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>
48 #include <asm/stacktrace.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);
73 EXPORT_SYMBOL(die_chain);
75 extern char last_sysfs_file[];
77 int register_die_notifier(struct notifier_block *nb)
80 return atomic_notifier_chain_register(&die_chain, nb);
82 EXPORT_SYMBOL(register_die_notifier); /* used modular by kdb */
84 int unregister_die_notifier(struct notifier_block *nb)
86 return atomic_notifier_chain_unregister(&die_chain, nb);
88 EXPORT_SYMBOL(unregister_die_notifier); /* used modular by kdb */
90 static inline void conditional_sti(struct pt_regs *regs)
92 if (regs->eflags & X86_EFLAGS_IF)
96 static inline void preempt_conditional_sti(struct pt_regs *regs)
99 if (regs->eflags & X86_EFLAGS_IF)
103 static inline void preempt_conditional_cli(struct pt_regs *regs)
105 if (regs->eflags & X86_EFLAGS_IF)
107 /* Make sure to not schedule here because we could be running
108 on an exception stack. */
109 preempt_enable_no_resched();
112 static int kstack_depth_to_print = 12;
113 #ifdef CONFIG_STACK_UNWIND
114 static int call_trace = 1;
116 #define call_trace (-1)
119 #ifdef CONFIG_KALLSYMS
120 # include <linux/kallsyms.h>
121 void printk_address(unsigned long address)
123 unsigned long offset = 0, symsize;
129 symname = kallsyms_lookup(address, &symsize, &offset,
132 printk(" [<%016lx>]\n", address);
136 modname = delim = "";
137 printk(" [<%016lx>] %s%s%s%s+0x%lx/0x%lx\n",
138 address, delim, modname, delim, symname, offset, symsize);
141 void printk_address(unsigned long address)
143 printk(" [<%016lx>]\n", address);
147 static unsigned long *in_exception_stack(unsigned cpu, unsigned long stack,
148 unsigned *usedp, char **idp)
150 static char ids[][8] = {
151 [DEBUG_STACK - 1] = "#DB",
152 [NMI_STACK - 1] = "NMI",
153 [DOUBLEFAULT_STACK - 1] = "#DF",
154 [STACKFAULT_STACK - 1] = "#SS",
155 [MCE_STACK - 1] = "#MC",
156 #if DEBUG_STKSZ > EXCEPTION_STKSZ
157 [N_EXCEPTION_STACKS ... N_EXCEPTION_STACKS + DEBUG_STKSZ / EXCEPTION_STKSZ - 2] = "#DB[?]"
163 * Iterate over all exception stacks, and figure out whether
164 * 'stack' is in one of them:
166 for (k = 0; k < N_EXCEPTION_STACKS; k++) {
170 * set 'end' to the end of the exception stack.
174 * TODO: this block is not needed i think, because
175 * setup64.c:cpu_init() sets up t->ist[DEBUG_STACK]
178 #if DEBUG_STKSZ > EXCEPTION_STKSZ
180 end = cpu_pda(cpu)->debugstack + DEBUG_STKSZ;
184 end = per_cpu(orig_ist, cpu).ist[k];
188 * Is 'stack' above this exception frame's end?
189 * If yes then skip to the next frame.
194 * Is 'stack' above this exception frame's start address?
195 * If yes then we found the right frame.
197 if (stack >= end - EXCEPTION_STKSZ) {
199 * Make sure we only iterate through an exception
200 * stack once. If it comes up for the second time
201 * then there's something wrong going on - just
202 * break out and return NULL:
204 if (*usedp & (1U << k))
208 return (unsigned long *)end;
211 * If this is a debug stack, and if it has a larger size than
212 * the usual exception stacks, then 'stack' might still
213 * be within the lower portion of the debug stack:
215 #if DEBUG_STKSZ > EXCEPTION_STKSZ
216 if (k == DEBUG_STACK - 1 && stack >= end - DEBUG_STKSZ) {
217 unsigned j = N_EXCEPTION_STACKS - 1;
220 * Black magic. A large debug stack is composed of
221 * multiple exception stack entries, which we
222 * iterate through now. Dont look:
226 end -= EXCEPTION_STKSZ;
227 ids[j][4] = '1' + (j - N_EXCEPTION_STACKS);
228 } while (stack < end - EXCEPTION_STKSZ);
229 if (*usedp & (1U << j))
233 return (unsigned long *)end;
240 struct ops_and_data {
241 struct stacktrace_ops *ops;
245 static int dump_trace_unwind(struct unwind_frame_info *info, void *context)
247 struct ops_and_data *oad = (struct ops_and_data *)context;
250 while (unwind(info) == 0 && UNW_PC(info)) {
252 oad->ops->address(oad->data, UNW_PC(info));
253 if (arch_unw_user_mode(info))
260 * x86-64 can have upto three kernel stacks:
263 * severe exception (double fault, nmi, stack fault, debug, mce) hardware stack
266 void dump_trace(struct task_struct *tsk, struct pt_regs *regs, unsigned long * stack,
267 struct stacktrace_ops *ops, void *data)
269 const unsigned cpu = safe_smp_processor_id();
270 unsigned long *irqstack_end = (unsigned long *)cpu_pda(cpu)->irqstackptr;
276 if (call_trace >= 0) {
278 struct unwind_frame_info info;
279 struct ops_and_data oad = { .ops = ops, .data = data };
282 if (unwind_init_frame_info(&info, tsk, regs) == 0)
283 unw_ret = dump_trace_unwind(&info, &oad);
284 } else if (tsk == current)
285 unw_ret = unwind_init_running(&info, dump_trace_unwind, &oad);
287 if (unwind_init_blocked(&info, tsk) == 0)
288 unw_ret = dump_trace_unwind(&info, &oad);
291 if (call_trace == 1 && !arch_unw_user_mode(&info)) {
292 ops->warning_symbol(data, "DWARF2 unwinder stuck at %s",
294 if ((long)UNW_SP(&info) < 0) {
295 ops->warning(data, "Leftover inexact backtrace:");
296 stack = (unsigned long *)UNW_SP(&info);
300 ops->warning(data, "Full inexact backtrace again:");
301 } else if (call_trace >= 1)
304 ops->warning(data, "Full inexact backtrace again:");
306 ops->warning(data, "Inexact backtrace:");
311 if (tsk && tsk != current)
312 stack = (unsigned long *)tsk->thread.rsp;
316 * Print function call entries within a stack. 'cond' is the
317 * "end of stackframe" condition, that the 'stack++'
318 * iteration will eventually trigger.
320 #define HANDLE_STACK(cond) \
322 unsigned long addr = *stack++; \
323 if (kernel_text_address(addr)) { \
325 * If the address is either in the text segment of the \
326 * kernel, or in the region which contains vmalloc'ed \
327 * memory, it *may* be the address of a calling \
328 * routine; if so, print it so that someone tracing \
329 * down the cause of the crash will be able to figure \
330 * out the call path that was taken. \
332 ops->address(data, addr); \
337 * Print function call entries in all stacks, starting at the
338 * current stack address. If the stacks consist of nested
343 unsigned long *estack_end;
344 estack_end = in_exception_stack(cpu, (unsigned long)stack,
348 if (ops->stack(data, id) < 0)
350 HANDLE_STACK (stack < estack_end);
351 ops->stack(data, "<EOE>");
353 * We link to the next stack via the
354 * second-to-last pointer (index -2 to end) in the
357 stack = (unsigned long *) estack_end[-2];
361 unsigned long *irqstack;
362 irqstack = irqstack_end -
363 (IRQSTACKSIZE - 64) / sizeof(*irqstack);
365 if (stack >= irqstack && stack < irqstack_end) {
366 if (ops->stack(data, "IRQ") < 0)
368 HANDLE_STACK (stack < irqstack_end);
370 * We link to the next stack (which would be
371 * the process stack normally) the last
372 * pointer (index -1 to end) in the IRQ stack:
374 stack = (unsigned long *) (irqstack_end[-1]);
376 ops->stack(data, "EOI");
384 * This handles the process stack:
386 HANDLE_STACK (((long) stack & (THREAD_SIZE-1)) != 0);
389 EXPORT_SYMBOL(dump_trace);
392 print_trace_warning_symbol(void *data, char *msg, unsigned long symbol)
394 print_symbol(msg, symbol);
398 static void print_trace_warning(void *data, char *msg)
403 static int print_trace_stack(void *data, char *name)
405 printk(" <%s> ", name);
409 static void print_trace_address(void *data, unsigned long addr)
411 printk_address(addr);
414 static struct stacktrace_ops print_trace_ops = {
415 .warning = print_trace_warning,
416 .warning_symbol = print_trace_warning_symbol,
417 .stack = print_trace_stack,
418 .address = print_trace_address,
422 show_trace(struct task_struct *tsk, struct pt_regs *regs, unsigned long *stack)
424 printk("\nCall Trace:\n");
425 dump_trace(tsk, regs, stack, &print_trace_ops, NULL);
430 _show_stack(struct task_struct *tsk, struct pt_regs *regs, unsigned long *rsp)
432 unsigned long *stack;
434 const int cpu = safe_smp_processor_id();
435 unsigned long *irqstack_end = (unsigned long *) (cpu_pda(cpu)->irqstackptr);
436 unsigned long *irqstack = (unsigned long *) (cpu_pda(cpu)->irqstackptr - IRQSTACKSIZE);
438 // debugging aid: "show_stack(NULL, NULL);" prints the
439 // back trace for this cpu.
443 rsp = (unsigned long *)tsk->thread.rsp;
445 rsp = (unsigned long *)&rsp;
449 for(i=0; i < kstack_depth_to_print; i++) {
450 if (stack >= irqstack && stack <= irqstack_end) {
451 if (stack == irqstack_end) {
452 stack = (unsigned long *) (irqstack_end[-1]);
456 if (((long) stack & (THREAD_SIZE-1)) == 0)
459 if (i && ((i % 4) == 0))
461 printk(" %016lx", *stack++);
462 touch_nmi_watchdog();
464 show_trace(tsk, regs, rsp);
467 void show_stack(struct task_struct *tsk, unsigned long * rsp)
469 _show_stack(tsk, NULL, rsp);
473 * The architecture-independent dump_stack generator
475 void dump_stack(void)
478 show_trace(NULL, NULL, &dummy);
481 EXPORT_SYMBOL(dump_stack);
483 void show_registers(struct pt_regs *regs)
486 int in_kernel = !user_mode(regs);
488 const int cpu = safe_smp_processor_id();
489 struct task_struct *cur = cpu_pda(cpu)->pcurrent;
493 printk("CPU %d ", cpu);
495 printk("Process %s (pid: %d[#%u], threadinfo %p, task %p)\n",
496 cur->comm, cur->pid, cur->xid,
497 task_thread_info(cur), cur);
500 * When in-kernel, we also print out the stack and code at the
501 * time of the fault..
506 _show_stack(NULL, regs, (unsigned long*)rsp);
509 if (regs->rip < PAGE_OFFSET)
512 for (i=0; i<20; i++) {
514 if (__get_user(c, &((unsigned char*)regs->rip)[i])) {
516 printk(" Bad RIP value.");
525 void handle_BUG(struct pt_regs *regs)
529 const char *prefix = "";
533 if (__copy_from_user(&f, (const void __user *) regs->rip,
534 sizeof(struct bug_frame)))
536 if (f.filename >= 0 ||
537 f.ud2[0] != 0x0f || f.ud2[1] != 0x0b)
539 len = __strnlen_user((char *)(long)f.filename, PATH_MAX) - 1;
540 if (len < 0 || len >= PATH_MAX)
541 f.filename = (int)(long)"unmapped filename";
543 f.filename += len - 50;
546 printk("----------- [cut here ] --------- [please bite here ] ---------\n");
547 printk(KERN_ALERT "Kernel BUG at %s%.50s:%d\n", prefix, (char *)(long)f.filename, f.line);
551 void out_of_line_bug(void)
555 EXPORT_SYMBOL(out_of_line_bug);
558 static DEFINE_SPINLOCK(die_lock);
559 static int die_owner = -1;
560 static unsigned int die_nest_count;
562 unsigned __kprobes long oops_begin(void)
564 int cpu = safe_smp_processor_id();
567 /* racy, but better than risking deadlock. */
568 local_irq_save(flags);
569 if (!spin_trylock(&die_lock)) {
570 if (cpu == die_owner)
571 /* nested oops. should stop eventually */;
573 spin_lock(&die_lock);
582 void __kprobes oops_end(unsigned long flags)
588 /* We still own the lock */
589 local_irq_restore(flags);
591 /* Nest count reaches zero, release the lock. */
592 spin_unlock_irqrestore(&die_lock, flags);
594 panic("Fatal exception");
597 void __kprobes __die(const char * str, struct pt_regs * regs, long err)
599 static int die_counter;
600 printk(KERN_EMERG "%s: %04lx [%u] ", str, err & 0xffff,++die_counter);
601 #ifdef CONFIG_PREEMPT
607 #ifdef CONFIG_DEBUG_PAGEALLOC
608 printk("DEBUG_PAGEALLOC");
612 printk(KERN_ALERT "last sysfs file: %s\n", last_sysfs_file);
614 notify_die(DIE_OOPS, str, regs, err, current->thread.trap_no, SIGSEGV);
615 show_registers(regs);
616 /* Executive summary in case the oops scrolled away */
617 printk(KERN_ALERT "RIP ");
618 printk_address(regs->rip);
619 printk(" RSP <%016lx>\n", regs->rsp);
620 if (kexec_should_crash(current))
624 void die(const char * str, struct pt_regs * regs, long err)
626 unsigned long flags = oops_begin();
629 __die(str, regs, err);
634 void __kprobes die_nmi(char *str, struct pt_regs *regs)
636 unsigned long flags = oops_begin();
639 * We are in trouble anyway, lets at least try
640 * to get a message out.
642 printk(str, safe_smp_processor_id());
643 show_registers(regs);
644 if (kexec_should_crash(current))
646 if (panic_on_timeout || panic_on_oops)
647 panic("nmi watchdog");
648 printk("console shuts up ...\n");
655 static void __kprobes do_trap(int trapnr, int signr, char *str,
656 struct pt_regs * regs, long error_code,
659 struct task_struct *tsk = current;
661 tsk->thread.error_code = error_code;
662 tsk->thread.trap_no = trapnr;
664 if (user_mode(regs)) {
665 if (exception_trace && unhandled_signal(tsk, signr))
667 "%s[%d] trap %s rip:%lx rsp:%lx error:%lx\n",
668 tsk->comm, tsk->pid, str,
669 regs->rip, regs->rsp, error_code);
672 force_sig_info(signr, info, tsk);
674 force_sig(signr, tsk);
681 const struct exception_table_entry *fixup;
682 fixup = search_exception_tables(regs->rip);
684 regs->rip = fixup->fixup;
686 die(str, regs, error_code);
691 #define DO_ERROR(trapnr, signr, str, name) \
692 asmlinkage void do_##name(struct pt_regs * regs, long error_code) \
694 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
697 conditional_sti(regs); \
698 do_trap(trapnr, signr, str, regs, error_code, NULL); \
701 #define DO_ERROR_INFO(trapnr, signr, str, name, sicode, siaddr) \
702 asmlinkage void do_##name(struct pt_regs * regs, long error_code) \
705 info.si_signo = signr; \
707 info.si_code = sicode; \
708 info.si_addr = (void __user *)siaddr; \
709 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
712 conditional_sti(regs); \
713 do_trap(trapnr, signr, str, regs, error_code, &info); \
716 DO_ERROR_INFO( 0, SIGFPE, "divide error", divide_error, FPE_INTDIV, regs->rip)
717 DO_ERROR( 4, SIGSEGV, "overflow", overflow)
718 DO_ERROR( 5, SIGSEGV, "bounds", bounds)
719 DO_ERROR_INFO( 6, SIGILL, "invalid opcode", invalid_op, ILL_ILLOPN, regs->rip)
720 DO_ERROR( 7, SIGSEGV, "device not available", device_not_available)
721 DO_ERROR( 9, SIGFPE, "coprocessor segment overrun", coprocessor_segment_overrun)
722 DO_ERROR(10, SIGSEGV, "invalid TSS", invalid_TSS)
723 DO_ERROR(11, SIGBUS, "segment not present", segment_not_present)
724 DO_ERROR_INFO(17, SIGBUS, "alignment check", alignment_check, BUS_ADRALN, 0)
725 DO_ERROR(18, SIGSEGV, "reserved", reserved)
727 /* Runs on IST stack */
728 asmlinkage void do_stack_segment(struct pt_regs *regs, long error_code)
730 if (notify_die(DIE_TRAP, "stack segment", regs, error_code,
731 12, SIGBUS) == NOTIFY_STOP)
733 preempt_conditional_sti(regs);
734 do_trap(12, SIGBUS, "stack segment", regs, error_code, NULL);
735 preempt_conditional_cli(regs);
738 asmlinkage void do_double_fault(struct pt_regs * regs, long error_code)
740 static const char str[] = "double fault";
741 struct task_struct *tsk = current;
743 /* Return not checked because double check cannot be ignored */
744 notify_die(DIE_TRAP, str, regs, error_code, 8, SIGSEGV);
746 tsk->thread.error_code = error_code;
747 tsk->thread.trap_no = 8;
749 /* This is always a kernel trap and never fixable (and thus must
752 die(str, regs, error_code);
755 asmlinkage void __kprobes do_general_protection(struct pt_regs * regs,
758 struct task_struct *tsk = current;
760 conditional_sti(regs);
762 tsk->thread.error_code = error_code;
763 tsk->thread.trap_no = 13;
765 if (user_mode(regs)) {
766 if (exception_trace && unhandled_signal(tsk, SIGSEGV))
768 "%s[%d] general protection rip:%lx rsp:%lx error:%lx\n",
770 regs->rip, regs->rsp, error_code);
772 force_sig(SIGSEGV, tsk);
778 const struct exception_table_entry *fixup;
779 fixup = search_exception_tables(regs->rip);
781 regs->rip = fixup->fixup;
784 if (notify_die(DIE_GPF, "general protection fault", regs,
785 error_code, 13, SIGSEGV) == NOTIFY_STOP)
787 die("general protection fault", regs, error_code);
791 static __kprobes void
792 mem_parity_error(unsigned char reason, struct pt_regs * regs)
794 printk("Uhhuh. NMI received. Dazed and confused, but trying to continue\n");
795 printk("You probably have a hardware problem with your RAM chips\n");
797 /* Clear and disable the memory parity error line. */
798 reason = (reason & 0xf) | 4;
802 static __kprobes void
803 io_check_error(unsigned char reason, struct pt_regs * regs)
805 printk("NMI: IOCK error (debug interrupt?)\n");
806 show_registers(regs);
808 /* Re-enable the IOCK line, wait for a few seconds */
809 reason = (reason & 0xf) | 8;
816 static __kprobes void
817 unknown_nmi_error(unsigned char reason, struct pt_regs * regs)
818 { printk("Uhhuh. NMI received for unknown reason %02x.\n", reason);
819 printk("Dazed and confused, but trying to continue\n");
820 printk("Do you have a strange power saving mode enabled?\n");
823 /* Runs on IST stack. This code must keep interrupts off all the time.
824 Nested NMIs are prevented by the CPU. */
825 asmlinkage __kprobes void default_do_nmi(struct pt_regs *regs)
827 unsigned char reason = 0;
830 cpu = smp_processor_id();
832 /* Only the BSP gets external NMIs from the system. */
834 reason = get_nmi_reason();
836 if (!(reason & 0xc0)) {
837 if (notify_die(DIE_NMI_IPI, "nmi_ipi", regs, reason, 2, SIGINT)
840 #ifdef CONFIG_X86_LOCAL_APIC
842 * Ok, so this is none of the documented NMI sources,
843 * so it must be the NMI watchdog.
845 if (nmi_watchdog > 0) {
846 nmi_watchdog_tick(regs,reason);
850 unknown_nmi_error(reason, regs);
853 if (notify_die(DIE_NMI, "nmi", regs, reason, 2, SIGINT) == NOTIFY_STOP)
856 /* AK: following checks seem to be broken on modern chipsets. FIXME */
859 mem_parity_error(reason, regs);
861 io_check_error(reason, regs);
864 /* runs on IST stack. */
865 asmlinkage void __kprobes do_int3(struct pt_regs * regs, long error_code)
867 if (notify_die(DIE_INT3, "int3", regs, error_code, 3, SIGTRAP) == NOTIFY_STOP) {
870 preempt_conditional_sti(regs);
871 do_trap(3, SIGTRAP, "int3", regs, error_code, NULL);
872 preempt_conditional_cli(regs);
875 /* Help handler running on IST stack to switch back to user stack
876 for scheduling or signal handling. The actual stack switch is done in
878 asmlinkage __kprobes struct pt_regs *sync_regs(struct pt_regs *eregs)
880 struct pt_regs *regs = eregs;
881 /* Did already sync */
882 if (eregs == (struct pt_regs *)eregs->rsp)
884 /* Exception from user space */
885 else if (user_mode(eregs))
886 regs = task_pt_regs(current);
887 /* Exception from kernel and interrupts are enabled. Move to
888 kernel process stack. */
889 else if (eregs->eflags & X86_EFLAGS_IF)
890 regs = (struct pt_regs *)(eregs->rsp -= sizeof(struct pt_regs));
896 /* runs on IST stack. */
897 asmlinkage void __kprobes do_debug(struct pt_regs * regs,
898 unsigned long error_code)
900 unsigned long condition;
901 struct task_struct *tsk = current;
904 get_debugreg(condition, 6);
906 if (notify_die(DIE_DEBUG, "debug", regs, condition, error_code,
907 SIGTRAP) == NOTIFY_STOP)
910 preempt_conditional_sti(regs);
912 /* Mask out spurious debug traps due to lazy DR7 setting */
913 if (condition & (DR_TRAP0|DR_TRAP1|DR_TRAP2|DR_TRAP3)) {
914 if (!tsk->thread.debugreg7) {
919 tsk->thread.debugreg6 = condition;
921 /* Mask out spurious TF errors due to lazy TF clearing */
922 if (condition & DR_STEP) {
924 * The TF error should be masked out only if the current
925 * process is not traced and if the TRAP flag has been set
926 * previously by a tracing process (condition detected by
927 * the PT_DTRACE flag); remember that the i386 TRAP flag
928 * can be modified by the process itself in user mode,
929 * allowing programs to debug themselves without the ptrace()
932 if (!user_mode(regs))
933 goto clear_TF_reenable;
936 /* Ok, finally something we can handle */
937 tsk->thread.trap_no = 1;
938 tsk->thread.error_code = error_code;
939 info.si_signo = SIGTRAP;
941 info.si_code = TRAP_BRKPT;
942 info.si_addr = user_mode(regs) ? (void __user *)regs->rip : NULL;
943 force_sig_info(SIGTRAP, &info, tsk);
946 set_debugreg(0UL, 7);
947 preempt_conditional_cli(regs);
951 set_tsk_thread_flag(tsk, TIF_SINGLESTEP);
952 regs->eflags &= ~TF_MASK;
953 preempt_conditional_cli(regs);
956 static int kernel_math_error(struct pt_regs *regs, const char *str, int trapnr)
958 const struct exception_table_entry *fixup;
959 fixup = search_exception_tables(regs->rip);
961 regs->rip = fixup->fixup;
964 notify_die(DIE_GPF, str, regs, 0, trapnr, SIGFPE);
965 /* Illegal floating point operation in the kernel */
966 current->thread.trap_no = trapnr;
972 * Note that we play around with the 'TS' bit in an attempt to get
973 * the correct behaviour even in the presence of the asynchronous
976 asmlinkage void do_coprocessor_error(struct pt_regs *regs)
978 void __user *rip = (void __user *)(regs->rip);
979 struct task_struct * task;
981 unsigned short cwd, swd;
983 conditional_sti(regs);
984 if (!user_mode(regs) &&
985 kernel_math_error(regs, "kernel x87 math error", 16))
989 * Save the info for the exception handler and clear the error.
993 task->thread.trap_no = 16;
994 task->thread.error_code = 0;
995 info.si_signo = SIGFPE;
997 info.si_code = __SI_FAULT;
1000 * (~cwd & swd) will mask out exceptions that are not set to unmasked
1001 * status. 0x3f is the exception bits in these regs, 0x200 is the
1002 * C1 reg you need in case of a stack fault, 0x040 is the stack
1003 * fault bit. We should only be taking one exception at a time,
1004 * so if this combination doesn't produce any single exception,
1005 * then we have a bad program that isn't synchronizing its FPU usage
1006 * and it will suffer the consequences since we won't be able to
1007 * fully reproduce the context of the exception
1009 cwd = get_fpu_cwd(task);
1010 swd = get_fpu_swd(task);
1011 switch (swd & ~cwd & 0x3f) {
1015 case 0x001: /* Invalid Op */
1017 * swd & 0x240 == 0x040: Stack Underflow
1018 * swd & 0x240 == 0x240: Stack Overflow
1019 * User must clear the SF bit (0x40) if set
1021 info.si_code = FPE_FLTINV;
1023 case 0x002: /* Denormalize */
1024 case 0x010: /* Underflow */
1025 info.si_code = FPE_FLTUND;
1027 case 0x004: /* Zero Divide */
1028 info.si_code = FPE_FLTDIV;
1030 case 0x008: /* Overflow */
1031 info.si_code = FPE_FLTOVF;
1033 case 0x020: /* Precision */
1034 info.si_code = FPE_FLTRES;
1037 force_sig_info(SIGFPE, &info, task);
1040 asmlinkage void bad_intr(void)
1042 printk("bad interrupt");
1045 asmlinkage void do_simd_coprocessor_error(struct pt_regs *regs)
1047 void __user *rip = (void __user *)(regs->rip);
1048 struct task_struct * task;
1050 unsigned short mxcsr;
1052 conditional_sti(regs);
1053 if (!user_mode(regs) &&
1054 kernel_math_error(regs, "kernel simd math error", 19))
1058 * Save the info for the exception handler and clear the error.
1061 save_init_fpu(task);
1062 task->thread.trap_no = 19;
1063 task->thread.error_code = 0;
1064 info.si_signo = SIGFPE;
1066 info.si_code = __SI_FAULT;
1069 * The SIMD FPU exceptions are handled a little differently, as there
1070 * is only a single status/control register. Thus, to determine which
1071 * unmasked exception was caught we must mask the exception mask bits
1072 * at 0x1f80, and then use these to mask the exception bits at 0x3f.
1074 mxcsr = get_fpu_mxcsr(task);
1075 switch (~((mxcsr & 0x1f80) >> 7) & (mxcsr & 0x3f)) {
1079 case 0x001: /* Invalid Op */
1080 info.si_code = FPE_FLTINV;
1082 case 0x002: /* Denormalize */
1083 case 0x010: /* Underflow */
1084 info.si_code = FPE_FLTUND;
1086 case 0x004: /* Zero Divide */
1087 info.si_code = FPE_FLTDIV;
1089 case 0x008: /* Overflow */
1090 info.si_code = FPE_FLTOVF;
1092 case 0x020: /* Precision */
1093 info.si_code = FPE_FLTRES;
1096 force_sig_info(SIGFPE, &info, task);
1099 asmlinkage void do_spurious_interrupt_bug(struct pt_regs * regs)
1103 asmlinkage void __attribute__((weak)) smp_thermal_interrupt(void)
1107 asmlinkage void __attribute__((weak)) mce_threshold_interrupt(void)
1112 * 'math_state_restore()' saves the current math information in the
1113 * old math state array, and gets the new ones from the current task
1115 * Careful.. There are problems with IBM-designed IRQ13 behaviour.
1116 * Don't touch unless you *really* know how it works.
1118 asmlinkage void math_state_restore(void)
1120 struct task_struct *me = current;
1121 clts(); /* Allow maths ops (or we recurse) */
1125 restore_fpu_checking(&me->thread.i387.fxsave);
1126 task_thread_info(me)->status |= TS_USEDFPU;
1129 void __init trap_init(void)
1131 set_intr_gate(0,÷_error);
1132 set_intr_gate_ist(1,&debug,DEBUG_STACK);
1133 set_intr_gate_ist(2,&nmi,NMI_STACK);
1134 set_system_gate_ist(3,&int3,DEBUG_STACK); /* int3 can be called from all */
1135 set_system_gate(4,&overflow); /* int4 can be called from all */
1136 set_intr_gate(5,&bounds);
1137 set_intr_gate(6,&invalid_op);
1138 set_intr_gate(7,&device_not_available);
1139 set_intr_gate_ist(8,&double_fault, DOUBLEFAULT_STACK);
1140 set_intr_gate(9,&coprocessor_segment_overrun);
1141 set_intr_gate(10,&invalid_TSS);
1142 set_intr_gate(11,&segment_not_present);
1143 set_intr_gate_ist(12,&stack_segment,STACKFAULT_STACK);
1144 set_intr_gate(13,&general_protection);
1145 set_intr_gate(14,&page_fault);
1146 set_intr_gate(15,&spurious_interrupt_bug);
1147 set_intr_gate(16,&coprocessor_error);
1148 set_intr_gate(17,&alignment_check);
1149 #ifdef CONFIG_X86_MCE
1150 set_intr_gate_ist(18,&machine_check, MCE_STACK);
1152 set_intr_gate(19,&simd_coprocessor_error);
1154 #ifdef CONFIG_IA32_EMULATION
1155 set_system_gate(IA32_SYSCALL_VECTOR, ia32_syscall);
1159 * Should be a barrier for any external CPU state.
1165 /* Actual parsing is done early in setup.c. */
1166 static int __init oops_dummy(char *s)
1171 __setup("oops=", oops_dummy);
1173 static int __init kstack_setup(char *s)
1175 kstack_depth_to_print = simple_strtoul(s,NULL,0);
1178 __setup("kstack=", kstack_setup);
1180 #ifdef CONFIG_STACK_UNWIND
1181 static int __init call_trace_setup(char *s)
1183 if (strcmp(s, "old") == 0)
1185 else if (strcmp(s, "both") == 0)
1187 else if (strcmp(s, "newfallback") == 0)
1189 else if (strcmp(s, "new") == 0)
1193 __setup("call_trace=", call_trace_setup);