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 void print_addr_and_symbol(unsigned long addr
, char *log_lvl
)
118 printk(" [<%08lx>] ", addr
);
119 print_symbol("%s", addr
);
123 static inline unsigned long print_context_stack(struct thread_info
*tinfo
,
124 unsigned long *stack
, unsigned long ebp
,
129 #ifdef CONFIG_FRAME_POINTER
130 while (valid_stack_ptr(tinfo
, (void *)ebp
)) {
131 addr
= *(unsigned long *)(ebp
+ 4);
132 print_addr_and_symbol(addr
, log_lvl
);
133 ebp
= *(unsigned long *)ebp
;
136 while (valid_stack_ptr(tinfo
, stack
)) {
138 if (__kernel_text_address(addr
))
139 print_addr_and_symbol(addr
, log_lvl
);
145 static void show_trace_log_lvl(struct task_struct
*task
,
146 unsigned long *stack
, char *log_lvl
)
153 if (task
== current
) {
154 /* Grab ebp right from our regs */
155 asm ("movl %%ebp, %0" : "=r" (ebp
) : );
157 /* ebp is the last reg pushed by switch_to */
158 ebp
= *(unsigned long *) task
->thread
.esp
;
162 struct thread_info
*context
;
163 context
= (struct thread_info
*)
164 ((unsigned long)stack
& (~(THREAD_SIZE
- 1)));
165 ebp
= print_context_stack(context
, stack
, ebp
, log_lvl
);
166 stack
= (unsigned long*)context
->previous_esp
;
169 printk(KERN_EMERG
" =======================\n");
173 void show_trace(struct task_struct
*task
, unsigned long * stack
)
175 show_trace_log_lvl(task
, stack
, "");
178 static void show_stack_log_lvl(struct task_struct
*task
, unsigned long *esp
,
181 unsigned long *stack
;
186 esp
= (unsigned long*)task
->thread
.esp
;
188 esp
= (unsigned long *)&esp
;
193 for(i
= 0; i
< kstack_depth_to_print
; i
++) {
194 if (kstack_end(stack
))
196 if (i
&& ((i
% 8) == 0)) {
201 printk("%08lx ", *stack
++);
205 printk("Call Trace:\n");
206 show_trace_log_lvl(task
, esp
, log_lvl
);
209 void show_stack(struct task_struct
*task
, unsigned long *esp
)
211 show_stack_log_lvl(task
, esp
, "");
215 * The architecture-independent dump_stack generator
217 void dump_stack(void)
221 show_trace(current
, &stack
);
224 EXPORT_SYMBOL(dump_stack
);
226 void show_registers(struct pt_regs
*regs
)
233 esp
= (unsigned long) (®s
->esp
);
235 if (user_mode(regs
)) {
238 ss
= regs
->xss
& 0xffff;
241 printk(KERN_EMERG
"CPU: %d\nEIP: %04x:[<%08lx>] %s VLI\n"
242 "EFLAGS: %08lx (%s) \n",
243 smp_processor_id(), 0xffff & regs
->xcs
, regs
->eip
,
244 print_tainted(), regs
->eflags
, system_utsname
.release
);
245 print_symbol(KERN_EMERG
"EIP is at %s\n", regs
->eip
);
246 printk(KERN_EMERG
"eax: %08lx ebx: %08lx ecx: %08lx edx: %08lx\n",
247 regs
->eax
, regs
->ebx
, regs
->ecx
, regs
->edx
);
248 printk(KERN_EMERG
"esi: %08lx edi: %08lx ebp: %08lx esp: %08lx\n",
249 regs
->esi
, regs
->edi
, regs
->ebp
, esp
);
250 printk(KERN_EMERG
"ds: %04x es: %04x ss: %04x\n",
251 regs
->xds
& 0xffff, regs
->xes
& 0xffff, ss
);
252 printk(KERN_EMERG
"Process %s (pid: %d, threadinfo=%p task=%p)",
253 current
->comm
, current
->pid
, current_thread_info(), current
);
255 * When in-kernel, we also print out the stack and code at the
256 * time of the fault..
261 printk("\n" KERN_EMERG
"Stack: ");
262 show_stack_log_lvl(NULL
, (unsigned long *)esp
, KERN_EMERG
);
264 printk(KERN_EMERG
"Code: ");
266 eip
= (u8 __user
*)regs
->eip
- 43;
267 for (i
= 0; i
< 64; i
++, eip
++) {
270 if (eip
< (u8 __user
*)PAGE_OFFSET
|| __get_user(c
, eip
)) {
271 printk(" Bad EIP value.");
274 if (eip
== (u8 __user
*)regs
->eip
)
275 printk("<%02x> ", c
);
283 static void handle_BUG(struct pt_regs
*regs
)
293 if (eip
< PAGE_OFFSET
)
295 if (__get_user(ud2
, (unsigned short __user
*)eip
))
299 if (__get_user(line
, (unsigned short __user
*)(eip
+ 2)))
301 if (__get_user(file
, (char * __user
*)(eip
+ 4)) ||
302 (unsigned long)file
< PAGE_OFFSET
|| __get_user(c
, file
))
303 file
= "<bad filename>";
305 printk(KERN_EMERG
"------------[ cut here ]------------\n");
306 printk(KERN_EMERG
"kernel BUG at %s:%d!\n", file
, line
);
311 /* Here we know it was a BUG but file-n-line is unavailable */
313 printk(KERN_EMERG
"Kernel BUG\n");
316 /* This is gone through when something in the kernel
317 * has done something bad and is about to be terminated.
319 void die(const char * str
, struct pt_regs
* regs
, long err
)
324 int lock_owner_depth
;
326 .lock
= SPIN_LOCK_UNLOCKED
,
328 .lock_owner_depth
= 0
330 static int die_counter
;
333 if (die
.lock_owner
!= raw_smp_processor_id()) {
335 spin_lock_irqsave(&die
.lock
, flags
);
336 die
.lock_owner
= smp_processor_id();
337 die
.lock_owner_depth
= 0;
341 local_save_flags(flags
);
343 if (++die
.lock_owner_depth
< 3) {
346 printk(KERN_EMERG
"%s: %04lx [#%d]\n", str
, err
& 0xffff, ++die_counter
);
347 #ifdef CONFIG_PREEMPT
348 printk(KERN_EMERG
"PREEMPT ");
357 #ifdef CONFIG_DEBUG_PAGEALLOC
360 printk("DEBUG_PAGEALLOC");
365 notify_die(DIE_OOPS
, (char *)str
, regs
, err
, 255, SIGSEGV
);
366 show_registers(regs
);
368 printk(KERN_EMERG
"Recursive die() failure, output suppressed\n");
372 spin_unlock_irqrestore(&die
.lock
, flags
);
374 if (kexec_should_crash(current
))
378 panic("Fatal exception in interrupt");
381 printk(KERN_EMERG
"Fatal exception: panic in 5 seconds\n");
383 panic("Fatal exception");
388 static inline void die_if_kernel(const char * str
, struct pt_regs
* regs
, long err
)
390 if (!user_mode_vm(regs
))
394 static void __kprobes
do_trap(int trapnr
, int signr
, char *str
, int vm86
,
395 struct pt_regs
* regs
, long error_code
,
398 struct task_struct
*tsk
= current
;
399 tsk
->thread
.error_code
= error_code
;
400 tsk
->thread
.trap_no
= trapnr
;
402 if (regs
->eflags
& VM_MASK
) {
408 if (!user_mode(regs
))
413 force_sig_info(signr
, info
, tsk
);
415 force_sig(signr
, tsk
);
420 if (!fixup_exception(regs
))
421 die(str
, regs
, error_code
);
426 int ret
= handle_vm86_trap((struct kernel_vm86_regs
*) regs
, error_code
, trapnr
);
427 if (ret
) goto trap_signal
;
432 #define DO_ERROR(trapnr, signr, str, name) \
433 fastcall void do_##name(struct pt_regs * regs, long error_code) \
435 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
438 do_trap(trapnr, signr, str, 0, regs, error_code, NULL); \
441 #define DO_ERROR_INFO(trapnr, signr, str, name, sicode, siaddr) \
442 fastcall void do_##name(struct pt_regs * regs, long error_code) \
445 info.si_signo = signr; \
447 info.si_code = sicode; \
448 info.si_addr = (void __user *)siaddr; \
449 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
452 do_trap(trapnr, signr, str, 0, regs, error_code, &info); \
455 #define DO_VM86_ERROR(trapnr, signr, str, name) \
456 fastcall void do_##name(struct pt_regs * regs, long error_code) \
458 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
461 do_trap(trapnr, signr, str, 1, regs, error_code, NULL); \
464 #define DO_VM86_ERROR_INFO(trapnr, signr, str, name, sicode, siaddr) \
465 fastcall void do_##name(struct pt_regs * regs, long error_code) \
468 info.si_signo = signr; \
470 info.si_code = sicode; \
471 info.si_addr = (void __user *)siaddr; \
472 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
475 do_trap(trapnr, signr, str, 1, regs, error_code, &info); \
478 DO_VM86_ERROR_INFO( 0, SIGFPE
, "divide error", divide_error
, FPE_INTDIV
, regs
->eip
)
479 #ifndef CONFIG_KPROBES
480 DO_VM86_ERROR( 3, SIGTRAP
, "int3", int3
)
482 DO_VM86_ERROR( 4, SIGSEGV
, "overflow", overflow
)
483 DO_VM86_ERROR( 5, SIGSEGV
, "bounds", bounds
)
484 DO_ERROR_INFO( 6, SIGILL
, "invalid opcode", invalid_op
, ILL_ILLOPN
, regs
->eip
)
485 DO_ERROR( 9, SIGFPE
, "coprocessor segment overrun", coprocessor_segment_overrun
)
486 DO_ERROR(10, SIGSEGV
, "invalid TSS", invalid_TSS
)
487 DO_ERROR(11, SIGBUS
, "segment not present", segment_not_present
)
488 DO_ERROR(12, SIGBUS
, "stack segment", stack_segment
)
489 DO_ERROR_INFO(17, SIGBUS
, "alignment check", alignment_check
, BUS_ADRALN
, 0)
490 DO_ERROR_INFO(32, SIGSEGV
, "iret exception", iret_error
, ILL_BADSTK
, 0)
492 fastcall
void __kprobes
do_general_protection(struct pt_regs
* regs
,
496 struct tss_struct
*tss
= &per_cpu(init_tss
, cpu
);
497 struct thread_struct
*thread
= ¤t
->thread
;
500 * Perform the lazy TSS's I/O bitmap copy. If the TSS has an
501 * invalid offset set (the LAZY one) and the faulting thread has
502 * a valid I/O bitmap pointer, we copy the I/O bitmap in the TSS
503 * and we set the offset field correctly. Then we let the CPU to
504 * restart the faulting instruction.
506 if (tss
->io_bitmap_base
== INVALID_IO_BITMAP_OFFSET_LAZY
&&
507 thread
->io_bitmap_ptr
) {
508 memcpy(tss
->io_bitmap
, thread
->io_bitmap_ptr
,
509 thread
->io_bitmap_max
);
511 * If the previously set map was extending to higher ports
512 * than the current one, pad extra space with 0xff (no access).
514 if (thread
->io_bitmap_max
< tss
->io_bitmap_max
)
515 memset((char *) tss
->io_bitmap
+
516 thread
->io_bitmap_max
, 0xff,
517 tss
->io_bitmap_max
- thread
->io_bitmap_max
);
518 tss
->io_bitmap_max
= thread
->io_bitmap_max
;
519 tss
->io_bitmap_base
= IO_BITMAP_OFFSET
;
520 tss
->io_bitmap_owner
= thread
;
526 current
->thread
.error_code
= error_code
;
527 current
->thread
.trap_no
= 13;
529 if (regs
->eflags
& VM_MASK
)
532 if (!user_mode(regs
))
535 current
->thread
.error_code
= error_code
;
536 current
->thread
.trap_no
= 13;
537 force_sig(SIGSEGV
, current
);
542 handle_vm86_fault((struct kernel_vm86_regs
*) regs
, error_code
);
546 if (!fixup_exception(regs
)) {
547 if (notify_die(DIE_GPF
, "general protection fault", regs
,
548 error_code
, 13, SIGSEGV
) == NOTIFY_STOP
)
550 die("general protection fault", regs
, error_code
);
554 static void mem_parity_error(unsigned char reason
, struct pt_regs
* regs
)
556 printk(KERN_EMERG
"Uhhuh. NMI received. Dazed and confused, but trying "
558 printk(KERN_EMERG
"You probably have a hardware problem with your RAM "
561 /* Clear and disable the memory parity error line. */
562 clear_mem_error(reason
);
565 static void io_check_error(unsigned char reason
, struct pt_regs
* regs
)
569 printk(KERN_EMERG
"NMI: IOCK error (debug interrupt?)\n");
570 show_registers(regs
);
572 /* Re-enable the IOCK line, wait for a few seconds */
573 reason
= (reason
& 0xf) | 8;
576 while (--i
) udelay(1000);
581 static void unknown_nmi_error(unsigned char reason
, struct pt_regs
* regs
)
584 /* Might actually be able to figure out what the guilty party
591 printk("Uhhuh. NMI received for unknown reason %02x on CPU %d.\n",
592 reason
, smp_processor_id());
593 printk("Dazed and confused, but trying to continue\n");
594 printk("Do you have a strange power saving mode enabled?\n");
597 static DEFINE_SPINLOCK(nmi_print_lock
);
599 void die_nmi (struct pt_regs
*regs
, const char *msg
)
601 if (notify_die(DIE_NMIWATCHDOG
, msg
, regs
, 0, 0, SIGINT
) ==
605 spin_lock(&nmi_print_lock
);
607 * We are in trouble anyway, lets at least try
608 * to get a message out.
611 printk(KERN_EMERG
"%s", msg
);
612 printk(" on CPU%d, eip %08lx, registers:\n",
613 smp_processor_id(), regs
->eip
);
614 show_registers(regs
);
615 printk(KERN_EMERG
"console shuts up ...\n");
617 spin_unlock(&nmi_print_lock
);
620 /* If we are in kernel we are probably nested up pretty bad
621 * and might aswell get out now while we still can.
623 if (!user_mode(regs
)) {
624 current
->thread
.trap_no
= 2;
631 static void default_do_nmi(struct pt_regs
* regs
)
633 unsigned char reason
= 0;
635 /* Only the BSP gets external NMIs from the system. */
636 if (!smp_processor_id())
637 reason
= get_nmi_reason();
639 if (!(reason
& 0xc0)) {
640 if (notify_die(DIE_NMI_IPI
, "nmi_ipi", regs
, reason
, 0, SIGINT
)
643 #ifdef CONFIG_X86_LOCAL_APIC
645 * Ok, so this is none of the documented NMI sources,
646 * so it must be the NMI watchdog.
649 nmi_watchdog_tick(regs
);
653 unknown_nmi_error(reason
, regs
);
656 if (notify_die(DIE_NMI
, "nmi", regs
, reason
, 0, SIGINT
) == NOTIFY_STOP
)
659 mem_parity_error(reason
, regs
);
661 io_check_error(reason
, regs
);
663 * Reassert NMI in case it became active meanwhile
664 * as it's edge-triggered.
669 static int dummy_nmi_callback(struct pt_regs
* regs
, int cpu
)
674 static nmi_callback_t nmi_callback
= dummy_nmi_callback
;
676 fastcall
void do_nmi(struct pt_regs
* regs
, long error_code
)
682 cpu
= smp_processor_id();
686 if (!rcu_dereference(nmi_callback
)(regs
, cpu
))
687 default_do_nmi(regs
);
692 void set_nmi_callback(nmi_callback_t callback
)
694 rcu_assign_pointer(nmi_callback
, callback
);
696 EXPORT_SYMBOL_GPL(set_nmi_callback
);
698 void unset_nmi_callback(void)
700 nmi_callback
= dummy_nmi_callback
;
702 EXPORT_SYMBOL_GPL(unset_nmi_callback
);
704 #ifdef CONFIG_KPROBES
705 fastcall
void __kprobes
do_int3(struct pt_regs
*regs
, long error_code
)
707 if (notify_die(DIE_INT3
, "int3", regs
, error_code
, 3, SIGTRAP
)
710 /* This is an interrupt gate, because kprobes wants interrupts
711 disabled. Normal trap handlers don't. */
712 restore_interrupts(regs
);
713 do_trap(3, SIGTRAP
, "int3", 1, regs
, error_code
, NULL
);
718 * Our handling of the processor debug registers is non-trivial.
719 * We do not clear them on entry and exit from the kernel. Therefore
720 * it is possible to get a watchpoint trap here from inside the kernel.
721 * However, the code in ./ptrace.c has ensured that the user can
722 * only set watchpoints on userspace addresses. Therefore the in-kernel
723 * watchpoint trap can only occur in code which is reading/writing
724 * from user space. Such code must not hold kernel locks (since it
725 * can equally take a page fault), therefore it is safe to call
726 * force_sig_info even though that claims and releases locks.
728 * Code in ./signal.c ensures that the debug control register
729 * is restored before we deliver any signal, and therefore that
730 * user code runs with the correct debug control register even though
733 * Being careful here means that we don't have to be as careful in a
734 * lot of more complicated places (task switching can be a bit lazy
735 * about restoring all the debug state, and ptrace doesn't have to
736 * find every occurrence of the TF bit that could be saved away even
739 fastcall
void __kprobes
do_debug(struct pt_regs
* regs
, long error_code
)
741 unsigned int condition
;
742 struct task_struct
*tsk
= current
;
744 get_debugreg(condition
, 6);
746 if (notify_die(DIE_DEBUG
, "debug", regs
, condition
, error_code
,
747 SIGTRAP
) == NOTIFY_STOP
)
749 /* It's safe to allow irq's after DR6 has been saved */
750 if (regs
->eflags
& X86_EFLAGS_IF
)
753 /* Mask out spurious debug traps due to lazy DR7 setting */
754 if (condition
& (DR_TRAP0
|DR_TRAP1
|DR_TRAP2
|DR_TRAP3
)) {
755 if (!tsk
->thread
.debugreg
[7])
759 if (regs
->eflags
& VM_MASK
)
762 /* Save debug status register where ptrace can see it */
763 tsk
->thread
.debugreg
[6] = condition
;
766 * Single-stepping through TF: make sure we ignore any events in
767 * kernel space (but re-enable TF when returning to user mode).
769 if (condition
& DR_STEP
) {
771 * We already checked v86 mode above, so we can
772 * check for kernel mode by just checking the CPL
775 if (!user_mode(regs
))
776 goto clear_TF_reenable
;
779 /* Ok, finally something we can handle */
780 send_sigtrap(tsk
, regs
, error_code
);
782 /* Disable additional traps. They'll be re-enabled when
783 * the signal is delivered.
790 handle_vm86_trap((struct kernel_vm86_regs
*) regs
, error_code
, 1);
794 set_tsk_thread_flag(tsk
, TIF_SINGLESTEP
);
795 regs
->eflags
&= ~TF_MASK
;
800 * Note that we play around with the 'TS' bit in an attempt to get
801 * the correct behaviour even in the presence of the asynchronous
804 void math_error(void __user
*eip
)
806 struct task_struct
* task
;
808 unsigned short cwd
, swd
;
811 * Save the info for the exception handler and clear the error.
815 task
->thread
.trap_no
= 16;
816 task
->thread
.error_code
= 0;
817 info
.si_signo
= SIGFPE
;
819 info
.si_code
= __SI_FAULT
;
822 * (~cwd & swd) will mask out exceptions that are not set to unmasked
823 * status. 0x3f is the exception bits in these regs, 0x200 is the
824 * C1 reg you need in case of a stack fault, 0x040 is the stack
825 * fault bit. We should only be taking one exception at a time,
826 * so if this combination doesn't produce any single exception,
827 * then we have a bad program that isn't syncronizing its FPU usage
828 * and it will suffer the consequences since we won't be able to
829 * fully reproduce the context of the exception
831 cwd
= get_fpu_cwd(task
);
832 swd
= get_fpu_swd(task
);
833 switch (swd
& ~cwd
& 0x3f) {
834 case 0x000: /* No unmasked exception */
836 default: /* Multiple exceptions */
838 case 0x001: /* Invalid Op */
840 * swd & 0x240 == 0x040: Stack Underflow
841 * swd & 0x240 == 0x240: Stack Overflow
842 * User must clear the SF bit (0x40) if set
844 info
.si_code
= FPE_FLTINV
;
846 case 0x002: /* Denormalize */
847 case 0x010: /* Underflow */
848 info
.si_code
= FPE_FLTUND
;
850 case 0x004: /* Zero Divide */
851 info
.si_code
= FPE_FLTDIV
;
853 case 0x008: /* Overflow */
854 info
.si_code
= FPE_FLTOVF
;
856 case 0x020: /* Precision */
857 info
.si_code
= FPE_FLTRES
;
860 force_sig_info(SIGFPE
, &info
, task
);
863 fastcall
void do_coprocessor_error(struct pt_regs
* regs
, long error_code
)
866 math_error((void __user
*)regs
->eip
);
869 static void simd_math_error(void __user
*eip
)
871 struct task_struct
* task
;
873 unsigned short mxcsr
;
876 * Save the info for the exception handler and clear the error.
880 task
->thread
.trap_no
= 19;
881 task
->thread
.error_code
= 0;
882 info
.si_signo
= SIGFPE
;
884 info
.si_code
= __SI_FAULT
;
887 * The SIMD FPU exceptions are handled a little differently, as there
888 * is only a single status/control register. Thus, to determine which
889 * unmasked exception was caught we must mask the exception mask bits
890 * at 0x1f80, and then use these to mask the exception bits at 0x3f.
892 mxcsr
= get_fpu_mxcsr(task
);
893 switch (~((mxcsr
& 0x1f80) >> 7) & (mxcsr
& 0x3f)) {
897 case 0x001: /* Invalid Op */
898 info
.si_code
= FPE_FLTINV
;
900 case 0x002: /* Denormalize */
901 case 0x010: /* Underflow */
902 info
.si_code
= FPE_FLTUND
;
904 case 0x004: /* Zero Divide */
905 info
.si_code
= FPE_FLTDIV
;
907 case 0x008: /* Overflow */
908 info
.si_code
= FPE_FLTOVF
;
910 case 0x020: /* Precision */
911 info
.si_code
= FPE_FLTRES
;
914 force_sig_info(SIGFPE
, &info
, task
);
917 fastcall
void do_simd_coprocessor_error(struct pt_regs
* regs
,
921 /* Handle SIMD FPU exceptions on PIII+ processors. */
923 simd_math_error((void __user
*)regs
->eip
);
926 * Handle strange cache flush from user space exception
927 * in all other cases. This is undocumented behaviour.
929 if (regs
->eflags
& VM_MASK
) {
930 handle_vm86_fault((struct kernel_vm86_regs
*)regs
,
934 current
->thread
.trap_no
= 19;
935 current
->thread
.error_code
= error_code
;
936 die_if_kernel("cache flush denied", regs
, error_code
);
937 force_sig(SIGSEGV
, current
);
941 fastcall
void do_spurious_interrupt_bug(struct pt_regs
* regs
,
945 /* No need to warn about this any longer. */
946 printk("Ignoring P6 Local APIC Spurious Interrupt Bug...\n");
950 fastcall
void setup_x86_bogus_stack(unsigned char * stk
)
952 unsigned long *switch16_ptr
, *switch32_ptr
;
953 struct pt_regs
*regs
;
954 unsigned long stack_top
, stack_bot
;
955 unsigned short iret_frame16_off
;
956 int cpu
= smp_processor_id();
957 /* reserve the space on 32bit stack for the magic switch16 pointer */
958 memmove(stk
, stk
+ 8, sizeof(struct pt_regs
));
959 switch16_ptr
= (unsigned long *)(stk
+ sizeof(struct pt_regs
));
960 regs
= (struct pt_regs
*)stk
;
961 /* now the switch32 on 16bit stack */
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 iret_frame16_off
= CPU_16BIT_STACK_SIZE
- 8 - 20;
966 /* copy iret frame on 16bit stack */
967 memcpy((void *)(stack_bot
+ iret_frame16_off
), ®s
->eip
, 20);
968 /* fill in the switch pointers */
969 switch16_ptr
[0] = (regs
->esp
& 0xffff0000) | iret_frame16_off
;
970 switch16_ptr
[1] = __ESPFIX_SS
;
971 switch32_ptr
[0] = (unsigned long)stk
+ sizeof(struct pt_regs
) +
972 8 - CPU_16BIT_STACK_SIZE
;
973 switch32_ptr
[1] = __KERNEL_DS
;
976 fastcall
unsigned char * fixup_x86_bogus_stack(unsigned short sp
)
978 unsigned long *switch32_ptr
;
979 unsigned char *stack16
, *stack32
;
980 unsigned long stack_top
, stack_bot
;
982 int cpu
= smp_processor_id();
983 stack_bot
= (unsigned long)&per_cpu(cpu_16bit_stack
, cpu
);
984 stack_top
= stack_bot
+ CPU_16BIT_STACK_SIZE
;
985 switch32_ptr
= (unsigned long *)(stack_top
- 8);
986 /* copy the data from 16bit stack to 32bit stack */
987 len
= CPU_16BIT_STACK_SIZE
- 8 - sp
;
988 stack16
= (unsigned char *)(stack_bot
+ sp
);
989 stack32
= (unsigned char *)
990 (switch32_ptr
[0] + CPU_16BIT_STACK_SIZE
- 8 - len
);
991 memcpy(stack32
, stack16
, len
);
996 * 'math_state_restore()' saves the current math information in the
997 * old math state array, and gets the new ones from the current task
999 * Careful.. There are problems with IBM-designed IRQ13 behaviour.
1000 * Don't touch unless you *really* know how it works.
1002 * Must be called with kernel preemption disabled (in this case,
1003 * local interrupts are disabled at the call-site in entry.S).
1005 asmlinkage
void math_state_restore(struct pt_regs regs
)
1007 struct thread_info
*thread
= current_thread_info();
1008 struct task_struct
*tsk
= thread
->task
;
1010 clts(); /* Allow maths ops (or we recurse) */
1011 if (!tsk_used_math(tsk
))
1014 thread
->status
|= TS_USEDFPU
; /* So we fnsave on switch_to() */
1017 #ifndef CONFIG_MATH_EMULATION
1019 asmlinkage
void math_emulate(long arg
)
1021 printk(KERN_EMERG
"math-emulation not enabled and no coprocessor found.\n");
1022 printk(KERN_EMERG
"killing %s.\n",current
->comm
);
1023 force_sig(SIGFPE
,current
);
1027 #endif /* CONFIG_MATH_EMULATION */
1029 #ifdef CONFIG_X86_F00F_BUG
1030 void __init
trap_init_f00f_bug(void)
1032 __set_fixmap(FIX_F00F_IDT
, __pa(&idt_table
), PAGE_KERNEL_RO
);
1035 * Update the IDT descriptor and reload the IDT so that
1036 * it uses the read-only mapped virtual address.
1038 idt_descr
.address
= fix_to_virt(FIX_F00F_IDT
);
1039 load_idt(&idt_descr
);
1043 #define _set_gate(gate_addr,type,dpl,addr,seg) \
1046 __asm__ __volatile__ ("movw %%dx,%%ax\n\t" \
1047 "movw %4,%%dx\n\t" \
1048 "movl %%eax,%0\n\t" \
1050 :"=m" (*((long *) (gate_addr))), \
1051 "=m" (*(1+(long *) (gate_addr))), "=&a" (__d0), "=&d" (__d1) \
1052 :"i" ((short) (0x8000+(dpl<<13)+(type<<8))), \
1053 "3" ((char *) (addr)),"2" ((seg) << 16)); \
1058 * This needs to use 'idt_table' rather than 'idt', and
1059 * thus use the _nonmapped_ version of the IDT, as the
1060 * Pentium F0 0F bugfix can have resulted in the mapped
1061 * IDT being write-protected.
1063 void set_intr_gate(unsigned int n
, void *addr
)
1065 _set_gate(idt_table
+n
,14,0,addr
,__KERNEL_CS
);
1069 * This routine sets up an interrupt gate at directory privilege level 3.
1071 static inline void set_system_intr_gate(unsigned int n
, void *addr
)
1073 _set_gate(idt_table
+n
, 14, 3, addr
, __KERNEL_CS
);
1076 static void __init
set_trap_gate(unsigned int n
, void *addr
)
1078 _set_gate(idt_table
+n
,15,0,addr
,__KERNEL_CS
);
1081 static void __init
set_system_gate(unsigned int n
, void *addr
)
1083 _set_gate(idt_table
+n
,15,3,addr
,__KERNEL_CS
);
1086 static void __init
set_task_gate(unsigned int n
, unsigned int gdt_entry
)
1088 _set_gate(idt_table
+n
,5,0,0,(gdt_entry
<<3));
1092 void __init
trap_init(void)
1095 void __iomem
*p
= ioremap(0x0FFFD9, 4);
1096 if (readl(p
) == 'E'+('I'<<8)+('S'<<16)+('A'<<24)) {
1102 #ifdef CONFIG_X86_LOCAL_APIC
1103 init_apic_mappings();
1106 set_trap_gate(0,÷_error
);
1107 set_intr_gate(1,&debug
);
1108 set_intr_gate(2,&nmi
);
1109 set_system_intr_gate(3, &int3
); /* int3/4 can be called from all */
1110 set_system_gate(4,&overflow
);
1111 set_trap_gate(5,&bounds
);
1112 set_trap_gate(6,&invalid_op
);
1113 set_trap_gate(7,&device_not_available
);
1114 set_task_gate(8,GDT_ENTRY_DOUBLEFAULT_TSS
);
1115 set_trap_gate(9,&coprocessor_segment_overrun
);
1116 set_trap_gate(10,&invalid_TSS
);
1117 set_trap_gate(11,&segment_not_present
);
1118 set_trap_gate(12,&stack_segment
);
1119 set_trap_gate(13,&general_protection
);
1120 set_intr_gate(14,&page_fault
);
1121 set_trap_gate(15,&spurious_interrupt_bug
);
1122 set_trap_gate(16,&coprocessor_error
);
1123 set_trap_gate(17,&alignment_check
);
1124 #ifdef CONFIG_X86_MCE
1125 set_trap_gate(18,&machine_check
);
1127 set_trap_gate(19,&simd_coprocessor_error
);
1131 * Verify that the FXSAVE/FXRSTOR data will be 16-byte aligned.
1132 * Generates a compile-time "error: zero width for bit-field" if
1133 * the alignment is wrong.
1135 struct fxsrAlignAssert
{
1136 int _
:!(offsetof(struct task_struct
,
1137 thread
.i387
.fxsave
) & 15);
1140 printk(KERN_INFO
"Enabling fast FPU save and restore... ");
1141 set_in_cr4(X86_CR4_OSFXSR
);
1145 printk(KERN_INFO
"Enabling unmasked SIMD FPU exception "
1147 set_in_cr4(X86_CR4_OSXMMEXCPT
);
1151 set_system_gate(SYSCALL_VECTOR
,&system_call
);
1154 * Should be a barrier for any external CPU state.
1161 static int __init
kstack_setup(char *s
)
1163 kstack_depth_to_print
= simple_strtoul(s
, NULL
, 0);
1166 __setup("kstack=", kstack_setup
);