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->flags & X86_EFLAGS_IF)
83 static inline void preempt_conditional_sti(struct pt_regs *regs)
86 if (regs->flags & X86_EFLAGS_IF)
90 static inline void preempt_conditional_cli(struct pt_regs *regs)
92 if (regs->flags & 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, int reliable)
104 unsigned long offset = 0, symsize;
109 char reliab[4] = "";;
111 symname = kallsyms_lookup(address, &symsize, &offset,
114 printk(" [<%016lx>]\n", address);
118 strcpy(reliab, "? ");
121 modname = delim = "";
122 printk(" [<%016lx>] %s%s%s%s%s+0x%lx/0x%lx\n",
123 address, reliab, delim, modname, delim, symname, offset, symsize);
126 void printk_address(unsigned long address, int reliable)
128 printk(" [<%016lx>]\n", address);
132 static unsigned long *in_exception_stack(unsigned cpu, unsigned long stack,
133 unsigned *usedp, char **idp)
135 static char ids[][8] = {
136 [DEBUG_STACK - 1] = "#DB",
137 [NMI_STACK - 1] = "NMI",
138 [DOUBLEFAULT_STACK - 1] = "#DF",
139 [STACKFAULT_STACK - 1] = "#SS",
140 [MCE_STACK - 1] = "#MC",
141 #if DEBUG_STKSZ > EXCEPTION_STKSZ
142 [N_EXCEPTION_STACKS ... N_EXCEPTION_STACKS + DEBUG_STKSZ / EXCEPTION_STKSZ - 2] = "#DB[?]"
148 * Iterate over all exception stacks, and figure out whether
149 * 'stack' is in one of them:
151 for (k = 0; k < N_EXCEPTION_STACKS; k++) {
152 unsigned long end = per_cpu(orig_ist, cpu).ist[k];
154 * Is 'stack' above this exception frame's end?
155 * If yes then skip to the next frame.
160 * Is 'stack' above this exception frame's start address?
161 * If yes then we found the right frame.
163 if (stack >= end - EXCEPTION_STKSZ) {
165 * Make sure we only iterate through an exception
166 * stack once. If it comes up for the second time
167 * then there's something wrong going on - just
168 * break out and return NULL:
170 if (*usedp & (1U << k))
174 return (unsigned long *)end;
177 * If this is a debug stack, and if it has a larger size than
178 * the usual exception stacks, then 'stack' might still
179 * be within the lower portion of the debug stack:
181 #if DEBUG_STKSZ > EXCEPTION_STKSZ
182 if (k == DEBUG_STACK - 1 && stack >= end - DEBUG_STKSZ) {
183 unsigned j = N_EXCEPTION_STACKS - 1;
186 * Black magic. A large debug stack is composed of
187 * multiple exception stack entries, which we
188 * iterate through now. Dont look:
192 end -= EXCEPTION_STKSZ;
193 ids[j][4] = '1' + (j - N_EXCEPTION_STACKS);
194 } while (stack < end - EXCEPTION_STKSZ);
195 if (*usedp & (1U << j))
199 return (unsigned long *)end;
206 #define MSG(txt) ops->warning(data, txt)
209 * x86-64 can have up to three kernel stacks:
212 * severe exception (double fault, nmi, stack fault, debug, mce) hardware stack
215 static inline int valid_stack_ptr(struct thread_info *tinfo, void *p)
217 void *t = (void *)tinfo;
218 return p > t && p < t + THREAD_SIZE - 3;
221 void dump_trace(struct task_struct *tsk, struct pt_regs *regs,
222 unsigned long *stack, unsigned long bp,
223 const struct stacktrace_ops *ops, void *data)
225 const unsigned cpu = get_cpu();
226 unsigned long *irqstack_end = (unsigned long*)cpu_pda(cpu)->irqstackptr;
228 struct thread_info *tinfo;
236 if (tsk && tsk != current)
237 stack = (unsigned long *)tsk->thread.sp;
241 * Print function call entries within a stack. 'cond' is the
242 * "end of stackframe" condition, that the 'stack++'
243 * iteration will eventually trigger.
245 #define HANDLE_STACK(cond) \
247 unsigned long addr = *stack++; \
248 /* Use unlocked access here because except for NMIs \
249 we should be already protected against module unloads */ \
250 if (__kernel_text_address(addr)) { \
252 * If the address is either in the text segment of the \
253 * kernel, or in the region which contains vmalloc'ed \
254 * memory, it *may* be the address of a calling \
255 * routine; if so, print it so that someone tracing \
256 * down the cause of the crash will be able to figure \
257 * out the call path that was taken. \
259 ops->address(data, addr, 1); \
264 * Print function call entries in all stacks, starting at the
265 * current stack address. If the stacks consist of nested
270 unsigned long *estack_end;
271 estack_end = in_exception_stack(cpu, (unsigned long)stack,
275 if (ops->stack(data, id) < 0)
277 HANDLE_STACK (stack < estack_end);
278 ops->stack(data, "<EOE>");
280 * We link to the next stack via the
281 * second-to-last pointer (index -2 to end) in the
284 stack = (unsigned long *) estack_end[-2];
288 unsigned long *irqstack;
289 irqstack = irqstack_end -
290 (IRQSTACKSIZE - 64) / sizeof(*irqstack);
292 if (stack >= irqstack && stack < irqstack_end) {
293 if (ops->stack(data, "IRQ") < 0)
295 HANDLE_STACK (stack < irqstack_end);
297 * We link to the next stack (which would be
298 * the process stack normally) the last
299 * pointer (index -1 to end) in the IRQ stack:
301 stack = (unsigned long *) (irqstack_end[-1]);
303 ops->stack(data, "EOI");
311 * This handles the process stack:
313 tinfo = task_thread_info(tsk);
314 HANDLE_STACK (valid_stack_ptr(tinfo, stack));
318 EXPORT_SYMBOL(dump_trace);
321 print_trace_warning_symbol(void *data, char *msg, unsigned long symbol)
323 print_symbol(msg, symbol);
327 static void print_trace_warning(void *data, char *msg)
332 static int print_trace_stack(void *data, char *name)
334 printk(" <%s> ", name);
338 static void print_trace_address(void *data, unsigned long addr, int reliable)
340 touch_nmi_watchdog();
341 printk_address(addr, reliable);
344 static const struct stacktrace_ops print_trace_ops = {
345 .warning = print_trace_warning,
346 .warning_symbol = print_trace_warning_symbol,
347 .stack = print_trace_stack,
348 .address = print_trace_address,
352 show_trace(struct task_struct *tsk, struct pt_regs *regs, unsigned long *stack,
355 printk("\nCall Trace:\n");
356 dump_trace(tsk, regs, stack, bp, &print_trace_ops, NULL);
361 _show_stack(struct task_struct *tsk, struct pt_regs *regs, unsigned long *sp,
364 unsigned long *stack;
366 const int cpu = smp_processor_id();
367 unsigned long *irqstack_end = (unsigned long *) (cpu_pda(cpu)->irqstackptr);
368 unsigned long *irqstack = (unsigned long *) (cpu_pda(cpu)->irqstackptr - IRQSTACKSIZE);
370 // debugging aid: "show_stack(NULL, NULL);" prints the
371 // back trace for this cpu.
375 sp = (unsigned long *)tsk->thread.sp;
377 sp = (unsigned long *)&sp;
381 for(i=0; i < kstack_depth_to_print; i++) {
382 if (stack >= irqstack && stack <= irqstack_end) {
383 if (stack == irqstack_end) {
384 stack = (unsigned long *) (irqstack_end[-1]);
388 if (((long) stack & (THREAD_SIZE-1)) == 0)
391 if (i && ((i % 4) == 0))
393 printk(" %016lx", *stack++);
394 touch_nmi_watchdog();
396 show_trace(tsk, regs, sp, bp);
399 void show_stack(struct task_struct *tsk, unsigned long * sp)
401 _show_stack(tsk, NULL, sp, 0);
405 * The architecture-independent dump_stack generator
407 void dump_stack(void)
410 unsigned long bp = 0;
412 printk("Pid: %d, comm: %.20s %s %s %.*s\n",
413 current->pid, current->comm, print_tainted(),
414 init_utsname()->release,
415 (int)strcspn(init_utsname()->version, " "),
416 init_utsname()->version);
417 show_trace(NULL, NULL, &dummy, bp);
420 EXPORT_SYMBOL(dump_stack);
422 void show_registers(struct pt_regs *regs)
425 int in_kernel = !user_mode(regs);
427 const int cpu = smp_processor_id();
428 struct task_struct *cur = cpu_pda(cpu)->pcurrent;
431 printk("CPU %d ", cpu);
433 printk("Process %s (pid: %d, threadinfo %p, task %p)\n",
434 cur->comm, cur->pid, task_thread_info(cur), cur);
437 * When in-kernel, we also print out the stack and code at the
438 * time of the fault..
442 _show_stack(NULL, regs, (unsigned long *)sp, regs->bp);
445 if (regs->ip < PAGE_OFFSET)
448 for (i=0; i<20; i++) {
450 if (__get_user(c, &((unsigned char*)regs->ip)[i])) {
452 printk(" Bad RIP value.");
461 int is_valid_bugaddr(unsigned long ip)
465 if (__copy_from_user(&ud2, (const void __user *) ip, sizeof(ud2)))
468 return ud2 == 0x0b0f;
471 static raw_spinlock_t die_lock = __RAW_SPIN_LOCK_UNLOCKED;
472 static int die_owner = -1;
473 static unsigned int die_nest_count;
475 unsigned __kprobes long oops_begin(void)
482 /* racy, but better than risking deadlock. */
483 raw_local_irq_save(flags);
484 cpu = smp_processor_id();
485 if (!__raw_spin_trylock(&die_lock)) {
486 if (cpu == die_owner)
487 /* nested oops. should stop eventually */;
489 __raw_spin_lock(&die_lock);
498 void __kprobes oops_end(unsigned long flags, struct pt_regs *regs, int signr)
504 /* Nest count reaches zero, release the lock. */
505 __raw_spin_unlock(&die_lock);
506 raw_local_irq_restore(flags);
512 panic("Fatal exception");
517 int __kprobes __die(const char * str, struct pt_regs * regs, long err)
519 static int die_counter;
520 printk(KERN_EMERG "%s: %04lx [%u] ", str, err & 0xffff,++die_counter);
521 #ifdef CONFIG_PREEMPT
527 #ifdef CONFIG_DEBUG_PAGEALLOC
528 printk("DEBUG_PAGEALLOC");
531 if (notify_die(DIE_OOPS, str, regs, err, current->thread.trap_no, SIGSEGV) == NOTIFY_STOP)
533 show_registers(regs);
534 add_taint(TAINT_DIE);
535 /* Executive summary in case the oops scrolled away */
536 printk(KERN_ALERT "RIP ");
537 printk_address(regs->ip, regs->bp);
538 printk(" RSP <%016lx>\n", regs->sp);
539 if (kexec_should_crash(current))
544 void die(const char * str, struct pt_regs * regs, long err)
546 unsigned long flags = oops_begin();
548 if (!user_mode(regs))
549 report_bug(regs->ip, regs);
551 if (__die(str, regs, err))
553 oops_end(flags, regs, SIGSEGV);
556 void __kprobes die_nmi(char *str, struct pt_regs *regs, int do_panic)
558 unsigned long flags = oops_begin();
561 * We are in trouble anyway, lets at least try
562 * to get a message out.
564 printk(str, smp_processor_id());
565 show_registers(regs);
566 if (kexec_should_crash(current))
568 if (do_panic || panic_on_oops)
569 panic("Non maskable interrupt");
570 oops_end(flags, NULL, SIGBUS);
576 static void __kprobes do_trap(int trapnr, int signr, char *str,
577 struct pt_regs * regs, long error_code,
580 struct task_struct *tsk = current;
582 if (user_mode(regs)) {
584 * We want error_code and trap_no set for userspace
585 * faults and kernelspace faults which result in
586 * die(), but not kernelspace faults which are fixed
587 * up. die() gives the process no chance to handle
588 * the signal and notice the kernel fault information,
589 * so that won't result in polluting the information
590 * about previously queued, but not yet delivered,
591 * faults. See also do_general_protection below.
593 tsk->thread.error_code = error_code;
594 tsk->thread.trap_no = trapnr;
596 if (show_unhandled_signals && unhandled_signal(tsk, signr) &&
599 "%s[%d] trap %s ip:%lx sp:%lx error:%lx\n",
600 tsk->comm, tsk->pid, str,
601 regs->ip, regs->sp, error_code);
604 force_sig_info(signr, info, tsk);
606 force_sig(signr, tsk);
611 if (!fixup_exception(regs)) {
612 tsk->thread.error_code = error_code;
613 tsk->thread.trap_no = trapnr;
614 die(str, regs, error_code);
619 #define DO_ERROR(trapnr, signr, str, name) \
620 asmlinkage void do_##name(struct pt_regs * regs, long error_code) \
622 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
625 conditional_sti(regs); \
626 do_trap(trapnr, signr, str, regs, error_code, NULL); \
629 #define DO_ERROR_INFO(trapnr, signr, str, name, sicode, siaddr) \
630 asmlinkage void do_##name(struct pt_regs * regs, long error_code) \
633 info.si_signo = signr; \
635 info.si_code = sicode; \
636 info.si_addr = (void __user *)siaddr; \
637 trace_hardirqs_fixup(); \
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->ip)
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->ip)
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 ip:%lx sp:%lx error:%lx\n",
700 regs->ip, regs->sp, error_code);
702 force_sig(SIGSEGV, tsk);
706 if (fixup_exception(regs))
709 tsk->thread.error_code = error_code;
710 tsk->thread.trap_no = 13;
711 if (notify_die(DIE_GPF, "general protection fault", regs,
712 error_code, 13, SIGSEGV) == NOTIFY_STOP)
714 die("general protection fault", regs, error_code);
717 static __kprobes void
718 mem_parity_error(unsigned char reason, struct pt_regs * regs)
720 printk(KERN_EMERG "Uhhuh. NMI received for unknown reason %02x.\n",
722 printk(KERN_EMERG "You have some hardware problem, likely on the PCI bus.\n");
724 #if defined(CONFIG_EDAC)
725 if(edac_handler_set()) {
726 edac_atomic_assert_error();
731 if (panic_on_unrecovered_nmi)
732 panic("NMI: Not continuing");
734 printk(KERN_EMERG "Dazed and confused, but trying to continue\n");
736 /* Clear and disable the memory parity error line. */
737 reason = (reason & 0xf) | 4;
741 static __kprobes void
742 io_check_error(unsigned char reason, struct pt_regs * regs)
744 printk("NMI: IOCK error (debug interrupt?)\n");
745 show_registers(regs);
747 /* Re-enable the IOCK line, wait for a few seconds */
748 reason = (reason & 0xf) | 8;
755 static __kprobes void
756 unknown_nmi_error(unsigned char reason, struct pt_regs * regs)
758 printk(KERN_EMERG "Uhhuh. NMI received for unknown reason %02x.\n",
760 printk(KERN_EMERG "Do you have a strange power saving mode enabled?\n");
762 if (panic_on_unrecovered_nmi)
763 panic("NMI: Not continuing");
765 printk(KERN_EMERG "Dazed and confused, but trying to continue\n");
768 /* Runs on IST stack. This code must keep interrupts off all the time.
769 Nested NMIs are prevented by the CPU. */
770 asmlinkage __kprobes void default_do_nmi(struct pt_regs *regs)
772 unsigned char reason = 0;
775 cpu = smp_processor_id();
777 /* Only the BSP gets external NMIs from the system. */
779 reason = get_nmi_reason();
781 if (!(reason & 0xc0)) {
782 if (notify_die(DIE_NMI_IPI, "nmi_ipi", regs, reason, 2, SIGINT)
786 * Ok, so this is none of the documented NMI sources,
787 * so it must be the NMI watchdog.
789 if (nmi_watchdog_tick(regs,reason))
791 if (!do_nmi_callback(regs,cpu))
792 unknown_nmi_error(reason, regs);
796 if (notify_die(DIE_NMI, "nmi", regs, reason, 2, SIGINT) == NOTIFY_STOP)
799 /* AK: following checks seem to be broken on modern chipsets. FIXME */
802 mem_parity_error(reason, regs);
804 io_check_error(reason, regs);
807 /* runs on IST stack. */
808 asmlinkage void __kprobes do_int3(struct pt_regs * regs, long error_code)
810 trace_hardirqs_fixup();
812 if (notify_die(DIE_INT3, "int3", regs, error_code, 3, SIGTRAP) == NOTIFY_STOP) {
815 preempt_conditional_sti(regs);
816 do_trap(3, SIGTRAP, "int3", regs, error_code, NULL);
817 preempt_conditional_cli(regs);
820 /* Help handler running on IST stack to switch back to user stack
821 for scheduling or signal handling. The actual stack switch is done in
823 asmlinkage __kprobes struct pt_regs *sync_regs(struct pt_regs *eregs)
825 struct pt_regs *regs = eregs;
826 /* Did already sync */
827 if (eregs == (struct pt_regs *)eregs->sp)
829 /* Exception from user space */
830 else if (user_mode(eregs))
831 regs = task_pt_regs(current);
832 /* Exception from kernel and interrupts are enabled. Move to
833 kernel process stack. */
834 else if (eregs->flags & X86_EFLAGS_IF)
835 regs = (struct pt_regs *)(eregs->sp -= sizeof(struct pt_regs));
841 /* runs on IST stack. */
842 asmlinkage void __kprobes do_debug(struct pt_regs * regs,
843 unsigned long error_code)
845 unsigned long condition;
846 struct task_struct *tsk = current;
849 trace_hardirqs_fixup();
851 get_debugreg(condition, 6);
854 * The processor cleared BTF, so don't mark that we need it set.
856 clear_tsk_thread_flag(tsk, TIF_DEBUGCTLMSR);
857 tsk->thread.debugctlmsr = 0;
859 if (notify_die(DIE_DEBUG, "debug", regs, condition, error_code,
860 SIGTRAP) == NOTIFY_STOP)
863 preempt_conditional_sti(regs);
865 /* Mask out spurious debug traps due to lazy DR7 setting */
866 if (condition & (DR_TRAP0|DR_TRAP1|DR_TRAP2|DR_TRAP3)) {
867 if (!tsk->thread.debugreg7) {
872 tsk->thread.debugreg6 = condition;
876 * Single-stepping through TF: make sure we ignore any events in
877 * kernel space (but re-enable TF when returning to user mode).
879 if (condition & DR_STEP) {
880 if (!user_mode(regs))
881 goto clear_TF_reenable;
884 /* Ok, finally something we can handle */
885 tsk->thread.trap_no = 1;
886 tsk->thread.error_code = error_code;
887 info.si_signo = SIGTRAP;
889 info.si_code = TRAP_BRKPT;
890 info.si_addr = user_mode(regs) ? (void __user *)regs->ip : NULL;
891 force_sig_info(SIGTRAP, &info, tsk);
894 set_debugreg(0UL, 7);
895 preempt_conditional_cli(regs);
899 set_tsk_thread_flag(tsk, TIF_SINGLESTEP);
900 regs->flags &= ~X86_EFLAGS_TF;
901 preempt_conditional_cli(regs);
904 static int kernel_math_error(struct pt_regs *regs, const char *str, int trapnr)
906 if (fixup_exception(regs))
909 notify_die(DIE_GPF, str, regs, 0, trapnr, SIGFPE);
910 /* Illegal floating point operation in the kernel */
911 current->thread.trap_no = trapnr;
917 * Note that we play around with the 'TS' bit in an attempt to get
918 * the correct behaviour even in the presence of the asynchronous
921 asmlinkage void do_coprocessor_error(struct pt_regs *regs)
923 void __user *ip = (void __user *)(regs->ip);
924 struct task_struct * task;
926 unsigned short cwd, swd;
928 conditional_sti(regs);
929 if (!user_mode(regs) &&
930 kernel_math_error(regs, "kernel x87 math error", 16))
934 * Save the info for the exception handler and clear the error.
938 task->thread.trap_no = 16;
939 task->thread.error_code = 0;
940 info.si_signo = SIGFPE;
942 info.si_code = __SI_FAULT;
945 * (~cwd & swd) will mask out exceptions that are not set to unmasked
946 * status. 0x3f is the exception bits in these regs, 0x200 is the
947 * C1 reg you need in case of a stack fault, 0x040 is the stack
948 * fault bit. We should only be taking one exception at a time,
949 * so if this combination doesn't produce any single exception,
950 * then we have a bad program that isn't synchronizing its FPU usage
951 * and it will suffer the consequences since we won't be able to
952 * fully reproduce the context of the exception
954 cwd = get_fpu_cwd(task);
955 swd = get_fpu_swd(task);
956 switch (swd & ~cwd & 0x3f) {
960 case 0x001: /* Invalid Op */
962 * swd & 0x240 == 0x040: Stack Underflow
963 * swd & 0x240 == 0x240: Stack Overflow
964 * User must clear the SF bit (0x40) if set
966 info.si_code = FPE_FLTINV;
968 case 0x002: /* Denormalize */
969 case 0x010: /* Underflow */
970 info.si_code = FPE_FLTUND;
972 case 0x004: /* Zero Divide */
973 info.si_code = FPE_FLTDIV;
975 case 0x008: /* Overflow */
976 info.si_code = FPE_FLTOVF;
978 case 0x020: /* Precision */
979 info.si_code = FPE_FLTRES;
982 force_sig_info(SIGFPE, &info, task);
985 asmlinkage void bad_intr(void)
987 printk("bad interrupt");
990 asmlinkage void do_simd_coprocessor_error(struct pt_regs *regs)
992 void __user *ip = (void __user *)(regs->ip);
993 struct task_struct * task;
995 unsigned short mxcsr;
997 conditional_sti(regs);
998 if (!user_mode(regs) &&
999 kernel_math_error(regs, "kernel simd math error", 19))
1003 * Save the info for the exception handler and clear the error.
1006 save_init_fpu(task);
1007 task->thread.trap_no = 19;
1008 task->thread.error_code = 0;
1009 info.si_signo = SIGFPE;
1011 info.si_code = __SI_FAULT;
1014 * The SIMD FPU exceptions are handled a little differently, as there
1015 * is only a single status/control register. Thus, to determine which
1016 * unmasked exception was caught we must mask the exception mask bits
1017 * at 0x1f80, and then use these to mask the exception bits at 0x3f.
1019 mxcsr = get_fpu_mxcsr(task);
1020 switch (~((mxcsr & 0x1f80) >> 7) & (mxcsr & 0x3f)) {
1024 case 0x001: /* Invalid Op */
1025 info.si_code = FPE_FLTINV;
1027 case 0x002: /* Denormalize */
1028 case 0x010: /* Underflow */
1029 info.si_code = FPE_FLTUND;
1031 case 0x004: /* Zero Divide */
1032 info.si_code = FPE_FLTDIV;
1034 case 0x008: /* Overflow */
1035 info.si_code = FPE_FLTOVF;
1037 case 0x020: /* Precision */
1038 info.si_code = FPE_FLTRES;
1041 force_sig_info(SIGFPE, &info, task);
1044 asmlinkage void do_spurious_interrupt_bug(struct pt_regs * regs)
1048 asmlinkage void __attribute__((weak)) smp_thermal_interrupt(void)
1052 asmlinkage void __attribute__((weak)) mce_threshold_interrupt(void)
1057 * 'math_state_restore()' saves the current math information in the
1058 * old math state array, and gets the new ones from the current task
1060 * Careful.. There are problems with IBM-designed IRQ13 behaviour.
1061 * Don't touch unless you *really* know how it works.
1063 asmlinkage void math_state_restore(void)
1065 struct task_struct *me = current;
1066 clts(); /* Allow maths ops (or we recurse) */
1070 restore_fpu_checking(&me->thread.i387.fxsave);
1071 task_thread_info(me)->status |= TS_USEDFPU;
1074 EXPORT_SYMBOL_GPL(math_state_restore);
1076 void __init trap_init(void)
1078 set_intr_gate(0,÷_error);
1079 set_intr_gate_ist(1,&debug,DEBUG_STACK);
1080 set_intr_gate_ist(2,&nmi,NMI_STACK);
1081 set_system_gate_ist(3,&int3,DEBUG_STACK); /* int3 can be called from all */
1082 set_system_gate(4,&overflow); /* int4 can be called from all */
1083 set_intr_gate(5,&bounds);
1084 set_intr_gate(6,&invalid_op);
1085 set_intr_gate(7,&device_not_available);
1086 set_intr_gate_ist(8,&double_fault, DOUBLEFAULT_STACK);
1087 set_intr_gate(9,&coprocessor_segment_overrun);
1088 set_intr_gate(10,&invalid_TSS);
1089 set_intr_gate(11,&segment_not_present);
1090 set_intr_gate_ist(12,&stack_segment,STACKFAULT_STACK);
1091 set_intr_gate(13,&general_protection);
1092 set_intr_gate(14,&page_fault);
1093 set_intr_gate(15,&spurious_interrupt_bug);
1094 set_intr_gate(16,&coprocessor_error);
1095 set_intr_gate(17,&alignment_check);
1096 #ifdef CONFIG_X86_MCE
1097 set_intr_gate_ist(18,&machine_check, MCE_STACK);
1099 set_intr_gate(19,&simd_coprocessor_error);
1101 #ifdef CONFIG_IA32_EMULATION
1102 set_system_gate(IA32_SYSCALL_VECTOR, ia32_syscall);
1106 * Should be a barrier for any external CPU state.
1112 static int __init oops_setup(char *s)
1116 if (!strcmp(s, "panic"))
1120 early_param("oops", oops_setup);
1122 static int __init kstack_setup(char *s)
1126 kstack_depth_to_print = simple_strtoul(s,NULL,0);
1129 early_param("kstack", kstack_setup);