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
printk_stack_address(unsigned long address,int reliable)28 static void printk_stack_address(unsigned long address, int reliable)
29 {
30 pr_cont(" [<%p>] %s%pB\n",
31 (void *)address, reliable ? "" : "? ", (void *)address);
32 }
33
printk_address(unsigned long address)34 void printk_address(unsigned long address)
35 {
36 pr_cont(" [<%p>] %pS\n", (void *)address, (void *)address);
37 }
38
39 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
40 static void
print_ftrace_graph_addr(unsigned long addr,void * data,const struct stacktrace_ops * ops,struct thread_info * tinfo,int * graph)41 print_ftrace_graph_addr(unsigned long addr, void *data,
42 const struct stacktrace_ops *ops,
43 struct thread_info *tinfo, int *graph)
44 {
45 struct task_struct *task;
46 unsigned long ret_addr;
47 int index;
48
49 if (addr != (unsigned long)return_to_handler)
50 return;
51
52 task = tinfo->task;
53 index = task->curr_ret_stack;
54
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
print_ftrace_graph_addr(unsigned long addr,void * data,const struct stacktrace_ops * ops,struct thread_info * tinfo,int * graph)67 print_ftrace_graph_addr(unsigned long addr, void *data,
68 const struct stacktrace_ops *ops,
69 struct thread_info *tinfo, int *graph)
70 { }
71 #endif
72
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
valid_stack_ptr(struct thread_info * tinfo,void * p,unsigned int size,void * end)80 static inline int valid_stack_ptr(struct thread_info *tinfo,
81 void *p, unsigned int size, void *end)
82 {
83 void *t = tinfo;
84 if (end) {
85 if (p < end && p >= (end-THREAD_SIZE))
86 return 1;
87 else
88 return 0;
89 }
90 return p > t && p < t + THREAD_SIZE - size;
91 }
92
93 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)94 print_context_stack(struct thread_info *tinfo,
95 unsigned long *stack, unsigned long bp,
96 const struct stacktrace_ops *ops, void *data,
97 unsigned long *end, int *graph)
98 {
99 struct stack_frame *frame = (struct stack_frame *)bp;
100
101 while (valid_stack_ptr(tinfo, stack, sizeof(*stack), end)) {
102 unsigned long addr;
103
104 addr = *stack;
105 if (__kernel_text_address(addr)) {
106 if ((unsigned long) stack == bp + sizeof(long)) {
107 ops->address(data, addr, 1);
108 frame = frame->next_frame;
109 bp = (unsigned long) frame;
110 } else {
111 ops->address(data, addr, 0);
112 }
113 print_ftrace_graph_addr(addr, data, ops, tinfo, graph);
114 }
115 stack++;
116 }
117 return bp;
118 }
119 EXPORT_SYMBOL_GPL(print_context_stack);
120
121 unsigned long
print_context_stack_bp(struct thread_info * tinfo,unsigned long * stack,unsigned long bp,const struct stacktrace_ops * ops,void * data,unsigned long * end,int * graph)122 print_context_stack_bp(struct thread_info *tinfo,
123 unsigned long *stack, unsigned long bp,
124 const struct stacktrace_ops *ops, void *data,
125 unsigned long *end, int *graph)
126 {
127 struct stack_frame *frame = (struct stack_frame *)bp;
128 unsigned long *ret_addr = &frame->return_address;
129
130 while (valid_stack_ptr(tinfo, ret_addr, sizeof(*ret_addr), end)) {
131 unsigned long addr = *ret_addr;
132
133 if (!__kernel_text_address(addr))
134 break;
135
136 ops->address(data, addr, 1);
137 frame = frame->next_frame;
138 ret_addr = &frame->return_address;
139 print_ftrace_graph_addr(addr, data, ops, tinfo, graph);
140 }
141
142 return (unsigned long)frame;
143 }
144 EXPORT_SYMBOL_GPL(print_context_stack_bp);
145
print_trace_stack(void * data,char * name)146 static int print_trace_stack(void *data, char *name)
147 {
148 printk("%s <%s> ", (char *)data, name);
149 return 0;
150 }
151
152 /*
153 * Print one address/symbol entries per line.
154 */
print_trace_address(void * data,unsigned long addr,int reliable)155 static void print_trace_address(void *data, unsigned long addr, int reliable)
156 {
157 touch_nmi_watchdog();
158 printk(data);
159 printk_stack_address(addr, reliable);
160 }
161
162 static const struct stacktrace_ops print_trace_ops = {
163 .stack = print_trace_stack,
164 .address = print_trace_address,
165 .walk_stack = print_context_stack,
166 };
167
168 void
show_trace_log_lvl(struct task_struct * task,struct pt_regs * regs,unsigned long * stack,unsigned long bp,char * log_lvl)169 show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs,
170 unsigned long *stack, unsigned long bp, char *log_lvl)
171 {
172 printk("%sCall Trace:\n", log_lvl);
173 dump_trace(task, regs, stack, bp, &print_trace_ops, log_lvl);
174 }
175
show_trace(struct task_struct * task,struct pt_regs * regs,unsigned long * stack,unsigned long bp)176 void show_trace(struct task_struct *task, struct pt_regs *regs,
177 unsigned long *stack, unsigned long bp)
178 {
179 show_trace_log_lvl(task, regs, stack, bp, "");
180 }
181
show_stack(struct task_struct * task,unsigned long * sp)182 void show_stack(struct task_struct *task, unsigned long *sp)
183 {
184 unsigned long bp = 0;
185 unsigned long stack;
186
187 /*
188 * Stack frames below this one aren't interesting. Don't show them
189 * if we're printing for %current.
190 */
191 if (!sp && (!task || task == current)) {
192 sp = &stack;
193 bp = stack_frame(current, NULL);
194 }
195
196 show_stack_log_lvl(task, NULL, sp, bp, "");
197 }
198
199 static arch_spinlock_t die_lock = __ARCH_SPIN_LOCK_UNLOCKED;
200 static int die_owner = -1;
201 static unsigned int die_nest_count;
202
oops_begin(void)203 unsigned long oops_begin(void)
204 {
205 int cpu;
206 unsigned long flags;
207
208 oops_enter();
209
210 /* racy, but better than risking deadlock. */
211 raw_local_irq_save(flags);
212 cpu = smp_processor_id();
213 if (!arch_spin_trylock(&die_lock)) {
214 if (cpu == die_owner)
215 /* nested oops. should stop eventually */;
216 else
217 arch_spin_lock(&die_lock);
218 }
219 die_nest_count++;
220 die_owner = cpu;
221 console_verbose();
222 bust_spinlocks(1);
223 return flags;
224 }
225 EXPORT_SYMBOL_GPL(oops_begin);
226 NOKPROBE_SYMBOL(oops_begin);
227
oops_end(unsigned long flags,struct pt_regs * regs,int signr)228 void oops_end(unsigned long flags, struct pt_regs *regs, int signr)
229 {
230 if (regs && kexec_should_crash(current))
231 crash_kexec(regs);
232
233 bust_spinlocks(0);
234 die_owner = -1;
235 add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
236 die_nest_count--;
237 if (!die_nest_count)
238 /* Nest count reaches zero, release the lock. */
239 arch_spin_unlock(&die_lock);
240 raw_local_irq_restore(flags);
241 oops_exit();
242
243 if (!signr)
244 return;
245 if (in_interrupt())
246 panic("Fatal exception in interrupt");
247 if (panic_on_oops)
248 panic("Fatal exception");
249 do_exit(signr);
250 }
251 NOKPROBE_SYMBOL(oops_end);
252
__die(const char * str,struct pt_regs * regs,long err)253 int __die(const char *str, struct pt_regs *regs, long err)
254 {
255 #ifdef CONFIG_X86_32
256 unsigned short ss;
257 unsigned long sp;
258 #endif
259 printk(KERN_DEFAULT
260 "%s: %04lx [#%d] ", str, err & 0xffff, ++die_counter);
261 #ifdef CONFIG_PREEMPT
262 printk("PREEMPT ");
263 #endif
264 #ifdef CONFIG_SMP
265 printk("SMP ");
266 #endif
267 #ifdef CONFIG_DEBUG_PAGEALLOC
268 printk("DEBUG_PAGEALLOC");
269 #endif
270 printk("\n");
271 if (notify_die(DIE_OOPS, str, regs, err,
272 current->thread.trap_nr, SIGSEGV) == NOTIFY_STOP)
273 return 1;
274
275 print_modules();
276 show_regs(regs);
277 #ifdef CONFIG_X86_32
278 if (user_mode_vm(regs)) {
279 sp = regs->sp;
280 ss = regs->ss & 0xffff;
281 } else {
282 sp = kernel_stack_pointer(regs);
283 savesegment(ss, ss);
284 }
285 printk(KERN_EMERG "EIP: [<%08lx>] ", regs->ip);
286 print_symbol("%s", regs->ip);
287 printk(" SS:ESP %04x:%08lx\n", ss, sp);
288 #else
289 /* Executive summary in case the oops scrolled away */
290 printk(KERN_ALERT "RIP ");
291 printk_address(regs->ip);
292 printk(" RSP <%016lx>\n", regs->sp);
293 #endif
294 return 0;
295 }
296 NOKPROBE_SYMBOL(__die);
297
298 /*
299 * This is gone through when something in the kernel has done something bad
300 * and is about to be terminated:
301 */
die(const char * str,struct pt_regs * regs,long err)302 void die(const char *str, struct pt_regs *regs, long err)
303 {
304 unsigned long flags = oops_begin();
305 int sig = SIGSEGV;
306
307 if (!user_mode_vm(regs))
308 report_bug(regs->ip, regs);
309
310 if (__die(str, regs, err))
311 sig = 0;
312 oops_end(flags, regs, sig);
313 }
314
kstack_setup(char * s)315 static int __init kstack_setup(char *s)
316 {
317 ssize_t ret;
318 unsigned long val;
319
320 if (!s)
321 return -EINVAL;
322
323 ret = kstrtoul(s, 0, &val);
324 if (ret)
325 return ret;
326 kstack_depth_to_print = val;
327 return 0;
328 }
329 early_param("kstack", kstack_setup);
330
code_bytes_setup(char * s)331 static int __init code_bytes_setup(char *s)
332 {
333 ssize_t ret;
334 unsigned long val;
335
336 if (!s)
337 return -EINVAL;
338
339 ret = kstrtoul(s, 0, &val);
340 if (ret)
341 return ret;
342
343 code_bytes = val;
344 if (code_bytes > 8192)
345 code_bytes = 8192;
346
347 return 1;
348 }
349 __setup("code_bytes=", code_bytes_setup);
350