1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright (C) 1992 obz under the linux copyright
5 * Dynamic diacritical handling - aeb@cwi.nl - Dec 1993
6 * Dynamic keymap and string allocation - aeb@cwi.nl - May 1994
7 * Restrict VT switching via ioctl() - grif@cs.ucr.edu - Dec 1995
8 * Some code moved for less code duplication - Andi Kleen - Mar 1997
9 * Check put/get_user, cleanups - acme@conectiva.com.br - Jun 2001
12 #include <linux/types.h>
13 #include <linux/errno.h>
14 #include <linux/sched/signal.h>
15 #include <linux/tty.h>
16 #include <linux/timer.h>
17 #include <linux/kernel.h>
18 #include <linux/compat.h>
19 #include <linux/module.h>
22 #include <linux/string.h>
23 #include <linux/slab.h>
24 #include <linux/major.h>
26 #include <linux/console.h>
27 #include <linux/consolemap.h>
28 #include <linux/signal.h>
29 #include <linux/suspend.h>
30 #include <linux/timex.h>
33 #include <linux/uaccess.h>
35 #include <linux/nospec.h>
37 #include <linux/kbd_kern.h>
38 #include <linux/vt_kern.h>
39 #include <linux/kbd_diacr.h>
40 #include <linux/selection.h>
44 static inline bool vt_in_use(unsigned int i)
46 const struct vc_data *vc = vc_cons[i].d;
49 * console_lock must be held to prevent the vc from being deallocated
50 * while we're checking whether it's in-use.
52 WARN_CONSOLE_UNLOCKED();
54 return vc && kref_read(&vc->port.kref) > 1;
57 static inline bool vt_busy(int i)
63 if (vc_is_sel(vc_cons[i].d))
70 * Console (vt and kd) routines, as defined by USL SVR4 manual, and by
71 * experimentation and study of X386 SYSV handling.
73 * One point of difference: SYSV vt's are /dev/vtX, which X >= 0, and
74 * /dev/console is a separate ttyp. Under Linux, /dev/tty0 is /dev/console,
75 * and the vc start at /dev/ttyX, X >= 1. We maintain that here, so we will
76 * always treat our set of vt as numbered 1..MAX_NR_CONSOLES (corresponding to
77 * ttys 0..MAX_NR_CONSOLES-1). Explicitly naming VT 0 is illegal, but using
78 * /dev/tty0 (fg_console) as a target is legal, since an implicit aliasing
79 * to the current console is done by the main ioctl code.
83 #include <asm/syscalls.h>
86 static void complete_change_console(struct vc_data *vc);
89 * User space VT_EVENT handlers
92 struct vt_event_wait {
93 struct list_head list;
94 struct vt_event event;
98 static LIST_HEAD(vt_events);
99 static DEFINE_SPINLOCK(vt_event_lock);
100 static DECLARE_WAIT_QUEUE_HEAD(vt_event_waitqueue);
104 * @event: the event that occurred
108 * Post an VT event to interested VT handlers
111 void vt_event_post(unsigned int event, unsigned int old, unsigned int new)
113 struct list_head *pos, *head;
117 spin_lock_irqsave(&vt_event_lock, flags);
120 list_for_each(pos, head) {
121 struct vt_event_wait *ve = list_entry(pos,
122 struct vt_event_wait, list);
123 if (!(ve->event.event & event))
125 ve->event.event = event;
126 /* kernel view is consoles 0..n-1, user space view is
127 console 1..n with 0 meaning current, so we must bias */
128 ve->event.oldev = old + 1;
129 ve->event.newev = new + 1;
133 spin_unlock_irqrestore(&vt_event_lock, flags);
135 wake_up_interruptible(&vt_event_waitqueue);
138 static void __vt_event_queue(struct vt_event_wait *vw)
141 /* Prepare the event */
142 INIT_LIST_HEAD(&vw->list);
144 /* Queue our event */
145 spin_lock_irqsave(&vt_event_lock, flags);
146 list_add(&vw->list, &vt_events);
147 spin_unlock_irqrestore(&vt_event_lock, flags);
150 static void __vt_event_wait(struct vt_event_wait *vw)
152 /* Wait for it to pass */
153 wait_event_interruptible(vt_event_waitqueue, vw->done);
156 static void __vt_event_dequeue(struct vt_event_wait *vw)
161 spin_lock_irqsave(&vt_event_lock, flags);
163 spin_unlock_irqrestore(&vt_event_lock, flags);
167 * vt_event_wait - wait for an event
170 * Waits for an event to occur which completes our vt_event_wait
171 * structure. On return the structure has wv->done set to 1 for success
172 * or 0 if some event such as a signal ended the wait.
175 static void vt_event_wait(struct vt_event_wait *vw)
177 __vt_event_queue(vw);
179 __vt_event_dequeue(vw);
183 * vt_event_wait_ioctl - event ioctl handler
184 * @arg: argument to ioctl
186 * Implement the VT_WAITEVENT ioctl using the VT event interface
189 static int vt_event_wait_ioctl(struct vt_event __user *event)
191 struct vt_event_wait vw;
193 if (copy_from_user(&vw.event, event, sizeof(struct vt_event)))
195 /* Highest supported event for now */
196 if (vw.event.event & ~VT_MAX_EVENT)
200 /* If it occurred report it */
202 if (copy_to_user(event, &vw.event, sizeof(struct vt_event)))
210 * vt_waitactive - active console wait
214 * Helper for event waits. Used to implement the legacy
215 * event waiting ioctls in terms of events
218 int vt_waitactive(int n)
220 struct vt_event_wait vw;
222 vw.event.event = VT_EVENT_SWITCH;
223 __vt_event_queue(&vw);
224 if (n == fg_console + 1) {
225 __vt_event_dequeue(&vw);
228 __vt_event_wait(&vw);
229 __vt_event_dequeue(&vw);
232 } while (vw.event.newev != n);
237 * these are the valid i/o ports we're allowed to change. they map all the
240 #define GPFIRST 0x3b4
242 #define GPNUM (GPLAST - GPFIRST + 1)
244 static int vt_k_ioctl(struct tty_struct *tty, unsigned int cmd,
245 unsigned long arg, bool perm)
247 struct vc_data *vc = tty->driver_data;
248 void __user *up = (void __user *)arg;
249 unsigned int console = vc->vc_num;
257 * The use of PIT_TICK_RATE is historic, it used to be
258 * the platform-dependent CLOCK_TICK_RATE between 2.6.12
259 * and 2.6.36, which was a minor but unfortunate ABI
260 * change. kd_mksound is locked by the input layer.
263 arg = PIT_TICK_RATE / arg;
271 unsigned int ticks, count;
274 * Generate the tone for the appropriate number of ticks.
275 * If the time is zero, turn off sound ourselves.
277 ticks = msecs_to_jiffies((arg >> 16) & 0xffff);
278 count = ticks ? (arg & 0xffff) : 0;
280 count = PIT_TICK_RATE / count;
281 kd_mksound(count, ticks);
289 return put_user(KB_101, (char __user *)arg);
292 * These cannot be implemented on any machine that implements
293 * ioperm() in user level (such as Alpha PCs) or not at all.
295 * XXX: you should never use these, just call ioperm directly..
301 * KDADDIO and KDDELIO may be able to add ports beyond what
302 * we reject here, but to be safe...
304 * These are locked internally via sys_ioperm
306 if (arg < GPFIRST || arg > GPLAST)
309 return ksys_ioperm(arg, 1, (cmd == KDADDIO)) ? -ENXIO : 0;
313 return ksys_ioperm(GPFIRST, GPNUM,
314 (cmd == KDENABIO)) ? -ENXIO : 0;
317 /* Linux m68k/i386 interface for setting the keyboard delay/repeat rate */
321 struct kbd_repeat kbrep;
323 if (!capable(CAP_SYS_TTY_CONFIG))
326 if (copy_from_user(&kbrep, up, sizeof(struct kbd_repeat)))
329 ret = kbd_rate(&kbrep);
332 if (copy_to_user(up, &kbrep, sizeof(struct kbd_repeat)))
339 * currently, setting the mode from KD_TEXT to KD_GRAPHICS
340 * doesn't do a whole lot. i'm not sure if it should do any
341 * restoration of modes or what...
343 * XXX It should at least call into the driver, fbdev's definitely
344 * need to restore their engine state. --BenH
359 /* FIXME: this needs the console lock extending */
360 if (vc->vc_mode == (unsigned char) arg)
362 vc->vc_mode = (unsigned char) arg;
363 if (console != fg_console)
366 * explicitly blank/unblank the screen if switching modes
370 do_unblank_screen(1);
377 return put_user(vc->vc_mode, (int __user *)arg);
382 * these work like a combination of mmap and KDENABIO.
383 * this could be easily finished.
390 ret = vt_do_kdskbmode(console, arg);
393 tty_ldisc_flush(tty);
397 return put_user(vt_do_kdgkbmode(console), (int __user *)arg);
399 /* this could be folded into KDSKBMODE, but for compatibility
400 reasons it is not so easy to fold KDGKBMETA into KDGKBMODE */
402 return vt_do_kdskbmeta(console, arg);
405 /* FIXME: should review whether this is worth locking */
406 return put_user(vt_do_kdgkbmeta(console), (int __user *)arg);
410 if(!capable(CAP_SYS_TTY_CONFIG))
412 return vt_do_kbkeycode_ioctl(cmd, up, perm);
416 return vt_do_kdsk_ioctl(cmd, up, perm, console);
420 return vt_do_kdgkb_ioctl(cmd, up, perm);
422 /* Diacritical processing. Handled in keyboard.c as it has
423 to operate on the keyboard locks and structures */
428 return vt_do_diacrit(cmd, up, perm);
430 /* the ioctls below read/set the flags usually shown in the leds */
431 /* don't use them - they will go away without warning */
436 return vt_do_kdskled(console, cmd, arg, perm);
439 * A process can indicate its willingness to accept signals
440 * generated by pressing an appropriate key combination.
441 * Thus, one can have a daemon that e.g. spawns a new console
442 * upon a keypress and then changes to it.
443 * See also the kbrequest field of inittab(5).
446 if (!perm || !capable(CAP_KILL))
448 if (!valid_signal(arg) || arg < 1 || arg == SIGKILL)
451 spin_lock_irq(&vt_spawn_con.lock);
452 put_pid(vt_spawn_con.pid);
453 vt_spawn_con.pid = get_pid(task_pid(current));
454 vt_spawn_con.sig = arg;
455 spin_unlock_irq(&vt_spawn_con.lock);
459 struct console_font_op op;
461 if (copy_from_user(&op, up, sizeof(op)))
463 if (!perm && op.op != KD_FONT_OP_GET)
465 ret = con_font_op(vc, &op);
468 if (copy_to_user(up, &op, sizeof(op)))
480 static inline int do_fontx_ioctl(int cmd,
481 struct consolefontdesc __user *user_cfd, int perm,
482 struct console_font_op *op)
484 struct consolefontdesc cfdarg;
487 if (copy_from_user(&cfdarg, user_cfd, sizeof(struct consolefontdesc)))
494 op->op = KD_FONT_OP_SET;
495 op->flags = KD_FONT_FLAG_OLD;
497 op->height = cfdarg.charheight;
498 op->charcount = cfdarg.charcount;
499 op->data = cfdarg.chardata;
500 return con_font_op(vc_cons[fg_console].d, op);
502 op->op = KD_FONT_OP_GET;
503 op->flags = KD_FONT_FLAG_OLD;
505 op->height = cfdarg.charheight;
506 op->charcount = cfdarg.charcount;
507 op->data = cfdarg.chardata;
508 i = con_font_op(vc_cons[fg_console].d, op);
511 cfdarg.charheight = op->height;
512 cfdarg.charcount = op->charcount;
513 if (copy_to_user(user_cfd, &cfdarg, sizeof(struct consolefontdesc)))
521 static inline int do_unimap_ioctl(int cmd, struct unimapdesc __user *user_ud,
522 int perm, struct vc_data *vc)
524 struct unimapdesc tmp;
526 if (copy_from_user(&tmp, user_ud, sizeof tmp))
532 return con_set_unimap(vc, tmp.entry_ct, tmp.entries);
534 if (!perm && fg_console != vc->vc_num)
536 return con_get_unimap(vc, tmp.entry_ct, &(user_ud->entry_ct),
542 /* deallocate a single console, if possible (leave 0) */
543 static int vt_disallocate(unsigned int vc_num)
545 struct vc_data *vc = NULL;
552 vc = vc_deallocate(vc_num);
555 if (vc && vc_num >= MIN_NR_CONSOLES)
556 tty_port_put(&vc->port);
561 /* deallocate all unused consoles, but leave 0 */
562 static void vt_disallocate_all(void)
564 struct vc_data *vc[MAX_NR_CONSOLES];
568 for (i = 1; i < MAX_NR_CONSOLES; i++)
570 vc[i] = vc_deallocate(i);
575 for (i = 1; i < MAX_NR_CONSOLES; i++) {
576 if (vc[i] && i >= MIN_NR_CONSOLES)
577 tty_port_put(&vc[i]->port);
582 * We handle the console-specific ioctl's here. We allow the
583 * capability to modify any console, not just the fg_console.
585 int vt_ioctl(struct tty_struct *tty,
586 unsigned int cmd, unsigned long arg)
588 struct vc_data *vc = tty->driver_data;
589 struct console_font_op op; /* used in multiple places here */
590 void __user *up = (void __user *)arg;
595 * To have permissions to do most of the vt ioctls, we either have
596 * to be the owner of the tty, or have CAP_SYS_TTY_CONFIG.
599 if (current->signal->tty == tty || capable(CAP_SYS_TTY_CONFIG))
602 ret = vt_k_ioctl(tty, cmd, arg, perm);
603 if (ret != -ENOIOCTLCMD)
608 return tioclinux(tty, arg);
615 if (copy_from_user(&tmp, up, sizeof(struct vt_mode)))
617 if (tmp.mode != VT_AUTO && tmp.mode != VT_PROCESS)
622 /* the frsig is ignored, so we set it to 0 */
623 vc->vt_mode.frsig = 0;
625 vc->vt_pid = get_pid(task_pid(current));
626 /* no switch is required -- saw@shade.msu.ru */
638 memcpy(&tmp, &vc->vt_mode, sizeof(struct vt_mode));
641 rc = copy_to_user(up, &tmp, sizeof(struct vt_mode));
648 * Returns global vt state. Note that VT 0 is always open, since
649 * it's an alias for the current VT, and people can't use it here.
650 * We cannot return state for more than 16 VTs, since v_state is short.
654 struct vt_stat __user *vtstat = up;
655 unsigned short state, mask;
657 if (put_user(fg_console + 1, &vtstat->v_active))
660 state = 1; /* /dev/tty0 is always open */
661 console_lock(); /* required by vt_in_use() */
662 for (i = 0, mask = 2; i < MAX_NR_CONSOLES && mask;
667 return 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 i = i < MAX_NR_CONSOLES ? (i+1) : -1;
680 return put_user(i, (int __user *)arg);
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);
704 struct vt_setactivate vsa;
710 if (copy_from_user(&vsa, (struct vt_setactivate __user *)arg,
711 sizeof(struct vt_setactivate)))
713 if (vsa.console == 0 || vsa.console > MAX_NR_CONSOLES)
716 vsa.console = array_index_nospec(vsa.console,
717 MAX_NR_CONSOLES + 1);
720 ret = vc_allocate(vsa.console);
726 /* This is safe providing we don't drop the
727 console sem between vc_allocate and
728 finishing referencing nvc */
729 nvc = vc_cons[vsa.console].d;
730 nvc->vt_mode = vsa.mode;
731 nvc->vt_mode.frsig = 0;
732 put_pid(nvc->vt_pid);
733 nvc->vt_pid = get_pid(task_pid(current));
736 /* Commence switch and lock */
737 /* Review set_console locks */
738 set_console(vsa.console);
743 * wait until the specified VT has been activated
748 if (arg == 0 || arg > MAX_NR_CONSOLES)
750 return vt_waitactive(arg);
753 * If a vt is under process control, the kernel will not switch to it
754 * immediately, but postpone the operation until the process calls this
755 * ioctl, allowing the switch to complete.
757 * According to the X sources this is the behavior:
758 * 0: pending switch-from not OK
759 * 1: pending switch-from OK
760 * 2: completed switch-to OK
767 if (vc->vt_mode.mode != VT_PROCESS) {
772 * Switching-from response
774 if (vc->vt_newvt >= 0) {
777 * Switch disallowed, so forget we were trying
784 * The current vt has been released, so
785 * complete the switch.
788 newvt = vc->vt_newvt;
790 ret = vc_allocate(newvt);
796 * When we actually do the console switch,
797 * make sure we are atomic with respect to
798 * other console switches..
800 complete_change_console(vc_cons[newvt].d);
804 * Switched-to response
807 * If it's just an ACK, ignore it
809 if (arg != VT_ACKACQ) {
818 * Disallocate memory associated to VT (but leave VT1)
821 if (arg > MAX_NR_CONSOLES)
825 vt_disallocate_all();
827 return vt_disallocate(--arg);
832 struct vt_sizes __user *vtsizes = up;
838 if (get_user(ll, &vtsizes->v_rows) ||
839 get_user(cc, &vtsizes->v_cols))
843 for (i = 0; i < MAX_NR_CONSOLES; i++) {
847 vc->vc_resize_user = 1;
848 /* FIXME: review v tty lock */
849 vc_resize(vc_cons[i].d, cc, ll);
861 if (copy_from_user(&v, up, sizeof(struct vt_consize)))
863 /* FIXME: Should check the copies properly */
865 v.v_vlin = vc->vc_scan_lines;
867 int rows = v.v_vlin/v.v_clin;
868 if (v.v_rows != rows) {
869 if (v.v_rows) /* Parameters don't add up */
874 if (v.v_vcol && v.v_ccol) {
875 int cols = v.v_vcol/v.v_ccol;
876 if (v.v_cols != cols) {
886 for (i = 0; i < MAX_NR_CONSOLES; i++) {
895 vcp->vc_scan_lines = v.v_vlin;
897 vcp->vc_font.height = v.v_clin;
898 vcp->vc_resize_user = 1;
899 vc_resize(vcp, v.v_cols, v.v_rows);
909 op.op = KD_FONT_OP_SET;
910 op.flags = KD_FONT_FLAG_OLD | KD_FONT_FLAG_DONT_RECALC; /* Compatibility */
915 return con_font_op(vc_cons[fg_console].d, &op);
918 op.op = KD_FONT_OP_GET;
919 op.flags = KD_FONT_FLAG_OLD;
924 return con_font_op(vc_cons[fg_console].d, &op);
929 return con_set_cmap(up);
932 return con_get_cmap(up);
936 return do_fontx_ioctl(cmd, up, perm, &op);
942 #ifdef BROKEN_GRAPHICS_PROGRAMS
943 /* With BROKEN_GRAPHICS_PROGRAMS defined, the default
944 font is not saved. */
947 op.op = KD_FONT_OP_SET_DEFAULT;
949 ret = con_font_op(vc_cons[fg_console].d, &op);
953 con_set_default_unimap(vc_cons[fg_console].d);
961 return con_set_trans_old(up);
964 return con_get_trans_old(up);
969 return con_set_trans_new(up);
972 return con_get_trans_new(up);
977 con_clear_unimap(vc);
982 return do_unimap_ioctl(cmd, up, perm, vc);
985 if (!capable(CAP_SYS_TTY_CONFIG))
987 vt_dont_switch = true;
989 case VT_UNLOCKSWITCH:
990 if (!capable(CAP_SYS_TTY_CONFIG))
992 vt_dont_switch = false;
994 case VT_GETHIFONTMASK:
995 return put_user(vc->vc_hi_font_mask,
996 (unsigned short __user *)arg);
998 return vt_event_wait_ioctl((struct vt_event __user *)arg);
1000 return -ENOIOCTLCMD;
1006 void reset_vc(struct vc_data *vc)
1008 vc->vc_mode = KD_TEXT;
1009 vt_reset_unicode(vc->vc_num);
1010 vc->vt_mode.mode = VT_AUTO;
1011 vc->vt_mode.waitv = 0;
1012 vc->vt_mode.relsig = 0;
1013 vc->vt_mode.acqsig = 0;
1014 vc->vt_mode.frsig = 0;
1015 put_pid(vc->vt_pid);
1018 if (!in_interrupt()) /* Via keyboard.c:SAK() - akpm */
1022 void vc_SAK(struct work_struct *work)
1025 container_of(work, struct vc, SAK_work);
1027 struct tty_struct *tty;
1032 /* FIXME: review tty ref counting */
1035 * SAK should also work in all raw modes and reset
1045 #ifdef CONFIG_COMPAT
1047 struct compat_consolefontdesc {
1048 unsigned short charcount; /* characters in font (256 or 512) */
1049 unsigned short charheight; /* scan lines per character (1-32) */
1050 compat_caddr_t chardata; /* font data in expanded form */
1054 compat_fontx_ioctl(int cmd, struct compat_consolefontdesc __user *user_cfd,
1055 int perm, struct console_font_op *op)
1057 struct compat_consolefontdesc cfdarg;
1060 if (copy_from_user(&cfdarg, user_cfd, sizeof(struct compat_consolefontdesc)))
1067 op->op = KD_FONT_OP_SET;
1068 op->flags = KD_FONT_FLAG_OLD;
1070 op->height = cfdarg.charheight;
1071 op->charcount = cfdarg.charcount;
1072 op->data = compat_ptr(cfdarg.chardata);
1073 return con_font_op(vc_cons[fg_console].d, op);
1075 op->op = KD_FONT_OP_GET;
1076 op->flags = KD_FONT_FLAG_OLD;
1078 op->height = cfdarg.charheight;
1079 op->charcount = cfdarg.charcount;
1080 op->data = compat_ptr(cfdarg.chardata);
1081 i = con_font_op(vc_cons[fg_console].d, op);
1084 cfdarg.charheight = op->height;
1085 cfdarg.charcount = op->charcount;
1086 if (copy_to_user(user_cfd, &cfdarg, sizeof(struct compat_consolefontdesc)))
1093 struct compat_console_font_op {
1094 compat_uint_t op; /* operation code KD_FONT_OP_* */
1095 compat_uint_t flags; /* KD_FONT_FLAG_* */
1096 compat_uint_t width, height; /* font size */
1097 compat_uint_t charcount;
1098 compat_caddr_t data; /* font data with height fixed to 32 */
1102 compat_kdfontop_ioctl(struct compat_console_font_op __user *fontop,
1103 int perm, struct console_font_op *op, struct vc_data *vc)
1107 if (copy_from_user(op, fontop, sizeof(struct compat_console_font_op)))
1109 if (!perm && op->op != KD_FONT_OP_GET)
1111 op->data = compat_ptr(((struct compat_console_font_op *)op)->data);
1112 i = con_font_op(vc, op);
1115 ((struct compat_console_font_op *)op)->data = (unsigned long)op->data;
1116 if (copy_to_user(fontop, op, sizeof(struct compat_console_font_op)))
1121 struct compat_unimapdesc {
1122 unsigned short entry_ct;
1123 compat_caddr_t entries;
1127 compat_unimap_ioctl(unsigned int cmd, struct compat_unimapdesc __user *user_ud,
1128 int perm, struct vc_data *vc)
1130 struct compat_unimapdesc tmp;
1131 struct unipair __user *tmp_entries;
1133 if (copy_from_user(&tmp, user_ud, sizeof tmp))
1135 tmp_entries = compat_ptr(tmp.entries);
1140 return con_set_unimap(vc, tmp.entry_ct, tmp_entries);
1142 if (!perm && fg_console != vc->vc_num)
1144 return con_get_unimap(vc, tmp.entry_ct, &(user_ud->entry_ct), tmp_entries);
1149 long vt_compat_ioctl(struct tty_struct *tty,
1150 unsigned int cmd, unsigned long arg)
1152 struct vc_data *vc = tty->driver_data;
1153 struct console_font_op op; /* used in multiple places here */
1154 void __user *up = compat_ptr(arg);
1158 * To have permissions to do most of the vt ioctls, we either have
1159 * to be the owner of the tty, or have CAP_SYS_TTY_CONFIG.
1162 if (current->signal->tty == tty || capable(CAP_SYS_TTY_CONFIG))
1167 * these need special handlers for incompatible data structures
1171 return compat_fontx_ioctl(cmd, up, perm, &op);
1174 return compat_kdfontop_ioctl(up, perm, &op, vc);
1178 return compat_unimap_ioctl(cmd, up, perm, vc);
1181 * all these treat 'arg' as an integer
1200 case VT_DISALLOCATE:
1203 return vt_ioctl(tty, cmd, arg);
1206 * the rest has a compatible data structure behind arg,
1207 * but we have to convert it to a proper 64 bit pointer.
1210 return vt_ioctl(tty, cmd, (unsigned long)up);
1215 #endif /* CONFIG_COMPAT */
1219 * Performs the back end of a vt switch. Called under the console
1222 static void complete_change_console(struct vc_data *vc)
1224 unsigned char old_vc_mode;
1225 int old = fg_console;
1227 last_console = fg_console;
1230 * If we're switching, we could be going from KD_GRAPHICS to
1231 * KD_TEXT mode or vice versa, which means we need to blank or
1232 * unblank the screen later.
1234 old_vc_mode = vc_cons[fg_console].d->vc_mode;
1238 * This can't appear below a successful kill_pid(). If it did,
1239 * then the *blank_screen operation could occur while X, having
1240 * received acqsig, is waking up on another processor. This
1241 * condition can lead to overlapping accesses to the VGA range
1242 * and the framebuffer (causing system lockups).
1244 * To account for this we duplicate this code below only if the
1245 * controlling process is gone and we've called reset_vc.
1247 if (old_vc_mode != vc->vc_mode) {
1248 if (vc->vc_mode == KD_TEXT)
1249 do_unblank_screen(1);
1255 * If this new console is under process control, send it a signal
1256 * telling it that it has acquired. Also check if it has died and
1257 * clean up (similar to logic employed in change_console())
1259 if (vc->vt_mode.mode == VT_PROCESS) {
1261 * Send the signal as privileged - kill_pid() will
1262 * tell us if the process has gone or something else
1265 if (kill_pid(vc->vt_pid, vc->vt_mode.acqsig, 1) != 0) {
1267 * The controlling process has died, so we revert back to
1268 * normal operation. In this case, we'll also change back
1269 * to KD_TEXT mode. I'm not sure if this is strictly correct
1270 * but it saves the agony when the X server dies and the screen
1271 * remains blanked due to KD_GRAPHICS! It would be nice to do
1272 * this outside of VT_PROCESS but there is no single process
1273 * to account for and tracking tty count may be undesirable.
1277 if (old_vc_mode != vc->vc_mode) {
1278 if (vc->vc_mode == KD_TEXT)
1279 do_unblank_screen(1);
1287 * Wake anyone waiting for their VT to activate
1289 vt_event_post(VT_EVENT_SWITCH, old, vc->vc_num);
1294 * Performs the front-end of a vt switch
1296 void change_console(struct vc_data *new_vc)
1300 if (!new_vc || new_vc->vc_num == fg_console || vt_dont_switch)
1304 * If this vt is in process mode, then we need to handshake with
1305 * that process before switching. Essentially, we store where that
1306 * vt wants to switch to and wait for it to tell us when it's done
1307 * (via VT_RELDISP ioctl).
1309 * We also check to see if the controlling process still exists.
1310 * If it doesn't, we reset this vt to auto mode and continue.
1311 * This is a cheap way to track process control. The worst thing
1312 * that can happen is: we send a signal to a process, it dies, and
1313 * the switch gets "lost" waiting for a response; hopefully, the
1314 * user will try again, we'll detect the process is gone (unless
1315 * the user waits just the right amount of time :-) and revert the
1316 * vt to auto control.
1318 vc = vc_cons[fg_console].d;
1319 if (vc->vt_mode.mode == VT_PROCESS) {
1321 * Send the signal as privileged - kill_pid() will
1322 * tell us if the process has gone or something else
1325 * We need to set vt_newvt *before* sending the signal or we
1328 vc->vt_newvt = new_vc->vc_num;
1329 if (kill_pid(vc->vt_pid, vc->vt_mode.relsig, 1) == 0) {
1331 * It worked. Mark the vt to switch to and
1332 * return. The process needs to send us a
1333 * VT_RELDISP ioctl to complete the switch.
1339 * The controlling process has died, so we revert back to
1340 * normal operation. In this case, we'll also change back
1341 * to KD_TEXT mode. I'm not sure if this is strictly correct
1342 * but it saves the agony when the X server dies and the screen
1343 * remains blanked due to KD_GRAPHICS! It would be nice to do
1344 * this outside of VT_PROCESS but there is no single process
1345 * to account for and tracking tty count may be undesirable.
1350 * Fall through to normal (VT_AUTO) handling of the switch...
1355 * Ignore all switches in KD_GRAPHICS+VT_AUTO mode
1357 if (vc->vc_mode == KD_GRAPHICS)
1360 complete_change_console(new_vc);
1363 /* Perform a kernel triggered VT switch for suspend/resume */
1365 static int disable_vt_switch;
1367 int vt_move_to_console(unsigned int vt, int alloc)
1372 /* Graphics mode - up to X */
1373 if (disable_vt_switch) {
1379 if (alloc && vc_allocate(vt)) {
1380 /* we can't have a free VC for now. Too bad,
1381 * we don't want to mess the screen for now. */
1386 if (set_console(vt)) {
1388 * We're unable to switch to the SUSPEND_CONSOLE.
1389 * Let the calling function know so it can decide
1396 if (vt_waitactive(vt + 1)) {
1397 pr_debug("Suspend: Can't switch VCs.");
1404 * Normally during a suspend, we allocate a new console and switch to it.
1405 * When we resume, we switch back to the original console. This switch
1406 * can be slow, so on systems where the framebuffer can handle restoration
1407 * of video registers anyways, there's little point in doing the console
1408 * switch. This function allows you to disable it by passing it '0'.
1410 void pm_set_vt_switch(int do_switch)
1413 disable_vt_switch = !do_switch;
1416 EXPORT_SYMBOL(pm_set_vt_switch);