Linux 2.6.33-rc8
[linux-2.6/lguest.git] / drivers / char / vt_ioctl.c
blob6aa10284104aeb6e4bc3a22833ea347e67c5d976
1 /*
2 * linux/drivers/char/vt_ioctl.c
4 * Copyright (C) 1992 obz under the linux copyright
6 * Dynamic diacritical handling - aeb@cwi.nl - Dec 1993
7 * Dynamic keymap and string allocation - aeb@cwi.nl - May 1994
8 * Restrict VT switching via ioctl() - grif@cs.ucr.edu - Dec 1995
9 * Some code moved for less code duplication - Andi Kleen - Mar 1997
10 * Check put/get_user, cleanups - acme@conectiva.com.br - Jun 2001
13 #include <linux/types.h>
14 #include <linux/errno.h>
15 #include <linux/sched.h>
16 #include <linux/tty.h>
17 #include <linux/timer.h>
18 #include <linux/kernel.h>
19 #include <linux/compat.h>
20 #include <linux/module.h>
21 #include <linux/kd.h>
22 #include <linux/vt.h>
23 #include <linux/string.h>
24 #include <linux/slab.h>
25 #include <linux/major.h>
26 #include <linux/fs.h>
27 #include <linux/console.h>
28 #include <linux/consolemap.h>
29 #include <linux/signal.h>
30 #include <linux/smp_lock.h>
31 #include <linux/timex.h>
33 #include <asm/io.h>
34 #include <asm/uaccess.h>
36 #include <linux/kbd_kern.h>
37 #include <linux/vt_kern.h>
38 #include <linux/kbd_diacr.h>
39 #include <linux/selection.h>
41 char vt_dont_switch;
42 extern struct tty_driver *console_driver;
44 #define VT_IS_IN_USE(i) (console_driver->ttys[i] && console_driver->ttys[i]->count)
45 #define VT_BUSY(i) (VT_IS_IN_USE(i) || i == fg_console || vc_cons[i].d == sel_cons)
48 * Console (vt and kd) routines, as defined by USL SVR4 manual, and by
49 * experimentation and study of X386 SYSV handling.
51 * One point of difference: SYSV vt's are /dev/vtX, which X >= 0, and
52 * /dev/console is a separate ttyp. Under Linux, /dev/tty0 is /dev/console,
53 * and the vc start at /dev/ttyX, X >= 1. We maintain that here, so we will
54 * always treat our set of vt as numbered 1..MAX_NR_CONSOLES (corresponding to
55 * ttys 0..MAX_NR_CONSOLES-1). Explicitly naming VT 0 is illegal, but using
56 * /dev/tty0 (fg_console) as a target is legal, since an implicit aliasing
57 * to the current console is done by the main ioctl code.
60 #ifdef CONFIG_X86
61 #include <linux/syscalls.h>
62 #endif
64 static void complete_change_console(struct vc_data *vc);
67 * User space VT_EVENT handlers
70 struct vt_event_wait {
71 struct list_head list;
72 struct vt_event event;
73 int done;
76 static LIST_HEAD(vt_events);
77 static DEFINE_SPINLOCK(vt_event_lock);
78 static DECLARE_WAIT_QUEUE_HEAD(vt_event_waitqueue);
80 /**
81 * vt_event_post
82 * @event: the event that occurred
83 * @old: old console
84 * @new: new console
86 * Post an VT event to interested VT handlers
89 void vt_event_post(unsigned int event, unsigned int old, unsigned int new)
91 struct list_head *pos, *head;
92 unsigned long flags;
93 int wake = 0;
95 spin_lock_irqsave(&vt_event_lock, flags);
96 head = &vt_events;
98 list_for_each(pos, head) {
99 struct vt_event_wait *ve = list_entry(pos,
100 struct vt_event_wait, list);
101 if (!(ve->event.event & event))
102 continue;
103 ve->event.event = event;
104 /* kernel view is consoles 0..n-1, user space view is
105 console 1..n with 0 meaning current, so we must bias */
106 ve->event.oldev = old + 1;
107 ve->event.newev = new + 1;
108 wake = 1;
109 ve->done = 1;
111 spin_unlock_irqrestore(&vt_event_lock, flags);
112 if (wake)
113 wake_up_interruptible(&vt_event_waitqueue);
117 * vt_event_wait - wait for an event
118 * @vw: our event
120 * Waits for an event to occur which completes our vt_event_wait
121 * structure. On return the structure has wv->done set to 1 for success
122 * or 0 if some event such as a signal ended the wait.
125 static void vt_event_wait(struct vt_event_wait *vw)
127 unsigned long flags;
128 /* Prepare the event */
129 INIT_LIST_HEAD(&vw->list);
130 vw->done = 0;
131 /* Queue our event */
132 spin_lock_irqsave(&vt_event_lock, flags);
133 list_add(&vw->list, &vt_events);
134 spin_unlock_irqrestore(&vt_event_lock, flags);
135 /* Wait for it to pass */
136 wait_event_interruptible(vt_event_waitqueue, vw->done);
137 /* Dequeue it */
138 spin_lock_irqsave(&vt_event_lock, flags);
139 list_del(&vw->list);
140 spin_unlock_irqrestore(&vt_event_lock, flags);
144 * vt_event_wait_ioctl - event ioctl handler
145 * @arg: argument to ioctl
147 * Implement the VT_WAITEVENT ioctl using the VT event interface
150 static int vt_event_wait_ioctl(struct vt_event __user *event)
152 struct vt_event_wait vw;
154 if (copy_from_user(&vw.event, event, sizeof(struct vt_event)))
155 return -EFAULT;
156 /* Highest supported event for now */
157 if (vw.event.event & ~VT_MAX_EVENT)
158 return -EINVAL;
160 vt_event_wait(&vw);
161 /* If it occurred report it */
162 if (vw.done) {
163 if (copy_to_user(event, &vw.event, sizeof(struct vt_event)))
164 return -EFAULT;
165 return 0;
167 return -EINTR;
171 * vt_waitactive - active console wait
172 * @event: event code
173 * @n: new console
175 * Helper for event waits. Used to implement the legacy
176 * event waiting ioctls in terms of events
179 int vt_waitactive(int n)
181 struct vt_event_wait vw;
182 do {
183 if (n == fg_console + 1)
184 break;
185 vw.event.event = VT_EVENT_SWITCH;
186 vt_event_wait(&vw);
187 if (vw.done == 0)
188 return -EINTR;
189 } while (vw.event.newev != n);
190 return 0;
194 * these are the valid i/o ports we're allowed to change. they map all the
195 * video ports
197 #define GPFIRST 0x3b4
198 #define GPLAST 0x3df
199 #define GPNUM (GPLAST - GPFIRST + 1)
201 #define i (tmp.kb_index)
202 #define s (tmp.kb_table)
203 #define v (tmp.kb_value)
204 static inline int
205 do_kdsk_ioctl(int cmd, struct kbentry __user *user_kbe, int perm, struct kbd_struct *kbd)
207 struct kbentry tmp;
208 ushort *key_map, val, ov;
210 if (copy_from_user(&tmp, user_kbe, sizeof(struct kbentry)))
211 return -EFAULT;
213 if (!capable(CAP_SYS_TTY_CONFIG))
214 perm = 0;
216 switch (cmd) {
217 case KDGKBENT:
218 key_map = key_maps[s];
219 if (key_map) {
220 val = U(key_map[i]);
221 if (kbd->kbdmode != VC_UNICODE && KTYP(val) >= NR_TYPES)
222 val = K_HOLE;
223 } else
224 val = (i ? K_HOLE : K_NOSUCHMAP);
225 return put_user(val, &user_kbe->kb_value);
226 case KDSKBENT:
227 if (!perm)
228 return -EPERM;
229 if (!i && v == K_NOSUCHMAP) {
230 /* deallocate map */
231 key_map = key_maps[s];
232 if (s && key_map) {
233 key_maps[s] = NULL;
234 if (key_map[0] == U(K_ALLOCATED)) {
235 kfree(key_map);
236 keymap_count--;
239 break;
242 if (KTYP(v) < NR_TYPES) {
243 if (KVAL(v) > max_vals[KTYP(v)])
244 return -EINVAL;
245 } else
246 if (kbd->kbdmode != VC_UNICODE)
247 return -EINVAL;
249 /* ++Geert: non-PC keyboards may generate keycode zero */
250 #if !defined(__mc68000__) && !defined(__powerpc__)
251 /* assignment to entry 0 only tests validity of args */
252 if (!i)
253 break;
254 #endif
256 if (!(key_map = key_maps[s])) {
257 int j;
259 if (keymap_count >= MAX_NR_OF_USER_KEYMAPS &&
260 !capable(CAP_SYS_RESOURCE))
261 return -EPERM;
263 key_map = kmalloc(sizeof(plain_map),
264 GFP_KERNEL);
265 if (!key_map)
266 return -ENOMEM;
267 key_maps[s] = key_map;
268 key_map[0] = U(K_ALLOCATED);
269 for (j = 1; j < NR_KEYS; j++)
270 key_map[j] = U(K_HOLE);
271 keymap_count++;
273 ov = U(key_map[i]);
274 if (v == ov)
275 break; /* nothing to do */
277 * Attention Key.
279 if (((ov == K_SAK) || (v == K_SAK)) && !capable(CAP_SYS_ADMIN))
280 return -EPERM;
281 key_map[i] = U(v);
282 if (!s && (KTYP(ov) == KT_SHIFT || KTYP(v) == KT_SHIFT))
283 compute_shiftstate();
284 break;
286 return 0;
288 #undef i
289 #undef s
290 #undef v
292 static inline int
293 do_kbkeycode_ioctl(int cmd, struct kbkeycode __user *user_kbkc, int perm)
295 struct kbkeycode tmp;
296 int kc = 0;
298 if (copy_from_user(&tmp, user_kbkc, sizeof(struct kbkeycode)))
299 return -EFAULT;
300 switch (cmd) {
301 case KDGETKEYCODE:
302 kc = getkeycode(tmp.scancode);
303 if (kc >= 0)
304 kc = put_user(kc, &user_kbkc->keycode);
305 break;
306 case KDSETKEYCODE:
307 if (!perm)
308 return -EPERM;
309 kc = setkeycode(tmp.scancode, tmp.keycode);
310 break;
312 return kc;
315 static inline int
316 do_kdgkb_ioctl(int cmd, struct kbsentry __user *user_kdgkb, int perm)
318 struct kbsentry *kbs;
319 char *p;
320 u_char *q;
321 u_char __user *up;
322 int sz;
323 int delta;
324 char *first_free, *fj, *fnw;
325 int i, j, k;
326 int ret;
328 if (!capable(CAP_SYS_TTY_CONFIG))
329 perm = 0;
331 kbs = kmalloc(sizeof(*kbs), GFP_KERNEL);
332 if (!kbs) {
333 ret = -ENOMEM;
334 goto reterr;
337 /* we mostly copy too much here (512bytes), but who cares ;) */
338 if (copy_from_user(kbs, user_kdgkb, sizeof(struct kbsentry))) {
339 ret = -EFAULT;
340 goto reterr;
342 kbs->kb_string[sizeof(kbs->kb_string)-1] = '\0';
343 i = kbs->kb_func;
345 switch (cmd) {
346 case KDGKBSENT:
347 sz = sizeof(kbs->kb_string) - 1; /* sz should have been
348 a struct member */
349 up = user_kdgkb->kb_string;
350 p = func_table[i];
351 if(p)
352 for ( ; *p && sz; p++, sz--)
353 if (put_user(*p, up++)) {
354 ret = -EFAULT;
355 goto reterr;
357 if (put_user('\0', up)) {
358 ret = -EFAULT;
359 goto reterr;
361 kfree(kbs);
362 return ((p && *p) ? -EOVERFLOW : 0);
363 case KDSKBSENT:
364 if (!perm) {
365 ret = -EPERM;
366 goto reterr;
369 q = func_table[i];
370 first_free = funcbufptr + (funcbufsize - funcbufleft);
371 for (j = i+1; j < MAX_NR_FUNC && !func_table[j]; j++)
373 if (j < MAX_NR_FUNC)
374 fj = func_table[j];
375 else
376 fj = first_free;
378 delta = (q ? -strlen(q) : 1) + strlen(kbs->kb_string);
379 if (delta <= funcbufleft) { /* it fits in current buf */
380 if (j < MAX_NR_FUNC) {
381 memmove(fj + delta, fj, first_free - fj);
382 for (k = j; k < MAX_NR_FUNC; k++)
383 if (func_table[k])
384 func_table[k] += delta;
386 if (!q)
387 func_table[i] = fj;
388 funcbufleft -= delta;
389 } else { /* allocate a larger buffer */
390 sz = 256;
391 while (sz < funcbufsize - funcbufleft + delta)
392 sz <<= 1;
393 fnw = kmalloc(sz, GFP_KERNEL);
394 if(!fnw) {
395 ret = -ENOMEM;
396 goto reterr;
399 if (!q)
400 func_table[i] = fj;
401 if (fj > funcbufptr)
402 memmove(fnw, funcbufptr, fj - funcbufptr);
403 for (k = 0; k < j; k++)
404 if (func_table[k])
405 func_table[k] = fnw + (func_table[k] - funcbufptr);
407 if (first_free > fj) {
408 memmove(fnw + (fj - funcbufptr) + delta, fj, first_free - fj);
409 for (k = j; k < MAX_NR_FUNC; k++)
410 if (func_table[k])
411 func_table[k] = fnw + (func_table[k] - funcbufptr) + delta;
413 if (funcbufptr != func_buf)
414 kfree(funcbufptr);
415 funcbufptr = fnw;
416 funcbufleft = funcbufleft - delta + sz - funcbufsize;
417 funcbufsize = sz;
419 strcpy(func_table[i], kbs->kb_string);
420 break;
422 ret = 0;
423 reterr:
424 kfree(kbs);
425 return ret;
428 static inline int
429 do_fontx_ioctl(int cmd, struct consolefontdesc __user *user_cfd, int perm, struct console_font_op *op)
431 struct consolefontdesc cfdarg;
432 int i;
434 if (copy_from_user(&cfdarg, user_cfd, sizeof(struct consolefontdesc)))
435 return -EFAULT;
437 switch (cmd) {
438 case PIO_FONTX:
439 if (!perm)
440 return -EPERM;
441 op->op = KD_FONT_OP_SET;
442 op->flags = KD_FONT_FLAG_OLD;
443 op->width = 8;
444 op->height = cfdarg.charheight;
445 op->charcount = cfdarg.charcount;
446 op->data = cfdarg.chardata;
447 return con_font_op(vc_cons[fg_console].d, op);
448 case GIO_FONTX: {
449 op->op = KD_FONT_OP_GET;
450 op->flags = KD_FONT_FLAG_OLD;
451 op->width = 8;
452 op->height = cfdarg.charheight;
453 op->charcount = cfdarg.charcount;
454 op->data = cfdarg.chardata;
455 i = con_font_op(vc_cons[fg_console].d, op);
456 if (i)
457 return i;
458 cfdarg.charheight = op->height;
459 cfdarg.charcount = op->charcount;
460 if (copy_to_user(user_cfd, &cfdarg, sizeof(struct consolefontdesc)))
461 return -EFAULT;
462 return 0;
465 return -EINVAL;
468 static inline int
469 do_unimap_ioctl(int cmd, struct unimapdesc __user *user_ud, int perm, struct vc_data *vc)
471 struct unimapdesc tmp;
473 if (copy_from_user(&tmp, user_ud, sizeof tmp))
474 return -EFAULT;
475 if (tmp.entries)
476 if (!access_ok(VERIFY_WRITE, tmp.entries,
477 tmp.entry_ct*sizeof(struct unipair)))
478 return -EFAULT;
479 switch (cmd) {
480 case PIO_UNIMAP:
481 if (!perm)
482 return -EPERM;
483 return con_set_unimap(vc, tmp.entry_ct, tmp.entries);
484 case GIO_UNIMAP:
485 if (!perm && fg_console != vc->vc_num)
486 return -EPERM;
487 return con_get_unimap(vc, tmp.entry_ct, &(user_ud->entry_ct), tmp.entries);
489 return 0;
495 * We handle the console-specific ioctl's here. We allow the
496 * capability to modify any console, not just the fg_console.
498 int vt_ioctl(struct tty_struct *tty, struct file * file,
499 unsigned int cmd, unsigned long arg)
501 struct vc_data *vc = tty->driver_data;
502 struct console_font_op op; /* used in multiple places here */
503 struct kbd_struct * kbd;
504 unsigned int console;
505 unsigned char ucval;
506 void __user *up = (void __user *)arg;
507 int i, perm;
508 int ret = 0;
510 console = vc->vc_num;
512 lock_kernel();
514 if (!vc_cons_allocated(console)) { /* impossible? */
515 ret = -ENOIOCTLCMD;
516 goto out;
521 * To have permissions to do most of the vt ioctls, we either have
522 * to be the owner of the tty, or have CAP_SYS_TTY_CONFIG.
524 perm = 0;
525 if (current->signal->tty == tty || capable(CAP_SYS_TTY_CONFIG))
526 perm = 1;
528 kbd = kbd_table + console;
529 switch (cmd) {
530 case TIOCLINUX:
531 ret = tioclinux(tty, arg);
532 break;
533 case KIOCSOUND:
534 if (!perm)
535 goto eperm;
536 /* FIXME: This is an old broken API but we need to keep it
537 supported and somehow separate the historic advertised
538 tick rate from any real one */
539 if (arg)
540 arg = CLOCK_TICK_RATE / arg;
541 kd_mksound(arg, 0);
542 break;
544 case KDMKTONE:
545 if (!perm)
546 goto eperm;
548 unsigned int ticks, count;
551 * Generate the tone for the appropriate number of ticks.
552 * If the time is zero, turn off sound ourselves.
554 ticks = HZ * ((arg >> 16) & 0xffff) / 1000;
555 count = ticks ? (arg & 0xffff) : 0;
556 /* FIXME: This is an old broken API but we need to keep it
557 supported and somehow separate the historic advertised
558 tick rate from any real one */
559 if (count)
560 count = CLOCK_TICK_RATE / count;
561 kd_mksound(count, ticks);
562 break;
565 case KDGKBTYPE:
567 * this is naive.
569 ucval = KB_101;
570 goto setchar;
573 * These cannot be implemented on any machine that implements
574 * ioperm() in user level (such as Alpha PCs) or not at all.
576 * XXX: you should never use these, just call ioperm directly..
578 #ifdef CONFIG_X86
579 case KDADDIO:
580 case KDDELIO:
582 * KDADDIO and KDDELIO may be able to add ports beyond what
583 * we reject here, but to be safe...
585 if (arg < GPFIRST || arg > GPLAST) {
586 ret = -EINVAL;
587 break;
589 ret = sys_ioperm(arg, 1, (cmd == KDADDIO)) ? -ENXIO : 0;
590 break;
592 case KDENABIO:
593 case KDDISABIO:
594 ret = sys_ioperm(GPFIRST, GPNUM,
595 (cmd == KDENABIO)) ? -ENXIO : 0;
596 break;
597 #endif
599 /* Linux m68k/i386 interface for setting the keyboard delay/repeat rate */
601 case KDKBDREP:
603 struct kbd_repeat kbrep;
605 if (!capable(CAP_SYS_TTY_CONFIG))
606 goto eperm;
608 if (copy_from_user(&kbrep, up, sizeof(struct kbd_repeat))) {
609 ret = -EFAULT;
610 break;
612 ret = kbd_rate(&kbrep);
613 if (ret)
614 break;
615 if (copy_to_user(up, &kbrep, sizeof(struct kbd_repeat)))
616 ret = -EFAULT;
617 break;
620 case KDSETMODE:
622 * currently, setting the mode from KD_TEXT to KD_GRAPHICS
623 * doesn't do a whole lot. i'm not sure if it should do any
624 * restoration of modes or what...
626 * XXX It should at least call into the driver, fbdev's definitely
627 * need to restore their engine state. --BenH
629 if (!perm)
630 goto eperm;
631 switch (arg) {
632 case KD_GRAPHICS:
633 break;
634 case KD_TEXT0:
635 case KD_TEXT1:
636 arg = KD_TEXT;
637 case KD_TEXT:
638 break;
639 default:
640 ret = -EINVAL;
641 goto out;
643 if (vc->vc_mode == (unsigned char) arg)
644 break;
645 vc->vc_mode = (unsigned char) arg;
646 if (console != fg_console)
647 break;
649 * explicitly blank/unblank the screen if switching modes
651 acquire_console_sem();
652 if (arg == KD_TEXT)
653 do_unblank_screen(1);
654 else
655 do_blank_screen(1);
656 release_console_sem();
657 break;
659 case KDGETMODE:
660 ucval = vc->vc_mode;
661 goto setint;
663 case KDMAPDISP:
664 case KDUNMAPDISP:
666 * these work like a combination of mmap and KDENABIO.
667 * this could be easily finished.
669 ret = -EINVAL;
670 break;
672 case KDSKBMODE:
673 if (!perm)
674 goto eperm;
675 switch(arg) {
676 case K_RAW:
677 kbd->kbdmode = VC_RAW;
678 break;
679 case K_MEDIUMRAW:
680 kbd->kbdmode = VC_MEDIUMRAW;
681 break;
682 case K_XLATE:
683 kbd->kbdmode = VC_XLATE;
684 compute_shiftstate();
685 break;
686 case K_UNICODE:
687 kbd->kbdmode = VC_UNICODE;
688 compute_shiftstate();
689 break;
690 default:
691 ret = -EINVAL;
692 goto out;
694 tty_ldisc_flush(tty);
695 break;
697 case KDGKBMODE:
698 ucval = ((kbd->kbdmode == VC_RAW) ? K_RAW :
699 (kbd->kbdmode == VC_MEDIUMRAW) ? K_MEDIUMRAW :
700 (kbd->kbdmode == VC_UNICODE) ? K_UNICODE :
701 K_XLATE);
702 goto setint;
704 /* this could be folded into KDSKBMODE, but for compatibility
705 reasons it is not so easy to fold KDGKBMETA into KDGKBMODE */
706 case KDSKBMETA:
707 switch(arg) {
708 case K_METABIT:
709 clr_vc_kbd_mode(kbd, VC_META);
710 break;
711 case K_ESCPREFIX:
712 set_vc_kbd_mode(kbd, VC_META);
713 break;
714 default:
715 ret = -EINVAL;
717 break;
719 case KDGKBMETA:
720 ucval = (vc_kbd_mode(kbd, VC_META) ? K_ESCPREFIX : K_METABIT);
721 setint:
722 ret = put_user(ucval, (int __user *)arg);
723 break;
725 case KDGETKEYCODE:
726 case KDSETKEYCODE:
727 if(!capable(CAP_SYS_TTY_CONFIG))
728 perm = 0;
729 ret = do_kbkeycode_ioctl(cmd, up, perm);
730 break;
732 case KDGKBENT:
733 case KDSKBENT:
734 ret = do_kdsk_ioctl(cmd, up, perm, kbd);
735 break;
737 case KDGKBSENT:
738 case KDSKBSENT:
739 ret = do_kdgkb_ioctl(cmd, up, perm);
740 break;
742 case KDGKBDIACR:
744 struct kbdiacrs __user *a = up;
745 struct kbdiacr diacr;
746 int i;
748 if (put_user(accent_table_size, &a->kb_cnt)) {
749 ret = -EFAULT;
750 break;
752 for (i = 0; i < accent_table_size; i++) {
753 diacr.diacr = conv_uni_to_8bit(accent_table[i].diacr);
754 diacr.base = conv_uni_to_8bit(accent_table[i].base);
755 diacr.result = conv_uni_to_8bit(accent_table[i].result);
756 if (copy_to_user(a->kbdiacr + i, &diacr, sizeof(struct kbdiacr))) {
757 ret = -EFAULT;
758 break;
761 break;
763 case KDGKBDIACRUC:
765 struct kbdiacrsuc __user *a = up;
767 if (put_user(accent_table_size, &a->kb_cnt))
768 ret = -EFAULT;
769 else if (copy_to_user(a->kbdiacruc, accent_table,
770 accent_table_size*sizeof(struct kbdiacruc)))
771 ret = -EFAULT;
772 break;
775 case KDSKBDIACR:
777 struct kbdiacrs __user *a = up;
778 struct kbdiacr diacr;
779 unsigned int ct;
780 int i;
782 if (!perm)
783 goto eperm;
784 if (get_user(ct,&a->kb_cnt)) {
785 ret = -EFAULT;
786 break;
788 if (ct >= MAX_DIACR) {
789 ret = -EINVAL;
790 break;
792 accent_table_size = ct;
793 for (i = 0; i < ct; i++) {
794 if (copy_from_user(&diacr, a->kbdiacr + i, sizeof(struct kbdiacr))) {
795 ret = -EFAULT;
796 break;
798 accent_table[i].diacr = conv_8bit_to_uni(diacr.diacr);
799 accent_table[i].base = conv_8bit_to_uni(diacr.base);
800 accent_table[i].result = conv_8bit_to_uni(diacr.result);
802 break;
805 case KDSKBDIACRUC:
807 struct kbdiacrsuc __user *a = up;
808 unsigned int ct;
810 if (!perm)
811 goto eperm;
812 if (get_user(ct,&a->kb_cnt)) {
813 ret = -EFAULT;
814 break;
816 if (ct >= MAX_DIACR) {
817 ret = -EINVAL;
818 break;
820 accent_table_size = ct;
821 if (copy_from_user(accent_table, a->kbdiacruc, ct*sizeof(struct kbdiacruc)))
822 ret = -EFAULT;
823 break;
826 /* the ioctls below read/set the flags usually shown in the leds */
827 /* don't use them - they will go away without warning */
828 case KDGKBLED:
829 ucval = kbd->ledflagstate | (kbd->default_ledflagstate << 4);
830 goto setchar;
832 case KDSKBLED:
833 if (!perm)
834 goto eperm;
835 if (arg & ~0x77) {
836 ret = -EINVAL;
837 break;
839 kbd->ledflagstate = (arg & 7);
840 kbd->default_ledflagstate = ((arg >> 4) & 7);
841 set_leds();
842 break;
844 /* the ioctls below only set the lights, not the functions */
845 /* for those, see KDGKBLED and KDSKBLED above */
846 case KDGETLED:
847 ucval = getledstate();
848 setchar:
849 ret = put_user(ucval, (char __user *)arg);
850 break;
852 case KDSETLED:
853 if (!perm)
854 goto eperm;
855 setledstate(kbd, arg);
856 break;
859 * A process can indicate its willingness to accept signals
860 * generated by pressing an appropriate key combination.
861 * Thus, one can have a daemon that e.g. spawns a new console
862 * upon a keypress and then changes to it.
863 * See also the kbrequest field of inittab(5).
865 case KDSIGACCEPT:
867 if (!perm || !capable(CAP_KILL))
868 goto eperm;
869 if (!valid_signal(arg) || arg < 1 || arg == SIGKILL)
870 ret = -EINVAL;
871 else {
872 spin_lock_irq(&vt_spawn_con.lock);
873 put_pid(vt_spawn_con.pid);
874 vt_spawn_con.pid = get_pid(task_pid(current));
875 vt_spawn_con.sig = arg;
876 spin_unlock_irq(&vt_spawn_con.lock);
878 break;
881 case VT_SETMODE:
883 struct vt_mode tmp;
885 if (!perm)
886 goto eperm;
887 if (copy_from_user(&tmp, up, sizeof(struct vt_mode))) {
888 ret = -EFAULT;
889 goto out;
891 if (tmp.mode != VT_AUTO && tmp.mode != VT_PROCESS) {
892 ret = -EINVAL;
893 goto out;
895 acquire_console_sem();
896 vc->vt_mode = tmp;
897 /* the frsig is ignored, so we set it to 0 */
898 vc->vt_mode.frsig = 0;
899 put_pid(vc->vt_pid);
900 vc->vt_pid = get_pid(task_pid(current));
901 /* no switch is required -- saw@shade.msu.ru */
902 vc->vt_newvt = -1;
903 release_console_sem();
904 break;
907 case VT_GETMODE:
909 struct vt_mode tmp;
910 int rc;
912 acquire_console_sem();
913 memcpy(&tmp, &vc->vt_mode, sizeof(struct vt_mode));
914 release_console_sem();
916 rc = copy_to_user(up, &tmp, sizeof(struct vt_mode));
917 if (rc)
918 ret = -EFAULT;
919 break;
923 * Returns global vt state. Note that VT 0 is always open, since
924 * it's an alias for the current VT, and people can't use it here.
925 * We cannot return state for more than 16 VTs, since v_state is short.
927 case VT_GETSTATE:
929 struct vt_stat __user *vtstat = up;
930 unsigned short state, mask;
932 if (put_user(fg_console + 1, &vtstat->v_active))
933 ret = -EFAULT;
934 else {
935 state = 1; /* /dev/tty0 is always open */
936 for (i = 0, mask = 2; i < MAX_NR_CONSOLES && mask;
937 ++i, mask <<= 1)
938 if (VT_IS_IN_USE(i))
939 state |= mask;
940 ret = put_user(state, &vtstat->v_state);
942 break;
946 * Returns the first available (non-opened) console.
948 case VT_OPENQRY:
949 for (i = 0; i < MAX_NR_CONSOLES; ++i)
950 if (! VT_IS_IN_USE(i))
951 break;
952 ucval = i < MAX_NR_CONSOLES ? (i+1) : -1;
953 goto setint;
956 * ioctl(fd, VT_ACTIVATE, num) will cause us to switch to vt # num,
957 * with num >= 1 (switches to vt 0, our console, are not allowed, just
958 * to preserve sanity).
960 case VT_ACTIVATE:
961 if (!perm)
962 goto eperm;
963 if (arg == 0 || arg > MAX_NR_CONSOLES)
964 ret = -ENXIO;
965 else {
966 arg--;
967 acquire_console_sem();
968 ret = vc_allocate(arg);
969 release_console_sem();
970 if (ret)
971 break;
972 set_console(arg);
974 break;
976 case VT_SETACTIVATE:
978 struct vt_setactivate vsa;
980 if (!perm)
981 goto eperm;
983 if (copy_from_user(&vsa, (struct vt_setactivate __user *)arg,
984 sizeof(struct vt_setactivate))) {
985 ret = -EFAULT;
986 goto out;
988 if (vsa.console == 0 || vsa.console > MAX_NR_CONSOLES)
989 ret = -ENXIO;
990 else {
991 vsa.console--;
992 acquire_console_sem();
993 ret = vc_allocate(vsa.console);
994 if (ret == 0) {
995 struct vc_data *nvc;
996 /* This is safe providing we don't drop the
997 console sem between vc_allocate and
998 finishing referencing nvc */
999 nvc = vc_cons[vsa.console].d;
1000 nvc->vt_mode = vsa.mode;
1001 nvc->vt_mode.frsig = 0;
1002 put_pid(nvc->vt_pid);
1003 nvc->vt_pid = get_pid(task_pid(current));
1005 release_console_sem();
1006 if (ret)
1007 break;
1008 /* Commence switch and lock */
1009 set_console(arg);
1014 * wait until the specified VT has been activated
1016 case VT_WAITACTIVE:
1017 if (!perm)
1018 goto eperm;
1019 if (arg == 0 || arg > MAX_NR_CONSOLES)
1020 ret = -ENXIO;
1021 else
1022 ret = vt_waitactive(arg);
1023 break;
1026 * If a vt is under process control, the kernel will not switch to it
1027 * immediately, but postpone the operation until the process calls this
1028 * ioctl, allowing the switch to complete.
1030 * According to the X sources this is the behavior:
1031 * 0: pending switch-from not OK
1032 * 1: pending switch-from OK
1033 * 2: completed switch-to OK
1035 case VT_RELDISP:
1036 if (!perm)
1037 goto eperm;
1039 if (vc->vt_mode.mode != VT_PROCESS) {
1040 ret = -EINVAL;
1041 break;
1044 * Switching-from response
1046 acquire_console_sem();
1047 if (vc->vt_newvt >= 0) {
1048 if (arg == 0)
1050 * Switch disallowed, so forget we were trying
1051 * to do it.
1053 vc->vt_newvt = -1;
1055 else {
1057 * The current vt has been released, so
1058 * complete the switch.
1060 int newvt;
1061 newvt = vc->vt_newvt;
1062 vc->vt_newvt = -1;
1063 ret = vc_allocate(newvt);
1064 if (ret) {
1065 release_console_sem();
1066 break;
1069 * When we actually do the console switch,
1070 * make sure we are atomic with respect to
1071 * other console switches..
1073 complete_change_console(vc_cons[newvt].d);
1075 } else {
1077 * Switched-to response
1080 * If it's just an ACK, ignore it
1082 if (arg != VT_ACKACQ)
1083 ret = -EINVAL;
1085 release_console_sem();
1086 break;
1089 * Disallocate memory associated to VT (but leave VT1)
1091 case VT_DISALLOCATE:
1092 if (arg > MAX_NR_CONSOLES) {
1093 ret = -ENXIO;
1094 break;
1096 if (arg == 0) {
1097 /* deallocate all unused consoles, but leave 0 */
1098 acquire_console_sem();
1099 for (i=1; i<MAX_NR_CONSOLES; i++)
1100 if (! VT_BUSY(i))
1101 vc_deallocate(i);
1102 release_console_sem();
1103 } else {
1104 /* deallocate a single console, if possible */
1105 arg--;
1106 if (VT_BUSY(arg))
1107 ret = -EBUSY;
1108 else if (arg) { /* leave 0 */
1109 acquire_console_sem();
1110 vc_deallocate(arg);
1111 release_console_sem();
1114 break;
1116 case VT_RESIZE:
1118 struct vt_sizes __user *vtsizes = up;
1119 struct vc_data *vc;
1121 ushort ll,cc;
1122 if (!perm)
1123 goto eperm;
1124 if (get_user(ll, &vtsizes->v_rows) ||
1125 get_user(cc, &vtsizes->v_cols))
1126 ret = -EFAULT;
1127 else {
1128 acquire_console_sem();
1129 for (i = 0; i < MAX_NR_CONSOLES; i++) {
1130 vc = vc_cons[i].d;
1132 if (vc) {
1133 vc->vc_resize_user = 1;
1134 vc_resize(vc_cons[i].d, cc, ll);
1137 release_console_sem();
1139 break;
1142 case VT_RESIZEX:
1144 struct vt_consize __user *vtconsize = up;
1145 ushort ll,cc,vlin,clin,vcol,ccol;
1146 if (!perm)
1147 goto eperm;
1148 if (!access_ok(VERIFY_READ, vtconsize,
1149 sizeof(struct vt_consize))) {
1150 ret = -EFAULT;
1151 break;
1153 /* FIXME: Should check the copies properly */
1154 __get_user(ll, &vtconsize->v_rows);
1155 __get_user(cc, &vtconsize->v_cols);
1156 __get_user(vlin, &vtconsize->v_vlin);
1157 __get_user(clin, &vtconsize->v_clin);
1158 __get_user(vcol, &vtconsize->v_vcol);
1159 __get_user(ccol, &vtconsize->v_ccol);
1160 vlin = vlin ? vlin : vc->vc_scan_lines;
1161 if (clin) {
1162 if (ll) {
1163 if (ll != vlin/clin) {
1164 /* Parameters don't add up */
1165 ret = -EINVAL;
1166 break;
1168 } else
1169 ll = vlin/clin;
1171 if (vcol && ccol) {
1172 if (cc) {
1173 if (cc != vcol/ccol) {
1174 ret = -EINVAL;
1175 break;
1177 } else
1178 cc = vcol/ccol;
1181 if (clin > 32) {
1182 ret = -EINVAL;
1183 break;
1186 for (i = 0; i < MAX_NR_CONSOLES; i++) {
1187 if (!vc_cons[i].d)
1188 continue;
1189 acquire_console_sem();
1190 if (vlin)
1191 vc_cons[i].d->vc_scan_lines = vlin;
1192 if (clin)
1193 vc_cons[i].d->vc_font.height = clin;
1194 vc_cons[i].d->vc_resize_user = 1;
1195 vc_resize(vc_cons[i].d, cc, ll);
1196 release_console_sem();
1198 break;
1201 case PIO_FONT: {
1202 if (!perm)
1203 goto eperm;
1204 op.op = KD_FONT_OP_SET;
1205 op.flags = KD_FONT_FLAG_OLD | KD_FONT_FLAG_DONT_RECALC; /* Compatibility */
1206 op.width = 8;
1207 op.height = 0;
1208 op.charcount = 256;
1209 op.data = up;
1210 ret = con_font_op(vc_cons[fg_console].d, &op);
1211 break;
1214 case GIO_FONT: {
1215 op.op = KD_FONT_OP_GET;
1216 op.flags = KD_FONT_FLAG_OLD;
1217 op.width = 8;
1218 op.height = 32;
1219 op.charcount = 256;
1220 op.data = up;
1221 ret = con_font_op(vc_cons[fg_console].d, &op);
1222 break;
1225 case PIO_CMAP:
1226 if (!perm)
1227 ret = -EPERM;
1228 else
1229 ret = con_set_cmap(up);
1230 break;
1232 case GIO_CMAP:
1233 ret = con_get_cmap(up);
1234 break;
1236 case PIO_FONTX:
1237 case GIO_FONTX:
1238 ret = do_fontx_ioctl(cmd, up, perm, &op);
1239 break;
1241 case PIO_FONTRESET:
1243 if (!perm)
1244 goto eperm;
1246 #ifdef BROKEN_GRAPHICS_PROGRAMS
1247 /* With BROKEN_GRAPHICS_PROGRAMS defined, the default
1248 font is not saved. */
1249 ret = -ENOSYS;
1250 break;
1251 #else
1253 op.op = KD_FONT_OP_SET_DEFAULT;
1254 op.data = NULL;
1255 ret = con_font_op(vc_cons[fg_console].d, &op);
1256 if (ret)
1257 break;
1258 con_set_default_unimap(vc_cons[fg_console].d);
1259 break;
1261 #endif
1264 case KDFONTOP: {
1265 if (copy_from_user(&op, up, sizeof(op))) {
1266 ret = -EFAULT;
1267 break;
1269 if (!perm && op.op != KD_FONT_OP_GET)
1270 goto eperm;
1271 ret = con_font_op(vc, &op);
1272 if (ret)
1273 break;
1274 if (copy_to_user(up, &op, sizeof(op)))
1275 ret = -EFAULT;
1276 break;
1279 case PIO_SCRNMAP:
1280 if (!perm)
1281 ret = -EPERM;
1282 else
1283 ret = con_set_trans_old(up);
1284 break;
1286 case GIO_SCRNMAP:
1287 ret = con_get_trans_old(up);
1288 break;
1290 case PIO_UNISCRNMAP:
1291 if (!perm)
1292 ret = -EPERM;
1293 else
1294 ret = con_set_trans_new(up);
1295 break;
1297 case GIO_UNISCRNMAP:
1298 ret = con_get_trans_new(up);
1299 break;
1301 case PIO_UNIMAPCLR:
1302 { struct unimapinit ui;
1303 if (!perm)
1304 goto eperm;
1305 ret = copy_from_user(&ui, up, sizeof(struct unimapinit));
1306 if (!ret)
1307 con_clear_unimap(vc, &ui);
1308 break;
1311 case PIO_UNIMAP:
1312 case GIO_UNIMAP:
1313 ret = do_unimap_ioctl(cmd, up, perm, vc);
1314 break;
1316 case VT_LOCKSWITCH:
1317 if (!capable(CAP_SYS_TTY_CONFIG))
1318 goto eperm;
1319 vt_dont_switch = 1;
1320 break;
1321 case VT_UNLOCKSWITCH:
1322 if (!capable(CAP_SYS_TTY_CONFIG))
1323 goto eperm;
1324 vt_dont_switch = 0;
1325 break;
1326 case VT_GETHIFONTMASK:
1327 ret = put_user(vc->vc_hi_font_mask,
1328 (unsigned short __user *)arg);
1329 break;
1330 case VT_WAITEVENT:
1331 ret = vt_event_wait_ioctl((struct vt_event __user *)arg);
1332 break;
1333 default:
1334 ret = -ENOIOCTLCMD;
1336 out:
1337 unlock_kernel();
1338 return ret;
1339 eperm:
1340 ret = -EPERM;
1341 goto out;
1344 void reset_vc(struct vc_data *vc)
1346 vc->vc_mode = KD_TEXT;
1347 kbd_table[vc->vc_num].kbdmode = default_utf8 ? VC_UNICODE : VC_XLATE;
1348 vc->vt_mode.mode = VT_AUTO;
1349 vc->vt_mode.waitv = 0;
1350 vc->vt_mode.relsig = 0;
1351 vc->vt_mode.acqsig = 0;
1352 vc->vt_mode.frsig = 0;
1353 put_pid(vc->vt_pid);
1354 vc->vt_pid = NULL;
1355 vc->vt_newvt = -1;
1356 if (!in_interrupt()) /* Via keyboard.c:SAK() - akpm */
1357 reset_palette(vc);
1360 void vc_SAK(struct work_struct *work)
1362 struct vc *vc_con =
1363 container_of(work, struct vc, SAK_work);
1364 struct vc_data *vc;
1365 struct tty_struct *tty;
1367 acquire_console_sem();
1368 vc = vc_con->d;
1369 if (vc) {
1370 tty = vc->vc_tty;
1372 * SAK should also work in all raw modes and reset
1373 * them properly.
1375 if (tty)
1376 __do_SAK(tty);
1377 reset_vc(vc);
1379 release_console_sem();
1382 #ifdef CONFIG_COMPAT
1384 struct compat_consolefontdesc {
1385 unsigned short charcount; /* characters in font (256 or 512) */
1386 unsigned short charheight; /* scan lines per character (1-32) */
1387 compat_caddr_t chardata; /* font data in expanded form */
1390 static inline int
1391 compat_fontx_ioctl(int cmd, struct compat_consolefontdesc __user *user_cfd,
1392 int perm, struct console_font_op *op)
1394 struct compat_consolefontdesc cfdarg;
1395 int i;
1397 if (copy_from_user(&cfdarg, user_cfd, sizeof(struct compat_consolefontdesc)))
1398 return -EFAULT;
1400 switch (cmd) {
1401 case PIO_FONTX:
1402 if (!perm)
1403 return -EPERM;
1404 op->op = KD_FONT_OP_SET;
1405 op->flags = KD_FONT_FLAG_OLD;
1406 op->width = 8;
1407 op->height = cfdarg.charheight;
1408 op->charcount = cfdarg.charcount;
1409 op->data = compat_ptr(cfdarg.chardata);
1410 return con_font_op(vc_cons[fg_console].d, op);
1411 case GIO_FONTX:
1412 op->op = KD_FONT_OP_GET;
1413 op->flags = KD_FONT_FLAG_OLD;
1414 op->width = 8;
1415 op->height = cfdarg.charheight;
1416 op->charcount = cfdarg.charcount;
1417 op->data = compat_ptr(cfdarg.chardata);
1418 i = con_font_op(vc_cons[fg_console].d, op);
1419 if (i)
1420 return i;
1421 cfdarg.charheight = op->height;
1422 cfdarg.charcount = op->charcount;
1423 if (copy_to_user(user_cfd, &cfdarg, sizeof(struct compat_consolefontdesc)))
1424 return -EFAULT;
1425 return 0;
1427 return -EINVAL;
1430 struct compat_console_font_op {
1431 compat_uint_t op; /* operation code KD_FONT_OP_* */
1432 compat_uint_t flags; /* KD_FONT_FLAG_* */
1433 compat_uint_t width, height; /* font size */
1434 compat_uint_t charcount;
1435 compat_caddr_t data; /* font data with height fixed to 32 */
1438 static inline int
1439 compat_kdfontop_ioctl(struct compat_console_font_op __user *fontop,
1440 int perm, struct console_font_op *op, struct vc_data *vc)
1442 int i;
1444 if (copy_from_user(op, fontop, sizeof(struct compat_console_font_op)))
1445 return -EFAULT;
1446 if (!perm && op->op != KD_FONT_OP_GET)
1447 return -EPERM;
1448 op->data = compat_ptr(((struct compat_console_font_op *)op)->data);
1449 op->flags |= KD_FONT_FLAG_OLD;
1450 i = con_font_op(vc, op);
1451 if (i)
1452 return i;
1453 ((struct compat_console_font_op *)op)->data = (unsigned long)op->data;
1454 if (copy_to_user(fontop, op, sizeof(struct compat_console_font_op)))
1455 return -EFAULT;
1456 return 0;
1459 struct compat_unimapdesc {
1460 unsigned short entry_ct;
1461 compat_caddr_t entries;
1464 static inline int
1465 compat_unimap_ioctl(unsigned int cmd, struct compat_unimapdesc __user *user_ud,
1466 int perm, struct vc_data *vc)
1468 struct compat_unimapdesc tmp;
1469 struct unipair __user *tmp_entries;
1471 if (copy_from_user(&tmp, user_ud, sizeof tmp))
1472 return -EFAULT;
1473 tmp_entries = compat_ptr(tmp.entries);
1474 if (tmp_entries)
1475 if (!access_ok(VERIFY_WRITE, tmp_entries,
1476 tmp.entry_ct*sizeof(struct unipair)))
1477 return -EFAULT;
1478 switch (cmd) {
1479 case PIO_UNIMAP:
1480 if (!perm)
1481 return -EPERM;
1482 return con_set_unimap(vc, tmp.entry_ct, tmp_entries);
1483 case GIO_UNIMAP:
1484 if (!perm && fg_console != vc->vc_num)
1485 return -EPERM;
1486 return con_get_unimap(vc, tmp.entry_ct, &(user_ud->entry_ct), tmp_entries);
1488 return 0;
1491 long vt_compat_ioctl(struct tty_struct *tty, struct file * file,
1492 unsigned int cmd, unsigned long arg)
1494 struct vc_data *vc = tty->driver_data;
1495 struct console_font_op op; /* used in multiple places here */
1496 struct kbd_struct *kbd;
1497 unsigned int console;
1498 void __user *up = (void __user *)arg;
1499 int perm;
1500 int ret = 0;
1502 console = vc->vc_num;
1504 lock_kernel();
1506 if (!vc_cons_allocated(console)) { /* impossible? */
1507 ret = -ENOIOCTLCMD;
1508 goto out;
1512 * To have permissions to do most of the vt ioctls, we either have
1513 * to be the owner of the tty, or have CAP_SYS_TTY_CONFIG.
1515 perm = 0;
1516 if (current->signal->tty == tty || capable(CAP_SYS_TTY_CONFIG))
1517 perm = 1;
1519 kbd = kbd_table + console;
1520 switch (cmd) {
1522 * these need special handlers for incompatible data structures
1524 case PIO_FONTX:
1525 case GIO_FONTX:
1526 ret = compat_fontx_ioctl(cmd, up, perm, &op);
1527 break;
1529 case KDFONTOP:
1530 ret = compat_kdfontop_ioctl(up, perm, &op, vc);
1531 break;
1533 case PIO_UNIMAP:
1534 case GIO_UNIMAP:
1535 ret = compat_unimap_ioctl(cmd, up, perm, vc);
1536 break;
1539 * all these treat 'arg' as an integer
1541 case KIOCSOUND:
1542 case KDMKTONE:
1543 #ifdef CONFIG_X86
1544 case KDADDIO:
1545 case KDDELIO:
1546 #endif
1547 case KDSETMODE:
1548 case KDMAPDISP:
1549 case KDUNMAPDISP:
1550 case KDSKBMODE:
1551 case KDSKBMETA:
1552 case KDSKBLED:
1553 case KDSETLED:
1554 case KDSIGACCEPT:
1555 case VT_ACTIVATE:
1556 case VT_WAITACTIVE:
1557 case VT_RELDISP:
1558 case VT_DISALLOCATE:
1559 case VT_RESIZE:
1560 case VT_RESIZEX:
1561 goto fallback;
1564 * the rest has a compatible data structure behind arg,
1565 * but we have to convert it to a proper 64 bit pointer.
1567 default:
1568 arg = (unsigned long)compat_ptr(arg);
1569 goto fallback;
1571 out:
1572 unlock_kernel();
1573 return ret;
1575 fallback:
1576 unlock_kernel();
1577 return vt_ioctl(tty, file, cmd, arg);
1581 #endif /* CONFIG_COMPAT */
1585 * Performs the back end of a vt switch. Called under the console
1586 * semaphore.
1588 static void complete_change_console(struct vc_data *vc)
1590 unsigned char old_vc_mode;
1591 int old = fg_console;
1593 last_console = fg_console;
1596 * If we're switching, we could be going from KD_GRAPHICS to
1597 * KD_TEXT mode or vice versa, which means we need to blank or
1598 * unblank the screen later.
1600 old_vc_mode = vc_cons[fg_console].d->vc_mode;
1601 switch_screen(vc);
1604 * This can't appear below a successful kill_pid(). If it did,
1605 * then the *blank_screen operation could occur while X, having
1606 * received acqsig, is waking up on another processor. This
1607 * condition can lead to overlapping accesses to the VGA range
1608 * and the framebuffer (causing system lockups).
1610 * To account for this we duplicate this code below only if the
1611 * controlling process is gone and we've called reset_vc.
1613 if (old_vc_mode != vc->vc_mode) {
1614 if (vc->vc_mode == KD_TEXT)
1615 do_unblank_screen(1);
1616 else
1617 do_blank_screen(1);
1621 * If this new console is under process control, send it a signal
1622 * telling it that it has acquired. Also check if it has died and
1623 * clean up (similar to logic employed in change_console())
1625 if (vc->vt_mode.mode == VT_PROCESS) {
1627 * Send the signal as privileged - kill_pid() will
1628 * tell us if the process has gone or something else
1629 * is awry
1631 if (kill_pid(vc->vt_pid, vc->vt_mode.acqsig, 1) != 0) {
1633 * The controlling process has died, so we revert back to
1634 * normal operation. In this case, we'll also change back
1635 * to KD_TEXT mode. I'm not sure if this is strictly correct
1636 * but it saves the agony when the X server dies and the screen
1637 * remains blanked due to KD_GRAPHICS! It would be nice to do
1638 * this outside of VT_PROCESS but there is no single process
1639 * to account for and tracking tty count may be undesirable.
1641 reset_vc(vc);
1643 if (old_vc_mode != vc->vc_mode) {
1644 if (vc->vc_mode == KD_TEXT)
1645 do_unblank_screen(1);
1646 else
1647 do_blank_screen(1);
1653 * Wake anyone waiting for their VT to activate
1655 vt_event_post(VT_EVENT_SWITCH, old, vc->vc_num);
1656 return;
1660 * Performs the front-end of a vt switch
1662 void change_console(struct vc_data *new_vc)
1664 struct vc_data *vc;
1666 if (!new_vc || new_vc->vc_num == fg_console || vt_dont_switch)
1667 return;
1670 * If this vt is in process mode, then we need to handshake with
1671 * that process before switching. Essentially, we store where that
1672 * vt wants to switch to and wait for it to tell us when it's done
1673 * (via VT_RELDISP ioctl).
1675 * We also check to see if the controlling process still exists.
1676 * If it doesn't, we reset this vt to auto mode and continue.
1677 * This is a cheap way to track process control. The worst thing
1678 * that can happen is: we send a signal to a process, it dies, and
1679 * the switch gets "lost" waiting for a response; hopefully, the
1680 * user will try again, we'll detect the process is gone (unless
1681 * the user waits just the right amount of time :-) and revert the
1682 * vt to auto control.
1684 vc = vc_cons[fg_console].d;
1685 if (vc->vt_mode.mode == VT_PROCESS) {
1687 * Send the signal as privileged - kill_pid() will
1688 * tell us if the process has gone or something else
1689 * is awry.
1691 * We need to set vt_newvt *before* sending the signal or we
1692 * have a race.
1694 vc->vt_newvt = new_vc->vc_num;
1695 if (kill_pid(vc->vt_pid, vc->vt_mode.relsig, 1) == 0) {
1697 * It worked. Mark the vt to switch to and
1698 * return. The process needs to send us a
1699 * VT_RELDISP ioctl to complete the switch.
1701 return;
1705 * The controlling process has died, so we revert back to
1706 * normal operation. In this case, we'll also change back
1707 * to KD_TEXT mode. I'm not sure if this is strictly correct
1708 * but it saves the agony when the X server dies and the screen
1709 * remains blanked due to KD_GRAPHICS! It would be nice to do
1710 * this outside of VT_PROCESS but there is no single process
1711 * to account for and tracking tty count may be undesirable.
1713 reset_vc(vc);
1716 * Fall through to normal (VT_AUTO) handling of the switch...
1721 * Ignore all switches in KD_GRAPHICS+VT_AUTO mode
1723 if (vc->vc_mode == KD_GRAPHICS)
1724 return;
1726 complete_change_console(new_vc);
1729 /* Perform a kernel triggered VT switch for suspend/resume */
1731 static int disable_vt_switch;
1733 int vt_move_to_console(unsigned int vt, int alloc)
1735 int prev;
1737 acquire_console_sem();
1738 /* Graphics mode - up to X */
1739 if (disable_vt_switch) {
1740 release_console_sem();
1741 return 0;
1743 prev = fg_console;
1745 if (alloc && vc_allocate(vt)) {
1746 /* we can't have a free VC for now. Too bad,
1747 * we don't want to mess the screen for now. */
1748 release_console_sem();
1749 return -ENOSPC;
1752 if (set_console(vt)) {
1754 * We're unable to switch to the SUSPEND_CONSOLE.
1755 * Let the calling function know so it can decide
1756 * what to do.
1758 release_console_sem();
1759 return -EIO;
1761 release_console_sem();
1762 if (vt_waitactive(vt + 1)) {
1763 pr_debug("Suspend: Can't switch VCs.");
1764 return -EINTR;
1766 return prev;
1770 * Normally during a suspend, we allocate a new console and switch to it.
1771 * When we resume, we switch back to the original console. This switch
1772 * can be slow, so on systems where the framebuffer can handle restoration
1773 * of video registers anyways, there's little point in doing the console
1774 * switch. This function allows you to disable it by passing it '0'.
1776 void pm_set_vt_switch(int do_switch)
1778 acquire_console_sem();
1779 disable_vt_switch = !do_switch;
1780 release_console_sem();
1782 EXPORT_SYMBOL(pm_set_vt_switch);