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/nospec.h>
36 #include <linux/kbd_kern.h>
37 #include <linux/vt_kern.h>
38 #include <linux/kbd_diacr.h>
39 #include <linux/selection.h>
43 static inline bool vt_in_use(unsigned int i)
45 const struct vc_data *vc = vc_cons[i].d;
48 * console_lock must be held to prevent the vc from being deallocated
49 * while we're checking whether it's in-use.
51 WARN_CONSOLE_UNLOCKED();
53 return vc && kref_read(&vc->port.kref) > 1;
56 static inline bool vt_busy(int i)
62 if (vc_is_sel(vc_cons[i].d))
69 * Console (vt and kd) routines, as defined by USL SVR4 manual, and by
70 * experimentation and study of X386 SYSV handling.
72 * One point of difference: SYSV vt's are /dev/vtX, which X >= 0, and
73 * /dev/console is a separate ttyp. Under Linux, /dev/tty0 is /dev/console,
74 * and the vc start at /dev/ttyX, X >= 1. We maintain that here, so we will
75 * always treat our set of vt as numbered 1..MAX_NR_CONSOLES (corresponding to
76 * ttys 0..MAX_NR_CONSOLES-1). Explicitly naming VT 0 is illegal, but using
77 * /dev/tty0 (fg_console) as a target is legal, since an implicit aliasing
78 * to the current console is done by the main ioctl code.
82 #include <linux/syscalls.h>
85 static void complete_change_console(struct vc_data *vc);
88 * User space VT_EVENT handlers
91 struct vt_event_wait {
92 struct list_head list;
93 struct vt_event event;
97 static LIST_HEAD(vt_events);
98 static DEFINE_SPINLOCK(vt_event_lock);
99 static DECLARE_WAIT_QUEUE_HEAD(vt_event_waitqueue);
103 * @event: the event that occurred
107 * Post an VT event to interested VT handlers
110 void vt_event_post(unsigned int event, unsigned int old, unsigned int new)
112 struct list_head *pos, *head;
116 spin_lock_irqsave(&vt_event_lock, flags);
119 list_for_each(pos, head) {
120 struct vt_event_wait *ve = list_entry(pos,
121 struct vt_event_wait, list);
122 if (!(ve->event.event & event))
124 ve->event.event = event;
125 /* kernel view is consoles 0..n-1, user space view is
126 console 1..n with 0 meaning current, so we must bias */
127 ve->event.oldev = old + 1;
128 ve->event.newev = new + 1;
132 spin_unlock_irqrestore(&vt_event_lock, flags);
134 wake_up_interruptible(&vt_event_waitqueue);
137 static void __vt_event_queue(struct vt_event_wait *vw)
140 /* Prepare the event */
141 INIT_LIST_HEAD(&vw->list);
143 /* Queue our event */
144 spin_lock_irqsave(&vt_event_lock, flags);
145 list_add(&vw->list, &vt_events);
146 spin_unlock_irqrestore(&vt_event_lock, flags);
149 static void __vt_event_wait(struct vt_event_wait *vw)
151 /* Wait for it to pass */
152 wait_event_interruptible(vt_event_waitqueue, vw->done);
155 static void __vt_event_dequeue(struct vt_event_wait *vw)
160 spin_lock_irqsave(&vt_event_lock, flags);
162 spin_unlock_irqrestore(&vt_event_lock, flags);
166 * vt_event_wait - wait for an event
169 * Waits for an event to occur which completes our vt_event_wait
170 * structure. On return the structure has wv->done set to 1 for success
171 * or 0 if some event such as a signal ended the wait.
174 static void vt_event_wait(struct vt_event_wait *vw)
176 __vt_event_queue(vw);
178 __vt_event_dequeue(vw);
182 * vt_event_wait_ioctl - event ioctl handler
183 * @arg: argument to ioctl
185 * Implement the VT_WAITEVENT ioctl using the VT event interface
188 static int vt_event_wait_ioctl(struct vt_event __user *event)
190 struct vt_event_wait vw;
192 if (copy_from_user(&vw.event, event, sizeof(struct vt_event)))
194 /* Highest supported event for now */
195 if (vw.event.event & ~VT_MAX_EVENT)
199 /* If it occurred report it */
201 if (copy_to_user(event, &vw.event, sizeof(struct vt_event)))
209 * vt_waitactive - active console wait
213 * Helper for event waits. Used to implement the legacy
214 * event waiting ioctls in terms of events
217 int vt_waitactive(int n)
219 struct vt_event_wait vw;
221 vw.event.event = VT_EVENT_SWITCH;
222 __vt_event_queue(&vw);
223 if (n == fg_console + 1) {
224 __vt_event_dequeue(&vw);
227 __vt_event_wait(&vw);
228 __vt_event_dequeue(&vw);
231 } while (vw.event.newev != n);
236 * these are the valid i/o ports we're allowed to change. they map all the
239 #define GPFIRST 0x3b4
241 #define GPNUM (GPLAST - GPFIRST + 1)
246 do_fontx_ioctl(struct vc_data *vc, int cmd, struct consolefontdesc __user *user_cfd, int perm, struct console_font_op *op)
248 struct consolefontdesc cfdarg;
251 if (copy_from_user(&cfdarg, user_cfd, sizeof(struct consolefontdesc)))
258 op->op = KD_FONT_OP_SET;
259 op->flags = KD_FONT_FLAG_OLD;
261 op->height = cfdarg.charheight;
262 op->charcount = cfdarg.charcount;
263 op->data = cfdarg.chardata;
264 return con_font_op(vc, op);
267 op->op = KD_FONT_OP_GET;
268 op->flags = KD_FONT_FLAG_OLD;
270 op->height = cfdarg.charheight;
271 op->charcount = cfdarg.charcount;
272 op->data = cfdarg.chardata;
273 i = con_font_op(vc, op);
276 cfdarg.charheight = op->height;
277 cfdarg.charcount = op->charcount;
278 if (copy_to_user(user_cfd, &cfdarg, sizeof(struct consolefontdesc)))
286 do_unimap_ioctl(int cmd, struct unimapdesc __user *user_ud, int perm, struct vc_data *vc)
288 struct unimapdesc tmp;
290 if (copy_from_user(&tmp, user_ud, sizeof tmp))
293 if (!access_ok(VERIFY_WRITE, tmp.entries,
294 tmp.entry_ct*sizeof(struct unipair)))
300 return con_set_unimap(vc, tmp.entry_ct, tmp.entries);
302 if (!perm && fg_console != vc->vc_num)
304 return con_get_unimap(vc, tmp.entry_ct, &(user_ud->entry_ct), tmp.entries);
309 /* deallocate a single console, if possible (leave 0) */
310 static int vt_disallocate(unsigned int vc_num)
312 struct vc_data *vc = NULL;
319 vc = vc_deallocate(vc_num);
322 if (vc && vc_num >= MIN_NR_CONSOLES)
323 tty_port_put(&vc->port);
328 /* deallocate all unused consoles, but leave 0 */
329 static void vt_disallocate_all(void)
331 struct vc_data *vc[MAX_NR_CONSOLES];
335 for (i = 1; i < MAX_NR_CONSOLES; i++)
337 vc[i] = vc_deallocate(i);
342 for (i = 1; i < MAX_NR_CONSOLES; i++) {
343 if (vc[i] && i >= MIN_NR_CONSOLES)
344 tty_port_put(&vc[i]->port);
350 * We handle the console-specific ioctl's here. We allow the
351 * capability to modify any console, not just the fg_console.
353 int vt_ioctl(struct tty_struct *tty,
354 unsigned int cmd, unsigned long arg)
356 struct vc_data *vc = tty->driver_data;
357 struct console_font_op op; /* used in multiple places here */
358 unsigned int console = vc->vc_num;
361 void __user *up = (void __user *)arg;
366 * To have permissions to do most of the vt ioctls, we either have
367 * to be the owner of the tty, or have CAP_SYS_TTY_CONFIG.
370 if (current->signal->tty == tty || capable(CAP_SYS_TTY_CONFIG))
375 ret = tioclinux(tty, arg);
381 * The use of PIT_TICK_RATE is historic, it used to be
382 * the platform-dependent CLOCK_TICK_RATE between 2.6.12
383 * and 2.6.36, which was a minor but unfortunate ABI
384 * change. kd_mksound is locked by the input layer.
387 arg = PIT_TICK_RATE / arg;
395 unsigned int ticks, count;
398 * Generate the tone for the appropriate number of ticks.
399 * If the time is zero, turn off sound ourselves.
401 ticks = msecs_to_jiffies((arg >> 16) & 0xffff);
402 count = ticks ? (arg & 0xffff) : 0;
404 count = PIT_TICK_RATE / count;
405 kd_mksound(count, ticks);
414 ret = put_user(ucval, (char __user *)arg);
418 * These cannot be implemented on any machine that implements
419 * ioperm() in user level (such as Alpha PCs) or not at all.
421 * XXX: you should never use these, just call ioperm directly..
427 * KDADDIO and KDDELIO may be able to add ports beyond what
428 * we reject here, but to be safe...
430 * These are locked internally via sys_ioperm
432 if (arg < GPFIRST || arg > GPLAST) {
436 ret = sys_ioperm(arg, 1, (cmd == KDADDIO)) ? -ENXIO : 0;
441 ret = sys_ioperm(GPFIRST, GPNUM,
442 (cmd == KDENABIO)) ? -ENXIO : 0;
446 /* Linux m68k/i386 interface for setting the keyboard delay/repeat rate */
450 struct kbd_repeat kbrep;
452 if (!capable(CAP_SYS_TTY_CONFIG))
455 if (copy_from_user(&kbrep, up, sizeof(struct kbd_repeat))) {
459 ret = kbd_rate(&kbrep);
462 if (copy_to_user(up, &kbrep, sizeof(struct kbd_repeat)))
469 * currently, setting the mode from KD_TEXT to KD_GRAPHICS
470 * doesn't do a whole lot. i'm not sure if it should do any
471 * restoration of modes or what...
473 * XXX It should at least call into the driver, fbdev's definitely
474 * need to restore their engine state. --BenH
490 /* FIXME: this needs the console lock extending */
491 if (vc->vc_mode == (unsigned char) arg)
493 vc->vc_mode = (unsigned char) arg;
494 if (console != fg_console)
497 * explicitly blank/unblank the screen if switching modes
501 do_unblank_screen(1);
514 * these work like a combination of mmap and KDENABIO.
515 * this could be easily finished.
523 ret = vt_do_kdskbmode(console, arg);
525 tty_ldisc_flush(tty);
529 uival = vt_do_kdgkbmode(console);
530 ret = put_user(uival, (int __user *)arg);
533 /* this could be folded into KDSKBMODE, but for compatibility
534 reasons it is not so easy to fold KDGKBMETA into KDGKBMODE */
536 ret = vt_do_kdskbmeta(console, arg);
540 /* FIXME: should review whether this is worth locking */
541 uival = vt_do_kdgkbmeta(console);
543 ret = put_user(uival, (int __user *)arg);
548 if(!capable(CAP_SYS_TTY_CONFIG))
550 ret = vt_do_kbkeycode_ioctl(cmd, up, perm);
555 ret = vt_do_kdsk_ioctl(cmd, up, perm, console);
560 ret = vt_do_kdgkb_ioctl(cmd, up, perm);
563 /* Diacritical processing. Handled in keyboard.c as it has
564 to operate on the keyboard locks and structures */
569 ret = vt_do_diacrit(cmd, up, perm);
572 /* the ioctls below read/set the flags usually shown in the leds */
573 /* don't use them - they will go away without warning */
578 ret = vt_do_kdskled(console, cmd, arg, perm);
582 * A process can indicate its willingness to accept signals
583 * generated by pressing an appropriate key combination.
584 * Thus, one can have a daemon that e.g. spawns a new console
585 * upon a keypress and then changes to it.
586 * See also the kbrequest field of inittab(5).
590 if (!perm || !capable(CAP_KILL))
592 if (!valid_signal(arg) || arg < 1 || arg == SIGKILL)
595 spin_lock_irq(&vt_spawn_con.lock);
596 put_pid(vt_spawn_con.pid);
597 vt_spawn_con.pid = get_pid(task_pid(current));
598 vt_spawn_con.sig = arg;
599 spin_unlock_irq(&vt_spawn_con.lock);
610 if (copy_from_user(&tmp, up, sizeof(struct vt_mode))) {
614 if (tmp.mode != VT_AUTO && tmp.mode != VT_PROCESS) {
620 /* the frsig is ignored, so we set it to 0 */
621 vc->vt_mode.frsig = 0;
623 vc->vt_pid = get_pid(task_pid(current));
624 /* no switch is required -- saw@shade.msu.ru */
636 memcpy(&tmp, &vc->vt_mode, sizeof(struct vt_mode));
639 rc = copy_to_user(up, &tmp, sizeof(struct vt_mode));
646 * Returns global vt state. Note that VT 0 is always open, since
647 * it's an alias for the current VT, and people can't use it here.
648 * We cannot return state for more than 16 VTs, since v_state is short.
652 struct vt_stat __user *vtstat = up;
653 unsigned short state, mask;
655 if (put_user(fg_console + 1, &vtstat->v_active))
658 state = 1; /* /dev/tty0 is always open */
659 console_lock(); /* required by vt_in_use() */
660 for (i = 0, mask = 2; i < MAX_NR_CONSOLES && mask;
665 ret = put_user(state, &vtstat->v_state);
671 * Returns the first available (non-opened) console.
674 console_lock(); /* required by vt_in_use() */
675 for (i = 0; i < MAX_NR_CONSOLES; ++i)
679 uival = i < MAX_NR_CONSOLES ? (i+1) : -1;
683 * ioctl(fd, VT_ACTIVATE, num) will cause us to switch to vt # num,
684 * with num >= 1 (switches to vt 0, our console, are not allowed, just
685 * to preserve sanity).
690 if (arg == 0 || arg > MAX_NR_CONSOLES)
695 ret = vc_allocate(arg);
705 struct vt_setactivate vsa;
710 if (copy_from_user(&vsa, (struct vt_setactivate __user *)arg,
711 sizeof(struct vt_setactivate))) {
715 if (vsa.console == 0 || vsa.console > MAX_NR_CONSOLES)
718 vsa.console = array_index_nospec(vsa.console,
719 MAX_NR_CONSOLES + 1);
722 ret = vc_allocate(vsa.console);
725 /* This is safe providing we don't drop the
726 console sem between vc_allocate and
727 finishing referencing nvc */
728 nvc = vc_cons[vsa.console].d;
729 nvc->vt_mode = vsa.mode;
730 nvc->vt_mode.frsig = 0;
731 put_pid(nvc->vt_pid);
732 nvc->vt_pid = get_pid(task_pid(current));
737 /* Commence switch and lock */
738 /* Review set_console locks */
739 set_console(vsa.console);
745 * wait until the specified VT has been activated
750 if (arg == 0 || arg > MAX_NR_CONSOLES)
753 ret = vt_waitactive(arg);
757 * If a vt is under process control, the kernel will not switch to it
758 * immediately, but postpone the operation until the process calls this
759 * ioctl, allowing the switch to complete.
761 * According to the X sources this is the behavior:
762 * 0: pending switch-from not OK
763 * 1: pending switch-from OK
764 * 2: completed switch-to OK
771 if (vc->vt_mode.mode != VT_PROCESS) {
777 * Switching-from response
779 if (vc->vt_newvt >= 0) {
782 * Switch disallowed, so forget we were trying
789 * The current vt has been released, so
790 * complete the switch.
793 newvt = vc->vt_newvt;
795 ret = vc_allocate(newvt);
801 * When we actually do the console switch,
802 * make sure we are atomic with respect to
803 * other console switches..
805 complete_change_console(vc_cons[newvt].d);
809 * Switched-to response
812 * If it's just an ACK, ignore it
814 if (arg != VT_ACKACQ)
821 * Disallocate memory associated to VT (but leave VT1)
824 if (arg > MAX_NR_CONSOLES) {
829 vt_disallocate_all();
831 ret = vt_disallocate(--arg);
836 struct vt_sizes __user *vtsizes = up;
842 if (get_user(ll, &vtsizes->v_rows) ||
843 get_user(cc, &vtsizes->v_cols))
847 for (i = 0; i < MAX_NR_CONSOLES; i++) {
851 vc->vc_resize_user = 1;
852 /* FIXME: review v tty lock */
853 vc_resize(vc_cons[i].d, cc, ll);
866 if (copy_from_user(&v, up, sizeof(struct vt_consize)))
868 /* FIXME: Should check the copies properly */
870 v.v_vlin = vc->vc_scan_lines;
872 int rows = v.v_vlin/v.v_clin;
873 if (v.v_rows != rows) {
874 if (v.v_rows) /* Parameters don't add up */
879 if (v.v_vcol && v.v_ccol) {
880 int cols = v.v_vcol/v.v_ccol;
881 if (v.v_cols != cols) {
891 for (i = 0; i < MAX_NR_CONSOLES; i++) {
900 int save_scan_lines = vcp->vc_scan_lines;
901 int save_cell_height = vcp->vc_cell_height;
904 vcp->vc_scan_lines = v.v_vlin;
906 vcp->vc_cell_height = v.v_clin;
907 vcp->vc_resize_user = 1;
908 ret = vc_resize(vcp, v.v_cols, v.v_rows);
910 vcp->vc_scan_lines = save_scan_lines;
911 vcp->vc_cell_height = save_cell_height;
924 op.op = KD_FONT_OP_SET;
925 op.flags = KD_FONT_FLAG_OLD | KD_FONT_FLAG_DONT_RECALC; /* Compatibility */
930 ret = con_font_op(vc, &op);
935 op.op = KD_FONT_OP_GET;
936 op.flags = KD_FONT_FLAG_OLD;
941 ret = con_font_op(vc, &op);
949 ret = con_set_cmap(up);
953 ret = con_get_cmap(up);
958 ret = do_fontx_ioctl(vc, cmd, up, perm, &op);
966 #ifdef BROKEN_GRAPHICS_PROGRAMS
967 /* With BROKEN_GRAPHICS_PROGRAMS defined, the default
968 font is not saved. */
973 op.op = KD_FONT_OP_SET_DEFAULT;
975 ret = con_font_op(vc, &op);
979 con_set_default_unimap(vc);
987 if (copy_from_user(&op, up, sizeof(op))) {
991 if (!perm && op.op != KD_FONT_OP_GET)
993 ret = con_font_op(vc, &op);
996 if (copy_to_user(up, &op, sizeof(op)))
1005 ret = con_set_trans_old(up);
1009 ret = con_get_trans_old(up);
1012 case PIO_UNISCRNMAP:
1016 ret = con_set_trans_new(up);
1019 case GIO_UNISCRNMAP:
1020 ret = con_get_trans_new(up);
1024 { struct unimapinit ui;
1027 ret = copy_from_user(&ui, up, sizeof(struct unimapinit));
1031 con_clear_unimap(vc, &ui);
1037 ret = do_unimap_ioctl(cmd, up, perm, vc);
1041 if (!capable(CAP_SYS_TTY_CONFIG))
1043 vt_dont_switch = true;
1045 case VT_UNLOCKSWITCH:
1046 if (!capable(CAP_SYS_TTY_CONFIG))
1048 vt_dont_switch = false;
1050 case VT_GETHIFONTMASK:
1051 ret = put_user(vc->vc_hi_font_mask,
1052 (unsigned short __user *)arg);
1055 ret = vt_event_wait_ioctl((struct vt_event __user *)arg);
1064 void reset_vc(struct vc_data *vc)
1066 vc->vc_mode = KD_TEXT;
1067 vt_reset_unicode(vc->vc_num);
1068 vc->vt_mode.mode = VT_AUTO;
1069 vc->vt_mode.waitv = 0;
1070 vc->vt_mode.relsig = 0;
1071 vc->vt_mode.acqsig = 0;
1072 vc->vt_mode.frsig = 0;
1073 put_pid(vc->vt_pid);
1076 if (!in_interrupt()) /* Via keyboard.c:SAK() - akpm */
1080 void vc_SAK(struct work_struct *work)
1083 container_of(work, struct vc, SAK_work);
1085 struct tty_struct *tty;
1090 /* FIXME: review tty ref counting */
1093 * SAK should also work in all raw modes and reset
1103 #ifdef CONFIG_COMPAT
1105 struct compat_consolefontdesc {
1106 unsigned short charcount; /* characters in font (256 or 512) */
1107 unsigned short charheight; /* scan lines per character (1-32) */
1108 compat_caddr_t chardata; /* font data in expanded form */
1112 compat_fontx_ioctl(struct vc_data *vc, int cmd,
1113 struct compat_consolefontdesc __user *user_cfd,
1114 int perm, struct console_font_op *op)
1116 struct compat_consolefontdesc cfdarg;
1119 if (copy_from_user(&cfdarg, user_cfd, sizeof(struct compat_consolefontdesc)))
1126 op->op = KD_FONT_OP_SET;
1127 op->flags = KD_FONT_FLAG_OLD;
1129 op->height = cfdarg.charheight;
1130 op->charcount = cfdarg.charcount;
1131 op->data = compat_ptr(cfdarg.chardata);
1132 return con_font_op(vc, op);
1135 op->op = KD_FONT_OP_GET;
1136 op->flags = KD_FONT_FLAG_OLD;
1138 op->height = cfdarg.charheight;
1139 op->charcount = cfdarg.charcount;
1140 op->data = compat_ptr(cfdarg.chardata);
1141 i = con_font_op(vc, op);
1144 cfdarg.charheight = op->height;
1145 cfdarg.charcount = op->charcount;
1146 if (copy_to_user(user_cfd, &cfdarg, sizeof(struct compat_consolefontdesc)))
1153 struct compat_console_font_op {
1154 compat_uint_t op; /* operation code KD_FONT_OP_* */
1155 compat_uint_t flags; /* KD_FONT_FLAG_* */
1156 compat_uint_t width, height; /* font size */
1157 compat_uint_t charcount;
1158 compat_caddr_t data; /* font data with height fixed to 32 */
1162 compat_kdfontop_ioctl(struct compat_console_font_op __user *fontop,
1163 int perm, struct console_font_op *op, struct vc_data *vc)
1167 if (copy_from_user(op, fontop, sizeof(struct compat_console_font_op)))
1169 if (!perm && op->op != KD_FONT_OP_GET)
1171 op->data = compat_ptr(((struct compat_console_font_op *)op)->data);
1172 i = con_font_op(vc, op);
1175 ((struct compat_console_font_op *)op)->data = (unsigned long)op->data;
1176 if (copy_to_user(fontop, op, sizeof(struct compat_console_font_op)))
1181 struct compat_unimapdesc {
1182 unsigned short entry_ct;
1183 compat_caddr_t entries;
1187 compat_unimap_ioctl(unsigned int cmd, struct compat_unimapdesc __user *user_ud,
1188 int perm, struct vc_data *vc)
1190 struct compat_unimapdesc tmp;
1191 struct unipair __user *tmp_entries;
1193 if (copy_from_user(&tmp, user_ud, sizeof tmp))
1195 tmp_entries = compat_ptr(tmp.entries);
1197 if (!access_ok(VERIFY_WRITE, tmp_entries,
1198 tmp.entry_ct*sizeof(struct unipair)))
1204 return con_set_unimap(vc, tmp.entry_ct, tmp_entries);
1206 if (!perm && fg_console != vc->vc_num)
1208 return con_get_unimap(vc, tmp.entry_ct, &(user_ud->entry_ct), tmp_entries);
1213 long vt_compat_ioctl(struct tty_struct *tty,
1214 unsigned int cmd, unsigned long arg)
1216 struct vc_data *vc = tty->driver_data;
1217 struct console_font_op op; /* used in multiple places here */
1218 void __user *up = (void __user *)arg;
1223 * To have permissions to do most of the vt ioctls, we either have
1224 * to be the owner of the tty, or have CAP_SYS_TTY_CONFIG.
1227 if (current->signal->tty == tty || capable(CAP_SYS_TTY_CONFIG))
1232 * these need special handlers for incompatible data structures
1236 ret = compat_fontx_ioctl(vc, cmd, up, perm, &op);
1240 ret = compat_kdfontop_ioctl(up, perm, &op, vc);
1245 ret = compat_unimap_ioctl(cmd, up, perm, vc);
1249 * all these treat 'arg' as an integer
1268 case VT_DISALLOCATE:
1274 * the rest has a compatible data structure behind arg,
1275 * but we have to convert it to a proper 64 bit pointer.
1278 arg = (unsigned long)compat_ptr(arg);
1285 return vt_ioctl(tty, cmd, arg);
1289 #endif /* CONFIG_COMPAT */
1293 * Performs the back end of a vt switch. Called under the console
1296 static void complete_change_console(struct vc_data *vc)
1298 unsigned char old_vc_mode;
1299 int old = fg_console;
1301 last_console = fg_console;
1304 * If we're switching, we could be going from KD_GRAPHICS to
1305 * KD_TEXT mode or vice versa, which means we need to blank or
1306 * unblank the screen later.
1308 old_vc_mode = vc_cons[fg_console].d->vc_mode;
1312 * This can't appear below a successful kill_pid(). If it did,
1313 * then the *blank_screen operation could occur while X, having
1314 * received acqsig, is waking up on another processor. This
1315 * condition can lead to overlapping accesses to the VGA range
1316 * and the framebuffer (causing system lockups).
1318 * To account for this we duplicate this code below only if the
1319 * controlling process is gone and we've called reset_vc.
1321 if (old_vc_mode != vc->vc_mode) {
1322 if (vc->vc_mode == KD_TEXT)
1323 do_unblank_screen(1);
1329 * If this new console is under process control, send it a signal
1330 * telling it that it has acquired. Also check if it has died and
1331 * clean up (similar to logic employed in change_console())
1333 if (vc->vt_mode.mode == VT_PROCESS) {
1335 * Send the signal as privileged - kill_pid() will
1336 * tell us if the process has gone or something else
1339 if (kill_pid(vc->vt_pid, vc->vt_mode.acqsig, 1) != 0) {
1341 * The controlling process has died, so we revert back to
1342 * normal operation. In this case, we'll also change back
1343 * to KD_TEXT mode. I'm not sure if this is strictly correct
1344 * but it saves the agony when the X server dies and the screen
1345 * remains blanked due to KD_GRAPHICS! It would be nice to do
1346 * this outside of VT_PROCESS but there is no single process
1347 * to account for and tracking tty count may be undesirable.
1351 if (old_vc_mode != vc->vc_mode) {
1352 if (vc->vc_mode == KD_TEXT)
1353 do_unblank_screen(1);
1361 * Wake anyone waiting for their VT to activate
1363 vt_event_post(VT_EVENT_SWITCH, old, vc->vc_num);
1368 * Performs the front-end of a vt switch
1370 void change_console(struct vc_data *new_vc)
1374 if (!new_vc || new_vc->vc_num == fg_console || vt_dont_switch)
1378 * If this vt is in process mode, then we need to handshake with
1379 * that process before switching. Essentially, we store where that
1380 * vt wants to switch to and wait for it to tell us when it's done
1381 * (via VT_RELDISP ioctl).
1383 * We also check to see if the controlling process still exists.
1384 * If it doesn't, we reset this vt to auto mode and continue.
1385 * This is a cheap way to track process control. The worst thing
1386 * that can happen is: we send a signal to a process, it dies, and
1387 * the switch gets "lost" waiting for a response; hopefully, the
1388 * user will try again, we'll detect the process is gone (unless
1389 * the user waits just the right amount of time :-) and revert the
1390 * vt to auto control.
1392 vc = vc_cons[fg_console].d;
1393 if (vc->vt_mode.mode == VT_PROCESS) {
1395 * Send the signal as privileged - kill_pid() will
1396 * tell us if the process has gone or something else
1399 * We need to set vt_newvt *before* sending the signal or we
1402 vc->vt_newvt = new_vc->vc_num;
1403 if (kill_pid(vc->vt_pid, vc->vt_mode.relsig, 1) == 0) {
1405 * It worked. Mark the vt to switch to and
1406 * return. The process needs to send us a
1407 * VT_RELDISP ioctl to complete the switch.
1413 * The controlling process has died, so we revert back to
1414 * normal operation. In this case, we'll also change back
1415 * to KD_TEXT mode. I'm not sure if this is strictly correct
1416 * but it saves the agony when the X server dies and the screen
1417 * remains blanked due to KD_GRAPHICS! It would be nice to do
1418 * this outside of VT_PROCESS but there is no single process
1419 * to account for and tracking tty count may be undesirable.
1424 * Fall through to normal (VT_AUTO) handling of the switch...
1429 * Ignore all switches in KD_GRAPHICS+VT_AUTO mode
1431 if (vc->vc_mode == KD_GRAPHICS)
1434 complete_change_console(new_vc);
1437 /* Perform a kernel triggered VT switch for suspend/resume */
1439 static int disable_vt_switch;
1441 int vt_move_to_console(unsigned int vt, int alloc)
1446 /* Graphics mode - up to X */
1447 if (disable_vt_switch) {
1453 if (alloc && vc_allocate(vt)) {
1454 /* we can't have a free VC for now. Too bad,
1455 * we don't want to mess the screen for now. */
1460 if (set_console(vt)) {
1462 * We're unable to switch to the SUSPEND_CONSOLE.
1463 * Let the calling function know so it can decide
1470 if (vt_waitactive(vt + 1)) {
1471 pr_debug("Suspend: Can't switch VCs.");
1478 * Normally during a suspend, we allocate a new console and switch to it.
1479 * When we resume, we switch back to the original console. This switch
1480 * can be slow, so on systems where the framebuffer can handle restoration
1481 * of video registers anyways, there's little point in doing the console
1482 * switch. This function allows you to disable it by passing it '0'.
1484 void pm_set_vt_switch(int do_switch)
1487 disable_vt_switch = !do_switch;
1490 EXPORT_SYMBOL(pm_set_vt_switch);