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/types.h>
14 #include <linux/errno.h>
15 #include <linux/sched.h>
16 #include <linux/tty.h>
17 #include <linux/timer.h>
18 #include <linux/kernel.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/timex.h>
31 #include <asm/uaccess.h>
33 #include <linux/kbd_kern.h>
34 #include <linux/vt_kern.h>
35 #include <linux/kbd_diacr.h>
36 #include <linux/selection.h>
39 extern struct tty_driver
*console_driver
;
41 #define VT_IS_IN_USE(i) (console_driver->ttys[i] && console_driver->ttys[i]->count)
42 #define VT_BUSY(i) (VT_IS_IN_USE(i) || i == fg_console || vc_cons[i].d == sel_cons)
45 * Console (vt and kd) routines, as defined by USL SVR4 manual, and by
46 * experimentation and study of X386 SYSV handling.
48 * One point of difference: SYSV vt's are /dev/vtX, which X >= 0, and
49 * /dev/console is a separate ttyp. Under Linux, /dev/tty0 is /dev/console,
50 * and the vc start at /dev/ttyX, X >= 1. We maintain that here, so we will
51 * always treat our set of vt as numbered 1..MAX_NR_CONSOLES (corresponding to
52 * ttys 0..MAX_NR_CONSOLES-1). Explicitly naming VT 0 is illegal, but using
53 * /dev/tty0 (fg_console) as a target is legal, since an implicit aliasing
54 * to the current console is done by the main ioctl code.
58 #include <linux/syscalls.h>
61 static void complete_change_console(struct vc_data
*vc
);
64 * these are the valid i/o ports we're allowed to change. they map all the
69 #define GPNUM (GPLAST - GPFIRST + 1)
71 #define i (tmp.kb_index)
72 #define s (tmp.kb_table)
73 #define v (tmp.kb_value)
75 do_kdsk_ioctl(int cmd
, struct kbentry __user
*user_kbe
, int perm
, struct kbd_struct
*kbd
)
78 ushort
*key_map
, val
, ov
;
80 if (copy_from_user(&tmp
, user_kbe
, sizeof(struct kbentry
)))
83 if (!capable(CAP_SYS_TTY_CONFIG
))
88 key_map
= key_maps
[s
];
91 if (kbd
->kbdmode
!= VC_UNICODE
&& KTYP(val
) >= NR_TYPES
)
94 val
= (i
? K_HOLE
: K_NOSUCHMAP
);
95 return put_user(val
, &user_kbe
->kb_value
);
99 if (!i
&& v
== K_NOSUCHMAP
) {
101 key_map
= key_maps
[s
];
104 if (key_map
[0] == U(K_ALLOCATED
)) {
112 if (KTYP(v
) < NR_TYPES
) {
113 if (KVAL(v
) > max_vals
[KTYP(v
)])
116 if (kbd
->kbdmode
!= VC_UNICODE
)
119 /* ++Geert: non-PC keyboards may generate keycode zero */
120 #if !defined(__mc68000__) && !defined(__powerpc__)
121 /* assignment to entry 0 only tests validity of args */
126 if (!(key_map
= key_maps
[s
])) {
129 if (keymap_count
>= MAX_NR_OF_USER_KEYMAPS
&&
130 !capable(CAP_SYS_RESOURCE
))
133 key_map
= kmalloc(sizeof(plain_map
),
137 key_maps
[s
] = key_map
;
138 key_map
[0] = U(K_ALLOCATED
);
139 for (j
= 1; j
< NR_KEYS
; j
++)
140 key_map
[j
] = U(K_HOLE
);
145 break; /* nothing to do */
149 if (((ov
== K_SAK
) || (v
== K_SAK
)) && !capable(CAP_SYS_ADMIN
))
152 if (!s
&& (KTYP(ov
) == KT_SHIFT
|| KTYP(v
) == KT_SHIFT
))
153 compute_shiftstate();
163 do_kbkeycode_ioctl(int cmd
, struct kbkeycode __user
*user_kbkc
, int perm
)
165 struct kbkeycode tmp
;
168 if (copy_from_user(&tmp
, user_kbkc
, sizeof(struct kbkeycode
)))
172 kc
= getkeycode(tmp
.scancode
);
174 kc
= put_user(kc
, &user_kbkc
->keycode
);
179 kc
= setkeycode(tmp
.scancode
, tmp
.keycode
);
186 do_kdgkb_ioctl(int cmd
, struct kbsentry __user
*user_kdgkb
, int perm
)
188 struct kbsentry
*kbs
;
194 char *first_free
, *fj
, *fnw
;
198 if (!capable(CAP_SYS_TTY_CONFIG
))
201 kbs
= kmalloc(sizeof(*kbs
), GFP_KERNEL
);
207 /* we mostly copy too much here (512bytes), but who cares ;) */
208 if (copy_from_user(kbs
, user_kdgkb
, sizeof(struct kbsentry
))) {
212 kbs
->kb_string
[sizeof(kbs
->kb_string
)-1] = '\0';
217 sz
= sizeof(kbs
->kb_string
) - 1; /* sz should have been
219 up
= user_kdgkb
->kb_string
;
222 for ( ; *p
&& sz
; p
++, sz
--)
223 if (put_user(*p
, up
++)) {
227 if (put_user('\0', up
)) {
232 return ((p
&& *p
) ? -EOVERFLOW
: 0);
240 first_free
= funcbufptr
+ (funcbufsize
- funcbufleft
);
241 for (j
= i
+1; j
< MAX_NR_FUNC
&& !func_table
[j
]; j
++)
248 delta
= (q
? -strlen(q
) : 1) + strlen(kbs
->kb_string
);
249 if (delta
<= funcbufleft
) { /* it fits in current buf */
250 if (j
< MAX_NR_FUNC
) {
251 memmove(fj
+ delta
, fj
, first_free
- fj
);
252 for (k
= j
; k
< MAX_NR_FUNC
; k
++)
254 func_table
[k
] += delta
;
258 funcbufleft
-= delta
;
259 } else { /* allocate a larger buffer */
261 while (sz
< funcbufsize
- funcbufleft
+ delta
)
263 fnw
= kmalloc(sz
, GFP_KERNEL
);
272 memmove(fnw
, funcbufptr
, fj
- funcbufptr
);
273 for (k
= 0; k
< j
; k
++)
275 func_table
[k
] = fnw
+ (func_table
[k
] - funcbufptr
);
277 if (first_free
> fj
) {
278 memmove(fnw
+ (fj
- funcbufptr
) + delta
, fj
, first_free
- fj
);
279 for (k
= j
; k
< MAX_NR_FUNC
; k
++)
281 func_table
[k
] = fnw
+ (func_table
[k
] - funcbufptr
) + delta
;
283 if (funcbufptr
!= func_buf
)
286 funcbufleft
= funcbufleft
- delta
+ sz
- funcbufsize
;
289 strcpy(func_table
[i
], kbs
->kb_string
);
299 do_fontx_ioctl(int cmd
, struct consolefontdesc __user
*user_cfd
, int perm
, struct console_font_op
*op
)
301 struct consolefontdesc cfdarg
;
304 if (copy_from_user(&cfdarg
, user_cfd
, sizeof(struct consolefontdesc
)))
311 op
->op
= KD_FONT_OP_SET
;
312 op
->flags
= KD_FONT_FLAG_OLD
;
314 op
->height
= cfdarg
.charheight
;
315 op
->charcount
= cfdarg
.charcount
;
316 op
->data
= cfdarg
.chardata
;
317 return con_font_op(vc_cons
[fg_console
].d
, op
);
319 op
->op
= KD_FONT_OP_GET
;
320 op
->flags
= KD_FONT_FLAG_OLD
;
322 op
->height
= cfdarg
.charheight
;
323 op
->charcount
= cfdarg
.charcount
;
324 op
->data
= cfdarg
.chardata
;
325 i
= con_font_op(vc_cons
[fg_console
].d
, op
);
328 cfdarg
.charheight
= op
->height
;
329 cfdarg
.charcount
= op
->charcount
;
330 if (copy_to_user(user_cfd
, &cfdarg
, sizeof(struct consolefontdesc
)))
339 do_unimap_ioctl(int cmd
, struct unimapdesc __user
*user_ud
, int perm
, struct vc_data
*vc
)
341 struct unimapdesc tmp
;
343 if (copy_from_user(&tmp
, user_ud
, sizeof tmp
))
346 if (!access_ok(VERIFY_WRITE
, tmp
.entries
,
347 tmp
.entry_ct
*sizeof(struct unipair
)))
353 return con_set_unimap(vc
, tmp
.entry_ct
, tmp
.entries
);
355 if (!perm
&& fg_console
!= vc
->vc_num
)
357 return con_get_unimap(vc
, tmp
.entry_ct
, &(user_ud
->entry_ct
), tmp
.entries
);
363 * We handle the console-specific ioctl's here. We allow the
364 * capability to modify any console, not just the fg_console.
366 int vt_ioctl(struct tty_struct
*tty
, struct file
* file
,
367 unsigned int cmd
, unsigned long arg
)
369 struct vc_data
*vc
= tty
->driver_data
;
370 struct console_font_op op
; /* used in multiple places here */
371 struct kbd_struct
* kbd
;
372 unsigned int console
;
374 void __user
*up
= (void __user
*)arg
;
378 console
= vc
->vc_num
;
382 if (!vc_cons_allocated(console
)) { /* impossible? */
389 * To have permissions to do most of the vt ioctls, we either have
390 * to be the owner of the tty, or have CAP_SYS_TTY_CONFIG.
393 if (current
->signal
->tty
== tty
|| capable(CAP_SYS_TTY_CONFIG
))
396 kbd
= kbd_table
+ console
;
399 return tioclinux(tty
, arg
);
404 arg
= CLOCK_TICK_RATE
/ arg
;
412 unsigned int ticks
, count
;
415 * Generate the tone for the appropriate number of ticks.
416 * If the time is zero, turn off sound ourselves.
418 ticks
= HZ
* ((arg
>> 16) & 0xffff) / 1000;
419 count
= ticks
? (arg
& 0xffff) : 0;
421 count
= CLOCK_TICK_RATE
/ count
;
422 kd_mksound(count
, ticks
);
434 * These cannot be implemented on any machine that implements
435 * ioperm() in user level (such as Alpha PCs) or not at all.
437 * XXX: you should never use these, just call ioperm directly..
443 * KDADDIO and KDDELIO may be able to add ports beyond what
444 * we reject here, but to be safe...
446 if (arg
< GPFIRST
|| arg
> GPLAST
) {
450 ret
= sys_ioperm(arg
, 1, (cmd
== KDADDIO
)) ? -ENXIO
: 0;
455 ret
= sys_ioperm(GPFIRST
, GPNUM
,
456 (cmd
== KDENABIO
)) ? -ENXIO
: 0;
460 /* Linux m68k/i386 interface for setting the keyboard delay/repeat rate */
464 struct kbd_repeat kbrep
;
466 if (!capable(CAP_SYS_TTY_CONFIG
))
469 if (copy_from_user(&kbrep
, up
, sizeof(struct kbd_repeat
))) {
473 ret
= kbd_rate(&kbrep
);
476 if (copy_to_user(up
, &kbrep
, sizeof(struct kbd_repeat
)))
483 * currently, setting the mode from KD_TEXT to KD_GRAPHICS
484 * doesn't do a whole lot. i'm not sure if it should do any
485 * restoration of modes or what...
487 * XXX It should at least call into the driver, fbdev's definitely
488 * need to restore their engine state. --BenH
504 if (vc
->vc_mode
== (unsigned char) arg
)
506 vc
->vc_mode
= (unsigned char) arg
;
507 if (console
!= fg_console
)
510 * explicitly blank/unblank the screen if switching modes
512 acquire_console_sem();
514 do_unblank_screen(1);
517 release_console_sem();
527 * these work like a combination of mmap and KDENABIO.
528 * this could be easily finished.
538 kbd
->kbdmode
= VC_RAW
;
541 kbd
->kbdmode
= VC_MEDIUMRAW
;
544 kbd
->kbdmode
= VC_XLATE
;
545 compute_shiftstate();
548 kbd
->kbdmode
= VC_UNICODE
;
549 compute_shiftstate();
555 tty_ldisc_flush(tty
);
559 ucval
= ((kbd
->kbdmode
== VC_RAW
) ? K_RAW
:
560 (kbd
->kbdmode
== VC_MEDIUMRAW
) ? K_MEDIUMRAW
:
561 (kbd
->kbdmode
== VC_UNICODE
) ? K_UNICODE
:
565 /* this could be folded into KDSKBMODE, but for compatibility
566 reasons it is not so easy to fold KDGKBMETA into KDGKBMODE */
570 clr_vc_kbd_mode(kbd
, VC_META
);
573 set_vc_kbd_mode(kbd
, VC_META
);
581 ucval
= (vc_kbd_mode(kbd
, VC_META
) ? K_ESCPREFIX
: K_METABIT
);
583 ret
= put_user(ucval
, (int __user
*)arg
);
588 if(!capable(CAP_SYS_TTY_CONFIG
))
590 ret
= do_kbkeycode_ioctl(cmd
, up
, perm
);
595 ret
= do_kdsk_ioctl(cmd
, up
, perm
, kbd
);
600 ret
= do_kdgkb_ioctl(cmd
, up
, perm
);
605 struct kbdiacrs __user
*a
= up
;
606 struct kbdiacr diacr
;
609 if (put_user(accent_table_size
, &a
->kb_cnt
)) {
613 for (i
= 0; i
< accent_table_size
; i
++) {
614 diacr
.diacr
= conv_uni_to_8bit(accent_table
[i
].diacr
);
615 diacr
.base
= conv_uni_to_8bit(accent_table
[i
].base
);
616 diacr
.result
= conv_uni_to_8bit(accent_table
[i
].result
);
617 if (copy_to_user(a
->kbdiacr
+ i
, &diacr
, sizeof(struct kbdiacr
))) {
626 struct kbdiacrsuc __user
*a
= up
;
628 if (put_user(accent_table_size
, &a
->kb_cnt
))
630 else if (copy_to_user(a
->kbdiacruc
, accent_table
,
631 accent_table_size
*sizeof(struct kbdiacruc
)))
638 struct kbdiacrs __user
*a
= up
;
639 struct kbdiacr diacr
;
645 if (get_user(ct
,&a
->kb_cnt
)) {
649 if (ct
>= MAX_DIACR
) {
653 accent_table_size
= ct
;
654 for (i
= 0; i
< ct
; i
++) {
655 if (copy_from_user(&diacr
, a
->kbdiacr
+ i
, sizeof(struct kbdiacr
))) {
659 accent_table
[i
].diacr
= conv_8bit_to_uni(diacr
.diacr
);
660 accent_table
[i
].base
= conv_8bit_to_uni(diacr
.base
);
661 accent_table
[i
].result
= conv_8bit_to_uni(diacr
.result
);
668 struct kbdiacrsuc __user
*a
= up
;
673 if (get_user(ct
,&a
->kb_cnt
)) {
677 if (ct
>= MAX_DIACR
) {
681 accent_table_size
= ct
;
682 if (copy_from_user(accent_table
, a
->kbdiacruc
, ct
*sizeof(struct kbdiacruc
)))
687 /* the ioctls below read/set the flags usually shown in the leds */
688 /* don't use them - they will go away without warning */
690 ucval
= kbd
->ledflagstate
| (kbd
->default_ledflagstate
<< 4);
700 kbd
->ledflagstate
= (arg
& 7);
701 kbd
->default_ledflagstate
= ((arg
>> 4) & 7);
705 /* the ioctls below only set the lights, not the functions */
706 /* for those, see KDGKBLED and KDSKBLED above */
708 ucval
= getledstate();
710 ret
= put_user(ucval
, (char __user
*)arg
);
716 setledstate(kbd
, arg
);
720 * A process can indicate its willingness to accept signals
721 * generated by pressing an appropriate key combination.
722 * Thus, one can have a daemon that e.g. spawns a new console
723 * upon a keypress and then changes to it.
724 * See also the kbrequest field of inittab(5).
728 if (!perm
|| !capable(CAP_KILL
))
730 if (!valid_signal(arg
) || arg
< 1 || arg
== SIGKILL
)
733 spin_lock_irq(&vt_spawn_con
.lock
);
734 put_pid(vt_spawn_con
.pid
);
735 vt_spawn_con
.pid
= get_pid(task_pid(current
));
736 vt_spawn_con
.sig
= arg
;
737 spin_unlock_irq(&vt_spawn_con
.lock
);
748 if (copy_from_user(&tmp
, up
, sizeof(struct vt_mode
))) {
752 if (tmp
.mode
!= VT_AUTO
&& tmp
.mode
!= VT_PROCESS
) {
756 acquire_console_sem();
758 /* the frsig is ignored, so we set it to 0 */
759 vc
->vt_mode
.frsig
= 0;
761 vc
->vt_pid
= get_pid(task_pid(current
));
762 /* no switch is required -- saw@shade.msu.ru */
764 release_console_sem();
773 acquire_console_sem();
774 memcpy(&tmp
, &vc
->vt_mode
, sizeof(struct vt_mode
));
775 release_console_sem();
777 rc
= copy_to_user(up
, &tmp
, sizeof(struct vt_mode
));
784 * Returns global vt state. Note that VT 0 is always open, since
785 * it's an alias for the current VT, and people can't use it here.
786 * We cannot return state for more than 16 VTs, since v_state is short.
790 struct vt_stat __user
*vtstat
= up
;
791 unsigned short state
, mask
;
793 if (put_user(fg_console
+ 1, &vtstat
->v_active
))
796 state
= 1; /* /dev/tty0 is always open */
797 for (i
= 0, mask
= 2; i
< MAX_NR_CONSOLES
&& mask
;
801 ret
= put_user(state
, &vtstat
->v_state
);
807 * Returns the first available (non-opened) console.
810 for (i
= 0; i
< MAX_NR_CONSOLES
; ++i
)
811 if (! VT_IS_IN_USE(i
))
813 ucval
= i
< MAX_NR_CONSOLES
? (i
+1) : -1;
817 * ioctl(fd, VT_ACTIVATE, num) will cause us to switch to vt # num,
818 * with num >= 1 (switches to vt 0, our console, are not allowed, just
819 * to preserve sanity).
824 if (arg
== 0 || arg
> MAX_NR_CONSOLES
)
828 acquire_console_sem();
829 ret
= vc_allocate(arg
);
830 release_console_sem();
838 * wait until the specified VT has been activated
843 if (arg
== 0 || arg
> MAX_NR_CONSOLES
)
846 ret
= vt_waitactive(arg
- 1);
850 * If a vt is under process control, the kernel will not switch to it
851 * immediately, but postpone the operation until the process calls this
852 * ioctl, allowing the switch to complete.
854 * According to the X sources this is the behavior:
855 * 0: pending switch-from not OK
856 * 1: pending switch-from OK
857 * 2: completed switch-to OK
863 if (vc
->vt_mode
.mode
!= VT_PROCESS
) {
868 * Switching-from response
870 acquire_console_sem();
871 if (vc
->vt_newvt
>= 0) {
874 * Switch disallowed, so forget we were trying
881 * The current vt has been released, so
882 * complete the switch.
885 newvt
= vc
->vt_newvt
;
887 ret
= vc_allocate(newvt
);
889 release_console_sem();
893 * When we actually do the console switch,
894 * make sure we are atomic with respect to
895 * other console switches..
897 complete_change_console(vc_cons
[newvt
].d
);
901 * Switched-to response
904 * If it's just an ACK, ignore it
906 if (arg
!= VT_ACKACQ
)
909 release_console_sem();
913 * Disallocate memory associated to VT (but leave VT1)
916 if (arg
> MAX_NR_CONSOLES
) {
921 /* deallocate all unused consoles, but leave 0 */
922 acquire_console_sem();
923 for (i
=1; i
<MAX_NR_CONSOLES
; i
++)
926 release_console_sem();
928 /* deallocate a single console, if possible */
932 else if (arg
) { /* leave 0 */
933 acquire_console_sem();
935 release_console_sem();
942 struct vt_sizes __user
*vtsizes
= up
;
948 if (get_user(ll
, &vtsizes
->v_rows
) ||
949 get_user(cc
, &vtsizes
->v_cols
))
952 acquire_console_sem();
953 for (i
= 0; i
< MAX_NR_CONSOLES
; i
++) {
957 vc
->vc_resize_user
= 1;
958 vc_resize(vc_cons
[i
].d
, cc
, ll
);
961 release_console_sem();
968 struct vt_consize __user
*vtconsize
= up
;
969 ushort ll
,cc
,vlin
,clin
,vcol
,ccol
;
972 if (!access_ok(VERIFY_READ
, vtconsize
,
973 sizeof(struct vt_consize
))) {
977 /* FIXME: Should check the copies properly */
978 __get_user(ll
, &vtconsize
->v_rows
);
979 __get_user(cc
, &vtconsize
->v_cols
);
980 __get_user(vlin
, &vtconsize
->v_vlin
);
981 __get_user(clin
, &vtconsize
->v_clin
);
982 __get_user(vcol
, &vtconsize
->v_vcol
);
983 __get_user(ccol
, &vtconsize
->v_ccol
);
984 vlin
= vlin
? vlin
: vc
->vc_scan_lines
;
987 if (ll
!= vlin
/clin
) {
988 /* Parameters don't add up */
997 if (cc
!= vcol
/ccol
) {
1010 for (i
= 0; i
< MAX_NR_CONSOLES
; i
++) {
1013 acquire_console_sem();
1015 vc_cons
[i
].d
->vc_scan_lines
= vlin
;
1017 vc_cons
[i
].d
->vc_font
.height
= clin
;
1018 vc_cons
[i
].d
->vc_resize_user
= 1;
1019 vc_resize(vc_cons
[i
].d
, cc
, ll
);
1020 release_console_sem();
1028 op
.op
= KD_FONT_OP_SET
;
1029 op
.flags
= KD_FONT_FLAG_OLD
| KD_FONT_FLAG_DONT_RECALC
; /* Compatibility */
1034 ret
= con_font_op(vc_cons
[fg_console
].d
, &op
);
1039 op
.op
= KD_FONT_OP_GET
;
1040 op
.flags
= KD_FONT_FLAG_OLD
;
1045 ret
= con_font_op(vc_cons
[fg_console
].d
, &op
);
1053 ret
= con_set_cmap(up
);
1057 ret
= con_get_cmap(up
);
1062 ret
= do_fontx_ioctl(cmd
, up
, perm
, &op
);
1070 #ifdef BROKEN_GRAPHICS_PROGRAMS
1071 /* With BROKEN_GRAPHICS_PROGRAMS defined, the default
1072 font is not saved. */
1077 op
.op
= KD_FONT_OP_SET_DEFAULT
;
1079 ret
= con_font_op(vc_cons
[fg_console
].d
, &op
);
1082 con_set_default_unimap(vc_cons
[fg_console
].d
);
1089 if (copy_from_user(&op
, up
, sizeof(op
))) {
1093 if (!perm
&& op
.op
!= KD_FONT_OP_GET
)
1095 ret
= con_font_op(vc
, &op
);
1098 if (copy_to_user(up
, &op
, sizeof(op
)))
1107 ret
= con_set_trans_old(up
);
1111 ret
= con_get_trans_old(up
);
1114 case PIO_UNISCRNMAP
:
1118 ret
= con_set_trans_new(up
);
1121 case GIO_UNISCRNMAP
:
1122 ret
= con_get_trans_new(up
);
1126 { struct unimapinit ui
;
1129 ret
= copy_from_user(&ui
, up
, sizeof(struct unimapinit
));
1131 con_clear_unimap(vc
, &ui
);
1137 ret
= do_unimap_ioctl(cmd
, up
, perm
, vc
);
1141 if (!capable(CAP_SYS_TTY_CONFIG
))
1145 case VT_UNLOCKSWITCH
:
1146 if (!capable(CAP_SYS_TTY_CONFIG
))
1150 case VT_GETHIFONTMASK
:
1151 ret
= put_user(vc
->vc_hi_font_mask
,
1152 (unsigned short __user
*)arg
);
1166 * Sometimes we want to wait until a particular VT has been activated. We
1167 * do it in a very simple manner. Everybody waits on a single queue and
1168 * get woken up at once. Those that are satisfied go on with their business,
1169 * while those not ready go back to sleep. Seems overkill to add a wait
1170 * to each vt just for this - usually this does nothing!
1172 static DECLARE_WAIT_QUEUE_HEAD(vt_activate_queue
);
1175 * Sleeps until a vt is activated, or the task is interrupted. Returns
1176 * 0 if activation, -EINTR if interrupted by a signal handler.
1178 int vt_waitactive(int vt
)
1181 DECLARE_WAITQUEUE(wait
, current
);
1183 add_wait_queue(&vt_activate_queue
, &wait
);
1188 * Synchronize with redraw_screen(). By acquiring the console
1189 * semaphore we make sure that the console switch is completed
1190 * before we return. If we didn't wait for the semaphore, we
1191 * could return at a point where fg_console has already been
1192 * updated, but the console switch hasn't been completed.
1194 acquire_console_sem();
1195 set_current_state(TASK_INTERRUPTIBLE
);
1196 if (vt
== fg_console
) {
1197 release_console_sem();
1200 release_console_sem();
1201 retval
= -ERESTARTNOHAND
;
1202 if (signal_pending(current
))
1206 remove_wait_queue(&vt_activate_queue
, &wait
);
1207 __set_current_state(TASK_RUNNING
);
1211 #define vt_wake_waitactive() wake_up(&vt_activate_queue)
1213 void reset_vc(struct vc_data
*vc
)
1215 vc
->vc_mode
= KD_TEXT
;
1216 kbd_table
[vc
->vc_num
].kbdmode
= default_utf8
? VC_UNICODE
: VC_XLATE
;
1217 vc
->vt_mode
.mode
= VT_AUTO
;
1218 vc
->vt_mode
.waitv
= 0;
1219 vc
->vt_mode
.relsig
= 0;
1220 vc
->vt_mode
.acqsig
= 0;
1221 vc
->vt_mode
.frsig
= 0;
1222 put_pid(vc
->vt_pid
);
1225 if (!in_interrupt()) /* Via keyboard.c:SAK() - akpm */
1229 void vc_SAK(struct work_struct
*work
)
1232 container_of(work
, struct vc
, SAK_work
);
1234 struct tty_struct
*tty
;
1236 acquire_console_sem();
1241 * SAK should also work in all raw modes and reset
1248 release_console_sem();
1252 * Performs the back end of a vt switch
1254 static void complete_change_console(struct vc_data
*vc
)
1256 unsigned char old_vc_mode
;
1258 last_console
= fg_console
;
1261 * If we're switching, we could be going from KD_GRAPHICS to
1262 * KD_TEXT mode or vice versa, which means we need to blank or
1263 * unblank the screen later.
1265 old_vc_mode
= vc_cons
[fg_console
].d
->vc_mode
;
1269 * This can't appear below a successful kill_pid(). If it did,
1270 * then the *blank_screen operation could occur while X, having
1271 * received acqsig, is waking up on another processor. This
1272 * condition can lead to overlapping accesses to the VGA range
1273 * and the framebuffer (causing system lockups).
1275 * To account for this we duplicate this code below only if the
1276 * controlling process is gone and we've called reset_vc.
1278 if (old_vc_mode
!= vc
->vc_mode
) {
1279 if (vc
->vc_mode
== KD_TEXT
)
1280 do_unblank_screen(1);
1286 * If this new console is under process control, send it a signal
1287 * telling it that it has acquired. Also check if it has died and
1288 * clean up (similar to logic employed in change_console())
1290 if (vc
->vt_mode
.mode
== VT_PROCESS
) {
1292 * Send the signal as privileged - kill_pid() will
1293 * tell us if the process has gone or something else
1296 if (kill_pid(vc
->vt_pid
, vc
->vt_mode
.acqsig
, 1) != 0) {
1298 * The controlling process has died, so we revert back to
1299 * normal operation. In this case, we'll also change back
1300 * to KD_TEXT mode. I'm not sure if this is strictly correct
1301 * but it saves the agony when the X server dies and the screen
1302 * remains blanked due to KD_GRAPHICS! It would be nice to do
1303 * this outside of VT_PROCESS but there is no single process
1304 * to account for and tracking tty count may be undesirable.
1308 if (old_vc_mode
!= vc
->vc_mode
) {
1309 if (vc
->vc_mode
== KD_TEXT
)
1310 do_unblank_screen(1);
1318 * Wake anyone waiting for their VT to activate
1320 vt_wake_waitactive();
1325 * Performs the front-end of a vt switch
1327 void change_console(struct vc_data
*new_vc
)
1331 if (!new_vc
|| new_vc
->vc_num
== fg_console
|| vt_dont_switch
)
1335 * If this vt is in process mode, then we need to handshake with
1336 * that process before switching. Essentially, we store where that
1337 * vt wants to switch to and wait for it to tell us when it's done
1338 * (via VT_RELDISP ioctl).
1340 * We also check to see if the controlling process still exists.
1341 * If it doesn't, we reset this vt to auto mode and continue.
1342 * This is a cheap way to track process control. The worst thing
1343 * that can happen is: we send a signal to a process, it dies, and
1344 * the switch gets "lost" waiting for a response; hopefully, the
1345 * user will try again, we'll detect the process is gone (unless
1346 * the user waits just the right amount of time :-) and revert the
1347 * vt to auto control.
1349 vc
= vc_cons
[fg_console
].d
;
1350 if (vc
->vt_mode
.mode
== VT_PROCESS
) {
1352 * Send the signal as privileged - kill_pid() will
1353 * tell us if the process has gone or something else
1356 * We need to set vt_newvt *before* sending the signal or we
1359 vc
->vt_newvt
= new_vc
->vc_num
;
1360 if (kill_pid(vc
->vt_pid
, vc
->vt_mode
.relsig
, 1) == 0) {
1362 * It worked. Mark the vt to switch to and
1363 * return. The process needs to send us a
1364 * VT_RELDISP ioctl to complete the switch.
1370 * The controlling process has died, so we revert back to
1371 * normal operation. In this case, we'll also change back
1372 * to KD_TEXT mode. I'm not sure if this is strictly correct
1373 * but it saves the agony when the X server dies and the screen
1374 * remains blanked due to KD_GRAPHICS! It would be nice to do
1375 * this outside of VT_PROCESS but there is no single process
1376 * to account for and tracking tty count may be undesirable.
1381 * Fall through to normal (VT_AUTO) handling of the switch...
1386 * Ignore all switches in KD_GRAPHICS+VT_AUTO mode
1388 if (vc
->vc_mode
== KD_GRAPHICS
)
1391 complete_change_console(new_vc
);
This page took 0.058608 seconds and 5 git commands to generate.