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v6.8
   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
  42bool vt_dont_switch;
  43
  44static inline bool vt_in_use(unsigned int i)
  45{
  46	const struct vc_data *vc = vc_cons[i].d;
  47
  48	/*
  49	 * console_lock must be held to prevent the vc from being deallocated
  50	 * while we're checking whether it's in-use.
  51	 */
  52	WARN_CONSOLE_UNLOCKED();
  53
  54	return vc && kref_read(&vc->port.kref) > 1;
  55}
  56
  57static inline bool vt_busy(int i)
  58{
  59	if (vt_in_use(i))
  60		return true;
  61	if (i == fg_console)
  62		return true;
  63	if (vc_is_sel(vc_cons[i].d))
  64		return true;
  65
  66	return false;
  67}
  68
  69/*
  70 * Console (vt and kd) routines, as defined by USL SVR4 manual, and by
  71 * experimentation and study of X386 SYSV handling.
  72 *
  73 * One point of difference: SYSV vt's are /dev/vtX, which X >= 0, and
  74 * /dev/console is a separate ttyp. Under Linux, /dev/tty0 is /dev/console,
  75 * and the vc start at /dev/ttyX, X >= 1. We maintain that here, so we will
  76 * always treat our set of vt as numbered 1..MAX_NR_CONSOLES (corresponding to
  77 * ttys 0..MAX_NR_CONSOLES-1). Explicitly naming VT 0 is illegal, but using
  78 * /dev/tty0 (fg_console) as a target is legal, since an implicit aliasing
  79 * to the current console is done by the main ioctl code.
  80 */
  81
  82#ifdef CONFIG_X86
  83#include <asm/syscalls.h>
  84#endif
  85
  86static void complete_change_console(struct vc_data *vc);
  87
  88/*
  89 *	User space VT_EVENT handlers
  90 */
  91
  92struct vt_event_wait {
  93	struct list_head list;
  94	struct vt_event event;
  95	int done;
  96};
  97
  98static LIST_HEAD(vt_events);
  99static DEFINE_SPINLOCK(vt_event_lock);
 100static DECLARE_WAIT_QUEUE_HEAD(vt_event_waitqueue);
 101
 102/**
 103 *	vt_event_post
 104 *	@event: the event that occurred
 105 *	@old: old console
 106 *	@new: new console
 107 *
 108 *	Post an VT event to interested VT handlers
 109 */
 110
 111void vt_event_post(unsigned int event, unsigned int old, unsigned int new)
 112{
 113	struct list_head *pos, *head;
 114	unsigned long flags;
 115	int wake = 0;
 116
 117	spin_lock_irqsave(&vt_event_lock, flags);
 118	head = &vt_events;
 119
 120	list_for_each(pos, head) {
 121		struct vt_event_wait *ve = list_entry(pos,
 122						struct vt_event_wait, list);
 123		if (!(ve->event.event & event))
 124			continue;
 125		ve->event.event = event;
 126		/* kernel view is consoles 0..n-1, user space view is
 127		   console 1..n with 0 meaning current, so we must bias */
 128		ve->event.oldev = old + 1;
 129		ve->event.newev = new + 1;
 130		wake = 1;
 131		ve->done = 1;
 132	}
 133	spin_unlock_irqrestore(&vt_event_lock, flags);
 134	if (wake)
 135		wake_up_interruptible(&vt_event_waitqueue);
 136}
 137
 138static void __vt_event_queue(struct vt_event_wait *vw)
 139{
 140	unsigned long flags;
 141	/* Prepare the event */
 142	INIT_LIST_HEAD(&vw->list);
 143	vw->done = 0;
 144	/* Queue our event */
 145	spin_lock_irqsave(&vt_event_lock, flags);
 146	list_add(&vw->list, &vt_events);
 147	spin_unlock_irqrestore(&vt_event_lock, flags);
 148}
 149
 150static void __vt_event_wait(struct vt_event_wait *vw)
 151{
 152	/* Wait for it to pass */
 153	wait_event_interruptible(vt_event_waitqueue, vw->done);
 154}
 155
 156static void __vt_event_dequeue(struct vt_event_wait *vw)
 157{
 158	unsigned long flags;
 159
 160	/* Dequeue it */
 161	spin_lock_irqsave(&vt_event_lock, flags);
 162	list_del(&vw->list);
 163	spin_unlock_irqrestore(&vt_event_lock, flags);
 164}
 165
 166/**
 167 *	vt_event_wait		-	wait for an event
 168 *	@vw: our event
 169 *
 170 *	Waits for an event to occur which completes our vt_event_wait
 171 *	structure. On return the structure has wv->done set to 1 for success
 172 *	or 0 if some event such as a signal ended the wait.
 173 */
 174
 175static void vt_event_wait(struct vt_event_wait *vw)
 176{
 177	__vt_event_queue(vw);
 178	__vt_event_wait(vw);
 179	__vt_event_dequeue(vw);
 180}
 181
 182/**
 183 *	vt_event_wait_ioctl	-	event ioctl handler
 184 *	@event: argument to ioctl (the event)
 185 *
 186 *	Implement the VT_WAITEVENT ioctl using the VT event interface
 187 */
 188
 189static int vt_event_wait_ioctl(struct vt_event __user *event)
 190{
 191	struct vt_event_wait vw;
 192
 193	if (copy_from_user(&vw.event, event, sizeof(struct vt_event)))
 194		return -EFAULT;
 195	/* Highest supported event for now */
 196	if (vw.event.event & ~VT_MAX_EVENT)
 197		return -EINVAL;
 198
 199	vt_event_wait(&vw);
 200	/* If it occurred report it */
 201	if (vw.done) {
 202		if (copy_to_user(event, &vw.event, sizeof(struct vt_event)))
 203			return -EFAULT;
 204		return 0;
 205	}
 206	return -EINTR;
 207}
 208
 209/**
 210 *	vt_waitactive	-	active console wait
 
 211 *	@n: new console
 212 *
 213 *	Helper for event waits. Used to implement the legacy
 214 *	event waiting ioctls in terms of events
 215 */
 216
 217int vt_waitactive(int n)
 218{
 219	struct vt_event_wait vw;
 220	do {
 221		vw.event.event = VT_EVENT_SWITCH;
 222		__vt_event_queue(&vw);
 223		if (n == fg_console + 1) {
 224			__vt_event_dequeue(&vw);
 225			break;
 226		}
 227		__vt_event_wait(&vw);
 228		__vt_event_dequeue(&vw);
 229		if (vw.done == 0)
 230			return -EINTR;
 231	} while (vw.event.newev != n);
 232	return 0;
 233}
 234
 235/*
 236 * these are the valid i/o ports we're allowed to change. they map all the
 237 * video ports
 238 */
 239#define GPFIRST 0x3b4
 240#define GPLAST 0x3df
 241#define GPNUM (GPLAST - GPFIRST + 1)
 242
 243/*
 244 * currently, setting the mode from KD_TEXT to KD_GRAPHICS doesn't do a whole
 245 * lot. i'm not sure if it should do any restoration of modes or what...
 246 *
 247 * XXX It should at least call into the driver, fbdev's definitely need to
 248 * restore their engine state. --BenH
 249 *
 250 * Called with the console lock held.
 251 */
 252static int vt_kdsetmode(struct vc_data *vc, unsigned long mode)
 253{
 254	switch (mode) {
 255	case KD_GRAPHICS:
 256		break;
 257	case KD_TEXT0:
 258	case KD_TEXT1:
 259		mode = KD_TEXT;
 260		fallthrough;
 261	case KD_TEXT:
 262		break;
 263	default:
 264		return -EINVAL;
 265	}
 266
 267	if (vc->vc_mode == mode)
 268		return 0;
 269
 270	vc->vc_mode = mode;
 271	if (vc->vc_num != fg_console)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 272		return 0;
 
 
 
 
 273
 274	/* explicitly blank/unblank the screen if switching modes */
 275	if (mode == KD_TEXT)
 276		do_unblank_screen(1);
 277	else
 278		do_blank_screen(1);
 279
 
 
 
 
 
 
 
 
 
 
 
 
 280	return 0;
 281}
 282
 283static int vt_k_ioctl(struct tty_struct *tty, unsigned int cmd,
 284		unsigned long arg, bool perm)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 285{
 286	struct vc_data *vc = tty->driver_data;
 
 
 
 
 287	void __user *up = (void __user *)arg;
 288	unsigned int console = vc->vc_num;
 289	int ret;
 
 
 
 
 
 
 
 
 
 290
 
 
 
 
 
 
 
 
 291	switch (cmd) {
 
 
 
 292	case KIOCSOUND:
 293		if (!perm)
 294			return -EPERM;
 295		/*
 296		 * The use of PIT_TICK_RATE is historic, it used to be
 297		 * the platform-dependent CLOCK_TICK_RATE between 2.6.12
 298		 * and 2.6.36, which was a minor but unfortunate ABI
 299		 * change. kd_mksound is locked by the input layer.
 300		 */
 301		if (arg)
 302			arg = PIT_TICK_RATE / arg;
 303		kd_mksound(arg, 0);
 304		break;
 305
 306	case KDMKTONE:
 307		if (!perm)
 308			return -EPERM;
 309	{
 310		unsigned int ticks, count;
 311
 312		/*
 313		 * Generate the tone for the appropriate number of ticks.
 314		 * If the time is zero, turn off sound ourselves.
 315		 */
 316		ticks = msecs_to_jiffies((arg >> 16) & 0xffff);
 317		count = ticks ? (arg & 0xffff) : 0;
 318		if (count)
 319			count = PIT_TICK_RATE / count;
 320		kd_mksound(count, ticks);
 321		break;
 322	}
 323
 324	case KDGKBTYPE:
 325		/*
 326		 * this is naïve.
 327		 */
 328		return put_user(KB_101, (char __user *)arg);
 
 
 329
 330		/*
 331		 * These cannot be implemented on any machine that implements
 332		 * ioperm() in user level (such as Alpha PCs) or not at all.
 333		 *
 334		 * XXX: you should never use these, just call ioperm directly..
 335		 */
 336#ifdef CONFIG_X86
 337	case KDADDIO:
 338	case KDDELIO:
 339		/*
 340		 * KDADDIO and KDDELIO may be able to add ports beyond what
 341		 * we reject here, but to be safe...
 342		 *
 343		 * These are locked internally via sys_ioperm
 344		 */
 345		if (arg < GPFIRST || arg > GPLAST)
 346			return -EINVAL;
 347
 348		return ksys_ioperm(arg, 1, (cmd == KDADDIO)) ? -ENXIO : 0;
 
 
 349
 350	case KDENABIO:
 351	case KDDISABIO:
 352		return ksys_ioperm(GPFIRST, GPNUM,
 353				  (cmd == KDENABIO)) ? -ENXIO : 0;
 
 354#endif
 355
 356	/* Linux m68k/i386 interface for setting the keyboard delay/repeat rate */
 357
 358	case KDKBDREP:
 359	{
 360		struct kbd_repeat kbrep;
 361
 362		if (!capable(CAP_SYS_TTY_CONFIG))
 363			return -EPERM;
 364
 365		if (copy_from_user(&kbrep, up, sizeof(struct kbd_repeat)))
 366			return -EFAULT;
 367
 
 368		ret = kbd_rate(&kbrep);
 369		if (ret)
 370			return ret;
 371		if (copy_to_user(up, &kbrep, sizeof(struct kbd_repeat)))
 372			return -EFAULT;
 373		break;
 374	}
 375
 376	case KDSETMODE:
 
 
 
 
 
 
 
 
 377		if (!perm)
 378			return -EPERM;
 379
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 380		console_lock();
 381		ret = vt_kdsetmode(vc, arg);
 
 
 
 382		console_unlock();
 383		return ret;
 384
 385	case KDGETMODE:
 386		return put_user(vc->vc_mode, (int __user *)arg);
 
 387
 388	case KDMAPDISP:
 389	case KDUNMAPDISP:
 390		/*
 391		 * these work like a combination of mmap and KDENABIO.
 392		 * this could be easily finished.
 393		 */
 394		return -EINVAL;
 
 395
 396	case KDSKBMODE:
 397		if (!perm)
 398			return -EPERM;
 399		ret = vt_do_kdskbmode(console, arg);
 400		if (ret)
 401			return ret;
 402		tty_ldisc_flush(tty);
 403		break;
 404
 405	case KDGKBMODE:
 406		return put_user(vt_do_kdgkbmode(console), (int __user *)arg);
 
 
 407
 408	/* this could be folded into KDSKBMODE, but for compatibility
 409	   reasons it is not so easy to fold KDGKBMETA into KDGKBMODE */
 410	case KDSKBMETA:
 411		return vt_do_kdskbmeta(console, arg);
 
 412
 413	case KDGKBMETA:
 414		/* FIXME: should review whether this is worth locking */
 415		return put_user(vt_do_kdgkbmeta(console), (int __user *)arg);
 
 
 
 416
 417	case KDGETKEYCODE:
 418	case KDSETKEYCODE:
 419		if(!capable(CAP_SYS_TTY_CONFIG))
 420			perm = 0;
 421		return vt_do_kbkeycode_ioctl(cmd, up, perm);
 
 422
 423	case KDGKBENT:
 424	case KDSKBENT:
 425		return vt_do_kdsk_ioctl(cmd, up, perm, console);
 
 426
 427	case KDGKBSENT:
 428	case KDSKBSENT:
 429		return vt_do_kdgkb_ioctl(cmd, up, perm);
 
 430
 431	/* Diacritical processing. Handled in keyboard.c as it has
 432	   to operate on the keyboard locks and structures */
 433	case KDGKBDIACR:
 434	case KDGKBDIACRUC:
 435	case KDSKBDIACR:
 436	case KDSKBDIACRUC:
 437		return vt_do_diacrit(cmd, up, perm);
 
 438
 439	/* the ioctls below read/set the flags usually shown in the leds */
 440	/* don't use them - they will go away without warning */
 441	case KDGKBLED:
 442	case KDSKBLED:
 443	case KDGETLED:
 444	case KDSETLED:
 445		return vt_do_kdskled(console, cmd, arg, perm);
 
 446
 447	/*
 448	 * A process can indicate its willingness to accept signals
 449	 * generated by pressing an appropriate key combination.
 450	 * Thus, one can have a daemon that e.g. spawns a new console
 451	 * upon a keypress and then changes to it.
 452	 * See also the kbrequest field of inittab(5).
 453	 */
 454	case KDSIGACCEPT:
 
 455		if (!perm || !capable(CAP_KILL))
 456			return -EPERM;
 457		if (!valid_signal(arg) || arg < 1 || arg == SIGKILL)
 458			return -EINVAL;
 459
 460		spin_lock_irq(&vt_spawn_con.lock);
 461		put_pid(vt_spawn_con.pid);
 462		vt_spawn_con.pid = get_pid(task_pid(current));
 463		vt_spawn_con.sig = arg;
 464		spin_unlock_irq(&vt_spawn_con.lock);
 465		break;
 466
 467	case KDFONTOP: {
 468		struct console_font_op op;
 469
 470		if (copy_from_user(&op, up, sizeof(op)))
 471			return -EFAULT;
 472		if (!perm && op.op != KD_FONT_OP_GET)
 473			return -EPERM;
 474		ret = con_font_op(vc, &op);
 475		if (ret)
 476			return ret;
 477		if (copy_to_user(up, &op, sizeof(op)))
 478			return -EFAULT;
 479		break;
 480	}
 481
 482	default:
 483		return -ENOIOCTLCMD;
 484	}
 485
 486	return 0;
 487}
 488
 489static inline int do_unimap_ioctl(int cmd, struct unimapdesc __user *user_ud,
 490		bool perm, struct vc_data *vc)
 491{
 492	struct unimapdesc tmp;
 493
 494	if (copy_from_user(&tmp, user_ud, sizeof tmp))
 495		return -EFAULT;
 496	switch (cmd) {
 497	case PIO_UNIMAP:
 498		if (!perm)
 499			return -EPERM;
 500		return con_set_unimap(vc, tmp.entry_ct, tmp.entries);
 501	case GIO_UNIMAP:
 502		if (!perm && fg_console != vc->vc_num)
 503			return -EPERM;
 504		return con_get_unimap(vc, tmp.entry_ct, &(user_ud->entry_ct),
 505				tmp.entries);
 506	}
 507	return 0;
 508}
 509
 510static int vt_io_ioctl(struct vc_data *vc, unsigned int cmd, void __user *up,
 511		bool perm)
 512{
 513	switch (cmd) {
 514	case PIO_CMAP:
 515		if (!perm)
 516			return -EPERM;
 517		return con_set_cmap(up);
 518
 519	case GIO_CMAP:
 520		return con_get_cmap(up);
 521
 522	case PIO_SCRNMAP:
 523		if (!perm)
 524			return -EPERM;
 525		return con_set_trans_old(up);
 526
 527	case GIO_SCRNMAP:
 528		return con_get_trans_old(up);
 529
 530	case PIO_UNISCRNMAP:
 531		if (!perm)
 532			return -EPERM;
 533		return con_set_trans_new(up);
 534
 535	case GIO_UNISCRNMAP:
 536		return con_get_trans_new(up);
 537
 538	case PIO_UNIMAPCLR:
 539		if (!perm)
 540			return -EPERM;
 541		con_clear_unimap(vc);
 542		break;
 543
 544	case PIO_UNIMAP:
 545	case GIO_UNIMAP:
 546		return do_unimap_ioctl(cmd, up, perm, vc);
 547
 548	default:
 549		return -ENOIOCTLCMD;
 550	}
 551
 552	return 0;
 553}
 554
 555static int vt_reldisp(struct vc_data *vc, unsigned int swtch)
 556{
 557	int newvt, ret;
 558
 559	if (vc->vt_mode.mode != VT_PROCESS)
 560		return -EINVAL;
 561
 562	/* Switched-to response */
 563	if (vc->vt_newvt < 0) {
 564		 /* If it's just an ACK, ignore it */
 565		return swtch == VT_ACKACQ ? 0 : -EINVAL;
 566	}
 567
 568	/* Switching-from response */
 569	if (swtch == 0) {
 570		/* Switch disallowed, so forget we were trying to do it. */
 571		vc->vt_newvt = -1;
 572		return 0;
 573	}
 574
 575	/* The current vt has been released, so complete the switch. */
 576	newvt = vc->vt_newvt;
 577	vc->vt_newvt = -1;
 578	ret = vc_allocate(newvt);
 579	if (ret)
 580		return ret;
 581
 582	/*
 583	 * When we actually do the console switch, make sure we are atomic with
 584	 * respect to other console switches..
 585	 */
 586	complete_change_console(vc_cons[newvt].d);
 587
 588	return 0;
 589}
 590
 591static int vt_setactivate(struct vt_setactivate __user *sa)
 592{
 593	struct vt_setactivate vsa;
 594	struct vc_data *nvc;
 595	int ret;
 596
 597	if (copy_from_user(&vsa, sa, sizeof(vsa)))
 598		return -EFAULT;
 599	if (vsa.console == 0 || vsa.console > MAX_NR_CONSOLES)
 600		return -ENXIO;
 601
 602	vsa.console--;
 603	vsa.console = array_index_nospec(vsa.console, MAX_NR_CONSOLES);
 604	console_lock();
 605	ret = vc_allocate(vsa.console);
 606	if (ret) {
 607		console_unlock();
 608		return ret;
 609	}
 610
 611	/*
 612	 * This is safe providing we don't drop the console sem between
 613	 * vc_allocate and finishing referencing nvc.
 614	 */
 615	nvc = vc_cons[vsa.console].d;
 616	nvc->vt_mode = vsa.mode;
 617	nvc->vt_mode.frsig = 0;
 618	put_pid(nvc->vt_pid);
 619	nvc->vt_pid = get_pid(task_pid(current));
 620	console_unlock();
 621
 622	/* Commence switch and lock */
 623	/* Review set_console locks */
 624	set_console(vsa.console);
 625
 626	return 0;
 627}
 628
 629/* deallocate a single console, if possible (leave 0) */
 630static int vt_disallocate(unsigned int vc_num)
 631{
 632	struct vc_data *vc = NULL;
 633	int ret = 0;
 634
 635	console_lock();
 636	if (vt_busy(vc_num))
 637		ret = -EBUSY;
 638	else if (vc_num)
 639		vc = vc_deallocate(vc_num);
 640	console_unlock();
 641
 642	if (vc && vc_num >= MIN_NR_CONSOLES)
 643		tty_port_put(&vc->port);
 644
 645	return ret;
 646}
 647
 648/* deallocate all unused consoles, but leave 0 */
 649static void vt_disallocate_all(void)
 650{
 651	struct vc_data *vc[MAX_NR_CONSOLES];
 652	int i;
 653
 654	console_lock();
 655	for (i = 1; i < MAX_NR_CONSOLES; i++)
 656		if (!vt_busy(i))
 657			vc[i] = vc_deallocate(i);
 658		else
 659			vc[i] = NULL;
 660	console_unlock();
 661
 662	for (i = 1; i < MAX_NR_CONSOLES; i++) {
 663		if (vc[i] && i >= MIN_NR_CONSOLES)
 664			tty_port_put(&vc[i]->port);
 665	}
 666}
 667
 668static int vt_resizex(struct vc_data *vc, struct vt_consize __user *cs)
 669{
 670	struct vt_consize v;
 671	int i;
 672
 673	if (copy_from_user(&v, cs, sizeof(struct vt_consize)))
 674		return -EFAULT;
 675
 676	/* FIXME: Should check the copies properly */
 677	if (!v.v_vlin)
 678		v.v_vlin = vc->vc_scan_lines;
 679
 680	if (v.v_clin) {
 681		int rows = v.v_vlin / v.v_clin;
 682		if (v.v_rows != rows) {
 683			if (v.v_rows) /* Parameters don't add up */
 684				return -EINVAL;
 685			v.v_rows = rows;
 686		}
 
 687	}
 688
 689	if (v.v_vcol && v.v_ccol) {
 690		int cols = v.v_vcol / v.v_ccol;
 691		if (v.v_cols != cols) {
 692			if (v.v_cols)
 693				return -EINVAL;
 694			v.v_cols = cols;
 695		}
 696	}
 697
 698	if (v.v_clin > 32)
 699		return -EINVAL;
 700
 701	for (i = 0; i < MAX_NR_CONSOLES; i++) {
 702		struct vc_data *vcp;
 703
 704		if (!vc_cons[i].d)
 705			continue;
 706		console_lock();
 707		vcp = vc_cons[i].d;
 708		if (vcp) {
 709			int ret;
 710			int save_scan_lines = vcp->vc_scan_lines;
 711			int save_cell_height = vcp->vc_cell_height;
 712
 713			if (v.v_vlin)
 714				vcp->vc_scan_lines = v.v_vlin;
 715			if (v.v_clin)
 716				vcp->vc_cell_height = v.v_clin;
 717			vcp->vc_resize_user = 1;
 718			ret = vc_resize(vcp, v.v_cols, v.v_rows);
 719			if (ret) {
 720				vcp->vc_scan_lines = save_scan_lines;
 721				vcp->vc_cell_height = save_cell_height;
 722				console_unlock();
 723				return ret;
 724			}
 725		}
 726		console_unlock();
 727	}
 728
 729	return 0;
 730}
 731
 732/*
 733 * We handle the console-specific ioctl's here.  We allow the
 734 * capability to modify any console, not just the fg_console.
 735 */
 736int vt_ioctl(struct tty_struct *tty,
 737	     unsigned int cmd, unsigned long arg)
 738{
 739	struct vc_data *vc = tty->driver_data;
 740	void __user *up = (void __user *)arg;
 741	int i, perm;
 742	int ret;
 743
 744	/*
 745	 * To have permissions to do most of the vt ioctls, we either have
 746	 * to be the owner of the tty, or have CAP_SYS_TTY_CONFIG.
 747	 */
 748	perm = 0;
 749	if (current->signal->tty == tty || capable(CAP_SYS_TTY_CONFIG))
 750		perm = 1;
 751
 752	ret = vt_k_ioctl(tty, cmd, arg, perm);
 753	if (ret != -ENOIOCTLCMD)
 754		return ret;
 755
 756	ret = vt_io_ioctl(vc, cmd, up, perm);
 757	if (ret != -ENOIOCTLCMD)
 758		return ret;
 759
 760	switch (cmd) {
 761	case TIOCLINUX:
 762		return tioclinux(tty, arg);
 763	case VT_SETMODE:
 764	{
 765		struct vt_mode tmp;
 766
 767		if (!perm)
 768			return -EPERM;
 769		if (copy_from_user(&tmp, up, sizeof(struct vt_mode)))
 770			return -EFAULT;
 771		if (tmp.mode != VT_AUTO && tmp.mode != VT_PROCESS)
 772			return -EINVAL;
 773
 
 
 
 774		console_lock();
 775		vc->vt_mode = tmp;
 776		/* the frsig is ignored, so we set it to 0 */
 777		vc->vt_mode.frsig = 0;
 778		put_pid(vc->vt_pid);
 779		vc->vt_pid = get_pid(task_pid(current));
 780		/* no switch is required -- saw@shade.msu.ru */
 781		vc->vt_newvt = -1;
 782		console_unlock();
 783		break;
 784	}
 785
 786	case VT_GETMODE:
 787	{
 788		struct vt_mode tmp;
 789		int rc;
 790
 791		console_lock();
 792		memcpy(&tmp, &vc->vt_mode, sizeof(struct vt_mode));
 793		console_unlock();
 794
 795		rc = copy_to_user(up, &tmp, sizeof(struct vt_mode));
 796		if (rc)
 797			return -EFAULT;
 798		break;
 799	}
 800
 801	/*
 802	 * Returns global vt state. Note that VT 0 is always open, since
 803	 * it's an alias for the current VT, and people can't use it here.
 804	 * We cannot return state for more than 16 VTs, since v_state is short.
 805	 */
 806	case VT_GETSTATE:
 807	{
 808		struct vt_stat __user *vtstat = up;
 809		unsigned short state, mask;
 810
 
 811		if (put_user(fg_console + 1, &vtstat->v_active))
 812			return -EFAULT;
 813
 814		state = 1;	/* /dev/tty0 is always open */
 815		console_lock(); /* required by vt_in_use() */
 816		for (i = 0, mask = 2; i < MAX_NR_CONSOLES && mask;
 817				++i, mask <<= 1)
 818			if (vt_in_use(i))
 819				state |= mask;
 820		console_unlock();
 821		return put_user(state, &vtstat->v_state);
 822	}
 823
 824	/*
 825	 * Returns the first available (non-opened) console.
 826	 */
 827	case VT_OPENQRY:
 828		console_lock(); /* required by vt_in_use() */
 829		for (i = 0; i < MAX_NR_CONSOLES; ++i)
 830			if (!vt_in_use(i))
 831				break;
 832		console_unlock();
 833		i = i < MAX_NR_CONSOLES ? (i+1) : -1;
 834		return put_user(i, (int __user *)arg);
 835
 836	/*
 837	 * ioctl(fd, VT_ACTIVATE, num) will cause us to switch to vt # num,
 838	 * with num >= 1 (switches to vt 0, our console, are not allowed, just
 839	 * to preserve sanity).
 840	 */
 841	case VT_ACTIVATE:
 842		if (!perm)
 843			return -EPERM;
 844		if (arg == 0 || arg > MAX_NR_CONSOLES)
 845			return -ENXIO;
 846
 847		arg--;
 848		arg = array_index_nospec(arg, MAX_NR_CONSOLES);
 849		console_lock();
 850		ret = vc_allocate(arg);
 851		console_unlock();
 852		if (ret)
 853			return ret;
 854		set_console(arg);
 855		break;
 856
 857	case VT_SETACTIVATE:
 
 
 
 858		if (!perm)
 859			return -EPERM;
 860
 861		return vt_setactivate(up);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 862
 863	/*
 864	 * wait until the specified VT has been activated
 865	 */
 866	case VT_WAITACTIVE:
 867		if (!perm)
 868			return -EPERM;
 869		if (arg == 0 || arg > MAX_NR_CONSOLES)
 870			return -ENXIO;
 871		return vt_waitactive(arg);
 
 
 872
 873	/*
 874	 * If a vt is under process control, the kernel will not switch to it
 875	 * immediately, but postpone the operation until the process calls this
 876	 * ioctl, allowing the switch to complete.
 877	 *
 878	 * According to the X sources this is the behavior:
 879	 *	0:	pending switch-from not OK
 880	 *	1:	pending switch-from OK
 881	 *	2:	completed switch-to OK
 882	 */
 883	case VT_RELDISP:
 884		if (!perm)
 885			return -EPERM;
 886
 887		console_lock();
 888		ret = vt_reldisp(vc, arg);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 889		console_unlock();
 890
 891		return ret;
 892
 893
 894	 /*
 895	  * Disallocate memory associated to VT (but leave VT1)
 896	  */
 897	 case VT_DISALLOCATE:
 898		if (arg > MAX_NR_CONSOLES)
 899			return -ENXIO;
 900
 901		if (arg == 0) {
 902			vt_disallocate_all();
 903			break;
 904		}
 905
 906		arg = array_index_nospec(arg - 1, MAX_NR_CONSOLES);
 907		return vt_disallocate(arg);
 
 
 908
 909	case VT_RESIZE:
 910	{
 911		struct vt_sizes __user *vtsizes = up;
 912		struct vc_data *vc;
 913		ushort ll,cc;
 914
 
 915		if (!perm)
 916			return -EPERM;
 917		if (get_user(ll, &vtsizes->v_rows) ||
 918		    get_user(cc, &vtsizes->v_cols))
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 919			return -EFAULT;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 920
 921		console_lock();
 922		for (i = 0; i < MAX_NR_CONSOLES; i++) {
 923			vc = vc_cons[i].d;
 924
 925			if (vc) {
 926				vc->vc_resize_user = 1;
 927				/* FIXME: review v tty lock */
 928				vc_resize(vc_cons[i].d, cc, ll);
 929			}
 
 
 
 
 
 
 930		}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 931		console_unlock();
 932		break;
 
 
 933	}
 934
 935	case VT_RESIZEX:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 936		if (!perm)
 937			return -EPERM;
 
 
 938
 939		return vt_resizex(vc, up);
 
 
 
 940
 941	case VT_LOCKSWITCH:
 942		if (!capable(CAP_SYS_TTY_CONFIG))
 943			return -EPERM;
 944		vt_dont_switch = true;
 945		break;
 946	case VT_UNLOCKSWITCH:
 947		if (!capable(CAP_SYS_TTY_CONFIG))
 948			return -EPERM;
 949		vt_dont_switch = false;
 950		break;
 951	case VT_GETHIFONTMASK:
 952		return put_user(vc->vc_hi_font_mask,
 953					(unsigned short __user *)arg);
 
 954	case VT_WAITEVENT:
 955		return vt_event_wait_ioctl((struct vt_event __user *)arg);
 
 956	default:
 957		return -ENOIOCTLCMD;
 958	}
 959
 960	return 0;
 961}
 962
 963void reset_vc(struct vc_data *vc)
 964{
 965	vc->vc_mode = KD_TEXT;
 966	vt_reset_unicode(vc->vc_num);
 967	vc->vt_mode.mode = VT_AUTO;
 968	vc->vt_mode.waitv = 0;
 969	vc->vt_mode.relsig = 0;
 970	vc->vt_mode.acqsig = 0;
 971	vc->vt_mode.frsig = 0;
 972	put_pid(vc->vt_pid);
 973	vc->vt_pid = NULL;
 974	vc->vt_newvt = -1;
 975	reset_palette(vc);
 
 976}
 977
 978void vc_SAK(struct work_struct *work)
 979{
 980	struct vc *vc_con =
 981		container_of(work, struct vc, SAK_work);
 982	struct vc_data *vc;
 983	struct tty_struct *tty;
 984
 985	console_lock();
 986	vc = vc_con->d;
 987	if (vc) {
 988		/* FIXME: review tty ref counting */
 989		tty = vc->port.tty;
 990		/*
 991		 * SAK should also work in all raw modes and reset
 992		 * them properly.
 993		 */
 994		if (tty)
 995			__do_SAK(tty);
 996		reset_vc(vc);
 997	}
 998	console_unlock();
 999}
1000
1001#ifdef CONFIG_COMPAT
1002
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1003struct compat_console_font_op {
1004	compat_uint_t op;        /* operation code KD_FONT_OP_* */
1005	compat_uint_t flags;     /* KD_FONT_FLAG_* */
1006	compat_uint_t width, height;     /* font size */
1007	compat_uint_t charcount;
1008	compat_caddr_t data;    /* font data with height fixed to 32 */
1009};
1010
1011static inline int
1012compat_kdfontop_ioctl(struct compat_console_font_op __user *fontop,
1013			 int perm, struct console_font_op *op, struct vc_data *vc)
1014{
1015	int i;
1016
1017	if (copy_from_user(op, fontop, sizeof(struct compat_console_font_op)))
1018		return -EFAULT;
1019	if (!perm && op->op != KD_FONT_OP_GET)
1020		return -EPERM;
1021	op->data = compat_ptr(((struct compat_console_font_op *)op)->data);
1022	i = con_font_op(vc, op);
1023	if (i)
1024		return i;
1025	((struct compat_console_font_op *)op)->data = (unsigned long)op->data;
1026	if (copy_to_user(fontop, op, sizeof(struct compat_console_font_op)))
1027		return -EFAULT;
1028	return 0;
1029}
1030
1031struct compat_unimapdesc {
1032	unsigned short entry_ct;
1033	compat_caddr_t entries;
1034};
1035
1036static inline int
1037compat_unimap_ioctl(unsigned int cmd, struct compat_unimapdesc __user *user_ud,
1038			 int perm, struct vc_data *vc)
1039{
1040	struct compat_unimapdesc tmp;
1041	struct unipair __user *tmp_entries;
1042
1043	if (copy_from_user(&tmp, user_ud, sizeof tmp))
1044		return -EFAULT;
1045	tmp_entries = compat_ptr(tmp.entries);
1046	switch (cmd) {
1047	case PIO_UNIMAP:
1048		if (!perm)
1049			return -EPERM;
1050		return con_set_unimap(vc, tmp.entry_ct, tmp_entries);
1051	case GIO_UNIMAP:
1052		if (!perm && fg_console != vc->vc_num)
1053			return -EPERM;
1054		return con_get_unimap(vc, tmp.entry_ct, &(user_ud->entry_ct), tmp_entries);
1055	}
1056	return 0;
1057}
1058
1059long vt_compat_ioctl(struct tty_struct *tty,
1060	     unsigned int cmd, unsigned long arg)
1061{
1062	struct vc_data *vc = tty->driver_data;
1063	struct console_font_op op;	/* used in multiple places here */
1064	void __user *up = compat_ptr(arg);
 
1065	int perm;
 
 
 
 
 
 
 
 
1066
1067	/*
1068	 * To have permissions to do most of the vt ioctls, we either have
1069	 * to be the owner of the tty, or have CAP_SYS_TTY_CONFIG.
1070	 */
1071	perm = 0;
1072	if (current->signal->tty == tty || capable(CAP_SYS_TTY_CONFIG))
1073		perm = 1;
1074
1075	switch (cmd) {
1076	/*
1077	 * these need special handlers for incompatible data structures
1078	 */
 
 
 
 
1079
1080	case KDFONTOP:
1081		return compat_kdfontop_ioctl(up, perm, &op, vc);
 
1082
1083	case PIO_UNIMAP:
1084	case GIO_UNIMAP:
1085		return compat_unimap_ioctl(cmd, up, perm, vc);
 
1086
1087	/*
1088	 * all these treat 'arg' as an integer
1089	 */
1090	case KIOCSOUND:
1091	case KDMKTONE:
1092#ifdef CONFIG_X86
1093	case KDADDIO:
1094	case KDDELIO:
1095#endif
1096	case KDSETMODE:
1097	case KDMAPDISP:
1098	case KDUNMAPDISP:
1099	case KDSKBMODE:
1100	case KDSKBMETA:
1101	case KDSKBLED:
1102	case KDSETLED:
1103	case KDSIGACCEPT:
1104	case VT_ACTIVATE:
1105	case VT_WAITACTIVE:
1106	case VT_RELDISP:
1107	case VT_DISALLOCATE:
1108	case VT_RESIZE:
1109	case VT_RESIZEX:
1110		return vt_ioctl(tty, cmd, arg);
1111
1112	/*
1113	 * the rest has a compatible data structure behind arg,
1114	 * but we have to convert it to a proper 64 bit pointer.
1115	 */
1116	default:
1117		return vt_ioctl(tty, cmd, (unsigned long)up);
 
1118	}
 
 
 
 
 
1119}
1120
1121
1122#endif /* CONFIG_COMPAT */
1123
1124
1125/*
1126 * Performs the back end of a vt switch. Called under the console
1127 * semaphore.
1128 */
1129static void complete_change_console(struct vc_data *vc)
1130{
1131	unsigned char old_vc_mode;
1132	int old = fg_console;
1133
1134	last_console = fg_console;
1135
1136	/*
1137	 * If we're switching, we could be going from KD_GRAPHICS to
1138	 * KD_TEXT mode or vice versa, which means we need to blank or
1139	 * unblank the screen later.
1140	 */
1141	old_vc_mode = vc_cons[fg_console].d->vc_mode;
1142	switch_screen(vc);
1143
1144	/*
1145	 * This can't appear below a successful kill_pid().  If it did,
1146	 * then the *blank_screen operation could occur while X, having
1147	 * received acqsig, is waking up on another processor.  This
1148	 * condition can lead to overlapping accesses to the VGA range
1149	 * and the framebuffer (causing system lockups).
1150	 *
1151	 * To account for this we duplicate this code below only if the
1152	 * controlling process is gone and we've called reset_vc.
1153	 */
1154	if (old_vc_mode != vc->vc_mode) {
1155		if (vc->vc_mode == KD_TEXT)
1156			do_unblank_screen(1);
1157		else
1158			do_blank_screen(1);
1159	}
1160
1161	/*
1162	 * If this new console is under process control, send it a signal
1163	 * telling it that it has acquired. Also check if it has died and
1164	 * clean up (similar to logic employed in change_console())
1165	 */
1166	if (vc->vt_mode.mode == VT_PROCESS) {
1167		/*
1168		 * Send the signal as privileged - kill_pid() will
1169		 * tell us if the process has gone or something else
1170		 * is awry
1171		 */
1172		if (kill_pid(vc->vt_pid, vc->vt_mode.acqsig, 1) != 0) {
1173		/*
1174		 * The controlling process has died, so we revert back to
1175		 * normal operation. In this case, we'll also change back
1176		 * to KD_TEXT mode. I'm not sure if this is strictly correct
1177		 * but it saves the agony when the X server dies and the screen
1178		 * remains blanked due to KD_GRAPHICS! It would be nice to do
1179		 * this outside of VT_PROCESS but there is no single process
1180		 * to account for and tracking tty count may be undesirable.
1181		 */
1182			reset_vc(vc);
1183
1184			if (old_vc_mode != vc->vc_mode) {
1185				if (vc->vc_mode == KD_TEXT)
1186					do_unblank_screen(1);
1187				else
1188					do_blank_screen(1);
1189			}
1190		}
1191	}
1192
1193	/*
1194	 * Wake anyone waiting for their VT to activate
1195	 */
1196	vt_event_post(VT_EVENT_SWITCH, old, vc->vc_num);
1197	return;
1198}
1199
1200/*
1201 * Performs the front-end of a vt switch
1202 */
1203void change_console(struct vc_data *new_vc)
1204{
1205	struct vc_data *vc;
1206
1207	if (!new_vc || new_vc->vc_num == fg_console || vt_dont_switch)
1208		return;
1209
1210	/*
1211	 * If this vt is in process mode, then we need to handshake with
1212	 * that process before switching. Essentially, we store where that
1213	 * vt wants to switch to and wait for it to tell us when it's done
1214	 * (via VT_RELDISP ioctl).
1215	 *
1216	 * We also check to see if the controlling process still exists.
1217	 * If it doesn't, we reset this vt to auto mode and continue.
1218	 * This is a cheap way to track process control. The worst thing
1219	 * that can happen is: we send a signal to a process, it dies, and
1220	 * the switch gets "lost" waiting for a response; hopefully, the
1221	 * user will try again, we'll detect the process is gone (unless
1222	 * the user waits just the right amount of time :-) and revert the
1223	 * vt to auto control.
1224	 */
1225	vc = vc_cons[fg_console].d;
1226	if (vc->vt_mode.mode == VT_PROCESS) {
1227		/*
1228		 * Send the signal as privileged - kill_pid() will
1229		 * tell us if the process has gone or something else
1230		 * is awry.
1231		 *
1232		 * We need to set vt_newvt *before* sending the signal or we
1233		 * have a race.
1234		 */
1235		vc->vt_newvt = new_vc->vc_num;
1236		if (kill_pid(vc->vt_pid, vc->vt_mode.relsig, 1) == 0) {
1237			/*
1238			 * It worked. Mark the vt to switch to and
1239			 * return. The process needs to send us a
1240			 * VT_RELDISP ioctl to complete the switch.
1241			 */
1242			return;
1243		}
1244
1245		/*
1246		 * The controlling process has died, so we revert back to
1247		 * normal operation. In this case, we'll also change back
1248		 * to KD_TEXT mode. I'm not sure if this is strictly correct
1249		 * but it saves the agony when the X server dies and the screen
1250		 * remains blanked due to KD_GRAPHICS! It would be nice to do
1251		 * this outside of VT_PROCESS but there is no single process
1252		 * to account for and tracking tty count may be undesirable.
1253		 */
1254		reset_vc(vc);
1255
1256		/*
1257		 * Fall through to normal (VT_AUTO) handling of the switch...
1258		 */
1259	}
1260
1261	/*
1262	 * Ignore all switches in KD_GRAPHICS+VT_AUTO mode
1263	 */
1264	if (vc->vc_mode == KD_GRAPHICS)
1265		return;
1266
1267	complete_change_console(new_vc);
1268}
1269
1270/* Perform a kernel triggered VT switch for suspend/resume */
1271
1272static int disable_vt_switch;
1273
1274int vt_move_to_console(unsigned int vt, int alloc)
1275{
1276	int prev;
1277
1278	console_lock();
1279	/* Graphics mode - up to X */
1280	if (disable_vt_switch) {
1281		console_unlock();
1282		return 0;
1283	}
1284	prev = fg_console;
1285
1286	if (alloc && vc_allocate(vt)) {
1287		/* we can't have a free VC for now. Too bad,
1288		 * we don't want to mess the screen for now. */
1289		console_unlock();
1290		return -ENOSPC;
1291	}
1292
1293	if (set_console(vt)) {
1294		/*
1295		 * We're unable to switch to the SUSPEND_CONSOLE.
1296		 * Let the calling function know so it can decide
1297		 * what to do.
1298		 */
1299		console_unlock();
1300		return -EIO;
1301	}
1302	console_unlock();
1303	if (vt_waitactive(vt + 1)) {
1304		pr_debug("Suspend: Can't switch VCs.");
1305		return -EINTR;
1306	}
1307	return prev;
1308}
1309
1310/*
1311 * Normally during a suspend, we allocate a new console and switch to it.
1312 * When we resume, we switch back to the original console.  This switch
1313 * can be slow, so on systems where the framebuffer can handle restoration
1314 * of video registers anyways, there's little point in doing the console
1315 * switch.  This function allows you to disable it by passing it '0'.
1316 */
1317void pm_set_vt_switch(int do_switch)
1318{
1319	console_lock();
1320	disable_vt_switch = !do_switch;
1321	console_unlock();
1322}
1323EXPORT_SYMBOL(pm_set_vt_switch);
v4.17
   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/kbd_kern.h>
  36#include <linux/vt_kern.h>
  37#include <linux/kbd_diacr.h>
  38#include <linux/selection.h>
  39
  40char vt_dont_switch;
  41extern struct tty_driver *console_driver;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  42
  43#define VT_IS_IN_USE(i)	(console_driver->ttys[i] && console_driver->ttys[i]->count)
  44#define VT_BUSY(i)	(VT_IS_IN_USE(i) || i == fg_console || vc_cons[i].d == sel_cons)
  45
  46/*
  47 * Console (vt and kd) routines, as defined by USL SVR4 manual, and by
  48 * experimentation and study of X386 SYSV handling.
  49 *
  50 * One point of difference: SYSV vt's are /dev/vtX, which X >= 0, and
  51 * /dev/console is a separate ttyp. Under Linux, /dev/tty0 is /dev/console,
  52 * and the vc start at /dev/ttyX, X >= 1. We maintain that here, so we will
  53 * always treat our set of vt as numbered 1..MAX_NR_CONSOLES (corresponding to
  54 * ttys 0..MAX_NR_CONSOLES-1). Explicitly naming VT 0 is illegal, but using
  55 * /dev/tty0 (fg_console) as a target is legal, since an implicit aliasing
  56 * to the current console is done by the main ioctl code.
  57 */
  58
  59#ifdef CONFIG_X86
  60#include <asm/syscalls.h>
  61#endif
  62
  63static void complete_change_console(struct vc_data *vc);
  64
  65/*
  66 *	User space VT_EVENT handlers
  67 */
  68
  69struct vt_event_wait {
  70	struct list_head list;
  71	struct vt_event event;
  72	int done;
  73};
  74
  75static LIST_HEAD(vt_events);
  76static DEFINE_SPINLOCK(vt_event_lock);
  77static DECLARE_WAIT_QUEUE_HEAD(vt_event_waitqueue);
  78
  79/**
  80 *	vt_event_post
  81 *	@event: the event that occurred
  82 *	@old: old console
  83 *	@new: new console
  84 *
  85 *	Post an VT event to interested VT handlers
  86 */
  87
  88void vt_event_post(unsigned int event, unsigned int old, unsigned int new)
  89{
  90	struct list_head *pos, *head;
  91	unsigned long flags;
  92	int wake = 0;
  93
  94	spin_lock_irqsave(&vt_event_lock, flags);
  95	head = &vt_events;
  96
  97	list_for_each(pos, head) {
  98		struct vt_event_wait *ve = list_entry(pos,
  99						struct vt_event_wait, list);
 100		if (!(ve->event.event & event))
 101			continue;
 102		ve->event.event = event;
 103		/* kernel view is consoles 0..n-1, user space view is
 104		   console 1..n with 0 meaning current, so we must bias */
 105		ve->event.oldev = old + 1;
 106		ve->event.newev = new + 1;
 107		wake = 1;
 108		ve->done = 1;
 109	}
 110	spin_unlock_irqrestore(&vt_event_lock, flags);
 111	if (wake)
 112		wake_up_interruptible(&vt_event_waitqueue);
 113}
 114
 115static void __vt_event_queue(struct vt_event_wait *vw)
 116{
 117	unsigned long flags;
 118	/* Prepare the event */
 119	INIT_LIST_HEAD(&vw->list);
 120	vw->done = 0;
 121	/* Queue our event */
 122	spin_lock_irqsave(&vt_event_lock, flags);
 123	list_add(&vw->list, &vt_events);
 124	spin_unlock_irqrestore(&vt_event_lock, flags);
 125}
 126
 127static void __vt_event_wait(struct vt_event_wait *vw)
 128{
 129	/* Wait for it to pass */
 130	wait_event_interruptible(vt_event_waitqueue, vw->done);
 131}
 132
 133static void __vt_event_dequeue(struct vt_event_wait *vw)
 134{
 135	unsigned long flags;
 136
 137	/* Dequeue it */
 138	spin_lock_irqsave(&vt_event_lock, flags);
 139	list_del(&vw->list);
 140	spin_unlock_irqrestore(&vt_event_lock, flags);
 141}
 142
 143/**
 144 *	vt_event_wait		-	wait for an event
 145 *	@vw: our event
 146 *
 147 *	Waits for an event to occur which completes our vt_event_wait
 148 *	structure. On return the structure has wv->done set to 1 for success
 149 *	or 0 if some event such as a signal ended the wait.
 150 */
 151
 152static void vt_event_wait(struct vt_event_wait *vw)
 153{
 154	__vt_event_queue(vw);
 155	__vt_event_wait(vw);
 156	__vt_event_dequeue(vw);
 157}
 158
 159/**
 160 *	vt_event_wait_ioctl	-	event ioctl handler
 161 *	@arg: argument to ioctl
 162 *
 163 *	Implement the VT_WAITEVENT ioctl using the VT event interface
 164 */
 165
 166static int vt_event_wait_ioctl(struct vt_event __user *event)
 167{
 168	struct vt_event_wait vw;
 169
 170	if (copy_from_user(&vw.event, event, sizeof(struct vt_event)))
 171		return -EFAULT;
 172	/* Highest supported event for now */
 173	if (vw.event.event & ~VT_MAX_EVENT)
 174		return -EINVAL;
 175
 176	vt_event_wait(&vw);
 177	/* If it occurred report it */
 178	if (vw.done) {
 179		if (copy_to_user(event, &vw.event, sizeof(struct vt_event)))
 180			return -EFAULT;
 181		return 0;
 182	}
 183	return -EINTR;
 184}
 185
 186/**
 187 *	vt_waitactive	-	active console wait
 188 *	@event: event code
 189 *	@n: new console
 190 *
 191 *	Helper for event waits. Used to implement the legacy
 192 *	event waiting ioctls in terms of events
 193 */
 194
 195int vt_waitactive(int n)
 196{
 197	struct vt_event_wait vw;
 198	do {
 199		vw.event.event = VT_EVENT_SWITCH;
 200		__vt_event_queue(&vw);
 201		if (n == fg_console + 1) {
 202			__vt_event_dequeue(&vw);
 203			break;
 204		}
 205		__vt_event_wait(&vw);
 206		__vt_event_dequeue(&vw);
 207		if (vw.done == 0)
 208			return -EINTR;
 209	} while (vw.event.newev != n);
 210	return 0;
 211}
 212
 213/*
 214 * these are the valid i/o ports we're allowed to change. they map all the
 215 * video ports
 216 */
 217#define GPFIRST 0x3b4
 218#define GPLAST 0x3df
 219#define GPNUM (GPLAST - GPFIRST + 1)
 220
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 221
 
 
 222
 223static inline int 
 224do_fontx_ioctl(int cmd, struct consolefontdesc __user *user_cfd, int perm, struct console_font_op *op)
 225{
 226	struct consolefontdesc cfdarg;
 227	int i;
 228
 229	if (copy_from_user(&cfdarg, user_cfd, sizeof(struct consolefontdesc))) 
 230		return -EFAULT;
 231 	
 232	switch (cmd) {
 233	case PIO_FONTX:
 234		if (!perm)
 235			return -EPERM;
 236		op->op = KD_FONT_OP_SET;
 237		op->flags = KD_FONT_FLAG_OLD;
 238		op->width = 8;
 239		op->height = cfdarg.charheight;
 240		op->charcount = cfdarg.charcount;
 241		op->data = cfdarg.chardata;
 242		return con_font_op(vc_cons[fg_console].d, op);
 243	case GIO_FONTX: {
 244		op->op = KD_FONT_OP_GET;
 245		op->flags = KD_FONT_FLAG_OLD;
 246		op->width = 8;
 247		op->height = cfdarg.charheight;
 248		op->charcount = cfdarg.charcount;
 249		op->data = cfdarg.chardata;
 250		i = con_font_op(vc_cons[fg_console].d, op);
 251		if (i)
 252			return i;
 253		cfdarg.charheight = op->height;
 254		cfdarg.charcount = op->charcount;
 255		if (copy_to_user(user_cfd, &cfdarg, sizeof(struct consolefontdesc)))
 256			return -EFAULT;
 257		return 0;
 258		}
 259	}
 260	return -EINVAL;
 261}
 262
 263static inline int 
 264do_unimap_ioctl(int cmd, struct unimapdesc __user *user_ud, int perm, struct vc_data *vc)
 265{
 266	struct unimapdesc tmp;
 
 267
 268	if (copy_from_user(&tmp, user_ud, sizeof tmp))
 269		return -EFAULT;
 270	switch (cmd) {
 271	case PIO_UNIMAP:
 272		if (!perm)
 273			return -EPERM;
 274		return con_set_unimap(vc, tmp.entry_ct, tmp.entries);
 275	case GIO_UNIMAP:
 276		if (!perm && fg_console != vc->vc_num)
 277			return -EPERM;
 278		return con_get_unimap(vc, tmp.entry_ct, &(user_ud->entry_ct), tmp.entries);
 279	}
 280	return 0;
 281}
 282
 283/* deallocate a single console, if possible (leave 0) */
 284static int vt_disallocate(unsigned int vc_num)
 285{
 286	struct vc_data *vc = NULL;
 287	int ret = 0;
 288
 289	console_lock();
 290	if (VT_BUSY(vc_num))
 291		ret = -EBUSY;
 292	else if (vc_num)
 293		vc = vc_deallocate(vc_num);
 294	console_unlock();
 295
 296	if (vc && vc_num >= MIN_NR_CONSOLES) {
 297		tty_port_destroy(&vc->port);
 298		kfree(vc);
 299	}
 300
 301	return ret;
 302}
 303
 304/* deallocate all unused consoles, but leave 0 */
 305static void vt_disallocate_all(void)
 306{
 307	struct vc_data *vc[MAX_NR_CONSOLES];
 308	int i;
 309
 310	console_lock();
 311	for (i = 1; i < MAX_NR_CONSOLES; i++)
 312		if (!VT_BUSY(i))
 313			vc[i] = vc_deallocate(i);
 314		else
 315			vc[i] = NULL;
 316	console_unlock();
 317
 318	for (i = 1; i < MAX_NR_CONSOLES; i++) {
 319		if (vc[i] && i >= MIN_NR_CONSOLES) {
 320			tty_port_destroy(&vc[i]->port);
 321			kfree(vc[i]);
 322		}
 323	}
 324}
 325
 326
 327/*
 328 * We handle the console-specific ioctl's here.  We allow the
 329 * capability to modify any console, not just the fg_console. 
 330 */
 331int vt_ioctl(struct tty_struct *tty,
 332	     unsigned int cmd, unsigned long arg)
 333{
 334	struct vc_data *vc = tty->driver_data;
 335	struct console_font_op op;	/* used in multiple places here */
 336	unsigned int console;
 337	unsigned char ucval;
 338	unsigned int uival;
 339	void __user *up = (void __user *)arg;
 340	int i, perm;
 341	int ret = 0;
 342
 343	console = vc->vc_num;
 344
 345
 346	if (!vc_cons_allocated(console)) { 	/* impossible? */
 347		ret = -ENOIOCTLCMD;
 348		goto out;
 349	}
 350
 351
 352	/*
 353	 * To have permissions to do most of the vt ioctls, we either have
 354	 * to be the owner of the tty, or have CAP_SYS_TTY_CONFIG.
 355	 */
 356	perm = 0;
 357	if (current->signal->tty == tty || capable(CAP_SYS_TTY_CONFIG))
 358		perm = 1;
 359 
 360	switch (cmd) {
 361	case TIOCLINUX:
 362		ret = tioclinux(tty, arg);
 363		break;
 364	case KIOCSOUND:
 365		if (!perm)
 366			return -EPERM;
 367		/*
 368		 * The use of PIT_TICK_RATE is historic, it used to be
 369		 * the platform-dependent CLOCK_TICK_RATE between 2.6.12
 370		 * and 2.6.36, which was a minor but unfortunate ABI
 371		 * change. kd_mksound is locked by the input layer.
 372		 */
 373		if (arg)
 374			arg = PIT_TICK_RATE / arg;
 375		kd_mksound(arg, 0);
 376		break;
 377
 378	case KDMKTONE:
 379		if (!perm)
 380			return -EPERM;
 381	{
 382		unsigned int ticks, count;
 383		
 384		/*
 385		 * Generate the tone for the appropriate number of ticks.
 386		 * If the time is zero, turn off sound ourselves.
 387		 */
 388		ticks = msecs_to_jiffies((arg >> 16) & 0xffff);
 389		count = ticks ? (arg & 0xffff) : 0;
 390		if (count)
 391			count = PIT_TICK_RATE / count;
 392		kd_mksound(count, ticks);
 393		break;
 394	}
 395
 396	case KDGKBTYPE:
 397		/*
 398		 * this is naïve.
 399		 */
 400		ucval = KB_101;
 401		ret = put_user(ucval, (char __user *)arg);
 402		break;
 403
 404		/*
 405		 * These cannot be implemented on any machine that implements
 406		 * ioperm() in user level (such as Alpha PCs) or not at all.
 407		 *
 408		 * XXX: you should never use these, just call ioperm directly..
 409		 */
 410#ifdef CONFIG_X86
 411	case KDADDIO:
 412	case KDDELIO:
 413		/*
 414		 * KDADDIO and KDDELIO may be able to add ports beyond what
 415		 * we reject here, but to be safe...
 416		 *
 417		 * These are locked internally via sys_ioperm
 418		 */
 419		if (arg < GPFIRST || arg > GPLAST) {
 420			ret = -EINVAL;
 421			break;
 422		}
 423		ret = ksys_ioperm(arg, 1, (cmd == KDADDIO)) ? -ENXIO : 0;
 424		break;
 425
 426	case KDENABIO:
 427	case KDDISABIO:
 428		ret = ksys_ioperm(GPFIRST, GPNUM,
 429				  (cmd == KDENABIO)) ? -ENXIO : 0;
 430		break;
 431#endif
 432
 433	/* Linux m68k/i386 interface for setting the keyboard delay/repeat rate */
 434		
 435	case KDKBDREP:
 436	{
 437		struct kbd_repeat kbrep;
 438		
 439		if (!capable(CAP_SYS_TTY_CONFIG))
 440			return -EPERM;
 441
 442		if (copy_from_user(&kbrep, up, sizeof(struct kbd_repeat))) {
 443			ret =  -EFAULT;
 444			break;
 445		}
 446		ret = kbd_rate(&kbrep);
 447		if (ret)
 448			break;
 449		if (copy_to_user(up, &kbrep, sizeof(struct kbd_repeat)))
 450			ret = -EFAULT;
 451		break;
 452	}
 453
 454	case KDSETMODE:
 455		/*
 456		 * currently, setting the mode from KD_TEXT to KD_GRAPHICS
 457		 * doesn't do a whole lot. i'm not sure if it should do any
 458		 * restoration of modes or what...
 459		 *
 460		 * XXX It should at least call into the driver, fbdev's definitely
 461		 * need to restore their engine state. --BenH
 462		 */
 463		if (!perm)
 464			return -EPERM;
 465		switch (arg) {
 466		case KD_GRAPHICS:
 467			break;
 468		case KD_TEXT0:
 469		case KD_TEXT1:
 470			arg = KD_TEXT;
 471		case KD_TEXT:
 472			break;
 473		default:
 474			ret = -EINVAL;
 475			goto out;
 476		}
 477		/* FIXME: this needs the console lock extending */
 478		if (vc->vc_mode == (unsigned char) arg)
 479			break;
 480		vc->vc_mode = (unsigned char) arg;
 481		if (console != fg_console)
 482			break;
 483		/*
 484		 * explicitly blank/unblank the screen if switching modes
 485		 */
 486		console_lock();
 487		if (arg == KD_TEXT)
 488			do_unblank_screen(1);
 489		else
 490			do_blank_screen(1);
 491		console_unlock();
 492		break;
 493
 494	case KDGETMODE:
 495		uival = vc->vc_mode;
 496		goto setint;
 497
 498	case KDMAPDISP:
 499	case KDUNMAPDISP:
 500		/*
 501		 * these work like a combination of mmap and KDENABIO.
 502		 * this could be easily finished.
 503		 */
 504		ret = -EINVAL;
 505		break;
 506
 507	case KDSKBMODE:
 508		if (!perm)
 509			return -EPERM;
 510		ret = vt_do_kdskbmode(console, arg);
 511		if (ret == 0)
 512			tty_ldisc_flush(tty);
 
 513		break;
 514
 515	case KDGKBMODE:
 516		uival = vt_do_kdgkbmode(console);
 517		ret = put_user(uival, (int __user *)arg);
 518		break;
 519
 520	/* this could be folded into KDSKBMODE, but for compatibility
 521	   reasons it is not so easy to fold KDGKBMETA into KDGKBMODE */
 522	case KDSKBMETA:
 523		ret = vt_do_kdskbmeta(console, arg);
 524		break;
 525
 526	case KDGKBMETA:
 527		/* FIXME: should review whether this is worth locking */
 528		uival = vt_do_kdgkbmeta(console);
 529	setint:
 530		ret = put_user(uival, (int __user *)arg);
 531		break;
 532
 533	case KDGETKEYCODE:
 534	case KDSETKEYCODE:
 535		if(!capable(CAP_SYS_TTY_CONFIG))
 536			perm = 0;
 537		ret = vt_do_kbkeycode_ioctl(cmd, up, perm);
 538		break;
 539
 540	case KDGKBENT:
 541	case KDSKBENT:
 542		ret = vt_do_kdsk_ioctl(cmd, up, perm, console);
 543		break;
 544
 545	case KDGKBSENT:
 546	case KDSKBSENT:
 547		ret = vt_do_kdgkb_ioctl(cmd, up, perm);
 548		break;
 549
 550	/* Diacritical processing. Handled in keyboard.c as it has
 551	   to operate on the keyboard locks and structures */
 552	case KDGKBDIACR:
 553	case KDGKBDIACRUC:
 554	case KDSKBDIACR:
 555	case KDSKBDIACRUC:
 556		ret = vt_do_diacrit(cmd, up, perm);
 557		break;
 558
 559	/* the ioctls below read/set the flags usually shown in the leds */
 560	/* don't use them - they will go away without warning */
 561	case KDGKBLED:
 562	case KDSKBLED:
 563	case KDGETLED:
 564	case KDSETLED:
 565		ret = vt_do_kdskled(console, cmd, arg, perm);
 566		break;
 567
 568	/*
 569	 * A process can indicate its willingness to accept signals
 570	 * generated by pressing an appropriate key combination.
 571	 * Thus, one can have a daemon that e.g. spawns a new console
 572	 * upon a keypress and then changes to it.
 573	 * See also the kbrequest field of inittab(5).
 574	 */
 575	case KDSIGACCEPT:
 576	{
 577		if (!perm || !capable(CAP_KILL))
 578			return -EPERM;
 579		if (!valid_signal(arg) || arg < 1 || arg == SIGKILL)
 580			ret = -EINVAL;
 581		else {
 582			spin_lock_irq(&vt_spawn_con.lock);
 583			put_pid(vt_spawn_con.pid);
 584			vt_spawn_con.pid = get_pid(task_pid(current));
 585			vt_spawn_con.sig = arg;
 586			spin_unlock_irq(&vt_spawn_con.lock);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 587		}
 588		break;
 589	}
 590
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 591	case VT_SETMODE:
 592	{
 593		struct vt_mode tmp;
 594
 595		if (!perm)
 596			return -EPERM;
 597		if (copy_from_user(&tmp, up, sizeof(struct vt_mode))) {
 598			ret = -EFAULT;
 599			goto out;
 600		}
 601		if (tmp.mode != VT_AUTO && tmp.mode != VT_PROCESS) {
 602			ret = -EINVAL;
 603			goto out;
 604		}
 605		console_lock();
 606		vc->vt_mode = tmp;
 607		/* the frsig is ignored, so we set it to 0 */
 608		vc->vt_mode.frsig = 0;
 609		put_pid(vc->vt_pid);
 610		vc->vt_pid = get_pid(task_pid(current));
 611		/* no switch is required -- saw@shade.msu.ru */
 612		vc->vt_newvt = -1;
 613		console_unlock();
 614		break;
 615	}
 616
 617	case VT_GETMODE:
 618	{
 619		struct vt_mode tmp;
 620		int rc;
 621
 622		console_lock();
 623		memcpy(&tmp, &vc->vt_mode, sizeof(struct vt_mode));
 624		console_unlock();
 625
 626		rc = copy_to_user(up, &tmp, sizeof(struct vt_mode));
 627		if (rc)
 628			ret = -EFAULT;
 629		break;
 630	}
 631
 632	/*
 633	 * Returns global vt state. Note that VT 0 is always open, since
 634	 * it's an alias for the current VT, and people can't use it here.
 635	 * We cannot return state for more than 16 VTs, since v_state is short.
 636	 */
 637	case VT_GETSTATE:
 638	{
 639		struct vt_stat __user *vtstat = up;
 640		unsigned short state, mask;
 641
 642		/* Review: FIXME: Console lock ? */
 643		if (put_user(fg_console + 1, &vtstat->v_active))
 644			ret = -EFAULT;
 645		else {
 646			state = 1;	/* /dev/tty0 is always open */
 647			for (i = 0, mask = 2; i < MAX_NR_CONSOLES && mask;
 648							++i, mask <<= 1)
 649				if (VT_IS_IN_USE(i))
 650					state |= mask;
 651			ret = put_user(state, &vtstat->v_state);
 652		}
 653		break;
 654	}
 655
 656	/*
 657	 * Returns the first available (non-opened) console.
 658	 */
 659	case VT_OPENQRY:
 660		/* FIXME: locking ? - but then this is a stupid API */
 661		for (i = 0; i < MAX_NR_CONSOLES; ++i)
 662			if (! VT_IS_IN_USE(i))
 663				break;
 664		uival = i < MAX_NR_CONSOLES ? (i+1) : -1;
 665		goto setint;		 
 
 666
 667	/*
 668	 * ioctl(fd, VT_ACTIVATE, num) will cause us to switch to vt # num,
 669	 * with num >= 1 (switches to vt 0, our console, are not allowed, just
 670	 * to preserve sanity).
 671	 */
 672	case VT_ACTIVATE:
 673		if (!perm)
 674			return -EPERM;
 675		if (arg == 0 || arg > MAX_NR_CONSOLES)
 676			ret =  -ENXIO;
 677		else {
 678			arg--;
 679			console_lock();
 680			ret = vc_allocate(arg);
 681			console_unlock();
 682			if (ret)
 683				break;
 684			set_console(arg);
 685		}
 686		break;
 687
 688	case VT_SETACTIVATE:
 689	{
 690		struct vt_setactivate vsa;
 691
 692		if (!perm)
 693			return -EPERM;
 694
 695		if (copy_from_user(&vsa, (struct vt_setactivate __user *)arg,
 696					sizeof(struct vt_setactivate))) {
 697			ret = -EFAULT;
 698			goto out;
 699		}
 700		if (vsa.console == 0 || vsa.console > MAX_NR_CONSOLES)
 701			ret = -ENXIO;
 702		else {
 703			vsa.console--;
 704			console_lock();
 705			ret = vc_allocate(vsa.console);
 706			if (ret == 0) {
 707				struct vc_data *nvc;
 708				/* This is safe providing we don't drop the
 709				   console sem between vc_allocate and
 710				   finishing referencing nvc */
 711				nvc = vc_cons[vsa.console].d;
 712				nvc->vt_mode = vsa.mode;
 713				nvc->vt_mode.frsig = 0;
 714				put_pid(nvc->vt_pid);
 715				nvc->vt_pid = get_pid(task_pid(current));
 716			}
 717			console_unlock();
 718			if (ret)
 719				break;
 720			/* Commence switch and lock */
 721			/* Review set_console locks */
 722			set_console(vsa.console);
 723		}
 724		break;
 725	}
 726
 727	/*
 728	 * wait until the specified VT has been activated
 729	 */
 730	case VT_WAITACTIVE:
 731		if (!perm)
 732			return -EPERM;
 733		if (arg == 0 || arg > MAX_NR_CONSOLES)
 734			ret = -ENXIO;
 735		else
 736			ret = vt_waitactive(arg);
 737		break;
 738
 739	/*
 740	 * If a vt is under process control, the kernel will not switch to it
 741	 * immediately, but postpone the operation until the process calls this
 742	 * ioctl, allowing the switch to complete.
 743	 *
 744	 * According to the X sources this is the behavior:
 745	 *	0:	pending switch-from not OK
 746	 *	1:	pending switch-from OK
 747	 *	2:	completed switch-to OK
 748	 */
 749	case VT_RELDISP:
 750		if (!perm)
 751			return -EPERM;
 752
 753		console_lock();
 754		if (vc->vt_mode.mode != VT_PROCESS) {
 755			console_unlock();
 756			ret = -EINVAL;
 757			break;
 758		}
 759		/*
 760		 * Switching-from response
 761		 */
 762		if (vc->vt_newvt >= 0) {
 763			if (arg == 0)
 764				/*
 765				 * Switch disallowed, so forget we were trying
 766				 * to do it.
 767				 */
 768				vc->vt_newvt = -1;
 769
 770			else {
 771				/*
 772				 * The current vt has been released, so
 773				 * complete the switch.
 774				 */
 775				int newvt;
 776				newvt = vc->vt_newvt;
 777				vc->vt_newvt = -1;
 778				ret = vc_allocate(newvt);
 779				if (ret) {
 780					console_unlock();
 781					break;
 782				}
 783				/*
 784				 * When we actually do the console switch,
 785				 * make sure we are atomic with respect to
 786				 * other console switches..
 787				 */
 788				complete_change_console(vc_cons[newvt].d);
 789			}
 790		} else {
 791			/*
 792			 * Switched-to response
 793			 */
 794			/*
 795			 * If it's just an ACK, ignore it
 796			 */
 797			if (arg != VT_ACKACQ)
 798				ret = -EINVAL;
 799		}
 800		console_unlock();
 801		break;
 
 
 802
 803	 /*
 804	  * Disallocate memory associated to VT (but leave VT1)
 805	  */
 806	 case VT_DISALLOCATE:
 807		if (arg > MAX_NR_CONSOLES) {
 808			ret = -ENXIO;
 
 
 
 809			break;
 810		}
 811		if (arg == 0)
 812			vt_disallocate_all();
 813		else
 814			ret = vt_disallocate(--arg);
 815		break;
 816
 817	case VT_RESIZE:
 818	{
 819		struct vt_sizes __user *vtsizes = up;
 820		struct vc_data *vc;
 
 821
 822		ushort ll,cc;
 823		if (!perm)
 824			return -EPERM;
 825		if (get_user(ll, &vtsizes->v_rows) ||
 826		    get_user(cc, &vtsizes->v_cols))
 827			ret = -EFAULT;
 828		else {
 829			console_lock();
 830			for (i = 0; i < MAX_NR_CONSOLES; i++) {
 831				vc = vc_cons[i].d;
 832
 833				if (vc) {
 834					vc->vc_resize_user = 1;
 835					/* FIXME: review v tty lock */
 836					vc_resize(vc_cons[i].d, cc, ll);
 837				}
 838			}
 839			console_unlock();
 840		}
 841		break;
 842	}
 843
 844	case VT_RESIZEX:
 845	{
 846		struct vt_consize v;
 847		if (!perm)
 848			return -EPERM;
 849		if (copy_from_user(&v, up, sizeof(struct vt_consize)))
 850			return -EFAULT;
 851		/* FIXME: Should check the copies properly */
 852		if (!v.v_vlin)
 853			v.v_vlin = vc->vc_scan_lines;
 854		if (v.v_clin) {
 855			int rows = v.v_vlin/v.v_clin;
 856			if (v.v_rows != rows) {
 857				if (v.v_rows) /* Parameters don't add up */
 858					return -EINVAL;
 859				v.v_rows = rows;
 860			}
 861		}
 862		if (v.v_vcol && v.v_ccol) {
 863			int cols = v.v_vcol/v.v_ccol;
 864			if (v.v_cols != cols) {
 865				if (v.v_cols)
 866					return -EINVAL;
 867				v.v_cols = cols;
 868			}
 869		}
 870
 871		if (v.v_clin > 32)
 872			return -EINVAL;
 
 873
 874		for (i = 0; i < MAX_NR_CONSOLES; i++) {
 875			if (!vc_cons[i].d)
 876				continue;
 877			console_lock();
 878			if (v.v_vlin)
 879				vc_cons[i].d->vc_scan_lines = v.v_vlin;
 880			if (v.v_clin)
 881				vc_cons[i].d->vc_font.height = v.v_clin;
 882			vc_cons[i].d->vc_resize_user = 1;
 883			vc_resize(vc_cons[i].d, v.v_cols, v.v_rows);
 884			console_unlock();
 885		}
 886		break;
 887	}
 888
 889	case PIO_FONT: {
 890		if (!perm)
 891			return -EPERM;
 892		op.op = KD_FONT_OP_SET;
 893		op.flags = KD_FONT_FLAG_OLD | KD_FONT_FLAG_DONT_RECALC;	/* Compatibility */
 894		op.width = 8;
 895		op.height = 0;
 896		op.charcount = 256;
 897		op.data = up;
 898		ret = con_font_op(vc_cons[fg_console].d, &op);
 899		break;
 900	}
 901
 902	case GIO_FONT: {
 903		op.op = KD_FONT_OP_GET;
 904		op.flags = KD_FONT_FLAG_OLD;
 905		op.width = 8;
 906		op.height = 32;
 907		op.charcount = 256;
 908		op.data = up;
 909		ret = con_font_op(vc_cons[fg_console].d, &op);
 910		break;
 911	}
 912
 913	case PIO_CMAP:
 914                if (!perm)
 915			ret = -EPERM;
 916		else
 917	                ret = con_set_cmap(up);
 918		break;
 919
 920	case GIO_CMAP:
 921                ret = con_get_cmap(up);
 922		break;
 923
 924	case PIO_FONTX:
 925	case GIO_FONTX:
 926		ret = do_fontx_ioctl(cmd, up, perm, &op);
 927		break;
 928
 929	case PIO_FONTRESET:
 930	{
 931		if (!perm)
 932			return -EPERM;
 933
 934#ifdef BROKEN_GRAPHICS_PROGRAMS
 935		/* With BROKEN_GRAPHICS_PROGRAMS defined, the default
 936		   font is not saved. */
 937		ret = -ENOSYS;
 938		break;
 939#else
 940		{
 941		op.op = KD_FONT_OP_SET_DEFAULT;
 942		op.data = NULL;
 943		ret = con_font_op(vc_cons[fg_console].d, &op);
 944		if (ret)
 945			break;
 946		console_lock();
 947		con_set_default_unimap(vc_cons[fg_console].d);
 948		console_unlock();
 949		break;
 950		}
 951#endif
 952	}
 953
 954	case KDFONTOP: {
 955		if (copy_from_user(&op, up, sizeof(op))) {
 956			ret = -EFAULT;
 957			break;
 958		}
 959		if (!perm && op.op != KD_FONT_OP_GET)
 960			return -EPERM;
 961		ret = con_font_op(vc, &op);
 962		if (ret)
 963			break;
 964		if (copy_to_user(up, &op, sizeof(op)))
 965			ret = -EFAULT;
 966		break;
 967	}
 968
 969	case PIO_SCRNMAP:
 970		if (!perm)
 971			ret = -EPERM;
 972		else
 973			ret = con_set_trans_old(up);
 974		break;
 975
 976	case GIO_SCRNMAP:
 977		ret = con_get_trans_old(up);
 978		break;
 979
 980	case PIO_UNISCRNMAP:
 981		if (!perm)
 982			ret = -EPERM;
 983		else
 984			ret = con_set_trans_new(up);
 985		break;
 986
 987	case GIO_UNISCRNMAP:
 988		ret = con_get_trans_new(up);
 989		break;
 990
 991	case PIO_UNIMAPCLR:
 992		if (!perm)
 993			return -EPERM;
 994		con_clear_unimap(vc);
 995		break;
 996
 997	case PIO_UNIMAP:
 998	case GIO_UNIMAP:
 999		ret = do_unimap_ioctl(cmd, up, perm, vc);
1000		break;
1001
1002	case VT_LOCKSWITCH:
1003		if (!capable(CAP_SYS_TTY_CONFIG))
1004			return -EPERM;
1005		vt_dont_switch = 1;
1006		break;
1007	case VT_UNLOCKSWITCH:
1008		if (!capable(CAP_SYS_TTY_CONFIG))
1009			return -EPERM;
1010		vt_dont_switch = 0;
1011		break;
1012	case VT_GETHIFONTMASK:
1013		ret = put_user(vc->vc_hi_font_mask,
1014					(unsigned short __user *)arg);
1015		break;
1016	case VT_WAITEVENT:
1017		ret = vt_event_wait_ioctl((struct vt_event __user *)arg);
1018		break;
1019	default:
1020		ret = -ENOIOCTLCMD;
1021	}
1022out:
1023	return ret;
1024}
1025
1026void reset_vc(struct vc_data *vc)
1027{
1028	vc->vc_mode = KD_TEXT;
1029	vt_reset_unicode(vc->vc_num);
1030	vc->vt_mode.mode = VT_AUTO;
1031	vc->vt_mode.waitv = 0;
1032	vc->vt_mode.relsig = 0;
1033	vc->vt_mode.acqsig = 0;
1034	vc->vt_mode.frsig = 0;
1035	put_pid(vc->vt_pid);
1036	vc->vt_pid = NULL;
1037	vc->vt_newvt = -1;
1038	if (!in_interrupt())    /* Via keyboard.c:SAK() - akpm */
1039		reset_palette(vc);
1040}
1041
1042void vc_SAK(struct work_struct *work)
1043{
1044	struct vc *vc_con =
1045		container_of(work, struct vc, SAK_work);
1046	struct vc_data *vc;
1047	struct tty_struct *tty;
1048
1049	console_lock();
1050	vc = vc_con->d;
1051	if (vc) {
1052		/* FIXME: review tty ref counting */
1053		tty = vc->port.tty;
1054		/*
1055		 * SAK should also work in all raw modes and reset
1056		 * them properly.
1057		 */
1058		if (tty)
1059			__do_SAK(tty);
1060		reset_vc(vc);
1061	}
1062	console_unlock();
1063}
1064
1065#ifdef CONFIG_COMPAT
1066
1067struct compat_consolefontdesc {
1068	unsigned short charcount;       /* characters in font (256 or 512) */
1069	unsigned short charheight;      /* scan lines per character (1-32) */
1070	compat_caddr_t chardata;	/* font data in expanded form */
1071};
1072
1073static inline int
1074compat_fontx_ioctl(int cmd, struct compat_consolefontdesc __user *user_cfd,
1075			 int perm, struct console_font_op *op)
1076{
1077	struct compat_consolefontdesc cfdarg;
1078	int i;
1079
1080	if (copy_from_user(&cfdarg, user_cfd, sizeof(struct compat_consolefontdesc)))
1081		return -EFAULT;
1082
1083	switch (cmd) {
1084	case PIO_FONTX:
1085		if (!perm)
1086			return -EPERM;
1087		op->op = KD_FONT_OP_SET;
1088		op->flags = KD_FONT_FLAG_OLD;
1089		op->width = 8;
1090		op->height = cfdarg.charheight;
1091		op->charcount = cfdarg.charcount;
1092		op->data = compat_ptr(cfdarg.chardata);
1093		return con_font_op(vc_cons[fg_console].d, op);
1094	case GIO_FONTX:
1095		op->op = KD_FONT_OP_GET;
1096		op->flags = KD_FONT_FLAG_OLD;
1097		op->width = 8;
1098		op->height = cfdarg.charheight;
1099		op->charcount = cfdarg.charcount;
1100		op->data = compat_ptr(cfdarg.chardata);
1101		i = con_font_op(vc_cons[fg_console].d, op);
1102		if (i)
1103			return i;
1104		cfdarg.charheight = op->height;
1105		cfdarg.charcount = op->charcount;
1106		if (copy_to_user(user_cfd, &cfdarg, sizeof(struct compat_consolefontdesc)))
1107			return -EFAULT;
1108		return 0;
1109	}
1110	return -EINVAL;
1111}
1112
1113struct compat_console_font_op {
1114	compat_uint_t op;        /* operation code KD_FONT_OP_* */
1115	compat_uint_t flags;     /* KD_FONT_FLAG_* */
1116	compat_uint_t width, height;     /* font size */
1117	compat_uint_t charcount;
1118	compat_caddr_t data;    /* font data with height fixed to 32 */
1119};
1120
1121static inline int
1122compat_kdfontop_ioctl(struct compat_console_font_op __user *fontop,
1123			 int perm, struct console_font_op *op, struct vc_data *vc)
1124{
1125	int i;
1126
1127	if (copy_from_user(op, fontop, sizeof(struct compat_console_font_op)))
1128		return -EFAULT;
1129	if (!perm && op->op != KD_FONT_OP_GET)
1130		return -EPERM;
1131	op->data = compat_ptr(((struct compat_console_font_op *)op)->data);
1132	i = con_font_op(vc, op);
1133	if (i)
1134		return i;
1135	((struct compat_console_font_op *)op)->data = (unsigned long)op->data;
1136	if (copy_to_user(fontop, op, sizeof(struct compat_console_font_op)))
1137		return -EFAULT;
1138	return 0;
1139}
1140
1141struct compat_unimapdesc {
1142	unsigned short entry_ct;
1143	compat_caddr_t entries;
1144};
1145
1146static inline int
1147compat_unimap_ioctl(unsigned int cmd, struct compat_unimapdesc __user *user_ud,
1148			 int perm, struct vc_data *vc)
1149{
1150	struct compat_unimapdesc tmp;
1151	struct unipair __user *tmp_entries;
1152
1153	if (copy_from_user(&tmp, user_ud, sizeof tmp))
1154		return -EFAULT;
1155	tmp_entries = compat_ptr(tmp.entries);
1156	switch (cmd) {
1157	case PIO_UNIMAP:
1158		if (!perm)
1159			return -EPERM;
1160		return con_set_unimap(vc, tmp.entry_ct, tmp_entries);
1161	case GIO_UNIMAP:
1162		if (!perm && fg_console != vc->vc_num)
1163			return -EPERM;
1164		return con_get_unimap(vc, tmp.entry_ct, &(user_ud->entry_ct), tmp_entries);
1165	}
1166	return 0;
1167}
1168
1169long vt_compat_ioctl(struct tty_struct *tty,
1170	     unsigned int cmd, unsigned long arg)
1171{
1172	struct vc_data *vc = tty->driver_data;
1173	struct console_font_op op;	/* used in multiple places here */
1174	unsigned int console;
1175	void __user *up = (void __user *)arg;
1176	int perm;
1177	int ret = 0;
1178
1179	console = vc->vc_num;
1180
1181	if (!vc_cons_allocated(console)) { 	/* impossible? */
1182		ret = -ENOIOCTLCMD;
1183		goto out;
1184	}
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		ret = compat_fontx_ioctl(cmd, up, perm, &op);
1201		break;
1202
1203	case KDFONTOP:
1204		ret = compat_kdfontop_ioctl(up, perm, &op, vc);
1205		break;
1206
1207	case PIO_UNIMAP:
1208	case GIO_UNIMAP:
1209		ret = compat_unimap_ioctl(cmd, up, perm, vc);
1210		break;
1211
1212	/*
1213	 * all these treat 'arg' as an integer
1214	 */
1215	case KIOCSOUND:
1216	case KDMKTONE:
1217#ifdef CONFIG_X86
1218	case KDADDIO:
1219	case KDDELIO:
1220#endif
1221	case KDSETMODE:
1222	case KDMAPDISP:
1223	case KDUNMAPDISP:
1224	case KDSKBMODE:
1225	case KDSKBMETA:
1226	case KDSKBLED:
1227	case KDSETLED:
1228	case KDSIGACCEPT:
1229	case VT_ACTIVATE:
1230	case VT_WAITACTIVE:
1231	case VT_RELDISP:
1232	case VT_DISALLOCATE:
1233	case VT_RESIZE:
1234	case VT_RESIZEX:
1235		goto fallback;
1236
1237	/*
1238	 * the rest has a compatible data structure behind arg,
1239	 * but we have to convert it to a proper 64 bit pointer.
1240	 */
1241	default:
1242		arg = (unsigned long)compat_ptr(arg);
1243		goto fallback;
1244	}
1245out:
1246	return ret;
1247
1248fallback:
1249	return vt_ioctl(tty, cmd, arg);
1250}
1251
1252
1253#endif /* CONFIG_COMPAT */
1254
1255
1256/*
1257 * Performs the back end of a vt switch. Called under the console
1258 * semaphore.
1259 */
1260static void complete_change_console(struct vc_data *vc)
1261{
1262	unsigned char old_vc_mode;
1263	int old = fg_console;
1264
1265	last_console = fg_console;
1266
1267	/*
1268	 * If we're switching, we could be going from KD_GRAPHICS to
1269	 * KD_TEXT mode or vice versa, which means we need to blank or
1270	 * unblank the screen later.
1271	 */
1272	old_vc_mode = vc_cons[fg_console].d->vc_mode;
1273	switch_screen(vc);
1274
1275	/*
1276	 * This can't appear below a successful kill_pid().  If it did,
1277	 * then the *blank_screen operation could occur while X, having
1278	 * received acqsig, is waking up on another processor.  This
1279	 * condition can lead to overlapping accesses to the VGA range
1280	 * and the framebuffer (causing system lockups).
1281	 *
1282	 * To account for this we duplicate this code below only if the
1283	 * controlling process is gone and we've called reset_vc.
1284	 */
1285	if (old_vc_mode != vc->vc_mode) {
1286		if (vc->vc_mode == KD_TEXT)
1287			do_unblank_screen(1);
1288		else
1289			do_blank_screen(1);
1290	}
1291
1292	/*
1293	 * If this new console is under process control, send it a signal
1294	 * telling it that it has acquired. Also check if it has died and
1295	 * clean up (similar to logic employed in change_console())
1296	 */
1297	if (vc->vt_mode.mode == VT_PROCESS) {
1298		/*
1299		 * Send the signal as privileged - kill_pid() will
1300		 * tell us if the process has gone or something else
1301		 * is awry
1302		 */
1303		if (kill_pid(vc->vt_pid, vc->vt_mode.acqsig, 1) != 0) {
1304		/*
1305		 * The controlling process has died, so we revert back to
1306		 * normal operation. In this case, we'll also change back
1307		 * to KD_TEXT mode. I'm not sure if this is strictly correct
1308		 * but it saves the agony when the X server dies and the screen
1309		 * remains blanked due to KD_GRAPHICS! It would be nice to do
1310		 * this outside of VT_PROCESS but there is no single process
1311		 * to account for and tracking tty count may be undesirable.
1312		 */
1313			reset_vc(vc);
1314
1315			if (old_vc_mode != vc->vc_mode) {
1316				if (vc->vc_mode == KD_TEXT)
1317					do_unblank_screen(1);
1318				else
1319					do_blank_screen(1);
1320			}
1321		}
1322	}
1323
1324	/*
1325	 * Wake anyone waiting for their VT to activate
1326	 */
1327	vt_event_post(VT_EVENT_SWITCH, old, vc->vc_num);
1328	return;
1329}
1330
1331/*
1332 * Performs the front-end of a vt switch
1333 */
1334void change_console(struct vc_data *new_vc)
1335{
1336	struct vc_data *vc;
1337
1338	if (!new_vc || new_vc->vc_num == fg_console || vt_dont_switch)
1339		return;
1340
1341	/*
1342	 * If this vt is in process mode, then we need to handshake with
1343	 * that process before switching. Essentially, we store where that
1344	 * vt wants to switch to and wait for it to tell us when it's done
1345	 * (via VT_RELDISP ioctl).
1346	 *
1347	 * We also check to see if the controlling process still exists.
1348	 * If it doesn't, we reset this vt to auto mode and continue.
1349	 * This is a cheap way to track process control. The worst thing
1350	 * that can happen is: we send a signal to a process, it dies, and
1351	 * the switch gets "lost" waiting for a response; hopefully, the
1352	 * user will try again, we'll detect the process is gone (unless
1353	 * the user waits just the right amount of time :-) and revert the
1354	 * vt to auto control.
1355	 */
1356	vc = vc_cons[fg_console].d;
1357	if (vc->vt_mode.mode == VT_PROCESS) {
1358		/*
1359		 * Send the signal as privileged - kill_pid() will
1360		 * tell us if the process has gone or something else
1361		 * is awry.
1362		 *
1363		 * We need to set vt_newvt *before* sending the signal or we
1364		 * have a race.
1365		 */
1366		vc->vt_newvt = new_vc->vc_num;
1367		if (kill_pid(vc->vt_pid, vc->vt_mode.relsig, 1) == 0) {
1368			/*
1369			 * It worked. Mark the vt to switch to and
1370			 * return. The process needs to send us a
1371			 * VT_RELDISP ioctl to complete the switch.
1372			 */
1373			return;
1374		}
1375
1376		/*
1377		 * The controlling process has died, so we revert back to
1378		 * normal operation. In this case, we'll also change back
1379		 * to KD_TEXT mode. I'm not sure if this is strictly correct
1380		 * but it saves the agony when the X server dies and the screen
1381		 * remains blanked due to KD_GRAPHICS! It would be nice to do
1382		 * this outside of VT_PROCESS but there is no single process
1383		 * to account for and tracking tty count may be undesirable.
1384		 */
1385		reset_vc(vc);
1386
1387		/*
1388		 * Fall through to normal (VT_AUTO) handling of the switch...
1389		 */
1390	}
1391
1392	/*
1393	 * Ignore all switches in KD_GRAPHICS+VT_AUTO mode
1394	 */
1395	if (vc->vc_mode == KD_GRAPHICS)
1396		return;
1397
1398	complete_change_console(new_vc);
1399}
1400
1401/* Perform a kernel triggered VT switch for suspend/resume */
1402
1403static int disable_vt_switch;
1404
1405int vt_move_to_console(unsigned int vt, int alloc)
1406{
1407	int prev;
1408
1409	console_lock();
1410	/* Graphics mode - up to X */
1411	if (disable_vt_switch) {
1412		console_unlock();
1413		return 0;
1414	}
1415	prev = fg_console;
1416
1417	if (alloc && vc_allocate(vt)) {
1418		/* we can't have a free VC for now. Too bad,
1419		 * we don't want to mess the screen for now. */
1420		console_unlock();
1421		return -ENOSPC;
1422	}
1423
1424	if (set_console(vt)) {
1425		/*
1426		 * We're unable to switch to the SUSPEND_CONSOLE.
1427		 * Let the calling function know so it can decide
1428		 * what to do.
1429		 */
1430		console_unlock();
1431		return -EIO;
1432	}
1433	console_unlock();
1434	if (vt_waitactive(vt + 1)) {
1435		pr_debug("Suspend: Can't switch VCs.");
1436		return -EINTR;
1437	}
1438	return prev;
1439}
1440
1441/*
1442 * Normally during a suspend, we allocate a new console and switch to it.
1443 * When we resume, we switch back to the original console.  This switch
1444 * can be slow, so on systems where the framebuffer can handle restoration
1445 * of video registers anyways, there's little point in doing the console
1446 * switch.  This function allows you to disable it by passing it '0'.
1447 */
1448void pm_set_vt_switch(int do_switch)
1449{
1450	console_lock();
1451	disable_vt_switch = !do_switch;
1452	console_unlock();
1453}
1454EXPORT_SYMBOL(pm_set_vt_switch);