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
)
102 spin_lock_irqsave(&die_notifier_lock
, flags
);
103 err
= notifier_chain_register(&i386die_chain
, nb
);
104 spin_unlock_irqrestore(&die_notifier_lock
, flags
);
107 EXPORT_SYMBOL(register_die_notifier
);
109 static inline int valid_stack_ptr(struct thread_info
*tinfo
, void *p
)
111 return p
> (void *)tinfo
&&
112 p
< (void *)tinfo
+ THREAD_SIZE
- 3;
115 static inline unsigned long print_context_stack(struct thread_info
*tinfo
,
116 unsigned long *stack
, unsigned long ebp
)
120 #ifdef CONFIG_FRAME_POINTER
121 while (valid_stack_ptr(tinfo
, (void *)ebp
)) {
122 addr
= *(unsigned long *)(ebp
+ 4);
123 printk(" [<%08lx>] ", addr
);
124 print_symbol("%s", addr
);
126 ebp
= *(unsigned long *)ebp
;
129 while (valid_stack_ptr(tinfo
, stack
)) {
131 if (__kernel_text_address(addr
)) {
132 printk(" [<%08lx>]", addr
);
133 print_symbol(" %s", addr
);
141 void show_trace(struct task_struct
*task
, unsigned long * stack
)
148 if (task
== current
) {
149 /* Grab ebp right from our regs */
150 asm ("movl %%ebp, %0" : "=r" (ebp
) : );
152 /* ebp is the last reg pushed by switch_to */
153 ebp
= *(unsigned long *) task
->thread
.esp
;
157 struct thread_info
*context
;
158 context
= (struct thread_info
*)
159 ((unsigned long)stack
& (~(THREAD_SIZE
- 1)));
160 ebp
= print_context_stack(context
, stack
, ebp
);
161 stack
= (unsigned long*)context
->previous_esp
;
164 printk(" =======================\n");
168 void show_stack(struct task_struct
*task
, unsigned long *esp
)
170 unsigned long *stack
;
175 esp
= (unsigned long*)task
->thread
.esp
;
177 esp
= (unsigned long *)&esp
;
181 for(i
= 0; i
< kstack_depth_to_print
; i
++) {
182 if (kstack_end(stack
))
184 if (i
&& ((i
% 8) == 0))
186 printk("%08lx ", *stack
++);
188 printk("\nCall Trace:\n");
189 show_trace(task
, esp
);
193 * The architecture-independent dump_stack generator
195 void dump_stack(void)
199 show_trace(current
, &stack
);
202 EXPORT_SYMBOL(dump_stack
);
204 void show_registers(struct pt_regs
*regs
)
211 esp
= (unsigned long) (®s
->esp
);
213 if (user_mode(regs
)) {
216 ss
= regs
->xss
& 0xffff;
219 printk("CPU: %d\nEIP: %04x:[<%08lx>] %s VLI\nEFLAGS: %08lx"
221 smp_processor_id(), 0xffff & regs
->xcs
, regs
->eip
,
222 print_tainted(), regs
->eflags
, system_utsname
.release
);
223 print_symbol("EIP is at %s\n", regs
->eip
);
224 printk("eax: %08lx ebx: %08lx ecx: %08lx edx: %08lx\n",
225 regs
->eax
, regs
->ebx
, regs
->ecx
, regs
->edx
);
226 printk("esi: %08lx edi: %08lx ebp: %08lx esp: %08lx\n",
227 regs
->esi
, regs
->edi
, regs
->ebp
, esp
);
228 printk("ds: %04x es: %04x ss: %04x\n",
229 regs
->xds
& 0xffff, regs
->xes
& 0xffff, ss
);
230 printk("Process %s (pid: %d, threadinfo=%p task=%p)",
231 current
->comm
, current
->pid
, current_thread_info(), current
);
233 * When in-kernel, we also print out the stack and code at the
234 * time of the fault..
240 show_stack(NULL
, (unsigned long*)esp
);
244 eip
= (u8 __user
*)regs
->eip
- 43;
245 for (i
= 0; i
< 64; i
++, eip
++) {
248 if (eip
< (u8 __user
*)PAGE_OFFSET
|| __get_user(c
, eip
)) {
249 printk(" Bad EIP value.");
252 if (eip
== (u8 __user
*)regs
->eip
)
253 printk("<%02x> ", c
);
261 static void handle_BUG(struct pt_regs
*regs
)
271 if (eip
< PAGE_OFFSET
)
273 if (__get_user(ud2
, (unsigned short __user
*)eip
))
277 if (__get_user(line
, (unsigned short __user
*)(eip
+ 2)))
279 if (__get_user(file
, (char * __user
*)(eip
+ 4)) ||
280 (unsigned long)file
< PAGE_OFFSET
|| __get_user(c
, file
))
281 file
= "<bad filename>";
283 printk("------------[ cut here ]------------\n");
284 printk(KERN_ALERT
"kernel BUG at %s:%d!\n", file
, line
);
289 /* Here we know it was a BUG but file-n-line is unavailable */
291 printk("Kernel BUG\n");
294 /* This is gone through when something in the kernel
295 * has done something bad and is about to be terminated.
297 void die(const char * str
, struct pt_regs
* regs
, long err
)
302 int lock_owner_depth
;
304 .lock
= SPIN_LOCK_UNLOCKED
,
306 .lock_owner_depth
= 0
308 static int die_counter
;
310 if (die
.lock_owner
!= raw_smp_processor_id()) {
312 spin_lock_irq(&die
.lock
);
313 die
.lock_owner
= smp_processor_id();
314 die
.lock_owner_depth
= 0;
318 if (++die
.lock_owner_depth
< 3) {
321 printk(KERN_ALERT
"%s: %04lx [#%d]\n", str
, err
& 0xffff, ++die_counter
);
322 #ifdef CONFIG_PREEMPT
330 #ifdef CONFIG_DEBUG_PAGEALLOC
331 printk("DEBUG_PAGEALLOC");
336 notify_die(DIE_OOPS
, (char *)str
, regs
, err
, 255, SIGSEGV
);
337 show_registers(regs
);
339 printk(KERN_ERR
"Recursive die() failure, output suppressed\n");
343 spin_unlock_irq(&die
.lock
);
345 if (kexec_should_crash(current
))
349 panic("Fatal exception in interrupt");
352 printk(KERN_EMERG
"Fatal exception: panic in 5 seconds\n");
354 panic("Fatal exception");
359 static inline void die_if_kernel(const char * str
, struct pt_regs
* regs
, long err
)
361 if (!user_mode_vm(regs
))
365 static void __kprobes
do_trap(int trapnr
, int signr
, char *str
, int vm86
,
366 struct pt_regs
* regs
, long error_code
,
369 struct task_struct
*tsk
= current
;
370 tsk
->thread
.error_code
= error_code
;
371 tsk
->thread
.trap_no
= trapnr
;
373 if (regs
->eflags
& VM_MASK
) {
379 if (!user_mode(regs
))
384 force_sig_info(signr
, info
, tsk
);
386 force_sig(signr
, tsk
);
391 if (!fixup_exception(regs
))
392 die(str
, regs
, error_code
);
397 int ret
= handle_vm86_trap((struct kernel_vm86_regs
*) regs
, error_code
, trapnr
);
398 if (ret
) goto trap_signal
;
403 #define DO_ERROR(trapnr, signr, str, name) \
404 fastcall void do_##name(struct pt_regs * regs, long error_code) \
406 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
409 do_trap(trapnr, signr, str, 0, regs, error_code, NULL); \
412 #define DO_ERROR_INFO(trapnr, signr, str, name, sicode, siaddr) \
413 fastcall void do_##name(struct pt_regs * regs, long error_code) \
416 info.si_signo = signr; \
418 info.si_code = sicode; \
419 info.si_addr = (void __user *)siaddr; \
420 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
423 do_trap(trapnr, signr, str, 0, regs, error_code, &info); \
426 #define DO_VM86_ERROR(trapnr, signr, str, name) \
427 fastcall void do_##name(struct pt_regs * regs, long error_code) \
429 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
432 do_trap(trapnr, signr, str, 1, regs, error_code, NULL); \
435 #define DO_VM86_ERROR_INFO(trapnr, signr, str, name, sicode, siaddr) \
436 fastcall void do_##name(struct pt_regs * regs, long error_code) \
439 info.si_signo = signr; \
441 info.si_code = sicode; \
442 info.si_addr = (void __user *)siaddr; \
443 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
446 do_trap(trapnr, signr, str, 1, regs, error_code, &info); \
449 DO_VM86_ERROR_INFO( 0, SIGFPE
, "divide error", divide_error
, FPE_INTDIV
, regs
->eip
)
450 #ifndef CONFIG_KPROBES
451 DO_VM86_ERROR( 3, SIGTRAP
, "int3", int3
)
453 DO_VM86_ERROR( 4, SIGSEGV
, "overflow", overflow
)
454 DO_VM86_ERROR( 5, SIGSEGV
, "bounds", bounds
)
455 DO_ERROR_INFO( 6, SIGILL
, "invalid operand", invalid_op
, ILL_ILLOPN
, regs
->eip
)
456 DO_ERROR( 9, SIGFPE
, "coprocessor segment overrun", coprocessor_segment_overrun
)
457 DO_ERROR(10, SIGSEGV
, "invalid TSS", invalid_TSS
)
458 DO_ERROR(11, SIGBUS
, "segment not present", segment_not_present
)
459 DO_ERROR(12, SIGBUS
, "stack segment", stack_segment
)
460 DO_ERROR_INFO(17, SIGBUS
, "alignment check", alignment_check
, BUS_ADRALN
, 0)
461 DO_ERROR_INFO(32, SIGSEGV
, "iret exception", iret_error
, ILL_BADSTK
, 0)
463 fastcall
void __kprobes
do_general_protection(struct pt_regs
* regs
,
467 struct tss_struct
*tss
= &per_cpu(init_tss
, cpu
);
468 struct thread_struct
*thread
= ¤t
->thread
;
471 * Perform the lazy TSS's I/O bitmap copy. If the TSS has an
472 * invalid offset set (the LAZY one) and the faulting thread has
473 * a valid I/O bitmap pointer, we copy the I/O bitmap in the TSS
474 * and we set the offset field correctly. Then we let the CPU to
475 * restart the faulting instruction.
477 if (tss
->io_bitmap_base
== INVALID_IO_BITMAP_OFFSET_LAZY
&&
478 thread
->io_bitmap_ptr
) {
479 memcpy(tss
->io_bitmap
, thread
->io_bitmap_ptr
,
480 thread
->io_bitmap_max
);
482 * If the previously set map was extending to higher ports
483 * than the current one, pad extra space with 0xff (no access).
485 if (thread
->io_bitmap_max
< tss
->io_bitmap_max
)
486 memset((char *) tss
->io_bitmap
+
487 thread
->io_bitmap_max
, 0xff,
488 tss
->io_bitmap_max
- thread
->io_bitmap_max
);
489 tss
->io_bitmap_max
= thread
->io_bitmap_max
;
490 tss
->io_bitmap_base
= IO_BITMAP_OFFSET
;
491 tss
->io_bitmap_owner
= thread
;
497 current
->thread
.error_code
= error_code
;
498 current
->thread
.trap_no
= 13;
500 if (regs
->eflags
& VM_MASK
)
503 if (!user_mode(regs
))
506 current
->thread
.error_code
= error_code
;
507 current
->thread
.trap_no
= 13;
508 force_sig(SIGSEGV
, current
);
513 handle_vm86_fault((struct kernel_vm86_regs
*) regs
, error_code
);
517 if (!fixup_exception(regs
)) {
518 if (notify_die(DIE_GPF
, "general protection fault", regs
,
519 error_code
, 13, SIGSEGV
) == NOTIFY_STOP
)
521 die("general protection fault", regs
, error_code
);
525 static void mem_parity_error(unsigned char reason
, struct pt_regs
* regs
)
527 printk("Uhhuh. NMI received. Dazed and confused, but trying to continue\n");
528 printk("You probably have a hardware problem with your RAM chips\n");
530 /* Clear and disable the memory parity error line. */
531 clear_mem_error(reason
);
534 static void io_check_error(unsigned char reason
, struct pt_regs
* regs
)
538 printk("NMI: IOCK error (debug interrupt?)\n");
539 show_registers(regs
);
541 /* Re-enable the IOCK line, wait for a few seconds */
542 reason
= (reason
& 0xf) | 8;
545 while (--i
) udelay(1000);
550 static void unknown_nmi_error(unsigned char reason
, struct pt_regs
* regs
)
553 /* Might actually be able to figure out what the guilty party
560 printk("Uhhuh. NMI received for unknown reason %02x on CPU %d.\n",
561 reason
, smp_processor_id());
562 printk("Dazed and confused, but trying to continue\n");
563 printk("Do you have a strange power saving mode enabled?\n");
566 static DEFINE_SPINLOCK(nmi_print_lock
);
568 void die_nmi (struct pt_regs
*regs
, const char *msg
)
570 if (notify_die(DIE_NMIWATCHDOG
, msg
, regs
, 0, 0, SIGINT
) ==
574 spin_lock(&nmi_print_lock
);
576 * We are in trouble anyway, lets at least try
577 * to get a message out.
581 printk(" on CPU%d, eip %08lx, registers:\n",
582 smp_processor_id(), regs
->eip
);
583 show_registers(regs
);
584 printk("console shuts up ...\n");
586 spin_unlock(&nmi_print_lock
);
589 /* If we are in kernel we are probably nested up pretty bad
590 * and might aswell get out now while we still can.
592 if (!user_mode(regs
)) {
593 current
->thread
.trap_no
= 2;
600 static void default_do_nmi(struct pt_regs
* regs
)
602 unsigned char reason
= 0;
604 /* Only the BSP gets external NMIs from the system. */
605 if (!smp_processor_id())
606 reason
= get_nmi_reason();
608 if (!(reason
& 0xc0)) {
609 if (notify_die(DIE_NMI_IPI
, "nmi_ipi", regs
, reason
, 0, SIGINT
)
612 #ifdef CONFIG_X86_LOCAL_APIC
614 * Ok, so this is none of the documented NMI sources,
615 * so it must be the NMI watchdog.
618 nmi_watchdog_tick(regs
);
622 unknown_nmi_error(reason
, regs
);
625 if (notify_die(DIE_NMI
, "nmi", regs
, reason
, 0, SIGINT
) == NOTIFY_STOP
)
628 mem_parity_error(reason
, regs
);
630 io_check_error(reason
, regs
);
632 * Reassert NMI in case it became active meanwhile
633 * as it's edge-triggered.
638 static int dummy_nmi_callback(struct pt_regs
* regs
, int cpu
)
643 static nmi_callback_t nmi_callback
= dummy_nmi_callback
;
645 fastcall
void do_nmi(struct pt_regs
* regs
, long error_code
)
651 cpu
= smp_processor_id();
653 #ifdef CONFIG_HOTPLUG_CPU
654 if (!cpu_online(cpu
)) {
662 if (!rcu_dereference(nmi_callback
)(regs
, cpu
))
663 default_do_nmi(regs
);
668 void set_nmi_callback(nmi_callback_t callback
)
670 rcu_assign_pointer(nmi_callback
, callback
);
672 EXPORT_SYMBOL_GPL(set_nmi_callback
);
674 void unset_nmi_callback(void)
676 nmi_callback
= dummy_nmi_callback
;
678 EXPORT_SYMBOL_GPL(unset_nmi_callback
);
680 #ifdef CONFIG_KPROBES
681 fastcall
void __kprobes
do_int3(struct pt_regs
*regs
, long error_code
)
683 if (notify_die(DIE_INT3
, "int3", regs
, error_code
, 3, SIGTRAP
)
686 /* This is an interrupt gate, because kprobes wants interrupts
687 disabled. Normal trap handlers don't. */
688 restore_interrupts(regs
);
689 do_trap(3, SIGTRAP
, "int3", 1, regs
, error_code
, NULL
);
694 * Our handling of the processor debug registers is non-trivial.
695 * We do not clear them on entry and exit from the kernel. Therefore
696 * it is possible to get a watchpoint trap here from inside the kernel.
697 * However, the code in ./ptrace.c has ensured that the user can
698 * only set watchpoints on userspace addresses. Therefore the in-kernel
699 * watchpoint trap can only occur in code which is reading/writing
700 * from user space. Such code must not hold kernel locks (since it
701 * can equally take a page fault), therefore it is safe to call
702 * force_sig_info even though that claims and releases locks.
704 * Code in ./signal.c ensures that the debug control register
705 * is restored before we deliver any signal, and therefore that
706 * user code runs with the correct debug control register even though
709 * Being careful here means that we don't have to be as careful in a
710 * lot of more complicated places (task switching can be a bit lazy
711 * about restoring all the debug state, and ptrace doesn't have to
712 * find every occurrence of the TF bit that could be saved away even
715 fastcall
void __kprobes
do_debug(struct pt_regs
* regs
, long error_code
)
717 unsigned int condition
;
718 struct task_struct
*tsk
= current
;
720 get_debugreg(condition
, 6);
722 if (notify_die(DIE_DEBUG
, "debug", regs
, condition
, error_code
,
723 SIGTRAP
) == NOTIFY_STOP
)
725 /* It's safe to allow irq's after DR6 has been saved */
726 if (regs
->eflags
& X86_EFLAGS_IF
)
729 /* Mask out spurious debug traps due to lazy DR7 setting */
730 if (condition
& (DR_TRAP0
|DR_TRAP1
|DR_TRAP2
|DR_TRAP3
)) {
731 if (!tsk
->thread
.debugreg
[7])
735 if (regs
->eflags
& VM_MASK
)
738 /* Save debug status register where ptrace can see it */
739 tsk
->thread
.debugreg
[6] = condition
;
742 * Single-stepping through TF: make sure we ignore any events in
743 * kernel space (but re-enable TF when returning to user mode).
745 if (condition
& DR_STEP
) {
747 * We already checked v86 mode above, so we can
748 * check for kernel mode by just checking the CPL
751 if (!user_mode(regs
))
752 goto clear_TF_reenable
;
755 /* Ok, finally something we can handle */
756 send_sigtrap(tsk
, regs
, error_code
);
758 /* Disable additional traps. They'll be re-enabled when
759 * the signal is delivered.
766 handle_vm86_trap((struct kernel_vm86_regs
*) regs
, error_code
, 1);
770 set_tsk_thread_flag(tsk
, TIF_SINGLESTEP
);
771 regs
->eflags
&= ~TF_MASK
;
776 * Note that we play around with the 'TS' bit in an attempt to get
777 * the correct behaviour even in the presence of the asynchronous
780 void math_error(void __user
*eip
)
782 struct task_struct
* task
;
784 unsigned short cwd
, swd
;
787 * Save the info for the exception handler and clear the error.
791 task
->thread
.trap_no
= 16;
792 task
->thread
.error_code
= 0;
793 info
.si_signo
= SIGFPE
;
795 info
.si_code
= __SI_FAULT
;
798 * (~cwd & swd) will mask out exceptions that are not set to unmasked
799 * status. 0x3f is the exception bits in these regs, 0x200 is the
800 * C1 reg you need in case of a stack fault, 0x040 is the stack
801 * fault bit. We should only be taking one exception at a time,
802 * so if this combination doesn't produce any single exception,
803 * then we have a bad program that isn't syncronizing its FPU usage
804 * and it will suffer the consequences since we won't be able to
805 * fully reproduce the context of the exception
807 cwd
= get_fpu_cwd(task
);
808 swd
= get_fpu_swd(task
);
809 switch (swd
& ~cwd
& 0x3f) {
810 case 0x000: /* No unmasked exception */
812 default: /* Multiple exceptions */
814 case 0x001: /* Invalid Op */
816 * swd & 0x240 == 0x040: Stack Underflow
817 * swd & 0x240 == 0x240: Stack Overflow
818 * User must clear the SF bit (0x40) if set
820 info
.si_code
= FPE_FLTINV
;
822 case 0x002: /* Denormalize */
823 case 0x010: /* Underflow */
824 info
.si_code
= FPE_FLTUND
;
826 case 0x004: /* Zero Divide */
827 info
.si_code
= FPE_FLTDIV
;
829 case 0x008: /* Overflow */
830 info
.si_code
= FPE_FLTOVF
;
832 case 0x020: /* Precision */
833 info
.si_code
= FPE_FLTRES
;
836 force_sig_info(SIGFPE
, &info
, task
);
839 fastcall
void do_coprocessor_error(struct pt_regs
* regs
, long error_code
)
842 math_error((void __user
*)regs
->eip
);
845 static void simd_math_error(void __user
*eip
)
847 struct task_struct
* task
;
849 unsigned short mxcsr
;
852 * Save the info for the exception handler and clear the error.
856 task
->thread
.trap_no
= 19;
857 task
->thread
.error_code
= 0;
858 info
.si_signo
= SIGFPE
;
860 info
.si_code
= __SI_FAULT
;
863 * The SIMD FPU exceptions are handled a little differently, as there
864 * is only a single status/control register. Thus, to determine which
865 * unmasked exception was caught we must mask the exception mask bits
866 * at 0x1f80, and then use these to mask the exception bits at 0x3f.
868 mxcsr
= get_fpu_mxcsr(task
);
869 switch (~((mxcsr
& 0x1f80) >> 7) & (mxcsr
& 0x3f)) {
873 case 0x001: /* Invalid Op */
874 info
.si_code
= FPE_FLTINV
;
876 case 0x002: /* Denormalize */
877 case 0x010: /* Underflow */
878 info
.si_code
= FPE_FLTUND
;
880 case 0x004: /* Zero Divide */
881 info
.si_code
= FPE_FLTDIV
;
883 case 0x008: /* Overflow */
884 info
.si_code
= FPE_FLTOVF
;
886 case 0x020: /* Precision */
887 info
.si_code
= FPE_FLTRES
;
890 force_sig_info(SIGFPE
, &info
, task
);
893 fastcall
void do_simd_coprocessor_error(struct pt_regs
* regs
,
897 /* Handle SIMD FPU exceptions on PIII+ processors. */
899 simd_math_error((void __user
*)regs
->eip
);
902 * Handle strange cache flush from user space exception
903 * in all other cases. This is undocumented behaviour.
905 if (regs
->eflags
& VM_MASK
) {
906 handle_vm86_fault((struct kernel_vm86_regs
*)regs
,
910 current
->thread
.trap_no
= 19;
911 current
->thread
.error_code
= error_code
;
912 die_if_kernel("cache flush denied", regs
, error_code
);
913 force_sig(SIGSEGV
, current
);
917 fastcall
void do_spurious_interrupt_bug(struct pt_regs
* regs
,
921 /* No need to warn about this any longer. */
922 printk("Ignoring P6 Local APIC Spurious Interrupt Bug...\n");
926 fastcall
void setup_x86_bogus_stack(unsigned char * stk
)
928 unsigned long *switch16_ptr
, *switch32_ptr
;
929 struct pt_regs
*regs
;
930 unsigned long stack_top
, stack_bot
;
931 unsigned short iret_frame16_off
;
932 int cpu
= smp_processor_id();
933 /* reserve the space on 32bit stack for the magic switch16 pointer */
934 memmove(stk
, stk
+ 8, sizeof(struct pt_regs
));
935 switch16_ptr
= (unsigned long *)(stk
+ sizeof(struct pt_regs
));
936 regs
= (struct pt_regs
*)stk
;
937 /* now the switch32 on 16bit stack */
938 stack_bot
= (unsigned long)&per_cpu(cpu_16bit_stack
, cpu
);
939 stack_top
= stack_bot
+ CPU_16BIT_STACK_SIZE
;
940 switch32_ptr
= (unsigned long *)(stack_top
- 8);
941 iret_frame16_off
= CPU_16BIT_STACK_SIZE
- 8 - 20;
942 /* copy iret frame on 16bit stack */
943 memcpy((void *)(stack_bot
+ iret_frame16_off
), ®s
->eip
, 20);
944 /* fill in the switch pointers */
945 switch16_ptr
[0] = (regs
->esp
& 0xffff0000) | iret_frame16_off
;
946 switch16_ptr
[1] = __ESPFIX_SS
;
947 switch32_ptr
[0] = (unsigned long)stk
+ sizeof(struct pt_regs
) +
948 8 - CPU_16BIT_STACK_SIZE
;
949 switch32_ptr
[1] = __KERNEL_DS
;
952 fastcall
unsigned char * fixup_x86_bogus_stack(unsigned short sp
)
954 unsigned long *switch32_ptr
;
955 unsigned char *stack16
, *stack32
;
956 unsigned long stack_top
, stack_bot
;
958 int cpu
= smp_processor_id();
959 stack_bot
= (unsigned long)&per_cpu(cpu_16bit_stack
, cpu
);
960 stack_top
= stack_bot
+ CPU_16BIT_STACK_SIZE
;
961 switch32_ptr
= (unsigned long *)(stack_top
- 8);
962 /* copy the data from 16bit stack to 32bit stack */
963 len
= CPU_16BIT_STACK_SIZE
- 8 - sp
;
964 stack16
= (unsigned char *)(stack_bot
+ sp
);
965 stack32
= (unsigned char *)
966 (switch32_ptr
[0] + CPU_16BIT_STACK_SIZE
- 8 - len
);
967 memcpy(stack32
, stack16
, len
);
972 * 'math_state_restore()' saves the current math information in the
973 * old math state array, and gets the new ones from the current task
975 * Careful.. There are problems with IBM-designed IRQ13 behaviour.
976 * Don't touch unless you *really* know how it works.
978 * Must be called with kernel preemption disabled (in this case,
979 * local interrupts are disabled at the call-site in entry.S).
981 asmlinkage
void math_state_restore(struct pt_regs regs
)
983 struct thread_info
*thread
= current_thread_info();
984 struct task_struct
*tsk
= thread
->task
;
986 clts(); /* Allow maths ops (or we recurse) */
987 if (!tsk_used_math(tsk
))
990 thread
->status
|= TS_USEDFPU
; /* So we fnsave on switch_to() */
993 #ifndef CONFIG_MATH_EMULATION
995 asmlinkage
void math_emulate(long arg
)
997 printk("math-emulation not enabled and no coprocessor found.\n");
998 printk("killing %s.\n",current
->comm
);
999 force_sig(SIGFPE
,current
);
1003 #endif /* CONFIG_MATH_EMULATION */
1005 #ifdef CONFIG_X86_F00F_BUG
1006 void __init
trap_init_f00f_bug(void)
1008 __set_fixmap(FIX_F00F_IDT
, __pa(&idt_table
), PAGE_KERNEL_RO
);
1011 * Update the IDT descriptor and reload the IDT so that
1012 * it uses the read-only mapped virtual address.
1014 idt_descr
.address
= fix_to_virt(FIX_F00F_IDT
);
1015 load_idt(&idt_descr
);
1019 #define _set_gate(gate_addr,type,dpl,addr,seg) \
1022 __asm__ __volatile__ ("movw %%dx,%%ax\n\t" \
1023 "movw %4,%%dx\n\t" \
1024 "movl %%eax,%0\n\t" \
1026 :"=m" (*((long *) (gate_addr))), \
1027 "=m" (*(1+(long *) (gate_addr))), "=&a" (__d0), "=&d" (__d1) \
1028 :"i" ((short) (0x8000+(dpl<<13)+(type<<8))), \
1029 "3" ((char *) (addr)),"2" ((seg) << 16)); \
1034 * This needs to use 'idt_table' rather than 'idt', and
1035 * thus use the _nonmapped_ version of the IDT, as the
1036 * Pentium F0 0F bugfix can have resulted in the mapped
1037 * IDT being write-protected.
1039 void set_intr_gate(unsigned int n
, void *addr
)
1041 _set_gate(idt_table
+n
,14,0,addr
,__KERNEL_CS
);
1045 * This routine sets up an interrupt gate at directory privilege level 3.
1047 static inline void set_system_intr_gate(unsigned int n
, void *addr
)
1049 _set_gate(idt_table
+n
, 14, 3, addr
, __KERNEL_CS
);
1052 static void __init
set_trap_gate(unsigned int n
, void *addr
)
1054 _set_gate(idt_table
+n
,15,0,addr
,__KERNEL_CS
);
1057 static void __init
set_system_gate(unsigned int n
, void *addr
)
1059 _set_gate(idt_table
+n
,15,3,addr
,__KERNEL_CS
);
1062 static void __init
set_task_gate(unsigned int n
, unsigned int gdt_entry
)
1064 _set_gate(idt_table
+n
,5,0,0,(gdt_entry
<<3));
1068 void __init
trap_init(void)
1071 void __iomem
*p
= ioremap(0x0FFFD9, 4);
1072 if (readl(p
) == 'E'+('I'<<8)+('S'<<16)+('A'<<24)) {
1078 #ifdef CONFIG_X86_LOCAL_APIC
1079 init_apic_mappings();
1082 set_trap_gate(0,÷_error
);
1083 set_intr_gate(1,&debug
);
1084 set_intr_gate(2,&nmi
);
1085 set_system_intr_gate(3, &int3
); /* int3-5 can be called from all */
1086 set_system_gate(4,&overflow
);
1087 set_system_gate(5,&bounds
);
1088 set_trap_gate(6,&invalid_op
);
1089 set_trap_gate(7,&device_not_available
);
1090 set_task_gate(8,GDT_ENTRY_DOUBLEFAULT_TSS
);
1091 set_trap_gate(9,&coprocessor_segment_overrun
);
1092 set_trap_gate(10,&invalid_TSS
);
1093 set_trap_gate(11,&segment_not_present
);
1094 set_trap_gate(12,&stack_segment
);
1095 set_trap_gate(13,&general_protection
);
1096 set_intr_gate(14,&page_fault
);
1097 set_trap_gate(15,&spurious_interrupt_bug
);
1098 set_trap_gate(16,&coprocessor_error
);
1099 set_trap_gate(17,&alignment_check
);
1100 #ifdef CONFIG_X86_MCE
1101 set_trap_gate(18,&machine_check
);
1103 set_trap_gate(19,&simd_coprocessor_error
);
1105 set_system_gate(SYSCALL_VECTOR
,&system_call
);
1108 * Should be a barrier for any external CPU state.
1115 static int __init
kstack_setup(char *s
)
1117 kstack_depth_to_print
= simple_strtoul(s
, NULL
, 0);
1120 __setup("kstack=", kstack_setup
);