2 * Copyright (C) 1992 obz under the linux copyright
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
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>
21 #include <linux/string.h>
22 #include <linux/slab.h>
23 #include <linux/major.h>
25 #include <linux/console.h>
26 #include <linux/consolemap.h>
27 #include <linux/signal.h>
28 #include <linux/suspend.h>
29 #include <linux/timex.h>
32 #include <asm/uaccess.h>
34 #include <linux/kbd_kern.h>
35 #include <linux/vt_kern.h>
36 #include <linux/kbd_diacr.h>
37 #include <linux/selection.h>
40 extern struct tty_driver *console_driver;
42 #define VT_IS_IN_USE(i) (console_driver->ttys[i] && console_driver->ttys[i]->count)
43 #define VT_BUSY(i) (VT_IS_IN_USE(i) || i == fg_console || vc_cons[i].d == sel_cons)
46 * Console (vt and kd) routines, as defined by USL SVR4 manual, and by
47 * experimentation and study of X386 SYSV handling.
49 * One point of difference: SYSV vt's are /dev/vtX, which X >= 0, and
50 * /dev/console is a separate ttyp. Under Linux, /dev/tty0 is /dev/console,
51 * and the vc start at /dev/ttyX, X >= 1. We maintain that here, so we will
52 * always treat our set of vt as numbered 1..MAX_NR_CONSOLES (corresponding to
53 * ttys 0..MAX_NR_CONSOLES-1). Explicitly naming VT 0 is illegal, but using
54 * /dev/tty0 (fg_console) as a target is legal, since an implicit aliasing
55 * to the current console is done by the main ioctl code.
59 #include <linux/syscalls.h>
62 static void complete_change_console(struct vc_data *vc);
65 * User space VT_EVENT handlers
68 struct vt_event_wait {
69 struct list_head list;
70 struct vt_event event;
74 static LIST_HEAD(vt_events);
75 static DEFINE_SPINLOCK(vt_event_lock);
76 static DECLARE_WAIT_QUEUE_HEAD(vt_event_waitqueue);
80 * @event: the event that occurred
84 * Post an VT event to interested VT handlers
87 void vt_event_post(unsigned int event, unsigned int old, unsigned int new)
89 struct list_head *pos, *head;
93 spin_lock_irqsave(&vt_event_lock, flags);
96 list_for_each(pos, head) {
97 struct vt_event_wait *ve = list_entry(pos,
98 struct vt_event_wait, list);
99 if (!(ve->event.event & event))
101 ve->event.event = event;
102 /* kernel view is consoles 0..n-1, user space view is
103 console 1..n with 0 meaning current, so we must bias */
104 ve->event.oldev = old + 1;
105 ve->event.newev = new + 1;
109 spin_unlock_irqrestore(&vt_event_lock, flags);
111 wake_up_interruptible(&vt_event_waitqueue);
114 static void __vt_event_queue(struct vt_event_wait *vw)
117 /* Prepare the event */
118 INIT_LIST_HEAD(&vw->list);
120 /* Queue our event */
121 spin_lock_irqsave(&vt_event_lock, flags);
122 list_add(&vw->list, &vt_events);
123 spin_unlock_irqrestore(&vt_event_lock, flags);
126 static void __vt_event_wait(struct vt_event_wait *vw)
128 /* Wait for it to pass */
129 wait_event_interruptible(vt_event_waitqueue, vw->done);
132 static void __vt_event_dequeue(struct vt_event_wait *vw)
137 spin_lock_irqsave(&vt_event_lock, flags);
139 spin_unlock_irqrestore(&vt_event_lock, flags);
143 * vt_event_wait - wait for an event
146 * Waits for an event to occur which completes our vt_event_wait
147 * structure. On return the structure has wv->done set to 1 for success
148 * or 0 if some event such as a signal ended the wait.
151 static void vt_event_wait(struct vt_event_wait *vw)
153 __vt_event_queue(vw);
155 __vt_event_dequeue(vw);
159 * vt_event_wait_ioctl - event ioctl handler
160 * @arg: argument to ioctl
162 * Implement the VT_WAITEVENT ioctl using the VT event interface
165 static int vt_event_wait_ioctl(struct vt_event __user *event)
167 struct vt_event_wait vw;
169 if (copy_from_user(&vw.event, event, sizeof(struct vt_event)))
171 /* Highest supported event for now */
172 if (vw.event.event & ~VT_MAX_EVENT)
176 /* If it occurred report it */
178 if (copy_to_user(event, &vw.event, sizeof(struct vt_event)))
186 * vt_waitactive - active console wait
190 * Helper for event waits. Used to implement the legacy
191 * event waiting ioctls in terms of events
194 int vt_waitactive(int n)
196 struct vt_event_wait vw;
198 vw.event.event = VT_EVENT_SWITCH;
199 __vt_event_queue(&vw);
200 if (n == fg_console + 1) {
201 __vt_event_dequeue(&vw);
204 __vt_event_wait(&vw);
205 __vt_event_dequeue(&vw);
208 } while (vw.event.newev != n);
213 * these are the valid i/o ports we're allowed to change. they map all the
216 #define GPFIRST 0x3b4
218 #define GPNUM (GPLAST - GPFIRST + 1)
223 do_fontx_ioctl(int cmd, struct consolefontdesc __user *user_cfd, int perm, struct console_font_op *op)
225 struct consolefontdesc cfdarg;
228 if (copy_from_user(&cfdarg, user_cfd, sizeof(struct consolefontdesc)))
235 op->op = KD_FONT_OP_SET;
236 op->flags = KD_FONT_FLAG_OLD;
238 op->height = cfdarg.charheight;
239 op->charcount = cfdarg.charcount;
240 op->data = cfdarg.chardata;
241 return con_font_op(vc_cons[fg_console].d, op);
243 op->op = KD_FONT_OP_GET;
244 op->flags = KD_FONT_FLAG_OLD;
246 op->height = cfdarg.charheight;
247 op->charcount = cfdarg.charcount;
248 op->data = cfdarg.chardata;
249 i = con_font_op(vc_cons[fg_console].d, op);
252 cfdarg.charheight = op->height;
253 cfdarg.charcount = op->charcount;
254 if (copy_to_user(user_cfd, &cfdarg, sizeof(struct consolefontdesc)))
263 do_unimap_ioctl(int cmd, struct unimapdesc __user *user_ud, int perm, struct vc_data *vc)
265 struct unimapdesc tmp;
267 if (copy_from_user(&tmp, user_ud, sizeof tmp))
270 if (!access_ok(VERIFY_WRITE, tmp.entries,
271 tmp.entry_ct*sizeof(struct unipair)))
277 return con_set_unimap(vc, tmp.entry_ct, tmp.entries);
279 if (!perm && fg_console != vc->vc_num)
281 return con_get_unimap(vc, tmp.entry_ct, &(user_ud->entry_ct), tmp.entries);
286 /* deallocate a single console, if possible (leave 0) */
287 static int vt_disallocate(unsigned int vc_num)
289 struct vc_data *vc = NULL;
299 vc = vc_deallocate(vc_num);
302 if (vc && vc_num >= MIN_NR_CONSOLES) {
303 tty_port_destroy(&vc->port);
310 /* deallocate all unused consoles, but leave 0 */
311 static void vt_disallocate_all(void)
313 struct vc_data *vc[MAX_NR_CONSOLES];
317 for (i = 1; i < MAX_NR_CONSOLES; i++)
319 vc[i] = vc_deallocate(i);
324 for (i = 1; i < MAX_NR_CONSOLES; i++) {
325 if (vc[i] && i >= MIN_NR_CONSOLES) {
326 tty_port_destroy(&vc[i]->port);
334 * We handle the console-specific ioctl's here. We allow the
335 * capability to modify any console, not just the fg_console.
337 int vt_ioctl(struct tty_struct *tty,
338 unsigned int cmd, unsigned long arg)
340 struct vc_data *vc = tty->driver_data;
341 struct console_font_op op; /* used in multiple places here */
342 unsigned int console;
345 void __user *up = (void __user *)arg;
349 console = vc->vc_num;
352 if (!vc_cons_allocated(console)) { /* impossible? */
359 * To have permissions to do most of the vt ioctls, we either have
360 * to be the owner of the tty, or have CAP_SYS_TTY_CONFIG.
363 if (current->signal->tty == tty || capable(CAP_SYS_TTY_CONFIG))
368 ret = tioclinux(tty, arg);
374 * The use of PIT_TICK_RATE is historic, it used to be
375 * the platform-dependent CLOCK_TICK_RATE between 2.6.12
376 * and 2.6.36, which was a minor but unfortunate ABI
377 * change. kd_mksound is locked by the input layer.
380 arg = PIT_TICK_RATE / arg;
388 unsigned int ticks, count;
391 * Generate the tone for the appropriate number of ticks.
392 * If the time is zero, turn off sound ourselves.
394 ticks = HZ * ((arg >> 16) & 0xffff) / 1000;
395 count = ticks ? (arg & 0xffff) : 0;
397 count = PIT_TICK_RATE / count;
398 kd_mksound(count, ticks);
407 ret = put_user(ucval, (char __user *)arg);
411 * These cannot be implemented on any machine that implements
412 * ioperm() in user level (such as Alpha PCs) or not at all.
414 * XXX: you should never use these, just call ioperm directly..
420 * KDADDIO and KDDELIO may be able to add ports beyond what
421 * we reject here, but to be safe...
423 * These are locked internally via sys_ioperm
425 if (arg < GPFIRST || arg > GPLAST) {
429 ret = sys_ioperm(arg, 1, (cmd == KDADDIO)) ? -ENXIO : 0;
434 ret = sys_ioperm(GPFIRST, GPNUM,
435 (cmd == KDENABIO)) ? -ENXIO : 0;
439 /* Linux m68k/i386 interface for setting the keyboard delay/repeat rate */
443 struct kbd_repeat kbrep;
445 if (!capable(CAP_SYS_TTY_CONFIG))
448 if (copy_from_user(&kbrep, up, sizeof(struct kbd_repeat))) {
452 ret = kbd_rate(&kbrep);
455 if (copy_to_user(up, &kbrep, sizeof(struct kbd_repeat)))
462 * currently, setting the mode from KD_TEXT to KD_GRAPHICS
463 * doesn't do a whole lot. i'm not sure if it should do any
464 * restoration of modes or what...
466 * XXX It should at least call into the driver, fbdev's definitely
467 * need to restore their engine state. --BenH
483 /* FIXME: this needs the console lock extending */
484 if (vc->vc_mode == (unsigned char) arg)
486 vc->vc_mode = (unsigned char) arg;
487 if (console != fg_console)
490 * explicitly blank/unblank the screen if switching modes
494 do_unblank_screen(1);
507 * these work like a combination of mmap and KDENABIO.
508 * this could be easily finished.
516 ret = vt_do_kdskbmode(console, arg);
518 tty_ldisc_flush(tty);
522 uival = vt_do_kdgkbmode(console);
523 ret = put_user(uival, (int __user *)arg);
526 /* this could be folded into KDSKBMODE, but for compatibility
527 reasons it is not so easy to fold KDGKBMETA into KDGKBMODE */
529 ret = vt_do_kdskbmeta(console, arg);
533 /* FIXME: should review whether this is worth locking */
534 uival = vt_do_kdgkbmeta(console);
536 ret = put_user(uival, (int __user *)arg);
541 if(!capable(CAP_SYS_TTY_CONFIG))
543 ret = vt_do_kbkeycode_ioctl(cmd, up, perm);
548 ret = vt_do_kdsk_ioctl(cmd, up, perm, console);
553 ret = vt_do_kdgkb_ioctl(cmd, up, perm);
556 /* Diacritical processing. Handled in keyboard.c as it has
557 to operate on the keyboard locks and structures */
562 ret = vt_do_diacrit(cmd, up, perm);
565 /* the ioctls below read/set the flags usually shown in the leds */
566 /* don't use them - they will go away without warning */
571 ret = vt_do_kdskled(console, cmd, arg, perm);
575 * A process can indicate its willingness to accept signals
576 * generated by pressing an appropriate key combination.
577 * Thus, one can have a daemon that e.g. spawns a new console
578 * upon a keypress and then changes to it.
579 * See also the kbrequest field of inittab(5).
583 if (!perm || !capable(CAP_KILL))
585 if (!valid_signal(arg) || arg < 1 || arg == SIGKILL)
588 spin_lock_irq(&vt_spawn_con.lock);
589 put_pid(vt_spawn_con.pid);
590 vt_spawn_con.pid = get_pid(task_pid(current));
591 vt_spawn_con.sig = arg;
592 spin_unlock_irq(&vt_spawn_con.lock);
603 if (copy_from_user(&tmp, up, sizeof(struct vt_mode))) {
607 if (tmp.mode != VT_AUTO && tmp.mode != VT_PROCESS) {
613 /* the frsig is ignored, so we set it to 0 */
614 vc->vt_mode.frsig = 0;
616 vc->vt_pid = get_pid(task_pid(current));
617 /* no switch is required -- saw@shade.msu.ru */
629 memcpy(&tmp, &vc->vt_mode, sizeof(struct vt_mode));
632 rc = copy_to_user(up, &tmp, sizeof(struct vt_mode));
639 * Returns global vt state. Note that VT 0 is always open, since
640 * it's an alias for the current VT, and people can't use it here.
641 * We cannot return state for more than 16 VTs, since v_state is short.
645 struct vt_stat __user *vtstat = up;
646 unsigned short state, mask;
648 /* Review: FIXME: Console lock ? */
649 if (put_user(fg_console + 1, &vtstat->v_active))
652 state = 1; /* /dev/tty0 is always open */
653 for (i = 0, mask = 2; i < MAX_NR_CONSOLES && mask;
657 ret = put_user(state, &vtstat->v_state);
663 * Returns the first available (non-opened) console.
666 /* FIXME: locking ? - but then this is a stupid API */
667 for (i = 0; i < MAX_NR_CONSOLES; ++i)
668 if (! VT_IS_IN_USE(i))
670 uival = i < MAX_NR_CONSOLES ? (i+1) : -1;
674 * ioctl(fd, VT_ACTIVATE, num) will cause us to switch to vt # num,
675 * with num >= 1 (switches to vt 0, our console, are not allowed, just
676 * to preserve sanity).
681 if (arg == 0 || arg > MAX_NR_CONSOLES)
686 ret = vc_allocate(arg);
696 struct vt_setactivate vsa;
701 if (copy_from_user(&vsa, (struct vt_setactivate __user *)arg,
702 sizeof(struct vt_setactivate))) {
706 if (vsa.console == 0 || vsa.console > MAX_NR_CONSOLES)
711 ret = vc_allocate(vsa.console);
714 /* This is safe providing we don't drop the
715 console sem between vc_allocate and
716 finishing referencing nvc */
717 nvc = vc_cons[vsa.console].d;
718 nvc->vt_mode = vsa.mode;
719 nvc->vt_mode.frsig = 0;
720 put_pid(nvc->vt_pid);
721 nvc->vt_pid = get_pid(task_pid(current));
726 /* Commence switch and lock */
727 /* Review set_console locks */
728 set_console(vsa.console);
734 * wait until the specified VT has been activated
739 if (arg == 0 || arg > MAX_NR_CONSOLES)
742 ret = vt_waitactive(arg);
746 * If a vt is under process control, the kernel will not switch to it
747 * immediately, but postpone the operation until the process calls this
748 * ioctl, allowing the switch to complete.
750 * According to the X sources this is the behavior:
751 * 0: pending switch-from not OK
752 * 1: pending switch-from OK
753 * 2: completed switch-to OK
760 if (vc->vt_mode.mode != VT_PROCESS) {
766 * Switching-from response
768 if (vc->vt_newvt >= 0) {
771 * Switch disallowed, so forget we were trying
778 * The current vt has been released, so
779 * complete the switch.
782 newvt = vc->vt_newvt;
784 ret = vc_allocate(newvt);
790 * When we actually do the console switch,
791 * make sure we are atomic with respect to
792 * other console switches..
794 complete_change_console(vc_cons[newvt].d);
798 * Switched-to response
801 * If it's just an ACK, ignore it
803 if (arg != VT_ACKACQ)
810 * Disallocate memory associated to VT (but leave VT1)
813 if (arg > MAX_NR_CONSOLES) {
818 vt_disallocate_all();
820 ret = vt_disallocate(--arg);
825 struct vt_sizes __user *vtsizes = up;
831 if (get_user(ll, &vtsizes->v_rows) ||
832 get_user(cc, &vtsizes->v_cols))
836 for (i = 0; i < MAX_NR_CONSOLES; i++) {
840 vc->vc_resize_user = 1;
841 /* FIXME: review v tty lock */
842 vc_resize(vc_cons[i].d, cc, ll);
852 struct vt_consize __user *vtconsize = up;
853 ushort ll,cc,vlin,clin,vcol,ccol;
856 if (!access_ok(VERIFY_READ, vtconsize,
857 sizeof(struct vt_consize))) {
861 /* FIXME: Should check the copies properly */
862 __get_user(ll, &vtconsize->v_rows);
863 __get_user(cc, &vtconsize->v_cols);
864 __get_user(vlin, &vtconsize->v_vlin);
865 __get_user(clin, &vtconsize->v_clin);
866 __get_user(vcol, &vtconsize->v_vcol);
867 __get_user(ccol, &vtconsize->v_ccol);
868 vlin = vlin ? vlin : vc->vc_scan_lines;
871 if (ll != vlin/clin) {
872 /* Parameters don't add up */
881 if (cc != vcol/ccol) {
894 for (i = 0; i < MAX_NR_CONSOLES; i++) {
899 vc_cons[i].d->vc_scan_lines = vlin;
901 vc_cons[i].d->vc_font.height = clin;
902 vc_cons[i].d->vc_resize_user = 1;
903 vc_resize(vc_cons[i].d, cc, ll);
912 op.op = KD_FONT_OP_SET;
913 op.flags = KD_FONT_FLAG_OLD | KD_FONT_FLAG_DONT_RECALC; /* Compatibility */
918 ret = con_font_op(vc_cons[fg_console].d, &op);
923 op.op = KD_FONT_OP_GET;
924 op.flags = KD_FONT_FLAG_OLD;
929 ret = con_font_op(vc_cons[fg_console].d, &op);
937 ret = con_set_cmap(up);
941 ret = con_get_cmap(up);
946 ret = do_fontx_ioctl(cmd, up, perm, &op);
954 #ifdef BROKEN_GRAPHICS_PROGRAMS
955 /* With BROKEN_GRAPHICS_PROGRAMS defined, the default
956 font is not saved. */
961 op.op = KD_FONT_OP_SET_DEFAULT;
963 ret = con_font_op(vc_cons[fg_console].d, &op);
967 con_set_default_unimap(vc_cons[fg_console].d);
975 if (copy_from_user(&op, up, sizeof(op))) {
979 if (!perm && op.op != KD_FONT_OP_GET)
981 ret = con_font_op(vc, &op);
984 if (copy_to_user(up, &op, sizeof(op)))
993 ret = con_set_trans_old(up);
997 ret = con_get_trans_old(up);
1000 case PIO_UNISCRNMAP:
1004 ret = con_set_trans_new(up);
1007 case GIO_UNISCRNMAP:
1008 ret = con_get_trans_new(up);
1012 { struct unimapinit ui;
1015 ret = copy_from_user(&ui, up, sizeof(struct unimapinit));
1019 con_clear_unimap(vc, &ui);
1025 ret = do_unimap_ioctl(cmd, up, perm, vc);
1029 if (!capable(CAP_SYS_TTY_CONFIG))
1033 case VT_UNLOCKSWITCH:
1034 if (!capable(CAP_SYS_TTY_CONFIG))
1038 case VT_GETHIFONTMASK:
1039 ret = put_user(vc->vc_hi_font_mask,
1040 (unsigned short __user *)arg);
1043 ret = vt_event_wait_ioctl((struct vt_event __user *)arg);
1052 void reset_vc(struct vc_data *vc)
1054 vc->vc_mode = KD_TEXT;
1055 vt_reset_unicode(vc->vc_num);
1056 vc->vt_mode.mode = VT_AUTO;
1057 vc->vt_mode.waitv = 0;
1058 vc->vt_mode.relsig = 0;
1059 vc->vt_mode.acqsig = 0;
1060 vc->vt_mode.frsig = 0;
1061 put_pid(vc->vt_pid);
1064 if (!in_interrupt()) /* Via keyboard.c:SAK() - akpm */
1068 void vc_SAK(struct work_struct *work)
1071 container_of(work, struct vc, SAK_work);
1073 struct tty_struct *tty;
1078 /* FIXME: review tty ref counting */
1081 * SAK should also work in all raw modes and reset
1091 #ifdef CONFIG_COMPAT
1093 struct compat_consolefontdesc {
1094 unsigned short charcount; /* characters in font (256 or 512) */
1095 unsigned short charheight; /* scan lines per character (1-32) */
1096 compat_caddr_t chardata; /* font data in expanded form */
1100 compat_fontx_ioctl(int cmd, struct compat_consolefontdesc __user *user_cfd,
1101 int perm, struct console_font_op *op)
1103 struct compat_consolefontdesc cfdarg;
1106 if (copy_from_user(&cfdarg, user_cfd, sizeof(struct compat_consolefontdesc)))
1113 op->op = KD_FONT_OP_SET;
1114 op->flags = KD_FONT_FLAG_OLD;
1116 op->height = cfdarg.charheight;
1117 op->charcount = cfdarg.charcount;
1118 op->data = compat_ptr(cfdarg.chardata);
1119 return con_font_op(vc_cons[fg_console].d, op);
1121 op->op = KD_FONT_OP_GET;
1122 op->flags = KD_FONT_FLAG_OLD;
1124 op->height = cfdarg.charheight;
1125 op->charcount = cfdarg.charcount;
1126 op->data = compat_ptr(cfdarg.chardata);
1127 i = con_font_op(vc_cons[fg_console].d, op);
1130 cfdarg.charheight = op->height;
1131 cfdarg.charcount = op->charcount;
1132 if (copy_to_user(user_cfd, &cfdarg, sizeof(struct compat_consolefontdesc)))
1139 struct compat_console_font_op {
1140 compat_uint_t op; /* operation code KD_FONT_OP_* */
1141 compat_uint_t flags; /* KD_FONT_FLAG_* */
1142 compat_uint_t width, height; /* font size */
1143 compat_uint_t charcount;
1144 compat_caddr_t data; /* font data with height fixed to 32 */
1148 compat_kdfontop_ioctl(struct compat_console_font_op __user *fontop,
1149 int perm, struct console_font_op *op, struct vc_data *vc)
1153 if (copy_from_user(op, fontop, sizeof(struct compat_console_font_op)))
1155 if (!perm && op->op != KD_FONT_OP_GET)
1157 op->data = compat_ptr(((struct compat_console_font_op *)op)->data);
1158 i = con_font_op(vc, op);
1161 ((struct compat_console_font_op *)op)->data = (unsigned long)op->data;
1162 if (copy_to_user(fontop, op, sizeof(struct compat_console_font_op)))
1167 struct compat_unimapdesc {
1168 unsigned short entry_ct;
1169 compat_caddr_t entries;
1173 compat_unimap_ioctl(unsigned int cmd, struct compat_unimapdesc __user *user_ud,
1174 int perm, struct vc_data *vc)
1176 struct compat_unimapdesc tmp;
1177 struct unipair __user *tmp_entries;
1179 if (copy_from_user(&tmp, user_ud, sizeof tmp))
1181 tmp_entries = compat_ptr(tmp.entries);
1183 if (!access_ok(VERIFY_WRITE, tmp_entries,
1184 tmp.entry_ct*sizeof(struct unipair)))
1190 return con_set_unimap(vc, tmp.entry_ct, tmp_entries);
1192 if (!perm && fg_console != vc->vc_num)
1194 return con_get_unimap(vc, tmp.entry_ct, &(user_ud->entry_ct), tmp_entries);
1199 long vt_compat_ioctl(struct tty_struct *tty,
1200 unsigned int cmd, unsigned long arg)
1202 struct vc_data *vc = tty->driver_data;
1203 struct console_font_op op; /* used in multiple places here */
1204 unsigned int console;
1205 void __user *up = (void __user *)arg;
1209 console = vc->vc_num;
1211 if (!vc_cons_allocated(console)) { /* impossible? */
1217 * To have permissions to do most of the vt ioctls, we either have
1218 * to be the owner of the tty, or have CAP_SYS_TTY_CONFIG.
1221 if (current->signal->tty == tty || capable(CAP_SYS_TTY_CONFIG))
1226 * these need special handlers for incompatible data structures
1230 ret = compat_fontx_ioctl(cmd, up, perm, &op);
1234 ret = compat_kdfontop_ioctl(up, perm, &op, vc);
1239 ret = compat_unimap_ioctl(cmd, up, perm, vc);
1243 * all these treat 'arg' as an integer
1262 case VT_DISALLOCATE:
1268 * the rest has a compatible data structure behind arg,
1269 * but we have to convert it to a proper 64 bit pointer.
1272 arg = (unsigned long)compat_ptr(arg);
1279 return vt_ioctl(tty, cmd, arg);
1283 #endif /* CONFIG_COMPAT */
1287 * Performs the back end of a vt switch. Called under the console
1290 static void complete_change_console(struct vc_data *vc)
1292 unsigned char old_vc_mode;
1293 int old = fg_console;
1295 last_console = fg_console;
1298 * If we're switching, we could be going from KD_GRAPHICS to
1299 * KD_TEXT mode or vice versa, which means we need to blank or
1300 * unblank the screen later.
1302 old_vc_mode = vc_cons[fg_console].d->vc_mode;
1306 * This can't appear below a successful kill_pid(). If it did,
1307 * then the *blank_screen operation could occur while X, having
1308 * received acqsig, is waking up on another processor. This
1309 * condition can lead to overlapping accesses to the VGA range
1310 * and the framebuffer (causing system lockups).
1312 * To account for this we duplicate this code below only if the
1313 * controlling process is gone and we've called reset_vc.
1315 if (old_vc_mode != vc->vc_mode) {
1316 if (vc->vc_mode == KD_TEXT)
1317 do_unblank_screen(1);
1323 * If this new console is under process control, send it a signal
1324 * telling it that it has acquired. Also check if it has died and
1325 * clean up (similar to logic employed in change_console())
1327 if (vc->vt_mode.mode == VT_PROCESS) {
1329 * Send the signal as privileged - kill_pid() will
1330 * tell us if the process has gone or something else
1333 if (kill_pid(vc->vt_pid, vc->vt_mode.acqsig, 1) != 0) {
1335 * The controlling process has died, so we revert back to
1336 * normal operation. In this case, we'll also change back
1337 * to KD_TEXT mode. I'm not sure if this is strictly correct
1338 * but it saves the agony when the X server dies and the screen
1339 * remains blanked due to KD_GRAPHICS! It would be nice to do
1340 * this outside of VT_PROCESS but there is no single process
1341 * to account for and tracking tty count may be undesirable.
1345 if (old_vc_mode != vc->vc_mode) {
1346 if (vc->vc_mode == KD_TEXT)
1347 do_unblank_screen(1);
1355 * Wake anyone waiting for their VT to activate
1357 vt_event_post(VT_EVENT_SWITCH, old, vc->vc_num);
1362 * Performs the front-end of a vt switch
1364 void change_console(struct vc_data *new_vc)
1368 if (!new_vc || new_vc->vc_num == fg_console || vt_dont_switch)
1372 * If this vt is in process mode, then we need to handshake with
1373 * that process before switching. Essentially, we store where that
1374 * vt wants to switch to and wait for it to tell us when it's done
1375 * (via VT_RELDISP ioctl).
1377 * We also check to see if the controlling process still exists.
1378 * If it doesn't, we reset this vt to auto mode and continue.
1379 * This is a cheap way to track process control. The worst thing
1380 * that can happen is: we send a signal to a process, it dies, and
1381 * the switch gets "lost" waiting for a response; hopefully, the
1382 * user will try again, we'll detect the process is gone (unless
1383 * the user waits just the right amount of time :-) and revert the
1384 * vt to auto control.
1386 vc = vc_cons[fg_console].d;
1387 if (vc->vt_mode.mode == VT_PROCESS) {
1389 * Send the signal as privileged - kill_pid() will
1390 * tell us if the process has gone or something else
1393 * We need to set vt_newvt *before* sending the signal or we
1396 vc->vt_newvt = new_vc->vc_num;
1397 if (kill_pid(vc->vt_pid, vc->vt_mode.relsig, 1) == 0) {
1399 * It worked. Mark the vt to switch to and
1400 * return. The process needs to send us a
1401 * VT_RELDISP ioctl to complete the switch.
1407 * The controlling process has died, so we revert back to
1408 * normal operation. In this case, we'll also change back
1409 * to KD_TEXT mode. I'm not sure if this is strictly correct
1410 * but it saves the agony when the X server dies and the screen
1411 * remains blanked due to KD_GRAPHICS! It would be nice to do
1412 * this outside of VT_PROCESS but there is no single process
1413 * to account for and tracking tty count may be undesirable.
1418 * Fall through to normal (VT_AUTO) handling of the switch...
1423 * Ignore all switches in KD_GRAPHICS+VT_AUTO mode
1425 if (vc->vc_mode == KD_GRAPHICS)
1428 complete_change_console(new_vc);
1431 /* Perform a kernel triggered VT switch for suspend/resume */
1433 static int disable_vt_switch;
1435 int vt_move_to_console(unsigned int vt, int alloc)
1440 /* Graphics mode - up to X */
1441 if (disable_vt_switch) {
1447 if (alloc && vc_allocate(vt)) {
1448 /* we can't have a free VC for now. Too bad,
1449 * we don't want to mess the screen for now. */
1454 if (set_console(vt)) {
1456 * We're unable to switch to the SUSPEND_CONSOLE.
1457 * Let the calling function know so it can decide
1464 if (vt_waitactive(vt + 1)) {
1465 pr_debug("Suspend: Can't switch VCs.");
1472 * Normally during a suspend, we allocate a new console and switch to it.
1473 * When we resume, we switch back to the original console. This switch
1474 * can be slow, so on systems where the framebuffer can handle restoration
1475 * of video registers anyways, there's little point in doing the console
1476 * switch. This function allows you to disable it by passing it '0'.
1478 void pm_set_vt_switch(int do_switch)
1481 disable_vt_switch = !do_switch;
1484 EXPORT_SYMBOL(pm_set_vt_switch);