2 * Copyright (C) 1991, 1992 Linus Torvalds
4 * Pentium III FXSR, SSE support
5 * Gareth Hughes <gareth@valinux.com>, May 2000
9 * 'Traps.c' handles hardware traps and faults after we have saved some
12 #include <linux/sched.h>
13 #include <linux/kernel.h>
14 #include <linux/string.h>
15 #include <linux/errno.h>
16 #include <linux/timer.h>
18 #include <linux/init.h>
19 #include <linux/delay.h>
20 #include <linux/spinlock.h>
21 #include <linux/interrupt.h>
22 #include <linux/highmem.h>
23 #include <linux/kallsyms.h>
24 #include <linux/ptrace.h>
25 #include <linux/utsname.h>
26 #include <linux/kprobes.h>
27 #include <linux/kexec.h>
28 #include <linux/unwind.h>
29 #include <linux/uaccess.h>
30 #include <linux/nmi.h>
31 #include <linux/bug.h>
34 #include <linux/ioport.h>
35 #include <linux/eisa.h>
39 #include <linux/mca.h>
42 #if defined(CONFIG_EDAC)
43 #include <linux/edac.h>
46 #include <asm/processor.h>
47 #include <asm/system.h>
49 #include <asm/atomic.h>
50 #include <asm/debugreg.h>
54 #include <asm/unwind.h>
56 #include <asm/arch_hooks.h>
57 #include <linux/kdebug.h>
58 #include <asm/stacktrace.h>
60 #include <linux/module.h>
62 #include "mach_traps.h"
64 int panic_on_unrecovered_nmi;
66 asmlinkage int system_call(void);
68 /* Do we ignore FPU interrupts ? */
69 char ignore_fpu_irq = 0;
72 * The IDT has to be page-aligned to simplify the Pentium
73 * F0 0F bug workaround.. We have a special link segment
76 struct desc_struct idt_table[256] __attribute__((__section__(".data.idt"))) = { {0, 0}, };
78 asmlinkage void divide_error(void);
79 asmlinkage void debug(void);
80 asmlinkage void nmi(void);
81 asmlinkage void int3(void);
82 asmlinkage void overflow(void);
83 asmlinkage void bounds(void);
84 asmlinkage void invalid_op(void);
85 asmlinkage void device_not_available(void);
86 asmlinkage void coprocessor_segment_overrun(void);
87 asmlinkage void invalid_TSS(void);
88 asmlinkage void segment_not_present(void);
89 asmlinkage void stack_segment(void);
90 asmlinkage void general_protection(void);
91 asmlinkage void page_fault(void);
92 asmlinkage void coprocessor_error(void);
93 asmlinkage void simd_coprocessor_error(void);
94 asmlinkage void alignment_check(void);
95 asmlinkage void spurious_interrupt_bug(void);
96 asmlinkage void machine_check(void);
98 int kstack_depth_to_print = 24;
99 static unsigned int code_bytes = 64;
101 static inline int valid_stack_ptr(struct thread_info *tinfo, void *p, unsigned size)
103 return p > (void *)tinfo &&
104 p <= (void *)tinfo + THREAD_SIZE - size;
107 /* The form of the top of the frame on the stack */
109 struct stack_frame *next_frame;
110 unsigned long return_address;
113 static inline unsigned long print_context_stack(struct thread_info *tinfo,
114 unsigned long *stack, unsigned long ebp,
115 const struct stacktrace_ops *ops, void *data)
117 #ifdef CONFIG_FRAME_POINTER
118 struct stack_frame *frame = (struct stack_frame *)ebp;
119 while (valid_stack_ptr(tinfo, frame, sizeof(*frame))) {
120 struct stack_frame *next;
123 addr = frame->return_address;
124 ops->address(data, addr);
126 * break out of recursive entries (such as
127 * end_of_stack_stop_unwind_function). Also,
128 * we can never allow a frame pointer to
131 next = frame->next_frame;
137 while (valid_stack_ptr(tinfo, stack, sizeof(*stack))) {
141 if (__kernel_text_address(addr))
142 ops->address(data, addr);
148 #define MSG(msg) ops->warning(data, msg)
150 void dump_trace(struct task_struct *task, struct pt_regs *regs,
151 unsigned long *stack,
152 const struct stacktrace_ops *ops, void *data)
154 unsigned long ebp = 0;
163 stack = (unsigned long *)task->thread.esp;
166 #ifdef CONFIG_FRAME_POINTER
168 if (task == current) {
169 /* Grab ebp right from our regs */
170 asm ("movl %%ebp, %0" : "=r" (ebp) : );
172 /* ebp is the last reg pushed by switch_to */
173 ebp = *(unsigned long *) task->thread.esp;
179 struct thread_info *context;
180 context = (struct thread_info *)
181 ((unsigned long)stack & (~(THREAD_SIZE - 1)));
182 ebp = print_context_stack(context, stack, ebp, ops, data);
183 /* Should be after the line below, but somewhere
184 in early boot context comes out corrupted and we
185 can't reference it -AK */
186 if (ops->stack(data, "IRQ") < 0)
188 stack = (unsigned long*)context->previous_esp;
191 touch_nmi_watchdog();
194 EXPORT_SYMBOL(dump_trace);
197 print_trace_warning_symbol(void *data, char *msg, unsigned long symbol)
200 print_symbol(msg, symbol);
204 static void print_trace_warning(void *data, char *msg)
206 printk("%s%s\n", (char *)data, msg);
209 static int print_trace_stack(void *data, char *name)
215 * Print one address/symbol entries per line.
217 static void print_trace_address(void *data, unsigned long addr)
219 printk("%s [<%08lx>] ", (char *)data, addr);
220 print_symbol("%s\n", addr);
221 touch_nmi_watchdog();
224 static const struct stacktrace_ops print_trace_ops = {
225 .warning = print_trace_warning,
226 .warning_symbol = print_trace_warning_symbol,
227 .stack = print_trace_stack,
228 .address = print_trace_address,
232 show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs,
233 unsigned long * stack, char *log_lvl)
235 dump_trace(task, regs, stack, &print_trace_ops, log_lvl);
236 printk("%s =======================\n", log_lvl);
239 void show_trace(struct task_struct *task, struct pt_regs *regs,
240 unsigned long * stack)
242 show_trace_log_lvl(task, regs, stack, "");
245 static void show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs,
246 unsigned long *esp, char *log_lvl)
248 unsigned long *stack;
253 esp = (unsigned long*)task->thread.esp;
255 esp = (unsigned long *)&esp;
259 for(i = 0; i < kstack_depth_to_print; i++) {
260 if (kstack_end(stack))
262 if (i && ((i % 8) == 0))
263 printk("\n%s ", log_lvl);
264 printk("%08lx ", *stack++);
266 printk("\n%sCall Trace:\n", log_lvl);
267 show_trace_log_lvl(task, regs, esp, log_lvl);
270 void show_stack(struct task_struct *task, unsigned long *esp)
273 show_stack_log_lvl(task, NULL, esp, "");
277 * The architecture-independent dump_stack generator
279 void dump_stack(void)
283 show_trace(current, NULL, &stack);
286 EXPORT_SYMBOL(dump_stack);
288 void show_registers(struct pt_regs *regs)
293 __show_registers(regs, 0);
294 printk(KERN_EMERG "Process %.*s (pid: %d, ti=%p task=%p task.ti=%p)",
295 TASK_COMM_LEN, current->comm, current->pid,
296 current_thread_info(), current, task_thread_info(current));
298 * When in-kernel, we also print out the stack and code at the
299 * time of the fault..
301 if (!user_mode_vm(regs)) {
303 unsigned int code_prologue = code_bytes * 43 / 64;
304 unsigned int code_len = code_bytes;
307 printk("\n" KERN_EMERG "Stack: ");
308 show_stack_log_lvl(NULL, regs, ®s->esp, KERN_EMERG);
310 printk(KERN_EMERG "Code: ");
312 eip = (u8 *)regs->eip - code_prologue;
313 if (eip < (u8 *)PAGE_OFFSET ||
314 probe_kernel_address(eip, c)) {
315 /* try starting at EIP */
316 eip = (u8 *)regs->eip;
317 code_len = code_len - code_prologue + 1;
319 for (i = 0; i < code_len; i++, eip++) {
320 if (eip < (u8 *)PAGE_OFFSET ||
321 probe_kernel_address(eip, c)) {
322 printk(" Bad EIP value.");
325 if (eip == (u8 *)regs->eip)
326 printk("<%02x> ", c);
334 int is_valid_bugaddr(unsigned long eip)
338 if (eip < PAGE_OFFSET)
340 if (probe_kernel_address((unsigned short *)eip, ud2))
343 return ud2 == 0x0b0f;
347 * This is gone through when something in the kernel has done something bad and
348 * is about to be terminated.
350 void die(const char * str, struct pt_regs * regs, long err)
355 int lock_owner_depth;
357 .lock = __SPIN_LOCK_UNLOCKED(die.lock),
359 .lock_owner_depth = 0
361 static int die_counter;
366 if (die.lock_owner != raw_smp_processor_id()) {
368 spin_lock_irqsave(&die.lock, flags);
369 die.lock_owner = smp_processor_id();
370 die.lock_owner_depth = 0;
374 local_save_flags(flags);
376 if (++die.lock_owner_depth < 3) {
380 report_bug(regs->eip, regs);
382 printk(KERN_EMERG "%s: %04lx [#%d] ", str, err & 0xffff,
384 #ifdef CONFIG_PREEMPT
390 #ifdef CONFIG_DEBUG_PAGEALLOC
391 printk("DEBUG_PAGEALLOC");
395 if (notify_die(DIE_OOPS, str, regs, err,
396 current->thread.trap_no, SIGSEGV) !=
398 show_registers(regs);
399 /* Executive summary in case the oops scrolled away */
400 esp = (unsigned long) (®s->esp);
402 if (user_mode(regs)) {
404 ss = regs->xss & 0xffff;
406 printk(KERN_EMERG "EIP: [<%08lx>] ", regs->eip);
407 print_symbol("%s", regs->eip);
408 printk(" SS:ESP %04x:%08lx\n", ss, esp);
413 printk(KERN_EMERG "Recursive die() failure, output suppressed\n");
417 add_taint(TAINT_DIE);
418 spin_unlock_irqrestore(&die.lock, flags);
423 if (kexec_should_crash(current))
427 panic("Fatal exception in interrupt");
430 panic("Fatal exception");
436 static inline void die_if_kernel(const char * str, struct pt_regs * regs, long err)
438 if (!user_mode_vm(regs))
442 static void __kprobes do_trap(int trapnr, int signr, char *str, int vm86,
443 struct pt_regs * regs, long error_code,
446 struct task_struct *tsk = current;
448 if (regs->eflags & VM_MASK) {
454 if (!user_mode(regs))
459 * We want error_code and trap_no set for userspace faults and
460 * kernelspace faults which result in die(), but not
461 * kernelspace faults which are fixed up. die() gives the
462 * process no chance to handle the signal and notice the
463 * kernel fault information, so that won't result in polluting
464 * the information about previously queued, but not yet
465 * delivered, faults. See also do_general_protection below.
467 tsk->thread.error_code = error_code;
468 tsk->thread.trap_no = trapnr;
471 force_sig_info(signr, info, tsk);
473 force_sig(signr, tsk);
478 if (!fixup_exception(regs)) {
479 tsk->thread.error_code = error_code;
480 tsk->thread.trap_no = trapnr;
481 die(str, regs, error_code);
487 int ret = handle_vm86_trap((struct kernel_vm86_regs *) regs, error_code, trapnr);
488 if (ret) goto trap_signal;
493 #define DO_ERROR(trapnr, signr, str, name) \
494 fastcall void do_##name(struct pt_regs * regs, long error_code) \
496 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
499 do_trap(trapnr, signr, str, 0, regs, error_code, NULL); \
502 #define DO_ERROR_INFO(trapnr, signr, str, name, sicode, siaddr, irq) \
503 fastcall void do_##name(struct pt_regs * regs, long error_code) \
507 local_irq_enable(); \
508 info.si_signo = signr; \
510 info.si_code = sicode; \
511 info.si_addr = (void __user *)siaddr; \
512 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
515 do_trap(trapnr, signr, str, 0, regs, error_code, &info); \
518 #define DO_VM86_ERROR(trapnr, signr, str, name) \
519 fastcall void do_##name(struct pt_regs * regs, long error_code) \
521 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
524 do_trap(trapnr, signr, str, 1, regs, error_code, NULL); \
527 #define DO_VM86_ERROR_INFO(trapnr, signr, str, name, sicode, siaddr) \
528 fastcall void do_##name(struct pt_regs * regs, long error_code) \
531 info.si_signo = signr; \
533 info.si_code = sicode; \
534 info.si_addr = (void __user *)siaddr; \
535 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
538 do_trap(trapnr, signr, str, 1, regs, error_code, &info); \
541 DO_VM86_ERROR_INFO( 0, SIGFPE, "divide error", divide_error, FPE_INTDIV, regs->eip)
542 #ifndef CONFIG_KPROBES
543 DO_VM86_ERROR( 3, SIGTRAP, "int3", int3)
545 DO_VM86_ERROR( 4, SIGSEGV, "overflow", overflow)
546 DO_VM86_ERROR( 5, SIGSEGV, "bounds", bounds)
547 DO_ERROR_INFO( 6, SIGILL, "invalid opcode", invalid_op, ILL_ILLOPN, regs->eip, 0)
548 DO_ERROR( 9, SIGFPE, "coprocessor segment overrun", coprocessor_segment_overrun)
549 DO_ERROR(10, SIGSEGV, "invalid TSS", invalid_TSS)
550 DO_ERROR(11, SIGBUS, "segment not present", segment_not_present)
551 DO_ERROR(12, SIGBUS, "stack segment", stack_segment)
552 DO_ERROR_INFO(17, SIGBUS, "alignment check", alignment_check, BUS_ADRALN, 0, 0)
553 DO_ERROR_INFO(32, SIGSEGV, "iret exception", iret_error, ILL_BADSTK, 0, 1)
555 fastcall void __kprobes do_general_protection(struct pt_regs * regs,
559 struct tss_struct *tss = &per_cpu(init_tss, cpu);
560 struct thread_struct *thread = ¤t->thread;
563 * Perform the lazy TSS's I/O bitmap copy. If the TSS has an
564 * invalid offset set (the LAZY one) and the faulting thread has
565 * a valid I/O bitmap pointer, we copy the I/O bitmap in the TSS
566 * and we set the offset field correctly. Then we let the CPU to
567 * restart the faulting instruction.
569 if (tss->x86_tss.io_bitmap_base == INVALID_IO_BITMAP_OFFSET_LAZY &&
570 thread->io_bitmap_ptr) {
571 memcpy(tss->io_bitmap, thread->io_bitmap_ptr,
572 thread->io_bitmap_max);
574 * If the previously set map was extending to higher ports
575 * than the current one, pad extra space with 0xff (no access).
577 if (thread->io_bitmap_max < tss->io_bitmap_max)
578 memset((char *) tss->io_bitmap +
579 thread->io_bitmap_max, 0xff,
580 tss->io_bitmap_max - thread->io_bitmap_max);
581 tss->io_bitmap_max = thread->io_bitmap_max;
582 tss->x86_tss.io_bitmap_base = IO_BITMAP_OFFSET;
583 tss->io_bitmap_owner = thread;
589 if (regs->eflags & VM_MASK)
592 if (!user_mode(regs))
595 current->thread.error_code = error_code;
596 current->thread.trap_no = 13;
597 if (show_unhandled_signals && unhandled_signal(current, SIGSEGV) &&
600 "%s[%d] general protection eip:%lx esp:%lx error:%lx\n",
601 current->comm, current->pid,
602 regs->eip, regs->esp, error_code);
604 force_sig(SIGSEGV, current);
609 handle_vm86_fault((struct kernel_vm86_regs *) regs, error_code);
613 if (!fixup_exception(regs)) {
614 current->thread.error_code = error_code;
615 current->thread.trap_no = 13;
616 if (notify_die(DIE_GPF, "general protection fault", regs,
617 error_code, 13, SIGSEGV) == NOTIFY_STOP)
619 die("general protection fault", regs, error_code);
623 static __kprobes void
624 mem_parity_error(unsigned char reason, struct pt_regs * regs)
626 printk(KERN_EMERG "Uhhuh. NMI received for unknown reason %02x on "
627 "CPU %d.\n", reason, smp_processor_id());
628 printk(KERN_EMERG "You have some hardware problem, likely on the PCI bus.\n");
630 #if defined(CONFIG_EDAC)
631 if(edac_handler_set()) {
632 edac_atomic_assert_error();
637 if (panic_on_unrecovered_nmi)
638 panic("NMI: Not continuing");
640 printk(KERN_EMERG "Dazed and confused, but trying to continue\n");
642 /* Clear and disable the memory parity error line. */
643 clear_mem_error(reason);
646 static __kprobes void
647 io_check_error(unsigned char reason, struct pt_regs * regs)
651 printk(KERN_EMERG "NMI: IOCK error (debug interrupt?)\n");
652 show_registers(regs);
654 /* Re-enable the IOCK line, wait for a few seconds */
655 reason = (reason & 0xf) | 8;
658 while (--i) udelay(1000);
663 static __kprobes void
664 unknown_nmi_error(unsigned char reason, struct pt_regs * regs)
667 /* Might actually be able to figure out what the guilty party
674 printk(KERN_EMERG "Uhhuh. NMI received for unknown reason %02x on "
675 "CPU %d.\n", reason, smp_processor_id());
676 printk(KERN_EMERG "Do you have a strange power saving mode enabled?\n");
677 if (panic_on_unrecovered_nmi)
678 panic("NMI: Not continuing");
680 printk(KERN_EMERG "Dazed and confused, but trying to continue\n");
683 static DEFINE_SPINLOCK(nmi_print_lock);
685 void __kprobes die_nmi(struct pt_regs *regs, const char *msg)
687 if (notify_die(DIE_NMIWATCHDOG, msg, regs, 0, 2, SIGINT) ==
691 spin_lock(&nmi_print_lock);
693 * We are in trouble anyway, lets at least try
694 * to get a message out.
697 printk(KERN_EMERG "%s", msg);
698 printk(" on CPU%d, eip %08lx, registers:\n",
699 smp_processor_id(), regs->eip);
700 show_registers(regs);
702 spin_unlock(&nmi_print_lock);
705 /* If we are in kernel we are probably nested up pretty bad
706 * and might aswell get out now while we still can.
708 if (!user_mode_vm(regs)) {
709 current->thread.trap_no = 2;
716 static __kprobes void default_do_nmi(struct pt_regs * regs)
718 unsigned char reason = 0;
720 /* Only the BSP gets external NMIs from the system. */
721 if (!smp_processor_id())
722 reason = get_nmi_reason();
724 if (!(reason & 0xc0)) {
725 if (notify_die(DIE_NMI_IPI, "nmi_ipi", regs, reason, 2, SIGINT)
728 #ifdef CONFIG_X86_LOCAL_APIC
730 * Ok, so this is none of the documented NMI sources,
731 * so it must be the NMI watchdog.
733 if (nmi_watchdog_tick(regs, reason))
735 if (!do_nmi_callback(regs, smp_processor_id()))
737 unknown_nmi_error(reason, regs);
741 if (notify_die(DIE_NMI, "nmi", regs, reason, 2, SIGINT) == NOTIFY_STOP)
744 mem_parity_error(reason, regs);
746 io_check_error(reason, regs);
748 * Reassert NMI in case it became active meanwhile
749 * as it's edge-triggered.
754 static int ignore_nmis;
756 fastcall __kprobes void do_nmi(struct pt_regs * regs, long error_code)
762 cpu = smp_processor_id();
767 default_do_nmi(regs);
778 void restart_nmi(void)
784 #ifdef CONFIG_KPROBES
785 fastcall void __kprobes do_int3(struct pt_regs *regs, long error_code)
787 if (notify_die(DIE_INT3, "int3", regs, error_code, 3, SIGTRAP)
790 /* This is an interrupt gate, because kprobes wants interrupts
791 disabled. Normal trap handlers don't. */
792 restore_interrupts(regs);
793 do_trap(3, SIGTRAP, "int3", 1, regs, error_code, NULL);
798 * Our handling of the processor debug registers is non-trivial.
799 * We do not clear them on entry and exit from the kernel. Therefore
800 * it is possible to get a watchpoint trap here from inside the kernel.
801 * However, the code in ./ptrace.c has ensured that the user can
802 * only set watchpoints on userspace addresses. Therefore the in-kernel
803 * watchpoint trap can only occur in code which is reading/writing
804 * from user space. Such code must not hold kernel locks (since it
805 * can equally take a page fault), therefore it is safe to call
806 * force_sig_info even though that claims and releases locks.
808 * Code in ./signal.c ensures that the debug control register
809 * is restored before we deliver any signal, and therefore that
810 * user code runs with the correct debug control register even though
813 * Being careful here means that we don't have to be as careful in a
814 * lot of more complicated places (task switching can be a bit lazy
815 * about restoring all the debug state, and ptrace doesn't have to
816 * find every occurrence of the TF bit that could be saved away even
819 fastcall void __kprobes do_debug(struct pt_regs * regs, long error_code)
821 unsigned int condition;
822 struct task_struct *tsk = current;
824 get_debugreg(condition, 6);
826 if (notify_die(DIE_DEBUG, "debug", regs, condition, error_code,
827 SIGTRAP) == NOTIFY_STOP)
829 /* It's safe to allow irq's after DR6 has been saved */
830 if (regs->eflags & X86_EFLAGS_IF)
833 /* Mask out spurious debug traps due to lazy DR7 setting */
834 if (condition & (DR_TRAP0|DR_TRAP1|DR_TRAP2|DR_TRAP3)) {
835 if (!tsk->thread.debugreg[7])
839 if (regs->eflags & VM_MASK)
842 /* Save debug status register where ptrace can see it */
843 tsk->thread.debugreg[6] = condition;
846 * Single-stepping through TF: make sure we ignore any events in
847 * kernel space (but re-enable TF when returning to user mode).
849 if (condition & DR_STEP) {
851 * We already checked v86 mode above, so we can
852 * check for kernel mode by just checking the CPL
855 if (!user_mode(regs))
856 goto clear_TF_reenable;
859 /* Ok, finally something we can handle */
860 send_sigtrap(tsk, regs, error_code);
862 /* Disable additional traps. They'll be re-enabled when
863 * the signal is delivered.
870 handle_vm86_trap((struct kernel_vm86_regs *) regs, error_code, 1);
874 set_tsk_thread_flag(tsk, TIF_SINGLESTEP);
875 regs->eflags &= ~TF_MASK;
880 * Note that we play around with the 'TS' bit in an attempt to get
881 * the correct behaviour even in the presence of the asynchronous
884 void math_error(void __user *eip)
886 struct task_struct * task;
888 unsigned short cwd, swd;
891 * Save the info for the exception handler and clear the error.
895 task->thread.trap_no = 16;
896 task->thread.error_code = 0;
897 info.si_signo = SIGFPE;
899 info.si_code = __SI_FAULT;
902 * (~cwd & swd) will mask out exceptions that are not set to unmasked
903 * status. 0x3f is the exception bits in these regs, 0x200 is the
904 * C1 reg you need in case of a stack fault, 0x040 is the stack
905 * fault bit. We should only be taking one exception at a time,
906 * so if this combination doesn't produce any single exception,
907 * then we have a bad program that isn't syncronizing its FPU usage
908 * and it will suffer the consequences since we won't be able to
909 * fully reproduce the context of the exception
911 cwd = get_fpu_cwd(task);
912 swd = get_fpu_swd(task);
913 switch (swd & ~cwd & 0x3f) {
914 case 0x000: /* No unmasked exception */
916 default: /* Multiple exceptions */
918 case 0x001: /* Invalid Op */
920 * swd & 0x240 == 0x040: Stack Underflow
921 * swd & 0x240 == 0x240: Stack Overflow
922 * User must clear the SF bit (0x40) if set
924 info.si_code = FPE_FLTINV;
926 case 0x002: /* Denormalize */
927 case 0x010: /* Underflow */
928 info.si_code = FPE_FLTUND;
930 case 0x004: /* Zero Divide */
931 info.si_code = FPE_FLTDIV;
933 case 0x008: /* Overflow */
934 info.si_code = FPE_FLTOVF;
936 case 0x020: /* Precision */
937 info.si_code = FPE_FLTRES;
940 force_sig_info(SIGFPE, &info, task);
943 fastcall void do_coprocessor_error(struct pt_regs * regs, long error_code)
946 math_error((void __user *)regs->eip);
949 static void simd_math_error(void __user *eip)
951 struct task_struct * task;
953 unsigned short mxcsr;
956 * Save the info for the exception handler and clear the error.
960 task->thread.trap_no = 19;
961 task->thread.error_code = 0;
962 info.si_signo = SIGFPE;
964 info.si_code = __SI_FAULT;
967 * The SIMD FPU exceptions are handled a little differently, as there
968 * is only a single status/control register. Thus, to determine which
969 * unmasked exception was caught we must mask the exception mask bits
970 * at 0x1f80, and then use these to mask the exception bits at 0x3f.
972 mxcsr = get_fpu_mxcsr(task);
973 switch (~((mxcsr & 0x1f80) >> 7) & (mxcsr & 0x3f)) {
977 case 0x001: /* Invalid Op */
978 info.si_code = FPE_FLTINV;
980 case 0x002: /* Denormalize */
981 case 0x010: /* Underflow */
982 info.si_code = FPE_FLTUND;
984 case 0x004: /* Zero Divide */
985 info.si_code = FPE_FLTDIV;
987 case 0x008: /* Overflow */
988 info.si_code = FPE_FLTOVF;
990 case 0x020: /* Precision */
991 info.si_code = FPE_FLTRES;
994 force_sig_info(SIGFPE, &info, task);
997 fastcall void do_simd_coprocessor_error(struct pt_regs * regs,
1001 /* Handle SIMD FPU exceptions on PIII+ processors. */
1003 simd_math_error((void __user *)regs->eip);
1006 * Handle strange cache flush from user space exception
1007 * in all other cases. This is undocumented behaviour.
1009 if (regs->eflags & VM_MASK) {
1010 handle_vm86_fault((struct kernel_vm86_regs *)regs,
1014 current->thread.trap_no = 19;
1015 current->thread.error_code = error_code;
1016 die_if_kernel("cache flush denied", regs, error_code);
1017 force_sig(SIGSEGV, current);
1021 fastcall void do_spurious_interrupt_bug(struct pt_regs * regs,
1025 /* No need to warn about this any longer. */
1026 printk("Ignoring P6 Local APIC Spurious Interrupt Bug...\n");
1030 fastcall unsigned long patch_espfix_desc(unsigned long uesp,
1033 struct desc_struct *gdt = __get_cpu_var(gdt_page).gdt;
1034 unsigned long base = (kesp - uesp) & -THREAD_SIZE;
1035 unsigned long new_kesp = kesp - base;
1036 unsigned long lim_pages = (new_kesp | (THREAD_SIZE - 1)) >> PAGE_SHIFT;
1037 __u64 desc = *(__u64 *)&gdt[GDT_ENTRY_ESPFIX_SS];
1038 /* Set up base for espfix segment */
1039 desc &= 0x00f0ff0000000000ULL;
1040 desc |= ((((__u64)base) << 16) & 0x000000ffffff0000ULL) |
1041 ((((__u64)base) << 32) & 0xff00000000000000ULL) |
1042 ((((__u64)lim_pages) << 32) & 0x000f000000000000ULL) |
1043 (lim_pages & 0xffff);
1044 *(__u64 *)&gdt[GDT_ENTRY_ESPFIX_SS] = desc;
1049 * 'math_state_restore()' saves the current math information in the
1050 * old math state array, and gets the new ones from the current task
1052 * Careful.. There are problems with IBM-designed IRQ13 behaviour.
1053 * Don't touch unless you *really* know how it works.
1055 * Must be called with kernel preemption disabled (in this case,
1056 * local interrupts are disabled at the call-site in entry.S).
1058 asmlinkage void math_state_restore(void)
1060 struct thread_info *thread = current_thread_info();
1061 struct task_struct *tsk = thread->task;
1063 clts(); /* Allow maths ops (or we recurse) */
1064 if (!tsk_used_math(tsk))
1067 thread->status |= TS_USEDFPU; /* So we fnsave on switch_to() */
1070 EXPORT_SYMBOL_GPL(math_state_restore);
1072 #ifndef CONFIG_MATH_EMULATION
1074 asmlinkage void math_emulate(long arg)
1076 printk(KERN_EMERG "math-emulation not enabled and no coprocessor found.\n");
1077 printk(KERN_EMERG "killing %s.\n",current->comm);
1078 force_sig(SIGFPE,current);
1082 #endif /* CONFIG_MATH_EMULATION */
1085 * This needs to use 'idt_table' rather than 'idt', and
1086 * thus use the _nonmapped_ version of the IDT, as the
1087 * Pentium F0 0F bugfix can have resulted in the mapped
1088 * IDT being write-protected.
1090 void set_intr_gate(unsigned int n, void *addr)
1092 _set_gate(n, DESCTYPE_INT, addr, __KERNEL_CS);
1096 * This routine sets up an interrupt gate at directory privilege level 3.
1098 static inline void set_system_intr_gate(unsigned int n, void *addr)
1100 _set_gate(n, DESCTYPE_INT | DESCTYPE_DPL3, addr, __KERNEL_CS);
1103 static void __init set_trap_gate(unsigned int n, void *addr)
1105 _set_gate(n, DESCTYPE_TRAP, addr, __KERNEL_CS);
1108 static void __init set_system_gate(unsigned int n, void *addr)
1110 _set_gate(n, DESCTYPE_TRAP | DESCTYPE_DPL3, addr, __KERNEL_CS);
1113 static void __init set_task_gate(unsigned int n, unsigned int gdt_entry)
1115 _set_gate(n, DESCTYPE_TASK, (void *)0, (gdt_entry<<3));
1119 void __init trap_init(void)
1122 void __iomem *p = ioremap(0x0FFFD9, 4);
1123 if (readl(p) == 'E'+('I'<<8)+('S'<<16)+('A'<<24)) {
1129 #ifdef CONFIG_X86_LOCAL_APIC
1130 init_apic_mappings();
1133 set_trap_gate(0,÷_error);
1134 set_intr_gate(1,&debug);
1135 set_intr_gate(2,&nmi);
1136 set_system_intr_gate(3, &int3); /* int3/4 can be called from all */
1137 set_system_gate(4,&overflow);
1138 set_trap_gate(5,&bounds);
1139 set_trap_gate(6,&invalid_op);
1140 set_trap_gate(7,&device_not_available);
1141 set_task_gate(8,GDT_ENTRY_DOUBLEFAULT_TSS);
1142 set_trap_gate(9,&coprocessor_segment_overrun);
1143 set_trap_gate(10,&invalid_TSS);
1144 set_trap_gate(11,&segment_not_present);
1145 set_trap_gate(12,&stack_segment);
1146 set_trap_gate(13,&general_protection);
1147 set_intr_gate(14,&page_fault);
1148 set_trap_gate(15,&spurious_interrupt_bug);
1149 set_trap_gate(16,&coprocessor_error);
1150 set_trap_gate(17,&alignment_check);
1151 #ifdef CONFIG_X86_MCE
1152 set_trap_gate(18,&machine_check);
1154 set_trap_gate(19,&simd_coprocessor_error);
1158 * Verify that the FXSAVE/FXRSTOR data will be 16-byte aligned.
1159 * Generates a compile-time "error: zero width for bit-field" if
1160 * the alignment is wrong.
1162 struct fxsrAlignAssert {
1163 int _:!(offsetof(struct task_struct,
1164 thread.i387.fxsave) & 15);
1167 printk(KERN_INFO "Enabling fast FPU save and restore... ");
1168 set_in_cr4(X86_CR4_OSFXSR);
1172 printk(KERN_INFO "Enabling unmasked SIMD FPU exception "
1174 set_in_cr4(X86_CR4_OSXMMEXCPT);
1178 set_system_gate(SYSCALL_VECTOR,&system_call);
1181 * Should be a barrier for any external CPU state.
1188 static int __init kstack_setup(char *s)
1190 kstack_depth_to_print = simple_strtoul(s, NULL, 0);
1193 __setup("kstack=", kstack_setup);
1195 static int __init code_bytes_setup(char *s)
1197 code_bytes = simple_strtoul(s, NULL, 0);
1198 if (code_bytes > 8192)
1203 __setup("code_bytes=", code_bytes_setup);