Commit | Line | Data |
---|---|---|
878719e8 NH |
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> | |
8 | #include <linux/utsname.h> | |
9 | #include <linux/hardirq.h> | |
10 | #include <linux/kdebug.h> | |
11 | #include <linux/module.h> | |
12 | #include <linux/ptrace.h> | |
712406a6 | 13 | #include <linux/ftrace.h> |
878719e8 NH |
14 | #include <linux/kexec.h> |
15 | #include <linux/bug.h> | |
16 | #include <linux/nmi.h> | |
17 | #include <linux/sysfs.h> | |
18 | ||
19 | #include <asm/stacktrace.h> | |
20 | ||
878719e8 NH |
21 | |
22 | int panic_on_unrecovered_nmi; | |
5211a242 | 23 | int panic_on_io_nmi; |
878719e8 NH |
24 | unsigned int code_bytes = 64; |
25 | int kstack_depth_to_print = 3 * STACKSLOTS_PER_LINE; | |
26 | static int die_counter; | |
27 | ||
1fc7f61c AS |
28 | static void printk_stack_address(unsigned long address, int reliable, |
29 | void *data) | |
878719e8 | 30 | { |
1fc7f61c AS |
31 | printk("%s [<%p>] %s%pB\n", |
32 | (char *)data, (void *)address, reliable ? "" : "? ", | |
33 | (void *)address); | |
878719e8 NH |
34 | } |
35 | ||
5f01c988 JS |
36 | void printk_address(unsigned long address) |
37 | { | |
38 | pr_cont(" [<%p>] %pS\n", (void *)address, (void *)address); | |
39 | } | |
40 | ||
7ee991fb SR |
41 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
42 | static void | |
43 | print_ftrace_graph_addr(unsigned long addr, void *data, | |
44 | const struct stacktrace_ops *ops, | |
da01e18a | 45 | struct task_struct *task, int *graph) |
7ee991fb | 46 | { |
7ee991fb | 47 | unsigned long ret_addr; |
65c0ff40 | 48 | int index; |
7ee991fb SR |
49 | |
50 | if (addr != (unsigned long)return_to_handler) | |
51 | return; | |
52 | ||
65c0ff40 HD |
53 | index = task->curr_ret_stack; |
54 | ||
7ee991fb SR |
55 | if (!task->ret_stack || index < *graph) |
56 | return; | |
57 | ||
58 | index -= *graph; | |
59 | ret_addr = task->ret_stack[index].ret; | |
60 | ||
61 | ops->address(data, ret_addr, 1); | |
62 | ||
63 | (*graph)++; | |
64 | } | |
65 | #else | |
66 | static inline void | |
67 | print_ftrace_graph_addr(unsigned long addr, void *data, | |
68 | const struct stacktrace_ops *ops, | |
da01e18a | 69 | struct task_struct *task, int *graph) |
7ee991fb SR |
70 | { } |
71 | #endif | |
72 | ||
878719e8 NH |
73 | /* |
74 | * x86-64 can have up to three kernel stacks: | |
75 | * process stack | |
76 | * interrupt stack | |
77 | * severe exception (double fault, nmi, stack fault, debug, mce) hardware stack | |
78 | */ | |
79 | ||
da01e18a | 80 | static inline int valid_stack_ptr(struct task_struct *task, |
878719e8 NH |
81 | void *p, unsigned int size, void *end) |
82 | { | |
aca9c293 | 83 | void *t = task_stack_page(task); |
878719e8 NH |
84 | if (end) { |
85 | if (p < end && p >= (end-THREAD_SIZE)) | |
86 | return 1; | |
87 | else | |
88 | return 0; | |
89 | } | |
9a2e9da3 | 90 | return p >= t && p < t + THREAD_SIZE - size; |
878719e8 NH |
91 | } |
92 | ||
93 | unsigned long | |
da01e18a | 94 | print_context_stack(struct task_struct *task, |
878719e8 NH |
95 | unsigned long *stack, unsigned long bp, |
96 | const struct stacktrace_ops *ops, void *data, | |
7ee991fb | 97 | unsigned long *end, int *graph) |
878719e8 NH |
98 | { |
99 | struct stack_frame *frame = (struct stack_frame *)bp; | |
100 | ||
9a2e9da3 AL |
101 | /* |
102 | * If we overflowed the stack into a guard page, jump back to the | |
103 | * bottom of the usable stack. | |
104 | */ | |
105 | if ((unsigned long)task_stack_page(task) - (unsigned long)stack < | |
106 | PAGE_SIZE) | |
107 | stack = (unsigned long *)task_stack_page(task); | |
108 | ||
da01e18a | 109 | while (valid_stack_ptr(task, stack, sizeof(*stack), end)) { |
878719e8 NH |
110 | unsigned long addr; |
111 | ||
112 | addr = *stack; | |
113 | if (__kernel_text_address(addr)) { | |
114 | if ((unsigned long) stack == bp + sizeof(long)) { | |
115 | ops->address(data, addr, 1); | |
116 | frame = frame->next_frame; | |
117 | bp = (unsigned long) frame; | |
118 | } else { | |
2c344e9d | 119 | ops->address(data, addr, 0); |
878719e8 | 120 | } |
da01e18a | 121 | print_ftrace_graph_addr(addr, data, ops, task, graph); |
878719e8 NH |
122 | } |
123 | stack++; | |
124 | } | |
125 | return bp; | |
126 | } | |
06d65bda FW |
127 | EXPORT_SYMBOL_GPL(print_context_stack); |
128 | ||
129 | unsigned long | |
da01e18a | 130 | print_context_stack_bp(struct task_struct *task, |
06d65bda FW |
131 | unsigned long *stack, unsigned long bp, |
132 | const struct stacktrace_ops *ops, void *data, | |
133 | unsigned long *end, int *graph) | |
134 | { | |
135 | struct stack_frame *frame = (struct stack_frame *)bp; | |
136 | unsigned long *ret_addr = &frame->return_address; | |
137 | ||
da01e18a | 138 | while (valid_stack_ptr(task, ret_addr, sizeof(*ret_addr), end)) { |
06d65bda FW |
139 | unsigned long addr = *ret_addr; |
140 | ||
c2c5d45d FW |
141 | if (!__kernel_text_address(addr)) |
142 | break; | |
143 | ||
568b329a AS |
144 | if (ops->address(data, addr, 1)) |
145 | break; | |
c2c5d45d FW |
146 | frame = frame->next_frame; |
147 | ret_addr = &frame->return_address; | |
da01e18a | 148 | print_ftrace_graph_addr(addr, data, ops, task, graph); |
06d65bda | 149 | } |
c2c5d45d | 150 | |
06d65bda FW |
151 | return (unsigned long)frame; |
152 | } | |
153 | EXPORT_SYMBOL_GPL(print_context_stack_bp); | |
878719e8 | 154 | |
878719e8 NH |
155 | static int print_trace_stack(void *data, char *name) |
156 | { | |
157 | printk("%s <%s> ", (char *)data, name); | |
158 | return 0; | |
159 | } | |
160 | ||
161 | /* | |
162 | * Print one address/symbol entries per line. | |
163 | */ | |
568b329a | 164 | static int print_trace_address(void *data, unsigned long addr, int reliable) |
878719e8 NH |
165 | { |
166 | touch_nmi_watchdog(); | |
1fc7f61c | 167 | printk_stack_address(addr, reliable, data); |
568b329a | 168 | return 0; |
878719e8 NH |
169 | } |
170 | ||
171 | static const struct stacktrace_ops print_trace_ops = { | |
06d65bda FW |
172 | .stack = print_trace_stack, |
173 | .address = print_trace_address, | |
61c1917f | 174 | .walk_stack = print_context_stack, |
878719e8 NH |
175 | }; |
176 | ||
177 | void | |
178 | show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs, | |
e8e999cf | 179 | unsigned long *stack, unsigned long bp, char *log_lvl) |
878719e8 NH |
180 | { |
181 | printk("%sCall Trace:\n", log_lvl); | |
e8e999cf | 182 | dump_trace(task, regs, stack, bp, &print_trace_ops, log_lvl); |
878719e8 NH |
183 | } |
184 | ||
185 | void show_trace(struct task_struct *task, struct pt_regs *regs, | |
e8e999cf | 186 | unsigned long *stack, unsigned long bp) |
878719e8 | 187 | { |
e8e999cf | 188 | show_trace_log_lvl(task, regs, stack, bp, ""); |
878719e8 NH |
189 | } |
190 | ||
191 | void show_stack(struct task_struct *task, unsigned long *sp) | |
192 | { | |
a77f2a4e TH |
193 | unsigned long bp = 0; |
194 | unsigned long stack; | |
195 | ||
196 | /* | |
197 | * Stack frames below this one aren't interesting. Don't show them | |
198 | * if we're printing for %current. | |
199 | */ | |
200 | if (!sp && (!task || task == current)) { | |
201 | sp = &stack; | |
202 | bp = stack_frame(current, NULL); | |
203 | } | |
204 | ||
205 | show_stack_log_lvl(task, NULL, sp, bp, ""); | |
878719e8 NH |
206 | } |
207 | ||
81c2949f BP |
208 | void show_stack_regs(struct pt_regs *regs) |
209 | { | |
210 | show_stack_log_lvl(current, regs, (unsigned long *)regs->sp, regs->bp, ""); | |
211 | } | |
212 | ||
edc35bd7 | 213 | static arch_spinlock_t die_lock = __ARCH_SPIN_LOCK_UNLOCKED; |
878719e8 NH |
214 | static int die_owner = -1; |
215 | static unsigned int die_nest_count; | |
216 | ||
9326638c | 217 | unsigned long oops_begin(void) |
878719e8 NH |
218 | { |
219 | int cpu; | |
220 | unsigned long flags; | |
221 | ||
222 | oops_enter(); | |
223 | ||
224 | /* racy, but better than risking deadlock. */ | |
225 | raw_local_irq_save(flags); | |
226 | cpu = smp_processor_id(); | |
0199c4e6 | 227 | if (!arch_spin_trylock(&die_lock)) { |
878719e8 NH |
228 | if (cpu == die_owner) |
229 | /* nested oops. should stop eventually */; | |
230 | else | |
0199c4e6 | 231 | arch_spin_lock(&die_lock); |
878719e8 NH |
232 | } |
233 | die_nest_count++; | |
234 | die_owner = cpu; | |
235 | console_verbose(); | |
236 | bust_spinlocks(1); | |
237 | return flags; | |
238 | } | |
81e88fdc | 239 | EXPORT_SYMBOL_GPL(oops_begin); |
9326638c | 240 | NOKPROBE_SYMBOL(oops_begin); |
878719e8 | 241 | |
2deb4be2 AL |
242 | void __noreturn rewind_stack_do_exit(int signr); |
243 | ||
9326638c | 244 | void oops_end(unsigned long flags, struct pt_regs *regs, int signr) |
878719e8 NH |
245 | { |
246 | if (regs && kexec_should_crash(current)) | |
247 | crash_kexec(regs); | |
248 | ||
249 | bust_spinlocks(0); | |
250 | die_owner = -1; | |
373d4d09 | 251 | add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE); |
878719e8 NH |
252 | die_nest_count--; |
253 | if (!die_nest_count) | |
254 | /* Nest count reaches zero, release the lock. */ | |
0199c4e6 | 255 | arch_spin_unlock(&die_lock); |
878719e8 NH |
256 | raw_local_irq_restore(flags); |
257 | oops_exit(); | |
258 | ||
259 | if (!signr) | |
260 | return; | |
261 | if (in_interrupt()) | |
262 | panic("Fatal exception in interrupt"); | |
263 | if (panic_on_oops) | |
264 | panic("Fatal exception"); | |
2deb4be2 AL |
265 | |
266 | /* | |
267 | * We're not going to return, but we might be on an IST stack or | |
268 | * have very little stack space left. Rewind the stack and kill | |
269 | * the task. | |
270 | */ | |
271 | rewind_stack_do_exit(signr); | |
878719e8 | 272 | } |
9326638c | 273 | NOKPROBE_SYMBOL(oops_end); |
878719e8 | 274 | |
9326638c | 275 | int __die(const char *str, struct pt_regs *regs, long err) |
878719e8 NH |
276 | { |
277 | #ifdef CONFIG_X86_32 | |
278 | unsigned short ss; | |
279 | unsigned long sp; | |
280 | #endif | |
b0f4c4b3 | 281 | printk(KERN_DEFAULT |
8fad7ec5 RV |
282 | "%s: %04lx [#%d]%s%s%s%s\n", str, err & 0xffff, ++die_counter, |
283 | IS_ENABLED(CONFIG_PREEMPT) ? " PREEMPT" : "", | |
284 | IS_ENABLED(CONFIG_SMP) ? " SMP" : "", | |
285 | debug_pagealloc_enabled() ? " DEBUG_PAGEALLOC" : "", | |
286 | IS_ENABLED(CONFIG_KASAN) ? " KASAN" : ""); | |
287 | ||
878719e8 | 288 | if (notify_die(DIE_OOPS, str, regs, err, |
51e7dc70 | 289 | current->thread.trap_nr, SIGSEGV) == NOTIFY_STOP) |
878719e8 NH |
290 | return 1; |
291 | ||
0fa0e2f0 | 292 | print_modules(); |
57da8b96 | 293 | show_regs(regs); |
878719e8 | 294 | #ifdef CONFIG_X86_32 |
f39b6f0e | 295 | if (user_mode(regs)) { |
878719e8 NH |
296 | sp = regs->sp; |
297 | ss = regs->ss & 0xffff; | |
a343c75d PA |
298 | } else { |
299 | sp = kernel_stack_pointer(regs); | |
300 | savesegment(ss, ss); | |
878719e8 NH |
301 | } |
302 | printk(KERN_EMERG "EIP: [<%08lx>] ", regs->ip); | |
303 | print_symbol("%s", regs->ip); | |
304 | printk(" SS:ESP %04x:%08lx\n", ss, sp); | |
305 | #else | |
306 | /* Executive summary in case the oops scrolled away */ | |
307 | printk(KERN_ALERT "RIP "); | |
5f01c988 | 308 | printk_address(regs->ip); |
878719e8 NH |
309 | printk(" RSP <%016lx>\n", regs->sp); |
310 | #endif | |
311 | return 0; | |
312 | } | |
9326638c | 313 | NOKPROBE_SYMBOL(__die); |
878719e8 NH |
314 | |
315 | /* | |
316 | * This is gone through when something in the kernel has done something bad | |
317 | * and is about to be terminated: | |
318 | */ | |
319 | void die(const char *str, struct pt_regs *regs, long err) | |
320 | { | |
321 | unsigned long flags = oops_begin(); | |
322 | int sig = SIGSEGV; | |
323 | ||
f39b6f0e | 324 | if (!user_mode(regs)) |
878719e8 NH |
325 | report_bug(regs->ip, regs); |
326 | ||
327 | if (__die(str, regs, err)) | |
328 | sig = 0; | |
329 | oops_end(flags, regs, sig); | |
330 | } | |
331 | ||
878719e8 NH |
332 | static int __init kstack_setup(char *s) |
333 | { | |
363f7ce3 SK |
334 | ssize_t ret; |
335 | unsigned long val; | |
336 | ||
878719e8 NH |
337 | if (!s) |
338 | return -EINVAL; | |
363f7ce3 SK |
339 | |
340 | ret = kstrtoul(s, 0, &val); | |
341 | if (ret) | |
342 | return ret; | |
343 | kstack_depth_to_print = val; | |
878719e8 NH |
344 | return 0; |
345 | } | |
346 | early_param("kstack", kstack_setup); | |
347 | ||
348 | static int __init code_bytes_setup(char *s) | |
349 | { | |
363f7ce3 SK |
350 | ssize_t ret; |
351 | unsigned long val; | |
352 | ||
353 | if (!s) | |
354 | return -EINVAL; | |
355 | ||
356 | ret = kstrtoul(s, 0, &val); | |
357 | if (ret) | |
358 | return ret; | |
359 | ||
360 | code_bytes = val; | |
878719e8 NH |
361 | if (code_bytes > 8192) |
362 | code_bytes = 8192; | |
363 | ||
364 | return 1; | |
365 | } | |
366 | __setup("code_bytes=", code_bytes_setup); |