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 inline void conditional_sti(struct pt_regs *regs)
79 if (regs->eflags & X86_EFLAGS_IF)
83 static inline void preempt_conditional_sti(struct pt_regs *regs)
86 if (regs->eflags & X86_EFLAGS_IF)
90 static inline void preempt_conditional_cli(struct pt_regs *regs)
92 if (regs->eflags & X86_EFLAGS_IF)
94 /* Make sure to not schedule here because we could be running
95 on an exception stack. */
96 preempt_enable_no_resched();
99 int kstack_depth_to_print = 12;
101 #ifdef CONFIG_KALLSYMS
102 void printk_address(unsigned long address)
104 unsigned long offset = 0, symsize;
110 symname = kallsyms_lookup(address, &symsize, &offset,
113 printk(" [<%016lx>]\n", address);
117 modname = delim = "";
118 printk(" [<%016lx>] %s%s%s%s+0x%lx/0x%lx\n",
119 address, delim, modname, delim, symname, offset, symsize);
122 void printk_address(unsigned long address)
124 printk(" [<%016lx>]\n", address);
128 static unsigned long *in_exception_stack(unsigned cpu, unsigned long stack,
129 unsigned *usedp, char **idp)
131 static char ids[][8] = {
132 [DEBUG_STACK - 1] = "#DB",
133 [NMI_STACK - 1] = "NMI",
134 [DOUBLEFAULT_STACK - 1] = "#DF",
135 [STACKFAULT_STACK - 1] = "#SS",
136 [MCE_STACK - 1] = "#MC",
137 #if DEBUG_STKSZ > EXCEPTION_STKSZ
138 [N_EXCEPTION_STACKS ... N_EXCEPTION_STACKS + DEBUG_STKSZ / EXCEPTION_STKSZ - 2] = "#DB[?]"
144 * Iterate over all exception stacks, and figure out whether
145 * 'stack' is in one of them:
147 for (k = 0; k < N_EXCEPTION_STACKS; k++) {
148 unsigned long end = per_cpu(orig_ist, cpu).ist[k];
150 * Is 'stack' above this exception frame's end?
151 * If yes then skip to the next frame.
156 * Is 'stack' above this exception frame's start address?
157 * If yes then we found the right frame.
159 if (stack >= end - EXCEPTION_STKSZ) {
161 * Make sure we only iterate through an exception
162 * stack once. If it comes up for the second time
163 * then there's something wrong going on - just
164 * break out and return NULL:
166 if (*usedp & (1U << k))
170 return (unsigned long *)end;
173 * If this is a debug stack, and if it has a larger size than
174 * the usual exception stacks, then 'stack' might still
175 * be within the lower portion of the debug stack:
177 #if DEBUG_STKSZ > EXCEPTION_STKSZ
178 if (k == DEBUG_STACK - 1 && stack >= end - DEBUG_STKSZ) {
179 unsigned j = N_EXCEPTION_STACKS - 1;
182 * Black magic. A large debug stack is composed of
183 * multiple exception stack entries, which we
184 * iterate through now. Dont look:
188 end -= EXCEPTION_STKSZ;
189 ids[j][4] = '1' + (j - N_EXCEPTION_STACKS);
190 } while (stack < end - EXCEPTION_STKSZ);
191 if (*usedp & (1U << j))
195 return (unsigned long *)end;
202 #define MSG(txt) ops->warning(data, txt)
205 * x86-64 can have up to three kernel stacks:
208 * severe exception (double fault, nmi, stack fault, debug, mce) hardware stack
211 static inline int valid_stack_ptr(struct thread_info *tinfo, void *p)
213 void *t = (void *)tinfo;
214 return p > t && p < t + THREAD_SIZE - 3;
217 void dump_trace(struct task_struct *tsk, struct pt_regs *regs,
218 unsigned long *stack,
219 const struct stacktrace_ops *ops, void *data)
221 const unsigned cpu = get_cpu();
222 unsigned long *irqstack_end = (unsigned long*)cpu_pda(cpu)->irqstackptr;
224 struct thread_info *tinfo;
232 if (tsk && tsk != current)
233 stack = (unsigned long *)tsk->thread.rsp;
237 * Print function call entries within a stack. 'cond' is the
238 * "end of stackframe" condition, that the 'stack++'
239 * iteration will eventually trigger.
241 #define HANDLE_STACK(cond) \
243 unsigned long addr = *stack++; \
244 /* Use unlocked access here because except for NMIs \
245 we should be already protected against module unloads */ \
246 if (__kernel_text_address(addr)) { \
248 * If the address is either in the text segment of the \
249 * kernel, or in the region which contains vmalloc'ed \
250 * memory, it *may* be the address of a calling \
251 * routine; if so, print it so that someone tracing \
252 * down the cause of the crash will be able to figure \
253 * out the call path that was taken. \
255 ops->address(data, addr); \
260 * Print function call entries in all stacks, starting at the
261 * current stack address. If the stacks consist of nested
266 unsigned long *estack_end;
267 estack_end = in_exception_stack(cpu, (unsigned long)stack,
271 if (ops->stack(data, id) < 0)
273 HANDLE_STACK (stack < estack_end);
274 ops->stack(data, "<EOE>");
276 * We link to the next stack via the
277 * second-to-last pointer (index -2 to end) in the
280 stack = (unsigned long *) estack_end[-2];
284 unsigned long *irqstack;
285 irqstack = irqstack_end -
286 (IRQSTACKSIZE - 64) / sizeof(*irqstack);
288 if (stack >= irqstack && stack < irqstack_end) {
289 if (ops->stack(data, "IRQ") < 0)
291 HANDLE_STACK (stack < irqstack_end);
293 * We link to the next stack (which would be
294 * the process stack normally) the last
295 * pointer (index -1 to end) in the IRQ stack:
297 stack = (unsigned long *) (irqstack_end[-1]);
299 ops->stack(data, "EOI");
307 * This handles the process stack:
309 tinfo = task_thread_info(tsk);
310 HANDLE_STACK (valid_stack_ptr(tinfo, stack));
314 EXPORT_SYMBOL(dump_trace);
317 print_trace_warning_symbol(void *data, char *msg, unsigned long symbol)
319 print_symbol(msg, symbol);
323 static void print_trace_warning(void *data, char *msg)
328 static int print_trace_stack(void *data, char *name)
330 printk(" <%s> ", name);
334 static void print_trace_address(void *data, unsigned long addr)
336 touch_nmi_watchdog();
337 printk_address(addr);
340 static const struct stacktrace_ops print_trace_ops = {
341 .warning = print_trace_warning,
342 .warning_symbol = print_trace_warning_symbol,
343 .stack = print_trace_stack,
344 .address = print_trace_address,
348 show_trace(struct task_struct *tsk, struct pt_regs *regs, unsigned long *stack)
350 printk("\nCall Trace:\n");
351 dump_trace(tsk, regs, stack, &print_trace_ops, NULL);
356 _show_stack(struct task_struct *tsk, struct pt_regs *regs, unsigned long *rsp)
358 unsigned long *stack;
360 const int cpu = smp_processor_id();
361 unsigned long *irqstack_end = (unsigned long *) (cpu_pda(cpu)->irqstackptr);
362 unsigned long *irqstack = (unsigned long *) (cpu_pda(cpu)->irqstackptr - IRQSTACKSIZE);
364 // debugging aid: "show_stack(NULL, NULL);" prints the
365 // back trace for this cpu.
369 rsp = (unsigned long *)tsk->thread.rsp;
371 rsp = (unsigned long *)&rsp;
375 for(i=0; i < kstack_depth_to_print; i++) {
376 if (stack >= irqstack && stack <= irqstack_end) {
377 if (stack == irqstack_end) {
378 stack = (unsigned long *) (irqstack_end[-1]);
382 if (((long) stack & (THREAD_SIZE-1)) == 0)
385 if (i && ((i % 4) == 0))
387 printk(" %016lx", *stack++);
388 touch_nmi_watchdog();
390 show_trace(tsk, regs, rsp);
393 void show_stack(struct task_struct *tsk, unsigned long * rsp)
395 _show_stack(tsk, NULL, rsp);
399 * The architecture-independent dump_stack generator
401 void dump_stack(void)
405 printk("Pid: %d, comm: %.20s %s %s %.*s\n",
406 current->pid, current->comm, print_tainted(),
407 init_utsname()->release,
408 (int)strcspn(init_utsname()->version, " "),
409 init_utsname()->version);
410 show_trace(NULL, NULL, &dummy);
413 EXPORT_SYMBOL(dump_stack);
415 void show_registers(struct pt_regs *regs)
418 int in_kernel = !user_mode(regs);
420 const int cpu = smp_processor_id();
421 struct task_struct *cur = cpu_pda(cpu)->pcurrent;
424 printk("CPU %d ", cpu);
426 printk("Process %s (pid: %d, threadinfo %p, task %p)\n",
427 cur->comm, cur->pid, task_thread_info(cur), cur);
430 * When in-kernel, we also print out the stack and code at the
431 * time of the fault..
435 _show_stack(NULL, regs, (unsigned long*)rsp);
438 if (regs->rip < PAGE_OFFSET)
441 for (i=0; i<20; i++) {
443 if (__get_user(c, &((unsigned char*)regs->rip)[i])) {
445 printk(" Bad RIP value.");
454 int is_valid_bugaddr(unsigned long rip)
458 if (__copy_from_user(&ud2, (const void __user *) rip, sizeof(ud2)))
461 return ud2 == 0x0b0f;
465 void out_of_line_bug(void)
469 EXPORT_SYMBOL(out_of_line_bug);
472 static raw_spinlock_t die_lock = __RAW_SPIN_LOCK_UNLOCKED;
473 static int die_owner = -1;
474 static unsigned int die_nest_count;
476 unsigned __kprobes long oops_begin(void)
483 /* racy, but better than risking deadlock. */
484 raw_local_irq_save(flags);
485 cpu = smp_processor_id();
486 if (!__raw_spin_trylock(&die_lock)) {
487 if (cpu == die_owner)
488 /* nested oops. should stop eventually */;
490 __raw_spin_lock(&die_lock);
499 void __kprobes oops_end(unsigned long flags)
505 /* Nest count reaches zero, release the lock. */
506 __raw_spin_unlock(&die_lock);
507 raw_local_irq_restore(flags);
509 panic("Fatal exception");
513 void __kprobes __die(const char * str, struct pt_regs * regs, long err)
515 static int die_counter;
516 printk(KERN_EMERG "%s: %04lx [%u] ", str, err & 0xffff,++die_counter);
517 #ifdef CONFIG_PREEMPT
523 #ifdef CONFIG_DEBUG_PAGEALLOC
524 printk("DEBUG_PAGEALLOC");
527 notify_die(DIE_OOPS, str, regs, err, current->thread.trap_no, SIGSEGV);
528 show_registers(regs);
529 add_taint(TAINT_DIE);
530 /* Executive summary in case the oops scrolled away */
531 printk(KERN_ALERT "RIP ");
532 printk_address(regs->rip);
533 printk(" RSP <%016lx>\n", regs->rsp);
534 if (kexec_should_crash(current))
538 void die(const char * str, struct pt_regs * regs, long err)
540 unsigned long flags = oops_begin();
542 if (!user_mode(regs))
543 report_bug(regs->rip, regs);
545 __die(str, regs, err);
550 void __kprobes die_nmi(char *str, struct pt_regs *regs, int do_panic)
552 unsigned long flags = oops_begin();
555 * We are in trouble anyway, lets at least try
556 * to get a message out.
558 printk(str, smp_processor_id());
559 show_registers(regs);
560 if (kexec_should_crash(current))
562 if (do_panic || panic_on_oops)
563 panic("Non maskable interrupt");
570 static void __kprobes do_trap(int trapnr, int signr, char *str,
571 struct pt_regs * regs, long error_code,
574 struct task_struct *tsk = current;
576 if (user_mode(regs)) {
578 * We want error_code and trap_no set for userspace
579 * faults and kernelspace faults which result in
580 * die(), but not kernelspace faults which are fixed
581 * up. die() gives the process no chance to handle
582 * the signal and notice the kernel fault information,
583 * so that won't result in polluting the information
584 * about previously queued, but not yet delivered,
585 * faults. See also do_general_protection below.
587 tsk->thread.error_code = error_code;
588 tsk->thread.trap_no = trapnr;
590 if (show_unhandled_signals && unhandled_signal(tsk, signr) &&
593 "%s[%d] trap %s rip:%lx rsp:%lx error:%lx\n",
594 tsk->comm, tsk->pid, str,
595 regs->rip, regs->rsp, error_code);
598 force_sig_info(signr, info, tsk);
600 force_sig(signr, tsk);
607 const struct exception_table_entry *fixup;
608 fixup = search_exception_tables(regs->rip);
610 regs->rip = fixup->fixup;
612 tsk->thread.error_code = error_code;
613 tsk->thread.trap_no = trapnr;
614 die(str, regs, error_code);
620 #define DO_ERROR(trapnr, signr, str, name) \
621 asmlinkage void do_##name(struct pt_regs * regs, long error_code) \
623 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
626 conditional_sti(regs); \
627 do_trap(trapnr, signr, str, regs, error_code, NULL); \
630 #define DO_ERROR_INFO(trapnr, signr, str, name, sicode, siaddr) \
631 asmlinkage void do_##name(struct pt_regs * regs, long error_code) \
634 info.si_signo = signr; \
636 info.si_code = sicode; \
637 info.si_addr = (void __user *)siaddr; \
638 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
641 conditional_sti(regs); \
642 do_trap(trapnr, signr, str, regs, error_code, &info); \
645 DO_ERROR_INFO( 0, SIGFPE, "divide error", divide_error, FPE_INTDIV, regs->rip)
646 DO_ERROR( 4, SIGSEGV, "overflow", overflow)
647 DO_ERROR( 5, SIGSEGV, "bounds", bounds)
648 DO_ERROR_INFO( 6, SIGILL, "invalid opcode", invalid_op, ILL_ILLOPN, regs->rip)
649 DO_ERROR( 7, SIGSEGV, "device not available", device_not_available)
650 DO_ERROR( 9, SIGFPE, "coprocessor segment overrun", coprocessor_segment_overrun)
651 DO_ERROR(10, SIGSEGV, "invalid TSS", invalid_TSS)
652 DO_ERROR(11, SIGBUS, "segment not present", segment_not_present)
653 DO_ERROR_INFO(17, SIGBUS, "alignment check", alignment_check, BUS_ADRALN, 0)
654 DO_ERROR(18, SIGSEGV, "reserved", reserved)
656 /* Runs on IST stack */
657 asmlinkage void do_stack_segment(struct pt_regs *regs, long error_code)
659 if (notify_die(DIE_TRAP, "stack segment", regs, error_code,
660 12, SIGBUS) == NOTIFY_STOP)
662 preempt_conditional_sti(regs);
663 do_trap(12, SIGBUS, "stack segment", regs, error_code, NULL);
664 preempt_conditional_cli(regs);
667 asmlinkage void do_double_fault(struct pt_regs * regs, long error_code)
669 static const char str[] = "double fault";
670 struct task_struct *tsk = current;
672 /* Return not checked because double check cannot be ignored */
673 notify_die(DIE_TRAP, str, regs, error_code, 8, SIGSEGV);
675 tsk->thread.error_code = error_code;
676 tsk->thread.trap_no = 8;
678 /* This is always a kernel trap and never fixable (and thus must
681 die(str, regs, error_code);
684 asmlinkage void __kprobes do_general_protection(struct pt_regs * regs,
687 struct task_struct *tsk = current;
689 conditional_sti(regs);
691 if (user_mode(regs)) {
692 tsk->thread.error_code = error_code;
693 tsk->thread.trap_no = 13;
695 if (show_unhandled_signals && unhandled_signal(tsk, SIGSEGV) &&
698 "%s[%d] general protection rip:%lx rsp:%lx error:%lx\n",
700 regs->rip, regs->rsp, error_code);
702 force_sig(SIGSEGV, tsk);
708 const struct exception_table_entry *fixup;
709 fixup = search_exception_tables(regs->rip);
711 regs->rip = fixup->fixup;
715 tsk->thread.error_code = error_code;
716 tsk->thread.trap_no = 13;
717 if (notify_die(DIE_GPF, "general protection fault", regs,
718 error_code, 13, SIGSEGV) == NOTIFY_STOP)
720 die("general protection fault", regs, error_code);
724 static __kprobes void
725 mem_parity_error(unsigned char reason, struct pt_regs * regs)
727 printk(KERN_EMERG "Uhhuh. NMI received for unknown reason %02x.\n",
729 printk(KERN_EMERG "You have some hardware problem, likely on the PCI bus.\n");
731 #if defined(CONFIG_EDAC)
732 if(edac_handler_set()) {
733 edac_atomic_assert_error();
738 if (panic_on_unrecovered_nmi)
739 panic("NMI: Not continuing");
741 printk(KERN_EMERG "Dazed and confused, but trying to continue\n");
743 /* Clear and disable the memory parity error line. */
744 reason = (reason & 0xf) | 4;
748 static __kprobes void
749 io_check_error(unsigned char reason, struct pt_regs * regs)
751 printk("NMI: IOCK error (debug interrupt?)\n");
752 show_registers(regs);
754 /* Re-enable the IOCK line, wait for a few seconds */
755 reason = (reason & 0xf) | 8;
762 static __kprobes void
763 unknown_nmi_error(unsigned char reason, struct pt_regs * regs)
765 printk(KERN_EMERG "Uhhuh. NMI received for unknown reason %02x.\n",
767 printk(KERN_EMERG "Do you have a strange power saving mode enabled?\n");
769 if (panic_on_unrecovered_nmi)
770 panic("NMI: Not continuing");
772 printk(KERN_EMERG "Dazed and confused, but trying to continue\n");
775 /* Runs on IST stack. This code must keep interrupts off all the time.
776 Nested NMIs are prevented by the CPU. */
777 asmlinkage __kprobes void default_do_nmi(struct pt_regs *regs)
779 unsigned char reason = 0;
782 cpu = smp_processor_id();
784 /* Only the BSP gets external NMIs from the system. */
786 reason = get_nmi_reason();
788 if (!(reason & 0xc0)) {
789 if (notify_die(DIE_NMI_IPI, "nmi_ipi", regs, reason, 2, SIGINT)
793 * Ok, so this is none of the documented NMI sources,
794 * so it must be the NMI watchdog.
796 if (nmi_watchdog_tick(regs,reason))
798 if (!do_nmi_callback(regs,cpu))
799 unknown_nmi_error(reason, regs);
803 if (notify_die(DIE_NMI, "nmi", regs, reason, 2, SIGINT) == NOTIFY_STOP)
806 /* AK: following checks seem to be broken on modern chipsets. FIXME */
809 mem_parity_error(reason, regs);
811 io_check_error(reason, regs);
814 /* runs on IST stack. */
815 asmlinkage void __kprobes do_int3(struct pt_regs * regs, long error_code)
817 trace_hardirqs_fixup();
819 if (notify_die(DIE_INT3, "int3", regs, error_code, 3, SIGTRAP) == NOTIFY_STOP) {
822 preempt_conditional_sti(regs);
823 do_trap(3, SIGTRAP, "int3", regs, error_code, NULL);
824 preempt_conditional_cli(regs);
827 /* Help handler running on IST stack to switch back to user stack
828 for scheduling or signal handling. The actual stack switch is done in
830 asmlinkage __kprobes struct pt_regs *sync_regs(struct pt_regs *eregs)
832 struct pt_regs *regs = eregs;
833 /* Did already sync */
834 if (eregs == (struct pt_regs *)eregs->rsp)
836 /* Exception from user space */
837 else if (user_mode(eregs))
838 regs = task_pt_regs(current);
839 /* Exception from kernel and interrupts are enabled. Move to
840 kernel process stack. */
841 else if (eregs->eflags & X86_EFLAGS_IF)
842 regs = (struct pt_regs *)(eregs->rsp -= sizeof(struct pt_regs));
848 /* runs on IST stack. */
849 asmlinkage void __kprobes do_debug(struct pt_regs * regs,
850 unsigned long error_code)
852 unsigned long condition;
853 struct task_struct *tsk = current;
856 trace_hardirqs_fixup();
858 get_debugreg(condition, 6);
860 if (notify_die(DIE_DEBUG, "debug", regs, condition, error_code,
861 SIGTRAP) == NOTIFY_STOP)
864 preempt_conditional_sti(regs);
866 /* Mask out spurious debug traps due to lazy DR7 setting */
867 if (condition & (DR_TRAP0|DR_TRAP1|DR_TRAP2|DR_TRAP3)) {
868 if (!tsk->thread.debugreg7) {
873 tsk->thread.debugreg6 = condition;
875 /* Mask out spurious TF errors due to lazy TF clearing */
876 if (condition & DR_STEP) {
878 * The TF error should be masked out only if the current
879 * process is not traced and if the TRAP flag has been set
880 * previously by a tracing process (condition detected by
881 * the PT_DTRACE flag); remember that the i386 TRAP flag
882 * can be modified by the process itself in user mode,
883 * allowing programs to debug themselves without the ptrace()
886 if (!user_mode(regs))
887 goto clear_TF_reenable;
889 * Was the TF flag set by a debugger? If so, clear it now,
890 * so that register information is correct.
892 if (tsk->ptrace & PT_DTRACE) {
893 regs->eflags &= ~TF_MASK;
894 tsk->ptrace &= ~PT_DTRACE;
898 /* Ok, finally something we can handle */
899 tsk->thread.trap_no = 1;
900 tsk->thread.error_code = error_code;
901 info.si_signo = SIGTRAP;
903 info.si_code = TRAP_BRKPT;
904 info.si_addr = user_mode(regs) ? (void __user *)regs->rip : NULL;
905 force_sig_info(SIGTRAP, &info, tsk);
908 set_debugreg(0UL, 7);
909 preempt_conditional_cli(regs);
913 set_tsk_thread_flag(tsk, TIF_SINGLESTEP);
914 regs->eflags &= ~TF_MASK;
915 preempt_conditional_cli(regs);
918 static int kernel_math_error(struct pt_regs *regs, const char *str, int trapnr)
920 const struct exception_table_entry *fixup;
921 fixup = search_exception_tables(regs->rip);
923 regs->rip = fixup->fixup;
926 notify_die(DIE_GPF, str, regs, 0, trapnr, SIGFPE);
927 /* Illegal floating point operation in the kernel */
928 current->thread.trap_no = trapnr;
934 * Note that we play around with the 'TS' bit in an attempt to get
935 * the correct behaviour even in the presence of the asynchronous
938 asmlinkage void do_coprocessor_error(struct pt_regs *regs)
940 void __user *rip = (void __user *)(regs->rip);
941 struct task_struct * task;
943 unsigned short cwd, swd;
945 conditional_sti(regs);
946 if (!user_mode(regs) &&
947 kernel_math_error(regs, "kernel x87 math error", 16))
951 * Save the info for the exception handler and clear the error.
955 task->thread.trap_no = 16;
956 task->thread.error_code = 0;
957 info.si_signo = SIGFPE;
959 info.si_code = __SI_FAULT;
962 * (~cwd & swd) will mask out exceptions that are not set to unmasked
963 * status. 0x3f is the exception bits in these regs, 0x200 is the
964 * C1 reg you need in case of a stack fault, 0x040 is the stack
965 * fault bit. We should only be taking one exception at a time,
966 * so if this combination doesn't produce any single exception,
967 * then we have a bad program that isn't synchronizing its FPU usage
968 * and it will suffer the consequences since we won't be able to
969 * fully reproduce the context of the exception
971 cwd = get_fpu_cwd(task);
972 swd = get_fpu_swd(task);
973 switch (swd & ~cwd & 0x3f) {
977 case 0x001: /* Invalid Op */
979 * swd & 0x240 == 0x040: Stack Underflow
980 * swd & 0x240 == 0x240: Stack Overflow
981 * User must clear the SF bit (0x40) if set
983 info.si_code = FPE_FLTINV;
985 case 0x002: /* Denormalize */
986 case 0x010: /* Underflow */
987 info.si_code = FPE_FLTUND;
989 case 0x004: /* Zero Divide */
990 info.si_code = FPE_FLTDIV;
992 case 0x008: /* Overflow */
993 info.si_code = FPE_FLTOVF;
995 case 0x020: /* Precision */
996 info.si_code = FPE_FLTRES;
999 force_sig_info(SIGFPE, &info, task);
1002 asmlinkage void bad_intr(void)
1004 printk("bad interrupt");
1007 asmlinkage void do_simd_coprocessor_error(struct pt_regs *regs)
1009 void __user *rip = (void __user *)(regs->rip);
1010 struct task_struct * task;
1012 unsigned short mxcsr;
1014 conditional_sti(regs);
1015 if (!user_mode(regs) &&
1016 kernel_math_error(regs, "kernel simd math error", 19))
1020 * Save the info for the exception handler and clear the error.
1023 save_init_fpu(task);
1024 task->thread.trap_no = 19;
1025 task->thread.error_code = 0;
1026 info.si_signo = SIGFPE;
1028 info.si_code = __SI_FAULT;
1031 * The SIMD FPU exceptions are handled a little differently, as there
1032 * is only a single status/control register. Thus, to determine which
1033 * unmasked exception was caught we must mask the exception mask bits
1034 * at 0x1f80, and then use these to mask the exception bits at 0x3f.
1036 mxcsr = get_fpu_mxcsr(task);
1037 switch (~((mxcsr & 0x1f80) >> 7) & (mxcsr & 0x3f)) {
1041 case 0x001: /* Invalid Op */
1042 info.si_code = FPE_FLTINV;
1044 case 0x002: /* Denormalize */
1045 case 0x010: /* Underflow */
1046 info.si_code = FPE_FLTUND;
1048 case 0x004: /* Zero Divide */
1049 info.si_code = FPE_FLTDIV;
1051 case 0x008: /* Overflow */
1052 info.si_code = FPE_FLTOVF;
1054 case 0x020: /* Precision */
1055 info.si_code = FPE_FLTRES;
1058 force_sig_info(SIGFPE, &info, task);
1061 asmlinkage void do_spurious_interrupt_bug(struct pt_regs * regs)
1065 asmlinkage void __attribute__((weak)) smp_thermal_interrupt(void)
1069 asmlinkage void __attribute__((weak)) mce_threshold_interrupt(void)
1074 * 'math_state_restore()' saves the current math information in the
1075 * old math state array, and gets the new ones from the current task
1077 * Careful.. There are problems with IBM-designed IRQ13 behaviour.
1078 * Don't touch unless you *really* know how it works.
1080 asmlinkage void math_state_restore(void)
1082 struct task_struct *me = current;
1083 clts(); /* Allow maths ops (or we recurse) */
1087 restore_fpu_checking(&me->thread.i387.fxsave);
1088 task_thread_info(me)->status |= TS_USEDFPU;
1092 void __init trap_init(void)
1094 set_intr_gate(0,÷_error);
1095 set_intr_gate_ist(1,&debug,DEBUG_STACK);
1096 set_intr_gate_ist(2,&nmi,NMI_STACK);
1097 set_system_gate_ist(3,&int3,DEBUG_STACK); /* int3 can be called from all */
1098 set_system_gate(4,&overflow); /* int4 can be called from all */
1099 set_intr_gate(5,&bounds);
1100 set_intr_gate(6,&invalid_op);
1101 set_intr_gate(7,&device_not_available);
1102 set_intr_gate_ist(8,&double_fault, DOUBLEFAULT_STACK);
1103 set_intr_gate(9,&coprocessor_segment_overrun);
1104 set_intr_gate(10,&invalid_TSS);
1105 set_intr_gate(11,&segment_not_present);
1106 set_intr_gate_ist(12,&stack_segment,STACKFAULT_STACK);
1107 set_intr_gate(13,&general_protection);
1108 set_intr_gate(14,&page_fault);
1109 set_intr_gate(15,&spurious_interrupt_bug);
1110 set_intr_gate(16,&coprocessor_error);
1111 set_intr_gate(17,&alignment_check);
1112 #ifdef CONFIG_X86_MCE
1113 set_intr_gate_ist(18,&machine_check, MCE_STACK);
1115 set_intr_gate(19,&simd_coprocessor_error);
1117 #ifdef CONFIG_IA32_EMULATION
1118 set_system_gate(IA32_SYSCALL_VECTOR, ia32_syscall);
1122 * Should be a barrier for any external CPU state.
1128 static int __init oops_setup(char *s)
1132 if (!strcmp(s, "panic"))
1136 early_param("oops", oops_setup);
1138 static int __init kstack_setup(char *s)
1142 kstack_depth_to_print = simple_strtoul(s,NULL,0);
1145 early_param("kstack", kstack_setup);