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 (exception_trace && unhandled_signal(tsk, signr))
589 "%s[%d] trap %s rip:%lx rsp:%lx error:%lx\n",
590 tsk->comm, tsk->pid, str,
591 regs->rip, regs->rsp, error_code);
594 force_sig_info(signr, info, tsk);
596 force_sig(signr, tsk);
603 const struct exception_table_entry *fixup;
604 fixup = search_exception_tables(regs->rip);
606 regs->rip = fixup->fixup;
608 tsk->thread.error_code = error_code;
609 tsk->thread.trap_no = trapnr;
610 die(str, regs, error_code);
616 #define DO_ERROR(trapnr, signr, str, name) \
617 asmlinkage void do_##name(struct pt_regs * regs, long error_code) \
619 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
622 conditional_sti(regs); \
623 do_trap(trapnr, signr, str, regs, error_code, NULL); \
626 #define DO_ERROR_INFO(trapnr, signr, str, name, sicode, siaddr) \
627 asmlinkage void do_##name(struct pt_regs * regs, long error_code) \
630 info.si_signo = signr; \
632 info.si_code = sicode; \
633 info.si_addr = (void __user *)siaddr; \
634 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
637 conditional_sti(regs); \
638 do_trap(trapnr, signr, str, regs, error_code, &info); \
641 DO_ERROR_INFO( 0, SIGFPE, "divide error", divide_error, FPE_INTDIV, regs->rip)
642 DO_ERROR( 4, SIGSEGV, "overflow", overflow)
643 DO_ERROR( 5, SIGSEGV, "bounds", bounds)
644 DO_ERROR_INFO( 6, SIGILL, "invalid opcode", invalid_op, ILL_ILLOPN, regs->rip)
645 DO_ERROR( 7, SIGSEGV, "device not available", device_not_available)
646 DO_ERROR( 9, SIGFPE, "coprocessor segment overrun", coprocessor_segment_overrun)
647 DO_ERROR(10, SIGSEGV, "invalid TSS", invalid_TSS)
648 DO_ERROR(11, SIGBUS, "segment not present", segment_not_present)
649 DO_ERROR_INFO(17, SIGBUS, "alignment check", alignment_check, BUS_ADRALN, 0)
650 DO_ERROR(18, SIGSEGV, "reserved", reserved)
652 /* Runs on IST stack */
653 asmlinkage void do_stack_segment(struct pt_regs *regs, long error_code)
655 if (notify_die(DIE_TRAP, "stack segment", regs, error_code,
656 12, SIGBUS) == NOTIFY_STOP)
658 preempt_conditional_sti(regs);
659 do_trap(12, SIGBUS, "stack segment", regs, error_code, NULL);
660 preempt_conditional_cli(regs);
663 asmlinkage void do_double_fault(struct pt_regs * regs, long error_code)
665 static const char str[] = "double fault";
666 struct task_struct *tsk = current;
668 /* Return not checked because double check cannot be ignored */
669 notify_die(DIE_TRAP, str, regs, error_code, 8, SIGSEGV);
671 tsk->thread.error_code = error_code;
672 tsk->thread.trap_no = 8;
674 /* This is always a kernel trap and never fixable (and thus must
677 die(str, regs, error_code);
680 asmlinkage void __kprobes do_general_protection(struct pt_regs * regs,
683 struct task_struct *tsk = current;
685 conditional_sti(regs);
687 if (user_mode(regs)) {
688 tsk->thread.error_code = error_code;
689 tsk->thread.trap_no = 13;
691 if (exception_trace && unhandled_signal(tsk, SIGSEGV))
693 "%s[%d] general protection rip:%lx rsp:%lx error:%lx\n",
695 regs->rip, regs->rsp, error_code);
697 force_sig(SIGSEGV, tsk);
703 const struct exception_table_entry *fixup;
704 fixup = search_exception_tables(regs->rip);
706 regs->rip = fixup->fixup;
710 tsk->thread.error_code = error_code;
711 tsk->thread.trap_no = 13;
712 if (notify_die(DIE_GPF, "general protection fault", regs,
713 error_code, 13, SIGSEGV) == NOTIFY_STOP)
715 die("general protection fault", regs, error_code);
719 static __kprobes void
720 mem_parity_error(unsigned char reason, struct pt_regs * regs)
722 printk(KERN_EMERG "Uhhuh. NMI received for unknown reason %02x.\n",
724 printk(KERN_EMERG "You have some hardware problem, likely on the PCI bus.\n");
726 #if defined(CONFIG_EDAC)
727 if(edac_handler_set()) {
728 edac_atomic_assert_error();
733 if (panic_on_unrecovered_nmi)
734 panic("NMI: Not continuing");
736 printk(KERN_EMERG "Dazed and confused, but trying to continue\n");
738 /* Clear and disable the memory parity error line. */
739 reason = (reason & 0xf) | 4;
743 static __kprobes void
744 io_check_error(unsigned char reason, struct pt_regs * regs)
746 printk("NMI: IOCK error (debug interrupt?)\n");
747 show_registers(regs);
749 /* Re-enable the IOCK line, wait for a few seconds */
750 reason = (reason & 0xf) | 8;
757 static __kprobes void
758 unknown_nmi_error(unsigned char reason, struct pt_regs * regs)
760 printk(KERN_EMERG "Uhhuh. NMI received for unknown reason %02x.\n",
762 printk(KERN_EMERG "Do you have a strange power saving mode enabled?\n");
764 if (panic_on_unrecovered_nmi)
765 panic("NMI: Not continuing");
767 printk(KERN_EMERG "Dazed and confused, but trying to continue\n");
770 /* Runs on IST stack. This code must keep interrupts off all the time.
771 Nested NMIs are prevented by the CPU. */
772 asmlinkage __kprobes void default_do_nmi(struct pt_regs *regs)
774 unsigned char reason = 0;
777 cpu = smp_processor_id();
779 /* Only the BSP gets external NMIs from the system. */
781 reason = get_nmi_reason();
783 if (!(reason & 0xc0)) {
784 if (notify_die(DIE_NMI_IPI, "nmi_ipi", regs, reason, 2, SIGINT)
788 * Ok, so this is none of the documented NMI sources,
789 * so it must be the NMI watchdog.
791 if (nmi_watchdog_tick(regs,reason))
793 if (!do_nmi_callback(regs,cpu))
794 unknown_nmi_error(reason, regs);
798 if (notify_die(DIE_NMI, "nmi", regs, reason, 2, SIGINT) == NOTIFY_STOP)
801 /* AK: following checks seem to be broken on modern chipsets. FIXME */
804 mem_parity_error(reason, regs);
806 io_check_error(reason, regs);
809 /* runs on IST stack. */
810 asmlinkage void __kprobes do_int3(struct pt_regs * regs, long error_code)
812 if (notify_die(DIE_INT3, "int3", regs, error_code, 3, SIGTRAP) == NOTIFY_STOP) {
815 preempt_conditional_sti(regs);
816 do_trap(3, SIGTRAP, "int3", regs, error_code, NULL);
817 preempt_conditional_cli(regs);
820 /* Help handler running on IST stack to switch back to user stack
821 for scheduling or signal handling. The actual stack switch is done in
823 asmlinkage __kprobes struct pt_regs *sync_regs(struct pt_regs *eregs)
825 struct pt_regs *regs = eregs;
826 /* Did already sync */
827 if (eregs == (struct pt_regs *)eregs->rsp)
829 /* Exception from user space */
830 else if (user_mode(eregs))
831 regs = task_pt_regs(current);
832 /* Exception from kernel and interrupts are enabled. Move to
833 kernel process stack. */
834 else if (eregs->eflags & X86_EFLAGS_IF)
835 regs = (struct pt_regs *)(eregs->rsp -= sizeof(struct pt_regs));
841 /* runs on IST stack. */
842 asmlinkage void __kprobes do_debug(struct pt_regs * regs,
843 unsigned long error_code)
845 unsigned long condition;
846 struct task_struct *tsk = current;
849 get_debugreg(condition, 6);
851 if (notify_die(DIE_DEBUG, "debug", regs, condition, error_code,
852 SIGTRAP) == NOTIFY_STOP)
855 preempt_conditional_sti(regs);
857 /* Mask out spurious debug traps due to lazy DR7 setting */
858 if (condition & (DR_TRAP0|DR_TRAP1|DR_TRAP2|DR_TRAP3)) {
859 if (!tsk->thread.debugreg7) {
864 tsk->thread.debugreg6 = condition;
866 /* Mask out spurious TF errors due to lazy TF clearing */
867 if (condition & DR_STEP) {
869 * The TF error should be masked out only if the current
870 * process is not traced and if the TRAP flag has been set
871 * previously by a tracing process (condition detected by
872 * the PT_DTRACE flag); remember that the i386 TRAP flag
873 * can be modified by the process itself in user mode,
874 * allowing programs to debug themselves without the ptrace()
877 if (!user_mode(regs))
878 goto clear_TF_reenable;
880 * Was the TF flag set by a debugger? If so, clear it now,
881 * so that register information is correct.
883 if (tsk->ptrace & PT_DTRACE) {
884 regs->eflags &= ~TF_MASK;
885 tsk->ptrace &= ~PT_DTRACE;
889 /* Ok, finally something we can handle */
890 tsk->thread.trap_no = 1;
891 tsk->thread.error_code = error_code;
892 info.si_signo = SIGTRAP;
894 info.si_code = TRAP_BRKPT;
895 info.si_addr = user_mode(regs) ? (void __user *)regs->rip : NULL;
896 force_sig_info(SIGTRAP, &info, tsk);
899 set_debugreg(0UL, 7);
900 preempt_conditional_cli(regs);
904 set_tsk_thread_flag(tsk, TIF_SINGLESTEP);
905 regs->eflags &= ~TF_MASK;
906 preempt_conditional_cli(regs);
909 static int kernel_math_error(struct pt_regs *regs, const char *str, int trapnr)
911 const struct exception_table_entry *fixup;
912 fixup = search_exception_tables(regs->rip);
914 regs->rip = fixup->fixup;
917 notify_die(DIE_GPF, str, regs, 0, trapnr, SIGFPE);
918 /* Illegal floating point operation in the kernel */
919 current->thread.trap_no = trapnr;
925 * Note that we play around with the 'TS' bit in an attempt to get
926 * the correct behaviour even in the presence of the asynchronous
929 asmlinkage void do_coprocessor_error(struct pt_regs *regs)
931 void __user *rip = (void __user *)(regs->rip);
932 struct task_struct * task;
934 unsigned short cwd, swd;
936 conditional_sti(regs);
937 if (!user_mode(regs) &&
938 kernel_math_error(regs, "kernel x87 math error", 16))
942 * Save the info for the exception handler and clear the error.
946 task->thread.trap_no = 16;
947 task->thread.error_code = 0;
948 info.si_signo = SIGFPE;
950 info.si_code = __SI_FAULT;
953 * (~cwd & swd) will mask out exceptions that are not set to unmasked
954 * status. 0x3f is the exception bits in these regs, 0x200 is the
955 * C1 reg you need in case of a stack fault, 0x040 is the stack
956 * fault bit. We should only be taking one exception at a time,
957 * so if this combination doesn't produce any single exception,
958 * then we have a bad program that isn't synchronizing its FPU usage
959 * and it will suffer the consequences since we won't be able to
960 * fully reproduce the context of the exception
962 cwd = get_fpu_cwd(task);
963 swd = get_fpu_swd(task);
964 switch (swd & ~cwd & 0x3f) {
968 case 0x001: /* Invalid Op */
970 * swd & 0x240 == 0x040: Stack Underflow
971 * swd & 0x240 == 0x240: Stack Overflow
972 * User must clear the SF bit (0x40) if set
974 info.si_code = FPE_FLTINV;
976 case 0x002: /* Denormalize */
977 case 0x010: /* Underflow */
978 info.si_code = FPE_FLTUND;
980 case 0x004: /* Zero Divide */
981 info.si_code = FPE_FLTDIV;
983 case 0x008: /* Overflow */
984 info.si_code = FPE_FLTOVF;
986 case 0x020: /* Precision */
987 info.si_code = FPE_FLTRES;
990 force_sig_info(SIGFPE, &info, task);
993 asmlinkage void bad_intr(void)
995 printk("bad interrupt");
998 asmlinkage void do_simd_coprocessor_error(struct pt_regs *regs)
1000 void __user *rip = (void __user *)(regs->rip);
1001 struct task_struct * task;
1003 unsigned short mxcsr;
1005 conditional_sti(regs);
1006 if (!user_mode(regs) &&
1007 kernel_math_error(regs, "kernel simd math error", 19))
1011 * Save the info for the exception handler and clear the error.
1014 save_init_fpu(task);
1015 task->thread.trap_no = 19;
1016 task->thread.error_code = 0;
1017 info.si_signo = SIGFPE;
1019 info.si_code = __SI_FAULT;
1022 * The SIMD FPU exceptions are handled a little differently, as there
1023 * is only a single status/control register. Thus, to determine which
1024 * unmasked exception was caught we must mask the exception mask bits
1025 * at 0x1f80, and then use these to mask the exception bits at 0x3f.
1027 mxcsr = get_fpu_mxcsr(task);
1028 switch (~((mxcsr & 0x1f80) >> 7) & (mxcsr & 0x3f)) {
1032 case 0x001: /* Invalid Op */
1033 info.si_code = FPE_FLTINV;
1035 case 0x002: /* Denormalize */
1036 case 0x010: /* Underflow */
1037 info.si_code = FPE_FLTUND;
1039 case 0x004: /* Zero Divide */
1040 info.si_code = FPE_FLTDIV;
1042 case 0x008: /* Overflow */
1043 info.si_code = FPE_FLTOVF;
1045 case 0x020: /* Precision */
1046 info.si_code = FPE_FLTRES;
1049 force_sig_info(SIGFPE, &info, task);
1052 asmlinkage void do_spurious_interrupt_bug(struct pt_regs * regs)
1056 asmlinkage void __attribute__((weak)) smp_thermal_interrupt(void)
1060 asmlinkage void __attribute__((weak)) mce_threshold_interrupt(void)
1065 * 'math_state_restore()' saves the current math information in the
1066 * old math state array, and gets the new ones from the current task
1068 * Careful.. There are problems with IBM-designed IRQ13 behaviour.
1069 * Don't touch unless you *really* know how it works.
1071 asmlinkage void math_state_restore(void)
1073 struct task_struct *me = current;
1074 clts(); /* Allow maths ops (or we recurse) */
1078 restore_fpu_checking(&me->thread.i387.fxsave);
1079 task_thread_info(me)->status |= TS_USEDFPU;
1083 void __init trap_init(void)
1085 set_intr_gate(0,÷_error);
1086 set_intr_gate_ist(1,&debug,DEBUG_STACK);
1087 set_intr_gate_ist(2,&nmi,NMI_STACK);
1088 set_system_gate_ist(3,&int3,DEBUG_STACK); /* int3 can be called from all */
1089 set_system_gate(4,&overflow); /* int4 can be called from all */
1090 set_intr_gate(5,&bounds);
1091 set_intr_gate(6,&invalid_op);
1092 set_intr_gate(7,&device_not_available);
1093 set_intr_gate_ist(8,&double_fault, DOUBLEFAULT_STACK);
1094 set_intr_gate(9,&coprocessor_segment_overrun);
1095 set_intr_gate(10,&invalid_TSS);
1096 set_intr_gate(11,&segment_not_present);
1097 set_intr_gate_ist(12,&stack_segment,STACKFAULT_STACK);
1098 set_intr_gate(13,&general_protection);
1099 set_intr_gate(14,&page_fault);
1100 set_intr_gate(15,&spurious_interrupt_bug);
1101 set_intr_gate(16,&coprocessor_error);
1102 set_intr_gate(17,&alignment_check);
1103 #ifdef CONFIG_X86_MCE
1104 set_intr_gate_ist(18,&machine_check, MCE_STACK);
1106 set_intr_gate(19,&simd_coprocessor_error);
1108 #ifdef CONFIG_IA32_EMULATION
1109 set_system_gate(IA32_SYSCALL_VECTOR, ia32_syscall);
1113 * Should be a barrier for any external CPU state.
1119 static int __init oops_setup(char *s)
1123 if (!strcmp(s, "panic"))
1127 early_param("oops", oops_setup);
1129 static int __init kstack_setup(char *s)
1133 kstack_depth_to_print = simple_strtoul(s,NULL,0);
1136 early_param("kstack", kstack_setup);