xref: /linux/drivers/tty/vt/vt_ioctl.c (revision 079c9534a96da9a85a2a2f9715851050fbfbf749)
1 /*
2  *  Copyright (C) 1992 obz under the linux copyright
3  *
4  *  Dynamic diacritical handling - aeb@cwi.nl - Dec 1993
5  *  Dynamic keymap and string allocation - aeb@cwi.nl - May 1994
6  *  Restrict VT switching via ioctl() - grif@cs.ucr.edu - Dec 1995
7  *  Some code moved for less code duplication - Andi Kleen - Mar 1997
8  *  Check put/get_user, cleanups - acme@conectiva.com.br - Jun 2001
9  */
10 
11 #include <linux/types.h>
12 #include <linux/errno.h>
13 #include <linux/sched.h>
14 #include <linux/tty.h>
15 #include <linux/timer.h>
16 #include <linux/kernel.h>
17 #include <linux/compat.h>
18 #include <linux/module.h>
19 #include <linux/kd.h>
20 #include <linux/vt.h>
21 #include <linux/string.h>
22 #include <linux/slab.h>
23 #include <linux/major.h>
24 #include <linux/fs.h>
25 #include <linux/console.h>
26 #include <linux/consolemap.h>
27 #include <linux/signal.h>
28 #include <linux/timex.h>
29 
30 #include <asm/io.h>
31 #include <asm/uaccess.h>
32 
33 #include <linux/kbd_kern.h>
34 #include <linux/vt_kern.h>
35 #include <linux/kbd_diacr.h>
36 #include <linux/selection.h>
37 
38 char vt_dont_switch;
39 extern struct tty_driver *console_driver;
40 
41 #define VT_IS_IN_USE(i)	(console_driver->ttys[i] && console_driver->ttys[i]->count)
42 #define VT_BUSY(i)	(VT_IS_IN_USE(i) || i == fg_console || vc_cons[i].d == sel_cons)
43 
44 /*
45  * Console (vt and kd) routines, as defined by USL SVR4 manual, and by
46  * experimentation and study of X386 SYSV handling.
47  *
48  * One point of difference: SYSV vt's are /dev/vtX, which X >= 0, and
49  * /dev/console is a separate ttyp. Under Linux, /dev/tty0 is /dev/console,
50  * and the vc start at /dev/ttyX, X >= 1. We maintain that here, so we will
51  * always treat our set of vt as numbered 1..MAX_NR_CONSOLES (corresponding to
52  * ttys 0..MAX_NR_CONSOLES-1). Explicitly naming VT 0 is illegal, but using
53  * /dev/tty0 (fg_console) as a target is legal, since an implicit aliasing
54  * to the current console is done by the main ioctl code.
55  */
56 
57 #ifdef CONFIG_X86
58 #include <linux/syscalls.h>
59 #endif
60 
61 static void complete_change_console(struct vc_data *vc);
62 
63 /*
64  *	User space VT_EVENT handlers
65  */
66 
67 struct vt_event_wait {
68 	struct list_head list;
69 	struct vt_event event;
70 	int done;
71 };
72 
73 static LIST_HEAD(vt_events);
74 static DEFINE_SPINLOCK(vt_event_lock);
75 static DECLARE_WAIT_QUEUE_HEAD(vt_event_waitqueue);
76 
77 /**
78  *	vt_event_post
79  *	@event: the event that occurred
80  *	@old: old console
81  *	@new: new console
82  *
83  *	Post an VT event to interested VT handlers
84  */
85 
86 void vt_event_post(unsigned int event, unsigned int old, unsigned int new)
87 {
88 	struct list_head *pos, *head;
89 	unsigned long flags;
90 	int wake = 0;
91 
92 	spin_lock_irqsave(&vt_event_lock, flags);
93 	head = &vt_events;
94 
95 	list_for_each(pos, head) {
96 		struct vt_event_wait *ve = list_entry(pos,
97 						struct vt_event_wait, list);
98 		if (!(ve->event.event & event))
99 			continue;
100 		ve->event.event = event;
101 		/* kernel view is consoles 0..n-1, user space view is
102 		   console 1..n with 0 meaning current, so we must bias */
103 		ve->event.oldev = old + 1;
104 		ve->event.newev = new + 1;
105 		wake = 1;
106 		ve->done = 1;
107 	}
108 	spin_unlock_irqrestore(&vt_event_lock, flags);
109 	if (wake)
110 		wake_up_interruptible(&vt_event_waitqueue);
111 }
112 
113 /**
114  *	vt_event_wait		-	wait for an event
115  *	@vw: our event
116  *
117  *	Waits for an event to occur which completes our vt_event_wait
118  *	structure. On return the structure has wv->done set to 1 for success
119  *	or 0 if some event such as a signal ended the wait.
120  */
121 
122 static void vt_event_wait(struct vt_event_wait *vw)
123 {
124 	unsigned long flags;
125 	/* Prepare the event */
126 	INIT_LIST_HEAD(&vw->list);
127 	vw->done = 0;
128 	/* Queue our event */
129 	spin_lock_irqsave(&vt_event_lock, flags);
130 	list_add(&vw->list, &vt_events);
131 	spin_unlock_irqrestore(&vt_event_lock, flags);
132 	/* Wait for it to pass */
133 	wait_event_interruptible_tty(vt_event_waitqueue, vw->done);
134 	/* Dequeue it */
135 	spin_lock_irqsave(&vt_event_lock, flags);
136 	list_del(&vw->list);
137 	spin_unlock_irqrestore(&vt_event_lock, flags);
138 }
139 
140 /**
141  *	vt_event_wait_ioctl	-	event ioctl handler
142  *	@arg: argument to ioctl
143  *
144  *	Implement the VT_WAITEVENT ioctl using the VT event interface
145  */
146 
147 static int vt_event_wait_ioctl(struct vt_event __user *event)
148 {
149 	struct vt_event_wait vw;
150 
151 	if (copy_from_user(&vw.event, event, sizeof(struct vt_event)))
152 		return -EFAULT;
153 	/* Highest supported event for now */
154 	if (vw.event.event & ~VT_MAX_EVENT)
155 		return -EINVAL;
156 
157 	vt_event_wait(&vw);
158 	/* If it occurred report it */
159 	if (vw.done) {
160 		if (copy_to_user(event, &vw.event, sizeof(struct vt_event)))
161 			return -EFAULT;
162 		return 0;
163 	}
164 	return -EINTR;
165 }
166 
167 /**
168  *	vt_waitactive	-	active console wait
169  *	@event: event code
170  *	@n: new console
171  *
172  *	Helper for event waits. Used to implement the legacy
173  *	event waiting ioctls in terms of events
174  */
175 
176 int vt_waitactive(int n)
177 {
178 	struct vt_event_wait vw;
179 	do {
180 		if (n == fg_console + 1)
181 			break;
182 		vw.event.event = VT_EVENT_SWITCH;
183 		vt_event_wait(&vw);
184 		if (vw.done == 0)
185 			return -EINTR;
186 	} while (vw.event.newev != n);
187 	return 0;
188 }
189 
190 /*
191  * these are the valid i/o ports we're allowed to change. they map all the
192  * video ports
193  */
194 #define GPFIRST 0x3b4
195 #define GPLAST 0x3df
196 #define GPNUM (GPLAST - GPFIRST + 1)
197 
198 
199 
200 static inline int
201 do_fontx_ioctl(int cmd, struct consolefontdesc __user *user_cfd, int perm, struct console_font_op *op)
202 {
203 	struct consolefontdesc cfdarg;
204 	int i;
205 
206 	if (copy_from_user(&cfdarg, user_cfd, sizeof(struct consolefontdesc)))
207 		return -EFAULT;
208 
209 	switch (cmd) {
210 	case PIO_FONTX:
211 		if (!perm)
212 			return -EPERM;
213 		op->op = KD_FONT_OP_SET;
214 		op->flags = KD_FONT_FLAG_OLD;
215 		op->width = 8;
216 		op->height = cfdarg.charheight;
217 		op->charcount = cfdarg.charcount;
218 		op->data = cfdarg.chardata;
219 		return con_font_op(vc_cons[fg_console].d, op);
220 	case GIO_FONTX: {
221 		op->op = KD_FONT_OP_GET;
222 		op->flags = KD_FONT_FLAG_OLD;
223 		op->width = 8;
224 		op->height = cfdarg.charheight;
225 		op->charcount = cfdarg.charcount;
226 		op->data = cfdarg.chardata;
227 		i = con_font_op(vc_cons[fg_console].d, op);
228 		if (i)
229 			return i;
230 		cfdarg.charheight = op->height;
231 		cfdarg.charcount = op->charcount;
232 		if (copy_to_user(user_cfd, &cfdarg, sizeof(struct consolefontdesc)))
233 			return -EFAULT;
234 		return 0;
235 		}
236 	}
237 	return -EINVAL;
238 }
239 
240 static inline int
241 do_unimap_ioctl(int cmd, struct unimapdesc __user *user_ud, int perm, struct vc_data *vc)
242 {
243 	struct unimapdesc tmp;
244 
245 	if (copy_from_user(&tmp, user_ud, sizeof tmp))
246 		return -EFAULT;
247 	if (tmp.entries)
248 		if (!access_ok(VERIFY_WRITE, tmp.entries,
249 				tmp.entry_ct*sizeof(struct unipair)))
250 			return -EFAULT;
251 	switch (cmd) {
252 	case PIO_UNIMAP:
253 		if (!perm)
254 			return -EPERM;
255 		return con_set_unimap(vc, tmp.entry_ct, tmp.entries);
256 	case GIO_UNIMAP:
257 		if (!perm && fg_console != vc->vc_num)
258 			return -EPERM;
259 		return con_get_unimap(vc, tmp.entry_ct, &(user_ud->entry_ct), tmp.entries);
260 	}
261 	return 0;
262 }
263 
264 
265 
266 /*
267  * We handle the console-specific ioctl's here.  We allow the
268  * capability to modify any console, not just the fg_console.
269  */
270 int vt_ioctl(struct tty_struct *tty,
271 	     unsigned int cmd, unsigned long arg)
272 {
273 	struct vc_data *vc = tty->driver_data;
274 	struct console_font_op op;	/* used in multiple places here */
275 	unsigned int console;
276 	unsigned char ucval;
277 	unsigned int uival;
278 	void __user *up = (void __user *)arg;
279 	int i, perm;
280 	int ret = 0;
281 
282 	console = vc->vc_num;
283 
284 	tty_lock();
285 
286 	if (!vc_cons_allocated(console)) { 	/* impossible? */
287 		ret = -ENOIOCTLCMD;
288 		goto out;
289 	}
290 
291 
292 	/*
293 	 * To have permissions to do most of the vt ioctls, we either have
294 	 * to be the owner of the tty, or have CAP_SYS_TTY_CONFIG.
295 	 */
296 	perm = 0;
297 	if (current->signal->tty == tty || capable(CAP_SYS_TTY_CONFIG))
298 		perm = 1;
299 
300 	switch (cmd) {
301 	case TIOCLINUX:
302 		ret = tioclinux(tty, arg);
303 		break;
304 	case KIOCSOUND:
305 		if (!perm)
306 			goto eperm;
307 		/*
308 		 * The use of PIT_TICK_RATE is historic, it used to be
309 		 * the platform-dependent CLOCK_TICK_RATE between 2.6.12
310 		 * and 2.6.36, which was a minor but unfortunate ABI
311 		 * change.
312 		 */
313 		if (arg)
314 			arg = PIT_TICK_RATE / arg;
315 		kd_mksound(arg, 0);
316 		break;
317 
318 	case KDMKTONE:
319 		if (!perm)
320 			goto eperm;
321 	{
322 		unsigned int ticks, count;
323 
324 		/*
325 		 * Generate the tone for the appropriate number of ticks.
326 		 * If the time is zero, turn off sound ourselves.
327 		 */
328 		ticks = HZ * ((arg >> 16) & 0xffff) / 1000;
329 		count = ticks ? (arg & 0xffff) : 0;
330 		if (count)
331 			count = PIT_TICK_RATE / count;
332 		kd_mksound(count, ticks);
333 		break;
334 	}
335 
336 	case KDGKBTYPE:
337 		/*
338 		 * this is naive.
339 		 */
340 		ucval = KB_101;
341 		ret = put_user(ucval, (char __user *)arg);
342 		break;
343 
344 		/*
345 		 * These cannot be implemented on any machine that implements
346 		 * ioperm() in user level (such as Alpha PCs) or not at all.
347 		 *
348 		 * XXX: you should never use these, just call ioperm directly..
349 		 */
350 #ifdef CONFIG_X86
351 	case KDADDIO:
352 	case KDDELIO:
353 		/*
354 		 * KDADDIO and KDDELIO may be able to add ports beyond what
355 		 * we reject here, but to be safe...
356 		 */
357 		if (arg < GPFIRST || arg > GPLAST) {
358 			ret = -EINVAL;
359 			break;
360 		}
361 		ret = sys_ioperm(arg, 1, (cmd == KDADDIO)) ? -ENXIO : 0;
362 		break;
363 
364 	case KDENABIO:
365 	case KDDISABIO:
366 		ret = sys_ioperm(GPFIRST, GPNUM,
367 				  (cmd == KDENABIO)) ? -ENXIO : 0;
368 		break;
369 #endif
370 
371 	/* Linux m68k/i386 interface for setting the keyboard delay/repeat rate */
372 
373 	case KDKBDREP:
374 	{
375 		struct kbd_repeat kbrep;
376 
377 		if (!capable(CAP_SYS_TTY_CONFIG))
378 			goto eperm;
379 
380 		if (copy_from_user(&kbrep, up, sizeof(struct kbd_repeat))) {
381 			ret =  -EFAULT;
382 			break;
383 		}
384 		ret = kbd_rate(&kbrep);
385 		if (ret)
386 			break;
387 		if (copy_to_user(up, &kbrep, sizeof(struct kbd_repeat)))
388 			ret = -EFAULT;
389 		break;
390 	}
391 
392 	case KDSETMODE:
393 		/*
394 		 * currently, setting the mode from KD_TEXT to KD_GRAPHICS
395 		 * doesn't do a whole lot. i'm not sure if it should do any
396 		 * restoration of modes or what...
397 		 *
398 		 * XXX It should at least call into the driver, fbdev's definitely
399 		 * need to restore their engine state. --BenH
400 		 */
401 		if (!perm)
402 			goto eperm;
403 		switch (arg) {
404 		case KD_GRAPHICS:
405 			break;
406 		case KD_TEXT0:
407 		case KD_TEXT1:
408 			arg = KD_TEXT;
409 		case KD_TEXT:
410 			break;
411 		default:
412 			ret = -EINVAL;
413 			goto out;
414 		}
415 		if (vc->vc_mode == (unsigned char) arg)
416 			break;
417 		vc->vc_mode = (unsigned char) arg;
418 		if (console != fg_console)
419 			break;
420 		/*
421 		 * explicitly blank/unblank the screen if switching modes
422 		 */
423 		console_lock();
424 		if (arg == KD_TEXT)
425 			do_unblank_screen(1);
426 		else
427 			do_blank_screen(1);
428 		console_unlock();
429 		break;
430 
431 	case KDGETMODE:
432 		uival = vc->vc_mode;
433 		goto setint;
434 
435 	case KDMAPDISP:
436 	case KDUNMAPDISP:
437 		/*
438 		 * these work like a combination of mmap and KDENABIO.
439 		 * this could be easily finished.
440 		 */
441 		ret = -EINVAL;
442 		break;
443 
444 	case KDSKBMODE:
445 		if (!perm)
446 			goto eperm;
447 		ret = vt_do_kdskbmode(console, arg);
448 		if (ret == 0)
449 			tty_ldisc_flush(tty);
450 		break;
451 
452 	case KDGKBMODE:
453 		uival = vt_do_kdgkbmode(console);
454 		ret = put_user(uival, (int __user *)arg);
455 		break;
456 
457 	/* this could be folded into KDSKBMODE, but for compatibility
458 	   reasons it is not so easy to fold KDGKBMETA into KDGKBMODE */
459 	case KDSKBMETA:
460 		ret = vt_do_kdskbmeta(console, arg);
461 		break;
462 
463 	case KDGKBMETA:
464 		/* FIXME: should review whether this is worth locking */
465 		uival = vt_do_kdgkbmeta(console);
466 	setint:
467 		ret = put_user(uival, (int __user *)arg);
468 		break;
469 
470 	case KDGETKEYCODE:
471 	case KDSETKEYCODE:
472 		if(!capable(CAP_SYS_TTY_CONFIG))
473 			perm = 0;
474 		ret = vt_do_kbkeycode_ioctl(cmd, up, perm);
475 		break;
476 
477 	case KDGKBENT:
478 	case KDSKBENT:
479 		ret = vt_do_kdsk_ioctl(cmd, up, perm, console);
480 		break;
481 
482 	case KDGKBSENT:
483 	case KDSKBSENT:
484 		ret = vt_do_kdgkb_ioctl(cmd, up, perm);
485 		break;
486 
487 	/* Diacritical processing. Handled in keyboard.c as it has
488 	   to operate on the keyboard locks and structures */
489 	case KDGKBDIACR:
490 	case KDGKBDIACRUC:
491 	case KDSKBDIACR:
492 	case KDSKBDIACRUC:
493 		ret = vt_do_diacrit(cmd, up, perm);
494 		break;
495 
496 	/* the ioctls below read/set the flags usually shown in the leds */
497 	/* don't use them - they will go away without warning */
498 	case KDGKBLED:
499 	case KDSKBLED:
500 	case KDGETLED:
501 	case KDSETLED:
502 		ret = vt_do_kdskled(console, cmd, arg, perm);
503 		break;
504 
505 	/*
506 	 * A process can indicate its willingness to accept signals
507 	 * generated by pressing an appropriate key combination.
508 	 * Thus, one can have a daemon that e.g. spawns a new console
509 	 * upon a keypress and then changes to it.
510 	 * See also the kbrequest field of inittab(5).
511 	 */
512 	case KDSIGACCEPT:
513 	{
514 		if (!perm || !capable(CAP_KILL))
515 			goto eperm;
516 		if (!valid_signal(arg) || arg < 1 || arg == SIGKILL)
517 			ret = -EINVAL;
518 		else {
519 			spin_lock_irq(&vt_spawn_con.lock);
520 			put_pid(vt_spawn_con.pid);
521 			vt_spawn_con.pid = get_pid(task_pid(current));
522 			vt_spawn_con.sig = arg;
523 			spin_unlock_irq(&vt_spawn_con.lock);
524 		}
525 		break;
526 	}
527 
528 	case VT_SETMODE:
529 	{
530 		struct vt_mode tmp;
531 
532 		if (!perm)
533 			goto eperm;
534 		if (copy_from_user(&tmp, up, sizeof(struct vt_mode))) {
535 			ret = -EFAULT;
536 			goto out;
537 		}
538 		if (tmp.mode != VT_AUTO && tmp.mode != VT_PROCESS) {
539 			ret = -EINVAL;
540 			goto out;
541 		}
542 		console_lock();
543 		vc->vt_mode = tmp;
544 		/* the frsig is ignored, so we set it to 0 */
545 		vc->vt_mode.frsig = 0;
546 		put_pid(vc->vt_pid);
547 		vc->vt_pid = get_pid(task_pid(current));
548 		/* no switch is required -- saw@shade.msu.ru */
549 		vc->vt_newvt = -1;
550 		console_unlock();
551 		break;
552 	}
553 
554 	case VT_GETMODE:
555 	{
556 		struct vt_mode tmp;
557 		int rc;
558 
559 		console_lock();
560 		memcpy(&tmp, &vc->vt_mode, sizeof(struct vt_mode));
561 		console_unlock();
562 
563 		rc = copy_to_user(up, &tmp, sizeof(struct vt_mode));
564 		if (rc)
565 			ret = -EFAULT;
566 		break;
567 	}
568 
569 	/*
570 	 * Returns global vt state. Note that VT 0 is always open, since
571 	 * it's an alias for the current VT, and people can't use it here.
572 	 * We cannot return state for more than 16 VTs, since v_state is short.
573 	 */
574 	case VT_GETSTATE:
575 	{
576 		struct vt_stat __user *vtstat = up;
577 		unsigned short state, mask;
578 
579 		if (put_user(fg_console + 1, &vtstat->v_active))
580 			ret = -EFAULT;
581 		else {
582 			state = 1;	/* /dev/tty0 is always open */
583 			for (i = 0, mask = 2; i < MAX_NR_CONSOLES && mask;
584 							++i, mask <<= 1)
585 				if (VT_IS_IN_USE(i))
586 					state |= mask;
587 			ret = put_user(state, &vtstat->v_state);
588 		}
589 		break;
590 	}
591 
592 	/*
593 	 * Returns the first available (non-opened) console.
594 	 */
595 	case VT_OPENQRY:
596 		for (i = 0; i < MAX_NR_CONSOLES; ++i)
597 			if (! VT_IS_IN_USE(i))
598 				break;
599 		uival = i < MAX_NR_CONSOLES ? (i+1) : -1;
600 		goto setint;
601 
602 	/*
603 	 * ioctl(fd, VT_ACTIVATE, num) will cause us to switch to vt # num,
604 	 * with num >= 1 (switches to vt 0, our console, are not allowed, just
605 	 * to preserve sanity).
606 	 */
607 	case VT_ACTIVATE:
608 		if (!perm)
609 			goto eperm;
610 		if (arg == 0 || arg > MAX_NR_CONSOLES)
611 			ret =  -ENXIO;
612 		else {
613 			arg--;
614 			console_lock();
615 			ret = vc_allocate(arg);
616 			console_unlock();
617 			if (ret)
618 				break;
619 			set_console(arg);
620 		}
621 		break;
622 
623 	case VT_SETACTIVATE:
624 	{
625 		struct vt_setactivate vsa;
626 
627 		if (!perm)
628 			goto eperm;
629 
630 		if (copy_from_user(&vsa, (struct vt_setactivate __user *)arg,
631 					sizeof(struct vt_setactivate))) {
632 			ret = -EFAULT;
633 			goto out;
634 		}
635 		if (vsa.console == 0 || vsa.console > MAX_NR_CONSOLES)
636 			ret = -ENXIO;
637 		else {
638 			vsa.console--;
639 			console_lock();
640 			ret = vc_allocate(vsa.console);
641 			if (ret == 0) {
642 				struct vc_data *nvc;
643 				/* This is safe providing we don't drop the
644 				   console sem between vc_allocate and
645 				   finishing referencing nvc */
646 				nvc = vc_cons[vsa.console].d;
647 				nvc->vt_mode = vsa.mode;
648 				nvc->vt_mode.frsig = 0;
649 				put_pid(nvc->vt_pid);
650 				nvc->vt_pid = get_pid(task_pid(current));
651 			}
652 			console_unlock();
653 			if (ret)
654 				break;
655 			/* Commence switch and lock */
656 			set_console(vsa.console);
657 		}
658 		break;
659 	}
660 
661 	/*
662 	 * wait until the specified VT has been activated
663 	 */
664 	case VT_WAITACTIVE:
665 		if (!perm)
666 			goto eperm;
667 		if (arg == 0 || arg > MAX_NR_CONSOLES)
668 			ret = -ENXIO;
669 		else
670 			ret = vt_waitactive(arg);
671 		break;
672 
673 	/*
674 	 * If a vt is under process control, the kernel will not switch to it
675 	 * immediately, but postpone the operation until the process calls this
676 	 * ioctl, allowing the switch to complete.
677 	 *
678 	 * According to the X sources this is the behavior:
679 	 *	0:	pending switch-from not OK
680 	 *	1:	pending switch-from OK
681 	 *	2:	completed switch-to OK
682 	 */
683 	case VT_RELDISP:
684 		if (!perm)
685 			goto eperm;
686 
687 		if (vc->vt_mode.mode != VT_PROCESS) {
688 			ret = -EINVAL;
689 			break;
690 		}
691 		/*
692 		 * Switching-from response
693 		 */
694 		console_lock();
695 		if (vc->vt_newvt >= 0) {
696 			if (arg == 0)
697 				/*
698 				 * Switch disallowed, so forget we were trying
699 				 * to do it.
700 				 */
701 				vc->vt_newvt = -1;
702 
703 			else {
704 				/*
705 				 * The current vt has been released, so
706 				 * complete the switch.
707 				 */
708 				int newvt;
709 				newvt = vc->vt_newvt;
710 				vc->vt_newvt = -1;
711 				ret = vc_allocate(newvt);
712 				if (ret) {
713 					console_unlock();
714 					break;
715 				}
716 				/*
717 				 * When we actually do the console switch,
718 				 * make sure we are atomic with respect to
719 				 * other console switches..
720 				 */
721 				complete_change_console(vc_cons[newvt].d);
722 			}
723 		} else {
724 			/*
725 			 * Switched-to response
726 			 */
727 			/*
728 			 * If it's just an ACK, ignore it
729 			 */
730 			if (arg != VT_ACKACQ)
731 				ret = -EINVAL;
732 		}
733 		console_unlock();
734 		break;
735 
736 	 /*
737 	  * Disallocate memory associated to VT (but leave VT1)
738 	  */
739 	 case VT_DISALLOCATE:
740 		if (arg > MAX_NR_CONSOLES) {
741 			ret = -ENXIO;
742 			break;
743 		}
744 		if (arg == 0) {
745 		    /* deallocate all unused consoles, but leave 0 */
746 			console_lock();
747 			for (i=1; i<MAX_NR_CONSOLES; i++)
748 				if (! VT_BUSY(i))
749 					vc_deallocate(i);
750 			console_unlock();
751 		} else {
752 			/* deallocate a single console, if possible */
753 			arg--;
754 			if (VT_BUSY(arg))
755 				ret = -EBUSY;
756 			else if (arg) {			      /* leave 0 */
757 				console_lock();
758 				vc_deallocate(arg);
759 				console_unlock();
760 			}
761 		}
762 		break;
763 
764 	case VT_RESIZE:
765 	{
766 		struct vt_sizes __user *vtsizes = up;
767 		struct vc_data *vc;
768 
769 		ushort ll,cc;
770 		if (!perm)
771 			goto eperm;
772 		if (get_user(ll, &vtsizes->v_rows) ||
773 		    get_user(cc, &vtsizes->v_cols))
774 			ret = -EFAULT;
775 		else {
776 			console_lock();
777 			for (i = 0; i < MAX_NR_CONSOLES; i++) {
778 				vc = vc_cons[i].d;
779 
780 				if (vc) {
781 					vc->vc_resize_user = 1;
782 					vc_resize(vc_cons[i].d, cc, ll);
783 				}
784 			}
785 			console_unlock();
786 		}
787 		break;
788 	}
789 
790 	case VT_RESIZEX:
791 	{
792 		struct vt_consize __user *vtconsize = up;
793 		ushort ll,cc,vlin,clin,vcol,ccol;
794 		if (!perm)
795 			goto eperm;
796 		if (!access_ok(VERIFY_READ, vtconsize,
797 				sizeof(struct vt_consize))) {
798 			ret = -EFAULT;
799 			break;
800 		}
801 		/* FIXME: Should check the copies properly */
802 		__get_user(ll, &vtconsize->v_rows);
803 		__get_user(cc, &vtconsize->v_cols);
804 		__get_user(vlin, &vtconsize->v_vlin);
805 		__get_user(clin, &vtconsize->v_clin);
806 		__get_user(vcol, &vtconsize->v_vcol);
807 		__get_user(ccol, &vtconsize->v_ccol);
808 		vlin = vlin ? vlin : vc->vc_scan_lines;
809 		if (clin) {
810 			if (ll) {
811 				if (ll != vlin/clin) {
812 					/* Parameters don't add up */
813 					ret = -EINVAL;
814 					break;
815 				}
816 			} else
817 				ll = vlin/clin;
818 		}
819 		if (vcol && ccol) {
820 			if (cc) {
821 				if (cc != vcol/ccol) {
822 					ret = -EINVAL;
823 					break;
824 				}
825 			} else
826 				cc = vcol/ccol;
827 		}
828 
829 		if (clin > 32) {
830 			ret =  -EINVAL;
831 			break;
832 		}
833 
834 		for (i = 0; i < MAX_NR_CONSOLES; i++) {
835 			if (!vc_cons[i].d)
836 				continue;
837 			console_lock();
838 			if (vlin)
839 				vc_cons[i].d->vc_scan_lines = vlin;
840 			if (clin)
841 				vc_cons[i].d->vc_font.height = clin;
842 			vc_cons[i].d->vc_resize_user = 1;
843 			vc_resize(vc_cons[i].d, cc, ll);
844 			console_unlock();
845 		}
846 		break;
847 	}
848 
849 	case PIO_FONT: {
850 		if (!perm)
851 			goto eperm;
852 		op.op = KD_FONT_OP_SET;
853 		op.flags = KD_FONT_FLAG_OLD | KD_FONT_FLAG_DONT_RECALC;	/* Compatibility */
854 		op.width = 8;
855 		op.height = 0;
856 		op.charcount = 256;
857 		op.data = up;
858 		ret = con_font_op(vc_cons[fg_console].d, &op);
859 		break;
860 	}
861 
862 	case GIO_FONT: {
863 		op.op = KD_FONT_OP_GET;
864 		op.flags = KD_FONT_FLAG_OLD;
865 		op.width = 8;
866 		op.height = 32;
867 		op.charcount = 256;
868 		op.data = up;
869 		ret = con_font_op(vc_cons[fg_console].d, &op);
870 		break;
871 	}
872 
873 	case PIO_CMAP:
874                 if (!perm)
875 			ret = -EPERM;
876 		else
877 	                ret = con_set_cmap(up);
878 		break;
879 
880 	case GIO_CMAP:
881                 ret = con_get_cmap(up);
882 		break;
883 
884 	case PIO_FONTX:
885 	case GIO_FONTX:
886 		ret = do_fontx_ioctl(cmd, up, perm, &op);
887 		break;
888 
889 	case PIO_FONTRESET:
890 	{
891 		if (!perm)
892 			goto eperm;
893 
894 #ifdef BROKEN_GRAPHICS_PROGRAMS
895 		/* With BROKEN_GRAPHICS_PROGRAMS defined, the default
896 		   font is not saved. */
897 		ret = -ENOSYS;
898 		break;
899 #else
900 		{
901 		op.op = KD_FONT_OP_SET_DEFAULT;
902 		op.data = NULL;
903 		ret = con_font_op(vc_cons[fg_console].d, &op);
904 		if (ret)
905 			break;
906 		con_set_default_unimap(vc_cons[fg_console].d);
907 		break;
908 		}
909 #endif
910 	}
911 
912 	case KDFONTOP: {
913 		if (copy_from_user(&op, up, sizeof(op))) {
914 			ret = -EFAULT;
915 			break;
916 		}
917 		if (!perm && op.op != KD_FONT_OP_GET)
918 			goto eperm;
919 		ret = con_font_op(vc, &op);
920 		if (ret)
921 			break;
922 		if (copy_to_user(up, &op, sizeof(op)))
923 			ret = -EFAULT;
924 		break;
925 	}
926 
927 	case PIO_SCRNMAP:
928 		if (!perm)
929 			ret = -EPERM;
930 		else
931 			ret = con_set_trans_old(up);
932 		break;
933 
934 	case GIO_SCRNMAP:
935 		ret = con_get_trans_old(up);
936 		break;
937 
938 	case PIO_UNISCRNMAP:
939 		if (!perm)
940 			ret = -EPERM;
941 		else
942 			ret = con_set_trans_new(up);
943 		break;
944 
945 	case GIO_UNISCRNMAP:
946 		ret = con_get_trans_new(up);
947 		break;
948 
949 	case PIO_UNIMAPCLR:
950 	      { struct unimapinit ui;
951 		if (!perm)
952 			goto eperm;
953 		ret = copy_from_user(&ui, up, sizeof(struct unimapinit));
954 		if (ret)
955 			ret = -EFAULT;
956 		else
957 			con_clear_unimap(vc, &ui);
958 		break;
959 	      }
960 
961 	case PIO_UNIMAP:
962 	case GIO_UNIMAP:
963 		ret = do_unimap_ioctl(cmd, up, perm, vc);
964 		break;
965 
966 	case VT_LOCKSWITCH:
967 		if (!capable(CAP_SYS_TTY_CONFIG))
968 			goto eperm;
969 		vt_dont_switch = 1;
970 		break;
971 	case VT_UNLOCKSWITCH:
972 		if (!capable(CAP_SYS_TTY_CONFIG))
973 			goto eperm;
974 		vt_dont_switch = 0;
975 		break;
976 	case VT_GETHIFONTMASK:
977 		ret = put_user(vc->vc_hi_font_mask,
978 					(unsigned short __user *)arg);
979 		break;
980 	case VT_WAITEVENT:
981 		ret = vt_event_wait_ioctl((struct vt_event __user *)arg);
982 		break;
983 	default:
984 		ret = -ENOIOCTLCMD;
985 	}
986 out:
987 	tty_unlock();
988 	return ret;
989 eperm:
990 	ret = -EPERM;
991 	goto out;
992 }
993 
994 void reset_vc(struct vc_data *vc)
995 {
996 	vc->vc_mode = KD_TEXT;
997 	vt_reset_unicode(vc->vc_num);
998 	vc->vt_mode.mode = VT_AUTO;
999 	vc->vt_mode.waitv = 0;
1000 	vc->vt_mode.relsig = 0;
1001 	vc->vt_mode.acqsig = 0;
1002 	vc->vt_mode.frsig = 0;
1003 	put_pid(vc->vt_pid);
1004 	vc->vt_pid = NULL;
1005 	vc->vt_newvt = -1;
1006 	if (!in_interrupt())    /* Via keyboard.c:SAK() - akpm */
1007 		reset_palette(vc);
1008 }
1009 
1010 void vc_SAK(struct work_struct *work)
1011 {
1012 	struct vc *vc_con =
1013 		container_of(work, struct vc, SAK_work);
1014 	struct vc_data *vc;
1015 	struct tty_struct *tty;
1016 
1017 	console_lock();
1018 	vc = vc_con->d;
1019 	if (vc) {
1020 		/* FIXME: review tty ref counting */
1021 		tty = vc->port.tty;
1022 		/*
1023 		 * SAK should also work in all raw modes and reset
1024 		 * them properly.
1025 		 */
1026 		if (tty)
1027 			__do_SAK(tty);
1028 		reset_vc(vc);
1029 	}
1030 	console_unlock();
1031 }
1032 
1033 #ifdef CONFIG_COMPAT
1034 
1035 struct compat_consolefontdesc {
1036 	unsigned short charcount;       /* characters in font (256 or 512) */
1037 	unsigned short charheight;      /* scan lines per character (1-32) */
1038 	compat_caddr_t chardata;	/* font data in expanded form */
1039 };
1040 
1041 static inline int
1042 compat_fontx_ioctl(int cmd, struct compat_consolefontdesc __user *user_cfd,
1043 			 int perm, struct console_font_op *op)
1044 {
1045 	struct compat_consolefontdesc cfdarg;
1046 	int i;
1047 
1048 	if (copy_from_user(&cfdarg, user_cfd, sizeof(struct compat_consolefontdesc)))
1049 		return -EFAULT;
1050 
1051 	switch (cmd) {
1052 	case PIO_FONTX:
1053 		if (!perm)
1054 			return -EPERM;
1055 		op->op = KD_FONT_OP_SET;
1056 		op->flags = KD_FONT_FLAG_OLD;
1057 		op->width = 8;
1058 		op->height = cfdarg.charheight;
1059 		op->charcount = cfdarg.charcount;
1060 		op->data = compat_ptr(cfdarg.chardata);
1061 		return con_font_op(vc_cons[fg_console].d, op);
1062 	case GIO_FONTX:
1063 		op->op = KD_FONT_OP_GET;
1064 		op->flags = KD_FONT_FLAG_OLD;
1065 		op->width = 8;
1066 		op->height = cfdarg.charheight;
1067 		op->charcount = cfdarg.charcount;
1068 		op->data = compat_ptr(cfdarg.chardata);
1069 		i = con_font_op(vc_cons[fg_console].d, op);
1070 		if (i)
1071 			return i;
1072 		cfdarg.charheight = op->height;
1073 		cfdarg.charcount = op->charcount;
1074 		if (copy_to_user(user_cfd, &cfdarg, sizeof(struct compat_consolefontdesc)))
1075 			return -EFAULT;
1076 		return 0;
1077 	}
1078 	return -EINVAL;
1079 }
1080 
1081 struct compat_console_font_op {
1082 	compat_uint_t op;        /* operation code KD_FONT_OP_* */
1083 	compat_uint_t flags;     /* KD_FONT_FLAG_* */
1084 	compat_uint_t width, height;     /* font size */
1085 	compat_uint_t charcount;
1086 	compat_caddr_t data;    /* font data with height fixed to 32 */
1087 };
1088 
1089 static inline int
1090 compat_kdfontop_ioctl(struct compat_console_font_op __user *fontop,
1091 			 int perm, struct console_font_op *op, struct vc_data *vc)
1092 {
1093 	int i;
1094 
1095 	if (copy_from_user(op, fontop, sizeof(struct compat_console_font_op)))
1096 		return -EFAULT;
1097 	if (!perm && op->op != KD_FONT_OP_GET)
1098 		return -EPERM;
1099 	op->data = compat_ptr(((struct compat_console_font_op *)op)->data);
1100 	i = con_font_op(vc, op);
1101 	if (i)
1102 		return i;
1103 	((struct compat_console_font_op *)op)->data = (unsigned long)op->data;
1104 	if (copy_to_user(fontop, op, sizeof(struct compat_console_font_op)))
1105 		return -EFAULT;
1106 	return 0;
1107 }
1108 
1109 struct compat_unimapdesc {
1110 	unsigned short entry_ct;
1111 	compat_caddr_t entries;
1112 };
1113 
1114 static inline int
1115 compat_unimap_ioctl(unsigned int cmd, struct compat_unimapdesc __user *user_ud,
1116 			 int perm, struct vc_data *vc)
1117 {
1118 	struct compat_unimapdesc tmp;
1119 	struct unipair __user *tmp_entries;
1120 
1121 	if (copy_from_user(&tmp, user_ud, sizeof tmp))
1122 		return -EFAULT;
1123 	tmp_entries = compat_ptr(tmp.entries);
1124 	if (tmp_entries)
1125 		if (!access_ok(VERIFY_WRITE, tmp_entries,
1126 				tmp.entry_ct*sizeof(struct unipair)))
1127 			return -EFAULT;
1128 	switch (cmd) {
1129 	case PIO_UNIMAP:
1130 		if (!perm)
1131 			return -EPERM;
1132 		return con_set_unimap(vc, tmp.entry_ct, tmp_entries);
1133 	case GIO_UNIMAP:
1134 		if (!perm && fg_console != vc->vc_num)
1135 			return -EPERM;
1136 		return con_get_unimap(vc, tmp.entry_ct, &(user_ud->entry_ct), tmp_entries);
1137 	}
1138 	return 0;
1139 }
1140 
1141 long vt_compat_ioctl(struct tty_struct *tty,
1142 	     unsigned int cmd, unsigned long arg)
1143 {
1144 	struct vc_data *vc = tty->driver_data;
1145 	struct console_font_op op;	/* used in multiple places here */
1146 	unsigned int console;
1147 	void __user *up = (void __user *)arg;
1148 	int perm;
1149 	int ret = 0;
1150 
1151 	console = vc->vc_num;
1152 
1153 	tty_lock();
1154 
1155 	if (!vc_cons_allocated(console)) { 	/* impossible? */
1156 		ret = -ENOIOCTLCMD;
1157 		goto out;
1158 	}
1159 
1160 	/*
1161 	 * To have permissions to do most of the vt ioctls, we either have
1162 	 * to be the owner of the tty, or have CAP_SYS_TTY_CONFIG.
1163 	 */
1164 	perm = 0;
1165 	if (current->signal->tty == tty || capable(CAP_SYS_TTY_CONFIG))
1166 		perm = 1;
1167 
1168 	switch (cmd) {
1169 	/*
1170 	 * these need special handlers for incompatible data structures
1171 	 */
1172 	case PIO_FONTX:
1173 	case GIO_FONTX:
1174 		ret = compat_fontx_ioctl(cmd, up, perm, &op);
1175 		break;
1176 
1177 	case KDFONTOP:
1178 		ret = compat_kdfontop_ioctl(up, perm, &op, vc);
1179 		break;
1180 
1181 	case PIO_UNIMAP:
1182 	case GIO_UNIMAP:
1183 		ret = compat_unimap_ioctl(cmd, up, perm, vc);
1184 		break;
1185 
1186 	/*
1187 	 * all these treat 'arg' as an integer
1188 	 */
1189 	case KIOCSOUND:
1190 	case KDMKTONE:
1191 #ifdef CONFIG_X86
1192 	case KDADDIO:
1193 	case KDDELIO:
1194 #endif
1195 	case KDSETMODE:
1196 	case KDMAPDISP:
1197 	case KDUNMAPDISP:
1198 	case KDSKBMODE:
1199 	case KDSKBMETA:
1200 	case KDSKBLED:
1201 	case KDSETLED:
1202 	case KDSIGACCEPT:
1203 	case VT_ACTIVATE:
1204 	case VT_WAITACTIVE:
1205 	case VT_RELDISP:
1206 	case VT_DISALLOCATE:
1207 	case VT_RESIZE:
1208 	case VT_RESIZEX:
1209 		goto fallback;
1210 
1211 	/*
1212 	 * the rest has a compatible data structure behind arg,
1213 	 * but we have to convert it to a proper 64 bit pointer.
1214 	 */
1215 	default:
1216 		arg = (unsigned long)compat_ptr(arg);
1217 		goto fallback;
1218 	}
1219 out:
1220 	tty_unlock();
1221 	return ret;
1222 
1223 fallback:
1224 	tty_unlock();
1225 	return vt_ioctl(tty, cmd, arg);
1226 }
1227 
1228 
1229 #endif /* CONFIG_COMPAT */
1230 
1231 
1232 /*
1233  * Performs the back end of a vt switch. Called under the console
1234  * semaphore.
1235  */
1236 static void complete_change_console(struct vc_data *vc)
1237 {
1238 	unsigned char old_vc_mode;
1239 	int old = fg_console;
1240 
1241 	last_console = fg_console;
1242 
1243 	/*
1244 	 * If we're switching, we could be going from KD_GRAPHICS to
1245 	 * KD_TEXT mode or vice versa, which means we need to blank or
1246 	 * unblank the screen later.
1247 	 */
1248 	old_vc_mode = vc_cons[fg_console].d->vc_mode;
1249 	switch_screen(vc);
1250 
1251 	/*
1252 	 * This can't appear below a successful kill_pid().  If it did,
1253 	 * then the *blank_screen operation could occur while X, having
1254 	 * received acqsig, is waking up on another processor.  This
1255 	 * condition can lead to overlapping accesses to the VGA range
1256 	 * and the framebuffer (causing system lockups).
1257 	 *
1258 	 * To account for this we duplicate this code below only if the
1259 	 * controlling process is gone and we've called reset_vc.
1260 	 */
1261 	if (old_vc_mode != vc->vc_mode) {
1262 		if (vc->vc_mode == KD_TEXT)
1263 			do_unblank_screen(1);
1264 		else
1265 			do_blank_screen(1);
1266 	}
1267 
1268 	/*
1269 	 * If this new console is under process control, send it a signal
1270 	 * telling it that it has acquired. Also check if it has died and
1271 	 * clean up (similar to logic employed in change_console())
1272 	 */
1273 	if (vc->vt_mode.mode == VT_PROCESS) {
1274 		/*
1275 		 * Send the signal as privileged - kill_pid() will
1276 		 * tell us if the process has gone or something else
1277 		 * is awry
1278 		 */
1279 		if (kill_pid(vc->vt_pid, vc->vt_mode.acqsig, 1) != 0) {
1280 		/*
1281 		 * The controlling process has died, so we revert back to
1282 		 * normal operation. In this case, we'll also change back
1283 		 * to KD_TEXT mode. I'm not sure if this is strictly correct
1284 		 * but it saves the agony when the X server dies and the screen
1285 		 * remains blanked due to KD_GRAPHICS! It would be nice to do
1286 		 * this outside of VT_PROCESS but there is no single process
1287 		 * to account for and tracking tty count may be undesirable.
1288 		 */
1289 			reset_vc(vc);
1290 
1291 			if (old_vc_mode != vc->vc_mode) {
1292 				if (vc->vc_mode == KD_TEXT)
1293 					do_unblank_screen(1);
1294 				else
1295 					do_blank_screen(1);
1296 			}
1297 		}
1298 	}
1299 
1300 	/*
1301 	 * Wake anyone waiting for their VT to activate
1302 	 */
1303 	vt_event_post(VT_EVENT_SWITCH, old, vc->vc_num);
1304 	return;
1305 }
1306 
1307 /*
1308  * Performs the front-end of a vt switch
1309  */
1310 void change_console(struct vc_data *new_vc)
1311 {
1312 	struct vc_data *vc;
1313 
1314 	if (!new_vc || new_vc->vc_num == fg_console || vt_dont_switch)
1315 		return;
1316 
1317 	/*
1318 	 * If this vt is in process mode, then we need to handshake with
1319 	 * that process before switching. Essentially, we store where that
1320 	 * vt wants to switch to and wait for it to tell us when it's done
1321 	 * (via VT_RELDISP ioctl).
1322 	 *
1323 	 * We also check to see if the controlling process still exists.
1324 	 * If it doesn't, we reset this vt to auto mode and continue.
1325 	 * This is a cheap way to track process control. The worst thing
1326 	 * that can happen is: we send a signal to a process, it dies, and
1327 	 * the switch gets "lost" waiting for a response; hopefully, the
1328 	 * user will try again, we'll detect the process is gone (unless
1329 	 * the user waits just the right amount of time :-) and revert the
1330 	 * vt to auto control.
1331 	 */
1332 	vc = vc_cons[fg_console].d;
1333 	if (vc->vt_mode.mode == VT_PROCESS) {
1334 		/*
1335 		 * Send the signal as privileged - kill_pid() will
1336 		 * tell us if the process has gone or something else
1337 		 * is awry.
1338 		 *
1339 		 * We need to set vt_newvt *before* sending the signal or we
1340 		 * have a race.
1341 		 */
1342 		vc->vt_newvt = new_vc->vc_num;
1343 		if (kill_pid(vc->vt_pid, vc->vt_mode.relsig, 1) == 0) {
1344 			/*
1345 			 * It worked. Mark the vt to switch to and
1346 			 * return. The process needs to send us a
1347 			 * VT_RELDISP ioctl to complete the switch.
1348 			 */
1349 			return;
1350 		}
1351 
1352 		/*
1353 		 * The controlling process has died, so we revert back to
1354 		 * normal operation. In this case, we'll also change back
1355 		 * to KD_TEXT mode. I'm not sure if this is strictly correct
1356 		 * but it saves the agony when the X server dies and the screen
1357 		 * remains blanked due to KD_GRAPHICS! It would be nice to do
1358 		 * this outside of VT_PROCESS but there is no single process
1359 		 * to account for and tracking tty count may be undesirable.
1360 		 */
1361 		reset_vc(vc);
1362 
1363 		/*
1364 		 * Fall through to normal (VT_AUTO) handling of the switch...
1365 		 */
1366 	}
1367 
1368 	/*
1369 	 * Ignore all switches in KD_GRAPHICS+VT_AUTO mode
1370 	 */
1371 	if (vc->vc_mode == KD_GRAPHICS)
1372 		return;
1373 
1374 	complete_change_console(new_vc);
1375 }
1376 
1377 /* Perform a kernel triggered VT switch for suspend/resume */
1378 
1379 static int disable_vt_switch;
1380 
1381 int vt_move_to_console(unsigned int vt, int alloc)
1382 {
1383 	int prev;
1384 
1385 	console_lock();
1386 	/* Graphics mode - up to X */
1387 	if (disable_vt_switch) {
1388 		console_unlock();
1389 		return 0;
1390 	}
1391 	prev = fg_console;
1392 
1393 	if (alloc && vc_allocate(vt)) {
1394 		/* we can't have a free VC for now. Too bad,
1395 		 * we don't want to mess the screen for now. */
1396 		console_unlock();
1397 		return -ENOSPC;
1398 	}
1399 
1400 	if (set_console(vt)) {
1401 		/*
1402 		 * We're unable to switch to the SUSPEND_CONSOLE.
1403 		 * Let the calling function know so it can decide
1404 		 * what to do.
1405 		 */
1406 		console_unlock();
1407 		return -EIO;
1408 	}
1409 	console_unlock();
1410 	tty_lock();
1411 	if (vt_waitactive(vt + 1)) {
1412 		pr_debug("Suspend: Can't switch VCs.");
1413 		tty_unlock();
1414 		return -EINTR;
1415 	}
1416 	tty_unlock();
1417 	return prev;
1418 }
1419 
1420 /*
1421  * Normally during a suspend, we allocate a new console and switch to it.
1422  * When we resume, we switch back to the original console.  This switch
1423  * can be slow, so on systems where the framebuffer can handle restoration
1424  * of video registers anyways, there's little point in doing the console
1425  * switch.  This function allows you to disable it by passing it '0'.
1426  */
1427 void pm_set_vt_switch(int do_switch)
1428 {
1429 	console_lock();
1430 	disable_vt_switch = !do_switch;
1431 	console_unlock();
1432 }
1433 EXPORT_SYMBOL(pm_set_vt_switch);
1434