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[PATCH] x86_64: clean up ptrace single-stepping
[net-next-2.6.git] / arch / x86_64 / kernel / traps.c
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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
123unsigned long *in_exception_stack(int cpu, unsigned long stack)
124{
125 int k;
126 for (k = 0; k < N_EXCEPTION_STACKS; k++) {
127 struct tss_struct *tss = &per_cpu(init_tss, cpu);
128 unsigned long start = tss->ist[k] - EXCEPTION_STKSZ;
129
130 if (stack >= start && stack < tss->ist[k])
131 return (unsigned long *)tss->ist[k];
132 }
133 return NULL;
134}
135
136/*
137 * x86-64 can have upto three kernel stacks:
138 * process stack
139 * interrupt stack
140 * severe exception (double fault, nmi, stack fault) hardware stack
141 * Check and process them in order.
142 */
143
144void show_trace(unsigned long *stack)
145{
146 unsigned long addr;
147 unsigned long *irqstack, *irqstack_end, *estack_end;
148 const int cpu = safe_smp_processor_id();
149 int i;
150
151 printk("\nCall Trace:");
152 i = 0;
153
154 estack_end = in_exception_stack(cpu, (unsigned long)stack);
155 if (estack_end) {
156 while (stack < estack_end) {
157 addr = *stack++;
158 if (__kernel_text_address(addr)) {
159 i += printk_address(addr);
160 i += printk(" ");
161 if (i > 50) {
162 printk("\n");
163 i = 0;
164 }
165 }
166 }
167 i += printk(" <EOE> ");
168 i += 7;
169 stack = (unsigned long *) estack_end[-2];
170 }
171
172 irqstack_end = (unsigned long *) (cpu_pda[cpu].irqstackptr);
173 irqstack = (unsigned long *) (cpu_pda[cpu].irqstackptr - IRQSTACKSIZE + 64);
174
175 if (stack >= irqstack && stack < irqstack_end) {
176 printk("<IRQ> ");
177 while (stack < irqstack_end) {
178 addr = *stack++;
179 /*
180 * If the address is either in the text segment of the
181 * kernel, or in the region which contains vmalloc'ed
182 * memory, it *may* be the address of a calling
183 * routine; if so, print it so that someone tracing
184 * down the cause of the crash will be able to figure
185 * out the call path that was taken.
186 */
187 if (__kernel_text_address(addr)) {
188 i += printk_address(addr);
189 i += printk(" ");
190 if (i > 50) {
191 printk("\n ");
192 i = 0;
193 }
194 }
195 }
196 stack = (unsigned long *) (irqstack_end[-1]);
197 printk(" <EOI> ");
198 i += 7;
199 }
200
201 while (((long) stack & (THREAD_SIZE-1)) != 0) {
202 addr = *stack++;
203 if (__kernel_text_address(addr)) {
204 i += printk_address(addr);
205 i += printk(" ");
206 if (i > 50) {
207 printk("\n ");
208 i = 0;
209 }
210 }
211 }
212 printk("\n");
213}
214
215void show_stack(struct task_struct *tsk, unsigned long * rsp)
216{
217 unsigned long *stack;
218 int i;
219 const int cpu = safe_smp_processor_id();
220 unsigned long *irqstack_end = (unsigned long *) (cpu_pda[cpu].irqstackptr);
221 unsigned long *irqstack = (unsigned long *) (cpu_pda[cpu].irqstackptr - IRQSTACKSIZE);
222
223 // debugging aid: "show_stack(NULL, NULL);" prints the
224 // back trace for this cpu.
225
226 if (rsp == NULL) {
227 if (tsk)
228 rsp = (unsigned long *)tsk->thread.rsp;
229 else
230 rsp = (unsigned long *)&rsp;
231 }
232
233 stack = rsp;
234 for(i=0; i < kstack_depth_to_print; i++) {
235 if (stack >= irqstack && stack <= irqstack_end) {
236 if (stack == irqstack_end) {
237 stack = (unsigned long *) (irqstack_end[-1]);
238 printk(" <EOI> ");
239 }
240 } else {
241 if (((long) stack & (THREAD_SIZE-1)) == 0)
242 break;
243 }
244 if (i && ((i % 4) == 0))
245 printk("\n ");
246 printk("%016lx ", *stack++);
35faa714 247 touch_nmi_watchdog();
1da177e4
LT		 248 }
249 show_trace((unsigned long *)rsp);
250}
251
252/*
253 * The architecture-independent dump_stack generator
254 */
255void dump_stack(void)
256{
257 unsigned long dummy;
258 show_trace(&dummy);
259}
260
261EXPORT_SYMBOL(dump_stack);
262
263void show_registers(struct pt_regs *regs)
264{
265 int i;
266 int in_kernel = (regs->cs & 3) == 0;
267 unsigned long rsp;
268 const int cpu = safe_smp_processor_id();
269 struct task_struct *cur = cpu_pda[cpu].pcurrent;
270
271 rsp = regs->rsp;
272
273 printk("CPU %d ", cpu);
274 __show_regs(regs);
275 printk("Process %s (pid: %d, threadinfo %p, task %p)\n",
276 cur->comm, cur->pid, cur->thread_info, cur);
277
278 /*
279 * When in-kernel, we also print out the stack and code at the
280 * time of the fault..
281 */
282 if (in_kernel) {
283
284 printk("Stack: ");
285 show_stack(NULL, (unsigned long*)rsp);
286
287 printk("\nCode: ");
288 if(regs->rip < PAGE_OFFSET)
289 goto bad;
290
291 for(i=0;i<20;i++)
292 {
293 unsigned char c;
294 if(__get_user(c, &((unsigned char*)regs->rip)[i])) {
295bad:
296 printk(" Bad RIP value.");
297 break;
298 }
299 printk("%02x ", c);
300 }
301 }
302 printk("\n");
303}
304
305void handle_BUG(struct pt_regs *regs)
306{
307 struct bug_frame f;
308 char tmp;
309
310 if (regs->cs & 3)
311 return;
312 if (__copy_from_user(&f, (struct bug_frame *) regs->rip,
313 sizeof(struct bug_frame)))
314 return;
315 if ((unsigned long)f.filename < __PAGE_OFFSET ||
316 f.ud2[0] != 0x0f || f.ud2[1] != 0x0b)
317 return;
318 if (__get_user(tmp, f.filename))
319 f.filename = "unmapped filename";
320 printk("----------- [cut here ] --------- [please bite here ] ---------\n");
321 printk(KERN_ALERT "Kernel BUG at %.50s:%d\n", f.filename, f.line);
322}
323
324void out_of_line_bug(void)
325{
326 BUG();
327}
328
329static DEFINE_SPINLOCK(die_lock);
330static int die_owner = -1;
331
332void oops_begin(void)
333{
334 int cpu = safe_smp_processor_id();
335 /* racy, but better than risking deadlock. */
336 local_irq_disable();
337 if (!spin_trylock(&die_lock)) {
338 if (cpu == die_owner)
339 /* nested oops. should stop eventually */;
340 else
341 spin_lock(&die_lock);
342 }
343 die_owner = cpu;
344 console_verbose();
345 bust_spinlocks(1);
346}
347
348void oops_end(void)
349{
350 die_owner = -1;
351 bust_spinlocks(0);
352 spin_unlock(&die_lock);
353 if (panic_on_oops)
354 panic("Oops");
355}
356
357void __die(const char * str, struct pt_regs * regs, long err)
358{
359 static int die_counter;
360 printk(KERN_EMERG "%s: %04lx [%u] ", str, err & 0xffff,++die_counter);
361#ifdef CONFIG_PREEMPT
362 printk("PREEMPT ");
363#endif
364#ifdef CONFIG_SMP
365 printk("SMP ");
366#endif
367#ifdef CONFIG_DEBUG_PAGEALLOC
368 printk("DEBUG_PAGEALLOC");
369#endif
370 printk("\n");
371 notify_die(DIE_OOPS, (char *)str, regs, err, 255, SIGSEGV);
372 show_registers(regs);
373 /* Executive summary in case the oops scrolled away */
374 printk(KERN_ALERT "RIP ");
375 printk_address(regs->rip);
376 printk(" RSP <%016lx>\n", regs->rsp);
377}
378
379void die(const char * str, struct pt_regs * regs, long err)
380{
381 oops_begin();
382 handle_BUG(regs);
383 __die(str, regs, err);
384 oops_end();
385 do_exit(SIGSEGV);
386}
387static inline void die_if_kernel(const char * str, struct pt_regs * regs, long err)
388{
389 if (!(regs->eflags & VM_MASK) && (regs->cs == __KERNEL_CS))
390 die(str, regs, err);
391}
392
393void die_nmi(char *str, struct pt_regs *regs)
394{
395 oops_begin();
396 /*
397 * We are in trouble anyway, lets at least try
398 * to get a message out.
399 */
400 printk(str, safe_smp_processor_id());
401 show_registers(regs);
402 if (panic_on_timeout || panic_on_oops)
403 panic("nmi watchdog");
404 printk("console shuts up ...\n");
405 oops_end();
406 do_exit(SIGSEGV);
407}
408
409static void do_trap(int trapnr, int signr, char *str,
410 struct pt_regs * regs, long error_code, siginfo_t *info)
411{
412 conditional_sti(regs);
413
414#ifdef CONFIG_CHECKING
415 {
416 unsigned long gs;
417 struct x8664_pda *pda = cpu_pda + safe_smp_processor_id();
418 rdmsrl(MSR_GS_BASE, gs);
419 if (gs != (unsigned long)pda) {
420 wrmsrl(MSR_GS_BASE, pda);
421 printk("%s: wrong gs %lx expected %p rip %lx\n", str, gs, pda,
422 regs->rip);
423 }
424 }
425#endif
426
427 if ((regs->cs & 3) != 0) {
428 struct task_struct *tsk = current;
429
430 if (exception_trace && unhandled_signal(tsk, signr))
431 printk(KERN_INFO
432 "%s[%d] trap %s rip:%lx rsp:%lx error:%lx\n",
433 tsk->comm, tsk->pid, str,
434 regs->rip,regs->rsp,error_code);
435
436 tsk->thread.error_code = error_code;
437 tsk->thread.trap_no = trapnr;
438 if (info)
439 force_sig_info(signr, info, tsk);
440 else
441 force_sig(signr, tsk);
442 return;
443 }
444
445
446 /* kernel trap */
447 {
448 const struct exception_table_entry *fixup;
449 fixup = search_exception_tables(regs->rip);
450 if (fixup) {
451 regs->rip = fixup->fixup;
452 } else
453 die(str, regs, error_code);
454 return;
455 }
456}
457
458#define DO_ERROR(trapnr, signr, str, name) \
459asmlinkage void do_##name(struct pt_regs * regs, long error_code) \
460{ \
461 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
462 == NOTIFY_STOP) \
463 return; \
464 do_trap(trapnr, signr, str, regs, error_code, NULL); \
465}
466
467#define DO_ERROR_INFO(trapnr, signr, str, name, sicode, siaddr) \
468asmlinkage void do_##name(struct pt_regs * regs, long error_code) \
469{ \
470 siginfo_t info; \
471 info.si_signo = signr; \
472 info.si_errno = 0; \
473 info.si_code = sicode; \
474 info.si_addr = (void __user *)siaddr; \
475 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
476 == NOTIFY_STOP) \
477 return; \
478 do_trap(trapnr, signr, str, regs, error_code, &info); \
479}
480
481DO_ERROR_INFO( 0, SIGFPE, "divide error", divide_error, FPE_INTDIV, regs->rip)
482DO_ERROR( 4, SIGSEGV, "overflow", overflow)
483DO_ERROR( 5, SIGSEGV, "bounds", bounds)
484DO_ERROR_INFO( 6, SIGILL, "invalid operand", invalid_op, ILL_ILLOPN, regs->rip)
485DO_ERROR( 7, SIGSEGV, "device not available", device_not_available)
486DO_ERROR( 9, SIGFPE, "coprocessor segment overrun", coprocessor_segment_overrun)
487DO_ERROR(10, SIGSEGV, "invalid TSS", invalid_TSS)
488DO_ERROR(11, SIGBUS, "segment not present", segment_not_present)
489DO_ERROR_INFO(17, SIGBUS, "alignment check", alignment_check, BUS_ADRALN, 0)
490DO_ERROR(18, SIGSEGV, "reserved", reserved)
491
492#define DO_ERROR_STACK(trapnr, signr, str, name) \
493asmlinkage void *do_##name(struct pt_regs * regs, long error_code) \
494{ \
495 struct pt_regs *pr = ((struct pt_regs *)(current->thread.rsp0))-1; \
496 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
497 == NOTIFY_STOP) \
498 return regs; \
499 if (regs->cs & 3) { \
500 memcpy(pr, regs, sizeof(struct pt_regs)); \
501 regs = pr; \
502 } \
503 do_trap(trapnr, signr, str, regs, error_code, NULL); \
504 return regs; \
505}
506
507DO_ERROR_STACK(12, SIGBUS, "stack segment", stack_segment)
508DO_ERROR_STACK( 8, SIGSEGV, "double fault", double_fault)
509
510asmlinkage void do_general_protection(struct pt_regs * regs, long error_code)
511{
512 conditional_sti(regs);
513
514#ifdef CONFIG_CHECKING
515 {
516 unsigned long gs;
517 struct x8664_pda *pda = cpu_pda + safe_smp_processor_id();
518 rdmsrl(MSR_GS_BASE, gs);
519 if (gs != (unsigned long)pda) {
520 wrmsrl(MSR_GS_BASE, pda);
521 oops_in_progress++;
522 printk("general protection handler: wrong gs %lx expected %p\n", gs, pda);
523 oops_in_progress--;
524 }
525 }
526#endif
527
528 if ((regs->cs & 3)!=0) {
529 struct task_struct *tsk = current;
530
531 if (exception_trace && unhandled_signal(tsk, SIGSEGV))
532 printk(KERN_INFO
533 "%s[%d] general protection rip:%lx rsp:%lx error:%lx\n",
534 tsk->comm, tsk->pid,
535 regs->rip,regs->rsp,error_code);
536
537 tsk->thread.error_code = error_code;
538 tsk->thread.trap_no = 13;
539 force_sig(SIGSEGV, tsk);
540 return;
541 }
542
543 /* kernel gp */
544 {
545 const struct exception_table_entry *fixup;
546 fixup = search_exception_tables(regs->rip);
547 if (fixup) {
548 regs->rip = fixup->fixup;
549 return;
550 }
551 if (notify_die(DIE_GPF, "general protection fault", regs,
552 error_code, 13, SIGSEGV) == NOTIFY_STOP)
553 return;
554 die("general protection fault", regs, error_code);
555 }
556}
557
558static void mem_parity_error(unsigned char reason, struct pt_regs * regs)
559{
560 printk("Uhhuh. NMI received. Dazed and confused, but trying to continue\n");
561 printk("You probably have a hardware problem with your RAM chips\n");
562
563 /* Clear and disable the memory parity error line. */
564 reason = (reason & 0xf) | 4;
565 outb(reason, 0x61);
566}
567
568static void io_check_error(unsigned char reason, struct pt_regs * regs)
569{
570 printk("NMI: IOCK error (debug interrupt?)\n");
571 show_registers(regs);
572
573 /* Re-enable the IOCK line, wait for a few seconds */
574 reason = (reason & 0xf) | 8;
575 outb(reason, 0x61);
576 mdelay(2000);
577 reason &= ~8;
578 outb(reason, 0x61);
579}
580
581static void unknown_nmi_error(unsigned char reason, struct pt_regs * regs)
582{ printk("Uhhuh. NMI received for unknown reason %02x.\n", reason);
583 printk("Dazed and confused, but trying to continue\n");
584 printk("Do you have a strange power saving mode enabled?\n");
585}
586
587asmlinkage void default_do_nmi(struct pt_regs *regs)
588{
589 unsigned char reason = 0;
590
591 /* Only the BSP gets external NMIs from the system. */
592 if (!smp_processor_id())
593 reason = get_nmi_reason();
594
595 if (!(reason & 0xc0)) {
596 if (notify_die(DIE_NMI_IPI, "nmi_ipi", regs, reason, 0, SIGINT)
597 == NOTIFY_STOP)
598 return;
599#ifdef CONFIG_X86_LOCAL_APIC
600 /*
601 * Ok, so this is none of the documented NMI sources,
602 * so it must be the NMI watchdog.
603 */
604 if (nmi_watchdog > 0) {
605 nmi_watchdog_tick(regs,reason);
606 return;
607 }
608#endif
609 unknown_nmi_error(reason, regs);
610 return;
611 }
612 if (notify_die(DIE_NMI, "nmi", regs, reason, 0, SIGINT) == NOTIFY_STOP)
613 return;
614
615 /* AK: following checks seem to be broken on modern chipsets. FIXME */
616
617 if (reason & 0x80)
618 mem_parity_error(reason, regs);
619 if (reason & 0x40)
620 io_check_error(reason, regs);
621}
622
623asmlinkage void do_int3(struct pt_regs * regs, long error_code)
624{
625 if (notify_die(DIE_INT3, "int3", regs, error_code, 3, SIGTRAP) == NOTIFY_STOP) {
626 return;
627 }
628 do_trap(3, SIGTRAP, "int3", regs, error_code, NULL);
629 return;
630}
631
632/* runs on IST stack. */
633asmlinkage void *do_debug(struct pt_regs * regs, unsigned long error_code)
634{
635 struct pt_regs *pr;
636 unsigned long condition;
637 struct task_struct *tsk = current;
638 siginfo_t info;
639
640 pr = (struct pt_regs *)(current->thread.rsp0)-1;
641 if (regs->cs & 3) {
642 memcpy(pr, regs, sizeof(struct pt_regs));
643 regs = pr;
644 }
645
646#ifdef CONFIG_CHECKING
647 {
648 /* RED-PEN interaction with debugger - could destroy gs */
649 unsigned long gs;
650 struct x8664_pda *pda = cpu_pda + safe_smp_processor_id();
651 rdmsrl(MSR_GS_BASE, gs);
652 if (gs != (unsigned long)pda) {
653 wrmsrl(MSR_GS_BASE, pda);
654 printk("debug handler: wrong gs %lx expected %p\n", gs, pda);
655 }
656 }
657#endif
658
659 asm("movq %%db6,%0" : "=r" (condition));
660
661 if (notify_die(DIE_DEBUG, "debug", regs, condition, error_code,
662 SIGTRAP) == NOTIFY_STOP) {
663 return regs;
664 }
665 conditional_sti(regs);
666
667 /* Mask out spurious debug traps due to lazy DR7 setting */
668 if (condition & (DR_TRAP0|DR_TRAP1|DR_TRAP2|DR_TRAP3)) {
669 if (!tsk->thread.debugreg7) {
670 goto clear_dr7;
671 }
672 }
673
674 tsk->thread.debugreg6 = condition;
675
676 /* Mask out spurious TF errors due to lazy TF clearing */
677 if ((condition & DR_STEP) &&
678 (notify_die(DIE_DEBUGSTEP, "debugstep", regs, condition,
679 1, SIGTRAP) != NOTIFY_STOP)) {
680 /*
681 * The TF error should be masked out only if the current
682 * process is not traced and if the TRAP flag has been set
683 * previously by a tracing process (condition detected by
684 * the PT_DTRACE flag); remember that the i386 TRAP flag
685 * can be modified by the process itself in user mode,
686 * allowing programs to debug themselves without the ptrace()
687 * interface.
688 */
689 if ((regs->cs & 3) == 0)
690 goto clear_TF_reenable;
691 if ((tsk->ptrace & (PT_DTRACE|PT_PTRACED)) == PT_DTRACE)
692 goto clear_TF;
693 }
694
695 /* Ok, finally something we can handle */
696 tsk->thread.trap_no = 1;
697 tsk->thread.error_code = error_code;
698 info.si_signo = SIGTRAP;
699 info.si_errno = 0;
700 info.si_code = TRAP_BRKPT;
701 if ((regs->cs & 3) == 0)
702 goto clear_dr7;
703
704 info.si_addr = (void __user *)regs->rip;
705 force_sig_info(SIGTRAP, &info, tsk);
706clear_dr7:
707 asm volatile("movq %0,%%db7"::"r"(0UL));
708 notify_die(DIE_DEBUG, "debug", regs, condition, 1, SIGTRAP);
709 return regs;
710
711clear_TF_reenable:
712 set_tsk_thread_flag(tsk, TIF_SINGLESTEP);
713
714clear_TF:
715 /* RED-PEN could cause spurious errors */
716 if (notify_die(DIE_DEBUG, "debug2", regs, condition, 1, SIGTRAP)
717 != NOTIFY_STOP)
718 regs->eflags &= ~TF_MASK;
719 return regs;
720}
721
722static int kernel_math_error(struct pt_regs *regs, char *str)
723{
724 const struct exception_table_entry *fixup;
725 fixup = search_exception_tables(regs->rip);
726 if (fixup) {
727 regs->rip = fixup->fixup;
728 return 1;
729 }
730 notify_die(DIE_GPF, str, regs, 0, 16, SIGFPE);
731#if 0
732 /* This should be a die, but warn only for now */
733 die(str, regs, 0);
734#else
735 printk(KERN_DEBUG "%s: %s at ", current->comm, str);
736 printk_address(regs->rip);
737 printk("\n");
738#endif
739 return 0;
740}
741
742/*
743 * Note that we play around with the 'TS' bit in an attempt to get
744 * the correct behaviour even in the presence of the asynchronous
745 * IRQ13 behaviour
746 */
747asmlinkage void do_coprocessor_error(struct pt_regs *regs)
748{
749 void __user *rip = (void __user *)(regs->rip);
750 struct task_struct * task;
751 siginfo_t info;
752 unsigned short cwd, swd;
753
754 conditional_sti(regs);
755 if ((regs->cs & 3) == 0 &&
756 kernel_math_error(regs, "kernel x87 math error"))
757 return;
758
759 /*
760 * Save the info for the exception handler and clear the error.
761 */
762 task = current;
763 save_init_fpu(task);
764 task->thread.trap_no = 16;
765 task->thread.error_code = 0;
766 info.si_signo = SIGFPE;
767 info.si_errno = 0;
768 info.si_code = __SI_FAULT;
769 info.si_addr = rip;
770 /*
771 * (~cwd & swd) will mask out exceptions that are not set to unmasked
772 * status. 0x3f is the exception bits in these regs, 0x200 is the
773 * C1 reg you need in case of a stack fault, 0x040 is the stack
774 * fault bit. We should only be taking one exception at a time,
775 * so if this combination doesn't produce any single exception,
776 * then we have a bad program that isn't synchronizing its FPU usage
777 * and it will suffer the consequences since we won't be able to
778 * fully reproduce the context of the exception
779 */
780 cwd = get_fpu_cwd(task);
781 swd = get_fpu_swd(task);
782 switch (((~cwd) & swd & 0x3f) | (swd & 0x240)) {
783 case 0x000:
784 default:
785 break;
786 case 0x001: /* Invalid Op */
787 case 0x041: /* Stack Fault */
788 case 0x241: /* Stack Fault | Direction */
789 info.si_code = FPE_FLTINV;
790 break;
791 case 0x002: /* Denormalize */
792 case 0x010: /* Underflow */
793 info.si_code = FPE_FLTUND;
794 break;
795 case 0x004: /* Zero Divide */
796 info.si_code = FPE_FLTDIV;
797 break;
798 case 0x008: /* Overflow */
799 info.si_code = FPE_FLTOVF;
800 break;
801 case 0x020: /* Precision */
802 info.si_code = FPE_FLTRES;
803 break;
804 }
805 force_sig_info(SIGFPE, &info, task);
806}
807
808asmlinkage void bad_intr(void)
809{
810 printk("bad interrupt");
811}
812
813asmlinkage void do_simd_coprocessor_error(struct pt_regs *regs)
814{
815 void __user *rip = (void __user *)(regs->rip);
816 struct task_struct * task;
817 siginfo_t info;
818 unsigned short mxcsr;
819
820 conditional_sti(regs);
821 if ((regs->cs & 3) == 0 &&
822 kernel_math_error(regs, "simd math error"))
823 return;
824
825 /*
826 * Save the info for the exception handler and clear the error.
827 */
828 task = current;
829 save_init_fpu(task);
830 task->thread.trap_no = 19;
831 task->thread.error_code = 0;
832 info.si_signo = SIGFPE;
833 info.si_errno = 0;
834 info.si_code = __SI_FAULT;
835 info.si_addr = rip;
836 /*
837 * The SIMD FPU exceptions are handled a little differently, as there
838 * is only a single status/control register. Thus, to determine which
839 * unmasked exception was caught we must mask the exception mask bits
840 * at 0x1f80, and then use these to mask the exception bits at 0x3f.
841 */
842 mxcsr = get_fpu_mxcsr(task);
843 switch (~((mxcsr & 0x1f80) >> 7) & (mxcsr & 0x3f)) {
844 case 0x000:
845 default:
846 break;
847 case 0x001: /* Invalid Op */
848 info.si_code = FPE_FLTINV;
849 break;
850 case 0x002: /* Denormalize */
851 case 0x010: /* Underflow */
852 info.si_code = FPE_FLTUND;
853 break;
854 case 0x004: /* Zero Divide */
855 info.si_code = FPE_FLTDIV;
856 break;
857 case 0x008: /* Overflow */
858 info.si_code = FPE_FLTOVF;
859 break;
860 case 0x020: /* Precision */
861 info.si_code = FPE_FLTRES;
862 break;
863 }
864 force_sig_info(SIGFPE, &info, task);
865}
866
867asmlinkage void do_spurious_interrupt_bug(struct pt_regs * regs)
868{
869}
870
871asmlinkage void __attribute__((weak)) smp_thermal_interrupt(void)
872{
873}
874
875/*
876 * 'math_state_restore()' saves the current math information in the
877 * old math state array, and gets the new ones from the current task
878 *
879 * Careful.. There are problems with IBM-designed IRQ13 behaviour.
880 * Don't touch unless you *really* know how it works.
881 */
882asmlinkage void math_state_restore(void)
883{
884 struct task_struct *me = current;
885 clts(); /* Allow maths ops (or we recurse) */
886
887 if (!used_math())
888 init_fpu(me);
889 restore_fpu_checking(&me->thread.i387.fxsave);
890 me->thread_info->status |= TS_USEDFPU;
891}
892
893void do_call_debug(struct pt_regs *regs)
894{
895 notify_die(DIE_CALL, "debug call", regs, 0, 255, SIGINT);
896}
897
898void __init trap_init(void)
899{
900 set_intr_gate(0,&divide_error);
901 set_intr_gate_ist(1,&debug,DEBUG_STACK);
902 set_intr_gate_ist(2,&nmi,NMI_STACK);
903 set_system_gate(3,&int3);
904 set_system_gate(4,&overflow); /* int4-5 can be called from all */
905 set_system_gate(5,&bounds);
906 set_intr_gate(6,&invalid_op);
907 set_intr_gate(7,&device_not_available);
908 set_intr_gate_ist(8,&double_fault, DOUBLEFAULT_STACK);
909 set_intr_gate(9,&coprocessor_segment_overrun);
910 set_intr_gate(10,&invalid_TSS);
911 set_intr_gate(11,&segment_not_present);
912 set_intr_gate_ist(12,&stack_segment,STACKFAULT_STACK);
913 set_intr_gate(13,&general_protection);
914 set_intr_gate(14,&page_fault);
915 set_intr_gate(15,&spurious_interrupt_bug);
916 set_intr_gate(16,&coprocessor_error);
917 set_intr_gate(17,&alignment_check);
918#ifdef CONFIG_X86_MCE
919 set_intr_gate_ist(18,&machine_check, MCE_STACK);
920#endif
921 set_intr_gate(19,&simd_coprocessor_error);
922
923#ifdef CONFIG_IA32_EMULATION
924 set_system_gate(IA32_SYSCALL_VECTOR, ia32_syscall);
925#endif
926
927 set_intr_gate(KDB_VECTOR, call_debug);
928
929 /*
930 * Should be a barrier for any external CPU state.
931 */
932 cpu_init();
933}
934
935
936/* Actual parsing is done early in setup.c. */
937static int __init oops_dummy(char *s)
938{
939 panic_on_oops = 1;
940 return -1;
941}
942__setup("oops=", oops_dummy);
943
944static int __init kstack_setup(char *s)
945{
946 kstack_depth_to_print = simple_strtoul(s,NULL,0);
947 return 0;
948}
949__setup("kstack=", kstack_setup);
950
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