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/sched.h>
16 #include <linux/kernel.h>
17 #include <linux/string.h>
18 #include <linux/errno.h>
19 #include <linux/ptrace.h>
20 #include <linux/timer.h>
22 #include <linux/init.h>
23 #include <linux/delay.h>
24 #include <linux/spinlock.h>
25 #include <linux/interrupt.h>
26 #include <linux/module.h>
27 #include <linux/moduleparam.h>
28 #include <linux/nmi.h>
29 #include <linux/kprobes.h>
30 #include <linux/kexec.h>
31 #include <linux/unwind.h>
33 #include <asm/system.h>
34 #include <asm/uaccess.h>
36 #include <asm/atomic.h>
37 #include <asm/debugreg.h>
40 #include <asm/kdebug.h>
41 #include <asm/processor.h>
42 #include <asm/unwind.h>
44 #include <asm/pgalloc.h>
46 #include <asm/proto.h>
49 asmlinkage void divide_error(void);
50 asmlinkage void debug(void);
51 asmlinkage void nmi(void);
52 asmlinkage void int3(void);
53 asmlinkage void overflow(void);
54 asmlinkage void bounds(void);
55 asmlinkage void invalid_op(void);
56 asmlinkage void device_not_available(void);
57 asmlinkage void double_fault(void);
58 asmlinkage void coprocessor_segment_overrun(void);
59 asmlinkage void invalid_TSS(void);
60 asmlinkage void segment_not_present(void);
61 asmlinkage void stack_segment(void);
62 asmlinkage void general_protection(void);
63 asmlinkage void page_fault(void);
64 asmlinkage void coprocessor_error(void);
65 asmlinkage void simd_coprocessor_error(void);
66 asmlinkage void reserved(void);
67 asmlinkage void alignment_check(void);
68 asmlinkage void machine_check(void);
69 asmlinkage void spurious_interrupt_bug(void);
71 ATOMIC_NOTIFIER_HEAD(die_chain);
72 EXPORT_SYMBOL(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 = 12;
110 static int call_trace = 1;
112 #ifdef CONFIG_KALLSYMS
113 #include <linux/kallsyms.h>
114 int printk_address(unsigned long address)
116 unsigned long offset = 0, symsize;
122 symname = kallsyms_lookup(address, &symsize, &offset, &modname, namebuf);
124 return printk("[<%016lx>]", address);
126 modname = delim = "";
127 return printk("<%016lx>{%s%s%s%s%+ld}",
128 address, delim, modname, delim, symname, offset);
131 int printk_address(unsigned long address)
133 return printk("[<%016lx>]", address);
137 static unsigned long *in_exception_stack(unsigned cpu, unsigned long stack,
138 unsigned *usedp, const char **idp)
140 static char ids[][8] = {
141 [DEBUG_STACK - 1] = "#DB",
142 [NMI_STACK - 1] = "NMI",
143 [DOUBLEFAULT_STACK - 1] = "#DF",
144 [STACKFAULT_STACK - 1] = "#SS",
145 [MCE_STACK - 1] = "#MC",
146 #if DEBUG_STKSZ > EXCEPTION_STKSZ
147 [N_EXCEPTION_STACKS ... N_EXCEPTION_STACKS + DEBUG_STKSZ / EXCEPTION_STKSZ - 2] = "#DB[?]"
152 for (k = 0; k < N_EXCEPTION_STACKS; k++) {
156 #if DEBUG_STKSZ > EXCEPTION_STKSZ
158 end = cpu_pda(cpu)->debugstack + DEBUG_STKSZ;
162 end = per_cpu(init_tss, cpu).ist[k];
167 if (stack >= end - EXCEPTION_STKSZ) {
168 if (*usedp & (1U << k))
172 return (unsigned long *)end;
174 #if DEBUG_STKSZ > EXCEPTION_STKSZ
175 if (k == DEBUG_STACK - 1 && stack >= end - DEBUG_STKSZ) {
176 unsigned j = N_EXCEPTION_STACKS - 1;
180 end -= EXCEPTION_STKSZ;
181 ids[j][4] = '1' + (j - N_EXCEPTION_STACKS);
182 } while (stack < end - EXCEPTION_STKSZ);
183 if (*usedp & (1U << j))
187 return (unsigned long *)end;
194 static int show_trace_unwind(struct unwind_frame_info *info, void *context)
198 while (unwind(info) == 0 && UNW_PC(info)) {
205 i += printk_address(UNW_PC(info));
206 if (arch_unw_user_mode(info))
214 * x86-64 can have upto three kernel stacks:
217 * severe exception (double fault, nmi, stack fault, debug, mce) hardware stack
220 void show_trace(struct task_struct *tsk, struct pt_regs *regs, unsigned long * stack)
222 const unsigned cpu = safe_smp_processor_id();
223 unsigned long *irqstack_end = (unsigned long *)cpu_pda(cpu)->irqstackptr;
227 printk("\nCall Trace:");
232 if (call_trace >= 0) {
234 struct unwind_frame_info info;
237 if (unwind_init_frame_info(&info, tsk, regs) == 0)
238 unw_ret = show_trace_unwind(&info, NULL);
239 } else if (tsk == current)
240 unw_ret = unwind_init_running(&info, show_trace_unwind, NULL);
242 if (unwind_init_blocked(&info, tsk) == 0)
243 unw_ret = show_trace_unwind(&info, NULL);
248 printk("Legacy call trace:");
253 #define HANDLE_STACK(cond) \
255 unsigned long addr = *stack++; \
256 if (kernel_text_address(addr)) { \
264 * If the address is either in the text segment of the \
265 * kernel, or in the region which contains vmalloc'ed \
266 * memory, it *may* be the address of a calling \
267 * routine; if so, print it so that someone tracing \
268 * down the cause of the crash will be able to figure \
269 * out the call path that was taken. \
271 i += printk_address(addr); \
277 unsigned long *estack_end;
278 estack_end = in_exception_stack(cpu, (unsigned long)stack,
282 i += printk(" <%s>", id);
283 HANDLE_STACK (stack < estack_end);
284 i += printk(" <EOE>");
285 stack = (unsigned long *) estack_end[-2];
289 unsigned long *irqstack;
290 irqstack = irqstack_end -
291 (IRQSTACKSIZE - 64) / sizeof(*irqstack);
293 if (stack >= irqstack && stack < irqstack_end) {
294 i += printk(" <IRQ>");
295 HANDLE_STACK (stack < irqstack_end);
296 stack = (unsigned long *) (irqstack_end[-1]);
298 i += printk(" <EOI>");
305 HANDLE_STACK (((long) stack & (THREAD_SIZE-1)) != 0);
310 static void _show_stack(struct task_struct *tsk, struct pt_regs *regs, unsigned long * rsp)
312 unsigned long *stack;
314 const int cpu = safe_smp_processor_id();
315 unsigned long *irqstack_end = (unsigned long *) (cpu_pda(cpu)->irqstackptr);
316 unsigned long *irqstack = (unsigned long *) (cpu_pda(cpu)->irqstackptr - IRQSTACKSIZE);
318 // debugging aid: "show_stack(NULL, NULL);" prints the
319 // back trace for this cpu.
323 rsp = (unsigned long *)tsk->thread.rsp;
325 rsp = (unsigned long *)&rsp;
329 for(i=0; i < kstack_depth_to_print; i++) {
330 if (stack >= irqstack && stack <= irqstack_end) {
331 if (stack == irqstack_end) {
332 stack = (unsigned long *) (irqstack_end[-1]);
336 if (((long) stack & (THREAD_SIZE-1)) == 0)
339 if (i && ((i % 4) == 0))
341 printk("%016lx ", *stack++);
342 touch_nmi_watchdog();
344 show_trace(tsk, regs, rsp);
347 void show_stack(struct task_struct *tsk, unsigned long * rsp)
349 _show_stack(tsk, NULL, rsp);
353 * The architecture-independent dump_stack generator
355 void dump_stack(void)
358 show_trace(NULL, NULL, &dummy);
361 EXPORT_SYMBOL(dump_stack);
363 void show_registers(struct pt_regs *regs)
366 int in_kernel = !user_mode(regs);
368 const int cpu = safe_smp_processor_id();
369 struct task_struct *cur = cpu_pda(cpu)->pcurrent;
373 printk("CPU %d ", cpu);
375 printk("Process %s (pid: %d, threadinfo %p, task %p)\n",
376 cur->comm, cur->pid, task_thread_info(cur), cur);
379 * When in-kernel, we also print out the stack and code at the
380 * time of the fault..
385 _show_stack(NULL, regs, (unsigned long*)rsp);
388 if (regs->rip < PAGE_OFFSET)
391 for (i=0; i<20; i++) {
393 if (__get_user(c, &((unsigned char*)regs->rip)[i])) {
395 printk(" Bad RIP value.");
404 void handle_BUG(struct pt_regs *regs)
408 const char *prefix = "";
412 if (__copy_from_user(&f, (const void __user *) regs->rip,
413 sizeof(struct bug_frame)))
415 if (f.filename >= 0 ||
416 f.ud2[0] != 0x0f || f.ud2[1] != 0x0b)
418 len = __strnlen_user((char *)(long)f.filename, PATH_MAX) - 1;
419 if (len < 0 || len >= PATH_MAX)
420 f.filename = (int)(long)"unmapped filename";
422 f.filename += len - 50;
425 printk("----------- [cut here ] --------- [please bite here ] ---------\n");
426 printk(KERN_ALERT "Kernel BUG at %s%.50s:%d\n", prefix, (char *)(long)f.filename, f.line);
430 void out_of_line_bug(void)
434 EXPORT_SYMBOL(out_of_line_bug);
437 static DEFINE_SPINLOCK(die_lock);
438 static int die_owner = -1;
439 static unsigned int die_nest_count;
441 unsigned __kprobes long oops_begin(void)
443 int cpu = safe_smp_processor_id();
446 /* racy, but better than risking deadlock. */
447 local_irq_save(flags);
448 if (!spin_trylock(&die_lock)) {
449 if (cpu == die_owner)
450 /* nested oops. should stop eventually */;
452 spin_lock(&die_lock);
461 void __kprobes oops_end(unsigned long flags)
467 /* We still own the lock */
468 local_irq_restore(flags);
470 /* Nest count reaches zero, release the lock. */
471 spin_unlock_irqrestore(&die_lock, flags);
476 void __kprobes __die(const char * str, struct pt_regs * regs, long err)
478 static int die_counter;
479 printk(KERN_EMERG "%s: %04lx [%u] ", str, err & 0xffff,++die_counter);
480 #ifdef CONFIG_PREEMPT
486 #ifdef CONFIG_DEBUG_PAGEALLOC
487 printk("DEBUG_PAGEALLOC");
490 notify_die(DIE_OOPS, str, regs, err, current->thread.trap_no, SIGSEGV);
491 show_registers(regs);
492 /* Executive summary in case the oops scrolled away */
493 printk(KERN_ALERT "RIP ");
494 printk_address(regs->rip);
495 printk(" RSP <%016lx>\n", regs->rsp);
496 if (kexec_should_crash(current))
500 void die(const char * str, struct pt_regs * regs, long err)
502 unsigned long flags = oops_begin();
505 __die(str, regs, err);
510 void __kprobes die_nmi(char *str, struct pt_regs *regs)
512 unsigned long flags = oops_begin();
515 * We are in trouble anyway, lets at least try
516 * to get a message out.
518 printk(str, safe_smp_processor_id());
519 show_registers(regs);
520 if (kexec_should_crash(current))
522 if (panic_on_timeout || panic_on_oops)
523 panic("nmi watchdog");
524 printk("console shuts up ...\n");
531 static void __kprobes do_trap(int trapnr, int signr, char *str,
532 struct pt_regs * regs, long error_code,
535 struct task_struct *tsk = current;
537 tsk->thread.error_code = error_code;
538 tsk->thread.trap_no = trapnr;
540 if (user_mode(regs)) {
541 if (exception_trace && unhandled_signal(tsk, signr))
543 "%s[%d] trap %s rip:%lx rsp:%lx error:%lx\n",
544 tsk->comm, tsk->pid, str,
545 regs->rip, regs->rsp, error_code);
548 force_sig_info(signr, info, tsk);
550 force_sig(signr, tsk);
557 const struct exception_table_entry *fixup;
558 fixup = search_exception_tables(regs->rip);
560 regs->rip = fixup->fixup;
562 die(str, regs, error_code);
567 #define DO_ERROR(trapnr, signr, str, name) \
568 asmlinkage void do_##name(struct pt_regs * regs, long error_code) \
570 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
573 conditional_sti(regs); \
574 do_trap(trapnr, signr, str, regs, error_code, NULL); \
577 #define DO_ERROR_INFO(trapnr, signr, str, name, sicode, siaddr) \
578 asmlinkage void do_##name(struct pt_regs * regs, long error_code) \
581 info.si_signo = signr; \
583 info.si_code = sicode; \
584 info.si_addr = (void __user *)siaddr; \
585 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
588 conditional_sti(regs); \
589 do_trap(trapnr, signr, str, regs, error_code, &info); \
592 DO_ERROR_INFO( 0, SIGFPE, "divide error", divide_error, FPE_INTDIV, regs->rip)
593 DO_ERROR( 4, SIGSEGV, "overflow", overflow)
594 DO_ERROR( 5, SIGSEGV, "bounds", bounds)
595 DO_ERROR_INFO( 6, SIGILL, "invalid opcode", invalid_op, ILL_ILLOPN, regs->rip)
596 DO_ERROR( 7, SIGSEGV, "device not available", device_not_available)
597 DO_ERROR( 9, SIGFPE, "coprocessor segment overrun", coprocessor_segment_overrun)
598 DO_ERROR(10, SIGSEGV, "invalid TSS", invalid_TSS)
599 DO_ERROR(11, SIGBUS, "segment not present", segment_not_present)
600 DO_ERROR_INFO(17, SIGBUS, "alignment check", alignment_check, BUS_ADRALN, 0)
601 DO_ERROR(18, SIGSEGV, "reserved", reserved)
603 /* Runs on IST stack */
604 asmlinkage void do_stack_segment(struct pt_regs *regs, long error_code)
606 if (notify_die(DIE_TRAP, "stack segment", regs, error_code,
607 12, SIGBUS) == NOTIFY_STOP)
609 preempt_conditional_sti(regs);
610 do_trap(12, SIGBUS, "stack segment", regs, error_code, NULL);
611 preempt_conditional_cli(regs);
614 asmlinkage void do_double_fault(struct pt_regs * regs, long error_code)
616 static const char str[] = "double fault";
617 struct task_struct *tsk = current;
619 /* Return not checked because double check cannot be ignored */
620 notify_die(DIE_TRAP, str, regs, error_code, 8, SIGSEGV);
622 tsk->thread.error_code = error_code;
623 tsk->thread.trap_no = 8;
625 /* This is always a kernel trap and never fixable (and thus must
628 die(str, regs, error_code);
631 asmlinkage void __kprobes do_general_protection(struct pt_regs * regs,
634 struct task_struct *tsk = current;
636 conditional_sti(regs);
638 tsk->thread.error_code = error_code;
639 tsk->thread.trap_no = 13;
641 if (user_mode(regs)) {
642 if (exception_trace && unhandled_signal(tsk, SIGSEGV))
644 "%s[%d] general protection rip:%lx rsp:%lx error:%lx\n",
646 regs->rip, regs->rsp, error_code);
648 force_sig(SIGSEGV, tsk);
654 const struct exception_table_entry *fixup;
655 fixup = search_exception_tables(regs->rip);
657 regs->rip = fixup->fixup;
660 if (notify_die(DIE_GPF, "general protection fault", regs,
661 error_code, 13, SIGSEGV) == NOTIFY_STOP)
663 die("general protection fault", regs, error_code);
667 static __kprobes void
668 mem_parity_error(unsigned char reason, struct pt_regs * regs)
670 printk("Uhhuh. NMI received. Dazed and confused, but trying to continue\n");
671 printk("You probably have a hardware problem with your RAM chips\n");
673 /* Clear and disable the memory parity error line. */
674 reason = (reason & 0xf) | 4;
678 static __kprobes void
679 io_check_error(unsigned char reason, struct pt_regs * regs)
681 printk("NMI: IOCK error (debug interrupt?)\n");
682 show_registers(regs);
684 /* Re-enable the IOCK line, wait for a few seconds */
685 reason = (reason & 0xf) | 8;
692 static __kprobes void
693 unknown_nmi_error(unsigned char reason, struct pt_regs * regs)
694 { printk("Uhhuh. NMI received for unknown reason %02x.\n", reason);
695 printk("Dazed and confused, but trying to continue\n");
696 printk("Do you have a strange power saving mode enabled?\n");
699 /* Runs on IST stack. This code must keep interrupts off all the time.
700 Nested NMIs are prevented by the CPU. */
701 asmlinkage __kprobes void default_do_nmi(struct pt_regs *regs)
703 unsigned char reason = 0;
706 cpu = smp_processor_id();
708 /* Only the BSP gets external NMIs from the system. */
710 reason = get_nmi_reason();
712 if (!(reason & 0xc0)) {
713 if (notify_die(DIE_NMI_IPI, "nmi_ipi", regs, reason, 2, SIGINT)
716 #ifdef CONFIG_X86_LOCAL_APIC
718 * Ok, so this is none of the documented NMI sources,
719 * so it must be the NMI watchdog.
721 if (nmi_watchdog > 0) {
722 nmi_watchdog_tick(regs,reason);
726 unknown_nmi_error(reason, regs);
729 if (notify_die(DIE_NMI, "nmi", regs, reason, 2, SIGINT) == NOTIFY_STOP)
732 /* AK: following checks seem to be broken on modern chipsets. FIXME */
735 mem_parity_error(reason, regs);
737 io_check_error(reason, regs);
740 /* runs on IST stack. */
741 asmlinkage void __kprobes do_int3(struct pt_regs * regs, long error_code)
743 if (notify_die(DIE_INT3, "int3", regs, error_code, 3, SIGTRAP) == NOTIFY_STOP) {
746 preempt_conditional_sti(regs);
747 do_trap(3, SIGTRAP, "int3", regs, error_code, NULL);
748 preempt_conditional_cli(regs);
751 /* Help handler running on IST stack to switch back to user stack
752 for scheduling or signal handling. The actual stack switch is done in
754 asmlinkage __kprobes struct pt_regs *sync_regs(struct pt_regs *eregs)
756 struct pt_regs *regs = eregs;
757 /* Did already sync */
758 if (eregs == (struct pt_regs *)eregs->rsp)
760 /* Exception from user space */
761 else if (user_mode(eregs))
762 regs = task_pt_regs(current);
763 /* Exception from kernel and interrupts are enabled. Move to
764 kernel process stack. */
765 else if (eregs->eflags & X86_EFLAGS_IF)
766 regs = (struct pt_regs *)(eregs->rsp -= sizeof(struct pt_regs));
772 /* runs on IST stack. */
773 asmlinkage void __kprobes do_debug(struct pt_regs * regs,
774 unsigned long error_code)
776 unsigned long condition;
777 struct task_struct *tsk = current;
780 get_debugreg(condition, 6);
782 if (notify_die(DIE_DEBUG, "debug", regs, condition, error_code,
783 SIGTRAP) == NOTIFY_STOP)
786 preempt_conditional_sti(regs);
788 /* Mask out spurious debug traps due to lazy DR7 setting */
789 if (condition & (DR_TRAP0|DR_TRAP1|DR_TRAP2|DR_TRAP3)) {
790 if (!tsk->thread.debugreg7) {
795 tsk->thread.debugreg6 = condition;
797 /* Mask out spurious TF errors due to lazy TF clearing */
798 if (condition & DR_STEP) {
800 * The TF error should be masked out only if the current
801 * process is not traced and if the TRAP flag has been set
802 * previously by a tracing process (condition detected by
803 * the PT_DTRACE flag); remember that the i386 TRAP flag
804 * can be modified by the process itself in user mode,
805 * allowing programs to debug themselves without the ptrace()
808 if (!user_mode(regs))
809 goto clear_TF_reenable;
811 * Was the TF flag set by a debugger? If so, clear it now,
812 * so that register information is correct.
814 if (tsk->ptrace & PT_DTRACE) {
815 regs->eflags &= ~TF_MASK;
816 tsk->ptrace &= ~PT_DTRACE;
820 /* Ok, finally something we can handle */
821 tsk->thread.trap_no = 1;
822 tsk->thread.error_code = error_code;
823 info.si_signo = SIGTRAP;
825 info.si_code = TRAP_BRKPT;
826 info.si_addr = user_mode(regs) ? (void __user *)regs->rip : NULL;
827 force_sig_info(SIGTRAP, &info, tsk);
830 set_debugreg(0UL, 7);
831 preempt_conditional_cli(regs);
835 set_tsk_thread_flag(tsk, TIF_SINGLESTEP);
836 regs->eflags &= ~TF_MASK;
837 preempt_conditional_cli(regs);
840 static int kernel_math_error(struct pt_regs *regs, const char *str, int trapnr)
842 const struct exception_table_entry *fixup;
843 fixup = search_exception_tables(regs->rip);
845 regs->rip = fixup->fixup;
848 notify_die(DIE_GPF, str, regs, 0, trapnr, SIGFPE);
849 /* Illegal floating point operation in the kernel */
850 current->thread.trap_no = trapnr;
856 * Note that we play around with the 'TS' bit in an attempt to get
857 * the correct behaviour even in the presence of the asynchronous
860 asmlinkage void do_coprocessor_error(struct pt_regs *regs)
862 void __user *rip = (void __user *)(regs->rip);
863 struct task_struct * task;
865 unsigned short cwd, swd;
867 conditional_sti(regs);
868 if (!user_mode(regs) &&
869 kernel_math_error(regs, "kernel x87 math error", 16))
873 * Save the info for the exception handler and clear the error.
877 task->thread.trap_no = 16;
878 task->thread.error_code = 0;
879 info.si_signo = SIGFPE;
881 info.si_code = __SI_FAULT;
884 * (~cwd & swd) will mask out exceptions that are not set to unmasked
885 * status. 0x3f is the exception bits in these regs, 0x200 is the
886 * C1 reg you need in case of a stack fault, 0x040 is the stack
887 * fault bit. We should only be taking one exception at a time,
888 * so if this combination doesn't produce any single exception,
889 * then we have a bad program that isn't synchronizing its FPU usage
890 * and it will suffer the consequences since we won't be able to
891 * fully reproduce the context of the exception
893 cwd = get_fpu_cwd(task);
894 swd = get_fpu_swd(task);
895 switch (swd & ~cwd & 0x3f) {
899 case 0x001: /* Invalid Op */
901 * swd & 0x240 == 0x040: Stack Underflow
902 * swd & 0x240 == 0x240: Stack Overflow
903 * User must clear the SF bit (0x40) if set
905 info.si_code = FPE_FLTINV;
907 case 0x002: /* Denormalize */
908 case 0x010: /* Underflow */
909 info.si_code = FPE_FLTUND;
911 case 0x004: /* Zero Divide */
912 info.si_code = FPE_FLTDIV;
914 case 0x008: /* Overflow */
915 info.si_code = FPE_FLTOVF;
917 case 0x020: /* Precision */
918 info.si_code = FPE_FLTRES;
921 force_sig_info(SIGFPE, &info, task);
924 asmlinkage void bad_intr(void)
926 printk("bad interrupt");
929 asmlinkage void do_simd_coprocessor_error(struct pt_regs *regs)
931 void __user *rip = (void __user *)(regs->rip);
932 struct task_struct * task;
934 unsigned short mxcsr;
936 conditional_sti(regs);
937 if (!user_mode(regs) &&
938 kernel_math_error(regs, "kernel simd math error", 19))
942 * Save the info for the exception handler and clear the error.
946 task->thread.trap_no = 19;
947 task->thread.error_code = 0;
948 info.si_signo = SIGFPE;
950 info.si_code = __SI_FAULT;
953 * The SIMD FPU exceptions are handled a little differently, as there
954 * is only a single status/control register. Thus, to determine which
955 * unmasked exception was caught we must mask the exception mask bits
956 * at 0x1f80, and then use these to mask the exception bits at 0x3f.
958 mxcsr = get_fpu_mxcsr(task);
959 switch (~((mxcsr & 0x1f80) >> 7) & (mxcsr & 0x3f)) {
963 case 0x001: /* Invalid Op */
964 info.si_code = FPE_FLTINV;
966 case 0x002: /* Denormalize */
967 case 0x010: /* Underflow */
968 info.si_code = FPE_FLTUND;
970 case 0x004: /* Zero Divide */
971 info.si_code = FPE_FLTDIV;
973 case 0x008: /* Overflow */
974 info.si_code = FPE_FLTOVF;
976 case 0x020: /* Precision */
977 info.si_code = FPE_FLTRES;
980 force_sig_info(SIGFPE, &info, task);
983 asmlinkage void do_spurious_interrupt_bug(struct pt_regs * regs)
987 asmlinkage void __attribute__((weak)) smp_thermal_interrupt(void)
991 asmlinkage void __attribute__((weak)) mce_threshold_interrupt(void)
996 * 'math_state_restore()' saves the current math information in the
997 * old math state array, and gets the new ones from the current task
999 * Careful.. There are problems with IBM-designed IRQ13 behaviour.
1000 * Don't touch unless you *really* know how it works.
1002 asmlinkage void math_state_restore(void)
1004 struct task_struct *me = current;
1005 clts(); /* Allow maths ops (or we recurse) */
1009 restore_fpu_checking(&me->thread.i387.fxsave);
1010 task_thread_info(me)->status |= TS_USEDFPU;
1013 void __init trap_init(void)
1015 set_intr_gate(0,÷_error);
1016 set_intr_gate_ist(1,&debug,DEBUG_STACK);
1017 set_intr_gate_ist(2,&nmi,NMI_STACK);
1018 set_system_gate_ist(3,&int3,DEBUG_STACK); /* int3 can be called from all */
1019 set_system_gate(4,&overflow); /* int4 can be called from all */
1020 set_intr_gate(5,&bounds);
1021 set_intr_gate(6,&invalid_op);
1022 set_intr_gate(7,&device_not_available);
1023 set_intr_gate_ist(8,&double_fault, DOUBLEFAULT_STACK);
1024 set_intr_gate(9,&coprocessor_segment_overrun);
1025 set_intr_gate(10,&invalid_TSS);
1026 set_intr_gate(11,&segment_not_present);
1027 set_intr_gate_ist(12,&stack_segment,STACKFAULT_STACK);
1028 set_intr_gate(13,&general_protection);
1029 set_intr_gate(14,&page_fault);
1030 set_intr_gate(15,&spurious_interrupt_bug);
1031 set_intr_gate(16,&coprocessor_error);
1032 set_intr_gate(17,&alignment_check);
1033 #ifdef CONFIG_X86_MCE
1034 set_intr_gate_ist(18,&machine_check, MCE_STACK);
1036 set_intr_gate(19,&simd_coprocessor_error);
1038 #ifdef CONFIG_IA32_EMULATION
1039 set_system_gate(IA32_SYSCALL_VECTOR, ia32_syscall);
1043 * Should be a barrier for any external CPU state.
1049 /* Actual parsing is done early in setup.c. */
1050 static int __init oops_dummy(char *s)
1055 __setup("oops=", oops_dummy);
1057 static int __init kstack_setup(char *s)
1059 kstack_depth_to_print = simple_strtoul(s,NULL,0);
1062 __setup("kstack=", kstack_setup);
1064 static int __init call_trace_setup(char *s)
1066 if (strcmp(s, "old") == 0)
1068 else if (strcmp(s, "both") == 0)
1070 else if (strcmp(s, "new") == 0)
1074 __setup("call_trace=", call_trace_setup);