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