/* * linux/arch/x86-64/traps.c * * Copyright (C) 1991, 1992 Linus Torvalds * Copyright (C) 2000, 2001, 2002 Andi Kleen, SuSE Labs * * Pentium III FXSR, SSE support * Gareth Hughes , May 2000 */ /* * 'Traps.c' handles hardware traps and faults after we have saved some * state in 'entry.S'. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include asmlinkage void divide_error(void); asmlinkage void debug(void); asmlinkage void nmi(void); asmlinkage void int3(void); asmlinkage void overflow(void); asmlinkage void bounds(void); asmlinkage void invalid_op(void); asmlinkage void device_not_available(void); asmlinkage void double_fault(void); asmlinkage void coprocessor_segment_overrun(void); asmlinkage void invalid_TSS(void); asmlinkage void segment_not_present(void); asmlinkage void stack_segment(void); asmlinkage void general_protection(void); asmlinkage void page_fault(void); asmlinkage void coprocessor_error(void); asmlinkage void simd_coprocessor_error(void); asmlinkage void reserved(void); asmlinkage void alignment_check(void); asmlinkage void machine_check(void); asmlinkage void spurious_interrupt_bug(void); ATOMIC_NOTIFIER_HEAD(die_chain); EXPORT_SYMBOL(die_chain); int register_die_notifier(struct notifier_block *nb) { vmalloc_sync_all(); return atomic_notifier_chain_register(&die_chain, nb); } EXPORT_SYMBOL(register_die_notifier); /* used modular by kdb */ int unregister_die_notifier(struct notifier_block *nb) { return atomic_notifier_chain_unregister(&die_chain, nb); } EXPORT_SYMBOL(unregister_die_notifier); /* used modular by kdb */ static inline void conditional_sti(struct pt_regs *regs) { if (regs->eflags & X86_EFLAGS_IF) local_irq_enable(); } static inline void preempt_conditional_sti(struct pt_regs *regs) { preempt_disable(); if (regs->eflags & X86_EFLAGS_IF) local_irq_enable(); } static inline void preempt_conditional_cli(struct pt_regs *regs) { if (regs->eflags & X86_EFLAGS_IF) local_irq_disable(); /* Make sure to not schedule here because we could be running on an exception stack. */ preempt_enable_no_resched(); } static int kstack_depth_to_print = 12; #ifdef CONFIG_STACK_UNWIND static int call_trace = 1; #else #define call_trace (-1) #endif #ifdef CONFIG_KALLSYMS # include void printk_address(unsigned long address) { unsigned long offset = 0, symsize; const char *symname; char *modname; char *delim = ":"; char namebuf[128]; symname = kallsyms_lookup(address, &symsize, &offset, &modname, namebuf); if (!symname) { printk(" [<%016lx>]\n", address); return; } if (!modname) modname = delim = ""; printk(" [<%016lx>] %s%s%s%s+0x%lx/0x%lx\n", address, delim, modname, delim, symname, offset, symsize); } #else void printk_address(unsigned long address) { printk(" [<%016lx>]\n", address); } #endif static unsigned long *in_exception_stack(unsigned cpu, unsigned long stack, unsigned *usedp, char **idp) { static char ids[][8] = { [DEBUG_STACK - 1] = "#DB", [NMI_STACK - 1] = "NMI", [DOUBLEFAULT_STACK - 1] = "#DF", [STACKFAULT_STACK - 1] = "#SS", [MCE_STACK - 1] = "#MC", #if DEBUG_STKSZ > EXCEPTION_STKSZ [N_EXCEPTION_STACKS ... N_EXCEPTION_STACKS + DEBUG_STKSZ / EXCEPTION_STKSZ - 2] = "#DB[?]" #endif }; unsigned k; /* * Iterate over all exception stacks, and figure out whether * 'stack' is in one of them: */ for (k = 0; k < N_EXCEPTION_STACKS; k++) { unsigned long end; /* * set 'end' to the end of the exception stack. */ switch (k + 1) { /* * TODO: this block is not needed i think, because * setup64.c:cpu_init() sets up t->ist[DEBUG_STACK] * properly too. */ #if DEBUG_STKSZ > EXCEPTION_STKSZ case DEBUG_STACK: end = cpu_pda(cpu)->debugstack + DEBUG_STKSZ; break; #endif default: end = per_cpu(orig_ist, cpu).ist[k]; break; } /* * Is 'stack' above this exception frame's end? * If yes then skip to the next frame. */ if (stack >= end) continue; /* * Is 'stack' above this exception frame's start address? * If yes then we found the right frame. */ if (stack >= end - EXCEPTION_STKSZ) { /* * Make sure we only iterate through an exception * stack once. If it comes up for the second time * then there's something wrong going on - just * break out and return NULL: */ if (*usedp & (1U << k)) break; *usedp |= 1U << k; *idp = ids[k]; return (unsigned long *)end; } /* * If this is a debug stack, and if it has a larger size than * the usual exception stacks, then 'stack' might still * be within the lower portion of the debug stack: */ #if DEBUG_STKSZ > EXCEPTION_STKSZ if (k == DEBUG_STACK - 1 && stack >= end - DEBUG_STKSZ) { unsigned j = N_EXCEPTION_STACKS - 1; /* * Black magic. A large debug stack is composed of * multiple exception stack entries, which we * iterate through now. Dont look: */ do { ++j; end -= EXCEPTION_STKSZ; ids[j][4] = '1' + (j - N_EXCEPTION_STACKS); } while (stack < end - EXCEPTION_STKSZ); if (*usedp & (1U << j)) break; *usedp |= 1U << j; *idp = ids[j]; return (unsigned long *)end; } #endif } return NULL; } struct ops_and_data { struct stacktrace_ops *ops; void *data; }; static int dump_trace_unwind(struct unwind_frame_info *info, void *context) { struct ops_and_data *oad = (struct ops_and_data *)context; int n = 0; while (unwind(info) == 0 && UNW_PC(info)) { n++; oad->ops->address(oad->data, UNW_PC(info)); if (arch_unw_user_mode(info)) break; } return n; } /* * x86-64 can have upto three kernel stacks: * process stack * interrupt stack * severe exception (double fault, nmi, stack fault, debug, mce) hardware stack */ void dump_trace(struct task_struct *tsk, struct pt_regs *regs, unsigned long * stack, struct stacktrace_ops *ops, void *data) { const unsigned cpu = safe_smp_processor_id(); unsigned long *irqstack_end = (unsigned long *)cpu_pda(cpu)->irqstackptr; unsigned used = 0; if (!tsk) tsk = current; if (call_trace >= 0) { int unw_ret = 0; struct unwind_frame_info info; struct ops_and_data oad = { .ops = ops, .data = data }; if (regs) { if (unwind_init_frame_info(&info, tsk, regs) == 0) unw_ret = dump_trace_unwind(&info, &oad); } else if (tsk == current) unw_ret = unwind_init_running(&info, dump_trace_unwind, &oad); else { if (unwind_init_blocked(&info, tsk) == 0) unw_ret = dump_trace_unwind(&info, &oad); } if (unw_ret > 0) { if (call_trace == 1 && !arch_unw_user_mode(&info)) { ops->warning_symbol(data, "DWARF2 unwinder stuck at %s\n", UNW_PC(&info)); if ((long)UNW_SP(&info) < 0) { ops->warning(data, "Leftover inexact backtrace:\n"); stack = (unsigned long *)UNW_SP(&info); if (!stack) return; } else ops->warning(data, "Full inexact backtrace again:\n"); } else if (call_trace >= 1) return; else ops->warning(data, "Full inexact backtrace again:\n"); } else ops->warning(data, "Inexact backtrace:\n"); } if (!stack) { unsigned long dummy; stack = &dummy; if (tsk && tsk != current) stack = (unsigned long *)tsk->thread.rsp; } /* * Print function call entries within a stack. 'cond' is the * "end of stackframe" condition, that the 'stack++' * iteration will eventually trigger. */ #define HANDLE_STACK(cond) \ do while (cond) { \ unsigned long addr = *stack++; \ if (kernel_text_address(addr)) { \ /* \ * If the address is either in the text segment of the \ * kernel, or in the region which contains vmalloc'ed \ * memory, it *may* be the address of a calling \ * routine; if so, print it so that someone tracing \ * down the cause of the crash will be able to figure \ * out the call path that was taken. \ */ \ ops->address(data, addr); \ } \ } while (0) /* * Print function call entries in all stacks, starting at the * current stack address. If the stacks consist of nested * exceptions */ for (;;) { char *id; unsigned long *estack_end; estack_end = in_exception_stack(cpu, (unsigned long)stack, &used, &id); if (estack_end) { if (ops->stack(data, id) < 0) break; HANDLE_STACK (stack < estack_end); ops->stack(data, ""); /* * We link to the next stack via the * second-to-last pointer (index -2 to end) in the * exception stack: */ stack = (unsigned long *) estack_end[-2]; continue; } if (irqstack_end) { unsigned long *irqstack; irqstack = irqstack_end - (IRQSTACKSIZE - 64) / sizeof(*irqstack); if (stack >= irqstack && stack < irqstack_end) { if (ops->stack(data, "IRQ") < 0) break; HANDLE_STACK (stack < irqstack_end); /* * We link to the next stack (which would be * the process stack normally) the last * pointer (index -1 to end) in the IRQ stack: */ stack = (unsigned long *) (irqstack_end[-1]); irqstack_end = NULL; ops->stack(data, "EOI"); continue; } } break; } /* * This handles the process stack: */ HANDLE_STACK (((long) stack & (THREAD_SIZE-1)) != 0); #undef HANDLE_STACK } EXPORT_SYMBOL(dump_trace); static void print_trace_warning_symbol(void *data, char *msg, unsigned long symbol) { print_symbol(msg, symbol); printk("\n"); } static void print_trace_warning(void *data, char *msg) { printk("%s\n", msg); } static int print_trace_stack(void *data, char *name) { printk(" <%s> ", name); return 0; } static void print_trace_address(void *data, unsigned long addr) { printk_address(addr); } static struct stacktrace_ops print_trace_ops = { .warning = print_trace_warning, .warning_symbol = print_trace_warning_symbol, .stack = print_trace_stack, .address = print_trace_address, }; void show_trace(struct task_struct *tsk, struct pt_regs *regs, unsigned long *stack) { printk("\nCall Trace:\n"); dump_trace(tsk, regs, stack, &print_trace_ops, NULL); printk("\n"); } static void _show_stack(struct task_struct *tsk, struct pt_regs *regs, unsigned long *rsp) { unsigned long *stack; int i; const int cpu = safe_smp_processor_id(); unsigned long *irqstack_end = (unsigned long *) (cpu_pda(cpu)->irqstackptr); unsigned long *irqstack = (unsigned long *) (cpu_pda(cpu)->irqstackptr - IRQSTACKSIZE); // debugging aid: "show_stack(NULL, NULL);" prints the // back trace for this cpu. if (rsp == NULL) { if (tsk) rsp = (unsigned long *)tsk->thread.rsp; else rsp = (unsigned long *)&rsp; } stack = rsp; for(i=0; i < kstack_depth_to_print; i++) { if (stack >= irqstack && stack <= irqstack_end) { if (stack == irqstack_end) { stack = (unsigned long *) (irqstack_end[-1]); printk(" "); } } else { if (((long) stack & (THREAD_SIZE-1)) == 0) break; } if (i && ((i % 4) == 0)) printk("\n"); printk(" %016lx", *stack++); touch_nmi_watchdog(); } show_trace(tsk, regs, rsp); } void show_stack(struct task_struct *tsk, unsigned long * rsp) { _show_stack(tsk, NULL, rsp); } /* * The architecture-independent dump_stack generator */ void dump_stack(void) { unsigned long dummy; show_trace(NULL, NULL, &dummy); } EXPORT_SYMBOL(dump_stack); void show_registers(struct pt_regs *regs) { int i; int in_kernel = !user_mode(regs); unsigned long rsp; const int cpu = safe_smp_processor_id(); struct task_struct *cur = cpu_pda(cpu)->pcurrent; rsp = regs->rsp; printk("CPU %d ", cpu); __show_regs(regs); printk("Process %s (pid: %d, threadinfo %p, task %p)\n", cur->comm, cur->pid, task_thread_info(cur), cur); /* * When in-kernel, we also print out the stack and code at the * time of the fault.. */ if (in_kernel) { printk("Stack: "); _show_stack(NULL, regs, (unsigned long*)rsp); printk("\nCode: "); if (regs->rip < PAGE_OFFSET) goto bad; for (i=0; i<20; i++) { unsigned char c; if (__get_user(c, &((unsigned char*)regs->rip)[i])) { bad: printk(" Bad RIP value."); break; } printk("%02x ", c); } } printk("\n"); } void handle_BUG(struct pt_regs *regs) { struct bug_frame f; long len; const char *prefix = ""; if (user_mode(regs)) return; if (__copy_from_user(&f, (const void __user *) regs->rip, sizeof(struct bug_frame))) return; if (f.filename >= 0 || f.ud2[0] != 0x0f || f.ud2[1] != 0x0b) return; len = __strnlen_user((char *)(long)f.filename, PATH_MAX) - 1; if (len < 0 || len >= PATH_MAX) f.filename = (int)(long)"unmapped filename"; else if (len > 50) { f.filename += len - 50; prefix = "..."; } printk("----------- [cut here ] --------- [please bite here ] ---------\n"); printk(KERN_ALERT "Kernel BUG at %s%.50s:%d\n", prefix, (char *)(long)f.filename, f.line); } #ifdef CONFIG_BUG void out_of_line_bug(void) { BUG(); } EXPORT_SYMBOL(out_of_line_bug); #endif static DEFINE_SPINLOCK(die_lock); static int die_owner = -1; static unsigned int die_nest_count; unsigned __kprobes long oops_begin(void) { int cpu = safe_smp_processor_id(); unsigned long flags; oops_enter(); /* racy, but better than risking deadlock. */ local_irq_save(flags); if (!spin_trylock(&die_lock)) { if (cpu == die_owner) /* nested oops. should stop eventually */; else spin_lock(&die_lock); } die_nest_count++; die_owner = cpu; console_verbose(); bust_spinlocks(1); return flags; } void __kprobes oops_end(unsigned long flags) { die_owner = -1; bust_spinlocks(0); die_nest_count--; if (die_nest_count) /* We still own the lock */ local_irq_restore(flags); else /* Nest count reaches zero, release the lock. */ spin_unlock_irqrestore(&die_lock, flags); if (panic_on_oops) panic("Fatal exception"); oops_exit(); } void __kprobes __die(const char * str, struct pt_regs * regs, long err) { static int die_counter; printk(KERN_EMERG "%s: %04lx [%u] ", str, err & 0xffff,++die_counter); #ifdef CONFIG_PREEMPT printk("PREEMPT "); #endif #ifdef CONFIG_SMP printk("SMP "); #endif #ifdef CONFIG_DEBUG_PAGEALLOC printk("DEBUG_PAGEALLOC"); #endif printk("\n"); notify_die(DIE_OOPS, str, regs, err, current->thread.trap_no, SIGSEGV); show_registers(regs); /* Executive summary in case the oops scrolled away */ printk(KERN_ALERT "RIP "); printk_address(regs->rip); printk(" RSP <%016lx>\n", regs->rsp); if (kexec_should_crash(current)) crash_kexec(regs); } void die(const char * str, struct pt_regs * regs, long err) { unsigned long flags = oops_begin(); handle_BUG(regs); __die(str, regs, err); oops_end(flags); do_exit(SIGSEGV); } void __kprobes die_nmi(char *str, struct pt_regs *regs, int do_panic) { unsigned long flags = oops_begin(); /* * We are in trouble anyway, lets at least try * to get a message out. */ printk(str, safe_smp_processor_id()); show_registers(regs); if (kexec_should_crash(current)) crash_kexec(regs); if (do_panic || panic_on_oops) panic("Non maskable interrupt"); oops_end(flags); nmi_exit(); local_irq_enable(); do_exit(SIGSEGV); } static void __kprobes do_trap(int trapnr, int signr, char *str, struct pt_regs * regs, long error_code, siginfo_t *info) { struct task_struct *tsk = current; tsk->thread.error_code = error_code; tsk->thread.trap_no = trapnr; if (user_mode(regs)) { if (exception_trace && unhandled_signal(tsk, signr)) printk(KERN_INFO "%s[%d] trap %s rip:%lx rsp:%lx error:%lx\n", tsk->comm, tsk->pid, str, regs->rip, regs->rsp, error_code); if (info) force_sig_info(signr, info, tsk); else force_sig(signr, tsk); return; } /* kernel trap */ { const struct exception_table_entry *fixup; fixup = search_exception_tables(regs->rip); if (fixup) regs->rip = fixup->fixup; else die(str, regs, error_code); return; } } #define DO_ERROR(trapnr, signr, str, name) \ asmlinkage void do_##name(struct pt_regs * regs, long error_code) \ { \ if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \ == NOTIFY_STOP) \ return; \ conditional_sti(regs); \ do_trap(trapnr, signr, str, regs, error_code, NULL); \ } #define DO_ERROR_INFO(trapnr, signr, str, name, sicode, siaddr) \ asmlinkage void do_##name(struct pt_regs * regs, long error_code) \ { \ siginfo_t info; \ info.si_signo = signr; \ info.si_errno = 0; \ info.si_code = sicode; \ info.si_addr = (void __user *)siaddr; \ if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \ == NOTIFY_STOP) \ return; \ conditional_sti(regs); \ do_trap(trapnr, signr, str, regs, error_code, &info); \ } DO_ERROR_INFO( 0, SIGFPE, "divide error", divide_error, FPE_INTDIV, regs->rip) DO_ERROR( 4, SIGSEGV, "overflow", overflow) DO_ERROR( 5, SIGSEGV, "bounds", bounds) DO_ERROR_INFO( 6, SIGILL, "invalid opcode", invalid_op, ILL_ILLOPN, regs->rip) DO_ERROR( 7, SIGSEGV, "device not available", device_not_available) DO_ERROR( 9, SIGFPE, "coprocessor segment overrun", coprocessor_segment_overrun) DO_ERROR(10, SIGSEGV, "invalid TSS", invalid_TSS) DO_ERROR(11, SIGBUS, "segment not present", segment_not_present) DO_ERROR_INFO(17, SIGBUS, "alignment check", alignment_check, BUS_ADRALN, 0) DO_ERROR(18, SIGSEGV, "reserved", reserved) /* Runs on IST stack */ asmlinkage void do_stack_segment(struct pt_regs *regs, long error_code) { if (notify_die(DIE_TRAP, "stack segment", regs, error_code, 12, SIGBUS) == NOTIFY_STOP) return; preempt_conditional_sti(regs); do_trap(12, SIGBUS, "stack segment", regs, error_code, NULL); preempt_conditional_cli(regs); } asmlinkage void do_double_fault(struct pt_regs * regs, long error_code) { static const char str[] = "double fault"; struct task_struct *tsk = current; /* Return not checked because double check cannot be ignored */ notify_die(DIE_TRAP, str, regs, error_code, 8, SIGSEGV); tsk->thread.error_code = error_code; tsk->thread.trap_no = 8; /* This is always a kernel trap and never fixable (and thus must never return). */ for (;;) die(str, regs, error_code); } asmlinkage void __kprobes do_general_protection(struct pt_regs * regs, long error_code) { struct task_struct *tsk = current; conditional_sti(regs); tsk->thread.error_code = error_code; tsk->thread.trap_no = 13; if (user_mode(regs)) { if (exception_trace && unhandled_signal(tsk, SIGSEGV)) printk(KERN_INFO "%s[%d] general protection rip:%lx rsp:%lx error:%lx\n", tsk->comm, tsk->pid, regs->rip, regs->rsp, error_code); force_sig(SIGSEGV, tsk); return; } /* kernel gp */ { const struct exception_table_entry *fixup; fixup = search_exception_tables(regs->rip); if (fixup) { regs->rip = fixup->fixup; return; } if (notify_die(DIE_GPF, "general protection fault", regs, error_code, 13, SIGSEGV) == NOTIFY_STOP) return; die("general protection fault", regs, error_code); } } static __kprobes void mem_parity_error(unsigned char reason, struct pt_regs * regs) { printk(KERN_EMERG "Uhhuh. NMI received for unknown reason %02x.\n", reason); printk(KERN_EMERG "You probably have a hardware problem with your " "RAM chips\n"); if (panic_on_unrecovered_nmi) panic("NMI: Not continuing"); printk(KERN_EMERG "Dazed and confused, but trying to continue\n"); /* Clear and disable the memory parity error line. */ reason = (reason & 0xf) | 4; outb(reason, 0x61); } static __kprobes void io_check_error(unsigned char reason, struct pt_regs * regs) { printk("NMI: IOCK error (debug interrupt?)\n"); show_registers(regs); /* Re-enable the IOCK line, wait for a few seconds */ reason = (reason & 0xf) | 8; outb(reason, 0x61); mdelay(2000); reason &= ~8; outb(reason, 0x61); } static __kprobes void unknown_nmi_error(unsigned char reason, struct pt_regs * regs) { printk(KERN_EMERG "Uhhuh. NMI received for unknown reason %02x.\n", reason); printk(KERN_EMERG "Do you have a strange power saving mode enabled?\n"); if (panic_on_unrecovered_nmi) panic("NMI: Not continuing"); printk(KERN_EMERG "Dazed and confused, but trying to continue\n"); } /* Runs on IST stack. This code must keep interrupts off all the time. Nested NMIs are prevented by the CPU. */ asmlinkage __kprobes void default_do_nmi(struct pt_regs *regs) { unsigned char reason = 0; int cpu; cpu = smp_processor_id(); /* Only the BSP gets external NMIs from the system. */ if (!cpu) reason = get_nmi_reason(); if (!(reason & 0xc0)) { if (notify_die(DIE_NMI_IPI, "nmi_ipi", regs, reason, 2, SIGINT) == NOTIFY_STOP) return; /* * Ok, so this is none of the documented NMI sources, * so it must be the NMI watchdog. */ if (nmi_watchdog_tick(regs,reason)) return; if (!do_nmi_callback(regs,cpu)) unknown_nmi_error(reason, regs); return; } if (notify_die(DIE_NMI, "nmi", regs, reason, 2, SIGINT) == NOTIFY_STOP) return; /* AK: following checks seem to be broken on modern chipsets. FIXME */ if (reason & 0x80) mem_parity_error(reason, regs); if (reason & 0x40) io_check_error(reason, regs); } /* runs on IST stack. */ asmlinkage void __kprobes do_int3(struct pt_regs * regs, long error_code) { if (notify_die(DIE_INT3, "int3", regs, error_code, 3, SIGTRAP) == NOTIFY_STOP) { return; } preempt_conditional_sti(regs); do_trap(3, SIGTRAP, "int3", regs, error_code, NULL); preempt_conditional_cli(regs); } /* Help handler running on IST stack to switch back to user stack for scheduling or signal handling. The actual stack switch is done in entry.S */ asmlinkage __kprobes struct pt_regs *sync_regs(struct pt_regs *eregs) { struct pt_regs *regs = eregs; /* Did already sync */ if (eregs == (struct pt_regs *)eregs->rsp) ; /* Exception from user space */ else if (user_mode(eregs)) regs = task_pt_regs(current); /* Exception from kernel and interrupts are enabled. Move to kernel process stack. */ else if (eregs->eflags & X86_EFLAGS_IF) regs = (struct pt_regs *)(eregs->rsp -= sizeof(struct pt_regs)); if (eregs != regs) *regs = *eregs; return regs; } /* runs on IST stack. */ asmlinkage void __kprobes do_debug(struct pt_regs * regs, unsigned long error_code) { unsigned long condition; struct task_struct *tsk = current; siginfo_t info; get_debugreg(condition, 6); if (notify_die(DIE_DEBUG, "debug", regs, condition, error_code, SIGTRAP) == NOTIFY_STOP) return; preempt_conditional_sti(regs); /* Mask out spurious debug traps due to lazy DR7 setting */ if (condition & (DR_TRAP0|DR_TRAP1|DR_TRAP2|DR_TRAP3)) { if (!tsk->thread.debugreg7) { goto clear_dr7; } } tsk->thread.debugreg6 = condition; /* Mask out spurious TF errors due to lazy TF clearing */ if (condition & DR_STEP) { /* * The TF error should be masked out only if the current * process is not traced and if the TRAP flag has been set * previously by a tracing process (condition detected by * the PT_DTRACE flag); remember that the i386 TRAP flag * can be modified by the process itself in user mode, * allowing programs to debug themselves without the ptrace() * interface. */ if (!user_mode(regs)) goto clear_TF_reenable; /* * Was the TF flag set by a debugger? If so, clear it now, * so that register information is correct. */ if (tsk->ptrace & PT_DTRACE) { regs->eflags &= ~TF_MASK; tsk->ptrace &= ~PT_DTRACE; } } /* Ok, finally something we can handle */ tsk->thread.trap_no = 1; tsk->thread.error_code = error_code; info.si_signo = SIGTRAP; info.si_errno = 0; info.si_code = TRAP_BRKPT; info.si_addr = user_mode(regs) ? (void __user *)regs->rip : NULL; force_sig_info(SIGTRAP, &info, tsk); clear_dr7: set_debugreg(0UL, 7); preempt_conditional_cli(regs); return; clear_TF_reenable: set_tsk_thread_flag(tsk, TIF_SINGLESTEP); regs->eflags &= ~TF_MASK; preempt_conditional_cli(regs); } static int kernel_math_error(struct pt_regs *regs, const char *str, int trapnr) { const struct exception_table_entry *fixup; fixup = search_exception_tables(regs->rip); if (fixup) { regs->rip = fixup->fixup; return 1; } notify_die(DIE_GPF, str, regs, 0, trapnr, SIGFPE); /* Illegal floating point operation in the kernel */ current->thread.trap_no = trapnr; die(str, regs, 0); return 0; } /* * Note that we play around with the 'TS' bit in an attempt to get * the correct behaviour even in the presence of the asynchronous * IRQ13 behaviour */ asmlinkage void do_coprocessor_error(struct pt_regs *regs) { void __user *rip = (void __user *)(regs->rip); struct task_struct * task; siginfo_t info; unsigned short cwd, swd; conditional_sti(regs); if (!user_mode(regs) && kernel_math_error(regs, "kernel x87 math error", 16)) return; /* * Save the info for the exception handler and clear the error. */ task = current; save_init_fpu(task); task->thread.trap_no = 16; task->thread.error_code = 0; info.si_signo = SIGFPE; info.si_errno = 0; info.si_code = __SI_FAULT; info.si_addr = rip; /* * (~cwd & swd) will mask out exceptions that are not set to unmasked * status. 0x3f is the exception bits in these regs, 0x200 is the * C1 reg you need in case of a stack fault, 0x040 is the stack * fault bit. We should only be taking one exception at a time, * so if this combination doesn't produce any single exception, * then we have a bad program that isn't synchronizing its FPU usage * and it will suffer the consequences since we won't be able to * fully reproduce the context of the exception */ cwd = get_fpu_cwd(task); swd = get_fpu_swd(task); switch (swd & ~cwd & 0x3f) { case 0x000: default: break; case 0x001: /* Invalid Op */ /* * swd & 0x240 == 0x040: Stack Underflow * swd & 0x240 == 0x240: Stack Overflow * User must clear the SF bit (0x40) if set */ info.si_code = FPE_FLTINV; break; case 0x002: /* Denormalize */ case 0x010: /* Underflow */ info.si_code = FPE_FLTUND; break; case 0x004: /* Zero Divide */ info.si_code = FPE_FLTDIV; break; case 0x008: /* Overflow */ info.si_code = FPE_FLTOVF; break; case 0x020: /* Precision */ info.si_code = FPE_FLTRES; break; } force_sig_info(SIGFPE, &info, task); } asmlinkage void bad_intr(void) { printk("bad interrupt"); } asmlinkage void do_simd_coprocessor_error(struct pt_regs *regs) { void __user *rip = (void __user *)(regs->rip); struct task_struct * task; siginfo_t info; unsigned short mxcsr; conditional_sti(regs); if (!user_mode(regs) && kernel_math_error(regs, "kernel simd math error", 19)) return; /* * Save the info for the exception handler and clear the error. */ task = current; save_init_fpu(task); task->thread.trap_no = 19; task->thread.error_code = 0; info.si_signo = SIGFPE; info.si_errno = 0; info.si_code = __SI_FAULT; info.si_addr = rip; /* * The SIMD FPU exceptions are handled a little differently, as there * is only a single status/control register. Thus, to determine which * unmasked exception was caught we must mask the exception mask bits * at 0x1f80, and then use these to mask the exception bits at 0x3f. */ mxcsr = get_fpu_mxcsr(task); switch (~((mxcsr & 0x1f80) >> 7) & (mxcsr & 0x3f)) { case 0x000: default: break; case 0x001: /* Invalid Op */ info.si_code = FPE_FLTINV; break; case 0x002: /* Denormalize */ case 0x010: /* Underflow */ info.si_code = FPE_FLTUND; break; case 0x004: /* Zero Divide */ info.si_code = FPE_FLTDIV; break; case 0x008: /* Overflow */ info.si_code = FPE_FLTOVF; break; case 0x020: /* Precision */ info.si_code = FPE_FLTRES; break; } force_sig_info(SIGFPE, &info, task); } asmlinkage void do_spurious_interrupt_bug(struct pt_regs * regs) { } asmlinkage void __attribute__((weak)) smp_thermal_interrupt(void) { } asmlinkage void __attribute__((weak)) mce_threshold_interrupt(void) { } /* * 'math_state_restore()' saves the current math information in the * old math state array, and gets the new ones from the current task * * Careful.. There are problems with IBM-designed IRQ13 behaviour. * Don't touch unless you *really* know how it works. */ asmlinkage void math_state_restore(void) { struct task_struct *me = current; clts(); /* Allow maths ops (or we recurse) */ if (!used_math()) init_fpu(me); restore_fpu_checking(&me->thread.i387.fxsave); task_thread_info(me)->status |= TS_USEDFPU; me->fpu_counter++; } void __init trap_init(void) { set_intr_gate(0,÷_error); set_intr_gate_ist(1,&debug,DEBUG_STACK); set_intr_gate_ist(2,&nmi,NMI_STACK); set_system_gate_ist(3,&int3,DEBUG_STACK); /* int3 can be called from all */ set_system_gate(4,&overflow); /* int4 can be called from all */ set_intr_gate(5,&bounds); set_intr_gate(6,&invalid_op); set_intr_gate(7,&device_not_available); set_intr_gate_ist(8,&double_fault, DOUBLEFAULT_STACK); set_intr_gate(9,&coprocessor_segment_overrun); set_intr_gate(10,&invalid_TSS); set_intr_gate(11,&segment_not_present); set_intr_gate_ist(12,&stack_segment,STACKFAULT_STACK); set_intr_gate(13,&general_protection); set_intr_gate(14,&page_fault); set_intr_gate(15,&spurious_interrupt_bug); set_intr_gate(16,&coprocessor_error); set_intr_gate(17,&alignment_check); #ifdef CONFIG_X86_MCE set_intr_gate_ist(18,&machine_check, MCE_STACK); #endif set_intr_gate(19,&simd_coprocessor_error); #ifdef CONFIG_IA32_EMULATION set_system_gate(IA32_SYSCALL_VECTOR, ia32_syscall); #endif /* * Should be a barrier for any external CPU state. */ cpu_init(); } static int __init oops_setup(char *s) { if (!s) return -EINVAL; if (!strcmp(s, "panic")) panic_on_oops = 1; return 0; } early_param("oops", oops_setup); static int __init kstack_setup(char *s) { if (!s) return -EINVAL; kstack_depth_to_print = simple_strtoul(s,NULL,0); return 0; } early_param("kstack", kstack_setup); #ifdef CONFIG_STACK_UNWIND static int __init call_trace_setup(char *s) { if (!s) return -EINVAL; if (strcmp(s, "old") == 0) call_trace = -1; else if (strcmp(s, "both") == 0) call_trace = 0; else if (strcmp(s, "newfallback") == 0) call_trace = 1; else if (strcmp(s, "new") == 0) call_trace = 2; return 0; } early_param("call_trace", call_trace_setup); #endif