2 * linux/drivers/char/vt_ioctl.c
4 * Copyright (C) 1992 obz under the linux copyright
6 * Dynamic diacritical handling - aeb@cwi.nl - Dec 1993
7 * Dynamic keymap and string allocation - aeb@cwi.nl - May 1994
8 * Restrict VT switching via ioctl() - grif@cs.ucr.edu - Dec 1995
9 * Some code moved for less code duplication - Andi Kleen - Mar 1997
10 * Check put/get_user, cleanups - acme@conectiva.com.br - Jun 2001
13 #include <linux/config.h>
14 #include <linux/types.h>
15 #include <linux/errno.h>
16 #include <linux/sched.h>
17 #include <linux/tty.h>
18 #include <linux/timer.h>
19 #include <linux/kernel.h>
22 #include <linux/string.h>
23 #include <linux/slab.h>
24 #include <linux/major.h>
26 #include <linux/console.h>
29 #include <asm/uaccess.h>
31 #include <linux/kbd_kern.h>
32 #include <linux/vt_kern.h>
33 #include <linux/kbd_diacr.h>
34 #include <linux/selection.h>
36 static char vt_dont_switch
;
37 extern struct tty_driver
*console_driver
;
39 #define VT_IS_IN_USE(i) (console_driver->ttys[i] && console_driver->ttys[i]->count)
40 #define VT_BUSY(i) (VT_IS_IN_USE(i) || i == fg_console || vc_cons[i].d == sel_cons)
43 * Console (vt and kd) routines, as defined by USL SVR4 manual, and by
44 * experimentation and study of X386 SYSV handling.
46 * One point of difference: SYSV vt's are /dev/vtX, which X >= 0, and
47 * /dev/console is a separate ttyp. Under Linux, /dev/tty0 is /dev/console,
48 * and the vc start at /dev/ttyX, X >= 1. We maintain that here, so we will
49 * always treat our set of vt as numbered 1..MAX_NR_CONSOLES (corresponding to
50 * ttys 0..MAX_NR_CONSOLES-1). Explicitly naming VT 0 is illegal, but using
51 * /dev/tty0 (fg_console) as a target is legal, since an implicit aliasing
52 * to the current console is done by the main ioctl code.
56 #include <linux/syscalls.h>
59 static void complete_change_console(struct vc_data
*vc
);
62 * these are the valid i/o ports we're allowed to change. they map all the
67 #define GPNUM (GPLAST - GPFIRST + 1)
69 #define i (tmp.kb_index)
70 #define s (tmp.kb_table)
71 #define v (tmp.kb_value)
73 do_kdsk_ioctl(int cmd
, struct kbentry __user
*user_kbe
, int perm
, struct kbd_struct
*kbd
)
76 ushort
*key_map
, val
, ov
;
78 if (copy_from_user(&tmp
, user_kbe
, sizeof(struct kbentry
)))
83 key_map
= key_maps
[s
];
86 if (kbd
->kbdmode
!= VC_UNICODE
&& KTYP(val
) >= NR_TYPES
)
89 val
= (i
? K_HOLE
: K_NOSUCHMAP
);
90 return put_user(val
, &user_kbe
->kb_value
);
94 if (!i
&& v
== K_NOSUCHMAP
) {
96 key_map
= key_maps
[s
];
99 if (key_map
[0] == U(K_ALLOCATED
)) {
107 if (KTYP(v
) < NR_TYPES
) {
108 if (KVAL(v
) > max_vals
[KTYP(v
)])
111 if (kbd
->kbdmode
!= VC_UNICODE
)
114 /* ++Geert: non-PC keyboards may generate keycode zero */
115 #if !defined(__mc68000__) && !defined(__powerpc__)
116 /* assignment to entry 0 only tests validity of args */
121 if (!(key_map
= key_maps
[s
])) {
124 if (keymap_count
>= MAX_NR_OF_USER_KEYMAPS
&&
125 !capable(CAP_SYS_RESOURCE
))
128 key_map
= (ushort
*) kmalloc(sizeof(plain_map
),
132 key_maps
[s
] = key_map
;
133 key_map
[0] = U(K_ALLOCATED
);
134 for (j
= 1; j
< NR_KEYS
; j
++)
135 key_map
[j
] = U(K_HOLE
);
140 break; /* nothing to do */
144 if (((ov
== K_SAK
) || (v
== K_SAK
)) && !capable(CAP_SYS_ADMIN
))
147 if (!s
&& (KTYP(ov
) == KT_SHIFT
|| KTYP(v
) == KT_SHIFT
))
148 compute_shiftstate();
158 do_kbkeycode_ioctl(int cmd
, struct kbkeycode __user
*user_kbkc
, int perm
)
160 struct kbkeycode tmp
;
163 if (copy_from_user(&tmp
, user_kbkc
, sizeof(struct kbkeycode
)))
167 kc
= getkeycode(tmp
.scancode
);
169 kc
= put_user(kc
, &user_kbkc
->keycode
);
174 kc
= setkeycode(tmp
.scancode
, tmp
.keycode
);
181 do_kdgkb_ioctl(int cmd
, struct kbsentry __user
*user_kdgkb
, int perm
)
183 struct kbsentry
*kbs
;
189 char *first_free
, *fj
, *fnw
;
193 kbs
= kmalloc(sizeof(*kbs
), GFP_KERNEL
);
199 /* we mostly copy too much here (512bytes), but who cares ;) */
200 if (copy_from_user(kbs
, user_kdgkb
, sizeof(struct kbsentry
))) {
204 kbs
->kb_string
[sizeof(kbs
->kb_string
)-1] = '\0';
209 sz
= sizeof(kbs
->kb_string
) - 1; /* sz should have been
211 up
= user_kdgkb
->kb_string
;
214 for ( ; *p
&& sz
; p
++, sz
--)
215 if (put_user(*p
, up
++)) {
219 if (put_user('\0', up
)) {
224 return ((p
&& *p
) ? -EOVERFLOW
: 0);
232 first_free
= funcbufptr
+ (funcbufsize
- funcbufleft
);
233 for (j
= i
+1; j
< MAX_NR_FUNC
&& !func_table
[j
]; j
++)
240 delta
= (q
? -strlen(q
) : 1) + strlen(kbs
->kb_string
);
241 if (delta
<= funcbufleft
) { /* it fits in current buf */
242 if (j
< MAX_NR_FUNC
) {
243 memmove(fj
+ delta
, fj
, first_free
- fj
);
244 for (k
= j
; k
< MAX_NR_FUNC
; k
++)
246 func_table
[k
] += delta
;
250 funcbufleft
-= delta
;
251 } else { /* allocate a larger buffer */
253 while (sz
< funcbufsize
- funcbufleft
+ delta
)
255 fnw
= (char *) kmalloc(sz
, GFP_KERNEL
);
264 memmove(fnw
, funcbufptr
, fj
- funcbufptr
);
265 for (k
= 0; k
< j
; k
++)
267 func_table
[k
] = fnw
+ (func_table
[k
] - funcbufptr
);
269 if (first_free
> fj
) {
270 memmove(fnw
+ (fj
- funcbufptr
) + delta
, fj
, first_free
- fj
);
271 for (k
= j
; k
< MAX_NR_FUNC
; k
++)
273 func_table
[k
] = fnw
+ (func_table
[k
] - funcbufptr
) + delta
;
275 if (funcbufptr
!= func_buf
)
278 funcbufleft
= funcbufleft
- delta
+ sz
- funcbufsize
;
281 strcpy(func_table
[i
], kbs
->kb_string
);
291 do_fontx_ioctl(int cmd
, struct consolefontdesc __user
*user_cfd
, int perm
, struct console_font_op
*op
)
293 struct consolefontdesc cfdarg
;
296 if (copy_from_user(&cfdarg
, user_cfd
, sizeof(struct consolefontdesc
)))
303 op
->op
= KD_FONT_OP_SET
;
304 op
->flags
= KD_FONT_FLAG_OLD
;
306 op
->height
= cfdarg
.charheight
;
307 op
->charcount
= cfdarg
.charcount
;
308 op
->data
= cfdarg
.chardata
;
309 return con_font_op(vc_cons
[fg_console
].d
, op
);
311 op
->op
= KD_FONT_OP_GET
;
312 op
->flags
= KD_FONT_FLAG_OLD
;
314 op
->height
= cfdarg
.charheight
;
315 op
->charcount
= cfdarg
.charcount
;
316 op
->data
= cfdarg
.chardata
;
317 i
= con_font_op(vc_cons
[fg_console
].d
, op
);
320 cfdarg
.charheight
= op
->height
;
321 cfdarg
.charcount
= op
->charcount
;
322 if (copy_to_user(user_cfd
, &cfdarg
, sizeof(struct consolefontdesc
)))
331 do_unimap_ioctl(int cmd
, struct unimapdesc __user
*user_ud
, int perm
, struct vc_data
*vc
)
333 struct unimapdesc tmp
;
335 if (copy_from_user(&tmp
, user_ud
, sizeof tmp
))
338 if (!access_ok(VERIFY_WRITE
, tmp
.entries
,
339 tmp
.entry_ct
*sizeof(struct unipair
)))
345 return con_set_unimap(vc
, tmp
.entry_ct
, tmp
.entries
);
347 if (!perm
&& fg_console
!= vc
->vc_num
)
349 return con_get_unimap(vc
, tmp
.entry_ct
, &(user_ud
->entry_ct
), tmp
.entries
);
355 * We handle the console-specific ioctl's here. We allow the
356 * capability to modify any console, not just the fg_console.
358 int vt_ioctl(struct tty_struct
*tty
, struct file
* file
,
359 unsigned int cmd
, unsigned long arg
)
361 struct vc_data
*vc
= (struct vc_data
*)tty
->driver_data
;
362 struct console_font_op op
; /* used in multiple places here */
363 struct kbd_struct
* kbd
;
364 unsigned int console
;
366 void __user
*up
= (void __user
*)arg
;
369 console
= vc
->vc_num
;
371 if (!vc_cons_allocated(console
)) /* impossible? */
375 * To have permissions to do most of the vt ioctls, we either have
376 * to be the owner of the tty, or have CAP_SYS_TTY_CONFIG.
379 if (current
->signal
->tty
== tty
|| capable(CAP_SYS_TTY_CONFIG
))
382 kbd
= kbd_table
+ console
;
396 unsigned int ticks
, count
;
399 * Generate the tone for the appropriate number of ticks.
400 * If the time is zero, turn off sound ourselves.
402 ticks
= HZ
* ((arg
>> 16) & 0xffff) / 1000;
403 count
= ticks
? (arg
& 0xffff) : 0;
405 count
= 1193182 / count
;
406 kd_mksound(count
, ticks
);
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 if (arg
< GPFIRST
|| arg
> GPLAST
)
432 return sys_ioperm(arg
, 1, (cmd
== KDADDIO
)) ? -ENXIO
: 0;
436 return sys_ioperm(GPFIRST
, GPNUM
,
437 (cmd
== KDENABIO
)) ? -ENXIO
: 0;
440 /* Linux m68k/i386 interface for setting the keyboard delay/repeat rate */
444 struct kbd_repeat kbrep
;
447 if (!capable(CAP_SYS_TTY_CONFIG
))
450 if (copy_from_user(&kbrep
, up
, sizeof(struct kbd_repeat
)))
452 err
= 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
482 if (vc
->vc_mode
== (unsigned char) arg
)
484 vc
->vc_mode
= (unsigned char) arg
;
485 if (console
!= fg_console
)
488 * explicitly blank/unblank the screen if switching modes
490 acquire_console_sem();
492 do_unblank_screen(1);
495 release_console_sem();
505 * these work like a combination of mmap and KDENABIO.
506 * this could be easily finished.
515 kbd
->kbdmode
= VC_RAW
;
518 kbd
->kbdmode
= VC_MEDIUMRAW
;
521 kbd
->kbdmode
= VC_XLATE
;
522 compute_shiftstate();
525 kbd
->kbdmode
= VC_UNICODE
;
526 compute_shiftstate();
531 tty_ldisc_flush(tty
);
535 ucval
= ((kbd
->kbdmode
== VC_RAW
) ? K_RAW
:
536 (kbd
->kbdmode
== VC_MEDIUMRAW
) ? K_MEDIUMRAW
:
537 (kbd
->kbdmode
== VC_UNICODE
) ? K_UNICODE
:
541 /* this could be folded into KDSKBMODE, but for compatibility
542 reasons it is not so easy to fold KDGKBMETA into KDGKBMODE */
546 clr_vc_kbd_mode(kbd
, VC_META
);
549 set_vc_kbd_mode(kbd
, VC_META
);
557 ucval
= (vc_kbd_mode(kbd
, VC_META
) ? K_ESCPREFIX
: K_METABIT
);
559 return put_user(ucval
, (int __user
*)arg
);
563 if(!capable(CAP_SYS_TTY_CONFIG
))
565 return do_kbkeycode_ioctl(cmd
, up
, perm
);
569 return do_kdsk_ioctl(cmd
, up
, perm
, kbd
);
573 return do_kdgkb_ioctl(cmd
, up
, perm
);
577 struct kbdiacrs __user
*a
= up
;
579 if (put_user(accent_table_size
, &a
->kb_cnt
))
581 if (copy_to_user(a
->kbdiacr
, accent_table
, accent_table_size
*sizeof(struct kbdiacr
)))
588 struct kbdiacrs __user
*a
= up
;
593 if (get_user(ct
,&a
->kb_cnt
))
597 accent_table_size
= ct
;
598 if (copy_from_user(accent_table
, a
->kbdiacr
, ct
*sizeof(struct kbdiacr
)))
603 /* the ioctls below read/set the flags usually shown in the leds */
604 /* don't use them - they will go away without warning */
606 ucval
= kbd
->ledflagstate
| (kbd
->default_ledflagstate
<< 4);
614 kbd
->ledflagstate
= (arg
& 7);
615 kbd
->default_ledflagstate
= ((arg
>> 4) & 7);
619 /* the ioctls below only set the lights, not the functions */
620 /* for those, see KDGKBLED and KDSKBLED above */
622 ucval
= getledstate();
624 return put_user(ucval
, (char __user
*)arg
);
629 setledstate(kbd
, arg
);
633 * A process can indicate its willingness to accept signals
634 * generated by pressing an appropriate key combination.
635 * Thus, one can have a daemon that e.g. spawns a new console
636 * upon a keypress and then changes to it.
637 * See also the kbrequest field of inittab(5).
641 extern int spawnpid
, spawnsig
;
642 if (!perm
|| !capable(CAP_KILL
))
644 if (arg
< 1 || arg
> _NSIG
|| arg
== SIGKILL
)
646 spawnpid
= current
->pid
;
657 if (copy_from_user(&tmp
, up
, sizeof(struct vt_mode
)))
659 if (tmp
.mode
!= VT_AUTO
&& tmp
.mode
!= VT_PROCESS
)
661 acquire_console_sem();
663 /* the frsig is ignored, so we set it to 0 */
664 vc
->vt_mode
.frsig
= 0;
665 vc
->vt_pid
= current
->pid
;
666 /* no switch is required -- saw@shade.msu.ru */
668 release_console_sem();
677 acquire_console_sem();
678 memcpy(&tmp
, &vc
->vt_mode
, sizeof(struct vt_mode
));
679 release_console_sem();
681 rc
= copy_to_user(up
, &tmp
, sizeof(struct vt_mode
));
682 return rc
? -EFAULT
: 0;
686 * Returns global vt state. Note that VT 0 is always open, since
687 * it's an alias for the current VT, and people can't use it here.
688 * We cannot return state for more than 16 VTs, since v_state is short.
692 struct vt_stat __user
*vtstat
= up
;
693 unsigned short state
, mask
;
695 if (put_user(fg_console
+ 1, &vtstat
->v_active
))
697 state
= 1; /* /dev/tty0 is always open */
698 for (i
= 0, mask
= 2; i
< MAX_NR_CONSOLES
&& mask
; ++i
, mask
<<= 1)
701 return put_user(state
, &vtstat
->v_state
);
705 * Returns the first available (non-opened) console.
708 for (i
= 0; i
< MAX_NR_CONSOLES
; ++i
)
709 if (! VT_IS_IN_USE(i
))
711 ucval
= i
< MAX_NR_CONSOLES
? (i
+1) : -1;
715 * ioctl(fd, VT_ACTIVATE, num) will cause us to switch to vt # num,
716 * with num >= 1 (switches to vt 0, our console, are not allowed, just
717 * to preserve sanity).
722 if (arg
== 0 || arg
> MAX_NR_CONSOLES
)
725 acquire_console_sem();
726 i
= vc_allocate(arg
);
727 release_console_sem();
734 * wait until the specified VT has been activated
739 if (arg
== 0 || arg
> MAX_NR_CONSOLES
)
741 return vt_waitactive(arg
-1);
744 * If a vt is under process control, the kernel will not switch to it
745 * immediately, but postpone the operation until the process calls this
746 * ioctl, allowing the switch to complete.
748 * According to the X sources this is the behavior:
749 * 0: pending switch-from not OK
750 * 1: pending switch-from OK
751 * 2: completed switch-to OK
756 if (vc
->vt_mode
.mode
!= VT_PROCESS
)
760 * Switching-from response
762 if (vc
->vt_newvt
>= 0) {
765 * Switch disallowed, so forget we were trying
772 * The current vt has been released, so
773 * complete the switch.
776 acquire_console_sem();
777 newvt
= vc
->vt_newvt
;
779 i
= vc_allocate(newvt
);
781 release_console_sem();
785 * When we actually do the console switch,
786 * make sure we are atomic with respect to
787 * other console switches..
789 complete_change_console(vc_cons
[newvt
].d
);
790 release_console_sem();
795 * Switched-to response
800 * If it's just an ACK, ignore it
802 if (arg
!= VT_ACKACQ
)
809 * Disallocate memory associated to VT (but leave VT1)
812 if (arg
> MAX_NR_CONSOLES
)
815 /* disallocate all unused consoles, but leave 0 */
816 acquire_console_sem();
817 for (i
=1; i
<MAX_NR_CONSOLES
; i
++)
820 release_console_sem();
822 /* disallocate a single console, if possible */
826 if (arg
) { /* leave 0 */
827 acquire_console_sem();
829 release_console_sem();
836 struct vt_sizes __user
*vtsizes
= up
;
840 if (get_user(ll
, &vtsizes
->v_rows
) ||
841 get_user(cc
, &vtsizes
->v_cols
))
843 for (i
= 0; i
< MAX_NR_CONSOLES
; i
++) {
844 acquire_console_sem();
845 vc_resize(vc_cons
[i
].d
, cc
, ll
);
846 release_console_sem();
853 struct vt_consize __user
*vtconsize
= up
;
854 ushort ll
,cc
,vlin
,clin
,vcol
,ccol
;
857 if (!access_ok(VERIFY_READ
, vtconsize
,
858 sizeof(struct vt_consize
)))
860 __get_user(ll
, &vtconsize
->v_rows
);
861 __get_user(cc
, &vtconsize
->v_cols
);
862 __get_user(vlin
, &vtconsize
->v_vlin
);
863 __get_user(clin
, &vtconsize
->v_clin
);
864 __get_user(vcol
, &vtconsize
->v_vcol
);
865 __get_user(ccol
, &vtconsize
->v_ccol
);
866 vlin
= vlin
? vlin
: vc
->vc_scan_lines
;
870 return -EINVAL
; /* Parameters don't add up */
885 for (i
= 0; i
< MAX_NR_CONSOLES
; i
++) {
888 acquire_console_sem();
890 vc_cons
[i
].d
->vc_scan_lines
= vlin
;
892 vc_cons
[i
].d
->vc_font
.height
= clin
;
893 vc_resize(vc_cons
[i
].d
, cc
, ll
);
894 release_console_sem();
902 op
.op
= KD_FONT_OP_SET
;
903 op
.flags
= KD_FONT_FLAG_OLD
| KD_FONT_FLAG_DONT_RECALC
; /* Compatibility */
908 return con_font_op(vc_cons
[fg_console
].d
, &op
);
912 op
.op
= KD_FONT_OP_GET
;
913 op
.flags
= KD_FONT_FLAG_OLD
;
918 return con_font_op(vc_cons
[fg_console
].d
, &op
);
924 return con_set_cmap(up
);
927 return con_get_cmap(up
);
931 return do_fontx_ioctl(cmd
, up
, perm
, &op
);
938 #ifdef BROKEN_GRAPHICS_PROGRAMS
939 /* With BROKEN_GRAPHICS_PROGRAMS defined, the default
940 font is not saved. */
944 op
.op
= KD_FONT_OP_SET_DEFAULT
;
946 i
= con_font_op(vc_cons
[fg_console
].d
, &op
);
949 con_set_default_unimap(vc_cons
[fg_console
].d
);
956 if (copy_from_user(&op
, up
, sizeof(op
)))
958 if (!perm
&& op
.op
!= KD_FONT_OP_GET
)
960 i
= con_font_op(vc
, &op
);
962 if (copy_to_user(up
, &op
, sizeof(op
)))
970 return con_set_trans_old(up
);
973 return con_get_trans_old(up
);
978 return con_set_trans_new(up
);
981 return con_get_trans_new(up
);
984 { struct unimapinit ui
;
987 i
= copy_from_user(&ui
, up
, sizeof(struct unimapinit
));
988 if (i
) return -EFAULT
;
989 con_clear_unimap(vc
, &ui
);
995 return do_unimap_ioctl(cmd
, up
, perm
, vc
);
998 if (!capable(CAP_SYS_TTY_CONFIG
))
1002 case VT_UNLOCKSWITCH
:
1003 if (!capable(CAP_SYS_TTY_CONFIG
))
1008 return -ENOIOCTLCMD
;
1013 * Sometimes we want to wait until a particular VT has been activated. We
1014 * do it in a very simple manner. Everybody waits on a single queue and
1015 * get woken up at once. Those that are satisfied go on with their business,
1016 * while those not ready go back to sleep. Seems overkill to add a wait
1017 * to each vt just for this - usually this does nothing!
1019 static DECLARE_WAIT_QUEUE_HEAD(vt_activate_queue
);
1022 * Sleeps until a vt is activated, or the task is interrupted. Returns
1023 * 0 if activation, -EINTR if interrupted.
1025 int vt_waitactive(int vt
)
1028 DECLARE_WAITQUEUE(wait
, current
);
1030 add_wait_queue(&vt_activate_queue
, &wait
);
1032 set_current_state(TASK_INTERRUPTIBLE
);
1034 if (vt
== fg_console
)
1037 if (signal_pending(current
))
1041 remove_wait_queue(&vt_activate_queue
, &wait
);
1042 current
->state
= TASK_RUNNING
;
1046 #define vt_wake_waitactive() wake_up(&vt_activate_queue)
1048 void reset_vc(struct vc_data
*vc
)
1050 vc
->vc_mode
= KD_TEXT
;
1051 kbd_table
[vc
->vc_num
].kbdmode
= VC_XLATE
;
1052 vc
->vt_mode
.mode
= VT_AUTO
;
1053 vc
->vt_mode
.waitv
= 0;
1054 vc
->vt_mode
.relsig
= 0;
1055 vc
->vt_mode
.acqsig
= 0;
1056 vc
->vt_mode
.frsig
= 0;
1059 if (!in_interrupt()) /* Via keyboard.c:SAK() - akpm */
1064 * Performs the back end of a vt switch
1066 static void complete_change_console(struct vc_data
*vc
)
1068 unsigned char old_vc_mode
;
1070 last_console
= fg_console
;
1073 * If we're switching, we could be going from KD_GRAPHICS to
1074 * KD_TEXT mode or vice versa, which means we need to blank or
1075 * unblank the screen later.
1077 old_vc_mode
= vc_cons
[fg_console
].d
->vc_mode
;
1081 * This can't appear below a successful kill_proc(). If it did,
1082 * then the *blank_screen operation could occur while X, having
1083 * received acqsig, is waking up on another processor. This
1084 * condition can lead to overlapping accesses to the VGA range
1085 * and the framebuffer (causing system lockups).
1087 * To account for this we duplicate this code below only if the
1088 * controlling process is gone and we've called reset_vc.
1090 if (old_vc_mode
!= vc
->vc_mode
) {
1091 if (vc
->vc_mode
== KD_TEXT
)
1092 do_unblank_screen(1);
1098 * If this new console is under process control, send it a signal
1099 * telling it that it has acquired. Also check if it has died and
1100 * clean up (similar to logic employed in change_console())
1102 if (vc
->vt_mode
.mode
== VT_PROCESS
) {
1104 * Send the signal as privileged - kill_proc() will
1105 * tell us if the process has gone or something else
1108 if (kill_proc(vc
->vt_pid
, vc
->vt_mode
.acqsig
, 1) != 0) {
1110 * The controlling process has died, so we revert back to
1111 * normal operation. In this case, we'll also change back
1112 * to KD_TEXT mode. I'm not sure if this is strictly correct
1113 * but it saves the agony when the X server dies and the screen
1114 * remains blanked due to KD_GRAPHICS! It would be nice to do
1115 * this outside of VT_PROCESS but there is no single process
1116 * to account for and tracking tty count may be undesirable.
1120 if (old_vc_mode
!= vc
->vc_mode
) {
1121 if (vc
->vc_mode
== KD_TEXT
)
1122 do_unblank_screen(1);
1130 * Wake anyone waiting for their VT to activate
1132 vt_wake_waitactive();
1137 * Performs the front-end of a vt switch
1139 void change_console(struct vc_data
*new_vc
)
1143 if (!new_vc
|| new_vc
->vc_num
== fg_console
|| vt_dont_switch
)
1147 * If this vt is in process mode, then we need to handshake with
1148 * that process before switching. Essentially, we store where that
1149 * vt wants to switch to and wait for it to tell us when it's done
1150 * (via VT_RELDISP ioctl).
1152 * We also check to see if the controlling process still exists.
1153 * If it doesn't, we reset this vt to auto mode and continue.
1154 * This is a cheap way to track process control. The worst thing
1155 * that can happen is: we send a signal to a process, it dies, and
1156 * the switch gets "lost" waiting for a response; hopefully, the
1157 * user will try again, we'll detect the process is gone (unless
1158 * the user waits just the right amount of time :-) and revert the
1159 * vt to auto control.
1161 vc
= vc_cons
[fg_console
].d
;
1162 if (vc
->vt_mode
.mode
== VT_PROCESS
) {
1164 * Send the signal as privileged - kill_proc() will
1165 * tell us if the process has gone or something else
1168 if (kill_proc(vc
->vt_pid
, vc
->vt_mode
.relsig
, 1) == 0) {
1170 * It worked. Mark the vt to switch to and
1171 * return. The process needs to send us a
1172 * VT_RELDISP ioctl to complete the switch.
1174 vc
->vt_newvt
= new_vc
->vc_num
;
1179 * The controlling process has died, so we revert back to
1180 * normal operation. In this case, we'll also change back
1181 * to KD_TEXT mode. I'm not sure if this is strictly correct
1182 * but it saves the agony when the X server dies and the screen
1183 * remains blanked due to KD_GRAPHICS! It would be nice to do
1184 * this outside of VT_PROCESS but there is no single process
1185 * to account for and tracking tty count may be undesirable.
1190 * Fall through to normal (VT_AUTO) handling of the switch...
1195 * Ignore all switches in KD_GRAPHICS+VT_AUTO mode
1197 if (vc
->vc_mode
== KD_GRAPHICS
)
1200 complete_change_console(new_vc
);