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v5.4
   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 *  Copyright (C) 1992 obz under the linux copyright
   4 *
   5 *  Dynamic diacritical handling - aeb@cwi.nl - Dec 1993
   6 *  Dynamic keymap and string allocation - aeb@cwi.nl - May 1994
   7 *  Restrict VT switching via ioctl() - grif@cs.ucr.edu - Dec 1995
   8 *  Some code moved for less code duplication - Andi Kleen - Mar 1997
   9 *  Check put/get_user, cleanups - acme@conectiva.com.br - Jun 2001
  10 */
  11
  12#include <linux/types.h>
  13#include <linux/errno.h>
  14#include <linux/sched/signal.h>
  15#include <linux/tty.h>
  16#include <linux/timer.h>
  17#include <linux/kernel.h>
  18#include <linux/compat.h>
  19#include <linux/module.h>
  20#include <linux/kd.h>
  21#include <linux/vt.h>
  22#include <linux/string.h>
  23#include <linux/slab.h>
  24#include <linux/major.h>
  25#include <linux/fs.h>
  26#include <linux/console.h>
  27#include <linux/consolemap.h>
  28#include <linux/signal.h>
  29#include <linux/suspend.h>
  30#include <linux/timex.h>
  31
  32#include <asm/io.h>
  33#include <linux/uaccess.h>
  34
  35#include <linux/nospec.h>
  36
  37#include <linux/kbd_kern.h>
  38#include <linux/vt_kern.h>
  39#include <linux/kbd_diacr.h>
  40#include <linux/selection.h>
  41
  42char vt_dont_switch;
  43extern struct tty_driver *console_driver;
  44
  45#define VT_IS_IN_USE(i)	(console_driver->ttys[i] && console_driver->ttys[i]->count)
  46#define VT_BUSY(i)	(VT_IS_IN_USE(i) || i == fg_console || vc_cons[i].d == sel_cons)
  47
  48/*
  49 * Console (vt and kd) routines, as defined by USL SVR4 manual, and by
  50 * experimentation and study of X386 SYSV handling.
  51 *
  52 * One point of difference: SYSV vt's are /dev/vtX, which X >= 0, and
  53 * /dev/console is a separate ttyp. Under Linux, /dev/tty0 is /dev/console,
  54 * and the vc start at /dev/ttyX, X >= 1. We maintain that here, so we will
  55 * always treat our set of vt as numbered 1..MAX_NR_CONSOLES (corresponding to
  56 * ttys 0..MAX_NR_CONSOLES-1). Explicitly naming VT 0 is illegal, but using
  57 * /dev/tty0 (fg_console) as a target is legal, since an implicit aliasing
  58 * to the current console is done by the main ioctl code.
  59 */
  60
  61#ifdef CONFIG_X86
  62#include <asm/syscalls.h>
  63#endif
  64
  65static void complete_change_console(struct vc_data *vc);
  66
  67/*
  68 *	User space VT_EVENT handlers
  69 */
  70
  71struct vt_event_wait {
  72	struct list_head list;
  73	struct vt_event event;
  74	int done;
  75};
  76
  77static LIST_HEAD(vt_events);
  78static DEFINE_SPINLOCK(vt_event_lock);
  79static DECLARE_WAIT_QUEUE_HEAD(vt_event_waitqueue);
  80
  81/**
  82 *	vt_event_post
  83 *	@event: the event that occurred
  84 *	@old: old console
  85 *	@new: new console
  86 *
  87 *	Post an VT event to interested VT handlers
  88 */
  89
  90void vt_event_post(unsigned int event, unsigned int old, unsigned int new)
  91{
  92	struct list_head *pos, *head;
  93	unsigned long flags;
  94	int wake = 0;
  95
  96	spin_lock_irqsave(&vt_event_lock, flags);
  97	head = &vt_events;
  98
  99	list_for_each(pos, head) {
 100		struct vt_event_wait *ve = list_entry(pos,
 101						struct vt_event_wait, list);
 102		if (!(ve->event.event & event))
 103			continue;
 104		ve->event.event = event;
 105		/* kernel view is consoles 0..n-1, user space view is
 106		   console 1..n with 0 meaning current, so we must bias */
 107		ve->event.oldev = old + 1;
 108		ve->event.newev = new + 1;
 109		wake = 1;
 110		ve->done = 1;
 111	}
 112	spin_unlock_irqrestore(&vt_event_lock, flags);
 113	if (wake)
 114		wake_up_interruptible(&vt_event_waitqueue);
 115}
 116
 117static void __vt_event_queue(struct vt_event_wait *vw)
 
 
 
 
 
 
 
 
 
 118{
 119	unsigned long flags;
 120	/* Prepare the event */
 121	INIT_LIST_HEAD(&vw->list);
 122	vw->done = 0;
 123	/* Queue our event */
 124	spin_lock_irqsave(&vt_event_lock, flags);
 125	list_add(&vw->list, &vt_events);
 126	spin_unlock_irqrestore(&vt_event_lock, flags);
 127}
 128
 129static void __vt_event_wait(struct vt_event_wait *vw)
 130{
 131	/* Wait for it to pass */
 132	wait_event_interruptible(vt_event_waitqueue, vw->done);
 133}
 134
 135static void __vt_event_dequeue(struct vt_event_wait *vw)
 136{
 137	unsigned long flags;
 138
 139	/* Dequeue it */
 140	spin_lock_irqsave(&vt_event_lock, flags);
 141	list_del(&vw->list);
 142	spin_unlock_irqrestore(&vt_event_lock, flags);
 143}
 144
 145/**
 146 *	vt_event_wait		-	wait for an event
 147 *	@vw: our event
 148 *
 149 *	Waits for an event to occur which completes our vt_event_wait
 150 *	structure. On return the structure has wv->done set to 1 for success
 151 *	or 0 if some event such as a signal ended the wait.
 152 */
 153
 154static void vt_event_wait(struct vt_event_wait *vw)
 155{
 156	__vt_event_queue(vw);
 157	__vt_event_wait(vw);
 158	__vt_event_dequeue(vw);
 159}
 160
 161/**
 162 *	vt_event_wait_ioctl	-	event ioctl handler
 163 *	@arg: argument to ioctl
 164 *
 165 *	Implement the VT_WAITEVENT ioctl using the VT event interface
 166 */
 167
 168static int vt_event_wait_ioctl(struct vt_event __user *event)
 169{
 170	struct vt_event_wait vw;
 171
 172	if (copy_from_user(&vw.event, event, sizeof(struct vt_event)))
 173		return -EFAULT;
 174	/* Highest supported event for now */
 175	if (vw.event.event & ~VT_MAX_EVENT)
 176		return -EINVAL;
 177
 178	vt_event_wait(&vw);
 179	/* If it occurred report it */
 180	if (vw.done) {
 181		if (copy_to_user(event, &vw.event, sizeof(struct vt_event)))
 182			return -EFAULT;
 183		return 0;
 184	}
 185	return -EINTR;
 186}
 187
 188/**
 189 *	vt_waitactive	-	active console wait
 190 *	@event: event code
 191 *	@n: new console
 192 *
 193 *	Helper for event waits. Used to implement the legacy
 194 *	event waiting ioctls in terms of events
 195 */
 196
 197int vt_waitactive(int n)
 198{
 199	struct vt_event_wait vw;
 200	do {
 201		vw.event.event = VT_EVENT_SWITCH;
 202		__vt_event_queue(&vw);
 203		if (n == fg_console + 1) {
 204			__vt_event_dequeue(&vw);
 205			break;
 206		}
 207		__vt_event_wait(&vw);
 208		__vt_event_dequeue(&vw);
 209		if (vw.done == 0)
 210			return -EINTR;
 211	} while (vw.event.newev != n);
 212	return 0;
 213}
 214
 215/*
 216 * these are the valid i/o ports we're allowed to change. they map all the
 217 * video ports
 218 */
 219#define GPFIRST 0x3b4
 220#define GPLAST 0x3df
 221#define GPNUM (GPLAST - GPFIRST + 1)
 222
 223
 224
 225static inline int 
 226do_fontx_ioctl(int cmd, struct consolefontdesc __user *user_cfd, int perm, struct console_font_op *op)
 227{
 228	struct consolefontdesc cfdarg;
 229	int i;
 230
 231	if (copy_from_user(&cfdarg, user_cfd, sizeof(struct consolefontdesc))) 
 232		return -EFAULT;
 233 	
 234	switch (cmd) {
 235	case PIO_FONTX:
 236		if (!perm)
 237			return -EPERM;
 238		op->op = KD_FONT_OP_SET;
 239		op->flags = KD_FONT_FLAG_OLD;
 240		op->width = 8;
 241		op->height = cfdarg.charheight;
 242		op->charcount = cfdarg.charcount;
 243		op->data = cfdarg.chardata;
 244		return con_font_op(vc_cons[fg_console].d, op);
 245	case GIO_FONTX: {
 246		op->op = KD_FONT_OP_GET;
 247		op->flags = KD_FONT_FLAG_OLD;
 248		op->width = 8;
 249		op->height = cfdarg.charheight;
 250		op->charcount = cfdarg.charcount;
 251		op->data = cfdarg.chardata;
 252		i = con_font_op(vc_cons[fg_console].d, op);
 253		if (i)
 254			return i;
 255		cfdarg.charheight = op->height;
 256		cfdarg.charcount = op->charcount;
 257		if (copy_to_user(user_cfd, &cfdarg, sizeof(struct consolefontdesc)))
 258			return -EFAULT;
 259		return 0;
 260		}
 261	}
 262	return -EINVAL;
 263}
 264
 265static inline int 
 266do_unimap_ioctl(int cmd, struct unimapdesc __user *user_ud, int perm, struct vc_data *vc)
 267{
 268	struct unimapdesc tmp;
 269
 270	if (copy_from_user(&tmp, user_ud, sizeof tmp))
 271		return -EFAULT;
 
 
 
 
 272	switch (cmd) {
 273	case PIO_UNIMAP:
 274		if (!perm)
 275			return -EPERM;
 276		return con_set_unimap(vc, tmp.entry_ct, tmp.entries);
 277	case GIO_UNIMAP:
 278		if (!perm && fg_console != vc->vc_num)
 279			return -EPERM;
 280		return con_get_unimap(vc, tmp.entry_ct, &(user_ud->entry_ct), tmp.entries);
 281	}
 282	return 0;
 283}
 284
 285/* deallocate a single console, if possible (leave 0) */
 286static int vt_disallocate(unsigned int vc_num)
 287{
 288	struct vc_data *vc = NULL;
 289	int ret = 0;
 290
 291	console_lock();
 292	if (VT_BUSY(vc_num))
 293		ret = -EBUSY;
 294	else if (vc_num)
 295		vc = vc_deallocate(vc_num);
 296	console_unlock();
 297
 298	if (vc && vc_num >= MIN_NR_CONSOLES) {
 299		tty_port_destroy(&vc->port);
 300		kfree(vc);
 301	}
 302
 303	return ret;
 304}
 305
 306/* deallocate all unused consoles, but leave 0 */
 307static void vt_disallocate_all(void)
 308{
 309	struct vc_data *vc[MAX_NR_CONSOLES];
 310	int i;
 311
 312	console_lock();
 313	for (i = 1; i < MAX_NR_CONSOLES; i++)
 314		if (!VT_BUSY(i))
 315			vc[i] = vc_deallocate(i);
 316		else
 317			vc[i] = NULL;
 318	console_unlock();
 319
 320	for (i = 1; i < MAX_NR_CONSOLES; i++) {
 321		if (vc[i] && i >= MIN_NR_CONSOLES) {
 322			tty_port_destroy(&vc[i]->port);
 323			kfree(vc[i]);
 324		}
 325	}
 326}
 327
 328
 329/*
 330 * We handle the console-specific ioctl's here.  We allow the
 331 * capability to modify any console, not just the fg_console. 
 332 */
 333int vt_ioctl(struct tty_struct *tty,
 334	     unsigned int cmd, unsigned long arg)
 335{
 336	struct vc_data *vc = tty->driver_data;
 337	struct console_font_op op;	/* used in multiple places here */
 338	unsigned int console;
 339	unsigned char ucval;
 340	unsigned int uival;
 341	void __user *up = (void __user *)arg;
 342	int i, perm;
 343	int ret = 0;
 344
 345	console = vc->vc_num;
 346
 347
 348	if (!vc_cons_allocated(console)) { 	/* impossible? */
 349		ret = -ENOIOCTLCMD;
 350		goto out;
 351	}
 352
 353
 354	/*
 355	 * To have permissions to do most of the vt ioctls, we either have
 356	 * to be the owner of the tty, or have CAP_SYS_TTY_CONFIG.
 357	 */
 358	perm = 0;
 359	if (current->signal->tty == tty || capable(CAP_SYS_TTY_CONFIG))
 360		perm = 1;
 361 
 362	switch (cmd) {
 363	case TIOCLINUX:
 364		ret = tioclinux(tty, arg);
 365		break;
 366	case KIOCSOUND:
 367		if (!perm)
 368			return -EPERM;
 369		/*
 370		 * The use of PIT_TICK_RATE is historic, it used to be
 371		 * the platform-dependent CLOCK_TICK_RATE between 2.6.12
 372		 * and 2.6.36, which was a minor but unfortunate ABI
 373		 * change. kd_mksound is locked by the input layer.
 374		 */
 375		if (arg)
 376			arg = PIT_TICK_RATE / arg;
 377		kd_mksound(arg, 0);
 378		break;
 379
 380	case KDMKTONE:
 381		if (!perm)
 382			return -EPERM;
 383	{
 384		unsigned int ticks, count;
 385		
 386		/*
 387		 * Generate the tone for the appropriate number of ticks.
 388		 * If the time is zero, turn off sound ourselves.
 389		 */
 390		ticks = msecs_to_jiffies((arg >> 16) & 0xffff);
 391		count = ticks ? (arg & 0xffff) : 0;
 392		if (count)
 393			count = PIT_TICK_RATE / count;
 394		kd_mksound(count, ticks);
 395		break;
 396	}
 397
 398	case KDGKBTYPE:
 399		/*
 400		 * this is naïve.
 401		 */
 402		ucval = KB_101;
 403		ret = put_user(ucval, (char __user *)arg);
 404		break;
 405
 406		/*
 407		 * These cannot be implemented on any machine that implements
 408		 * ioperm() in user level (such as Alpha PCs) or not at all.
 409		 *
 410		 * XXX: you should never use these, just call ioperm directly..
 411		 */
 412#ifdef CONFIG_X86
 413	case KDADDIO:
 414	case KDDELIO:
 415		/*
 416		 * KDADDIO and KDDELIO may be able to add ports beyond what
 417		 * we reject here, but to be safe...
 418		 *
 419		 * These are locked internally via sys_ioperm
 420		 */
 421		if (arg < GPFIRST || arg > GPLAST) {
 422			ret = -EINVAL;
 423			break;
 424		}
 425		ret = ksys_ioperm(arg, 1, (cmd == KDADDIO)) ? -ENXIO : 0;
 426		break;
 427
 428	case KDENABIO:
 429	case KDDISABIO:
 430		ret = ksys_ioperm(GPFIRST, GPNUM,
 431				  (cmd == KDENABIO)) ? -ENXIO : 0;
 432		break;
 433#endif
 434
 435	/* Linux m68k/i386 interface for setting the keyboard delay/repeat rate */
 436		
 437	case KDKBDREP:
 438	{
 439		struct kbd_repeat kbrep;
 440		
 441		if (!capable(CAP_SYS_TTY_CONFIG))
 442			return -EPERM;
 443
 444		if (copy_from_user(&kbrep, up, sizeof(struct kbd_repeat))) {
 445			ret =  -EFAULT;
 446			break;
 447		}
 448		ret = kbd_rate(&kbrep);
 449		if (ret)
 450			break;
 451		if (copy_to_user(up, &kbrep, sizeof(struct kbd_repeat)))
 452			ret = -EFAULT;
 453		break;
 454	}
 455
 456	case KDSETMODE:
 457		/*
 458		 * currently, setting the mode from KD_TEXT to KD_GRAPHICS
 459		 * doesn't do a whole lot. i'm not sure if it should do any
 460		 * restoration of modes or what...
 461		 *
 462		 * XXX It should at least call into the driver, fbdev's definitely
 463		 * need to restore their engine state. --BenH
 464		 */
 465		if (!perm)
 466			return -EPERM;
 467		switch (arg) {
 468		case KD_GRAPHICS:
 469			break;
 470		case KD_TEXT0:
 471		case KD_TEXT1:
 472			arg = KD_TEXT;
 473		case KD_TEXT:
 474			break;
 475		default:
 476			ret = -EINVAL;
 477			goto out;
 478		}
 479		/* FIXME: this needs the console lock extending */
 480		if (vc->vc_mode == (unsigned char) arg)
 481			break;
 482		vc->vc_mode = (unsigned char) arg;
 483		if (console != fg_console)
 484			break;
 485		/*
 486		 * explicitly blank/unblank the screen if switching modes
 487		 */
 488		console_lock();
 489		if (arg == KD_TEXT)
 490			do_unblank_screen(1);
 491		else
 492			do_blank_screen(1);
 493		console_unlock();
 494		break;
 495
 496	case KDGETMODE:
 497		uival = vc->vc_mode;
 498		goto setint;
 499
 500	case KDMAPDISP:
 501	case KDUNMAPDISP:
 502		/*
 503		 * these work like a combination of mmap and KDENABIO.
 504		 * this could be easily finished.
 505		 */
 506		ret = -EINVAL;
 507		break;
 508
 509	case KDSKBMODE:
 510		if (!perm)
 511			return -EPERM;
 512		ret = vt_do_kdskbmode(console, arg);
 513		if (ret == 0)
 514			tty_ldisc_flush(tty);
 515		break;
 516
 517	case KDGKBMODE:
 518		uival = vt_do_kdgkbmode(console);
 519		ret = put_user(uival, (int __user *)arg);
 520		break;
 521
 522	/* this could be folded into KDSKBMODE, but for compatibility
 523	   reasons it is not so easy to fold KDGKBMETA into KDGKBMODE */
 524	case KDSKBMETA:
 525		ret = vt_do_kdskbmeta(console, arg);
 526		break;
 527
 528	case KDGKBMETA:
 529		/* FIXME: should review whether this is worth locking */
 530		uival = vt_do_kdgkbmeta(console);
 531	setint:
 532		ret = put_user(uival, (int __user *)arg);
 533		break;
 534
 535	case KDGETKEYCODE:
 536	case KDSETKEYCODE:
 537		if(!capable(CAP_SYS_TTY_CONFIG))
 538			perm = 0;
 539		ret = vt_do_kbkeycode_ioctl(cmd, up, perm);
 540		break;
 541
 542	case KDGKBENT:
 543	case KDSKBENT:
 544		ret = vt_do_kdsk_ioctl(cmd, up, perm, console);
 545		break;
 546
 547	case KDGKBSENT:
 548	case KDSKBSENT:
 549		ret = vt_do_kdgkb_ioctl(cmd, up, perm);
 550		break;
 551
 552	/* Diacritical processing. Handled in keyboard.c as it has
 553	   to operate on the keyboard locks and structures */
 554	case KDGKBDIACR:
 555	case KDGKBDIACRUC:
 556	case KDSKBDIACR:
 557	case KDSKBDIACRUC:
 558		ret = vt_do_diacrit(cmd, up, perm);
 559		break;
 560
 561	/* the ioctls below read/set the flags usually shown in the leds */
 562	/* don't use them - they will go away without warning */
 563	case KDGKBLED:
 564	case KDSKBLED:
 565	case KDGETLED:
 566	case KDSETLED:
 567		ret = vt_do_kdskled(console, cmd, arg, perm);
 568		break;
 569
 570	/*
 571	 * A process can indicate its willingness to accept signals
 572	 * generated by pressing an appropriate key combination.
 573	 * Thus, one can have a daemon that e.g. spawns a new console
 574	 * upon a keypress and then changes to it.
 575	 * See also the kbrequest field of inittab(5).
 576	 */
 577	case KDSIGACCEPT:
 578	{
 579		if (!perm || !capable(CAP_KILL))
 580			return -EPERM;
 581		if (!valid_signal(arg) || arg < 1 || arg == SIGKILL)
 582			ret = -EINVAL;
 583		else {
 584			spin_lock_irq(&vt_spawn_con.lock);
 585			put_pid(vt_spawn_con.pid);
 586			vt_spawn_con.pid = get_pid(task_pid(current));
 587			vt_spawn_con.sig = arg;
 588			spin_unlock_irq(&vt_spawn_con.lock);
 589		}
 590		break;
 591	}
 592
 593	case VT_SETMODE:
 594	{
 595		struct vt_mode tmp;
 596
 597		if (!perm)
 598			return -EPERM;
 599		if (copy_from_user(&tmp, up, sizeof(struct vt_mode))) {
 600			ret = -EFAULT;
 601			goto out;
 602		}
 603		if (tmp.mode != VT_AUTO && tmp.mode != VT_PROCESS) {
 604			ret = -EINVAL;
 605			goto out;
 606		}
 607		console_lock();
 608		vc->vt_mode = tmp;
 609		/* the frsig is ignored, so we set it to 0 */
 610		vc->vt_mode.frsig = 0;
 611		put_pid(vc->vt_pid);
 612		vc->vt_pid = get_pid(task_pid(current));
 613		/* no switch is required -- saw@shade.msu.ru */
 614		vc->vt_newvt = -1;
 615		console_unlock();
 616		break;
 617	}
 618
 619	case VT_GETMODE:
 620	{
 621		struct vt_mode tmp;
 622		int rc;
 623
 624		console_lock();
 625		memcpy(&tmp, &vc->vt_mode, sizeof(struct vt_mode));
 626		console_unlock();
 627
 628		rc = copy_to_user(up, &tmp, sizeof(struct vt_mode));
 629		if (rc)
 630			ret = -EFAULT;
 631		break;
 632	}
 633
 634	/*
 635	 * Returns global vt state. Note that VT 0 is always open, since
 636	 * it's an alias for the current VT, and people can't use it here.
 637	 * We cannot return state for more than 16 VTs, since v_state is short.
 638	 */
 639	case VT_GETSTATE:
 640	{
 641		struct vt_stat __user *vtstat = up;
 642		unsigned short state, mask;
 643
 644		/* Review: FIXME: Console lock ? */
 645		if (put_user(fg_console + 1, &vtstat->v_active))
 646			ret = -EFAULT;
 647		else {
 648			state = 1;	/* /dev/tty0 is always open */
 649			for (i = 0, mask = 2; i < MAX_NR_CONSOLES && mask;
 650							++i, mask <<= 1)
 651				if (VT_IS_IN_USE(i))
 652					state |= mask;
 653			ret = put_user(state, &vtstat->v_state);
 654		}
 655		break;
 656	}
 657
 658	/*
 659	 * Returns the first available (non-opened) console.
 660	 */
 661	case VT_OPENQRY:
 662		/* FIXME: locking ? - but then this is a stupid API */
 663		for (i = 0; i < MAX_NR_CONSOLES; ++i)
 664			if (! VT_IS_IN_USE(i))
 665				break;
 666		uival = i < MAX_NR_CONSOLES ? (i+1) : -1;
 667		goto setint;		 
 668
 669	/*
 670	 * ioctl(fd, VT_ACTIVATE, num) will cause us to switch to vt # num,
 671	 * with num >= 1 (switches to vt 0, our console, are not allowed, just
 672	 * to preserve sanity).
 673	 */
 674	case VT_ACTIVATE:
 675		if (!perm)
 676			return -EPERM;
 677		if (arg == 0 || arg > MAX_NR_CONSOLES)
 678			ret =  -ENXIO;
 679		else {
 680			arg--;
 681			console_lock();
 682			ret = vc_allocate(arg);
 683			console_unlock();
 684			if (ret)
 685				break;
 686			set_console(arg);
 687		}
 688		break;
 689
 690	case VT_SETACTIVATE:
 691	{
 692		struct vt_setactivate vsa;
 693
 694		if (!perm)
 695			return -EPERM;
 696
 697		if (copy_from_user(&vsa, (struct vt_setactivate __user *)arg,
 698					sizeof(struct vt_setactivate))) {
 699			ret = -EFAULT;
 700			goto out;
 701		}
 702		if (vsa.console == 0 || vsa.console > MAX_NR_CONSOLES)
 703			ret = -ENXIO;
 704		else {
 705			vsa.console = array_index_nospec(vsa.console,
 706							 MAX_NR_CONSOLES + 1);
 707			vsa.console--;
 708			console_lock();
 709			ret = vc_allocate(vsa.console);
 710			if (ret == 0) {
 711				struct vc_data *nvc;
 712				/* This is safe providing we don't drop the
 713				   console sem between vc_allocate and
 714				   finishing referencing nvc */
 715				nvc = vc_cons[vsa.console].d;
 716				nvc->vt_mode = vsa.mode;
 717				nvc->vt_mode.frsig = 0;
 718				put_pid(nvc->vt_pid);
 719				nvc->vt_pid = get_pid(task_pid(current));
 720			}
 721			console_unlock();
 722			if (ret)
 723				break;
 724			/* Commence switch and lock */
 725			/* Review set_console locks */
 726			set_console(vsa.console);
 727		}
 728		break;
 729	}
 730
 731	/*
 732	 * wait until the specified VT has been activated
 733	 */
 734	case VT_WAITACTIVE:
 735		if (!perm)
 736			return -EPERM;
 737		if (arg == 0 || arg > MAX_NR_CONSOLES)
 738			ret = -ENXIO;
 739		else
 740			ret = vt_waitactive(arg);
 741		break;
 742
 743	/*
 744	 * If a vt is under process control, the kernel will not switch to it
 745	 * immediately, but postpone the operation until the process calls this
 746	 * ioctl, allowing the switch to complete.
 747	 *
 748	 * According to the X sources this is the behavior:
 749	 *	0:	pending switch-from not OK
 750	 *	1:	pending switch-from OK
 751	 *	2:	completed switch-to OK
 752	 */
 753	case VT_RELDISP:
 754		if (!perm)
 755			return -EPERM;
 756
 757		console_lock();
 758		if (vc->vt_mode.mode != VT_PROCESS) {
 759			console_unlock();
 760			ret = -EINVAL;
 761			break;
 762		}
 763		/*
 764		 * Switching-from response
 765		 */
 766		if (vc->vt_newvt >= 0) {
 767			if (arg == 0)
 768				/*
 769				 * Switch disallowed, so forget we were trying
 770				 * to do it.
 771				 */
 772				vc->vt_newvt = -1;
 773
 774			else {
 775				/*
 776				 * The current vt has been released, so
 777				 * complete the switch.
 778				 */
 779				int newvt;
 780				newvt = vc->vt_newvt;
 781				vc->vt_newvt = -1;
 782				ret = vc_allocate(newvt);
 783				if (ret) {
 784					console_unlock();
 785					break;
 786				}
 787				/*
 788				 * When we actually do the console switch,
 789				 * make sure we are atomic with respect to
 790				 * other console switches..
 791				 */
 792				complete_change_console(vc_cons[newvt].d);
 793			}
 794		} else {
 795			/*
 796			 * Switched-to response
 797			 */
 798			/*
 799			 * If it's just an ACK, ignore it
 800			 */
 801			if (arg != VT_ACKACQ)
 802				ret = -EINVAL;
 803		}
 804		console_unlock();
 805		break;
 806
 807	 /*
 808	  * Disallocate memory associated to VT (but leave VT1)
 809	  */
 810	 case VT_DISALLOCATE:
 811		if (arg > MAX_NR_CONSOLES) {
 812			ret = -ENXIO;
 813			break;
 814		}
 815		if (arg == 0)
 816			vt_disallocate_all();
 817		else
 818			ret = vt_disallocate(--arg);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 819		break;
 820
 821	case VT_RESIZE:
 822	{
 823		struct vt_sizes __user *vtsizes = up;
 824		struct vc_data *vc;
 825
 826		ushort ll,cc;
 827		if (!perm)
 828			return -EPERM;
 829		if (get_user(ll, &vtsizes->v_rows) ||
 830		    get_user(cc, &vtsizes->v_cols))
 831			ret = -EFAULT;
 832		else {
 833			console_lock();
 834			for (i = 0; i < MAX_NR_CONSOLES; i++) {
 835				vc = vc_cons[i].d;
 836
 837				if (vc) {
 838					vc->vc_resize_user = 1;
 839					/* FIXME: review v tty lock */
 840					vc_resize(vc_cons[i].d, cc, ll);
 841				}
 842			}
 843			console_unlock();
 844		}
 845		break;
 846	}
 847
 848	case VT_RESIZEX:
 849	{
 850		struct vt_consize v;
 
 851		if (!perm)
 852			return -EPERM;
 853		if (copy_from_user(&v, up, sizeof(struct vt_consize)))
 854			return -EFAULT;
 
 
 
 855		/* FIXME: Should check the copies properly */
 856		if (!v.v_vlin)
 857			v.v_vlin = vc->vc_scan_lines;
 858		if (v.v_clin) {
 859			int rows = v.v_vlin/v.v_clin;
 860			if (v.v_rows != rows) {
 861				if (v.v_rows) /* Parameters don't add up */
 862					return -EINVAL;
 863				v.v_rows = rows;
 864			}
 
 
 
 
 
 
 
 865		}
 866		if (v.v_vcol && v.v_ccol) {
 867			int cols = v.v_vcol/v.v_ccol;
 868			if (v.v_cols != cols) {
 869				if (v.v_cols)
 870					return -EINVAL;
 871				v.v_cols = cols;
 872			}
 
 873		}
 874
 875		if (v.v_clin > 32)
 876			return -EINVAL;
 877
 
 
 878		for (i = 0; i < MAX_NR_CONSOLES; i++) {
 879			if (!vc_cons[i].d)
 880				continue;
 881			console_lock();
 882			if (v.v_vlin)
 883				vc_cons[i].d->vc_scan_lines = v.v_vlin;
 884			if (v.v_clin)
 885				vc_cons[i].d->vc_font.height = v.v_clin;
 886			vc_cons[i].d->vc_resize_user = 1;
 887			vc_resize(vc_cons[i].d, v.v_cols, v.v_rows);
 888			console_unlock();
 889		}
 890		break;
 891	}
 892
 893	case PIO_FONT: {
 894		if (!perm)
 895			return -EPERM;
 896		op.op = KD_FONT_OP_SET;
 897		op.flags = KD_FONT_FLAG_OLD | KD_FONT_FLAG_DONT_RECALC;	/* Compatibility */
 898		op.width = 8;
 899		op.height = 0;
 900		op.charcount = 256;
 901		op.data = up;
 902		ret = con_font_op(vc_cons[fg_console].d, &op);
 903		break;
 904	}
 905
 906	case GIO_FONT: {
 907		op.op = KD_FONT_OP_GET;
 908		op.flags = KD_FONT_FLAG_OLD;
 909		op.width = 8;
 910		op.height = 32;
 911		op.charcount = 256;
 912		op.data = up;
 913		ret = con_font_op(vc_cons[fg_console].d, &op);
 914		break;
 915	}
 916
 917	case PIO_CMAP:
 918                if (!perm)
 919			ret = -EPERM;
 920		else
 921	                ret = con_set_cmap(up);
 922		break;
 923
 924	case GIO_CMAP:
 925                ret = con_get_cmap(up);
 926		break;
 927
 928	case PIO_FONTX:
 929	case GIO_FONTX:
 930		ret = do_fontx_ioctl(cmd, up, perm, &op);
 931		break;
 932
 933	case PIO_FONTRESET:
 934	{
 935		if (!perm)
 936			return -EPERM;
 937
 938#ifdef BROKEN_GRAPHICS_PROGRAMS
 939		/* With BROKEN_GRAPHICS_PROGRAMS defined, the default
 940		   font is not saved. */
 941		ret = -ENOSYS;
 942		break;
 943#else
 944		{
 945		op.op = KD_FONT_OP_SET_DEFAULT;
 946		op.data = NULL;
 947		ret = con_font_op(vc_cons[fg_console].d, &op);
 948		if (ret)
 949			break;
 950		console_lock();
 951		con_set_default_unimap(vc_cons[fg_console].d);
 952		console_unlock();
 953		break;
 954		}
 955#endif
 956	}
 957
 958	case KDFONTOP: {
 959		if (copy_from_user(&op, up, sizeof(op))) {
 960			ret = -EFAULT;
 961			break;
 962		}
 963		if (!perm && op.op != KD_FONT_OP_GET)
 964			return -EPERM;
 965		ret = con_font_op(vc, &op);
 966		if (ret)
 967			break;
 968		if (copy_to_user(up, &op, sizeof(op)))
 969			ret = -EFAULT;
 970		break;
 971	}
 972
 973	case PIO_SCRNMAP:
 974		if (!perm)
 975			ret = -EPERM;
 976		else
 977			ret = con_set_trans_old(up);
 978		break;
 979
 980	case GIO_SCRNMAP:
 981		ret = con_get_trans_old(up);
 982		break;
 983
 984	case PIO_UNISCRNMAP:
 985		if (!perm)
 986			ret = -EPERM;
 987		else
 988			ret = con_set_trans_new(up);
 989		break;
 990
 991	case GIO_UNISCRNMAP:
 992		ret = con_get_trans_new(up);
 993		break;
 994
 995	case PIO_UNIMAPCLR:
 
 996		if (!perm)
 997			return -EPERM;
 998		con_clear_unimap(vc);
 
 
 
 
 999		break;
 
1000
1001	case PIO_UNIMAP:
1002	case GIO_UNIMAP:
1003		ret = do_unimap_ioctl(cmd, up, perm, vc);
1004		break;
1005
1006	case VT_LOCKSWITCH:
1007		if (!capable(CAP_SYS_TTY_CONFIG))
1008			return -EPERM;
1009		vt_dont_switch = 1;
1010		break;
1011	case VT_UNLOCKSWITCH:
1012		if (!capable(CAP_SYS_TTY_CONFIG))
1013			return -EPERM;
1014		vt_dont_switch = 0;
1015		break;
1016	case VT_GETHIFONTMASK:
1017		ret = put_user(vc->vc_hi_font_mask,
1018					(unsigned short __user *)arg);
1019		break;
1020	case VT_WAITEVENT:
1021		ret = vt_event_wait_ioctl((struct vt_event __user *)arg);
1022		break;
1023	default:
1024		ret = -ENOIOCTLCMD;
1025	}
1026out:
1027	return ret;
1028}
1029
1030void reset_vc(struct vc_data *vc)
1031{
1032	vc->vc_mode = KD_TEXT;
1033	vt_reset_unicode(vc->vc_num);
1034	vc->vt_mode.mode = VT_AUTO;
1035	vc->vt_mode.waitv = 0;
1036	vc->vt_mode.relsig = 0;
1037	vc->vt_mode.acqsig = 0;
1038	vc->vt_mode.frsig = 0;
1039	put_pid(vc->vt_pid);
1040	vc->vt_pid = NULL;
1041	vc->vt_newvt = -1;
1042	if (!in_interrupt())    /* Via keyboard.c:SAK() - akpm */
1043		reset_palette(vc);
1044}
1045
1046void vc_SAK(struct work_struct *work)
1047{
1048	struct vc *vc_con =
1049		container_of(work, struct vc, SAK_work);
1050	struct vc_data *vc;
1051	struct tty_struct *tty;
1052
1053	console_lock();
1054	vc = vc_con->d;
1055	if (vc) {
1056		/* FIXME: review tty ref counting */
1057		tty = vc->port.tty;
1058		/*
1059		 * SAK should also work in all raw modes and reset
1060		 * them properly.
1061		 */
1062		if (tty)
1063			__do_SAK(tty);
1064		reset_vc(vc);
1065	}
1066	console_unlock();
1067}
1068
1069#ifdef CONFIG_COMPAT
1070
1071struct compat_consolefontdesc {
1072	unsigned short charcount;       /* characters in font (256 or 512) */
1073	unsigned short charheight;      /* scan lines per character (1-32) */
1074	compat_caddr_t chardata;	/* font data in expanded form */
1075};
1076
1077static inline int
1078compat_fontx_ioctl(int cmd, struct compat_consolefontdesc __user *user_cfd,
1079			 int perm, struct console_font_op *op)
1080{
1081	struct compat_consolefontdesc cfdarg;
1082	int i;
1083
1084	if (copy_from_user(&cfdarg, user_cfd, sizeof(struct compat_consolefontdesc)))
1085		return -EFAULT;
1086
1087	switch (cmd) {
1088	case PIO_FONTX:
1089		if (!perm)
1090			return -EPERM;
1091		op->op = KD_FONT_OP_SET;
1092		op->flags = KD_FONT_FLAG_OLD;
1093		op->width = 8;
1094		op->height = cfdarg.charheight;
1095		op->charcount = cfdarg.charcount;
1096		op->data = compat_ptr(cfdarg.chardata);
1097		return con_font_op(vc_cons[fg_console].d, op);
1098	case GIO_FONTX:
1099		op->op = KD_FONT_OP_GET;
1100		op->flags = KD_FONT_FLAG_OLD;
1101		op->width = 8;
1102		op->height = cfdarg.charheight;
1103		op->charcount = cfdarg.charcount;
1104		op->data = compat_ptr(cfdarg.chardata);
1105		i = con_font_op(vc_cons[fg_console].d, op);
1106		if (i)
1107			return i;
1108		cfdarg.charheight = op->height;
1109		cfdarg.charcount = op->charcount;
1110		if (copy_to_user(user_cfd, &cfdarg, sizeof(struct compat_consolefontdesc)))
1111			return -EFAULT;
1112		return 0;
1113	}
1114	return -EINVAL;
1115}
1116
1117struct compat_console_font_op {
1118	compat_uint_t op;        /* operation code KD_FONT_OP_* */
1119	compat_uint_t flags;     /* KD_FONT_FLAG_* */
1120	compat_uint_t width, height;     /* font size */
1121	compat_uint_t charcount;
1122	compat_caddr_t data;    /* font data with height fixed to 32 */
1123};
1124
1125static inline int
1126compat_kdfontop_ioctl(struct compat_console_font_op __user *fontop,
1127			 int perm, struct console_font_op *op, struct vc_data *vc)
1128{
1129	int i;
1130
1131	if (copy_from_user(op, fontop, sizeof(struct compat_console_font_op)))
1132		return -EFAULT;
1133	if (!perm && op->op != KD_FONT_OP_GET)
1134		return -EPERM;
1135	op->data = compat_ptr(((struct compat_console_font_op *)op)->data);
1136	i = con_font_op(vc, op);
1137	if (i)
1138		return i;
1139	((struct compat_console_font_op *)op)->data = (unsigned long)op->data;
1140	if (copy_to_user(fontop, op, sizeof(struct compat_console_font_op)))
1141		return -EFAULT;
1142	return 0;
1143}
1144
1145struct compat_unimapdesc {
1146	unsigned short entry_ct;
1147	compat_caddr_t entries;
1148};
1149
1150static inline int
1151compat_unimap_ioctl(unsigned int cmd, struct compat_unimapdesc __user *user_ud,
1152			 int perm, struct vc_data *vc)
1153{
1154	struct compat_unimapdesc tmp;
1155	struct unipair __user *tmp_entries;
1156
1157	if (copy_from_user(&tmp, user_ud, sizeof tmp))
1158		return -EFAULT;
1159	tmp_entries = compat_ptr(tmp.entries);
 
 
 
 
1160	switch (cmd) {
1161	case PIO_UNIMAP:
1162		if (!perm)
1163			return -EPERM;
1164		return con_set_unimap(vc, tmp.entry_ct, tmp_entries);
1165	case GIO_UNIMAP:
1166		if (!perm && fg_console != vc->vc_num)
1167			return -EPERM;
1168		return con_get_unimap(vc, tmp.entry_ct, &(user_ud->entry_ct), tmp_entries);
1169	}
1170	return 0;
1171}
1172
1173long vt_compat_ioctl(struct tty_struct *tty,
1174	     unsigned int cmd, unsigned long arg)
1175{
1176	struct vc_data *vc = tty->driver_data;
1177	struct console_font_op op;	/* used in multiple places here */
1178	unsigned int console = vc->vc_num;
1179	void __user *up = compat_ptr(arg);
1180	int perm;
 
1181
 
1182
1183	if (!vc_cons_allocated(console)) 	/* impossible? */
1184		return -ENOIOCTLCMD;
 
 
1185
1186	/*
1187	 * To have permissions to do most of the vt ioctls, we either have
1188	 * to be the owner of the tty, or have CAP_SYS_TTY_CONFIG.
1189	 */
1190	perm = 0;
1191	if (current->signal->tty == tty || capable(CAP_SYS_TTY_CONFIG))
1192		perm = 1;
1193
1194	switch (cmd) {
1195	/*
1196	 * these need special handlers for incompatible data structures
1197	 */
1198	case PIO_FONTX:
1199	case GIO_FONTX:
1200		return compat_fontx_ioctl(cmd, up, perm, &op);
 
1201
1202	case KDFONTOP:
1203		return compat_kdfontop_ioctl(up, perm, &op, vc);
 
1204
1205	case PIO_UNIMAP:
1206	case GIO_UNIMAP:
1207		return compat_unimap_ioctl(cmd, up, perm, vc);
 
1208
1209	/*
1210	 * all these treat 'arg' as an integer
1211	 */
1212	case KIOCSOUND:
1213	case KDMKTONE:
1214#ifdef CONFIG_X86
1215	case KDADDIO:
1216	case KDDELIO:
1217#endif
1218	case KDSETMODE:
1219	case KDMAPDISP:
1220	case KDUNMAPDISP:
1221	case KDSKBMODE:
1222	case KDSKBMETA:
1223	case KDSKBLED:
1224	case KDSETLED:
1225	case KDSIGACCEPT:
1226	case VT_ACTIVATE:
1227	case VT_WAITACTIVE:
1228	case VT_RELDISP:
1229	case VT_DISALLOCATE:
1230	case VT_RESIZE:
1231	case VT_RESIZEX:
1232		return vt_ioctl(tty, cmd, arg);
1233
1234	/*
1235	 * the rest has a compatible data structure behind arg,
1236	 * but we have to convert it to a proper 64 bit pointer.
1237	 */
1238	default:
1239		return vt_ioctl(tty, cmd, (unsigned long)up);
 
1240	}
 
 
 
 
 
1241}
1242
1243
1244#endif /* CONFIG_COMPAT */
1245
1246
1247/*
1248 * Performs the back end of a vt switch. Called under the console
1249 * semaphore.
1250 */
1251static void complete_change_console(struct vc_data *vc)
1252{
1253	unsigned char old_vc_mode;
1254	int old = fg_console;
1255
1256	last_console = fg_console;
1257
1258	/*
1259	 * If we're switching, we could be going from KD_GRAPHICS to
1260	 * KD_TEXT mode or vice versa, which means we need to blank or
1261	 * unblank the screen later.
1262	 */
1263	old_vc_mode = vc_cons[fg_console].d->vc_mode;
1264	switch_screen(vc);
1265
1266	/*
1267	 * This can't appear below a successful kill_pid().  If it did,
1268	 * then the *blank_screen operation could occur while X, having
1269	 * received acqsig, is waking up on another processor.  This
1270	 * condition can lead to overlapping accesses to the VGA range
1271	 * and the framebuffer (causing system lockups).
1272	 *
1273	 * To account for this we duplicate this code below only if the
1274	 * controlling process is gone and we've called reset_vc.
1275	 */
1276	if (old_vc_mode != vc->vc_mode) {
1277		if (vc->vc_mode == KD_TEXT)
1278			do_unblank_screen(1);
1279		else
1280			do_blank_screen(1);
1281	}
1282
1283	/*
1284	 * If this new console is under process control, send it a signal
1285	 * telling it that it has acquired. Also check if it has died and
1286	 * clean up (similar to logic employed in change_console())
1287	 */
1288	if (vc->vt_mode.mode == VT_PROCESS) {
1289		/*
1290		 * Send the signal as privileged - kill_pid() will
1291		 * tell us if the process has gone or something else
1292		 * is awry
1293		 */
1294		if (kill_pid(vc->vt_pid, vc->vt_mode.acqsig, 1) != 0) {
1295		/*
1296		 * The controlling process has died, so we revert back to
1297		 * normal operation. In this case, we'll also change back
1298		 * to KD_TEXT mode. I'm not sure if this is strictly correct
1299		 * but it saves the agony when the X server dies and the screen
1300		 * remains blanked due to KD_GRAPHICS! It would be nice to do
1301		 * this outside of VT_PROCESS but there is no single process
1302		 * to account for and tracking tty count may be undesirable.
1303		 */
1304			reset_vc(vc);
1305
1306			if (old_vc_mode != vc->vc_mode) {
1307				if (vc->vc_mode == KD_TEXT)
1308					do_unblank_screen(1);
1309				else
1310					do_blank_screen(1);
1311			}
1312		}
1313	}
1314
1315	/*
1316	 * Wake anyone waiting for their VT to activate
1317	 */
1318	vt_event_post(VT_EVENT_SWITCH, old, vc->vc_num);
1319	return;
1320}
1321
1322/*
1323 * Performs the front-end of a vt switch
1324 */
1325void change_console(struct vc_data *new_vc)
1326{
1327	struct vc_data *vc;
1328
1329	if (!new_vc || new_vc->vc_num == fg_console || vt_dont_switch)
1330		return;
1331
1332	/*
1333	 * If this vt is in process mode, then we need to handshake with
1334	 * that process before switching. Essentially, we store where that
1335	 * vt wants to switch to and wait for it to tell us when it's done
1336	 * (via VT_RELDISP ioctl).
1337	 *
1338	 * We also check to see if the controlling process still exists.
1339	 * If it doesn't, we reset this vt to auto mode and continue.
1340	 * This is a cheap way to track process control. The worst thing
1341	 * that can happen is: we send a signal to a process, it dies, and
1342	 * the switch gets "lost" waiting for a response; hopefully, the
1343	 * user will try again, we'll detect the process is gone (unless
1344	 * the user waits just the right amount of time :-) and revert the
1345	 * vt to auto control.
1346	 */
1347	vc = vc_cons[fg_console].d;
1348	if (vc->vt_mode.mode == VT_PROCESS) {
1349		/*
1350		 * Send the signal as privileged - kill_pid() will
1351		 * tell us if the process has gone or something else
1352		 * is awry.
1353		 *
1354		 * We need to set vt_newvt *before* sending the signal or we
1355		 * have a race.
1356		 */
1357		vc->vt_newvt = new_vc->vc_num;
1358		if (kill_pid(vc->vt_pid, vc->vt_mode.relsig, 1) == 0) {
1359			/*
1360			 * It worked. Mark the vt to switch to and
1361			 * return. The process needs to send us a
1362			 * VT_RELDISP ioctl to complete the switch.
1363			 */
1364			return;
1365		}
1366
1367		/*
1368		 * The controlling process has died, so we revert back to
1369		 * normal operation. In this case, we'll also change back
1370		 * to KD_TEXT mode. I'm not sure if this is strictly correct
1371		 * but it saves the agony when the X server dies and the screen
1372		 * remains blanked due to KD_GRAPHICS! It would be nice to do
1373		 * this outside of VT_PROCESS but there is no single process
1374		 * to account for and tracking tty count may be undesirable.
1375		 */
1376		reset_vc(vc);
1377
1378		/*
1379		 * Fall through to normal (VT_AUTO) handling of the switch...
1380		 */
1381	}
1382
1383	/*
1384	 * Ignore all switches in KD_GRAPHICS+VT_AUTO mode
1385	 */
1386	if (vc->vc_mode == KD_GRAPHICS)
1387		return;
1388
1389	complete_change_console(new_vc);
1390}
1391
1392/* Perform a kernel triggered VT switch for suspend/resume */
1393
1394static int disable_vt_switch;
1395
1396int vt_move_to_console(unsigned int vt, int alloc)
1397{
1398	int prev;
1399
1400	console_lock();
1401	/* Graphics mode - up to X */
1402	if (disable_vt_switch) {
1403		console_unlock();
1404		return 0;
1405	}
1406	prev = fg_console;
1407
1408	if (alloc && vc_allocate(vt)) {
1409		/* we can't have a free VC for now. Too bad,
1410		 * we don't want to mess the screen for now. */
1411		console_unlock();
1412		return -ENOSPC;
1413	}
1414
1415	if (set_console(vt)) {
1416		/*
1417		 * We're unable to switch to the SUSPEND_CONSOLE.
1418		 * Let the calling function know so it can decide
1419		 * what to do.
1420		 */
1421		console_unlock();
1422		return -EIO;
1423	}
1424	console_unlock();
1425	if (vt_waitactive(vt + 1)) {
1426		pr_debug("Suspend: Can't switch VCs.");
1427		return -EINTR;
1428	}
1429	return prev;
1430}
1431
1432/*
1433 * Normally during a suspend, we allocate a new console and switch to it.
1434 * When we resume, we switch back to the original console.  This switch
1435 * can be slow, so on systems where the framebuffer can handle restoration
1436 * of video registers anyways, there's little point in doing the console
1437 * switch.  This function allows you to disable it by passing it '0'.
1438 */
1439void pm_set_vt_switch(int do_switch)
1440{
1441	console_lock();
1442	disable_vt_switch = !do_switch;
1443	console_unlock();
1444}
1445EXPORT_SYMBOL(pm_set_vt_switch);
v3.5.6
 
   1/*
   2 *  Copyright (C) 1992 obz under the linux copyright
   3 *
   4 *  Dynamic diacritical handling - aeb@cwi.nl - Dec 1993
   5 *  Dynamic keymap and string allocation - aeb@cwi.nl - May 1994
   6 *  Restrict VT switching via ioctl() - grif@cs.ucr.edu - Dec 1995
   7 *  Some code moved for less code duplication - Andi Kleen - Mar 1997
   8 *  Check put/get_user, cleanups - acme@conectiva.com.br - Jun 2001
   9 */
  10
  11#include <linux/types.h>
  12#include <linux/errno.h>
  13#include <linux/sched.h>
  14#include <linux/tty.h>
  15#include <linux/timer.h>
  16#include <linux/kernel.h>
  17#include <linux/compat.h>
  18#include <linux/module.h>
  19#include <linux/kd.h>
  20#include <linux/vt.h>
  21#include <linux/string.h>
  22#include <linux/slab.h>
  23#include <linux/major.h>
  24#include <linux/fs.h>
  25#include <linux/console.h>
  26#include <linux/consolemap.h>
  27#include <linux/signal.h>
 
  28#include <linux/timex.h>
  29
  30#include <asm/io.h>
  31#include <asm/uaccess.h>
 
 
  32
  33#include <linux/kbd_kern.h>
  34#include <linux/vt_kern.h>
  35#include <linux/kbd_diacr.h>
  36#include <linux/selection.h>
  37
  38char vt_dont_switch;
  39extern struct tty_driver *console_driver;
  40
  41#define VT_IS_IN_USE(i)	(console_driver->ttys[i] && console_driver->ttys[i]->count)
  42#define VT_BUSY(i)	(VT_IS_IN_USE(i) || i == fg_console || vc_cons[i].d == sel_cons)
  43
  44/*
  45 * Console (vt and kd) routines, as defined by USL SVR4 manual, and by
  46 * experimentation and study of X386 SYSV handling.
  47 *
  48 * One point of difference: SYSV vt's are /dev/vtX, which X >= 0, and
  49 * /dev/console is a separate ttyp. Under Linux, /dev/tty0 is /dev/console,
  50 * and the vc start at /dev/ttyX, X >= 1. We maintain that here, so we will
  51 * always treat our set of vt as numbered 1..MAX_NR_CONSOLES (corresponding to
  52 * ttys 0..MAX_NR_CONSOLES-1). Explicitly naming VT 0 is illegal, but using
  53 * /dev/tty0 (fg_console) as a target is legal, since an implicit aliasing
  54 * to the current console is done by the main ioctl code.
  55 */
  56
  57#ifdef CONFIG_X86
  58#include <linux/syscalls.h>
  59#endif
  60
  61static void complete_change_console(struct vc_data *vc);
  62
  63/*
  64 *	User space VT_EVENT handlers
  65 */
  66
  67struct vt_event_wait {
  68	struct list_head list;
  69	struct vt_event event;
  70	int done;
  71};
  72
  73static LIST_HEAD(vt_events);
  74static DEFINE_SPINLOCK(vt_event_lock);
  75static DECLARE_WAIT_QUEUE_HEAD(vt_event_waitqueue);
  76
  77/**
  78 *	vt_event_post
  79 *	@event: the event that occurred
  80 *	@old: old console
  81 *	@new: new console
  82 *
  83 *	Post an VT event to interested VT handlers
  84 */
  85
  86void vt_event_post(unsigned int event, unsigned int old, unsigned int new)
  87{
  88	struct list_head *pos, *head;
  89	unsigned long flags;
  90	int wake = 0;
  91
  92	spin_lock_irqsave(&vt_event_lock, flags);
  93	head = &vt_events;
  94
  95	list_for_each(pos, head) {
  96		struct vt_event_wait *ve = list_entry(pos,
  97						struct vt_event_wait, list);
  98		if (!(ve->event.event & event))
  99			continue;
 100		ve->event.event = event;
 101		/* kernel view is consoles 0..n-1, user space view is
 102		   console 1..n with 0 meaning current, so we must bias */
 103		ve->event.oldev = old + 1;
 104		ve->event.newev = new + 1;
 105		wake = 1;
 106		ve->done = 1;
 107	}
 108	spin_unlock_irqrestore(&vt_event_lock, flags);
 109	if (wake)
 110		wake_up_interruptible(&vt_event_waitqueue);
 111}
 112
 113/**
 114 *	vt_event_wait		-	wait for an event
 115 *	@vw: our event
 116 *
 117 *	Waits for an event to occur which completes our vt_event_wait
 118 *	structure. On return the structure has wv->done set to 1 for success
 119 *	or 0 if some event such as a signal ended the wait.
 120 */
 121
 122static void vt_event_wait(struct vt_event_wait *vw)
 123{
 124	unsigned long flags;
 125	/* Prepare the event */
 126	INIT_LIST_HEAD(&vw->list);
 127	vw->done = 0;
 128	/* Queue our event */
 129	spin_lock_irqsave(&vt_event_lock, flags);
 130	list_add(&vw->list, &vt_events);
 131	spin_unlock_irqrestore(&vt_event_lock, flags);
 
 
 
 
 132	/* Wait for it to pass */
 133	wait_event_interruptible(vt_event_waitqueue, vw->done);
 
 
 
 
 
 
 134	/* Dequeue it */
 135	spin_lock_irqsave(&vt_event_lock, flags);
 136	list_del(&vw->list);
 137	spin_unlock_irqrestore(&vt_event_lock, flags);
 138}
 139
 140/**
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 141 *	vt_event_wait_ioctl	-	event ioctl handler
 142 *	@arg: argument to ioctl
 143 *
 144 *	Implement the VT_WAITEVENT ioctl using the VT event interface
 145 */
 146
 147static int vt_event_wait_ioctl(struct vt_event __user *event)
 148{
 149	struct vt_event_wait vw;
 150
 151	if (copy_from_user(&vw.event, event, sizeof(struct vt_event)))
 152		return -EFAULT;
 153	/* Highest supported event for now */
 154	if (vw.event.event & ~VT_MAX_EVENT)
 155		return -EINVAL;
 156
 157	vt_event_wait(&vw);
 158	/* If it occurred report it */
 159	if (vw.done) {
 160		if (copy_to_user(event, &vw.event, sizeof(struct vt_event)))
 161			return -EFAULT;
 162		return 0;
 163	}
 164	return -EINTR;
 165}
 166
 167/**
 168 *	vt_waitactive	-	active console wait
 169 *	@event: event code
 170 *	@n: new console
 171 *
 172 *	Helper for event waits. Used to implement the legacy
 173 *	event waiting ioctls in terms of events
 174 */
 175
 176int vt_waitactive(int n)
 177{
 178	struct vt_event_wait vw;
 179	do {
 180		if (n == fg_console + 1)
 
 
 
 181			break;
 182		vw.event.event = VT_EVENT_SWITCH;
 183		vt_event_wait(&vw);
 
 184		if (vw.done == 0)
 185			return -EINTR;
 186	} while (vw.event.newev != n);
 187	return 0;
 188}
 189
 190/*
 191 * these are the valid i/o ports we're allowed to change. they map all the
 192 * video ports
 193 */
 194#define GPFIRST 0x3b4
 195#define GPLAST 0x3df
 196#define GPNUM (GPLAST - GPFIRST + 1)
 197
 198
 199
 200static inline int 
 201do_fontx_ioctl(int cmd, struct consolefontdesc __user *user_cfd, int perm, struct console_font_op *op)
 202{
 203	struct consolefontdesc cfdarg;
 204	int i;
 205
 206	if (copy_from_user(&cfdarg, user_cfd, sizeof(struct consolefontdesc))) 
 207		return -EFAULT;
 208 	
 209	switch (cmd) {
 210	case PIO_FONTX:
 211		if (!perm)
 212			return -EPERM;
 213		op->op = KD_FONT_OP_SET;
 214		op->flags = KD_FONT_FLAG_OLD;
 215		op->width = 8;
 216		op->height = cfdarg.charheight;
 217		op->charcount = cfdarg.charcount;
 218		op->data = cfdarg.chardata;
 219		return con_font_op(vc_cons[fg_console].d, op);
 220	case GIO_FONTX: {
 221		op->op = KD_FONT_OP_GET;
 222		op->flags = KD_FONT_FLAG_OLD;
 223		op->width = 8;
 224		op->height = cfdarg.charheight;
 225		op->charcount = cfdarg.charcount;
 226		op->data = cfdarg.chardata;
 227		i = con_font_op(vc_cons[fg_console].d, op);
 228		if (i)
 229			return i;
 230		cfdarg.charheight = op->height;
 231		cfdarg.charcount = op->charcount;
 232		if (copy_to_user(user_cfd, &cfdarg, sizeof(struct consolefontdesc)))
 233			return -EFAULT;
 234		return 0;
 235		}
 236	}
 237	return -EINVAL;
 238}
 239
 240static inline int 
 241do_unimap_ioctl(int cmd, struct unimapdesc __user *user_ud, int perm, struct vc_data *vc)
 242{
 243	struct unimapdesc tmp;
 244
 245	if (copy_from_user(&tmp, user_ud, sizeof tmp))
 246		return -EFAULT;
 247	if (tmp.entries)
 248		if (!access_ok(VERIFY_WRITE, tmp.entries,
 249				tmp.entry_ct*sizeof(struct unipair)))
 250			return -EFAULT;
 251	switch (cmd) {
 252	case PIO_UNIMAP:
 253		if (!perm)
 254			return -EPERM;
 255		return con_set_unimap(vc, tmp.entry_ct, tmp.entries);
 256	case GIO_UNIMAP:
 257		if (!perm && fg_console != vc->vc_num)
 258			return -EPERM;
 259		return con_get_unimap(vc, tmp.entry_ct, &(user_ud->entry_ct), tmp.entries);
 260	}
 261	return 0;
 262}
 263
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 264
 265
 266/*
 267 * We handle the console-specific ioctl's here.  We allow the
 268 * capability to modify any console, not just the fg_console. 
 269 */
 270int vt_ioctl(struct tty_struct *tty,
 271	     unsigned int cmd, unsigned long arg)
 272{
 273	struct vc_data *vc = tty->driver_data;
 274	struct console_font_op op;	/* used in multiple places here */
 275	unsigned int console;
 276	unsigned char ucval;
 277	unsigned int uival;
 278	void __user *up = (void __user *)arg;
 279	int i, perm;
 280	int ret = 0;
 281
 282	console = vc->vc_num;
 283
 284
 285	if (!vc_cons_allocated(console)) { 	/* impossible? */
 286		ret = -ENOIOCTLCMD;
 287		goto out;
 288	}
 289
 290
 291	/*
 292	 * To have permissions to do most of the vt ioctls, we either have
 293	 * to be the owner of the tty, or have CAP_SYS_TTY_CONFIG.
 294	 */
 295	perm = 0;
 296	if (current->signal->tty == tty || capable(CAP_SYS_TTY_CONFIG))
 297		perm = 1;
 298 
 299	switch (cmd) {
 300	case TIOCLINUX:
 301		ret = tioclinux(tty, arg);
 302		break;
 303	case KIOCSOUND:
 304		if (!perm)
 305			return -EPERM;
 306		/*
 307		 * The use of PIT_TICK_RATE is historic, it used to be
 308		 * the platform-dependent CLOCK_TICK_RATE between 2.6.12
 309		 * and 2.6.36, which was a minor but unfortunate ABI
 310		 * change. kd_mksound is locked by the input layer.
 311		 */
 312		if (arg)
 313			arg = PIT_TICK_RATE / arg;
 314		kd_mksound(arg, 0);
 315		break;
 316
 317	case KDMKTONE:
 318		if (!perm)
 319			return -EPERM;
 320	{
 321		unsigned int ticks, count;
 322		
 323		/*
 324		 * Generate the tone for the appropriate number of ticks.
 325		 * If the time is zero, turn off sound ourselves.
 326		 */
 327		ticks = HZ * ((arg >> 16) & 0xffff) / 1000;
 328		count = ticks ? (arg & 0xffff) : 0;
 329		if (count)
 330			count = PIT_TICK_RATE / count;
 331		kd_mksound(count, ticks);
 332		break;
 333	}
 334
 335	case KDGKBTYPE:
 336		/*
 337		 * this is naïve.
 338		 */
 339		ucval = KB_101;
 340		ret = put_user(ucval, (char __user *)arg);
 341		break;
 342
 343		/*
 344		 * These cannot be implemented on any machine that implements
 345		 * ioperm() in user level (such as Alpha PCs) or not at all.
 346		 *
 347		 * XXX: you should never use these, just call ioperm directly..
 348		 */
 349#ifdef CONFIG_X86
 350	case KDADDIO:
 351	case KDDELIO:
 352		/*
 353		 * KDADDIO and KDDELIO may be able to add ports beyond what
 354		 * we reject here, but to be safe...
 355		 *
 356		 * These are locked internally via sys_ioperm
 357		 */
 358		if (arg < GPFIRST || arg > GPLAST) {
 359			ret = -EINVAL;
 360			break;
 361		}
 362		ret = sys_ioperm(arg, 1, (cmd == KDADDIO)) ? -ENXIO : 0;
 363		break;
 364
 365	case KDENABIO:
 366	case KDDISABIO:
 367		ret = sys_ioperm(GPFIRST, GPNUM,
 368				  (cmd == KDENABIO)) ? -ENXIO : 0;
 369		break;
 370#endif
 371
 372	/* Linux m68k/i386 interface for setting the keyboard delay/repeat rate */
 373		
 374	case KDKBDREP:
 375	{
 376		struct kbd_repeat kbrep;
 377		
 378		if (!capable(CAP_SYS_TTY_CONFIG))
 379			return -EPERM;
 380
 381		if (copy_from_user(&kbrep, up, sizeof(struct kbd_repeat))) {
 382			ret =  -EFAULT;
 383			break;
 384		}
 385		ret = kbd_rate(&kbrep);
 386		if (ret)
 387			break;
 388		if (copy_to_user(up, &kbrep, sizeof(struct kbd_repeat)))
 389			ret = -EFAULT;
 390		break;
 391	}
 392
 393	case KDSETMODE:
 394		/*
 395		 * currently, setting the mode from KD_TEXT to KD_GRAPHICS
 396		 * doesn't do a whole lot. i'm not sure if it should do any
 397		 * restoration of modes or what...
 398		 *
 399		 * XXX It should at least call into the driver, fbdev's definitely
 400		 * need to restore their engine state. --BenH
 401		 */
 402		if (!perm)
 403			return -EPERM;
 404		switch (arg) {
 405		case KD_GRAPHICS:
 406			break;
 407		case KD_TEXT0:
 408		case KD_TEXT1:
 409			arg = KD_TEXT;
 410		case KD_TEXT:
 411			break;
 412		default:
 413			ret = -EINVAL;
 414			goto out;
 415		}
 416		/* FIXME: this needs the console lock extending */
 417		if (vc->vc_mode == (unsigned char) arg)
 418			break;
 419		vc->vc_mode = (unsigned char) arg;
 420		if (console != fg_console)
 421			break;
 422		/*
 423		 * explicitly blank/unblank the screen if switching modes
 424		 */
 425		console_lock();
 426		if (arg == KD_TEXT)
 427			do_unblank_screen(1);
 428		else
 429			do_blank_screen(1);
 430		console_unlock();
 431		break;
 432
 433	case KDGETMODE:
 434		uival = vc->vc_mode;
 435		goto setint;
 436
 437	case KDMAPDISP:
 438	case KDUNMAPDISP:
 439		/*
 440		 * these work like a combination of mmap and KDENABIO.
 441		 * this could be easily finished.
 442		 */
 443		ret = -EINVAL;
 444		break;
 445
 446	case KDSKBMODE:
 447		if (!perm)
 448			return -EPERM;
 449		ret = vt_do_kdskbmode(console, arg);
 450		if (ret == 0)
 451			tty_ldisc_flush(tty);
 452		break;
 453
 454	case KDGKBMODE:
 455		uival = vt_do_kdgkbmode(console);
 456		ret = put_user(uival, (int __user *)arg);
 457		break;
 458
 459	/* this could be folded into KDSKBMODE, but for compatibility
 460	   reasons it is not so easy to fold KDGKBMETA into KDGKBMODE */
 461	case KDSKBMETA:
 462		ret = vt_do_kdskbmeta(console, arg);
 463		break;
 464
 465	case KDGKBMETA:
 466		/* FIXME: should review whether this is worth locking */
 467		uival = vt_do_kdgkbmeta(console);
 468	setint:
 469		ret = put_user(uival, (int __user *)arg);
 470		break;
 471
 472	case KDGETKEYCODE:
 473	case KDSETKEYCODE:
 474		if(!capable(CAP_SYS_TTY_CONFIG))
 475			perm = 0;
 476		ret = vt_do_kbkeycode_ioctl(cmd, up, perm);
 477		break;
 478
 479	case KDGKBENT:
 480	case KDSKBENT:
 481		ret = vt_do_kdsk_ioctl(cmd, up, perm, console);
 482		break;
 483
 484	case KDGKBSENT:
 485	case KDSKBSENT:
 486		ret = vt_do_kdgkb_ioctl(cmd, up, perm);
 487		break;
 488
 489	/* Diacritical processing. Handled in keyboard.c as it has
 490	   to operate on the keyboard locks and structures */
 491	case KDGKBDIACR:
 492	case KDGKBDIACRUC:
 493	case KDSKBDIACR:
 494	case KDSKBDIACRUC:
 495		ret = vt_do_diacrit(cmd, up, perm);
 496		break;
 497
 498	/* the ioctls below read/set the flags usually shown in the leds */
 499	/* don't use them - they will go away without warning */
 500	case KDGKBLED:
 501	case KDSKBLED:
 502	case KDGETLED:
 503	case KDSETLED:
 504		ret = vt_do_kdskled(console, cmd, arg, perm);
 505		break;
 506
 507	/*
 508	 * A process can indicate its willingness to accept signals
 509	 * generated by pressing an appropriate key combination.
 510	 * Thus, one can have a daemon that e.g. spawns a new console
 511	 * upon a keypress and then changes to it.
 512	 * See also the kbrequest field of inittab(5).
 513	 */
 514	case KDSIGACCEPT:
 515	{
 516		if (!perm || !capable(CAP_KILL))
 517			return -EPERM;
 518		if (!valid_signal(arg) || arg < 1 || arg == SIGKILL)
 519			ret = -EINVAL;
 520		else {
 521			spin_lock_irq(&vt_spawn_con.lock);
 522			put_pid(vt_spawn_con.pid);
 523			vt_spawn_con.pid = get_pid(task_pid(current));
 524			vt_spawn_con.sig = arg;
 525			spin_unlock_irq(&vt_spawn_con.lock);
 526		}
 527		break;
 528	}
 529
 530	case VT_SETMODE:
 531	{
 532		struct vt_mode tmp;
 533
 534		if (!perm)
 535			return -EPERM;
 536		if (copy_from_user(&tmp, up, sizeof(struct vt_mode))) {
 537			ret = -EFAULT;
 538			goto out;
 539		}
 540		if (tmp.mode != VT_AUTO && tmp.mode != VT_PROCESS) {
 541			ret = -EINVAL;
 542			goto out;
 543		}
 544		console_lock();
 545		vc->vt_mode = tmp;
 546		/* the frsig is ignored, so we set it to 0 */
 547		vc->vt_mode.frsig = 0;
 548		put_pid(vc->vt_pid);
 549		vc->vt_pid = get_pid(task_pid(current));
 550		/* no switch is required -- saw@shade.msu.ru */
 551		vc->vt_newvt = -1;
 552		console_unlock();
 553		break;
 554	}
 555
 556	case VT_GETMODE:
 557	{
 558		struct vt_mode tmp;
 559		int rc;
 560
 561		console_lock();
 562		memcpy(&tmp, &vc->vt_mode, sizeof(struct vt_mode));
 563		console_unlock();
 564
 565		rc = copy_to_user(up, &tmp, sizeof(struct vt_mode));
 566		if (rc)
 567			ret = -EFAULT;
 568		break;
 569	}
 570
 571	/*
 572	 * Returns global vt state. Note that VT 0 is always open, since
 573	 * it's an alias for the current VT, and people can't use it here.
 574	 * We cannot return state for more than 16 VTs, since v_state is short.
 575	 */
 576	case VT_GETSTATE:
 577	{
 578		struct vt_stat __user *vtstat = up;
 579		unsigned short state, mask;
 580
 581		/* Review: FIXME: Console lock ? */
 582		if (put_user(fg_console + 1, &vtstat->v_active))
 583			ret = -EFAULT;
 584		else {
 585			state = 1;	/* /dev/tty0 is always open */
 586			for (i = 0, mask = 2; i < MAX_NR_CONSOLES && mask;
 587							++i, mask <<= 1)
 588				if (VT_IS_IN_USE(i))
 589					state |= mask;
 590			ret = put_user(state, &vtstat->v_state);
 591		}
 592		break;
 593	}
 594
 595	/*
 596	 * Returns the first available (non-opened) console.
 597	 */
 598	case VT_OPENQRY:
 599		/* FIXME: locking ? - but then this is a stupid API */
 600		for (i = 0; i < MAX_NR_CONSOLES; ++i)
 601			if (! VT_IS_IN_USE(i))
 602				break;
 603		uival = i < MAX_NR_CONSOLES ? (i+1) : -1;
 604		goto setint;		 
 605
 606	/*
 607	 * ioctl(fd, VT_ACTIVATE, num) will cause us to switch to vt # num,
 608	 * with num >= 1 (switches to vt 0, our console, are not allowed, just
 609	 * to preserve sanity).
 610	 */
 611	case VT_ACTIVATE:
 612		if (!perm)
 613			return -EPERM;
 614		if (arg == 0 || arg > MAX_NR_CONSOLES)
 615			ret =  -ENXIO;
 616		else {
 617			arg--;
 618			console_lock();
 619			ret = vc_allocate(arg);
 620			console_unlock();
 621			if (ret)
 622				break;
 623			set_console(arg);
 624		}
 625		break;
 626
 627	case VT_SETACTIVATE:
 628	{
 629		struct vt_setactivate vsa;
 630
 631		if (!perm)
 632			return -EPERM;
 633
 634		if (copy_from_user(&vsa, (struct vt_setactivate __user *)arg,
 635					sizeof(struct vt_setactivate))) {
 636			ret = -EFAULT;
 637			goto out;
 638		}
 639		if (vsa.console == 0 || vsa.console > MAX_NR_CONSOLES)
 640			ret = -ENXIO;
 641		else {
 
 
 642			vsa.console--;
 643			console_lock();
 644			ret = vc_allocate(vsa.console);
 645			if (ret == 0) {
 646				struct vc_data *nvc;
 647				/* This is safe providing we don't drop the
 648				   console sem between vc_allocate and
 649				   finishing referencing nvc */
 650				nvc = vc_cons[vsa.console].d;
 651				nvc->vt_mode = vsa.mode;
 652				nvc->vt_mode.frsig = 0;
 653				put_pid(nvc->vt_pid);
 654				nvc->vt_pid = get_pid(task_pid(current));
 655			}
 656			console_unlock();
 657			if (ret)
 658				break;
 659			/* Commence switch and lock */
 660			/* Review set_console locks */
 661			set_console(vsa.console);
 662		}
 663		break;
 664	}
 665
 666	/*
 667	 * wait until the specified VT has been activated
 668	 */
 669	case VT_WAITACTIVE:
 670		if (!perm)
 671			return -EPERM;
 672		if (arg == 0 || arg > MAX_NR_CONSOLES)
 673			ret = -ENXIO;
 674		else
 675			ret = vt_waitactive(arg);
 676		break;
 677
 678	/*
 679	 * If a vt is under process control, the kernel will not switch to it
 680	 * immediately, but postpone the operation until the process calls this
 681	 * ioctl, allowing the switch to complete.
 682	 *
 683	 * According to the X sources this is the behavior:
 684	 *	0:	pending switch-from not OK
 685	 *	1:	pending switch-from OK
 686	 *	2:	completed switch-to OK
 687	 */
 688	case VT_RELDISP:
 689		if (!perm)
 690			return -EPERM;
 691
 692		console_lock();
 693		if (vc->vt_mode.mode != VT_PROCESS) {
 694			console_unlock();
 695			ret = -EINVAL;
 696			break;
 697		}
 698		/*
 699		 * Switching-from response
 700		 */
 701		if (vc->vt_newvt >= 0) {
 702			if (arg == 0)
 703				/*
 704				 * Switch disallowed, so forget we were trying
 705				 * to do it.
 706				 */
 707				vc->vt_newvt = -1;
 708
 709			else {
 710				/*
 711				 * The current vt has been released, so
 712				 * complete the switch.
 713				 */
 714				int newvt;
 715				newvt = vc->vt_newvt;
 716				vc->vt_newvt = -1;
 717				ret = vc_allocate(newvt);
 718				if (ret) {
 719					console_unlock();
 720					break;
 721				}
 722				/*
 723				 * When we actually do the console switch,
 724				 * make sure we are atomic with respect to
 725				 * other console switches..
 726				 */
 727				complete_change_console(vc_cons[newvt].d);
 728			}
 729		} else {
 730			/*
 731			 * Switched-to response
 732			 */
 733			/*
 734			 * If it's just an ACK, ignore it
 735			 */
 736			if (arg != VT_ACKACQ)
 737				ret = -EINVAL;
 738		}
 739		console_unlock();
 740		break;
 741
 742	 /*
 743	  * Disallocate memory associated to VT (but leave VT1)
 744	  */
 745	 case VT_DISALLOCATE:
 746		if (arg > MAX_NR_CONSOLES) {
 747			ret = -ENXIO;
 748			break;
 749		}
 750		if (arg == 0) {
 751		    /* deallocate all unused consoles, but leave 0 */
 752			console_lock();
 753			for (i=1; i<MAX_NR_CONSOLES; i++)
 754				if (! VT_BUSY(i))
 755					vc_deallocate(i);
 756			console_unlock();
 757		} else {
 758			/* deallocate a single console, if possible */
 759			arg--;
 760			if (VT_BUSY(arg))
 761				ret = -EBUSY;
 762			else if (arg) {			      /* leave 0 */
 763				console_lock();
 764				vc_deallocate(arg);
 765				console_unlock();
 766			}
 767		}
 768		break;
 769
 770	case VT_RESIZE:
 771	{
 772		struct vt_sizes __user *vtsizes = up;
 773		struct vc_data *vc;
 774
 775		ushort ll,cc;
 776		if (!perm)
 777			return -EPERM;
 778		if (get_user(ll, &vtsizes->v_rows) ||
 779		    get_user(cc, &vtsizes->v_cols))
 780			ret = -EFAULT;
 781		else {
 782			console_lock();
 783			for (i = 0; i < MAX_NR_CONSOLES; i++) {
 784				vc = vc_cons[i].d;
 785
 786				if (vc) {
 787					vc->vc_resize_user = 1;
 788					/* FIXME: review v tty lock */
 789					vc_resize(vc_cons[i].d, cc, ll);
 790				}
 791			}
 792			console_unlock();
 793		}
 794		break;
 795	}
 796
 797	case VT_RESIZEX:
 798	{
 799		struct vt_consize __user *vtconsize = up;
 800		ushort ll,cc,vlin,clin,vcol,ccol;
 801		if (!perm)
 802			return -EPERM;
 803		if (!access_ok(VERIFY_READ, vtconsize,
 804				sizeof(struct vt_consize))) {
 805			ret = -EFAULT;
 806			break;
 807		}
 808		/* FIXME: Should check the copies properly */
 809		__get_user(ll, &vtconsize->v_rows);
 810		__get_user(cc, &vtconsize->v_cols);
 811		__get_user(vlin, &vtconsize->v_vlin);
 812		__get_user(clin, &vtconsize->v_clin);
 813		__get_user(vcol, &vtconsize->v_vcol);
 814		__get_user(ccol, &vtconsize->v_ccol);
 815		vlin = vlin ? vlin : vc->vc_scan_lines;
 816		if (clin) {
 817			if (ll) {
 818				if (ll != vlin/clin) {
 819					/* Parameters don't add up */
 820					ret = -EINVAL;
 821					break;
 822				}
 823			} else 
 824				ll = vlin/clin;
 825		}
 826		if (vcol && ccol) {
 827			if (cc) {
 828				if (cc != vcol/ccol) {
 829					ret = -EINVAL;
 830					break;
 831				}
 832			} else
 833				cc = vcol/ccol;
 834		}
 835
 836		if (clin > 32) {
 837			ret =  -EINVAL;
 838			break;
 839		}
 840		    
 841		for (i = 0; i < MAX_NR_CONSOLES; i++) {
 842			if (!vc_cons[i].d)
 843				continue;
 844			console_lock();
 845			if (vlin)
 846				vc_cons[i].d->vc_scan_lines = vlin;
 847			if (clin)
 848				vc_cons[i].d->vc_font.height = clin;
 849			vc_cons[i].d->vc_resize_user = 1;
 850			vc_resize(vc_cons[i].d, cc, ll);
 851			console_unlock();
 852		}
 853		break;
 854	}
 855
 856	case PIO_FONT: {
 857		if (!perm)
 858			return -EPERM;
 859		op.op = KD_FONT_OP_SET;
 860		op.flags = KD_FONT_FLAG_OLD | KD_FONT_FLAG_DONT_RECALC;	/* Compatibility */
 861		op.width = 8;
 862		op.height = 0;
 863		op.charcount = 256;
 864		op.data = up;
 865		ret = con_font_op(vc_cons[fg_console].d, &op);
 866		break;
 867	}
 868
 869	case GIO_FONT: {
 870		op.op = KD_FONT_OP_GET;
 871		op.flags = KD_FONT_FLAG_OLD;
 872		op.width = 8;
 873		op.height = 32;
 874		op.charcount = 256;
 875		op.data = up;
 876		ret = con_font_op(vc_cons[fg_console].d, &op);
 877		break;
 878	}
 879
 880	case PIO_CMAP:
 881                if (!perm)
 882			ret = -EPERM;
 883		else
 884	                ret = con_set_cmap(up);
 885		break;
 886
 887	case GIO_CMAP:
 888                ret = con_get_cmap(up);
 889		break;
 890
 891	case PIO_FONTX:
 892	case GIO_FONTX:
 893		ret = do_fontx_ioctl(cmd, up, perm, &op);
 894		break;
 895
 896	case PIO_FONTRESET:
 897	{
 898		if (!perm)
 899			return -EPERM;
 900
 901#ifdef BROKEN_GRAPHICS_PROGRAMS
 902		/* With BROKEN_GRAPHICS_PROGRAMS defined, the default
 903		   font is not saved. */
 904		ret = -ENOSYS;
 905		break;
 906#else
 907		{
 908		op.op = KD_FONT_OP_SET_DEFAULT;
 909		op.data = NULL;
 910		ret = con_font_op(vc_cons[fg_console].d, &op);
 911		if (ret)
 912			break;
 913		console_lock();
 914		con_set_default_unimap(vc_cons[fg_console].d);
 915		console_unlock();
 916		break;
 917		}
 918#endif
 919	}
 920
 921	case KDFONTOP: {
 922		if (copy_from_user(&op, up, sizeof(op))) {
 923			ret = -EFAULT;
 924			break;
 925		}
 926		if (!perm && op.op != KD_FONT_OP_GET)
 927			return -EPERM;
 928		ret = con_font_op(vc, &op);
 929		if (ret)
 930			break;
 931		if (copy_to_user(up, &op, sizeof(op)))
 932			ret = -EFAULT;
 933		break;
 934	}
 935
 936	case PIO_SCRNMAP:
 937		if (!perm)
 938			ret = -EPERM;
 939		else
 940			ret = con_set_trans_old(up);
 941		break;
 942
 943	case GIO_SCRNMAP:
 944		ret = con_get_trans_old(up);
 945		break;
 946
 947	case PIO_UNISCRNMAP:
 948		if (!perm)
 949			ret = -EPERM;
 950		else
 951			ret = con_set_trans_new(up);
 952		break;
 953
 954	case GIO_UNISCRNMAP:
 955		ret = con_get_trans_new(up);
 956		break;
 957
 958	case PIO_UNIMAPCLR:
 959	      { struct unimapinit ui;
 960		if (!perm)
 961			return -EPERM;
 962		ret = copy_from_user(&ui, up, sizeof(struct unimapinit));
 963		if (ret)
 964			ret = -EFAULT;
 965		else
 966			con_clear_unimap(vc, &ui);
 967		break;
 968	      }
 969
 970	case PIO_UNIMAP:
 971	case GIO_UNIMAP:
 972		ret = do_unimap_ioctl(cmd, up, perm, vc);
 973		break;
 974
 975	case VT_LOCKSWITCH:
 976		if (!capable(CAP_SYS_TTY_CONFIG))
 977			return -EPERM;
 978		vt_dont_switch = 1;
 979		break;
 980	case VT_UNLOCKSWITCH:
 981		if (!capable(CAP_SYS_TTY_CONFIG))
 982			return -EPERM;
 983		vt_dont_switch = 0;
 984		break;
 985	case VT_GETHIFONTMASK:
 986		ret = put_user(vc->vc_hi_font_mask,
 987					(unsigned short __user *)arg);
 988		break;
 989	case VT_WAITEVENT:
 990		ret = vt_event_wait_ioctl((struct vt_event __user *)arg);
 991		break;
 992	default:
 993		ret = -ENOIOCTLCMD;
 994	}
 995out:
 996	return ret;
 997}
 998
 999void reset_vc(struct vc_data *vc)
1000{
1001	vc->vc_mode = KD_TEXT;
1002	vt_reset_unicode(vc->vc_num);
1003	vc->vt_mode.mode = VT_AUTO;
1004	vc->vt_mode.waitv = 0;
1005	vc->vt_mode.relsig = 0;
1006	vc->vt_mode.acqsig = 0;
1007	vc->vt_mode.frsig = 0;
1008	put_pid(vc->vt_pid);
1009	vc->vt_pid = NULL;
1010	vc->vt_newvt = -1;
1011	if (!in_interrupt())    /* Via keyboard.c:SAK() - akpm */
1012		reset_palette(vc);
1013}
1014
1015void vc_SAK(struct work_struct *work)
1016{
1017	struct vc *vc_con =
1018		container_of(work, struct vc, SAK_work);
1019	struct vc_data *vc;
1020	struct tty_struct *tty;
1021
1022	console_lock();
1023	vc = vc_con->d;
1024	if (vc) {
1025		/* FIXME: review tty ref counting */
1026		tty = vc->port.tty;
1027		/*
1028		 * SAK should also work in all raw modes and reset
1029		 * them properly.
1030		 */
1031		if (tty)
1032			__do_SAK(tty);
1033		reset_vc(vc);
1034	}
1035	console_unlock();
1036}
1037
1038#ifdef CONFIG_COMPAT
1039
1040struct compat_consolefontdesc {
1041	unsigned short charcount;       /* characters in font (256 or 512) */
1042	unsigned short charheight;      /* scan lines per character (1-32) */
1043	compat_caddr_t chardata;	/* font data in expanded form */
1044};
1045
1046static inline int
1047compat_fontx_ioctl(int cmd, struct compat_consolefontdesc __user *user_cfd,
1048			 int perm, struct console_font_op *op)
1049{
1050	struct compat_consolefontdesc cfdarg;
1051	int i;
1052
1053	if (copy_from_user(&cfdarg, user_cfd, sizeof(struct compat_consolefontdesc)))
1054		return -EFAULT;
1055
1056	switch (cmd) {
1057	case PIO_FONTX:
1058		if (!perm)
1059			return -EPERM;
1060		op->op = KD_FONT_OP_SET;
1061		op->flags = KD_FONT_FLAG_OLD;
1062		op->width = 8;
1063		op->height = cfdarg.charheight;
1064		op->charcount = cfdarg.charcount;
1065		op->data = compat_ptr(cfdarg.chardata);
1066		return con_font_op(vc_cons[fg_console].d, op);
1067	case GIO_FONTX:
1068		op->op = KD_FONT_OP_GET;
1069		op->flags = KD_FONT_FLAG_OLD;
1070		op->width = 8;
1071		op->height = cfdarg.charheight;
1072		op->charcount = cfdarg.charcount;
1073		op->data = compat_ptr(cfdarg.chardata);
1074		i = con_font_op(vc_cons[fg_console].d, op);
1075		if (i)
1076			return i;
1077		cfdarg.charheight = op->height;
1078		cfdarg.charcount = op->charcount;
1079		if (copy_to_user(user_cfd, &cfdarg, sizeof(struct compat_consolefontdesc)))
1080			return -EFAULT;
1081		return 0;
1082	}
1083	return -EINVAL;
1084}
1085
1086struct compat_console_font_op {
1087	compat_uint_t op;        /* operation code KD_FONT_OP_* */
1088	compat_uint_t flags;     /* KD_FONT_FLAG_* */
1089	compat_uint_t width, height;     /* font size */
1090	compat_uint_t charcount;
1091	compat_caddr_t data;    /* font data with height fixed to 32 */
1092};
1093
1094static inline int
1095compat_kdfontop_ioctl(struct compat_console_font_op __user *fontop,
1096			 int perm, struct console_font_op *op, struct vc_data *vc)
1097{
1098	int i;
1099
1100	if (copy_from_user(op, fontop, sizeof(struct compat_console_font_op)))
1101		return -EFAULT;
1102	if (!perm && op->op != KD_FONT_OP_GET)
1103		return -EPERM;
1104	op->data = compat_ptr(((struct compat_console_font_op *)op)->data);
1105	i = con_font_op(vc, op);
1106	if (i)
1107		return i;
1108	((struct compat_console_font_op *)op)->data = (unsigned long)op->data;
1109	if (copy_to_user(fontop, op, sizeof(struct compat_console_font_op)))
1110		return -EFAULT;
1111	return 0;
1112}
1113
1114struct compat_unimapdesc {
1115	unsigned short entry_ct;
1116	compat_caddr_t entries;
1117};
1118
1119static inline int
1120compat_unimap_ioctl(unsigned int cmd, struct compat_unimapdesc __user *user_ud,
1121			 int perm, struct vc_data *vc)
1122{
1123	struct compat_unimapdesc tmp;
1124	struct unipair __user *tmp_entries;
1125
1126	if (copy_from_user(&tmp, user_ud, sizeof tmp))
1127		return -EFAULT;
1128	tmp_entries = compat_ptr(tmp.entries);
1129	if (tmp_entries)
1130		if (!access_ok(VERIFY_WRITE, tmp_entries,
1131				tmp.entry_ct*sizeof(struct unipair)))
1132			return -EFAULT;
1133	switch (cmd) {
1134	case PIO_UNIMAP:
1135		if (!perm)
1136			return -EPERM;
1137		return con_set_unimap(vc, tmp.entry_ct, tmp_entries);
1138	case GIO_UNIMAP:
1139		if (!perm && fg_console != vc->vc_num)
1140			return -EPERM;
1141		return con_get_unimap(vc, tmp.entry_ct, &(user_ud->entry_ct), tmp_entries);
1142	}
1143	return 0;
1144}
1145
1146long vt_compat_ioctl(struct tty_struct *tty,
1147	     unsigned int cmd, unsigned long arg)
1148{
1149	struct vc_data *vc = tty->driver_data;
1150	struct console_font_op op;	/* used in multiple places here */
1151	unsigned int console;
1152	void __user *up = (void __user *)arg;
1153	int perm;
1154	int ret = 0;
1155
1156	console = vc->vc_num;
1157
1158	if (!vc_cons_allocated(console)) { 	/* impossible? */
1159		ret = -ENOIOCTLCMD;
1160		goto out;
1161	}
1162
1163	/*
1164	 * To have permissions to do most of the vt ioctls, we either have
1165	 * to be the owner of the tty, or have CAP_SYS_TTY_CONFIG.
1166	 */
1167	perm = 0;
1168	if (current->signal->tty == tty || capable(CAP_SYS_TTY_CONFIG))
1169		perm = 1;
1170
1171	switch (cmd) {
1172	/*
1173	 * these need special handlers for incompatible data structures
1174	 */
1175	case PIO_FONTX:
1176	case GIO_FONTX:
1177		ret = compat_fontx_ioctl(cmd, up, perm, &op);
1178		break;
1179
1180	case KDFONTOP:
1181		ret = compat_kdfontop_ioctl(up, perm, &op, vc);
1182		break;
1183
1184	case PIO_UNIMAP:
1185	case GIO_UNIMAP:
1186		ret = compat_unimap_ioctl(cmd, up, perm, vc);
1187		break;
1188
1189	/*
1190	 * all these treat 'arg' as an integer
1191	 */
1192	case KIOCSOUND:
1193	case KDMKTONE:
1194#ifdef CONFIG_X86
1195	case KDADDIO:
1196	case KDDELIO:
1197#endif
1198	case KDSETMODE:
1199	case KDMAPDISP:
1200	case KDUNMAPDISP:
1201	case KDSKBMODE:
1202	case KDSKBMETA:
1203	case KDSKBLED:
1204	case KDSETLED:
1205	case KDSIGACCEPT:
1206	case VT_ACTIVATE:
1207	case VT_WAITACTIVE:
1208	case VT_RELDISP:
1209	case VT_DISALLOCATE:
1210	case VT_RESIZE:
1211	case VT_RESIZEX:
1212		goto fallback;
1213
1214	/*
1215	 * the rest has a compatible data structure behind arg,
1216	 * but we have to convert it to a proper 64 bit pointer.
1217	 */
1218	default:
1219		arg = (unsigned long)compat_ptr(arg);
1220		goto fallback;
1221	}
1222out:
1223	return ret;
1224
1225fallback:
1226	return vt_ioctl(tty, cmd, arg);
1227}
1228
1229
1230#endif /* CONFIG_COMPAT */
1231
1232
1233/*
1234 * Performs the back end of a vt switch. Called under the console
1235 * semaphore.
1236 */
1237static void complete_change_console(struct vc_data *vc)
1238{
1239	unsigned char old_vc_mode;
1240	int old = fg_console;
1241
1242	last_console = fg_console;
1243
1244	/*
1245	 * If we're switching, we could be going from KD_GRAPHICS to
1246	 * KD_TEXT mode or vice versa, which means we need to blank or
1247	 * unblank the screen later.
1248	 */
1249	old_vc_mode = vc_cons[fg_console].d->vc_mode;
1250	switch_screen(vc);
1251
1252	/*
1253	 * This can't appear below a successful kill_pid().  If it did,
1254	 * then the *blank_screen operation could occur while X, having
1255	 * received acqsig, is waking up on another processor.  This
1256	 * condition can lead to overlapping accesses to the VGA range
1257	 * and the framebuffer (causing system lockups).
1258	 *
1259	 * To account for this we duplicate this code below only if the
1260	 * controlling process is gone and we've called reset_vc.
1261	 */
1262	if (old_vc_mode != vc->vc_mode) {
1263		if (vc->vc_mode == KD_TEXT)
1264			do_unblank_screen(1);
1265		else
1266			do_blank_screen(1);
1267	}
1268
1269	/*
1270	 * If this new console is under process control, send it a signal
1271	 * telling it that it has acquired. Also check if it has died and
1272	 * clean up (similar to logic employed in change_console())
1273	 */
1274	if (vc->vt_mode.mode == VT_PROCESS) {
1275		/*
1276		 * Send the signal as privileged - kill_pid() will
1277		 * tell us if the process has gone or something else
1278		 * is awry
1279		 */
1280		if (kill_pid(vc->vt_pid, vc->vt_mode.acqsig, 1) != 0) {
1281		/*
1282		 * The controlling process has died, so we revert back to
1283		 * normal operation. In this case, we'll also change back
1284		 * to KD_TEXT mode. I'm not sure if this is strictly correct
1285		 * but it saves the agony when the X server dies and the screen
1286		 * remains blanked due to KD_GRAPHICS! It would be nice to do
1287		 * this outside of VT_PROCESS but there is no single process
1288		 * to account for and tracking tty count may be undesirable.
1289		 */
1290			reset_vc(vc);
1291
1292			if (old_vc_mode != vc->vc_mode) {
1293				if (vc->vc_mode == KD_TEXT)
1294					do_unblank_screen(1);
1295				else
1296					do_blank_screen(1);
1297			}
1298		}
1299	}
1300
1301	/*
1302	 * Wake anyone waiting for their VT to activate
1303	 */
1304	vt_event_post(VT_EVENT_SWITCH, old, vc->vc_num);
1305	return;
1306}
1307
1308/*
1309 * Performs the front-end of a vt switch
1310 */
1311void change_console(struct vc_data *new_vc)
1312{
1313	struct vc_data *vc;
1314
1315	if (!new_vc || new_vc->vc_num == fg_console || vt_dont_switch)
1316		return;
1317
1318	/*
1319	 * If this vt is in process mode, then we need to handshake with
1320	 * that process before switching. Essentially, we store where that
1321	 * vt wants to switch to and wait for it to tell us when it's done
1322	 * (via VT_RELDISP ioctl).
1323	 *
1324	 * We also check to see if the controlling process still exists.
1325	 * If it doesn't, we reset this vt to auto mode and continue.
1326	 * This is a cheap way to track process control. The worst thing
1327	 * that can happen is: we send a signal to a process, it dies, and
1328	 * the switch gets "lost" waiting for a response; hopefully, the
1329	 * user will try again, we'll detect the process is gone (unless
1330	 * the user waits just the right amount of time :-) and revert the
1331	 * vt to auto control.
1332	 */
1333	vc = vc_cons[fg_console].d;
1334	if (vc->vt_mode.mode == VT_PROCESS) {
1335		/*
1336		 * Send the signal as privileged - kill_pid() will
1337		 * tell us if the process has gone or something else
1338		 * is awry.
1339		 *
1340		 * We need to set vt_newvt *before* sending the signal or we
1341		 * have a race.
1342		 */
1343		vc->vt_newvt = new_vc->vc_num;
1344		if (kill_pid(vc->vt_pid, vc->vt_mode.relsig, 1) == 0) {
1345			/*
1346			 * It worked. Mark the vt to switch to and
1347			 * return. The process needs to send us a
1348			 * VT_RELDISP ioctl to complete the switch.
1349			 */
1350			return;
1351		}
1352
1353		/*
1354		 * The controlling process has died, so we revert back to
1355		 * normal operation. In this case, we'll also change back
1356		 * to KD_TEXT mode. I'm not sure if this is strictly correct
1357		 * but it saves the agony when the X server dies and the screen
1358		 * remains blanked due to KD_GRAPHICS! It would be nice to do
1359		 * this outside of VT_PROCESS but there is no single process
1360		 * to account for and tracking tty count may be undesirable.
1361		 */
1362		reset_vc(vc);
1363
1364		/*
1365		 * Fall through to normal (VT_AUTO) handling of the switch...
1366		 */
1367	}
1368
1369	/*
1370	 * Ignore all switches in KD_GRAPHICS+VT_AUTO mode
1371	 */
1372	if (vc->vc_mode == KD_GRAPHICS)
1373		return;
1374
1375	complete_change_console(new_vc);
1376}
1377
1378/* Perform a kernel triggered VT switch for suspend/resume */
1379
1380static int disable_vt_switch;
1381
1382int vt_move_to_console(unsigned int vt, int alloc)
1383{
1384	int prev;
1385
1386	console_lock();
1387	/* Graphics mode - up to X */
1388	if (disable_vt_switch) {
1389		console_unlock();
1390		return 0;
1391	}
1392	prev = fg_console;
1393
1394	if (alloc && vc_allocate(vt)) {
1395		/* we can't have a free VC for now. Too bad,
1396		 * we don't want to mess the screen for now. */
1397		console_unlock();
1398		return -ENOSPC;
1399	}
1400
1401	if (set_console(vt)) {
1402		/*
1403		 * We're unable to switch to the SUSPEND_CONSOLE.
1404		 * Let the calling function know so it can decide
1405		 * what to do.
1406		 */
1407		console_unlock();
1408		return -EIO;
1409	}
1410	console_unlock();
1411	if (vt_waitactive(vt + 1)) {
1412		pr_debug("Suspend: Can't switch VCs.");
1413		return -EINTR;
1414	}
1415	return prev;
1416}
1417
1418/*
1419 * Normally during a suspend, we allocate a new console and switch to it.
1420 * When we resume, we switch back to the original console.  This switch
1421 * can be slow, so on systems where the framebuffer can handle restoration
1422 * of video registers anyways, there's little point in doing the console
1423 * switch.  This function allows you to disable it by passing it '0'.
1424 */
1425void pm_set_vt_switch(int do_switch)
1426{
1427	console_lock();
1428	disable_vt_switch = !do_switch;
1429	console_unlock();
1430}
1431EXPORT_SYMBOL(pm_set_vt_switch);