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/moduleparam.h>
14 #include <linux/interrupt.h>
15 #include <linux/kallsyms.h>
16 #include <linux/spinlock.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>
36 #if defined(CONFIG_EDAC)
37 #include <linux/edac.h>
40 #include <asm/stacktrace.h>
41 #include <asm/processor.h>
42 #include <asm/debugreg.h>
43 #include <asm/atomic.h>
44 #include <asm/system.h>
45 #include <asm/unwind.h>
51 #include <asm/pgalloc.h>
52 #include <asm/proto.h>
54 #include <asm/traps.h>
56 #include <mach_traps.h>
58 int panic_on_unrecovered_nmi
;
59 int kstack_depth_to_print
= 12;
60 static unsigned int code_bytes
= 64;
61 static int ignore_nmis
;
62 static int die_counter
;
64 static inline void conditional_sti(struct pt_regs
*regs
)
66 if (regs
->flags
& X86_EFLAGS_IF
)
70 static inline void preempt_conditional_sti(struct pt_regs
*regs
)
73 if (regs
->flags
& X86_EFLAGS_IF
)
77 static inline void preempt_conditional_cli(struct pt_regs
*regs
)
79 if (regs
->flags
& X86_EFLAGS_IF
)
81 /* Make sure to not schedule here because we could be running
82 on an exception stack. */
86 void printk_address(unsigned long address
, int reliable
)
88 printk(" [<%016lx>] %s%pS\n", address
, reliable
? "": "? ", (void *) address
);
91 static unsigned long *in_exception_stack(unsigned cpu
, unsigned long stack
,
92 unsigned *usedp
, char **idp
)
94 static char ids
[][8] = {
95 [DEBUG_STACK
- 1] = "#DB",
96 [NMI_STACK
- 1] = "NMI",
97 [DOUBLEFAULT_STACK
- 1] = "#DF",
98 [STACKFAULT_STACK
- 1] = "#SS",
99 [MCE_STACK
- 1] = "#MC",
100 #if DEBUG_STKSZ > EXCEPTION_STKSZ
101 [N_EXCEPTION_STACKS
... N_EXCEPTION_STACKS
+ DEBUG_STKSZ
/ EXCEPTION_STKSZ
- 2] = "#DB[?]"
107 * Iterate over all exception stacks, and figure out whether
108 * 'stack' is in one of them:
110 for (k
= 0; k
< N_EXCEPTION_STACKS
; k
++) {
111 unsigned long end
= per_cpu(orig_ist
, cpu
).ist
[k
];
113 * Is 'stack' above this exception frame's end?
114 * If yes then skip to the next frame.
119 * Is 'stack' above this exception frame's start address?
120 * If yes then we found the right frame.
122 if (stack
>= end
- EXCEPTION_STKSZ
) {
124 * Make sure we only iterate through an exception
125 * stack once. If it comes up for the second time
126 * then there's something wrong going on - just
127 * break out and return NULL:
129 if (*usedp
& (1U << k
))
133 return (unsigned long *)end
;
136 * If this is a debug stack, and if it has a larger size than
137 * the usual exception stacks, then 'stack' might still
138 * be within the lower portion of the debug stack:
140 #if DEBUG_STKSZ > EXCEPTION_STKSZ
141 if (k
== DEBUG_STACK
- 1 && stack
>= end
- DEBUG_STKSZ
) {
142 unsigned j
= N_EXCEPTION_STACKS
- 1;
145 * Black magic. A large debug stack is composed of
146 * multiple exception stack entries, which we
147 * iterate through now. Dont look:
151 end
-= EXCEPTION_STKSZ
;
152 ids
[j
][4] = '1' + (j
- N_EXCEPTION_STACKS
);
153 } while (stack
< end
- EXCEPTION_STKSZ
);
154 if (*usedp
& (1U << j
))
158 return (unsigned long *)end
;
166 * x86-64 can have up to three kernel stacks:
169 * severe exception (double fault, nmi, stack fault, debug, mce) hardware stack
172 static inline int valid_stack_ptr(struct thread_info
*tinfo
,
173 void *p
, unsigned int size
, void *end
)
177 if (p
< end
&& p
>= (end
-THREAD_SIZE
))
182 return p
> t
&& p
< t
+ THREAD_SIZE
- size
;
185 /* The form of the top of the frame on the stack */
187 struct stack_frame
*next_frame
;
188 unsigned long return_address
;
191 static inline unsigned long
192 print_context_stack(struct thread_info
*tinfo
,
193 unsigned long *stack
, unsigned long bp
,
194 const struct stacktrace_ops
*ops
, void *data
,
197 struct stack_frame
*frame
= (struct stack_frame
*)bp
;
199 while (valid_stack_ptr(tinfo
, stack
, sizeof(*stack
), end
)) {
203 if (__kernel_text_address(addr
)) {
204 if ((unsigned long) stack
== bp
+ 8) {
205 ops
->address(data
, addr
, 1);
206 frame
= frame
->next_frame
;
207 bp
= (unsigned long) frame
;
209 ops
->address(data
, addr
, bp
== 0);
217 void dump_trace(struct task_struct
*task
, struct pt_regs
*regs
,
218 unsigned long *stack
, unsigned long bp
,
219 const struct stacktrace_ops
*ops
, void *data
)
221 const unsigned cpu
= get_cpu();
222 unsigned long *irqstack_end
= (unsigned long*)cpu_pda(cpu
)->irqstackptr
;
224 struct thread_info
*tinfo
;
232 if (task
&& task
!= current
)
233 stack
= (unsigned long *)task
->thread
.sp
;
236 #ifdef CONFIG_FRAME_POINTER
238 if (task
== current
) {
239 /* Grab bp right from our regs */
240 asm("movq %%rbp, %0" : "=r" (bp
) :);
242 /* bp is the last reg pushed by switch_to */
243 bp
= *(unsigned long *) task
->thread
.sp
;
249 * Print function call entries in all stacks, starting at the
250 * current stack address. If the stacks consist of nested
253 tinfo
= task_thread_info(task
);
256 unsigned long *estack_end
;
257 estack_end
= in_exception_stack(cpu
, (unsigned long)stack
,
261 if (ops
->stack(data
, id
) < 0)
264 bp
= print_context_stack(tinfo
, stack
, bp
, ops
,
266 ops
->stack(data
, "<EOE>");
268 * We link to the next stack via the
269 * second-to-last pointer (index -2 to end) in the
272 stack
= (unsigned long *) estack_end
[-2];
276 unsigned long *irqstack
;
277 irqstack
= irqstack_end
-
278 (IRQSTACKSIZE
- 64) / sizeof(*irqstack
);
280 if (stack
>= irqstack
&& stack
< irqstack_end
) {
281 if (ops
->stack(data
, "IRQ") < 0)
283 bp
= print_context_stack(tinfo
, stack
, bp
,
284 ops
, data
, irqstack_end
);
286 * We link to the next stack (which would be
287 * the process stack normally) the last
288 * pointer (index -1 to end) in the IRQ stack:
290 stack
= (unsigned long *) (irqstack_end
[-1]);
292 ops
->stack(data
, "EOI");
300 * This handles the process stack:
302 bp
= print_context_stack(tinfo
, stack
, bp
, ops
, data
, NULL
);
305 EXPORT_SYMBOL(dump_trace
);
308 print_trace_warning_symbol(void *data
, char *msg
, unsigned long symbol
)
310 print_symbol(msg
, symbol
);
314 static void print_trace_warning(void *data
, char *msg
)
319 static int print_trace_stack(void *data
, char *name
)
321 printk(" <%s> ", name
);
325 static void print_trace_address(void *data
, unsigned long addr
, int reliable
)
327 touch_nmi_watchdog();
328 printk_address(addr
, reliable
);
331 static const struct stacktrace_ops print_trace_ops
= {
332 .warning
= print_trace_warning
,
333 .warning_symbol
= print_trace_warning_symbol
,
334 .stack
= print_trace_stack
,
335 .address
= print_trace_address
,
339 show_trace_log_lvl(struct task_struct
*task
, struct pt_regs
*regs
,
340 unsigned long *stack
, unsigned long bp
, char *log_lvl
)
342 printk("Call Trace:\n");
343 dump_trace(task
, regs
, stack
, bp
, &print_trace_ops
, log_lvl
);
346 void show_trace(struct task_struct
*task
, struct pt_regs
*regs
,
347 unsigned long *stack
, unsigned long bp
)
349 show_trace_log_lvl(task
, regs
, stack
, bp
, "");
353 show_stack_log_lvl(struct task_struct
*task
, struct pt_regs
*regs
,
354 unsigned long *sp
, unsigned long bp
, char *log_lvl
)
356 unsigned long *stack
;
358 const int cpu
= smp_processor_id();
359 unsigned long *irqstack_end
= (unsigned long *) (cpu_pda(cpu
)->irqstackptr
);
360 unsigned long *irqstack
= (unsigned long *) (cpu_pda(cpu
)->irqstackptr
- IRQSTACKSIZE
);
362 // debugging aid: "show_stack(NULL, NULL);" prints the
363 // back trace for this cpu.
367 sp
= (unsigned long *)task
->thread
.sp
;
369 sp
= (unsigned long *)&sp
;
373 for (i
= 0; i
< kstack_depth_to_print
; i
++) {
374 if (stack
>= irqstack
&& stack
<= irqstack_end
) {
375 if (stack
== irqstack_end
) {
376 stack
= (unsigned long *) (irqstack_end
[-1]);
380 if (((long) stack
& (THREAD_SIZE
-1)) == 0)
383 if (i
&& ((i
% 4) == 0))
385 printk(" %016lx", *stack
++);
386 touch_nmi_watchdog();
389 show_trace_log_lvl(task
, regs
, sp
, bp
, log_lvl
);
392 void show_stack(struct task_struct
*task
, unsigned long *sp
)
394 show_stack_log_lvl(task
, NULL
, sp
, 0, "");
398 * The architecture-independent dump_stack generator
400 void dump_stack(void)
402 unsigned long bp
= 0;
405 #ifdef CONFIG_FRAME_POINTER
407 asm("movq %%rbp, %0" : "=r" (bp
):);
410 printk("Pid: %d, comm: %.20s %s %s %.*s\n",
411 current
->pid
, current
->comm
, print_tainted(),
412 init_utsname()->release
,
413 (int)strcspn(init_utsname()->version
, " "),
414 init_utsname()->version
);
415 show_trace(NULL
, NULL
, &stack
, bp
);
418 EXPORT_SYMBOL(dump_stack
);
420 void show_registers(struct pt_regs
*regs
)
424 const int cpu
= smp_processor_id();
425 struct task_struct
*cur
= cpu_pda(cpu
)->pcurrent
;
428 printk("CPU %d ", cpu
);
430 printk("Process %s (pid: %d, threadinfo %p, task %p)\n",
431 cur
->comm
, cur
->pid
, task_thread_info(cur
), cur
);
434 * When in-kernel, we also print out the stack and code at the
435 * time of the fault..
437 if (!user_mode(regs
)) {
438 unsigned int code_prologue
= code_bytes
* 43 / 64;
439 unsigned int code_len
= code_bytes
;
444 show_stack_log_lvl(NULL
, regs
, (unsigned long *)sp
,
447 printk(KERN_EMERG
"Code: ");
449 ip
= (u8
*)regs
->ip
- code_prologue
;
450 if (ip
< (u8
*)PAGE_OFFSET
|| probe_kernel_address(ip
, c
)) {
451 /* try starting at RIP */
453 code_len
= code_len
- code_prologue
+ 1;
455 for (i
= 0; i
< code_len
; i
++, ip
++) {
456 if (ip
< (u8
*)PAGE_OFFSET
||
457 probe_kernel_address(ip
, c
)) {
458 printk(" Bad RIP value.");
461 if (ip
== (u8
*)regs
->ip
)
462 printk("<%02x> ", c
);
470 int is_valid_bugaddr(unsigned long ip
)
474 if (__copy_from_user(&ud2
, (const void __user
*) ip
, sizeof(ud2
)))
477 return ud2
== 0x0b0f;
480 static raw_spinlock_t die_lock
= __RAW_SPIN_LOCK_UNLOCKED
;
481 static int die_owner
= -1;
482 static unsigned int die_nest_count
;
484 unsigned __kprobes
long oops_begin(void)
491 /* racy, but better than risking deadlock. */
492 raw_local_irq_save(flags
);
493 cpu
= smp_processor_id();
494 if (!__raw_spin_trylock(&die_lock
)) {
495 if (cpu
== die_owner
)
496 /* nested oops. should stop eventually */;
498 __raw_spin_lock(&die_lock
);
507 void __kprobes
oops_end(unsigned long flags
, struct pt_regs
*regs
, int signr
)
513 /* Nest count reaches zero, release the lock. */
514 __raw_spin_unlock(&die_lock
);
515 raw_local_irq_restore(flags
);
521 panic("Fatal exception");
526 int __kprobes
__die(const char *str
, struct pt_regs
*regs
, long err
)
528 printk(KERN_EMERG
"%s: %04lx [%u] ", str
, err
& 0xffff, ++die_counter
);
529 #ifdef CONFIG_PREEMPT
535 #ifdef CONFIG_DEBUG_PAGEALLOC
536 printk("DEBUG_PAGEALLOC");
539 if (notify_die(DIE_OOPS
, str
, regs
, err
,
540 current
->thread
.trap_no
, SIGSEGV
) == NOTIFY_STOP
)
543 show_registers(regs
);
544 add_taint(TAINT_DIE
);
545 /* Executive summary in case the oops scrolled away */
546 printk(KERN_ALERT
"RIP ");
547 printk_address(regs
->ip
, 1);
548 printk(" RSP <%016lx>\n", regs
->sp
);
549 if (kexec_should_crash(current
))
554 void die(const char *str
, struct pt_regs
*regs
, long err
)
556 unsigned long flags
= oops_begin();
558 if (!user_mode(regs
))
559 report_bug(regs
->ip
, regs
);
561 if (__die(str
, regs
, err
))
563 oops_end(flags
, regs
, SIGSEGV
);
566 notrace __kprobes
void
567 die_nmi(char *str
, struct pt_regs
*regs
, int do_panic
)
571 if (notify_die(DIE_NMIWATCHDOG
, str
, regs
, 0, 2, SIGINT
) == NOTIFY_STOP
)
574 flags
= oops_begin();
576 * We are in trouble anyway, lets at least try
577 * to get a message out.
579 printk(KERN_EMERG
"%s", str
);
580 printk(" on CPU%d, ip %08lx, registers:\n",
581 smp_processor_id(), regs
->ip
);
582 show_registers(regs
);
583 if (kexec_should_crash(current
))
585 if (do_panic
|| panic_on_oops
)
586 panic("Non maskable interrupt");
587 oops_end(flags
, NULL
, SIGBUS
);
593 static void __kprobes
594 do_trap(int trapnr
, int signr
, char *str
, struct pt_regs
*regs
,
595 long error_code
, siginfo_t
*info
)
597 struct task_struct
*tsk
= current
;
599 if (!user_mode(regs
))
603 * We want error_code and trap_no set for userspace faults and
604 * kernelspace faults which result in die(), but not
605 * kernelspace faults which are fixed up. die() gives the
606 * process no chance to handle the signal and notice the
607 * kernel fault information, so that won't result in polluting
608 * the information about previously queued, but not yet
609 * delivered, faults. See also do_general_protection below.
611 tsk
->thread
.error_code
= error_code
;
612 tsk
->thread
.trap_no
= trapnr
;
614 if (show_unhandled_signals
&& unhandled_signal(tsk
, signr
) &&
615 printk_ratelimit()) {
617 "%s[%d] trap %s ip:%lx sp:%lx error:%lx",
618 tsk
->comm
, tsk
->pid
, str
,
619 regs
->ip
, regs
->sp
, error_code
);
620 print_vma_addr(" in ", regs
->ip
);
625 force_sig_info(signr
, info
, tsk
);
627 force_sig(signr
, tsk
);
631 if (!fixup_exception(regs
)) {
632 tsk
->thread
.error_code
= error_code
;
633 tsk
->thread
.trap_no
= trapnr
;
634 die(str
, regs
, error_code
);
639 #define DO_ERROR(trapnr, signr, str, name) \
640 asmlinkage void do_##name(struct pt_regs * regs, long error_code) \
642 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
645 conditional_sti(regs); \
646 do_trap(trapnr, signr, str, regs, error_code, NULL); \
649 #define DO_ERROR_INFO(trapnr, signr, str, name, sicode, siaddr) \
650 asmlinkage void do_##name(struct pt_regs * regs, long error_code) \
653 info.si_signo = signr; \
655 info.si_code = sicode; \
656 info.si_addr = (void __user *)siaddr; \
657 trace_hardirqs_fixup(); \
658 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
661 conditional_sti(regs); \
662 do_trap(trapnr, signr, str, regs, error_code, &info); \
665 DO_ERROR_INFO(0, SIGFPE
, "divide error", divide_error
, FPE_INTDIV
, regs
->ip
)
666 DO_ERROR(4, SIGSEGV
, "overflow", overflow
)
667 DO_ERROR(5, SIGSEGV
, "bounds", bounds
)
668 DO_ERROR_INFO(6, SIGILL
, "invalid opcode", invalid_op
, ILL_ILLOPN
, regs
->ip
)
669 DO_ERROR(9, SIGFPE
, "coprocessor segment overrun", coprocessor_segment_overrun
)
670 DO_ERROR(10, SIGSEGV
, "invalid TSS", invalid_TSS
)
671 DO_ERROR(11, SIGBUS
, "segment not present", segment_not_present
)
672 DO_ERROR_INFO(17, SIGBUS
, "alignment check", alignment_check
, BUS_ADRALN
, 0)
674 /* Runs on IST stack */
675 asmlinkage
void do_stack_segment(struct pt_regs
*regs
, long error_code
)
677 if (notify_die(DIE_TRAP
, "stack segment", regs
, error_code
,
678 12, SIGBUS
) == NOTIFY_STOP
)
680 preempt_conditional_sti(regs
);
681 do_trap(12, SIGBUS
, "stack segment", regs
, error_code
, NULL
);
682 preempt_conditional_cli(regs
);
685 asmlinkage
void do_double_fault(struct pt_regs
* regs
, long error_code
)
687 static const char str
[] = "double fault";
688 struct task_struct
*tsk
= current
;
690 /* Return not checked because double check cannot be ignored */
691 notify_die(DIE_TRAP
, str
, regs
, error_code
, 8, SIGSEGV
);
693 tsk
->thread
.error_code
= error_code
;
694 tsk
->thread
.trap_no
= 8;
696 /* This is always a kernel trap and never fixable (and thus must
699 die(str
, regs
, error_code
);
702 asmlinkage
void __kprobes
703 do_general_protection(struct pt_regs
*regs
, long error_code
)
705 struct task_struct
*tsk
;
707 conditional_sti(regs
);
710 if (!user_mode(regs
))
713 tsk
->thread
.error_code
= error_code
;
714 tsk
->thread
.trap_no
= 13;
716 if (show_unhandled_signals
&& unhandled_signal(tsk
, SIGSEGV
) &&
717 printk_ratelimit()) {
719 "%s[%d] general protection ip:%lx sp:%lx error:%lx",
721 regs
->ip
, regs
->sp
, error_code
);
722 print_vma_addr(" in ", regs
->ip
);
726 force_sig(SIGSEGV
, tsk
);
730 if (fixup_exception(regs
))
733 tsk
->thread
.error_code
= error_code
;
734 tsk
->thread
.trap_no
= 13;
735 if (notify_die(DIE_GPF
, "general protection fault", regs
,
736 error_code
, 13, SIGSEGV
) == NOTIFY_STOP
)
738 die("general protection fault", regs
, error_code
);
741 static notrace __kprobes
void
742 mem_parity_error(unsigned char reason
, struct pt_regs
*regs
)
744 printk(KERN_EMERG
"Uhhuh. NMI received for unknown reason %02x.\n",
746 printk(KERN_EMERG
"You have some hardware problem, likely on the PCI bus.\n");
748 #if defined(CONFIG_EDAC)
749 if (edac_handler_set()) {
750 edac_atomic_assert_error();
755 if (panic_on_unrecovered_nmi
)
756 panic("NMI: Not continuing");
758 printk(KERN_EMERG
"Dazed and confused, but trying to continue\n");
760 /* Clear and disable the memory parity error line. */
761 reason
= (reason
& 0xf) | 4;
765 static notrace __kprobes
void
766 io_check_error(unsigned char reason
, struct pt_regs
*regs
)
768 printk("NMI: IOCK error (debug interrupt?)\n");
769 show_registers(regs
);
771 /* Re-enable the IOCK line, wait for a few seconds */
772 reason
= (reason
& 0xf) | 8;
779 static notrace __kprobes
void
780 unknown_nmi_error(unsigned char reason
, struct pt_regs
* regs
)
782 if (notify_die(DIE_NMIUNKNOWN
, "nmi", regs
, reason
, 2, SIGINT
) == NOTIFY_STOP
)
784 printk(KERN_EMERG
"Uhhuh. NMI received for unknown reason %02x.\n",
786 printk(KERN_EMERG
"Do you have a strange power saving mode enabled?\n");
788 if (panic_on_unrecovered_nmi
)
789 panic("NMI: Not continuing");
791 printk(KERN_EMERG
"Dazed and confused, but trying to continue\n");
794 /* Runs on IST stack. This code must keep interrupts off all the time.
795 Nested NMIs are prevented by the CPU. */
796 asmlinkage notrace __kprobes
void default_do_nmi(struct pt_regs
*regs
)
798 unsigned char reason
= 0;
801 cpu
= smp_processor_id();
803 /* Only the BSP gets external NMIs from the system. */
805 reason
= get_nmi_reason();
807 if (!(reason
& 0xc0)) {
808 if (notify_die(DIE_NMI_IPI
, "nmi_ipi", regs
, reason
, 2, SIGINT
)
812 * Ok, so this is none of the documented NMI sources,
813 * so it must be the NMI watchdog.
815 if (nmi_watchdog_tick(regs
, reason
))
817 if (!do_nmi_callback(regs
, cpu
))
818 unknown_nmi_error(reason
, regs
);
822 if (notify_die(DIE_NMI
, "nmi", regs
, reason
, 2, SIGINT
) == NOTIFY_STOP
)
825 /* AK: following checks seem to be broken on modern chipsets. FIXME */
827 mem_parity_error(reason
, regs
);
829 io_check_error(reason
, regs
);
832 asmlinkage notrace __kprobes
void
833 do_nmi(struct pt_regs
*regs
, long error_code
)
837 add_pda(__nmi_count
, 1);
840 default_do_nmi(regs
);
851 void restart_nmi(void)
857 /* runs on IST stack. */
858 asmlinkage
void __kprobes
do_int3(struct pt_regs
*regs
, long error_code
)
860 trace_hardirqs_fixup();
862 if (notify_die(DIE_INT3
, "int3", regs
, error_code
, 3, SIGTRAP
)
866 preempt_conditional_sti(regs
);
867 do_trap(3, SIGTRAP
, "int3", regs
, error_code
, NULL
);
868 preempt_conditional_cli(regs
);
871 /* Help handler running on IST stack to switch back to user stack
872 for scheduling or signal handling. The actual stack switch is done in
874 asmlinkage __kprobes
struct pt_regs
*sync_regs(struct pt_regs
*eregs
)
876 struct pt_regs
*regs
= eregs
;
877 /* Did already sync */
878 if (eregs
== (struct pt_regs
*)eregs
->sp
)
880 /* Exception from user space */
881 else if (user_mode(eregs
))
882 regs
= task_pt_regs(current
);
883 /* Exception from kernel and interrupts are enabled. Move to
884 kernel process stack. */
885 else if (eregs
->flags
& X86_EFLAGS_IF
)
886 regs
= (struct pt_regs
*)(eregs
->sp
-= sizeof(struct pt_regs
));
892 /* runs on IST stack. */
893 asmlinkage
void __kprobes
do_debug(struct pt_regs
* regs
,
894 unsigned long error_code
)
896 struct task_struct
*tsk
= current
;
897 unsigned long condition
;
900 trace_hardirqs_fixup();
902 get_debugreg(condition
, 6);
905 * The processor cleared BTF, so don't mark that we need it set.
907 clear_tsk_thread_flag(tsk
, TIF_DEBUGCTLMSR
);
908 tsk
->thread
.debugctlmsr
= 0;
910 if (notify_die(DIE_DEBUG
, "debug", regs
, condition
, error_code
,
911 SIGTRAP
) == NOTIFY_STOP
)
914 preempt_conditional_sti(regs
);
916 /* Mask out spurious debug traps due to lazy DR7 setting */
917 if (condition
& (DR_TRAP0
|DR_TRAP1
|DR_TRAP2
|DR_TRAP3
)) {
918 if (!tsk
->thread
.debugreg7
)
922 tsk
->thread
.debugreg6
= condition
;
925 * Single-stepping through TF: make sure we ignore any events in
926 * kernel space (but re-enable TF when returning to user mode).
928 if (condition
& DR_STEP
) {
929 if (!user_mode(regs
))
930 goto clear_TF_reenable
;
933 /* Ok, finally something we can handle */
934 tsk
->thread
.trap_no
= 1;
935 tsk
->thread
.error_code
= error_code
;
936 info
.si_signo
= SIGTRAP
;
938 info
.si_code
= TRAP_BRKPT
;
939 info
.si_addr
= user_mode(regs
) ? (void __user
*)regs
->ip
: NULL
;
940 force_sig_info(SIGTRAP
, &info
, tsk
);
944 preempt_conditional_cli(regs
);
948 set_tsk_thread_flag(tsk
, TIF_SINGLESTEP
);
949 regs
->flags
&= ~X86_EFLAGS_TF
;
950 preempt_conditional_cli(regs
);
954 static int kernel_math_error(struct pt_regs
*regs
, const char *str
, int trapnr
)
956 if (fixup_exception(regs
))
959 notify_die(DIE_GPF
, str
, regs
, 0, trapnr
, SIGFPE
);
960 /* Illegal floating point operation in the kernel */
961 current
->thread
.trap_no
= trapnr
;
967 * Note that we play around with the 'TS' bit in an attempt to get
968 * the correct behaviour even in the presence of the asynchronous
971 asmlinkage
void do_coprocessor_error(struct pt_regs
*regs
)
973 void __user
*ip
= (void __user
*)(regs
->ip
);
974 struct task_struct
*task
;
976 unsigned short cwd
, swd
;
978 conditional_sti(regs
);
979 if (!user_mode(regs
) &&
980 kernel_math_error(regs
, "kernel x87 math error", 16))
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 */
1008 default: /* Multiple exceptions */
1010 case 0x001: /* Invalid Op */
1012 * swd & 0x240 == 0x040: Stack Underflow
1013 * swd & 0x240 == 0x240: Stack Overflow
1014 * User must clear the SF bit (0x40) if set
1016 info
.si_code
= FPE_FLTINV
;
1018 case 0x002: /* Denormalize */
1019 case 0x010: /* Underflow */
1020 info
.si_code
= FPE_FLTUND
;
1022 case 0x004: /* Zero Divide */
1023 info
.si_code
= FPE_FLTDIV
;
1025 case 0x008: /* Overflow */
1026 info
.si_code
= FPE_FLTOVF
;
1028 case 0x020: /* Precision */
1029 info
.si_code
= FPE_FLTRES
;
1032 force_sig_info(SIGFPE
, &info
, task
);
1035 asmlinkage
void bad_intr(void)
1037 printk("bad interrupt");
1040 asmlinkage
void do_simd_coprocessor_error(struct pt_regs
*regs
)
1042 void __user
*ip
= (void __user
*)(regs
->ip
);
1043 struct task_struct
*task
;
1045 unsigned short mxcsr
;
1047 conditional_sti(regs
);
1048 if (!user_mode(regs
) &&
1049 kernel_math_error(regs
, "kernel simd math error", 19))
1053 * Save the info for the exception handler and clear the error.
1056 save_init_fpu(task
);
1057 task
->thread
.trap_no
= 19;
1058 task
->thread
.error_code
= 0;
1059 info
.si_signo
= SIGFPE
;
1061 info
.si_code
= __SI_FAULT
;
1064 * The SIMD FPU exceptions are handled a little differently, as there
1065 * is only a single status/control register. Thus, to determine which
1066 * unmasked exception was caught we must mask the exception mask bits
1067 * at 0x1f80, and then use these to mask the exception bits at 0x3f.
1069 mxcsr
= get_fpu_mxcsr(task
);
1070 switch (~((mxcsr
& 0x1f80) >> 7) & (mxcsr
& 0x3f)) {
1074 case 0x001: /* Invalid Op */
1075 info
.si_code
= FPE_FLTINV
;
1077 case 0x002: /* Denormalize */
1078 case 0x010: /* Underflow */
1079 info
.si_code
= FPE_FLTUND
;
1081 case 0x004: /* Zero Divide */
1082 info
.si_code
= FPE_FLTDIV
;
1084 case 0x008: /* Overflow */
1085 info
.si_code
= FPE_FLTOVF
;
1087 case 0x020: /* Precision */
1088 info
.si_code
= FPE_FLTRES
;
1091 force_sig_info(SIGFPE
, &info
, task
);
1094 asmlinkage
void do_spurious_interrupt_bug(struct pt_regs
* regs
)
1098 asmlinkage
void __attribute__((weak
)) smp_thermal_interrupt(void)
1102 asmlinkage
void __attribute__((weak
)) mce_threshold_interrupt(void)
1107 * 'math_state_restore()' saves the current math information in the
1108 * old math state array, and gets the new ones from the current task
1110 * Careful.. There are problems with IBM-designed IRQ13 behaviour.
1111 * Don't touch unless you *really* know how it works.
1113 asmlinkage
void math_state_restore(void)
1115 struct task_struct
*me
= current
;
1120 * does a slab alloc which can sleep
1124 * ran out of memory!
1126 do_group_exit(SIGKILL
);
1129 local_irq_disable();
1132 clts(); /* Allow maths ops (or we recurse) */
1133 restore_fpu_checking(&me
->thread
.xstate
->fxsave
);
1134 task_thread_info(me
)->status
|= TS_USEDFPU
;
1137 EXPORT_SYMBOL_GPL(math_state_restore
);
1139 void __init
trap_init(void)
1141 set_intr_gate(0, ÷_error
);
1142 set_intr_gate_ist(1, &debug
, DEBUG_STACK
);
1143 set_intr_gate_ist(2, &nmi
, NMI_STACK
);
1144 set_system_gate_ist(3, &int3
, DEBUG_STACK
); /* int3 can be called from all */
1145 set_system_gate(4, &overflow
); /* int4 can be called from all */
1146 set_intr_gate(5, &bounds
);
1147 set_intr_gate(6, &invalid_op
);
1148 set_intr_gate(7, &device_not_available
);
1149 set_intr_gate_ist(8, &double_fault
, DOUBLEFAULT_STACK
);
1150 set_intr_gate(9, &coprocessor_segment_overrun
);
1151 set_intr_gate(10, &invalid_TSS
);
1152 set_intr_gate(11, &segment_not_present
);
1153 set_intr_gate_ist(12, &stack_segment
, STACKFAULT_STACK
);
1154 set_intr_gate(13, &general_protection
);
1155 set_intr_gate(14, &page_fault
);
1156 set_intr_gate(15, &spurious_interrupt_bug
);
1157 set_intr_gate(16, &coprocessor_error
);
1158 set_intr_gate(17, &alignment_check
);
1159 #ifdef CONFIG_X86_MCE
1160 set_intr_gate_ist(18, &machine_check
, MCE_STACK
);
1162 set_intr_gate(19, &simd_coprocessor_error
);
1164 #ifdef CONFIG_IA32_EMULATION
1165 set_system_gate(IA32_SYSCALL_VECTOR
, ia32_syscall
);
1168 * initialize the per thread extended state:
1170 init_thread_xstate();
1172 * Should be a barrier for any external CPU state:
1177 static int __init
oops_setup(char *s
)
1181 if (!strcmp(s
, "panic"))
1185 early_param("oops", oops_setup
);
1187 static int __init
kstack_setup(char *s
)
1191 kstack_depth_to_print
= simple_strtoul(s
, NULL
, 0);
1194 early_param("kstack", kstack_setup
);
1196 static int __init
code_bytes_setup(char *s
)
1198 code_bytes
= simple_strtoul(s
, NULL
, 0);
1199 if (code_bytes
> 8192)
1204 __setup("code_bytes=", code_bytes_setup
);