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 #include <mach_traps.h>
38 #if defined(CONFIG_EDAC)
39 #include <linux/edac.h>
42 #include <asm/system.h>
44 #include <asm/atomic.h>
45 #include <asm/debugreg.h>
48 #include <asm/processor.h>
49 #include <asm/unwind.h>
51 #include <asm/pgalloc.h>
53 #include <asm/proto.h>
55 #include <asm/stacktrace.h>
57 asmlinkage void divide_error(void);
58 asmlinkage void debug(void);
59 asmlinkage void nmi(void);
60 asmlinkage void int3(void);
61 asmlinkage void overflow(void);
62 asmlinkage void bounds(void);
63 asmlinkage void invalid_op(void);
64 asmlinkage void device_not_available(void);
65 asmlinkage void double_fault(void);
66 asmlinkage void coprocessor_segment_overrun(void);
67 asmlinkage void invalid_TSS(void);
68 asmlinkage void segment_not_present(void);
69 asmlinkage void stack_segment(void);
70 asmlinkage void general_protection(void);
71 asmlinkage void page_fault(void);
72 asmlinkage void coprocessor_error(void);
73 asmlinkage void simd_coprocessor_error(void);
74 asmlinkage void reserved(void);
75 asmlinkage void alignment_check(void);
76 asmlinkage void machine_check(void);
77 asmlinkage void spurious_interrupt_bug(void);
79 static unsigned int code_bytes = 64;
81 static inline void conditional_sti(struct pt_regs *regs)
83 if (regs->flags & X86_EFLAGS_IF)
87 static inline void preempt_conditional_sti(struct pt_regs *regs)
90 if (regs->flags & X86_EFLAGS_IF)
94 static inline void preempt_conditional_cli(struct pt_regs *regs)
96 if (regs->flags & X86_EFLAGS_IF)
98 /* Make sure to not schedule here because we could be running
99 on an exception stack. */
103 int kstack_depth_to_print = 12;
105 void printk_address(unsigned long address, int reliable)
107 #ifdef CONFIG_KALLSYMS
108 unsigned long offset = 0, symsize;
112 char namebuf[KSYM_NAME_LEN];
115 symname = kallsyms_lookup(address, &symsize, &offset,
118 printk(" [<%016lx>]\n", address);
122 strcpy(reliab, "? ");
125 modname = delim = "";
126 printk(" [<%016lx>] %s%s%s%s%s+0x%lx/0x%lx\n",
127 address, reliab, delim, modname, delim, symname, offset, symsize);
129 printk(" [<%016lx>]\n", address);
133 static unsigned long *in_exception_stack(unsigned cpu, unsigned long stack,
134 unsigned *usedp, char **idp)
136 static char ids[][8] = {
137 [DEBUG_STACK - 1] = "#DB",
138 [NMI_STACK - 1] = "NMI",
139 [DOUBLEFAULT_STACK - 1] = "#DF",
140 [STACKFAULT_STACK - 1] = "#SS",
141 [MCE_STACK - 1] = "#MC",
142 #if DEBUG_STKSZ > EXCEPTION_STKSZ
143 [N_EXCEPTION_STACKS ... N_EXCEPTION_STACKS + DEBUG_STKSZ / EXCEPTION_STKSZ - 2] = "#DB[?]"
149 * Iterate over all exception stacks, and figure out whether
150 * 'stack' is in one of them:
152 for (k = 0; k < N_EXCEPTION_STACKS; k++) {
153 unsigned long end = per_cpu(orig_ist, cpu).ist[k];
155 * Is 'stack' above this exception frame's end?
156 * If yes then skip to the next frame.
161 * Is 'stack' above this exception frame's start address?
162 * If yes then we found the right frame.
164 if (stack >= end - EXCEPTION_STKSZ) {
166 * Make sure we only iterate through an exception
167 * stack once. If it comes up for the second time
168 * then there's something wrong going on - just
169 * break out and return NULL:
171 if (*usedp & (1U << k))
175 return (unsigned long *)end;
178 * If this is a debug stack, and if it has a larger size than
179 * the usual exception stacks, then 'stack' might still
180 * be within the lower portion of the debug stack:
182 #if DEBUG_STKSZ > EXCEPTION_STKSZ
183 if (k == DEBUG_STACK - 1 && stack >= end - DEBUG_STKSZ) {
184 unsigned j = N_EXCEPTION_STACKS - 1;
187 * Black magic. A large debug stack is composed of
188 * multiple exception stack entries, which we
189 * iterate through now. Dont look:
193 end -= EXCEPTION_STKSZ;
194 ids[j][4] = '1' + (j - N_EXCEPTION_STACKS);
195 } while (stack < end - EXCEPTION_STKSZ);
196 if (*usedp & (1U << j))
200 return (unsigned long *)end;
207 #define MSG(txt) ops->warning(data, txt)
210 * x86-64 can have up to three kernel stacks:
213 * severe exception (double fault, nmi, stack fault, debug, mce) hardware stack
216 static inline int valid_stack_ptr(struct thread_info *tinfo,
217 void *p, unsigned int size, void *end)
221 if (p < end && p >= (end-THREAD_SIZE))
226 return p > t && p < t + THREAD_SIZE - size;
229 /* The form of the top of the frame on the stack */
231 struct stack_frame *next_frame;
232 unsigned long return_address;
236 static inline unsigned long print_context_stack(struct thread_info *tinfo,
237 unsigned long *stack, unsigned long bp,
238 const struct stacktrace_ops *ops, void *data,
241 struct stack_frame *frame = (struct stack_frame *)bp;
243 while (valid_stack_ptr(tinfo, stack, sizeof(*stack), end)) {
247 if (__kernel_text_address(addr)) {
248 if ((unsigned long) stack == bp + 8) {
249 ops->address(data, addr, 1);
250 frame = frame->next_frame;
251 bp = (unsigned long) frame;
253 ops->address(data, addr, bp == 0);
261 void dump_trace(struct task_struct *tsk, struct pt_regs *regs,
262 unsigned long *stack, unsigned long bp,
263 const struct stacktrace_ops *ops, void *data)
265 const unsigned cpu = get_cpu();
266 unsigned long *irqstack_end = (unsigned long*)cpu_pda(cpu)->irqstackptr;
268 struct thread_info *tinfo;
272 tinfo = task_thread_info(tsk);
277 if (tsk && tsk != current)
278 stack = (unsigned long *)tsk->thread.sp;
281 #ifdef CONFIG_FRAME_POINTER
283 if (tsk == current) {
284 /* Grab bp right from our regs */
285 asm("movq %%rbp, %0" : "=r" (bp):);
287 /* bp is the last reg pushed by switch_to */
288 bp = *(unsigned long *) tsk->thread.sp;
296 * Print function call entries in all stacks, starting at the
297 * current stack address. If the stacks consist of nested
302 unsigned long *estack_end;
303 estack_end = in_exception_stack(cpu, (unsigned long)stack,
307 if (ops->stack(data, id) < 0)
310 bp = print_context_stack(tinfo, stack, bp, ops,
312 ops->stack(data, "<EOE>");
314 * We link to the next stack via the
315 * second-to-last pointer (index -2 to end) in the
318 stack = (unsigned long *) estack_end[-2];
322 unsigned long *irqstack;
323 irqstack = irqstack_end -
324 (IRQSTACKSIZE - 64) / sizeof(*irqstack);
326 if (stack >= irqstack && stack < irqstack_end) {
327 if (ops->stack(data, "IRQ") < 0)
329 bp = print_context_stack(tinfo, stack, bp,
330 ops, data, irqstack_end);
332 * We link to the next stack (which would be
333 * the process stack normally) the last
334 * pointer (index -1 to end) in the IRQ stack:
336 stack = (unsigned long *) (irqstack_end[-1]);
338 ops->stack(data, "EOI");
346 * This handles the process stack:
348 bp = print_context_stack(tinfo, stack, bp, ops, data, NULL);
351 EXPORT_SYMBOL(dump_trace);
354 print_trace_warning_symbol(void *data, char *msg, unsigned long symbol)
356 print_symbol(msg, symbol);
360 static void print_trace_warning(void *data, char *msg)
365 static int print_trace_stack(void *data, char *name)
367 printk(" <%s> ", name);
371 static void print_trace_address(void *data, unsigned long addr, int reliable)
373 touch_nmi_watchdog();
374 printk_address(addr, reliable);
377 static const struct stacktrace_ops print_trace_ops = {
378 .warning = print_trace_warning,
379 .warning_symbol = print_trace_warning_symbol,
380 .stack = print_trace_stack,
381 .address = print_trace_address,
385 show_trace(struct task_struct *tsk, struct pt_regs *regs, unsigned long *stack,
388 printk("\nCall Trace:\n");
389 dump_trace(tsk, regs, stack, bp, &print_trace_ops, NULL);
394 _show_stack(struct task_struct *tsk, struct pt_regs *regs, unsigned long *sp,
397 unsigned long *stack;
399 const int cpu = smp_processor_id();
400 unsigned long *irqstack_end = (unsigned long *) (cpu_pda(cpu)->irqstackptr);
401 unsigned long *irqstack = (unsigned long *) (cpu_pda(cpu)->irqstackptr - IRQSTACKSIZE);
403 // debugging aid: "show_stack(NULL, NULL);" prints the
404 // back trace for this cpu.
408 sp = (unsigned long *)tsk->thread.sp;
410 sp = (unsigned long *)&sp;
414 for(i=0; i < kstack_depth_to_print; i++) {
415 if (stack >= irqstack && stack <= irqstack_end) {
416 if (stack == irqstack_end) {
417 stack = (unsigned long *) (irqstack_end[-1]);
421 if (((long) stack & (THREAD_SIZE-1)) == 0)
424 if (i && ((i % 4) == 0))
426 printk(" %016lx", *stack++);
427 touch_nmi_watchdog();
429 show_trace(tsk, regs, sp, bp);
432 void show_stack(struct task_struct *tsk, unsigned long * sp)
434 _show_stack(tsk, NULL, sp, 0);
438 * The architecture-independent dump_stack generator
440 void dump_stack(void)
443 unsigned long bp = 0;
445 #ifdef CONFIG_FRAME_POINTER
447 asm("movq %%rbp, %0" : "=r" (bp):);
450 printk("Pid: %d, comm: %.20s %s %s %.*s\n",
451 current->pid, current->comm, print_tainted(),
452 init_utsname()->release,
453 (int)strcspn(init_utsname()->version, " "),
454 init_utsname()->version);
455 show_trace(NULL, NULL, &dummy, bp);
458 EXPORT_SYMBOL(dump_stack);
460 void show_registers(struct pt_regs *regs)
464 const int cpu = smp_processor_id();
465 struct task_struct *cur = cpu_pda(cpu)->pcurrent;
467 unsigned int code_prologue = code_bytes * 43 / 64;
468 unsigned int code_len = code_bytes;
471 ip = (u8 *) regs->ip - code_prologue;
472 printk("CPU %d ", cpu);
474 printk("Process %s (pid: %d, threadinfo %p, task %p)\n",
475 cur->comm, cur->pid, task_thread_info(cur), cur);
478 * When in-kernel, we also print out the stack and code at the
479 * time of the fault..
481 if (!user_mode(regs)) {
484 _show_stack(NULL, regs, (unsigned long *)sp, regs->bp);
487 printk(KERN_EMERG "Code: ");
488 if (ip < (u8 *)PAGE_OFFSET || probe_kernel_address(ip, c)) {
489 /* try starting at RIP */
490 ip = (u8 *) regs->ip;
491 code_len = code_len - code_prologue + 1;
493 for (i = 0; i < code_len; i++, ip++) {
494 if (ip < (u8 *)PAGE_OFFSET ||
495 probe_kernel_address(ip, c)) {
496 printk(" Bad RIP value.");
499 if (ip == (u8 *)regs->ip)
500 printk("<%02x> ", c);
508 int is_valid_bugaddr(unsigned long ip)
512 if (__copy_from_user(&ud2, (const void __user *) ip, sizeof(ud2)))
515 return ud2 == 0x0b0f;
518 static raw_spinlock_t die_lock = __RAW_SPIN_LOCK_UNLOCKED;
519 static int die_owner = -1;
520 static unsigned int die_nest_count;
522 unsigned __kprobes long oops_begin(void)
529 /* racy, but better than risking deadlock. */
530 raw_local_irq_save(flags);
531 cpu = smp_processor_id();
532 if (!__raw_spin_trylock(&die_lock)) {
533 if (cpu == die_owner)
534 /* nested oops. should stop eventually */;
536 __raw_spin_lock(&die_lock);
545 void __kprobes oops_end(unsigned long flags, struct pt_regs *regs, int signr)
551 /* Nest count reaches zero, release the lock. */
552 __raw_spin_unlock(&die_lock);
553 raw_local_irq_restore(flags);
559 panic("Fatal exception");
564 int __kprobes __die(const char * str, struct pt_regs * regs, long err)
566 static int die_counter;
567 printk(KERN_EMERG "%s: %04lx [%u] ", str, err & 0xffff,++die_counter);
568 #ifdef CONFIG_PREEMPT
574 #ifdef CONFIG_DEBUG_PAGEALLOC
575 printk("DEBUG_PAGEALLOC");
578 if (notify_die(DIE_OOPS, str, regs, err, current->thread.trap_no, SIGSEGV) == NOTIFY_STOP)
580 show_registers(regs);
581 add_taint(TAINT_DIE);
582 /* Executive summary in case the oops scrolled away */
583 printk(KERN_ALERT "RIP ");
584 printk_address(regs->ip, 1);
585 printk(" RSP <%016lx>\n", regs->sp);
586 if (kexec_should_crash(current))
591 void die(const char * str, struct pt_regs * regs, long err)
593 unsigned long flags = oops_begin();
595 if (!user_mode(regs))
596 report_bug(regs->ip, regs);
598 if (__die(str, regs, err))
600 oops_end(flags, regs, SIGSEGV);
603 void __kprobes die_nmi(char *str, struct pt_regs *regs, int do_panic)
607 if (notify_die(DIE_NMIWATCHDOG, str, regs, 0, 2, SIGINT) ==
611 flags = oops_begin();
613 * We are in trouble anyway, lets at least try
614 * to get a message out.
616 printk(str, smp_processor_id());
617 show_registers(regs);
618 if (kexec_should_crash(current))
620 if (do_panic || panic_on_oops)
621 panic("Non maskable interrupt");
622 oops_end(flags, NULL, SIGBUS);
628 static void __kprobes do_trap(int trapnr, int signr, char *str,
629 struct pt_regs * regs, long error_code,
632 struct task_struct *tsk = current;
634 if (user_mode(regs)) {
636 * We want error_code and trap_no set for userspace
637 * faults and kernelspace faults which result in
638 * die(), but not kernelspace faults which are fixed
639 * up. die() gives the process no chance to handle
640 * the signal and notice the kernel fault information,
641 * so that won't result in polluting the information
642 * about previously queued, but not yet delivered,
643 * faults. See also do_general_protection below.
645 tsk->thread.error_code = error_code;
646 tsk->thread.trap_no = trapnr;
648 if (show_unhandled_signals && unhandled_signal(tsk, signr) &&
649 printk_ratelimit()) {
651 "%s[%d] trap %s ip:%lx sp:%lx error:%lx",
652 tsk->comm, tsk->pid, str,
653 regs->ip, regs->sp, error_code);
654 print_vma_addr(" in ", regs->ip);
659 force_sig_info(signr, info, tsk);
661 force_sig(signr, tsk);
666 if (!fixup_exception(regs)) {
667 tsk->thread.error_code = error_code;
668 tsk->thread.trap_no = trapnr;
669 die(str, regs, error_code);
674 #define DO_ERROR(trapnr, signr, str, name) \
675 asmlinkage void do_##name(struct pt_regs * regs, long error_code) \
677 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
680 conditional_sti(regs); \
681 do_trap(trapnr, signr, str, regs, error_code, NULL); \
684 #define DO_ERROR_INFO(trapnr, signr, str, name, sicode, siaddr) \
685 asmlinkage void do_##name(struct pt_regs * regs, long error_code) \
688 info.si_signo = signr; \
690 info.si_code = sicode; \
691 info.si_addr = (void __user *)siaddr; \
692 trace_hardirqs_fixup(); \
693 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
696 conditional_sti(regs); \
697 do_trap(trapnr, signr, str, regs, error_code, &info); \
700 DO_ERROR_INFO( 0, SIGFPE, "divide error", divide_error, FPE_INTDIV, regs->ip)
701 DO_ERROR( 4, SIGSEGV, "overflow", overflow)
702 DO_ERROR( 5, SIGSEGV, "bounds", bounds)
703 DO_ERROR_INFO( 6, SIGILL, "invalid opcode", invalid_op, ILL_ILLOPN, regs->ip)
704 DO_ERROR( 7, SIGSEGV, "device not available", device_not_available)
705 DO_ERROR( 9, SIGFPE, "coprocessor segment overrun", coprocessor_segment_overrun)
706 DO_ERROR(10, SIGSEGV, "invalid TSS", invalid_TSS)
707 DO_ERROR(11, SIGBUS, "segment not present", segment_not_present)
708 DO_ERROR_INFO(17, SIGBUS, "alignment check", alignment_check, BUS_ADRALN, 0)
709 DO_ERROR(18, SIGSEGV, "reserved", reserved)
711 /* Runs on IST stack */
712 asmlinkage void do_stack_segment(struct pt_regs *regs, long error_code)
714 if (notify_die(DIE_TRAP, "stack segment", regs, error_code,
715 12, SIGBUS) == NOTIFY_STOP)
717 preempt_conditional_sti(regs);
718 do_trap(12, SIGBUS, "stack segment", regs, error_code, NULL);
719 preempt_conditional_cli(regs);
722 asmlinkage void do_double_fault(struct pt_regs * regs, long error_code)
724 static const char str[] = "double fault";
725 struct task_struct *tsk = current;
727 /* Return not checked because double check cannot be ignored */
728 notify_die(DIE_TRAP, str, regs, error_code, 8, SIGSEGV);
730 tsk->thread.error_code = error_code;
731 tsk->thread.trap_no = 8;
733 /* This is always a kernel trap and never fixable (and thus must
736 die(str, regs, error_code);
739 asmlinkage void __kprobes do_general_protection(struct pt_regs * regs,
742 struct task_struct *tsk = current;
744 conditional_sti(regs);
746 if (user_mode(regs)) {
747 tsk->thread.error_code = error_code;
748 tsk->thread.trap_no = 13;
750 if (show_unhandled_signals && unhandled_signal(tsk, SIGSEGV) &&
751 printk_ratelimit()) {
753 "%s[%d] general protection ip:%lx sp:%lx error:%lx",
755 regs->ip, regs->sp, error_code);
756 print_vma_addr(" in ", regs->ip);
760 force_sig(SIGSEGV, tsk);
764 if (fixup_exception(regs))
767 tsk->thread.error_code = error_code;
768 tsk->thread.trap_no = 13;
769 if (notify_die(DIE_GPF, "general protection fault", regs,
770 error_code, 13, SIGSEGV) == NOTIFY_STOP)
772 die("general protection fault", regs, error_code);
775 static __kprobes void
776 mem_parity_error(unsigned char reason, struct pt_regs * regs)
778 printk(KERN_EMERG "Uhhuh. NMI received for unknown reason %02x.\n",
780 printk(KERN_EMERG "You have some hardware problem, likely on the PCI bus.\n");
782 #if defined(CONFIG_EDAC)
783 if(edac_handler_set()) {
784 edac_atomic_assert_error();
789 if (panic_on_unrecovered_nmi)
790 panic("NMI: Not continuing");
792 printk(KERN_EMERG "Dazed and confused, but trying to continue\n");
794 /* Clear and disable the memory parity error line. */
795 reason = (reason & 0xf) | 4;
799 static __kprobes void
800 io_check_error(unsigned char reason, struct pt_regs * regs)
802 printk("NMI: IOCK error (debug interrupt?)\n");
803 show_registers(regs);
805 /* Re-enable the IOCK line, wait for a few seconds */
806 reason = (reason & 0xf) | 8;
813 static __kprobes void
814 unknown_nmi_error(unsigned char reason, struct pt_regs * regs)
816 if (notify_die(DIE_NMIUNKNOWN, "nmi", regs, reason, 2, SIGINT) == NOTIFY_STOP)
818 printk(KERN_EMERG "Uhhuh. NMI received for unknown reason %02x.\n",
820 printk(KERN_EMERG "Do you have a strange power saving mode enabled?\n");
822 if (panic_on_unrecovered_nmi)
823 panic("NMI: Not continuing");
825 printk(KERN_EMERG "Dazed and confused, but trying to continue\n");
828 /* Runs on IST stack. This code must keep interrupts off all the time.
829 Nested NMIs are prevented by the CPU. */
830 asmlinkage __kprobes void default_do_nmi(struct pt_regs *regs)
832 unsigned char reason = 0;
835 cpu = smp_processor_id();
837 /* Only the BSP gets external NMIs from the system. */
839 reason = get_nmi_reason();
841 if (!(reason & 0xc0)) {
842 if (notify_die(DIE_NMI_IPI, "nmi_ipi", regs, reason, 2, SIGINT)
846 * Ok, so this is none of the documented NMI sources,
847 * so it must be the NMI watchdog.
849 if (nmi_watchdog_tick(regs,reason))
851 if (!do_nmi_callback(regs,cpu))
852 unknown_nmi_error(reason, regs);
856 if (notify_die(DIE_NMI, "nmi", regs, reason, 2, SIGINT) == NOTIFY_STOP)
859 /* AK: following checks seem to be broken on modern chipsets. FIXME */
862 mem_parity_error(reason, regs);
864 io_check_error(reason, regs);
867 /* runs on IST stack. */
868 asmlinkage void __kprobes do_int3(struct pt_regs * regs, long error_code)
870 trace_hardirqs_fixup();
872 if (notify_die(DIE_INT3, "int3", regs, error_code, 3, SIGTRAP) == NOTIFY_STOP) {
875 preempt_conditional_sti(regs);
876 do_trap(3, SIGTRAP, "int3", regs, error_code, NULL);
877 preempt_conditional_cli(regs);
880 /* Help handler running on IST stack to switch back to user stack
881 for scheduling or signal handling. The actual stack switch is done in
883 asmlinkage __kprobes struct pt_regs *sync_regs(struct pt_regs *eregs)
885 struct pt_regs *regs = eregs;
886 /* Did already sync */
887 if (eregs == (struct pt_regs *)eregs->sp)
889 /* Exception from user space */
890 else if (user_mode(eregs))
891 regs = task_pt_regs(current);
892 /* Exception from kernel and interrupts are enabled. Move to
893 kernel process stack. */
894 else if (eregs->flags & X86_EFLAGS_IF)
895 regs = (struct pt_regs *)(eregs->sp -= sizeof(struct pt_regs));
901 /* runs on IST stack. */
902 asmlinkage void __kprobes do_debug(struct pt_regs * regs,
903 unsigned long error_code)
905 unsigned long condition;
906 struct task_struct *tsk = current;
909 trace_hardirqs_fixup();
911 get_debugreg(condition, 6);
914 * The processor cleared BTF, so don't mark that we need it set.
916 clear_tsk_thread_flag(tsk, TIF_DEBUGCTLMSR);
917 tsk->thread.debugctlmsr = 0;
919 if (notify_die(DIE_DEBUG, "debug", regs, condition, error_code,
920 SIGTRAP) == NOTIFY_STOP)
923 preempt_conditional_sti(regs);
925 /* Mask out spurious debug traps due to lazy DR7 setting */
926 if (condition & (DR_TRAP0|DR_TRAP1|DR_TRAP2|DR_TRAP3)) {
927 if (!tsk->thread.debugreg7) {
932 tsk->thread.debugreg6 = condition;
936 * Single-stepping through TF: make sure we ignore any events in
937 * kernel space (but re-enable TF when returning to user mode).
939 if (condition & DR_STEP) {
940 if (!user_mode(regs))
941 goto clear_TF_reenable;
944 /* Ok, finally something we can handle */
945 tsk->thread.trap_no = 1;
946 tsk->thread.error_code = error_code;
947 info.si_signo = SIGTRAP;
949 info.si_code = TRAP_BRKPT;
950 info.si_addr = user_mode(regs) ? (void __user *)regs->ip : NULL;
951 force_sig_info(SIGTRAP, &info, tsk);
954 set_debugreg(0UL, 7);
955 preempt_conditional_cli(regs);
959 set_tsk_thread_flag(tsk, TIF_SINGLESTEP);
960 regs->flags &= ~X86_EFLAGS_TF;
961 preempt_conditional_cli(regs);
964 static int kernel_math_error(struct pt_regs *regs, const char *str, int trapnr)
966 if (fixup_exception(regs))
969 notify_die(DIE_GPF, str, regs, 0, trapnr, SIGFPE);
970 /* Illegal floating point operation in the kernel */
971 current->thread.trap_no = trapnr;
977 * Note that we play around with the 'TS' bit in an attempt to get
978 * the correct behaviour even in the presence of the asynchronous
981 asmlinkage void do_coprocessor_error(struct pt_regs *regs)
983 void __user *ip = (void __user *)(regs->ip);
984 struct task_struct * task;
986 unsigned short cwd, swd;
988 conditional_sti(regs);
989 if (!user_mode(regs) &&
990 kernel_math_error(regs, "kernel x87 math error", 16))
994 * Save the info for the exception handler and clear the error.
998 task->thread.trap_no = 16;
999 task->thread.error_code = 0;
1000 info.si_signo = SIGFPE;
1002 info.si_code = __SI_FAULT;
1005 * (~cwd & swd) will mask out exceptions that are not set to unmasked
1006 * status. 0x3f is the exception bits in these regs, 0x200 is the
1007 * C1 reg you need in case of a stack fault, 0x040 is the stack
1008 * fault bit. We should only be taking one exception at a time,
1009 * so if this combination doesn't produce any single exception,
1010 * then we have a bad program that isn't synchronizing its FPU usage
1011 * and it will suffer the consequences since we won't be able to
1012 * fully reproduce the context of the exception
1014 cwd = get_fpu_cwd(task);
1015 swd = get_fpu_swd(task);
1016 switch (swd & ~cwd & 0x3f) {
1020 case 0x001: /* Invalid Op */
1022 * swd & 0x240 == 0x040: Stack Underflow
1023 * swd & 0x240 == 0x240: Stack Overflow
1024 * User must clear the SF bit (0x40) if set
1026 info.si_code = FPE_FLTINV;
1028 case 0x002: /* Denormalize */
1029 case 0x010: /* Underflow */
1030 info.si_code = FPE_FLTUND;
1032 case 0x004: /* Zero Divide */
1033 info.si_code = FPE_FLTDIV;
1035 case 0x008: /* Overflow */
1036 info.si_code = FPE_FLTOVF;
1038 case 0x020: /* Precision */
1039 info.si_code = FPE_FLTRES;
1042 force_sig_info(SIGFPE, &info, task);
1045 asmlinkage void bad_intr(void)
1047 printk("bad interrupt");
1050 asmlinkage void do_simd_coprocessor_error(struct pt_regs *regs)
1052 void __user *ip = (void __user *)(regs->ip);
1053 struct task_struct * task;
1055 unsigned short mxcsr;
1057 conditional_sti(regs);
1058 if (!user_mode(regs) &&
1059 kernel_math_error(regs, "kernel simd math error", 19))
1063 * Save the info for the exception handler and clear the error.
1066 save_init_fpu(task);
1067 task->thread.trap_no = 19;
1068 task->thread.error_code = 0;
1069 info.si_signo = SIGFPE;
1071 info.si_code = __SI_FAULT;
1074 * The SIMD FPU exceptions are handled a little differently, as there
1075 * is only a single status/control register. Thus, to determine which
1076 * unmasked exception was caught we must mask the exception mask bits
1077 * at 0x1f80, and then use these to mask the exception bits at 0x3f.
1079 mxcsr = get_fpu_mxcsr(task);
1080 switch (~((mxcsr & 0x1f80) >> 7) & (mxcsr & 0x3f)) {
1084 case 0x001: /* Invalid Op */
1085 info.si_code = FPE_FLTINV;
1087 case 0x002: /* Denormalize */
1088 case 0x010: /* Underflow */
1089 info.si_code = FPE_FLTUND;
1091 case 0x004: /* Zero Divide */
1092 info.si_code = FPE_FLTDIV;
1094 case 0x008: /* Overflow */
1095 info.si_code = FPE_FLTOVF;
1097 case 0x020: /* Precision */
1098 info.si_code = FPE_FLTRES;
1101 force_sig_info(SIGFPE, &info, task);
1104 asmlinkage void do_spurious_interrupt_bug(struct pt_regs * regs)
1108 asmlinkage void __attribute__((weak)) smp_thermal_interrupt(void)
1112 asmlinkage void __attribute__((weak)) mce_threshold_interrupt(void)
1117 * 'math_state_restore()' saves the current math information in the
1118 * old math state array, and gets the new ones from the current task
1120 * Careful.. There are problems with IBM-designed IRQ13 behaviour.
1121 * Don't touch unless you *really* know how it works.
1123 asmlinkage void math_state_restore(void)
1125 struct task_struct *me = current;
1126 clts(); /* Allow maths ops (or we recurse) */
1130 restore_fpu_checking(&me->thread.i387.fxsave);
1131 task_thread_info(me)->status |= TS_USEDFPU;
1134 EXPORT_SYMBOL_GPL(math_state_restore);
1136 void __init trap_init(void)
1138 set_intr_gate(0,÷_error);
1139 set_intr_gate_ist(1,&debug,DEBUG_STACK);
1140 set_intr_gate_ist(2,&nmi,NMI_STACK);
1141 set_system_gate_ist(3,&int3,DEBUG_STACK); /* int3 can be called from all */
1142 set_system_gate(4,&overflow); /* int4 can be called from all */
1143 set_intr_gate(5,&bounds);
1144 set_intr_gate(6,&invalid_op);
1145 set_intr_gate(7,&device_not_available);
1146 set_intr_gate_ist(8,&double_fault, DOUBLEFAULT_STACK);
1147 set_intr_gate(9,&coprocessor_segment_overrun);
1148 set_intr_gate(10,&invalid_TSS);
1149 set_intr_gate(11,&segment_not_present);
1150 set_intr_gate_ist(12,&stack_segment,STACKFAULT_STACK);
1151 set_intr_gate(13,&general_protection);
1152 set_intr_gate(14,&page_fault);
1153 set_intr_gate(15,&spurious_interrupt_bug);
1154 set_intr_gate(16,&coprocessor_error);
1155 set_intr_gate(17,&alignment_check);
1156 #ifdef CONFIG_X86_MCE
1157 set_intr_gate_ist(18,&machine_check, MCE_STACK);
1159 set_intr_gate(19,&simd_coprocessor_error);
1161 #ifdef CONFIG_IA32_EMULATION
1162 set_system_gate(IA32_SYSCALL_VECTOR, ia32_syscall);
1166 * Should be a barrier for any external CPU state.
1172 static int __init oops_setup(char *s)
1176 if (!strcmp(s, "panic"))
1180 early_param("oops", oops_setup);
1182 static int __init kstack_setup(char *s)
1186 kstack_depth_to_print = simple_strtoul(s,NULL,0);
1189 early_param("kstack", kstack_setup);
1192 static int __init code_bytes_setup(char *s)
1194 code_bytes = simple_strtoul(s, NULL, 0);
1195 if (code_bytes > 8192)
1200 __setup("code_bytes=", code_bytes_setup);