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/suspend.h>
29#include <linux/timex.h>
30
31#include <asm/io.h>
32#include <asm/uaccess.h>
33
34#include <linux/kbd_kern.h>
35#include <linux/vt_kern.h>
36#include <linux/kbd_diacr.h>
37#include <linux/selection.h>
38
39char vt_dont_switch;
40extern struct tty_driver *console_driver;
41
42#define VT_IS_IN_USE(i)	(console_driver->ttys[i] && console_driver->ttys[i]->count)
43#define VT_BUSY(i)	(VT_IS_IN_USE(i) || i == fg_console || vc_cons[i].d == sel_cons)
44
45/*
46 * Console (vt and kd) routines, as defined by USL SVR4 manual, and by
47 * experimentation and study of X386 SYSV handling.
48 *
49 * One point of difference: SYSV vt's are /dev/vtX, which X >= 0, and
50 * /dev/console is a separate ttyp. Under Linux, /dev/tty0 is /dev/console,
51 * and the vc start at /dev/ttyX, X >= 1. We maintain that here, so we will
52 * always treat our set of vt as numbered 1..MAX_NR_CONSOLES (corresponding to
53 * ttys 0..MAX_NR_CONSOLES-1). Explicitly naming VT 0 is illegal, but using
54 * /dev/tty0 (fg_console) as a target is legal, since an implicit aliasing
55 * to the current console is done by the main ioctl code.
56 */
57
58#ifdef CONFIG_X86
59#include <linux/syscalls.h>
60#endif
61
62static void complete_change_console(struct vc_data *vc);
63
64/*
65 *	User space VT_EVENT handlers
66 */
67
68struct vt_event_wait {
69	struct list_head list;
70	struct vt_event event;
71	int done;
72};
73
74static LIST_HEAD(vt_events);
75static DEFINE_SPINLOCK(vt_event_lock);
76static DECLARE_WAIT_QUEUE_HEAD(vt_event_waitqueue);
77
78/**
79 *	vt_event_post
80 *	@event: the event that occurred
81 *	@old: old console
82 *	@new: new console
83 *
84 *	Post an VT event to interested VT handlers
85 */
86
87void vt_event_post(unsigned int event, unsigned int old, unsigned int new)
88{
89	struct list_head *pos, *head;
90	unsigned long flags;
91	int wake = 0;
92
93	spin_lock_irqsave(&vt_event_lock, flags);
94	head = &vt_events;
95
96	list_for_each(pos, head) {
97		struct vt_event_wait *ve = list_entry(pos,
98						struct vt_event_wait, list);
99		if (!(ve->event.event & event))
100			continue;
101		ve->event.event = event;
102		/* kernel view is consoles 0..n-1, user space view is
103		   console 1..n with 0 meaning current, so we must bias */
104		ve->event.oldev = old + 1;
105		ve->event.newev = new + 1;
106		wake = 1;
107		ve->done = 1;
108	}
109	spin_unlock_irqrestore(&vt_event_lock, flags);
110	if (wake)
111		wake_up_interruptible(&vt_event_waitqueue);
112}
113
114static void __vt_event_queue(struct vt_event_wait *vw)
115{
116	unsigned long flags;
117	/* Prepare the event */
118	INIT_LIST_HEAD(&vw->list);
119	vw->done = 0;
120	/* Queue our event */
121	spin_lock_irqsave(&vt_event_lock, flags);
122	list_add(&vw->list, &vt_events);
123	spin_unlock_irqrestore(&vt_event_lock, flags);
124}
125
126static void __vt_event_wait(struct vt_event_wait *vw)
127{
128	/* Wait for it to pass */
129	wait_event_interruptible(vt_event_waitqueue, vw->done);
130}
131
132static void __vt_event_dequeue(struct vt_event_wait *vw)
133{
134	unsigned long flags;
135
136	/* Dequeue it */
137	spin_lock_irqsave(&vt_event_lock, flags);
138	list_del(&vw->list);
139	spin_unlock_irqrestore(&vt_event_lock, flags);
140}
141
142/**
143 *	vt_event_wait		-	wait for an event
144 *	@vw: our event
145 *
146 *	Waits for an event to occur which completes our vt_event_wait
147 *	structure. On return the structure has wv->done set to 1 for success
148 *	or 0 if some event such as a signal ended the wait.
149 */
150
151static void vt_event_wait(struct vt_event_wait *vw)
152{
153	__vt_event_queue(vw);
154	__vt_event_wait(vw);
155	__vt_event_dequeue(vw);
156}
157
158/**
159 *	vt_event_wait_ioctl	-	event ioctl handler
160 *	@arg: argument to ioctl
161 *
162 *	Implement the VT_WAITEVENT ioctl using the VT event interface
163 */
164
165static int vt_event_wait_ioctl(struct vt_event __user *event)
166{
167	struct vt_event_wait vw;
168
169	if (copy_from_user(&vw.event, event, sizeof(struct vt_event)))
170		return -EFAULT;
171	/* Highest supported event for now */
172	if (vw.event.event & ~VT_MAX_EVENT)
173		return -EINVAL;
174
175	vt_event_wait(&vw);
176	/* If it occurred report it */
177	if (vw.done) {
178		if (copy_to_user(event, &vw.event, sizeof(struct vt_event)))
179			return -EFAULT;
180		return 0;
181	}
182	return -EINTR;
183}
184
185/**
186 *	vt_waitactive	-	active console wait
187 *	@event: event code
188 *	@n: new console
189 *
190 *	Helper for event waits. Used to implement the legacy
191 *	event waiting ioctls in terms of events
192 */
193
194int vt_waitactive(int n)
195{
196	struct vt_event_wait vw;
197	do {
198		vw.event.event = VT_EVENT_SWITCH;
199		__vt_event_queue(&vw);
200		if (n == fg_console + 1) {
201			__vt_event_dequeue(&vw);
202			break;
203		}
204		__vt_event_wait(&vw);
205		__vt_event_dequeue(&vw);
206		if (vw.done == 0)
207			return -EINTR;
208	} while (vw.event.newev != n);
209	return 0;
210}
211
212/*
213 * these are the valid i/o ports we're allowed to change. they map all the
214 * video ports
215 */
216#define GPFIRST 0x3b4
217#define GPLAST 0x3df
218#define GPNUM (GPLAST - GPFIRST + 1)
219
220
221
222static inline int
223do_fontx_ioctl(int cmd, struct consolefontdesc __user *user_cfd, int perm, struct console_font_op *op)
224{
225	struct consolefontdesc cfdarg;
226	int i;
227
228	if (copy_from_user(&cfdarg, user_cfd, sizeof(struct consolefontdesc)))
229		return -EFAULT;
230
231	switch (cmd) {
232	case PIO_FONTX:
233		if (!perm)
234			return -EPERM;
235		op->op = KD_FONT_OP_SET;
236		op->flags = KD_FONT_FLAG_OLD;
237		op->width = 8;
238		op->height = cfdarg.charheight;
239		op->charcount = cfdarg.charcount;
240		op->data = cfdarg.chardata;
241		return con_font_op(vc_cons[fg_console].d, op);
242	case GIO_FONTX: {
243		op->op = KD_FONT_OP_GET;
244		op->flags = KD_FONT_FLAG_OLD;
245		op->width = 8;
246		op->height = cfdarg.charheight;
247		op->charcount = cfdarg.charcount;
248		op->data = cfdarg.chardata;
249		i = con_font_op(vc_cons[fg_console].d, op);
250		if (i)
251			return i;
252		cfdarg.charheight = op->height;
253		cfdarg.charcount = op->charcount;
254		if (copy_to_user(user_cfd, &cfdarg, sizeof(struct consolefontdesc)))
255			return -EFAULT;
256		return 0;
257		}
258	}
259	return -EINVAL;
260}
261
262static inline int
263do_unimap_ioctl(int cmd, struct unimapdesc __user *user_ud, int perm, struct vc_data *vc)
264{
265	struct unimapdesc tmp;
266
267	if (copy_from_user(&tmp, user_ud, sizeof tmp))
268		return -EFAULT;
269	if (tmp.entries)
270		if (!access_ok(VERIFY_WRITE, tmp.entries,
271				tmp.entry_ct*sizeof(struct unipair)))
272			return -EFAULT;
273	switch (cmd) {
274	case PIO_UNIMAP:
275		if (!perm)
276			return -EPERM;
277		return con_set_unimap(vc, tmp.entry_ct, tmp.entries);
278	case GIO_UNIMAP:
279		if (!perm && fg_console != vc->vc_num)
280			return -EPERM;
281		return con_get_unimap(vc, tmp.entry_ct, &(user_ud->entry_ct), tmp.entries);
282	}
283	return 0;
284}
285
286/* deallocate a single console, if possible (leave 0) */
287static int vt_disallocate(unsigned int vc_num)
288{
289	struct vc_data *vc = NULL;
290	int ret = 0;
291
292	console_lock();
293	if (VT_BUSY(vc_num))
294		ret = -EBUSY;
295	else if (vc_num)
296		vc = vc_deallocate(vc_num);
297	console_unlock();
298
299	if (vc && vc_num >= MIN_NR_CONSOLES) {
300		tty_port_destroy(&vc->port);
301		kfree(vc);
302	}
303
304	return ret;
305}
306
307/* deallocate all unused consoles, but leave 0 */
308static void vt_disallocate_all(void)
309{
310	struct vc_data *vc[MAX_NR_CONSOLES];
311	int i;
312
313	console_lock();
314	for (i = 1; i < MAX_NR_CONSOLES; i++)
315		if (!VT_BUSY(i))
316			vc[i] = vc_deallocate(i);
317		else
318			vc[i] = NULL;
319	console_unlock();
320
321	for (i = 1; i < MAX_NR_CONSOLES; i++) {
322		if (vc[i] && i >= MIN_NR_CONSOLES) {
323			tty_port_destroy(&vc[i]->port);
324			kfree(vc[i]);
325		}
326	}
327}
328
329
330/*
331 * We handle the console-specific ioctl's here.  We allow the
332 * capability to modify any console, not just the fg_console.
333 */
334int vt_ioctl(struct tty_struct *tty,
335	     unsigned int cmd, unsigned long arg)
336{
337	struct vc_data *vc = tty->driver_data;
338	struct console_font_op op;	/* used in multiple places here */
339	unsigned int console;
340	unsigned char ucval;
341	unsigned int uival;
342	void __user *up = (void __user *)arg;
343	int i, perm;
344	int ret = 0;
345
346	console = vc->vc_num;
347
348
349	if (!vc_cons_allocated(console)) { 	/* impossible? */
350		ret = -ENOIOCTLCMD;
351		goto out;
352	}
353
354
355	/*
356	 * To have permissions to do most of the vt ioctls, we either have
357	 * to be the owner of the tty, or have CAP_SYS_TTY_CONFIG.
358	 */
359	perm = 0;
360	if (current->signal->tty == tty || capable(CAP_SYS_TTY_CONFIG))
361		perm = 1;
362
363	switch (cmd) {
364	case TIOCLINUX:
365		ret = tioclinux(tty, arg);
366		break;
367	case KIOCSOUND:
368		if (!perm)
369			return -EPERM;
370		/*
371		 * The use of PIT_TICK_RATE is historic, it used to be
372		 * the platform-dependent CLOCK_TICK_RATE between 2.6.12
373		 * and 2.6.36, which was a minor but unfortunate ABI
374		 * change. kd_mksound is locked by the input layer.
375		 */
376		if (arg)
377			arg = PIT_TICK_RATE / arg;
378		kd_mksound(arg, 0);
379		break;
380
381	case KDMKTONE:
382		if (!perm)
383			return -EPERM;
384	{
385		unsigned int ticks, count;
386
387		/*
388		 * Generate the tone for the appropriate number of ticks.
389		 * If the time is zero, turn off sound ourselves.
390		 */
391		ticks = msecs_to_jiffies((arg >> 16) & 0xffff);
392		count = ticks ? (arg & 0xffff) : 0;
393		if (count)
394			count = PIT_TICK_RATE / count;
395		kd_mksound(count, ticks);
396		break;
397	}
398
399	case KDGKBTYPE:
400		/*
401		 * this is na��ve.
402		 */
403		ucval = KB_101;
404		ret = put_user(ucval, (char __user *)arg);
405		break;
406
407		/*
408		 * These cannot be implemented on any machine that implements
409		 * ioperm() in user level (such as Alpha PCs) or not at all.
410		 *
411		 * XXX: you should never use these, just call ioperm directly..
412		 */
413#ifdef CONFIG_X86
414	case KDADDIO:
415	case KDDELIO:
416		/*
417		 * KDADDIO and KDDELIO may be able to add ports beyond what
418		 * we reject here, but to be safe...
419		 *
420		 * These are locked internally via sys_ioperm
421		 */
422		if (arg < GPFIRST || arg > GPLAST) {
423			ret = -EINVAL;
424			break;
425		}
426		ret = sys_ioperm(arg, 1, (cmd == KDADDIO)) ? -ENXIO : 0;
427		break;
428
429	case KDENABIO:
430	case KDDISABIO:
431		ret = sys_ioperm(GPFIRST, GPNUM,
432				  (cmd == KDENABIO)) ? -ENXIO : 0;
433		break;
434#endif
435
436	/* Linux m68k/i386 interface for setting the keyboard delay/repeat rate */
437
438	case KDKBDREP:
439	{
440		struct kbd_repeat kbrep;
441
442		if (!capable(CAP_SYS_TTY_CONFIG))
443			return -EPERM;
444
445		if (copy_from_user(&kbrep, up, sizeof(struct kbd_repeat))) {
446			ret =  -EFAULT;
447			break;
448		}
449		ret = kbd_rate(&kbrep);
450		if (ret)
451			break;
452		if (copy_to_user(up, &kbrep, sizeof(struct kbd_repeat)))
453			ret = -EFAULT;
454		break;
455	}
456
457	case KDSETMODE:
458		/*
459		 * currently, setting the mode from KD_TEXT to KD_GRAPHICS
460		 * doesn't do a whole lot. i'm not sure if it should do any
461		 * restoration of modes or what...
462		 *
463		 * XXX It should at least call into the driver, fbdev's definitely
464		 * need to restore their engine state. --BenH
465		 */
466		if (!perm)
467			return -EPERM;
468		switch (arg) {
469		case KD_GRAPHICS:
470			break;
471		case KD_TEXT0:
472		case KD_TEXT1:
473			arg = KD_TEXT;
474		case KD_TEXT:
475			break;
476		default:
477			ret = -EINVAL;
478			goto out;
479		}
480		/* FIXME: this needs the console lock extending */
481		if (vc->vc_mode == (unsigned char) arg)
482			break;
483		vc->vc_mode = (unsigned char) arg;
484		if (console != fg_console)
485			break;
486		/*
487		 * explicitly blank/unblank the screen if switching modes
488		 */
489		console_lock();
490		if (arg == KD_TEXT)
491			do_unblank_screen(1);
492		else
493			do_blank_screen(1);
494		console_unlock();
495		break;
496
497	case KDGETMODE:
498		uival = vc->vc_mode;
499		goto setint;
500
501	case KDMAPDISP:
502	case KDUNMAPDISP:
503		/*
504		 * these work like a combination of mmap and KDENABIO.
505		 * this could be easily finished.
506		 */
507		ret = -EINVAL;
508		break;
509
510	case KDSKBMODE:
511		if (!perm)
512			return -EPERM;
513		ret = vt_do_kdskbmode(console, arg);
514		if (ret == 0)
515			tty_ldisc_flush(tty);
516		break;
517
518	case KDGKBMODE:
519		uival = vt_do_kdgkbmode(console);
520		ret = put_user(uival, (int __user *)arg);
521		break;
522
523	/* this could be folded into KDSKBMODE, but for compatibility
524	   reasons it is not so easy to fold KDGKBMETA into KDGKBMODE */
525	case KDSKBMETA:
526		ret = vt_do_kdskbmeta(console, arg);
527		break;
528
529	case KDGKBMETA:
530		/* FIXME: should review whether this is worth locking */
531		uival = vt_do_kdgkbmeta(console);
532	setint:
533		ret = put_user(uival, (int __user *)arg);
534		break;
535
536	case KDGETKEYCODE:
537	case KDSETKEYCODE:
538		if(!capable(CAP_SYS_TTY_CONFIG))
539			perm = 0;
540		ret = vt_do_kbkeycode_ioctl(cmd, up, perm);
541		break;
542
543	case KDGKBENT:
544	case KDSKBENT:
545		ret = vt_do_kdsk_ioctl(cmd, up, perm, console);
546		break;
547
548	case KDGKBSENT:
549	case KDSKBSENT:
550		ret = vt_do_kdgkb_ioctl(cmd, up, perm);
551		break;
552
553	/* Diacritical processing. Handled in keyboard.c as it has
554	   to operate on the keyboard locks and structures */
555	case KDGKBDIACR:
556	case KDGKBDIACRUC:
557	case KDSKBDIACR:
558	case KDSKBDIACRUC:
559		ret = vt_do_diacrit(cmd, up, perm);
560		break;
561
562	/* the ioctls below read/set the flags usually shown in the leds */
563	/* don't use them - they will go away without warning */
564	case KDGKBLED:
565	case KDSKBLED:
566	case KDGETLED:
567	case KDSETLED:
568		ret = vt_do_kdskled(console, cmd, arg, perm);
569		break;
570
571	/*
572	 * A process can indicate its willingness to accept signals
573	 * generated by pressing an appropriate key combination.
574	 * Thus, one can have a daemon that e.g. spawns a new console
575	 * upon a keypress and then changes to it.
576	 * See also the kbrequest field of inittab(5).
577	 */
578	case KDSIGACCEPT:
579	{
580		if (!perm || !capable(CAP_KILL))
581			return -EPERM;
582		if (!valid_signal(arg) || arg < 1 || arg == SIGKILL)
583			ret = -EINVAL;
584		else {
585			spin_lock_irq(&vt_spawn_con.lock);
586			put_pid(vt_spawn_con.pid);
587			vt_spawn_con.pid = get_pid(task_pid(current));
588			vt_spawn_con.sig = arg;
589			spin_unlock_irq(&vt_spawn_con.lock);
590		}
591		break;
592	}
593
594	case VT_SETMODE:
595	{
596		struct vt_mode tmp;
597
598		if (!perm)
599			return -EPERM;
600		if (copy_from_user(&tmp, up, sizeof(struct vt_mode))) {
601			ret = -EFAULT;
602			goto out;
603		}
604		if (tmp.mode != VT_AUTO && tmp.mode != VT_PROCESS) {
605			ret = -EINVAL;
606			goto out;
607		}
608		console_lock();
609		vc->vt_mode = tmp;
610		/* the frsig is ignored, so we set it to 0 */
611		vc->vt_mode.frsig = 0;
612		put_pid(vc->vt_pid);
613		vc->vt_pid = get_pid(task_pid(current));
614		/* no switch is required -- saw@shade.msu.ru */
615		vc->vt_newvt = -1;
616		console_unlock();
617		break;
618	}
619
620	case VT_GETMODE:
621	{
622		struct vt_mode tmp;
623		int rc;
624
625		console_lock();
626		memcpy(&tmp, &vc->vt_mode, sizeof(struct vt_mode));
627		console_unlock();
628
629		rc = copy_to_user(up, &tmp, sizeof(struct vt_mode));
630		if (rc)
631			ret = -EFAULT;
632		break;
633	}
634
635	/*
636	 * Returns global vt state. Note that VT 0 is always open, since
637	 * it's an alias for the current VT, and people can't use it here.
638	 * We cannot return state for more than 16 VTs, since v_state is short.
639	 */
640	case VT_GETSTATE:
641	{
642		struct vt_stat __user *vtstat = up;
643		unsigned short state, mask;
644
645		/* Review: FIXME: Console lock ? */
646		if (put_user(fg_console + 1, &vtstat->v_active))
647			ret = -EFAULT;
648		else {
649			state = 1;	/* /dev/tty0 is always open */
650			for (i = 0, mask = 2; i < MAX_NR_CONSOLES && mask;
651							++i, mask <<= 1)
652				if (VT_IS_IN_USE(i))
653					state |= mask;
654			ret = put_user(state, &vtstat->v_state);
655		}
656		break;
657	}
658
659	/*
660	 * Returns the first available (non-opened) console.
661	 */
662	case VT_OPENQRY:
663		/* FIXME: locking ? - but then this is a stupid API */
664		for (i = 0; i < MAX_NR_CONSOLES; ++i)
665			if (! VT_IS_IN_USE(i))
666				break;
667		uival = i < MAX_NR_CONSOLES ? (i+1) : -1;
668		goto setint;
669
670	/*
671	 * ioctl(fd, VT_ACTIVATE, num) will cause us to switch to vt # num,
672	 * with num >= 1 (switches to vt 0, our console, are not allowed, just
673	 * to preserve sanity).
674	 */
675	case VT_ACTIVATE:
676		if (!perm)
677			return -EPERM;
678		if (arg == 0 || arg > MAX_NR_CONSOLES)
679			ret =  -ENXIO;
680		else {
681			arg--;
682			console_lock();
683			ret = vc_allocate(arg);
684			console_unlock();
685			if (ret)
686				break;
687			set_console(arg);
688		}
689		break;
690
691	case VT_SETACTIVATE:
692	{
693		struct vt_setactivate vsa;
694
695		if (!perm)
696			return -EPERM;
697
698		if (copy_from_user(&vsa, (struct vt_setactivate __user *)arg,
699					sizeof(struct vt_setactivate))) {
700			ret = -EFAULT;
701			goto out;
702		}
703		if (vsa.console == 0 || vsa.console > MAX_NR_CONSOLES)
704			ret = -ENXIO;
705		else {
706			vsa.console--;
707			console_lock();
708			ret = vc_allocate(vsa.console);
709			if (ret == 0) {
710				struct vc_data *nvc;
711				/* This is safe providing we don't drop the
712				   console sem between vc_allocate and
713				   finishing referencing nvc */
714				nvc = vc_cons[vsa.console].d;
715				nvc->vt_mode = vsa.mode;
716				nvc->vt_mode.frsig = 0;
717				put_pid(nvc->vt_pid);
718				nvc->vt_pid = get_pid(task_pid(current));
719			}
720			console_unlock();
721			if (ret)
722				break;
723			/* Commence switch and lock */
724			/* Review set_console locks */
725			set_console(vsa.console);
726		}
727		break;
728	}
729
730	/*
731	 * wait until the specified VT has been activated
732	 */
733	case VT_WAITACTIVE:
734		if (!perm)
735			return -EPERM;
736		if (arg == 0 || arg > MAX_NR_CONSOLES)
737			ret = -ENXIO;
738		else
739			ret = vt_waitactive(arg);
740		break;
741
742	/*
743	 * If a vt is under process control, the kernel will not switch to it
744	 * immediately, but postpone the operation until the process calls this
745	 * ioctl, allowing the switch to complete.
746	 *
747	 * According to the X sources this is the behavior:
748	 *	0:	pending switch-from not OK
749	 *	1:	pending switch-from OK
750	 *	2:	completed switch-to OK
751	 */
752	case VT_RELDISP:
753		if (!perm)
754			return -EPERM;
755
756		console_lock();
757		if (vc->vt_mode.mode != VT_PROCESS) {
758			console_unlock();
759			ret = -EINVAL;
760			break;
761		}
762		/*
763		 * Switching-from response
764		 */
765		if (vc->vt_newvt >= 0) {
766			if (arg == 0)
767				/*
768				 * Switch disallowed, so forget we were trying
769				 * to do it.
770				 */
771				vc->vt_newvt = -1;
772
773			else {
774				/*
775				 * The current vt has been released, so
776				 * complete the switch.
777				 */
778				int newvt;
779				newvt = vc->vt_newvt;
780				vc->vt_newvt = -1;
781				ret = vc_allocate(newvt);
782				if (ret) {
783					console_unlock();
784					break;
785				}
786				/*
787				 * When we actually do the console switch,
788				 * make sure we are atomic with respect to
789				 * other console switches..
790				 */
791				complete_change_console(vc_cons[newvt].d);
792			}
793		} else {
794			/*
795			 * Switched-to response
796			 */
797			/*
798			 * If it's just an ACK, ignore it
799			 */
800			if (arg != VT_ACKACQ)
801				ret = -EINVAL;
802		}
803		console_unlock();
804		break;
805
806	 /*
807	  * Disallocate memory associated to VT (but leave VT1)
808	  */
809	 case VT_DISALLOCATE:
810		if (arg > MAX_NR_CONSOLES) {
811			ret = -ENXIO;
812			break;
813		}
814		if (arg == 0)
815			vt_disallocate_all();
816		else
817			ret = vt_disallocate(--arg);
818		break;
819
820	case VT_RESIZE:
821	{
822		struct vt_sizes __user *vtsizes = up;
823		struct vc_data *vc;
824
825		ushort ll,cc;
826		if (!perm)
827			return -EPERM;
828		if (get_user(ll, &vtsizes->v_rows) ||
829		    get_user(cc, &vtsizes->v_cols))
830			ret = -EFAULT;
831		else {
832			console_lock();
833			for (i = 0; i < MAX_NR_CONSOLES; i++) {
834				vc = vc_cons[i].d;
835
836				if (vc) {
837					vc->vc_resize_user = 1;
838					/* FIXME: review v tty lock */
839					vc_resize(vc_cons[i].d, cc, ll);
840				}
841			}
842			console_unlock();
843		}
844		break;
845	}
846
847	case VT_RESIZEX:
848	{
849		struct vt_consize __user *vtconsize = up;
850		ushort ll,cc,vlin,clin,vcol,ccol;
851		if (!perm)
852			return -EPERM;
853		if (!access_ok(VERIFY_READ, vtconsize,
854				sizeof(struct vt_consize))) {
855			ret = -EFAULT;
856			break;
857		}
858		/* FIXME: Should check the copies properly */
859		__get_user(ll, &vtconsize->v_rows);
860		__get_user(cc, &vtconsize->v_cols);
861		__get_user(vlin, &vtconsize->v_vlin);
862		__get_user(clin, &vtconsize->v_clin);
863		__get_user(vcol, &vtconsize->v_vcol);
864		__get_user(ccol, &vtconsize->v_ccol);
865		vlin = vlin ? vlin : vc->vc_scan_lines;
866		if (clin) {
867			if (ll) {
868				if (ll != vlin/clin) {
869					/* Parameters don't add up */
870					ret = -EINVAL;
871					break;
872				}
873			} else
874				ll = vlin/clin;
875		}
876		if (vcol && ccol) {
877			if (cc) {
878				if (cc != vcol/ccol) {
879					ret = -EINVAL;
880					break;
881				}
882			} else
883				cc = vcol/ccol;
884		}
885
886		if (clin > 32) {
887			ret =  -EINVAL;
888			break;
889		}
890
891		for (i = 0; i < MAX_NR_CONSOLES; i++) {
892			if (!vc_cons[i].d)
893				continue;
894			console_lock();
895			if (vlin)
896				vc_cons[i].d->vc_scan_lines = vlin;
897			if (clin)
898				vc_cons[i].d->vc_font.height = clin;
899			vc_cons[i].d->vc_resize_user = 1;
900			vc_resize(vc_cons[i].d, cc, ll);
901			console_unlock();
902		}
903		break;
904	}
905
906	case PIO_FONT: {
907		if (!perm)
908			return -EPERM;
909		op.op = KD_FONT_OP_SET;
910		op.flags = KD_FONT_FLAG_OLD | KD_FONT_FLAG_DONT_RECALC;	/* Compatibility */
911		op.width = 8;
912		op.height = 0;
913		op.charcount = 256;
914		op.data = up;
915		ret = con_font_op(vc_cons[fg_console].d, &op);
916		break;
917	}
918
919	case GIO_FONT: {
920		op.op = KD_FONT_OP_GET;
921		op.flags = KD_FONT_FLAG_OLD;
922		op.width = 8;
923		op.height = 32;
924		op.charcount = 256;
925		op.data = up;
926		ret = con_font_op(vc_cons[fg_console].d, &op);
927		break;
928	}
929
930	case PIO_CMAP:
931                if (!perm)
932			ret = -EPERM;
933		else
934	                ret = con_set_cmap(up);
935		break;
936
937	case GIO_CMAP:
938                ret = con_get_cmap(up);
939		break;
940
941	case PIO_FONTX:
942	case GIO_FONTX:
943		ret = do_fontx_ioctl(cmd, up, perm, &op);
944		break;
945
946	case PIO_FONTRESET:
947	{
948		if (!perm)
949			return -EPERM;
950
951#ifdef BROKEN_GRAPHICS_PROGRAMS
952		/* With BROKEN_GRAPHICS_PROGRAMS defined, the default
953		   font is not saved. */
954		ret = -ENOSYS;
955		break;
956#else
957		{
958		op.op = KD_FONT_OP_SET_DEFAULT;
959		op.data = NULL;
960		ret = con_font_op(vc_cons[fg_console].d, &op);
961		if (ret)
962			break;
963		console_lock();
964		con_set_default_unimap(vc_cons[fg_console].d);
965		console_unlock();
966		break;
967		}
968#endif
969	}
970
971	case KDFONTOP: {
972		if (copy_from_user(&op, up, sizeof(op))) {
973			ret = -EFAULT;
974			break;
975		}
976		if (!perm && op.op != KD_FONT_OP_GET)
977			return -EPERM;
978		ret = con_font_op(vc, &op);
979		if (ret)
980			break;
981		if (copy_to_user(up, &op, sizeof(op)))
982			ret = -EFAULT;
983		break;
984	}
985
986	case PIO_SCRNMAP:
987		if (!perm)
988			ret = -EPERM;
989		else
990			ret = con_set_trans_old(up);
991		break;
992
993	case GIO_SCRNMAP:
994		ret = con_get_trans_old(up);
995		break;
996
997	case PIO_UNISCRNMAP:
998		if (!perm)
999			ret = -EPERM;
1000		else
1001			ret = con_set_trans_new(up);
1002		break;
1003
1004	case GIO_UNISCRNMAP:
1005		ret = con_get_trans_new(up);
1006		break;
1007
1008	case PIO_UNIMAPCLR:
1009	      { struct unimapinit ui;
1010		if (!perm)
1011			return -EPERM;
1012		ret = copy_from_user(&ui, up, sizeof(struct unimapinit));
1013		if (ret)
1014			ret = -EFAULT;
1015		else
1016			con_clear_unimap(vc, &ui);
1017		break;
1018	      }
1019
1020	case PIO_UNIMAP:
1021	case GIO_UNIMAP:
1022		ret = do_unimap_ioctl(cmd, up, perm, vc);
1023		break;
1024
1025	case VT_LOCKSWITCH:
1026		if (!capable(CAP_SYS_TTY_CONFIG))
1027			return -EPERM;
1028		vt_dont_switch = 1;
1029		break;
1030	case VT_UNLOCKSWITCH:
1031		if (!capable(CAP_SYS_TTY_CONFIG))
1032			return -EPERM;
1033		vt_dont_switch = 0;
1034		break;
1035	case VT_GETHIFONTMASK:
1036		ret = put_user(vc->vc_hi_font_mask,
1037					(unsigned short __user *)arg);
1038		break;
1039	case VT_WAITEVENT:
1040		ret = vt_event_wait_ioctl((struct vt_event __user *)arg);
1041		break;
1042	default:
1043		ret = -ENOIOCTLCMD;
1044	}
1045out:
1046	return ret;
1047}
1048
1049void reset_vc(struct vc_data *vc)
1050{
1051	vc->vc_mode = KD_TEXT;
1052	vt_reset_unicode(vc->vc_num);
1053	vc->vt_mode.mode = VT_AUTO;
1054	vc->vt_mode.waitv = 0;
1055	vc->vt_mode.relsig = 0;
1056	vc->vt_mode.acqsig = 0;
1057	vc->vt_mode.frsig = 0;
1058	put_pid(vc->vt_pid);
1059	vc->vt_pid = NULL;
1060	vc->vt_newvt = -1;
1061	if (!in_interrupt())    /* Via keyboard.c:SAK() - akpm */
1062		reset_palette(vc);
1063}
1064
1065void vc_SAK(struct work_struct *work)
1066{
1067	struct vc *vc_con =
1068		container_of(work, struct vc, SAK_work);
1069	struct vc_data *vc;
1070	struct tty_struct *tty;
1071
1072	console_lock();
1073	vc = vc_con->d;
1074	if (vc) {
1075		/* FIXME: review tty ref counting */
1076		tty = vc->port.tty;
1077		/*
1078		 * SAK should also work in all raw modes and reset
1079		 * them properly.
1080		 */
1081		if (tty)
1082			__do_SAK(tty);
1083		reset_vc(vc);
1084	}
1085	console_unlock();
1086}
1087
1088#ifdef CONFIG_COMPAT
1089
1090struct compat_consolefontdesc {
1091	unsigned short charcount;       /* characters in font (256 or 512) */
1092	unsigned short charheight;      /* scan lines per character (1-32) */
1093	compat_caddr_t chardata;	/* font data in expanded form */
1094};
1095
1096static inline int
1097compat_fontx_ioctl(int cmd, struct compat_consolefontdesc __user *user_cfd,
1098			 int perm, struct console_font_op *op)
1099{
1100	struct compat_consolefontdesc cfdarg;
1101	int i;
1102
1103	if (copy_from_user(&cfdarg, user_cfd, sizeof(struct compat_consolefontdesc)))
1104		return -EFAULT;
1105
1106	switch (cmd) {
1107	case PIO_FONTX:
1108		if (!perm)
1109			return -EPERM;
1110		op->op = KD_FONT_OP_SET;
1111		op->flags = KD_FONT_FLAG_OLD;
1112		op->width = 8;
1113		op->height = cfdarg.charheight;
1114		op->charcount = cfdarg.charcount;
1115		op->data = compat_ptr(cfdarg.chardata);
1116		return con_font_op(vc_cons[fg_console].d, op);
1117	case GIO_FONTX:
1118		op->op = KD_FONT_OP_GET;
1119		op->flags = KD_FONT_FLAG_OLD;
1120		op->width = 8;
1121		op->height = cfdarg.charheight;
1122		op->charcount = cfdarg.charcount;
1123		op->data = compat_ptr(cfdarg.chardata);
1124		i = con_font_op(vc_cons[fg_console].d, op);
1125		if (i)
1126			return i;
1127		cfdarg.charheight = op->height;
1128		cfdarg.charcount = op->charcount;
1129		if (copy_to_user(user_cfd, &cfdarg, sizeof(struct compat_consolefontdesc)))
1130			return -EFAULT;
1131		return 0;
1132	}
1133	return -EINVAL;
1134}
1135
1136struct compat_console_font_op {
1137	compat_uint_t op;        /* operation code KD_FONT_OP_* */
1138	compat_uint_t flags;     /* KD_FONT_FLAG_* */
1139	compat_uint_t width, height;     /* font size */
1140	compat_uint_t charcount;
1141	compat_caddr_t data;    /* font data with height fixed to 32 */
1142};
1143
1144static inline int
1145compat_kdfontop_ioctl(struct compat_console_font_op __user *fontop,
1146			 int perm, struct console_font_op *op, struct vc_data *vc)
1147{
1148	int i;
1149
1150	if (copy_from_user(op, fontop, sizeof(struct compat_console_font_op)))
1151		return -EFAULT;
1152	if (!perm && op->op != KD_FONT_OP_GET)
1153		return -EPERM;
1154	op->data = compat_ptr(((struct compat_console_font_op *)op)->data);
1155	i = con_font_op(vc, op);
1156	if (i)
1157		return i;
1158	((struct compat_console_font_op *)op)->data = (unsigned long)op->data;
1159	if (copy_to_user(fontop, op, sizeof(struct compat_console_font_op)))
1160		return -EFAULT;
1161	return 0;
1162}
1163
1164struct compat_unimapdesc {
1165	unsigned short entry_ct;
1166	compat_caddr_t entries;
1167};
1168
1169static inline int
1170compat_unimap_ioctl(unsigned int cmd, struct compat_unimapdesc __user *user_ud,
1171			 int perm, struct vc_data *vc)
1172{
1173	struct compat_unimapdesc tmp;
1174	struct unipair __user *tmp_entries;
1175
1176	if (copy_from_user(&tmp, user_ud, sizeof tmp))
1177		return -EFAULT;
1178	tmp_entries = compat_ptr(tmp.entries);
1179	if (tmp_entries)
1180		if (!access_ok(VERIFY_WRITE, tmp_entries,
1181				tmp.entry_ct*sizeof(struct unipair)))
1182			return -EFAULT;
1183	switch (cmd) {
1184	case PIO_UNIMAP:
1185		if (!perm)
1186			return -EPERM;
1187		return con_set_unimap(vc, tmp.entry_ct, tmp_entries);
1188	case GIO_UNIMAP:
1189		if (!perm && fg_console != vc->vc_num)
1190			return -EPERM;
1191		return con_get_unimap(vc, tmp.entry_ct, &(user_ud->entry_ct), tmp_entries);
1192	}
1193	return 0;
1194}
1195
1196long vt_compat_ioctl(struct tty_struct *tty,
1197	     unsigned int cmd, unsigned long arg)
1198{
1199	struct vc_data *vc = tty->driver_data;
1200	struct console_font_op op;	/* used in multiple places here */
1201	unsigned int console;
1202	void __user *up = (void __user *)arg;
1203	int perm;
1204	int ret = 0;
1205
1206	console = vc->vc_num;
1207
1208	if (!vc_cons_allocated(console)) { 	/* impossible? */
1209		ret = -ENOIOCTLCMD;
1210		goto out;
1211	}
1212
1213	/*
1214	 * To have permissions to do most of the vt ioctls, we either have
1215	 * to be the owner of the tty, or have CAP_SYS_TTY_CONFIG.
1216	 */
1217	perm = 0;
1218	if (current->signal->tty == tty || capable(CAP_SYS_TTY_CONFIG))
1219		perm = 1;
1220
1221	switch (cmd) {
1222	/*
1223	 * these need special handlers for incompatible data structures
1224	 */
1225	case PIO_FONTX:
1226	case GIO_FONTX:
1227		ret = compat_fontx_ioctl(cmd, up, perm, &op);
1228		break;
1229
1230	case KDFONTOP:
1231		ret = compat_kdfontop_ioctl(up, perm, &op, vc);
1232		break;
1233
1234	case PIO_UNIMAP:
1235	case GIO_UNIMAP:
1236		ret = compat_unimap_ioctl(cmd, up, perm, vc);
1237		break;
1238
1239	/*
1240	 * all these treat 'arg' as an integer
1241	 */
1242	case KIOCSOUND:
1243	case KDMKTONE:
1244#ifdef CONFIG_X86
1245	case KDADDIO:
1246	case KDDELIO:
1247#endif
1248	case KDSETMODE:
1249	case KDMAPDISP:
1250	case KDUNMAPDISP:
1251	case KDSKBMODE:
1252	case KDSKBMETA:
1253	case KDSKBLED:
1254	case KDSETLED:
1255	case KDSIGACCEPT:
1256	case VT_ACTIVATE:
1257	case VT_WAITACTIVE:
1258	case VT_RELDISP:
1259	case VT_DISALLOCATE:
1260	case VT_RESIZE:
1261	case VT_RESIZEX:
1262		goto fallback;
1263
1264	/*
1265	 * the rest has a compatible data structure behind arg,
1266	 * but we have to convert it to a proper 64 bit pointer.
1267	 */
1268	default:
1269		arg = (unsigned long)compat_ptr(arg);
1270		goto fallback;
1271	}
1272out:
1273	return ret;
1274
1275fallback:
1276	return vt_ioctl(tty, cmd, arg);
1277}
1278
1279
1280#endif /* CONFIG_COMPAT */
1281
1282
1283/*
1284 * Performs the back end of a vt switch. Called under the console
1285 * semaphore.
1286 */
1287static void complete_change_console(struct vc_data *vc)
1288{
1289	unsigned char old_vc_mode;
1290	int old = fg_console;
1291
1292	last_console = fg_console;
1293
1294	/*
1295	 * If we're switching, we could be going from KD_GRAPHICS to
1296	 * KD_TEXT mode or vice versa, which means we need to blank or
1297	 * unblank the screen later.
1298	 */
1299	old_vc_mode = vc_cons[fg_console].d->vc_mode;
1300	switch_screen(vc);
1301
1302	/*
1303	 * This can't appear below a successful kill_pid().  If it did,
1304	 * then the *blank_screen operation could occur while X, having
1305	 * received acqsig, is waking up on another processor.  This
1306	 * condition can lead to overlapping accesses to the VGA range
1307	 * and the framebuffer (causing system lockups).
1308	 *
1309	 * To account for this we duplicate this code below only if the
1310	 * controlling process is gone and we've called reset_vc.
1311	 */
1312	if (old_vc_mode != vc->vc_mode) {
1313		if (vc->vc_mode == KD_TEXT)
1314			do_unblank_screen(1);
1315		else
1316			do_blank_screen(1);
1317	}
1318
1319	/*
1320	 * If this new console is under process control, send it a signal
1321	 * telling it that it has acquired. Also check if it has died and
1322	 * clean up (similar to logic employed in change_console())
1323	 */
1324	if (vc->vt_mode.mode == VT_PROCESS) {
1325		/*
1326		 * Send the signal as privileged - kill_pid() will
1327		 * tell us if the process has gone or something else
1328		 * is awry
1329		 */
1330		if (kill_pid(vc->vt_pid, vc->vt_mode.acqsig, 1) != 0) {
1331		/*
1332		 * The controlling process has died, so we revert back to
1333		 * normal operation. In this case, we'll also change back
1334		 * to KD_TEXT mode. I'm not sure if this is strictly correct
1335		 * but it saves the agony when the X server dies and the screen
1336		 * remains blanked due to KD_GRAPHICS! It would be nice to do
1337		 * this outside of VT_PROCESS but there is no single process
1338		 * to account for and tracking tty count may be undesirable.
1339		 */
1340			reset_vc(vc);
1341
1342			if (old_vc_mode != vc->vc_mode) {
1343				if (vc->vc_mode == KD_TEXT)
1344					do_unblank_screen(1);
1345				else
1346					do_blank_screen(1);
1347			}
1348		}
1349	}
1350
1351	/*
1352	 * Wake anyone waiting for their VT to activate
1353	 */
1354	vt_event_post(VT_EVENT_SWITCH, old, vc->vc_num);
1355	return;
1356}
1357
1358/*
1359 * Performs the front-end of a vt switch
1360 */
1361void change_console(struct vc_data *new_vc)
1362{
1363	struct vc_data *vc;
1364
1365	if (!new_vc || new_vc->vc_num == fg_console || vt_dont_switch)
1366		return;
1367
1368	/*
1369	 * If this vt is in process mode, then we need to handshake with
1370	 * that process before switching. Essentially, we store where that
1371	 * vt wants to switch to and wait for it to tell us when it's done
1372	 * (via VT_RELDISP ioctl).
1373	 *
1374	 * We also check to see if the controlling process still exists.
1375	 * If it doesn't, we reset this vt to auto mode and continue.
1376	 * This is a cheap way to track process control. The worst thing
1377	 * that can happen is: we send a signal to a process, it dies, and
1378	 * the switch gets "lost" waiting for a response; hopefully, the
1379	 * user will try again, we'll detect the process is gone (unless
1380	 * the user waits just the right amount of time :-) and revert the
1381	 * vt to auto control.
1382	 */
1383	vc = vc_cons[fg_console].d;
1384	if (vc->vt_mode.mode == VT_PROCESS) {
1385		/*
1386		 * Send the signal as privileged - kill_pid() will
1387		 * tell us if the process has gone or something else
1388		 * is awry.
1389		 *
1390		 * We need to set vt_newvt *before* sending the signal or we
1391		 * have a race.
1392		 */
1393		vc->vt_newvt = new_vc->vc_num;
1394		if (kill_pid(vc->vt_pid, vc->vt_mode.relsig, 1) == 0) {
1395			/*
1396			 * It worked. Mark the vt to switch to and
1397			 * return. The process needs to send us a
1398			 * VT_RELDISP ioctl to complete the switch.
1399			 */
1400			return;
1401		}
1402
1403		/*
1404		 * The controlling process has died, so we revert back to
1405		 * normal operation. In this case, we'll also change back
1406		 * to KD_TEXT mode. I'm not sure if this is strictly correct
1407		 * but it saves the agony when the X server dies and the screen
1408		 * remains blanked due to KD_GRAPHICS! It would be nice to do
1409		 * this outside of VT_PROCESS but there is no single process
1410		 * to account for and tracking tty count may be undesirable.
1411		 */
1412		reset_vc(vc);
1413
1414		/*
1415		 * Fall through to normal (VT_AUTO) handling of the switch...
1416		 */
1417	}
1418
1419	/*
1420	 * Ignore all switches in KD_GRAPHICS+VT_AUTO mode
1421	 */
1422	if (vc->vc_mode == KD_GRAPHICS)
1423		return;
1424
1425	complete_change_console(new_vc);
1426}
1427
1428/* Perform a kernel triggered VT switch for suspend/resume */
1429
1430static int disable_vt_switch;
1431
1432int vt_move_to_console(unsigned int vt, int alloc)
1433{
1434	int prev;
1435
1436	console_lock();
1437	/* Graphics mode - up to X */
1438	if (disable_vt_switch) {
1439		console_unlock();
1440		return 0;
1441	}
1442	prev = fg_console;
1443
1444	if (alloc && vc_allocate(vt)) {
1445		/* we can't have a free VC for now. Too bad,
1446		 * we don't want to mess the screen for now. */
1447		console_unlock();
1448		return -ENOSPC;
1449	}
1450
1451	if (set_console(vt)) {
1452		/*
1453		 * We're unable to switch to the SUSPEND_CONSOLE.
1454		 * Let the calling function know so it can decide
1455		 * what to do.
1456		 */
1457		console_unlock();
1458		return -EIO;
1459	}
1460	console_unlock();
1461	if (vt_waitactive(vt + 1)) {
1462		pr_debug("Suspend: Can't switch VCs.");
1463		return -EINTR;
1464	}
1465	return prev;
1466}
1467
1468/*
1469 * Normally during a suspend, we allocate a new console and switch to it.
1470 * When we resume, we switch back to the original console.  This switch
1471 * can be slow, so on systems where the framebuffer can handle restoration
1472 * of video registers anyways, there's little point in doing the console
1473 * switch.  This function allows you to disable it by passing it '0'.
1474 */
1475void pm_set_vt_switch(int do_switch)
1476{
1477	console_lock();
1478	disable_vt_switch = !do_switch;
1479	console_unlock();
1480}
1481EXPORT_SYMBOL(pm_set_vt_switch);
1482