2 * linux/arch/i386/traps.c
4 * Copyright (C) 1991, 1992 Linus Torvalds
6 * Pentium III FXSR, SSE support
7 * Gareth Hughes <gareth@valinux.com>, May 2000
11 * 'Traps.c' handles hardware traps and faults after we have saved some
14 #include <linux/config.h>
15 #include <linux/sched.h>
16 #include <linux/kernel.h>
17 #include <linux/string.h>
18 #include <linux/errno.h>
19 #include <linux/timer.h>
21 #include <linux/init.h>
22 #include <linux/delay.h>
23 #include <linux/spinlock.h>
24 #include <linux/interrupt.h>
25 #include <linux/highmem.h>
26 #include <linux/kallsyms.h>
27 #include <linux/ptrace.h>
28 #include <linux/utsname.h>
29 #include <linux/kprobes.h>
32 #include <linux/ioport.h>
33 #include <linux/eisa.h>
37 #include <linux/mca.h>
40 #include <asm/processor.h>
41 #include <asm/system.h>
42 #include <asm/uaccess.h>
44 #include <asm/atomic.h>
45 #include <asm/debugreg.h>
51 #include <asm/arch_hooks.h>
52 #include <asm/kdebug.h>
54 #include <linux/irq.h>
55 #include <linux/module.h>
57 #include "mach_traps.h"
59 asmlinkage int system_call(void);
61 struct desc_struct default_ldt[] = { { 0, 0 }, { 0, 0 }, { 0, 0 },
64 /* Do we ignore FPU interrupts ? */
65 char ignore_fpu_irq = 0;
68 * The IDT has to be page-aligned to simplify the Pentium
69 * F0 0F bug workaround.. We have a special link segment
72 struct desc_struct idt_table[256] __attribute__((__section__(".data.idt"))) = { {0, 0}, };
74 asmlinkage void divide_error(void);
75 asmlinkage void debug(void);
76 asmlinkage void nmi(void);
77 asmlinkage void int3(void);
78 asmlinkage void overflow(void);
79 asmlinkage void bounds(void);
80 asmlinkage void invalid_op(void);
81 asmlinkage void device_not_available(void);
82 asmlinkage void coprocessor_segment_overrun(void);
83 asmlinkage void invalid_TSS(void);
84 asmlinkage void segment_not_present(void);
85 asmlinkage void stack_segment(void);
86 asmlinkage void general_protection(void);
87 asmlinkage void page_fault(void);
88 asmlinkage void coprocessor_error(void);
89 asmlinkage void simd_coprocessor_error(void);
90 asmlinkage void alignment_check(void);
91 asmlinkage void spurious_interrupt_bug(void);
92 asmlinkage void machine_check(void);
94 static int kstack_depth_to_print = 24;
95 struct notifier_block *i386die_chain;
96 static spinlock_t die_notifier_lock = SPIN_LOCK_UNLOCKED;
98 int register_die_notifier(struct notifier_block *nb)
102 spin_lock_irqsave(&die_notifier_lock, flags);
103 err = notifier_chain_register(&i386die_chain, nb);
104 spin_unlock_irqrestore(&die_notifier_lock, flags);
108 static inline int valid_stack_ptr(struct thread_info *tinfo, void *p)
110 return p > (void *)tinfo &&
111 p < (void *)tinfo + THREAD_SIZE - 3;
114 static inline unsigned long print_context_stack(struct thread_info *tinfo,
115 unsigned long *stack, unsigned long ebp)
119 #ifdef CONFIG_FRAME_POINTER
120 while (valid_stack_ptr(tinfo, (void *)ebp)) {
121 addr = *(unsigned long *)(ebp + 4);
122 printk(" [<%08lx>] ", addr);
123 print_symbol("%s", addr);
125 ebp = *(unsigned long *)ebp;
128 while (valid_stack_ptr(tinfo, stack)) {
130 if (__kernel_text_address(addr)) {
131 printk(" [<%08lx>]", addr);
132 print_symbol(" %s", addr);
140 void show_trace(struct task_struct *task, unsigned long * stack)
147 if (task == current) {
148 /* Grab ebp right from our regs */
149 asm ("movl %%ebp, %0" : "=r" (ebp) : );
151 /* ebp is the last reg pushed by switch_to */
152 ebp = *(unsigned long *) task->thread.esp;
156 struct thread_info *context;
157 context = (struct thread_info *)
158 ((unsigned long)stack & (~(THREAD_SIZE - 1)));
159 ebp = print_context_stack(context, stack, ebp);
160 stack = (unsigned long*)context->previous_esp;
163 printk(" =======================\n");
167 void show_stack(struct task_struct *task, unsigned long *esp)
169 unsigned long *stack;
174 esp = (unsigned long*)task->thread.esp;
176 esp = (unsigned long *)&esp;
180 for(i = 0; i < kstack_depth_to_print; i++) {
181 if (kstack_end(stack))
183 if (i && ((i % 8) == 0))
185 printk("%08lx ", *stack++);
187 printk("\nCall Trace:\n");
188 show_trace(task, esp);
192 * The architecture-independent dump_stack generator
194 void dump_stack(void)
198 show_trace(current, &stack);
201 EXPORT_SYMBOL(dump_stack);
203 void show_registers(struct pt_regs *regs)
210 esp = (unsigned long) (®s->esp);
215 ss = regs->xss & 0xffff;
218 printk("CPU: %d\nEIP: %04x:[<%08lx>] %s VLI\nEFLAGS: %08lx"
220 smp_processor_id(), 0xffff & regs->xcs, regs->eip,
221 print_tainted(), regs->eflags, system_utsname.release);
222 print_symbol("EIP is at %s\n", regs->eip);
223 printk("eax: %08lx ebx: %08lx ecx: %08lx edx: %08lx\n",
224 regs->eax, regs->ebx, regs->ecx, regs->edx);
225 printk("esi: %08lx edi: %08lx ebp: %08lx esp: %08lx\n",
226 regs->esi, regs->edi, regs->ebp, esp);
227 printk("ds: %04x es: %04x ss: %04x\n",
228 regs->xds & 0xffff, regs->xes & 0xffff, ss);
229 printk("Process %s (pid: %d, threadinfo=%p task=%p)",
230 current->comm, current->pid, current_thread_info(), current);
232 * When in-kernel, we also print out the stack and code at the
233 * time of the fault..
239 show_stack(NULL, (unsigned long*)esp);
243 eip = (u8 *)regs->eip - 43;
244 for (i = 0; i < 64; i++, eip++) {
247 if (eip < (u8 *)PAGE_OFFSET || __get_user(c, eip)) {
248 printk(" Bad EIP value.");
251 if (eip == (u8 *)regs->eip)
252 printk("<%02x> ", c);
260 static void handle_BUG(struct pt_regs *regs)
269 goto no_bug; /* Not in kernel */
273 if (eip < PAGE_OFFSET)
275 if (__get_user(ud2, (unsigned short *)eip))
279 if (__get_user(line, (unsigned short *)(eip + 2)))
281 if (__get_user(file, (char **)(eip + 4)) ||
282 (unsigned long)file < PAGE_OFFSET || __get_user(c, file))
283 file = "<bad filename>";
285 printk("------------[ cut here ]------------\n");
286 printk(KERN_ALERT "kernel BUG at %s:%d!\n", file, line);
291 /* Here we know it was a BUG but file-n-line is unavailable */
293 printk("Kernel BUG\n");
296 void die(const char * str, struct pt_regs * regs, long err)
301 int lock_owner_depth;
303 .lock = SPIN_LOCK_UNLOCKED,
305 .lock_owner_depth = 0
307 static int die_counter;
309 if (die.lock_owner != smp_processor_id()) {
311 spin_lock_irq(&die.lock);
312 die.lock_owner = smp_processor_id();
313 die.lock_owner_depth = 0;
317 if (++die.lock_owner_depth < 3) {
320 printk(KERN_ALERT "%s: %04lx [#%d]\n", str, err & 0xffff, ++die_counter);
321 #ifdef CONFIG_PREEMPT
329 #ifdef CONFIG_DEBUG_PAGEALLOC
330 printk("DEBUG_PAGEALLOC");
335 notify_die(DIE_OOPS, (char *)str, regs, err, 255, SIGSEGV);
336 show_registers(regs);
339 printk(KERN_ERR "Recursive die() failure, output suppressed\n");
343 spin_unlock_irq(&die.lock);
345 panic("Fatal exception in interrupt");
350 printk(KERN_EMERG "Fatal exception: panic in 5 seconds\n");
351 set_current_state(TASK_UNINTERRUPTIBLE);
352 schedule_timeout(5 * HZ);
353 panic("Fatal exception");
358 static inline void die_if_kernel(const char * str, struct pt_regs * regs, long err)
360 if (!(regs->eflags & VM_MASK) && !(3 & regs->xcs))
364 static void do_trap(int trapnr, int signr, char *str, int vm86,
365 struct pt_regs * regs, long error_code, siginfo_t *info)
367 if (regs->eflags & VM_MASK) {
373 if (!(regs->xcs & 3))
377 struct task_struct *tsk = current;
378 tsk->thread.error_code = error_code;
379 tsk->thread.trap_no = trapnr;
381 force_sig_info(signr, info, tsk);
383 force_sig(signr, tsk);
388 if (!fixup_exception(regs))
389 die(str, regs, error_code);
394 int ret = handle_vm86_trap((struct kernel_vm86_regs *) regs, error_code, trapnr);
395 if (ret) goto trap_signal;
400 #define DO_ERROR(trapnr, signr, str, name) \
401 fastcall void do_##name(struct pt_regs * regs, long error_code) \
403 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
406 do_trap(trapnr, signr, str, 0, regs, error_code, NULL); \
409 #define DO_ERROR_INFO(trapnr, signr, str, name, sicode, siaddr) \
410 fastcall void do_##name(struct pt_regs * regs, long error_code) \
413 info.si_signo = signr; \
415 info.si_code = sicode; \
416 info.si_addr = (void __user *)siaddr; \
417 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
420 do_trap(trapnr, signr, str, 0, regs, error_code, &info); \
423 #define DO_VM86_ERROR(trapnr, signr, str, name) \
424 fastcall void do_##name(struct pt_regs * regs, long error_code) \
426 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
429 do_trap(trapnr, signr, str, 1, regs, error_code, NULL); \
432 #define DO_VM86_ERROR_INFO(trapnr, signr, str, name, sicode, siaddr) \
433 fastcall void do_##name(struct pt_regs * regs, long error_code) \
436 info.si_signo = signr; \
438 info.si_code = sicode; \
439 info.si_addr = (void __user *)siaddr; \
440 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
443 do_trap(trapnr, signr, str, 1, regs, error_code, &info); \
446 DO_VM86_ERROR_INFO( 0, SIGFPE, "divide error", divide_error, FPE_INTDIV, regs->eip)
447 #ifndef CONFIG_KPROBES
448 DO_VM86_ERROR( 3, SIGTRAP, "int3", int3)
450 DO_VM86_ERROR( 4, SIGSEGV, "overflow", overflow)
451 DO_VM86_ERROR( 5, SIGSEGV, "bounds", bounds)
452 DO_ERROR_INFO( 6, SIGILL, "invalid operand", invalid_op, ILL_ILLOPN, regs->eip)
453 DO_ERROR( 9, SIGFPE, "coprocessor segment overrun", coprocessor_segment_overrun)
454 DO_ERROR(10, SIGSEGV, "invalid TSS", invalid_TSS)
455 DO_ERROR(11, SIGBUS, "segment not present", segment_not_present)
456 DO_ERROR(12, SIGBUS, "stack segment", stack_segment)
457 DO_ERROR_INFO(17, SIGBUS, "alignment check", alignment_check, BUS_ADRALN, 0)
460 * the original non-exec stack patch was written by
461 * Solar Designer <solar at openwall.com>. Thanks!
463 fastcall void do_general_protection(struct pt_regs * regs, long error_code)
466 struct tss_struct *tss = &per_cpu(init_tss, cpu);
467 struct thread_struct *thread = ¤t->thread;
470 * Perform the lazy TSS's I/O bitmap copy. If the TSS has an
471 * invalid offset set (the LAZY one) and the faulting thread has
472 * a valid I/O bitmap pointer, we copy the I/O bitmap in the TSS
473 * and we set the offset field correctly. Then we let the CPU to
474 * restart the faulting instruction.
476 if (tss->io_bitmap_base == INVALID_IO_BITMAP_OFFSET_LAZY &&
477 thread->io_bitmap_ptr) {
478 memcpy(tss->io_bitmap, thread->io_bitmap_ptr,
479 thread->io_bitmap_max);
481 * If the previously set map was extending to higher ports
482 * than the current one, pad extra space with 0xff (no access).
484 if (thread->io_bitmap_max < tss->io_bitmap_max)
485 memset((char *) tss->io_bitmap +
486 thread->io_bitmap_max, 0xff,
487 tss->io_bitmap_max - thread->io_bitmap_max);
488 tss->io_bitmap_max = thread->io_bitmap_max;
489 tss->io_bitmap_base = IO_BITMAP_OFFSET;
495 if (regs->eflags & VM_MASK)
498 if (!(regs->xcs & 3))
502 * lazy-check for CS validity on exec-shield binaries:
505 int cpu = smp_processor_id();
506 struct desc_struct *desc1, *desc2;
507 struct vm_area_struct *vma;
508 unsigned long limit = 0;
510 spin_lock(¤t->mm->page_table_lock);
511 for (vma = current->mm->mmap; vma; vma = vma->vm_next)
512 if ((vma->vm_flags & VM_EXEC) && (vma->vm_end > limit))
514 spin_unlock(¤t->mm->page_table_lock);
516 current->mm->context.exec_limit = limit;
517 set_user_cs(¤t->mm->context.user_cs, limit);
519 desc1 = ¤t->mm->context.user_cs;
520 desc2 = per_cpu(cpu_gdt_table, cpu) + GDT_ENTRY_DEFAULT_USER_CS;
523 * The CS was not in sync - reload it and retry the
524 * instruction. If the instruction still faults then
525 * we wont hit this branch next time around.
527 if (desc1->a != desc2->a || desc1->b != desc2->b) {
528 if (print_fatal_signals >= 2) {
529 printk("#GPF fixup (%ld[seg:%lx]) at %08lx, CPU#%d.\n", error_code, error_code/8, regs->eip, smp_processor_id());
530 printk(" exec_limit: %08lx, user_cs: %08lx/%08lx, CPU_cs: %08lx/%08lx.\n", current->mm->context.exec_limit, desc1->a, desc1->b, desc2->a, desc2->b);
532 load_user_cs_desc(cpu, current->mm);
536 if (print_fatal_signals) {
537 printk("#GPF(%ld[seg:%lx]) at %08lx, CPU#%d.\n", error_code, error_code/8, regs->eip, smp_processor_id());
538 printk(" exec_limit: %08lx, user_cs: %08lx/%08lx.\n", current->mm->context.exec_limit, current->mm->context.user_cs.a, current->mm->context.user_cs.b);
541 current->thread.error_code = error_code;
542 current->thread.trap_no = 13;
543 force_sig(SIGSEGV, current);
548 handle_vm86_fault((struct kernel_vm86_regs *) regs, error_code);
552 if (!fixup_exception(regs)) {
553 if (notify_die(DIE_GPF, "general protection fault", regs,
554 error_code, 13, SIGSEGV) == NOTIFY_STOP)
556 die("general protection fault", regs, error_code);
560 static void mem_parity_error(unsigned char reason, struct pt_regs * regs)
562 printk("Uhhuh. NMI received. Dazed and confused, but trying to continue\n");
563 printk("You probably have a hardware problem with your RAM chips\n");
565 /* Clear and disable the memory parity error line. */
566 clear_mem_error(reason);
569 static void io_check_error(unsigned char reason, struct pt_regs * regs)
573 printk("NMI: IOCK error (debug interrupt?)\n");
574 show_registers(regs);
576 /* Re-enable the IOCK line, wait for a few seconds */
577 reason = (reason & 0xf) | 8;
580 while (--i) udelay(1000);
585 static void unknown_nmi_error(unsigned char reason, struct pt_regs * regs)
588 /* Might actually be able to figure out what the guilty party
595 printk("Uhhuh. NMI received for unknown reason %02x on CPU %d.\n",
596 reason, smp_processor_id());
597 printk("Dazed and confused, but trying to continue\n");
598 printk("Do you have a strange power saving mode enabled?\n");
601 static spinlock_t nmi_print_lock = SPIN_LOCK_UNLOCKED;
603 void die_nmi (struct pt_regs *regs, const char *msg)
605 spin_lock(&nmi_print_lock);
607 * We are in trouble anyway, lets at least try
608 * to get a message out.
612 printk(" on CPU%d, eip %08lx, registers:\n",
613 smp_processor_id(), regs->eip);
614 show_registers(regs);
615 printk("console shuts up ...\n");
617 spin_unlock(&nmi_print_lock);
622 static void default_do_nmi(struct pt_regs * regs)
624 unsigned char reason = 0;
626 /* Only the BSP gets external NMIs from the system. */
627 if (!smp_processor_id())
628 reason = get_nmi_reason();
630 if (!(reason & 0xc0)) {
631 if (notify_die(DIE_NMI_IPI, "nmi_ipi", regs, reason, 0, SIGINT)
634 #ifdef CONFIG_X86_LOCAL_APIC
636 * Ok, so this is none of the documented NMI sources,
637 * so it must be the NMI watchdog.
640 nmi_watchdog_tick(regs);
644 unknown_nmi_error(reason, regs);
647 if (notify_die(DIE_NMI, "nmi", regs, reason, 0, SIGINT) == NOTIFY_STOP)
650 mem_parity_error(reason, regs);
652 io_check_error(reason, regs);
654 * Reassert NMI in case it became active meanwhile
655 * as it's edge-triggered.
660 static int dummy_nmi_callback(struct pt_regs * regs, int cpu)
665 static nmi_callback_t nmi_callback = dummy_nmi_callback;
667 fastcall void do_nmi(struct pt_regs * regs, long error_code)
673 cpu = smp_processor_id();
676 if (!nmi_callback(regs, cpu))
677 default_do_nmi(regs);
682 void set_nmi_callback(nmi_callback_t callback)
684 nmi_callback = callback;
687 void unset_nmi_callback(void)
689 nmi_callback = dummy_nmi_callback;
692 #ifdef CONFIG_KPROBES
693 fastcall int do_int3(struct pt_regs *regs, long error_code)
695 if (notify_die(DIE_INT3, "int3", regs, error_code, 3, SIGTRAP)
698 /* This is an interrupt gate, because kprobes wants interrupts
699 disabled. Normal trap handlers don't. */
700 restore_interrupts(regs);
701 do_trap(3, SIGTRAP, "int3", 1, regs, error_code, NULL);
707 * Our handling of the processor debug registers is non-trivial.
708 * We do not clear them on entry and exit from the kernel. Therefore
709 * it is possible to get a watchpoint trap here from inside the kernel.
710 * However, the code in ./ptrace.c has ensured that the user can
711 * only set watchpoints on userspace addresses. Therefore the in-kernel
712 * watchpoint trap can only occur in code which is reading/writing
713 * from user space. Such code must not hold kernel locks (since it
714 * can equally take a page fault), therefore it is safe to call
715 * force_sig_info even though that claims and releases locks.
717 * Code in ./signal.c ensures that the debug control register
718 * is restored before we deliver any signal, and therefore that
719 * user code runs with the correct debug control register even though
722 * Being careful here means that we don't have to be as careful in a
723 * lot of more complicated places (task switching can be a bit lazy
724 * about restoring all the debug state, and ptrace doesn't have to
725 * find every occurrence of the TF bit that could be saved away even
728 fastcall void do_debug(struct pt_regs * regs, long error_code)
730 unsigned int condition;
731 struct task_struct *tsk = current;
734 __asm__ __volatile__("movl %%db6,%0" : "=r" (condition));
736 if (notify_die(DIE_DEBUG, "debug", regs, condition, error_code,
737 SIGTRAP) == NOTIFY_STOP)
739 /* It's safe to allow irq's after DR6 has been saved */
740 if (regs->eflags & X86_EFLAGS_IF)
743 /* Mask out spurious debug traps due to lazy DR7 setting */
744 if (condition & (DR_TRAP0|DR_TRAP1|DR_TRAP2|DR_TRAP3)) {
745 if (!tsk->thread.debugreg[7])
749 if (regs->eflags & VM_MASK)
752 /* Save debug status register where ptrace can see it */
753 tsk->thread.debugreg[6] = condition;
755 /* Mask out spurious TF errors due to lazy TF clearing */
756 if (condition & DR_STEP) {
758 * The TF error should be masked out only if the current
759 * process is not traced and if the TRAP flag has been set
760 * previously by a tracing process (condition detected by
761 * the PT_DTRACE flag); remember that the i386 TRAP flag
762 * can be modified by the process itself in user mode,
763 * allowing programs to debug themselves without the ptrace()
766 if ((regs->xcs & 3) == 0)
767 goto clear_TF_reenable;
768 if ((tsk->ptrace & (PT_DTRACE|PT_PTRACED)) == PT_DTRACE)
772 /* Ok, finally something we can handle */
773 tsk->thread.trap_no = 1;
774 tsk->thread.error_code = error_code;
775 info.si_signo = SIGTRAP;
777 info.si_code = TRAP_BRKPT;
779 /* If this is a kernel mode trap, save the user PC on entry to
780 * the kernel, that's what the debugger can make sense of.
782 info.si_addr = ((regs->xcs & 3) == 0) ? (void __user *)tsk->thread.eip
783 : (void __user *)regs->eip;
784 force_sig_info(SIGTRAP, &info, tsk);
786 /* Disable additional traps. They'll be re-enabled when
787 * the signal is delivered.
790 __asm__("movl %0,%%db7"
796 handle_vm86_trap((struct kernel_vm86_regs *) regs, error_code, 1);
800 set_tsk_thread_flag(tsk, TIF_SINGLESTEP);
802 regs->eflags &= ~TF_MASK;
807 * Note that we play around with the 'TS' bit in an attempt to get
808 * the correct behaviour even in the presence of the asynchronous
811 void math_error(void __user *eip)
813 struct task_struct * task;
815 unsigned short cwd, swd;
818 * Save the info for the exception handler and clear the error.
822 task->thread.trap_no = 16;
823 task->thread.error_code = 0;
824 info.si_signo = SIGFPE;
826 info.si_code = __SI_FAULT;
829 * (~cwd & swd) will mask out exceptions that are not set to unmasked
830 * status. 0x3f is the exception bits in these regs, 0x200 is the
831 * C1 reg you need in case of a stack fault, 0x040 is the stack
832 * fault bit. We should only be taking one exception at a time,
833 * so if this combination doesn't produce any single exception,
834 * then we have a bad program that isn't syncronizing its FPU usage
835 * and it will suffer the consequences since we won't be able to
836 * fully reproduce the context of the exception
838 cwd = get_fpu_cwd(task);
839 swd = get_fpu_swd(task);
840 switch (((~cwd) & swd & 0x3f) | (swd & 0x240)) {
844 case 0x001: /* Invalid Op */
845 case 0x041: /* Stack Fault */
846 case 0x241: /* Stack Fault | Direction */
847 info.si_code = FPE_FLTINV;
848 /* Should we clear the SF or let user space do it ???? */
850 case 0x002: /* Denormalize */
851 case 0x010: /* Underflow */
852 info.si_code = FPE_FLTUND;
854 case 0x004: /* Zero Divide */
855 info.si_code = FPE_FLTDIV;
857 case 0x008: /* Overflow */
858 info.si_code = FPE_FLTOVF;
860 case 0x020: /* Precision */
861 info.si_code = FPE_FLTRES;
864 force_sig_info(SIGFPE, &info, task);
867 fastcall void do_coprocessor_error(struct pt_regs * regs, long error_code)
870 math_error((void __user *)regs->eip);
873 void simd_math_error(void __user *eip)
875 struct task_struct * task;
877 unsigned short mxcsr;
880 * Save the info for the exception handler and clear the error.
884 task->thread.trap_no = 19;
885 task->thread.error_code = 0;
886 info.si_signo = SIGFPE;
888 info.si_code = __SI_FAULT;
891 * The SIMD FPU exceptions are handled a little differently, as there
892 * is only a single status/control register. Thus, to determine which
893 * unmasked exception was caught we must mask the exception mask bits
894 * at 0x1f80, and then use these to mask the exception bits at 0x3f.
896 mxcsr = get_fpu_mxcsr(task);
897 switch (~((mxcsr & 0x1f80) >> 7) & (mxcsr & 0x3f)) {
901 case 0x001: /* Invalid Op */
902 info.si_code = FPE_FLTINV;
904 case 0x002: /* Denormalize */
905 case 0x010: /* Underflow */
906 info.si_code = FPE_FLTUND;
908 case 0x004: /* Zero Divide */
909 info.si_code = FPE_FLTDIV;
911 case 0x008: /* Overflow */
912 info.si_code = FPE_FLTOVF;
914 case 0x020: /* Precision */
915 info.si_code = FPE_FLTRES;
918 force_sig_info(SIGFPE, &info, task);
921 fastcall void do_simd_coprocessor_error(struct pt_regs * regs,
925 /* Handle SIMD FPU exceptions on PIII+ processors. */
927 simd_math_error((void __user *)regs->eip);
930 * Handle strange cache flush from user space exception
931 * in all other cases. This is undocumented behaviour.
933 if (regs->eflags & VM_MASK) {
934 handle_vm86_fault((struct kernel_vm86_regs *)regs,
938 die_if_kernel("cache flush denied", regs, error_code);
939 current->thread.trap_no = 19;
940 current->thread.error_code = error_code;
941 force_sig(SIGSEGV, current);
945 fastcall void do_spurious_interrupt_bug(struct pt_regs * regs,
949 /* No need to warn about this any longer. */
950 printk("Ignoring P6 Local APIC Spurious Interrupt Bug...\n");
955 * 'math_state_restore()' saves the current math information in the
956 * old math state array, and gets the new ones from the current task
958 * Careful.. There are problems with IBM-designed IRQ13 behaviour.
959 * Don't touch unless you *really* know how it works.
961 * Must be called with kernel preemption disabled (in this case,
962 * local interrupts are disabled at the call-site in entry.S).
964 asmlinkage void math_state_restore(struct pt_regs regs)
966 struct thread_info *thread = current_thread_info();
967 struct task_struct *tsk = thread->task;
969 clts(); /* Allow maths ops (or we recurse) */
973 thread->status |= TS_USEDFPU; /* So we fnsave on switch_to() */
976 #ifndef CONFIG_MATH_EMULATION
978 asmlinkage void math_emulate(long arg)
980 printk("math-emulation not enabled and no coprocessor found.\n");
981 printk("killing %s.\n",current->comm);
982 force_sig(SIGFPE,current);
986 #endif /* CONFIG_MATH_EMULATION */
988 #ifdef CONFIG_X86_F00F_BUG
989 void __init trap_init_f00f_bug(void)
991 __set_fixmap(FIX_F00F_IDT, __pa(&idt_table), PAGE_KERNEL_RO);
994 * Update the IDT descriptor and reload the IDT so that
995 * it uses the read-only mapped virtual address.
997 idt_descr.address = fix_to_virt(FIX_F00F_IDT);
998 __asm__ __volatile__("lidt %0" : : "m" (idt_descr));
1002 #define _set_gate(gate_addr,type,dpl,addr,seg) \
1005 __asm__ __volatile__ ("movw %%dx,%%ax\n\t" \
1006 "movw %4,%%dx\n\t" \
1007 "movl %%eax,%0\n\t" \
1009 :"=m" (*((long *) (gate_addr))), \
1010 "=m" (*(1+(long *) (gate_addr))), "=&a" (__d0), "=&d" (__d1) \
1011 :"i" ((short) (0x8000+(dpl<<13)+(type<<8))), \
1012 "3" ((char *) (addr)),"2" ((seg) << 16)); \
1017 * This needs to use 'idt_table' rather than 'idt', and
1018 * thus use the _nonmapped_ version of the IDT, as the
1019 * Pentium F0 0F bugfix can have resulted in the mapped
1020 * IDT being write-protected.
1022 void set_intr_gate(unsigned int n, void *addr)
1024 _set_gate(idt_table+n,14,0,addr,__KERNEL_CS);
1028 * This routine sets up an interrupt gate at directory privilege level 3.
1030 static inline void set_system_intr_gate(unsigned int n, void *addr)
1032 _set_gate(idt_table+n, 14, 3, addr, __KERNEL_CS);
1035 static void __init set_trap_gate(unsigned int n, void *addr)
1037 _set_gate(idt_table+n,15,0,addr,__KERNEL_CS);
1040 static void __init set_system_gate(unsigned int n, void *addr)
1042 _set_gate(idt_table+n,15,3,addr,__KERNEL_CS);
1045 static void __init set_task_gate(unsigned int n, unsigned int gdt_entry)
1047 _set_gate(idt_table+n,5,0,0,(gdt_entry<<3));
1051 void __init trap_init(void)
1054 if (isa_readl(0x0FFFD9) == 'E'+('I'<<8)+('S'<<16)+('A'<<24)) {
1059 #ifdef CONFIG_X86_LOCAL_APIC
1060 init_apic_mappings();
1063 set_trap_gate(0,÷_error);
1064 set_intr_gate(1,&debug);
1065 set_intr_gate(2,&nmi);
1066 set_system_intr_gate(3, &int3); /* int3-5 can be called from all */
1067 set_system_gate(4,&overflow);
1068 set_system_gate(5,&bounds);
1069 set_trap_gate(6,&invalid_op);
1070 set_trap_gate(7,&device_not_available);
1071 set_task_gate(8,GDT_ENTRY_DOUBLEFAULT_TSS);
1072 set_trap_gate(9,&coprocessor_segment_overrun);
1073 set_trap_gate(10,&invalid_TSS);
1074 set_trap_gate(11,&segment_not_present);
1075 set_trap_gate(12,&stack_segment);
1076 set_trap_gate(13,&general_protection);
1077 set_intr_gate(14,&page_fault);
1078 set_trap_gate(15,&spurious_interrupt_bug);
1079 set_trap_gate(16,&coprocessor_error);
1080 set_trap_gate(17,&alignment_check);
1081 #ifdef CONFIG_X86_MCE
1082 set_trap_gate(18,&machine_check);
1084 set_trap_gate(19,&simd_coprocessor_error);
1086 set_system_gate(SYSCALL_VECTOR,&system_call);
1089 * Should be a barrier for any external CPU state.