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-rw-r--r--arch/x86_64/kernel/traps.c948
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diff --git a/arch/x86_64/kernel/traps.c b/arch/x86_64/kernel/traps.c
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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>
31
32#include <asm/system.h>
33#include <asm/uaccess.h>
34#include <asm/io.h>
35#include <asm/atomic.h>
36#include <asm/debugreg.h>
37#include <asm/desc.h>
38#include <asm/i387.h>
39#include <asm/kdebug.h>
40#include <asm/processor.h>
41
42#include <asm/smp.h>
43#include <asm/pgalloc.h>
44#include <asm/pda.h>
45#include <asm/proto.h>
46#include <asm/nmi.h>
47
48#include <linux/irq.h>
49
50
51extern struct gate_struct idt_table[256];
52
53asmlinkage void divide_error(void);
54asmlinkage void debug(void);
55asmlinkage void nmi(void);
56asmlinkage void int3(void);
57asmlinkage void overflow(void);
58asmlinkage void bounds(void);
59asmlinkage void invalid_op(void);
60asmlinkage void device_not_available(void);
61asmlinkage void double_fault(void);
62asmlinkage void coprocessor_segment_overrun(void);
63asmlinkage void invalid_TSS(void);
64asmlinkage void segment_not_present(void);
65asmlinkage void stack_segment(void);
66asmlinkage void general_protection(void);
67asmlinkage void page_fault(void);
68asmlinkage void coprocessor_error(void);
69asmlinkage void simd_coprocessor_error(void);
70asmlinkage void reserved(void);
71asmlinkage void alignment_check(void);
72asmlinkage void machine_check(void);
73asmlinkage void spurious_interrupt_bug(void);
74asmlinkage void call_debug(void);
75
76struct notifier_block *die_chain;
77static DEFINE_SPINLOCK(die_notifier_lock);
78
79int register_die_notifier(struct notifier_block *nb)
80{
81 int err = 0;
82 unsigned long flags;
83 spin_lock_irqsave(&die_notifier_lock, flags);
84 err = notifier_chain_register(&die_chain, nb);
85 spin_unlock_irqrestore(&die_notifier_lock, flags);
86 return err;
87}
88
89static inline void conditional_sti(struct pt_regs *regs)
90{
91 if (regs->eflags & X86_EFLAGS_IF)
92 local_irq_enable();
93}
94
95static int kstack_depth_to_print = 10;
96
97#ifdef CONFIG_KALLSYMS
98#include <linux/kallsyms.h>
99int printk_address(unsigned long address)
100{
101 unsigned long offset = 0, symsize;
102 const char *symname;
103 char *modname;
104 char *delim = ":";
105 char namebuf[128];
106
107 symname = kallsyms_lookup(address, &symsize, &offset, &modname, namebuf);
108 if (!symname)
109 return printk("[<%016lx>]", address);
110 if (!modname)
111 modname = delim = "";
112 return printk("<%016lx>{%s%s%s%s%+ld}",
113 address,delim,modname,delim,symname,offset);
114}
115#else
116int printk_address(unsigned long address)
117{
118 return printk("[<%016lx>]", address);
119}
120#endif
121
122unsigned long *in_exception_stack(int cpu, unsigned long stack)
123{
124 int k;
125 for (k = 0; k < N_EXCEPTION_STACKS; k++) {
126 struct tss_struct *tss = &per_cpu(init_tss, cpu);
127 unsigned long start = tss->ist[k] - EXCEPTION_STKSZ;
128
129 if (stack >= start && stack < tss->ist[k])
130 return (unsigned long *)tss->ist[k];
131 }
132 return NULL;
133}
134
135/*
136 * x86-64 can have upto three kernel stacks:
137 * process stack
138 * interrupt stack
139 * severe exception (double fault, nmi, stack fault) hardware stack
140 * Check and process them in order.
141 */
142
143void show_trace(unsigned long *stack)
144{
145 unsigned long addr;
146 unsigned long *irqstack, *irqstack_end, *estack_end;
147 const int cpu = safe_smp_processor_id();
148 int i;
149
150 printk("\nCall Trace:");
151 i = 0;
152
153 estack_end = in_exception_stack(cpu, (unsigned long)stack);
154 if (estack_end) {
155 while (stack < estack_end) {
156 addr = *stack++;
157 if (__kernel_text_address(addr)) {
158 i += printk_address(addr);
159 i += printk(" ");
160 if (i > 50) {
161 printk("\n");
162 i = 0;
163 }
164 }
165 }
166 i += printk(" <EOE> ");
167 i += 7;
168 stack = (unsigned long *) estack_end[-2];
169 }
170
171 irqstack_end = (unsigned long *) (cpu_pda[cpu].irqstackptr);
172 irqstack = (unsigned long *) (cpu_pda[cpu].irqstackptr - IRQSTACKSIZE + 64);
173
174 if (stack >= irqstack && stack < irqstack_end) {
175 printk("<IRQ> ");
176 while (stack < irqstack_end) {
177 addr = *stack++;
178 /*
179 * If the address is either in the text segment of the
180 * kernel, or in the region which contains vmalloc'ed
181 * memory, it *may* be the address of a calling
182 * routine; if so, print it so that someone tracing
183 * down the cause of the crash will be able to figure
184 * out the call path that was taken.
185 */
186 if (__kernel_text_address(addr)) {
187 i += printk_address(addr);
188 i += printk(" ");
189 if (i > 50) {
190 printk("\n ");
191 i = 0;
192 }
193 }
194 }
195 stack = (unsigned long *) (irqstack_end[-1]);
196 printk(" <EOI> ");
197 i += 7;
198 }
199
200 while (((long) stack & (THREAD_SIZE-1)) != 0) {
201 addr = *stack++;
202 if (__kernel_text_address(addr)) {
203 i += printk_address(addr);
204 i += printk(" ");
205 if (i > 50) {
206 printk("\n ");
207 i = 0;
208 }
209 }
210 }
211 printk("\n");
212}
213
214void show_stack(struct task_struct *tsk, unsigned long * rsp)
215{
216 unsigned long *stack;
217 int i;
218 const int cpu = safe_smp_processor_id();
219 unsigned long *irqstack_end = (unsigned long *) (cpu_pda[cpu].irqstackptr);
220 unsigned long *irqstack = (unsigned long *) (cpu_pda[cpu].irqstackptr - IRQSTACKSIZE);
221
222 // debugging aid: "show_stack(NULL, NULL);" prints the
223 // back trace for this cpu.
224
225 if (rsp == NULL) {
226 if (tsk)
227 rsp = (unsigned long *)tsk->thread.rsp;
228 else
229 rsp = (unsigned long *)&rsp;
230 }
231
232 stack = rsp;
233 for(i=0; i < kstack_depth_to_print; i++) {
234 if (stack >= irqstack && stack <= irqstack_end) {
235 if (stack == irqstack_end) {
236 stack = (unsigned long *) (irqstack_end[-1]);
237 printk(" <EOI> ");
238 }
239 } else {
240 if (((long) stack & (THREAD_SIZE-1)) == 0)
241 break;
242 }
243 if (i && ((i % 4) == 0))
244 printk("\n ");
245 printk("%016lx ", *stack++);
246 }
247 show_trace((unsigned long *)rsp);
248}
249
250/*
251 * The architecture-independent dump_stack generator
252 */
253void dump_stack(void)
254{
255 unsigned long dummy;
256 show_trace(&dummy);
257}
258
259EXPORT_SYMBOL(dump_stack);
260
261void show_registers(struct pt_regs *regs)
262{
263 int i;
264 int in_kernel = (regs->cs & 3) == 0;
265 unsigned long rsp;
266 const int cpu = safe_smp_processor_id();
267 struct task_struct *cur = cpu_pda[cpu].pcurrent;
268
269 rsp = regs->rsp;
270
271 printk("CPU %d ", cpu);
272 __show_regs(regs);
273 printk("Process %s (pid: %d, threadinfo %p, task %p)\n",
274 cur->comm, cur->pid, cur->thread_info, cur);
275
276 /*
277 * When in-kernel, we also print out the stack and code at the
278 * time of the fault..
279 */
280 if (in_kernel) {
281
282 printk("Stack: ");
283 show_stack(NULL, (unsigned long*)rsp);
284
285 printk("\nCode: ");
286 if(regs->rip < PAGE_OFFSET)
287 goto bad;
288
289 for(i=0;i<20;i++)
290 {
291 unsigned char c;
292 if(__get_user(c, &((unsigned char*)regs->rip)[i])) {
293bad:
294 printk(" Bad RIP value.");
295 break;
296 }
297 printk("%02x ", c);
298 }
299 }
300 printk("\n");
301}
302
303void handle_BUG(struct pt_regs *regs)
304{
305 struct bug_frame f;
306 char tmp;
307
308 if (regs->cs & 3)
309 return;
310 if (__copy_from_user(&f, (struct bug_frame *) regs->rip,
311 sizeof(struct bug_frame)))
312 return;
313 if ((unsigned long)f.filename < __PAGE_OFFSET ||
314 f.ud2[0] != 0x0f || f.ud2[1] != 0x0b)
315 return;
316 if (__get_user(tmp, f.filename))
317 f.filename = "unmapped filename";
318 printk("----------- [cut here ] --------- [please bite here ] ---------\n");
319 printk(KERN_ALERT "Kernel BUG at %.50s:%d\n", f.filename, f.line);
320}
321
322void out_of_line_bug(void)
323{
324 BUG();
325}
326
327static DEFINE_SPINLOCK(die_lock);
328static int die_owner = -1;
329
330void oops_begin(void)
331{
332 int cpu = safe_smp_processor_id();
333 /* racy, but better than risking deadlock. */
334 local_irq_disable();
335 if (!spin_trylock(&die_lock)) {
336 if (cpu == die_owner)
337 /* nested oops. should stop eventually */;
338 else
339 spin_lock(&die_lock);
340 }
341 die_owner = cpu;
342 console_verbose();
343 bust_spinlocks(1);
344}
345
346void oops_end(void)
347{
348 die_owner = -1;
349 bust_spinlocks(0);
350 spin_unlock(&die_lock);
351 if (panic_on_oops)
352 panic("Oops");
353}
354
355void __die(const char * str, struct pt_regs * regs, long err)
356{
357 static int die_counter;
358 printk(KERN_EMERG "%s: %04lx [%u] ", str, err & 0xffff,++die_counter);
359#ifdef CONFIG_PREEMPT
360 printk("PREEMPT ");
361#endif
362#ifdef CONFIG_SMP
363 printk("SMP ");
364#endif
365#ifdef CONFIG_DEBUG_PAGEALLOC
366 printk("DEBUG_PAGEALLOC");
367#endif
368 printk("\n");
369 notify_die(DIE_OOPS, (char *)str, regs, err, 255, SIGSEGV);
370 show_registers(regs);
371 /* Executive summary in case the oops scrolled away */
372 printk(KERN_ALERT "RIP ");
373 printk_address(regs->rip);
374 printk(" RSP <%016lx>\n", regs->rsp);
375}
376
377void die(const char * str, struct pt_regs * regs, long err)
378{
379 oops_begin();
380 handle_BUG(regs);
381 __die(str, regs, err);
382 oops_end();
383 do_exit(SIGSEGV);
384}
385static inline void die_if_kernel(const char * str, struct pt_regs * regs, long err)
386{
387 if (!(regs->eflags & VM_MASK) && (regs->cs == __KERNEL_CS))
388 die(str, regs, err);
389}
390
391void die_nmi(char *str, struct pt_regs *regs)
392{
393 oops_begin();
394 /*
395 * We are in trouble anyway, lets at least try
396 * to get a message out.
397 */
398 printk(str, safe_smp_processor_id());
399 show_registers(regs);
400 if (panic_on_timeout || panic_on_oops)
401 panic("nmi watchdog");
402 printk("console shuts up ...\n");
403 oops_end();
404 do_exit(SIGSEGV);
405}
406
407static void do_trap(int trapnr, int signr, char *str,
408 struct pt_regs * regs, long error_code, siginfo_t *info)
409{
410 conditional_sti(regs);
411
412#ifdef CONFIG_CHECKING
413 {
414 unsigned long gs;
415 struct x8664_pda *pda = cpu_pda + safe_smp_processor_id();
416 rdmsrl(MSR_GS_BASE, gs);
417 if (gs != (unsigned long)pda) {
418 wrmsrl(MSR_GS_BASE, pda);
419 printk("%s: wrong gs %lx expected %p rip %lx\n", str, gs, pda,
420 regs->rip);
421 }
422 }
423#endif
424
425 if ((regs->cs & 3) != 0) {
426 struct task_struct *tsk = current;
427
428 if (exception_trace && unhandled_signal(tsk, signr))
429 printk(KERN_INFO
430 "%s[%d] trap %s rip:%lx rsp:%lx error:%lx\n",
431 tsk->comm, tsk->pid, str,
432 regs->rip,regs->rsp,error_code);
433
434 tsk->thread.error_code = error_code;
435 tsk->thread.trap_no = trapnr;
436 if (info)
437 force_sig_info(signr, info, tsk);
438 else
439 force_sig(signr, tsk);
440 return;
441 }
442
443
444 /* kernel trap */
445 {
446 const struct exception_table_entry *fixup;
447 fixup = search_exception_tables(regs->rip);
448 if (fixup) {
449 regs->rip = fixup->fixup;
450 } else
451 die(str, regs, error_code);
452 return;
453 }
454}
455
456#define DO_ERROR(trapnr, signr, str, name) \
457asmlinkage void do_##name(struct pt_regs * regs, long error_code) \
458{ \
459 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
460 == NOTIFY_STOP) \
461 return; \
462 do_trap(trapnr, signr, str, regs, error_code, NULL); \
463}
464
465#define DO_ERROR_INFO(trapnr, signr, str, name, sicode, siaddr) \
466asmlinkage void do_##name(struct pt_regs * regs, long error_code) \
467{ \
468 siginfo_t info; \
469 info.si_signo = signr; \
470 info.si_errno = 0; \
471 info.si_code = sicode; \
472 info.si_addr = (void __user *)siaddr; \
473 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
474 == NOTIFY_STOP) \
475 return; \
476 do_trap(trapnr, signr, str, regs, error_code, &info); \
477}
478
479DO_ERROR_INFO( 0, SIGFPE, "divide error", divide_error, FPE_INTDIV, regs->rip)
480DO_ERROR( 4, SIGSEGV, "overflow", overflow)
481DO_ERROR( 5, SIGSEGV, "bounds", bounds)
482DO_ERROR_INFO( 6, SIGILL, "invalid operand", invalid_op, ILL_ILLOPN, regs->rip)
483DO_ERROR( 7, SIGSEGV, "device not available", device_not_available)
484DO_ERROR( 9, SIGFPE, "coprocessor segment overrun", coprocessor_segment_overrun)
485DO_ERROR(10, SIGSEGV, "invalid TSS", invalid_TSS)
486DO_ERROR(11, SIGBUS, "segment not present", segment_not_present)
487DO_ERROR_INFO(17, SIGBUS, "alignment check", alignment_check, BUS_ADRALN, 0)
488DO_ERROR(18, SIGSEGV, "reserved", reserved)
489
490#define DO_ERROR_STACK(trapnr, signr, str, name) \
491asmlinkage void *do_##name(struct pt_regs * regs, long error_code) \
492{ \
493 struct pt_regs *pr = ((struct pt_regs *)(current->thread.rsp0))-1; \
494 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
495 == NOTIFY_STOP) \
496 return regs; \
497 if (regs->cs & 3) { \
498 memcpy(pr, regs, sizeof(struct pt_regs)); \
499 regs = pr; \
500 } \
501 do_trap(trapnr, signr, str, regs, error_code, NULL); \
502 return regs; \
503}
504
505DO_ERROR_STACK(12, SIGBUS, "stack segment", stack_segment)
506DO_ERROR_STACK( 8, SIGSEGV, "double fault", double_fault)
507
508asmlinkage void do_general_protection(struct pt_regs * regs, long error_code)
509{
510 conditional_sti(regs);
511
512#ifdef CONFIG_CHECKING
513 {
514 unsigned long gs;
515 struct x8664_pda *pda = cpu_pda + safe_smp_processor_id();
516 rdmsrl(MSR_GS_BASE, gs);
517 if (gs != (unsigned long)pda) {
518 wrmsrl(MSR_GS_BASE, pda);
519 oops_in_progress++;
520 printk("general protection handler: wrong gs %lx expected %p\n", gs, pda);
521 oops_in_progress--;
522 }
523 }
524#endif
525
526 if ((regs->cs & 3)!=0) {
527 struct task_struct *tsk = current;
528
529 if (exception_trace && unhandled_signal(tsk, SIGSEGV))
530 printk(KERN_INFO
531 "%s[%d] general protection rip:%lx rsp:%lx error:%lx\n",
532 tsk->comm, tsk->pid,
533 regs->rip,regs->rsp,error_code);
534
535 tsk->thread.error_code = error_code;
536 tsk->thread.trap_no = 13;
537 force_sig(SIGSEGV, tsk);
538 return;
539 }
540
541 /* kernel gp */
542 {
543 const struct exception_table_entry *fixup;
544 fixup = search_exception_tables(regs->rip);
545 if (fixup) {
546 regs->rip = fixup->fixup;
547 return;
548 }
549 if (notify_die(DIE_GPF, "general protection fault", regs,
550 error_code, 13, SIGSEGV) == NOTIFY_STOP)
551 return;
552 die("general protection fault", regs, error_code);
553 }
554}
555
556static void mem_parity_error(unsigned char reason, struct pt_regs * regs)
557{
558 printk("Uhhuh. NMI received. Dazed and confused, but trying to continue\n");
559 printk("You probably have a hardware problem with your RAM chips\n");
560
561 /* Clear and disable the memory parity error line. */
562 reason = (reason & 0xf) | 4;
563 outb(reason, 0x61);
564}
565
566static void io_check_error(unsigned char reason, struct pt_regs * regs)
567{
568 printk("NMI: IOCK error (debug interrupt?)\n");
569 show_registers(regs);
570
571 /* Re-enable the IOCK line, wait for a few seconds */
572 reason = (reason & 0xf) | 8;
573 outb(reason, 0x61);
574 mdelay(2000);
575 reason &= ~8;
576 outb(reason, 0x61);
577}
578
579static void unknown_nmi_error(unsigned char reason, struct pt_regs * regs)
580{ printk("Uhhuh. NMI received for unknown reason %02x.\n", reason);
581 printk("Dazed and confused, but trying to continue\n");
582 printk("Do you have a strange power saving mode enabled?\n");
583}
584
585asmlinkage void default_do_nmi(struct pt_regs *regs)
586{
587 unsigned char reason = 0;
588
589 /* Only the BSP gets external NMIs from the system. */
590 if (!smp_processor_id())
591 reason = get_nmi_reason();
592
593 if (!(reason & 0xc0)) {
594 if (notify_die(DIE_NMI_IPI, "nmi_ipi", regs, reason, 0, SIGINT)
595 == NOTIFY_STOP)
596 return;
597#ifdef CONFIG_X86_LOCAL_APIC
598 /*
599 * Ok, so this is none of the documented NMI sources,
600 * so it must be the NMI watchdog.
601 */
602 if (nmi_watchdog > 0) {
603 nmi_watchdog_tick(regs,reason);
604 return;
605 }
606#endif
607 unknown_nmi_error(reason, regs);
608 return;
609 }
610 if (notify_die(DIE_NMI, "nmi", regs, reason, 0, SIGINT) == NOTIFY_STOP)
611 return;
612
613 /* AK: following checks seem to be broken on modern chipsets. FIXME */
614
615 if (reason & 0x80)
616 mem_parity_error(reason, regs);
617 if (reason & 0x40)
618 io_check_error(reason, regs);
619}
620
621asmlinkage void do_int3(struct pt_regs * regs, long error_code)
622{
623 if (notify_die(DIE_INT3, "int3", regs, error_code, 3, SIGTRAP) == NOTIFY_STOP) {
624 return;
625 }
626 do_trap(3, SIGTRAP, "int3", regs, error_code, NULL);
627 return;
628}
629
630/* runs on IST stack. */
631asmlinkage void *do_debug(struct pt_regs * regs, unsigned long error_code)
632{
633 struct pt_regs *pr;
634 unsigned long condition;
635 struct task_struct *tsk = current;
636 siginfo_t info;
637
638 pr = (struct pt_regs *)(current->thread.rsp0)-1;
639 if (regs->cs & 3) {
640 memcpy(pr, regs, sizeof(struct pt_regs));
641 regs = pr;
642 }
643
644#ifdef CONFIG_CHECKING
645 {
646 /* RED-PEN interaction with debugger - could destroy gs */
647 unsigned long gs;
648 struct x8664_pda *pda = cpu_pda + safe_smp_processor_id();
649 rdmsrl(MSR_GS_BASE, gs);
650 if (gs != (unsigned long)pda) {
651 wrmsrl(MSR_GS_BASE, pda);
652 printk("debug handler: wrong gs %lx expected %p\n", gs, pda);
653 }
654 }
655#endif
656
657 asm("movq %%db6,%0" : "=r" (condition));
658
659 if (notify_die(DIE_DEBUG, "debug", regs, condition, error_code,
660 SIGTRAP) == NOTIFY_STOP) {
661 return regs;
662 }
663 conditional_sti(regs);
664
665 /* Mask out spurious debug traps due to lazy DR7 setting */
666 if (condition & (DR_TRAP0|DR_TRAP1|DR_TRAP2|DR_TRAP3)) {
667 if (!tsk->thread.debugreg7) {
668 goto clear_dr7;
669 }
670 }
671
672 tsk->thread.debugreg6 = condition;
673
674 /* Mask out spurious TF errors due to lazy TF clearing */
675 if ((condition & DR_STEP) &&
676 (notify_die(DIE_DEBUGSTEP, "debugstep", regs, condition,
677 1, SIGTRAP) != NOTIFY_STOP)) {
678 /*
679 * The TF error should be masked out only if the current
680 * process is not traced and if the TRAP flag has been set
681 * previously by a tracing process (condition detected by
682 * the PT_DTRACE flag); remember that the i386 TRAP flag
683 * can be modified by the process itself in user mode,
684 * allowing programs to debug themselves without the ptrace()
685 * interface.
686 */
687 if ((regs->cs & 3) == 0)
688 goto clear_TF_reenable;
689 if ((tsk->ptrace & (PT_DTRACE|PT_PTRACED)) == PT_DTRACE)
690 goto clear_TF;
691 }
692
693 /* Ok, finally something we can handle */
694 tsk->thread.trap_no = 1;
695 tsk->thread.error_code = error_code;
696 info.si_signo = SIGTRAP;
697 info.si_errno = 0;
698 info.si_code = TRAP_BRKPT;
699 if ((regs->cs & 3) == 0)
700 goto clear_dr7;
701
702 info.si_addr = (void __user *)regs->rip;
703 force_sig_info(SIGTRAP, &info, tsk);
704clear_dr7:
705 asm volatile("movq %0,%%db7"::"r"(0UL));
706 notify_die(DIE_DEBUG, "debug", regs, condition, 1, SIGTRAP);
707 return regs;
708
709clear_TF_reenable:
710 set_tsk_thread_flag(tsk, TIF_SINGLESTEP);
711
712clear_TF:
713 /* RED-PEN could cause spurious errors */
714 if (notify_die(DIE_DEBUG, "debug2", regs, condition, 1, SIGTRAP)
715 != NOTIFY_STOP)
716 regs->eflags &= ~TF_MASK;
717 return regs;
718}
719
720static int kernel_math_error(struct pt_regs *regs, char *str)
721{
722 const struct exception_table_entry *fixup;
723 fixup = search_exception_tables(regs->rip);
724 if (fixup) {
725 regs->rip = fixup->fixup;
726 return 1;
727 }
728 notify_die(DIE_GPF, str, regs, 0, 16, SIGFPE);
729#if 0
730 /* This should be a die, but warn only for now */
731 die(str, regs, 0);
732#else
733 printk(KERN_DEBUG "%s: %s at ", current->comm, str);
734 printk_address(regs->rip);
735 printk("\n");
736#endif
737 return 0;
738}
739
740/*
741 * Note that we play around with the 'TS' bit in an attempt to get
742 * the correct behaviour even in the presence of the asynchronous
743 * IRQ13 behaviour
744 */
745asmlinkage void do_coprocessor_error(struct pt_regs *regs)
746{
747 void __user *rip = (void __user *)(regs->rip);
748 struct task_struct * task;
749 siginfo_t info;
750 unsigned short cwd, swd;
751
752 conditional_sti(regs);
753 if ((regs->cs & 3) == 0 &&
754 kernel_math_error(regs, "kernel x87 math error"))
755 return;
756
757 /*
758 * Save the info for the exception handler and clear the error.
759 */
760 task = current;
761 save_init_fpu(task);
762 task->thread.trap_no = 16;
763 task->thread.error_code = 0;
764 info.si_signo = SIGFPE;
765 info.si_errno = 0;
766 info.si_code = __SI_FAULT;
767 info.si_addr = rip;
768 /*
769 * (~cwd & swd) will mask out exceptions that are not set to unmasked
770 * status. 0x3f is the exception bits in these regs, 0x200 is the
771 * C1 reg you need in case of a stack fault, 0x040 is the stack
772 * fault bit. We should only be taking one exception at a time,
773 * so if this combination doesn't produce any single exception,
774 * then we have a bad program that isn't synchronizing its FPU usage
775 * and it will suffer the consequences since we won't be able to
776 * fully reproduce the context of the exception
777 */
778 cwd = get_fpu_cwd(task);
779 swd = get_fpu_swd(task);
780 switch (((~cwd) & swd & 0x3f) | (swd & 0x240)) {
781 case 0x000:
782 default:
783 break;
784 case 0x001: /* Invalid Op */
785 case 0x041: /* Stack Fault */
786 case 0x241: /* Stack Fault | Direction */
787 info.si_code = FPE_FLTINV;
788 break;
789 case 0x002: /* Denormalize */
790 case 0x010: /* Underflow */
791 info.si_code = FPE_FLTUND;
792 break;
793 case 0x004: /* Zero Divide */
794 info.si_code = FPE_FLTDIV;
795 break;
796 case 0x008: /* Overflow */
797 info.si_code = FPE_FLTOVF;
798 break;
799 case 0x020: /* Precision */
800 info.si_code = FPE_FLTRES;
801 break;
802 }
803 force_sig_info(SIGFPE, &info, task);
804}
805
806asmlinkage void bad_intr(void)
807{
808 printk("bad interrupt");
809}
810
811asmlinkage void do_simd_coprocessor_error(struct pt_regs *regs)
812{
813 void __user *rip = (void __user *)(regs->rip);
814 struct task_struct * task;
815 siginfo_t info;
816 unsigned short mxcsr;
817
818 conditional_sti(regs);
819 if ((regs->cs & 3) == 0 &&
820 kernel_math_error(regs, "simd math error"))
821 return;
822
823 /*
824 * Save the info for the exception handler and clear the error.
825 */
826 task = current;
827 save_init_fpu(task);
828 task->thread.trap_no = 19;
829 task->thread.error_code = 0;
830 info.si_signo = SIGFPE;
831 info.si_errno = 0;
832 info.si_code = __SI_FAULT;
833 info.si_addr = rip;
834 /*
835 * The SIMD FPU exceptions are handled a little differently, as there
836 * is only a single status/control register. Thus, to determine which
837 * unmasked exception was caught we must mask the exception mask bits
838 * at 0x1f80, and then use these to mask the exception bits at 0x3f.
839 */
840 mxcsr = get_fpu_mxcsr(task);
841 switch (~((mxcsr & 0x1f80) >> 7) & (mxcsr & 0x3f)) {
842 case 0x000:
843 default:
844 break;
845 case 0x001: /* Invalid Op */
846 info.si_code = FPE_FLTINV;
847 break;
848 case 0x002: /* Denormalize */
849 case 0x010: /* Underflow */
850 info.si_code = FPE_FLTUND;
851 break;
852 case 0x004: /* Zero Divide */
853 info.si_code = FPE_FLTDIV;
854 break;
855 case 0x008: /* Overflow */
856 info.si_code = FPE_FLTOVF;
857 break;
858 case 0x020: /* Precision */
859 info.si_code = FPE_FLTRES;
860 break;
861 }
862 force_sig_info(SIGFPE, &info, task);
863}
864
865asmlinkage void do_spurious_interrupt_bug(struct pt_regs * regs)
866{
867}
868
869asmlinkage void __attribute__((weak)) smp_thermal_interrupt(void)
870{
871}
872
873/*
874 * 'math_state_restore()' saves the current math information in the
875 * old math state array, and gets the new ones from the current task
876 *
877 * Careful.. There are problems with IBM-designed IRQ13 behaviour.
878 * Don't touch unless you *really* know how it works.
879 */
880asmlinkage void math_state_restore(void)
881{
882 struct task_struct *me = current;
883 clts(); /* Allow maths ops (or we recurse) */
884
885 if (!used_math())
886 init_fpu(me);
887 restore_fpu_checking(&me->thread.i387.fxsave);
888 me->thread_info->status |= TS_USEDFPU;
889}
890
891void do_call_debug(struct pt_regs *regs)
892{
893 notify_die(DIE_CALL, "debug call", regs, 0, 255, SIGINT);
894}
895
896void __init trap_init(void)
897{
898 set_intr_gate(0,&divide_error);
899 set_intr_gate_ist(1,&debug,DEBUG_STACK);
900 set_intr_gate_ist(2,&nmi,NMI_STACK);
901 set_system_gate(3,&int3);
902 set_system_gate(4,&overflow); /* int4-5 can be called from all */
903 set_system_gate(5,&bounds);
904 set_intr_gate(6,&invalid_op);
905 set_intr_gate(7,&device_not_available);
906 set_intr_gate_ist(8,&double_fault, DOUBLEFAULT_STACK);
907 set_intr_gate(9,&coprocessor_segment_overrun);
908 set_intr_gate(10,&invalid_TSS);
909 set_intr_gate(11,&segment_not_present);
910 set_intr_gate_ist(12,&stack_segment,STACKFAULT_STACK);
911 set_intr_gate(13,&general_protection);
912 set_intr_gate(14,&page_fault);
913 set_intr_gate(15,&spurious_interrupt_bug);
914 set_intr_gate(16,&coprocessor_error);
915 set_intr_gate(17,&alignment_check);
916#ifdef CONFIG_X86_MCE
917 set_intr_gate_ist(18,&machine_check, MCE_STACK);
918#endif
919 set_intr_gate(19,&simd_coprocessor_error);
920
921#ifdef CONFIG_IA32_EMULATION
922 set_system_gate(IA32_SYSCALL_VECTOR, ia32_syscall);
923#endif
924
925 set_intr_gate(KDB_VECTOR, call_debug);
926
927 /*
928 * Should be a barrier for any external CPU state.
929 */
930 cpu_init();
931}
932
933
934/* Actual parsing is done early in setup.c. */
935static int __init oops_dummy(char *s)
936{
937 panic_on_oops = 1;
938 return -1;
939}
940__setup("oops=", oops_dummy);
941
942static int __init kstack_setup(char *s)
943{
944 kstack_depth_to_print = simple_strtoul(s,NULL,0);
945 return 0;
946}
947__setup("kstack=", kstack_setup);
948
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