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>
36 #include <asm/system.h>
38 #include <asm/atomic.h>
39 #include <asm/debugreg.h>
42 #include <asm/kdebug.h>
43 #include <asm/processor.h>
44 #include <asm/unwind.h>
46 #include <asm/pgalloc.h>
48 #include <asm/proto.h>
50 #include <asm/stacktrace.h>
52 asmlinkage void divide_error(void);
53 asmlinkage void debug(void);
54 asmlinkage void nmi(void);
55 asmlinkage void int3(void);
56 asmlinkage void overflow(void);
57 asmlinkage void bounds(void);
58 asmlinkage void invalid_op(void);
59 asmlinkage void device_not_available(void);
60 asmlinkage void double_fault(void);
61 asmlinkage void coprocessor_segment_overrun(void);
62 asmlinkage void invalid_TSS(void);
63 asmlinkage void segment_not_present(void);
64 asmlinkage void stack_segment(void);
65 asmlinkage void general_protection(void);
66 asmlinkage void page_fault(void);
67 asmlinkage void coprocessor_error(void);
68 asmlinkage void simd_coprocessor_error(void);
69 asmlinkage void reserved(void);
70 asmlinkage void alignment_check(void);
71 asmlinkage void machine_check(void);
72 asmlinkage void spurious_interrupt_bug(void);
74 ATOMIC_NOTIFIER_HEAD(die_chain);
75 EXPORT_SYMBOL(die_chain);
77 extern char last_sysfs_file[];
79 int register_die_notifier(struct notifier_block *nb)
82 return atomic_notifier_chain_register(&die_chain, nb);
84 EXPORT_SYMBOL(register_die_notifier); /* used modular by kdb */
86 int unregister_die_notifier(struct notifier_block *nb)
88 return atomic_notifier_chain_unregister(&die_chain, nb);
90 EXPORT_SYMBOL(unregister_die_notifier); /* used modular by kdb */
92 static inline void conditional_sti(struct pt_regs *regs)
94 if (regs->eflags & X86_EFLAGS_IF)
98 static inline void preempt_conditional_sti(struct pt_regs *regs)
101 if (regs->eflags & X86_EFLAGS_IF)
105 static inline void preempt_conditional_cli(struct pt_regs *regs)
107 if (regs->eflags & X86_EFLAGS_IF)
109 /* Make sure to not schedule here because we could be running
110 on an exception stack. */
111 preempt_enable_no_resched();
114 int kstack_depth_to_print = 12;
116 #ifdef CONFIG_KALLSYMS
117 void printk_address(unsigned long address)
119 unsigned long offset = 0, symsize;
125 symname = kallsyms_lookup(address, &symsize, &offset,
128 printk(" [<%016lx>]\n", address);
132 modname = delim = "";
133 printk(" [<%016lx>] %s%s%s%s+0x%lx/0x%lx\n",
134 address, delim, modname, delim, symname, offset, symsize);
137 void printk_address(unsigned long address)
139 printk(" [<%016lx>]\n", address);
143 static unsigned long *in_exception_stack(unsigned cpu, unsigned long stack,
144 unsigned *usedp, char **idp)
146 static char ids[][8] = {
147 [DEBUG_STACK - 1] = "#DB",
148 [NMI_STACK - 1] = "NMI",
149 [DOUBLEFAULT_STACK - 1] = "#DF",
150 [STACKFAULT_STACK - 1] = "#SS",
151 [MCE_STACK - 1] = "#MC",
152 #if DEBUG_STKSZ > EXCEPTION_STKSZ
153 [N_EXCEPTION_STACKS ... N_EXCEPTION_STACKS + DEBUG_STKSZ / EXCEPTION_STKSZ - 2] = "#DB[?]"
159 * Iterate over all exception stacks, and figure out whether
160 * 'stack' is in one of them:
162 for (k = 0; k < N_EXCEPTION_STACKS; k++) {
163 unsigned long end = per_cpu(orig_ist, cpu).ist[k];
165 * Is 'stack' above this exception frame's end?
166 * If yes then skip to the next frame.
171 * Is 'stack' above this exception frame's start address?
172 * If yes then we found the right frame.
174 if (stack >= end - EXCEPTION_STKSZ) {
176 * Make sure we only iterate through an exception
177 * stack once. If it comes up for the second time
178 * then there's something wrong going on - just
179 * break out and return NULL:
181 if (*usedp & (1U << k))
185 return (unsigned long *)end;
188 * If this is a debug stack, and if it has a larger size than
189 * the usual exception stacks, then 'stack' might still
190 * be within the lower portion of the debug stack:
192 #if DEBUG_STKSZ > EXCEPTION_STKSZ
193 if (k == DEBUG_STACK - 1 && stack >= end - DEBUG_STKSZ) {
194 unsigned j = N_EXCEPTION_STACKS - 1;
197 * Black magic. A large debug stack is composed of
198 * multiple exception stack entries, which we
199 * iterate through now. Dont look:
203 end -= EXCEPTION_STKSZ;
204 ids[j][4] = '1' + (j - N_EXCEPTION_STACKS);
205 } while (stack < end - EXCEPTION_STKSZ);
206 if (*usedp & (1U << j))
210 return (unsigned long *)end;
217 #define MSG(txt) ops->warning(data, txt)
220 * x86-64 can have upto three kernel stacks:
223 * severe exception (double fault, nmi, stack fault, debug, mce) hardware stack
226 static inline int valid_stack_ptr(struct thread_info *tinfo, void *p)
228 void *t = (void *)tinfo;
229 return p > t && p < t + THREAD_SIZE - 3;
232 void dump_trace(struct task_struct *tsk, struct pt_regs *regs,
233 unsigned long *stack,
234 struct stacktrace_ops *ops, void *data)
236 const unsigned cpu = get_cpu();
237 unsigned long *irqstack_end = (unsigned long*)cpu_pda(cpu)->irqstackptr;
239 struct thread_info *tinfo;
247 if (tsk && tsk != current)
248 stack = (unsigned long *)tsk->thread.rsp;
252 * Print function call entries within a stack. 'cond' is the
253 * "end of stackframe" condition, that the 'stack++'
254 * iteration will eventually trigger.
256 #define HANDLE_STACK(cond) \
258 unsigned long addr = *stack++; \
259 /* Use unlocked access here because except for NMIs \
260 we should be already protected against module unloads */ \
261 if (__kernel_text_address(addr)) { \
263 * If the address is either in the text segment of the \
264 * kernel, or in the region which contains vmalloc'ed \
265 * memory, it *may* be the address of a calling \
266 * routine; if so, print it so that someone tracing \
267 * down the cause of the crash will be able to figure \
268 * out the call path that was taken. \
270 ops->address(data, addr); \
275 * Print function call entries in all stacks, starting at the
276 * current stack address. If the stacks consist of nested
281 unsigned long *estack_end;
282 estack_end = in_exception_stack(cpu, (unsigned long)stack,
286 if (ops->stack(data, id) < 0)
288 HANDLE_STACK (stack < estack_end);
289 ops->stack(data, "<EOE>");
291 * We link to the next stack via the
292 * second-to-last pointer (index -2 to end) in the
295 stack = (unsigned long *) estack_end[-2];
299 unsigned long *irqstack;
300 irqstack = irqstack_end -
301 (IRQSTACKSIZE - 64) / sizeof(*irqstack);
303 if (stack >= irqstack && stack < irqstack_end) {
304 if (ops->stack(data, "IRQ") < 0)
306 HANDLE_STACK (stack < irqstack_end);
308 * We link to the next stack (which would be
309 * the process stack normally) the last
310 * pointer (index -1 to end) in the IRQ stack:
312 stack = (unsigned long *) (irqstack_end[-1]);
314 ops->stack(data, "EOI");
322 * This handles the process stack:
324 tinfo = task_thread_info(tsk);
325 HANDLE_STACK (valid_stack_ptr(tinfo, stack));
329 EXPORT_SYMBOL(dump_trace);
332 print_trace_warning_symbol(void *data, char *msg, unsigned long symbol)
334 print_symbol(msg, symbol);
338 static void print_trace_warning(void *data, char *msg)
343 static int print_trace_stack(void *data, char *name)
345 printk(" <%s> ", name);
349 static void print_trace_address(void *data, unsigned long addr)
351 printk_address(addr);
354 static struct stacktrace_ops print_trace_ops = {
355 .warning = print_trace_warning,
356 .warning_symbol = print_trace_warning_symbol,
357 .stack = print_trace_stack,
358 .address = print_trace_address,
362 show_trace(struct task_struct *tsk, struct pt_regs *regs, unsigned long *stack)
364 printk("\nCall Trace:\n");
365 dump_trace(tsk, regs, stack, &print_trace_ops, NULL);
370 _show_stack(struct task_struct *tsk, struct pt_regs *regs, unsigned long *rsp)
372 unsigned long *stack;
374 const int cpu = smp_processor_id();
375 unsigned long *irqstack_end = (unsigned long *) (cpu_pda(cpu)->irqstackptr);
376 unsigned long *irqstack = (unsigned long *) (cpu_pda(cpu)->irqstackptr - IRQSTACKSIZE);
378 // debugging aid: "show_stack(NULL, NULL);" prints the
379 // back trace for this cpu.
383 rsp = (unsigned long *)tsk->thread.rsp;
385 rsp = (unsigned long *)&rsp;
389 for(i=0; i < kstack_depth_to_print; i++) {
390 if (stack >= irqstack && stack <= irqstack_end) {
391 if (stack == irqstack_end) {
392 stack = (unsigned long *) (irqstack_end[-1]);
396 if (((long) stack & (THREAD_SIZE-1)) == 0)
399 if (i && ((i % 4) == 0))
401 printk(" %016lx", *stack++);
402 touch_nmi_watchdog();
404 show_trace(tsk, regs, rsp);
407 void show_stack(struct task_struct *tsk, unsigned long * rsp)
409 _show_stack(tsk, NULL, rsp);
413 * The architecture-independent dump_stack generator
415 void dump_stack(void)
418 show_trace(NULL, NULL, &dummy);
421 EXPORT_SYMBOL(dump_stack);
423 void show_registers(struct pt_regs *regs)
426 int in_kernel = !user_mode(regs);
428 const int cpu = smp_processor_id();
429 struct task_struct *cur = cpu_pda(cpu)->pcurrent;
433 printk("CPU %d ", cpu);
435 printk("Process %s (pid: %d[#%u], threadinfo %p, task %p)\n",
436 cur->comm, cur->pid, cur->xid,
437 task_thread_info(cur), cur);
440 * When in-kernel, we also print out the stack and code at the
441 * time of the fault..
446 _show_stack(NULL, regs, (unsigned long*)rsp);
449 if (regs->rip < PAGE_OFFSET)
452 for (i=0; i<20; i++) {
454 if (__get_user(c, &((unsigned char*)regs->rip)[i])) {
456 printk(" Bad RIP value.");
465 int is_valid_bugaddr(unsigned long rip)
469 if (__copy_from_user(&ud2, (const void __user *) rip, sizeof(ud2)))
472 return ud2 == 0x0b0f;
476 void out_of_line_bug(void)
480 EXPORT_SYMBOL(out_of_line_bug);
483 static DEFINE_SPINLOCK(die_lock);
484 static int die_owner = -1;
485 static unsigned int die_nest_count;
487 unsigned __kprobes long oops_begin(void)
489 int cpu = smp_processor_id();
494 /* racy, but better than risking deadlock. */
495 local_irq_save(flags);
496 if (!spin_trylock(&die_lock)) {
497 if (cpu == die_owner)
498 /* nested oops. should stop eventually */;
500 spin_lock(&die_lock);
509 void __kprobes oops_end(unsigned long flags)
515 /* We still own the lock */
516 local_irq_restore(flags);
518 /* Nest count reaches zero, release the lock. */
519 spin_unlock_irqrestore(&die_lock, flags);
521 panic("Fatal exception");
525 void __kprobes __die(const char * str, struct pt_regs * regs, long err)
527 static int die_counter;
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");
540 printk(KERN_ALERT "last sysfs file: %s\n", last_sysfs_file);
542 notify_die(DIE_OOPS, str, regs, err, current->thread.trap_no, SIGSEGV);
543 show_registers(regs);
544 /* Executive summary in case the oops scrolled away */
545 printk(KERN_ALERT "RIP ");
546 printk_address(regs->rip);
547 printk(" RSP <%016lx>\n", regs->rsp);
548 if (kexec_should_crash(current))
552 void die(const char * str, struct pt_regs * regs, long err)
554 unsigned long flags = oops_begin();
556 if (!user_mode(regs))
557 report_bug(regs->rip);
559 __die(str, regs, err);
564 void __kprobes die_nmi(char *str, struct pt_regs *regs, int do_panic)
566 unsigned long flags = oops_begin();
569 * We are in trouble anyway, lets at least try
570 * to get a message out.
572 printk(str, smp_processor_id());
573 show_registers(regs);
574 if (kexec_should_crash(current))
576 if (do_panic || panic_on_oops)
577 panic("Non maskable interrupt");
584 static void __kprobes do_trap(int trapnr, int signr, char *str,
585 struct pt_regs * regs, long error_code,
588 struct task_struct *tsk = current;
590 tsk->thread.error_code = error_code;
591 tsk->thread.trap_no = trapnr;
593 if (user_mode(regs)) {
594 if (exception_trace && unhandled_signal(tsk, signr))
596 "%s[%d:#%u] trap %s rip:%lx rsp:%lx error:%lx\n",
597 tsk->comm, tsk->pid, tsk->xid, str,
598 regs->rip, regs->rsp, error_code);
601 force_sig_info(signr, info, tsk);
603 force_sig(signr, tsk);
610 const struct exception_table_entry *fixup;
611 fixup = search_exception_tables(regs->rip);
613 regs->rip = fixup->fixup;
615 die(str, regs, error_code);
620 #define DO_ERROR(trapnr, signr, str, name) \
621 asmlinkage void do_##name(struct pt_regs * regs, long error_code) \
623 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
626 conditional_sti(regs); \
627 do_trap(trapnr, signr, str, regs, error_code, NULL); \
630 #define DO_ERROR_INFO(trapnr, signr, str, name, sicode, siaddr) \
631 asmlinkage void do_##name(struct pt_regs * regs, long error_code) \
634 info.si_signo = signr; \
636 info.si_code = sicode; \
637 info.si_addr = (void __user *)siaddr; \
638 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
641 conditional_sti(regs); \
642 do_trap(trapnr, signr, str, regs, error_code, &info); \
645 DO_ERROR_INFO( 0, SIGFPE, "divide error", divide_error, FPE_INTDIV, regs->rip)
646 DO_ERROR( 4, SIGSEGV, "overflow", overflow)
647 DO_ERROR( 5, SIGSEGV, "bounds", bounds)
648 DO_ERROR_INFO( 6, SIGILL, "invalid opcode", invalid_op, ILL_ILLOPN, regs->rip)
649 DO_ERROR( 7, SIGSEGV, "device not available", device_not_available)
650 DO_ERROR( 9, SIGFPE, "coprocessor segment overrun", coprocessor_segment_overrun)
651 DO_ERROR(10, SIGSEGV, "invalid TSS", invalid_TSS)
652 DO_ERROR(11, SIGBUS, "segment not present", segment_not_present)
653 DO_ERROR_INFO(17, SIGBUS, "alignment check", alignment_check, BUS_ADRALN, 0)
654 DO_ERROR(18, SIGSEGV, "reserved", reserved)
656 /* Runs on IST stack */
657 asmlinkage void do_stack_segment(struct pt_regs *regs, long error_code)
659 if (notify_die(DIE_TRAP, "stack segment", regs, error_code,
660 12, SIGBUS) == NOTIFY_STOP)
662 preempt_conditional_sti(regs);
663 do_trap(12, SIGBUS, "stack segment", regs, error_code, NULL);
664 preempt_conditional_cli(regs);
667 asmlinkage void do_double_fault(struct pt_regs * regs, long error_code)
669 static const char str[] = "double fault";
670 struct task_struct *tsk = current;
672 /* Return not checked because double check cannot be ignored */
673 notify_die(DIE_TRAP, str, regs, error_code, 8, SIGSEGV);
675 tsk->thread.error_code = error_code;
676 tsk->thread.trap_no = 8;
678 /* This is always a kernel trap and never fixable (and thus must
681 die(str, regs, error_code);
684 asmlinkage void __kprobes do_general_protection(struct pt_regs * regs,
687 struct task_struct *tsk = current;
689 conditional_sti(regs);
691 tsk->thread.error_code = error_code;
692 tsk->thread.trap_no = 13;
694 if (user_mode(regs)) {
695 if (exception_trace && unhandled_signal(tsk, SIGSEGV))
697 "%s[%d:#%u] general protection rip:%lx rsp:%lx error:%lx\n",
698 tsk->comm, tsk->pid, tsk->xid,
699 regs->rip, regs->rsp, error_code);
701 force_sig(SIGSEGV, tsk);
707 const struct exception_table_entry *fixup;
708 fixup = search_exception_tables(regs->rip);
710 regs->rip = fixup->fixup;
713 if (notify_die(DIE_GPF, "general protection fault", regs,
714 error_code, 13, SIGSEGV) == NOTIFY_STOP)
716 die("general protection fault", regs, error_code);
720 static __kprobes void
721 mem_parity_error(unsigned char reason, struct pt_regs * regs)
723 printk(KERN_EMERG "Uhhuh. NMI received for unknown reason %02x.\n",
725 printk(KERN_EMERG "You have some hardware problem, likely on the PCI bus.\n");
727 if (panic_on_unrecovered_nmi)
728 panic("NMI: Not continuing");
730 printk(KERN_EMERG "Dazed and confused, but trying to continue\n");
732 /* Clear and disable the memory parity error line. */
733 reason = (reason & 0xf) | 4;
737 static __kprobes void
738 io_check_error(unsigned char reason, struct pt_regs * regs)
740 printk("NMI: IOCK error (debug interrupt?)\n");
741 show_registers(regs);
743 /* Re-enable the IOCK line, wait for a few seconds */
744 reason = (reason & 0xf) | 8;
751 static __kprobes void
752 unknown_nmi_error(unsigned char reason, struct pt_regs * regs)
754 printk(KERN_EMERG "Uhhuh. NMI received for unknown reason %02x.\n",
756 printk(KERN_EMERG "Do you have a strange power saving mode enabled?\n");
758 if (panic_on_unrecovered_nmi)
759 panic("NMI: Not continuing");
761 printk(KERN_EMERG "Dazed and confused, but trying to continue\n");
764 /* Runs on IST stack. This code must keep interrupts off all the time.
765 Nested NMIs are prevented by the CPU. */
766 asmlinkage __kprobes void default_do_nmi(struct pt_regs *regs)
768 unsigned char reason = 0;
771 cpu = smp_processor_id();
773 /* Only the BSP gets external NMIs from the system. */
775 reason = get_nmi_reason();
777 if (!(reason & 0xc0)) {
778 if (notify_die(DIE_NMI_IPI, "nmi_ipi", regs, reason, 2, SIGINT)
782 * Ok, so this is none of the documented NMI sources,
783 * so it must be the NMI watchdog.
785 if (nmi_watchdog_tick(regs,reason))
787 if (!do_nmi_callback(regs,cpu))
788 unknown_nmi_error(reason, regs);
792 if (notify_die(DIE_NMI, "nmi", regs, reason, 2, SIGINT) == NOTIFY_STOP)
795 /* AK: following checks seem to be broken on modern chipsets. FIXME */
798 mem_parity_error(reason, regs);
800 io_check_error(reason, regs);
803 /* runs on IST stack. */
804 asmlinkage void __kprobes do_int3(struct pt_regs * regs, long error_code)
806 if (notify_die(DIE_INT3, "int3", regs, error_code, 3, SIGTRAP) == NOTIFY_STOP) {
809 preempt_conditional_sti(regs);
810 do_trap(3, SIGTRAP, "int3", regs, error_code, NULL);
811 preempt_conditional_cli(regs);
814 /* Help handler running on IST stack to switch back to user stack
815 for scheduling or signal handling. The actual stack switch is done in
817 asmlinkage __kprobes struct pt_regs *sync_regs(struct pt_regs *eregs)
819 struct pt_regs *regs = eregs;
820 /* Did already sync */
821 if (eregs == (struct pt_regs *)eregs->rsp)
823 /* Exception from user space */
824 else if (user_mode(eregs))
825 regs = task_pt_regs(current);
826 /* Exception from kernel and interrupts are enabled. Move to
827 kernel process stack. */
828 else if (eregs->eflags & X86_EFLAGS_IF)
829 regs = (struct pt_regs *)(eregs->rsp -= sizeof(struct pt_regs));
835 /* runs on IST stack. */
836 asmlinkage void __kprobes do_debug(struct pt_regs * regs,
837 unsigned long error_code)
839 unsigned long condition;
840 struct task_struct *tsk = current;
843 get_debugreg(condition, 6);
845 if (notify_die(DIE_DEBUG, "debug", regs, condition, error_code,
846 SIGTRAP) == NOTIFY_STOP)
849 preempt_conditional_sti(regs);
851 /* Mask out spurious debug traps due to lazy DR7 setting */
852 if (condition & (DR_TRAP0|DR_TRAP1|DR_TRAP2|DR_TRAP3)) {
853 if (!tsk->thread.debugreg7) {
858 tsk->thread.debugreg6 = condition;
860 /* Mask out spurious TF errors due to lazy TF clearing */
861 if (condition & DR_STEP) {
863 * The TF error should be masked out only if the current
864 * process is not traced and if the TRAP flag has been set
865 * previously by a tracing process (condition detected by
866 * the PT_DTRACE flag); remember that the i386 TRAP flag
867 * can be modified by the process itself in user mode,
868 * allowing programs to debug themselves without the ptrace()
871 if (!user_mode(regs))
872 goto clear_TF_reenable;
875 /* Ok, finally something we can handle */
876 tsk->thread.trap_no = 1;
877 tsk->thread.error_code = error_code;
878 info.si_signo = SIGTRAP;
880 info.si_code = TRAP_BRKPT;
881 info.si_addr = user_mode(regs) ? (void __user *)regs->rip : NULL;
882 force_sig_info(SIGTRAP, &info, tsk);
885 set_debugreg(0UL, 7);
886 preempt_conditional_cli(regs);
890 set_tsk_thread_flag(tsk, TIF_SINGLESTEP);
891 regs->eflags &= ~TF_MASK;
892 preempt_conditional_cli(regs);
895 static int kernel_math_error(struct pt_regs *regs, const char *str, int trapnr)
897 const struct exception_table_entry *fixup;
898 fixup = search_exception_tables(regs->rip);
900 regs->rip = fixup->fixup;
903 notify_die(DIE_GPF, str, regs, 0, trapnr, SIGFPE);
904 /* Illegal floating point operation in the kernel */
905 current->thread.trap_no = trapnr;
911 * Note that we play around with the 'TS' bit in an attempt to get
912 * the correct behaviour even in the presence of the asynchronous
915 asmlinkage void do_coprocessor_error(struct pt_regs *regs)
917 void __user *rip = (void __user *)(regs->rip);
918 struct task_struct * task;
920 unsigned short cwd, swd;
922 conditional_sti(regs);
923 if (!user_mode(regs) &&
924 kernel_math_error(regs, "kernel x87 math error", 16))
928 * Save the info for the exception handler and clear the error.
932 task->thread.trap_no = 16;
933 task->thread.error_code = 0;
934 info.si_signo = SIGFPE;
936 info.si_code = __SI_FAULT;
939 * (~cwd & swd) will mask out exceptions that are not set to unmasked
940 * status. 0x3f is the exception bits in these regs, 0x200 is the
941 * C1 reg you need in case of a stack fault, 0x040 is the stack
942 * fault bit. We should only be taking one exception at a time,
943 * so if this combination doesn't produce any single exception,
944 * then we have a bad program that isn't synchronizing its FPU usage
945 * and it will suffer the consequences since we won't be able to
946 * fully reproduce the context of the exception
948 cwd = get_fpu_cwd(task);
949 swd = get_fpu_swd(task);
950 switch (swd & ~cwd & 0x3f) {
954 case 0x001: /* Invalid Op */
956 * swd & 0x240 == 0x040: Stack Underflow
957 * swd & 0x240 == 0x240: Stack Overflow
958 * User must clear the SF bit (0x40) if set
960 info.si_code = FPE_FLTINV;
962 case 0x002: /* Denormalize */
963 case 0x010: /* Underflow */
964 info.si_code = FPE_FLTUND;
966 case 0x004: /* Zero Divide */
967 info.si_code = FPE_FLTDIV;
969 case 0x008: /* Overflow */
970 info.si_code = FPE_FLTOVF;
972 case 0x020: /* Precision */
973 info.si_code = FPE_FLTRES;
976 force_sig_info(SIGFPE, &info, task);
979 asmlinkage void bad_intr(void)
981 printk("bad interrupt");
984 asmlinkage void do_simd_coprocessor_error(struct pt_regs *regs)
986 void __user *rip = (void __user *)(regs->rip);
987 struct task_struct * task;
989 unsigned short mxcsr;
991 conditional_sti(regs);
992 if (!user_mode(regs) &&
993 kernel_math_error(regs, "kernel simd math error", 19))
997 * Save the info for the exception handler and clear the error.
1000 save_init_fpu(task);
1001 task->thread.trap_no = 19;
1002 task->thread.error_code = 0;
1003 info.si_signo = SIGFPE;
1005 info.si_code = __SI_FAULT;
1008 * The SIMD FPU exceptions are handled a little differently, as there
1009 * is only a single status/control register. Thus, to determine which
1010 * unmasked exception was caught we must mask the exception mask bits
1011 * at 0x1f80, and then use these to mask the exception bits at 0x3f.
1013 mxcsr = get_fpu_mxcsr(task);
1014 switch (~((mxcsr & 0x1f80) >> 7) & (mxcsr & 0x3f)) {
1018 case 0x001: /* Invalid Op */
1019 info.si_code = FPE_FLTINV;
1021 case 0x002: /* Denormalize */
1022 case 0x010: /* Underflow */
1023 info.si_code = FPE_FLTUND;
1025 case 0x004: /* Zero Divide */
1026 info.si_code = FPE_FLTDIV;
1028 case 0x008: /* Overflow */
1029 info.si_code = FPE_FLTOVF;
1031 case 0x020: /* Precision */
1032 info.si_code = FPE_FLTRES;
1035 force_sig_info(SIGFPE, &info, task);
1038 asmlinkage void do_spurious_interrupt_bug(struct pt_regs * regs)
1042 asmlinkage void __attribute__((weak)) smp_thermal_interrupt(void)
1046 asmlinkage void __attribute__((weak)) mce_threshold_interrupt(void)
1051 * 'math_state_restore()' saves the current math information in the
1052 * old math state array, and gets the new ones from the current task
1054 * Careful.. There are problems with IBM-designed IRQ13 behaviour.
1055 * Don't touch unless you *really* know how it works.
1057 asmlinkage void math_state_restore(void)
1059 struct task_struct *me = current;
1060 clts(); /* Allow maths ops (or we recurse) */
1064 restore_fpu_checking(&me->thread.i387.fxsave);
1065 task_thread_info(me)->status |= TS_USEDFPU;
1069 void __init trap_init(void)
1071 set_intr_gate(0,÷_error);
1072 set_intr_gate_ist(1,&debug,DEBUG_STACK);
1073 set_intr_gate_ist(2,&nmi,NMI_STACK);
1074 set_system_gate_ist(3,&int3,DEBUG_STACK); /* int3 can be called from all */
1075 set_system_gate(4,&overflow); /* int4 can be called from all */
1076 set_intr_gate(5,&bounds);
1077 set_intr_gate(6,&invalid_op);
1078 set_intr_gate(7,&device_not_available);
1079 set_intr_gate_ist(8,&double_fault, DOUBLEFAULT_STACK);
1080 set_intr_gate(9,&coprocessor_segment_overrun);
1081 set_intr_gate(10,&invalid_TSS);
1082 set_intr_gate(11,&segment_not_present);
1083 set_intr_gate_ist(12,&stack_segment,STACKFAULT_STACK);
1084 set_intr_gate(13,&general_protection);
1085 set_intr_gate(14,&page_fault);
1086 set_intr_gate(15,&spurious_interrupt_bug);
1087 set_intr_gate(16,&coprocessor_error);
1088 set_intr_gate(17,&alignment_check);
1089 #ifdef CONFIG_X86_MCE
1090 set_intr_gate_ist(18,&machine_check, MCE_STACK);
1092 set_intr_gate(19,&simd_coprocessor_error);
1094 #ifdef CONFIG_IA32_EMULATION
1095 set_system_gate(IA32_SYSCALL_VECTOR, ia32_syscall);
1099 * Should be a barrier for any external CPU state.
1105 static int __init oops_setup(char *s)
1109 if (!strcmp(s, "panic"))
1113 early_param("oops", oops_setup);
1115 static int __init kstack_setup(char *s)
1119 kstack_depth_to_print = simple_strtoul(s,NULL,0);
1122 early_param("kstack", kstack_setup);