vt_ioctl.c

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		 * we reject here, but to be safe...
		 */
		if (arg < GPFIRST || arg > GPLAST)
			return -EINVAL;
		return sys_ioperm(arg, 1, (cmd == KDADDIO)) ? -ENXIO : 0;

	case KDENABIO:
	case KDDISABIO:
		return sys_ioperm(GPFIRST, GPNUM,
				  (cmd == KDENABIO)) ? -ENXIO : 0;
#endif

	/* Linux m68k/i386 interface for setting the keyboard delay/repeat rate */
		
	case KDKBDREP:
	{
		struct kbd_repeat kbrep;
		int err;
		
		if (!capable(CAP_SYS_TTY_CONFIG))
			return -EPERM;

		if (copy_from_user(&kbrep, up, sizeof(struct kbd_repeat)))
			return -EFAULT;
		err = kbd_rate(&kbrep);
		if (err)
			return err;
		if (copy_to_user(up, &kbrep, sizeof(struct kbd_repeat)))
			return -EFAULT;
		return 0;
	}

	case KDSETMODE:
		/*
		 * currently, setting the mode from KD_TEXT to KD_GRAPHICS
		 * doesn't do a whole lot. i'm not sure if it should do any
		 * restoration of modes or what...
		 *
		 * XXX It should at least call into the driver, fbdev's definitely
		 * need to restore their engine state. --BenH
		 */
		if (!perm)
			return -EPERM;
		switch (arg) {
		case KD_GRAPHICS:
			break;
		case KD_TEXT0:
		case KD_TEXT1:
			arg = KD_TEXT;
		case KD_TEXT:
			break;
		default:
			return -EINVAL;
		}
		if (vc->vc_mode == (unsigned char) arg)
			return 0;
		vc->vc_mode = (unsigned char) arg;
		if (console != fg_console)
			return 0;
		/*
		 * explicitly blank/unblank the screen if switching modes
		 */
		acquire_console_sem();
		if (arg == KD_TEXT)
			do_unblank_screen(1);
		else
			do_blank_screen(1);
		release_console_sem();
		return 0;

	case KDGETMODE:
		ucval = vc->vc_mode;
		goto setint;

	case KDMAPDISP:
	case KDUNMAPDISP:
		/*
		 * these work like a combination of mmap and KDENABIO.
		 * this could be easily finished.
		 */
		return -EINVAL;

	case KDSKBMODE:
		if (!perm)
			return -EPERM;
		switch(arg) {
		  case K_RAW:
			kbd->kbdmode = VC_RAW;
			break;
		  case K_MEDIUMRAW:
			kbd->kbdmode = VC_MEDIUMRAW;
			break;
		  case K_XLATE:
			kbd->kbdmode = VC_XLATE;
			compute_shiftstate();
			break;
		  case K_UNICODE:
			kbd->kbdmode = VC_UNICODE;
			compute_shiftstate();
			break;
		  default:
			return -EINVAL;
		}
		tty_ldisc_flush(tty);
		return 0;

	case KDGKBMODE:
		ucval = ((kbd->kbdmode == VC_RAW) ? K_RAW :
				 (kbd->kbdmode == VC_MEDIUMRAW) ? K_MEDIUMRAW :
				 (kbd->kbdmode == VC_UNICODE) ? K_UNICODE :
				 K_XLATE);
		goto setint;

	/* this could be folded into KDSKBMODE, but for compatibility
	   reasons it is not so easy to fold KDGKBMETA into KDGKBMODE */
	case KDSKBMETA:
		switch(arg) {
		  case K_METABIT:
			clr_vc_kbd_mode(kbd, VC_META);
			break;
		  case K_ESCPREFIX:
			set_vc_kbd_mode(kbd, VC_META);
			break;
		  default:
			return -EINVAL;
		}
		return 0;

	case KDGKBMETA:
		ucval = (vc_kbd_mode(kbd, VC_META) ? K_ESCPREFIX : K_METABIT);
	setint:
		return put_user(ucval, (int __user *)arg); 

	case KDGETKEYCODE:
	case KDSETKEYCODE:
		if(!capable(CAP_SYS_TTY_CONFIG))
			perm=0;
		return do_kbkeycode_ioctl(cmd, up, perm);

	case KDGKBENT:
	case KDSKBENT:
		return do_kdsk_ioctl(cmd, up, perm, kbd);

	case KDGKBSENT:
	case KDSKBSENT:
		return do_kdgkb_ioctl(cmd, up, perm);

	case KDGKBDIACR:
	{
		struct kbdiacrs __user *a = up;
		struct kbdiacr diacr;
		int i;

		if (put_user(accent_table_size, &a->kb_cnt))
			return -EFAULT;
		for (i = 0; i < accent_table_size; i++) {
			diacr.diacr = conv_uni_to_8bit(accent_table[i].diacr);
			diacr.base = conv_uni_to_8bit(accent_table[i].base);
			diacr.result = conv_uni_to_8bit(accent_table[i].result);
			if (copy_to_user(a->kbdiacr + i, &diacr, sizeof(struct kbdiacr)))
				return -EFAULT;
		}
		return 0;
	}
	case KDGKBDIACRUC:
	{
		struct kbdiacrsuc __user *a = up;

		if (put_user(accent_table_size, &a->kb_cnt))
			return -EFAULT;
		if (copy_to_user(a->kbdiacruc, accent_table, accent_table_size*sizeof(struct kbdiacruc)))
			return -EFAULT;
		return 0;
	}

	case KDSKBDIACR:
	{
		struct kbdiacrs __user *a = up;
		struct kbdiacr diacr;
		unsigned int ct;
		int i;

		if (!perm)
			return -EPERM;
		if (get_user(ct,&a->kb_cnt))
			return -EFAULT;
		if (ct >= MAX_DIACR)
			return -EINVAL;
		accent_table_size = ct;
		for (i = 0; i < ct; i++) {
			if (copy_from_user(&diacr, a->kbdiacr + i, sizeof(struct kbdiacr)))
				return -EFAULT;
			accent_table[i].diacr = conv_8bit_to_uni(diacr.diacr);
			accent_table[i].base = conv_8bit_to_uni(diacr.base);
			accent_table[i].result = conv_8bit_to_uni(diacr.result);
		}
		return 0;
	}

	case KDSKBDIACRUC:
	{
		struct kbdiacrsuc __user *a = up;
		unsigned int ct;

		if (!perm)
			return -EPERM;
		if (get_user(ct,&a->kb_cnt))
			return -EFAULT;
		if (ct >= MAX_DIACR)
			return -EINVAL;
		accent_table_size = ct;
		if (copy_from_user(accent_table, a->kbdiacruc, ct*sizeof(struct kbdiacruc)))
			return -EFAULT;
		return 0;
	}

	/* the ioctls below read/set the flags usually shown in the leds */
	/* don't use them - they will go away without warning */
	case KDGKBLED:
		ucval = kbd->ledflagstate | (kbd->default_ledflagstate << 4);
		goto setchar;

	case KDSKBLED:
		if (!perm)
			return -EPERM;
		if (arg & ~0x77)
			return -EINVAL;
		kbd->ledflagstate = (arg & 7);
		kbd->default_ledflagstate = ((arg >> 4) & 7);
		set_leds();
		return 0;

	/* the ioctls below only set the lights, not the functions */
	/* for those, see KDGKBLED and KDSKBLED above */
	case KDGETLED:
		ucval = getledstate();
	setchar:
		return put_user(ucval, (char __user *)arg);

	case KDSETLED:
		if (!perm)
		  return -EPERM;
		setledstate(kbd, arg);
		return 0;

	/*
	 * A process can indicate its willingness to accept signals
	 * generated by pressing an appropriate key combination.
	 * Thus, one can have a daemon that e.g. spawns a new console
	 * upon a keypress and then changes to it.
	 * See also the kbrequest field of inittab(5).
	 */
	case KDSIGACCEPT:
	{
		if (!perm || !capable(CAP_KILL))
		  return -EPERM;
		if (!valid_signal(arg) || arg < 1 || arg == SIGKILL)
		  return -EINVAL;

		spin_lock_irq(&vt_spawn_con.lock);
		put_pid(vt_spawn_con.pid);
		vt_spawn_con.pid = get_pid(task_pid(current));
		vt_spawn_con.sig = arg;
		spin_unlock_irq(&vt_spawn_con.lock);
		return 0;
	}

	case VT_SETMODE:
	{
		struct vt_mode tmp;

		if (!perm)
			return -EPERM;
		if (copy_from_user(&tmp, up, sizeof(struct vt_mode)))
			return -EFAULT;
		if (tmp.mode != VT_AUTO && tmp.mode != VT_PROCESS)
			return -EINVAL;
		acquire_console_sem();
		vc->vt_mode = tmp;
		/* the frsig is ignored, so we set it to 0 */
		vc->vt_mode.frsig = 0;
		put_pid(vc->vt_pid);
		vc->vt_pid = get_pid(task_pid(current));
		/* no switch is required -- [e-mail] */
		vc->vt_newvt = -1;
		release_console_sem();
		return 0;
	}

	case VT_GETMODE:
	{
		struct vt_mode tmp;
		int rc;

		acquire_console_sem();
		memcpy(&tmp, &vc->vt_mode, sizeof(struct vt_mode));
		release_console_sem();

		rc = copy_to_user(up, &tmp, sizeof(struct vt_mode));
		return rc ? -EFAULT : 0;
	}

	/*
	 * Returns global vt state. Note that VT 0 is always open, since
	 * it's an alias for the current VT, and people can't use it here.
	 * We cannot return state for more than 16 VTs, since v_state is short.
	 */
	case VT_GETSTATE:
	{
		struct vt_stat __user *vtstat = up;
		unsigned short state, mask;

		if (put_user(fg_console + 1, &vtstat->v_active))
			return -EFAULT;
		state = 1;	/* /dev/tty0 is always open */
		for (i = 0, mask = 2; i < MAX_NR_CONSOLES && mask; ++i, mask <<= 1)
			if (VT_IS_IN_USE(i))
				state |= mask;
		return put_user(state, &vtstat->v_state);
	}

	/*
	 * Returns the first available (non-opened) console.
	 */
	case VT_OPENQRY:
		for (i = 0; i < MAX_NR_CONSOLES; ++i)
			if (! VT_IS_IN_USE(i))
				break;
		ucval = i < MAX_NR_CONSOLES ? (i+1) : -1;
		goto setint;		 

	/*
	 * ioctl(fd, VT_ACTIVATE, num) will cause us to switch to vt # num,
	 * with num >= 1 (switches to vt 0, our console, are not allowed, just
	 * to preserve sanity).
	 */
	case VT_ACTIVATE:
		if (!perm)
			return -EPERM;
		if (arg == 0 || arg > MAX_NR_CONSOLES)
			return -ENXIO;
		arg--;
		acquire_console_sem();
		i = vc_allocate(arg);
		release_console_sem();
		if (i)
			return i;
		set_console(arg);
		return 0;

	/*
	 * wait until the specified VT has been activated
	 */
	case VT_WAITACTIVE:
		if (!perm)
			return -EPERM;
		if (arg == 0 || arg > MAX_NR_CONSOLES)
			return -ENXIO;
		return vt_waitactive(arg-1);

	/*
	 * If a vt is under process control, the kernel will not switch to it
	 * immediately, but postpone the operation until the process calls this
	 * ioctl, allowing the switch to complete.
	 *
	 * According to the X sources this is the behavior:
	 *	0:	pending switch-from not OK
	 *	1:	pending switch-from OK
	 *	2:	completed switch-to OK
	 */
	case VT_RELDISP:
		if (!perm)
			return -EPERM;
		if (vc->vt_mode.mode != VT_PROCESS)
			return -EINVAL;

		/*
		 * Switching-from response
		 */
		acquire_console_sem();
		if (vc->vt_newvt >= 0) {
			if (arg == 0)
				/*
				 * Switch disallowed, so forget we were trying
				 * to do it.
				 */
				vc->vt_newvt = -1;

			else {
				/*
				 * The current vt has been released, so
				 * complete the switch.
				 */
				int newvt;
				newvt = vc->vt_newvt;
				vc->vt_newvt = -1;
				i = vc_allocate(newvt);
				if (i) {
					release_console_sem();
					return i;
				}
				/*
				 * When we actually do the console switch,
				 * make sure we are atomic with respect to
				 * other console switches..
				 */
				complete_change_console(vc_cons[newvt].d);
			}
		}

		/*
		 * Switched-to response
		 */
		else
		{
			/*
			 * If it's just an ACK, ignore it
			 */
			if (arg != VT_ACKACQ) {
				release_console_sem();
				return -EINVAL;
			}
		}
		release_console_sem();

		return 0;

	 /*
	  * Disallocate memory associated to VT (but leave VT1)
	  */
	 case VT_DISALLOCATE:
		if (arg > MAX_NR_CONSOLES)
			return -ENXIO;
		if (arg == 0) {
		    /* deallocate all unused consoles, but leave 0 */