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