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/arch_hooks.h>
50 #include <asm/stacktrace.h>
51 #include <asm/processor.h>
52 #include <asm/debugreg.h>
53 #include <asm/atomic.h>
54 #include <asm/system.h>
55 #include <asm/unwind.h>
62 #include "mach_traps.h"
64 DECLARE_BITMAP(used_vectors
, NR_VECTORS
);
65 EXPORT_SYMBOL_GPL(used_vectors
);
67 asmlinkage
int system_call(void);
69 /* Do we ignore FPU interrupts ? */
73 * The IDT has to be page-aligned to simplify the Pentium
74 * F0 0F bug workaround.. We have a special link segment
77 gate_desc idt_table
[256]
78 __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 panic_on_unrecovered_nmi
;
101 int kstack_depth_to_print
= 24;
102 static unsigned int code_bytes
= 64;
103 static int ignore_nmis
;
104 static int die_counter
;
106 void printk_address(unsigned long address
, int reliable
)
108 #ifdef CONFIG_KALLSYMS
109 char namebuf
[KSYM_NAME_LEN
];
110 unsigned long offset
= 0;
111 unsigned long symsize
;
117 symname
= kallsyms_lookup(address
, &symsize
, &offset
,
120 printk(" [<%08lx>]\n", address
);
124 strcpy(reliab
, "? ");
127 modname
= delim
= "";
128 printk(" [<%08lx>] %s%s%s%s%s+0x%lx/0x%lx\n",
129 address
, reliab
, delim
, modname
, delim
, symname
, offset
, symsize
);
131 printk(" [<%08lx>]\n", address
);
135 static inline int valid_stack_ptr(struct thread_info
*tinfo
,
136 void *p
, unsigned int size
)
138 return p
> (void *)tinfo
&&
139 p
<= (void *)tinfo
+ THREAD_SIZE
- size
;
142 /* The form of the top of the frame on the stack */
144 struct stack_frame
*next_frame
;
145 unsigned long return_address
;
148 static inline unsigned long
149 print_context_stack(struct thread_info
*tinfo
,
150 unsigned long *stack
, unsigned long bp
,
151 const struct stacktrace_ops
*ops
, void *data
)
153 struct stack_frame
*frame
= (struct stack_frame
*)bp
;
155 while (valid_stack_ptr(tinfo
, stack
, sizeof(*stack
))) {
159 if (__kernel_text_address(addr
)) {
160 if ((unsigned long) stack
== bp
+ 4) {
161 ops
->address(data
, addr
, 1);
162 frame
= frame
->next_frame
;
163 bp
= (unsigned long) frame
;
165 ops
->address(data
, addr
, bp
== 0);
173 void dump_trace(struct task_struct
*task
, struct pt_regs
*regs
,
174 unsigned long *stack
, unsigned long bp
,
175 const struct stacktrace_ops
*ops
, void *data
)
184 stack
= (unsigned long *)task
->thread
.sp
;
187 #ifdef CONFIG_FRAME_POINTER
189 if (task
== current
) {
190 /* Grab bp right from our regs */
191 asm("movl %%ebp, %0" : "=r" (bp
) :);
193 /* bp is the last reg pushed by switch_to */
194 bp
= *(unsigned long *) task
->thread
.sp
;
200 struct thread_info
*context
;
202 context
= (struct thread_info
*)
203 ((unsigned long)stack
& (~(THREAD_SIZE
- 1)));
204 bp
= print_context_stack(context
, stack
, bp
, ops
, data
);
206 * Should be after the line below, but somewhere
207 * in early boot context comes out corrupted and we
208 * can't reference it:
210 if (ops
->stack(data
, "IRQ") < 0)
212 stack
= (unsigned long *)context
->previous_esp
;
215 touch_nmi_watchdog();
218 EXPORT_SYMBOL(dump_trace
);
221 print_trace_warning_symbol(void *data
, char *msg
, unsigned long symbol
)
224 print_symbol(msg
, symbol
);
228 static void print_trace_warning(void *data
, char *msg
)
230 printk("%s%s\n", (char *)data
, msg
);
233 static int print_trace_stack(void *data
, char *name
)
239 * Print one address/symbol entries per line.
241 static void print_trace_address(void *data
, unsigned long addr
, int reliable
)
243 printk("%s [<%08lx>] ", (char *)data
, addr
);
246 print_symbol("%s\n", addr
);
247 touch_nmi_watchdog();
250 static const struct stacktrace_ops print_trace_ops
= {
251 .warning
= print_trace_warning
,
252 .warning_symbol
= print_trace_warning_symbol
,
253 .stack
= print_trace_stack
,
254 .address
= print_trace_address
,
258 show_trace_log_lvl(struct task_struct
*task
, struct pt_regs
*regs
,
259 unsigned long *stack
, unsigned long bp
, char *log_lvl
)
261 dump_trace(task
, regs
, stack
, bp
, &print_trace_ops
, log_lvl
);
262 printk("%s =======================\n", log_lvl
);
265 void show_trace(struct task_struct
*task
, struct pt_regs
*regs
,
266 unsigned long *stack
, unsigned long bp
)
268 show_trace_log_lvl(task
, regs
, stack
, bp
, "");
272 show_stack_log_lvl(struct task_struct
*task
, struct pt_regs
*regs
,
273 unsigned long *sp
, unsigned long bp
, char *log_lvl
)
275 unsigned long *stack
;
280 sp
= (unsigned long *)task
->thread
.sp
;
282 sp
= (unsigned long *)&sp
;
286 for (i
= 0; i
< kstack_depth_to_print
; i
++) {
287 if (kstack_end(stack
))
289 if (i
&& ((i
% 8) == 0))
290 printk("\n%s ", log_lvl
);
291 printk("%08lx ", *stack
++);
293 printk("\n%sCall Trace:\n", log_lvl
);
295 show_trace_log_lvl(task
, regs
, sp
, bp
, log_lvl
);
298 void show_stack(struct task_struct
*task
, unsigned long *sp
)
301 show_stack_log_lvl(task
, NULL
, sp
, 0, "");
305 * The architecture-independent dump_stack generator
307 void dump_stack(void)
309 unsigned long bp
= 0;
312 #ifdef CONFIG_FRAME_POINTER
314 asm("movl %%ebp, %0" : "=r" (bp
):);
317 printk("Pid: %d, comm: %.20s %s %s %.*s\n",
318 current
->pid
, current
->comm
, print_tainted(),
319 init_utsname()->release
,
320 (int)strcspn(init_utsname()->version
, " "),
321 init_utsname()->version
);
323 show_trace(current
, NULL
, &stack
, bp
);
326 EXPORT_SYMBOL(dump_stack
);
328 void show_registers(struct pt_regs
*regs
)
333 __show_registers(regs
, 0);
335 printk(KERN_EMERG
"Process %.*s (pid: %d, ti=%p task=%p task.ti=%p)",
336 TASK_COMM_LEN
, current
->comm
, task_pid_nr(current
),
337 current_thread_info(), current
, task_thread_info(current
));
339 * When in-kernel, we also print out the stack and code at the
340 * time of the fault..
342 if (!user_mode_vm(regs
)) {
343 unsigned int code_prologue
= code_bytes
* 43 / 64;
344 unsigned int code_len
= code_bytes
;
348 printk("\n" KERN_EMERG
"Stack: ");
349 show_stack_log_lvl(NULL
, regs
, ®s
->sp
, 0, KERN_EMERG
);
351 printk(KERN_EMERG
"Code: ");
353 ip
= (u8
*)regs
->ip
- code_prologue
;
354 if (ip
< (u8
*)PAGE_OFFSET
|| probe_kernel_address(ip
, c
)) {
355 /* try starting at EIP */
357 code_len
= code_len
- code_prologue
+ 1;
359 for (i
= 0; i
< code_len
; i
++, ip
++) {
360 if (ip
< (u8
*)PAGE_OFFSET
||
361 probe_kernel_address(ip
, c
)) {
362 printk(" Bad EIP value.");
365 if (ip
== (u8
*)regs
->ip
)
366 printk("<%02x> ", c
);
374 int is_valid_bugaddr(unsigned long ip
)
378 if (ip
< PAGE_OFFSET
)
380 if (probe_kernel_address((unsigned short *)ip
, ud2
))
383 return ud2
== 0x0b0f;
386 int __kprobes
__die(const char *str
, struct pt_regs
*regs
, long err
)
391 printk(KERN_EMERG
"%s: %04lx [#%d] ", str
, err
& 0xffff, ++die_counter
);
392 #ifdef CONFIG_PREEMPT
398 #ifdef CONFIG_DEBUG_PAGEALLOC
399 printk("DEBUG_PAGEALLOC");
402 if (notify_die(DIE_OOPS
, str
, regs
, err
,
403 current
->thread
.trap_no
, SIGSEGV
) == NOTIFY_STOP
)
406 show_registers(regs
);
407 /* Executive summary in case the oops scrolled away */
408 sp
= (unsigned long) (®s
->sp
);
410 if (user_mode(regs
)) {
412 ss
= regs
->ss
& 0xffff;
414 printk(KERN_EMERG
"EIP: [<%08lx>] ", regs
->ip
);
415 print_symbol("%s", regs
->ip
);
416 printk(" SS:ESP %04x:%08lx\n", ss
, sp
);
421 * This is gone through when something in the kernel has done something bad
422 * and is about to be terminated:
424 void die(const char *str
, struct pt_regs
*regs
, long err
)
429 int lock_owner_depth
;
431 .lock
= __RAW_SPIN_LOCK_UNLOCKED
,
433 .lock_owner_depth
= 0
439 if (die
.lock_owner
!= raw_smp_processor_id()) {
441 raw_local_irq_save(flags
);
442 __raw_spin_lock(&die
.lock
);
443 die
.lock_owner
= smp_processor_id();
444 die
.lock_owner_depth
= 0;
447 raw_local_irq_save(flags
);
450 if (++die
.lock_owner_depth
< 3) {
451 report_bug(regs
->ip
, regs
);
453 if (__die(str
, regs
, err
))
456 printk(KERN_EMERG
"Recursive die() failure, output suppressed\n");
461 add_taint(TAINT_DIE
);
462 __raw_spin_unlock(&die
.lock
);
463 raw_local_irq_restore(flags
);
468 if (kexec_should_crash(current
))
472 panic("Fatal exception in interrupt");
475 panic("Fatal exception");
482 die_if_kernel(const char *str
, struct pt_regs
*regs
, long err
)
484 if (!user_mode_vm(regs
))
488 static void __kprobes
489 do_trap(int trapnr
, int signr
, char *str
, int vm86
, struct pt_regs
*regs
,
490 long error_code
, siginfo_t
*info
)
492 struct task_struct
*tsk
= current
;
494 if (regs
->flags
& X86_VM_MASK
) {
500 if (!user_mode(regs
))
505 * We want error_code and trap_no set for userspace faults and
506 * kernelspace faults which result in die(), but not
507 * kernelspace faults which are fixed up. die() gives the
508 * process no chance to handle the signal and notice the
509 * kernel fault information, so that won't result in polluting
510 * the information about previously queued, but not yet
511 * delivered, faults. See also do_general_protection below.
513 tsk
->thread
.error_code
= error_code
;
514 tsk
->thread
.trap_no
= trapnr
;
517 force_sig_info(signr
, info
, tsk
);
519 force_sig(signr
, tsk
);
523 if (!fixup_exception(regs
)) {
524 tsk
->thread
.error_code
= error_code
;
525 tsk
->thread
.trap_no
= trapnr
;
526 die(str
, regs
, error_code
);
531 if (handle_vm86_trap((struct kernel_vm86_regs
*) regs
,
537 #define DO_ERROR(trapnr, signr, str, name) \
538 void do_##name(struct pt_regs *regs, long error_code) \
540 trace_hardirqs_fixup(); \
541 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
544 do_trap(trapnr, signr, str, 0, regs, error_code, NULL); \
547 #define DO_ERROR_INFO(trapnr, signr, str, name, sicode, siaddr, irq) \
548 void do_##name(struct pt_regs *regs, long error_code) \
552 local_irq_enable(); \
553 info.si_signo = signr; \
555 info.si_code = sicode; \
556 info.si_addr = (void __user *)siaddr; \
557 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
560 do_trap(trapnr, signr, str, 0, regs, error_code, &info); \
563 #define DO_VM86_ERROR(trapnr, signr, str, name) \
564 void do_##name(struct pt_regs *regs, long error_code) \
566 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
569 do_trap(trapnr, signr, str, 1, regs, error_code, NULL); \
572 #define DO_VM86_ERROR_INFO(trapnr, signr, str, name, sicode, siaddr) \
573 void do_##name(struct pt_regs *regs, long error_code) \
576 info.si_signo = signr; \
578 info.si_code = sicode; \
579 info.si_addr = (void __user *)siaddr; \
580 trace_hardirqs_fixup(); \
581 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
584 do_trap(trapnr, signr, str, 1, regs, error_code, &info); \
587 DO_VM86_ERROR_INFO(0, SIGFPE
, "divide error", divide_error
, FPE_INTDIV
, regs
->ip
)
588 #ifndef CONFIG_KPROBES
589 DO_VM86_ERROR(3, SIGTRAP
, "int3", int3
)
591 DO_VM86_ERROR(4, SIGSEGV
, "overflow", overflow
)
592 DO_VM86_ERROR(5, SIGSEGV
, "bounds", bounds
)
593 DO_ERROR_INFO(6, SIGILL
, "invalid opcode", invalid_op
, ILL_ILLOPN
, regs
->ip
, 0)
594 DO_ERROR(9, SIGFPE
, "coprocessor segment overrun", coprocessor_segment_overrun
)
595 DO_ERROR(10, SIGSEGV
, "invalid TSS", invalid_TSS
)
596 DO_ERROR(11, SIGBUS
, "segment not present", segment_not_present
)
597 DO_ERROR(12, SIGBUS
, "stack segment", stack_segment
)
598 DO_ERROR_INFO(17, SIGBUS
, "alignment check", alignment_check
, BUS_ADRALN
, 0, 0)
599 DO_ERROR_INFO(32, SIGILL
, "iret exception", iret_error
, ILL_BADSTK
, 0, 1)
602 do_general_protection(struct pt_regs
*regs
, long error_code
)
604 struct task_struct
*tsk
;
605 struct thread_struct
*thread
;
606 struct tss_struct
*tss
;
610 tss
= &per_cpu(init_tss
, cpu
);
611 thread
= ¤t
->thread
;
614 * Perform the lazy TSS's I/O bitmap copy. If the TSS has an
615 * invalid offset set (the LAZY one) and the faulting thread has
616 * a valid I/O bitmap pointer, we copy the I/O bitmap in the TSS
617 * and we set the offset field correctly. Then we let the CPU to
618 * restart the faulting instruction.
620 if (tss
->x86_tss
.io_bitmap_base
== INVALID_IO_BITMAP_OFFSET_LAZY
&&
621 thread
->io_bitmap_ptr
) {
622 memcpy(tss
->io_bitmap
, thread
->io_bitmap_ptr
,
623 thread
->io_bitmap_max
);
625 * If the previously set map was extending to higher ports
626 * than the current one, pad extra space with 0xff (no access).
628 if (thread
->io_bitmap_max
< tss
->io_bitmap_max
) {
629 memset((char *) tss
->io_bitmap
+
630 thread
->io_bitmap_max
, 0xff,
631 tss
->io_bitmap_max
- thread
->io_bitmap_max
);
633 tss
->io_bitmap_max
= thread
->io_bitmap_max
;
634 tss
->x86_tss
.io_bitmap_base
= IO_BITMAP_OFFSET
;
635 tss
->io_bitmap_owner
= thread
;
642 if (regs
->flags
& X86_VM_MASK
)
646 if (!user_mode(regs
))
649 tsk
->thread
.error_code
= error_code
;
650 tsk
->thread
.trap_no
= 13;
652 if (show_unhandled_signals
&& unhandled_signal(tsk
, SIGSEGV
) &&
653 printk_ratelimit()) {
655 "%s[%d] general protection ip:%lx sp:%lx error:%lx",
656 tsk
->comm
, task_pid_nr(tsk
),
657 regs
->ip
, regs
->sp
, error_code
);
658 print_vma_addr(" in ", regs
->ip
);
662 force_sig(SIGSEGV
, tsk
);
667 handle_vm86_fault((struct kernel_vm86_regs
*) regs
, error_code
);
671 if (fixup_exception(regs
))
674 tsk
->thread
.error_code
= error_code
;
675 tsk
->thread
.trap_no
= 13;
676 if (notify_die(DIE_GPF
, "general protection fault", regs
,
677 error_code
, 13, SIGSEGV
) == NOTIFY_STOP
)
679 die("general protection fault", regs
, error_code
);
682 static notrace __kprobes
void
683 mem_parity_error(unsigned char reason
, struct pt_regs
*regs
)
686 "Uhhuh. NMI received for unknown reason %02x on CPU %d.\n",
687 reason
, smp_processor_id());
690 "You have some hardware problem, likely on the PCI bus.\n");
692 #if defined(CONFIG_EDAC)
693 if (edac_handler_set()) {
694 edac_atomic_assert_error();
699 if (panic_on_unrecovered_nmi
)
700 panic("NMI: Not continuing");
702 printk(KERN_EMERG
"Dazed and confused, but trying to continue\n");
704 /* Clear and disable the memory parity error line. */
705 clear_mem_error(reason
);
708 static notrace __kprobes
void
709 io_check_error(unsigned char reason
, struct pt_regs
*regs
)
713 printk(KERN_EMERG
"NMI: IOCK error (debug interrupt?)\n");
714 show_registers(regs
);
716 /* Re-enable the IOCK line, wait for a few seconds */
717 reason
= (reason
& 0xf) | 8;
728 static notrace __kprobes
void
729 unknown_nmi_error(unsigned char reason
, struct pt_regs
*regs
)
731 if (notify_die(DIE_NMIUNKNOWN
, "nmi", regs
, reason
, 2, SIGINT
) == NOTIFY_STOP
)
735 * Might actually be able to figure out what the guilty party
744 "Uhhuh. NMI received for unknown reason %02x on CPU %d.\n",
745 reason
, smp_processor_id());
747 printk(KERN_EMERG
"Do you have a strange power saving mode enabled?\n");
748 if (panic_on_unrecovered_nmi
)
749 panic("NMI: Not continuing");
751 printk(KERN_EMERG
"Dazed and confused, but trying to continue\n");
754 static DEFINE_SPINLOCK(nmi_print_lock
);
756 void notrace __kprobes
die_nmi(char *str
, struct pt_regs
*regs
, int do_panic
)
758 if (notify_die(DIE_NMIWATCHDOG
, str
, regs
, 0, 2, SIGINT
) == NOTIFY_STOP
)
761 spin_lock(&nmi_print_lock
);
763 * We are in trouble anyway, lets at least try
764 * to get a message out:
767 printk(KERN_EMERG
"%s", str
);
768 printk(" on CPU%d, ip %08lx, registers:\n",
769 smp_processor_id(), regs
->ip
);
770 show_registers(regs
);
772 panic("Non maskable interrupt");
774 spin_unlock(&nmi_print_lock
);
778 * If we are in kernel we are probably nested up pretty bad
779 * and might aswell get out now while we still can:
781 if (!user_mode_vm(regs
)) {
782 current
->thread
.trap_no
= 2;
789 static notrace __kprobes
void default_do_nmi(struct pt_regs
*regs
)
791 unsigned char reason
= 0;
794 cpu
= smp_processor_id();
796 /* Only the BSP gets external NMIs from the system. */
798 reason
= get_nmi_reason();
800 if (!(reason
& 0xc0)) {
801 if (notify_die(DIE_NMI_IPI
, "nmi_ipi", regs
, reason
, 2, SIGINT
)
804 #ifdef CONFIG_X86_LOCAL_APIC
806 * Ok, so this is none of the documented NMI sources,
807 * so it must be the NMI watchdog.
809 if (nmi_watchdog_tick(regs
, reason
))
811 if (!do_nmi_callback(regs
, cpu
))
812 unknown_nmi_error(reason
, regs
);
814 unknown_nmi_error(reason
, regs
);
819 if (notify_die(DIE_NMI
, "nmi", regs
, reason
, 2, SIGINT
) == NOTIFY_STOP
)
822 /* AK: following checks seem to be broken on modern chipsets. FIXME */
824 mem_parity_error(reason
, regs
);
826 io_check_error(reason
, regs
);
828 * Reassert NMI in case it became active meanwhile
829 * as it's edge-triggered:
834 notrace __kprobes
void do_nmi(struct pt_regs
*regs
, long error_code
)
840 cpu
= smp_processor_id();
845 default_do_nmi(regs
);
856 void restart_nmi(void)
862 #ifdef CONFIG_KPROBES
863 void __kprobes
do_int3(struct pt_regs
*regs
, long error_code
)
865 trace_hardirqs_fixup();
867 if (notify_die(DIE_INT3
, "int3", regs
, error_code
, 3, SIGTRAP
)
871 * This is an interrupt gate, because kprobes wants interrupts
872 * disabled. Normal trap handlers don't.
874 restore_interrupts(regs
);
876 do_trap(3, SIGTRAP
, "int3", 1, regs
, error_code
, NULL
);
881 * Our handling of the processor debug registers is non-trivial.
882 * We do not clear them on entry and exit from the kernel. Therefore
883 * it is possible to get a watchpoint trap here from inside the kernel.
884 * However, the code in ./ptrace.c has ensured that the user can
885 * only set watchpoints on userspace addresses. Therefore the in-kernel
886 * watchpoint trap can only occur in code which is reading/writing
887 * from user space. Such code must not hold kernel locks (since it
888 * can equally take a page fault), therefore it is safe to call
889 * force_sig_info even though that claims and releases locks.
891 * Code in ./signal.c ensures that the debug control register
892 * is restored before we deliver any signal, and therefore that
893 * user code runs with the correct debug control register even though
896 * Being careful here means that we don't have to be as careful in a
897 * lot of more complicated places (task switching can be a bit lazy
898 * about restoring all the debug state, and ptrace doesn't have to
899 * find every occurrence of the TF bit that could be saved away even
902 void __kprobes
do_debug(struct pt_regs
*regs
, long error_code
)
904 struct task_struct
*tsk
= current
;
905 unsigned int condition
;
907 trace_hardirqs_fixup();
909 get_debugreg(condition
, 6);
912 * The processor cleared BTF, so don't mark that we need it set.
914 clear_tsk_thread_flag(tsk
, TIF_DEBUGCTLMSR
);
915 tsk
->thread
.debugctlmsr
= 0;
917 if (notify_die(DIE_DEBUG
, "debug", regs
, condition
, error_code
,
918 SIGTRAP
) == NOTIFY_STOP
)
920 /* It's safe to allow irq's after DR6 has been saved */
921 if (regs
->flags
& X86_EFLAGS_IF
)
924 /* Mask out spurious debug traps due to lazy DR7 setting */
925 if (condition
& (DR_TRAP0
|DR_TRAP1
|DR_TRAP2
|DR_TRAP3
)) {
926 if (!tsk
->thread
.debugreg7
)
930 if (regs
->flags
& X86_VM_MASK
)
933 /* Save debug status register where ptrace can see it */
934 tsk
->thread
.debugreg6
= condition
;
937 * Single-stepping through TF: make sure we ignore any events in
938 * kernel space (but re-enable TF when returning to user mode).
940 if (condition
& DR_STEP
) {
942 * We already checked v86 mode above, so we can
943 * check for kernel mode by just checking the CPL
946 if (!user_mode(regs
))
947 goto clear_TF_reenable
;
950 /* Ok, finally something we can handle */
951 send_sigtrap(tsk
, regs
, error_code
);
954 * Disable additional traps. They'll be re-enabled when
955 * the signal is delivered.
962 handle_vm86_trap((struct kernel_vm86_regs
*) regs
, error_code
, 1);
966 set_tsk_thread_flag(tsk
, TIF_SINGLESTEP
);
967 regs
->flags
&= ~X86_EFLAGS_TF
;
972 * Note that we play around with the 'TS' bit in an attempt to get
973 * the correct behaviour even in the presence of the asynchronous
976 void math_error(void __user
*ip
)
978 struct task_struct
*task
;
984 * Save the info for the exception handler and clear the error.
988 task
->thread
.trap_no
= 16;
989 task
->thread
.error_code
= 0;
990 info
.si_signo
= SIGFPE
;
992 info
.si_code
= __SI_FAULT
;
995 * (~cwd & swd) will mask out exceptions that are not set to unmasked
996 * status. 0x3f is the exception bits in these regs, 0x200 is the
997 * C1 reg you need in case of a stack fault, 0x040 is the stack
998 * fault bit. We should only be taking one exception at a time,
999 * so if this combination doesn't produce any single exception,
1000 * then we have a bad program that isn't synchronizing its FPU usage
1001 * and it will suffer the consequences since we won't be able to
1002 * fully reproduce the context of the exception
1004 cwd
= get_fpu_cwd(task
);
1005 swd
= get_fpu_swd(task
);
1006 switch (swd
& ~cwd
& 0x3f) {
1007 case 0x000: /* No unmasked exception */
1009 default: /* Multiple exceptions */
1011 case 0x001: /* Invalid Op */
1013 * swd & 0x240 == 0x040: Stack Underflow
1014 * swd & 0x240 == 0x240: Stack Overflow
1015 * User must clear the SF bit (0x40) if set
1017 info
.si_code
= FPE_FLTINV
;
1019 case 0x002: /* Denormalize */
1020 case 0x010: /* Underflow */
1021 info
.si_code
= FPE_FLTUND
;
1023 case 0x004: /* Zero Divide */
1024 info
.si_code
= FPE_FLTDIV
;
1026 case 0x008: /* Overflow */
1027 info
.si_code
= FPE_FLTOVF
;
1029 case 0x020: /* Precision */
1030 info
.si_code
= FPE_FLTRES
;
1033 force_sig_info(SIGFPE
, &info
, task
);
1036 void do_coprocessor_error(struct pt_regs
*regs
, long error_code
)
1039 math_error((void __user
*)regs
->ip
);
1042 static void simd_math_error(void __user
*ip
)
1044 struct task_struct
*task
;
1045 unsigned short mxcsr
;
1049 * Save the info for the exception handler and clear the error.
1052 save_init_fpu(task
);
1053 task
->thread
.trap_no
= 19;
1054 task
->thread
.error_code
= 0;
1055 info
.si_signo
= SIGFPE
;
1057 info
.si_code
= __SI_FAULT
;
1060 * The SIMD FPU exceptions are handled a little differently, as there
1061 * is only a single status/control register. Thus, to determine which
1062 * unmasked exception was caught we must mask the exception mask bits
1063 * at 0x1f80, and then use these to mask the exception bits at 0x3f.
1065 mxcsr
= get_fpu_mxcsr(task
);
1066 switch (~((mxcsr
& 0x1f80) >> 7) & (mxcsr
& 0x3f)) {
1070 case 0x001: /* Invalid Op */
1071 info
.si_code
= FPE_FLTINV
;
1073 case 0x002: /* Denormalize */
1074 case 0x010: /* Underflow */
1075 info
.si_code
= FPE_FLTUND
;
1077 case 0x004: /* Zero Divide */
1078 info
.si_code
= FPE_FLTDIV
;
1080 case 0x008: /* Overflow */
1081 info
.si_code
= FPE_FLTOVF
;
1083 case 0x020: /* Precision */
1084 info
.si_code
= FPE_FLTRES
;
1087 force_sig_info(SIGFPE
, &info
, task
);
1090 void do_simd_coprocessor_error(struct pt_regs
*regs
, long error_code
)
1093 /* Handle SIMD FPU exceptions on PIII+ processors. */
1095 simd_math_error((void __user
*)regs
->ip
);
1099 * Handle strange cache flush from user space exception
1100 * in all other cases. This is undocumented behaviour.
1102 if (regs
->flags
& X86_VM_MASK
) {
1103 handle_vm86_fault((struct kernel_vm86_regs
*)regs
, error_code
);
1106 current
->thread
.trap_no
= 19;
1107 current
->thread
.error_code
= error_code
;
1108 die_if_kernel("cache flush denied", regs
, error_code
);
1109 force_sig(SIGSEGV
, current
);
1112 void do_spurious_interrupt_bug(struct pt_regs
*regs
, long error_code
)
1115 /* No need to warn about this any longer. */
1116 printk(KERN_INFO
"Ignoring P6 Local APIC Spurious Interrupt Bug...\n");
1120 unsigned long patch_espfix_desc(unsigned long uesp
, unsigned long kesp
)
1122 struct desc_struct
*gdt
= get_cpu_gdt_table(smp_processor_id());
1123 unsigned long base
= (kesp
- uesp
) & -THREAD_SIZE
;
1124 unsigned long new_kesp
= kesp
- base
;
1125 unsigned long lim_pages
= (new_kesp
| (THREAD_SIZE
- 1)) >> PAGE_SHIFT
;
1126 __u64 desc
= *(__u64
*)&gdt
[GDT_ENTRY_ESPFIX_SS
];
1128 /* Set up base for espfix segment */
1129 desc
&= 0x00f0ff0000000000ULL
;
1130 desc
|= ((((__u64
)base
) << 16) & 0x000000ffffff0000ULL
) |
1131 ((((__u64
)base
) << 32) & 0xff00000000000000ULL
) |
1132 ((((__u64
)lim_pages
) << 32) & 0x000f000000000000ULL
) |
1133 (lim_pages
& 0xffff);
1134 *(__u64
*)&gdt
[GDT_ENTRY_ESPFIX_SS
] = desc
;
1140 * 'math_state_restore()' saves the current math information in the
1141 * old math state array, and gets the new ones from the current task
1143 * Careful.. There are problems with IBM-designed IRQ13 behaviour.
1144 * Don't touch unless you *really* know how it works.
1146 * Must be called with kernel preemption disabled (in this case,
1147 * local interrupts are disabled at the call-site in entry.S).
1149 asmlinkage
void math_state_restore(void)
1151 struct thread_info
*thread
= current_thread_info();
1152 struct task_struct
*tsk
= thread
->task
;
1154 if (!tsk_used_math(tsk
)) {
1157 * does a slab alloc which can sleep
1159 if (init_fpu(tsk
)) {
1161 * ran out of memory!
1163 do_group_exit(SIGKILL
);
1166 local_irq_disable();
1169 clts(); /* Allow maths ops (or we recurse) */
1171 thread
->status
|= TS_USEDFPU
; /* So we fnsave on switch_to() */
1174 EXPORT_SYMBOL_GPL(math_state_restore
);
1176 #ifndef CONFIG_MATH_EMULATION
1178 asmlinkage
void math_emulate(long arg
)
1181 "math-emulation not enabled and no coprocessor found.\n");
1182 printk(KERN_EMERG
"killing %s.\n", current
->comm
);
1183 force_sig(SIGFPE
, current
);
1187 #endif /* CONFIG_MATH_EMULATION */
1189 void __init
trap_init(void)
1194 void __iomem
*p
= early_ioremap(0x0FFFD9, 4);
1196 if (readl(p
) == 'E' + ('I'<<8) + ('S'<<16) + ('A'<<24))
1198 early_iounmap(p
, 4);
1201 set_trap_gate(0, ÷_error
);
1202 set_intr_gate(1, &debug
);
1203 set_intr_gate(2, &nmi
);
1204 set_system_intr_gate(3, &int3
); /* int3 can be called from all */
1205 set_system_gate(4, &overflow
); /* int4 can be called from all */
1206 set_trap_gate(5, &bounds
);
1207 set_trap_gate(6, &invalid_op
);
1208 set_trap_gate(7, &device_not_available
);
1209 set_task_gate(8, GDT_ENTRY_DOUBLEFAULT_TSS
);
1210 set_trap_gate(9, &coprocessor_segment_overrun
);
1211 set_trap_gate(10, &invalid_TSS
);
1212 set_trap_gate(11, &segment_not_present
);
1213 set_trap_gate(12, &stack_segment
);
1214 set_trap_gate(13, &general_protection
);
1215 set_intr_gate(14, &page_fault
);
1216 set_trap_gate(15, &spurious_interrupt_bug
);
1217 set_trap_gate(16, &coprocessor_error
);
1218 set_trap_gate(17, &alignment_check
);
1219 #ifdef CONFIG_X86_MCE
1220 set_trap_gate(18, &machine_check
);
1222 set_trap_gate(19, &simd_coprocessor_error
);
1225 printk(KERN_INFO
"Enabling fast FPU save and restore... ");
1226 set_in_cr4(X86_CR4_OSFXSR
);
1231 "Enabling unmasked SIMD FPU exception support... ");
1232 set_in_cr4(X86_CR4_OSXMMEXCPT
);
1236 set_system_gate(SYSCALL_VECTOR
, &system_call
);
1238 /* Reserve all the builtin and the syscall vector: */
1239 for (i
= 0; i
< FIRST_EXTERNAL_VECTOR
; i
++)
1240 set_bit(i
, used_vectors
);
1242 set_bit(SYSCALL_VECTOR
, used_vectors
);
1244 init_thread_xstate();
1246 * Should be a barrier for any external CPU state:
1253 static int __init
kstack_setup(char *s
)
1255 kstack_depth_to_print
= simple_strtoul(s
, NULL
, 0);
1259 __setup("kstack=", kstack_setup
);
1261 static int __init
code_bytes_setup(char *s
)
1263 code_bytes
= simple_strtoul(s
, NULL
, 0);
1264 if (code_bytes
> 8192)
1269 __setup("code_bytes=", code_bytes_setup
);