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/sched.h>
14 #include <linux/kernel.h>
15 #include <linux/string.h>
16 #include <linux/errno.h>
17 #include <linux/ptrace.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/kallsyms.h>
25 #include <linux/module.h>
26 #include <linux/moduleparam.h>
27 #include <linux/nmi.h>
28 #include <linux/kprobes.h>
29 #include <linux/kexec.h>
30 #include <linux/unwind.h>
31 #include <linux/uaccess.h>
32 #include <linux/bug.h>
33 #include <linux/kdebug.h>
35 #if defined(CONFIG_EDAC)
36 #include <linux/edac.h>
39 #include <asm/system.h>
41 #include <asm/atomic.h>
42 #include <asm/debugreg.h>
45 #include <asm/processor.h>
46 #include <asm/unwind.h>
48 #include <asm/pgalloc.h>
50 #include <asm/proto.h>
52 #include <asm/stacktrace.h>
54 asmlinkage
void divide_error(void);
55 asmlinkage
void debug(void);
56 asmlinkage
void nmi(void);
57 asmlinkage
void int3(void);
58 asmlinkage
void overflow(void);
59 asmlinkage
void bounds(void);
60 asmlinkage
void invalid_op(void);
61 asmlinkage
void device_not_available(void);
62 asmlinkage
void double_fault(void);
63 asmlinkage
void coprocessor_segment_overrun(void);
64 asmlinkage
void invalid_TSS(void);
65 asmlinkage
void segment_not_present(void);
66 asmlinkage
void stack_segment(void);
67 asmlinkage
void general_protection(void);
68 asmlinkage
void page_fault(void);
69 asmlinkage
void coprocessor_error(void);
70 asmlinkage
void simd_coprocessor_error(void);
71 asmlinkage
void reserved(void);
72 asmlinkage
void alignment_check(void);
73 asmlinkage
void machine_check(void);
74 asmlinkage
void spurious_interrupt_bug(void);
76 static inline void conditional_sti(struct pt_regs
*regs
)
78 if (regs
->eflags
& X86_EFLAGS_IF
)
82 static inline void preempt_conditional_sti(struct pt_regs
*regs
)
85 if (regs
->eflags
& X86_EFLAGS_IF
)
89 static inline void preempt_conditional_cli(struct pt_regs
*regs
)
91 if (regs
->eflags
& X86_EFLAGS_IF
)
93 /* Make sure to not schedule here because we could be running
94 on an exception stack. */
95 preempt_enable_no_resched();
98 int kstack_depth_to_print
= 12;
100 #ifdef CONFIG_KALLSYMS
101 void printk_address(unsigned long address
)
103 unsigned long offset
= 0, symsize
;
109 symname
= kallsyms_lookup(address
, &symsize
, &offset
,
112 printk(" [<%016lx>]\n", address
);
116 modname
= delim
= "";
117 printk(" [<%016lx>] %s%s%s%s+0x%lx/0x%lx\n",
118 address
, delim
, modname
, delim
, symname
, offset
, symsize
);
121 void printk_address(unsigned long address
)
123 printk(" [<%016lx>]\n", address
);
127 static unsigned long *in_exception_stack(unsigned cpu
, unsigned long stack
,
128 unsigned *usedp
, char **idp
)
130 static char ids
[][8] = {
131 [DEBUG_STACK
- 1] = "#DB",
132 [NMI_STACK
- 1] = "NMI",
133 [DOUBLEFAULT_STACK
- 1] = "#DF",
134 [STACKFAULT_STACK
- 1] = "#SS",
135 [MCE_STACK
- 1] = "#MC",
136 #if DEBUG_STKSZ > EXCEPTION_STKSZ
137 [N_EXCEPTION_STACKS
... N_EXCEPTION_STACKS
+ DEBUG_STKSZ
/ EXCEPTION_STKSZ
- 2] = "#DB[?]"
143 * Iterate over all exception stacks, and figure out whether
144 * 'stack' is in one of them:
146 for (k
= 0; k
< N_EXCEPTION_STACKS
; k
++) {
147 unsigned long end
= per_cpu(orig_ist
, cpu
).ist
[k
];
149 * Is 'stack' above this exception frame's end?
150 * If yes then skip to the next frame.
155 * Is 'stack' above this exception frame's start address?
156 * If yes then we found the right frame.
158 if (stack
>= end
- EXCEPTION_STKSZ
) {
160 * Make sure we only iterate through an exception
161 * stack once. If it comes up for the second time
162 * then there's something wrong going on - just
163 * break out and return NULL:
165 if (*usedp
& (1U << k
))
169 return (unsigned long *)end
;
172 * If this is a debug stack, and if it has a larger size than
173 * the usual exception stacks, then 'stack' might still
174 * be within the lower portion of the debug stack:
176 #if DEBUG_STKSZ > EXCEPTION_STKSZ
177 if (k
== DEBUG_STACK
- 1 && stack
>= end
- DEBUG_STKSZ
) {
178 unsigned j
= N_EXCEPTION_STACKS
- 1;
181 * Black magic. A large debug stack is composed of
182 * multiple exception stack entries, which we
183 * iterate through now. Dont look:
187 end
-= EXCEPTION_STKSZ
;
188 ids
[j
][4] = '1' + (j
- N_EXCEPTION_STACKS
);
189 } while (stack
< end
- EXCEPTION_STKSZ
);
190 if (*usedp
& (1U << j
))
194 return (unsigned long *)end
;
201 #define MSG(txt) ops->warning(data, txt)
204 * x86-64 can have up to three kernel stacks:
207 * severe exception (double fault, nmi, stack fault, debug, mce) hardware stack
210 static inline int valid_stack_ptr(struct thread_info
*tinfo
, void *p
)
212 void *t
= (void *)tinfo
;
213 return p
> t
&& p
< t
+ THREAD_SIZE
- 3;
216 void dump_trace(struct task_struct
*tsk
, struct pt_regs
*regs
,
217 unsigned long *stack
,
218 const struct stacktrace_ops
*ops
, void *data
)
220 const unsigned cpu
= get_cpu();
221 unsigned long *irqstack_end
= (unsigned long*)cpu_pda(cpu
)->irqstackptr
;
223 struct thread_info
*tinfo
;
231 if (tsk
&& tsk
!= current
)
232 stack
= (unsigned long *)tsk
->thread
.rsp
;
236 * Print function call entries within a stack. 'cond' is the
237 * "end of stackframe" condition, that the 'stack++'
238 * iteration will eventually trigger.
240 #define HANDLE_STACK(cond) \
242 unsigned long addr = *stack++; \
243 /* Use unlocked access here because except for NMIs \
244 we should be already protected against module unloads */ \
245 if (__kernel_text_address(addr)) { \
247 * If the address is either in the text segment of the \
248 * kernel, or in the region which contains vmalloc'ed \
249 * memory, it *may* be the address of a calling \
250 * routine; if so, print it so that someone tracing \
251 * down the cause of the crash will be able to figure \
252 * out the call path that was taken. \
254 ops->address(data, addr); \
259 * Print function call entries in all stacks, starting at the
260 * current stack address. If the stacks consist of nested
265 unsigned long *estack_end
;
266 estack_end
= in_exception_stack(cpu
, (unsigned long)stack
,
270 if (ops
->stack(data
, id
) < 0)
272 HANDLE_STACK (stack
< estack_end
);
273 ops
->stack(data
, "<EOE>");
275 * We link to the next stack via the
276 * second-to-last pointer (index -2 to end) in the
279 stack
= (unsigned long *) estack_end
[-2];
283 unsigned long *irqstack
;
284 irqstack
= irqstack_end
-
285 (IRQSTACKSIZE
- 64) / sizeof(*irqstack
);
287 if (stack
>= irqstack
&& stack
< irqstack_end
) {
288 if (ops
->stack(data
, "IRQ") < 0)
290 HANDLE_STACK (stack
< irqstack_end
);
292 * We link to the next stack (which would be
293 * the process stack normally) the last
294 * pointer (index -1 to end) in the IRQ stack:
296 stack
= (unsigned long *) (irqstack_end
[-1]);
298 ops
->stack(data
, "EOI");
306 * This handles the process stack:
308 tinfo
= task_thread_info(tsk
);
309 HANDLE_STACK (valid_stack_ptr(tinfo
, stack
));
313 EXPORT_SYMBOL(dump_trace
);
316 print_trace_warning_symbol(void *data
, char *msg
, unsigned long symbol
)
318 print_symbol(msg
, symbol
);
322 static void print_trace_warning(void *data
, char *msg
)
327 static int print_trace_stack(void *data
, char *name
)
329 printk(" <%s> ", name
);
333 static void print_trace_address(void *data
, unsigned long addr
)
335 touch_nmi_watchdog();
336 printk_address(addr
);
339 static const struct stacktrace_ops print_trace_ops
= {
340 .warning
= print_trace_warning
,
341 .warning_symbol
= print_trace_warning_symbol
,
342 .stack
= print_trace_stack
,
343 .address
= print_trace_address
,
347 show_trace(struct task_struct
*tsk
, struct pt_regs
*regs
, unsigned long *stack
)
349 printk("\nCall Trace:\n");
350 dump_trace(tsk
, regs
, stack
, &print_trace_ops
, NULL
);
355 _show_stack(struct task_struct
*tsk
, struct pt_regs
*regs
, unsigned long *rsp
)
357 unsigned long *stack
;
359 const int cpu
= smp_processor_id();
360 unsigned long *irqstack_end
= (unsigned long *) (cpu_pda(cpu
)->irqstackptr
);
361 unsigned long *irqstack
= (unsigned long *) (cpu_pda(cpu
)->irqstackptr
- IRQSTACKSIZE
);
363 // debugging aid: "show_stack(NULL, NULL);" prints the
364 // back trace for this cpu.
368 rsp
= (unsigned long *)tsk
->thread
.rsp
;
370 rsp
= (unsigned long *)&rsp
;
374 for(i
=0; i
< kstack_depth_to_print
; i
++) {
375 if (stack
>= irqstack
&& stack
<= irqstack_end
) {
376 if (stack
== irqstack_end
) {
377 stack
= (unsigned long *) (irqstack_end
[-1]);
381 if (((long) stack
& (THREAD_SIZE
-1)) == 0)
384 if (i
&& ((i
% 4) == 0))
386 printk(" %016lx", *stack
++);
387 touch_nmi_watchdog();
389 show_trace(tsk
, regs
, rsp
);
392 void show_stack(struct task_struct
*tsk
, unsigned long * rsp
)
394 _show_stack(tsk
, NULL
, rsp
);
398 * The architecture-independent dump_stack generator
400 void dump_stack(void)
403 show_trace(NULL
, NULL
, &dummy
);
406 EXPORT_SYMBOL(dump_stack
);
408 void show_registers(struct pt_regs
*regs
)
411 int in_kernel
= !user_mode(regs
);
413 const int cpu
= smp_processor_id();
414 struct task_struct
*cur
= cpu_pda(cpu
)->pcurrent
;
417 printk("CPU %d ", cpu
);
419 printk("Process %s (pid: %d, threadinfo %p, task %p)\n",
420 cur
->comm
, cur
->pid
, task_thread_info(cur
), cur
);
423 * When in-kernel, we also print out the stack and code at the
424 * time of the fault..
428 _show_stack(NULL
, regs
, (unsigned long*)rsp
);
431 if (regs
->rip
< PAGE_OFFSET
)
434 for (i
=0; i
<20; i
++) {
436 if (__get_user(c
, &((unsigned char*)regs
->rip
)[i
])) {
438 printk(" Bad RIP value.");
447 int is_valid_bugaddr(unsigned long rip
)
451 if (__copy_from_user(&ud2
, (const void __user
*) rip
, sizeof(ud2
)))
454 return ud2
== 0x0b0f;
458 void out_of_line_bug(void)
462 EXPORT_SYMBOL(out_of_line_bug
);
465 static raw_spinlock_t die_lock
= __RAW_SPIN_LOCK_UNLOCKED
;
466 static int die_owner
= -1;
467 static unsigned int die_nest_count
;
469 unsigned __kprobes
long oops_begin(void)
476 /* racy, but better than risking deadlock. */
477 raw_local_irq_save(flags
);
478 cpu
= smp_processor_id();
479 if (!__raw_spin_trylock(&die_lock
)) {
480 if (cpu
== die_owner
)
481 /* nested oops. should stop eventually */;
483 __raw_spin_lock(&die_lock
);
492 void __kprobes
oops_end(unsigned long flags
)
498 /* Nest count reaches zero, release the lock. */
499 __raw_spin_unlock(&die_lock
);
500 raw_local_irq_restore(flags
);
502 panic("Fatal exception");
506 void __kprobes
__die(const char * str
, struct pt_regs
* regs
, long err
)
508 static int die_counter
;
509 printk(KERN_EMERG
"%s: %04lx [%u] ", str
, err
& 0xffff,++die_counter
);
510 #ifdef CONFIG_PREEMPT
516 #ifdef CONFIG_DEBUG_PAGEALLOC
517 printk("DEBUG_PAGEALLOC");
520 notify_die(DIE_OOPS
, str
, regs
, err
, current
->thread
.trap_no
, SIGSEGV
);
521 show_registers(regs
);
522 add_taint(TAINT_DIE
);
523 /* Executive summary in case the oops scrolled away */
524 printk(KERN_ALERT
"RIP ");
525 printk_address(regs
->rip
);
526 printk(" RSP <%016lx>\n", regs
->rsp
);
527 if (kexec_should_crash(current
))
531 void die(const char * str
, struct pt_regs
* regs
, long err
)
533 unsigned long flags
= oops_begin();
535 if (!user_mode(regs
))
536 report_bug(regs
->rip
, regs
);
538 __die(str
, regs
, err
);
543 void __kprobes
die_nmi(char *str
, struct pt_regs
*regs
, int do_panic
)
545 unsigned long flags
= oops_begin();
548 * We are in trouble anyway, lets at least try
549 * to get a message out.
551 printk(str
, smp_processor_id());
552 show_registers(regs
);
553 if (kexec_should_crash(current
))
555 if (do_panic
|| panic_on_oops
)
556 panic("Non maskable interrupt");
563 static void __kprobes
do_trap(int trapnr
, int signr
, char *str
,
564 struct pt_regs
* regs
, long error_code
,
567 struct task_struct
*tsk
= current
;
569 if (user_mode(regs
)) {
571 * We want error_code and trap_no set for userspace
572 * faults and kernelspace faults which result in
573 * die(), but not kernelspace faults which are fixed
574 * up. die() gives the process no chance to handle
575 * the signal and notice the kernel fault information,
576 * so that won't result in polluting the information
577 * about previously queued, but not yet delivered,
578 * faults. See also do_general_protection below.
580 tsk
->thread
.error_code
= error_code
;
581 tsk
->thread
.trap_no
= trapnr
;
583 if (show_unhandled_signals
&& unhandled_signal(tsk
, signr
) &&
586 "%s[%d] trap %s rip:%lx rsp:%lx error:%lx\n",
587 tsk
->comm
, tsk
->pid
, str
,
588 regs
->rip
, regs
->rsp
, error_code
);
591 force_sig_info(signr
, info
, tsk
);
593 force_sig(signr
, tsk
);
600 const struct exception_table_entry
*fixup
;
601 fixup
= search_exception_tables(regs
->rip
);
603 regs
->rip
= fixup
->fixup
;
605 tsk
->thread
.error_code
= error_code
;
606 tsk
->thread
.trap_no
= trapnr
;
607 die(str
, regs
, error_code
);
613 #define DO_ERROR(trapnr, signr, str, name) \
614 asmlinkage void do_##name(struct pt_regs * regs, long error_code) \
616 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
619 conditional_sti(regs); \
620 do_trap(trapnr, signr, str, regs, error_code, NULL); \
623 #define DO_ERROR_INFO(trapnr, signr, str, name, sicode, siaddr) \
624 asmlinkage void do_##name(struct pt_regs * regs, long error_code) \
627 info.si_signo = signr; \
629 info.si_code = sicode; \
630 info.si_addr = (void __user *)siaddr; \
631 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
634 conditional_sti(regs); \
635 do_trap(trapnr, signr, str, regs, error_code, &info); \
638 DO_ERROR_INFO( 0, SIGFPE
, "divide error", divide_error
, FPE_INTDIV
, regs
->rip
)
639 DO_ERROR( 4, SIGSEGV
, "overflow", overflow
)
640 DO_ERROR( 5, SIGSEGV
, "bounds", bounds
)
641 DO_ERROR_INFO( 6, SIGILL
, "invalid opcode", invalid_op
, ILL_ILLOPN
, regs
->rip
)
642 DO_ERROR( 7, SIGSEGV
, "device not available", device_not_available
)
643 DO_ERROR( 9, SIGFPE
, "coprocessor segment overrun", coprocessor_segment_overrun
)
644 DO_ERROR(10, SIGSEGV
, "invalid TSS", invalid_TSS
)
645 DO_ERROR(11, SIGBUS
, "segment not present", segment_not_present
)
646 DO_ERROR_INFO(17, SIGBUS
, "alignment check", alignment_check
, BUS_ADRALN
, 0)
647 DO_ERROR(18, SIGSEGV
, "reserved", reserved
)
649 /* Runs on IST stack */
650 asmlinkage
void do_stack_segment(struct pt_regs
*regs
, long error_code
)
652 if (notify_die(DIE_TRAP
, "stack segment", regs
, error_code
,
653 12, SIGBUS
) == NOTIFY_STOP
)
655 preempt_conditional_sti(regs
);
656 do_trap(12, SIGBUS
, "stack segment", regs
, error_code
, NULL
);
657 preempt_conditional_cli(regs
);
660 asmlinkage
void do_double_fault(struct pt_regs
* regs
, long error_code
)
662 static const char str
[] = "double fault";
663 struct task_struct
*tsk
= current
;
665 /* Return not checked because double check cannot be ignored */
666 notify_die(DIE_TRAP
, str
, regs
, error_code
, 8, SIGSEGV
);
668 tsk
->thread
.error_code
= error_code
;
669 tsk
->thread
.trap_no
= 8;
671 /* This is always a kernel trap and never fixable (and thus must
674 die(str
, regs
, error_code
);
677 asmlinkage
void __kprobes
do_general_protection(struct pt_regs
* regs
,
680 struct task_struct
*tsk
= current
;
682 conditional_sti(regs
);
684 if (user_mode(regs
)) {
685 tsk
->thread
.error_code
= error_code
;
686 tsk
->thread
.trap_no
= 13;
688 if (show_unhandled_signals
&& unhandled_signal(tsk
, SIGSEGV
) &&
691 "%s[%d] general protection rip:%lx rsp:%lx error:%lx\n",
693 regs
->rip
, regs
->rsp
, error_code
);
695 force_sig(SIGSEGV
, tsk
);
701 const struct exception_table_entry
*fixup
;
702 fixup
= search_exception_tables(regs
->rip
);
704 regs
->rip
= fixup
->fixup
;
708 tsk
->thread
.error_code
= error_code
;
709 tsk
->thread
.trap_no
= 13;
710 if (notify_die(DIE_GPF
, "general protection fault", regs
,
711 error_code
, 13, SIGSEGV
) == NOTIFY_STOP
)
713 die("general protection fault", regs
, error_code
);
717 static __kprobes
void
718 mem_parity_error(unsigned char reason
, struct pt_regs
* regs
)
720 printk(KERN_EMERG
"Uhhuh. NMI received for unknown reason %02x.\n",
722 printk(KERN_EMERG
"You have some hardware problem, likely on the PCI bus.\n");
724 #if defined(CONFIG_EDAC)
725 if(edac_handler_set()) {
726 edac_atomic_assert_error();
731 if (panic_on_unrecovered_nmi
)
732 panic("NMI: Not continuing");
734 printk(KERN_EMERG
"Dazed and confused, but trying to continue\n");
736 /* Clear and disable the memory parity error line. */
737 reason
= (reason
& 0xf) | 4;
741 static __kprobes
void
742 io_check_error(unsigned char reason
, struct pt_regs
* regs
)
744 printk("NMI: IOCK error (debug interrupt?)\n");
745 show_registers(regs
);
747 /* Re-enable the IOCK line, wait for a few seconds */
748 reason
= (reason
& 0xf) | 8;
755 static __kprobes
void
756 unknown_nmi_error(unsigned char reason
, struct pt_regs
* regs
)
758 printk(KERN_EMERG
"Uhhuh. NMI received for unknown reason %02x.\n",
760 printk(KERN_EMERG
"Do you have a strange power saving mode enabled?\n");
762 if (panic_on_unrecovered_nmi
)
763 panic("NMI: Not continuing");
765 printk(KERN_EMERG
"Dazed and confused, but trying to continue\n");
768 /* Runs on IST stack. This code must keep interrupts off all the time.
769 Nested NMIs are prevented by the CPU. */
770 asmlinkage __kprobes
void default_do_nmi(struct pt_regs
*regs
)
772 unsigned char reason
= 0;
775 cpu
= smp_processor_id();
777 /* Only the BSP gets external NMIs from the system. */
779 reason
= get_nmi_reason();
781 if (!(reason
& 0xc0)) {
782 if (notify_die(DIE_NMI_IPI
, "nmi_ipi", regs
, reason
, 2, SIGINT
)
786 * Ok, so this is none of the documented NMI sources,
787 * so it must be the NMI watchdog.
789 if (nmi_watchdog_tick(regs
,reason
))
791 if (!do_nmi_callback(regs
,cpu
))
792 unknown_nmi_error(reason
, regs
);
796 if (notify_die(DIE_NMI
, "nmi", regs
, reason
, 2, SIGINT
) == NOTIFY_STOP
)
799 /* AK: following checks seem to be broken on modern chipsets. FIXME */
802 mem_parity_error(reason
, regs
);
804 io_check_error(reason
, regs
);
807 /* runs on IST stack. */
808 asmlinkage
void __kprobes
do_int3(struct pt_regs
* regs
, long error_code
)
810 if (notify_die(DIE_INT3
, "int3", regs
, error_code
, 3, SIGTRAP
) == NOTIFY_STOP
) {
813 preempt_conditional_sti(regs
);
814 do_trap(3, SIGTRAP
, "int3", regs
, error_code
, NULL
);
815 preempt_conditional_cli(regs
);
818 /* Help handler running on IST stack to switch back to user stack
819 for scheduling or signal handling. The actual stack switch is done in
821 asmlinkage __kprobes
struct pt_regs
*sync_regs(struct pt_regs
*eregs
)
823 struct pt_regs
*regs
= eregs
;
824 /* Did already sync */
825 if (eregs
== (struct pt_regs
*)eregs
->rsp
)
827 /* Exception from user space */
828 else if (user_mode(eregs
))
829 regs
= task_pt_regs(current
);
830 /* Exception from kernel and interrupts are enabled. Move to
831 kernel process stack. */
832 else if (eregs
->eflags
& X86_EFLAGS_IF
)
833 regs
= (struct pt_regs
*)(eregs
->rsp
-= sizeof(struct pt_regs
));
839 /* runs on IST stack. */
840 asmlinkage
void __kprobes
do_debug(struct pt_regs
* regs
,
841 unsigned long error_code
)
843 unsigned long condition
;
844 struct task_struct
*tsk
= current
;
847 get_debugreg(condition
, 6);
849 if (notify_die(DIE_DEBUG
, "debug", regs
, condition
, error_code
,
850 SIGTRAP
) == NOTIFY_STOP
)
853 preempt_conditional_sti(regs
);
855 /* Mask out spurious debug traps due to lazy DR7 setting */
856 if (condition
& (DR_TRAP0
|DR_TRAP1
|DR_TRAP2
|DR_TRAP3
)) {
857 if (!tsk
->thread
.debugreg7
) {
862 tsk
->thread
.debugreg6
= condition
;
864 /* Mask out spurious TF errors due to lazy TF clearing */
865 if (condition
& DR_STEP
) {
867 * The TF error should be masked out only if the current
868 * process is not traced and if the TRAP flag has been set
869 * previously by a tracing process (condition detected by
870 * the PT_DTRACE flag); remember that the i386 TRAP flag
871 * can be modified by the process itself in user mode,
872 * allowing programs to debug themselves without the ptrace()
875 if (!user_mode(regs
))
876 goto clear_TF_reenable
;
878 * Was the TF flag set by a debugger? If so, clear it now,
879 * so that register information is correct.
881 if (tsk
->ptrace
& PT_DTRACE
) {
882 regs
->eflags
&= ~TF_MASK
;
883 tsk
->ptrace
&= ~PT_DTRACE
;
887 /* Ok, finally something we can handle */
888 tsk
->thread
.trap_no
= 1;
889 tsk
->thread
.error_code
= error_code
;
890 info
.si_signo
= SIGTRAP
;
892 info
.si_code
= TRAP_BRKPT
;
893 info
.si_addr
= user_mode(regs
) ? (void __user
*)regs
->rip
: NULL
;
894 force_sig_info(SIGTRAP
, &info
, tsk
);
897 set_debugreg(0UL, 7);
898 preempt_conditional_cli(regs
);
902 set_tsk_thread_flag(tsk
, TIF_SINGLESTEP
);
903 regs
->eflags
&= ~TF_MASK
;
904 preempt_conditional_cli(regs
);
907 static int kernel_math_error(struct pt_regs
*regs
, const char *str
, int trapnr
)
909 const struct exception_table_entry
*fixup
;
910 fixup
= search_exception_tables(regs
->rip
);
912 regs
->rip
= fixup
->fixup
;
915 notify_die(DIE_GPF
, str
, regs
, 0, trapnr
, SIGFPE
);
916 /* Illegal floating point operation in the kernel */
917 current
->thread
.trap_no
= trapnr
;
923 * Note that we play around with the 'TS' bit in an attempt to get
924 * the correct behaviour even in the presence of the asynchronous
927 asmlinkage
void do_coprocessor_error(struct pt_regs
*regs
)
929 void __user
*rip
= (void __user
*)(regs
->rip
);
930 struct task_struct
* task
;
932 unsigned short cwd
, swd
;
934 conditional_sti(regs
);
935 if (!user_mode(regs
) &&
936 kernel_math_error(regs
, "kernel x87 math error", 16))
940 * Save the info for the exception handler and clear the error.
944 task
->thread
.trap_no
= 16;
945 task
->thread
.error_code
= 0;
946 info
.si_signo
= SIGFPE
;
948 info
.si_code
= __SI_FAULT
;
951 * (~cwd & swd) will mask out exceptions that are not set to unmasked
952 * status. 0x3f is the exception bits in these regs, 0x200 is the
953 * C1 reg you need in case of a stack fault, 0x040 is the stack
954 * fault bit. We should only be taking one exception at a time,
955 * so if this combination doesn't produce any single exception,
956 * then we have a bad program that isn't synchronizing its FPU usage
957 * and it will suffer the consequences since we won't be able to
958 * fully reproduce the context of the exception
960 cwd
= get_fpu_cwd(task
);
961 swd
= get_fpu_swd(task
);
962 switch (swd
& ~cwd
& 0x3f) {
966 case 0x001: /* Invalid Op */
968 * swd & 0x240 == 0x040: Stack Underflow
969 * swd & 0x240 == 0x240: Stack Overflow
970 * User must clear the SF bit (0x40) if set
972 info
.si_code
= FPE_FLTINV
;
974 case 0x002: /* Denormalize */
975 case 0x010: /* Underflow */
976 info
.si_code
= FPE_FLTUND
;
978 case 0x004: /* Zero Divide */
979 info
.si_code
= FPE_FLTDIV
;
981 case 0x008: /* Overflow */
982 info
.si_code
= FPE_FLTOVF
;
984 case 0x020: /* Precision */
985 info
.si_code
= FPE_FLTRES
;
988 force_sig_info(SIGFPE
, &info
, task
);
991 asmlinkage
void bad_intr(void)
993 printk("bad interrupt");
996 asmlinkage
void do_simd_coprocessor_error(struct pt_regs
*regs
)
998 void __user
*rip
= (void __user
*)(regs
->rip
);
999 struct task_struct
* task
;
1001 unsigned short mxcsr
;
1003 conditional_sti(regs
);
1004 if (!user_mode(regs
) &&
1005 kernel_math_error(regs
, "kernel simd math error", 19))
1009 * Save the info for the exception handler and clear the error.
1012 save_init_fpu(task
);
1013 task
->thread
.trap_no
= 19;
1014 task
->thread
.error_code
= 0;
1015 info
.si_signo
= SIGFPE
;
1017 info
.si_code
= __SI_FAULT
;
1020 * The SIMD FPU exceptions are handled a little differently, as there
1021 * is only a single status/control register. Thus, to determine which
1022 * unmasked exception was caught we must mask the exception mask bits
1023 * at 0x1f80, and then use these to mask the exception bits at 0x3f.
1025 mxcsr
= get_fpu_mxcsr(task
);
1026 switch (~((mxcsr
& 0x1f80) >> 7) & (mxcsr
& 0x3f)) {
1030 case 0x001: /* Invalid Op */
1031 info
.si_code
= FPE_FLTINV
;
1033 case 0x002: /* Denormalize */
1034 case 0x010: /* Underflow */
1035 info
.si_code
= FPE_FLTUND
;
1037 case 0x004: /* Zero Divide */
1038 info
.si_code
= FPE_FLTDIV
;
1040 case 0x008: /* Overflow */
1041 info
.si_code
= FPE_FLTOVF
;
1043 case 0x020: /* Precision */
1044 info
.si_code
= FPE_FLTRES
;
1047 force_sig_info(SIGFPE
, &info
, task
);
1050 asmlinkage
void do_spurious_interrupt_bug(struct pt_regs
* regs
)
1054 asmlinkage
void __attribute__((weak
)) smp_thermal_interrupt(void)
1058 asmlinkage
void __attribute__((weak
)) mce_threshold_interrupt(void)
1063 * 'math_state_restore()' saves the current math information in the
1064 * old math state array, and gets the new ones from the current task
1066 * Careful.. There are problems with IBM-designed IRQ13 behaviour.
1067 * Don't touch unless you *really* know how it works.
1069 asmlinkage
void math_state_restore(void)
1071 struct task_struct
*me
= current
;
1072 clts(); /* Allow maths ops (or we recurse) */
1076 restore_fpu_checking(&me
->thread
.i387
.fxsave
);
1077 task_thread_info(me
)->status
|= TS_USEDFPU
;
1081 void __init
trap_init(void)
1083 set_intr_gate(0,÷_error
);
1084 set_intr_gate_ist(1,&debug
,DEBUG_STACK
);
1085 set_intr_gate_ist(2,&nmi
,NMI_STACK
);
1086 set_system_gate_ist(3,&int3
,DEBUG_STACK
); /* int3 can be called from all */
1087 set_system_gate(4,&overflow
); /* int4 can be called from all */
1088 set_intr_gate(5,&bounds
);
1089 set_intr_gate(6,&invalid_op
);
1090 set_intr_gate(7,&device_not_available
);
1091 set_intr_gate_ist(8,&double_fault
, DOUBLEFAULT_STACK
);
1092 set_intr_gate(9,&coprocessor_segment_overrun
);
1093 set_intr_gate(10,&invalid_TSS
);
1094 set_intr_gate(11,&segment_not_present
);
1095 set_intr_gate_ist(12,&stack_segment
,STACKFAULT_STACK
);
1096 set_intr_gate(13,&general_protection
);
1097 set_intr_gate(14,&page_fault
);
1098 set_intr_gate(15,&spurious_interrupt_bug
);
1099 set_intr_gate(16,&coprocessor_error
);
1100 set_intr_gate(17,&alignment_check
);
1101 #ifdef CONFIG_X86_MCE
1102 set_intr_gate_ist(18,&machine_check
, MCE_STACK
);
1104 set_intr_gate(19,&simd_coprocessor_error
);
1106 #ifdef CONFIG_IA32_EMULATION
1107 set_system_gate(IA32_SYSCALL_VECTOR
, ia32_syscall
);
1111 * Should be a barrier for any external CPU state.
1117 static int __init
oops_setup(char *s
)
1121 if (!strcmp(s
, "panic"))
1125 early_param("oops", oops_setup
);
1127 static int __init
kstack_setup(char *s
)
1131 kstack_depth_to_print
= simple_strtoul(s
,NULL
,0);
1134 early_param("kstack", kstack_setup
);