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(KERN_EMERG
" [<%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(KERN_EMERG
" [<%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(KERN_EMERG
" =======================\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
;
182 for(i
= 0; i
< kstack_depth_to_print
; i
++) {
183 if (kstack_end(stack
))
185 if (i
&& ((i
% 8) == 0))
186 printk("\n" KERN_EMERG
" ");
187 printk("%08lx ", *stack
++);
189 printk("\n" KERN_EMERG
"Call Trace:\n");
190 show_trace(task
, esp
);
194 * The architecture-independent dump_stack generator
196 void dump_stack(void)
200 show_trace(current
, &stack
);
203 EXPORT_SYMBOL(dump_stack
);
205 void show_registers(struct pt_regs
*regs
)
212 esp
= (unsigned long) (®s
->esp
);
214 if (user_mode(regs
)) {
217 ss
= regs
->xss
& 0xffff;
220 printk(KERN_EMERG
"CPU: %d\nEIP: %04x:[<%08lx>] %s VLI\n"
221 "EFLAGS: %08lx (%s) \n",
222 smp_processor_id(), 0xffff & regs
->xcs
, regs
->eip
,
223 print_tainted(), regs
->eflags
, system_utsname
.release
);
224 print_symbol(KERN_EMERG
"EIP is at %s\n", regs
->eip
);
225 printk(KERN_EMERG
"eax: %08lx ebx: %08lx ecx: %08lx edx: %08lx\n",
226 regs
->eax
, regs
->ebx
, regs
->ecx
, regs
->edx
);
227 printk(KERN_EMERG
"esi: %08lx edi: %08lx ebp: %08lx esp: %08lx\n",
228 regs
->esi
, regs
->edi
, regs
->ebp
, esp
);
229 printk(KERN_EMERG
"ds: %04x es: %04x ss: %04x\n",
230 regs
->xds
& 0xffff, regs
->xes
& 0xffff, ss
);
231 printk(KERN_EMERG
"Process %s (pid: %d, threadinfo=%p task=%p)",
232 current
->comm
, current
->pid
, current_thread_info(), current
);
234 * When in-kernel, we also print out the stack and code at the
235 * time of the fault..
240 printk("\n" KERN_EMERG
"Stack: ");
241 show_stack(NULL
, (unsigned long*)esp
);
243 printk(KERN_EMERG
"Code: ");
245 eip
= (u8 __user
*)regs
->eip
- 43;
246 for (i
= 0; i
< 64; i
++, eip
++) {
249 if (eip
< (u8 __user
*)PAGE_OFFSET
|| __get_user(c
, eip
)) {
250 printk(" Bad EIP value.");
253 if (eip
== (u8 __user
*)regs
->eip
)
254 printk("<%02x> ", c
);
262 static void handle_BUG(struct pt_regs
*regs
)
272 if (eip
< PAGE_OFFSET
)
274 if (__get_user(ud2
, (unsigned short __user
*)eip
))
278 if (__get_user(line
, (unsigned short __user
*)(eip
+ 2)))
280 if (__get_user(file
, (char * __user
*)(eip
+ 4)) ||
281 (unsigned long)file
< PAGE_OFFSET
|| __get_user(c
, file
))
282 file
= "<bad filename>";
284 printk(KERN_EMERG
"------------[ cut here ]------------\n");
285 printk(KERN_EMERG
"kernel BUG at %s:%d!\n", file
, line
);
290 /* Here we know it was a BUG but file-n-line is unavailable */
292 printk(KERN_EMERG
"Kernel BUG\n");
295 /* This is gone through when something in the kernel
296 * has done something bad and is about to be terminated.
298 void die(const char * str
, struct pt_regs
* regs
, long err
)
303 int lock_owner_depth
;
305 .lock
= SPIN_LOCK_UNLOCKED
,
307 .lock_owner_depth
= 0
309 static int die_counter
;
312 if (die
.lock_owner
!= raw_smp_processor_id()) {
314 spin_lock_irqsave(&die
.lock
, flags
);
315 die
.lock_owner
= smp_processor_id();
316 die
.lock_owner_depth
= 0;
320 local_save_flags(flags
);
322 if (++die
.lock_owner_depth
< 3) {
325 printk(KERN_EMERG
"%s: %04lx [#%d]\n", str
, err
& 0xffff, ++die_counter
);
326 #ifdef CONFIG_PREEMPT
327 printk(KERN_EMERG
"PREEMPT ");
336 #ifdef CONFIG_DEBUG_PAGEALLOC
339 printk("DEBUG_PAGEALLOC");
344 notify_die(DIE_OOPS
, (char *)str
, regs
, err
, 255, SIGSEGV
);
345 show_registers(regs
);
347 printk(KERN_EMERG
"Recursive die() failure, output suppressed\n");
351 spin_unlock_irqrestore(&die
.lock
, flags
);
353 if (kexec_should_crash(current
))
357 panic("Fatal exception in interrupt");
360 printk(KERN_EMERG
"Fatal exception: panic in 5 seconds\n");
362 panic("Fatal exception");
367 static inline void die_if_kernel(const char * str
, struct pt_regs
* regs
, long err
)
369 if (!user_mode_vm(regs
))
373 static void __kprobes
do_trap(int trapnr
, int signr
, char *str
, int vm86
,
374 struct pt_regs
* regs
, long error_code
,
377 struct task_struct
*tsk
= current
;
378 tsk
->thread
.error_code
= error_code
;
379 tsk
->thread
.trap_no
= trapnr
;
381 if (regs
->eflags
& VM_MASK
) {
387 if (!user_mode(regs
))
392 force_sig_info(signr
, info
, tsk
);
394 force_sig(signr
, tsk
);
399 if (!fixup_exception(regs
))
400 die(str
, regs
, error_code
);
405 int ret
= handle_vm86_trap((struct kernel_vm86_regs
*) regs
, error_code
, trapnr
);
406 if (ret
) goto trap_signal
;
411 #define DO_ERROR(trapnr, signr, str, name) \
412 fastcall void do_##name(struct pt_regs * regs, long error_code) \
414 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
417 do_trap(trapnr, signr, str, 0, regs, error_code, NULL); \
420 #define DO_ERROR_INFO(trapnr, signr, str, name, sicode, siaddr) \
421 fastcall void do_##name(struct pt_regs * regs, long error_code) \
424 info.si_signo = signr; \
426 info.si_code = sicode; \
427 info.si_addr = (void __user *)siaddr; \
428 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
431 do_trap(trapnr, signr, str, 0, regs, error_code, &info); \
434 #define DO_VM86_ERROR(trapnr, signr, str, name) \
435 fastcall void do_##name(struct pt_regs * regs, long error_code) \
437 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
440 do_trap(trapnr, signr, str, 1, regs, error_code, NULL); \
443 #define DO_VM86_ERROR_INFO(trapnr, signr, str, name, sicode, siaddr) \
444 fastcall void do_##name(struct pt_regs * regs, long error_code) \
447 info.si_signo = signr; \
449 info.si_code = sicode; \
450 info.si_addr = (void __user *)siaddr; \
451 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
454 do_trap(trapnr, signr, str, 1, regs, error_code, &info); \
457 DO_VM86_ERROR_INFO( 0, SIGFPE
, "divide error", divide_error
, FPE_INTDIV
, regs
->eip
)
458 #ifndef CONFIG_KPROBES
459 DO_VM86_ERROR( 3, SIGTRAP
, "int3", int3
)
461 DO_VM86_ERROR( 4, SIGSEGV
, "overflow", overflow
)
462 DO_VM86_ERROR( 5, SIGSEGV
, "bounds", bounds
)
463 DO_ERROR_INFO( 6, SIGILL
, "invalid opcode", invalid_op
, ILL_ILLOPN
, regs
->eip
)
464 DO_ERROR( 9, SIGFPE
, "coprocessor segment overrun", coprocessor_segment_overrun
)
465 DO_ERROR(10, SIGSEGV
, "invalid TSS", invalid_TSS
)
466 DO_ERROR(11, SIGBUS
, "segment not present", segment_not_present
)
467 DO_ERROR(12, SIGBUS
, "stack segment", stack_segment
)
468 DO_ERROR_INFO(17, SIGBUS
, "alignment check", alignment_check
, BUS_ADRALN
, 0)
469 DO_ERROR_INFO(32, SIGSEGV
, "iret exception", iret_error
, ILL_BADSTK
, 0)
471 fastcall
void __kprobes
do_general_protection(struct pt_regs
* regs
,
475 struct tss_struct
*tss
= &per_cpu(init_tss
, cpu
);
476 struct thread_struct
*thread
= ¤t
->thread
;
479 * Perform the lazy TSS's I/O bitmap copy. If the TSS has an
480 * invalid offset set (the LAZY one) and the faulting thread has
481 * a valid I/O bitmap pointer, we copy the I/O bitmap in the TSS
482 * and we set the offset field correctly. Then we let the CPU to
483 * restart the faulting instruction.
485 if (tss
->io_bitmap_base
== INVALID_IO_BITMAP_OFFSET_LAZY
&&
486 thread
->io_bitmap_ptr
) {
487 memcpy(tss
->io_bitmap
, thread
->io_bitmap_ptr
,
488 thread
->io_bitmap_max
);
490 * If the previously set map was extending to higher ports
491 * than the current one, pad extra space with 0xff (no access).
493 if (thread
->io_bitmap_max
< tss
->io_bitmap_max
)
494 memset((char *) tss
->io_bitmap
+
495 thread
->io_bitmap_max
, 0xff,
496 tss
->io_bitmap_max
- thread
->io_bitmap_max
);
497 tss
->io_bitmap_max
= thread
->io_bitmap_max
;
498 tss
->io_bitmap_base
= IO_BITMAP_OFFSET
;
499 tss
->io_bitmap_owner
= thread
;
505 current
->thread
.error_code
= error_code
;
506 current
->thread
.trap_no
= 13;
508 if (regs
->eflags
& VM_MASK
)
511 if (!user_mode(regs
))
514 current
->thread
.error_code
= error_code
;
515 current
->thread
.trap_no
= 13;
516 force_sig(SIGSEGV
, current
);
521 handle_vm86_fault((struct kernel_vm86_regs
*) regs
, error_code
);
525 if (!fixup_exception(regs
)) {
526 if (notify_die(DIE_GPF
, "general protection fault", regs
,
527 error_code
, 13, SIGSEGV
) == NOTIFY_STOP
)
529 die("general protection fault", regs
, error_code
);
533 static void mem_parity_error(unsigned char reason
, struct pt_regs
* regs
)
535 printk(KERN_EMERG
"Uhhuh. NMI received. Dazed and confused, but trying "
537 printk(KERN_EMERG
"You probably have a hardware problem with your RAM "
540 /* Clear and disable the memory parity error line. */
541 clear_mem_error(reason
);
544 static void io_check_error(unsigned char reason
, struct pt_regs
* regs
)
548 printk(KERN_EMERG
"NMI: IOCK error (debug interrupt?)\n");
549 show_registers(regs
);
551 /* Re-enable the IOCK line, wait for a few seconds */
552 reason
= (reason
& 0xf) | 8;
555 while (--i
) udelay(1000);
560 static void unknown_nmi_error(unsigned char reason
, struct pt_regs
* regs
)
563 /* Might actually be able to figure out what the guilty party
570 printk("Uhhuh. NMI received for unknown reason %02x on CPU %d.\n",
571 reason
, smp_processor_id());
572 printk("Dazed and confused, but trying to continue\n");
573 printk("Do you have a strange power saving mode enabled?\n");
576 static DEFINE_SPINLOCK(nmi_print_lock
);
578 void die_nmi (struct pt_regs
*regs
, const char *msg
)
580 if (notify_die(DIE_NMIWATCHDOG
, msg
, regs
, 0, 0, SIGINT
) ==
584 spin_lock(&nmi_print_lock
);
586 * We are in trouble anyway, lets at least try
587 * to get a message out.
590 printk(KERN_EMERG
"%s", msg
);
591 printk(" on CPU%d, eip %08lx, registers:\n",
592 smp_processor_id(), regs
->eip
);
593 show_registers(regs
);
594 printk(KERN_EMERG
"console shuts up ...\n");
596 spin_unlock(&nmi_print_lock
);
599 /* If we are in kernel we are probably nested up pretty bad
600 * and might aswell get out now while we still can.
602 if (!user_mode(regs
)) {
603 current
->thread
.trap_no
= 2;
610 static void default_do_nmi(struct pt_regs
* regs
)
612 unsigned char reason
= 0;
614 /* Only the BSP gets external NMIs from the system. */
615 if (!smp_processor_id())
616 reason
= get_nmi_reason();
618 if (!(reason
& 0xc0)) {
619 if (notify_die(DIE_NMI_IPI
, "nmi_ipi", regs
, reason
, 0, SIGINT
)
622 #ifdef CONFIG_X86_LOCAL_APIC
624 * Ok, so this is none of the documented NMI sources,
625 * so it must be the NMI watchdog.
628 nmi_watchdog_tick(regs
);
632 unknown_nmi_error(reason
, regs
);
635 if (notify_die(DIE_NMI
, "nmi", regs
, reason
, 0, SIGINT
) == NOTIFY_STOP
)
638 mem_parity_error(reason
, regs
);
640 io_check_error(reason
, regs
);
642 * Reassert NMI in case it became active meanwhile
643 * as it's edge-triggered.
648 static int dummy_nmi_callback(struct pt_regs
* regs
, int cpu
)
653 static nmi_callback_t nmi_callback
= dummy_nmi_callback
;
655 fastcall
void do_nmi(struct pt_regs
* regs
, long error_code
)
661 cpu
= smp_processor_id();
665 if (!rcu_dereference(nmi_callback
)(regs
, cpu
))
666 default_do_nmi(regs
);
671 void set_nmi_callback(nmi_callback_t callback
)
673 rcu_assign_pointer(nmi_callback
, callback
);
675 EXPORT_SYMBOL_GPL(set_nmi_callback
);
677 void unset_nmi_callback(void)
679 nmi_callback
= dummy_nmi_callback
;
681 EXPORT_SYMBOL_GPL(unset_nmi_callback
);
683 #ifdef CONFIG_KPROBES
684 fastcall
void __kprobes
do_int3(struct pt_regs
*regs
, long error_code
)
686 if (notify_die(DIE_INT3
, "int3", regs
, error_code
, 3, SIGTRAP
)
689 /* This is an interrupt gate, because kprobes wants interrupts
690 disabled. Normal trap handlers don't. */
691 restore_interrupts(regs
);
692 do_trap(3, SIGTRAP
, "int3", 1, regs
, error_code
, NULL
);
697 * Our handling of the processor debug registers is non-trivial.
698 * We do not clear them on entry and exit from the kernel. Therefore
699 * it is possible to get a watchpoint trap here from inside the kernel.
700 * However, the code in ./ptrace.c has ensured that the user can
701 * only set watchpoints on userspace addresses. Therefore the in-kernel
702 * watchpoint trap can only occur in code which is reading/writing
703 * from user space. Such code must not hold kernel locks (since it
704 * can equally take a page fault), therefore it is safe to call
705 * force_sig_info even though that claims and releases locks.
707 * Code in ./signal.c ensures that the debug control register
708 * is restored before we deliver any signal, and therefore that
709 * user code runs with the correct debug control register even though
712 * Being careful here means that we don't have to be as careful in a
713 * lot of more complicated places (task switching can be a bit lazy
714 * about restoring all the debug state, and ptrace doesn't have to
715 * find every occurrence of the TF bit that could be saved away even
718 fastcall
void __kprobes
do_debug(struct pt_regs
* regs
, long error_code
)
720 unsigned int condition
;
721 struct task_struct
*tsk
= current
;
723 get_debugreg(condition
, 6);
725 if (notify_die(DIE_DEBUG
, "debug", regs
, condition
, error_code
,
726 SIGTRAP
) == NOTIFY_STOP
)
728 /* It's safe to allow irq's after DR6 has been saved */
729 if (regs
->eflags
& X86_EFLAGS_IF
)
732 /* Mask out spurious debug traps due to lazy DR7 setting */
733 if (condition
& (DR_TRAP0
|DR_TRAP1
|DR_TRAP2
|DR_TRAP3
)) {
734 if (!tsk
->thread
.debugreg
[7])
738 if (regs
->eflags
& VM_MASK
)
741 /* Save debug status register where ptrace can see it */
742 tsk
->thread
.debugreg
[6] = condition
;
745 * Single-stepping through TF: make sure we ignore any events in
746 * kernel space (but re-enable TF when returning to user mode).
748 if (condition
& DR_STEP
) {
750 * We already checked v86 mode above, so we can
751 * check for kernel mode by just checking the CPL
754 if (!user_mode(regs
))
755 goto clear_TF_reenable
;
758 /* Ok, finally something we can handle */
759 send_sigtrap(tsk
, regs
, error_code
);
761 /* Disable additional traps. They'll be re-enabled when
762 * the signal is delivered.
769 handle_vm86_trap((struct kernel_vm86_regs
*) regs
, error_code
, 1);
773 set_tsk_thread_flag(tsk
, TIF_SINGLESTEP
);
774 regs
->eflags
&= ~TF_MASK
;
779 * Note that we play around with the 'TS' bit in an attempt to get
780 * the correct behaviour even in the presence of the asynchronous
783 void math_error(void __user
*eip
)
785 struct task_struct
* task
;
787 unsigned short cwd
, swd
;
790 * Save the info for the exception handler and clear the error.
794 task
->thread
.trap_no
= 16;
795 task
->thread
.error_code
= 0;
796 info
.si_signo
= SIGFPE
;
798 info
.si_code
= __SI_FAULT
;
801 * (~cwd & swd) will mask out exceptions that are not set to unmasked
802 * status. 0x3f is the exception bits in these regs, 0x200 is the
803 * C1 reg you need in case of a stack fault, 0x040 is the stack
804 * fault bit. We should only be taking one exception at a time,
805 * so if this combination doesn't produce any single exception,
806 * then we have a bad program that isn't syncronizing its FPU usage
807 * and it will suffer the consequences since we won't be able to
808 * fully reproduce the context of the exception
810 cwd
= get_fpu_cwd(task
);
811 swd
= get_fpu_swd(task
);
812 switch (swd
& ~cwd
& 0x3f) {
813 case 0x000: /* No unmasked exception */
815 default: /* Multiple exceptions */
817 case 0x001: /* Invalid Op */
819 * swd & 0x240 == 0x040: Stack Underflow
820 * swd & 0x240 == 0x240: Stack Overflow
821 * User must clear the SF bit (0x40) if set
823 info
.si_code
= FPE_FLTINV
;
825 case 0x002: /* Denormalize */
826 case 0x010: /* Underflow */
827 info
.si_code
= FPE_FLTUND
;
829 case 0x004: /* Zero Divide */
830 info
.si_code
= FPE_FLTDIV
;
832 case 0x008: /* Overflow */
833 info
.si_code
= FPE_FLTOVF
;
835 case 0x020: /* Precision */
836 info
.si_code
= FPE_FLTRES
;
839 force_sig_info(SIGFPE
, &info
, task
);
842 fastcall
void do_coprocessor_error(struct pt_regs
* regs
, long error_code
)
845 math_error((void __user
*)regs
->eip
);
848 static void simd_math_error(void __user
*eip
)
850 struct task_struct
* task
;
852 unsigned short mxcsr
;
855 * Save the info for the exception handler and clear the error.
859 task
->thread
.trap_no
= 19;
860 task
->thread
.error_code
= 0;
861 info
.si_signo
= SIGFPE
;
863 info
.si_code
= __SI_FAULT
;
866 * The SIMD FPU exceptions are handled a little differently, as there
867 * is only a single status/control register. Thus, to determine which
868 * unmasked exception was caught we must mask the exception mask bits
869 * at 0x1f80, and then use these to mask the exception bits at 0x3f.
871 mxcsr
= get_fpu_mxcsr(task
);
872 switch (~((mxcsr
& 0x1f80) >> 7) & (mxcsr
& 0x3f)) {
876 case 0x001: /* Invalid Op */
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_simd_coprocessor_error(struct pt_regs
* regs
,
900 /* Handle SIMD FPU exceptions on PIII+ processors. */
902 simd_math_error((void __user
*)regs
->eip
);
905 * Handle strange cache flush from user space exception
906 * in all other cases. This is undocumented behaviour.
908 if (regs
->eflags
& VM_MASK
) {
909 handle_vm86_fault((struct kernel_vm86_regs
*)regs
,
913 current
->thread
.trap_no
= 19;
914 current
->thread
.error_code
= error_code
;
915 die_if_kernel("cache flush denied", regs
, error_code
);
916 force_sig(SIGSEGV
, current
);
920 fastcall
void do_spurious_interrupt_bug(struct pt_regs
* regs
,
924 /* No need to warn about this any longer. */
925 printk("Ignoring P6 Local APIC Spurious Interrupt Bug...\n");
929 fastcall
void setup_x86_bogus_stack(unsigned char * stk
)
931 unsigned long *switch16_ptr
, *switch32_ptr
;
932 struct pt_regs
*regs
;
933 unsigned long stack_top
, stack_bot
;
934 unsigned short iret_frame16_off
;
935 int cpu
= smp_processor_id();
936 /* reserve the space on 32bit stack for the magic switch16 pointer */
937 memmove(stk
, stk
+ 8, sizeof(struct pt_regs
));
938 switch16_ptr
= (unsigned long *)(stk
+ sizeof(struct pt_regs
));
939 regs
= (struct pt_regs
*)stk
;
940 /* now the switch32 on 16bit stack */
941 stack_bot
= (unsigned long)&per_cpu(cpu_16bit_stack
, cpu
);
942 stack_top
= stack_bot
+ CPU_16BIT_STACK_SIZE
;
943 switch32_ptr
= (unsigned long *)(stack_top
- 8);
944 iret_frame16_off
= CPU_16BIT_STACK_SIZE
- 8 - 20;
945 /* copy iret frame on 16bit stack */
946 memcpy((void *)(stack_bot
+ iret_frame16_off
), ®s
->eip
, 20);
947 /* fill in the switch pointers */
948 switch16_ptr
[0] = (regs
->esp
& 0xffff0000) | iret_frame16_off
;
949 switch16_ptr
[1] = __ESPFIX_SS
;
950 switch32_ptr
[0] = (unsigned long)stk
+ sizeof(struct pt_regs
) +
951 8 - CPU_16BIT_STACK_SIZE
;
952 switch32_ptr
[1] = __KERNEL_DS
;
955 fastcall
unsigned char * fixup_x86_bogus_stack(unsigned short sp
)
957 unsigned long *switch32_ptr
;
958 unsigned char *stack16
, *stack32
;
959 unsigned long stack_top
, stack_bot
;
961 int cpu
= smp_processor_id();
962 stack_bot
= (unsigned long)&per_cpu(cpu_16bit_stack
, cpu
);
963 stack_top
= stack_bot
+ CPU_16BIT_STACK_SIZE
;
964 switch32_ptr
= (unsigned long *)(stack_top
- 8);
965 /* copy the data from 16bit stack to 32bit stack */
966 len
= CPU_16BIT_STACK_SIZE
- 8 - sp
;
967 stack16
= (unsigned char *)(stack_bot
+ sp
);
968 stack32
= (unsigned char *)
969 (switch32_ptr
[0] + CPU_16BIT_STACK_SIZE
- 8 - len
);
970 memcpy(stack32
, stack16
, len
);
975 * 'math_state_restore()' saves the current math information in the
976 * old math state array, and gets the new ones from the current task
978 * Careful.. There are problems with IBM-designed IRQ13 behaviour.
979 * Don't touch unless you *really* know how it works.
981 * Must be called with kernel preemption disabled (in this case,
982 * local interrupts are disabled at the call-site in entry.S).
984 asmlinkage
void math_state_restore(struct pt_regs regs
)
986 struct thread_info
*thread
= current_thread_info();
987 struct task_struct
*tsk
= thread
->task
;
989 clts(); /* Allow maths ops (or we recurse) */
990 if (!tsk_used_math(tsk
))
993 thread
->status
|= TS_USEDFPU
; /* So we fnsave on switch_to() */
996 #ifndef CONFIG_MATH_EMULATION
998 asmlinkage
void math_emulate(long arg
)
1000 printk(KERN_EMERG
"math-emulation not enabled and no coprocessor found.\n");
1001 printk(KERN_EMERG
"killing %s.\n",current
->comm
);
1002 force_sig(SIGFPE
,current
);
1006 #endif /* CONFIG_MATH_EMULATION */
1008 #ifdef CONFIG_X86_F00F_BUG
1009 void __init
trap_init_f00f_bug(void)
1011 __set_fixmap(FIX_F00F_IDT
, __pa(&idt_table
), PAGE_KERNEL_RO
);
1014 * Update the IDT descriptor and reload the IDT so that
1015 * it uses the read-only mapped virtual address.
1017 idt_descr
.address
= fix_to_virt(FIX_F00F_IDT
);
1018 load_idt(&idt_descr
);
1022 #define _set_gate(gate_addr,type,dpl,addr,seg) \
1025 __asm__ __volatile__ ("movw %%dx,%%ax\n\t" \
1026 "movw %4,%%dx\n\t" \
1027 "movl %%eax,%0\n\t" \
1029 :"=m" (*((long *) (gate_addr))), \
1030 "=m" (*(1+(long *) (gate_addr))), "=&a" (__d0), "=&d" (__d1) \
1031 :"i" ((short) (0x8000+(dpl<<13)+(type<<8))), \
1032 "3" ((char *) (addr)),"2" ((seg) << 16)); \
1037 * This needs to use 'idt_table' rather than 'idt', and
1038 * thus use the _nonmapped_ version of the IDT, as the
1039 * Pentium F0 0F bugfix can have resulted in the mapped
1040 * IDT being write-protected.
1042 void set_intr_gate(unsigned int n
, void *addr
)
1044 _set_gate(idt_table
+n
,14,0,addr
,__KERNEL_CS
);
1048 * This routine sets up an interrupt gate at directory privilege level 3.
1050 static inline void set_system_intr_gate(unsigned int n
, void *addr
)
1052 _set_gate(idt_table
+n
, 14, 3, addr
, __KERNEL_CS
);
1055 static void __init
set_trap_gate(unsigned int n
, void *addr
)
1057 _set_gate(idt_table
+n
,15,0,addr
,__KERNEL_CS
);
1060 static void __init
set_system_gate(unsigned int n
, void *addr
)
1062 _set_gate(idt_table
+n
,15,3,addr
,__KERNEL_CS
);
1065 static void __init
set_task_gate(unsigned int n
, unsigned int gdt_entry
)
1067 _set_gate(idt_table
+n
,5,0,0,(gdt_entry
<<3));
1071 void __init
trap_init(void)
1074 void __iomem
*p
= ioremap(0x0FFFD9, 4);
1075 if (readl(p
) == 'E'+('I'<<8)+('S'<<16)+('A'<<24)) {
1081 #ifdef CONFIG_X86_LOCAL_APIC
1082 init_apic_mappings();
1085 set_trap_gate(0,÷_error
);
1086 set_intr_gate(1,&debug
);
1087 set_intr_gate(2,&nmi
);
1088 set_system_intr_gate(3, &int3
); /* int3/4 can be called from all */
1089 set_system_gate(4,&overflow
);
1090 set_trap_gate(5,&bounds
);
1091 set_trap_gate(6,&invalid_op
);
1092 set_trap_gate(7,&device_not_available
);
1093 set_task_gate(8,GDT_ENTRY_DOUBLEFAULT_TSS
);
1094 set_trap_gate(9,&coprocessor_segment_overrun
);
1095 set_trap_gate(10,&invalid_TSS
);
1096 set_trap_gate(11,&segment_not_present
);
1097 set_trap_gate(12,&stack_segment
);
1098 set_trap_gate(13,&general_protection
);
1099 set_intr_gate(14,&page_fault
);
1100 set_trap_gate(15,&spurious_interrupt_bug
);
1101 set_trap_gate(16,&coprocessor_error
);
1102 set_trap_gate(17,&alignment_check
);
1103 #ifdef CONFIG_X86_MCE
1104 set_trap_gate(18,&machine_check
);
1106 set_trap_gate(19,&simd_coprocessor_error
);
1110 * Verify that the FXSAVE/FXRSTOR data will be 16-byte aligned.
1111 * Generates a compile-time "error: zero width for bit-field" if
1112 * the alignment is wrong.
1114 struct fxsrAlignAssert
{
1115 int _
:!(offsetof(struct task_struct
,
1116 thread
.i387
.fxsave
) & 15);
1119 printk(KERN_INFO
"Enabling fast FPU save and restore... ");
1120 set_in_cr4(X86_CR4_OSFXSR
);
1124 printk(KERN_INFO
"Enabling unmasked SIMD FPU exception "
1126 set_in_cr4(X86_CR4_OSXMMEXCPT
);
1130 set_system_gate(SYSCALL_VECTOR
,&system_call
);
1133 * Should be a barrier for any external CPU state.
1140 static int __init
kstack_setup(char *s
)
1142 kstack_depth_to_print
= simple_strtoul(s
, NULL
, 0);
1145 __setup("kstack=", kstack_setup
);