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/sched.h>
15 #include <linux/kernel.h>
16 #include <linux/string.h>
17 #include <linux/errno.h>
18 #include <linux/timer.h>
20 #include <linux/init.h>
21 #include <linux/delay.h>
22 #include <linux/spinlock.h>
23 #include <linux/interrupt.h>
24 #include <linux/highmem.h>
25 #include <linux/kallsyms.h>
26 #include <linux/ptrace.h>
27 #include <linux/utsname.h>
28 #include <linux/kprobes.h>
29 #include <linux/kexec.h>
30 #include <linux/unwind.h>
31 #include <linux/uaccess.h>
32 #include <linux/nmi.h>
33 #include <linux/bug.h>
36 #include <linux/ioport.h>
37 #include <linux/eisa.h>
41 #include <linux/mca.h>
44 #if defined(CONFIG_EDAC)
45 #include <linux/edac.h>
48 #include <asm/processor.h>
49 #include <asm/system.h>
51 #include <asm/atomic.h>
52 #include <asm/debugreg.h>
56 #include <asm/unwind.h>
58 #include <asm/arch_hooks.h>
59 #include <linux/kdebug.h>
60 #include <asm/stacktrace.h>
62 #include <linux/module.h>
64 #include "mach_traps.h"
66 int panic_on_unrecovered_nmi
;
68 asmlinkage
int system_call(void);
70 /* Do we ignore FPU interrupts ? */
71 char ignore_fpu_irq
= 0;
74 * The IDT has to be page-aligned to simplify the Pentium
75 * F0 0F bug workaround.. We have a special link segment
78 struct desc_struct idt_table
[256] __attribute__((__section__(".data.idt"))) = { {0, 0}, };
80 asmlinkage
void divide_error(void);
81 asmlinkage
void debug(void);
82 asmlinkage
void nmi(void);
83 asmlinkage
void int3(void);
84 asmlinkage
void overflow(void);
85 asmlinkage
void bounds(void);
86 asmlinkage
void invalid_op(void);
87 asmlinkage
void device_not_available(void);
88 asmlinkage
void coprocessor_segment_overrun(void);
89 asmlinkage
void invalid_TSS(void);
90 asmlinkage
void segment_not_present(void);
91 asmlinkage
void stack_segment(void);
92 asmlinkage
void general_protection(void);
93 asmlinkage
void page_fault(void);
94 asmlinkage
void coprocessor_error(void);
95 asmlinkage
void simd_coprocessor_error(void);
96 asmlinkage
void alignment_check(void);
97 asmlinkage
void spurious_interrupt_bug(void);
98 asmlinkage
void machine_check(void);
100 int kstack_depth_to_print
= 24;
101 static unsigned int code_bytes
= 64;
103 static inline int valid_stack_ptr(struct thread_info
*tinfo
, void *p
, unsigned size
)
105 return p
> (void *)tinfo
&&
106 p
<= (void *)tinfo
+ THREAD_SIZE
- size
;
109 /* The form of the top of the frame on the stack */
111 struct stack_frame
*next_frame
;
112 unsigned long return_address
;
115 static inline unsigned long print_context_stack(struct thread_info
*tinfo
,
116 unsigned long *stack
, unsigned long ebp
,
117 struct stacktrace_ops
*ops
, void *data
)
119 #ifdef CONFIG_FRAME_POINTER
120 struct stack_frame
*frame
= (struct stack_frame
*)ebp
;
121 while (valid_stack_ptr(tinfo
, frame
, sizeof(*frame
))) {
122 struct stack_frame
*next
;
125 addr
= frame
->return_address
;
126 ops
->address(data
, addr
);
128 * break out of recursive entries (such as
129 * end_of_stack_stop_unwind_function). Also,
130 * we can never allow a frame pointer to
133 next
= frame
->next_frame
;
139 while (valid_stack_ptr(tinfo
, stack
, sizeof(*stack
))) {
143 if (__kernel_text_address(addr
))
144 ops
->address(data
, addr
);
150 #define MSG(msg) ops->warning(data, msg)
152 void dump_trace(struct task_struct
*task
, struct pt_regs
*regs
,
153 unsigned long *stack
,
154 struct stacktrace_ops
*ops
, void *data
)
156 unsigned long ebp
= 0;
165 stack
= (unsigned long *)task
->thread
.esp
;
168 #ifdef CONFIG_FRAME_POINTER
170 if (task
== current
) {
171 /* Grab ebp right from our regs */
172 asm ("movl %%ebp, %0" : "=r" (ebp
) : );
174 /* ebp is the last reg pushed by switch_to */
175 ebp
= *(unsigned long *) task
->thread
.esp
;
181 struct thread_info
*context
;
182 context
= (struct thread_info
*)
183 ((unsigned long)stack
& (~(THREAD_SIZE
- 1)));
184 ebp
= print_context_stack(context
, stack
, ebp
, ops
, data
);
185 /* Should be after the line below, but somewhere
186 in early boot context comes out corrupted and we
187 can't reference it -AK */
188 if (ops
->stack(data
, "IRQ") < 0)
190 stack
= (unsigned long*)context
->previous_esp
;
193 touch_nmi_watchdog();
196 EXPORT_SYMBOL(dump_trace
);
199 print_trace_warning_symbol(void *data
, char *msg
, unsigned long symbol
)
202 print_symbol(msg
, symbol
);
206 static void print_trace_warning(void *data
, char *msg
)
208 printk("%s%s\n", (char *)data
, msg
);
211 static int print_trace_stack(void *data
, char *name
)
217 * Print one address/symbol entries per line.
219 static void print_trace_address(void *data
, unsigned long addr
)
221 printk("%s [<%08lx>] ", (char *)data
, addr
);
222 print_symbol("%s\n", addr
);
223 touch_nmi_watchdog();
226 static struct stacktrace_ops print_trace_ops
= {
227 .warning
= print_trace_warning
,
228 .warning_symbol
= print_trace_warning_symbol
,
229 .stack
= print_trace_stack
,
230 .address
= print_trace_address
,
234 show_trace_log_lvl(struct task_struct
*task
, struct pt_regs
*regs
,
235 unsigned long * stack
, char *log_lvl
)
237 dump_trace(task
, regs
, stack
, &print_trace_ops
, log_lvl
);
238 printk("%s =======================\n", log_lvl
);
241 void show_trace(struct task_struct
*task
, struct pt_regs
*regs
,
242 unsigned long * stack
)
244 show_trace_log_lvl(task
, regs
, stack
, "");
247 static void show_stack_log_lvl(struct task_struct
*task
, struct pt_regs
*regs
,
248 unsigned long *esp
, char *log_lvl
)
250 unsigned long *stack
;
255 esp
= (unsigned long*)task
->thread
.esp
;
257 esp
= (unsigned long *)&esp
;
261 for(i
= 0; i
< kstack_depth_to_print
; i
++) {
262 if (kstack_end(stack
))
264 if (i
&& ((i
% 8) == 0))
265 printk("\n%s ", log_lvl
);
266 printk("%08lx ", *stack
++);
268 printk("\n%sCall Trace:\n", log_lvl
);
269 show_trace_log_lvl(task
, regs
, esp
, log_lvl
);
272 void show_stack(struct task_struct
*task
, unsigned long *esp
)
275 show_stack_log_lvl(task
, NULL
, esp
, "");
279 * The architecture-independent dump_stack generator
281 void dump_stack(void)
285 show_trace(current
, NULL
, &stack
);
288 EXPORT_SYMBOL(dump_stack
);
290 void show_registers(struct pt_regs
*regs
)
295 unsigned short ss
, gs
;
297 esp
= (unsigned long) (®s
->esp
);
300 if (user_mode_vm(regs
)) {
303 ss
= regs
->xss
& 0xffff;
306 printk(KERN_EMERG
"CPU: %d\n"
307 KERN_EMERG
"EIP: %04x:[<%08lx>] %s VLI\n"
308 KERN_EMERG
"EFLAGS: %08lx (%s %.*s)\n",
309 smp_processor_id(), 0xffff & regs
->xcs
, regs
->eip
,
310 print_tainted(), regs
->eflags
, init_utsname()->release
,
311 (int)strcspn(init_utsname()->version
, " "),
312 init_utsname()->version
);
313 print_symbol(KERN_EMERG
"EIP is at %s\n", regs
->eip
);
314 printk(KERN_EMERG
"eax: %08lx ebx: %08lx ecx: %08lx edx: %08lx\n",
315 regs
->eax
, regs
->ebx
, regs
->ecx
, regs
->edx
);
316 printk(KERN_EMERG
"esi: %08lx edi: %08lx ebp: %08lx esp: %08lx\n",
317 regs
->esi
, regs
->edi
, regs
->ebp
, esp
);
318 printk(KERN_EMERG
"ds: %04x es: %04x fs: %04x gs: %04x ss: %04x\n",
319 regs
->xds
& 0xffff, regs
->xes
& 0xffff, regs
->xfs
& 0xffff, gs
, ss
);
320 printk(KERN_EMERG
"Process %.*s (pid: %d, ti=%p task=%p task.ti=%p)",
321 TASK_COMM_LEN
, current
->comm
, current
->pid
,
322 current_thread_info(), current
, task_thread_info(current
));
324 * When in-kernel, we also print out the stack and code at the
325 * time of the fault..
329 unsigned int code_prologue
= code_bytes
* 43 / 64;
330 unsigned int code_len
= code_bytes
;
333 printk("\n" KERN_EMERG
"Stack: ");
334 show_stack_log_lvl(NULL
, regs
, (unsigned long *)esp
, KERN_EMERG
);
336 printk(KERN_EMERG
"Code: ");
338 eip
= (u8
*)regs
->eip
- code_prologue
;
339 if (eip
< (u8
*)PAGE_OFFSET
||
340 probe_kernel_address(eip
, c
)) {
341 /* try starting at EIP */
342 eip
= (u8
*)regs
->eip
;
343 code_len
= code_len
- code_prologue
+ 1;
345 for (i
= 0; i
< code_len
; i
++, eip
++) {
346 if (eip
< (u8
*)PAGE_OFFSET
||
347 probe_kernel_address(eip
, c
)) {
348 printk(" Bad EIP value.");
351 if (eip
== (u8
*)regs
->eip
)
352 printk("<%02x> ", c
);
360 int is_valid_bugaddr(unsigned long eip
)
364 if (eip
< PAGE_OFFSET
)
366 if (probe_kernel_address((unsigned short *)eip
, ud2
))
369 return ud2
== 0x0b0f;
373 * This is gone through when something in the kernel has done something bad and
374 * is about to be terminated.
376 void die(const char * str
, struct pt_regs
* regs
, long err
)
381 int lock_owner_depth
;
383 .lock
= __SPIN_LOCK_UNLOCKED(die
.lock
),
385 .lock_owner_depth
= 0
387 static int die_counter
;
392 if (die
.lock_owner
!= raw_smp_processor_id()) {
394 spin_lock_irqsave(&die
.lock
, flags
);
395 die
.lock_owner
= smp_processor_id();
396 die
.lock_owner_depth
= 0;
400 local_save_flags(flags
);
402 if (++die
.lock_owner_depth
< 3) {
407 report_bug(regs
->eip
, regs
);
409 printk(KERN_EMERG
"%s: %04lx [#%d]\n", str
, err
& 0xffff, ++die_counter
);
410 #ifdef CONFIG_PREEMPT
411 printk(KERN_EMERG
"PREEMPT ");
420 #ifdef CONFIG_DEBUG_PAGEALLOC
423 printk("DEBUG_PAGEALLOC");
428 if (notify_die(DIE_OOPS
, str
, regs
, err
,
429 current
->thread
.trap_no
, SIGSEGV
) !=
431 show_registers(regs
);
432 /* Executive summary in case the oops scrolled away */
433 esp
= (unsigned long) (®s
->esp
);
435 if (user_mode(regs
)) {
437 ss
= regs
->xss
& 0xffff;
439 printk(KERN_EMERG
"EIP: [<%08lx>] ", regs
->eip
);
440 print_symbol("%s", regs
->eip
);
441 printk(" SS:ESP %04x:%08lx\n", ss
, esp
);
446 printk(KERN_EMERG
"Recursive die() failure, output suppressed\n");
450 add_taint(TAINT_DIE
);
451 spin_unlock_irqrestore(&die
.lock
, flags
);
456 if (kexec_should_crash(current
))
460 panic("Fatal exception in interrupt");
463 panic("Fatal exception");
469 static inline void die_if_kernel(const char * str
, struct pt_regs
* regs
, long err
)
471 if (!user_mode_vm(regs
))
475 static void __kprobes
do_trap(int trapnr
, int signr
, char *str
, int vm86
,
476 struct pt_regs
* regs
, long error_code
,
479 struct task_struct
*tsk
= current
;
481 if (regs
->eflags
& VM_MASK
) {
487 if (!user_mode(regs
))
492 * We want error_code and trap_no set for userspace faults and
493 * kernelspace faults which result in die(), but not
494 * kernelspace faults which are fixed up. die() gives the
495 * process no chance to handle the signal and notice the
496 * kernel fault information, so that won't result in polluting
497 * the information about previously queued, but not yet
498 * delivered, faults. See also do_general_protection below.
500 tsk
->thread
.error_code
= error_code
;
501 tsk
->thread
.trap_no
= trapnr
;
504 force_sig_info(signr
, info
, tsk
);
506 force_sig(signr
, tsk
);
511 if (!fixup_exception(regs
)) {
512 tsk
->thread
.error_code
= error_code
;
513 tsk
->thread
.trap_no
= trapnr
;
514 die(str
, regs
, error_code
);
520 int ret
= handle_vm86_trap((struct kernel_vm86_regs
*) regs
, error_code
, trapnr
);
521 if (ret
) goto trap_signal
;
526 #define DO_ERROR(trapnr, signr, str, name) \
527 fastcall void do_##name(struct pt_regs * regs, long error_code) \
529 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
532 do_trap(trapnr, signr, str, 0, regs, error_code, NULL); \
535 #define DO_ERROR_INFO(trapnr, signr, str, name, sicode, siaddr, irq) \
536 fastcall void do_##name(struct pt_regs * regs, long error_code) \
540 local_irq_enable(); \
541 info.si_signo = signr; \
543 info.si_code = sicode; \
544 info.si_addr = (void __user *)siaddr; \
545 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
548 do_trap(trapnr, signr, str, 0, regs, error_code, &info); \
551 #define DO_VM86_ERROR(trapnr, signr, str, name) \
552 fastcall void do_##name(struct pt_regs * regs, long error_code) \
554 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
557 do_trap(trapnr, signr, str, 1, regs, error_code, NULL); \
560 #define DO_VM86_ERROR_INFO(trapnr, signr, str, name, sicode, siaddr) \
561 fastcall void do_##name(struct pt_regs * regs, long error_code) \
564 info.si_signo = signr; \
566 info.si_code = sicode; \
567 info.si_addr = (void __user *)siaddr; \
568 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
571 do_trap(trapnr, signr, str, 1, regs, error_code, &info); \
574 DO_VM86_ERROR_INFO( 0, SIGFPE
, "divide error", divide_error
, FPE_INTDIV
, regs
->eip
)
575 #ifndef CONFIG_KPROBES
576 DO_VM86_ERROR( 3, SIGTRAP
, "int3", int3
)
578 DO_VM86_ERROR( 4, SIGSEGV
, "overflow", overflow
)
579 DO_VM86_ERROR( 5, SIGSEGV
, "bounds", bounds
)
580 DO_ERROR_INFO( 6, SIGILL
, "invalid opcode", invalid_op
, ILL_ILLOPN
, regs
->eip
, 0)
581 DO_ERROR( 9, SIGFPE
, "coprocessor segment overrun", coprocessor_segment_overrun
)
582 DO_ERROR(10, SIGSEGV
, "invalid TSS", invalid_TSS
)
583 DO_ERROR(11, SIGBUS
, "segment not present", segment_not_present
)
584 DO_ERROR(12, SIGBUS
, "stack segment", stack_segment
)
585 DO_ERROR_INFO(17, SIGBUS
, "alignment check", alignment_check
, BUS_ADRALN
, 0, 0)
586 DO_ERROR_INFO(32, SIGSEGV
, "iret exception", iret_error
, ILL_BADSTK
, 0, 1)
588 fastcall
void __kprobes
do_general_protection(struct pt_regs
* regs
,
592 struct tss_struct
*tss
= &per_cpu(init_tss
, cpu
);
593 struct thread_struct
*thread
= ¤t
->thread
;
596 * Perform the lazy TSS's I/O bitmap copy. If the TSS has an
597 * invalid offset set (the LAZY one) and the faulting thread has
598 * a valid I/O bitmap pointer, we copy the I/O bitmap in the TSS
599 * and we set the offset field correctly. Then we let the CPU to
600 * restart the faulting instruction.
602 if (tss
->x86_tss
.io_bitmap_base
== INVALID_IO_BITMAP_OFFSET_LAZY
&&
603 thread
->io_bitmap_ptr
) {
604 memcpy(tss
->io_bitmap
, thread
->io_bitmap_ptr
,
605 thread
->io_bitmap_max
);
607 * If the previously set map was extending to higher ports
608 * than the current one, pad extra space with 0xff (no access).
610 if (thread
->io_bitmap_max
< tss
->io_bitmap_max
)
611 memset((char *) tss
->io_bitmap
+
612 thread
->io_bitmap_max
, 0xff,
613 tss
->io_bitmap_max
- thread
->io_bitmap_max
);
614 tss
->io_bitmap_max
= thread
->io_bitmap_max
;
615 tss
->x86_tss
.io_bitmap_base
= IO_BITMAP_OFFSET
;
616 tss
->io_bitmap_owner
= thread
;
622 if (regs
->eflags
& VM_MASK
)
625 if (!user_mode(regs
))
628 current
->thread
.error_code
= error_code
;
629 current
->thread
.trap_no
= 13;
630 if (show_unhandled_signals
&& unhandled_signal(current
, SIGSEGV
) &&
633 "%s[%d] general protection eip:%lx esp:%lx error:%lx\n",
634 current
->comm
, current
->pid
,
635 regs
->eip
, regs
->esp
, error_code
);
637 force_sig(SIGSEGV
, current
);
642 handle_vm86_fault((struct kernel_vm86_regs
*) regs
, error_code
);
646 if (!fixup_exception(regs
)) {
647 current
->thread
.error_code
= error_code
;
648 current
->thread
.trap_no
= 13;
649 if (notify_die(DIE_GPF
, "general protection fault", regs
,
650 error_code
, 13, SIGSEGV
) == NOTIFY_STOP
)
652 die("general protection fault", regs
, error_code
);
656 static __kprobes
void
657 mem_parity_error(unsigned char reason
, struct pt_regs
* regs
)
659 printk(KERN_EMERG
"Uhhuh. NMI received for unknown reason %02x on "
660 "CPU %d.\n", reason
, smp_processor_id());
661 printk(KERN_EMERG
"You have some hardware problem, likely on the PCI bus.\n");
663 #if defined(CONFIG_EDAC)
664 if(edac_handler_set()) {
665 edac_atomic_assert_error();
670 if (panic_on_unrecovered_nmi
)
671 panic("NMI: Not continuing");
673 printk(KERN_EMERG
"Dazed and confused, but trying to continue\n");
675 /* Clear and disable the memory parity error line. */
676 clear_mem_error(reason
);
679 static __kprobes
void
680 io_check_error(unsigned char reason
, struct pt_regs
* regs
)
684 printk(KERN_EMERG
"NMI: IOCK error (debug interrupt?)\n");
685 show_registers(regs
);
687 /* Re-enable the IOCK line, wait for a few seconds */
688 reason
= (reason
& 0xf) | 8;
691 while (--i
) udelay(1000);
696 static __kprobes
void
697 unknown_nmi_error(unsigned char reason
, struct pt_regs
* regs
)
700 /* Might actually be able to figure out what the guilty party
707 printk(KERN_EMERG
"Uhhuh. NMI received for unknown reason %02x on "
708 "CPU %d.\n", reason
, smp_processor_id());
709 printk(KERN_EMERG
"Do you have a strange power saving mode enabled?\n");
710 if (panic_on_unrecovered_nmi
)
711 panic("NMI: Not continuing");
713 printk(KERN_EMERG
"Dazed and confused, but trying to continue\n");
716 static DEFINE_SPINLOCK(nmi_print_lock
);
718 void __kprobes
die_nmi(struct pt_regs
*regs
, const char *msg
)
720 if (notify_die(DIE_NMIWATCHDOG
, msg
, regs
, 0, 2, SIGINT
) ==
724 spin_lock(&nmi_print_lock
);
726 * We are in trouble anyway, lets at least try
727 * to get a message out.
730 printk(KERN_EMERG
"%s", msg
);
731 printk(" on CPU%d, eip %08lx, registers:\n",
732 smp_processor_id(), regs
->eip
);
733 show_registers(regs
);
735 spin_unlock(&nmi_print_lock
);
738 /* If we are in kernel we are probably nested up pretty bad
739 * and might aswell get out now while we still can.
741 if (!user_mode_vm(regs
)) {
742 current
->thread
.trap_no
= 2;
749 static __kprobes
void default_do_nmi(struct pt_regs
* regs
)
751 unsigned char reason
= 0;
753 /* Only the BSP gets external NMIs from the system. */
754 if (!smp_processor_id())
755 reason
= get_nmi_reason();
757 if (!(reason
& 0xc0)) {
758 if (notify_die(DIE_NMI_IPI
, "nmi_ipi", regs
, reason
, 2, SIGINT
)
761 #ifdef CONFIG_X86_LOCAL_APIC
763 * Ok, so this is none of the documented NMI sources,
764 * so it must be the NMI watchdog.
766 if (nmi_watchdog_tick(regs
, reason
))
768 if (!do_nmi_callback(regs
, smp_processor_id()))
770 unknown_nmi_error(reason
, regs
);
774 if (notify_die(DIE_NMI
, "nmi", regs
, reason
, 2, SIGINT
) == NOTIFY_STOP
)
777 mem_parity_error(reason
, regs
);
779 io_check_error(reason
, regs
);
781 * Reassert NMI in case it became active meanwhile
782 * as it's edge-triggered.
787 static int ignore_nmis
;
789 fastcall __kprobes
void do_nmi(struct pt_regs
* regs
, long error_code
)
795 cpu
= smp_processor_id();
800 default_do_nmi(regs
);
811 void restart_nmi(void)
817 #ifdef CONFIG_KPROBES
818 fastcall
void __kprobes
do_int3(struct pt_regs
*regs
, long error_code
)
820 if (notify_die(DIE_INT3
, "int3", regs
, error_code
, 3, SIGTRAP
)
823 /* This is an interrupt gate, because kprobes wants interrupts
824 disabled. Normal trap handlers don't. */
825 restore_interrupts(regs
);
826 do_trap(3, SIGTRAP
, "int3", 1, regs
, error_code
, NULL
);
831 * Our handling of the processor debug registers is non-trivial.
832 * We do not clear them on entry and exit from the kernel. Therefore
833 * it is possible to get a watchpoint trap here from inside the kernel.
834 * However, the code in ./ptrace.c has ensured that the user can
835 * only set watchpoints on userspace addresses. Therefore the in-kernel
836 * watchpoint trap can only occur in code which is reading/writing
837 * from user space. Such code must not hold kernel locks (since it
838 * can equally take a page fault), therefore it is safe to call
839 * force_sig_info even though that claims and releases locks.
841 * Code in ./signal.c ensures that the debug control register
842 * is restored before we deliver any signal, and therefore that
843 * user code runs with the correct debug control register even though
846 * Being careful here means that we don't have to be as careful in a
847 * lot of more complicated places (task switching can be a bit lazy
848 * about restoring all the debug state, and ptrace doesn't have to
849 * find every occurrence of the TF bit that could be saved away even
852 fastcall
void __kprobes
do_debug(struct pt_regs
* regs
, long error_code
)
854 unsigned int condition
;
855 struct task_struct
*tsk
= current
;
857 get_debugreg(condition
, 6);
859 if (notify_die(DIE_DEBUG
, "debug", regs
, condition
, error_code
,
860 SIGTRAP
) == NOTIFY_STOP
)
862 /* It's safe to allow irq's after DR6 has been saved */
863 if (regs
->eflags
& X86_EFLAGS_IF
)
866 /* Mask out spurious debug traps due to lazy DR7 setting */
867 if (condition
& (DR_TRAP0
|DR_TRAP1
|DR_TRAP2
|DR_TRAP3
)) {
868 if (!tsk
->thread
.debugreg
[7])
872 if (regs
->eflags
& VM_MASK
)
875 /* Save debug status register where ptrace can see it */
876 tsk
->thread
.debugreg
[6] = condition
;
879 * Single-stepping through TF: make sure we ignore any events in
880 * kernel space (but re-enable TF when returning to user mode).
882 if (condition
& DR_STEP
) {
884 * We already checked v86 mode above, so we can
885 * check for kernel mode by just checking the CPL
888 if (!user_mode(regs
))
889 goto clear_TF_reenable
;
892 /* Ok, finally something we can handle */
893 send_sigtrap(tsk
, regs
, error_code
);
895 /* Disable additional traps. They'll be re-enabled when
896 * the signal is delivered.
903 handle_vm86_trap((struct kernel_vm86_regs
*) regs
, error_code
, 1);
907 set_tsk_thread_flag(tsk
, TIF_SINGLESTEP
);
908 regs
->eflags
&= ~TF_MASK
;
913 * Note that we play around with the 'TS' bit in an attempt to get
914 * the correct behaviour even in the presence of the asynchronous
917 void math_error(void __user
*eip
)
919 struct task_struct
* task
;
921 unsigned short cwd
, swd
;
924 * Save the info for the exception handler and clear the error.
928 task
->thread
.trap_no
= 16;
929 task
->thread
.error_code
= 0;
930 info
.si_signo
= SIGFPE
;
932 info
.si_code
= __SI_FAULT
;
935 * (~cwd & swd) will mask out exceptions that are not set to unmasked
936 * status. 0x3f is the exception bits in these regs, 0x200 is the
937 * C1 reg you need in case of a stack fault, 0x040 is the stack
938 * fault bit. We should only be taking one exception at a time,
939 * so if this combination doesn't produce any single exception,
940 * then we have a bad program that isn't syncronizing its FPU usage
941 * and it will suffer the consequences since we won't be able to
942 * fully reproduce the context of the exception
944 cwd
= get_fpu_cwd(task
);
945 swd
= get_fpu_swd(task
);
946 switch (swd
& ~cwd
& 0x3f) {
947 case 0x000: /* No unmasked exception */
949 default: /* Multiple exceptions */
951 case 0x001: /* Invalid Op */
953 * swd & 0x240 == 0x040: Stack Underflow
954 * swd & 0x240 == 0x240: Stack Overflow
955 * User must clear the SF bit (0x40) if set
957 info
.si_code
= FPE_FLTINV
;
959 case 0x002: /* Denormalize */
960 case 0x010: /* Underflow */
961 info
.si_code
= FPE_FLTUND
;
963 case 0x004: /* Zero Divide */
964 info
.si_code
= FPE_FLTDIV
;
966 case 0x008: /* Overflow */
967 info
.si_code
= FPE_FLTOVF
;
969 case 0x020: /* Precision */
970 info
.si_code
= FPE_FLTRES
;
973 force_sig_info(SIGFPE
, &info
, task
);
976 fastcall
void do_coprocessor_error(struct pt_regs
* regs
, long error_code
)
979 math_error((void __user
*)regs
->eip
);
982 static void simd_math_error(void __user
*eip
)
984 struct task_struct
* task
;
986 unsigned short mxcsr
;
989 * Save the info for the exception handler and clear the error.
993 task
->thread
.trap_no
= 19;
994 task
->thread
.error_code
= 0;
995 info
.si_signo
= SIGFPE
;
997 info
.si_code
= __SI_FAULT
;
1000 * The SIMD FPU exceptions are handled a little differently, as there
1001 * is only a single status/control register. Thus, to determine which
1002 * unmasked exception was caught we must mask the exception mask bits
1003 * at 0x1f80, and then use these to mask the exception bits at 0x3f.
1005 mxcsr
= get_fpu_mxcsr(task
);
1006 switch (~((mxcsr
& 0x1f80) >> 7) & (mxcsr
& 0x3f)) {
1010 case 0x001: /* Invalid Op */
1011 info
.si_code
= FPE_FLTINV
;
1013 case 0x002: /* Denormalize */
1014 case 0x010: /* Underflow */
1015 info
.si_code
= FPE_FLTUND
;
1017 case 0x004: /* Zero Divide */
1018 info
.si_code
= FPE_FLTDIV
;
1020 case 0x008: /* Overflow */
1021 info
.si_code
= FPE_FLTOVF
;
1023 case 0x020: /* Precision */
1024 info
.si_code
= FPE_FLTRES
;
1027 force_sig_info(SIGFPE
, &info
, task
);
1030 fastcall
void do_simd_coprocessor_error(struct pt_regs
* regs
,
1034 /* Handle SIMD FPU exceptions on PIII+ processors. */
1036 simd_math_error((void __user
*)regs
->eip
);
1039 * Handle strange cache flush from user space exception
1040 * in all other cases. This is undocumented behaviour.
1042 if (regs
->eflags
& VM_MASK
) {
1043 handle_vm86_fault((struct kernel_vm86_regs
*)regs
,
1047 current
->thread
.trap_no
= 19;
1048 current
->thread
.error_code
= error_code
;
1049 die_if_kernel("cache flush denied", regs
, error_code
);
1050 force_sig(SIGSEGV
, current
);
1054 fastcall
void do_spurious_interrupt_bug(struct pt_regs
* regs
,
1058 /* No need to warn about this any longer. */
1059 printk("Ignoring P6 Local APIC Spurious Interrupt Bug...\n");
1063 fastcall
unsigned long patch_espfix_desc(unsigned long uesp
,
1066 struct desc_struct
*gdt
= __get_cpu_var(gdt_page
).gdt
;
1067 unsigned long base
= (kesp
- uesp
) & -THREAD_SIZE
;
1068 unsigned long new_kesp
= kesp
- base
;
1069 unsigned long lim_pages
= (new_kesp
| (THREAD_SIZE
- 1)) >> PAGE_SHIFT
;
1070 __u64 desc
= *(__u64
*)&gdt
[GDT_ENTRY_ESPFIX_SS
];
1071 /* Set up base for espfix segment */
1072 desc
&= 0x00f0ff0000000000ULL
;
1073 desc
|= ((((__u64
)base
) << 16) & 0x000000ffffff0000ULL
) |
1074 ((((__u64
)base
) << 32) & 0xff00000000000000ULL
) |
1075 ((((__u64
)lim_pages
) << 32) & 0x000f000000000000ULL
) |
1076 (lim_pages
& 0xffff);
1077 *(__u64
*)&gdt
[GDT_ENTRY_ESPFIX_SS
] = desc
;
1082 * 'math_state_restore()' saves the current math information in the
1083 * old math state array, and gets the new ones from the current task
1085 * Careful.. There are problems with IBM-designed IRQ13 behaviour.
1086 * Don't touch unless you *really* know how it works.
1088 * Must be called with kernel preemption disabled (in this case,
1089 * local interrupts are disabled at the call-site in entry.S).
1091 asmlinkage
void math_state_restore(void)
1093 struct thread_info
*thread
= current_thread_info();
1094 struct task_struct
*tsk
= thread
->task
;
1096 clts(); /* Allow maths ops (or we recurse) */
1097 if (!tsk_used_math(tsk
))
1100 thread
->status
|= TS_USEDFPU
; /* So we fnsave on switch_to() */
1103 EXPORT_SYMBOL_GPL(math_state_restore
);
1105 #ifndef CONFIG_MATH_EMULATION
1107 asmlinkage
void math_emulate(long arg
)
1109 printk(KERN_EMERG
"math-emulation not enabled and no coprocessor found.\n");
1110 printk(KERN_EMERG
"killing %s.\n",current
->comm
);
1111 force_sig(SIGFPE
,current
);
1115 #endif /* CONFIG_MATH_EMULATION */
1117 #ifdef CONFIG_X86_F00F_BUG
1118 void __init
trap_init_f00f_bug(void)
1120 __set_fixmap(FIX_F00F_IDT
, __pa(&idt_table
), PAGE_KERNEL_RO
);
1123 * Update the IDT descriptor and reload the IDT so that
1124 * it uses the read-only mapped virtual address.
1126 idt_descr
.address
= fix_to_virt(FIX_F00F_IDT
);
1127 load_idt(&idt_descr
);
1132 * This needs to use 'idt_table' rather than 'idt', and
1133 * thus use the _nonmapped_ version of the IDT, as the
1134 * Pentium F0 0F bugfix can have resulted in the mapped
1135 * IDT being write-protected.
1137 void set_intr_gate(unsigned int n
, void *addr
)
1139 _set_gate(n
, DESCTYPE_INT
, addr
, __KERNEL_CS
);
1143 * This routine sets up an interrupt gate at directory privilege level 3.
1145 static inline void set_system_intr_gate(unsigned int n
, void *addr
)
1147 _set_gate(n
, DESCTYPE_INT
| DESCTYPE_DPL3
, addr
, __KERNEL_CS
);
1150 static void __init
set_trap_gate(unsigned int n
, void *addr
)
1152 _set_gate(n
, DESCTYPE_TRAP
, addr
, __KERNEL_CS
);
1155 static void __init
set_system_gate(unsigned int n
, void *addr
)
1157 _set_gate(n
, DESCTYPE_TRAP
| DESCTYPE_DPL3
, addr
, __KERNEL_CS
);
1160 static void __init
set_task_gate(unsigned int n
, unsigned int gdt_entry
)
1162 _set_gate(n
, DESCTYPE_TASK
, (void *)0, (gdt_entry
<<3));
1166 void __init
trap_init(void)
1169 void __iomem
*p
= ioremap(0x0FFFD9, 4);
1170 if (readl(p
) == 'E'+('I'<<8)+('S'<<16)+('A'<<24)) {
1176 #ifdef CONFIG_X86_LOCAL_APIC
1177 init_apic_mappings();
1180 set_trap_gate(0,÷_error
);
1181 set_intr_gate(1,&debug
);
1182 set_intr_gate(2,&nmi
);
1183 set_system_intr_gate(3, &int3
); /* int3/4 can be called from all */
1184 set_system_gate(4,&overflow
);
1185 set_trap_gate(5,&bounds
);
1186 set_trap_gate(6,&invalid_op
);
1187 set_trap_gate(7,&device_not_available
);
1188 set_task_gate(8,GDT_ENTRY_DOUBLEFAULT_TSS
);
1189 set_trap_gate(9,&coprocessor_segment_overrun
);
1190 set_trap_gate(10,&invalid_TSS
);
1191 set_trap_gate(11,&segment_not_present
);
1192 set_trap_gate(12,&stack_segment
);
1193 set_trap_gate(13,&general_protection
);
1194 set_intr_gate(14,&page_fault
);
1195 set_trap_gate(15,&spurious_interrupt_bug
);
1196 set_trap_gate(16,&coprocessor_error
);
1197 set_trap_gate(17,&alignment_check
);
1198 #ifdef CONFIG_X86_MCE
1199 set_trap_gate(18,&machine_check
);
1201 set_trap_gate(19,&simd_coprocessor_error
);
1205 * Verify that the FXSAVE/FXRSTOR data will be 16-byte aligned.
1206 * Generates a compile-time "error: zero width for bit-field" if
1207 * the alignment is wrong.
1209 struct fxsrAlignAssert
{
1210 int _
:!(offsetof(struct task_struct
,
1211 thread
.i387
.fxsave
) & 15);
1214 printk(KERN_INFO
"Enabling fast FPU save and restore... ");
1215 set_in_cr4(X86_CR4_OSFXSR
);
1219 printk(KERN_INFO
"Enabling unmasked SIMD FPU exception "
1221 set_in_cr4(X86_CR4_OSXMMEXCPT
);
1225 set_system_gate(SYSCALL_VECTOR
,&system_call
);
1228 * Should be a barrier for any external CPU state.
1235 static int __init
kstack_setup(char *s
)
1237 kstack_depth_to_print
= simple_strtoul(s
, NULL
, 0);
1240 __setup("kstack=", kstack_setup
);
1242 static int __init
code_bytes_setup(char *s
)
1244 code_bytes
= simple_strtoul(s
, NULL
, 0);
1245 if (code_bytes
> 8192)
1250 __setup("code_bytes=", code_bytes_setup
);