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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 1992 obz under the linux copyright
4 *
5 * Dynamic diacritical handling - aeb@cwi.nl - Dec 1993
6 * Dynamic keymap and string allocation - aeb@cwi.nl - May 1994
7 * Restrict VT switching via ioctl() - grif@cs.ucr.edu - Dec 1995
8 * Some code moved for less code duplication - Andi Kleen - Mar 1997
9 * Check put/get_user, cleanups - acme@conectiva.com.br - Jun 2001
10 */
11
12#include <linux/types.h>
13#include <linux/errno.h>
14#include <linux/sched/signal.h>
15#include <linux/tty.h>
16#include <linux/timer.h>
17#include <linux/kernel.h>
18#include <linux/compat.h>
19#include <linux/module.h>
20#include <linux/kd.h>
21#include <linux/vt.h>
22#include <linux/string.h>
23#include <linux/slab.h>
24#include <linux/major.h>
25#include <linux/fs.h>
26#include <linux/console.h>
27#include <linux/consolemap.h>
28#include <linux/signal.h>
29#include <linux/suspend.h>
30#include <linux/timex.h>
31
32#include <asm/io.h>
33#include <linux/uaccess.h>
34
35#include <linux/nospec.h>
36
37#include <linux/kbd_kern.h>
38#include <linux/vt_kern.h>
39#include <linux/kbd_diacr.h>
40#include <linux/selection.h>
41
42bool vt_dont_switch;
43
44static inline bool vt_in_use(unsigned int i)
45{
46 const struct vc_data *vc = vc_cons[i].d;
47
48 /*
49 * console_lock must be held to prevent the vc from being deallocated
50 * while we're checking whether it's in-use.
51 */
52 WARN_CONSOLE_UNLOCKED();
53
54 return vc && kref_read(&vc->port.kref) > 1;
55}
56
57static inline bool vt_busy(int i)
58{
59 if (vt_in_use(i))
60 return true;
61 if (i == fg_console)
62 return true;
63 if (vc_is_sel(vc_cons[i].d))
64 return true;
65
66 return false;
67}
68
69/*
70 * Console (vt and kd) routines, as defined by USL SVR4 manual, and by
71 * experimentation and study of X386 SYSV handling.
72 *
73 * One point of difference: SYSV vt's are /dev/vtX, which X >= 0, and
74 * /dev/console is a separate ttyp. Under Linux, /dev/tty0 is /dev/console,
75 * and the vc start at /dev/ttyX, X >= 1. We maintain that here, so we will
76 * always treat our set of vt as numbered 1..MAX_NR_CONSOLES (corresponding to
77 * ttys 0..MAX_NR_CONSOLES-1). Explicitly naming VT 0 is illegal, but using
78 * /dev/tty0 (fg_console) as a target is legal, since an implicit aliasing
79 * to the current console is done by the main ioctl code.
80 */
81
82#ifdef CONFIG_X86
83#include <asm/syscalls.h>
84#endif
85
86static void complete_change_console(struct vc_data *vc);
87
88/*
89 * User space VT_EVENT handlers
90 */
91
92struct vt_event_wait {
93 struct list_head list;
94 struct vt_event event;
95 int done;
96};
97
98static LIST_HEAD(vt_events);
99static DEFINE_SPINLOCK(vt_event_lock);
100static DECLARE_WAIT_QUEUE_HEAD(vt_event_waitqueue);
101
102/**
103 * vt_event_post
104 * @event: the event that occurred
105 * @old: old console
106 * @new: new console
107 *
108 * Post an VT event to interested VT handlers
109 */
110
111void vt_event_post(unsigned int event, unsigned int old, unsigned int new)
112{
113 struct list_head *pos, *head;
114 unsigned long flags;
115 int wake = 0;
116
117 spin_lock_irqsave(&vt_event_lock, flags);
118 head = &vt_events;
119
120 list_for_each(pos, head) {
121 struct vt_event_wait *ve = list_entry(pos,
122 struct vt_event_wait, list);
123 if (!(ve->event.event & event))
124 continue;
125 ve->event.event = event;
126 /* kernel view is consoles 0..n-1, user space view is
127 console 1..n with 0 meaning current, so we must bias */
128 ve->event.oldev = old + 1;
129 ve->event.newev = new + 1;
130 wake = 1;
131 ve->done = 1;
132 }
133 spin_unlock_irqrestore(&vt_event_lock, flags);
134 if (wake)
135 wake_up_interruptible(&vt_event_waitqueue);
136}
137
138static void __vt_event_queue(struct vt_event_wait *vw)
139{
140 unsigned long flags;
141 /* Prepare the event */
142 INIT_LIST_HEAD(&vw->list);
143 vw->done = 0;
144 /* Queue our event */
145 spin_lock_irqsave(&vt_event_lock, flags);
146 list_add(&vw->list, &vt_events);
147 spin_unlock_irqrestore(&vt_event_lock, flags);
148}
149
150static void __vt_event_wait(struct vt_event_wait *vw)
151{
152 /* Wait for it to pass */
153 wait_event_interruptible(vt_event_waitqueue, vw->done);
154}
155
156static void __vt_event_dequeue(struct vt_event_wait *vw)
157{
158 unsigned long flags;
159
160 /* Dequeue it */
161 spin_lock_irqsave(&vt_event_lock, flags);
162 list_del(&vw->list);
163 spin_unlock_irqrestore(&vt_event_lock, flags);
164}
165
166/**
167 * vt_event_wait - wait for an event
168 * @vw: our event
169 *
170 * Waits for an event to occur which completes our vt_event_wait
171 * structure. On return the structure has wv->done set to 1 for success
172 * or 0 if some event such as a signal ended the wait.
173 */
174
175static void vt_event_wait(struct vt_event_wait *vw)
176{
177 __vt_event_queue(vw);
178 __vt_event_wait(vw);
179 __vt_event_dequeue(vw);
180}
181
182/**
183 * vt_event_wait_ioctl - event ioctl handler
184 * @event: argument to ioctl (the event)
185 *
186 * Implement the VT_WAITEVENT ioctl using the VT event interface
187 */
188
189static int vt_event_wait_ioctl(struct vt_event __user *event)
190{
191 struct vt_event_wait vw;
192
193 if (copy_from_user(&vw.event, event, sizeof(struct vt_event)))
194 return -EFAULT;
195 /* Highest supported event for now */
196 if (vw.event.event & ~VT_MAX_EVENT)
197 return -EINVAL;
198
199 vt_event_wait(&vw);
200 /* If it occurred report it */
201 if (vw.done) {
202 if (copy_to_user(event, &vw.event, sizeof(struct vt_event)))
203 return -EFAULT;
204 return 0;
205 }
206 return -EINTR;
207}
208
209/**
210 * vt_waitactive - active console wait
211 * @n: new console
212 *
213 * Helper for event waits. Used to implement the legacy
214 * event waiting ioctls in terms of events
215 */
216
217int vt_waitactive(int n)
218{
219 struct vt_event_wait vw;
220 do {
221 vw.event.event = VT_EVENT_SWITCH;
222 __vt_event_queue(&vw);
223 if (n == fg_console + 1) {
224 __vt_event_dequeue(&vw);
225 break;
226 }
227 __vt_event_wait(&vw);
228 __vt_event_dequeue(&vw);
229 if (vw.done == 0)
230 return -EINTR;
231 } while (vw.event.newev != n);
232 return 0;
233}
234
235/*
236 * these are the valid i/o ports we're allowed to change. they map all the
237 * video ports
238 */
239#define GPFIRST 0x3b4
240#define GPLAST 0x3df
241#define GPNUM (GPLAST - GPFIRST + 1)
242
243/*
244 * currently, setting the mode from KD_TEXT to KD_GRAPHICS doesn't do a whole
245 * lot. i'm not sure if it should do any restoration of modes or what...
246 *
247 * XXX It should at least call into the driver, fbdev's definitely need to
248 * restore their engine state. --BenH
249 *
250 * Called with the console lock held.
251 */
252static int vt_kdsetmode(struct vc_data *vc, unsigned long mode)
253{
254 switch (mode) {
255 case KD_GRAPHICS:
256 break;
257 case KD_TEXT0:
258 case KD_TEXT1:
259 mode = KD_TEXT;
260 fallthrough;
261 case KD_TEXT:
262 break;
263 default:
264 return -EINVAL;
265 }
266
267 if (vc->vc_mode == mode)
268 return 0;
269
270 vc->vc_mode = mode;
271 if (vc->vc_num != fg_console)
272 return 0;
273
274 /* explicitly blank/unblank the screen if switching modes */
275 if (mode == KD_TEXT)
276 do_unblank_screen(1);
277 else
278 do_blank_screen(1);
279
280 return 0;
281}
282
283static int vt_k_ioctl(struct tty_struct *tty, unsigned int cmd,
284 unsigned long arg, bool perm)
285{
286 struct vc_data *vc = tty->driver_data;
287 void __user *up = (void __user *)arg;
288 unsigned int console = vc->vc_num;
289 int ret;
290
291 switch (cmd) {
292 case KIOCSOUND:
293 if (!perm)
294 return -EPERM;
295 /*
296 * The use of PIT_TICK_RATE is historic, it used to be
297 * the platform-dependent CLOCK_TICK_RATE between 2.6.12
298 * and 2.6.36, which was a minor but unfortunate ABI
299 * change. kd_mksound is locked by the input layer.
300 */
301 if (arg)
302 arg = PIT_TICK_RATE / arg;
303 kd_mksound(arg, 0);
304 break;
305
306 case KDMKTONE:
307 if (!perm)
308 return -EPERM;
309 {
310 unsigned int ticks, count;
311
312 /*
313 * Generate the tone for the appropriate number of ticks.
314 * If the time is zero, turn off sound ourselves.
315 */
316 ticks = msecs_to_jiffies((arg >> 16) & 0xffff);
317 count = ticks ? (arg & 0xffff) : 0;
318 if (count)
319 count = PIT_TICK_RATE / count;
320 kd_mksound(count, ticks);
321 break;
322 }
323
324 case KDGKBTYPE:
325 /*
326 * this is naïve.
327 */
328 return put_user(KB_101, (char __user *)arg);
329
330 /*
331 * These cannot be implemented on any machine that implements
332 * ioperm() in user level (such as Alpha PCs) or not at all.
333 *
334 * XXX: you should never use these, just call ioperm directly..
335 */
336#ifdef CONFIG_X86
337 case KDADDIO:
338 case KDDELIO:
339 /*
340 * KDADDIO and KDDELIO may be able to add ports beyond what
341 * we reject here, but to be safe...
342 *
343 * These are locked internally via sys_ioperm
344 */
345 if (arg < GPFIRST || arg > GPLAST)
346 return -EINVAL;
347
348 return ksys_ioperm(arg, 1, (cmd == KDADDIO)) ? -ENXIO : 0;
349
350 case KDENABIO:
351 case KDDISABIO:
352 return ksys_ioperm(GPFIRST, GPNUM,
353 (cmd == KDENABIO)) ? -ENXIO : 0;
354#endif
355
356 /* Linux m68k/i386 interface for setting the keyboard delay/repeat rate */
357
358 case KDKBDREP:
359 {
360 struct kbd_repeat kbrep;
361
362 if (!capable(CAP_SYS_TTY_CONFIG))
363 return -EPERM;
364
365 if (copy_from_user(&kbrep, up, sizeof(struct kbd_repeat)))
366 return -EFAULT;
367
368 ret = kbd_rate(&kbrep);
369 if (ret)
370 return ret;
371 if (copy_to_user(up, &kbrep, sizeof(struct kbd_repeat)))
372 return -EFAULT;
373 break;
374 }
375
376 case KDSETMODE:
377 if (!perm)
378 return -EPERM;
379
380 console_lock();
381 ret = vt_kdsetmode(vc, arg);
382 console_unlock();
383 return ret;
384
385 case KDGETMODE:
386 return put_user(vc->vc_mode, (int __user *)arg);
387
388 case KDMAPDISP:
389 case KDUNMAPDISP:
390 /*
391 * these work like a combination of mmap and KDENABIO.
392 * this could be easily finished.
393 */
394 return -EINVAL;
395
396 case KDSKBMODE:
397 if (!perm)
398 return -EPERM;
399 ret = vt_do_kdskbmode(console, arg);
400 if (ret)
401 return ret;
402 tty_ldisc_flush(tty);
403 break;
404
405 case KDGKBMODE:
406 return put_user(vt_do_kdgkbmode(console), (int __user *)arg);
407
408 /* this could be folded into KDSKBMODE, but for compatibility
409 reasons it is not so easy to fold KDGKBMETA into KDGKBMODE */
410 case KDSKBMETA:
411 return vt_do_kdskbmeta(console, arg);
412
413 case KDGKBMETA:
414 /* FIXME: should review whether this is worth locking */
415 return put_user(vt_do_kdgkbmeta(console), (int __user *)arg);
416
417 case KDGETKEYCODE:
418 case KDSETKEYCODE:
419 if(!capable(CAP_SYS_TTY_CONFIG))
420 perm = 0;
421 return vt_do_kbkeycode_ioctl(cmd, up, perm);
422
423 case KDGKBENT:
424 case KDSKBENT:
425 return vt_do_kdsk_ioctl(cmd, up, perm, console);
426
427 case KDGKBSENT:
428 case KDSKBSENT:
429 return vt_do_kdgkb_ioctl(cmd, up, perm);
430
431 /* Diacritical processing. Handled in keyboard.c as it has
432 to operate on the keyboard locks and structures */
433 case KDGKBDIACR:
434 case KDGKBDIACRUC:
435 case KDSKBDIACR:
436 case KDSKBDIACRUC:
437 return vt_do_diacrit(cmd, up, perm);
438
439 /* the ioctls below read/set the flags usually shown in the leds */
440 /* don't use them - they will go away without warning */
441 case KDGKBLED:
442 case KDSKBLED:
443 case KDGETLED:
444 case KDSETLED:
445 return vt_do_kdskled(console, cmd, arg, perm);
446
447 /*
448 * A process can indicate its willingness to accept signals
449 * generated by pressing an appropriate key combination.
450 * Thus, one can have a daemon that e.g. spawns a new console
451 * upon a keypress and then changes to it.
452 * See also the kbrequest field of inittab(5).
453 */
454 case KDSIGACCEPT:
455 if (!perm || !capable(CAP_KILL))
456 return -EPERM;
457 if (!valid_signal(arg) || arg < 1 || arg == SIGKILL)
458 return -EINVAL;
459
460 spin_lock_irq(&vt_spawn_con.lock);
461 put_pid(vt_spawn_con.pid);
462 vt_spawn_con.pid = get_pid(task_pid(current));
463 vt_spawn_con.sig = arg;
464 spin_unlock_irq(&vt_spawn_con.lock);
465 break;
466
467 case KDFONTOP: {
468 struct console_font_op op;
469
470 if (copy_from_user(&op, up, sizeof(op)))
471 return -EFAULT;
472 if (!perm && op.op != KD_FONT_OP_GET)
473 return -EPERM;
474 ret = con_font_op(vc, &op);
475 if (ret)
476 return ret;
477 if (copy_to_user(up, &op, sizeof(op)))
478 return -EFAULT;
479 break;
480 }
481
482 default:
483 return -ENOIOCTLCMD;
484 }
485
486 return 0;
487}
488
489static inline int do_unimap_ioctl(int cmd, struct unimapdesc __user *user_ud,
490 bool perm, struct vc_data *vc)
491{
492 struct unimapdesc tmp;
493
494 if (copy_from_user(&tmp, user_ud, sizeof tmp))
495 return -EFAULT;
496 switch (cmd) {
497 case PIO_UNIMAP:
498 if (!perm)
499 return -EPERM;
500 return con_set_unimap(vc, tmp.entry_ct, tmp.entries);
501 case GIO_UNIMAP:
502 if (!perm && fg_console != vc->vc_num)
503 return -EPERM;
504 return con_get_unimap(vc, tmp.entry_ct, &(user_ud->entry_ct),
505 tmp.entries);
506 }
507 return 0;
508}
509
510static int vt_io_ioctl(struct vc_data *vc, unsigned int cmd, void __user *up,
511 bool perm)
512{
513 switch (cmd) {
514 case PIO_CMAP:
515 if (!perm)
516 return -EPERM;
517 return con_set_cmap(up);
518
519 case GIO_CMAP:
520 return con_get_cmap(up);
521
522 case PIO_SCRNMAP:
523 if (!perm)
524 return -EPERM;
525 return con_set_trans_old(up);
526
527 case GIO_SCRNMAP:
528 return con_get_trans_old(up);
529
530 case PIO_UNISCRNMAP:
531 if (!perm)
532 return -EPERM;
533 return con_set_trans_new(up);
534
535 case GIO_UNISCRNMAP:
536 return con_get_trans_new(up);
537
538 case PIO_UNIMAPCLR:
539 if (!perm)
540 return -EPERM;
541 con_clear_unimap(vc);
542 break;
543
544 case PIO_UNIMAP:
545 case GIO_UNIMAP:
546 return do_unimap_ioctl(cmd, up, perm, vc);
547
548 default:
549 return -ENOIOCTLCMD;
550 }
551
552 return 0;
553}
554
555static int vt_reldisp(struct vc_data *vc, unsigned int swtch)
556{
557 int newvt, ret;
558
559 if (vc->vt_mode.mode != VT_PROCESS)
560 return -EINVAL;
561
562 /* Switched-to response */
563 if (vc->vt_newvt < 0) {
564 /* If it's just an ACK, ignore it */
565 return swtch == VT_ACKACQ ? 0 : -EINVAL;
566 }
567
568 /* Switching-from response */
569 if (swtch == 0) {
570 /* Switch disallowed, so forget we were trying to do it. */
571 vc->vt_newvt = -1;
572 return 0;
573 }
574
575 /* The current vt has been released, so complete the switch. */
576 newvt = vc->vt_newvt;
577 vc->vt_newvt = -1;
578 ret = vc_allocate(newvt);
579 if (ret)
580 return ret;
581
582 /*
583 * When we actually do the console switch, make sure we are atomic with
584 * respect to other console switches..
585 */
586 complete_change_console(vc_cons[newvt].d);
587
588 return 0;
589}
590
591static int vt_setactivate(struct vt_setactivate __user *sa)
592{
593 struct vt_setactivate vsa;
594 struct vc_data *nvc;
595 int ret;
596
597 if (copy_from_user(&vsa, sa, sizeof(vsa)))
598 return -EFAULT;
599 if (vsa.console == 0 || vsa.console > MAX_NR_CONSOLES)
600 return -ENXIO;
601
602 vsa.console--;
603 vsa.console = array_index_nospec(vsa.console, MAX_NR_CONSOLES);
604 console_lock();
605 ret = vc_allocate(vsa.console);
606 if (ret) {
607 console_unlock();
608 return ret;
609 }
610
611 /*
612 * This is safe providing we don't drop the console sem between
613 * vc_allocate and finishing referencing nvc.
614 */
615 nvc = vc_cons[vsa.console].d;
616 nvc->vt_mode = vsa.mode;
617 nvc->vt_mode.frsig = 0;
618 put_pid(nvc->vt_pid);
619 nvc->vt_pid = get_pid(task_pid(current));
620 console_unlock();
621
622 /* Commence switch and lock */
623 /* Review set_console locks */
624 set_console(vsa.console);
625
626 return 0;
627}
628
629/* deallocate a single console, if possible (leave 0) */
630static int vt_disallocate(unsigned int vc_num)
631{
632 struct vc_data *vc = NULL;
633 int ret = 0;
634
635 console_lock();
636 if (vt_busy(vc_num))
637 ret = -EBUSY;
638 else if (vc_num)
639 vc = vc_deallocate(vc_num);
640 console_unlock();
641
642 if (vc && vc_num >= MIN_NR_CONSOLES)
643 tty_port_put(&vc->port);
644
645 return ret;
646}
647
648/* deallocate all unused consoles, but leave 0 */
649static void vt_disallocate_all(void)
650{
651 struct vc_data *vc[MAX_NR_CONSOLES];
652 int i;
653
654 console_lock();
655 for (i = 1; i < MAX_NR_CONSOLES; i++)
656 if (!vt_busy(i))
657 vc[i] = vc_deallocate(i);
658 else
659 vc[i] = NULL;
660 console_unlock();
661
662 for (i = 1; i < MAX_NR_CONSOLES; i++) {
663 if (vc[i] && i >= MIN_NR_CONSOLES)
664 tty_port_put(&vc[i]->port);
665 }
666}
667
668static int vt_resizex(struct vc_data *vc, struct vt_consize __user *cs)
669{
670 struct vt_consize v;
671 int i;
672
673 if (copy_from_user(&v, cs, sizeof(struct vt_consize)))
674 return -EFAULT;
675
676 /* FIXME: Should check the copies properly */
677 if (!v.v_vlin)
678 v.v_vlin = vc->vc_scan_lines;
679
680 if (v.v_clin) {
681 int rows = v.v_vlin / v.v_clin;
682 if (v.v_rows != rows) {
683 if (v.v_rows) /* Parameters don't add up */
684 return -EINVAL;
685 v.v_rows = rows;
686 }
687 }
688
689 if (v.v_vcol && v.v_ccol) {
690 int cols = v.v_vcol / v.v_ccol;
691 if (v.v_cols != cols) {
692 if (v.v_cols)
693 return -EINVAL;
694 v.v_cols = cols;
695 }
696 }
697
698 if (v.v_clin > 32)
699 return -EINVAL;
700
701 for (i = 0; i < MAX_NR_CONSOLES; i++) {
702 struct vc_data *vcp;
703
704 if (!vc_cons[i].d)
705 continue;
706 console_lock();
707 vcp = vc_cons[i].d;
708 if (vcp) {
709 int ret;
710 int save_scan_lines = vcp->vc_scan_lines;
711 int save_cell_height = vcp->vc_cell_height;
712
713 if (v.v_vlin)
714 vcp->vc_scan_lines = v.v_vlin;
715 if (v.v_clin)
716 vcp->vc_cell_height = v.v_clin;
717 vcp->vc_resize_user = 1;
718 ret = vc_resize(vcp, v.v_cols, v.v_rows);
719 if (ret) {
720 vcp->vc_scan_lines = save_scan_lines;
721 vcp->vc_cell_height = save_cell_height;
722 console_unlock();
723 return ret;
724 }
725 }
726 console_unlock();
727 }
728
729 return 0;
730}
731
732/*
733 * We handle the console-specific ioctl's here. We allow the
734 * capability to modify any console, not just the fg_console.
735 */
736int vt_ioctl(struct tty_struct *tty,
737 unsigned int cmd, unsigned long arg)
738{
739 struct vc_data *vc = tty->driver_data;
740 void __user *up = (void __user *)arg;
741 int i, perm;
742 int ret;
743
744 /*
745 * To have permissions to do most of the vt ioctls, we either have
746 * to be the owner of the tty, or have CAP_SYS_TTY_CONFIG.
747 */
748 perm = 0;
749 if (current->signal->tty == tty || capable(CAP_SYS_TTY_CONFIG))
750 perm = 1;
751
752 ret = vt_k_ioctl(tty, cmd, arg, perm);
753 if (ret != -ENOIOCTLCMD)
754 return ret;
755
756 ret = vt_io_ioctl(vc, cmd, up, perm);
757 if (ret != -ENOIOCTLCMD)
758 return ret;
759
760 switch (cmd) {
761 case TIOCLINUX:
762 return tioclinux(tty, arg);
763 case VT_SETMODE:
764 {
765 struct vt_mode tmp;
766
767 if (!perm)
768 return -EPERM;
769 if (copy_from_user(&tmp, up, sizeof(struct vt_mode)))
770 return -EFAULT;
771 if (tmp.mode != VT_AUTO && tmp.mode != VT_PROCESS)
772 return -EINVAL;
773
774 console_lock();
775 vc->vt_mode = tmp;
776 /* the frsig is ignored, so we set it to 0 */
777 vc->vt_mode.frsig = 0;
778 put_pid(vc->vt_pid);
779 vc->vt_pid = get_pid(task_pid(current));
780 /* no switch is required -- saw@shade.msu.ru */
781 vc->vt_newvt = -1;
782 console_unlock();
783 break;
784 }
785
786 case VT_GETMODE:
787 {
788 struct vt_mode tmp;
789 int rc;
790
791 console_lock();
792 memcpy(&tmp, &vc->vt_mode, sizeof(struct vt_mode));
793 console_unlock();
794
795 rc = copy_to_user(up, &tmp, sizeof(struct vt_mode));
796 if (rc)
797 return -EFAULT;
798 break;
799 }
800
801 /*
802 * Returns global vt state. Note that VT 0 is always open, since
803 * it's an alias for the current VT, and people can't use it here.
804 * We cannot return state for more than 16 VTs, since v_state is short.
805 */
806 case VT_GETSTATE:
807 {
808 struct vt_stat __user *vtstat = up;
809 unsigned short state, mask;
810
811 if (put_user(fg_console + 1, &vtstat->v_active))
812 return -EFAULT;
813
814 state = 1; /* /dev/tty0 is always open */
815 console_lock(); /* required by vt_in_use() */
816 for (i = 0, mask = 2; i < MAX_NR_CONSOLES && mask;
817 ++i, mask <<= 1)
818 if (vt_in_use(i))
819 state |= mask;
820 console_unlock();
821 return put_user(state, &vtstat->v_state);
822 }
823
824 /*
825 * Returns the first available (non-opened) console.
826 */
827 case VT_OPENQRY:
828 console_lock(); /* required by vt_in_use() */
829 for (i = 0; i < MAX_NR_CONSOLES; ++i)
830 if (!vt_in_use(i))
831 break;
832 console_unlock();
833 i = i < MAX_NR_CONSOLES ? (i+1) : -1;
834 return put_user(i, (int __user *)arg);
835
836 /*
837 * ioctl(fd, VT_ACTIVATE, num) will cause us to switch to vt # num,
838 * with num >= 1 (switches to vt 0, our console, are not allowed, just
839 * to preserve sanity).
840 */
841 case VT_ACTIVATE:
842 if (!perm)
843 return -EPERM;
844 if (arg == 0 || arg > MAX_NR_CONSOLES)
845 return -ENXIO;
846
847 arg--;
848 arg = array_index_nospec(arg, MAX_NR_CONSOLES);
849 console_lock();
850 ret = vc_allocate(arg);
851 console_unlock();
852 if (ret)
853 return ret;
854 set_console(arg);
855 break;
856
857 case VT_SETACTIVATE:
858 if (!perm)
859 return -EPERM;
860
861 return vt_setactivate(up);
862
863 /*
864 * wait until the specified VT has been activated
865 */
866 case VT_WAITACTIVE:
867 if (!perm)
868 return -EPERM;
869 if (arg == 0 || arg > MAX_NR_CONSOLES)
870 return -ENXIO;
871 return vt_waitactive(arg);
872
873 /*
874 * If a vt is under process control, the kernel will not switch to it
875 * immediately, but postpone the operation until the process calls this
876 * ioctl, allowing the switch to complete.
877 *
878 * According to the X sources this is the behavior:
879 * 0: pending switch-from not OK
880 * 1: pending switch-from OK
881 * 2: completed switch-to OK
882 */
883 case VT_RELDISP:
884 if (!perm)
885 return -EPERM;
886
887 console_lock();
888 ret = vt_reldisp(vc, arg);
889 console_unlock();
890
891 return ret;
892
893
894 /*
895 * Disallocate memory associated to VT (but leave VT1)
896 */
897 case VT_DISALLOCATE:
898 if (arg > MAX_NR_CONSOLES)
899 return -ENXIO;
900
901 if (arg == 0) {
902 vt_disallocate_all();
903 break;
904 }
905
906 arg = array_index_nospec(arg - 1, MAX_NR_CONSOLES);
907 return vt_disallocate(arg);
908
909 case VT_RESIZE:
910 {
911 struct vt_sizes __user *vtsizes = up;
912 struct vc_data *vc;
913 ushort ll,cc;
914
915 if (!perm)
916 return -EPERM;
917 if (get_user(ll, &vtsizes->v_rows) ||
918 get_user(cc, &vtsizes->v_cols))
919 return -EFAULT;
920
921 console_lock();
922 for (i = 0; i < MAX_NR_CONSOLES; i++) {
923 vc = vc_cons[i].d;
924
925 if (vc) {
926 vc->vc_resize_user = 1;
927 /* FIXME: review v tty lock */
928 vc_resize(vc_cons[i].d, cc, ll);
929 }
930 }
931 console_unlock();
932 break;
933 }
934
935 case VT_RESIZEX:
936 if (!perm)
937 return -EPERM;
938
939 return vt_resizex(vc, up);
940
941 case VT_LOCKSWITCH:
942 if (!capable(CAP_SYS_TTY_CONFIG))
943 return -EPERM;
944 vt_dont_switch = true;
945 break;
946 case VT_UNLOCKSWITCH:
947 if (!capable(CAP_SYS_TTY_CONFIG))
948 return -EPERM;
949 vt_dont_switch = false;
950 break;
951 case VT_GETHIFONTMASK:
952 return put_user(vc->vc_hi_font_mask,
953 (unsigned short __user *)arg);
954 case VT_WAITEVENT:
955 return vt_event_wait_ioctl((struct vt_event __user *)arg);
956 default:
957 return -ENOIOCTLCMD;
958 }
959
960 return 0;
961}
962
963void reset_vc(struct vc_data *vc)
964{
965 vc->vc_mode = KD_TEXT;
966 vt_reset_unicode(vc->vc_num);
967 vc->vt_mode.mode = VT_AUTO;
968 vc->vt_mode.waitv = 0;
969 vc->vt_mode.relsig = 0;
970 vc->vt_mode.acqsig = 0;
971 vc->vt_mode.frsig = 0;
972 put_pid(vc->vt_pid);
973 vc->vt_pid = NULL;
974 vc->vt_newvt = -1;
975 reset_palette(vc);
976}
977
978void vc_SAK(struct work_struct *work)
979{
980 struct vc *vc_con =
981 container_of(work, struct vc, SAK_work);
982 struct vc_data *vc;
983 struct tty_struct *tty;
984
985 console_lock();
986 vc = vc_con->d;
987 if (vc) {
988 /* FIXME: review tty ref counting */
989 tty = vc->port.tty;
990 /*
991 * SAK should also work in all raw modes and reset
992 * them properly.
993 */
994 if (tty)
995 __do_SAK(tty);
996 reset_vc(vc);
997 }
998 console_unlock();
999}
1000
1001#ifdef CONFIG_COMPAT
1002
1003struct compat_console_font_op {
1004 compat_uint_t op; /* operation code KD_FONT_OP_* */
1005 compat_uint_t flags; /* KD_FONT_FLAG_* */
1006 compat_uint_t width, height; /* font size */
1007 compat_uint_t charcount;
1008 compat_caddr_t data; /* font data with height fixed to 32 */
1009};
1010
1011static inline int
1012compat_kdfontop_ioctl(struct compat_console_font_op __user *fontop,
1013 int perm, struct console_font_op *op, struct vc_data *vc)
1014{
1015 int i;
1016
1017 if (copy_from_user(op, fontop, sizeof(struct compat_console_font_op)))
1018 return -EFAULT;
1019 if (!perm && op->op != KD_FONT_OP_GET)
1020 return -EPERM;
1021 op->data = compat_ptr(((struct compat_console_font_op *)op)->data);
1022 i = con_font_op(vc, op);
1023 if (i)
1024 return i;
1025 ((struct compat_console_font_op *)op)->data = (unsigned long)op->data;
1026 if (copy_to_user(fontop, op, sizeof(struct compat_console_font_op)))
1027 return -EFAULT;
1028 return 0;
1029}
1030
1031struct compat_unimapdesc {
1032 unsigned short entry_ct;
1033 compat_caddr_t entries;
1034};
1035
1036static inline int
1037compat_unimap_ioctl(unsigned int cmd, struct compat_unimapdesc __user *user_ud,
1038 int perm, struct vc_data *vc)
1039{
1040 struct compat_unimapdesc tmp;
1041 struct unipair __user *tmp_entries;
1042
1043 if (copy_from_user(&tmp, user_ud, sizeof tmp))
1044 return -EFAULT;
1045 tmp_entries = compat_ptr(tmp.entries);
1046 switch (cmd) {
1047 case PIO_UNIMAP:
1048 if (!perm)
1049 return -EPERM;
1050 return con_set_unimap(vc, tmp.entry_ct, tmp_entries);
1051 case GIO_UNIMAP:
1052 if (!perm && fg_console != vc->vc_num)
1053 return -EPERM;
1054 return con_get_unimap(vc, tmp.entry_ct, &(user_ud->entry_ct), tmp_entries);
1055 }
1056 return 0;
1057}
1058
1059long vt_compat_ioctl(struct tty_struct *tty,
1060 unsigned int cmd, unsigned long arg)
1061{
1062 struct vc_data *vc = tty->driver_data;
1063 struct console_font_op op; /* used in multiple places here */
1064 void __user *up = compat_ptr(arg);
1065 int perm;
1066
1067 /*
1068 * To have permissions to do most of the vt ioctls, we either have
1069 * to be the owner of the tty, or have CAP_SYS_TTY_CONFIG.
1070 */
1071 perm = 0;
1072 if (current->signal->tty == tty || capable(CAP_SYS_TTY_CONFIG))
1073 perm = 1;
1074
1075 switch (cmd) {
1076 /*
1077 * these need special handlers for incompatible data structures
1078 */
1079
1080 case KDFONTOP:
1081 return compat_kdfontop_ioctl(up, perm, &op, vc);
1082
1083 case PIO_UNIMAP:
1084 case GIO_UNIMAP:
1085 return compat_unimap_ioctl(cmd, up, perm, vc);
1086
1087 /*
1088 * all these treat 'arg' as an integer
1089 */
1090 case KIOCSOUND:
1091 case KDMKTONE:
1092#ifdef CONFIG_X86
1093 case KDADDIO:
1094 case KDDELIO:
1095#endif
1096 case KDSETMODE:
1097 case KDMAPDISP:
1098 case KDUNMAPDISP:
1099 case KDSKBMODE:
1100 case KDSKBMETA:
1101 case KDSKBLED:
1102 case KDSETLED:
1103 case KDSIGACCEPT:
1104 case VT_ACTIVATE:
1105 case VT_WAITACTIVE:
1106 case VT_RELDISP:
1107 case VT_DISALLOCATE:
1108 case VT_RESIZE:
1109 case VT_RESIZEX:
1110 return vt_ioctl(tty, cmd, arg);
1111
1112 /*
1113 * the rest has a compatible data structure behind arg,
1114 * but we have to convert it to a proper 64 bit pointer.
1115 */
1116 default:
1117 return vt_ioctl(tty, cmd, (unsigned long)up);
1118 }
1119}
1120
1121
1122#endif /* CONFIG_COMPAT */
1123
1124
1125/*
1126 * Performs the back end of a vt switch. Called under the console
1127 * semaphore.
1128 */
1129static void complete_change_console(struct vc_data *vc)
1130{
1131 unsigned char old_vc_mode;
1132 int old = fg_console;
1133
1134 last_console = fg_console;
1135
1136 /*
1137 * If we're switching, we could be going from KD_GRAPHICS to
1138 * KD_TEXT mode or vice versa, which means we need to blank or
1139 * unblank the screen later.
1140 */
1141 old_vc_mode = vc_cons[fg_console].d->vc_mode;
1142 switch_screen(vc);
1143
1144 /*
1145 * This can't appear below a successful kill_pid(). If it did,
1146 * then the *blank_screen operation could occur while X, having
1147 * received acqsig, is waking up on another processor. This
1148 * condition can lead to overlapping accesses to the VGA range
1149 * and the framebuffer (causing system lockups).
1150 *
1151 * To account for this we duplicate this code below only if the
1152 * controlling process is gone and we've called reset_vc.
1153 */
1154 if (old_vc_mode != vc->vc_mode) {
1155 if (vc->vc_mode == KD_TEXT)
1156 do_unblank_screen(1);
1157 else
1158 do_blank_screen(1);
1159 }
1160
1161 /*
1162 * If this new console is under process control, send it a signal
1163 * telling it that it has acquired. Also check if it has died and
1164 * clean up (similar to logic employed in change_console())
1165 */
1166 if (vc->vt_mode.mode == VT_PROCESS) {
1167 /*
1168 * Send the signal as privileged - kill_pid() will
1169 * tell us if the process has gone or something else
1170 * is awry
1171 */
1172 if (kill_pid(vc->vt_pid, vc->vt_mode.acqsig, 1) != 0) {
1173 /*
1174 * The controlling process has died, so we revert back to
1175 * normal operation. In this case, we'll also change back
1176 * to KD_TEXT mode. I'm not sure if this is strictly correct
1177 * but it saves the agony when the X server dies and the screen
1178 * remains blanked due to KD_GRAPHICS! It would be nice to do
1179 * this outside of VT_PROCESS but there is no single process
1180 * to account for and tracking tty count may be undesirable.
1181 */
1182 reset_vc(vc);
1183
1184 if (old_vc_mode != vc->vc_mode) {
1185 if (vc->vc_mode == KD_TEXT)
1186 do_unblank_screen(1);
1187 else
1188 do_blank_screen(1);
1189 }
1190 }
1191 }
1192
1193 /*
1194 * Wake anyone waiting for their VT to activate
1195 */
1196 vt_event_post(VT_EVENT_SWITCH, old, vc->vc_num);
1197 return;
1198}
1199
1200/*
1201 * Performs the front-end of a vt switch
1202 */
1203void change_console(struct vc_data *new_vc)
1204{
1205 struct vc_data *vc;
1206
1207 if (!new_vc || new_vc->vc_num == fg_console || vt_dont_switch)
1208 return;
1209
1210 /*
1211 * If this vt is in process mode, then we need to handshake with
1212 * that process before switching. Essentially, we store where that
1213 * vt wants to switch to and wait for it to tell us when it's done
1214 * (via VT_RELDISP ioctl).
1215 *
1216 * We also check to see if the controlling process still exists.
1217 * If it doesn't, we reset this vt to auto mode and continue.
1218 * This is a cheap way to track process control. The worst thing
1219 * that can happen is: we send a signal to a process, it dies, and
1220 * the switch gets "lost" waiting for a response; hopefully, the
1221 * user will try again, we'll detect the process is gone (unless
1222 * the user waits just the right amount of time :-) and revert the
1223 * vt to auto control.
1224 */
1225 vc = vc_cons[fg_console].d;
1226 if (vc->vt_mode.mode == VT_PROCESS) {
1227 /*
1228 * Send the signal as privileged - kill_pid() will
1229 * tell us if the process has gone or something else
1230 * is awry.
1231 *
1232 * We need to set vt_newvt *before* sending the signal or we
1233 * have a race.
1234 */
1235 vc->vt_newvt = new_vc->vc_num;
1236 if (kill_pid(vc->vt_pid, vc->vt_mode.relsig, 1) == 0) {
1237 /*
1238 * It worked. Mark the vt to switch to and
1239 * return. The process needs to send us a
1240 * VT_RELDISP ioctl to complete the switch.
1241 */
1242 return;
1243 }
1244
1245 /*
1246 * The controlling process has died, so we revert back to
1247 * normal operation. In this case, we'll also change back
1248 * to KD_TEXT mode. I'm not sure if this is strictly correct
1249 * but it saves the agony when the X server dies and the screen
1250 * remains blanked due to KD_GRAPHICS! It would be nice to do
1251 * this outside of VT_PROCESS but there is no single process
1252 * to account for and tracking tty count may be undesirable.
1253 */
1254 reset_vc(vc);
1255
1256 /*
1257 * Fall through to normal (VT_AUTO) handling of the switch...
1258 */
1259 }
1260
1261 /*
1262 * Ignore all switches in KD_GRAPHICS+VT_AUTO mode
1263 */
1264 if (vc->vc_mode == KD_GRAPHICS)
1265 return;
1266
1267 complete_change_console(new_vc);
1268}
1269
1270/* Perform a kernel triggered VT switch for suspend/resume */
1271
1272static int disable_vt_switch;
1273
1274int vt_move_to_console(unsigned int vt, int alloc)
1275{
1276 int prev;
1277
1278 console_lock();
1279 /* Graphics mode - up to X */
1280 if (disable_vt_switch) {
1281 console_unlock();
1282 return 0;
1283 }
1284 prev = fg_console;
1285
1286 if (alloc && vc_allocate(vt)) {
1287 /* we can't have a free VC for now. Too bad,
1288 * we don't want to mess the screen for now. */
1289 console_unlock();
1290 return -ENOSPC;
1291 }
1292
1293 if (set_console(vt)) {
1294 /*
1295 * We're unable to switch to the SUSPEND_CONSOLE.
1296 * Let the calling function know so it can decide
1297 * what to do.
1298 */
1299 console_unlock();
1300 return -EIO;
1301 }
1302 console_unlock();
1303 if (vt_waitactive(vt + 1)) {
1304 pr_debug("Suspend: Can't switch VCs.");
1305 return -EINTR;
1306 }
1307 return prev;
1308}
1309
1310/*
1311 * Normally during a suspend, we allocate a new console and switch to it.
1312 * When we resume, we switch back to the original console. This switch
1313 * can be slow, so on systems where the framebuffer can handle restoration
1314 * of video registers anyways, there's little point in doing the console
1315 * switch. This function allows you to disable it by passing it '0'.
1316 */
1317void pm_set_vt_switch(int do_switch)
1318{
1319 console_lock();
1320 disable_vt_switch = !do_switch;
1321 console_unlock();
1322}
1323EXPORT_SYMBOL(pm_set_vt_switch);
1/*
2 * Copyright (C) 1992 obz under the linux copyright
3 *
4 * Dynamic diacritical handling - aeb@cwi.nl - Dec 1993
5 * Dynamic keymap and string allocation - aeb@cwi.nl - May 1994
6 * Restrict VT switching via ioctl() - grif@cs.ucr.edu - Dec 1995
7 * Some code moved for less code duplication - Andi Kleen - Mar 1997
8 * Check put/get_user, cleanups - acme@conectiva.com.br - Jun 2001
9 */
10
11#include <linux/types.h>
12#include <linux/errno.h>
13#include <linux/sched.h>
14#include <linux/tty.h>
15#include <linux/timer.h>
16#include <linux/kernel.h>
17#include <linux/compat.h>
18#include <linux/module.h>
19#include <linux/kd.h>
20#include <linux/vt.h>
21#include <linux/string.h>
22#include <linux/slab.h>
23#include <linux/major.h>
24#include <linux/fs.h>
25#include <linux/console.h>
26#include <linux/consolemap.h>
27#include <linux/signal.h>
28#include <linux/timex.h>
29
30#include <asm/io.h>
31#include <asm/uaccess.h>
32
33#include <linux/kbd_kern.h>
34#include <linux/vt_kern.h>
35#include <linux/kbd_diacr.h>
36#include <linux/selection.h>
37
38char vt_dont_switch;
39extern struct tty_driver *console_driver;
40
41#define VT_IS_IN_USE(i) (console_driver->ttys[i] && console_driver->ttys[i]->count)
42#define VT_BUSY(i) (VT_IS_IN_USE(i) || i == fg_console || vc_cons[i].d == sel_cons)
43
44/*
45 * Console (vt and kd) routines, as defined by USL SVR4 manual, and by
46 * experimentation and study of X386 SYSV handling.
47 *
48 * One point of difference: SYSV vt's are /dev/vtX, which X >= 0, and
49 * /dev/console is a separate ttyp. Under Linux, /dev/tty0 is /dev/console,
50 * and the vc start at /dev/ttyX, X >= 1. We maintain that here, so we will
51 * always treat our set of vt as numbered 1..MAX_NR_CONSOLES (corresponding to
52 * ttys 0..MAX_NR_CONSOLES-1). Explicitly naming VT 0 is illegal, but using
53 * /dev/tty0 (fg_console) as a target is legal, since an implicit aliasing
54 * to the current console is done by the main ioctl code.
55 */
56
57#ifdef CONFIG_X86
58#include <linux/syscalls.h>
59#endif
60
61static void complete_change_console(struct vc_data *vc);
62
63/*
64 * User space VT_EVENT handlers
65 */
66
67struct vt_event_wait {
68 struct list_head list;
69 struct vt_event event;
70 int done;
71};
72
73static LIST_HEAD(vt_events);
74static DEFINE_SPINLOCK(vt_event_lock);
75static DECLARE_WAIT_QUEUE_HEAD(vt_event_waitqueue);
76
77/**
78 * vt_event_post
79 * @event: the event that occurred
80 * @old: old console
81 * @new: new console
82 *
83 * Post an VT event to interested VT handlers
84 */
85
86void vt_event_post(unsigned int event, unsigned int old, unsigned int new)
87{
88 struct list_head *pos, *head;
89 unsigned long flags;
90 int wake = 0;
91
92 spin_lock_irqsave(&vt_event_lock, flags);
93 head = &vt_events;
94
95 list_for_each(pos, head) {
96 struct vt_event_wait *ve = list_entry(pos,
97 struct vt_event_wait, list);
98 if (!(ve->event.event & event))
99 continue;
100 ve->event.event = event;
101 /* kernel view is consoles 0..n-1, user space view is
102 console 1..n with 0 meaning current, so we must bias */
103 ve->event.oldev = old + 1;
104 ve->event.newev = new + 1;
105 wake = 1;
106 ve->done = 1;
107 }
108 spin_unlock_irqrestore(&vt_event_lock, flags);
109 if (wake)
110 wake_up_interruptible(&vt_event_waitqueue);
111}
112
113/**
114 * vt_event_wait - wait for an event
115 * @vw: our event
116 *
117 * Waits for an event to occur which completes our vt_event_wait
118 * structure. On return the structure has wv->done set to 1 for success
119 * or 0 if some event such as a signal ended the wait.
120 */
121
122static void vt_event_wait(struct vt_event_wait *vw)
123{
124 unsigned long flags;
125 /* Prepare the event */
126 INIT_LIST_HEAD(&vw->list);
127 vw->done = 0;
128 /* Queue our event */
129 spin_lock_irqsave(&vt_event_lock, flags);
130 list_add(&vw->list, &vt_events);
131 spin_unlock_irqrestore(&vt_event_lock, flags);
132 /* Wait for it to pass */
133 wait_event_interruptible_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
147static int vt_event_wait_ioctl(struct vt_event __user *event)
148{
149 struct vt_event_wait vw;
150
151 if (copy_from_user(&vw.event, event, sizeof(struct vt_event)))
152 return -EFAULT;
153 /* Highest supported event for now */
154 if (vw.event.event & ~VT_MAX_EVENT)
155 return -EINVAL;
156
157 vt_event_wait(&vw);
158 /* If it occurred report it */
159 if (vw.done) {
160 if (copy_to_user(event, &vw.event, sizeof(struct vt_event)))
161 return -EFAULT;
162 return 0;
163 }
164 return -EINTR;
165}
166
167/**
168 * vt_waitactive - active console wait
169 * @event: event code
170 * @n: new console
171 *
172 * Helper for event waits. Used to implement the legacy
173 * event waiting ioctls in terms of events
174 */
175
176int vt_waitactive(int n)
177{
178 struct vt_event_wait vw;
179 do {
180 if (n == fg_console + 1)
181 break;
182 vw.event.event = VT_EVENT_SWITCH;
183 vt_event_wait(&vw);
184 if (vw.done == 0)
185 return -EINTR;
186 } while (vw.event.newev != n);
187 return 0;
188}
189
190/*
191 * these are the valid i/o ports we're allowed to change. they map all the
192 * video ports
193 */
194#define GPFIRST 0x3b4
195#define GPLAST 0x3df
196#define GPNUM (GPLAST - GPFIRST + 1)
197
198#define i (tmp.kb_index)
199#define s (tmp.kb_table)
200#define v (tmp.kb_value)
201static inline int
202do_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
289static inline int
290do_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
312static inline int
313do_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;
420reterr:
421 kfree(kbs);
422 return ret;
423}
424
425static inline int
426do_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
465static inline int
466do_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 */
495int 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 }
1353out:
1354 tty_unlock();
1355 return ret;
1356eperm:
1357 ret = -EPERM;
1358 goto out;
1359}
1360
1361void 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
1377void 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
1401struct 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
1407static inline int
1408compat_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
1447struct 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
1455static inline int
1456compat_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
1476struct compat_unimapdesc {
1477 unsigned short entry_ct;
1478 compat_caddr_t entries;
1479};
1480
1481static inline int
1482compat_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
1508long 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 }
1586out:
1587 tty_unlock();
1588 return ret;
1589
1590fallback:
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 */
1603static 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 */
1677void 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
1746static int disable_vt_switch;
1747
1748int 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 */
1794void pm_set_vt_switch(int do_switch)
1795{
1796 console_lock();
1797 disable_vt_switch = !do_switch;
1798 console_unlock();
1799}
1800EXPORT_SYMBOL(pm_set_vt_switch);