2 * linux/arch/x86-64/traps.c
4 * Copyright (C) 1991, 1992 Linus Torvalds
5 * Copyright (C) 2000, 2001, 2002 Andi Kleen, SuSE Labs
7 * Pentium III FXSR, SSE support
8 * Gareth Hughes <gareth@valinux.com>, May 2000
12 * 'Traps.c' handles hardware traps and faults after we have saved some
15 #include <linux/config.h>
16 #include <linux/sched.h>
17 #include <linux/kernel.h>
18 #include <linux/string.h>
19 #include <linux/errno.h>
20 #include <linux/ptrace.h>
21 #include <linux/timer.h>
23 #include <linux/init.h>
24 #include <linux/delay.h>
25 #include <linux/spinlock.h>
26 #include <linux/interrupt.h>
27 #include <linux/module.h>
28 #include <linux/moduleparam.h>
29 #include <linux/nmi.h>
30 #include <linux/kprobes.h>
31 #include <linux/kexec.h>
32 #include <linux/unwind.h>
34 #include <asm/system.h>
35 #include <asm/uaccess.h>
37 #include <asm/atomic.h>
38 #include <asm/debugreg.h>
41 #include <asm/kdebug.h>
42 #include <asm/processor.h>
43 #include <asm/unwind.h>
45 #include <asm/pgalloc.h>
47 #include <asm/proto.h>
50 asmlinkage void divide_error(void);
51 asmlinkage void debug(void);
52 asmlinkage void nmi(void);
53 asmlinkage void int3(void);
54 asmlinkage void overflow(void);
55 asmlinkage void bounds(void);
56 asmlinkage void invalid_op(void);
57 asmlinkage void device_not_available(void);
58 asmlinkage void double_fault(void);
59 asmlinkage void coprocessor_segment_overrun(void);
60 asmlinkage void invalid_TSS(void);
61 asmlinkage void segment_not_present(void);
62 asmlinkage void stack_segment(void);
63 asmlinkage void general_protection(void);
64 asmlinkage void page_fault(void);
65 asmlinkage void coprocessor_error(void);
66 asmlinkage void simd_coprocessor_error(void);
67 asmlinkage void reserved(void);
68 asmlinkage void alignment_check(void);
69 asmlinkage void machine_check(void);
70 asmlinkage void spurious_interrupt_bug(void);
72 ATOMIC_NOTIFIER_HEAD(die_chain);
74 int register_die_notifier(struct notifier_block *nb)
77 return atomic_notifier_chain_register(&die_chain, nb);
79 EXPORT_SYMBOL(register_die_notifier);
81 int unregister_die_notifier(struct notifier_block *nb)
83 return atomic_notifier_chain_unregister(&die_chain, nb);
85 EXPORT_SYMBOL(unregister_die_notifier);
87 static inline void conditional_sti(struct pt_regs *regs)
89 if (regs->eflags & X86_EFLAGS_IF)
93 static inline void preempt_conditional_sti(struct pt_regs *regs)
96 if (regs->eflags & X86_EFLAGS_IF)
100 static inline void preempt_conditional_cli(struct pt_regs *regs)
102 if (regs->eflags & X86_EFLAGS_IF)
104 /* Make sure to not schedule here because we could be running
105 on an exception stack. */
106 preempt_enable_no_resched();
109 static int kstack_depth_to_print = 10;
111 #ifdef CONFIG_KALLSYMS
112 #include <linux/kallsyms.h>
113 int printk_address(unsigned long address)
115 unsigned long offset = 0, symsize;
121 symname = kallsyms_lookup(address, &symsize, &offset, &modname, namebuf);
123 return printk("[<%016lx>]", address);
125 modname = delim = "";
126 return printk("<%016lx>{%s%s%s%s%+ld}",
127 address, delim, modname, delim, symname, offset);
130 int printk_address(unsigned long address)
132 return printk("[<%016lx>]", address);
136 static unsigned long *in_exception_stack(unsigned cpu, unsigned long stack,
137 unsigned *usedp, const char **idp)
139 static char ids[][8] = {
140 [DEBUG_STACK - 1] = "#DB",
141 [NMI_STACK - 1] = "NMI",
142 [DOUBLEFAULT_STACK - 1] = "#DF",
143 [STACKFAULT_STACK - 1] = "#SS",
144 [MCE_STACK - 1] = "#MC",
145 #if DEBUG_STKSZ > EXCEPTION_STKSZ
146 [N_EXCEPTION_STACKS ... N_EXCEPTION_STACKS + DEBUG_STKSZ / EXCEPTION_STKSZ - 2] = "#DB[?]"
151 for (k = 0; k < N_EXCEPTION_STACKS; k++) {
155 #if DEBUG_STKSZ > EXCEPTION_STKSZ
157 end = cpu_pda(cpu)->debugstack + DEBUG_STKSZ;
161 end = per_cpu(init_tss, cpu).ist[k];
166 if (stack >= end - EXCEPTION_STKSZ) {
167 if (*usedp & (1U << k))
171 return (unsigned long *)end;
173 #if DEBUG_STKSZ > EXCEPTION_STKSZ
174 if (k == DEBUG_STACK - 1 && stack >= end - DEBUG_STKSZ) {
175 unsigned j = N_EXCEPTION_STACKS - 1;
179 end -= EXCEPTION_STKSZ;
180 ids[j][4] = '1' + (j - N_EXCEPTION_STACKS);
181 } while (stack < end - EXCEPTION_STKSZ);
182 if (*usedp & (1U << j))
186 return (unsigned long *)end;
193 static void show_trace_unwind(struct unwind_frame_info *info, void *context)
197 while (unwind(info) == 0 && UNW_PC(info)) {
203 i += printk_address(UNW_PC(info));
204 if (arch_unw_user_mode(info))
211 * x86-64 can have upto three kernel stacks:
214 * severe exception (double fault, nmi, stack fault, debug, mce) hardware stack
217 void show_trace(struct task_struct *tsk, struct pt_regs *regs, unsigned long * stack)
219 const unsigned cpu = safe_smp_processor_id();
220 unsigned long *irqstack_end = (unsigned long *)cpu_pda(cpu)->irqstackptr;
223 struct unwind_frame_info info;
225 printk("\nCall Trace:");
231 if (unwind_init_frame_info(&info, tsk, regs) == 0) {
232 show_trace_unwind(&info, NULL);
235 } else if (tsk == current) {
236 if (unwind_init_running(&info, show_trace_unwind, NULL) == 0)
239 if (unwind_init_blocked(&info, tsk) == 0) {
240 show_trace_unwind(&info, NULL);
245 #define HANDLE_STACK(cond) \
247 unsigned long addr = *stack++; \
248 if (kernel_text_address(addr)) { \
256 * If the address is either in the text segment of the \
257 * kernel, or in the region which contains vmalloc'ed \
258 * memory, it *may* be the address of a calling \
259 * routine; if so, print it so that someone tracing \
260 * down the cause of the crash will be able to figure \
261 * out the call path that was taken. \
263 i += printk_address(addr); \
269 unsigned long *estack_end;
270 estack_end = in_exception_stack(cpu, (unsigned long)stack,
274 i += printk(" <%s>", id);
275 HANDLE_STACK (stack < estack_end);
276 i += printk(" <EOE>");
277 stack = (unsigned long *) estack_end[-2];
281 unsigned long *irqstack;
282 irqstack = irqstack_end -
283 (IRQSTACKSIZE - 64) / sizeof(*irqstack);
285 if (stack >= irqstack && stack < irqstack_end) {
286 i += printk(" <IRQ>");
287 HANDLE_STACK (stack < irqstack_end);
288 stack = (unsigned long *) (irqstack_end[-1]);
290 i += printk(" <EOI>");
297 HANDLE_STACK (((long) stack & (THREAD_SIZE-1)) != 0);
302 static void _show_stack(struct task_struct *tsk, struct pt_regs *regs, unsigned long * rsp)
304 unsigned long *stack;
306 const int cpu = safe_smp_processor_id();
307 unsigned long *irqstack_end = (unsigned long *) (cpu_pda(cpu)->irqstackptr);
308 unsigned long *irqstack = (unsigned long *) (cpu_pda(cpu)->irqstackptr - IRQSTACKSIZE);
310 // debugging aid: "show_stack(NULL, NULL);" prints the
311 // back trace for this cpu.
315 rsp = (unsigned long *)tsk->thread.rsp;
317 rsp = (unsigned long *)&rsp;
321 for(i=0; i < kstack_depth_to_print; i++) {
322 if (stack >= irqstack && stack <= irqstack_end) {
323 if (stack == irqstack_end) {
324 stack = (unsigned long *) (irqstack_end[-1]);
328 if (((long) stack & (THREAD_SIZE-1)) == 0)
331 if (i && ((i % 4) == 0))
333 printk("%016lx ", *stack++);
334 touch_nmi_watchdog();
336 show_trace(tsk, regs, rsp);
339 void show_stack(struct task_struct *tsk, unsigned long * rsp)
341 _show_stack(tsk, NULL, rsp);
345 * The architecture-independent dump_stack generator
347 void dump_stack(void)
350 show_trace(NULL, NULL, &dummy);
353 EXPORT_SYMBOL(dump_stack);
355 void show_registers(struct pt_regs *regs)
358 int in_kernel = !user_mode(regs);
360 const int cpu = safe_smp_processor_id();
361 struct task_struct *cur = cpu_pda(cpu)->pcurrent;
365 printk("CPU %d ", cpu);
367 printk("Process %s (pid: %d, threadinfo %p, task %p)\n",
368 cur->comm, cur->pid, task_thread_info(cur), cur);
371 * When in-kernel, we also print out the stack and code at the
372 * time of the fault..
377 _show_stack(NULL, regs, (unsigned long*)rsp);
380 if (regs->rip < PAGE_OFFSET)
383 for (i=0; i<20; i++) {
385 if (__get_user(c, &((unsigned char*)regs->rip)[i])) {
387 printk(" Bad RIP value.");
396 void handle_BUG(struct pt_regs *regs)
400 const char *prefix = "";
404 if (__copy_from_user(&f, (const void __user *) regs->rip,
405 sizeof(struct bug_frame)))
407 if (f.filename >= 0 ||
408 f.ud2[0] != 0x0f || f.ud2[1] != 0x0b)
410 len = __strnlen_user((char *)(long)f.filename, PATH_MAX) - 1;
411 if (len < 0 || len >= PATH_MAX)
412 f.filename = (int)(long)"unmapped filename";
414 f.filename += len - 50;
417 printk("----------- [cut here ] --------- [please bite here ] ---------\n");
418 printk(KERN_ALERT "Kernel BUG at %s%.50s:%d\n", prefix, (char *)(long)f.filename, f.line);
422 void out_of_line_bug(void)
428 static DEFINE_SPINLOCK(die_lock);
429 static int die_owner = -1;
430 static unsigned int die_nest_count;
432 unsigned __kprobes long oops_begin(void)
434 int cpu = safe_smp_processor_id();
437 /* racy, but better than risking deadlock. */
438 local_irq_save(flags);
439 if (!spin_trylock(&die_lock)) {
440 if (cpu == die_owner)
441 /* nested oops. should stop eventually */;
443 spin_lock(&die_lock);
452 void __kprobes oops_end(unsigned long flags)
458 /* We still own the lock */
459 local_irq_restore(flags);
461 /* Nest count reaches zero, release the lock. */
462 spin_unlock_irqrestore(&die_lock, flags);
467 void __kprobes __die(const char * str, struct pt_regs * regs, long err)
469 static int die_counter;
470 printk(KERN_EMERG "%s: %04lx [%u] ", str, err & 0xffff,++die_counter);
471 #ifdef CONFIG_PREEMPT
477 #ifdef CONFIG_DEBUG_PAGEALLOC
478 printk("DEBUG_PAGEALLOC");
481 notify_die(DIE_OOPS, str, regs, err, current->thread.trap_no, SIGSEGV);
482 show_registers(regs);
483 /* Executive summary in case the oops scrolled away */
484 printk(KERN_ALERT "RIP ");
485 printk_address(regs->rip);
486 printk(" RSP <%016lx>\n", regs->rsp);
487 if (kexec_should_crash(current))
491 void die(const char * str, struct pt_regs * regs, long err)
493 unsigned long flags = oops_begin();
496 __die(str, regs, err);
501 void __kprobes die_nmi(char *str, struct pt_regs *regs)
503 unsigned long flags = oops_begin();
506 * We are in trouble anyway, lets at least try
507 * to get a message out.
509 printk(str, safe_smp_processor_id());
510 show_registers(regs);
511 if (kexec_should_crash(current))
513 if (panic_on_timeout || panic_on_oops)
514 panic("nmi watchdog");
515 printk("console shuts up ...\n");
522 static void __kprobes do_trap(int trapnr, int signr, char *str,
523 struct pt_regs * regs, long error_code,
526 struct task_struct *tsk = current;
528 tsk->thread.error_code = error_code;
529 tsk->thread.trap_no = trapnr;
531 if (user_mode(regs)) {
532 if (exception_trace && unhandled_signal(tsk, signr))
534 "%s[%d] trap %s rip:%lx rsp:%lx error:%lx\n",
535 tsk->comm, tsk->pid, str,
536 regs->rip, regs->rsp, error_code);
539 force_sig_info(signr, info, tsk);
541 force_sig(signr, tsk);
548 const struct exception_table_entry *fixup;
549 fixup = search_exception_tables(regs->rip);
551 regs->rip = fixup->fixup;
553 die(str, regs, error_code);
558 #define DO_ERROR(trapnr, signr, str, name) \
559 asmlinkage void do_##name(struct pt_regs * regs, long error_code) \
561 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
564 conditional_sti(regs); \
565 do_trap(trapnr, signr, str, regs, error_code, NULL); \
568 #define DO_ERROR_INFO(trapnr, signr, str, name, sicode, siaddr) \
569 asmlinkage void do_##name(struct pt_regs * regs, long error_code) \
572 info.si_signo = signr; \
574 info.si_code = sicode; \
575 info.si_addr = (void __user *)siaddr; \
576 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
579 conditional_sti(regs); \
580 do_trap(trapnr, signr, str, regs, error_code, &info); \
583 DO_ERROR_INFO( 0, SIGFPE, "divide error", divide_error, FPE_INTDIV, regs->rip)
584 DO_ERROR( 4, SIGSEGV, "overflow", overflow)
585 DO_ERROR( 5, SIGSEGV, "bounds", bounds)
586 DO_ERROR_INFO( 6, SIGILL, "invalid opcode", invalid_op, ILL_ILLOPN, regs->rip)
587 DO_ERROR( 7, SIGSEGV, "device not available", device_not_available)
588 DO_ERROR( 9, SIGFPE, "coprocessor segment overrun", coprocessor_segment_overrun)
589 DO_ERROR(10, SIGSEGV, "invalid TSS", invalid_TSS)
590 DO_ERROR(11, SIGBUS, "segment not present", segment_not_present)
591 DO_ERROR_INFO(17, SIGBUS, "alignment check", alignment_check, BUS_ADRALN, 0)
592 DO_ERROR(18, SIGSEGV, "reserved", reserved)
594 /* Runs on IST stack */
595 asmlinkage void do_stack_segment(struct pt_regs *regs, long error_code)
597 if (notify_die(DIE_TRAP, "stack segment", regs, error_code,
598 12, SIGBUS) == NOTIFY_STOP)
600 preempt_conditional_sti(regs);
601 do_trap(12, SIGBUS, "stack segment", regs, error_code, NULL);
602 preempt_conditional_cli(regs);
605 asmlinkage void do_double_fault(struct pt_regs * regs, long error_code)
607 static const char str[] = "double fault";
608 struct task_struct *tsk = current;
610 /* Return not checked because double check cannot be ignored */
611 notify_die(DIE_TRAP, str, regs, error_code, 8, SIGSEGV);
613 tsk->thread.error_code = error_code;
614 tsk->thread.trap_no = 8;
616 /* This is always a kernel trap and never fixable (and thus must
619 die(str, regs, error_code);
622 asmlinkage void __kprobes do_general_protection(struct pt_regs * regs,
625 struct task_struct *tsk = current;
627 conditional_sti(regs);
629 tsk->thread.error_code = error_code;
630 tsk->thread.trap_no = 13;
632 if (user_mode(regs)) {
633 if (exception_trace && unhandled_signal(tsk, SIGSEGV))
635 "%s[%d] general protection rip:%lx rsp:%lx error:%lx\n",
637 regs->rip, regs->rsp, error_code);
639 force_sig(SIGSEGV, tsk);
645 const struct exception_table_entry *fixup;
646 fixup = search_exception_tables(regs->rip);
648 regs->rip = fixup->fixup;
651 if (notify_die(DIE_GPF, "general protection fault", regs,
652 error_code, 13, SIGSEGV) == NOTIFY_STOP)
654 die("general protection fault", regs, error_code);
658 static __kprobes void
659 mem_parity_error(unsigned char reason, struct pt_regs * regs)
661 printk("Uhhuh. NMI received. Dazed and confused, but trying to continue\n");
662 printk("You probably have a hardware problem with your RAM chips\n");
664 /* Clear and disable the memory parity error line. */
665 reason = (reason & 0xf) | 4;
669 static __kprobes void
670 io_check_error(unsigned char reason, struct pt_regs * regs)
672 printk("NMI: IOCK error (debug interrupt?)\n");
673 show_registers(regs);
675 /* Re-enable the IOCK line, wait for a few seconds */
676 reason = (reason & 0xf) | 8;
683 static __kprobes void
684 unknown_nmi_error(unsigned char reason, struct pt_regs * regs)
685 { printk("Uhhuh. NMI received for unknown reason %02x.\n", reason);
686 printk("Dazed and confused, but trying to continue\n");
687 printk("Do you have a strange power saving mode enabled?\n");
690 /* Runs on IST stack. This code must keep interrupts off all the time.
691 Nested NMIs are prevented by the CPU. */
692 asmlinkage __kprobes void default_do_nmi(struct pt_regs *regs)
694 unsigned char reason = 0;
697 cpu = smp_processor_id();
699 /* Only the BSP gets external NMIs from the system. */
701 reason = get_nmi_reason();
703 if (!(reason & 0xc0)) {
704 if (notify_die(DIE_NMI_IPI, "nmi_ipi", regs, reason, 2, SIGINT)
707 #ifdef CONFIG_X86_LOCAL_APIC
709 * Ok, so this is none of the documented NMI sources,
710 * so it must be the NMI watchdog.
712 if (nmi_watchdog > 0) {
713 nmi_watchdog_tick(regs,reason);
717 unknown_nmi_error(reason, regs);
720 if (notify_die(DIE_NMI, "nmi", regs, reason, 2, SIGINT) == NOTIFY_STOP)
723 /* AK: following checks seem to be broken on modern chipsets. FIXME */
726 mem_parity_error(reason, regs);
728 io_check_error(reason, regs);
731 /* runs on IST stack. */
732 asmlinkage void __kprobes do_int3(struct pt_regs * regs, long error_code)
734 if (notify_die(DIE_INT3, "int3", regs, error_code, 3, SIGTRAP) == NOTIFY_STOP) {
737 preempt_conditional_sti(regs);
738 do_trap(3, SIGTRAP, "int3", regs, error_code, NULL);
739 preempt_conditional_cli(regs);
742 /* Help handler running on IST stack to switch back to user stack
743 for scheduling or signal handling. The actual stack switch is done in
745 asmlinkage __kprobes struct pt_regs *sync_regs(struct pt_regs *eregs)
747 struct pt_regs *regs = eregs;
748 /* Did already sync */
749 if (eregs == (struct pt_regs *)eregs->rsp)
751 /* Exception from user space */
752 else if (user_mode(eregs))
753 regs = task_pt_regs(current);
754 /* Exception from kernel and interrupts are enabled. Move to
755 kernel process stack. */
756 else if (eregs->eflags & X86_EFLAGS_IF)
757 regs = (struct pt_regs *)(eregs->rsp -= sizeof(struct pt_regs));
763 /* runs on IST stack. */
764 asmlinkage void __kprobes do_debug(struct pt_regs * regs,
765 unsigned long error_code)
767 unsigned long condition;
768 struct task_struct *tsk = current;
771 get_debugreg(condition, 6);
773 if (notify_die(DIE_DEBUG, "debug", regs, condition, error_code,
774 SIGTRAP) == NOTIFY_STOP)
777 preempt_conditional_sti(regs);
779 /* Mask out spurious debug traps due to lazy DR7 setting */
780 if (condition & (DR_TRAP0|DR_TRAP1|DR_TRAP2|DR_TRAP3)) {
781 if (!tsk->thread.debugreg7) {
786 tsk->thread.debugreg6 = condition;
788 /* Mask out spurious TF errors due to lazy TF clearing */
789 if (condition & DR_STEP) {
791 * The TF error should be masked out only if the current
792 * process is not traced and if the TRAP flag has been set
793 * previously by a tracing process (condition detected by
794 * the PT_DTRACE flag); remember that the i386 TRAP flag
795 * can be modified by the process itself in user mode,
796 * allowing programs to debug themselves without the ptrace()
799 if (!user_mode(regs))
800 goto clear_TF_reenable;
802 * Was the TF flag set by a debugger? If so, clear it now,
803 * so that register information is correct.
805 if (tsk->ptrace & PT_DTRACE) {
806 regs->eflags &= ~TF_MASK;
807 tsk->ptrace &= ~PT_DTRACE;
811 /* Ok, finally something we can handle */
812 tsk->thread.trap_no = 1;
813 tsk->thread.error_code = error_code;
814 info.si_signo = SIGTRAP;
816 info.si_code = TRAP_BRKPT;
817 info.si_addr = user_mode(regs) ? (void __user *)regs->rip : NULL;
818 force_sig_info(SIGTRAP, &info, tsk);
821 set_debugreg(0UL, 7);
822 preempt_conditional_cli(regs);
826 set_tsk_thread_flag(tsk, TIF_SINGLESTEP);
827 regs->eflags &= ~TF_MASK;
828 preempt_conditional_cli(regs);
831 static int kernel_math_error(struct pt_regs *regs, const char *str, int trapnr)
833 const struct exception_table_entry *fixup;
834 fixup = search_exception_tables(regs->rip);
836 regs->rip = fixup->fixup;
839 notify_die(DIE_GPF, str, regs, 0, trapnr, SIGFPE);
840 /* Illegal floating point operation in the kernel */
841 current->thread.trap_no = trapnr;
847 * Note that we play around with the 'TS' bit in an attempt to get
848 * the correct behaviour even in the presence of the asynchronous
851 asmlinkage void do_coprocessor_error(struct pt_regs *regs)
853 void __user *rip = (void __user *)(regs->rip);
854 struct task_struct * task;
856 unsigned short cwd, swd;
858 conditional_sti(regs);
859 if (!user_mode(regs) &&
860 kernel_math_error(regs, "kernel x87 math error", 16))
864 * Save the info for the exception handler and clear the error.
868 task->thread.trap_no = 16;
869 task->thread.error_code = 0;
870 info.si_signo = SIGFPE;
872 info.si_code = __SI_FAULT;
875 * (~cwd & swd) will mask out exceptions that are not set to unmasked
876 * status. 0x3f is the exception bits in these regs, 0x200 is the
877 * C1 reg you need in case of a stack fault, 0x040 is the stack
878 * fault bit. We should only be taking one exception at a time,
879 * so if this combination doesn't produce any single exception,
880 * then we have a bad program that isn't synchronizing its FPU usage
881 * and it will suffer the consequences since we won't be able to
882 * fully reproduce the context of the exception
884 cwd = get_fpu_cwd(task);
885 swd = get_fpu_swd(task);
886 switch (swd & ~cwd & 0x3f) {
890 case 0x001: /* Invalid Op */
892 * swd & 0x240 == 0x040: Stack Underflow
893 * swd & 0x240 == 0x240: Stack Overflow
894 * User must clear the SF bit (0x40) if set
896 info.si_code = FPE_FLTINV;
898 case 0x002: /* Denormalize */
899 case 0x010: /* Underflow */
900 info.si_code = FPE_FLTUND;
902 case 0x004: /* Zero Divide */
903 info.si_code = FPE_FLTDIV;
905 case 0x008: /* Overflow */
906 info.si_code = FPE_FLTOVF;
908 case 0x020: /* Precision */
909 info.si_code = FPE_FLTRES;
912 force_sig_info(SIGFPE, &info, task);
915 asmlinkage void bad_intr(void)
917 printk("bad interrupt");
920 asmlinkage void do_simd_coprocessor_error(struct pt_regs *regs)
922 void __user *rip = (void __user *)(regs->rip);
923 struct task_struct * task;
925 unsigned short mxcsr;
927 conditional_sti(regs);
928 if (!user_mode(regs) &&
929 kernel_math_error(regs, "kernel simd math error", 19))
933 * Save the info for the exception handler and clear the error.
937 task->thread.trap_no = 19;
938 task->thread.error_code = 0;
939 info.si_signo = SIGFPE;
941 info.si_code = __SI_FAULT;
944 * The SIMD FPU exceptions are handled a little differently, as there
945 * is only a single status/control register. Thus, to determine which
946 * unmasked exception was caught we must mask the exception mask bits
947 * at 0x1f80, and then use these to mask the exception bits at 0x3f.
949 mxcsr = get_fpu_mxcsr(task);
950 switch (~((mxcsr & 0x1f80) >> 7) & (mxcsr & 0x3f)) {
954 case 0x001: /* Invalid Op */
955 info.si_code = FPE_FLTINV;
957 case 0x002: /* Denormalize */
958 case 0x010: /* Underflow */
959 info.si_code = FPE_FLTUND;
961 case 0x004: /* Zero Divide */
962 info.si_code = FPE_FLTDIV;
964 case 0x008: /* Overflow */
965 info.si_code = FPE_FLTOVF;
967 case 0x020: /* Precision */
968 info.si_code = FPE_FLTRES;
971 force_sig_info(SIGFPE, &info, task);
974 asmlinkage void do_spurious_interrupt_bug(struct pt_regs * regs)
978 asmlinkage void __attribute__((weak)) smp_thermal_interrupt(void)
982 asmlinkage void __attribute__((weak)) mce_threshold_interrupt(void)
987 * 'math_state_restore()' saves the current math information in the
988 * old math state array, and gets the new ones from the current task
990 * Careful.. There are problems with IBM-designed IRQ13 behaviour.
991 * Don't touch unless you *really* know how it works.
993 asmlinkage void math_state_restore(void)
995 struct task_struct *me = current;
996 clts(); /* Allow maths ops (or we recurse) */
1000 restore_fpu_checking(&me->thread.i387.fxsave);
1001 task_thread_info(me)->status |= TS_USEDFPU;
1004 void __init trap_init(void)
1006 set_intr_gate(0,÷_error);
1007 set_intr_gate_ist(1,&debug,DEBUG_STACK);
1008 set_intr_gate_ist(2,&nmi,NMI_STACK);
1009 set_system_gate_ist(3,&int3,DEBUG_STACK); /* int3 can be called from all */
1010 set_system_gate(4,&overflow); /* int4 can be called from all */
1011 set_intr_gate(5,&bounds);
1012 set_intr_gate(6,&invalid_op);
1013 set_intr_gate(7,&device_not_available);
1014 set_intr_gate_ist(8,&double_fault, DOUBLEFAULT_STACK);
1015 set_intr_gate(9,&coprocessor_segment_overrun);
1016 set_intr_gate(10,&invalid_TSS);
1017 set_intr_gate(11,&segment_not_present);
1018 set_intr_gate_ist(12,&stack_segment,STACKFAULT_STACK);
1019 set_intr_gate(13,&general_protection);
1020 set_intr_gate(14,&page_fault);
1021 set_intr_gate(15,&spurious_interrupt_bug);
1022 set_intr_gate(16,&coprocessor_error);
1023 set_intr_gate(17,&alignment_check);
1024 #ifdef CONFIG_X86_MCE
1025 set_intr_gate_ist(18,&machine_check, MCE_STACK);
1027 set_intr_gate(19,&simd_coprocessor_error);
1029 #ifdef CONFIG_IA32_EMULATION
1030 set_system_gate(IA32_SYSCALL_VECTOR, ia32_syscall);
1034 * Should be a barrier for any external CPU state.
1040 /* Actual parsing is done early in setup.c. */
1041 static int __init oops_dummy(char *s)
1046 __setup("oops=", oops_dummy);
1048 static int __init kstack_setup(char *s)
1050 kstack_depth_to_print = simple_strtoul(s,NULL,0);
1053 __setup("kstack=", kstack_setup);