2 * Copyright (C) 1991, 1992 Linus Torvalds
3 * Copyright (C) 2000, 2001, 2002 Andi Kleen, SuSE Labs
5 * Pentium III FXSR, SSE support
6 * Gareth Hughes <gareth@valinux.com>, May 2000
10 * 'Traps.c' handles hardware traps and faults after we have saved some
13 #include <linux/interrupt.h>
14 #include <linux/kallsyms.h>
15 #include <linux/spinlock.h>
16 #include <linux/highmem.h>
17 #include <linux/kprobes.h>
18 #include <linux/uaccess.h>
19 #include <linux/utsname.h>
20 #include <linux/kdebug.h>
21 #include <linux/kernel.h>
22 #include <linux/module.h>
23 #include <linux/ptrace.h>
24 #include <linux/string.h>
25 #include <linux/unwind.h>
26 #include <linux/delay.h>
27 #include <linux/errno.h>
28 #include <linux/kexec.h>
29 #include <linux/sched.h>
30 #include <linux/timer.h>
31 #include <linux/init.h>
32 #include <linux/bug.h>
33 #include <linux/nmi.h>
37 #include <linux/ioport.h>
38 #include <linux/eisa.h>
42 #include <linux/mca.h>
45 #if defined(CONFIG_EDAC)
46 #include <linux/edac.h>
49 #include <asm/processor-flags.h>
50 #include <asm/arch_hooks.h>
51 #include <asm/stacktrace.h>
52 #include <asm/processor.h>
53 #include <asm/debugreg.h>
54 #include <asm/atomic.h>
55 #include <asm/system.h>
56 #include <asm/unwind.h>
62 #include <asm/traps.h>
64 #include "mach_traps.h"
66 DECLARE_BITMAP(used_vectors
, NR_VECTORS
);
67 EXPORT_SYMBOL_GPL(used_vectors
);
69 asmlinkage
int system_call(void);
71 /* Do we ignore FPU interrupts ? */
75 * The IDT has to be page-aligned to simplify the Pentium
76 * F0 0F bug workaround.. We have a special link segment
79 gate_desc idt_table
[256]
80 __attribute__((__section__(".data.idt"))) = { { { { 0, 0 } } }, };
82 int panic_on_unrecovered_nmi
;
83 int kstack_depth_to_print
= 24;
84 static unsigned int code_bytes
= 64;
85 static int ignore_nmis
;
86 static int die_counter
;
88 static inline void conditional_sti(struct pt_regs
*regs
)
90 if (regs
->flags
& X86_EFLAGS_IF
)
94 void printk_address(unsigned long address
, int reliable
)
96 #ifdef CONFIG_KALLSYMS
97 unsigned long offset
= 0;
98 unsigned long symsize
;
102 char namebuf
[KSYM_NAME_LEN
];
105 symname
= kallsyms_lookup(address
, &symsize
, &offset
,
108 printk(" [<%08lx>]\n", address
);
112 strcpy(reliab
, "? ");
115 modname
= delim
= "";
116 printk(" [<%08lx>] %s%s%s%s%s+0x%lx/0x%lx\n",
117 address
, reliab
, delim
, modname
, delim
, symname
, offset
, symsize
);
119 printk(" [<%08lx>]\n", address
);
123 static inline int valid_stack_ptr(struct thread_info
*tinfo
,
124 void *p
, unsigned int size
)
127 return p
> t
&& p
<= t
+ THREAD_SIZE
- size
;
130 /* The form of the top of the frame on the stack */
132 struct stack_frame
*next_frame
;
133 unsigned long return_address
;
136 static inline unsigned long
137 print_context_stack(struct thread_info
*tinfo
,
138 unsigned long *stack
, unsigned long bp
,
139 const struct stacktrace_ops
*ops
, void *data
)
141 struct stack_frame
*frame
= (struct stack_frame
*)bp
;
143 while (valid_stack_ptr(tinfo
, stack
, sizeof(*stack
))) {
147 if (__kernel_text_address(addr
)) {
148 if ((unsigned long) stack
== bp
+ 4) {
149 ops
->address(data
, addr
, 1);
150 frame
= frame
->next_frame
;
151 bp
= (unsigned long) frame
;
153 ops
->address(data
, addr
, bp
== 0);
161 void dump_trace(struct task_struct
*task
, struct pt_regs
*regs
,
162 unsigned long *stack
, unsigned long bp
,
163 const struct stacktrace_ops
*ops
, void *data
)
172 stack
= (unsigned long *)task
->thread
.sp
;
175 #ifdef CONFIG_FRAME_POINTER
177 if (task
== current
) {
178 /* Grab bp right from our regs */
179 asm("movl %%ebp, %0" : "=r" (bp
) :);
181 /* bp is the last reg pushed by switch_to */
182 bp
= *(unsigned long *) task
->thread
.sp
;
188 struct thread_info
*context
;
190 context
= (struct thread_info
*)
191 ((unsigned long)stack
& (~(THREAD_SIZE
- 1)));
192 bp
= print_context_stack(context
, stack
, bp
, ops
, data
);
194 * Should be after the line below, but somewhere
195 * in early boot context comes out corrupted and we
196 * can't reference it:
198 if (ops
->stack(data
, "IRQ") < 0)
200 stack
= (unsigned long *)context
->previous_esp
;
203 touch_nmi_watchdog();
206 EXPORT_SYMBOL(dump_trace
);
209 print_trace_warning_symbol(void *data
, char *msg
, unsigned long symbol
)
212 print_symbol(msg
, symbol
);
216 static void print_trace_warning(void *data
, char *msg
)
218 printk("%s%s\n", (char *)data
, msg
);
221 static int print_trace_stack(void *data
, char *name
)
227 * Print one address/symbol entries per line.
229 static void print_trace_address(void *data
, unsigned long addr
, int reliable
)
231 printk("%s [<%08lx>] ", (char *)data
, addr
);
234 print_symbol("%s\n", addr
);
235 touch_nmi_watchdog();
238 static const struct stacktrace_ops print_trace_ops
= {
239 .warning
= print_trace_warning
,
240 .warning_symbol
= print_trace_warning_symbol
,
241 .stack
= print_trace_stack
,
242 .address
= print_trace_address
,
246 show_trace_log_lvl(struct task_struct
*task
, struct pt_regs
*regs
,
247 unsigned long *stack
, unsigned long bp
, char *log_lvl
)
249 dump_trace(task
, regs
, stack
, bp
, &print_trace_ops
, log_lvl
);
250 printk("%s =======================\n", log_lvl
);
253 void show_trace(struct task_struct
*task
, struct pt_regs
*regs
,
254 unsigned long *stack
, unsigned long bp
)
256 show_trace_log_lvl(task
, regs
, stack
, bp
, "");
260 show_stack_log_lvl(struct task_struct
*task
, struct pt_regs
*regs
,
261 unsigned long *sp
, unsigned long bp
, char *log_lvl
)
263 unsigned long *stack
;
268 sp
= (unsigned long *)task
->thread
.sp
;
270 sp
= (unsigned long *)&sp
;
274 for (i
= 0; i
< kstack_depth_to_print
; i
++) {
275 if (kstack_end(stack
))
277 if (i
&& ((i
% 8) == 0))
278 printk("\n%s ", log_lvl
);
279 printk("%08lx ", *stack
++);
281 printk("\n%sCall Trace:\n", log_lvl
);
283 show_trace_log_lvl(task
, regs
, sp
, bp
, log_lvl
);
286 void show_stack(struct task_struct
*task
, unsigned long *sp
)
289 show_stack_log_lvl(task
, NULL
, sp
, 0, "");
293 * The architecture-independent dump_stack generator
295 void dump_stack(void)
297 unsigned long bp
= 0;
300 #ifdef CONFIG_FRAME_POINTER
302 asm("movl %%ebp, %0" : "=r" (bp
):);
305 printk("Pid: %d, comm: %.20s %s %s %.*s\n",
306 current
->pid
, current
->comm
, print_tainted(),
307 init_utsname()->release
,
308 (int)strcspn(init_utsname()->version
, " "),
309 init_utsname()->version
);
311 show_trace(current
, NULL
, &stack
, bp
);
314 EXPORT_SYMBOL(dump_stack
);
316 void show_registers(struct pt_regs
*regs
)
321 __show_registers(regs
, 0);
323 printk(KERN_EMERG
"Process %.*s (pid: %d, ti=%p task=%p task.ti=%p)",
324 TASK_COMM_LEN
, current
->comm
, task_pid_nr(current
),
325 current_thread_info(), current
, task_thread_info(current
));
327 * When in-kernel, we also print out the stack and code at the
328 * time of the fault..
330 if (!user_mode_vm(regs
)) {
331 unsigned int code_prologue
= code_bytes
* 43 / 64;
332 unsigned int code_len
= code_bytes
;
336 printk("\n" KERN_EMERG
"Stack: ");
337 show_stack_log_lvl(NULL
, regs
, ®s
->sp
, 0, KERN_EMERG
);
339 printk(KERN_EMERG
"Code: ");
341 ip
= (u8
*)regs
->ip
- code_prologue
;
342 if (ip
< (u8
*)PAGE_OFFSET
|| probe_kernel_address(ip
, c
)) {
343 /* try starting at EIP */
345 code_len
= code_len
- code_prologue
+ 1;
347 for (i
= 0; i
< code_len
; i
++, ip
++) {
348 if (ip
< (u8
*)PAGE_OFFSET
||
349 probe_kernel_address(ip
, c
)) {
350 printk(" Bad EIP value.");
353 if (ip
== (u8
*)regs
->ip
)
354 printk("<%02x> ", c
);
362 int is_valid_bugaddr(unsigned long ip
)
366 if (ip
< PAGE_OFFSET
)
368 if (probe_kernel_address((unsigned short *)ip
, ud2
))
371 return ud2
== 0x0b0f;
374 static raw_spinlock_t die_lock
= __RAW_SPIN_LOCK_UNLOCKED
;
375 static int die_owner
= -1;
376 static unsigned int die_nest_count
;
378 unsigned __kprobes
long oops_begin(void)
384 if (die_owner
!= raw_smp_processor_id()) {
386 raw_local_irq_save(flags
);
387 __raw_spin_lock(&die_lock
);
388 die_owner
= smp_processor_id();
392 raw_local_irq_save(flags
);
398 void __kprobes
oops_end(unsigned long flags
, struct pt_regs
*regs
, int signr
)
402 add_taint(TAINT_DIE
);
403 __raw_spin_unlock(&die_lock
);
404 raw_local_irq_restore(flags
);
409 if (kexec_should_crash(current
))
413 panic("Fatal exception in interrupt");
416 panic("Fatal exception");
422 int __kprobes
__die(const char *str
, struct pt_regs
*regs
, long err
)
427 printk(KERN_EMERG
"%s: %04lx [#%d] ", str
, err
& 0xffff, ++die_counter
);
428 #ifdef CONFIG_PREEMPT
434 #ifdef CONFIG_DEBUG_PAGEALLOC
435 printk("DEBUG_PAGEALLOC");
438 if (notify_die(DIE_OOPS
, str
, regs
, err
,
439 current
->thread
.trap_no
, SIGSEGV
) == NOTIFY_STOP
)
442 show_registers(regs
);
443 /* Executive summary in case the oops scrolled away */
444 sp
= (unsigned long) (®s
->sp
);
446 if (user_mode(regs
)) {
448 ss
= regs
->ss
& 0xffff;
450 printk(KERN_EMERG
"EIP: [<%08lx>] ", regs
->ip
);
451 print_symbol("%s", regs
->ip
);
452 printk(" SS:ESP %04x:%08lx\n", ss
, sp
);
457 * This is gone through when something in the kernel has done something bad
458 * and is about to be terminated:
460 void die(const char *str
, struct pt_regs
*regs
, long err
)
462 unsigned long flags
= oops_begin();
464 if (die_nest_count
< 3) {
465 report_bug(regs
->ip
, regs
);
467 if (__die(str
, regs
, err
))
470 printk(KERN_EMERG
"Recursive die() failure, output suppressed\n");
473 oops_end(flags
, regs
, SIGSEGV
);
477 die_if_kernel(const char *str
, struct pt_regs
*regs
, long err
)
479 if (!user_mode_vm(regs
))
483 static void __kprobes
484 do_trap(int trapnr
, int signr
, char *str
, int vm86
, struct pt_regs
*regs
,
485 long error_code
, siginfo_t
*info
)
487 struct task_struct
*tsk
= current
;
489 if (regs
->flags
& X86_VM_MASK
) {
495 if (!user_mode(regs
))
500 * We want error_code and trap_no set for userspace faults and
501 * kernelspace faults which result in die(), but not
502 * kernelspace faults which are fixed up. die() gives the
503 * process no chance to handle the signal and notice the
504 * kernel fault information, so that won't result in polluting
505 * the information about previously queued, but not yet
506 * delivered, faults. See also do_general_protection below.
508 tsk
->thread
.error_code
= error_code
;
509 tsk
->thread
.trap_no
= trapnr
;
512 force_sig_info(signr
, info
, tsk
);
514 force_sig(signr
, tsk
);
518 if (!fixup_exception(regs
)) {
519 tsk
->thread
.error_code
= error_code
;
520 tsk
->thread
.trap_no
= trapnr
;
521 die(str
, regs
, error_code
);
526 if (handle_vm86_trap((struct kernel_vm86_regs
*) regs
,
532 #define DO_TRAP(trapnr, signr, str, name) \
533 void do_##name(struct pt_regs *regs, long error_code) \
535 trace_hardirqs_fixup(); \
536 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
539 do_trap(trapnr, signr, str, 0, regs, error_code, NULL); \
542 #define DO_TRAP_INFO(trapnr, signr, str, name, sicode, siaddr, irq) \
543 void do_##name(struct pt_regs *regs, long error_code) \
547 local_irq_enable(); \
548 info.si_signo = signr; \
550 info.si_code = sicode; \
551 info.si_addr = (void __user *)siaddr; \
552 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
555 do_trap(trapnr, signr, str, 0, regs, error_code, &info); \
558 #define DO_VM86_TRAP(trapnr, signr, str, name) \
559 void do_##name(struct pt_regs *regs, long error_code) \
561 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
564 do_trap(trapnr, signr, str, 1, regs, error_code, NULL); \
567 #define DO_VM86_TRAP_INFO(trapnr, signr, str, name, sicode, siaddr) \
568 void do_##name(struct pt_regs *regs, long error_code) \
571 info.si_signo = signr; \
573 info.si_code = sicode; \
574 info.si_addr = (void __user *)siaddr; \
575 trace_hardirqs_fixup(); \
576 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
579 do_trap(trapnr, signr, str, 1, regs, error_code, &info); \
582 #define DO_ERROR(trapnr, signr, str, name) \
583 void do_##name(struct pt_regs *regs, long error_code) \
585 trace_hardirqs_fixup(); \
586 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
589 conditional_sti(regs); \
590 do_trap(trapnr, signr, str, 0, regs, error_code, NULL); \
593 #define DO_ERROR_INFO(trapnr, signr, str, name, sicode, siaddr, irq) \
594 void do_##name(struct pt_regs *regs, long error_code) \
598 local_irq_enable(); \
599 info.si_signo = signr; \
601 info.si_code = sicode; \
602 info.si_addr = (void __user *)siaddr; \
603 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
606 conditional_sti(regs); \
607 do_trap(trapnr, signr, str, 0, regs, error_code, &info); \
610 #define DO_VM86_ERROR(trapnr, signr, str, name) \
611 void do_##name(struct pt_regs *regs, long error_code) \
613 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
616 conditional_sti(regs); \
617 do_trap(trapnr, signr, str, 1, regs, error_code, NULL); \
620 #define DO_VM86_ERROR_INFO(trapnr, signr, str, name, sicode, siaddr) \
621 void do_##name(struct pt_regs *regs, long error_code) \
624 info.si_signo = signr; \
626 info.si_code = sicode; \
627 info.si_addr = (void __user *)siaddr; \
628 trace_hardirqs_fixup(); \
629 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
632 conditional_sti(regs); \
633 do_trap(trapnr, signr, str, 1, regs, error_code, &info); \
636 DO_VM86_ERROR_INFO(0, SIGFPE
, "divide error", divide_error
, FPE_INTDIV
, regs
->ip
)
637 DO_VM86_ERROR(4, SIGSEGV
, "overflow", overflow
)
638 DO_VM86_ERROR(5, SIGSEGV
, "bounds", bounds
)
639 DO_ERROR_INFO(6, SIGILL
, "invalid opcode", invalid_op
, ILL_ILLOPN
, regs
->ip
, 0)
640 DO_ERROR(9, SIGFPE
, "coprocessor segment overrun", coprocessor_segment_overrun
)
641 DO_ERROR(10, SIGSEGV
, "invalid TSS", invalid_TSS
)
642 DO_ERROR(11, SIGBUS
, "segment not present", segment_not_present
)
643 DO_ERROR(12, SIGBUS
, "stack segment", stack_segment
)
644 DO_TRAP_INFO(17, SIGBUS
, "alignment check", alignment_check
, BUS_ADRALN
, 0, 0)
645 DO_TRAP_INFO(32, SIGILL
, "iret exception", iret_error
, ILL_BADSTK
, 0, 1)
648 do_general_protection(struct pt_regs
*regs
, long error_code
)
650 struct task_struct
*tsk
;
651 struct thread_struct
*thread
;
652 struct tss_struct
*tss
;
655 conditional_sti(regs
);
658 tss
= &per_cpu(init_tss
, cpu
);
659 thread
= ¤t
->thread
;
662 * Perform the lazy TSS's I/O bitmap copy. If the TSS has an
663 * invalid offset set (the LAZY one) and the faulting thread has
664 * a valid I/O bitmap pointer, we copy the I/O bitmap in the TSS
665 * and we set the offset field correctly. Then we let the CPU to
666 * restart the faulting instruction.
668 if (tss
->x86_tss
.io_bitmap_base
== INVALID_IO_BITMAP_OFFSET_LAZY
&&
669 thread
->io_bitmap_ptr
) {
670 memcpy(tss
->io_bitmap
, thread
->io_bitmap_ptr
,
671 thread
->io_bitmap_max
);
673 * If the previously set map was extending to higher ports
674 * than the current one, pad extra space with 0xff (no access).
676 if (thread
->io_bitmap_max
< tss
->io_bitmap_max
) {
677 memset((char *) tss
->io_bitmap
+
678 thread
->io_bitmap_max
, 0xff,
679 tss
->io_bitmap_max
- thread
->io_bitmap_max
);
681 tss
->io_bitmap_max
= thread
->io_bitmap_max
;
682 tss
->x86_tss
.io_bitmap_base
= IO_BITMAP_OFFSET
;
683 tss
->io_bitmap_owner
= thread
;
690 if (regs
->flags
& X86_VM_MASK
)
694 if (!user_mode(regs
))
697 tsk
->thread
.error_code
= error_code
;
698 tsk
->thread
.trap_no
= 13;
700 if (show_unhandled_signals
&& unhandled_signal(tsk
, SIGSEGV
) &&
701 printk_ratelimit()) {
703 "%s[%d] general protection ip:%lx sp:%lx error:%lx",
704 tsk
->comm
, task_pid_nr(tsk
),
705 regs
->ip
, regs
->sp
, error_code
);
706 print_vma_addr(" in ", regs
->ip
);
710 force_sig(SIGSEGV
, tsk
);
715 handle_vm86_fault((struct kernel_vm86_regs
*) regs
, error_code
);
719 if (fixup_exception(regs
))
722 tsk
->thread
.error_code
= error_code
;
723 tsk
->thread
.trap_no
= 13;
724 if (notify_die(DIE_GPF
, "general protection fault", regs
,
725 error_code
, 13, SIGSEGV
) == NOTIFY_STOP
)
727 die("general protection fault", regs
, error_code
);
730 static notrace __kprobes
void
731 mem_parity_error(unsigned char reason
, struct pt_regs
*regs
)
734 "Uhhuh. NMI received for unknown reason %02x on CPU %d.\n",
735 reason
, smp_processor_id());
738 "You have some hardware problem, likely on the PCI bus.\n");
740 #if defined(CONFIG_EDAC)
741 if (edac_handler_set()) {
742 edac_atomic_assert_error();
747 if (panic_on_unrecovered_nmi
)
748 panic("NMI: Not continuing");
750 printk(KERN_EMERG
"Dazed and confused, but trying to continue\n");
752 /* Clear and disable the memory parity error line. */
753 clear_mem_error(reason
);
756 static notrace __kprobes
void
757 io_check_error(unsigned char reason
, struct pt_regs
*regs
)
761 printk(KERN_EMERG
"NMI: IOCK error (debug interrupt?)\n");
762 show_registers(regs
);
764 /* Re-enable the IOCK line, wait for a few seconds */
765 reason
= (reason
& 0xf) | 8;
776 static notrace __kprobes
void
777 unknown_nmi_error(unsigned char reason
, struct pt_regs
*regs
)
779 if (notify_die(DIE_NMIUNKNOWN
, "nmi", regs
, reason
, 2, SIGINT
) == NOTIFY_STOP
)
783 * Might actually be able to figure out what the guilty party
792 "Uhhuh. NMI received for unknown reason %02x on CPU %d.\n",
793 reason
, smp_processor_id());
795 printk(KERN_EMERG
"Do you have a strange power saving mode enabled?\n");
796 if (panic_on_unrecovered_nmi
)
797 panic("NMI: Not continuing");
799 printk(KERN_EMERG
"Dazed and confused, but trying to continue\n");
802 static DEFINE_SPINLOCK(nmi_print_lock
);
804 void notrace __kprobes
die_nmi(char *str
, struct pt_regs
*regs
, int do_panic
)
806 if (notify_die(DIE_NMIWATCHDOG
, str
, regs
, 0, 2, SIGINT
) == NOTIFY_STOP
)
809 spin_lock(&nmi_print_lock
);
811 * We are in trouble anyway, lets at least try
812 * to get a message out:
815 printk(KERN_EMERG
"%s", str
);
816 printk(" on CPU%d, ip %08lx, registers:\n",
817 smp_processor_id(), regs
->ip
);
818 show_registers(regs
);
820 panic("Non maskable interrupt");
822 spin_unlock(&nmi_print_lock
);
826 * If we are in kernel we are probably nested up pretty bad
827 * and might aswell get out now while we still can:
829 if (!user_mode_vm(regs
)) {
830 current
->thread
.trap_no
= 2;
837 static notrace __kprobes
void default_do_nmi(struct pt_regs
*regs
)
839 unsigned char reason
= 0;
842 cpu
= smp_processor_id();
844 /* Only the BSP gets external NMIs from the system. */
846 reason
= get_nmi_reason();
848 if (!(reason
& 0xc0)) {
849 if (notify_die(DIE_NMI_IPI
, "nmi_ipi", regs
, reason
, 2, SIGINT
)
852 #ifdef CONFIG_X86_LOCAL_APIC
854 * Ok, so this is none of the documented NMI sources,
855 * so it must be the NMI watchdog.
857 if (nmi_watchdog_tick(regs
, reason
))
859 if (!do_nmi_callback(regs
, cpu
))
860 unknown_nmi_error(reason
, regs
);
862 unknown_nmi_error(reason
, regs
);
867 if (notify_die(DIE_NMI
, "nmi", regs
, reason
, 2, SIGINT
) == NOTIFY_STOP
)
870 /* AK: following checks seem to be broken on modern chipsets. FIXME */
872 mem_parity_error(reason
, regs
);
874 io_check_error(reason
, regs
);
876 * Reassert NMI in case it became active meanwhile
877 * as it's edge-triggered:
882 notrace __kprobes
void do_nmi(struct pt_regs
*regs
, long error_code
)
888 cpu
= smp_processor_id();
893 default_do_nmi(regs
);
904 void restart_nmi(void)
910 void __kprobes
do_int3(struct pt_regs
*regs
, long error_code
)
912 #ifdef CONFIG_KPROBES
913 trace_hardirqs_fixup();
915 if (notify_die(DIE_INT3
, "int3", regs
, error_code
, 3, SIGTRAP
)
919 * This is an interrupt gate, because kprobes wants interrupts
920 * disabled. Normal trap handlers don't.
922 conditional_sti(regs
);
924 if (notify_die(DIE_TRAP
, "int3", regs
, error_code
, 3, SIGTRAP
)
929 do_trap(3, SIGTRAP
, "int3", 1, regs
, error_code
, NULL
);
933 * Our handling of the processor debug registers is non-trivial.
934 * We do not clear them on entry and exit from the kernel. Therefore
935 * it is possible to get a watchpoint trap here from inside the kernel.
936 * However, the code in ./ptrace.c has ensured that the user can
937 * only set watchpoints on userspace addresses. Therefore the in-kernel
938 * watchpoint trap can only occur in code which is reading/writing
939 * from user space. Such code must not hold kernel locks (since it
940 * can equally take a page fault), therefore it is safe to call
941 * force_sig_info even though that claims and releases locks.
943 * Code in ./signal.c ensures that the debug control register
944 * is restored before we deliver any signal, and therefore that
945 * user code runs with the correct debug control register even though
948 * Being careful here means that we don't have to be as careful in a
949 * lot of more complicated places (task switching can be a bit lazy
950 * about restoring all the debug state, and ptrace doesn't have to
951 * find every occurrence of the TF bit that could be saved away even
954 void __kprobes
do_debug(struct pt_regs
*regs
, long error_code
)
956 struct task_struct
*tsk
= current
;
957 unsigned int condition
;
960 trace_hardirqs_fixup();
962 get_debugreg(condition
, 6);
965 * The processor cleared BTF, so don't mark that we need it set.
967 clear_tsk_thread_flag(tsk
, TIF_DEBUGCTLMSR
);
968 tsk
->thread
.debugctlmsr
= 0;
970 if (notify_die(DIE_DEBUG
, "debug", regs
, condition
, error_code
,
971 SIGTRAP
) == NOTIFY_STOP
)
973 /* It's safe to allow irq's after DR6 has been saved */
974 if (regs
->flags
& X86_EFLAGS_IF
)
977 /* Mask out spurious debug traps due to lazy DR7 setting */
978 if (condition
& (DR_TRAP0
|DR_TRAP1
|DR_TRAP2
|DR_TRAP3
)) {
979 if (!tsk
->thread
.debugreg7
)
983 if (regs
->flags
& X86_VM_MASK
)
986 /* Save debug status register where ptrace can see it */
987 tsk
->thread
.debugreg6
= condition
;
990 * Single-stepping through TF: make sure we ignore any events in
991 * kernel space (but re-enable TF when returning to user mode).
993 if (condition
& DR_STEP
) {
995 * We already checked v86 mode above, so we can
996 * check for kernel mode by just checking the CPL
999 if (!user_mode(regs
))
1000 goto clear_TF_reenable
;
1003 si_code
= get_si_code((unsigned long)condition
);
1004 /* Ok, finally something we can handle */
1005 send_sigtrap(tsk
, regs
, error_code
, si_code
);
1008 * Disable additional traps. They'll be re-enabled when
1009 * the signal is delivered.
1016 handle_vm86_trap((struct kernel_vm86_regs
*) regs
, error_code
, 1);
1020 set_tsk_thread_flag(tsk
, TIF_SINGLESTEP
);
1021 regs
->flags
&= ~X86_EFLAGS_TF
;
1026 * Note that we play around with the 'TS' bit in an attempt to get
1027 * the correct behaviour even in the presence of the asynchronous
1030 void math_error(void __user
*ip
)
1032 struct task_struct
*task
;
1034 unsigned short cwd
, swd
;
1037 * Save the info for the exception handler and clear the error.
1040 save_init_fpu(task
);
1041 task
->thread
.trap_no
= 16;
1042 task
->thread
.error_code
= 0;
1043 info
.si_signo
= SIGFPE
;
1045 info
.si_code
= __SI_FAULT
;
1048 * (~cwd & swd) will mask out exceptions that are not set to unmasked
1049 * status. 0x3f is the exception bits in these regs, 0x200 is the
1050 * C1 reg you need in case of a stack fault, 0x040 is the stack
1051 * fault bit. We should only be taking one exception at a time,
1052 * so if this combination doesn't produce any single exception,
1053 * then we have a bad program that isn't synchronizing its FPU usage
1054 * and it will suffer the consequences since we won't be able to
1055 * fully reproduce the context of the exception
1057 cwd
= get_fpu_cwd(task
);
1058 swd
= get_fpu_swd(task
);
1059 switch (swd
& ~cwd
& 0x3f) {
1060 case 0x000: /* No unmasked exception */
1062 default: /* Multiple exceptions */
1064 case 0x001: /* Invalid Op */
1066 * swd & 0x240 == 0x040: Stack Underflow
1067 * swd & 0x240 == 0x240: Stack Overflow
1068 * User must clear the SF bit (0x40) if set
1070 info
.si_code
= FPE_FLTINV
;
1072 case 0x002: /* Denormalize */
1073 case 0x010: /* Underflow */
1074 info
.si_code
= FPE_FLTUND
;
1076 case 0x004: /* Zero Divide */
1077 info
.si_code
= FPE_FLTDIV
;
1079 case 0x008: /* Overflow */
1080 info
.si_code
= FPE_FLTOVF
;
1082 case 0x020: /* Precision */
1083 info
.si_code
= FPE_FLTRES
;
1086 force_sig_info(SIGFPE
, &info
, task
);
1089 void do_coprocessor_error(struct pt_regs
*regs
, long error_code
)
1092 math_error((void __user
*)regs
->ip
);
1095 static void simd_math_error(void __user
*ip
)
1097 struct task_struct
*task
;
1099 unsigned short mxcsr
;
1102 * Save the info for the exception handler and clear the error.
1105 save_init_fpu(task
);
1106 task
->thread
.trap_no
= 19;
1107 task
->thread
.error_code
= 0;
1108 info
.si_signo
= SIGFPE
;
1110 info
.si_code
= __SI_FAULT
;
1113 * The SIMD FPU exceptions are handled a little differently, as there
1114 * is only a single status/control register. Thus, to determine which
1115 * unmasked exception was caught we must mask the exception mask bits
1116 * at 0x1f80, and then use these to mask the exception bits at 0x3f.
1118 mxcsr
= get_fpu_mxcsr(task
);
1119 switch (~((mxcsr
& 0x1f80) >> 7) & (mxcsr
& 0x3f)) {
1123 case 0x001: /* Invalid Op */
1124 info
.si_code
= FPE_FLTINV
;
1126 case 0x002: /* Denormalize */
1127 case 0x010: /* Underflow */
1128 info
.si_code
= FPE_FLTUND
;
1130 case 0x004: /* Zero Divide */
1131 info
.si_code
= FPE_FLTDIV
;
1133 case 0x008: /* Overflow */
1134 info
.si_code
= FPE_FLTOVF
;
1136 case 0x020: /* Precision */
1137 info
.si_code
= FPE_FLTRES
;
1140 force_sig_info(SIGFPE
, &info
, task
);
1143 void do_simd_coprocessor_error(struct pt_regs
*regs
, long error_code
)
1146 /* Handle SIMD FPU exceptions on PIII+ processors. */
1148 simd_math_error((void __user
*)regs
->ip
);
1152 * Handle strange cache flush from user space exception
1153 * in all other cases. This is undocumented behaviour.
1155 if (regs
->flags
& X86_VM_MASK
) {
1156 handle_vm86_fault((struct kernel_vm86_regs
*)regs
, error_code
);
1159 current
->thread
.trap_no
= 19;
1160 current
->thread
.error_code
= error_code
;
1161 die_if_kernel("cache flush denied", regs
, error_code
);
1162 force_sig(SIGSEGV
, current
);
1165 void do_spurious_interrupt_bug(struct pt_regs
*regs
, long error_code
)
1167 conditional_sti(regs
);
1169 /* No need to warn about this any longer. */
1170 printk(KERN_INFO
"Ignoring P6 Local APIC Spurious Interrupt Bug...\n");
1174 unsigned long patch_espfix_desc(unsigned long uesp
, unsigned long kesp
)
1176 struct desc_struct
*gdt
= get_cpu_gdt_table(smp_processor_id());
1177 unsigned long base
= (kesp
- uesp
) & -THREAD_SIZE
;
1178 unsigned long new_kesp
= kesp
- base
;
1179 unsigned long lim_pages
= (new_kesp
| (THREAD_SIZE
- 1)) >> PAGE_SHIFT
;
1180 __u64 desc
= *(__u64
*)&gdt
[GDT_ENTRY_ESPFIX_SS
];
1182 /* Set up base for espfix segment */
1183 desc
&= 0x00f0ff0000000000ULL
;
1184 desc
|= ((((__u64
)base
) << 16) & 0x000000ffffff0000ULL
) |
1185 ((((__u64
)base
) << 32) & 0xff00000000000000ULL
) |
1186 ((((__u64
)lim_pages
) << 32) & 0x000f000000000000ULL
) |
1187 (lim_pages
& 0xffff);
1188 *(__u64
*)&gdt
[GDT_ENTRY_ESPFIX_SS
] = desc
;
1194 * 'math_state_restore()' saves the current math information in the
1195 * old math state array, and gets the new ones from the current task
1197 * Careful.. There are problems with IBM-designed IRQ13 behaviour.
1198 * Don't touch unless you *really* know how it works.
1200 * Must be called with kernel preemption disabled (in this case,
1201 * local interrupts are disabled at the call-site in entry.S).
1203 asmlinkage
void math_state_restore(void)
1205 struct thread_info
*thread
= current_thread_info();
1206 struct task_struct
*tsk
= thread
->task
;
1208 if (!tsk_used_math(tsk
)) {
1211 * does a slab alloc which can sleep
1213 if (init_fpu(tsk
)) {
1215 * ran out of memory!
1217 do_group_exit(SIGKILL
);
1220 local_irq_disable();
1223 clts(); /* Allow maths ops (or we recurse) */
1225 thread
->status
|= TS_USEDFPU
; /* So we fnsave on switch_to() */
1228 EXPORT_SYMBOL_GPL(math_state_restore
);
1230 #ifndef CONFIG_MATH_EMULATION
1232 asmlinkage
void math_emulate(long arg
)
1235 "math-emulation not enabled and no coprocessor found.\n");
1236 printk(KERN_EMERG
"killing %s.\n", current
->comm
);
1237 force_sig(SIGFPE
, current
);
1241 #endif /* CONFIG_MATH_EMULATION */
1243 void __kprobes
do_device_not_available(struct pt_regs
*regs
, long error
)
1245 if (read_cr0() & X86_CR0_EM
) {
1246 conditional_sti(regs
);
1249 math_state_restore(); /* interrupts still off */
1250 conditional_sti(regs
);
1254 void __init
trap_init(void)
1259 void __iomem
*p
= early_ioremap(0x0FFFD9, 4);
1261 if (readl(p
) == 'E' + ('I'<<8) + ('S'<<16) + ('A'<<24))
1263 early_iounmap(p
, 4);
1266 set_intr_gate(0, ÷_error
);
1267 set_intr_gate(1, &debug
);
1268 set_intr_gate(2, &nmi
);
1269 set_system_intr_gate(3, &int3
); /* int3 can be called from all */
1270 set_system_intr_gate(4, &overflow
); /* int4 can be called from all */
1271 set_intr_gate(5, &bounds
);
1272 set_intr_gate(6, &invalid_op
);
1273 set_intr_gate(7, &device_not_available
);
1274 set_task_gate(8, GDT_ENTRY_DOUBLEFAULT_TSS
);
1275 set_intr_gate(9, &coprocessor_segment_overrun
);
1276 set_intr_gate(10, &invalid_TSS
);
1277 set_intr_gate(11, &segment_not_present
);
1278 set_intr_gate(12, &stack_segment
);
1279 set_intr_gate(13, &general_protection
);
1280 set_intr_gate(14, &page_fault
);
1281 set_intr_gate(15, &spurious_interrupt_bug
);
1282 set_trap_gate(16, &coprocessor_error
);
1283 set_trap_gate(17, &alignment_check
);
1284 #ifdef CONFIG_X86_MCE
1285 set_trap_gate(18, &machine_check
);
1287 set_trap_gate(19, &simd_coprocessor_error
);
1290 printk(KERN_INFO
"Enabling fast FPU save and restore... ");
1291 set_in_cr4(X86_CR4_OSFXSR
);
1296 "Enabling unmasked SIMD FPU exception support... ");
1297 set_in_cr4(X86_CR4_OSXMMEXCPT
);
1301 set_system_gate(SYSCALL_VECTOR
, &system_call
);
1303 /* Reserve all the builtin and the syscall vector: */
1304 for (i
= 0; i
< FIRST_EXTERNAL_VECTOR
; i
++)
1305 set_bit(i
, used_vectors
);
1307 set_bit(SYSCALL_VECTOR
, used_vectors
);
1310 * Should be a barrier for any external CPU state:
1317 static int __init
kstack_setup(char *s
)
1319 kstack_depth_to_print
= simple_strtoul(s
, NULL
, 0);
1323 __setup("kstack=", kstack_setup
);
1325 static int __init
code_bytes_setup(char *s
)
1327 code_bytes
= simple_strtoul(s
, NULL
, 0);
1328 if (code_bytes
> 8192)
1333 __setup("code_bytes=", code_bytes_setup
);