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_address(unsigned long address,int reliable)28 void printk_address(unsigned long address, int reliable)
29 {
30 pr_cont(" [<%p>] %s%pB\n",
31 (void *)address, reliable ? "" : "? ", (void *)address);
32 }
33
34 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
35 static void
print_ftrace_graph_addr(unsigned long addr,void * data,const struct stacktrace_ops * ops,struct thread_info * tinfo,int * graph)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;
41 unsigned long ret_addr;
42 int index;
43
44 if (addr != (unsigned long)return_to_handler)
45 return;
46
47 task = tinfo->task;
48 index = task->curr_ret_stack;
49
50 if (!task->ret_stack || index < *graph)
51 return;
52
53 index -= *graph;
54 ret_addr = task->ret_stack[index].ret;
55
56 ops->address(data, ret_addr, 1);
57
58 (*graph)++;
59 }
60 #else
61 static inline void
print_ftrace_graph_addr(unsigned long addr,void * data,const struct stacktrace_ops * ops,struct thread_info * tinfo,int * graph)62 print_ftrace_graph_addr(unsigned long addr, void *data,
63 const struct stacktrace_ops *ops,
64 struct thread_info *tinfo, int *graph)
65 { }
66 #endif
67
68 /*
69 * x86-64 can have up to three kernel stacks:
70 * process stack
71 * interrupt stack
72 * severe exception (double fault, nmi, stack fault, debug, mce) hardware stack
73 */
74
valid_stack_ptr(struct thread_info * tinfo,void * p,unsigned int size,void * end)75 static inline int valid_stack_ptr(struct thread_info *tinfo,
76 void *p, unsigned int size, void *end)
77 {
78 void *t = tinfo;
79 if (end) {
80 if (p < end && p >= (end-THREAD_SIZE))
81 return 1;
82 else
83 return 0;
84 }
85 return p > t && p < t + THREAD_SIZE - size;
86 }
87
88 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)89 print_context_stack(struct thread_info *tinfo,
90 unsigned long *stack, unsigned long bp,
91 const struct stacktrace_ops *ops, void *data,
92 unsigned long *end, int *graph)
93 {
94 struct stack_frame *frame = (struct stack_frame *)bp;
95
96 while (valid_stack_ptr(tinfo, stack, sizeof(*stack), end)) {
97 unsigned long addr;
98
99 addr = *stack;
100 if (__kernel_text_address(addr)) {
101 if ((unsigned long) stack == bp + sizeof(long)) {
102 ops->address(data, addr, 1);
103 frame = frame->next_frame;
104 bp = (unsigned long) frame;
105 } else {
106 ops->address(data, addr, 0);
107 }
108 print_ftrace_graph_addr(addr, data, ops, tinfo, graph);
109 }
110 stack++;
111 }
112 return bp;
113 }
114 EXPORT_SYMBOL_GPL(print_context_stack);
115
116 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)117 print_context_stack_bp(struct thread_info *tinfo,
118 unsigned long *stack, unsigned long bp,
119 const struct stacktrace_ops *ops, void *data,
120 unsigned long *end, int *graph)
121 {
122 struct stack_frame *frame = (struct stack_frame *)bp;
123 unsigned long *ret_addr = &frame->return_address;
124
125 while (valid_stack_ptr(tinfo, ret_addr, sizeof(*ret_addr), end)) {
126 unsigned long addr = *ret_addr;
127
128 if (!__kernel_text_address(addr))
129 break;
130
131 ops->address(data, addr, 1);
132 frame = frame->next_frame;
133 ret_addr = &frame->return_address;
134 print_ftrace_graph_addr(addr, data, ops, tinfo, graph);
135 }
136
137 return (unsigned long)frame;
138 }
139 EXPORT_SYMBOL_GPL(print_context_stack_bp);
140
print_trace_stack(void * data,char * name)141 static int print_trace_stack(void *data, char *name)
142 {
143 printk("%s <%s> ", (char *)data, name);
144 return 0;
145 }
146
147 /*
148 * Print one address/symbol entries per line.
149 */
print_trace_address(void * data,unsigned long addr,int reliable)150 static void print_trace_address(void *data, unsigned long addr, int reliable)
151 {
152 touch_nmi_watchdog();
153 printk(data);
154 printk_address(addr, reliable);
155 }
156
157 static const struct stacktrace_ops print_trace_ops = {
158 .stack = print_trace_stack,
159 .address = print_trace_address,
160 .walk_stack = print_context_stack,
161 };
162
163 void
show_trace_log_lvl(struct task_struct * task,struct pt_regs * regs,unsigned long * stack,unsigned long bp,char * log_lvl)164 show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs,
165 unsigned long *stack, unsigned long bp, char *log_lvl)
166 {
167 printk("%sCall Trace:\n", log_lvl);
168 dump_trace(task, regs, stack, bp, &print_trace_ops, log_lvl);
169 }
170
show_trace(struct task_struct * task,struct pt_regs * regs,unsigned long * stack,unsigned long bp)171 void show_trace(struct task_struct *task, struct pt_regs *regs,
172 unsigned long *stack, unsigned long bp)
173 {
174 show_trace_log_lvl(task, regs, stack, bp, "");
175 }
176
show_stack(struct task_struct * task,unsigned long * sp)177 void show_stack(struct task_struct *task, unsigned long *sp)
178 {
179 unsigned long bp = 0;
180 unsigned long stack;
181
182 /*
183 * Stack frames below this one aren't interesting. Don't show them
184 * if we're printing for %current.
185 */
186 if (!sp && (!task || task == current)) {
187 sp = &stack;
188 bp = stack_frame(current, NULL);
189 }
190
191 show_stack_log_lvl(task, NULL, sp, bp, "");
192 }
193
194 static arch_spinlock_t die_lock = __ARCH_SPIN_LOCK_UNLOCKED;
195 static int die_owner = -1;
196 static unsigned int die_nest_count;
197
oops_begin(void)198 unsigned __kprobes long oops_begin(void)
199 {
200 int cpu;
201 unsigned long flags;
202
203 oops_enter();
204
205 /* racy, but better than risking deadlock. */
206 raw_local_irq_save(flags);
207 cpu = smp_processor_id();
208 if (!arch_spin_trylock(&die_lock)) {
209 if (cpu == die_owner)
210 /* nested oops. should stop eventually */;
211 else
212 arch_spin_lock(&die_lock);
213 }
214 die_nest_count++;
215 die_owner = cpu;
216 console_verbose();
217 bust_spinlocks(1);
218 return flags;
219 }
220 EXPORT_SYMBOL_GPL(oops_begin);
221
oops_end(unsigned long flags,struct pt_regs * regs,int signr)222 void __kprobes oops_end(unsigned long flags, struct pt_regs *regs, int signr)
223 {
224 if (regs && kexec_should_crash(current))
225 crash_kexec(regs);
226
227 bust_spinlocks(0);
228 die_owner = -1;
229 add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
230 die_nest_count--;
231 if (!die_nest_count)
232 /* Nest count reaches zero, release the lock. */
233 arch_spin_unlock(&die_lock);
234 raw_local_irq_restore(flags);
235 oops_exit();
236
237 if (!signr)
238 return;
239 if (in_interrupt())
240 panic("Fatal exception in interrupt");
241 if (panic_on_oops)
242 panic("Fatal exception");
243 do_exit(signr);
244 }
245
__die(const char * str,struct pt_regs * regs,long err)246 int __kprobes __die(const char *str, struct pt_regs *regs, long err)
247 {
248 #ifdef CONFIG_X86_32
249 unsigned short ss;
250 unsigned long sp;
251 #endif
252 printk(KERN_DEFAULT
253 "%s: %04lx [#%d] ", str, err & 0xffff, ++die_counter);
254 #ifdef CONFIG_PREEMPT
255 printk("PREEMPT ");
256 #endif
257 #ifdef CONFIG_SMP
258 printk("SMP ");
259 #endif
260 #ifdef CONFIG_DEBUG_PAGEALLOC
261 printk("DEBUG_PAGEALLOC");
262 #endif
263 printk("\n");
264 if (notify_die(DIE_OOPS, str, regs, err,
265 current->thread.trap_nr, SIGSEGV) == NOTIFY_STOP)
266 return 1;
267
268 print_modules();
269 show_regs(regs);
270 #ifdef CONFIG_X86_32
271 if (user_mode_vm(regs)) {
272 sp = regs->sp;
273 ss = regs->ss & 0xffff;
274 } else {
275 sp = kernel_stack_pointer(regs);
276 savesegment(ss, ss);
277 }
278 printk(KERN_EMERG "EIP: [<%08lx>] ", regs->ip);
279 print_symbol("%s", regs->ip);
280 printk(" SS:ESP %04x:%08lx\n", ss, sp);
281 #else
282 /* Executive summary in case the oops scrolled away */
283 printk(KERN_ALERT "RIP ");
284 printk_address(regs->ip, 1);
285 printk(" RSP <%016lx>\n", regs->sp);
286 #endif
287 return 0;
288 }
289
290 /*
291 * This is gone through when something in the kernel has done something bad
292 * and is about to be terminated:
293 */
die(const char * str,struct pt_regs * regs,long err)294 void die(const char *str, struct pt_regs *regs, long err)
295 {
296 unsigned long flags = oops_begin();
297 int sig = SIGSEGV;
298
299 if (!user_mode_vm(regs))
300 report_bug(regs->ip, regs);
301
302 if (__die(str, regs, err))
303 sig = 0;
304 oops_end(flags, regs, sig);
305 }
306
kstack_setup(char * s)307 static int __init kstack_setup(char *s)
308 {
309 ssize_t ret;
310 unsigned long val;
311
312 if (!s)
313 return -EINVAL;
314
315 ret = kstrtoul(s, 0, &val);
316 if (ret)
317 return ret;
318 kstack_depth_to_print = val;
319 return 0;
320 }
321 early_param("kstack", kstack_setup);
322
code_bytes_setup(char * s)323 static int __init code_bytes_setup(char *s)
324 {
325 ssize_t ret;
326 unsigned long val;
327
328 if (!s)
329 return -EINVAL;
330
331 ret = kstrtoul(s, 0, &val);
332 if (ret)
333 return ret;
334
335 code_bytes = val;
336 if (code_bytes > 8192)
337 code_bytes = 8192;
338
339 return 1;
340 }
341 __setup("code_bytes=", code_bytes_setup);
342