2 * Copyright (C) 1991, 1992 Linus Torvalds
3 * Copyright (C) 2000, 2001, 2002 Andi Kleen, SuSE Labs
5 * Pentium III FXSR, SSE support
6 * Gareth Hughes <gareth@valinux.com>, May 2000
10 * 'Traps.c' handles hardware traps and faults after we have saved some
13 #include <linux/sched.h>
14 #include <linux/kernel.h>
15 #include <linux/string.h>
16 #include <linux/errno.h>
17 #include <linux/ptrace.h>
18 #include <linux/timer.h>
20 #include <linux/init.h>
21 #include <linux/delay.h>
22 #include <linux/spinlock.h>
23 #include <linux/interrupt.h>
24 #include <linux/kallsyms.h>
25 #include <linux/module.h>
26 #include <linux/moduleparam.h>
27 #include <linux/nmi.h>
28 #include <linux/kprobes.h>
29 #include <linux/kexec.h>
30 #include <linux/unwind.h>
31 #include <linux/uaccess.h>
32 #include <linux/bug.h>
33 #include <linux/kdebug.h>
34 #include <linux/utsname.h>
36 #if defined(CONFIG_EDAC)
37 #include <linux/edac.h>
40 #include <asm/system.h>
42 #include <asm/atomic.h>
43 #include <asm/debugreg.h>
46 #include <asm/processor.h>
47 #include <asm/unwind.h>
49 #include <asm/pgalloc.h>
51 #include <asm/proto.h>
53 #include <asm/stacktrace.h>
55 asmlinkage void divide_error(void);
56 asmlinkage void debug(void);
57 asmlinkage void nmi(void);
58 asmlinkage void int3(void);
59 asmlinkage void overflow(void);
60 asmlinkage void bounds(void);
61 asmlinkage void invalid_op(void);
62 asmlinkage void device_not_available(void);
63 asmlinkage void double_fault(void);
64 asmlinkage void coprocessor_segment_overrun(void);
65 asmlinkage void invalid_TSS(void);
66 asmlinkage void segment_not_present(void);
67 asmlinkage void stack_segment(void);
68 asmlinkage void general_protection(void);
69 asmlinkage void page_fault(void);
70 asmlinkage void coprocessor_error(void);
71 asmlinkage void simd_coprocessor_error(void);
72 asmlinkage void reserved(void);
73 asmlinkage void alignment_check(void);
74 asmlinkage void machine_check(void);
75 asmlinkage void spurious_interrupt_bug(void);
77 static unsigned int code_bytes = 64;
79 static inline void conditional_sti(struct pt_regs *regs)
81 if (regs->flags & X86_EFLAGS_IF)
85 static inline void preempt_conditional_sti(struct pt_regs *regs)
88 if (regs->flags & X86_EFLAGS_IF)
92 static inline void preempt_conditional_cli(struct pt_regs *regs)
94 if (regs->flags & X86_EFLAGS_IF)
96 /* Make sure to not schedule here because we could be running
97 on an exception stack. */
98 preempt_enable_no_resched();
101 int kstack_depth_to_print = 12;
103 #ifdef CONFIG_KALLSYMS
104 void printk_address(unsigned long address, int reliable)
106 unsigned long offset = 0, symsize;
111 char reliab[4] = "";;
113 symname = kallsyms_lookup(address, &symsize, &offset,
116 printk(" [<%016lx>]\n", address);
120 strcpy(reliab, "? ");
123 modname = delim = "";
124 printk(" [<%016lx>] %s%s%s%s%s+0x%lx/0x%lx\n",
125 address, reliab, delim, modname, delim, symname, offset, symsize);
128 void printk_address(unsigned long address, int reliable)
130 printk(" [<%016lx>]\n", address);
134 static unsigned long *in_exception_stack(unsigned cpu, unsigned long stack,
135 unsigned *usedp, char **idp)
137 static char ids[][8] = {
138 [DEBUG_STACK - 1] = "#DB",
139 [NMI_STACK - 1] = "NMI",
140 [DOUBLEFAULT_STACK - 1] = "#DF",
141 [STACKFAULT_STACK - 1] = "#SS",
142 [MCE_STACK - 1] = "#MC",
143 #if DEBUG_STKSZ > EXCEPTION_STKSZ
144 [N_EXCEPTION_STACKS ... N_EXCEPTION_STACKS + DEBUG_STKSZ / EXCEPTION_STKSZ - 2] = "#DB[?]"
150 * Iterate over all exception stacks, and figure out whether
151 * 'stack' is in one of them:
153 for (k = 0; k < N_EXCEPTION_STACKS; k++) {
154 unsigned long end = per_cpu(orig_ist, cpu).ist[k];
156 * Is 'stack' above this exception frame's end?
157 * If yes then skip to the next frame.
162 * Is 'stack' above this exception frame's start address?
163 * If yes then we found the right frame.
165 if (stack >= end - EXCEPTION_STKSZ) {
167 * Make sure we only iterate through an exception
168 * stack once. If it comes up for the second time
169 * then there's something wrong going on - just
170 * break out and return NULL:
172 if (*usedp & (1U << k))
176 return (unsigned long *)end;
179 * If this is a debug stack, and if it has a larger size than
180 * the usual exception stacks, then 'stack' might still
181 * be within the lower portion of the debug stack:
183 #if DEBUG_STKSZ > EXCEPTION_STKSZ
184 if (k == DEBUG_STACK - 1 && stack >= end - DEBUG_STKSZ) {
185 unsigned j = N_EXCEPTION_STACKS - 1;
188 * Black magic. A large debug stack is composed of
189 * multiple exception stack entries, which we
190 * iterate through now. Dont look:
194 end -= EXCEPTION_STKSZ;
195 ids[j][4] = '1' + (j - N_EXCEPTION_STACKS);
196 } while (stack < end - EXCEPTION_STKSZ);
197 if (*usedp & (1U << j))
201 return (unsigned long *)end;
208 #define MSG(txt) ops->warning(data, txt)
211 * x86-64 can have up to three kernel stacks:
214 * severe exception (double fault, nmi, stack fault, debug, mce) hardware stack
217 static inline int valid_stack_ptr(struct thread_info *tinfo,
218 void *p, unsigned int size, void *end)
220 void *t = (void *)tinfo;
222 if (p < end && p >= (end-THREAD_SIZE))
227 return p > t && p < t + THREAD_SIZE - size;
230 /* The form of the top of the frame on the stack */
232 struct stack_frame *next_frame;
233 unsigned long return_address;
237 static inline unsigned long print_context_stack(struct thread_info *tinfo,
238 unsigned long *stack, unsigned long bp,
239 const struct stacktrace_ops *ops, void *data,
242 struct stack_frame *frame = (struct stack_frame *)bp;
244 while (valid_stack_ptr(tinfo, stack, sizeof(*stack), end)) {
248 if (__kernel_text_address(addr)) {
249 if ((unsigned long) stack == bp + 8) {
250 ops->address(data, addr, 1);
251 frame = frame->next_frame;
252 bp = (unsigned long) frame;
254 ops->address(data, addr, bp == 0);
262 void dump_trace(struct task_struct *tsk, struct pt_regs *regs,
263 unsigned long *stack, unsigned long bp,
264 const struct stacktrace_ops *ops, void *data)
266 const unsigned cpu = get_cpu();
267 unsigned long *irqstack_end = (unsigned long*)cpu_pda(cpu)->irqstackptr;
269 struct thread_info *tinfo;
273 tinfo = task_thread_info(tsk);
278 if (tsk && tsk != current)
279 stack = (unsigned long *)tsk->thread.sp;
282 #ifdef CONFIG_FRAME_POINTER
284 if (tsk == current) {
285 /* Grab bp right from our regs */
286 asm("movq %%rbp, %0" : "=r" (bp):);
288 /* bp is the last reg pushed by switch_to */
289 bp = *(unsigned long *) tsk->thread.sp;
297 * Print function call entries in all stacks, starting at the
298 * current stack address. If the stacks consist of nested
303 unsigned long *estack_end;
304 estack_end = in_exception_stack(cpu, (unsigned long)stack,
308 if (ops->stack(data, id) < 0)
311 bp = print_context_stack(tinfo, stack, bp, ops,
313 ops->stack(data, "<EOE>");
315 * We link to the next stack via the
316 * second-to-last pointer (index -2 to end) in the
319 stack = (unsigned long *) estack_end[-2];
323 unsigned long *irqstack;
324 irqstack = irqstack_end -
325 (IRQSTACKSIZE - 64) / sizeof(*irqstack);
327 if (stack >= irqstack && stack < irqstack_end) {
328 if (ops->stack(data, "IRQ") < 0)
330 bp = print_context_stack(tinfo, stack, bp,
331 ops, data, irqstack_end);
333 * We link to the next stack (which would be
334 * the process stack normally) the last
335 * pointer (index -1 to end) in the IRQ stack:
337 stack = (unsigned long *) (irqstack_end[-1]);
339 ops->stack(data, "EOI");
347 * This handles the process stack:
349 bp = print_context_stack(tinfo, stack, bp, ops, data, NULL);
352 EXPORT_SYMBOL(dump_trace);
355 print_trace_warning_symbol(void *data, char *msg, unsigned long symbol)
357 print_symbol(msg, symbol);
361 static void print_trace_warning(void *data, char *msg)
366 static int print_trace_stack(void *data, char *name)
368 printk(" <%s> ", name);
372 static void print_trace_address(void *data, unsigned long addr, int reliable)
374 touch_nmi_watchdog();
375 printk_address(addr, reliable);
378 static const struct stacktrace_ops print_trace_ops = {
379 .warning = print_trace_warning,
380 .warning_symbol = print_trace_warning_symbol,
381 .stack = print_trace_stack,
382 .address = print_trace_address,
386 show_trace(struct task_struct *tsk, struct pt_regs *regs, unsigned long *stack,
389 printk("\nCall Trace:\n");
390 dump_trace(tsk, regs, stack, bp, &print_trace_ops, NULL);
395 _show_stack(struct task_struct *tsk, struct pt_regs *regs, unsigned long *sp,
398 unsigned long *stack;
400 const int cpu = smp_processor_id();
401 unsigned long *irqstack_end = (unsigned long *) (cpu_pda(cpu)->irqstackptr);
402 unsigned long *irqstack = (unsigned long *) (cpu_pda(cpu)->irqstackptr - IRQSTACKSIZE);
404 // debugging aid: "show_stack(NULL, NULL);" prints the
405 // back trace for this cpu.
409 sp = (unsigned long *)tsk->thread.sp;
411 sp = (unsigned long *)&sp;
415 for(i=0; i < kstack_depth_to_print; i++) {
416 if (stack >= irqstack && stack <= irqstack_end) {
417 if (stack == irqstack_end) {
418 stack = (unsigned long *) (irqstack_end[-1]);
422 if (((long) stack & (THREAD_SIZE-1)) == 0)
425 if (i && ((i % 4) == 0))
427 printk(" %016lx", *stack++);
428 touch_nmi_watchdog();
430 show_trace(tsk, regs, sp, bp);
433 void show_stack(struct task_struct *tsk, unsigned long * sp)
435 _show_stack(tsk, NULL, sp, 0);
439 * The architecture-independent dump_stack generator
441 void dump_stack(void)
444 unsigned long bp = 0;
446 #ifdef CONFIG_FRAME_POINTER
448 asm("movq %%rbp, %0" : "=r" (bp):);
451 printk("Pid: %d, comm: %.20s %s %s %.*s\n",
452 current->pid, current->comm, print_tainted(),
453 init_utsname()->release,
454 (int)strcspn(init_utsname()->version, " "),
455 init_utsname()->version);
456 show_trace(NULL, NULL, &dummy, bp);
459 EXPORT_SYMBOL(dump_stack);
461 void show_registers(struct pt_regs *regs)
465 const int cpu = smp_processor_id();
466 struct task_struct *cur = cpu_pda(cpu)->pcurrent;
468 unsigned int code_prologue = code_bytes * 43 / 64;
469 unsigned int code_len = code_bytes;
472 ip = (u8 *) regs->ip - code_prologue;
473 printk("CPU %d ", cpu);
475 printk("Process %s (pid: %d, threadinfo %p, task %p)\n",
476 cur->comm, cur->pid, task_thread_info(cur), cur);
479 * When in-kernel, we also print out the stack and code at the
480 * time of the fault..
482 if (!user_mode(regs)) {
485 _show_stack(NULL, regs, (unsigned long *)sp, regs->bp);
488 printk(KERN_EMERG "Code: ");
489 if (ip < (u8 *)PAGE_OFFSET || probe_kernel_address(ip, c)) {
490 /* try starting at RIP */
491 ip = (u8 *) regs->ip;
492 code_len = code_len - code_prologue + 1;
494 for (i = 0; i < code_len; i++, ip++) {
495 if (ip < (u8 *)PAGE_OFFSET ||
496 probe_kernel_address(ip, c)) {
497 printk(" Bad RIP value.");
500 if (ip == (u8 *)regs->ip)
501 printk("<%02x> ", c);
509 int is_valid_bugaddr(unsigned long ip)
513 if (__copy_from_user(&ud2, (const void __user *) ip, sizeof(ud2)))
516 return ud2 == 0x0b0f;
519 static raw_spinlock_t die_lock = __RAW_SPIN_LOCK_UNLOCKED;
520 static int die_owner = -1;
521 static unsigned int die_nest_count;
523 unsigned __kprobes long oops_begin(void)
530 /* racy, but better than risking deadlock. */
531 raw_local_irq_save(flags);
532 cpu = smp_processor_id();
533 if (!__raw_spin_trylock(&die_lock)) {
534 if (cpu == die_owner)
535 /* nested oops. should stop eventually */;
537 __raw_spin_lock(&die_lock);
546 void __kprobes oops_end(unsigned long flags, struct pt_regs *regs, int signr)
552 /* Nest count reaches zero, release the lock. */
553 __raw_spin_unlock(&die_lock);
554 raw_local_irq_restore(flags);
560 panic("Fatal exception");
565 int __kprobes __die(const char * str, struct pt_regs * regs, long err)
567 static int die_counter;
568 printk(KERN_EMERG "%s: %04lx [%u] ", str, err & 0xffff,++die_counter);
569 #ifdef CONFIG_PREEMPT
575 #ifdef CONFIG_DEBUG_PAGEALLOC
576 printk("DEBUG_PAGEALLOC");
579 if (notify_die(DIE_OOPS, str, regs, err, current->thread.trap_no, SIGSEGV) == NOTIFY_STOP)
581 show_registers(regs);
582 add_taint(TAINT_DIE);
583 /* Executive summary in case the oops scrolled away */
584 printk(KERN_ALERT "RIP ");
585 printk_address(regs->ip, regs->bp);
586 printk(" RSP <%016lx>\n", regs->sp);
587 if (kexec_should_crash(current))
592 void die(const char * str, struct pt_regs * regs, long err)
594 unsigned long flags = oops_begin();
596 if (!user_mode(regs))
597 report_bug(regs->ip, regs);
599 if (__die(str, regs, err))
601 oops_end(flags, regs, SIGSEGV);
604 void __kprobes die_nmi(char *str, struct pt_regs *regs, int do_panic)
606 unsigned long flags = oops_begin();
609 * We are in trouble anyway, lets at least try
610 * to get a message out.
612 printk(str, smp_processor_id());
613 show_registers(regs);
614 if (kexec_should_crash(current))
616 if (do_panic || panic_on_oops)
617 panic("Non maskable interrupt");
618 oops_end(flags, NULL, SIGBUS);
624 static void __kprobes do_trap(int trapnr, int signr, char *str,
625 struct pt_regs * regs, long error_code,
628 struct task_struct *tsk = current;
630 if (user_mode(regs)) {
632 * We want error_code and trap_no set for userspace
633 * faults and kernelspace faults which result in
634 * die(), but not kernelspace faults which are fixed
635 * up. die() gives the process no chance to handle
636 * the signal and notice the kernel fault information,
637 * so that won't result in polluting the information
638 * about previously queued, but not yet delivered,
639 * faults. See also do_general_protection below.
641 tsk->thread.error_code = error_code;
642 tsk->thread.trap_no = trapnr;
644 if (show_unhandled_signals && unhandled_signal(tsk, signr) &&
647 "%s[%d] trap %s ip:%lx sp:%lx error:%lx\n",
648 tsk->comm, tsk->pid, str,
649 regs->ip, regs->sp, error_code);
652 force_sig_info(signr, info, tsk);
654 force_sig(signr, tsk);
659 if (!fixup_exception(regs)) {
660 tsk->thread.error_code = error_code;
661 tsk->thread.trap_no = trapnr;
662 die(str, regs, error_code);
667 #define DO_ERROR(trapnr, signr, str, name) \
668 asmlinkage void do_##name(struct pt_regs * regs, long error_code) \
670 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
673 conditional_sti(regs); \
674 do_trap(trapnr, signr, str, regs, error_code, NULL); \
677 #define DO_ERROR_INFO(trapnr, signr, str, name, sicode, siaddr) \
678 asmlinkage void do_##name(struct pt_regs * regs, long error_code) \
681 info.si_signo = signr; \
683 info.si_code = sicode; \
684 info.si_addr = (void __user *)siaddr; \
685 trace_hardirqs_fixup(); \
686 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
689 conditional_sti(regs); \
690 do_trap(trapnr, signr, str, regs, error_code, &info); \
693 DO_ERROR_INFO( 0, SIGFPE, "divide error", divide_error, FPE_INTDIV, regs->ip)
694 DO_ERROR( 4, SIGSEGV, "overflow", overflow)
695 DO_ERROR( 5, SIGSEGV, "bounds", bounds)
696 DO_ERROR_INFO( 6, SIGILL, "invalid opcode", invalid_op, ILL_ILLOPN, regs->ip)
697 DO_ERROR( 7, SIGSEGV, "device not available", device_not_available)
698 DO_ERROR( 9, SIGFPE, "coprocessor segment overrun", coprocessor_segment_overrun)
699 DO_ERROR(10, SIGSEGV, "invalid TSS", invalid_TSS)
700 DO_ERROR(11, SIGBUS, "segment not present", segment_not_present)
701 DO_ERROR_INFO(17, SIGBUS, "alignment check", alignment_check, BUS_ADRALN, 0)
702 DO_ERROR(18, SIGSEGV, "reserved", reserved)
704 /* Runs on IST stack */
705 asmlinkage void do_stack_segment(struct pt_regs *regs, long error_code)
707 if (notify_die(DIE_TRAP, "stack segment", regs, error_code,
708 12, SIGBUS) == NOTIFY_STOP)
710 preempt_conditional_sti(regs);
711 do_trap(12, SIGBUS, "stack segment", regs, error_code, NULL);
712 preempt_conditional_cli(regs);
715 asmlinkage void do_double_fault(struct pt_regs * regs, long error_code)
717 static const char str[] = "double fault";
718 struct task_struct *tsk = current;
720 /* Return not checked because double check cannot be ignored */
721 notify_die(DIE_TRAP, str, regs, error_code, 8, SIGSEGV);
723 tsk->thread.error_code = error_code;
724 tsk->thread.trap_no = 8;
726 /* This is always a kernel trap and never fixable (and thus must
729 die(str, regs, error_code);
732 asmlinkage void __kprobes do_general_protection(struct pt_regs * regs,
735 struct task_struct *tsk = current;
737 conditional_sti(regs);
739 if (user_mode(regs)) {
740 tsk->thread.error_code = error_code;
741 tsk->thread.trap_no = 13;
743 if (show_unhandled_signals && unhandled_signal(tsk, SIGSEGV) &&
746 "%s[%d] general protection ip:%lx sp:%lx error:%lx\n",
748 regs->ip, regs->sp, error_code);
750 force_sig(SIGSEGV, tsk);
754 if (fixup_exception(regs))
757 tsk->thread.error_code = error_code;
758 tsk->thread.trap_no = 13;
759 if (notify_die(DIE_GPF, "general protection fault", regs,
760 error_code, 13, SIGSEGV) == NOTIFY_STOP)
762 die("general protection fault", regs, error_code);
765 static __kprobes void
766 mem_parity_error(unsigned char reason, struct pt_regs * regs)
768 printk(KERN_EMERG "Uhhuh. NMI received for unknown reason %02x.\n",
770 printk(KERN_EMERG "You have some hardware problem, likely on the PCI bus.\n");
772 #if defined(CONFIG_EDAC)
773 if(edac_handler_set()) {
774 edac_atomic_assert_error();
779 if (panic_on_unrecovered_nmi)
780 panic("NMI: Not continuing");
782 printk(KERN_EMERG "Dazed and confused, but trying to continue\n");
784 /* Clear and disable the memory parity error line. */
785 reason = (reason & 0xf) | 4;
789 static __kprobes void
790 io_check_error(unsigned char reason, struct pt_regs * regs)
792 printk("NMI: IOCK error (debug interrupt?)\n");
793 show_registers(regs);
795 /* Re-enable the IOCK line, wait for a few seconds */
796 reason = (reason & 0xf) | 8;
803 static __kprobes void
804 unknown_nmi_error(unsigned char reason, struct pt_regs * regs)
806 printk(KERN_EMERG "Uhhuh. NMI received for unknown reason %02x.\n",
808 printk(KERN_EMERG "Do you have a strange power saving mode enabled?\n");
810 if (panic_on_unrecovered_nmi)
811 panic("NMI: Not continuing");
813 printk(KERN_EMERG "Dazed and confused, but trying to continue\n");
816 /* Runs on IST stack. This code must keep interrupts off all the time.
817 Nested NMIs are prevented by the CPU. */
818 asmlinkage __kprobes void default_do_nmi(struct pt_regs *regs)
820 unsigned char reason = 0;
823 cpu = smp_processor_id();
825 /* Only the BSP gets external NMIs from the system. */
827 reason = get_nmi_reason();
829 if (!(reason & 0xc0)) {
830 if (notify_die(DIE_NMI_IPI, "nmi_ipi", regs, reason, 2, SIGINT)
834 * Ok, so this is none of the documented NMI sources,
835 * so it must be the NMI watchdog.
837 if (nmi_watchdog_tick(regs,reason))
839 if (!do_nmi_callback(regs,cpu))
840 unknown_nmi_error(reason, regs);
844 if (notify_die(DIE_NMI, "nmi", regs, reason, 2, SIGINT) == NOTIFY_STOP)
847 /* AK: following checks seem to be broken on modern chipsets. FIXME */
850 mem_parity_error(reason, regs);
852 io_check_error(reason, regs);
855 /* runs on IST stack. */
856 asmlinkage void __kprobes do_int3(struct pt_regs * regs, long error_code)
858 trace_hardirqs_fixup();
860 if (notify_die(DIE_INT3, "int3", regs, error_code, 3, SIGTRAP) == NOTIFY_STOP) {
863 preempt_conditional_sti(regs);
864 do_trap(3, SIGTRAP, "int3", regs, error_code, NULL);
865 preempt_conditional_cli(regs);
868 /* Help handler running on IST stack to switch back to user stack
869 for scheduling or signal handling. The actual stack switch is done in
871 asmlinkage __kprobes struct pt_regs *sync_regs(struct pt_regs *eregs)
873 struct pt_regs *regs = eregs;
874 /* Did already sync */
875 if (eregs == (struct pt_regs *)eregs->sp)
877 /* Exception from user space */
878 else if (user_mode(eregs))
879 regs = task_pt_regs(current);
880 /* Exception from kernel and interrupts are enabled. Move to
881 kernel process stack. */
882 else if (eregs->flags & X86_EFLAGS_IF)
883 regs = (struct pt_regs *)(eregs->sp -= sizeof(struct pt_regs));
889 /* runs on IST stack. */
890 asmlinkage void __kprobes do_debug(struct pt_regs * regs,
891 unsigned long error_code)
893 unsigned long condition;
894 struct task_struct *tsk = current;
897 trace_hardirqs_fixup();
899 get_debugreg(condition, 6);
902 * The processor cleared BTF, so don't mark that we need it set.
904 clear_tsk_thread_flag(tsk, TIF_DEBUGCTLMSR);
905 tsk->thread.debugctlmsr = 0;
907 if (notify_die(DIE_DEBUG, "debug", regs, condition, error_code,
908 SIGTRAP) == NOTIFY_STOP)
911 preempt_conditional_sti(regs);
913 /* Mask out spurious debug traps due to lazy DR7 setting */
914 if (condition & (DR_TRAP0|DR_TRAP1|DR_TRAP2|DR_TRAP3)) {
915 if (!tsk->thread.debugreg7) {
920 tsk->thread.debugreg6 = condition;
924 * Single-stepping through TF: make sure we ignore any events in
925 * kernel space (but re-enable TF when returning to user mode).
927 if (condition & DR_STEP) {
928 if (!user_mode(regs))
929 goto clear_TF_reenable;
932 /* Ok, finally something we can handle */
933 tsk->thread.trap_no = 1;
934 tsk->thread.error_code = error_code;
935 info.si_signo = SIGTRAP;
937 info.si_code = TRAP_BRKPT;
938 info.si_addr = user_mode(regs) ? (void __user *)regs->ip : NULL;
939 force_sig_info(SIGTRAP, &info, tsk);
942 set_debugreg(0UL, 7);
943 preempt_conditional_cli(regs);
947 set_tsk_thread_flag(tsk, TIF_SINGLESTEP);
948 regs->flags &= ~X86_EFLAGS_TF;
949 preempt_conditional_cli(regs);
952 static int kernel_math_error(struct pt_regs *regs, const char *str, int trapnr)
954 if (fixup_exception(regs))
957 notify_die(DIE_GPF, str, regs, 0, trapnr, SIGFPE);
958 /* Illegal floating point operation in the kernel */
959 current->thread.trap_no = trapnr;
965 * Note that we play around with the 'TS' bit in an attempt to get
966 * the correct behaviour even in the presence of the asynchronous
969 asmlinkage void do_coprocessor_error(struct pt_regs *regs)
971 void __user *ip = (void __user *)(regs->ip);
972 struct task_struct * task;
974 unsigned short cwd, swd;
976 conditional_sti(regs);
977 if (!user_mode(regs) &&
978 kernel_math_error(regs, "kernel x87 math error", 16))
982 * Save the info for the exception handler and clear the error.
986 task->thread.trap_no = 16;
987 task->thread.error_code = 0;
988 info.si_signo = SIGFPE;
990 info.si_code = __SI_FAULT;
993 * (~cwd & swd) will mask out exceptions that are not set to unmasked
994 * status. 0x3f is the exception bits in these regs, 0x200 is the
995 * C1 reg you need in case of a stack fault, 0x040 is the stack
996 * fault bit. We should only be taking one exception at a time,
997 * so if this combination doesn't produce any single exception,
998 * then we have a bad program that isn't synchronizing its FPU usage
999 * and it will suffer the consequences since we won't be able to
1000 * fully reproduce the context of the exception
1002 cwd = get_fpu_cwd(task);
1003 swd = get_fpu_swd(task);
1004 switch (swd & ~cwd & 0x3f) {
1008 case 0x001: /* Invalid Op */
1010 * swd & 0x240 == 0x040: Stack Underflow
1011 * swd & 0x240 == 0x240: Stack Overflow
1012 * User must clear the SF bit (0x40) if set
1014 info.si_code = FPE_FLTINV;
1016 case 0x002: /* Denormalize */
1017 case 0x010: /* Underflow */
1018 info.si_code = FPE_FLTUND;
1020 case 0x004: /* Zero Divide */
1021 info.si_code = FPE_FLTDIV;
1023 case 0x008: /* Overflow */
1024 info.si_code = FPE_FLTOVF;
1026 case 0x020: /* Precision */
1027 info.si_code = FPE_FLTRES;
1030 force_sig_info(SIGFPE, &info, task);
1033 asmlinkage void bad_intr(void)
1035 printk("bad interrupt");
1038 asmlinkage void do_simd_coprocessor_error(struct pt_regs *regs)
1040 void __user *ip = (void __user *)(regs->ip);
1041 struct task_struct * task;
1043 unsigned short mxcsr;
1045 conditional_sti(regs);
1046 if (!user_mode(regs) &&
1047 kernel_math_error(regs, "kernel simd math error", 19))
1051 * Save the info for the exception handler and clear the error.
1054 save_init_fpu(task);
1055 task->thread.trap_no = 19;
1056 task->thread.error_code = 0;
1057 info.si_signo = SIGFPE;
1059 info.si_code = __SI_FAULT;
1062 * The SIMD FPU exceptions are handled a little differently, as there
1063 * is only a single status/control register. Thus, to determine which
1064 * unmasked exception was caught we must mask the exception mask bits
1065 * at 0x1f80, and then use these to mask the exception bits at 0x3f.
1067 mxcsr = get_fpu_mxcsr(task);
1068 switch (~((mxcsr & 0x1f80) >> 7) & (mxcsr & 0x3f)) {
1072 case 0x001: /* Invalid Op */
1073 info.si_code = FPE_FLTINV;
1075 case 0x002: /* Denormalize */
1076 case 0x010: /* Underflow */
1077 info.si_code = FPE_FLTUND;
1079 case 0x004: /* Zero Divide */
1080 info.si_code = FPE_FLTDIV;
1082 case 0x008: /* Overflow */
1083 info.si_code = FPE_FLTOVF;
1085 case 0x020: /* Precision */
1086 info.si_code = FPE_FLTRES;
1089 force_sig_info(SIGFPE, &info, task);
1092 asmlinkage void do_spurious_interrupt_bug(struct pt_regs * regs)
1096 asmlinkage void __attribute__((weak)) smp_thermal_interrupt(void)
1100 asmlinkage void __attribute__((weak)) mce_threshold_interrupt(void)
1105 * 'math_state_restore()' saves the current math information in the
1106 * old math state array, and gets the new ones from the current task
1108 * Careful.. There are problems with IBM-designed IRQ13 behaviour.
1109 * Don't touch unless you *really* know how it works.
1111 asmlinkage void math_state_restore(void)
1113 struct task_struct *me = current;
1114 clts(); /* Allow maths ops (or we recurse) */
1118 restore_fpu_checking(&me->thread.i387.fxsave);
1119 task_thread_info(me)->status |= TS_USEDFPU;
1122 EXPORT_SYMBOL_GPL(math_state_restore);
1124 void __init trap_init(void)
1126 set_intr_gate(0,÷_error);
1127 set_intr_gate_ist(1,&debug,DEBUG_STACK);
1128 set_intr_gate_ist(2,&nmi,NMI_STACK);
1129 set_system_gate_ist(3,&int3,DEBUG_STACK); /* int3 can be called from all */
1130 set_system_gate(4,&overflow); /* int4 can be called from all */
1131 set_intr_gate(5,&bounds);
1132 set_intr_gate(6,&invalid_op);
1133 set_intr_gate(7,&device_not_available);
1134 set_intr_gate_ist(8,&double_fault, DOUBLEFAULT_STACK);
1135 set_intr_gate(9,&coprocessor_segment_overrun);
1136 set_intr_gate(10,&invalid_TSS);
1137 set_intr_gate(11,&segment_not_present);
1138 set_intr_gate_ist(12,&stack_segment,STACKFAULT_STACK);
1139 set_intr_gate(13,&general_protection);
1140 set_intr_gate(14,&page_fault);
1141 set_intr_gate(15,&spurious_interrupt_bug);
1142 set_intr_gate(16,&coprocessor_error);
1143 set_intr_gate(17,&alignment_check);
1144 #ifdef CONFIG_X86_MCE
1145 set_intr_gate_ist(18,&machine_check, MCE_STACK);
1147 set_intr_gate(19,&simd_coprocessor_error);
1149 #ifdef CONFIG_IA32_EMULATION
1150 set_system_gate(IA32_SYSCALL_VECTOR, ia32_syscall);
1154 * Should be a barrier for any external CPU state.
1160 static int __init oops_setup(char *s)
1164 if (!strcmp(s, "panic"))
1168 early_param("oops", oops_setup);
1170 static int __init kstack_setup(char *s)
1174 kstack_depth_to_print = simple_strtoul(s,NULL,0);
1177 early_param("kstack", kstack_setup);
1180 static int __init code_bytes_setup(char *s)
1182 code_bytes = simple_strtoul(s, NULL, 0);
1183 if (code_bytes > 8192)
1188 __setup("code_bytes=", code_bytes_setup);