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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>
13 #include <linux/ftrace.h>
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
21
22 int panic_on_unrecovered_nmi;
23 int panic_on_io_nmi;
24 unsigned int code_bytes = 64;
25 int kstack_depth_to_print = 3 * STACKSLOTS_PER_LINE;
26 static int die_counter;
27
28 void printk_address(unsigned long address, int reliable)
29 {
30 printk(" [<%p>] %s%pS\n", (void *) address,
31 reliable ? "" : "? ", (void *) address);
32 }
33
34 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
35 static void
36 print_ftrace_graph_addr(unsigned long addr, void *data,
37 const struct stacktrace_ops *ops,
38 struct thread_info *tinfo, int *graph)
39 {
40 struct task_struct *task = tinfo->task;
41 unsigned long ret_addr;
42 int index = task->curr_ret_stack;
43
44 if (addr != (unsigned long)return_to_handler)
45 return;
46
47 if (!task->ret_stack || index < *graph)
48 return;
49
50 index -= *graph;
51 ret_addr = task->ret_stack[index].ret;
52
53 ops->address(data, ret_addr, 1);
54
55 (*graph)++;
56 }
57 #else
58 static inline void
59 print_ftrace_graph_addr(unsigned long addr, void *data,
60 const struct stacktrace_ops *ops,
61 struct thread_info *tinfo, int *graph)
62 { }
63 #endif
64
65 /*
66 * x86-64 can have up to three kernel stacks:
67 * process stack
68 * interrupt stack
69 * severe exception (double fault, nmi, stack fault, debug, mce) hardware stack
70 */
71
72 static inline int valid_stack_ptr(struct thread_info *tinfo,
73 void *p, unsigned int size, void *end)
74 {
75 void *t = tinfo;
76 if (end) {
77 if (p < end && p >= (end-THREAD_SIZE))
78 return 1;
79 else
80 return 0;
81 }
82 return p > t && p < t + THREAD_SIZE - size;
83 }
84
85 unsigned long
86 print_context_stack(struct thread_info *tinfo,
87 unsigned long *stack, unsigned long bp,
88 const struct stacktrace_ops *ops, void *data,
89 unsigned long *end, int *graph)
90 {
91 struct stack_frame *frame = (struct stack_frame *)bp;
92
93 while (valid_stack_ptr(tinfo, stack, sizeof(*stack), end)) {
94 unsigned long addr;
95
96 addr = *stack;
97 if (__kernel_text_address(addr)) {
98 if ((unsigned long) stack == bp + sizeof(long)) {
99 ops->address(data, addr, 1);
100 frame = frame->next_frame;
101 bp = (unsigned long) frame;
102 } else {
103 ops->address(data, addr, 0);
104 }
105 print_ftrace_graph_addr(addr, data, ops, tinfo, graph);
106 }
107 stack++;
108 }
109 return bp;
110 }
111 EXPORT_SYMBOL_GPL(print_context_stack);
112
113 unsigned long
114 print_context_stack_bp(struct thread_info *tinfo,
115 unsigned long *stack, unsigned long bp,
116 const struct stacktrace_ops *ops, void *data,
117 unsigned long *end, int *graph)
118 {
119 struct stack_frame *frame = (struct stack_frame *)bp;
120 unsigned long *ret_addr = &frame->return_address;
121
122 while (valid_stack_ptr(tinfo, ret_addr, sizeof(*ret_addr), end)) {
123 unsigned long addr = *ret_addr;
124
125 if (!__kernel_text_address(addr))
126 break;
127
128 ops->address(data, addr, 1);
129 frame = frame->next_frame;
130 ret_addr = &frame->return_address;
131 print_ftrace_graph_addr(addr, data, ops, tinfo, graph);
132 }
133
134 return (unsigned long)frame;
135 }
136 EXPORT_SYMBOL_GPL(print_context_stack_bp);
137
138
139 static void
140 print_trace_warning_symbol(void *data, char *msg, unsigned long symbol)
141 {
142 printk(data);
143 print_symbol(msg, symbol);
144 printk("\n");
145 }
146
147 static void print_trace_warning(void *data, char *msg)
148 {
149 printk("%s%s\n", (char *)data, msg);
150 }
151
152 static int print_trace_stack(void *data, char *name)
153 {
154 printk("%s <%s> ", (char *)data, name);
155 return 0;
156 }
157
158 /*
159 * Print one address/symbol entries per line.
160 */
161 static void print_trace_address(void *data, unsigned long addr, int reliable)
162 {
163 touch_nmi_watchdog();
164 printk(data);
165 printk_address(addr, reliable);
166 }
167
168 static const struct stacktrace_ops print_trace_ops = {
169 .warning = print_trace_warning,
170 .warning_symbol = print_trace_warning_symbol,
171 .stack = print_trace_stack,
172 .address = print_trace_address,
173 .walk_stack = print_context_stack,
174 };
175
176 void
177 show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs,
178 unsigned long *stack, char *log_lvl)
179 {
180 printk("%sCall Trace:\n", log_lvl);
181 dump_trace(task, regs, stack, &print_trace_ops, log_lvl);
182 }
183
184 void show_trace(struct task_struct *task, struct pt_regs *regs,
185 unsigned long *stack)
186 {
187 show_trace_log_lvl(task, regs, stack, "");
188 }
189
190 void show_stack(struct task_struct *task, unsigned long *sp)
191 {
192 show_stack_log_lvl(task, NULL, sp, "");
193 }
194
195 /*
196 * The architecture-independent dump_stack generator
197 */
198 void dump_stack(void)
199 {
200 unsigned long stack;
201
202 printk("Pid: %d, comm: %.20s %s %s %.*s\n",
203 current->pid, current->comm, print_tainted(),
204 init_utsname()->release,
205 (int)strcspn(init_utsname()->version, " "),
206 init_utsname()->version);
207 show_trace(NULL, NULL, &stack);
208 }
209 EXPORT_SYMBOL(dump_stack);
210
211 static arch_spinlock_t die_lock = __ARCH_SPIN_LOCK_UNLOCKED;
212 static int die_owner = -1;
213 static unsigned int die_nest_count;
214
215 unsigned __kprobes long oops_begin(void)
216 {
217 int cpu;
218 unsigned long flags;
219
220 oops_enter();
221
222 /* racy, but better than risking deadlock. */
223 raw_local_irq_save(flags);
224 cpu = smp_processor_id();
225 if (!arch_spin_trylock(&die_lock)) {
226 if (cpu == die_owner)
227 /* nested oops. should stop eventually */;
228 else
229 arch_spin_lock(&die_lock);
230 }
231 die_nest_count++;
232 die_owner = cpu;
233 console_verbose();
234 bust_spinlocks(1);
235 return flags;
236 }
237 EXPORT_SYMBOL_GPL(oops_begin);
238
239 void __kprobes oops_end(unsigned long flags, struct pt_regs *regs, int signr)
240 {
241 if (regs && kexec_should_crash(current))
242 crash_kexec(regs);
243
244 bust_spinlocks(0);
245 die_owner = -1;
246 add_taint(TAINT_DIE);
247 die_nest_count--;
248 if (!die_nest_count)
249 /* Nest count reaches zero, release the lock. */
250 arch_spin_unlock(&die_lock);
251 raw_local_irq_restore(flags);
252 oops_exit();
253
254 if (!signr)
255 return;
256 if (in_interrupt())
257 panic("Fatal exception in interrupt");
258 if (panic_on_oops)
259 panic("Fatal exception");
260 do_exit(signr);
261 }
262
263 int __kprobes __die(const char *str, struct pt_regs *regs, long err)
264 {
265 #ifdef CONFIG_X86_32
266 unsigned short ss;
267 unsigned long sp;
268 #endif
269 printk(KERN_EMERG "%s: %04lx [#%d] ", str, err & 0xffff, ++die_counter);
270 #ifdef CONFIG_PREEMPT
271 printk("PREEMPT ");
272 #endif
273 #ifdef CONFIG_SMP
274 printk("SMP ");
275 #endif
276 #ifdef CONFIG_DEBUG_PAGEALLOC
277 printk("DEBUG_PAGEALLOC");
278 #endif
279 printk("\n");
280 sysfs_printk_last_file();
281 if (notify_die(DIE_OOPS, str, regs, err,
282 current->thread.trap_no, SIGSEGV) == NOTIFY_STOP)
283 return 1;
284
285 show_registers(regs);
286 #ifdef CONFIG_X86_32
287 if (user_mode_vm(regs)) {
288 sp = regs->sp;
289 ss = regs->ss & 0xffff;
290 } else {
291 sp = kernel_stack_pointer(regs);
292 savesegment(ss, ss);
293 }
294 printk(KERN_EMERG "EIP: [<%08lx>] ", regs->ip);
295 print_symbol("%s", regs->ip);
296 printk(" SS:ESP %04x:%08lx\n", ss, sp);
297 #else
298 /* Executive summary in case the oops scrolled away */
299 printk(KERN_ALERT "RIP ");
300 printk_address(regs->ip, 1);
301 printk(" RSP <%016lx>\n", regs->sp);
302 #endif
303 return 0;
304 }
305
306 /*
307 * This is gone through when something in the kernel has done something bad
308 * and is about to be terminated:
309 */
310 void die(const char *str, struct pt_regs *regs, long err)
311 {
312 unsigned long flags = oops_begin();
313 int sig = SIGSEGV;
314
315 if (!user_mode_vm(regs))
316 report_bug(regs->ip, regs);
317
318 if (__die(str, regs, err))
319 sig = 0;
320 oops_end(flags, regs, sig);
321 }
322
323 void notrace __kprobes
324 die_nmi(char *str, struct pt_regs *regs, int do_panic)
325 {
326 unsigned long flags;
327
328 if (notify_die(DIE_NMIWATCHDOG, str, regs, 0, 2, SIGINT) == NOTIFY_STOP)
329 return;
330
331 /*
332 * We are in trouble anyway, lets at least try
333 * to get a message out.
334 */
335 flags = oops_begin();
336 printk(KERN_EMERG "%s", str);
337 printk(" on CPU%d, ip %08lx, registers:\n",
338 smp_processor_id(), regs->ip);
339 show_registers(regs);
340 oops_end(flags, regs, 0);
341 if (do_panic || panic_on_oops)
342 panic("Non maskable interrupt");
343 nmi_exit();
344 local_irq_enable();
345 do_exit(SIGBUS);
346 }
347
348 static int __init oops_setup(char *s)
349 {
350 if (!s)
351 return -EINVAL;
352 if (!strcmp(s, "panic"))
353 panic_on_oops = 1;
354 return 0;
355 }
356 early_param("oops", oops_setup);
357
358 static int __init kstack_setup(char *s)
359 {
360 if (!s)
361 return -EINVAL;
362 kstack_depth_to_print = simple_strtoul(s, NULL, 0);
363 return 0;
364 }
365 early_param("kstack", kstack_setup);
366
367 static int __init code_bytes_setup(char *s)
368 {
369 code_bytes = simple_strtoul(s, NULL, 0);
370 if (code_bytes > 8192)
371 code_bytes = 8192;
372
373 return 1;
374 }
375 __setup("code_bytes=", code_bytes_setup);