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)
245 * currently, setting the mode from KD_TEXT to KD_GRAPHICS doesn't do a whole
246 * lot. i'm not sure if it should do any restoration of modes or what...
248 * XXX It should at least call into the driver, fbdev's definitely need to
249 * restore their engine state. --BenH
251 static int vt_kdsetmode(struct vc_data *vc, unsigned long mode)
266 /* FIXME: this needs the console lock extending */
267 if (vc->vc_mode == mode)
271 if (vc->vc_num != fg_console)
274 /* explicitly blank/unblank the screen if switching modes */
277 do_unblank_screen(1);
285 static int vt_k_ioctl(struct tty_struct *tty, unsigned int cmd,
286 unsigned long arg, bool perm)
288 struct vc_data *vc = tty->driver_data;
289 void __user *up = (void __user *)arg;
290 unsigned int console = vc->vc_num;
298 * The use of PIT_TICK_RATE is historic, it used to be
299 * the platform-dependent CLOCK_TICK_RATE between 2.6.12
300 * and 2.6.36, which was a minor but unfortunate ABI
301 * change. kd_mksound is locked by the input layer.
304 arg = PIT_TICK_RATE / arg;
312 unsigned int ticks, count;
315 * Generate the tone for the appropriate number of ticks.
316 * If the time is zero, turn off sound ourselves.
318 ticks = msecs_to_jiffies((arg >> 16) & 0xffff);
319 count = ticks ? (arg & 0xffff) : 0;
321 count = PIT_TICK_RATE / count;
322 kd_mksound(count, ticks);
330 return put_user(KB_101, (char __user *)arg);
333 * These cannot be implemented on any machine that implements
334 * ioperm() in user level (such as Alpha PCs) or not at all.
336 * XXX: you should never use these, just call ioperm directly..
342 * KDADDIO and KDDELIO may be able to add ports beyond what
343 * we reject here, but to be safe...
345 * These are locked internally via sys_ioperm
347 if (arg < GPFIRST || arg > GPLAST)
350 return ksys_ioperm(arg, 1, (cmd == KDADDIO)) ? -ENXIO : 0;
354 return ksys_ioperm(GPFIRST, GPNUM,
355 (cmd == KDENABIO)) ? -ENXIO : 0;
358 /* Linux m68k/i386 interface for setting the keyboard delay/repeat rate */
362 struct kbd_repeat kbrep;
364 if (!capable(CAP_SYS_TTY_CONFIG))
367 if (copy_from_user(&kbrep, up, sizeof(struct kbd_repeat)))
370 ret = kbd_rate(&kbrep);
373 if (copy_to_user(up, &kbrep, sizeof(struct kbd_repeat)))
382 return vt_kdsetmode(vc, arg);
385 return put_user(vc->vc_mode, (int __user *)arg);
390 * these work like a combination of mmap and KDENABIO.
391 * this could be easily finished.
398 ret = vt_do_kdskbmode(console, arg);
401 tty_ldisc_flush(tty);
405 return put_user(vt_do_kdgkbmode(console), (int __user *)arg);
407 /* this could be folded into KDSKBMODE, but for compatibility
408 reasons it is not so easy to fold KDGKBMETA into KDGKBMODE */
410 return vt_do_kdskbmeta(console, arg);
413 /* FIXME: should review whether this is worth locking */
414 return put_user(vt_do_kdgkbmeta(console), (int __user *)arg);
418 if(!capable(CAP_SYS_TTY_CONFIG))
420 return vt_do_kbkeycode_ioctl(cmd, up, perm);
424 return vt_do_kdsk_ioctl(cmd, up, perm, console);
428 return vt_do_kdgkb_ioctl(cmd, up, perm);
430 /* Diacritical processing. Handled in keyboard.c as it has
431 to operate on the keyboard locks and structures */
436 return vt_do_diacrit(cmd, up, perm);
438 /* the ioctls below read/set the flags usually shown in the leds */
439 /* don't use them - they will go away without warning */
444 return vt_do_kdskled(console, cmd, arg, perm);
447 * A process can indicate its willingness to accept signals
448 * generated by pressing an appropriate key combination.
449 * Thus, one can have a daemon that e.g. spawns a new console
450 * upon a keypress and then changes to it.
451 * See also the kbrequest field of inittab(5).
454 if (!perm || !capable(CAP_KILL))
456 if (!valid_signal(arg) || arg < 1 || arg == SIGKILL)
459 spin_lock_irq(&vt_spawn_con.lock);
460 put_pid(vt_spawn_con.pid);
461 vt_spawn_con.pid = get_pid(task_pid(current));
462 vt_spawn_con.sig = arg;
463 spin_unlock_irq(&vt_spawn_con.lock);
467 struct console_font_op op;
469 if (copy_from_user(&op, up, sizeof(op)))
471 if (!perm && op.op != KD_FONT_OP_GET)
473 ret = con_font_op(vc, &op);
476 if (copy_to_user(up, &op, sizeof(op)))
488 static inline int do_fontx_ioctl(int cmd,
489 struct consolefontdesc __user *user_cfd,
490 struct console_font_op *op)
492 struct consolefontdesc cfdarg;
495 if (copy_from_user(&cfdarg, user_cfd, sizeof(struct consolefontdesc)))
500 op->op = KD_FONT_OP_SET;
501 op->flags = KD_FONT_FLAG_OLD;
503 op->height = cfdarg.charheight;
504 op->charcount = cfdarg.charcount;
505 op->data = cfdarg.chardata;
506 return con_font_op(vc_cons[fg_console].d, op);
508 op->op = KD_FONT_OP_GET;
509 op->flags = KD_FONT_FLAG_OLD;
511 op->height = cfdarg.charheight;
512 op->charcount = cfdarg.charcount;
513 op->data = cfdarg.chardata;
514 i = con_font_op(vc_cons[fg_console].d, op);
517 cfdarg.charheight = op->height;
518 cfdarg.charcount = op->charcount;
519 if (copy_to_user(user_cfd, &cfdarg, sizeof(struct consolefontdesc)))
527 static int vt_io_fontreset(struct console_font_op *op)
531 if (__is_defined(BROKEN_GRAPHICS_PROGRAMS)) {
533 * With BROKEN_GRAPHICS_PROGRAMS defined, the default font is
539 op->op = KD_FONT_OP_SET_DEFAULT;
541 ret = con_font_op(vc_cons[fg_console].d, op);
546 con_set_default_unimap(vc_cons[fg_console].d);
552 static inline int do_unimap_ioctl(int cmd, struct unimapdesc __user *user_ud,
555 struct unimapdesc tmp;
557 if (copy_from_user(&tmp, user_ud, sizeof tmp))
561 return con_set_unimap(vc, tmp.entry_ct, tmp.entries);
563 if (fg_console != vc->vc_num)
565 return con_get_unimap(vc, tmp.entry_ct, &(user_ud->entry_ct),
571 static int vt_io_ioctl(struct vc_data *vc, unsigned int cmd, void __user *up,
574 struct console_font_op op; /* used in multiple places here */
580 op.op = KD_FONT_OP_SET;
581 op.flags = KD_FONT_FLAG_OLD | KD_FONT_FLAG_DONT_RECALC; /* Compatibility */
586 return con_font_op(vc_cons[fg_console].d, &op);
589 op.op = KD_FONT_OP_GET;
590 op.flags = KD_FONT_FLAG_OLD;
595 return con_font_op(vc_cons[fg_console].d, &op);
600 return con_set_cmap(up);
603 return con_get_cmap(up);
611 return do_fontx_ioctl(cmd, up, &op);
617 return vt_io_fontreset(&op);
622 return con_set_trans_old(up);
625 return con_get_trans_old(up);
630 return con_set_trans_new(up);
633 return con_get_trans_new(up);
638 con_clear_unimap(vc);
646 return do_unimap_ioctl(cmd, up, vc);
655 static int vt_reldisp(struct vc_data *vc, unsigned int swtch)
659 if (vc->vt_mode.mode != VT_PROCESS)
662 /* Switched-to response */
663 if (vc->vt_newvt < 0) {
664 /* If it's just an ACK, ignore it */
665 return swtch == VT_ACKACQ ? 0 : -EINVAL;
668 /* Switching-from response */
670 /* Switch disallowed, so forget we were trying to do it. */
675 /* The current vt has been released, so complete the switch. */
676 newvt = vc->vt_newvt;
678 ret = vc_allocate(newvt);
683 * When we actually do the console switch, make sure we are atomic with
684 * respect to other console switches..
686 complete_change_console(vc_cons[newvt].d);
691 static int vt_setactivate(struct vt_setactivate __user *sa)
693 struct vt_setactivate vsa;
697 if (copy_from_user(&vsa, sa, sizeof(vsa)))
699 if (vsa.console == 0 || vsa.console > MAX_NR_CONSOLES)
702 vsa.console = array_index_nospec(vsa.console, MAX_NR_CONSOLES + 1);
705 ret = vc_allocate(vsa.console);
712 * This is safe providing we don't drop the console sem between
713 * vc_allocate and finishing referencing nvc.
715 nvc = vc_cons[vsa.console].d;
716 nvc->vt_mode = vsa.mode;
717 nvc->vt_mode.frsig = 0;
718 put_pid(nvc->vt_pid);
719 nvc->vt_pid = get_pid(task_pid(current));
722 /* Commence switch and lock */
723 /* Review set_console locks */
724 set_console(vsa.console);
729 /* deallocate a single console, if possible (leave 0) */
730 static int vt_disallocate(unsigned int vc_num)
732 struct vc_data *vc = NULL;
739 vc = vc_deallocate(vc_num);
742 if (vc && vc_num >= MIN_NR_CONSOLES)
743 tty_port_put(&vc->port);
748 /* deallocate all unused consoles, but leave 0 */
749 static void vt_disallocate_all(void)
751 struct vc_data *vc[MAX_NR_CONSOLES];
755 for (i = 1; i < MAX_NR_CONSOLES; i++)
757 vc[i] = vc_deallocate(i);
762 for (i = 1; i < MAX_NR_CONSOLES; i++) {
763 if (vc[i] && i >= MIN_NR_CONSOLES)
764 tty_port_put(&vc[i]->port);
768 static int vt_resizex(struct vc_data *vc, struct vt_consize __user *cs)
773 if (copy_from_user(&v, cs, sizeof(struct vt_consize)))
776 /* FIXME: Should check the copies properly */
778 v.v_vlin = vc->vc_scan_lines;
781 int rows = v.v_vlin / v.v_clin;
782 if (v.v_rows != rows) {
783 if (v.v_rows) /* Parameters don't add up */
789 if (v.v_vcol && v.v_ccol) {
790 int cols = v.v_vcol / v.v_ccol;
791 if (v.v_cols != cols) {
801 for (i = 0; i < MAX_NR_CONSOLES; i++) {
810 int save_scan_lines = vcp->vc_scan_lines;
811 int save_font_height = vcp->vc_font.height;
814 vcp->vc_scan_lines = v.v_vlin;
816 vcp->vc_font.height = v.v_clin;
817 vcp->vc_resize_user = 1;
818 ret = vc_resize(vcp, v.v_cols, v.v_rows);
820 vcp->vc_scan_lines = save_scan_lines;
821 vcp->vc_font.height = save_font_height;
833 * We handle the console-specific ioctl's here. We allow the
834 * capability to modify any console, not just the fg_console.
836 int vt_ioctl(struct tty_struct *tty,
837 unsigned int cmd, unsigned long arg)
839 struct vc_data *vc = tty->driver_data;
840 void __user *up = (void __user *)arg;
845 * To have permissions to do most of the vt ioctls, we either have
846 * to be the owner of the tty, or have CAP_SYS_TTY_CONFIG.
849 if (current->signal->tty == tty || capable(CAP_SYS_TTY_CONFIG))
852 ret = vt_k_ioctl(tty, cmd, arg, perm);
853 if (ret != -ENOIOCTLCMD)
856 ret = vt_io_ioctl(vc, cmd, up, perm);
857 if (ret != -ENOIOCTLCMD)
862 return tioclinux(tty, arg);
869 if (copy_from_user(&tmp, up, sizeof(struct vt_mode)))
871 if (tmp.mode != VT_AUTO && tmp.mode != VT_PROCESS)
876 /* the frsig is ignored, so we set it to 0 */
877 vc->vt_mode.frsig = 0;
879 vc->vt_pid = get_pid(task_pid(current));
880 /* no switch is required -- saw@shade.msu.ru */
892 memcpy(&tmp, &vc->vt_mode, sizeof(struct vt_mode));
895 rc = copy_to_user(up, &tmp, sizeof(struct vt_mode));
902 * Returns global vt state. Note that VT 0 is always open, since
903 * it's an alias for the current VT, and people can't use it here.
904 * We cannot return state for more than 16 VTs, since v_state is short.
908 struct vt_stat __user *vtstat = up;
909 unsigned short state, mask;
911 if (put_user(fg_console + 1, &vtstat->v_active))
914 state = 1; /* /dev/tty0 is always open */
915 console_lock(); /* required by vt_in_use() */
916 for (i = 0, mask = 2; i < MAX_NR_CONSOLES && mask;
921 return put_user(state, &vtstat->v_state);
925 * Returns the first available (non-opened) console.
928 console_lock(); /* required by vt_in_use() */
929 for (i = 0; i < MAX_NR_CONSOLES; ++i)
933 i = i < MAX_NR_CONSOLES ? (i+1) : -1;
934 return put_user(i, (int __user *)arg);
937 * ioctl(fd, VT_ACTIVATE, num) will cause us to switch to vt # num,
938 * with num >= 1 (switches to vt 0, our console, are not allowed, just
939 * to preserve sanity).
944 if (arg == 0 || arg > MAX_NR_CONSOLES)
949 ret = vc_allocate(arg);
960 return vt_setactivate(up);
963 * wait until the specified VT has been activated
968 if (arg == 0 || arg > MAX_NR_CONSOLES)
970 return vt_waitactive(arg);
973 * If a vt is under process control, the kernel will not switch to it
974 * immediately, but postpone the operation until the process calls this
975 * ioctl, allowing the switch to complete.
977 * According to the X sources this is the behavior:
978 * 0: pending switch-from not OK
979 * 1: pending switch-from OK
980 * 2: completed switch-to OK
987 ret = vt_reldisp(vc, arg);
994 * Disallocate memory associated to VT (but leave VT1)
997 if (arg > MAX_NR_CONSOLES)
1001 vt_disallocate_all();
1003 return vt_disallocate(--arg);
1008 struct vt_sizes __user *vtsizes = up;
1014 if (get_user(ll, &vtsizes->v_rows) ||
1015 get_user(cc, &vtsizes->v_cols))
1019 for (i = 0; i < MAX_NR_CONSOLES; i++) {
1023 vc->vc_resize_user = 1;
1024 /* FIXME: review v tty lock */
1025 vc_resize(vc_cons[i].d, cc, ll);
1036 return vt_resizex(vc, up);
1039 if (!capable(CAP_SYS_TTY_CONFIG))
1041 vt_dont_switch = true;
1043 case VT_UNLOCKSWITCH:
1044 if (!capable(CAP_SYS_TTY_CONFIG))
1046 vt_dont_switch = false;
1048 case VT_GETHIFONTMASK:
1049 return put_user(vc->vc_hi_font_mask,
1050 (unsigned short __user *)arg);
1052 return vt_event_wait_ioctl((struct vt_event __user *)arg);
1054 return -ENOIOCTLCMD;
1060 void reset_vc(struct vc_data *vc)
1062 vc->vc_mode = KD_TEXT;
1063 vt_reset_unicode(vc->vc_num);
1064 vc->vt_mode.mode = VT_AUTO;
1065 vc->vt_mode.waitv = 0;
1066 vc->vt_mode.relsig = 0;
1067 vc->vt_mode.acqsig = 0;
1068 vc->vt_mode.frsig = 0;
1069 put_pid(vc->vt_pid);
1072 if (!in_interrupt()) /* Via keyboard.c:SAK() - akpm */
1076 void vc_SAK(struct work_struct *work)
1079 container_of(work, struct vc, SAK_work);
1081 struct tty_struct *tty;
1086 /* FIXME: review tty ref counting */
1089 * SAK should also work in all raw modes and reset
1099 #ifdef CONFIG_COMPAT
1101 struct compat_consolefontdesc {
1102 unsigned short charcount; /* characters in font (256 or 512) */
1103 unsigned short charheight; /* scan lines per character (1-32) */
1104 compat_caddr_t chardata; /* font data in expanded form */
1108 compat_fontx_ioctl(int cmd, struct compat_consolefontdesc __user *user_cfd,
1109 int perm, struct console_font_op *op)
1111 struct compat_consolefontdesc cfdarg;
1114 if (copy_from_user(&cfdarg, user_cfd, sizeof(struct compat_consolefontdesc)))
1121 op->op = KD_FONT_OP_SET;
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 return con_font_op(vc_cons[fg_console].d, op);
1129 op->op = KD_FONT_OP_GET;
1130 op->flags = KD_FONT_FLAG_OLD;
1132 op->height = cfdarg.charheight;
1133 op->charcount = cfdarg.charcount;
1134 op->data = compat_ptr(cfdarg.chardata);
1135 i = con_font_op(vc_cons[fg_console].d, op);
1138 cfdarg.charheight = op->height;
1139 cfdarg.charcount = op->charcount;
1140 if (copy_to_user(user_cfd, &cfdarg, sizeof(struct compat_consolefontdesc)))
1147 struct compat_console_font_op {
1148 compat_uint_t op; /* operation code KD_FONT_OP_* */
1149 compat_uint_t flags; /* KD_FONT_FLAG_* */
1150 compat_uint_t width, height; /* font size */
1151 compat_uint_t charcount;
1152 compat_caddr_t data; /* font data with height fixed to 32 */
1156 compat_kdfontop_ioctl(struct compat_console_font_op __user *fontop,
1157 int perm, struct console_font_op *op, struct vc_data *vc)
1161 if (copy_from_user(op, fontop, sizeof(struct compat_console_font_op)))
1163 if (!perm && op->op != KD_FONT_OP_GET)
1165 op->data = compat_ptr(((struct compat_console_font_op *)op)->data);
1166 i = con_font_op(vc, op);
1169 ((struct compat_console_font_op *)op)->data = (unsigned long)op->data;
1170 if (copy_to_user(fontop, op, sizeof(struct compat_console_font_op)))
1175 struct compat_unimapdesc {
1176 unsigned short entry_ct;
1177 compat_caddr_t entries;
1181 compat_unimap_ioctl(unsigned int cmd, struct compat_unimapdesc __user *user_ud,
1182 int perm, struct vc_data *vc)
1184 struct compat_unimapdesc tmp;
1185 struct unipair __user *tmp_entries;
1187 if (copy_from_user(&tmp, user_ud, sizeof tmp))
1189 tmp_entries = compat_ptr(tmp.entries);
1194 return con_set_unimap(vc, tmp.entry_ct, tmp_entries);
1196 if (!perm && fg_console != vc->vc_num)
1198 return con_get_unimap(vc, tmp.entry_ct, &(user_ud->entry_ct), tmp_entries);
1203 long vt_compat_ioctl(struct tty_struct *tty,
1204 unsigned int cmd, unsigned long arg)
1206 struct vc_data *vc = tty->driver_data;
1207 struct console_font_op op; /* used in multiple places here */
1208 void __user *up = compat_ptr(arg);
1212 * To have permissions to do most of the vt ioctls, we either have
1213 * to be the owner of the tty, or have CAP_SYS_TTY_CONFIG.
1216 if (current->signal->tty == tty || capable(CAP_SYS_TTY_CONFIG))
1221 * these need special handlers for incompatible data structures
1225 return compat_fontx_ioctl(cmd, up, perm, &op);
1228 return compat_kdfontop_ioctl(up, perm, &op, vc);
1232 return compat_unimap_ioctl(cmd, up, perm, vc);
1235 * all these treat 'arg' as an integer
1254 case VT_DISALLOCATE:
1257 return vt_ioctl(tty, cmd, arg);
1260 * the rest has a compatible data structure behind arg,
1261 * but we have to convert it to a proper 64 bit pointer.
1264 return vt_ioctl(tty, cmd, (unsigned long)up);
1269 #endif /* CONFIG_COMPAT */
1273 * Performs the back end of a vt switch. Called under the console
1276 static void complete_change_console(struct vc_data *vc)
1278 unsigned char old_vc_mode;
1279 int old = fg_console;
1281 last_console = fg_console;
1284 * If we're switching, we could be going from KD_GRAPHICS to
1285 * KD_TEXT mode or vice versa, which means we need to blank or
1286 * unblank the screen later.
1288 old_vc_mode = vc_cons[fg_console].d->vc_mode;
1292 * This can't appear below a successful kill_pid(). If it did,
1293 * then the *blank_screen operation could occur while X, having
1294 * received acqsig, is waking up on another processor. This
1295 * condition can lead to overlapping accesses to the VGA range
1296 * and the framebuffer (causing system lockups).
1298 * To account for this we duplicate this code below only if the
1299 * controlling process is gone and we've called reset_vc.
1301 if (old_vc_mode != vc->vc_mode) {
1302 if (vc->vc_mode == KD_TEXT)
1303 do_unblank_screen(1);
1309 * If this new console is under process control, send it a signal
1310 * telling it that it has acquired. Also check if it has died and
1311 * clean up (similar to logic employed in change_console())
1313 if (vc->vt_mode.mode == VT_PROCESS) {
1315 * Send the signal as privileged - kill_pid() will
1316 * tell us if the process has gone or something else
1319 if (kill_pid(vc->vt_pid, vc->vt_mode.acqsig, 1) != 0) {
1321 * The controlling process has died, so we revert back to
1322 * normal operation. In this case, we'll also change back
1323 * to KD_TEXT mode. I'm not sure if this is strictly correct
1324 * but it saves the agony when the X server dies and the screen
1325 * remains blanked due to KD_GRAPHICS! It would be nice to do
1326 * this outside of VT_PROCESS but there is no single process
1327 * to account for and tracking tty count may be undesirable.
1331 if (old_vc_mode != vc->vc_mode) {
1332 if (vc->vc_mode == KD_TEXT)
1333 do_unblank_screen(1);
1341 * Wake anyone waiting for their VT to activate
1343 vt_event_post(VT_EVENT_SWITCH, old, vc->vc_num);
1348 * Performs the front-end of a vt switch
1350 void change_console(struct vc_data *new_vc)
1354 if (!new_vc || new_vc->vc_num == fg_console || vt_dont_switch)
1358 * If this vt is in process mode, then we need to handshake with
1359 * that process before switching. Essentially, we store where that
1360 * vt wants to switch to and wait for it to tell us when it's done
1361 * (via VT_RELDISP ioctl).
1363 * We also check to see if the controlling process still exists.
1364 * If it doesn't, we reset this vt to auto mode and continue.
1365 * This is a cheap way to track process control. The worst thing
1366 * that can happen is: we send a signal to a process, it dies, and
1367 * the switch gets "lost" waiting for a response; hopefully, the
1368 * user will try again, we'll detect the process is gone (unless
1369 * the user waits just the right amount of time :-) and revert the
1370 * vt to auto control.
1372 vc = vc_cons[fg_console].d;
1373 if (vc->vt_mode.mode == VT_PROCESS) {
1375 * Send the signal as privileged - kill_pid() will
1376 * tell us if the process has gone or something else
1379 * We need to set vt_newvt *before* sending the signal or we
1382 vc->vt_newvt = new_vc->vc_num;
1383 if (kill_pid(vc->vt_pid, vc->vt_mode.relsig, 1) == 0) {
1385 * It worked. Mark the vt to switch to and
1386 * return. The process needs to send us a
1387 * VT_RELDISP ioctl to complete the switch.
1393 * The controlling process has died, so we revert back to
1394 * normal operation. In this case, we'll also change back
1395 * to KD_TEXT mode. I'm not sure if this is strictly correct
1396 * but it saves the agony when the X server dies and the screen
1397 * remains blanked due to KD_GRAPHICS! It would be nice to do
1398 * this outside of VT_PROCESS but there is no single process
1399 * to account for and tracking tty count may be undesirable.
1404 * Fall through to normal (VT_AUTO) handling of the switch...
1409 * Ignore all switches in KD_GRAPHICS+VT_AUTO mode
1411 if (vc->vc_mode == KD_GRAPHICS)
1414 complete_change_console(new_vc);
1417 /* Perform a kernel triggered VT switch for suspend/resume */
1419 static int disable_vt_switch;
1421 int vt_move_to_console(unsigned int vt, int alloc)
1426 /* Graphics mode - up to X */
1427 if (disable_vt_switch) {
1433 if (alloc && vc_allocate(vt)) {
1434 /* we can't have a free VC for now. Too bad,
1435 * we don't want to mess the screen for now. */
1440 if (set_console(vt)) {
1442 * We're unable to switch to the SUSPEND_CONSOLE.
1443 * Let the calling function know so it can decide
1450 if (vt_waitactive(vt + 1)) {
1451 pr_debug("Suspend: Can't switch VCs.");
1458 * Normally during a suspend, we allocate a new console and switch to it.
1459 * When we resume, we switch back to the original console. This switch
1460 * can be slow, so on systems where the framebuffer can handle restoration
1461 * of video registers anyways, there's little point in doing the console
1462 * switch. This function allows you to disable it by passing it '0'.
1464 void pm_set_vt_switch(int do_switch)
1467 disable_vt_switch = !do_switch;
1470 EXPORT_SYMBOL(pm_set_vt_switch);