| /* |
| * linux/arch/i386/traps.c |
| * |
| * Copyright (C) 1991, 1992 Linus Torvalds |
| * |
| * Pentium III FXSR, SSE support |
| * Gareth Hughes <gareth@valinux.com>, May 2000 |
| */ |
| |
| /* |
| * 'Traps.c' handles hardware traps and faults after we have saved some |
| * state in 'asm.s'. |
| */ |
| #include <linux/config.h> |
| #include <linux/sched.h> |
| #include <linux/kernel.h> |
| #include <linux/string.h> |
| #include <linux/errno.h> |
| #include <linux/timer.h> |
| #include <linux/mm.h> |
| #include <linux/init.h> |
| #include <linux/delay.h> |
| #include <linux/spinlock.h> |
| #include <linux/interrupt.h> |
| #include <linux/highmem.h> |
| #include <linux/kallsyms.h> |
| #include <linux/ptrace.h> |
| #include <linux/utsname.h> |
| #include <linux/kprobes.h> |
| #include <linux/kexec.h> |
| |
| #ifdef CONFIG_EISA |
| #include <linux/ioport.h> |
| #include <linux/eisa.h> |
| #endif |
| |
| #ifdef CONFIG_MCA |
| #include <linux/mca.h> |
| #endif |
| |
| #include <asm/processor.h> |
| #include <asm/system.h> |
| #include <asm/uaccess.h> |
| #include <asm/io.h> |
| #include <asm/atomic.h> |
| #include <asm/debugreg.h> |
| #include <asm/desc.h> |
| #include <asm/i387.h> |
| #include <asm/nmi.h> |
| |
| #include <asm/smp.h> |
| #include <asm/arch_hooks.h> |
| #include <asm/kdebug.h> |
| |
| #include <linux/module.h> |
| |
| #include "mach_traps.h" |
| |
| asmlinkage int system_call(void); |
| |
| struct desc_struct default_ldt[] = { { 0, 0 }, { 0, 0 }, { 0, 0 }, |
| { 0, 0 }, { 0, 0 } }; |
| |
| /* Do we ignore FPU interrupts ? */ |
| char ignore_fpu_irq = 0; |
| |
| /* |
| * The IDT has to be page-aligned to simplify the Pentium |
| * F0 0F bug workaround.. We have a special link segment |
| * for this. |
| */ |
| struct desc_struct idt_table[256] __attribute__((__section__(".data.idt"))) = { {0, 0}, }; |
| |
| 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 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 alignment_check(void); |
| asmlinkage void spurious_interrupt_bug(void); |
| asmlinkage void machine_check(void); |
| |
| static int kstack_depth_to_print = 24; |
| ATOMIC_NOTIFIER_HEAD(i386die_chain); |
| |
| int register_die_notifier(struct notifier_block *nb) |
| { |
| vmalloc_sync_all(); |
| return atomic_notifier_chain_register(&i386die_chain, nb); |
| } |
| EXPORT_SYMBOL(register_die_notifier); |
| |
| int unregister_die_notifier(struct notifier_block *nb) |
| { |
| return atomic_notifier_chain_unregister(&i386die_chain, nb); |
| } |
| EXPORT_SYMBOL(unregister_die_notifier); |
| |
| static inline int valid_stack_ptr(struct thread_info *tinfo, void *p) |
| { |
| return p > (void *)tinfo && |
| p < (void *)tinfo + THREAD_SIZE - 3; |
| } |
| |
| /* |
| * Print CONFIG_STACK_BACKTRACE_COLS address/symbol entries per line. |
| */ |
| static inline int print_addr_and_symbol(unsigned long addr, char *log_lvl, |
| int printed) |
| { |
| if (!printed) |
| printk(log_lvl); |
| |
| #if CONFIG_STACK_BACKTRACE_COLS == 1 |
| printk(" [<%08lx>] ", addr); |
| #else |
| printk(" <%08lx> ", addr); |
| #endif |
| print_symbol("%s", addr); |
| |
| printed = (printed + 1) % CONFIG_STACK_BACKTRACE_COLS; |
| if (printed) |
| printk(" "); |
| else |
| printk("\n"); |
| |
| return printed; |
| } |
| |
| static inline unsigned long print_context_stack(struct thread_info *tinfo, |
| unsigned long *stack, unsigned long ebp, |
| char *log_lvl) |
| { |
| unsigned long addr; |
| int printed = 0; /* nr of entries already printed on current line */ |
| |
| #ifdef CONFIG_FRAME_POINTER |
| while (valid_stack_ptr(tinfo, (void *)ebp)) { |
| addr = *(unsigned long *)(ebp + 4); |
| printed = print_addr_and_symbol(addr, log_lvl, printed); |
| /* |
| * break out of recursive entries (such as |
| * end_of_stack_stop_unwind_function): |
| */ |
| if (ebp == *(unsigned long *)ebp) |
| break; |
| ebp = *(unsigned long *)ebp; |
| } |
| #else |
| while (valid_stack_ptr(tinfo, stack)) { |
| addr = *stack++; |
| if (__kernel_text_address(addr)) |
| printed = print_addr_and_symbol(addr, log_lvl, printed); |
| } |
| #endif |
| if (printed) |
| printk("\n"); |
| |
| return ebp; |
| } |
| |
| static void show_trace_log_lvl(struct task_struct *task, |
| unsigned long *stack, char *log_lvl) |
| { |
| unsigned long ebp; |
| |
| if (!task) |
| task = current; |
| |
| if (task == current) { |
| /* Grab ebp right from our regs */ |
| asm ("movl %%ebp, %0" : "=r" (ebp) : ); |
| } else { |
| /* ebp is the last reg pushed by switch_to */ |
| ebp = *(unsigned long *) task->thread.esp; |
| } |
| |
| while (1) { |
| struct thread_info *context; |
| context = (struct thread_info *) |
| ((unsigned long)stack & (~(THREAD_SIZE - 1))); |
| ebp = print_context_stack(context, stack, ebp, log_lvl); |
| stack = (unsigned long*)context->previous_esp; |
| if (!stack) |
| break; |
| printk("%s =======================\n", log_lvl); |
| } |
| } |
| |
| void show_trace(struct task_struct *task, unsigned long * stack) |
| { |
| show_trace_log_lvl(task, stack, ""); |
| } |
| |
| static void show_stack_log_lvl(struct task_struct *task, unsigned long *esp, |
| char *log_lvl) |
| { |
| unsigned long *stack; |
| int i; |
| |
| if (esp == NULL) { |
| if (task) |
| esp = (unsigned long*)task->thread.esp; |
| else |
| esp = (unsigned long *)&esp; |
| } |
| |
| stack = esp; |
| for(i = 0; i < kstack_depth_to_print; i++) { |
| if (kstack_end(stack)) |
| break; |
| if (i && ((i % 8) == 0)) |
| printk("\n%s ", log_lvl); |
| printk("%08lx ", *stack++); |
| } |
| printk("\n%sCall Trace:\n", log_lvl); |
| show_trace_log_lvl(task, esp, log_lvl); |
| } |
| |
| void show_stack(struct task_struct *task, unsigned long *esp) |
| { |
| printk(" "); |
| show_stack_log_lvl(task, esp, ""); |
| } |
| |
| /* |
| * The architecture-independent dump_stack generator |
| */ |
| void dump_stack(void) |
| { |
| unsigned long stack; |
| |
| show_trace(current, &stack); |
| } |
| |
| EXPORT_SYMBOL(dump_stack); |
| |
| void show_registers(struct pt_regs *regs) |
| { |
| int i; |
| int in_kernel = 1; |
| unsigned long esp; |
| unsigned short ss; |
| |
| esp = (unsigned long) (®s->esp); |
| savesegment(ss, ss); |
| if (user_mode_vm(regs)) { |
| in_kernel = 0; |
| esp = regs->esp; |
| ss = regs->xss & 0xffff; |
| } |
| print_modules(); |
| printk(KERN_EMERG "CPU: %d\nEIP: %04x:[<%08lx>] %s VLI\n" |
| "EFLAGS: %08lx (%s %.*s) \n", |
| smp_processor_id(), 0xffff & regs->xcs, regs->eip, |
| print_tainted(), regs->eflags, system_utsname.release, |
| (int)strcspn(system_utsname.version, " "), |
| system_utsname.version); |
| print_symbol(KERN_EMERG "EIP is at %s\n", regs->eip); |
| printk(KERN_EMERG "eax: %08lx ebx: %08lx ecx: %08lx edx: %08lx\n", |
| regs->eax, regs->ebx, regs->ecx, regs->edx); |
| printk(KERN_EMERG "esi: %08lx edi: %08lx ebp: %08lx esp: %08lx\n", |
| regs->esi, regs->edi, regs->ebp, esp); |
| printk(KERN_EMERG "ds: %04x es: %04x ss: %04x\n", |
| regs->xds & 0xffff, regs->xes & 0xffff, ss); |
| printk(KERN_EMERG "Process %s (pid: %d, threadinfo=%p task=%p)", |
| current->comm, current->pid, current_thread_info(), current); |
| /* |
| * When in-kernel, we also print out the stack and code at the |
| * time of the fault.. |
| */ |
| if (in_kernel) { |
| u8 __user *eip; |
| |
| printk("\n" KERN_EMERG "Stack: "); |
| show_stack_log_lvl(NULL, (unsigned long *)esp, KERN_EMERG); |
| |
| printk(KERN_EMERG "Code: "); |
| |
| eip = (u8 __user *)regs->eip - 43; |
| for (i = 0; i < 64; i++, eip++) { |
| unsigned char c; |
| |
| if (eip < (u8 __user *)PAGE_OFFSET || __get_user(c, eip)) { |
| printk(" Bad EIP value."); |
| break; |
| } |
| if (eip == (u8 __user *)regs->eip) |
| printk("<%02x> ", c); |
| else |
| printk("%02x ", c); |
| } |
| } |
| printk("\n"); |
| } |
| |
| static void handle_BUG(struct pt_regs *regs) |
| { |
| unsigned short ud2; |
| unsigned short line; |
| char *file; |
| char c; |
| unsigned long eip; |
| |
| eip = regs->eip; |
| |
| if (eip < PAGE_OFFSET) |
| goto no_bug; |
| if (__get_user(ud2, (unsigned short __user *)eip)) |
| goto no_bug; |
| if (ud2 != 0x0b0f) |
| goto no_bug; |
| if (__get_user(line, (unsigned short __user *)(eip + 2))) |
| goto bug; |
| if (__get_user(file, (char * __user *)(eip + 4)) || |
| (unsigned long)file < PAGE_OFFSET || __get_user(c, file)) |
| file = "<bad filename>"; |
| |
| printk(KERN_EMERG "------------[ cut here ]------------\n"); |
| printk(KERN_EMERG "kernel BUG at %s:%d!\n", file, line); |
| |
| no_bug: |
| return; |
| |
| /* Here we know it was a BUG but file-n-line is unavailable */ |
| bug: |
| printk(KERN_EMERG "Kernel BUG\n"); |
| } |
| |
| /* This is gone through when something in the kernel |
| * has done something bad and is about to be terminated. |
| */ |
| void die(const char * str, struct pt_regs * regs, long err) |
| { |
| static struct { |
| spinlock_t lock; |
| u32 lock_owner; |
| int lock_owner_depth; |
| } die = { |
| .lock = SPIN_LOCK_UNLOCKED, |
| .lock_owner = -1, |
| .lock_owner_depth = 0 |
| }; |
| static int die_counter; |
| unsigned long flags; |
| |
| oops_enter(); |
| |
| if (die.lock_owner != raw_smp_processor_id()) { |
| console_verbose(); |
| spin_lock_irqsave(&die.lock, flags); |
| die.lock_owner = smp_processor_id(); |
| die.lock_owner_depth = 0; |
| bust_spinlocks(1); |
| } |
| else |
| local_save_flags(flags); |
| |
| if (++die.lock_owner_depth < 3) { |
| int nl = 0; |
| unsigned long esp; |
| unsigned short ss; |
| |
| handle_BUG(regs); |
| printk(KERN_EMERG "%s: %04lx [#%d]\n", str, err & 0xffff, ++die_counter); |
| #ifdef CONFIG_PREEMPT |
| printk(KERN_EMERG "PREEMPT "); |
| nl = 1; |
| #endif |
| #ifdef CONFIG_SMP |
| if (!nl) |
| printk(KERN_EMERG); |
| printk("SMP "); |
| nl = 1; |
| #endif |
| #ifdef CONFIG_DEBUG_PAGEALLOC |
| if (!nl) |
| printk(KERN_EMERG); |
| printk("DEBUG_PAGEALLOC"); |
| nl = 1; |
| #endif |
| if (nl) |
| printk("\n"); |
| if (notify_die(DIE_OOPS, str, regs, err, |
| current->thread.trap_no, SIGSEGV) != |
| NOTIFY_STOP) { |
| show_registers(regs); |
| /* Executive summary in case the oops scrolled away */ |
| esp = (unsigned long) (®s->esp); |
| savesegment(ss, ss); |
| if (user_mode(regs)) { |
| esp = regs->esp; |
| ss = regs->xss & 0xffff; |
| } |
| printk(KERN_EMERG "EIP: [<%08lx>] ", regs->eip); |
| print_symbol("%s", regs->eip); |
| printk(" SS:ESP %04x:%08lx\n", ss, esp); |
| } |
| else |
| regs = NULL; |
| } else |
| printk(KERN_EMERG "Recursive die() failure, output suppressed\n"); |
| |
| bust_spinlocks(0); |
| die.lock_owner = -1; |
| spin_unlock_irqrestore(&die.lock, flags); |
| |
| if (!regs) |
| return; |
| |
| if (kexec_should_crash(current)) |
| crash_kexec(regs); |
| |
| if (in_interrupt()) |
| panic("Fatal exception in interrupt"); |
| |
| if (panic_on_oops) { |
| printk(KERN_EMERG "Fatal exception: panic in 5 seconds\n"); |
| ssleep(5); |
| panic("Fatal exception"); |
| } |
| oops_exit(); |
| do_exit(SIGSEGV); |
| } |
| |
| static inline void die_if_kernel(const char * str, struct pt_regs * regs, long err) |
| { |
| if (!user_mode_vm(regs)) |
| die(str, regs, err); |
| } |
| |
| static void __kprobes do_trap(int trapnr, int signr, char *str, int vm86, |
| 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 (regs->eflags & VM_MASK) { |
| if (vm86) |
| goto vm86_trap; |
| goto trap_signal; |
| } |
| |
| if (!user_mode(regs)) |
| goto kernel_trap; |
| |
| trap_signal: { |
| if (info) |
| force_sig_info(signr, info, tsk); |
| else |
| force_sig(signr, tsk); |
| return; |
| } |
| |
| kernel_trap: { |
| if (!fixup_exception(regs)) |
| die(str, regs, error_code); |
| return; |
| } |
| |
| vm86_trap: { |
| int ret = handle_vm86_trap((struct kernel_vm86_regs *) regs, error_code, trapnr); |
| if (ret) goto trap_signal; |
| return; |
| } |
| } |
| |
| #define DO_ERROR(trapnr, signr, str, name) \ |
| fastcall void do_##name(struct pt_regs * regs, long error_code) \ |
| { \ |
| if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \ |
| == NOTIFY_STOP) \ |
| return; \ |
| do_trap(trapnr, signr, str, 0, regs, error_code, NULL); \ |
| } |
| |
| #define DO_ERROR_INFO(trapnr, signr, str, name, sicode, siaddr) \ |
| fastcall 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; \ |
| do_trap(trapnr, signr, str, 0, regs, error_code, &info); \ |
| } |
| |
| #define DO_VM86_ERROR(trapnr, signr, str, name) \ |
| fastcall void do_##name(struct pt_regs * regs, long error_code) \ |
| { \ |
| if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \ |
| == NOTIFY_STOP) \ |
| return; \ |
| do_trap(trapnr, signr, str, 1, regs, error_code, NULL); \ |
| } |
| |
| #define DO_VM86_ERROR_INFO(trapnr, signr, str, name, sicode, siaddr) \ |
| fastcall 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; \ |
| do_trap(trapnr, signr, str, 1, regs, error_code, &info); \ |
| } |
| |
| DO_VM86_ERROR_INFO( 0, SIGFPE, "divide error", divide_error, FPE_INTDIV, regs->eip) |
| #ifndef CONFIG_KPROBES |
| DO_VM86_ERROR( 3, SIGTRAP, "int3", int3) |
| #endif |
| DO_VM86_ERROR( 4, SIGSEGV, "overflow", overflow) |
| DO_VM86_ERROR( 5, SIGSEGV, "bounds", bounds) |
| DO_ERROR_INFO( 6, SIGILL, "invalid opcode", invalid_op, ILL_ILLOPN, regs->eip) |
| 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(12, SIGBUS, "stack segment", stack_segment) |
| DO_ERROR_INFO(17, SIGBUS, "alignment check", alignment_check, BUS_ADRALN, 0) |
| DO_ERROR_INFO(32, SIGSEGV, "iret exception", iret_error, ILL_BADSTK, 0) |
| |
| fastcall void __kprobes do_general_protection(struct pt_regs * regs, |
| long error_code) |
| { |
| int cpu = get_cpu(); |
| struct tss_struct *tss = &per_cpu(init_tss, cpu); |
| struct thread_struct *thread = ¤t->thread; |
| |
| /* |
| * Perform the lazy TSS's I/O bitmap copy. If the TSS has an |
| * invalid offset set (the LAZY one) and the faulting thread has |
| * a valid I/O bitmap pointer, we copy the I/O bitmap in the TSS |
| * and we set the offset field correctly. Then we let the CPU to |
| * restart the faulting instruction. |
| */ |
| if (tss->io_bitmap_base == INVALID_IO_BITMAP_OFFSET_LAZY && |
| thread->io_bitmap_ptr) { |
| memcpy(tss->io_bitmap, thread->io_bitmap_ptr, |
| thread->io_bitmap_max); |
| /* |
| * If the previously set map was extending to higher ports |
| * than the current one, pad extra space with 0xff (no access). |
| */ |
| if (thread->io_bitmap_max < tss->io_bitmap_max) |
| memset((char *) tss->io_bitmap + |
| thread->io_bitmap_max, 0xff, |
| tss->io_bitmap_max - thread->io_bitmap_max); |
| tss->io_bitmap_max = thread->io_bitmap_max; |
| tss->io_bitmap_base = IO_BITMAP_OFFSET; |
| tss->io_bitmap_owner = thread; |
| put_cpu(); |
| return; |
| } |
| put_cpu(); |
| |
| current->thread.error_code = error_code; |
| current->thread.trap_no = 13; |
| |
| if (regs->eflags & VM_MASK) |
| goto gp_in_vm86; |
| |
| if (!user_mode(regs)) |
| goto gp_in_kernel; |
| |
| current->thread.error_code = error_code; |
| current->thread.trap_no = 13; |
| force_sig(SIGSEGV, current); |
| return; |
| |
| gp_in_vm86: |
| local_irq_enable(); |
| handle_vm86_fault((struct kernel_vm86_regs *) regs, error_code); |
| return; |
| |
| gp_in_kernel: |
| if (!fixup_exception(regs)) { |
| if (notify_die(DIE_GPF, "general protection fault", regs, |
| error_code, 13, SIGSEGV) == NOTIFY_STOP) |
| return; |
| die("general protection fault", regs, error_code); |
| } |
| } |
| |
| static void mem_parity_error(unsigned char reason, struct pt_regs * regs) |
| { |
| printk(KERN_EMERG "Uhhuh. NMI received. Dazed and confused, but trying " |
| "to continue\n"); |
| printk(KERN_EMERG "You probably have a hardware problem with your RAM " |
| "chips\n"); |
| |
| /* Clear and disable the memory parity error line. */ |
| clear_mem_error(reason); |
| } |
| |
| static void io_check_error(unsigned char reason, struct pt_regs * regs) |
| { |
| unsigned long i; |
| |
| printk(KERN_EMERG "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); |
| i = 2000; |
| while (--i) udelay(1000); |
| reason &= ~8; |
| outb(reason, 0x61); |
| } |
| |
| static void unknown_nmi_error(unsigned char reason, struct pt_regs * regs) |
| { |
| #ifdef CONFIG_MCA |
| /* Might actually be able to figure out what the guilty party |
| * is. */ |
| if( MCA_bus ) { |
| mca_handle_nmi(); |
| return; |
| } |
| #endif |
| printk("Uhhuh. NMI received for unknown reason %02x on CPU %d.\n", |
| reason, smp_processor_id()); |
| printk("Dazed and confused, but trying to continue\n"); |
| printk("Do you have a strange power saving mode enabled?\n"); |
| } |
| |
| static DEFINE_SPINLOCK(nmi_print_lock); |
| |
| void die_nmi (struct pt_regs *regs, const char *msg) |
| { |
| if (notify_die(DIE_NMIWATCHDOG, msg, regs, 0, 2, SIGINT) == |
| NOTIFY_STOP) |
| return; |
| |
| spin_lock(&nmi_print_lock); |
| /* |
| * We are in trouble anyway, lets at least try |
| * to get a message out. |
| */ |
| bust_spinlocks(1); |
| printk(KERN_EMERG "%s", msg); |
| printk(" on CPU%d, eip %08lx, registers:\n", |
| smp_processor_id(), regs->eip); |
| show_registers(regs); |
| printk(KERN_EMERG "console shuts up ...\n"); |
| console_silent(); |
| spin_unlock(&nmi_print_lock); |
| bust_spinlocks(0); |
| |
| /* If we are in kernel we are probably nested up pretty bad |
| * and might aswell get out now while we still can. |
| */ |
| if (!user_mode_vm(regs)) { |
| current->thread.trap_no = 2; |
| crash_kexec(regs); |
| } |
| |
| do_exit(SIGSEGV); |
| } |
| |
| static void default_do_nmi(struct pt_regs * regs) |
| { |
| unsigned char reason = 0; |
| |
| /* Only the BSP gets external NMIs from the system. */ |
| if (!smp_processor_id()) |
| reason = get_nmi_reason(); |
| |
| if (!(reason & 0xc0)) { |
| if (notify_die(DIE_NMI_IPI, "nmi_ipi", regs, reason, 2, SIGINT) |
| == NOTIFY_STOP) |
| return; |
| #ifdef CONFIG_X86_LOCAL_APIC |
| /* |
| * Ok, so this is none of the documented NMI sources, |
| * so it must be the NMI watchdog. |
| */ |
| if (nmi_watchdog) { |
| nmi_watchdog_tick(regs); |
| return; |
| } |
| #endif |
| unknown_nmi_error(reason, regs); |
| return; |
| } |
| if (notify_die(DIE_NMI, "nmi", regs, reason, 2, SIGINT) == NOTIFY_STOP) |
| return; |
| if (reason & 0x80) |
| mem_parity_error(reason, regs); |
| if (reason & 0x40) |
| io_check_error(reason, regs); |
| /* |
| * Reassert NMI in case it became active meanwhile |
| * as it's edge-triggered. |
| */ |
| reassert_nmi(); |
| } |
| |
| static int dummy_nmi_callback(struct pt_regs * regs, int cpu) |
| { |
| return 0; |
| } |
| |
| static nmi_callback_t nmi_callback = dummy_nmi_callback; |
| |
| fastcall void do_nmi(struct pt_regs * regs, long error_code) |
| { |
| int cpu; |
| |
| nmi_enter(); |
| |
| cpu = smp_processor_id(); |
| |
| ++nmi_count(cpu); |
| |
| if (!rcu_dereference(nmi_callback)(regs, cpu)) |
| default_do_nmi(regs); |
| |
| nmi_exit(); |
| } |
| |
| void set_nmi_callback(nmi_callback_t callback) |
| { |
| vmalloc_sync_all(); |
| rcu_assign_pointer(nmi_callback, callback); |
| } |
| EXPORT_SYMBOL_GPL(set_nmi_callback); |
| |
| void unset_nmi_callback(void) |
| { |
| nmi_callback = dummy_nmi_callback; |
| } |
| EXPORT_SYMBOL_GPL(unset_nmi_callback); |
| |
| #ifdef CONFIG_KPROBES |
| fastcall 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; |
| /* This is an interrupt gate, because kprobes wants interrupts |
| disabled. Normal trap handlers don't. */ |
| restore_interrupts(regs); |
| do_trap(3, SIGTRAP, "int3", 1, regs, error_code, NULL); |
| } |
| #endif |
| |
| /* |
| * Our handling of the processor debug registers is non-trivial. |
| * We do not clear them on entry and exit from the kernel. Therefore |
| * it is possible to get a watchpoint trap here from inside the kernel. |
| * However, the code in ./ptrace.c has ensured that the user can |
| * only set watchpoints on userspace addresses. Therefore the in-kernel |
| * watchpoint trap can only occur in code which is reading/writing |
| * from user space. Such code must not hold kernel locks (since it |
| * can equally take a page fault), therefore it is safe to call |
| * force_sig_info even though that claims and releases locks. |
| * |
| * Code in ./signal.c ensures that the debug control register |
| * is restored before we deliver any signal, and therefore that |
| * user code runs with the correct debug control register even though |
| * we clear it here. |
| * |
| * Being careful here means that we don't have to be as careful in a |
| * lot of more complicated places (task switching can be a bit lazy |
| * about restoring all the debug state, and ptrace doesn't have to |
| * find every occurrence of the TF bit that could be saved away even |
| * by user code) |
| */ |
| fastcall void __kprobes do_debug(struct pt_regs * regs, long error_code) |
| { |
| unsigned int condition; |
| struct task_struct *tsk = current; |
| |
| get_debugreg(condition, 6); |
| |
| if (notify_die(DIE_DEBUG, "debug", regs, condition, error_code, |
| SIGTRAP) == NOTIFY_STOP) |
| return; |
| /* It's safe to allow irq's after DR6 has been saved */ |
| if (regs->eflags & X86_EFLAGS_IF) |
| local_irq_enable(); |
| |
| /* Mask out spurious debug traps due to lazy DR7 setting */ |
| if (condition & (DR_TRAP0|DR_TRAP1|DR_TRAP2|DR_TRAP3)) { |
| if (!tsk->thread.debugreg[7]) |
| goto clear_dr7; |
| } |
| |
| if (regs->eflags & VM_MASK) |
| goto debug_vm86; |
| |
| /* Save debug status register where ptrace can see it */ |
| tsk->thread.debugreg[6] = condition; |
| |
| /* |
| * Single-stepping through TF: make sure we ignore any events in |
| * kernel space (but re-enable TF when returning to user mode). |
| */ |
| if (condition & DR_STEP) { |
| /* |
| * We already checked v86 mode above, so we can |
| * check for kernel mode by just checking the CPL |
| * of CS. |
| */ |
| if (!user_mode(regs)) |
| goto clear_TF_reenable; |
| } |
| |
| /* Ok, finally something we can handle */ |
| send_sigtrap(tsk, regs, error_code); |
| |
| /* Disable additional traps. They'll be re-enabled when |
| * the signal is delivered. |
| */ |
| clear_dr7: |
| set_debugreg(0, 7); |
| return; |
| |
| debug_vm86: |
| handle_vm86_trap((struct kernel_vm86_regs *) regs, error_code, 1); |
| return; |
| |
| clear_TF_reenable: |
| set_tsk_thread_flag(tsk, TIF_SINGLESTEP); |
| regs->eflags &= ~TF_MASK; |
| return; |
| } |
| |
| /* |
| * 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 |
| */ |
| void math_error(void __user *eip) |
| { |
| struct task_struct * task; |
| siginfo_t info; |
| unsigned short cwd, swd; |
| |
| /* |
| * 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 = eip; |
| /* |
| * (~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 syncronizing 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: /* No unmasked exception */ |
| return; |
| default: /* Multiple exceptions */ |
| 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); |
| } |
| |
| fastcall void do_coprocessor_error(struct pt_regs * regs, long error_code) |
| { |
| ignore_fpu_irq = 1; |
| math_error((void __user *)regs->eip); |
| } |
| |
| static void simd_math_error(void __user *eip) |
| { |
| struct task_struct * task; |
| siginfo_t info; |
| unsigned short mxcsr; |
| |
| /* |
| * 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 = eip; |
| /* |
| * 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); |
| } |
| |
| fastcall void do_simd_coprocessor_error(struct pt_regs * regs, |
| long error_code) |
| { |
| if (cpu_has_xmm) { |
| /* Handle SIMD FPU exceptions on PIII+ processors. */ |
| ignore_fpu_irq = 1; |
| simd_math_error((void __user *)regs->eip); |
| } else { |
| /* |
| * Handle strange cache flush from user space exception |
| * in all other cases. This is undocumented behaviour. |
| */ |
| if (regs->eflags & VM_MASK) { |
| handle_vm86_fault((struct kernel_vm86_regs *)regs, |
| error_code); |
| return; |
| } |
| current->thread.trap_no = 19; |
| current->thread.error_code = error_code; |
| die_if_kernel("cache flush denied", regs, error_code); |
| force_sig(SIGSEGV, current); |
| } |
| } |
| |
| fastcall void do_spurious_interrupt_bug(struct pt_regs * regs, |
| long error_code) |
| { |
| #if 0 |
| /* No need to warn about this any longer. */ |
| printk("Ignoring P6 Local APIC Spurious Interrupt Bug...\n"); |
| #endif |
| } |
| |
| fastcall void setup_x86_bogus_stack(unsigned char * stk) |
| { |
| unsigned long *switch16_ptr, *switch32_ptr; |
| struct pt_regs *regs; |
| unsigned long stack_top, stack_bot; |
| unsigned short iret_frame16_off; |
| int cpu = smp_processor_id(); |
| /* reserve the space on 32bit stack for the magic switch16 pointer */ |
| memmove(stk, stk + 8, sizeof(struct pt_regs)); |
| switch16_ptr = (unsigned long *)(stk + sizeof(struct pt_regs)); |
| regs = (struct pt_regs *)stk; |
| /* now the switch32 on 16bit stack */ |
| stack_bot = (unsigned long)&per_cpu(cpu_16bit_stack, cpu); |
| stack_top = stack_bot + CPU_16BIT_STACK_SIZE; |
| switch32_ptr = (unsigned long *)(stack_top - 8); |
| iret_frame16_off = CPU_16BIT_STACK_SIZE - 8 - 20; |
| /* copy iret frame on 16bit stack */ |
| memcpy((void *)(stack_bot + iret_frame16_off), ®s->eip, 20); |
| /* fill in the switch pointers */ |
| switch16_ptr[0] = (regs->esp & 0xffff0000) | iret_frame16_off; |
| switch16_ptr[1] = __ESPFIX_SS; |
| switch32_ptr[0] = (unsigned long)stk + sizeof(struct pt_regs) + |
| 8 - CPU_16BIT_STACK_SIZE; |
| switch32_ptr[1] = __KERNEL_DS; |
| } |
| |
| fastcall unsigned char * fixup_x86_bogus_stack(unsigned short sp) |
| { |
| unsigned long *switch32_ptr; |
| unsigned char *stack16, *stack32; |
| unsigned long stack_top, stack_bot; |
| int len; |
| int cpu = smp_processor_id(); |
| stack_bot = (unsigned long)&per_cpu(cpu_16bit_stack, cpu); |
| stack_top = stack_bot + CPU_16BIT_STACK_SIZE; |
| switch32_ptr = (unsigned long *)(stack_top - 8); |
| /* copy the data from 16bit stack to 32bit stack */ |
| len = CPU_16BIT_STACK_SIZE - 8 - sp; |
| stack16 = (unsigned char *)(stack_bot + sp); |
| stack32 = (unsigned char *) |
| (switch32_ptr[0] + CPU_16BIT_STACK_SIZE - 8 - len); |
| memcpy(stack32, stack16, len); |
| return stack32; |
| } |
| |
| /* |
| * '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. |
| * |
| * Must be called with kernel preemption disabled (in this case, |
| * local interrupts are disabled at the call-site in entry.S). |
| */ |
| asmlinkage void math_state_restore(struct pt_regs regs) |
| { |
| struct thread_info *thread = current_thread_info(); |
| struct task_struct *tsk = thread->task; |
| |
| clts(); /* Allow maths ops (or we recurse) */ |
| if (!tsk_used_math(tsk)) |
| init_fpu(tsk); |
| restore_fpu(tsk); |
| thread->status |= TS_USEDFPU; /* So we fnsave on switch_to() */ |
| } |
| |
| #ifndef CONFIG_MATH_EMULATION |
| |
| asmlinkage void math_emulate(long arg) |
| { |
| printk(KERN_EMERG "math-emulation not enabled and no coprocessor found.\n"); |
| printk(KERN_EMERG "killing %s.\n",current->comm); |
| force_sig(SIGFPE,current); |
| schedule(); |
| } |
| |
| #endif /* CONFIG_MATH_EMULATION */ |
| |
| #ifdef CONFIG_X86_F00F_BUG |
| void __init trap_init_f00f_bug(void) |
| { |
| __set_fixmap(FIX_F00F_IDT, __pa(&idt_table), PAGE_KERNEL_RO); |
| |
| /* |
| * Update the IDT descriptor and reload the IDT so that |
| * it uses the read-only mapped virtual address. |
| */ |
| idt_descr.address = fix_to_virt(FIX_F00F_IDT); |
| load_idt(&idt_descr); |
| } |
| #endif |
| |
| #define _set_gate(gate_addr,type,dpl,addr,seg) \ |
| do { \ |
| int __d0, __d1; \ |
| __asm__ __volatile__ ("movw %%dx,%%ax\n\t" \ |
| "movw %4,%%dx\n\t" \ |
| "movl %%eax,%0\n\t" \ |
| "movl %%edx,%1" \ |
| :"=m" (*((long *) (gate_addr))), \ |
| "=m" (*(1+(long *) (gate_addr))), "=&a" (__d0), "=&d" (__d1) \ |
| :"i" ((short) (0x8000+(dpl<<13)+(type<<8))), \ |
| "3" ((char *) (addr)),"2" ((seg) << 16)); \ |
| } while (0) |
| |
| |
| /* |
| * This needs to use 'idt_table' rather than 'idt', and |
| * thus use the _nonmapped_ version of the IDT, as the |
| * Pentium F0 0F bugfix can have resulted in the mapped |
| * IDT being write-protected. |
| */ |
| void set_intr_gate(unsigned int n, void *addr) |
| { |
| _set_gate(idt_table+n,14,0,addr,__KERNEL_CS); |
| } |
| |
| /* |
| * This routine sets up an interrupt gate at directory privilege level 3. |
| */ |
| static inline void set_system_intr_gate(unsigned int n, void *addr) |
| { |
| _set_gate(idt_table+n, 14, 3, addr, __KERNEL_CS); |
| } |
| |
| static void __init set_trap_gate(unsigned int n, void *addr) |
| { |
| _set_gate(idt_table+n,15,0,addr,__KERNEL_CS); |
| } |
| |
| static void __init set_system_gate(unsigned int n, void *addr) |
| { |
| _set_gate(idt_table+n,15,3,addr,__KERNEL_CS); |
| } |
| |
| static void __init set_task_gate(unsigned int n, unsigned int gdt_entry) |
| { |
| _set_gate(idt_table+n,5,0,0,(gdt_entry<<3)); |
| } |
| |
| |
| void __init trap_init(void) |
| { |
| #ifdef CONFIG_EISA |
| void __iomem *p = ioremap(0x0FFFD9, 4); |
| if (readl(p) == 'E'+('I'<<8)+('S'<<16)+('A'<<24)) { |
| EISA_bus = 1; |
| } |
| iounmap(p); |
| #endif |
| |
| #ifdef CONFIG_X86_LOCAL_APIC |
| init_apic_mappings(); |
| #endif |
| |
| set_trap_gate(0,÷_error); |
| set_intr_gate(1,&debug); |
| set_intr_gate(2,&nmi); |
| set_system_intr_gate(3, &int3); /* int3/4 can be called from all */ |
| set_system_gate(4,&overflow); |
| set_trap_gate(5,&bounds); |
| set_trap_gate(6,&invalid_op); |
| set_trap_gate(7,&device_not_available); |
| set_task_gate(8,GDT_ENTRY_DOUBLEFAULT_TSS); |
| set_trap_gate(9,&coprocessor_segment_overrun); |
| set_trap_gate(10,&invalid_TSS); |
| set_trap_gate(11,&segment_not_present); |
| set_trap_gate(12,&stack_segment); |
| set_trap_gate(13,&general_protection); |
| set_intr_gate(14,&page_fault); |
| set_trap_gate(15,&spurious_interrupt_bug); |
| set_trap_gate(16,&coprocessor_error); |
| set_trap_gate(17,&alignment_check); |
| #ifdef CONFIG_X86_MCE |
| set_trap_gate(18,&machine_check); |
| #endif |
| set_trap_gate(19,&simd_coprocessor_error); |
| |
| if (cpu_has_fxsr) { |
| /* |
| * Verify that the FXSAVE/FXRSTOR data will be 16-byte aligned. |
| * Generates a compile-time "error: zero width for bit-field" if |
| * the alignment is wrong. |
| */ |
| struct fxsrAlignAssert { |
| int _:!(offsetof(struct task_struct, |
| thread.i387.fxsave) & 15); |
| }; |
| |
| printk(KERN_INFO "Enabling fast FPU save and restore... "); |
| set_in_cr4(X86_CR4_OSFXSR); |
| printk("done.\n"); |
| } |
| if (cpu_has_xmm) { |
| printk(KERN_INFO "Enabling unmasked SIMD FPU exception " |
| "support... "); |
| set_in_cr4(X86_CR4_OSXMMEXCPT); |
| printk("done.\n"); |
| } |
| |
| set_system_gate(SYSCALL_VECTOR,&system_call); |
| |
| /* |
| * Should be a barrier for any external CPU state. |
| */ |
| cpu_init(); |
| |
| trap_init_hook(); |
| } |
| |
| static int __init kstack_setup(char *s) |
| { |
| kstack_depth_to_print = simple_strtoul(s, NULL, 0); |
| return 1; |
| } |
| __setup("kstack=", kstack_setup); |