *data) |
145 | { | |
146 | const unsigned cpu = get_cpu(); | |
26f80bd6 BG |
147 | unsigned long *irq_stack_end = |
148 | (unsigned long *)per_cpu(irq_stack_ptr, cpu); | |
6fcbede3 AH |
149 | unsigned used = 0; |
150 | struct thread_info *tinfo; | |
7ee991fb | 151 | int graph = 0; |
2e5aa682 | 152 | unsigned long dummy; |
6fcbede3 AH |
153 | |
154 | if (!task) | |
155 | task = current; | |
156 | ||
157 | if (!stack) { | |
6fcbede3 AH |
158 | stack = &dummy; |
159 | if (task && task != current) | |
160 | stack = (unsigned long *)task->thread.sp; | |
161 | } | |
162 | ||
e8e999cf NK |
163 | if (!bp) |
164 | bp = stack_frame(task, regs); | |
6fcbede3 AH |
165 | /* |
166 | * Print function call entries in all stacks, starting at the | |
167 | * current stack address. If the stacks consist of nested | |
168 | * exceptions | |
169 | */ | |
170 | tinfo = task_thread_info(task); | |
171 | for (;;) { | |
172 | char *id; | |
173 | unsigned long *estack_end; | |
174 | estack_end = in_exception_stack(cpu, (unsigned long)stack, | |
175 | &used, &id); | |
176 | ||
177 | if (estack_end) { | |
178 | if (ops->stack(data, id) < 0) | |
179 | break; | |
180 | ||
61c1917f FW |
181 | bp = ops->walk_stack(tinfo, stack, bp, ops, |
182 | data, estack_end, &graph); | |
6fcbede3 AH |
183 | ops->stack(data, "<EOE>"); |
184 | /* | |
185 | * We link to the next stack via the | |
186 | * second-to-last pointer (index -2 to end) in the | |
187 | * exception stack: | |
188 | */ | |
189 | stack = (unsigned long *) estack_end[-2]; | |
190 | continue; | |
191 | } | |
26f80bd6 BG |
192 | if (irq_stack_end) { |
193 | unsigned long *irq_stack; | |
194 | irq_stack = irq_stack_end - | |
195 | (IRQ_STACK_SIZE - 64) / sizeof(*irq_stack); | |
6fcbede3 | 196 | |
af2d8289 | 197 | if (in_irq_stack(stack, irq_stack, irq_stack_end)) { |
6fcbede3 AH |
198 | if (ops->stack(data, "IRQ") < 0) |
199 | break; | |
61e67fb9 | 200 | bp = ops->walk_stack(tinfo, stack, bp, |
26f80bd6 | 201 | ops, data, irq_stack_end, &graph); |
6fcbede3 AH |
202 | /* |
203 | * We link to the next stack (which would be | |
204 | * the process stack normally) the last | |
205 | * pointer (index -1 to end) in the IRQ stack: | |
206 | */ | |
26f80bd6 | 207 | stack = (unsigned long *) (irq_stack_end[-1]); |
af2d8289 FW |
208 | bp = fixup_bp_irq_link(bp, stack, irq_stack, |
209 | irq_stack_end); | |
26f80bd6 | 210 | irq_stack_end = NULL; |
6fcbede3 AH |
211 | ops->stack(data, "EOI"); |
212 | continue; | |
213 | } | |
214 | } | |
215 | break; | |
216 | } | |
217 | ||
218 | /* | |
219 | * This handles the process stack: | |
220 | */ | |
61e67fb9 | 221 | bp = ops->walk_stack(tinfo, stack, bp, ops, data, NULL, &graph); |
6fcbede3 AH |
222 | put_cpu(); |
223 | } | |
224 | EXPORT_SYMBOL(dump_trace); | |
225 | ||
878719e8 | 226 | void |
6fcbede3 | 227 | show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs, |
e8e999cf | 228 | unsigned long *sp, unsigned long bp, char *log_lvl) |
6fcbede3 | 229 | { |
67f2de0b IM |
230 | unsigned long *irq_stack_end; |
231 | unsigned long *irq_stack; | |
6fcbede3 | 232 | unsigned long *stack; |
67f2de0b | 233 | int cpu; |
6fcbede3 | 234 | int i; |
67f2de0b IM |
235 | |
236 | preempt_disable(); | |
237 | cpu = smp_processor_id(); | |
238 | ||
239 | irq_stack_end = (unsigned long *)(per_cpu(irq_stack_ptr, cpu)); | |
240 | irq_stack = (unsigned long *)(per_cpu(irq_stack_ptr, cpu) - IRQ_STACK_SIZE); | |
6fcbede3 AH |
241 | |
242 | /* | |
67f2de0b IM |
243 | * Debugging aid: "show_stack(NULL, NULL);" prints the |
244 | * back trace for this cpu: | |
6fcbede3 | 245 | */ |
6fcbede3 AH |
246 | if (sp == NULL) { |
247 | if (task) | |
248 | sp = (unsigned long *)task->thread.sp; | |
249 | else | |
250 | sp = (unsigned long *)&sp; | |
251 | } | |
252 | ||
253 | stack = sp; | |
254 | for (i = 0; i < kstack_depth_to_print; i++) { | |
26f80bd6 BG |
255 | if (stack >= irq_stack && stack <= irq_stack_end) { |
256 | if (stack == irq_stack_end) { | |
257 | stack = (unsigned long *) (irq_stack_end[-1]); | |
e4072a9a | 258 | printk(KERN_CONT " <EOI> "); |
6fcbede3 AH |
259 | } |
260 | } else { | |
261 | if (((long) stack & (THREAD_SIZE-1)) == 0) | |
262 | break; | |
263 | } | |
8a541665 | 264 | if (i && ((i % STACKSLOTS_PER_LINE) == 0)) |
e4072a9a JS |
265 | printk(KERN_CONT "\n"); |
266 | printk(KERN_CONT " %016lx", *stack++); | |
6fcbede3 AH |
267 | touch_nmi_watchdog(); |
268 | } | |
67f2de0b IM |
269 | preempt_enable(); |
270 | ||
e4072a9a | 271 | printk(KERN_CONT "\n"); |
e8e999cf | 272 | show_trace_log_lvl(task, regs, sp, bp, log_lvl); |
6fcbede3 AH |
273 | } |
274 | ||
6fcbede3 AH |
275 | void show_registers(struct pt_regs *regs) |
276 | { | |
277 | int i; | |
278 | unsigned long sp; | |
279 | const int cpu = smp_processor_id(); | |
c6f5e0ac | 280 | struct task_struct *cur = current; |
6fcbede3 AH |
281 | |
282 | sp = regs->sp; | |
283 | printk("CPU %d ", cpu); | |
f266d7f5 | 284 | print_modules(); |
6fcbede3 AH |
285 | __show_regs(regs, 1); |
286 | printk("Process %s (pid: %d, threadinfo %p, task %p)\n", | |
287 | cur->comm, cur->pid, task_thread_info(cur), cur); | |
288 | ||
289 | /* | |
290 | * When in-kernel, we also print out the stack and code at the | |
291 | * time of the fault.. | |
292 | */ | |
293 | if (!user_mode(regs)) { | |
294 | unsigned int code_prologue = code_bytes * 43 / 64; | |
295 | unsigned int code_len = code_bytes; | |
296 | unsigned char c; | |
297 | u8 *ip; | |
298 | ||
ca0a8164 | 299 | printk(KERN_EMERG "Stack:\n"); |
6fcbede3 | 300 | show_stack_log_lvl(NULL, regs, (unsigned long *)sp, |
e8e999cf | 301 | 0, KERN_EMERG); |
6fcbede3 AH |
302 | |
303 | printk(KERN_EMERG "Code: "); | |
304 | ||
305 | ip = (u8 *)regs->ip - code_prologue; | |
306 | if (ip < (u8 *)PAGE_OFFSET || probe_kernel_address(ip, c)) { | |
8a541665 | 307 | /* try starting at IP */ |
6fcbede3 AH |
308 | ip = (u8 *)regs->ip; |
309 | code_len = code_len - code_prologue + 1; | |
310 | } | |
311 | for (i = 0; i < code_len; i++, ip++) { | |
312 | if (ip < (u8 *)PAGE_OFFSET || | |
313 | probe_kernel_address(ip, c)) { | |
314 | printk(" Bad RIP value."); | |
315 | break; | |
316 | } | |
317 | if (ip == (u8 *)regs->ip) | |
318 | printk("<%02x> ", c); | |
319 | else | |
320 | printk("%02x ", c); | |
321 | } | |
322 | } | |
323 | printk("\n"); | |
324 | } | |
325 | ||
326 | int is_valid_bugaddr(unsigned long ip) | |
327 | { | |
328 | unsigned short ud2; | |
329 | ||
330 | if (__copy_from_user(&ud2, (const void __user *) ip, sizeof(ud2))) | |
331 | return 0; | |
332 | ||
333 | return ud2 == 0x0b0f; | |
334 | } |