1 /*
2 * Copyright (C) 1991, 1992 Linus Torvalds
3 * Copyright (C) 2000, 2001, 2002 Andi Kleen, SuSE Labs
4 *
5 * Pentium III FXSR, SSE support
6 * Gareth Hughes <gareth@valinux.com>, May 2000
7 */
8
9 /*
10 * 'Traps.c' handles hardware traps and faults after we have saved some
11 * state in 'entry.S'.
12 */
13 #include <linux/sched.h>
14 #include <linux/kernel.h>
15 #include <linux/string.h>
16 #include <linux/errno.h>
17 #include <linux/ptrace.h>
18 #include <linux/timer.h>
19 #include <linux/mm.h>
20 #include <linux/init.h>
21 #include <linux/delay.h>
22 #include <linux/spinlock.h>
23 #include <linux/interrupt.h>
24 #include <linux/kallsyms.h>
25 #include <linux/module.h>
26 #include <linux/moduleparam.h>
27 #include <linux/nmi.h>
28 #include <linux/kprobes.h>
29 #include <linux/kexec.h>
30 #include <linux/unwind.h>
31 #include <linux/uaccess.h>
32 #include <linux/bug.h>
33 #include <linux/kdebug.h>
34 #include <linux/utsname.h>
35
36 #include <linux/ftrace.h>
37
38 #if defined(CONFIG_EDAC)
39 #include <linux/edac.h>
40 #endif
41
42 #include <asm/system.h>
43 #include <asm/io.h>
44 #include <asm/atomic.h>
45 #include <asm/debugreg.h>
46 #include <asm/desc.h>
47 #include <asm/i387.h>
48 #include <asm/processor.h>
49 #include <asm/unwind.h>
50 #include <asm/smp.h>
51 #include <asm/pgalloc.h>
52 #include <asm/pda.h>
53 #include <asm/proto.h>
54 #include <asm/nmi.h>
55 #include <asm/stacktrace.h>
56
57 asmlinkage void divide_error(void);
58 asmlinkage void debug(void);
59 asmlinkage void nmi(void);
60 asmlinkage void int3(void);
61 asmlinkage void overflow(void);
62 asmlinkage void bounds(void);
63 asmlinkage void invalid_op(void);
64 asmlinkage void device_not_available(void);
65 asmlinkage void double_fault(void);
66 asmlinkage void coprocessor_segment_overrun(void);
67 asmlinkage void invalid_TSS(void);
68 asmlinkage void segment_not_present(void);
69 asmlinkage void stack_segment(void);
70 asmlinkage void general_protection(void);
71 asmlinkage void page_fault(void);
72 asmlinkage void coprocessor_error(void);
73 asmlinkage void simd_coprocessor_error(void);
74 asmlinkage void reserved(void);
75 asmlinkage void alignment_check(void);
76 asmlinkage void machine_check(void);
77 asmlinkage void spurious_interrupt_bug(void);
78
79 static unsigned int code_bytes = 64;
80
81 static inline void conditional_sti(struct pt_regs *regs)
82 {
83 if (regs->flags & X86_EFLAGS_IF)
84 local_irq_enable();
85 }
86
87 static inline void preempt_conditional_sti(struct pt_regs *regs, int stack)
88 {
89 if (stack)
90 inc_preempt_count();
91 if (regs->flags & X86_EFLAGS_IF)
92 local_irq_enable();
93 }
94
95 static inline void preempt_conditional_cli(struct pt_regs *regs, int stack)
96 {
97 if (regs->flags & X86_EFLAGS_IF)
98 local_irq_disable();
99 /* Make sure to not schedule here because we could be running
100 on an exception stack. */
101 if (stack)
102 dec_preempt_count();
103 }
104
105 int kstack_depth_to_print = 12;
106
107 void printk_address(unsigned long address, int reliable)
108 {
109 #ifdef CONFIG_KALLSYMS
110 unsigned long offset = 0, symsize;
111 const char *symname;
112 char *modname;
113 char *delim = ":";
114 char namebuf[KSYM_NAME_LEN];
115 char reliab[4] = "";
116
117 symname = kallsyms_lookup(address, &symsize, &offset,
118 &modname, namebuf);
119 if (!symname) {
120 printk(" [<%016lx>]\n", address);
121 return;
122 }
123 if (!reliable)
124 strcpy(reliab, "? ");
125
126 if (!modname)
127 modname = delim = "";
128 printk(" [<%016lx>] %s%s%s%s%s+0x%lx/0x%lx\n",
129 address, reliab, delim, modname, delim, symname, offset, symsize);
130 #else
131 printk(" [<%016lx>]\n", address);
132 #endif
133 }
134
135 static unsigned long *in_exception_stack(unsigned cpu, unsigned long stack,
136 unsigned *usedp, char **idp)
137 {
138 static char ids[][8] = {
139 #if DEBUG_STACK > 0
140 [DEBUG_STACK - 1] = "#DB",
141 #endif
142 [NMI_STACK - 1] = "NMI",
143 [DOUBLEFAULT_STACK - 1] = "#DF",
144 #if STACKFAULT_STACK > 0
145 [STACKFAULT_STACK - 1] = "#SS",
146 #endif
147 [MCE_STACK - 1] = "#MC",
148 #if DEBUG_STKSZ > EXCEPTION_STKSZ
149 [N_EXCEPTION_STACKS ... N_EXCEPTION_STACKS + DEBUG_STKSZ / EXCEPTION_STKSZ - 2] = "#DB[?]"
150 #endif
151 };
152 unsigned k;
153
154 /*
155 * Iterate over all exception stacks, and figure out whether
156 * 'stack' is in one of them:
157 */
158 for (k = 0; k < N_EXCEPTION_STACKS; k++) {
159 unsigned long end = per_cpu(orig_ist, cpu).ist[k];
160 /*
161 * Is 'stack' above this exception frame's end?
162 * If yes then skip to the next frame.
163 */
164 if (stack >= end)
165 continue;
166 /*
167 * Is 'stack' above this exception frame's start address?
168 * If yes then we found the right frame.
169 */
170 if (stack >= end - EXCEPTION_STKSZ) {
171 /*
172 * Make sure we only iterate through an exception
173 * stack once. If it comes up for the second time
174 * then there's something wrong going on - just
175 * break out and return NULL:
176 */
177 if (*usedp & (1U << k))
178 break;
179 *usedp |= 1U << k;
180 *idp = ids[k];
181 return (unsigned long *)end;
182 }
183 /*
184 * If this is a debug stack, and if it has a larger size than
185 * the usual exception stacks, then 'stack' might still
186 * be within the lower portion of the debug stack:
187 */
188 #if DEBUG_STKSZ > EXCEPTION_STKSZ
189 if (k == DEBUG_STACK - 1 && stack >= end - DEBUG_STKSZ) {
190 unsigned j = N_EXCEPTION_STACKS - 1;
191
192 /*
193 * Black magic. A large debug stack is composed of
194 * multiple exception stack entries, which we
195 * iterate through now. Dont look:
196 */
197 do {
198 ++j;
199 end -= EXCEPTION_STKSZ;
200 ids[j][4] = '1' + (j - N_EXCEPTION_STACKS);
201 } while (stack < end - EXCEPTION_STKSZ);
202 if (*usedp & (1U << j))
203 break;
204 *usedp |= 1U << j;
205 *idp = ids[j];
206 return (unsigned long *)end;
207 }
208 #endif
209 }
210 return NULL;
211 }
212
213 #define MSG(txt) ops->warning(data, txt)
214
215 /*
216 * x86-64 can have up to three kernel stacks:
217 * process stack
218 * interrupt stack
219 * severe exception (double fault, nmi, stack fault, debug, mce) hardware stack
220 */
221
222 static inline int valid_stack_ptr(struct thread_info *tinfo,
223 void *p, unsigned int size, void *end)
224 {
225 void *t = tinfo;
226 if (end) {
227 if (p < end && p >= (end-THREAD_SIZE))
228 return 1;
229 else
230 return 0;
231 }
232 return p > t && p < t + THREAD_SIZE - size;
233 }
234
235 /* The form of the top of the frame on the stack */
236 struct stack_frame {
237 struct stack_frame *next_frame;
238 unsigned long return_address;
239 };
240
241
242 static inline unsigned long print_context_stack(struct thread_info *tinfo,
243 unsigned long *stack, unsigned long bp,
244 const struct stacktrace_ops *ops, void *data,
245 unsigned long *end)
246 {
247 struct stack_frame *frame = (struct stack_frame *)bp;
248
249 while (valid_stack_ptr(tinfo, stack, sizeof(*stack), end)) {
250 unsigned long addr;
251
252 addr = *stack;
253 if (__kernel_text_address(addr)) {
254 if ((unsigned long) stack == bp + 8) {
255 ops->address(data, addr, 1);
256 frame = frame->next_frame;
257 bp = (unsigned long) frame;
258 } else {
259 ops->address(data, addr, bp == 0);
260 }
261 }
262 stack++;
263 }
264 return bp;
265 }
266
267 void dump_trace(struct task_struct *tsk, struct pt_regs *regs,
268 unsigned long *stack, unsigned long bp,
269 const struct stacktrace_ops *ops, void *data)
270 {
271 const unsigned cpu = raw_smp_processor_id();
272 unsigned long *irqstack_end = (unsigned long*)cpu_pda(cpu)->irqstackptr;
273 unsigned used = 0;
274 struct thread_info *tinfo;
275
276 if (!tsk)
277 tsk = current;
278 tinfo = task_thread_info(tsk);
279
280 if (!stack) {
281 unsigned long dummy;
282 stack = &dummy;
283 if (tsk && tsk != current)
284 stack = (unsigned long *)tsk->thread.sp;
285 }
286
287 #ifdef CONFIG_FRAME_POINTER
288 if (!bp) {
289 if (tsk == current) {
290 /* Grab bp right from our regs */
291 asm("movq %%rbp, %0" : "=r" (bp):);
292 } else {
293 /* bp is the last reg pushed by switch_to */
294 bp = *(unsigned long *) tsk->thread.sp;
295 }
296 }
297 #endif
298
299
300
301 /*
302 * Print function call entries in all stacks, starting at the
303 * current stack address. If the stacks consist of nested
304 * exceptions
305 */
306 for (;;) {
307 char *id;
308 unsigned long *estack_end;
309 estack_end = in_exception_stack(cpu, (unsigned long)stack,
310 &used, &id);
311
312 if (estack_end) {
313 if (ops->stack(data, id) < 0)
314 break;
315
316 bp = print_context_stack(tinfo, stack, bp, ops,
317 data, estack_end);
318 ops->stack(data, "<EOE>");
319 /*
320 * We link to the next stack via the
321 * second-to-last pointer (index -2 to end) in the
322 * exception stack:
323 */
324 stack = (unsigned long *) estack_end[-2];
325 continue;
326 }
327 if (irqstack_end) {
328 unsigned long *irqstack;
329 irqstack = irqstack_end -
330 (IRQSTACKSIZE - 64) / sizeof(*irqstack);
331
332 if (stack >= irqstack && stack < irqstack_end) {
333 if (ops->stack(data, "IRQ") < 0)
334 break;
335 bp = print_context_stack(tinfo, stack, bp,
336 ops, data, irqstack_end);
337 /*
338 * We link to the next stack (which would be
339 * the process stack normally) the last
340 * pointer (index -1 to end) in the IRQ stack:
341 */
342 stack = (unsigned long *) (irqstack_end[-1]);
343 irqstack_end = NULL;
344 ops->stack(data, "EOI");
345 continue;
346 }
347 }
348 break;
349 }
350
351 /*
352 * This handles the process stack:
353 */
354 bp = print_context_stack(tinfo, stack, bp, ops, data, NULL);
355 }
356 EXPORT_SYMBOL(dump_trace);
357
358 static void
359 print_trace_warning_symbol(void *data, char *msg, unsigned long symbol)
360 {
361 print_symbol(msg, symbol);
362 printk("\n");
363 }
364
365 static void print_trace_warning(void *data, char *msg)
366 {
367 printk("%s\n", msg);
368 }
369
370 static int print_trace_stack(void *data, char *name)
371 {
372 printk(" <%s> ", name);
373 return 0;
374 }
375
376 static void print_trace_address(void *data, unsigned long addr, int reliable)
377 {
378 touch_nmi_watchdog();
379 printk_address(addr, reliable);
380 }
381
382 static const struct stacktrace_ops print_trace_ops = {
383 .warning = print_trace_warning,
384 .warning_symbol = print_trace_warning_symbol,
385 .stack = print_trace_stack,
386 .address = print_trace_address,
387 };
388
389 void
390 show_trace(struct task_struct *tsk, struct pt_regs *regs, unsigned long *stack,
391 unsigned long bp)
392 {
393 pause_on_oops_head();
394 printk("\nCall Trace:\n");
395 dump_trace(tsk, regs, stack, bp, &print_trace_ops, NULL);
396 printk("\n");
397 debug_show_held_locks(tsk);
398 pause_on_oops_tail();
399 print_preempt_trace(tsk);
400 }
401
402 static void
403 _show_stack(struct task_struct *tsk, struct pt_regs *regs, unsigned long *sp,
404 unsigned long bp)
405 {
406 unsigned long *stack;
407 int i;
408 const int cpu = raw_smp_processor_id();
409 unsigned long *irqstack_end = (unsigned long *) (cpu_pda(cpu)->irqstackptr);
410 unsigned long *irqstack = (unsigned long *) (cpu_pda(cpu)->irqstackptr - IRQSTACKSIZE);
411
412 // debugging aid: "show_stack(NULL, NULL);" prints the
413 // back trace for this cpu.
414
415 if (sp == NULL) {
416 if (tsk)
417 sp = (unsigned long *)tsk->thread.sp;
418 else
419 sp = (unsigned long *)&sp;
420 }
421
422 stack = sp;
423 for(i=0; i < kstack_depth_to_print; i++) {
424 if (stack >= irqstack && stack <= irqstack_end) {
425 if (stack == irqstack_end) {
426 stack = (unsigned long *) (irqstack_end[-1]);
427 printk(" <EOI> ");
428 }
429 } else {
430 if (((long) stack & (THREAD_SIZE-1)) == 0)
431 break;
432 }
433 if (i && ((i % 4) == 0))
434 printk("\n");
435 printk(" %016lx", *stack++);
436 touch_nmi_watchdog();
437 }
438 show_trace(tsk, regs, sp, bp);
439 }
440
441 void show_stack(struct task_struct *tsk, unsigned long * sp)
442 {
443 _show_stack(tsk, NULL, sp, 0);
444 }
445
446 /*
447 * The architecture-independent dump_stack generator
448 */
449 void dump_stack(void)
450 {
451 unsigned long dummy;
452 unsigned long bp = 0;
453
454 #ifdef CONFIG_FRAME_POINTER
455 if (!bp)
456 asm("movq %%rbp, %0" : "=r" (bp):);
457 #endif
458
459 printk("Pid: %d, comm: %.20s %s %s %.*s\n",
460 current->pid, current->comm, print_tainted(),
461 init_utsname()->release,
462 (int)strcspn(init_utsname()->version, " "),
463 init_utsname()->version);
464 show_trace(NULL, NULL, &dummy, bp);
465 }
466
467 EXPORT_SYMBOL(dump_stack);
468
469 void show_registers(struct pt_regs *regs)
470 {
471 int i;
472 unsigned long sp;
473 const int cpu = smp_processor_id();
474 struct task_struct *cur = cpu_pda(cpu)->pcurrent;
475 u8 *ip;
476 unsigned int code_prologue = code_bytes * 43 / 64;
477 unsigned int code_len = code_bytes;
478
479 sp = regs->sp;
480 ip = (u8 *) regs->ip - code_prologue;
481 printk("CPU %d ", cpu);
482 __show_regs(regs);
483 printk("Process %s (pid: %d, threadinfo %p, task %p)\n",
484 cur->comm, cur->pid, task_thread_info(cur), cur);
485
486 /*
487 * When in-kernel, we also print out the stack and code at the
488 * time of the fault..
489 */
490 if (!user_mode(regs)) {
491 unsigned char c;
492 printk("Stack: ");
493 _show_stack(NULL, regs, (unsigned long *)sp, regs->bp);
494 printk("\n");
495
496 printk(KERN_EMERG "Code: ");
497 if (ip < (u8 *)PAGE_OFFSET || probe_kernel_address(ip, c)) {
498 /* try starting at RIP */
499 ip = (u8 *) regs->ip;
500 code_len = code_len - code_prologue + 1;
501 }
502 for (i = 0; i < code_len; i++, ip++) {
503 if (ip < (u8 *)PAGE_OFFSET ||
504 probe_kernel_address(ip, c)) {
505 printk(" Bad RIP value.");
506 break;
507 }
508 if (ip == (u8 *)regs->ip)
509 printk("<%02x> ", c);
510 else
511 printk("%02x ", c);
512 }
513 }
514 printk("\n");
515 }
516
517 int is_valid_bugaddr(unsigned long ip)
518 {
519 unsigned short ud2;
520
521 if (__copy_from_user(&ud2, (const void __user *) ip, sizeof(ud2)))
522 return 0;
523
524 return ud2 == 0x0b0f;
525 }
526
527 static raw_spinlock_t die_lock = RAW_SPIN_LOCK_UNLOCKED(die_lock);
528 static int die_owner = -1;
529 static unsigned int die_nest_count;
530
531 unsigned __kprobes long oops_begin(void)
532 {
533 int cpu;
534 unsigned long flags;
535
536 oops_enter();
537
538 /* racy, but better than risking deadlock. */
539 raw_local_irq_save(flags);
540 cpu = smp_processor_id();
541 if (!spin_trylock(&die_lock)) {
542 if (cpu == die_owner)
543 /* nested oops. should stop eventually */;
544 else
545 spin_lock(&die_lock);
546 }
547 die_nest_count++;
548 die_owner = cpu;
549 console_verbose();
550 bust_spinlocks(1);
551 return flags;
552 }
553
554 void __kprobes oops_end(unsigned long flags, struct pt_regs *regs, int signr)
555 {
556 die_owner = -1;
557 bust_spinlocks(0);
558 die_nest_count--;
559 if (!die_nest_count)
560 /* Nest count reaches zero, release the lock. */
561 spin_unlock(&die_lock);
562 raw_local_irq_restore(flags);
563 if (!regs) {
564 oops_exit();
565 return;
566 }
567 if (panic_on_oops)
568 panic("Fatal exception");
569 oops_exit();
570 do_exit(signr);
571 }
572
573 int __kprobes __die(const char * str, struct pt_regs * regs, long err)
574 {
575 static int die_counter;
576
577 ftrace_stop();
578
579 printk(KERN_EMERG "%s: %04lx [%u] ", str, err & 0xffff,++die_counter);
580 #ifdef CONFIG_PREEMPT
581 printk("PREEMPT ");
582 #endif
583 #ifdef CONFIG_SMP
584 printk("SMP ");
585 #endif
586 #ifdef CONFIG_DEBUG_PAGEALLOC
587 printk("DEBUG_PAGEALLOC");
588 #endif
589 printk("\n");
590 if (notify_die(DIE_OOPS, str, regs, err, current->thread.trap_no, SIGSEGV) == NOTIFY_STOP)
591 return 1;
592 show_registers(regs);
593 add_taint(TAINT_DIE);
594 /* Executive summary in case the oops scrolled away */
595 printk(KERN_ALERT "RIP ");
596 printk_address(regs->ip, 1);
597 printk(" RSP <%016lx>\n", regs->sp);
598 if (kexec_should_crash(current))
599 crash_kexec(regs);
600 return 0;
601 }
602
603 void die(const char * str, struct pt_regs * regs, long err)
604 {
605 unsigned long flags = oops_begin();
606
607 if (!user_mode(regs))
608 report_bug(regs->ip, regs);
609
610 if (__die(str, regs, err))
611 regs = NULL;
612 oops_end(flags, regs, SIGSEGV);
613 }
614
615 void __kprobes die_nmi(char *str, struct pt_regs *regs, int do_panic)
616 {
617 unsigned long flags = oops_begin();
618
619 /*
620 * We are in trouble anyway, lets at least try
621 * to get a message out.
622 */
623 printk(str, smp_processor_id());
624 show_registers(regs);
625 if (kexec_should_crash(current))
626 crash_kexec(regs);
627 if (do_panic || panic_on_oops)
628 panic("Non maskable interrupt");
629 oops_end(flags, NULL, SIGBUS);
630 nmi_exit();
631 local_irq_enable();
632 do_exit(SIGBUS);
633 }
634
635 static void __kprobes do_trap(int trapnr, int signr, char *str,
636 struct pt_regs * regs, long error_code,
637 siginfo_t *info)
638 {
639 struct task_struct *tsk = current;
640
641 if (user_mode(regs)) {
642 /*
643 * We want error_code and trap_no set for userspace
644 * faults and kernelspace faults which result in
645 * die(), but not kernelspace faults which are fixed
646 * up. die() gives the process no chance to handle
647 * the signal and notice the kernel fault information,
648 * so that won't result in polluting the information
649 * about previously queued, but not yet delivered,
650 * faults. See also do_general_protection below.
651 */
652 tsk->thread.error_code = error_code;
653 tsk->thread.trap_no = trapnr;
654
655 if (show_unhandled_signals && unhandled_signal(tsk, signr) &&
656 printk_ratelimit()) {
657 printk(KERN_INFO
658 "%s[%d] trap %s ip:%lx sp:%lx error:%lx",
659 tsk->comm, tsk->pid, str,
660 regs->ip, regs->sp, error_code);
661 print_vma_addr(" in ", regs->ip);
662 printk("\n");
663 }
664
665 if (info)
666 force_sig_info(signr, info, tsk);
667 else
668 force_sig(signr, tsk);
669 return;
670 }
671
672
673 if (!fixup_exception(regs)) {
674 tsk->thread.error_code = error_code;
675 tsk->thread.trap_no = trapnr;
676 die(str, regs, error_code);
677 }
678 return;
679 }
680
681 #define DO_ERROR(trapnr, signr, str, name) \
682 asmlinkage void do_##name(struct pt_regs * regs, long error_code) \
683 { \
684 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
685 == NOTIFY_STOP) \
686 return; \
687 conditional_sti(regs); \
688 do_trap(trapnr, signr, str, regs, error_code, NULL); \
689 }
690
691 #define DO_ERROR_INFO(trapnr, signr, str, name, sicode, siaddr) \
692 asmlinkage void do_##name(struct pt_regs * regs, long error_code) \
693 { \
694 siginfo_t info; \
695 info.si_signo = signr; \
696 info.si_errno = 0; \
697 info.si_code = sicode; \
698 info.si_addr = (void __user *)siaddr; \
699 trace_hardirqs_fixup(); \
700 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
701 == NOTIFY_STOP) \
702 return; \
703 conditional_sti(regs); \
704 do_trap(trapnr, signr, str, regs, error_code, &info); \
705 }
706
707 DO_ERROR_INFO( 0, SIGFPE, "divide error", divide_error, FPE_INTDIV, regs->ip)
708 DO_ERROR( 4, SIGSEGV, "overflow", overflow)
709 DO_ERROR( 5, SIGSEGV, "bounds", bounds)
710 DO_ERROR_INFO( 6, SIGILL, "invalid opcode", invalid_op, ILL_ILLOPN, regs->ip)
711 DO_ERROR( 7, SIGSEGV, "device not available", device_not_available)
712 DO_ERROR( 9, SIGFPE, "coprocessor segment overrun", coprocessor_segment_overrun)
713 DO_ERROR(10, SIGSEGV, "invalid TSS", invalid_TSS)
714 DO_ERROR(11, SIGBUS, "segment not present", segment_not_present)
715 DO_ERROR_INFO(17, SIGBUS, "alignment check", alignment_check, BUS_ADRALN, 0)
716 DO_ERROR(18, SIGSEGV, "reserved", reserved)
717
718 /* Runs on IST stack */
719 asmlinkage void do_stack_segment(struct pt_regs *regs, long error_code)
720 {
721 if (notify_die(DIE_TRAP, "stack segment", regs, error_code,
722 12, SIGBUS) == NOTIFY_STOP)
723 return;
724 preempt_conditional_sti(regs, STACKFAULT_STACK);
725 do_trap(12, SIGBUS, "stack segment", regs, error_code, NULL);
726 preempt_conditional_cli(regs, STACKFAULT_STACK);
727 }
728
729 asmlinkage void do_double_fault(struct pt_regs * regs, long error_code)
730 {
731 static const char str[] = "double fault";
732 struct task_struct *tsk = current;
733
734 /* Return not checked because double check cannot be ignored */
735 notify_die(DIE_TRAP, str, regs, error_code, 8, SIGSEGV);
736
737 tsk->thread.error_code = error_code;
738 tsk->thread.trap_no = 8;
739
740 /* This is always a kernel trap and never fixable (and thus must
741 never return). */
742 for (;;)
743 die(str, regs, error_code);
744 }
745
746 asmlinkage void __kprobes do_general_protection(struct pt_regs * regs,
747 long error_code)
748 {
749 struct task_struct *tsk = current;
750
751 conditional_sti(regs);
752
753 if (user_mode(regs)) {
754 tsk->thread.error_code = error_code;
755 tsk->thread.trap_no = 13;
756
757 if (show_unhandled_signals && unhandled_signal(tsk, SIGSEGV) &&
758 printk_ratelimit()) {
759 printk(KERN_INFO
760 "%s[%d] general protection ip:%lx sp:%lx error:%lx",
761 tsk->comm, tsk->pid,
762 regs->ip, regs->sp, error_code);
763 print_vma_addr(" in ", regs->ip);
764 printk("\n");
765 }
766
767 force_sig(SIGSEGV, tsk);
768 return;
769 }
770
771 if (fixup_exception(regs))
772 return;
773
774 tsk->thread.error_code = error_code;
775 tsk->thread.trap_no = 13;
776 if (notify_die(DIE_GPF, "general protection fault", regs,
777 error_code, 13, SIGSEGV) == NOTIFY_STOP)
778 return;
779 die("general protection fault", regs, error_code);
780 }
781
782 static __kprobes void
783 mem_parity_error(unsigned char reason, struct pt_regs * regs)
784 {
785 printk(KERN_EMERG "Uhhuh. NMI received for unknown reason %02x.\n",
786 reason);
787 printk(KERN_EMERG "You have some hardware problem, likely on the PCI bus.\n");
788
789 #if defined(CONFIG_EDAC)
790 if(edac_handler_set()) {
791 edac_atomic_assert_error();
792 return;
793 }
794 #endif
795
796 if (panic_on_unrecovered_nmi)
797 panic("NMI: Not continuing");
798
799 printk(KERN_EMERG "Dazed and confused, but trying to continue\n");
800
801 /* Clear and disable the memory parity error line. */
802 reason = (reason & 0xf) | 4;
803 outb(reason, 0x61);
804 }
805
806 static __kprobes void
807 io_check_error(unsigned char reason, struct pt_regs * regs)
808 {
809 printk("NMI: IOCK error (debug interrupt?)\n");
810 show_registers(regs);
811
812 /* Re-enable the IOCK line, wait for a few seconds */
813 reason = (reason & 0xf) | 8;
814 outb(reason, 0x61);
815 mdelay(2000);
816 reason &= ~8;
817 outb(reason, 0x61);
818 }
819
820 static __kprobes void
821 unknown_nmi_error(unsigned char reason, struct pt_regs * regs)
822 {
823 printk(KERN_EMERG "Uhhuh. NMI received for unknown reason %02x.\n",
824 reason);
825 printk(KERN_EMERG "Do you have a strange power saving mode enabled?\n");
826
827 if (panic_on_unrecovered_nmi)
828 panic("NMI: Not continuing");
829
830 printk(KERN_EMERG "Dazed and confused, but trying to continue\n");
831 }
832
833 /* Runs on IST stack. This code must keep interrupts off all the time.
834 Nested NMIs are prevented by the CPU. */
835 asmlinkage __kprobes void default_do_nmi(struct pt_regs *regs)
836 {
837 unsigned char reason = 0;
838 int cpu;
839
840 cpu = smp_processor_id();
841
842 ftrace_event_irq(-1, user_mode(regs), regs->ip);
843
844 /* Only the BSP gets external NMIs from the system. */
845 if (!cpu)
846 reason = get_nmi_reason();
847
848 if (!(reason & 0xc0)) {
849 if (notify_die(DIE_NMI_IPI, "nmi_ipi", regs, reason, 2, SIGINT)
850 == NOTIFY_STOP)
851 return;
852 /*
853 * Ok, so this is none of the documented NMI sources,
854 * so it must be the NMI watchdog.
855 */
856 if (nmi_watchdog_tick(regs,reason))
857 return;
858 if (!do_nmi_callback(regs,cpu))
859 unknown_nmi_error(reason, regs);
860
861 return;
862 }
863 if (notify_die(DIE_NMI, "nmi", regs, reason, 2, SIGINT) == NOTIFY_STOP)
864 return;
865
866 /* AK: following checks seem to be broken on modern chipsets. FIXME */
867
868 if (reason & 0x80)
869 mem_parity_error(reason, regs);
870 if (reason & 0x40)
871 io_check_error(reason, regs);
872 }
873
874 /* runs on IST stack. */
875 asmlinkage void __kprobes do_int3(struct pt_regs * regs, long error_code)
876 {
877 trace_hardirqs_fixup();
878
879 if (notify_die(DIE_INT3, "int3", regs, error_code, 3, SIGTRAP) == NOTIFY_STOP) {
880 return;
881 }
882 preempt_conditional_sti(regs, DEBUG_STACK);
883 do_trap(3, SIGTRAP, "int3", regs, error_code, NULL);
884 preempt_conditional_cli(regs, DEBUG_STACK);
885 }
886
887 /* Help handler running on IST stack to switch back to user stack
888 for scheduling or signal handling. The actual stack switch is done in
889 entry.S */
890 asmlinkage __kprobes struct pt_regs *sync_regs(struct pt_regs *eregs)
891 {
892 struct pt_regs *regs = eregs;
893 /* Did already sync */
894 if (eregs == (struct pt_regs *)eregs->sp)
895 ;
896 /* Exception from user space */
897 else if (user_mode(eregs))
898 regs = task_pt_regs(current);
899 /* Exception from kernel and interrupts are enabled. Move to
900 kernel process stack. */
901 else if (eregs->flags & X86_EFLAGS_IF)
902 regs = (struct pt_regs *)(eregs->sp -= sizeof(struct pt_regs));
903 if (eregs != regs)
904 *regs = *eregs;
905 return regs;
906 }
907
908 /* runs on IST stack. */
909 asmlinkage void __kprobes do_debug(struct pt_regs * regs,
910 unsigned long error_code)
911 {
912 unsigned long condition;
913 struct task_struct *tsk = current;
914 siginfo_t info;
915
916 trace_hardirqs_fixup();
917
918 get_debugreg(condition, 6);
919
920 /*
921 * The processor cleared BTF, so don't mark that we need it set.
922 */
923 clear_tsk_thread_flag(tsk, TIF_DEBUGCTLMSR);
924 tsk->thread.debugctlmsr = 0;
925
926 if (notify_die(DIE_DEBUG, "debug", regs, condition, error_code,
927 SIGTRAP) == NOTIFY_STOP)
928 return;
929
930 preempt_conditional_sti(regs, DEBUG_STACK);
931
932 /* Mask out spurious debug traps due to lazy DR7 setting */
933 if (condition & (DR_TRAP0|DR_TRAP1|DR_TRAP2|DR_TRAP3)) {
934 if (!tsk->thread.debugreg7) {
935 goto clear_dr7;
936 }
937 }
938
939 tsk->thread.debugreg6 = condition;
940
941
942 /*
943 * Single-stepping through TF: make sure we ignore any events in
944 * kernel space (but re-enable TF when returning to user mode).
945 */
946 if (condition & DR_STEP) {
947 if (!user_mode(regs))
948 goto clear_TF_reenable;
949 }
950
951 /* Ok, finally something we can handle */
952 tsk->thread.trap_no = 1;
953 tsk->thread.error_code = error_code;
954 info.si_signo = SIGTRAP;
955 info.si_errno = 0;
956 info.si_code = TRAP_BRKPT;
957 info.si_addr = user_mode(regs) ? (void __user *)regs->ip : NULL;
958 force_sig_info(SIGTRAP, &info, tsk);
959
960 clear_dr7:
961 set_debugreg(0UL, 7);
962 preempt_conditional_cli(regs, DEBUG_STACK);
963 return;
964
965 clear_TF_reenable:
966 set_tsk_thread_flag(tsk, TIF_SINGLESTEP);
967 regs->flags &= ~X86_EFLAGS_TF;
968 preempt_conditional_cli(regs, DEBUG_STACK);
969 }
970
971 static int kernel_math_error(struct pt_regs *regs, const char *str, int trapnr)
972 {
973 if (fixup_exception(regs))
974 return 1;
975
976 notify_die(DIE_GPF, str, regs, 0, trapnr, SIGFPE);
977 /* Illegal floating point operation in the kernel */
978 current->thread.trap_no = trapnr;
979 die(str, regs, 0);
980 return 0;
981 }
982
983 /*
984 * Note that we play around with the 'TS' bit in an attempt to get
985 * the correct behaviour even in the presence of the asynchronous
986 * IRQ13 behaviour
987 */
988 asmlinkage void do_coprocessor_error(struct pt_regs *regs)
989 {
990 void __user *ip = (void __user *)(regs->ip);
991 struct task_struct * task;
992 siginfo_t info;
993 unsigned short cwd, swd;
994
995 conditional_sti(regs);
996 if (!user_mode(regs) &&
997 kernel_math_error(regs, "kernel x87 math error", 16))
998 return;
999
1000 /*
1001 * Save the info for the exception handler and clear the error.
1002 */
1003 task = current;
1004 save_init_fpu(task);
1005 task->thread.trap_no = 16;
1006 task->thread.error_code = 0;
1007 info.si_signo = SIGFPE;
1008 info.si_errno = 0;
1009 info.si_code = __SI_FAULT;
1010 info.si_addr = ip;
1011 /*
1012 * (~cwd & swd) will mask out exceptions that are not set to unmasked
1013 * status. 0x3f is the exception bits in these regs, 0x200 is the
1014 * C1 reg you need in case of a stack fault, 0x040 is the stack
1015 * fault bit. We should only be taking one exception at a time,
1016 * so if this combination doesn't produce any single exception,
1017 * then we have a bad program that isn't synchronizing its FPU usage
1018 * and it will suffer the consequences since we won't be able to
1019 * fully reproduce the context of the exception
1020 */
1021 cwd = get_fpu_cwd(task);
1022 swd = get_fpu_swd(task);
1023 switch (swd & ~cwd & 0x3f) {
1024 case 0x000:
1025 default:
1026 break;
1027 case 0x001: /* Invalid Op */
1028 /*
1029 * swd & 0x240 == 0x040: Stack Underflow
1030 * swd & 0x240 == 0x240: Stack Overflow
1031 * User must clear the SF bit (0x40) if set
1032 */
1033 info.si_code = FPE_FLTINV;
1034 break;
1035 case 0x002: /* Denormalize */
1036 case 0x010: /* Underflow */
1037 info.si_code = FPE_FLTUND;
1038 break;
1039 case 0x004: /* Zero Divide */
1040 info.si_code = FPE_FLTDIV;
1041 break;
1042 case 0x008: /* Overflow */
1043 info.si_code = FPE_FLTOVF;
1044 break;
1045 case 0x020: /* Precision */
1046 info.si_code = FPE_FLTRES;
1047 break;
1048 }
1049 force_sig_info(SIGFPE, &info, task);
1050 }
1051
1052 asmlinkage void bad_intr(void)
1053 {
1054 printk("bad interrupt");
1055 }
1056
1057 asmlinkage void do_simd_coprocessor_error(struct pt_regs *regs)
1058 {
1059 void __user *ip = (void __user *)(regs->ip);
1060 struct task_struct * task;
1061 siginfo_t info;
1062 unsigned short mxcsr;
1063
1064 conditional_sti(regs);
1065 if (!user_mode(regs) &&
1066 kernel_math_error(regs, "kernel simd math error", 19))
1067 return;
1068
1069 /*
1070 * Save the info for the exception handler and clear the error.
1071 */
1072 task = current;
1073 save_init_fpu(task);
1074 task->thread.trap_no = 19;
1075 task->thread.error_code = 0;
1076 info.si_signo = SIGFPE;
1077 info.si_errno = 0;
1078 info.si_code = __SI_FAULT;
1079 info.si_addr = ip;
1080 /*
1081 * The SIMD FPU exceptions are handled a little differently, as there
1082 * is only a single status/control register. Thus, to determine which
1083 * unmasked exception was caught we must mask the exception mask bits
1084 * at 0x1f80, and then use these to mask the exception bits at 0x3f.
1085 */
1086 mxcsr = get_fpu_mxcsr(task);
1087 switch (~((mxcsr & 0x1f80) >> 7) & (mxcsr & 0x3f)) {
1088 case 0x000:
1089 default:
1090 break;
1091 case 0x001: /* Invalid Op */
1092 info.si_code = FPE_FLTINV;
1093 break;
1094 case 0x002: /* Denormalize */
1095 case 0x010: /* Underflow */
1096 info.si_code = FPE_FLTUND;
1097 break;
1098 case 0x004: /* Zero Divide */
1099 info.si_code = FPE_FLTDIV;
1100 break;
1101 case 0x008: /* Overflow */
1102 info.si_code = FPE_FLTOVF;
1103 break;
1104 case 0x020: /* Precision */
1105 info.si_code = FPE_FLTRES;
1106 break;
1107 }
1108 force_sig_info(SIGFPE, &info, task);
1109 }
1110
1111 asmlinkage void do_spurious_interrupt_bug(struct pt_regs * regs)
1112 {
1113 }
1114
1115 asmlinkage void __attribute__((weak)) smp_thermal_interrupt(void)
1116 {
1117 }
1118
1119 asmlinkage void __attribute__((weak)) mce_threshold_interrupt(void)
1120 {
1121 }
1122
1123 /*
1124 * 'math_state_restore()' saves the current math information in the
1125 * old math state array, and gets the new ones from the current task
1126 *
1127 * Careful.. There are problems with IBM-designed IRQ13 behaviour.
1128 * Don't touch unless you *really* know how it works.
1129 */
1130 asmlinkage void math_state_restore(void)
1131 {
1132 struct task_struct *me = current;
1133 clts(); /* Allow maths ops (or we recurse) */
1134
1135 if (!used_math())
1136 init_fpu(me);
1137 restore_fpu_checking(&me->thread.i387.fxsave);
1138 task_thread_info(me)->status |= TS_USEDFPU;
1139 me->fpu_counter++;
1140 }
1141 EXPORT_SYMBOL_GPL(math_state_restore);
1142
1143 void __init trap_init(void)
1144 {
1145 set_intr_gate(0,÷_error);
1146 set_intr_gate_ist(1,&debug,DEBUG_STACK);
1147 set_intr_gate_ist(2,&nmi,NMI_STACK);
1148 set_system_gate_ist(3,&int3,DEBUG_STACK); /* int3 can be called from all */
1149 set_system_gate(4,&overflow); /* int4 can be called from all */
1150 set_intr_gate(5,&bounds);
1151 set_intr_gate(6,&invalid_op);
1152 set_intr_gate(7,&device_not_available);
1153 set_intr_gate_ist(8,&double_fault, DOUBLEFAULT_STACK);
1154 set_intr_gate(9,&coprocessor_segment_overrun);
1155 set_intr_gate(10,&invalid_TSS);
1156 set_intr_gate(11,&segment_not_present);
1157 set_intr_gate_ist(12,&stack_segment,STACKFAULT_STACK);
1158 set_intr_gate(13,&general_protection);
1159 set_intr_gate(14,&page_fault);
1160 set_intr_gate(15,&spurious_interrupt_bug);
1161 set_intr_gate(16,&coprocessor_error);
1162 set_intr_gate(17,&alignment_check);
1163 #ifdef CONFIG_X86_MCE
1164 set_intr_gate_ist(18,&machine_check, MCE_STACK);
1165 #endif
1166 set_intr_gate(19,&simd_coprocessor_error);
1167
1168 #ifdef CONFIG_IA32_EMULATION
1169 set_system_gate(IA32_SYSCALL_VECTOR, ia32_syscall);
1170 #endif
1171
1172 /*
1173 * Should be a barrier for any external CPU state.
1174 */
1175 cpu_init();
1176 }
1177
1178
1179 static int __init oops_setup(char *s)
1180 {
1181 if (!s)
1182 return -EINVAL;
1183 if (!strcmp(s, "panic"))
1184 panic_on_oops = 1;
1185 return 0;
1186 }
1187 early_param("oops", oops_setup);
1188
1189 static int __init kstack_setup(char *s)
1190 {
1191 if (!s)
1192 return -EINVAL;
1193 kstack_depth_to_print = simple_strtoul(s,NULL,0);
1194 return 0;
1195 }
1196 early_param("kstack", kstack_setup);
1197
1198
1199 static int __init code_bytes_setup(char *s)
1200 {
1201 code_bytes = simple_strtoul(s, NULL, 0);
1202 if (code_bytes > 8192)
1203 code_bytes = 8192;
1204
1205 return 1;
1206 }
1207 __setup("code_bytes=", code_bytes_setup);
1208
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