2 * linux/arch/i386/traps.c
4 * Copyright (C) 1991, 1992 Linus Torvalds
6 * Pentium III FXSR, SSE support
7 * Gareth Hughes <gareth@valinux.com>, May 2000
11 * 'Traps.c' handles hardware traps and faults after we have saved some
14 #include <linux/config.h>
15 #include <linux/sched.h>
16 #include <linux/kernel.h>
17 #include <linux/string.h>
18 #include <linux/errno.h>
19 #include <linux/timer.h>
21 #include <linux/init.h>
22 #include <linux/delay.h>
23 #include <linux/spinlock.h>
24 #include <linux/interrupt.h>
25 #include <linux/highmem.h>
26 #include <linux/kallsyms.h>
27 #include <linux/ptrace.h>
28 #include <linux/utsname.h>
29 #include <linux/kprobes.h>
30 #include <linux/kexec.h>
33 #include <linux/ioport.h>
34 #include <linux/eisa.h>
38 #include <linux/mca.h>
41 #include <asm/processor.h>
42 #include <asm/system.h>
43 #include <asm/uaccess.h>
45 #include <asm/atomic.h>
46 #include <asm/debugreg.h>
52 #include <asm/arch_hooks.h>
53 #include <asm/kdebug.h>
55 #include <linux/module.h>
57 #include "mach_traps.h"
59 asmlinkage int system_call(void);
61 struct desc_struct default_ldt[] = { { 0, 0 }, { 0, 0 }, { 0, 0 },
64 /* Do we ignore FPU interrupts ? */
65 char ignore_fpu_irq = 0;
68 * The IDT has to be page-aligned to simplify the Pentium
69 * F0 0F bug workaround.. We have a special link segment
72 struct desc_struct idt_table[256] __attribute__((__section__(".data.idt"))) = { {0, 0}, };
74 asmlinkage void divide_error(void);
75 asmlinkage void debug(void);
76 asmlinkage void nmi(void);
77 asmlinkage void int3(void);
78 asmlinkage void overflow(void);
79 asmlinkage void bounds(void);
80 asmlinkage void invalid_op(void);
81 asmlinkage void device_not_available(void);
82 asmlinkage void coprocessor_segment_overrun(void);
83 asmlinkage void invalid_TSS(void);
84 asmlinkage void segment_not_present(void);
85 asmlinkage void stack_segment(void);
86 asmlinkage void general_protection(void);
87 asmlinkage void page_fault(void);
88 asmlinkage void coprocessor_error(void);
89 asmlinkage void simd_coprocessor_error(void);
90 asmlinkage void alignment_check(void);
91 asmlinkage void spurious_interrupt_bug(void);
92 asmlinkage void machine_check(void);
94 static int kstack_depth_to_print = 24;
95 struct notifier_block *i386die_chain;
96 static DEFINE_SPINLOCK(die_notifier_lock);
98 int register_die_notifier(struct notifier_block *nb)
104 spin_lock_irqsave(&die_notifier_lock, flags);
105 err = notifier_chain_register(&i386die_chain, nb);
106 spin_unlock_irqrestore(&die_notifier_lock, flags);
109 EXPORT_SYMBOL(register_die_notifier);
111 static inline int valid_stack_ptr(struct thread_info *tinfo, void *p)
113 return p > (void *)tinfo &&
114 p < (void *)tinfo + THREAD_SIZE - 3;
118 * Print CONFIG_STACK_BACKTRACE_COLS address/symbol entries per line.
120 static inline int print_addr_and_symbol(unsigned long addr, char *log_lvl,
126 #if CONFIG_STACK_BACKTRACE_COLS == 1
127 printk(" [<%08lx>] ", addr);
129 printk(" <%08lx> ", addr);
131 print_symbol("%s", addr);
133 printed = (printed + 1) % CONFIG_STACK_BACKTRACE_COLS;
143 static inline unsigned long print_context_stack(struct thread_info *tinfo,
144 unsigned long *stack, unsigned long ebp,
148 int printed = 0; /* nr of entries already printed on current line */
150 #ifdef CONFIG_FRAME_POINTER
151 while (valid_stack_ptr(tinfo, (void *)ebp)) {
152 addr = *(unsigned long *)(ebp + 4);
153 printed = print_addr_and_symbol(addr, log_lvl, printed);
154 ebp = *(unsigned long *)ebp;
157 while (valid_stack_ptr(tinfo, stack)) {
159 if (__kernel_text_address(addr))
160 printed = print_addr_and_symbol(addr, log_lvl, printed);
169 static void show_trace_log_lvl(struct task_struct *task,
170 unsigned long *stack, char *log_lvl)
177 if (task == current) {
178 /* Grab ebp right from our regs */
179 asm ("movl %%ebp, %0" : "=r" (ebp) : );
181 /* ebp is the last reg pushed by switch_to */
182 ebp = *(unsigned long *) task->thread.esp;
186 struct thread_info *context;
187 context = (struct thread_info *)
188 ((unsigned long)stack & (~(THREAD_SIZE - 1)));
189 ebp = print_context_stack(context, stack, ebp, log_lvl);
190 stack = (unsigned long*)context->previous_esp;
193 printk("%s =======================\n", log_lvl);
197 void show_trace(struct task_struct *task, unsigned long * stack)
199 show_trace_log_lvl(task, stack, "");
202 static void show_stack_log_lvl(struct task_struct *task, unsigned long *esp,
205 unsigned long *stack;
210 esp = (unsigned long*)task->thread.esp;
212 esp = (unsigned long *)&esp;
217 for(i = 0; i < kstack_depth_to_print; i++) {
218 if (kstack_end(stack))
220 if (i && ((i % 8) == 0))
221 printk("\n%s ", log_lvl);
222 printk("%08lx ", *stack++);
224 printk("\n%sCall Trace:\n", log_lvl);
225 show_trace_log_lvl(task, esp, log_lvl);
228 void show_stack(struct task_struct *task, unsigned long *esp)
231 show_stack_log_lvl(task, esp, "");
235 * The architecture-independent dump_stack generator
237 void dump_stack(void)
241 show_trace(current, &stack);
244 EXPORT_SYMBOL(dump_stack);
246 void show_registers(struct pt_regs *regs)
253 esp = (unsigned long) (®s->esp);
255 if (user_mode_vm(regs)) {
258 ss = regs->xss & 0xffff;
261 printk(KERN_EMERG "CPU: %d\nEIP: %04x:[<%08lx>] %s VLI\n"
262 "EFLAGS: %08lx (%s %.*s) \n",
263 smp_processor_id(), 0xffff & regs->xcs, regs->eip,
264 print_tainted(), regs->eflags, system_utsname.release,
265 (int)strcspn(system_utsname.version, " "),
266 system_utsname.version);
267 print_symbol(KERN_EMERG "EIP is at %s\n", regs->eip);
268 printk(KERN_EMERG "eax: %08lx ebx: %08lx ecx: %08lx edx: %08lx\n",
269 regs->eax, regs->ebx, regs->ecx, regs->edx);
270 printk(KERN_EMERG "esi: %08lx edi: %08lx ebp: %08lx esp: %08lx\n",
271 regs->esi, regs->edi, regs->ebp, esp);
272 printk(KERN_EMERG "ds: %04x es: %04x ss: %04x\n",
273 regs->xds & 0xffff, regs->xes & 0xffff, ss);
274 printk(KERN_EMERG "Process %s (pid: %d, threadinfo=%p task=%p)",
275 current->comm, current->pid, current_thread_info(), current);
277 * When in-kernel, we also print out the stack and code at the
278 * time of the fault..
283 printk("\n" KERN_EMERG "Stack: ");
284 show_stack_log_lvl(NULL, (unsigned long *)esp, KERN_EMERG);
286 printk(KERN_EMERG "Code: ");
288 eip = (u8 __user *)regs->eip - 43;
289 for (i = 0; i < 64; i++, eip++) {
292 if (eip < (u8 __user *)PAGE_OFFSET || __get_user(c, eip)) {
293 printk(" Bad EIP value.");
296 if (eip == (u8 __user *)regs->eip)
297 printk("<%02x> ", c);
305 static void handle_BUG(struct pt_regs *regs)
315 if (eip < PAGE_OFFSET)
317 if (__get_user(ud2, (unsigned short __user *)eip))
321 if (__get_user(line, (unsigned short __user *)(eip + 2)))
323 if (__get_user(file, (char * __user *)(eip + 4)) ||
324 (unsigned long)file < PAGE_OFFSET || __get_user(c, file))
325 file = "<bad filename>";
327 printk(KERN_EMERG "------------[ cut here ]------------\n");
328 printk(KERN_EMERG "kernel BUG at %s:%d!\n", file, line);
333 /* Here we know it was a BUG but file-n-line is unavailable */
335 printk(KERN_EMERG "Kernel BUG\n");
338 /* This is gone through when something in the kernel
339 * has done something bad and is about to be terminated.
341 void die(const char * str, struct pt_regs * regs, long err)
346 int lock_owner_depth;
348 .lock = SPIN_LOCK_UNLOCKED,
350 .lock_owner_depth = 0
352 static int die_counter;
357 if (die.lock_owner != raw_smp_processor_id()) {
359 spin_lock_irqsave(&die.lock, flags);
360 die.lock_owner = smp_processor_id();
361 die.lock_owner_depth = 0;
365 local_save_flags(flags);
367 if (++die.lock_owner_depth < 3) {
370 printk(KERN_EMERG "%s: %04lx [#%d]\n", str, err & 0xffff, ++die_counter);
371 #ifdef CONFIG_PREEMPT
372 printk(KERN_EMERG "PREEMPT ");
381 #ifdef CONFIG_DEBUG_PAGEALLOC
384 printk("DEBUG_PAGEALLOC");
389 if (notify_die(DIE_OOPS, str, regs, err,
390 current->thread.trap_no, SIGSEGV) !=
392 show_registers(regs);
396 printk(KERN_EMERG "Recursive die() failure, output suppressed\n");
400 spin_unlock_irqrestore(&die.lock, flags);
405 if (kexec_should_crash(current))
409 panic("Fatal exception in interrupt");
412 printk(KERN_EMERG "Fatal exception: panic in 5 seconds\n");
414 panic("Fatal exception");
420 static inline void die_if_kernel(const char * str, struct pt_regs * regs, long err)
422 if (!user_mode_vm(regs))
426 static void __kprobes do_trap(int trapnr, int signr, char *str, int vm86,
427 struct pt_regs * regs, long error_code,
430 struct task_struct *tsk = current;
431 tsk->thread.error_code = error_code;
432 tsk->thread.trap_no = trapnr;
434 if (regs->eflags & VM_MASK) {
440 if (!user_mode(regs))
445 force_sig_info(signr, info, tsk);
447 force_sig(signr, tsk);
452 if (!fixup_exception(regs))
453 die(str, regs, error_code);
458 int ret = handle_vm86_trap((struct kernel_vm86_regs *) regs, error_code, trapnr);
459 if (ret) goto trap_signal;
464 #define DO_ERROR(trapnr, signr, str, name) \
465 fastcall void do_##name(struct pt_regs * regs, long error_code) \
467 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
470 do_trap(trapnr, signr, str, 0, regs, error_code, NULL); \
473 #define DO_ERROR_INFO(trapnr, signr, str, name, sicode, siaddr) \
474 fastcall void do_##name(struct pt_regs * regs, long error_code) \
477 info.si_signo = signr; \
479 info.si_code = sicode; \
480 info.si_addr = (void __user *)siaddr; \
481 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
484 do_trap(trapnr, signr, str, 0, regs, error_code, &info); \
487 #define DO_VM86_ERROR(trapnr, signr, str, name) \
488 fastcall void do_##name(struct pt_regs * regs, long error_code) \
490 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
493 do_trap(trapnr, signr, str, 1, regs, error_code, NULL); \
496 #define DO_VM86_ERROR_INFO(trapnr, signr, str, name, sicode, siaddr) \
497 fastcall void do_##name(struct pt_regs * regs, long error_code) \
500 info.si_signo = signr; \
502 info.si_code = sicode; \
503 info.si_addr = (void __user *)siaddr; \
504 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
507 do_trap(trapnr, signr, str, 1, regs, error_code, &info); \
510 DO_VM86_ERROR_INFO( 0, SIGFPE, "divide error", divide_error, FPE_INTDIV, regs->eip)
511 #ifndef CONFIG_KPROBES
512 DO_VM86_ERROR( 3, SIGTRAP, "int3", int3)
514 DO_VM86_ERROR( 4, SIGSEGV, "overflow", overflow)
515 DO_VM86_ERROR( 5, SIGSEGV, "bounds", bounds)
516 DO_ERROR_INFO( 6, SIGILL, "invalid opcode", invalid_op, ILL_ILLOPN, regs->eip)
517 DO_ERROR( 9, SIGFPE, "coprocessor segment overrun", coprocessor_segment_overrun)
518 DO_ERROR(10, SIGSEGV, "invalid TSS", invalid_TSS)
519 DO_ERROR(11, SIGBUS, "segment not present", segment_not_present)
520 DO_ERROR(12, SIGBUS, "stack segment", stack_segment)
521 DO_ERROR_INFO(17, SIGBUS, "alignment check", alignment_check, BUS_ADRALN, 0)
522 DO_ERROR_INFO(32, SIGSEGV, "iret exception", iret_error, ILL_BADSTK, 0)
524 fastcall void __kprobes do_general_protection(struct pt_regs * regs,
528 struct tss_struct *tss = &per_cpu(init_tss, cpu);
529 struct thread_struct *thread = ¤t->thread;
532 * Perform the lazy TSS's I/O bitmap copy. If the TSS has an
533 * invalid offset set (the LAZY one) and the faulting thread has
534 * a valid I/O bitmap pointer, we copy the I/O bitmap in the TSS
535 * and we set the offset field correctly. Then we let the CPU to
536 * restart the faulting instruction.
538 if (tss->io_bitmap_base == INVALID_IO_BITMAP_OFFSET_LAZY &&
539 thread->io_bitmap_ptr) {
540 memcpy(tss->io_bitmap, thread->io_bitmap_ptr,
541 thread->io_bitmap_max);
543 * If the previously set map was extending to higher ports
544 * than the current one, pad extra space with 0xff (no access).
546 if (thread->io_bitmap_max < tss->io_bitmap_max)
547 memset((char *) tss->io_bitmap +
548 thread->io_bitmap_max, 0xff,
549 tss->io_bitmap_max - thread->io_bitmap_max);
550 tss->io_bitmap_max = thread->io_bitmap_max;
551 tss->io_bitmap_base = IO_BITMAP_OFFSET;
552 tss->io_bitmap_owner = thread;
558 current->thread.error_code = error_code;
559 current->thread.trap_no = 13;
561 if (regs->eflags & VM_MASK)
564 if (!user_mode(regs))
567 current->thread.error_code = error_code;
568 current->thread.trap_no = 13;
569 force_sig(SIGSEGV, current);
574 handle_vm86_fault((struct kernel_vm86_regs *) regs, error_code);
578 if (!fixup_exception(regs)) {
579 if (notify_die(DIE_GPF, "general protection fault", regs,
580 error_code, 13, SIGSEGV) == NOTIFY_STOP)
582 die("general protection fault", regs, error_code);
586 static void mem_parity_error(unsigned char reason, struct pt_regs * regs)
588 printk(KERN_EMERG "Uhhuh. NMI received. Dazed and confused, but trying "
590 printk(KERN_EMERG "You probably have a hardware problem with your RAM "
593 /* Clear and disable the memory parity error line. */
594 clear_mem_error(reason);
597 static void io_check_error(unsigned char reason, struct pt_regs * regs)
601 printk(KERN_EMERG "NMI: IOCK error (debug interrupt?)\n");
602 show_registers(regs);
604 /* Re-enable the IOCK line, wait for a few seconds */
605 reason = (reason & 0xf) | 8;
608 while (--i) udelay(1000);
613 static void unknown_nmi_error(unsigned char reason, struct pt_regs * regs)
616 /* Might actually be able to figure out what the guilty party
623 printk("Uhhuh. NMI received for unknown reason %02x on CPU %d.\n",
624 reason, smp_processor_id());
625 printk("Dazed and confused, but trying to continue\n");
626 printk("Do you have a strange power saving mode enabled?\n");
629 static DEFINE_SPINLOCK(nmi_print_lock);
631 void die_nmi (struct pt_regs *regs, const char *msg)
633 if (notify_die(DIE_NMIWATCHDOG, msg, regs, 0, 2, SIGINT) ==
637 spin_lock(&nmi_print_lock);
639 * We are in trouble anyway, lets at least try
640 * to get a message out.
643 printk(KERN_EMERG "%s", msg);
644 printk(" on CPU%d, eip %08lx, registers:\n",
645 smp_processor_id(), regs->eip);
646 show_registers(regs);
647 printk(KERN_EMERG "console shuts up ...\n");
649 spin_unlock(&nmi_print_lock);
652 /* If we are in kernel we are probably nested up pretty bad
653 * and might aswell get out now while we still can.
655 if (!user_mode_vm(regs)) {
656 current->thread.trap_no = 2;
663 static void default_do_nmi(struct pt_regs * regs)
665 unsigned char reason = 0;
667 /* Only the BSP gets external NMIs from the system. */
668 if (!smp_processor_id())
669 reason = get_nmi_reason();
671 if (!(reason & 0xc0)) {
672 if (notify_die(DIE_NMI_IPI, "nmi_ipi", regs, reason, 2, SIGINT)
675 #ifdef CONFIG_X86_LOCAL_APIC
677 * Ok, so this is none of the documented NMI sources,
678 * so it must be the NMI watchdog.
681 nmi_watchdog_tick(regs);
685 unknown_nmi_error(reason, regs);
688 if (notify_die(DIE_NMI, "nmi", regs, reason, 2, SIGINT) == NOTIFY_STOP)
691 mem_parity_error(reason, regs);
693 io_check_error(reason, regs);
695 * Reassert NMI in case it became active meanwhile
696 * as it's edge-triggered.
701 static int dummy_nmi_callback(struct pt_regs * regs, int cpu)
706 static nmi_callback_t nmi_callback = dummy_nmi_callback;
708 fastcall void do_nmi(struct pt_regs * regs, long error_code)
714 cpu = smp_processor_id();
718 if (!rcu_dereference(nmi_callback)(regs, cpu))
719 default_do_nmi(regs);
724 void set_nmi_callback(nmi_callback_t callback)
727 rcu_assign_pointer(nmi_callback, callback);
729 EXPORT_SYMBOL_GPL(set_nmi_callback);
731 void unset_nmi_callback(void)
733 nmi_callback = dummy_nmi_callback;
735 EXPORT_SYMBOL_GPL(unset_nmi_callback);
737 #ifdef CONFIG_KPROBES
738 fastcall void __kprobes do_int3(struct pt_regs *regs, long error_code)
740 if (notify_die(DIE_INT3, "int3", regs, error_code, 3, SIGTRAP)
743 /* This is an interrupt gate, because kprobes wants interrupts
744 disabled. Normal trap handlers don't. */
745 restore_interrupts(regs);
746 do_trap(3, SIGTRAP, "int3", 1, regs, error_code, NULL);
751 * Our handling of the processor debug registers is non-trivial.
752 * We do not clear them on entry and exit from the kernel. Therefore
753 * it is possible to get a watchpoint trap here from inside the kernel.
754 * However, the code in ./ptrace.c has ensured that the user can
755 * only set watchpoints on userspace addresses. Therefore the in-kernel
756 * watchpoint trap can only occur in code which is reading/writing
757 * from user space. Such code must not hold kernel locks (since it
758 * can equally take a page fault), therefore it is safe to call
759 * force_sig_info even though that claims and releases locks.
761 * Code in ./signal.c ensures that the debug control register
762 * is restored before we deliver any signal, and therefore that
763 * user code runs with the correct debug control register even though
766 * Being careful here means that we don't have to be as careful in a
767 * lot of more complicated places (task switching can be a bit lazy
768 * about restoring all the debug state, and ptrace doesn't have to
769 * find every occurrence of the TF bit that could be saved away even
772 fastcall void __kprobes do_debug(struct pt_regs * regs, long error_code)
774 unsigned int condition;
775 struct task_struct *tsk = current;
777 get_debugreg(condition, 6);
779 if (notify_die(DIE_DEBUG, "debug", regs, condition, error_code,
780 SIGTRAP) == NOTIFY_STOP)
782 /* It's safe to allow irq's after DR6 has been saved */
783 if (regs->eflags & X86_EFLAGS_IF)
786 /* Mask out spurious debug traps due to lazy DR7 setting */
787 if (condition & (DR_TRAP0|DR_TRAP1|DR_TRAP2|DR_TRAP3)) {
788 if (!tsk->thread.debugreg[7])
792 if (regs->eflags & VM_MASK)
795 /* Save debug status register where ptrace can see it */
796 tsk->thread.debugreg[6] = condition;
799 * Single-stepping through TF: make sure we ignore any events in
800 * kernel space (but re-enable TF when returning to user mode).
802 if (condition & DR_STEP) {
804 * We already checked v86 mode above, so we can
805 * check for kernel mode by just checking the CPL
808 if (!user_mode(regs))
809 goto clear_TF_reenable;
812 /* Ok, finally something we can handle */
813 send_sigtrap(tsk, regs, error_code);
815 /* Disable additional traps. They'll be re-enabled when
816 * the signal is delivered.
823 handle_vm86_trap((struct kernel_vm86_regs *) regs, error_code, 1);
827 set_tsk_thread_flag(tsk, TIF_SINGLESTEP);
828 regs->eflags &= ~TF_MASK;
833 * Note that we play around with the 'TS' bit in an attempt to get
834 * the correct behaviour even in the presence of the asynchronous
837 void math_error(void __user *eip)
839 struct task_struct * task;
841 unsigned short cwd, swd;
844 * Save the info for the exception handler and clear the error.
848 task->thread.trap_no = 16;
849 task->thread.error_code = 0;
850 info.si_signo = SIGFPE;
852 info.si_code = __SI_FAULT;
855 * (~cwd & swd) will mask out exceptions that are not set to unmasked
856 * status. 0x3f is the exception bits in these regs, 0x200 is the
857 * C1 reg you need in case of a stack fault, 0x040 is the stack
858 * fault bit. We should only be taking one exception at a time,
859 * so if this combination doesn't produce any single exception,
860 * then we have a bad program that isn't syncronizing its FPU usage
861 * and it will suffer the consequences since we won't be able to
862 * fully reproduce the context of the exception
864 cwd = get_fpu_cwd(task);
865 swd = get_fpu_swd(task);
866 switch (swd & ~cwd & 0x3f) {
867 case 0x000: /* No unmasked exception */
869 default: /* Multiple exceptions */
871 case 0x001: /* Invalid Op */
873 * swd & 0x240 == 0x040: Stack Underflow
874 * swd & 0x240 == 0x240: Stack Overflow
875 * User must clear the SF bit (0x40) if set
877 info.si_code = FPE_FLTINV;
879 case 0x002: /* Denormalize */
880 case 0x010: /* Underflow */
881 info.si_code = FPE_FLTUND;
883 case 0x004: /* Zero Divide */
884 info.si_code = FPE_FLTDIV;
886 case 0x008: /* Overflow */
887 info.si_code = FPE_FLTOVF;
889 case 0x020: /* Precision */
890 info.si_code = FPE_FLTRES;
893 force_sig_info(SIGFPE, &info, task);
896 fastcall void do_coprocessor_error(struct pt_regs * regs, long error_code)
899 math_error((void __user *)regs->eip);
902 static void simd_math_error(void __user *eip)
904 struct task_struct * task;
906 unsigned short mxcsr;
909 * Save the info for the exception handler and clear the error.
913 task->thread.trap_no = 19;
914 task->thread.error_code = 0;
915 info.si_signo = SIGFPE;
917 info.si_code = __SI_FAULT;
920 * The SIMD FPU exceptions are handled a little differently, as there
921 * is only a single status/control register. Thus, to determine which
922 * unmasked exception was caught we must mask the exception mask bits
923 * at 0x1f80, and then use these to mask the exception bits at 0x3f.
925 mxcsr = get_fpu_mxcsr(task);
926 switch (~((mxcsr & 0x1f80) >> 7) & (mxcsr & 0x3f)) {
930 case 0x001: /* Invalid Op */
931 info.si_code = FPE_FLTINV;
933 case 0x002: /* Denormalize */
934 case 0x010: /* Underflow */
935 info.si_code = FPE_FLTUND;
937 case 0x004: /* Zero Divide */
938 info.si_code = FPE_FLTDIV;
940 case 0x008: /* Overflow */
941 info.si_code = FPE_FLTOVF;
943 case 0x020: /* Precision */
944 info.si_code = FPE_FLTRES;
947 force_sig_info(SIGFPE, &info, task);
950 fastcall void do_simd_coprocessor_error(struct pt_regs * regs,
954 /* Handle SIMD FPU exceptions on PIII+ processors. */
956 simd_math_error((void __user *)regs->eip);
959 * Handle strange cache flush from user space exception
960 * in all other cases. This is undocumented behaviour.
962 if (regs->eflags & VM_MASK) {
963 handle_vm86_fault((struct kernel_vm86_regs *)regs,
967 current->thread.trap_no = 19;
968 current->thread.error_code = error_code;
969 die_if_kernel("cache flush denied", regs, error_code);
970 force_sig(SIGSEGV, current);
974 fastcall void do_spurious_interrupt_bug(struct pt_regs * regs,
978 /* No need to warn about this any longer. */
979 printk("Ignoring P6 Local APIC Spurious Interrupt Bug...\n");
983 fastcall void setup_x86_bogus_stack(unsigned char * stk)
985 unsigned long *switch16_ptr, *switch32_ptr;
986 struct pt_regs *regs;
987 unsigned long stack_top, stack_bot;
988 unsigned short iret_frame16_off;
989 int cpu = smp_processor_id();
990 /* reserve the space on 32bit stack for the magic switch16 pointer */
991 memmove(stk, stk + 8, sizeof(struct pt_regs));
992 switch16_ptr = (unsigned long *)(stk + sizeof(struct pt_regs));
993 regs = (struct pt_regs *)stk;
994 /* now the switch32 on 16bit stack */
995 stack_bot = (unsigned long)&per_cpu(cpu_16bit_stack, cpu);
996 stack_top = stack_bot + CPU_16BIT_STACK_SIZE;
997 switch32_ptr = (unsigned long *)(stack_top - 8);
998 iret_frame16_off = CPU_16BIT_STACK_SIZE - 8 - 20;
999 /* copy iret frame on 16bit stack */
1000 memcpy((void *)(stack_bot + iret_frame16_off), ®s->eip, 20);
1001 /* fill in the switch pointers */
1002 switch16_ptr[0] = (regs->esp & 0xffff0000) | iret_frame16_off;
1003 switch16_ptr[1] = __ESPFIX_SS;
1004 switch32_ptr[0] = (unsigned long)stk + sizeof(struct pt_regs) +
1005 8 - CPU_16BIT_STACK_SIZE;
1006 switch32_ptr[1] = __KERNEL_DS;
1009 fastcall unsigned char * fixup_x86_bogus_stack(unsigned short sp)
1011 unsigned long *switch32_ptr;
1012 unsigned char *stack16, *stack32;
1013 unsigned long stack_top, stack_bot;
1015 int cpu = smp_processor_id();
1016 stack_bot = (unsigned long)&per_cpu(cpu_16bit_stack, cpu);
1017 stack_top = stack_bot + CPU_16BIT_STACK_SIZE;
1018 switch32_ptr = (unsigned long *)(stack_top - 8);
1019 /* copy the data from 16bit stack to 32bit stack */
1020 len = CPU_16BIT_STACK_SIZE - 8 - sp;
1021 stack16 = (unsigned char *)(stack_bot + sp);
1022 stack32 = (unsigned char *)
1023 (switch32_ptr[0] + CPU_16BIT_STACK_SIZE - 8 - len);
1024 memcpy(stack32, stack16, len);
1029 * 'math_state_restore()' saves the current math information in the
1030 * old math state array, and gets the new ones from the current task
1032 * Careful.. There are problems with IBM-designed IRQ13 behaviour.
1033 * Don't touch unless you *really* know how it works.
1035 * Must be called with kernel preemption disabled (in this case,
1036 * local interrupts are disabled at the call-site in entry.S).
1038 asmlinkage void math_state_restore(struct pt_regs regs)
1040 struct thread_info *thread = current_thread_info();
1041 struct task_struct *tsk = thread->task;
1043 clts(); /* Allow maths ops (or we recurse) */
1044 if (!tsk_used_math(tsk))
1047 thread->status |= TS_USEDFPU; /* So we fnsave on switch_to() */
1050 #ifndef CONFIG_MATH_EMULATION
1052 asmlinkage void math_emulate(long arg)
1054 printk(KERN_EMERG "math-emulation not enabled and no coprocessor found.\n");
1055 printk(KERN_EMERG "killing %s.\n",current->comm);
1056 force_sig(SIGFPE,current);
1060 #endif /* CONFIG_MATH_EMULATION */
1062 #ifdef CONFIG_X86_F00F_BUG
1063 void __init trap_init_f00f_bug(void)
1065 __set_fixmap(FIX_F00F_IDT, __pa(&idt_table), PAGE_KERNEL_RO);
1068 * Update the IDT descriptor and reload the IDT so that
1069 * it uses the read-only mapped virtual address.
1071 idt_descr.address = fix_to_virt(FIX_F00F_IDT);
1072 load_idt(&idt_descr);
1076 #define _set_gate(gate_addr,type,dpl,addr,seg) \
1079 __asm__ __volatile__ ("movw %%dx,%%ax\n\t" \
1080 "movw %4,%%dx\n\t" \
1081 "movl %%eax,%0\n\t" \
1083 :"=m" (*((long *) (gate_addr))), \
1084 "=m" (*(1+(long *) (gate_addr))), "=&a" (__d0), "=&d" (__d1) \
1085 :"i" ((short) (0x8000+(dpl<<13)+(type<<8))), \
1086 "3" ((char *) (addr)),"2" ((seg) << 16)); \
1091 * This needs to use 'idt_table' rather than 'idt', and
1092 * thus use the _nonmapped_ version of the IDT, as the
1093 * Pentium F0 0F bugfix can have resulted in the mapped
1094 * IDT being write-protected.
1096 void set_intr_gate(unsigned int n, void *addr)
1098 _set_gate(idt_table+n,14,0,addr,__KERNEL_CS);
1102 * This routine sets up an interrupt gate at directory privilege level 3.
1104 static inline void set_system_intr_gate(unsigned int n, void *addr)
1106 _set_gate(idt_table+n, 14, 3, addr, __KERNEL_CS);
1109 static void __init set_trap_gate(unsigned int n, void *addr)
1111 _set_gate(idt_table+n,15,0,addr,__KERNEL_CS);
1114 static void __init set_system_gate(unsigned int n, void *addr)
1116 _set_gate(idt_table+n,15,3,addr,__KERNEL_CS);
1119 static void __init set_task_gate(unsigned int n, unsigned int gdt_entry)
1121 _set_gate(idt_table+n,5,0,0,(gdt_entry<<3));
1125 void __init trap_init(void)
1128 void __iomem *p = ioremap(0x0FFFD9, 4);
1129 if (readl(p) == 'E'+('I'<<8)+('S'<<16)+('A'<<24)) {
1135 #ifdef CONFIG_X86_LOCAL_APIC
1136 init_apic_mappings();
1139 set_trap_gate(0,÷_error);
1140 set_intr_gate(1,&debug);
1141 set_intr_gate(2,&nmi);
1142 set_system_intr_gate(3, &int3); /* int3/4 can be called from all */
1143 set_system_gate(4,&overflow);
1144 set_trap_gate(5,&bounds);
1145 set_trap_gate(6,&invalid_op);
1146 set_trap_gate(7,&device_not_available);
1147 set_task_gate(8,GDT_ENTRY_DOUBLEFAULT_TSS);
1148 set_trap_gate(9,&coprocessor_segment_overrun);
1149 set_trap_gate(10,&invalid_TSS);
1150 set_trap_gate(11,&segment_not_present);
1151 set_trap_gate(12,&stack_segment);
1152 set_trap_gate(13,&general_protection);
1153 set_intr_gate(14,&page_fault);
1154 set_trap_gate(15,&spurious_interrupt_bug);
1155 set_trap_gate(16,&coprocessor_error);
1156 set_trap_gate(17,&alignment_check);
1157 #ifdef CONFIG_X86_MCE
1158 set_trap_gate(18,&machine_check);
1160 set_trap_gate(19,&simd_coprocessor_error);
1164 * Verify that the FXSAVE/FXRSTOR data will be 16-byte aligned.
1165 * Generates a compile-time "error: zero width for bit-field" if
1166 * the alignment is wrong.
1168 struct fxsrAlignAssert {
1169 int _:!(offsetof(struct task_struct,
1170 thread.i387.fxsave) & 15);
1173 printk(KERN_INFO "Enabling fast FPU save and restore... ");
1174 set_in_cr4(X86_CR4_OSFXSR);
1178 printk(KERN_INFO "Enabling unmasked SIMD FPU exception "
1180 set_in_cr4(X86_CR4_OSXMMEXCPT);
1184 set_system_gate(SYSCALL_VECTOR,&system_call);
1187 * Should be a barrier for any external CPU state.
1194 static int __init kstack_setup(char *s)
1196 kstack_depth_to_print = simple_strtoul(s, NULL, 0);
1199 __setup("kstack=", kstack_setup);