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/smp_lock.h>
29 #include <linux/timex.h>
32 #include <asm/uaccess.h>
34 #include <linux/kbd_kern.h>
35 #include <linux/vt_kern.h>
36 #include <linux/kbd_diacr.h>
37 #include <linux/selection.h>
40 extern struct tty_driver *console_driver;
42 #define VT_IS_IN_USE(i) (console_driver->ttys[i] && console_driver->ttys[i]->count)
43 #define VT_BUSY(i) (VT_IS_IN_USE(i) || i == fg_console || vc_cons[i].d == sel_cons)
46 * Console (vt and kd) routines, as defined by USL SVR4 manual, and by
47 * experimentation and study of X386 SYSV handling.
49 * One point of difference: SYSV vt's are /dev/vtX, which X >= 0, and
50 * /dev/console is a separate ttyp. Under Linux, /dev/tty0 is /dev/console,
51 * and the vc start at /dev/ttyX, X >= 1. We maintain that here, so we will
52 * always treat our set of vt as numbered 1..MAX_NR_CONSOLES (corresponding to
53 * ttys 0..MAX_NR_CONSOLES-1). Explicitly naming VT 0 is illegal, but using
54 * /dev/tty0 (fg_console) as a target is legal, since an implicit aliasing
55 * to the current console is done by the main ioctl code.
59 #include <linux/syscalls.h>
62 static void complete_change_console(struct vc_data *vc);
65 * these are the valid i/o ports we're allowed to change. they map all the
70 #define GPNUM (GPLAST - GPFIRST + 1)
72 #define i (tmp.kb_index)
73 #define s (tmp.kb_table)
74 #define v (tmp.kb_value)
76 do_kdsk_ioctl(int cmd, struct kbentry __user *user_kbe, int perm, struct kbd_struct *kbd)
79 ushort *key_map, val, ov;
81 if (copy_from_user(&tmp, user_kbe, sizeof(struct kbentry)))
84 if (!capable(CAP_SYS_TTY_CONFIG))
89 key_map = key_maps[s];
92 if (kbd->kbdmode != VC_UNICODE && KTYP(val) >= NR_TYPES)
95 val = (i ? K_HOLE : K_NOSUCHMAP);
96 return put_user(val, &user_kbe->kb_value);
100 if (!i && v == K_NOSUCHMAP) {
102 key_map = key_maps[s];
105 if (key_map[0] == U(K_ALLOCATED)) {
113 if (KTYP(v) < NR_TYPES) {
114 if (KVAL(v) > max_vals[KTYP(v)])
117 if (kbd->kbdmode != VC_UNICODE)
120 /* ++Geert: non-PC keyboards may generate keycode zero */
121 #if !defined(__mc68000__) && !defined(__powerpc__)
122 /* assignment to entry 0 only tests validity of args */
127 if (!(key_map = key_maps[s])) {
130 if (keymap_count >= MAX_NR_OF_USER_KEYMAPS &&
131 !capable(CAP_SYS_RESOURCE))
134 key_map = kmalloc(sizeof(plain_map),
138 key_maps[s] = key_map;
139 key_map[0] = U(K_ALLOCATED);
140 for (j = 1; j < NR_KEYS; j++)
141 key_map[j] = U(K_HOLE);
146 break; /* nothing to do */
150 if (((ov == K_SAK) || (v == K_SAK)) && !capable(CAP_SYS_ADMIN))
153 if (!s && (KTYP(ov) == KT_SHIFT || KTYP(v) == KT_SHIFT))
154 compute_shiftstate();
164 do_kbkeycode_ioctl(int cmd, struct kbkeycode __user *user_kbkc, int perm)
166 struct kbkeycode tmp;
169 if (copy_from_user(&tmp, user_kbkc, sizeof(struct kbkeycode)))
173 kc = getkeycode(tmp.scancode);
175 kc = put_user(kc, &user_kbkc->keycode);
180 kc = setkeycode(tmp.scancode, tmp.keycode);
187 do_kdgkb_ioctl(int cmd, struct kbsentry __user *user_kdgkb, int perm)
189 struct kbsentry *kbs;
195 char *first_free, *fj, *fnw;
199 if (!capable(CAP_SYS_TTY_CONFIG))
202 kbs = kmalloc(sizeof(*kbs), GFP_KERNEL);
208 /* we mostly copy too much here (512bytes), but who cares ;) */
209 if (copy_from_user(kbs, user_kdgkb, sizeof(struct kbsentry))) {
213 kbs->kb_string[sizeof(kbs->kb_string)-1] = '\0';
218 sz = sizeof(kbs->kb_string) - 1; /* sz should have been
220 up = user_kdgkb->kb_string;
223 for ( ; *p && sz; p++, sz--)
224 if (put_user(*p, up++)) {
228 if (put_user('\0', up)) {
233 return ((p && *p) ? -EOVERFLOW : 0);
241 first_free = funcbufptr + (funcbufsize - funcbufleft);
242 for (j = i+1; j < MAX_NR_FUNC && !func_table[j]; j++)
249 delta = (q ? -strlen(q) : 1) + strlen(kbs->kb_string);
250 if (delta <= funcbufleft) { /* it fits in current buf */
251 if (j < MAX_NR_FUNC) {
252 memmove(fj + delta, fj, first_free - fj);
253 for (k = j; k < MAX_NR_FUNC; k++)
255 func_table[k] += delta;
259 funcbufleft -= delta;
260 } else { /* allocate a larger buffer */
262 while (sz < funcbufsize - funcbufleft + delta)
264 fnw = kmalloc(sz, GFP_KERNEL);
273 memmove(fnw, funcbufptr, fj - funcbufptr);
274 for (k = 0; k < j; k++)
276 func_table[k] = fnw + (func_table[k] - funcbufptr);
278 if (first_free > fj) {
279 memmove(fnw + (fj - funcbufptr) + delta, fj, first_free - fj);
280 for (k = j; k < MAX_NR_FUNC; k++)
282 func_table[k] = fnw + (func_table[k] - funcbufptr) + delta;
284 if (funcbufptr != func_buf)
287 funcbufleft = funcbufleft - delta + sz - funcbufsize;
290 strcpy(func_table[i], kbs->kb_string);
300 do_fontx_ioctl(int cmd, struct consolefontdesc __user *user_cfd, int perm, struct console_font_op *op)
302 struct consolefontdesc cfdarg;
305 if (copy_from_user(&cfdarg, user_cfd, sizeof(struct consolefontdesc)))
312 op->op = KD_FONT_OP_SET;
313 op->flags = KD_FONT_FLAG_OLD;
315 op->height = cfdarg.charheight;
316 op->charcount = cfdarg.charcount;
317 op->data = cfdarg.chardata;
318 return con_font_op(vc_cons[fg_console].d, op);
320 op->op = KD_FONT_OP_GET;
321 op->flags = KD_FONT_FLAG_OLD;
323 op->height = cfdarg.charheight;
324 op->charcount = cfdarg.charcount;
325 op->data = cfdarg.chardata;
326 i = con_font_op(vc_cons[fg_console].d, op);
329 cfdarg.charheight = op->height;
330 cfdarg.charcount = op->charcount;
331 if (copy_to_user(user_cfd, &cfdarg, sizeof(struct consolefontdesc)))
340 do_unimap_ioctl(int cmd, struct unimapdesc __user *user_ud, int perm, struct vc_data *vc)
342 struct unimapdesc tmp;
344 if (copy_from_user(&tmp, user_ud, sizeof tmp))
347 if (!access_ok(VERIFY_WRITE, tmp.entries,
348 tmp.entry_ct*sizeof(struct unipair)))
354 return con_set_unimap(vc, tmp.entry_ct, tmp.entries);
356 if (!perm && fg_console != vc->vc_num)
358 return con_get_unimap(vc, tmp.entry_ct, &(user_ud->entry_ct), tmp.entries);
364 * We handle the console-specific ioctl's here. We allow the
365 * capability to modify any console, not just the fg_console.
367 int vt_ioctl(struct tty_struct *tty, struct file * file,
368 unsigned int cmd, unsigned long arg)
370 struct vc_data *vc = tty->driver_data;
371 struct console_font_op op; /* used in multiple places here */
372 struct kbd_struct * kbd;
373 unsigned int console;
375 void __user *up = (void __user *)arg;
379 console = vc->vc_num;
383 if (!vc_cons_allocated(console)) { /* impossible? */
390 * To have permissions to do most of the vt ioctls, we either have
391 * to be the owner of the tty, or have CAP_SYS_TTY_CONFIG.
394 if (current->signal->tty == tty || capable(CAP_SYS_TTY_CONFIG))
397 kbd = kbd_table + console;
400 ret = tioclinux(tty, arg);
405 /* FIXME: This is an old broken API but we need to keep it
406 supported and somehow separate the historic advertised
407 tick rate from any real one */
409 arg = CLOCK_TICK_RATE / arg;
417 unsigned int ticks, count;
420 * Generate the tone for the appropriate number of ticks.
421 * If the time is zero, turn off sound ourselves.
423 ticks = HZ * ((arg >> 16) & 0xffff) / 1000;
424 count = ticks ? (arg & 0xffff) : 0;
425 /* FIXME: This is an old broken API but we need to keep it
426 supported and somehow separate the historic advertised
427 tick rate from any real one */
429 count = CLOCK_TICK_RATE / count;
430 kd_mksound(count, ticks);
442 * These cannot be implemented on any machine that implements
443 * ioperm() in user level (such as Alpha PCs) or not at all.
445 * XXX: you should never use these, just call ioperm directly..
451 * KDADDIO and KDDELIO may be able to add ports beyond what
452 * we reject here, but to be safe...
454 if (arg < GPFIRST || arg > GPLAST) {
458 ret = sys_ioperm(arg, 1, (cmd == KDADDIO)) ? -ENXIO : 0;
463 ret = sys_ioperm(GPFIRST, GPNUM,
464 (cmd == KDENABIO)) ? -ENXIO : 0;
468 /* Linux m68k/i386 interface for setting the keyboard delay/repeat rate */
472 struct kbd_repeat kbrep;
474 if (!capable(CAP_SYS_TTY_CONFIG))
477 if (copy_from_user(&kbrep, up, sizeof(struct kbd_repeat))) {
481 ret = kbd_rate(&kbrep);
484 if (copy_to_user(up, &kbrep, sizeof(struct kbd_repeat)))
491 * currently, setting the mode from KD_TEXT to KD_GRAPHICS
492 * doesn't do a whole lot. i'm not sure if it should do any
493 * restoration of modes or what...
495 * XXX It should at least call into the driver, fbdev's definitely
496 * need to restore their engine state. --BenH
512 if (vc->vc_mode == (unsigned char) arg)
514 vc->vc_mode = (unsigned char) arg;
515 if (console != fg_console)
518 * explicitly blank/unblank the screen if switching modes
520 acquire_console_sem();
522 do_unblank_screen(1);
525 release_console_sem();
535 * these work like a combination of mmap and KDENABIO.
536 * this could be easily finished.
546 kbd->kbdmode = VC_RAW;
549 kbd->kbdmode = VC_MEDIUMRAW;
552 kbd->kbdmode = VC_XLATE;
553 compute_shiftstate();
556 kbd->kbdmode = VC_UNICODE;
557 compute_shiftstate();
563 tty_ldisc_flush(tty);
567 ucval = ((kbd->kbdmode == VC_RAW) ? K_RAW :
568 (kbd->kbdmode == VC_MEDIUMRAW) ? K_MEDIUMRAW :
569 (kbd->kbdmode == VC_UNICODE) ? K_UNICODE :
573 /* this could be folded into KDSKBMODE, but for compatibility
574 reasons it is not so easy to fold KDGKBMETA into KDGKBMODE */
578 clr_vc_kbd_mode(kbd, VC_META);
581 set_vc_kbd_mode(kbd, VC_META);
589 ucval = (vc_kbd_mode(kbd, VC_META) ? K_ESCPREFIX : K_METABIT);
591 ret = put_user(ucval, (int __user *)arg);
596 if(!capable(CAP_SYS_TTY_CONFIG))
598 ret = do_kbkeycode_ioctl(cmd, up, perm);
603 ret = do_kdsk_ioctl(cmd, up, perm, kbd);
608 ret = do_kdgkb_ioctl(cmd, up, perm);
613 struct kbdiacrs __user *a = up;
614 struct kbdiacr diacr;
617 if (put_user(accent_table_size, &a->kb_cnt)) {
621 for (i = 0; i < accent_table_size; i++) {
622 diacr.diacr = conv_uni_to_8bit(accent_table[i].diacr);
623 diacr.base = conv_uni_to_8bit(accent_table[i].base);
624 diacr.result = conv_uni_to_8bit(accent_table[i].result);
625 if (copy_to_user(a->kbdiacr + i, &diacr, sizeof(struct kbdiacr))) {
634 struct kbdiacrsuc __user *a = up;
636 if (put_user(accent_table_size, &a->kb_cnt))
638 else if (copy_to_user(a->kbdiacruc, accent_table,
639 accent_table_size*sizeof(struct kbdiacruc)))
646 struct kbdiacrs __user *a = up;
647 struct kbdiacr diacr;
653 if (get_user(ct,&a->kb_cnt)) {
657 if (ct >= MAX_DIACR) {
661 accent_table_size = ct;
662 for (i = 0; i < ct; i++) {
663 if (copy_from_user(&diacr, a->kbdiacr + i, sizeof(struct kbdiacr))) {
667 accent_table[i].diacr = conv_8bit_to_uni(diacr.diacr);
668 accent_table[i].base = conv_8bit_to_uni(diacr.base);
669 accent_table[i].result = conv_8bit_to_uni(diacr.result);
676 struct kbdiacrsuc __user *a = up;
681 if (get_user(ct,&a->kb_cnt)) {
685 if (ct >= MAX_DIACR) {
689 accent_table_size = ct;
690 if (copy_from_user(accent_table, a->kbdiacruc, ct*sizeof(struct kbdiacruc)))
695 /* the ioctls below read/set the flags usually shown in the leds */
696 /* don't use them - they will go away without warning */
698 ucval = kbd->ledflagstate | (kbd->default_ledflagstate << 4);
708 kbd->ledflagstate = (arg & 7);
709 kbd->default_ledflagstate = ((arg >> 4) & 7);
713 /* the ioctls below only set the lights, not the functions */
714 /* for those, see KDGKBLED and KDSKBLED above */
716 ucval = getledstate();
718 ret = put_user(ucval, (char __user *)arg);
724 setledstate(kbd, arg);
728 * A process can indicate its willingness to accept signals
729 * generated by pressing an appropriate key combination.
730 * Thus, one can have a daemon that e.g. spawns a new console
731 * upon a keypress and then changes to it.
732 * See also the kbrequest field of inittab(5).
736 if (!perm || !capable(CAP_KILL))
738 if (!valid_signal(arg) || arg < 1 || arg == SIGKILL)
741 spin_lock_irq(&vt_spawn_con.lock);
742 put_pid(vt_spawn_con.pid);
743 vt_spawn_con.pid = get_pid(task_pid(current));
744 vt_spawn_con.sig = arg;
745 spin_unlock_irq(&vt_spawn_con.lock);
756 if (copy_from_user(&tmp, up, sizeof(struct vt_mode))) {
760 if (tmp.mode != VT_AUTO && tmp.mode != VT_PROCESS) {
764 acquire_console_sem();
766 /* the frsig is ignored, so we set it to 0 */
767 vc->vt_mode.frsig = 0;
769 vc->vt_pid = get_pid(task_pid(current));
770 /* no switch is required -- saw@shade.msu.ru */
772 release_console_sem();
781 acquire_console_sem();
782 memcpy(&tmp, &vc->vt_mode, sizeof(struct vt_mode));
783 release_console_sem();
785 rc = copy_to_user(up, &tmp, sizeof(struct vt_mode));
792 * Returns global vt state. Note that VT 0 is always open, since
793 * it's an alias for the current VT, and people can't use it here.
794 * We cannot return state for more than 16 VTs, since v_state is short.
798 struct vt_stat __user *vtstat = up;
799 unsigned short state, mask;
801 if (put_user(fg_console + 1, &vtstat->v_active))
804 state = 1; /* /dev/tty0 is always open */
805 for (i = 0, mask = 2; i < MAX_NR_CONSOLES && mask;
809 ret = put_user(state, &vtstat->v_state);
815 * Returns the first available (non-opened) console.
818 for (i = 0; i < MAX_NR_CONSOLES; ++i)
819 if (! VT_IS_IN_USE(i))
821 ucval = i < MAX_NR_CONSOLES ? (i+1) : -1;
825 * ioctl(fd, VT_ACTIVATE, num) will cause us to switch to vt # num,
826 * with num >= 1 (switches to vt 0, our console, are not allowed, just
827 * to preserve sanity).
832 if (arg == 0 || arg > MAX_NR_CONSOLES)
836 acquire_console_sem();
837 ret = vc_allocate(arg);
838 release_console_sem();
846 * wait until the specified VT has been activated
851 if (arg == 0 || arg > MAX_NR_CONSOLES)
854 ret = vt_waitactive(arg - 1);
858 * If a vt is under process control, the kernel will not switch to it
859 * immediately, but postpone the operation until the process calls this
860 * ioctl, allowing the switch to complete.
862 * According to the X sources this is the behavior:
863 * 0: pending switch-from not OK
864 * 1: pending switch-from OK
865 * 2: completed switch-to OK
871 if (vc->vt_mode.mode != VT_PROCESS) {
876 * Switching-from response
878 acquire_console_sem();
879 if (vc->vt_newvt >= 0) {
882 * Switch disallowed, so forget we were trying
889 * The current vt has been released, so
890 * complete the switch.
893 newvt = vc->vt_newvt;
895 ret = vc_allocate(newvt);
897 release_console_sem();
901 * When we actually do the console switch,
902 * make sure we are atomic with respect to
903 * other console switches..
905 complete_change_console(vc_cons[newvt].d);
909 * Switched-to response
912 * If it's just an ACK, ignore it
914 if (arg != VT_ACKACQ)
917 release_console_sem();
921 * Disallocate memory associated to VT (but leave VT1)
924 if (arg > MAX_NR_CONSOLES) {
929 /* deallocate all unused consoles, but leave 0 */
930 acquire_console_sem();
931 for (i=1; i<MAX_NR_CONSOLES; i++)
934 release_console_sem();
936 /* deallocate a single console, if possible */
940 else if (arg) { /* leave 0 */
941 acquire_console_sem();
943 release_console_sem();
950 struct vt_sizes __user *vtsizes = up;
956 if (get_user(ll, &vtsizes->v_rows) ||
957 get_user(cc, &vtsizes->v_cols))
960 acquire_console_sem();
961 for (i = 0; i < MAX_NR_CONSOLES; i++) {
965 vc->vc_resize_user = 1;
966 vc_resize(vc_cons[i].d, cc, ll);
969 release_console_sem();
976 struct vt_consize __user *vtconsize = up;
977 ushort ll,cc,vlin,clin,vcol,ccol;
980 if (!access_ok(VERIFY_READ, vtconsize,
981 sizeof(struct vt_consize))) {
985 /* FIXME: Should check the copies properly */
986 __get_user(ll, &vtconsize->v_rows);
987 __get_user(cc, &vtconsize->v_cols);
988 __get_user(vlin, &vtconsize->v_vlin);
989 __get_user(clin, &vtconsize->v_clin);
990 __get_user(vcol, &vtconsize->v_vcol);
991 __get_user(ccol, &vtconsize->v_ccol);
992 vlin = vlin ? vlin : vc->vc_scan_lines;
995 if (ll != vlin/clin) {
996 /* Parameters don't add up */
1005 if (cc != vcol/ccol) {
1018 for (i = 0; i < MAX_NR_CONSOLES; i++) {
1021 acquire_console_sem();
1023 vc_cons[i].d->vc_scan_lines = vlin;
1025 vc_cons[i].d->vc_font.height = clin;
1026 vc_cons[i].d->vc_resize_user = 1;
1027 vc_resize(vc_cons[i].d, cc, ll);
1028 release_console_sem();
1036 op.op = KD_FONT_OP_SET;
1037 op.flags = KD_FONT_FLAG_OLD | KD_FONT_FLAG_DONT_RECALC; /* Compatibility */
1042 ret = con_font_op(vc_cons[fg_console].d, &op);
1047 op.op = KD_FONT_OP_GET;
1048 op.flags = KD_FONT_FLAG_OLD;
1053 ret = con_font_op(vc_cons[fg_console].d, &op);
1061 ret = con_set_cmap(up);
1065 ret = con_get_cmap(up);
1070 ret = do_fontx_ioctl(cmd, up, perm, &op);
1078 #ifdef BROKEN_GRAPHICS_PROGRAMS
1079 /* With BROKEN_GRAPHICS_PROGRAMS defined, the default
1080 font is not saved. */
1085 op.op = KD_FONT_OP_SET_DEFAULT;
1087 ret = con_font_op(vc_cons[fg_console].d, &op);
1090 con_set_default_unimap(vc_cons[fg_console].d);
1097 if (copy_from_user(&op, up, sizeof(op))) {
1101 if (!perm && op.op != KD_FONT_OP_GET)
1103 ret = con_font_op(vc, &op);
1106 if (copy_to_user(up, &op, sizeof(op)))
1115 ret = con_set_trans_old(up);
1119 ret = con_get_trans_old(up);
1122 case PIO_UNISCRNMAP:
1126 ret = con_set_trans_new(up);
1129 case GIO_UNISCRNMAP:
1130 ret = con_get_trans_new(up);
1134 { struct unimapinit ui;
1137 ret = copy_from_user(&ui, up, sizeof(struct unimapinit));
1139 con_clear_unimap(vc, &ui);
1145 ret = do_unimap_ioctl(cmd, up, perm, vc);
1149 if (!capable(CAP_SYS_TTY_CONFIG))
1153 case VT_UNLOCKSWITCH:
1154 if (!capable(CAP_SYS_TTY_CONFIG))
1158 case VT_GETHIFONTMASK:
1159 ret = put_user(vc->vc_hi_font_mask,
1160 (unsigned short __user *)arg);
1174 * Sometimes we want to wait until a particular VT has been activated. We
1175 * do it in a very simple manner. Everybody waits on a single queue and
1176 * get woken up at once. Those that are satisfied go on with their business,
1177 * while those not ready go back to sleep. Seems overkill to add a wait
1178 * to each vt just for this - usually this does nothing!
1180 static DECLARE_WAIT_QUEUE_HEAD(vt_activate_queue);
1183 * Sleeps until a vt is activated, or the task is interrupted. Returns
1184 * 0 if activation, -EINTR if interrupted by a signal handler.
1186 int vt_waitactive(int vt)
1189 DECLARE_WAITQUEUE(wait, current);
1191 add_wait_queue(&vt_activate_queue, &wait);
1196 * Synchronize with redraw_screen(). By acquiring the console
1197 * semaphore we make sure that the console switch is completed
1198 * before we return. If we didn't wait for the semaphore, we
1199 * could return at a point where fg_console has already been
1200 * updated, but the console switch hasn't been completed.
1202 acquire_console_sem();
1203 set_current_state(TASK_INTERRUPTIBLE);
1204 if (vt == fg_console) {
1205 release_console_sem();
1208 release_console_sem();
1209 retval = -ERESTARTNOHAND;
1210 if (signal_pending(current))
1214 remove_wait_queue(&vt_activate_queue, &wait);
1215 __set_current_state(TASK_RUNNING);
1219 #define vt_wake_waitactive() wake_up(&vt_activate_queue)
1221 void reset_vc(struct vc_data *vc)
1223 vc->vc_mode = KD_TEXT;
1224 kbd_table[vc->vc_num].kbdmode = default_utf8 ? VC_UNICODE : VC_XLATE;
1225 vc->vt_mode.mode = VT_AUTO;
1226 vc->vt_mode.waitv = 0;
1227 vc->vt_mode.relsig = 0;
1228 vc->vt_mode.acqsig = 0;
1229 vc->vt_mode.frsig = 0;
1230 put_pid(vc->vt_pid);
1233 if (!in_interrupt()) /* Via keyboard.c:SAK() - akpm */
1237 void vc_SAK(struct work_struct *work)
1240 container_of(work, struct vc, SAK_work);
1242 struct tty_struct *tty;
1244 acquire_console_sem();
1249 * SAK should also work in all raw modes and reset
1256 release_console_sem();
1260 * Performs the back end of a vt switch
1262 static void complete_change_console(struct vc_data *vc)
1264 unsigned char old_vc_mode;
1266 last_console = fg_console;
1269 * If we're switching, we could be going from KD_GRAPHICS to
1270 * KD_TEXT mode or vice versa, which means we need to blank or
1271 * unblank the screen later.
1273 old_vc_mode = vc_cons[fg_console].d->vc_mode;
1277 * This can't appear below a successful kill_pid(). If it did,
1278 * then the *blank_screen operation could occur while X, having
1279 * received acqsig, is waking up on another processor. This
1280 * condition can lead to overlapping accesses to the VGA range
1281 * and the framebuffer (causing system lockups).
1283 * To account for this we duplicate this code below only if the
1284 * controlling process is gone and we've called reset_vc.
1286 if (old_vc_mode != vc->vc_mode) {
1287 if (vc->vc_mode == KD_TEXT)
1288 do_unblank_screen(1);
1294 * If this new console is under process control, send it a signal
1295 * telling it that it has acquired. Also check if it has died and
1296 * clean up (similar to logic employed in change_console())
1298 if (vc->vt_mode.mode == VT_PROCESS) {
1300 * Send the signal as privileged - kill_pid() will
1301 * tell us if the process has gone or something else
1304 if (kill_pid(vc->vt_pid, vc->vt_mode.acqsig, 1) != 0) {
1306 * The controlling process has died, so we revert back to
1307 * normal operation. In this case, we'll also change back
1308 * to KD_TEXT mode. I'm not sure if this is strictly correct
1309 * but it saves the agony when the X server dies and the screen
1310 * remains blanked due to KD_GRAPHICS! It would be nice to do
1311 * this outside of VT_PROCESS but there is no single process
1312 * to account for and tracking tty count may be undesirable.
1316 if (old_vc_mode != vc->vc_mode) {
1317 if (vc->vc_mode == KD_TEXT)
1318 do_unblank_screen(1);
1326 * Wake anyone waiting for their VT to activate
1328 vt_wake_waitactive();
1333 * Performs the front-end of a vt switch
1335 void change_console(struct vc_data *new_vc)
1339 if (!new_vc || new_vc->vc_num == fg_console || vt_dont_switch)
1343 * If this vt is in process mode, then we need to handshake with
1344 * that process before switching. Essentially, we store where that
1345 * vt wants to switch to and wait for it to tell us when it's done
1346 * (via VT_RELDISP ioctl).
1348 * We also check to see if the controlling process still exists.
1349 * If it doesn't, we reset this vt to auto mode and continue.
1350 * This is a cheap way to track process control. The worst thing
1351 * that can happen is: we send a signal to a process, it dies, and
1352 * the switch gets "lost" waiting for a response; hopefully, the
1353 * user will try again, we'll detect the process is gone (unless
1354 * the user waits just the right amount of time :-) and revert the
1355 * vt to auto control.
1357 vc = vc_cons[fg_console].d;
1358 if (vc->vt_mode.mode == VT_PROCESS) {
1360 * Send the signal as privileged - kill_pid() will
1361 * tell us if the process has gone or something else
1364 * We need to set vt_newvt *before* sending the signal or we
1367 vc->vt_newvt = new_vc->vc_num;
1368 if (kill_pid(vc->vt_pid, vc->vt_mode.relsig, 1) == 0) {
1370 * It worked. Mark the vt to switch to and
1371 * return. The process needs to send us a
1372 * VT_RELDISP ioctl to complete the switch.
1378 * The controlling process has died, so we revert back to
1379 * normal operation. In this case, we'll also change back
1380 * to KD_TEXT mode. I'm not sure if this is strictly correct
1381 * but it saves the agony when the X server dies and the screen
1382 * remains blanked due to KD_GRAPHICS! It would be nice to do
1383 * this outside of VT_PROCESS but there is no single process
1384 * to account for and tracking tty count may be undesirable.
1389 * Fall through to normal (VT_AUTO) handling of the switch...
1394 * Ignore all switches in KD_GRAPHICS+VT_AUTO mode
1396 if (vc->vc_mode == KD_GRAPHICS)
1399 complete_change_console(new_vc);