xref: /openbmc/linux/drivers/tty/vt/vt_ioctl.c (revision 28f65c11)
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 #define i (tmp.kb_index)
199 #define s (tmp.kb_table)
200 #define v (tmp.kb_value)
201 static inline int
202 do_kdsk_ioctl(int cmd, struct kbentry __user *user_kbe, int perm, struct kbd_struct *kbd)
203 {
204 	struct kbentry tmp;
205 	ushort *key_map, val, ov;
206 
207 	if (copy_from_user(&tmp, user_kbe, sizeof(struct kbentry)))
208 		return -EFAULT;
209 
210 	if (!capable(CAP_SYS_TTY_CONFIG))
211 		perm = 0;
212 
213 	switch (cmd) {
214 	case KDGKBENT:
215 		key_map = key_maps[s];
216 		if (key_map) {
217 		    val = U(key_map[i]);
218 		    if (kbd->kbdmode != VC_UNICODE && KTYP(val) >= NR_TYPES)
219 			val = K_HOLE;
220 		} else
221 		    val = (i ? K_HOLE : K_NOSUCHMAP);
222 		return put_user(val, &user_kbe->kb_value);
223 	case KDSKBENT:
224 		if (!perm)
225 			return -EPERM;
226 		if (!i && v == K_NOSUCHMAP) {
227 			/* deallocate map */
228 			key_map = key_maps[s];
229 			if (s && key_map) {
230 			    key_maps[s] = NULL;
231 			    if (key_map[0] == U(K_ALLOCATED)) {
232 					kfree(key_map);
233 					keymap_count--;
234 			    }
235 			}
236 			break;
237 		}
238 
239 		if (KTYP(v) < NR_TYPES) {
240 		    if (KVAL(v) > max_vals[KTYP(v)])
241 				return -EINVAL;
242 		} else
243 		    if (kbd->kbdmode != VC_UNICODE)
244 				return -EINVAL;
245 
246 		/* ++Geert: non-PC keyboards may generate keycode zero */
247 #if !defined(__mc68000__) && !defined(__powerpc__)
248 		/* assignment to entry 0 only tests validity of args */
249 		if (!i)
250 			break;
251 #endif
252 
253 		if (!(key_map = key_maps[s])) {
254 			int j;
255 
256 			if (keymap_count >= MAX_NR_OF_USER_KEYMAPS &&
257 			    !capable(CAP_SYS_RESOURCE))
258 				return -EPERM;
259 
260 			key_map = kmalloc(sizeof(plain_map),
261 						     GFP_KERNEL);
262 			if (!key_map)
263 				return -ENOMEM;
264 			key_maps[s] = key_map;
265 			key_map[0] = U(K_ALLOCATED);
266 			for (j = 1; j < NR_KEYS; j++)
267 				key_map[j] = U(K_HOLE);
268 			keymap_count++;
269 		}
270 		ov = U(key_map[i]);
271 		if (v == ov)
272 			break;	/* nothing to do */
273 		/*
274 		 * Attention Key.
275 		 */
276 		if (((ov == K_SAK) || (v == K_SAK)) && !capable(CAP_SYS_ADMIN))
277 			return -EPERM;
278 		key_map[i] = U(v);
279 		if (!s && (KTYP(ov) == KT_SHIFT || KTYP(v) == KT_SHIFT))
280 			compute_shiftstate();
281 		break;
282 	}
283 	return 0;
284 }
285 #undef i
286 #undef s
287 #undef v
288 
289 static inline int
290 do_kbkeycode_ioctl(int cmd, struct kbkeycode __user *user_kbkc, int perm)
291 {
292 	struct kbkeycode tmp;
293 	int kc = 0;
294 
295 	if (copy_from_user(&tmp, user_kbkc, sizeof(struct kbkeycode)))
296 		return -EFAULT;
297 	switch (cmd) {
298 	case KDGETKEYCODE:
299 		kc = getkeycode(tmp.scancode);
300 		if (kc >= 0)
301 			kc = put_user(kc, &user_kbkc->keycode);
302 		break;
303 	case KDSETKEYCODE:
304 		if (!perm)
305 			return -EPERM;
306 		kc = setkeycode(tmp.scancode, tmp.keycode);
307 		break;
308 	}
309 	return kc;
310 }
311 
312 static inline int
313 do_kdgkb_ioctl(int cmd, struct kbsentry __user *user_kdgkb, int perm)
314 {
315 	struct kbsentry *kbs;
316 	char *p;
317 	u_char *q;
318 	u_char __user *up;
319 	int sz;
320 	int delta;
321 	char *first_free, *fj, *fnw;
322 	int i, j, k;
323 	int ret;
324 
325 	if (!capable(CAP_SYS_TTY_CONFIG))
326 		perm = 0;
327 
328 	kbs = kmalloc(sizeof(*kbs), GFP_KERNEL);
329 	if (!kbs) {
330 		ret = -ENOMEM;
331 		goto reterr;
332 	}
333 
334 	/* we mostly copy too much here (512bytes), but who cares ;) */
335 	if (copy_from_user(kbs, user_kdgkb, sizeof(struct kbsentry))) {
336 		ret = -EFAULT;
337 		goto reterr;
338 	}
339 	kbs->kb_string[sizeof(kbs->kb_string)-1] = '\0';
340 	i = kbs->kb_func;
341 
342 	switch (cmd) {
343 	case KDGKBSENT:
344 		sz = sizeof(kbs->kb_string) - 1; /* sz should have been
345 						  a struct member */
346 		up = user_kdgkb->kb_string;
347 		p = func_table[i];
348 		if(p)
349 			for ( ; *p && sz; p++, sz--)
350 				if (put_user(*p, up++)) {
351 					ret = -EFAULT;
352 					goto reterr;
353 				}
354 		if (put_user('\0', up)) {
355 			ret = -EFAULT;
356 			goto reterr;
357 		}
358 		kfree(kbs);
359 		return ((p && *p) ? -EOVERFLOW : 0);
360 	case KDSKBSENT:
361 		if (!perm) {
362 			ret = -EPERM;
363 			goto reterr;
364 		}
365 
366 		q = func_table[i];
367 		first_free = funcbufptr + (funcbufsize - funcbufleft);
368 		for (j = i+1; j < MAX_NR_FUNC && !func_table[j]; j++)
369 			;
370 		if (j < MAX_NR_FUNC)
371 			fj = func_table[j];
372 		else
373 			fj = first_free;
374 
375 		delta = (q ? -strlen(q) : 1) + strlen(kbs->kb_string);
376 		if (delta <= funcbufleft) { 	/* it fits in current buf */
377 		    if (j < MAX_NR_FUNC) {
378 			memmove(fj + delta, fj, first_free - fj);
379 			for (k = j; k < MAX_NR_FUNC; k++)
380 			    if (func_table[k])
381 				func_table[k] += delta;
382 		    }
383 		    if (!q)
384 		      func_table[i] = fj;
385 		    funcbufleft -= delta;
386 		} else {			/* allocate a larger buffer */
387 		    sz = 256;
388 		    while (sz < funcbufsize - funcbufleft + delta)
389 		      sz <<= 1;
390 		    fnw = kmalloc(sz, GFP_KERNEL);
391 		    if(!fnw) {
392 		      ret = -ENOMEM;
393 		      goto reterr;
394 		    }
395 
396 		    if (!q)
397 		      func_table[i] = fj;
398 		    if (fj > funcbufptr)
399 			memmove(fnw, funcbufptr, fj - funcbufptr);
400 		    for (k = 0; k < j; k++)
401 		      if (func_table[k])
402 			func_table[k] = fnw + (func_table[k] - funcbufptr);
403 
404 		    if (first_free > fj) {
405 			memmove(fnw + (fj - funcbufptr) + delta, fj, first_free - fj);
406 			for (k = j; k < MAX_NR_FUNC; k++)
407 			  if (func_table[k])
408 			    func_table[k] = fnw + (func_table[k] - funcbufptr) + delta;
409 		    }
410 		    if (funcbufptr != func_buf)
411 		      kfree(funcbufptr);
412 		    funcbufptr = fnw;
413 		    funcbufleft = funcbufleft - delta + sz - funcbufsize;
414 		    funcbufsize = sz;
415 		}
416 		strcpy(func_table[i], kbs->kb_string);
417 		break;
418 	}
419 	ret = 0;
420 reterr:
421 	kfree(kbs);
422 	return ret;
423 }
424 
425 static inline int
426 do_fontx_ioctl(int cmd, struct consolefontdesc __user *user_cfd, int perm, struct console_font_op *op)
427 {
428 	struct consolefontdesc cfdarg;
429 	int i;
430 
431 	if (copy_from_user(&cfdarg, user_cfd, sizeof(struct consolefontdesc)))
432 		return -EFAULT;
433 
434 	switch (cmd) {
435 	case PIO_FONTX:
436 		if (!perm)
437 			return -EPERM;
438 		op->op = KD_FONT_OP_SET;
439 		op->flags = KD_FONT_FLAG_OLD;
440 		op->width = 8;
441 		op->height = cfdarg.charheight;
442 		op->charcount = cfdarg.charcount;
443 		op->data = cfdarg.chardata;
444 		return con_font_op(vc_cons[fg_console].d, op);
445 	case GIO_FONTX: {
446 		op->op = KD_FONT_OP_GET;
447 		op->flags = KD_FONT_FLAG_OLD;
448 		op->width = 8;
449 		op->height = cfdarg.charheight;
450 		op->charcount = cfdarg.charcount;
451 		op->data = cfdarg.chardata;
452 		i = con_font_op(vc_cons[fg_console].d, op);
453 		if (i)
454 			return i;
455 		cfdarg.charheight = op->height;
456 		cfdarg.charcount = op->charcount;
457 		if (copy_to_user(user_cfd, &cfdarg, sizeof(struct consolefontdesc)))
458 			return -EFAULT;
459 		return 0;
460 		}
461 	}
462 	return -EINVAL;
463 }
464 
465 static inline int
466 do_unimap_ioctl(int cmd, struct unimapdesc __user *user_ud, int perm, struct vc_data *vc)
467 {
468 	struct unimapdesc tmp;
469 
470 	if (copy_from_user(&tmp, user_ud, sizeof tmp))
471 		return -EFAULT;
472 	if (tmp.entries)
473 		if (!access_ok(VERIFY_WRITE, tmp.entries,
474 				tmp.entry_ct*sizeof(struct unipair)))
475 			return -EFAULT;
476 	switch (cmd) {
477 	case PIO_UNIMAP:
478 		if (!perm)
479 			return -EPERM;
480 		return con_set_unimap(vc, tmp.entry_ct, tmp.entries);
481 	case GIO_UNIMAP:
482 		if (!perm && fg_console != vc->vc_num)
483 			return -EPERM;
484 		return con_get_unimap(vc, tmp.entry_ct, &(user_ud->entry_ct), tmp.entries);
485 	}
486 	return 0;
487 }
488 
489 
490 
491 /*
492  * We handle the console-specific ioctl's here.  We allow the
493  * capability to modify any console, not just the fg_console.
494  */
495 int vt_ioctl(struct tty_struct *tty,
496 	     unsigned int cmd, unsigned long arg)
497 {
498 	struct vc_data *vc = tty->driver_data;
499 	struct console_font_op op;	/* used in multiple places here */
500 	struct kbd_struct * kbd;
501 	unsigned int console;
502 	unsigned char ucval;
503 	unsigned int uival;
504 	void __user *up = (void __user *)arg;
505 	int i, perm;
506 	int ret = 0;
507 
508 	console = vc->vc_num;
509 
510 	tty_lock();
511 
512 	if (!vc_cons_allocated(console)) { 	/* impossible? */
513 		ret = -ENOIOCTLCMD;
514 		goto out;
515 	}
516 
517 
518 	/*
519 	 * To have permissions to do most of the vt ioctls, we either have
520 	 * to be the owner of the tty, or have CAP_SYS_TTY_CONFIG.
521 	 */
522 	perm = 0;
523 	if (current->signal->tty == tty || capable(CAP_SYS_TTY_CONFIG))
524 		perm = 1;
525 
526 	kbd = kbd_table + console;
527 	switch (cmd) {
528 	case TIOCLINUX:
529 		ret = tioclinux(tty, arg);
530 		break;
531 	case KIOCSOUND:
532 		if (!perm)
533 			goto eperm;
534 		/*
535 		 * The use of PIT_TICK_RATE is historic, it used to be
536 		 * the platform-dependent CLOCK_TICK_RATE between 2.6.12
537 		 * and 2.6.36, which was a minor but unfortunate ABI
538 		 * change.
539 		 */
540 		if (arg)
541 			arg = PIT_TICK_RATE / arg;
542 		kd_mksound(arg, 0);
543 		break;
544 
545 	case KDMKTONE:
546 		if (!perm)
547 			goto eperm;
548 	{
549 		unsigned int ticks, count;
550 
551 		/*
552 		 * Generate the tone for the appropriate number of ticks.
553 		 * If the time is zero, turn off sound ourselves.
554 		 */
555 		ticks = HZ * ((arg >> 16) & 0xffff) / 1000;
556 		count = ticks ? (arg & 0xffff) : 0;
557 		if (count)
558 			count = PIT_TICK_RATE / count;
559 		kd_mksound(count, ticks);
560 		break;
561 	}
562 
563 	case KDGKBTYPE:
564 		/*
565 		 * this is naive.
566 		 */
567 		ucval = KB_101;
568 		goto setchar;
569 
570 		/*
571 		 * These cannot be implemented on any machine that implements
572 		 * ioperm() in user level (such as Alpha PCs) or not at all.
573 		 *
574 		 * XXX: you should never use these, just call ioperm directly..
575 		 */
576 #ifdef CONFIG_X86
577 	case KDADDIO:
578 	case KDDELIO:
579 		/*
580 		 * KDADDIO and KDDELIO may be able to add ports beyond what
581 		 * we reject here, but to be safe...
582 		 */
583 		if (arg < GPFIRST || arg > GPLAST) {
584 			ret = -EINVAL;
585 			break;
586 		}
587 		ret = sys_ioperm(arg, 1, (cmd == KDADDIO)) ? -ENXIO : 0;
588 		break;
589 
590 	case KDENABIO:
591 	case KDDISABIO:
592 		ret = sys_ioperm(GPFIRST, GPNUM,
593 				  (cmd == KDENABIO)) ? -ENXIO : 0;
594 		break;
595 #endif
596 
597 	/* Linux m68k/i386 interface for setting the keyboard delay/repeat rate */
598 
599 	case KDKBDREP:
600 	{
601 		struct kbd_repeat kbrep;
602 
603 		if (!capable(CAP_SYS_TTY_CONFIG))
604 			goto eperm;
605 
606 		if (copy_from_user(&kbrep, up, sizeof(struct kbd_repeat))) {
607 			ret =  -EFAULT;
608 			break;
609 		}
610 		ret = kbd_rate(&kbrep);
611 		if (ret)
612 			break;
613 		if (copy_to_user(up, &kbrep, sizeof(struct kbd_repeat)))
614 			ret = -EFAULT;
615 		break;
616 	}
617 
618 	case KDSETMODE:
619 		/*
620 		 * currently, setting the mode from KD_TEXT to KD_GRAPHICS
621 		 * doesn't do a whole lot. i'm not sure if it should do any
622 		 * restoration of modes or what...
623 		 *
624 		 * XXX It should at least call into the driver, fbdev's definitely
625 		 * need to restore their engine state. --BenH
626 		 */
627 		if (!perm)
628 			goto eperm;
629 		switch (arg) {
630 		case KD_GRAPHICS:
631 			break;
632 		case KD_TEXT0:
633 		case KD_TEXT1:
634 			arg = KD_TEXT;
635 		case KD_TEXT:
636 			break;
637 		default:
638 			ret = -EINVAL;
639 			goto out;
640 		}
641 		if (vc->vc_mode == (unsigned char) arg)
642 			break;
643 		vc->vc_mode = (unsigned char) arg;
644 		if (console != fg_console)
645 			break;
646 		/*
647 		 * explicitly blank/unblank the screen if switching modes
648 		 */
649 		console_lock();
650 		if (arg == KD_TEXT)
651 			do_unblank_screen(1);
652 		else
653 			do_blank_screen(1);
654 		console_unlock();
655 		break;
656 
657 	case KDGETMODE:
658 		uival = vc->vc_mode;
659 		goto setint;
660 
661 	case KDMAPDISP:
662 	case KDUNMAPDISP:
663 		/*
664 		 * these work like a combination of mmap and KDENABIO.
665 		 * this could be easily finished.
666 		 */
667 		ret = -EINVAL;
668 		break;
669 
670 	case KDSKBMODE:
671 		if (!perm)
672 			goto eperm;
673 		switch(arg) {
674 		  case K_RAW:
675 			kbd->kbdmode = VC_RAW;
676 			break;
677 		  case K_MEDIUMRAW:
678 			kbd->kbdmode = VC_MEDIUMRAW;
679 			break;
680 		  case K_XLATE:
681 			kbd->kbdmode = VC_XLATE;
682 			compute_shiftstate();
683 			break;
684 		  case K_UNICODE:
685 			kbd->kbdmode = VC_UNICODE;
686 			compute_shiftstate();
687 			break;
688 		  case K_OFF:
689 			kbd->kbdmode = VC_OFF;
690 			break;
691 		  default:
692 			ret = -EINVAL;
693 			goto out;
694 		}
695 		tty_ldisc_flush(tty);
696 		break;
697 
698 	case KDGKBMODE:
699 		switch (kbd->kbdmode) {
700 		case VC_RAW:
701 			uival = K_RAW;
702 			break;
703 		case VC_MEDIUMRAW:
704 			uival = K_MEDIUMRAW;
705 			break;
706 		case VC_UNICODE:
707 			uival = K_UNICODE;
708 			break;
709 		case VC_OFF:
710 			uival = K_OFF;
711 			break;
712 		default:
713 			uival = K_XLATE;
714 			break;
715 		}
716 		goto setint;
717 
718 	/* this could be folded into KDSKBMODE, but for compatibility
719 	   reasons it is not so easy to fold KDGKBMETA into KDGKBMODE */
720 	case KDSKBMETA:
721 		switch(arg) {
722 		  case K_METABIT:
723 			clr_vc_kbd_mode(kbd, VC_META);
724 			break;
725 		  case K_ESCPREFIX:
726 			set_vc_kbd_mode(kbd, VC_META);
727 			break;
728 		  default:
729 			ret = -EINVAL;
730 		}
731 		break;
732 
733 	case KDGKBMETA:
734 		uival = (vc_kbd_mode(kbd, VC_META) ? K_ESCPREFIX : K_METABIT);
735 	setint:
736 		ret = put_user(uival, (int __user *)arg);
737 		break;
738 
739 	case KDGETKEYCODE:
740 	case KDSETKEYCODE:
741 		if(!capable(CAP_SYS_TTY_CONFIG))
742 			perm = 0;
743 		ret = do_kbkeycode_ioctl(cmd, up, perm);
744 		break;
745 
746 	case KDGKBENT:
747 	case KDSKBENT:
748 		ret = do_kdsk_ioctl(cmd, up, perm, kbd);
749 		break;
750 
751 	case KDGKBSENT:
752 	case KDSKBSENT:
753 		ret = do_kdgkb_ioctl(cmd, up, perm);
754 		break;
755 
756 	case KDGKBDIACR:
757 	{
758 		struct kbdiacrs __user *a = up;
759 		struct kbdiacr diacr;
760 		int i;
761 
762 		if (put_user(accent_table_size, &a->kb_cnt)) {
763 			ret = -EFAULT;
764 			break;
765 		}
766 		for (i = 0; i < accent_table_size; i++) {
767 			diacr.diacr = conv_uni_to_8bit(accent_table[i].diacr);
768 			diacr.base = conv_uni_to_8bit(accent_table[i].base);
769 			diacr.result = conv_uni_to_8bit(accent_table[i].result);
770 			if (copy_to_user(a->kbdiacr + i, &diacr, sizeof(struct kbdiacr))) {
771 				ret = -EFAULT;
772 				break;
773 			}
774 		}
775 		break;
776 	}
777 	case KDGKBDIACRUC:
778 	{
779 		struct kbdiacrsuc __user *a = up;
780 
781 		if (put_user(accent_table_size, &a->kb_cnt))
782 			ret = -EFAULT;
783 		else if (copy_to_user(a->kbdiacruc, accent_table,
784 				accent_table_size*sizeof(struct kbdiacruc)))
785 			ret = -EFAULT;
786 		break;
787 	}
788 
789 	case KDSKBDIACR:
790 	{
791 		struct kbdiacrs __user *a = up;
792 		struct kbdiacr diacr;
793 		unsigned int ct;
794 		int i;
795 
796 		if (!perm)
797 			goto eperm;
798 		if (get_user(ct,&a->kb_cnt)) {
799 			ret = -EFAULT;
800 			break;
801 		}
802 		if (ct >= MAX_DIACR) {
803 			ret = -EINVAL;
804 			break;
805 		}
806 		accent_table_size = ct;
807 		for (i = 0; i < ct; i++) {
808 			if (copy_from_user(&diacr, a->kbdiacr + i, sizeof(struct kbdiacr))) {
809 				ret = -EFAULT;
810 				break;
811 			}
812 			accent_table[i].diacr = conv_8bit_to_uni(diacr.diacr);
813 			accent_table[i].base = conv_8bit_to_uni(diacr.base);
814 			accent_table[i].result = conv_8bit_to_uni(diacr.result);
815 		}
816 		break;
817 	}
818 
819 	case KDSKBDIACRUC:
820 	{
821 		struct kbdiacrsuc __user *a = up;
822 		unsigned int ct;
823 
824 		if (!perm)
825 			goto eperm;
826 		if (get_user(ct,&a->kb_cnt)) {
827 			ret = -EFAULT;
828 			break;
829 		}
830 		if (ct >= MAX_DIACR) {
831 			ret = -EINVAL;
832 			break;
833 		}
834 		accent_table_size = ct;
835 		if (copy_from_user(accent_table, a->kbdiacruc, ct*sizeof(struct kbdiacruc)))
836 			ret = -EFAULT;
837 		break;
838 	}
839 
840 	/* the ioctls below read/set the flags usually shown in the leds */
841 	/* don't use them - they will go away without warning */
842 	case KDGKBLED:
843 		ucval = kbd->ledflagstate | (kbd->default_ledflagstate << 4);
844 		goto setchar;
845 
846 	case KDSKBLED:
847 		if (!perm)
848 			goto eperm;
849 		if (arg & ~0x77) {
850 			ret = -EINVAL;
851 			break;
852 		}
853 		kbd->ledflagstate = (arg & 7);
854 		kbd->default_ledflagstate = ((arg >> 4) & 7);
855 		set_leds();
856 		break;
857 
858 	/* the ioctls below only set the lights, not the functions */
859 	/* for those, see KDGKBLED and KDSKBLED above */
860 	case KDGETLED:
861 		ucval = getledstate();
862 	setchar:
863 		ret = put_user(ucval, (char __user *)arg);
864 		break;
865 
866 	case KDSETLED:
867 		if (!perm)
868 			goto eperm;
869 		setledstate(kbd, arg);
870 		break;
871 
872 	/*
873 	 * A process can indicate its willingness to accept signals
874 	 * generated by pressing an appropriate key combination.
875 	 * Thus, one can have a daemon that e.g. spawns a new console
876 	 * upon a keypress and then changes to it.
877 	 * See also the kbrequest field of inittab(5).
878 	 */
879 	case KDSIGACCEPT:
880 	{
881 		if (!perm || !capable(CAP_KILL))
882 			goto eperm;
883 		if (!valid_signal(arg) || arg < 1 || arg == SIGKILL)
884 			ret = -EINVAL;
885 		else {
886 			spin_lock_irq(&vt_spawn_con.lock);
887 			put_pid(vt_spawn_con.pid);
888 			vt_spawn_con.pid = get_pid(task_pid(current));
889 			vt_spawn_con.sig = arg;
890 			spin_unlock_irq(&vt_spawn_con.lock);
891 		}
892 		break;
893 	}
894 
895 	case VT_SETMODE:
896 	{
897 		struct vt_mode tmp;
898 
899 		if (!perm)
900 			goto eperm;
901 		if (copy_from_user(&tmp, up, sizeof(struct vt_mode))) {
902 			ret = -EFAULT;
903 			goto out;
904 		}
905 		if (tmp.mode != VT_AUTO && tmp.mode != VT_PROCESS) {
906 			ret = -EINVAL;
907 			goto out;
908 		}
909 		console_lock();
910 		vc->vt_mode = tmp;
911 		/* the frsig is ignored, so we set it to 0 */
912 		vc->vt_mode.frsig = 0;
913 		put_pid(vc->vt_pid);
914 		vc->vt_pid = get_pid(task_pid(current));
915 		/* no switch is required -- saw@shade.msu.ru */
916 		vc->vt_newvt = -1;
917 		console_unlock();
918 		break;
919 	}
920 
921 	case VT_GETMODE:
922 	{
923 		struct vt_mode tmp;
924 		int rc;
925 
926 		console_lock();
927 		memcpy(&tmp, &vc->vt_mode, sizeof(struct vt_mode));
928 		console_unlock();
929 
930 		rc = copy_to_user(up, &tmp, sizeof(struct vt_mode));
931 		if (rc)
932 			ret = -EFAULT;
933 		break;
934 	}
935 
936 	/*
937 	 * Returns global vt state. Note that VT 0 is always open, since
938 	 * it's an alias for the current VT, and people can't use it here.
939 	 * We cannot return state for more than 16 VTs, since v_state is short.
940 	 */
941 	case VT_GETSTATE:
942 	{
943 		struct vt_stat __user *vtstat = up;
944 		unsigned short state, mask;
945 
946 		if (put_user(fg_console + 1, &vtstat->v_active))
947 			ret = -EFAULT;
948 		else {
949 			state = 1;	/* /dev/tty0 is always open */
950 			for (i = 0, mask = 2; i < MAX_NR_CONSOLES && mask;
951 							++i, mask <<= 1)
952 				if (VT_IS_IN_USE(i))
953 					state |= mask;
954 			ret = put_user(state, &vtstat->v_state);
955 		}
956 		break;
957 	}
958 
959 	/*
960 	 * Returns the first available (non-opened) console.
961 	 */
962 	case VT_OPENQRY:
963 		for (i = 0; i < MAX_NR_CONSOLES; ++i)
964 			if (! VT_IS_IN_USE(i))
965 				break;
966 		uival = i < MAX_NR_CONSOLES ? (i+1) : -1;
967 		goto setint;
968 
969 	/*
970 	 * ioctl(fd, VT_ACTIVATE, num) will cause us to switch to vt # num,
971 	 * with num >= 1 (switches to vt 0, our console, are not allowed, just
972 	 * to preserve sanity).
973 	 */
974 	case VT_ACTIVATE:
975 		if (!perm)
976 			goto eperm;
977 		if (arg == 0 || arg > MAX_NR_CONSOLES)
978 			ret =  -ENXIO;
979 		else {
980 			arg--;
981 			console_lock();
982 			ret = vc_allocate(arg);
983 			console_unlock();
984 			if (ret)
985 				break;
986 			set_console(arg);
987 		}
988 		break;
989 
990 	case VT_SETACTIVATE:
991 	{
992 		struct vt_setactivate vsa;
993 
994 		if (!perm)
995 			goto eperm;
996 
997 		if (copy_from_user(&vsa, (struct vt_setactivate __user *)arg,
998 					sizeof(struct vt_setactivate))) {
999 			ret = -EFAULT;
1000 			goto out;
1001 		}
1002 		if (vsa.console == 0 || vsa.console > MAX_NR_CONSOLES)
1003 			ret = -ENXIO;
1004 		else {
1005 			vsa.console--;
1006 			console_lock();
1007 			ret = vc_allocate(vsa.console);
1008 			if (ret == 0) {
1009 				struct vc_data *nvc;
1010 				/* This is safe providing we don't drop the
1011 				   console sem between vc_allocate and
1012 				   finishing referencing nvc */
1013 				nvc = vc_cons[vsa.console].d;
1014 				nvc->vt_mode = vsa.mode;
1015 				nvc->vt_mode.frsig = 0;
1016 				put_pid(nvc->vt_pid);
1017 				nvc->vt_pid = get_pid(task_pid(current));
1018 			}
1019 			console_unlock();
1020 			if (ret)
1021 				break;
1022 			/* Commence switch and lock */
1023 			set_console(vsa.console);
1024 		}
1025 		break;
1026 	}
1027 
1028 	/*
1029 	 * wait until the specified VT has been activated
1030 	 */
1031 	case VT_WAITACTIVE:
1032 		if (!perm)
1033 			goto eperm;
1034 		if (arg == 0 || arg > MAX_NR_CONSOLES)
1035 			ret = -ENXIO;
1036 		else
1037 			ret = vt_waitactive(arg);
1038 		break;
1039 
1040 	/*
1041 	 * If a vt is under process control, the kernel will not switch to it
1042 	 * immediately, but postpone the operation until the process calls this
1043 	 * ioctl, allowing the switch to complete.
1044 	 *
1045 	 * According to the X sources this is the behavior:
1046 	 *	0:	pending switch-from not OK
1047 	 *	1:	pending switch-from OK
1048 	 *	2:	completed switch-to OK
1049 	 */
1050 	case VT_RELDISP:
1051 		if (!perm)
1052 			goto eperm;
1053 
1054 		if (vc->vt_mode.mode != VT_PROCESS) {
1055 			ret = -EINVAL;
1056 			break;
1057 		}
1058 		/*
1059 		 * Switching-from response
1060 		 */
1061 		console_lock();
1062 		if (vc->vt_newvt >= 0) {
1063 			if (arg == 0)
1064 				/*
1065 				 * Switch disallowed, so forget we were trying
1066 				 * to do it.
1067 				 */
1068 				vc->vt_newvt = -1;
1069 
1070 			else {
1071 				/*
1072 				 * The current vt has been released, so
1073 				 * complete the switch.
1074 				 */
1075 				int newvt;
1076 				newvt = vc->vt_newvt;
1077 				vc->vt_newvt = -1;
1078 				ret = vc_allocate(newvt);
1079 				if (ret) {
1080 					console_unlock();
1081 					break;
1082 				}
1083 				/*
1084 				 * When we actually do the console switch,
1085 				 * make sure we are atomic with respect to
1086 				 * other console switches..
1087 				 */
1088 				complete_change_console(vc_cons[newvt].d);
1089 			}
1090 		} else {
1091 			/*
1092 			 * Switched-to response
1093 			 */
1094 			/*
1095 			 * If it's just an ACK, ignore it
1096 			 */
1097 			if (arg != VT_ACKACQ)
1098 				ret = -EINVAL;
1099 		}
1100 		console_unlock();
1101 		break;
1102 
1103 	 /*
1104 	  * Disallocate memory associated to VT (but leave VT1)
1105 	  */
1106 	 case VT_DISALLOCATE:
1107 		if (arg > MAX_NR_CONSOLES) {
1108 			ret = -ENXIO;
1109 			break;
1110 		}
1111 		if (arg == 0) {
1112 		    /* deallocate all unused consoles, but leave 0 */
1113 			console_lock();
1114 			for (i=1; i<MAX_NR_CONSOLES; i++)
1115 				if (! VT_BUSY(i))
1116 					vc_deallocate(i);
1117 			console_unlock();
1118 		} else {
1119 			/* deallocate a single console, if possible */
1120 			arg--;
1121 			if (VT_BUSY(arg))
1122 				ret = -EBUSY;
1123 			else if (arg) {			      /* leave 0 */
1124 				console_lock();
1125 				vc_deallocate(arg);
1126 				console_unlock();
1127 			}
1128 		}
1129 		break;
1130 
1131 	case VT_RESIZE:
1132 	{
1133 		struct vt_sizes __user *vtsizes = up;
1134 		struct vc_data *vc;
1135 
1136 		ushort ll,cc;
1137 		if (!perm)
1138 			goto eperm;
1139 		if (get_user(ll, &vtsizes->v_rows) ||
1140 		    get_user(cc, &vtsizes->v_cols))
1141 			ret = -EFAULT;
1142 		else {
1143 			console_lock();
1144 			for (i = 0; i < MAX_NR_CONSOLES; i++) {
1145 				vc = vc_cons[i].d;
1146 
1147 				if (vc) {
1148 					vc->vc_resize_user = 1;
1149 					vc_resize(vc_cons[i].d, cc, ll);
1150 				}
1151 			}
1152 			console_unlock();
1153 		}
1154 		break;
1155 	}
1156 
1157 	case VT_RESIZEX:
1158 	{
1159 		struct vt_consize __user *vtconsize = up;
1160 		ushort ll,cc,vlin,clin,vcol,ccol;
1161 		if (!perm)
1162 			goto eperm;
1163 		if (!access_ok(VERIFY_READ, vtconsize,
1164 				sizeof(struct vt_consize))) {
1165 			ret = -EFAULT;
1166 			break;
1167 		}
1168 		/* FIXME: Should check the copies properly */
1169 		__get_user(ll, &vtconsize->v_rows);
1170 		__get_user(cc, &vtconsize->v_cols);
1171 		__get_user(vlin, &vtconsize->v_vlin);
1172 		__get_user(clin, &vtconsize->v_clin);
1173 		__get_user(vcol, &vtconsize->v_vcol);
1174 		__get_user(ccol, &vtconsize->v_ccol);
1175 		vlin = vlin ? vlin : vc->vc_scan_lines;
1176 		if (clin) {
1177 			if (ll) {
1178 				if (ll != vlin/clin) {
1179 					/* Parameters don't add up */
1180 					ret = -EINVAL;
1181 					break;
1182 				}
1183 			} else
1184 				ll = vlin/clin;
1185 		}
1186 		if (vcol && ccol) {
1187 			if (cc) {
1188 				if (cc != vcol/ccol) {
1189 					ret = -EINVAL;
1190 					break;
1191 				}
1192 			} else
1193 				cc = vcol/ccol;
1194 		}
1195 
1196 		if (clin > 32) {
1197 			ret =  -EINVAL;
1198 			break;
1199 		}
1200 
1201 		for (i = 0; i < MAX_NR_CONSOLES; i++) {
1202 			if (!vc_cons[i].d)
1203 				continue;
1204 			console_lock();
1205 			if (vlin)
1206 				vc_cons[i].d->vc_scan_lines = vlin;
1207 			if (clin)
1208 				vc_cons[i].d->vc_font.height = clin;
1209 			vc_cons[i].d->vc_resize_user = 1;
1210 			vc_resize(vc_cons[i].d, cc, ll);
1211 			console_unlock();
1212 		}
1213 		break;
1214 	}
1215 
1216 	case PIO_FONT: {
1217 		if (!perm)
1218 			goto eperm;
1219 		op.op = KD_FONT_OP_SET;
1220 		op.flags = KD_FONT_FLAG_OLD | KD_FONT_FLAG_DONT_RECALC;	/* Compatibility */
1221 		op.width = 8;
1222 		op.height = 0;
1223 		op.charcount = 256;
1224 		op.data = up;
1225 		ret = con_font_op(vc_cons[fg_console].d, &op);
1226 		break;
1227 	}
1228 
1229 	case GIO_FONT: {
1230 		op.op = KD_FONT_OP_GET;
1231 		op.flags = KD_FONT_FLAG_OLD;
1232 		op.width = 8;
1233 		op.height = 32;
1234 		op.charcount = 256;
1235 		op.data = up;
1236 		ret = con_font_op(vc_cons[fg_console].d, &op);
1237 		break;
1238 	}
1239 
1240 	case PIO_CMAP:
1241                 if (!perm)
1242 			ret = -EPERM;
1243 		else
1244 	                ret = con_set_cmap(up);
1245 		break;
1246 
1247 	case GIO_CMAP:
1248                 ret = con_get_cmap(up);
1249 		break;
1250 
1251 	case PIO_FONTX:
1252 	case GIO_FONTX:
1253 		ret = do_fontx_ioctl(cmd, up, perm, &op);
1254 		break;
1255 
1256 	case PIO_FONTRESET:
1257 	{
1258 		if (!perm)
1259 			goto eperm;
1260 
1261 #ifdef BROKEN_GRAPHICS_PROGRAMS
1262 		/* With BROKEN_GRAPHICS_PROGRAMS defined, the default
1263 		   font is not saved. */
1264 		ret = -ENOSYS;
1265 		break;
1266 #else
1267 		{
1268 		op.op = KD_FONT_OP_SET_DEFAULT;
1269 		op.data = NULL;
1270 		ret = con_font_op(vc_cons[fg_console].d, &op);
1271 		if (ret)
1272 			break;
1273 		con_set_default_unimap(vc_cons[fg_console].d);
1274 		break;
1275 		}
1276 #endif
1277 	}
1278 
1279 	case KDFONTOP: {
1280 		if (copy_from_user(&op, up, sizeof(op))) {
1281 			ret = -EFAULT;
1282 			break;
1283 		}
1284 		if (!perm && op.op != KD_FONT_OP_GET)
1285 			goto eperm;
1286 		ret = con_font_op(vc, &op);
1287 		if (ret)
1288 			break;
1289 		if (copy_to_user(up, &op, sizeof(op)))
1290 			ret = -EFAULT;
1291 		break;
1292 	}
1293 
1294 	case PIO_SCRNMAP:
1295 		if (!perm)
1296 			ret = -EPERM;
1297 		else
1298 			ret = con_set_trans_old(up);
1299 		break;
1300 
1301 	case GIO_SCRNMAP:
1302 		ret = con_get_trans_old(up);
1303 		break;
1304 
1305 	case PIO_UNISCRNMAP:
1306 		if (!perm)
1307 			ret = -EPERM;
1308 		else
1309 			ret = con_set_trans_new(up);
1310 		break;
1311 
1312 	case GIO_UNISCRNMAP:
1313 		ret = con_get_trans_new(up);
1314 		break;
1315 
1316 	case PIO_UNIMAPCLR:
1317 	      { struct unimapinit ui;
1318 		if (!perm)
1319 			goto eperm;
1320 		ret = copy_from_user(&ui, up, sizeof(struct unimapinit));
1321 		if (ret)
1322 			ret = -EFAULT;
1323 		else
1324 			con_clear_unimap(vc, &ui);
1325 		break;
1326 	      }
1327 
1328 	case PIO_UNIMAP:
1329 	case GIO_UNIMAP:
1330 		ret = do_unimap_ioctl(cmd, up, perm, vc);
1331 		break;
1332 
1333 	case VT_LOCKSWITCH:
1334 		if (!capable(CAP_SYS_TTY_CONFIG))
1335 			goto eperm;
1336 		vt_dont_switch = 1;
1337 		break;
1338 	case VT_UNLOCKSWITCH:
1339 		if (!capable(CAP_SYS_TTY_CONFIG))
1340 			goto eperm;
1341 		vt_dont_switch = 0;
1342 		break;
1343 	case VT_GETHIFONTMASK:
1344 		ret = put_user(vc->vc_hi_font_mask,
1345 					(unsigned short __user *)arg);
1346 		break;
1347 	case VT_WAITEVENT:
1348 		ret = vt_event_wait_ioctl((struct vt_event __user *)arg);
1349 		break;
1350 	default:
1351 		ret = -ENOIOCTLCMD;
1352 	}
1353 out:
1354 	tty_unlock();
1355 	return ret;
1356 eperm:
1357 	ret = -EPERM;
1358 	goto out;
1359 }
1360 
1361 void reset_vc(struct vc_data *vc)
1362 {
1363 	vc->vc_mode = KD_TEXT;
1364 	kbd_table[vc->vc_num].kbdmode = default_utf8 ? VC_UNICODE : VC_XLATE;
1365 	vc->vt_mode.mode = VT_AUTO;
1366 	vc->vt_mode.waitv = 0;
1367 	vc->vt_mode.relsig = 0;
1368 	vc->vt_mode.acqsig = 0;
1369 	vc->vt_mode.frsig = 0;
1370 	put_pid(vc->vt_pid);
1371 	vc->vt_pid = NULL;
1372 	vc->vt_newvt = -1;
1373 	if (!in_interrupt())    /* Via keyboard.c:SAK() - akpm */
1374 		reset_palette(vc);
1375 }
1376 
1377 void vc_SAK(struct work_struct *work)
1378 {
1379 	struct vc *vc_con =
1380 		container_of(work, struct vc, SAK_work);
1381 	struct vc_data *vc;
1382 	struct tty_struct *tty;
1383 
1384 	console_lock();
1385 	vc = vc_con->d;
1386 	if (vc) {
1387 		tty = vc->port.tty;
1388 		/*
1389 		 * SAK should also work in all raw modes and reset
1390 		 * them properly.
1391 		 */
1392 		if (tty)
1393 			__do_SAK(tty);
1394 		reset_vc(vc);
1395 	}
1396 	console_unlock();
1397 }
1398 
1399 #ifdef CONFIG_COMPAT
1400 
1401 struct compat_consolefontdesc {
1402 	unsigned short charcount;       /* characters in font (256 or 512) */
1403 	unsigned short charheight;      /* scan lines per character (1-32) */
1404 	compat_caddr_t chardata;	/* font data in expanded form */
1405 };
1406 
1407 static inline int
1408 compat_fontx_ioctl(int cmd, struct compat_consolefontdesc __user *user_cfd,
1409 			 int perm, struct console_font_op *op)
1410 {
1411 	struct compat_consolefontdesc cfdarg;
1412 	int i;
1413 
1414 	if (copy_from_user(&cfdarg, user_cfd, sizeof(struct compat_consolefontdesc)))
1415 		return -EFAULT;
1416 
1417 	switch (cmd) {
1418 	case PIO_FONTX:
1419 		if (!perm)
1420 			return -EPERM;
1421 		op->op = KD_FONT_OP_SET;
1422 		op->flags = KD_FONT_FLAG_OLD;
1423 		op->width = 8;
1424 		op->height = cfdarg.charheight;
1425 		op->charcount = cfdarg.charcount;
1426 		op->data = compat_ptr(cfdarg.chardata);
1427 		return con_font_op(vc_cons[fg_console].d, op);
1428 	case GIO_FONTX:
1429 		op->op = KD_FONT_OP_GET;
1430 		op->flags = KD_FONT_FLAG_OLD;
1431 		op->width = 8;
1432 		op->height = cfdarg.charheight;
1433 		op->charcount = cfdarg.charcount;
1434 		op->data = compat_ptr(cfdarg.chardata);
1435 		i = con_font_op(vc_cons[fg_console].d, op);
1436 		if (i)
1437 			return i;
1438 		cfdarg.charheight = op->height;
1439 		cfdarg.charcount = op->charcount;
1440 		if (copy_to_user(user_cfd, &cfdarg, sizeof(struct compat_consolefontdesc)))
1441 			return -EFAULT;
1442 		return 0;
1443 	}
1444 	return -EINVAL;
1445 }
1446 
1447 struct compat_console_font_op {
1448 	compat_uint_t op;        /* operation code KD_FONT_OP_* */
1449 	compat_uint_t flags;     /* KD_FONT_FLAG_* */
1450 	compat_uint_t width, height;     /* font size */
1451 	compat_uint_t charcount;
1452 	compat_caddr_t data;    /* font data with height fixed to 32 */
1453 };
1454 
1455 static inline int
1456 compat_kdfontop_ioctl(struct compat_console_font_op __user *fontop,
1457 			 int perm, struct console_font_op *op, struct vc_data *vc)
1458 {
1459 	int i;
1460 
1461 	if (copy_from_user(op, fontop, sizeof(struct compat_console_font_op)))
1462 		return -EFAULT;
1463 	if (!perm && op->op != KD_FONT_OP_GET)
1464 		return -EPERM;
1465 	op->data = compat_ptr(((struct compat_console_font_op *)op)->data);
1466 	op->flags |= KD_FONT_FLAG_OLD;
1467 	i = con_font_op(vc, op);
1468 	if (i)
1469 		return i;
1470 	((struct compat_console_font_op *)op)->data = (unsigned long)op->data;
1471 	if (copy_to_user(fontop, op, sizeof(struct compat_console_font_op)))
1472 		return -EFAULT;
1473 	return 0;
1474 }
1475 
1476 struct compat_unimapdesc {
1477 	unsigned short entry_ct;
1478 	compat_caddr_t entries;
1479 };
1480 
1481 static inline int
1482 compat_unimap_ioctl(unsigned int cmd, struct compat_unimapdesc __user *user_ud,
1483 			 int perm, struct vc_data *vc)
1484 {
1485 	struct compat_unimapdesc tmp;
1486 	struct unipair __user *tmp_entries;
1487 
1488 	if (copy_from_user(&tmp, user_ud, sizeof tmp))
1489 		return -EFAULT;
1490 	tmp_entries = compat_ptr(tmp.entries);
1491 	if (tmp_entries)
1492 		if (!access_ok(VERIFY_WRITE, tmp_entries,
1493 				tmp.entry_ct*sizeof(struct unipair)))
1494 			return -EFAULT;
1495 	switch (cmd) {
1496 	case PIO_UNIMAP:
1497 		if (!perm)
1498 			return -EPERM;
1499 		return con_set_unimap(vc, tmp.entry_ct, tmp_entries);
1500 	case GIO_UNIMAP:
1501 		if (!perm && fg_console != vc->vc_num)
1502 			return -EPERM;
1503 		return con_get_unimap(vc, tmp.entry_ct, &(user_ud->entry_ct), tmp_entries);
1504 	}
1505 	return 0;
1506 }
1507 
1508 long vt_compat_ioctl(struct tty_struct *tty,
1509 	     unsigned int cmd, unsigned long arg)
1510 {
1511 	struct vc_data *vc = tty->driver_data;
1512 	struct console_font_op op;	/* used in multiple places here */
1513 	unsigned int console;
1514 	void __user *up = (void __user *)arg;
1515 	int perm;
1516 	int ret = 0;
1517 
1518 	console = vc->vc_num;
1519 
1520 	tty_lock();
1521 
1522 	if (!vc_cons_allocated(console)) { 	/* impossible? */
1523 		ret = -ENOIOCTLCMD;
1524 		goto out;
1525 	}
1526 
1527 	/*
1528 	 * To have permissions to do most of the vt ioctls, we either have
1529 	 * to be the owner of the tty, or have CAP_SYS_TTY_CONFIG.
1530 	 */
1531 	perm = 0;
1532 	if (current->signal->tty == tty || capable(CAP_SYS_TTY_CONFIG))
1533 		perm = 1;
1534 
1535 	switch (cmd) {
1536 	/*
1537 	 * these need special handlers for incompatible data structures
1538 	 */
1539 	case PIO_FONTX:
1540 	case GIO_FONTX:
1541 		ret = compat_fontx_ioctl(cmd, up, perm, &op);
1542 		break;
1543 
1544 	case KDFONTOP:
1545 		ret = compat_kdfontop_ioctl(up, perm, &op, vc);
1546 		break;
1547 
1548 	case PIO_UNIMAP:
1549 	case GIO_UNIMAP:
1550 		ret = compat_unimap_ioctl(cmd, up, perm, vc);
1551 		break;
1552 
1553 	/*
1554 	 * all these treat 'arg' as an integer
1555 	 */
1556 	case KIOCSOUND:
1557 	case KDMKTONE:
1558 #ifdef CONFIG_X86
1559 	case KDADDIO:
1560 	case KDDELIO:
1561 #endif
1562 	case KDSETMODE:
1563 	case KDMAPDISP:
1564 	case KDUNMAPDISP:
1565 	case KDSKBMODE:
1566 	case KDSKBMETA:
1567 	case KDSKBLED:
1568 	case KDSETLED:
1569 	case KDSIGACCEPT:
1570 	case VT_ACTIVATE:
1571 	case VT_WAITACTIVE:
1572 	case VT_RELDISP:
1573 	case VT_DISALLOCATE:
1574 	case VT_RESIZE:
1575 	case VT_RESIZEX:
1576 		goto fallback;
1577 
1578 	/*
1579 	 * the rest has a compatible data structure behind arg,
1580 	 * but we have to convert it to a proper 64 bit pointer.
1581 	 */
1582 	default:
1583 		arg = (unsigned long)compat_ptr(arg);
1584 		goto fallback;
1585 	}
1586 out:
1587 	tty_unlock();
1588 	return ret;
1589 
1590 fallback:
1591 	tty_unlock();
1592 	return vt_ioctl(tty, cmd, arg);
1593 }
1594 
1595 
1596 #endif /* CONFIG_COMPAT */
1597 
1598 
1599 /*
1600  * Performs the back end of a vt switch. Called under the console
1601  * semaphore.
1602  */
1603 static void complete_change_console(struct vc_data *vc)
1604 {
1605 	unsigned char old_vc_mode;
1606 	int old = fg_console;
1607 
1608 	last_console = fg_console;
1609 
1610 	/*
1611 	 * If we're switching, we could be going from KD_GRAPHICS to
1612 	 * KD_TEXT mode or vice versa, which means we need to blank or
1613 	 * unblank the screen later.
1614 	 */
1615 	old_vc_mode = vc_cons[fg_console].d->vc_mode;
1616 	switch_screen(vc);
1617 
1618 	/*
1619 	 * This can't appear below a successful kill_pid().  If it did,
1620 	 * then the *blank_screen operation could occur while X, having
1621 	 * received acqsig, is waking up on another processor.  This
1622 	 * condition can lead to overlapping accesses to the VGA range
1623 	 * and the framebuffer (causing system lockups).
1624 	 *
1625 	 * To account for this we duplicate this code below only if the
1626 	 * controlling process is gone and we've called reset_vc.
1627 	 */
1628 	if (old_vc_mode != vc->vc_mode) {
1629 		if (vc->vc_mode == KD_TEXT)
1630 			do_unblank_screen(1);
1631 		else
1632 			do_blank_screen(1);
1633 	}
1634 
1635 	/*
1636 	 * If this new console is under process control, send it a signal
1637 	 * telling it that it has acquired. Also check if it has died and
1638 	 * clean up (similar to logic employed in change_console())
1639 	 */
1640 	if (vc->vt_mode.mode == VT_PROCESS) {
1641 		/*
1642 		 * Send the signal as privileged - kill_pid() will
1643 		 * tell us if the process has gone or something else
1644 		 * is awry
1645 		 */
1646 		if (kill_pid(vc->vt_pid, vc->vt_mode.acqsig, 1) != 0) {
1647 		/*
1648 		 * The controlling process has died, so we revert back to
1649 		 * normal operation. In this case, we'll also change back
1650 		 * to KD_TEXT mode. I'm not sure if this is strictly correct
1651 		 * but it saves the agony when the X server dies and the screen
1652 		 * remains blanked due to KD_GRAPHICS! It would be nice to do
1653 		 * this outside of VT_PROCESS but there is no single process
1654 		 * to account for and tracking tty count may be undesirable.
1655 		 */
1656 			reset_vc(vc);
1657 
1658 			if (old_vc_mode != vc->vc_mode) {
1659 				if (vc->vc_mode == KD_TEXT)
1660 					do_unblank_screen(1);
1661 				else
1662 					do_blank_screen(1);
1663 			}
1664 		}
1665 	}
1666 
1667 	/*
1668 	 * Wake anyone waiting for their VT to activate
1669 	 */
1670 	vt_event_post(VT_EVENT_SWITCH, old, vc->vc_num);
1671 	return;
1672 }
1673 
1674 /*
1675  * Performs the front-end of a vt switch
1676  */
1677 void change_console(struct vc_data *new_vc)
1678 {
1679 	struct vc_data *vc;
1680 
1681 	if (!new_vc || new_vc->vc_num == fg_console || vt_dont_switch)
1682 		return;
1683 
1684 	/*
1685 	 * If this vt is in process mode, then we need to handshake with
1686 	 * that process before switching. Essentially, we store where that
1687 	 * vt wants to switch to and wait for it to tell us when it's done
1688 	 * (via VT_RELDISP ioctl).
1689 	 *
1690 	 * We also check to see if the controlling process still exists.
1691 	 * If it doesn't, we reset this vt to auto mode and continue.
1692 	 * This is a cheap way to track process control. The worst thing
1693 	 * that can happen is: we send a signal to a process, it dies, and
1694 	 * the switch gets "lost" waiting for a response; hopefully, the
1695 	 * user will try again, we'll detect the process is gone (unless
1696 	 * the user waits just the right amount of time :-) and revert the
1697 	 * vt to auto control.
1698 	 */
1699 	vc = vc_cons[fg_console].d;
1700 	if (vc->vt_mode.mode == VT_PROCESS) {
1701 		/*
1702 		 * Send the signal as privileged - kill_pid() will
1703 		 * tell us if the process has gone or something else
1704 		 * is awry.
1705 		 *
1706 		 * We need to set vt_newvt *before* sending the signal or we
1707 		 * have a race.
1708 		 */
1709 		vc->vt_newvt = new_vc->vc_num;
1710 		if (kill_pid(vc->vt_pid, vc->vt_mode.relsig, 1) == 0) {
1711 			/*
1712 			 * It worked. Mark the vt to switch to and
1713 			 * return. The process needs to send us a
1714 			 * VT_RELDISP ioctl to complete the switch.
1715 			 */
1716 			return;
1717 		}
1718 
1719 		/*
1720 		 * The controlling process has died, so we revert back to
1721 		 * normal operation. In this case, we'll also change back
1722 		 * to KD_TEXT mode. I'm not sure if this is strictly correct
1723 		 * but it saves the agony when the X server dies and the screen
1724 		 * remains blanked due to KD_GRAPHICS! It would be nice to do
1725 		 * this outside of VT_PROCESS but there is no single process
1726 		 * to account for and tracking tty count may be undesirable.
1727 		 */
1728 		reset_vc(vc);
1729 
1730 		/*
1731 		 * Fall through to normal (VT_AUTO) handling of the switch...
1732 		 */
1733 	}
1734 
1735 	/*
1736 	 * Ignore all switches in KD_GRAPHICS+VT_AUTO mode
1737 	 */
1738 	if (vc->vc_mode == KD_GRAPHICS)
1739 		return;
1740 
1741 	complete_change_console(new_vc);
1742 }
1743 
1744 /* Perform a kernel triggered VT switch for suspend/resume */
1745 
1746 static int disable_vt_switch;
1747 
1748 int vt_move_to_console(unsigned int vt, int alloc)
1749 {
1750 	int prev;
1751 
1752 	console_lock();
1753 	/* Graphics mode - up to X */
1754 	if (disable_vt_switch) {
1755 		console_unlock();
1756 		return 0;
1757 	}
1758 	prev = fg_console;
1759 
1760 	if (alloc && vc_allocate(vt)) {
1761 		/* we can't have a free VC for now. Too bad,
1762 		 * we don't want to mess the screen for now. */
1763 		console_unlock();
1764 		return -ENOSPC;
1765 	}
1766 
1767 	if (set_console(vt)) {
1768 		/*
1769 		 * We're unable to switch to the SUSPEND_CONSOLE.
1770 		 * Let the calling function know so it can decide
1771 		 * what to do.
1772 		 */
1773 		console_unlock();
1774 		return -EIO;
1775 	}
1776 	console_unlock();
1777 	tty_lock();
1778 	if (vt_waitactive(vt + 1)) {
1779 		pr_debug("Suspend: Can't switch VCs.");
1780 		tty_unlock();
1781 		return -EINTR;
1782 	}
1783 	tty_unlock();
1784 	return prev;
1785 }
1786 
1787 /*
1788  * Normally during a suspend, we allocate a new console and switch to it.
1789  * When we resume, we switch back to the original console.  This switch
1790  * can be slow, so on systems where the framebuffer can handle restoration
1791  * of video registers anyways, there's little point in doing the console
1792  * switch.  This function allows you to disable it by passing it '0'.
1793  */
1794 void pm_set_vt_switch(int do_switch)
1795 {
1796 	console_lock();
1797 	disable_vt_switch = !do_switch;
1798 	console_unlock();
1799 }
1800 EXPORT_SYMBOL(pm_set_vt_switch);
1801