2 * linux/arch/x86-64/traps.c
4 * Copyright (C) 1991, 1992 Linus Torvalds
5 * Copyright (C) 2000, 2001, 2002 Andi Kleen, SuSE Labs
7 * Pentium III FXSR, SSE support
8 * Gareth Hughes <gareth@valinux.com>, May 2000
12 * 'Traps.c' handles hardware traps and faults after we have saved some
15 #include <linux/sched.h>
16 #include <linux/kernel.h>
17 #include <linux/string.h>
18 #include <linux/errno.h>
19 #include <linux/ptrace.h>
20 #include <linux/timer.h>
22 #include <linux/init.h>
23 #include <linux/delay.h>
24 #include <linux/spinlock.h>
25 #include <linux/interrupt.h>
26 #include <linux/kallsyms.h>
27 #include <linux/module.h>
28 #include <linux/moduleparam.h>
29 #include <linux/nmi.h>
30 #include <linux/kprobes.h>
31 #include <linux/kexec.h>
32 #include <linux/unwind.h>
33 #include <linux/uaccess.h>
34 #include <linux/bug.h>
35 #include <linux/kdebug.h>
37 #if defined(CONFIG_EDAC)
38 #include <linux/edac.h>
41 #include <asm/system.h>
43 #include <asm/atomic.h>
44 #include <asm/debugreg.h>
47 #include <asm/processor.h>
48 #include <asm/unwind.h>
50 #include <asm/pgalloc.h>
52 #include <asm/proto.h>
54 #include <asm/stacktrace.h>
56 asmlinkage
void divide_error(void);
57 asmlinkage
void debug(void);
58 asmlinkage
void nmi(void);
59 asmlinkage
void int3(void);
60 asmlinkage
void overflow(void);
61 asmlinkage
void bounds(void);
62 asmlinkage
void invalid_op(void);
63 asmlinkage
void device_not_available(void);
64 asmlinkage
void double_fault(void);
65 asmlinkage
void coprocessor_segment_overrun(void);
66 asmlinkage
void invalid_TSS(void);
67 asmlinkage
void segment_not_present(void);
68 asmlinkage
void stack_segment(void);
69 asmlinkage
void general_protection(void);
70 asmlinkage
void page_fault(void);
71 asmlinkage
void coprocessor_error(void);
72 asmlinkage
void simd_coprocessor_error(void);
73 asmlinkage
void reserved(void);
74 asmlinkage
void alignment_check(void);
75 asmlinkage
void machine_check(void);
76 asmlinkage
void spurious_interrupt_bug(void);
78 static inline void conditional_sti(struct pt_regs
*regs
)
80 if (regs
->eflags
& X86_EFLAGS_IF
)
84 static inline void preempt_conditional_sti(struct pt_regs
*regs
)
87 if (regs
->eflags
& X86_EFLAGS_IF
)
91 static inline void preempt_conditional_cli(struct pt_regs
*regs
)
93 if (regs
->eflags
& X86_EFLAGS_IF
)
95 /* Make sure to not schedule here because we could be running
96 on an exception stack. */
97 preempt_enable_no_resched();
100 int kstack_depth_to_print
= 12;
102 #ifdef CONFIG_KALLSYMS
103 void printk_address(unsigned long address
)
105 unsigned long offset
= 0, symsize
;
111 symname
= kallsyms_lookup(address
, &symsize
, &offset
,
114 printk(" [<%016lx>]\n", address
);
118 modname
= delim
= "";
119 printk(" [<%016lx>] %s%s%s%s+0x%lx/0x%lx\n",
120 address
, delim
, modname
, delim
, symname
, offset
, symsize
);
123 void printk_address(unsigned long address
)
125 printk(" [<%016lx>]\n", address
);
129 static unsigned long *in_exception_stack(unsigned cpu
, unsigned long stack
,
130 unsigned *usedp
, char **idp
)
132 static char ids
[][8] = {
133 [DEBUG_STACK
- 1] = "#DB",
134 [NMI_STACK
- 1] = "NMI",
135 [DOUBLEFAULT_STACK
- 1] = "#DF",
136 [STACKFAULT_STACK
- 1] = "#SS",
137 [MCE_STACK
- 1] = "#MC",
138 #if DEBUG_STKSZ > EXCEPTION_STKSZ
139 [N_EXCEPTION_STACKS
... N_EXCEPTION_STACKS
+ DEBUG_STKSZ
/ EXCEPTION_STKSZ
- 2] = "#DB[?]"
145 * Iterate over all exception stacks, and figure out whether
146 * 'stack' is in one of them:
148 for (k
= 0; k
< N_EXCEPTION_STACKS
; k
++) {
149 unsigned long end
= per_cpu(orig_ist
, cpu
).ist
[k
];
151 * Is 'stack' above this exception frame's end?
152 * If yes then skip to the next frame.
157 * Is 'stack' above this exception frame's start address?
158 * If yes then we found the right frame.
160 if (stack
>= end
- EXCEPTION_STKSZ
) {
162 * Make sure we only iterate through an exception
163 * stack once. If it comes up for the second time
164 * then there's something wrong going on - just
165 * break out and return NULL:
167 if (*usedp
& (1U << k
))
171 return (unsigned long *)end
;
174 * If this is a debug stack, and if it has a larger size than
175 * the usual exception stacks, then 'stack' might still
176 * be within the lower portion of the debug stack:
178 #if DEBUG_STKSZ > EXCEPTION_STKSZ
179 if (k
== DEBUG_STACK
- 1 && stack
>= end
- DEBUG_STKSZ
) {
180 unsigned j
= N_EXCEPTION_STACKS
- 1;
183 * Black magic. A large debug stack is composed of
184 * multiple exception stack entries, which we
185 * iterate through now. Dont look:
189 end
-= EXCEPTION_STKSZ
;
190 ids
[j
][4] = '1' + (j
- N_EXCEPTION_STACKS
);
191 } while (stack
< end
- EXCEPTION_STKSZ
);
192 if (*usedp
& (1U << j
))
196 return (unsigned long *)end
;
203 #define MSG(txt) ops->warning(data, txt)
206 * x86-64 can have upto three kernel stacks:
209 * severe exception (double fault, nmi, stack fault, debug, mce) hardware stack
212 static inline int valid_stack_ptr(struct thread_info
*tinfo
, void *p
)
214 void *t
= (void *)tinfo
;
215 return p
> t
&& p
< t
+ THREAD_SIZE
- 3;
218 void dump_trace(struct task_struct
*tsk
, struct pt_regs
*regs
,
219 unsigned long *stack
,
220 struct stacktrace_ops
*ops
, void *data
)
222 const unsigned cpu
= get_cpu();
223 unsigned long *irqstack_end
= (unsigned long*)cpu_pda(cpu
)->irqstackptr
;
225 struct thread_info
*tinfo
;
233 if (tsk
&& tsk
!= current
)
234 stack
= (unsigned long *)tsk
->thread
.rsp
;
238 * Print function call entries within a stack. 'cond' is the
239 * "end of stackframe" condition, that the 'stack++'
240 * iteration will eventually trigger.
242 #define HANDLE_STACK(cond) \
244 unsigned long addr = *stack++; \
245 /* Use unlocked access here because except for NMIs \
246 we should be already protected against module unloads */ \
247 if (__kernel_text_address(addr)) { \
249 * If the address is either in the text segment of the \
250 * kernel, or in the region which contains vmalloc'ed \
251 * memory, it *may* be the address of a calling \
252 * routine; if so, print it so that someone tracing \
253 * down the cause of the crash will be able to figure \
254 * out the call path that was taken. \
256 ops->address(data, addr); \
261 * Print function call entries in all stacks, starting at the
262 * current stack address. If the stacks consist of nested
267 unsigned long *estack_end
;
268 estack_end
= in_exception_stack(cpu
, (unsigned long)stack
,
272 if (ops
->stack(data
, id
) < 0)
274 HANDLE_STACK (stack
< estack_end
);
275 ops
->stack(data
, "<EOE>");
277 * We link to the next stack via the
278 * second-to-last pointer (index -2 to end) in the
281 stack
= (unsigned long *) estack_end
[-2];
285 unsigned long *irqstack
;
286 irqstack
= irqstack_end
-
287 (IRQSTACKSIZE
- 64) / sizeof(*irqstack
);
289 if (stack
>= irqstack
&& stack
< irqstack_end
) {
290 if (ops
->stack(data
, "IRQ") < 0)
292 HANDLE_STACK (stack
< irqstack_end
);
294 * We link to the next stack (which would be
295 * the process stack normally) the last
296 * pointer (index -1 to end) in the IRQ stack:
298 stack
= (unsigned long *) (irqstack_end
[-1]);
300 ops
->stack(data
, "EOI");
308 * This handles the process stack:
310 tinfo
= task_thread_info(tsk
);
311 HANDLE_STACK (valid_stack_ptr(tinfo
, stack
));
315 EXPORT_SYMBOL(dump_trace
);
318 print_trace_warning_symbol(void *data
, char *msg
, unsigned long symbol
)
320 print_symbol(msg
, symbol
);
324 static void print_trace_warning(void *data
, char *msg
)
329 static int print_trace_stack(void *data
, char *name
)
331 printk(" <%s> ", name
);
335 static void print_trace_address(void *data
, unsigned long addr
)
337 touch_nmi_watchdog();
338 printk_address(addr
);
341 static struct stacktrace_ops print_trace_ops
= {
342 .warning
= print_trace_warning
,
343 .warning_symbol
= print_trace_warning_symbol
,
344 .stack
= print_trace_stack
,
345 .address
= print_trace_address
,
349 show_trace(struct task_struct
*tsk
, struct pt_regs
*regs
, unsigned long *stack
)
351 printk("\nCall Trace:\n");
352 dump_trace(tsk
, regs
, stack
, &print_trace_ops
, NULL
);
357 _show_stack(struct task_struct
*tsk
, struct pt_regs
*regs
, unsigned long *rsp
)
359 unsigned long *stack
;
361 const int cpu
= smp_processor_id();
362 unsigned long *irqstack_end
= (unsigned long *) (cpu_pda(cpu
)->irqstackptr
);
363 unsigned long *irqstack
= (unsigned long *) (cpu_pda(cpu
)->irqstackptr
- IRQSTACKSIZE
);
365 // debugging aid: "show_stack(NULL, NULL);" prints the
366 // back trace for this cpu.
370 rsp
= (unsigned long *)tsk
->thread
.rsp
;
372 rsp
= (unsigned long *)&rsp
;
376 for(i
=0; i
< kstack_depth_to_print
; i
++) {
377 if (stack
>= irqstack
&& stack
<= irqstack_end
) {
378 if (stack
== irqstack_end
) {
379 stack
= (unsigned long *) (irqstack_end
[-1]);
383 if (((long) stack
& (THREAD_SIZE
-1)) == 0)
386 if (i
&& ((i
% 4) == 0))
388 printk(" %016lx", *stack
++);
389 touch_nmi_watchdog();
391 show_trace(tsk
, regs
, rsp
);
394 void show_stack(struct task_struct
*tsk
, unsigned long * rsp
)
396 _show_stack(tsk
, NULL
, rsp
);
400 * The architecture-independent dump_stack generator
402 void dump_stack(void)
405 show_trace(NULL
, NULL
, &dummy
);
408 EXPORT_SYMBOL(dump_stack
);
410 void show_registers(struct pt_regs
*regs
)
413 int in_kernel
= !user_mode(regs
);
415 const int cpu
= smp_processor_id();
416 struct task_struct
*cur
= cpu_pda(cpu
)->pcurrent
;
419 printk("CPU %d ", cpu
);
421 printk("Process %s (pid: %d, threadinfo %p, task %p)\n",
422 cur
->comm
, cur
->pid
, task_thread_info(cur
), cur
);
425 * When in-kernel, we also print out the stack and code at the
426 * time of the fault..
430 _show_stack(NULL
, regs
, (unsigned long*)rsp
);
433 if (regs
->rip
< PAGE_OFFSET
)
436 for (i
=0; i
<20; i
++) {
438 if (__get_user(c
, &((unsigned char*)regs
->rip
)[i
])) {
440 printk(" Bad RIP value.");
449 int is_valid_bugaddr(unsigned long rip
)
453 if (__copy_from_user(&ud2
, (const void __user
*) rip
, sizeof(ud2
)))
456 return ud2
== 0x0b0f;
460 void out_of_line_bug(void)
464 EXPORT_SYMBOL(out_of_line_bug
);
467 static DEFINE_SPINLOCK(die_lock
);
468 static int die_owner
= -1;
469 static unsigned int die_nest_count
;
471 unsigned __kprobes
long oops_begin(void)
478 /* racy, but better than risking deadlock. */
479 local_irq_save(flags
);
480 cpu
= smp_processor_id();
481 if (!spin_trylock(&die_lock
)) {
482 if (cpu
== die_owner
)
483 /* nested oops. should stop eventually */;
485 spin_lock(&die_lock
);
494 void __kprobes
oops_end(unsigned long flags
)
500 /* We still own the lock */
501 local_irq_restore(flags
);
503 /* Nest count reaches zero, release the lock. */
504 spin_unlock_irqrestore(&die_lock
, flags
);
506 panic("Fatal exception");
510 void __kprobes
__die(const char * str
, struct pt_regs
* regs
, long err
)
512 static int die_counter
;
513 printk(KERN_EMERG
"%s: %04lx [%u] ", str
, err
& 0xffff,++die_counter
);
514 #ifdef CONFIG_PREEMPT
520 #ifdef CONFIG_DEBUG_PAGEALLOC
521 printk("DEBUG_PAGEALLOC");
524 notify_die(DIE_OOPS
, str
, regs
, err
, current
->thread
.trap_no
, SIGSEGV
);
525 show_registers(regs
);
526 add_taint(TAINT_DIE
);
527 /* Executive summary in case the oops scrolled away */
528 printk(KERN_ALERT
"RIP ");
529 printk_address(regs
->rip
);
530 printk(" RSP <%016lx>\n", regs
->rsp
);
531 if (kexec_should_crash(current
))
535 void die(const char * str
, struct pt_regs
* regs
, long err
)
537 unsigned long flags
= oops_begin();
539 if (!user_mode(regs
))
540 report_bug(regs
->rip
, regs
);
542 __die(str
, regs
, err
);
547 void __kprobes
die_nmi(char *str
, struct pt_regs
*regs
, int do_panic
)
549 unsigned long flags
= oops_begin();
552 * We are in trouble anyway, lets at least try
553 * to get a message out.
555 printk(str
, smp_processor_id());
556 show_registers(regs
);
557 if (kexec_should_crash(current
))
559 if (do_panic
|| panic_on_oops
)
560 panic("Non maskable interrupt");
567 static void __kprobes
do_trap(int trapnr
, int signr
, char *str
,
568 struct pt_regs
* regs
, long error_code
,
571 struct task_struct
*tsk
= current
;
573 if (user_mode(regs
)) {
575 * We want error_code and trap_no set for userspace
576 * faults and kernelspace faults which result in
577 * die(), but not kernelspace faults which are fixed
578 * up. die() gives the process no chance to handle
579 * the signal and notice the kernel fault information,
580 * so that won't result in polluting the information
581 * about previously queued, but not yet delivered,
582 * faults. See also do_general_protection below.
584 tsk
->thread
.error_code
= error_code
;
585 tsk
->thread
.trap_no
= trapnr
;
587 if (show_unhandled_signals
&& unhandled_signal(tsk
, signr
) &&
590 "%s[%d] trap %s rip:%lx rsp:%lx error:%lx\n",
591 tsk
->comm
, tsk
->pid
, str
,
592 regs
->rip
, regs
->rsp
, error_code
);
595 force_sig_info(signr
, info
, tsk
);
597 force_sig(signr
, tsk
);
604 const struct exception_table_entry
*fixup
;
605 fixup
= search_exception_tables(regs
->rip
);
607 regs
->rip
= fixup
->fixup
;
609 tsk
->thread
.error_code
= error_code
;
610 tsk
->thread
.trap_no
= trapnr
;
611 die(str
, regs
, error_code
);
617 #define DO_ERROR(trapnr, signr, str, name) \
618 asmlinkage void do_##name(struct pt_regs * regs, long error_code) \
620 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
623 conditional_sti(regs); \
624 do_trap(trapnr, signr, str, regs, error_code, NULL); \
627 #define DO_ERROR_INFO(trapnr, signr, str, name, sicode, siaddr) \
628 asmlinkage void do_##name(struct pt_regs * regs, long error_code) \
631 info.si_signo = signr; \
633 info.si_code = sicode; \
634 info.si_addr = (void __user *)siaddr; \
635 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
638 conditional_sti(regs); \
639 do_trap(trapnr, signr, str, regs, error_code, &info); \
642 DO_ERROR_INFO( 0, SIGFPE
, "divide error", divide_error
, FPE_INTDIV
, regs
->rip
)
643 DO_ERROR( 4, SIGSEGV
, "overflow", overflow
)
644 DO_ERROR( 5, SIGSEGV
, "bounds", bounds
)
645 DO_ERROR_INFO( 6, SIGILL
, "invalid opcode", invalid_op
, ILL_ILLOPN
, regs
->rip
)
646 DO_ERROR( 7, SIGSEGV
, "device not available", device_not_available
)
647 DO_ERROR( 9, SIGFPE
, "coprocessor segment overrun", coprocessor_segment_overrun
)
648 DO_ERROR(10, SIGSEGV
, "invalid TSS", invalid_TSS
)
649 DO_ERROR(11, SIGBUS
, "segment not present", segment_not_present
)
650 DO_ERROR_INFO(17, SIGBUS
, "alignment check", alignment_check
, BUS_ADRALN
, 0)
651 DO_ERROR(18, SIGSEGV
, "reserved", reserved
)
653 /* Runs on IST stack */
654 asmlinkage
void do_stack_segment(struct pt_regs
*regs
, long error_code
)
656 if (notify_die(DIE_TRAP
, "stack segment", regs
, error_code
,
657 12, SIGBUS
) == NOTIFY_STOP
)
659 preempt_conditional_sti(regs
);
660 do_trap(12, SIGBUS
, "stack segment", regs
, error_code
, NULL
);
661 preempt_conditional_cli(regs
);
664 asmlinkage
void do_double_fault(struct pt_regs
* regs
, long error_code
)
666 static const char str
[] = "double fault";
667 struct task_struct
*tsk
= current
;
669 /* Return not checked because double check cannot be ignored */
670 notify_die(DIE_TRAP
, str
, regs
, error_code
, 8, SIGSEGV
);
672 tsk
->thread
.error_code
= error_code
;
673 tsk
->thread
.trap_no
= 8;
675 /* This is always a kernel trap and never fixable (and thus must
678 die(str
, regs
, error_code
);
681 asmlinkage
void __kprobes
do_general_protection(struct pt_regs
* regs
,
684 struct task_struct
*tsk
= current
;
686 conditional_sti(regs
);
688 if (user_mode(regs
)) {
689 tsk
->thread
.error_code
= error_code
;
690 tsk
->thread
.trap_no
= 13;
692 if (show_unhandled_signals
&& unhandled_signal(tsk
, SIGSEGV
) &&
695 "%s[%d] general protection rip:%lx rsp:%lx error:%lx\n",
697 regs
->rip
, regs
->rsp
, error_code
);
699 force_sig(SIGSEGV
, tsk
);
705 const struct exception_table_entry
*fixup
;
706 fixup
= search_exception_tables(regs
->rip
);
708 regs
->rip
= fixup
->fixup
;
712 tsk
->thread
.error_code
= error_code
;
713 tsk
->thread
.trap_no
= 13;
714 if (notify_die(DIE_GPF
, "general protection fault", regs
,
715 error_code
, 13, SIGSEGV
) == NOTIFY_STOP
)
717 die("general protection fault", regs
, error_code
);
721 static __kprobes
void
722 mem_parity_error(unsigned char reason
, struct pt_regs
* regs
)
724 printk(KERN_EMERG
"Uhhuh. NMI received for unknown reason %02x.\n",
726 printk(KERN_EMERG
"You have some hardware problem, likely on the PCI bus.\n");
728 #if defined(CONFIG_EDAC)
729 if(edac_handler_set()) {
730 edac_atomic_assert_error();
735 if (panic_on_unrecovered_nmi
)
736 panic("NMI: Not continuing");
738 printk(KERN_EMERG
"Dazed and confused, but trying to continue\n");
740 /* Clear and disable the memory parity error line. */
741 reason
= (reason
& 0xf) | 4;
745 static __kprobes
void
746 io_check_error(unsigned char reason
, struct pt_regs
* regs
)
748 printk("NMI: IOCK error (debug interrupt?)\n");
749 show_registers(regs
);
751 /* Re-enable the IOCK line, wait for a few seconds */
752 reason
= (reason
& 0xf) | 8;
759 static __kprobes
void
760 unknown_nmi_error(unsigned char reason
, struct pt_regs
* regs
)
762 printk(KERN_EMERG
"Uhhuh. NMI received for unknown reason %02x.\n",
764 printk(KERN_EMERG
"Do you have a strange power saving mode enabled?\n");
766 if (panic_on_unrecovered_nmi
)
767 panic("NMI: Not continuing");
769 printk(KERN_EMERG
"Dazed and confused, but trying to continue\n");
772 /* Runs on IST stack. This code must keep interrupts off all the time.
773 Nested NMIs are prevented by the CPU. */
774 asmlinkage __kprobes
void default_do_nmi(struct pt_regs
*regs
)
776 unsigned char reason
= 0;
779 cpu
= smp_processor_id();
781 /* Only the BSP gets external NMIs from the system. */
783 reason
= get_nmi_reason();
785 if (!(reason
& 0xc0)) {
786 if (notify_die(DIE_NMI_IPI
, "nmi_ipi", regs
, reason
, 2, SIGINT
)
790 * Ok, so this is none of the documented NMI sources,
791 * so it must be the NMI watchdog.
793 if (nmi_watchdog_tick(regs
,reason
))
795 if (!do_nmi_callback(regs
,cpu
))
796 unknown_nmi_error(reason
, regs
);
800 if (notify_die(DIE_NMI
, "nmi", regs
, reason
, 2, SIGINT
) == NOTIFY_STOP
)
803 /* AK: following checks seem to be broken on modern chipsets. FIXME */
806 mem_parity_error(reason
, regs
);
808 io_check_error(reason
, regs
);
811 /* runs on IST stack. */
812 asmlinkage
void __kprobes
do_int3(struct pt_regs
* regs
, long error_code
)
814 if (notify_die(DIE_INT3
, "int3", regs
, error_code
, 3, SIGTRAP
) == NOTIFY_STOP
) {
817 preempt_conditional_sti(regs
);
818 do_trap(3, SIGTRAP
, "int3", regs
, error_code
, NULL
);
819 preempt_conditional_cli(regs
);
822 /* Help handler running on IST stack to switch back to user stack
823 for scheduling or signal handling. The actual stack switch is done in
825 asmlinkage __kprobes
struct pt_regs
*sync_regs(struct pt_regs
*eregs
)
827 struct pt_regs
*regs
= eregs
;
828 /* Did already sync */
829 if (eregs
== (struct pt_regs
*)eregs
->rsp
)
831 /* Exception from user space */
832 else if (user_mode(eregs
))
833 regs
= task_pt_regs(current
);
834 /* Exception from kernel and interrupts are enabled. Move to
835 kernel process stack. */
836 else if (eregs
->eflags
& X86_EFLAGS_IF
)
837 regs
= (struct pt_regs
*)(eregs
->rsp
-= sizeof(struct pt_regs
));
843 /* runs on IST stack. */
844 asmlinkage
void __kprobes
do_debug(struct pt_regs
* regs
,
845 unsigned long error_code
)
847 unsigned long condition
;
848 struct task_struct
*tsk
= current
;
851 get_debugreg(condition
, 6);
853 if (notify_die(DIE_DEBUG
, "debug", regs
, condition
, error_code
,
854 SIGTRAP
) == NOTIFY_STOP
)
857 preempt_conditional_sti(regs
);
859 /* Mask out spurious debug traps due to lazy DR7 setting */
860 if (condition
& (DR_TRAP0
|DR_TRAP1
|DR_TRAP2
|DR_TRAP3
)) {
861 if (!tsk
->thread
.debugreg7
) {
866 tsk
->thread
.debugreg6
= condition
;
868 /* Mask out spurious TF errors due to lazy TF clearing */
869 if (condition
& DR_STEP
) {
871 * The TF error should be masked out only if the current
872 * process is not traced and if the TRAP flag has been set
873 * previously by a tracing process (condition detected by
874 * the PT_DTRACE flag); remember that the i386 TRAP flag
875 * can be modified by the process itself in user mode,
876 * allowing programs to debug themselves without the ptrace()
879 if (!user_mode(regs
))
880 goto clear_TF_reenable
;
882 * Was the TF flag set by a debugger? If so, clear it now,
883 * so that register information is correct.
885 if (tsk
->ptrace
& PT_DTRACE
) {
886 regs
->eflags
&= ~TF_MASK
;
887 tsk
->ptrace
&= ~PT_DTRACE
;
891 /* Ok, finally something we can handle */
892 tsk
->thread
.trap_no
= 1;
893 tsk
->thread
.error_code
= error_code
;
894 info
.si_signo
= SIGTRAP
;
896 info
.si_code
= TRAP_BRKPT
;
897 info
.si_addr
= user_mode(regs
) ? (void __user
*)regs
->rip
: NULL
;
898 force_sig_info(SIGTRAP
, &info
, tsk
);
901 set_debugreg(0UL, 7);
902 preempt_conditional_cli(regs
);
906 set_tsk_thread_flag(tsk
, TIF_SINGLESTEP
);
907 regs
->eflags
&= ~TF_MASK
;
908 preempt_conditional_cli(regs
);
911 static int kernel_math_error(struct pt_regs
*regs
, const char *str
, int trapnr
)
913 const struct exception_table_entry
*fixup
;
914 fixup
= search_exception_tables(regs
->rip
);
916 regs
->rip
= fixup
->fixup
;
919 notify_die(DIE_GPF
, str
, regs
, 0, trapnr
, SIGFPE
);
920 /* Illegal floating point operation in the kernel */
921 current
->thread
.trap_no
= trapnr
;
927 * Note that we play around with the 'TS' bit in an attempt to get
928 * the correct behaviour even in the presence of the asynchronous
931 asmlinkage
void do_coprocessor_error(struct pt_regs
*regs
)
933 void __user
*rip
= (void __user
*)(regs
->rip
);
934 struct task_struct
* task
;
936 unsigned short cwd
, swd
;
938 conditional_sti(regs
);
939 if (!user_mode(regs
) &&
940 kernel_math_error(regs
, "kernel x87 math error", 16))
944 * Save the info for the exception handler and clear the error.
948 task
->thread
.trap_no
= 16;
949 task
->thread
.error_code
= 0;
950 info
.si_signo
= SIGFPE
;
952 info
.si_code
= __SI_FAULT
;
955 * (~cwd & swd) will mask out exceptions that are not set to unmasked
956 * status. 0x3f is the exception bits in these regs, 0x200 is the
957 * C1 reg you need in case of a stack fault, 0x040 is the stack
958 * fault bit. We should only be taking one exception at a time,
959 * so if this combination doesn't produce any single exception,
960 * then we have a bad program that isn't synchronizing its FPU usage
961 * and it will suffer the consequences since we won't be able to
962 * fully reproduce the context of the exception
964 cwd
= get_fpu_cwd(task
);
965 swd
= get_fpu_swd(task
);
966 switch (swd
& ~cwd
& 0x3f) {
970 case 0x001: /* Invalid Op */
972 * swd & 0x240 == 0x040: Stack Underflow
973 * swd & 0x240 == 0x240: Stack Overflow
974 * User must clear the SF bit (0x40) if set
976 info
.si_code
= FPE_FLTINV
;
978 case 0x002: /* Denormalize */
979 case 0x010: /* Underflow */
980 info
.si_code
= FPE_FLTUND
;
982 case 0x004: /* Zero Divide */
983 info
.si_code
= FPE_FLTDIV
;
985 case 0x008: /* Overflow */
986 info
.si_code
= FPE_FLTOVF
;
988 case 0x020: /* Precision */
989 info
.si_code
= FPE_FLTRES
;
992 force_sig_info(SIGFPE
, &info
, task
);
995 asmlinkage
void bad_intr(void)
997 printk("bad interrupt");
1000 asmlinkage
void do_simd_coprocessor_error(struct pt_regs
*regs
)
1002 void __user
*rip
= (void __user
*)(regs
->rip
);
1003 struct task_struct
* task
;
1005 unsigned short mxcsr
;
1007 conditional_sti(regs
);
1008 if (!user_mode(regs
) &&
1009 kernel_math_error(regs
, "kernel simd math error", 19))
1013 * Save the info for the exception handler and clear the error.
1016 save_init_fpu(task
);
1017 task
->thread
.trap_no
= 19;
1018 task
->thread
.error_code
= 0;
1019 info
.si_signo
= SIGFPE
;
1021 info
.si_code
= __SI_FAULT
;
1024 * The SIMD FPU exceptions are handled a little differently, as there
1025 * is only a single status/control register. Thus, to determine which
1026 * unmasked exception was caught we must mask the exception mask bits
1027 * at 0x1f80, and then use these to mask the exception bits at 0x3f.
1029 mxcsr
= get_fpu_mxcsr(task
);
1030 switch (~((mxcsr
& 0x1f80) >> 7) & (mxcsr
& 0x3f)) {
1034 case 0x001: /* Invalid Op */
1035 info
.si_code
= FPE_FLTINV
;
1037 case 0x002: /* Denormalize */
1038 case 0x010: /* Underflow */
1039 info
.si_code
= FPE_FLTUND
;
1041 case 0x004: /* Zero Divide */
1042 info
.si_code
= FPE_FLTDIV
;
1044 case 0x008: /* Overflow */
1045 info
.si_code
= FPE_FLTOVF
;
1047 case 0x020: /* Precision */
1048 info
.si_code
= FPE_FLTRES
;
1051 force_sig_info(SIGFPE
, &info
, task
);
1054 asmlinkage
void do_spurious_interrupt_bug(struct pt_regs
* regs
)
1058 asmlinkage
void __attribute__((weak
)) smp_thermal_interrupt(void)
1062 asmlinkage
void __attribute__((weak
)) mce_threshold_interrupt(void)
1067 * 'math_state_restore()' saves the current math information in the
1068 * old math state array, and gets the new ones from the current task
1070 * Careful.. There are problems with IBM-designed IRQ13 behaviour.
1071 * Don't touch unless you *really* know how it works.
1073 asmlinkage
void math_state_restore(void)
1075 struct task_struct
*me
= current
;
1076 clts(); /* Allow maths ops (or we recurse) */
1080 restore_fpu_checking(&me
->thread
.i387
.fxsave
);
1081 task_thread_info(me
)->status
|= TS_USEDFPU
;
1085 void __init
trap_init(void)
1087 set_intr_gate(0,÷_error
);
1088 set_intr_gate_ist(1,&debug
,DEBUG_STACK
);
1089 set_intr_gate_ist(2,&nmi
,NMI_STACK
);
1090 set_system_gate_ist(3,&int3
,DEBUG_STACK
); /* int3 can be called from all */
1091 set_system_gate(4,&overflow
); /* int4 can be called from all */
1092 set_intr_gate(5,&bounds
);
1093 set_intr_gate(6,&invalid_op
);
1094 set_intr_gate(7,&device_not_available
);
1095 set_intr_gate_ist(8,&double_fault
, DOUBLEFAULT_STACK
);
1096 set_intr_gate(9,&coprocessor_segment_overrun
);
1097 set_intr_gate(10,&invalid_TSS
);
1098 set_intr_gate(11,&segment_not_present
);
1099 set_intr_gate_ist(12,&stack_segment
,STACKFAULT_STACK
);
1100 set_intr_gate(13,&general_protection
);
1101 set_intr_gate(14,&page_fault
);
1102 set_intr_gate(15,&spurious_interrupt_bug
);
1103 set_intr_gate(16,&coprocessor_error
);
1104 set_intr_gate(17,&alignment_check
);
1105 #ifdef CONFIG_X86_MCE
1106 set_intr_gate_ist(18,&machine_check
, MCE_STACK
);
1108 set_intr_gate(19,&simd_coprocessor_error
);
1110 #ifdef CONFIG_IA32_EMULATION
1111 set_system_gate(IA32_SYSCALL_VECTOR
, ia32_syscall
);
1115 * Should be a barrier for any external CPU state.
1121 static int __init
oops_setup(char *s
)
1125 if (!strcmp(s
, "panic"))
1129 early_param("oops", oops_setup
);
1131 static int __init
kstack_setup(char *s
)
1135 kstack_depth_to_print
= simple_strtoul(s
,NULL
,0);
1138 early_param("kstack", kstack_setup
);