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/kexec.h>
14 #include <linux/bug.h>
15 #include <linux/nmi.h>
16 #include <linux/sysfs.h>
17
18 #include <asm/stacktrace.h>
19
20 #include "dumpstack.h"
21
22 int panic_on_unrecovered_nmi;
23 unsigned int code_bytes = 64;
24 int kstack_depth_to_print = 3 * STACKSLOTS_PER_LINE;
25 static int die_counter;
26
printk_address(unsigned long address,int reliable)27 void printk_address(unsigned long address, int reliable)
28 {
29 printk(" [<%p>] %s%pS\n", (void *) address,
30 reliable ? "" : "? ", (void *) address);
31 }
32
33 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
34 static void
print_ftrace_graph_addr(unsigned long addr,void * data,const struct stacktrace_ops * ops,struct thread_info * tinfo,int * graph)35 print_ftrace_graph_addr(unsigned long addr, void *data,
36 const struct stacktrace_ops *ops,
37 struct thread_info *tinfo, int *graph)
38 {
39 struct task_struct *task = tinfo->task;
40 unsigned long ret_addr;
41 int index = task->curr_ret_stack;
42
43 if (addr != (unsigned long)return_to_handler)
44 return;
45
46 if (!task->ret_stack || index < *graph)
47 return;
48
49 index -= *graph;
50 ret_addr = task->ret_stack[index].ret;
51
52 ops->address(data, ret_addr, 1);
53
54 (*graph)++;
55 }
56 #else
57 static inline void
print_ftrace_graph_addr(unsigned long addr,void * data,const struct stacktrace_ops * ops,struct thread_info * tinfo,int * graph)58 print_ftrace_graph_addr(unsigned long addr, void *data,
59 const struct stacktrace_ops *ops,
60 struct thread_info *tinfo, int *graph)
61 { }
62 #endif
63
64 /*
65 * x86-64 can have up to three kernel stacks:
66 * process stack
67 * interrupt stack
68 * severe exception (double fault, nmi, stack fault, debug, mce) hardware stack
69 */
70
valid_stack_ptr(struct thread_info * tinfo,void * p,unsigned int size,void * end)71 static inline int valid_stack_ptr(struct thread_info *tinfo,
72 void *p, unsigned int size, void *end)
73 {
74 void *t = tinfo;
75 if (end) {
76 if (p < end && p >= (end-THREAD_SIZE))
77 return 1;
78 else
79 return 0;
80 }
81 return p > t && p < t + THREAD_SIZE - size;
82 }
83
84 unsigned long
print_context_stack(struct thread_info * tinfo,unsigned long * stack,unsigned long bp,const struct stacktrace_ops * ops,void * data,unsigned long * end,int * graph)85 print_context_stack(struct thread_info *tinfo,
86 unsigned long *stack, unsigned long bp,
87 const struct stacktrace_ops *ops, void *data,
88 unsigned long *end, int *graph)
89 {
90 struct stack_frame *frame = (struct stack_frame *)bp;
91
92 while (valid_stack_ptr(tinfo, stack, sizeof(*stack), end)) {
93 unsigned long addr;
94
95 addr = *stack;
96 if (__kernel_text_address(addr)) {
97 if ((unsigned long) stack == bp + sizeof(long)) {
98 ops->address(data, addr, 1);
99 frame = frame->next_frame;
100 bp = (unsigned long) frame;
101 } else {
102 ops->address(data, addr, bp == 0);
103 }
104 print_ftrace_graph_addr(addr, data, ops, tinfo, graph);
105 }
106 stack++;
107 }
108 return bp;
109 }
110
111
112 static void
print_trace_warning_symbol(void * data,char * msg,unsigned long symbol)113 print_trace_warning_symbol(void *data, char *msg, unsigned long symbol)
114 {
115 printk(data);
116 print_symbol(msg, symbol);
117 printk("\n");
118 }
119
print_trace_warning(void * data,char * msg)120 static void print_trace_warning(void *data, char *msg)
121 {
122 printk("%s%s\n", (char *)data, msg);
123 }
124
print_trace_stack(void * data,char * name)125 static int print_trace_stack(void *data, char *name)
126 {
127 printk("%s <%s> ", (char *)data, name);
128 return 0;
129 }
130
131 /*
132 * Print one address/symbol entries per line.
133 */
print_trace_address(void * data,unsigned long addr,int reliable)134 static void print_trace_address(void *data, unsigned long addr, int reliable)
135 {
136 touch_nmi_watchdog();
137 printk(data);
138 printk_address(addr, reliable);
139 }
140
141 static const struct stacktrace_ops print_trace_ops = {
142 .warning = print_trace_warning,
143 .warning_symbol = print_trace_warning_symbol,
144 .stack = print_trace_stack,
145 .address = print_trace_address,
146 };
147
148 void
show_trace_log_lvl(struct task_struct * task,struct pt_regs * regs,unsigned long * stack,unsigned long bp,char * log_lvl)149 show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs,
150 unsigned long *stack, unsigned long bp, char *log_lvl)
151 {
152 printk("%sCall Trace:\n", log_lvl);
153 dump_trace(task, regs, stack, bp, &print_trace_ops, log_lvl);
154 }
155
show_trace(struct task_struct * task,struct pt_regs * regs,unsigned long * stack,unsigned long bp)156 void show_trace(struct task_struct *task, struct pt_regs *regs,
157 unsigned long *stack, unsigned long bp)
158 {
159 show_trace_log_lvl(task, regs, stack, bp, "");
160 }
161
show_stack(struct task_struct * task,unsigned long * sp)162 void show_stack(struct task_struct *task, unsigned long *sp)
163 {
164 show_stack_log_lvl(task, NULL, sp, 0, "");
165 }
166
167 /*
168 * The architecture-independent dump_stack generator
169 */
dump_stack(void)170 void dump_stack(void)
171 {
172 unsigned long bp = 0;
173 unsigned long stack;
174
175 #ifdef CONFIG_FRAME_POINTER
176 if (!bp)
177 get_bp(bp);
178 #endif
179
180 printk("Pid: %d, comm: %.20s %s %s %.*s\n",
181 current->pid, current->comm, print_tainted(),
182 init_utsname()->release,
183 (int)strcspn(init_utsname()->version, " "),
184 init_utsname()->version);
185 show_trace(NULL, NULL, &stack, bp);
186 }
187 EXPORT_SYMBOL(dump_stack);
188
189 static raw_spinlock_t die_lock = __RAW_SPIN_LOCK_UNLOCKED;
190 static int die_owner = -1;
191 static unsigned int die_nest_count;
192
oops_begin(void)193 unsigned __kprobes long oops_begin(void)
194 {
195 int cpu;
196 unsigned long flags;
197
198 oops_enter();
199
200 /* racy, but better than risking deadlock. */
201 raw_local_irq_save(flags);
202 cpu = smp_processor_id();
203 if (!__raw_spin_trylock(&die_lock)) {
204 if (cpu == die_owner)
205 /* nested oops. should stop eventually */;
206 else
207 __raw_spin_lock(&die_lock);
208 }
209 die_nest_count++;
210 die_owner = cpu;
211 console_verbose();
212 bust_spinlocks(1);
213 return flags;
214 }
215
oops_end(unsigned long flags,struct pt_regs * regs,int signr)216 void __kprobes oops_end(unsigned long flags, struct pt_regs *regs, int signr)
217 {
218 if (regs && kexec_should_crash(current))
219 crash_kexec(regs);
220
221 bust_spinlocks(0);
222 die_owner = -1;
223 add_taint(TAINT_DIE);
224 die_nest_count--;
225 if (!die_nest_count)
226 /* Nest count reaches zero, release the lock. */
227 __raw_spin_unlock(&die_lock);
228 raw_local_irq_restore(flags);
229 oops_exit();
230
231 if (!signr)
232 return;
233 if (in_interrupt())
234 panic("Fatal exception in interrupt");
235 if (panic_on_oops)
236 panic("Fatal exception");
237 do_exit(signr);
238 }
239
__die(const char * str,struct pt_regs * regs,long err)240 int __kprobes __die(const char *str, struct pt_regs *regs, long err)
241 {
242 #ifdef CONFIG_X86_32
243 unsigned short ss;
244 unsigned long sp;
245 #endif
246 printk(KERN_EMERG "%s: %04lx [#%d] ", str, err & 0xffff, ++die_counter);
247 #ifdef CONFIG_PREEMPT
248 printk("PREEMPT ");
249 #endif
250 #ifdef CONFIG_SMP
251 printk("SMP ");
252 #endif
253 #ifdef CONFIG_DEBUG_PAGEALLOC
254 printk("DEBUG_PAGEALLOC");
255 #endif
256 printk("\n");
257 sysfs_printk_last_file();
258 if (notify_die(DIE_OOPS, str, regs, err,
259 current->thread.trap_no, SIGSEGV) == NOTIFY_STOP)
260 return 1;
261
262 show_registers(regs);
263 #ifdef CONFIG_X86_32
264 sp = (unsigned long) (®s->sp);
265 savesegment(ss, ss);
266 if (user_mode(regs)) {
267 sp = regs->sp;
268 ss = regs->ss & 0xffff;
269 }
270 printk(KERN_EMERG "EIP: [<%08lx>] ", regs->ip);
271 print_symbol("%s", regs->ip);
272 printk(" SS:ESP %04x:%08lx\n", ss, sp);
273 #else
274 /* Executive summary in case the oops scrolled away */
275 printk(KERN_ALERT "RIP ");
276 printk_address(regs->ip, 1);
277 printk(" RSP <%016lx>\n", regs->sp);
278 #endif
279 return 0;
280 }
281
282 /*
283 * This is gone through when something in the kernel has done something bad
284 * and is about to be terminated:
285 */
die(const char * str,struct pt_regs * regs,long err)286 void die(const char *str, struct pt_regs *regs, long err)
287 {
288 unsigned long flags = oops_begin();
289 int sig = SIGSEGV;
290
291 if (!user_mode_vm(regs))
292 report_bug(regs->ip, regs);
293
294 if (__die(str, regs, err))
295 sig = 0;
296 oops_end(flags, regs, sig);
297 }
298
299 void notrace __kprobes
die_nmi(char * str,struct pt_regs * regs,int do_panic)300 die_nmi(char *str, struct pt_regs *regs, int do_panic)
301 {
302 unsigned long flags;
303
304 if (notify_die(DIE_NMIWATCHDOG, str, regs, 0, 2, SIGINT) == NOTIFY_STOP)
305 return;
306
307 /*
308 * We are in trouble anyway, lets at least try
309 * to get a message out.
310 */
311 flags = oops_begin();
312 printk(KERN_EMERG "%s", str);
313 printk(" on CPU%d, ip %08lx, registers:\n",
314 smp_processor_id(), regs->ip);
315 show_registers(regs);
316 oops_end(flags, regs, 0);
317 if (do_panic || panic_on_oops)
318 panic("Non maskable interrupt");
319 nmi_exit();
320 local_irq_enable();
321 do_exit(SIGBUS);
322 }
323
oops_setup(char * s)324 static int __init oops_setup(char *s)
325 {
326 if (!s)
327 return -EINVAL;
328 if (!strcmp(s, "panic"))
329 panic_on_oops = 1;
330 return 0;
331 }
332 early_param("oops", oops_setup);
333
kstack_setup(char * s)334 static int __init kstack_setup(char *s)
335 {
336 if (!s)
337 return -EINVAL;
338 kstack_depth_to_print = simple_strtoul(s, NULL, 0);
339 return 0;
340 }
341 early_param("kstack", kstack_setup);
342
code_bytes_setup(char * s)343 static int __init code_bytes_setup(char *s)
344 {
345 code_bytes = simple_strtoul(s, NULL, 0);
346 if (code_bytes > 8192)
347 code_bytes = 8192;
348
349 return 1;
350 }
351 __setup("code_bytes=", code_bytes_setup);
352