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2
3
4
5#include <linux/kallsyms.h>
6#include <linux/kprobes.h>
7#include <linux/uaccess.h>
8#include <linux/hardirq.h>
9#include <linux/kdebug.h>
10#include <linux/module.h>
11#include <linux/ptrace.h>
12#include <linux/kexec.h>
13#include <linux/sysfs.h>
14#include <linux/bug.h>
15#include <linux/nmi.h>
16
17#include <asm/stacktrace.h>
18
19
20#define N_EXCEPTION_STACKS_END \
21 (N_EXCEPTION_STACKS + DEBUG_STKSZ/EXCEPTION_STKSZ - 2)
22
23static char x86_stack_ids[][8] = {
24 [ DEBUG_STACK-1 ] = "#DB",
25 [ NMI_STACK-1 ] = "NMI",
26 [ DOUBLEFAULT_STACK-1 ] = "#DF",
27 [ STACKFAULT_STACK-1 ] = "#SS",
28 [ MCE_STACK-1 ] = "#MC",
29#if DEBUG_STKSZ > EXCEPTION_STKSZ
30 [ N_EXCEPTION_STACKS ...
31 N_EXCEPTION_STACKS_END ] = "#DB[?]"
32#endif
33};
34
35static unsigned long *in_exception_stack(unsigned cpu, unsigned long stack,
36 unsigned *usedp, char **idp)
37{
38 unsigned k;
39
40
41
42
43
44 for (k = 0; k < N_EXCEPTION_STACKS; k++) {
45 unsigned long end = per_cpu(orig_ist, cpu).ist[k];
46
47
48
49
50 if (stack >= end)
51 continue;
52
53
54
55
56 if (stack >= end - EXCEPTION_STKSZ) {
57
58
59
60
61
62
63 if (*usedp & (1U << k))
64 break;
65 *usedp |= 1U << k;
66 *idp = x86_stack_ids[k];
67 return (unsigned long *)end;
68 }
69
70
71
72
73
74#if DEBUG_STKSZ > EXCEPTION_STKSZ
75 if (k == DEBUG_STACK - 1 && stack >= end - DEBUG_STKSZ) {
76 unsigned j = N_EXCEPTION_STACKS - 1;
77
78
79
80
81
82
83 do {
84 ++j;
85 end -= EXCEPTION_STKSZ;
86 x86_stack_ids[j][4] = '1' +
87 (j - N_EXCEPTION_STACKS);
88 } while (stack < end - EXCEPTION_STKSZ);
89 if (*usedp & (1U << j))
90 break;
91 *usedp |= 1U << j;
92 *idp = x86_stack_ids[j];
93 return (unsigned long *)end;
94 }
95#endif
96 }
97 return NULL;
98}
99
100static inline int
101in_irq_stack(unsigned long *stack, unsigned long *irq_stack,
102 unsigned long *irq_stack_end)
103{
104 return (stack >= irq_stack && stack < irq_stack_end);
105}
106
107
108
109
110
111
112
113
114void dump_trace(struct task_struct *task, struct pt_regs *regs,
115 unsigned long *stack, unsigned long bp,
116 const struct stacktrace_ops *ops, void *data)
117{
118 const unsigned cpu = get_cpu();
119 unsigned long *irq_stack_end =
120 (unsigned long *)per_cpu(irq_stack_ptr, cpu);
121 unsigned used = 0;
122 struct thread_info *tinfo;
123 int graph = 0;
124 unsigned long dummy;
125
126 if (!task)
127 task = current;
128
129 if (!stack) {
130 if (regs)
131 stack = (unsigned long *)regs->sp;
132 else if (task != current)
133 stack = (unsigned long *)task->thread.sp;
134 else
135 stack = &dummy;
136 }
137
138 if (!bp)
139 bp = stack_frame(task, regs);
140
141
142
143
144
145 tinfo = task_thread_info(task);
146 for (;;) {
147 char *id;
148 unsigned long *estack_end;
149 estack_end = in_exception_stack(cpu, (unsigned long)stack,
150 &used, &id);
151
152 if (estack_end) {
153 if (ops->stack(data, id) < 0)
154 break;
155
156 bp = ops->walk_stack(tinfo, stack, bp, ops,
157 data, estack_end, &graph);
158 ops->stack(data, "<EOE>");
159
160
161
162
163
164 stack = (unsigned long *) estack_end[-2];
165 continue;
166 }
167 if (irq_stack_end) {
168 unsigned long *irq_stack;
169 irq_stack = irq_stack_end -
170 (IRQ_STACK_SIZE - 64) / sizeof(*irq_stack);
171
172 if (in_irq_stack(stack, irq_stack, irq_stack_end)) {
173 if (ops->stack(data, "IRQ") < 0)
174 break;
175 bp = ops->walk_stack(tinfo, stack, bp,
176 ops, data, irq_stack_end, &graph);
177
178
179
180
181
182 stack = (unsigned long *) (irq_stack_end[-1]);
183 irq_stack_end = NULL;
184 ops->stack(data, "EOI");
185 continue;
186 }
187 }
188 break;
189 }
190
191
192
193
194 bp = ops->walk_stack(tinfo, stack, bp, ops, data, NULL, &graph);
195 put_cpu();
196}
197EXPORT_SYMBOL(dump_trace);
198
199void
200show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs,
201 unsigned long *sp, unsigned long bp, char *log_lvl)
202{
203 unsigned long *irq_stack_end;
204 unsigned long *irq_stack;
205 unsigned long *stack;
206 int cpu;
207 int i;
208
209 preempt_disable();
210 cpu = smp_processor_id();
211
212 irq_stack_end = (unsigned long *)(per_cpu(irq_stack_ptr, cpu));
213 irq_stack = (unsigned long *)(per_cpu(irq_stack_ptr, cpu) - IRQ_STACK_SIZE);
214
215
216
217
218
219 if (sp == NULL) {
220 if (task)
221 sp = (unsigned long *)task->thread.sp;
222 else
223 sp = (unsigned long *)&sp;
224 }
225
226 stack = sp;
227 for (i = 0; i < kstack_depth_to_print; i++) {
228 if (stack >= irq_stack && stack <= irq_stack_end) {
229 if (stack == irq_stack_end) {
230 stack = (unsigned long *) (irq_stack_end[-1]);
231 pr_cont(" <EOI> ");
232 }
233 } else {
234 if (((long) stack & (THREAD_SIZE-1)) == 0)
235 break;
236 }
237 if (i && ((i % STACKSLOTS_PER_LINE) == 0))
238 pr_cont("\n");
239 pr_cont(" %016lx", *stack++);
240 touch_nmi_watchdog();
241 }
242 preempt_enable();
243
244 pr_cont("\n");
245 show_trace_log_lvl(task, regs, sp, bp, log_lvl);
246}
247
248void show_regs(struct pt_regs *regs)
249{
250 int i;
251 unsigned long sp;
252
253 sp = regs->sp;
254 show_regs_print_info(KERN_DEFAULT);
255 __show_regs(regs, 1);
256
257
258
259
260
261 if (!user_mode(regs)) {
262 unsigned int code_prologue = code_bytes * 43 / 64;
263 unsigned int code_len = code_bytes;
264 unsigned char c;
265 u8 *ip;
266
267 printk(KERN_DEFAULT "Stack:\n");
268 show_stack_log_lvl(NULL, regs, (unsigned long *)sp,
269 0, KERN_DEFAULT);
270
271 printk(KERN_DEFAULT "Code: ");
272
273 ip = (u8 *)regs->ip - code_prologue;
274 if (ip < (u8 *)PAGE_OFFSET || probe_kernel_address(ip, c)) {
275
276 ip = (u8 *)regs->ip;
277 code_len = code_len - code_prologue + 1;
278 }
279 for (i = 0; i < code_len; i++, ip++) {
280 if (ip < (u8 *)PAGE_OFFSET ||
281 probe_kernel_address(ip, c)) {
282 pr_cont(" Bad RIP value.");
283 break;
284 }
285 if (ip == (u8 *)regs->ip)
286 pr_cont("<%02x> ", c);
287 else
288 pr_cont("%02x ", c);
289 }
290 }
291 pr_cont("\n");
292}
293
294int is_valid_bugaddr(unsigned long ip)
295{
296 unsigned short ud2;
297
298 if (__copy_from_user(&ud2, (const void __user *) ip, sizeof(ud2)))
299 return 0;
300
301 return ud2 == 0x0b0f;
302}
303