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[PATCH] x86-64: Clean up nmi error message
[net-next-2.6.git] / arch / x86_64 / kernel / traps.c
CommitLineData
1da177e4
LT		 1/*
2 * linux/arch/x86-64/traps.c
3 *
4 * Copyright (C) 1991, 1992 Linus Torvalds
5 * Copyright (C) 2000, 2001, 2002 Andi Kleen, SuSE Labs
6 *
7 * Pentium III FXSR, SSE support
8 * Gareth Hughes <gareth@valinux.com>, May 2000
9 *
10 * $Id: traps.c,v 1.36 2002/03/24 11:09:10 ak Exp $
11 */
12
13/*
14 * 'Traps.c' handles hardware traps and faults after we have saved some
15 * state in 'entry.S'.
16 */
17#include <linux/config.h>
18#include <linux/sched.h>
19#include <linux/kernel.h>
20#include <linux/string.h>
21#include <linux/errno.h>
22#include <linux/ptrace.h>
23#include <linux/timer.h>
24#include <linux/mm.h>
25#include <linux/init.h>
26#include <linux/delay.h>
27#include <linux/spinlock.h>
28#include <linux/interrupt.h>
29#include <linux/module.h>
30#include <linux/moduleparam.h>
35faa714 31#include <linux/nmi.h>
0f2fbdcb 32#include <linux/kprobes.h>
1da177e4
LT		 33
34#include <asm/system.h>
35#include <asm/uaccess.h>
36#include <asm/io.h>
37#include <asm/atomic.h>
38#include <asm/debugreg.h>
39#include <asm/desc.h>
40#include <asm/i387.h>
41#include <asm/kdebug.h>
42#include <asm/processor.h>
43
44#include <asm/smp.h>
45#include <asm/pgalloc.h>
46#include <asm/pda.h>
47#include <asm/proto.h>
48#include <asm/nmi.h>
49
50#include <linux/irq.h>
51
52
53extern struct gate_struct idt_table[256];
54
55asmlinkage void divide_error(void);
56asmlinkage void debug(void);
57asmlinkage void nmi(void);
58asmlinkage void int3(void);
59asmlinkage void overflow(void);
60asmlinkage void bounds(void);
61asmlinkage void invalid_op(void);
62asmlinkage void device_not_available(void);
63asmlinkage void double_fault(void);
64asmlinkage void coprocessor_segment_overrun(void);
65asmlinkage void invalid_TSS(void);
66asmlinkage void segment_not_present(void);
67asmlinkage void stack_segment(void);
68asmlinkage void general_protection(void);
69asmlinkage void page_fault(void);
70asmlinkage void coprocessor_error(void);
71asmlinkage void simd_coprocessor_error(void);
72asmlinkage void reserved(void);
73asmlinkage void alignment_check(void);
74asmlinkage void machine_check(void);
75asmlinkage void spurious_interrupt_bug(void);
76asmlinkage void call_debug(void);
77
78struct notifier_block *die_chain;
79static DEFINE_SPINLOCK(die_notifier_lock);
80
81int register_die_notifier(struct notifier_block *nb)
82{
83 int err = 0;
84 unsigned long flags;
85 spin_lock_irqsave(&die_notifier_lock, flags);
86 err = notifier_chain_register(&die_chain, nb);
87 spin_unlock_irqrestore(&die_notifier_lock, flags);
88 return err;
89}
90
91static inline void conditional_sti(struct pt_regs *regs)
92{
93 if (regs->eflags & X86_EFLAGS_IF)
94 local_irq_enable();
95}
96
97static int kstack_depth_to_print = 10;
98
99#ifdef CONFIG_KALLSYMS
100#include <linux/kallsyms.h>
101int printk_address(unsigned long address)
102{
103 unsigned long offset = 0, symsize;
104 const char *symname;
105 char *modname;
106 char *delim = ":";
107 char namebuf[128];
108
109 symname = kallsyms_lookup(address, &symsize, &offset, &modname, namebuf);
110 if (!symname)
111 return printk("[<%016lx>]", address);
112 if (!modname)
113 modname = delim = "";
114 return printk("<%016lx>{%s%s%s%s%+ld}",
115 address,delim,modname,delim,symname,offset);
116}
117#else
118int printk_address(unsigned long address)
119{
120 return printk("[<%016lx>]", address);
121}
122#endif
123
0a658002
AK		 124static unsigned long *in_exception_stack(unsigned cpu, unsigned long stack,
125 unsigned *usedp, const char **idp)
126{
127 static const char ids[N_EXCEPTION_STACKS][8] = {
128 [DEBUG_STACK - 1] = "#DB",
129 [NMI_STACK - 1] = "NMI",
130 [DOUBLEFAULT_STACK - 1] = "#DF",
131 [STACKFAULT_STACK - 1] = "#SS",
132 [MCE_STACK - 1] = "#MC",
133 };
134 unsigned k;
1da177e4 135
0a658002
AK		 136 for (k = 0; k < N_EXCEPTION_STACKS; k++) {
137 unsigned long end;
138
139 end = per_cpu(init_tss, cpu).ist[k];
140 if (stack >= end)
141 continue;
142 if (stack >= end - EXCEPTION_STKSZ) {
143 if (*usedp & (1U << k))
144 break;
145 *usedp |= 1U << k;
146 *idp = ids[k];
147 return (unsigned long *)end;
148 }
1da177e4
LT		 149 }
150 return NULL;
0a658002 151}
1da177e4
LT		 152
153/*
154 * x86-64 can have upto three kernel stacks:
155 * process stack
156 * interrupt stack
0a658002 157 * severe exception (double fault, nmi, stack fault, debug, mce) hardware stack
1da177e4
LT		 158 */
159
160void show_trace(unsigned long *stack)
161{
162 unsigned long addr;
0a658002
AK		 163 const unsigned cpu = safe_smp_processor_id();
164 unsigned long *irqstack_end = (unsigned long *)cpu_pda[cpu].irqstackptr;
1da177e4 165 int i;
0a658002 166 unsigned used = 0;
1da177e4
LT		 167
168 printk("\nCall Trace:");
0a658002
AK		 169
170#define HANDLE_STACK(cond) \
171 do while (cond) { \
172 addr = *stack++; \
173 if (kernel_text_address(addr)) { \
174 /* \
175 * If the address is either in the text segment of the \
176 * kernel, or in the region which contains vmalloc'ed \
177 * memory, it *may* be the address of a calling \
178 * routine; if so, print it so that someone tracing \
179 * down the cause of the crash will be able to figure \
180 * out the call path that was taken. \
181 */ \
182 i += printk_address(addr); \
183 if (i > 50) { \
184 printk("\n "); \
185 i = 0; \
186 } \
187 else \
188 i += printk(" "); \
189 } \
190 } while (0)
191
192 for(i = 0; ; ) {
193 const char *id;
194 unsigned long *estack_end;
195 estack_end = in_exception_stack(cpu, (unsigned long)stack,
196 &used, &id);
197
198 if (estack_end) {
199 i += printk(" <%s> ", id);
200 HANDLE_STACK (stack < estack_end);
201 i += printk(" <EOE> ");
202 stack = (unsigned long *) estack_end[-2];
203 continue;
1da177e4 204 }
0a658002
AK		 205 if (irqstack_end) {
206 unsigned long *irqstack;
207 irqstack = irqstack_end -
208 (IRQSTACKSIZE - 64) / sizeof(*irqstack);
209
210 if (stack >= irqstack && stack < irqstack_end) {
211 i += printk(" <IRQ> ");
212 HANDLE_STACK (stack < irqstack_end);
213 stack = (unsigned long *) (irqstack_end[-1]);
214 irqstack_end = NULL;
215 i += printk(" <EOI> ");
216 continue;
1da177e4 217 }
1da177e4 218 }
0a658002 219 break;
1da177e4 220 }
0a658002
AK		 221
222 HANDLE_STACK (((long) stack & (THREAD_SIZE-1)) != 0);
223#undef HANDLE_STACK
1da177e4
LT		 224 printk("\n");
225}
226
227void show_stack(struct task_struct *tsk, unsigned long * rsp)
228{
229 unsigned long *stack;
230 int i;
231 const int cpu = safe_smp_processor_id();
232 unsigned long *irqstack_end = (unsigned long *) (cpu_pda[cpu].irqstackptr);
233 unsigned long *irqstack = (unsigned long *) (cpu_pda[cpu].irqstackptr - IRQSTACKSIZE);
234
235 // debugging aid: "show_stack(NULL, NULL);" prints the
236 // back trace for this cpu.
237
238 if (rsp == NULL) {
239 if (tsk)
240 rsp = (unsigned long *)tsk->thread.rsp;
241 else
242 rsp = (unsigned long *)&rsp;
243 }
244
245 stack = rsp;
246 for(i=0; i < kstack_depth_to_print; i++) {
247 if (stack >= irqstack && stack <= irqstack_end) {
248 if (stack == irqstack_end) {
249 stack = (unsigned long *) (irqstack_end[-1]);
250 printk(" <EOI> ");
251 }
252 } else {
253 if (((long) stack & (THREAD_SIZE-1)) == 0)
254 break;
255 }
256 if (i && ((i % 4) == 0))
257 printk("\n ");
258 printk("%016lx ", *stack++);
35faa714 259 touch_nmi_watchdog();
1da177e4
LT		 260 }
261 show_trace((unsigned long *)rsp);
262}
263
264/*
265 * The architecture-independent dump_stack generator
266 */
267void dump_stack(void)
268{
269 unsigned long dummy;
270 show_trace(&dummy);
271}
272
273EXPORT_SYMBOL(dump_stack);
274
275void show_registers(struct pt_regs *regs)
276{
277 int i;
76381fee 278 int in_kernel = !user_mode(regs);
1da177e4
LT		 279 unsigned long rsp;
280 const int cpu = safe_smp_processor_id();
281 struct task_struct *cur = cpu_pda[cpu].pcurrent;
282
283 rsp = regs->rsp;
284
285 printk("CPU %d ", cpu);
286 __show_regs(regs);
287 printk("Process %s (pid: %d, threadinfo %p, task %p)\n",
288 cur->comm, cur->pid, cur->thread_info, cur);
289
290 /*
291 * When in-kernel, we also print out the stack and code at the
292 * time of the fault..
293 */
294 if (in_kernel) {
295
296 printk("Stack: ");
297 show_stack(NULL, (unsigned long*)rsp);
298
299 printk("\nCode: ");
300 if(regs->rip < PAGE_OFFSET)
301 goto bad;
302
303 for(i=0;i<20;i++)
304 {
305 unsigned char c;
306 if(__get_user(c, &((unsigned char*)regs->rip)[i])) {
307bad:
308 printk(" Bad RIP value.");
309 break;
310 }
311 printk("%02x ", c);
312 }
313 }
314 printk("\n");
315}
316
317void handle_BUG(struct pt_regs *regs)
318{
319 struct bug_frame f;
320 char tmp;
321
76381fee 322 if (user_mode(regs))
1da177e4
LT		 323 return;
324 if (__copy_from_user(&f, (struct bug_frame *) regs->rip,
325 sizeof(struct bug_frame)))
326 return;
327 if ((unsigned long)f.filename < __PAGE_OFFSET ||
328 f.ud2[0] != 0x0f || f.ud2[1] != 0x0b)
329 return;
330 if (__get_user(tmp, f.filename))
331 f.filename = "unmapped filename";
332 printk("----------- [cut here ] --------- [please bite here ] ---------\n");
333 printk(KERN_ALERT "Kernel BUG at %.50s:%d\n", f.filename, f.line);
334}
335
4f60fdf6 336#ifdef CONFIG_BUG
1da177e4
LT		 337void out_of_line_bug(void)
338{
339 BUG();
340}
4f60fdf6 341#endif
1da177e4
LT		 342
343static DEFINE_SPINLOCK(die_lock);
344static int die_owner = -1;
345
1209140c 346unsigned long oops_begin(void)
1da177e4 347{
1209140c
JB		 348 int cpu = safe_smp_processor_id();
349 unsigned long flags;
350
351 /* racy, but better than risking deadlock. */
352 local_irq_save(flags);
1da177e4
LT		 353 if (!spin_trylock(&die_lock)) {
354 if (cpu == die_owner)
355 /* nested oops. should stop eventually */;
356 else
1209140c 357 spin_lock(&die_lock);
1da177e4 358 }
1209140c 359 die_owner = cpu;
1da177e4 360 console_verbose();
1209140c
JB		 361 bust_spinlocks(1);
362 return flags;
1da177e4
LT		 363}
364
1209140c 365void oops_end(unsigned long flags)
1da177e4
LT		 366{
367 die_owner = -1;
1209140c
JB		 368 bust_spinlocks(0);
369 spin_unlock_irqrestore(&die_lock, flags);
1da177e4 370 if (panic_on_oops)
1209140c
JB		 371 panic("Oops");
372}
1da177e4
LT		 373
374void __die(const char * str, struct pt_regs * regs, long err)
375{
376 static int die_counter;
377 printk(KERN_EMERG "%s: %04lx [%u] ", str, err & 0xffff,++die_counter);
378#ifdef CONFIG_PREEMPT
379 printk("PREEMPT ");
380#endif
381#ifdef CONFIG_SMP
382 printk("SMP ");
383#endif
384#ifdef CONFIG_DEBUG_PAGEALLOC
385 printk("DEBUG_PAGEALLOC");
386#endif
387 printk("\n");
388 notify_die(DIE_OOPS, (char *)str, regs, err, 255, SIGSEGV);
389 show_registers(regs);
390 /* Executive summary in case the oops scrolled away */
391 printk(KERN_ALERT "RIP ");
392 printk_address(regs->rip);
393 printk(" RSP <%016lx>\n", regs->rsp);
394}
395
396void die(const char * str, struct pt_regs * regs, long err)
397{
1209140c
JB		 398 unsigned long flags = oops_begin();
399
1da177e4
LT		 400 handle_BUG(regs);
401 __die(str, regs, err);
1209140c 402 oops_end(flags);
1da177e4
LT		 403 do_exit(SIGSEGV);
404}
405static inline void die_if_kernel(const char * str, struct pt_regs * regs, long err)
406{
407 if (!(regs->eflags & VM_MASK) && (regs->cs == __KERNEL_CS))
408 die(str, regs, err);
409}
410
411void die_nmi(char *str, struct pt_regs *regs)
412{
1209140c
JB		 413 unsigned long flags = oops_begin();
414
1da177e4
LT		 415 /*
416 * We are in trouble anyway, lets at least try
417 * to get a message out.
418 */
419 printk(str, safe_smp_processor_id());
420 show_registers(regs);
421 if (panic_on_timeout || panic_on_oops)
422 panic("nmi watchdog");
423 printk("console shuts up ...\n");
1209140c 424 oops_end(flags);
1da177e4
LT		 425 do_exit(SIGSEGV);
426}
427
0f2fbdcb
PP		 428static void __kprobes do_trap(int trapnr, int signr, char *str,
429 struct pt_regs * regs, long error_code,
430 siginfo_t *info)
1da177e4
LT		 431{
432 conditional_sti(regs);
433
434#ifdef CONFIG_CHECKING
435 {
436 unsigned long gs;
437 struct x8664_pda *pda = cpu_pda + safe_smp_processor_id();
438 rdmsrl(MSR_GS_BASE, gs);
439 if (gs != (unsigned long)pda) {
440 wrmsrl(MSR_GS_BASE, pda);
441 printk("%s: wrong gs %lx expected %p rip %lx\n", str, gs, pda,
442 regs->rip);
443 }
444 }
445#endif
446
76381fee 447 if (user_mode(regs)) {
1da177e4
LT		 448 struct task_struct *tsk = current;
449
450 if (exception_trace && unhandled_signal(tsk, signr))
451 printk(KERN_INFO
452 "%s[%d] trap %s rip:%lx rsp:%lx error:%lx\n",
453 tsk->comm, tsk->pid, str,
454 regs->rip,regs->rsp,error_code);
455
456 tsk->thread.error_code = error_code;
457 tsk->thread.trap_no = trapnr;
458 if (info)
459 force_sig_info(signr, info, tsk);
460 else
461 force_sig(signr, tsk);
462 return;
463 }
464
465
466 /* kernel trap */
467 {
468 const struct exception_table_entry *fixup;
469 fixup = search_exception_tables(regs->rip);
470 if (fixup) {
471 regs->rip = fixup->fixup;
472 } else
473 die(str, regs, error_code);
474 return;
475 }
476}
477
478#define DO_ERROR(trapnr, signr, str, name) \
479asmlinkage void do_##name(struct pt_regs * regs, long error_code) \
480{ \
481 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
482 == NOTIFY_STOP) \
483 return; \
484 do_trap(trapnr, signr, str, regs, error_code, NULL); \
485}
486
487#define DO_ERROR_INFO(trapnr, signr, str, name, sicode, siaddr) \
488asmlinkage void do_##name(struct pt_regs * regs, long error_code) \
489{ \
490 siginfo_t info; \
491 info.si_signo = signr; \
492 info.si_errno = 0; \
493 info.si_code = sicode; \
494 info.si_addr = (void __user *)siaddr; \
495 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
496 == NOTIFY_STOP) \
497 return; \
498 do_trap(trapnr, signr, str, regs, error_code, &info); \
499}
500
501DO_ERROR_INFO( 0, SIGFPE, "divide error", divide_error, FPE_INTDIV, regs->rip)
502DO_ERROR( 4, SIGSEGV, "overflow", overflow)
503DO_ERROR( 5, SIGSEGV, "bounds", bounds)
504DO_ERROR_INFO( 6, SIGILL, "invalid operand", invalid_op, ILL_ILLOPN, regs->rip)
505DO_ERROR( 7, SIGSEGV, "device not available", device_not_available)
506DO_ERROR( 9, SIGFPE, "coprocessor segment overrun", coprocessor_segment_overrun)
507DO_ERROR(10, SIGSEGV, "invalid TSS", invalid_TSS)
508DO_ERROR(11, SIGBUS, "segment not present", segment_not_present)
509DO_ERROR_INFO(17, SIGBUS, "alignment check", alignment_check, BUS_ADRALN, 0)
510DO_ERROR(18, SIGSEGV, "reserved", reserved)
6fefb0d1
AK		 511DO_ERROR(12, SIGBUS, "stack segment", stack_segment)
512DO_ERROR( 8, SIGSEGV, "double fault", double_fault)
1da177e4 513
0f2fbdcb
PP		 514asmlinkage void __kprobes do_general_protection(struct pt_regs * regs,
515 long error_code)
1da177e4
LT		 516{
517 conditional_sti(regs);
518
519#ifdef CONFIG_CHECKING
520 {
521 unsigned long gs;
522 struct x8664_pda *pda = cpu_pda + safe_smp_processor_id();
523 rdmsrl(MSR_GS_BASE, gs);
524 if (gs != (unsigned long)pda) {
525 wrmsrl(MSR_GS_BASE, pda);
526 oops_in_progress++;
527 printk("general protection handler: wrong gs %lx expected %p\n", gs, pda);
528 oops_in_progress--;
529 }
530 }
531#endif
532
76381fee 533 if (user_mode(regs)) {
1da177e4
LT		 534 struct task_struct *tsk = current;
535
536 if (exception_trace && unhandled_signal(tsk, SIGSEGV))
537 printk(KERN_INFO
538 "%s[%d] general protection rip:%lx rsp:%lx error:%lx\n",
539 tsk->comm, tsk->pid,
540 regs->rip,regs->rsp,error_code);
541
542 tsk->thread.error_code = error_code;
543 tsk->thread.trap_no = 13;
544 force_sig(SIGSEGV, tsk);
545 return;
546 }
547
548 /* kernel gp */
549 {
550 const struct exception_table_entry *fixup;
551 fixup = search_exception_tables(regs->rip);
552 if (fixup) {
553 regs->rip = fixup->fixup;
554 return;
555 }
556 if (notify_die(DIE_GPF, "general protection fault", regs,
557 error_code, 13, SIGSEGV) == NOTIFY_STOP)
558 return;
559 die("general protection fault", regs, error_code);
560 }
561}
562
563static void mem_parity_error(unsigned char reason, struct pt_regs * regs)
564{
565 printk("Uhhuh. NMI received. Dazed and confused, but trying to continue\n");
566 printk("You probably have a hardware problem with your RAM chips\n");
567
568 /* Clear and disable the memory parity error line. */
569 reason = (reason & 0xf) | 4;
570 outb(reason, 0x61);
571}
572
573static void io_check_error(unsigned char reason, struct pt_regs * regs)
574{
575 printk("NMI: IOCK error (debug interrupt?)\n");
576 show_registers(regs);
577
578 /* Re-enable the IOCK line, wait for a few seconds */
579 reason = (reason & 0xf) | 8;
580 outb(reason, 0x61);
581 mdelay(2000);
582 reason &= ~8;
583 outb(reason, 0x61);
584}
585
586static void unknown_nmi_error(unsigned char reason, struct pt_regs * regs)
587{ printk("Uhhuh. NMI received for unknown reason %02x.\n", reason);
588 printk("Dazed and confused, but trying to continue\n");
589 printk("Do you have a strange power saving mode enabled?\n");
590}
591
6fefb0d1
AK		 592/* Runs on IST stack. This code must keep interrupts off all the time.
593 Nested NMIs are prevented by the CPU. */
1da177e4
LT		 594asmlinkage void default_do_nmi(struct pt_regs *regs)
595{
596 unsigned char reason = 0;
76e4f660
AR		 597 int cpu;
598
599 cpu = smp_processor_id();
1da177e4
LT		 600
601 /* Only the BSP gets external NMIs from the system. */
76e4f660 602 if (!cpu)
1da177e4
LT		 603 reason = get_nmi_reason();
604
605 if (!(reason & 0xc0)) {
606 if (notify_die(DIE_NMI_IPI, "nmi_ipi", regs, reason, 0, SIGINT)
607 == NOTIFY_STOP)
608 return;
609#ifdef CONFIG_X86_LOCAL_APIC
610 /*
611 * Ok, so this is none of the documented NMI sources,
612 * so it must be the NMI watchdog.
613 */
614 if (nmi_watchdog > 0) {
615 nmi_watchdog_tick(regs,reason);
616 return;
617 }
618#endif
619 unknown_nmi_error(reason, regs);
620 return;
621 }
622 if (notify_die(DIE_NMI, "nmi", regs, reason, 0, SIGINT) == NOTIFY_STOP)
623 return;
624
625 /* AK: following checks seem to be broken on modern chipsets. FIXME */
626
627 if (reason & 0x80)
628 mem_parity_error(reason, regs);
629 if (reason & 0x40)
630 io_check_error(reason, regs);
631}
632
0f2fbdcb 633asmlinkage void __kprobes do_int3(struct pt_regs * regs, long error_code)
1da177e4
LT		 634{
635 if (notify_die(DIE_INT3, "int3", regs, error_code, 3, SIGTRAP) == NOTIFY_STOP) {
636 return;
637 }
638 do_trap(3, SIGTRAP, "int3", regs, error_code, NULL);
639 return;
640}
641
6fefb0d1
AK		 642/* Help handler running on IST stack to switch back to user stack
643 for scheduling or signal handling. The actual stack switch is done in
644 entry.S */
645asmlinkage struct pt_regs *sync_regs(struct pt_regs *eregs)
646{
647 struct pt_regs *regs = eregs;
648 /* Did already sync */
649 if (eregs == (struct pt_regs *)eregs->rsp)
650 ;
651 /* Exception from user space */
76381fee 652 else if (user_mode(eregs))
6fefb0d1
AK		 653 regs = ((struct pt_regs *)current->thread.rsp0) - 1;
654 /* Exception from kernel and interrupts are enabled. Move to
655 kernel process stack. */
656 else if (eregs->eflags & X86_EFLAGS_IF)
657 regs = (struct pt_regs *)(eregs->rsp -= sizeof(struct pt_regs));
658 if (eregs != regs)
659 *regs = *eregs;
660 return regs;
661}
662
1da177e4 663/* runs on IST stack. */
0f2fbdcb
PP		 664asmlinkage void __kprobes do_debug(struct pt_regs * regs,
665 unsigned long error_code)
1da177e4 666{
1da177e4
LT		 667 unsigned long condition;
668 struct task_struct *tsk = current;
669 siginfo_t info;
670
1da177e4
LT		 671#ifdef CONFIG_CHECKING
672 {
673 /* RED-PEN interaction with debugger - could destroy gs */
674 unsigned long gs;
675 struct x8664_pda *pda = cpu_pda + safe_smp_processor_id();
676 rdmsrl(MSR_GS_BASE, gs);
677 if (gs != (unsigned long)pda) {
678 wrmsrl(MSR_GS_BASE, pda);
679 printk("debug handler: wrong gs %lx expected %p\n", gs, pda);
680 }
681 }
682#endif
683
e9129e56 684 get_debugreg(condition, 6);
1da177e4
LT		 685
686 if (notify_die(DIE_DEBUG, "debug", regs, condition, error_code,
daeeafec 687 SIGTRAP) == NOTIFY_STOP)
6fefb0d1 688 return;
daeeafec 689
1da177e4
LT		 690 conditional_sti(regs);
691
692 /* Mask out spurious debug traps due to lazy DR7 setting */
693 if (condition & (DR_TRAP0|DR_TRAP1|DR_TRAP2|DR_TRAP3)) {
694 if (!tsk->thread.debugreg7) {
695 goto clear_dr7;
696 }
697 }
698
699 tsk->thread.debugreg6 = condition;
700
701 /* Mask out spurious TF errors due to lazy TF clearing */
daeeafec 702 if (condition & DR_STEP) {
1da177e4
LT		 703 /*
704 * The TF error should be masked out only if the current
705 * process is not traced and if the TRAP flag has been set
706 * previously by a tracing process (condition detected by
707 * the PT_DTRACE flag); remember that the i386 TRAP flag
708 * can be modified by the process itself in user mode,
709 * allowing programs to debug themselves without the ptrace()
710 * interface.
711 */
76381fee 712 if (!user_mode(regs))
1da177e4 713 goto clear_TF_reenable;
be61bff7
AK		 714 /*
715 * Was the TF flag set by a debugger? If so, clear it now,
716 * so that register information is correct.
717 */
718 if (tsk->ptrace & PT_DTRACE) {
719 regs->eflags &= ~TF_MASK;
720 tsk->ptrace &= ~PT_DTRACE;
721 }
1da177e4
LT		 722 }
723
724 /* Ok, finally something we can handle */
725 tsk->thread.trap_no = 1;
726 tsk->thread.error_code = error_code;
727 info.si_signo = SIGTRAP;
728 info.si_errno = 0;
729 info.si_code = TRAP_BRKPT;
76381fee 730 if (!user_mode(regs))
1da177e4
LT		 731 goto clear_dr7;
732
733 info.si_addr = (void __user *)regs->rip;
734 force_sig_info(SIGTRAP, &info, tsk);
735clear_dr7:
e9129e56 736 set_debugreg(0UL, 7);
6fefb0d1 737 return;
1da177e4
LT		 738
739clear_TF_reenable:
740 set_tsk_thread_flag(tsk, TIF_SINGLESTEP);
1da177e4 741 regs->eflags &= ~TF_MASK;
1da177e4
LT		 742}
743
744static int kernel_math_error(struct pt_regs *regs, char *str)
745{
746 const struct exception_table_entry *fixup;
747 fixup = search_exception_tables(regs->rip);
748 if (fixup) {
749 regs->rip = fixup->fixup;
750 return 1;
751 }
752 notify_die(DIE_GPF, str, regs, 0, 16, SIGFPE);
3a848f63 753 /* Illegal floating point operation in the kernel */
1da177e4 754 die(str, regs, 0);
1da177e4
LT		 755 return 0;
756}
757
758/*
759 * Note that we play around with the 'TS' bit in an attempt to get
760 * the correct behaviour even in the presence of the asynchronous
761 * IRQ13 behaviour
762 */
763asmlinkage void do_coprocessor_error(struct pt_regs *regs)
764{
765 void __user *rip = (void __user *)(regs->rip);
766 struct task_struct * task;
767 siginfo_t info;
768 unsigned short cwd, swd;
769
770 conditional_sti(regs);
76381fee 771 if (!user_mode(regs) &&
1da177e4
LT		 772 kernel_math_error(regs, "kernel x87 math error"))
773 return;
774
775 /*
776 * Save the info for the exception handler and clear the error.
777 */
778 task = current;
779 save_init_fpu(task);
780 task->thread.trap_no = 16;
781 task->thread.error_code = 0;
782 info.si_signo = SIGFPE;
783 info.si_errno = 0;
784 info.si_code = __SI_FAULT;
785 info.si_addr = rip;
786 /*
787 * (~cwd & swd) will mask out exceptions that are not set to unmasked
788 * status. 0x3f is the exception bits in these regs, 0x200 is the
789 * C1 reg you need in case of a stack fault, 0x040 is the stack
790 * fault bit. We should only be taking one exception at a time,
791 * so if this combination doesn't produce any single exception,
792 * then we have a bad program that isn't synchronizing its FPU usage
793 * and it will suffer the consequences since we won't be able to
794 * fully reproduce the context of the exception
795 */
796 cwd = get_fpu_cwd(task);
797 swd = get_fpu_swd(task);
798 switch (((~cwd) & swd & 0x3f) | (swd & 0x240)) {
799 case 0x000:
800 default:
801 break;
802 case 0x001: /* Invalid Op */
803 case 0x041: /* Stack Fault */
804 case 0x241: /* Stack Fault | Direction */
805 info.si_code = FPE_FLTINV;
806 break;
807 case 0x002: /* Denormalize */
808 case 0x010: /* Underflow */
809 info.si_code = FPE_FLTUND;
810 break;
811 case 0x004: /* Zero Divide */
812 info.si_code = FPE_FLTDIV;
813 break;
814 case 0x008: /* Overflow */
815 info.si_code = FPE_FLTOVF;
816 break;
817 case 0x020: /* Precision */
818 info.si_code = FPE_FLTRES;
819 break;
820 }
821 force_sig_info(SIGFPE, &info, task);
822}
823
824asmlinkage void bad_intr(void)
825{
826 printk("bad interrupt");
827}
828
829asmlinkage void do_simd_coprocessor_error(struct pt_regs *regs)
830{
831 void __user *rip = (void __user *)(regs->rip);
832 struct task_struct * task;
833 siginfo_t info;
834 unsigned short mxcsr;
835
836 conditional_sti(regs);
76381fee 837 if (!user_mode(regs) &&
3a848f63 838 kernel_math_error(regs, "kernel simd math error"))
1da177e4
LT		 839 return;
840
841 /*
842 * Save the info for the exception handler and clear the error.
843 */
844 task = current;
845 save_init_fpu(task);
846 task->thread.trap_no = 19;
847 task->thread.error_code = 0;
848 info.si_signo = SIGFPE;
849 info.si_errno = 0;
850 info.si_code = __SI_FAULT;
851 info.si_addr = rip;
852 /*
853 * The SIMD FPU exceptions are handled a little differently, as there
854 * is only a single status/control register. Thus, to determine which
855 * unmasked exception was caught we must mask the exception mask bits
856 * at 0x1f80, and then use these to mask the exception bits at 0x3f.
857 */
858 mxcsr = get_fpu_mxcsr(task);
859 switch (~((mxcsr & 0x1f80) >> 7) & (mxcsr & 0x3f)) {
860 case 0x000:
861 default:
862 break;
863 case 0x001: /* Invalid Op */
864 info.si_code = FPE_FLTINV;
865 break;
866 case 0x002: /* Denormalize */
867 case 0x010: /* Underflow */
868 info.si_code = FPE_FLTUND;
869 break;
870 case 0x004: /* Zero Divide */
871 info.si_code = FPE_FLTDIV;
872 break;
873 case 0x008: /* Overflow */
874 info.si_code = FPE_FLTOVF;
875 break;
876 case 0x020: /* Precision */
877 info.si_code = FPE_FLTRES;
878 break;
879 }
880 force_sig_info(SIGFPE, &info, task);
881}
882
883asmlinkage void do_spurious_interrupt_bug(struct pt_regs * regs)
884{
885}
886
887asmlinkage void __attribute__((weak)) smp_thermal_interrupt(void)
888{
889}
890
891/*
892 * 'math_state_restore()' saves the current math information in the
893 * old math state array, and gets the new ones from the current task
894 *
895 * Careful.. There are problems with IBM-designed IRQ13 behaviour.
896 * Don't touch unless you *really* know how it works.
897 */
898asmlinkage void math_state_restore(void)
899{
900 struct task_struct *me = current;
901 clts(); /* Allow maths ops (or we recurse) */
902
903 if (!used_math())
904 init_fpu(me);
905 restore_fpu_checking(&me->thread.i387.fxsave);
906 me->thread_info->status |= TS_USEDFPU;
907}
908
909void do_call_debug(struct pt_regs *regs)
910{
911 notify_die(DIE_CALL, "debug call", regs, 0, 255, SIGINT);
912}
913
914void __init trap_init(void)
915{
916 set_intr_gate(0,&divide_error);
917 set_intr_gate_ist(1,&debug,DEBUG_STACK);
918 set_intr_gate_ist(2,&nmi,NMI_STACK);
919 set_system_gate(3,&int3);
920 set_system_gate(4,&overflow); /* int4-5 can be called from all */
921 set_system_gate(5,&bounds);
922 set_intr_gate(6,&invalid_op);
923 set_intr_gate(7,&device_not_available);
924 set_intr_gate_ist(8,&double_fault, DOUBLEFAULT_STACK);
925 set_intr_gate(9,&coprocessor_segment_overrun);
926 set_intr_gate(10,&invalid_TSS);
927 set_intr_gate(11,&segment_not_present);
928 set_intr_gate_ist(12,&stack_segment,STACKFAULT_STACK);
929 set_intr_gate(13,&general_protection);
930 set_intr_gate(14,&page_fault);
931 set_intr_gate(15,&spurious_interrupt_bug);
932 set_intr_gate(16,&coprocessor_error);
933 set_intr_gate(17,&alignment_check);
934#ifdef CONFIG_X86_MCE
935 set_intr_gate_ist(18,&machine_check, MCE_STACK);
936#endif
937 set_intr_gate(19,&simd_coprocessor_error);
938
939#ifdef CONFIG_IA32_EMULATION
940 set_system_gate(IA32_SYSCALL_VECTOR, ia32_syscall);
941#endif
942
943 set_intr_gate(KDB_VECTOR, call_debug);
944
945 /*
946 * Should be a barrier for any external CPU state.
947 */
948 cpu_init();
949}
950
951
952/* Actual parsing is done early in setup.c. */
953static int __init oops_dummy(char *s)
954{
955 panic_on_oops = 1;
956 return -1;
957}
958__setup("oops=", oops_dummy);
959
960static int __init kstack_setup(char *s)
961{
962 kstack_depth_to_print = simple_strtoul(s,NULL,0);
963 return 0;
964}
965__setup("kstack=", kstack_setup);
966
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