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authorAlexander van Heukelum <heukelum@fastmail.fm>2008-09-30 07:12:15 -0400
committerIngo Molnar <mingo@elte.hu>2008-10-13 04:33:17 -0400
commit6fcbede3fdfbd83d8de97296286f5a9ff5a8f371 (patch)
treec65eceb4a1c023a17a7e5f2474ebadb038072c5f /arch/x86/kernel/traps_64.c
parent2bc5f927d489f9e47b6fa71f323b653e8ec81782 (diff)
x86_64: split out dumpstack code from traps_64.c
The dumpstack code is logically quite independent from the hardware traps. Split it out into its own file. Signed-off-by: Alexander van Heukelum <heukelum@fastmail.fm> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86/kernel/traps_64.c')
-rw-r--r--arch/x86/kernel/traps_64.c545
1 files changed, 0 insertions, 545 deletions
diff --git a/arch/x86/kernel/traps_64.c b/arch/x86/kernel/traps_64.c
index 729157ee4c17..1cd61ddd90be 100644
--- a/arch/x86/kernel/traps_64.c
+++ b/arch/x86/kernel/traps_64.c
@@ -54,11 +54,7 @@
54 54
55#include <mach_traps.h> 55#include <mach_traps.h>
56 56
57int panic_on_unrecovered_nmi;
58int kstack_depth_to_print = 12;
59static unsigned int code_bytes = 64;
60static int ignore_nmis; 57static int ignore_nmis;
61static int die_counter;
62 58
63static inline void conditional_sti(struct pt_regs *regs) 59static inline void conditional_sti(struct pt_regs *regs)
64{ 60{
@@ -82,518 +78,6 @@ static inline void preempt_conditional_cli(struct pt_regs *regs)
82 dec_preempt_count(); 78 dec_preempt_count();
83} 79}
84 80
85void printk_address(unsigned long address, int reliable)
86{
87 printk(" [<%016lx>] %s%pS\n",
88 address, reliable ? "" : "? ", (void *) address);
89}
90
91static unsigned long *in_exception_stack(unsigned cpu, unsigned long stack,
92 unsigned *usedp, char **idp)
93{
94 static char ids[][8] = {
95 [DEBUG_STACK - 1] = "#DB",
96 [NMI_STACK - 1] = "NMI",
97 [DOUBLEFAULT_STACK - 1] = "#DF",
98 [STACKFAULT_STACK - 1] = "#SS",
99 [MCE_STACK - 1] = "#MC",
100#if DEBUG_STKSZ > EXCEPTION_STKSZ
101 [N_EXCEPTION_STACKS ...
102 N_EXCEPTION_STACKS + DEBUG_STKSZ / EXCEPTION_STKSZ - 2] = "#DB[?]"
103#endif
104 };
105 unsigned k;
106
107 /*
108 * Iterate over all exception stacks, and figure out whether
109 * 'stack' is in one of them:
110 */
111 for (k = 0; k < N_EXCEPTION_STACKS; k++) {
112 unsigned long end = per_cpu(orig_ist, cpu).ist[k];
113 /*
114 * Is 'stack' above this exception frame's end?
115 * If yes then skip to the next frame.
116 */
117 if (stack >= end)
118 continue;
119 /*
120 * Is 'stack' above this exception frame's start address?
121 * If yes then we found the right frame.
122 */
123 if (stack >= end - EXCEPTION_STKSZ) {
124 /*
125 * Make sure we only iterate through an exception
126 * stack once. If it comes up for the second time
127 * then there's something wrong going on - just
128 * break out and return NULL:
129 */
130 if (*usedp & (1U << k))
131 break;
132 *usedp |= 1U << k;
133 *idp = ids[k];
134 return (unsigned long *)end;
135 }
136 /*
137 * If this is a debug stack, and if it has a larger size than
138 * the usual exception stacks, then 'stack' might still
139 * be within the lower portion of the debug stack:
140 */
141#if DEBUG_STKSZ > EXCEPTION_STKSZ
142 if (k == DEBUG_STACK - 1 && stack >= end - DEBUG_STKSZ) {
143 unsigned j = N_EXCEPTION_STACKS - 1;
144
145 /*
146 * Black magic. A large debug stack is composed of
147 * multiple exception stack entries, which we
148 * iterate through now. Dont look:
149 */
150 do {
151 ++j;
152 end -= EXCEPTION_STKSZ;
153 ids[j][4] = '1' + (j - N_EXCEPTION_STACKS);
154 } while (stack < end - EXCEPTION_STKSZ);
155 if (*usedp & (1U << j))
156 break;
157 *usedp |= 1U << j;
158 *idp = ids[j];
159 return (unsigned long *)end;
160 }
161#endif
162 }
163 return NULL;
164}
165
166/*
167 * x86-64 can have up to three kernel stacks:
168 * process stack
169 * interrupt stack
170 * severe exception (double fault, nmi, stack fault, debug, mce) hardware stack
171 */
172
173static inline int valid_stack_ptr(struct thread_info *tinfo,
174 void *p, unsigned int size, void *end)
175{
176 void *t = tinfo;
177 if (end) {
178 if (p < end && p >= (end-THREAD_SIZE))
179 return 1;
180 else
181 return 0;
182 }
183 return p > t && p < t + THREAD_SIZE - size;
184}
185
186/* The form of the top of the frame on the stack */
187struct stack_frame {
188 struct stack_frame *next_frame;
189 unsigned long return_address;
190};
191
192static inline unsigned long
193print_context_stack(struct thread_info *tinfo,
194 unsigned long *stack, unsigned long bp,
195 const struct stacktrace_ops *ops, void *data,
196 unsigned long *end)
197{
198 struct stack_frame *frame = (struct stack_frame *)bp;
199
200 while (valid_stack_ptr(tinfo, stack, sizeof(*stack), end)) {
201 unsigned long addr;
202
203 addr = *stack;
204 if (__kernel_text_address(addr)) {
205 if ((unsigned long) stack == bp + 8) {
206 ops->address(data, addr, 1);
207 frame = frame->next_frame;
208 bp = (unsigned long) frame;
209 } else {
210 ops->address(data, addr, bp == 0);
211 }
212 }
213 stack++;
214 }
215 return bp;
216}
217
218void dump_trace(struct task_struct *task, struct pt_regs *regs,
219 unsigned long *stack, unsigned long bp,
220 const struct stacktrace_ops *ops, void *data)
221{
222 const unsigned cpu = get_cpu();
223 unsigned long *irqstack_end = (unsigned long *)cpu_pda(cpu)->irqstackptr;
224 unsigned used = 0;
225 struct thread_info *tinfo;
226
227 if (!task)
228 task = current;
229
230 if (!stack) {
231 unsigned long dummy;
232 stack = &dummy;
233 if (task && task != current)
234 stack = (unsigned long *)task->thread.sp;
235 }
236
237#ifdef CONFIG_FRAME_POINTER
238 if (!bp) {
239 if (task == current) {
240 /* Grab bp right from our regs */
241 asm("movq %%rbp, %0" : "=r" (bp) : );
242 } else {
243 /* bp is the last reg pushed by switch_to */
244 bp = *(unsigned long *) task->thread.sp;
245 }
246 }
247#endif
248
249 /*
250 * Print function call entries in all stacks, starting at the
251 * current stack address. If the stacks consist of nested
252 * exceptions
253 */
254 tinfo = task_thread_info(task);
255 for (;;) {
256 char *id;
257 unsigned long *estack_end;
258 estack_end = in_exception_stack(cpu, (unsigned long)stack,
259 &used, &id);
260
261 if (estack_end) {
262 if (ops->stack(data, id) < 0)
263 break;
264
265 bp = print_context_stack(tinfo, stack, bp, ops,
266 data, estack_end);
267 ops->stack(data, "<EOE>");
268 /*
269 * We link to the next stack via the
270 * second-to-last pointer (index -2 to end) in the
271 * exception stack:
272 */
273 stack = (unsigned long *) estack_end[-2];
274 continue;
275 }
276 if (irqstack_end) {
277 unsigned long *irqstack;
278 irqstack = irqstack_end -
279 (IRQSTACKSIZE - 64) / sizeof(*irqstack);
280
281 if (stack >= irqstack && stack < irqstack_end) {
282 if (ops->stack(data, "IRQ") < 0)
283 break;
284 bp = print_context_stack(tinfo, stack, bp,
285 ops, data, irqstack_end);
286 /*
287 * We link to the next stack (which would be
288 * the process stack normally) the last
289 * pointer (index -1 to end) in the IRQ stack:
290 */
291 stack = (unsigned long *) (irqstack_end[-1]);
292 irqstack_end = NULL;
293 ops->stack(data, "EOI");
294 continue;
295 }
296 }
297 break;
298 }
299
300 /*
301 * This handles the process stack:
302 */
303 bp = print_context_stack(tinfo, stack, bp, ops, data, NULL);
304 put_cpu();
305}
306EXPORT_SYMBOL(dump_trace);
307
308static void
309print_trace_warning_symbol(void *data, char *msg, unsigned long symbol)
310{
311 print_symbol(msg, symbol);
312 printk("\n");
313}
314
315static void print_trace_warning(void *data, char *msg)
316{
317 printk("%s\n", msg);
318}
319
320static int print_trace_stack(void *data, char *name)
321{
322 printk(" <%s> ", name);
323 return 0;
324}
325
326static void print_trace_address(void *data, unsigned long addr, int reliable)
327{
328 touch_nmi_watchdog();
329 printk_address(addr, reliable);
330}
331
332static const struct stacktrace_ops print_trace_ops = {
333 .warning = print_trace_warning,
334 .warning_symbol = print_trace_warning_symbol,
335 .stack = print_trace_stack,
336 .address = print_trace_address,
337};
338
339static void
340show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs,
341 unsigned long *stack, unsigned long bp, char *log_lvl)
342{
343 printk("Call Trace:\n");
344 dump_trace(task, regs, stack, bp, &print_trace_ops, log_lvl);
345}
346
347void show_trace(struct task_struct *task, struct pt_regs *regs,
348 unsigned long *stack, unsigned long bp)
349{
350 show_trace_log_lvl(task, regs, stack, bp, "");
351}
352
353static void
354show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs,
355 unsigned long *sp, unsigned long bp, char *log_lvl)
356{
357 unsigned long *stack;
358 int i;
359 const int cpu = smp_processor_id();
360 unsigned long *irqstack_end =
361 (unsigned long *) (cpu_pda(cpu)->irqstackptr);
362 unsigned long *irqstack =
363 (unsigned long *) (cpu_pda(cpu)->irqstackptr - IRQSTACKSIZE);
364
365 /*
366 * debugging aid: "show_stack(NULL, NULL);" prints the
367 * back trace for this cpu.
368 */
369
370 if (sp == NULL) {
371 if (task)
372 sp = (unsigned long *)task->thread.sp;
373 else
374 sp = (unsigned long *)&sp;
375 }
376
377 stack = sp;
378 for (i = 0; i < kstack_depth_to_print; i++) {
379 if (stack >= irqstack && stack <= irqstack_end) {
380 if (stack == irqstack_end) {
381 stack = (unsigned long *) (irqstack_end[-1]);
382 printk(" <EOI> ");
383 }
384 } else {
385 if (((long) stack & (THREAD_SIZE-1)) == 0)
386 break;
387 }
388 if (i && ((i % 4) == 0))
389 printk("\n");
390 printk(" %016lx", *stack++);
391 touch_nmi_watchdog();
392 }
393 printk("\n");
394 show_trace_log_lvl(task, regs, sp, bp, log_lvl);
395}
396
397void show_stack(struct task_struct *task, unsigned long *sp)
398{
399 show_stack_log_lvl(task, NULL, sp, 0, "");
400}
401
402/*
403 * The architecture-independent dump_stack generator
404 */
405void dump_stack(void)
406{
407 unsigned long bp = 0;
408 unsigned long stack;
409
410#ifdef CONFIG_FRAME_POINTER
411 if (!bp)
412 asm("movq %%rbp, %0" : "=r" (bp) : );
413#endif
414
415 printk("Pid: %d, comm: %.20s %s %s %.*s\n",
416 current->pid, current->comm, print_tainted(),
417 init_utsname()->release,
418 (int)strcspn(init_utsname()->version, " "),
419 init_utsname()->version);
420 show_trace(NULL, NULL, &stack, bp);
421}
422EXPORT_SYMBOL(dump_stack);
423
424void show_registers(struct pt_regs *regs)
425{
426 int i;
427 unsigned long sp;
428 const int cpu = smp_processor_id();
429 struct task_struct *cur = cpu_pda(cpu)->pcurrent;
430
431 sp = regs->sp;
432 printk("CPU %d ", cpu);
433 __show_regs(regs, 1);
434 printk("Process %s (pid: %d, threadinfo %p, task %p)\n",
435 cur->comm, cur->pid, task_thread_info(cur), cur);
436
437 /*
438 * When in-kernel, we also print out the stack and code at the
439 * time of the fault..
440 */
441 if (!user_mode(regs)) {
442 unsigned int code_prologue = code_bytes * 43 / 64;
443 unsigned int code_len = code_bytes;
444 unsigned char c;
445 u8 *ip;
446
447 printk("Stack: ");
448 show_stack_log_lvl(NULL, regs, (unsigned long *)sp,
449 regs->bp, "");
450
451 printk(KERN_EMERG "Code: ");
452
453 ip = (u8 *)regs->ip - code_prologue;
454 if (ip < (u8 *)PAGE_OFFSET || probe_kernel_address(ip, c)) {
455 /* try starting at RIP */
456 ip = (u8 *)regs->ip;
457 code_len = code_len - code_prologue + 1;
458 }
459 for (i = 0; i < code_len; i++, ip++) {
460 if (ip < (u8 *)PAGE_OFFSET ||
461 probe_kernel_address(ip, c)) {
462 printk(" Bad RIP value.");
463 break;
464 }
465 if (ip == (u8 *)regs->ip)
466 printk("<%02x> ", c);
467 else
468 printk("%02x ", c);
469 }
470 }
471 printk("\n");
472}
473
474int is_valid_bugaddr(unsigned long ip)
475{
476 unsigned short ud2;
477
478 if (__copy_from_user(&ud2, (const void __user *) ip, sizeof(ud2)))
479 return 0;
480
481 return ud2 == 0x0b0f;
482}
483
484static raw_spinlock_t die_lock = __RAW_SPIN_LOCK_UNLOCKED;
485static int die_owner = -1;
486static unsigned int die_nest_count;
487
488unsigned __kprobes long oops_begin(void)
489{
490 int cpu;
491 unsigned long flags;
492
493 oops_enter();
494
495 /* racy, but better than risking deadlock. */
496 raw_local_irq_save(flags);
497 cpu = smp_processor_id();
498 if (!__raw_spin_trylock(&die_lock)) {
499 if (cpu == die_owner)
500 /* nested oops. should stop eventually */;
501 else
502 __raw_spin_lock(&die_lock);
503 }
504 die_nest_count++;
505 die_owner = cpu;
506 console_verbose();
507 bust_spinlocks(1);
508 return flags;
509}
510
511void __kprobes oops_end(unsigned long flags, struct pt_regs *regs, int signr)
512{
513 die_owner = -1;
514 bust_spinlocks(0);
515 die_nest_count--;
516 if (!die_nest_count)
517 /* Nest count reaches zero, release the lock. */
518 __raw_spin_unlock(&die_lock);
519 raw_local_irq_restore(flags);
520 if (!regs) {
521 oops_exit();
522 return;
523 }
524 if (panic_on_oops)
525 panic("Fatal exception");
526 oops_exit();
527 do_exit(signr);
528}
529
530int __kprobes __die(const char *str, struct pt_regs *regs, long err)
531{
532 printk(KERN_EMERG "%s: %04lx [%u] ", str, err & 0xffff, ++die_counter);
533#ifdef CONFIG_PREEMPT
534 printk("PREEMPT ");
535#endif
536#ifdef CONFIG_SMP
537 printk("SMP ");
538#endif
539#ifdef CONFIG_DEBUG_PAGEALLOC
540 printk("DEBUG_PAGEALLOC");
541#endif
542 printk("\n");
543 if (notify_die(DIE_OOPS, str, regs, err,
544 current->thread.trap_no, SIGSEGV) == NOTIFY_STOP)
545 return 1;
546
547 show_registers(regs);
548 add_taint(TAINT_DIE);
549 /* Executive summary in case the oops scrolled away */
550 printk(KERN_ALERT "RIP ");
551 printk_address(regs->ip, 1);
552 printk(" RSP <%016lx>\n", regs->sp);
553 if (kexec_should_crash(current))
554 crash_kexec(regs);
555 return 0;
556}
557
558void die(const char *str, struct pt_regs *regs, long err)
559{
560 unsigned long flags = oops_begin();
561
562 if (!user_mode(regs))
563 report_bug(regs->ip, regs);
564
565 if (__die(str, regs, err))
566 regs = NULL;
567 oops_end(flags, regs, SIGSEGV);
568}
569
570notrace __kprobes void
571die_nmi(char *str, struct pt_regs *regs, int do_panic)
572{
573 unsigned long flags;
574
575 if (notify_die(DIE_NMIWATCHDOG, str, regs, 0, 2, SIGINT) == NOTIFY_STOP)
576 return;
577
578 flags = oops_begin();
579 /*
580 * We are in trouble anyway, lets at least try
581 * to get a message out.
582 */
583 printk(KERN_EMERG "%s", str);
584 printk(" on CPU%d, ip %08lx, registers:\n",
585 smp_processor_id(), regs->ip);
586 show_registers(regs);
587 if (kexec_should_crash(current))
588 crash_kexec(regs);
589 if (do_panic || panic_on_oops)
590 panic("Non maskable interrupt");
591 oops_end(flags, NULL, SIGBUS);
592 nmi_exit();
593 local_irq_enable();
594 do_exit(SIGBUS);
595}
596
597static void __kprobes 81static void __kprobes
598do_trap(int trapnr, int signr, char *str, struct pt_regs *regs, 82do_trap(int trapnr, int signr, char *str, struct pt_regs *regs,
599 long error_code, siginfo_t *info) 83 long error_code, siginfo_t *info)
@@ -1178,32 +662,3 @@ void __init trap_init(void)
1178 */ 662 */
1179 cpu_init(); 663 cpu_init();
1180} 664}
1181
1182static int __init oops_setup(char *s)
1183{
1184 if (!s)
1185 return -EINVAL;
1186 if (!strcmp(s, "panic"))
1187 panic_on_oops = 1;
1188 return 0;
1189}
1190early_param("oops", oops_setup);
1191
1192static int __init kstack_setup(char *s)
1193{
1194 if (!s)
1195 return -EINVAL;
1196 kstack_depth_to_print = simple_strtoul(s, NULL, 0);
1197 return 0;
1198}
1199early_param("kstack", kstack_setup);
1200
1201static int __init code_bytes_setup(char *s)
1202{
1203 code_bytes = simple_strtoul(s, NULL, 0);
1204 if (code_bytes > 8192)
1205 code_bytes = 8192;
1206
1207 return 1;
1208}
1209__setup("code_bytes=", code_bytes_setup);
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