1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright (C) 1992 obz under the linux copyright 4 * 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 10 */ 11 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> 20 #include <linux/kd.h> 21 #include <linux/vt.h> 22 #include <linux/string.h> 23 #include <linux/slab.h> 24 #include <linux/major.h> 25 #include <linux/fs.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> 31 32 #include <asm/io.h> 33 #include <linux/uaccess.h> 34 35 #include <linux/nospec.h> 36 37 #include <linux/kbd_kern.h> 38 #include <linux/vt_kern.h> 39 #include <linux/kbd_diacr.h> 40 #include <linux/selection.h> 41 42 bool vt_dont_switch; 43 44 static inline bool vt_in_use(unsigned int i) 45 { 46 const struct vc_data *vc = vc_cons[i].d; 47 48 /* 49 * console_lock must be held to prevent the vc from being deallocated 50 * while we're checking whether it's in-use. 51 */ 52 WARN_CONSOLE_UNLOCKED(); 53 54 return vc && kref_read(&vc->port.kref) > 1; 55 } 56 57 static inline bool vt_busy(int i) 58 { 59 if (vt_in_use(i)) 60 return true; 61 if (i == fg_console) 62 return true; 63 if (vc_is_sel(vc_cons[i].d)) 64 return true; 65 66 return false; 67 } 68 69 /* 70 * Console (vt and kd) routines, as defined by USL SVR4 manual, and by 71 * experimentation and study of X386 SYSV handling. 72 * 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. 80 */ 81 82 #ifdef CONFIG_X86 83 #include <asm/syscalls.h> 84 #endif 85 86 static void complete_change_console(struct vc_data *vc); 87 88 /* 89 * User space VT_EVENT handlers 90 */ 91 92 struct vt_event_wait { 93 struct list_head list; 94 struct vt_event event; 95 int done; 96 }; 97 98 static LIST_HEAD(vt_events); 99 static DEFINE_SPINLOCK(vt_event_lock); 100 static DECLARE_WAIT_QUEUE_HEAD(vt_event_waitqueue); 101 102 /** 103 * vt_event_post 104 * @event: the event that occurred 105 * @old: old console 106 * @new: new console 107 * 108 * Post an VT event to interested VT handlers 109 */ 110 111 void vt_event_post(unsigned int event, unsigned int old, unsigned int new) 112 { 113 struct list_head *pos, *head; 114 unsigned long flags; 115 int wake = 0; 116 117 spin_lock_irqsave(&vt_event_lock, flags); 118 head = &vt_events; 119 120 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)) 124 continue; 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; 130 wake = 1; 131 ve->done = 1; 132 } 133 spin_unlock_irqrestore(&vt_event_lock, flags); 134 if (wake) 135 wake_up_interruptible(&vt_event_waitqueue); 136 } 137 138 static void __vt_event_queue(struct vt_event_wait *vw) 139 { 140 unsigned long flags; 141 /* Prepare the event */ 142 INIT_LIST_HEAD(&vw->list); 143 vw->done = 0; 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); 148 } 149 150 static void __vt_event_wait(struct vt_event_wait *vw) 151 { 152 /* Wait for it to pass */ 153 wait_event_interruptible(vt_event_waitqueue, vw->done); 154 } 155 156 static void __vt_event_dequeue(struct vt_event_wait *vw) 157 { 158 unsigned long flags; 159 160 /* Dequeue it */ 161 spin_lock_irqsave(&vt_event_lock, flags); 162 list_del(&vw->list); 163 spin_unlock_irqrestore(&vt_event_lock, flags); 164 } 165 166 /** 167 * vt_event_wait - wait for an event 168 * @vw: our event 169 * 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. 173 */ 174 175 static void vt_event_wait(struct vt_event_wait *vw) 176 { 177 __vt_event_queue(vw); 178 __vt_event_wait(vw); 179 __vt_event_dequeue(vw); 180 } 181 182 /** 183 * vt_event_wait_ioctl - event ioctl handler 184 * @event: argument to ioctl (the event) 185 * 186 * Implement the VT_WAITEVENT ioctl using the VT event interface 187 */ 188 189 static int vt_event_wait_ioctl(struct vt_event __user *event) 190 { 191 struct vt_event_wait vw; 192 193 if (copy_from_user(&vw.event, event, sizeof(struct vt_event))) 194 return -EFAULT; 195 /* Highest supported event for now */ 196 if (vw.event.event & ~VT_MAX_EVENT) 197 return -EINVAL; 198 199 vt_event_wait(&vw); 200 /* If it occurred report it */ 201 if (vw.done) { 202 if (copy_to_user(event, &vw.event, sizeof(struct vt_event))) 203 return -EFAULT; 204 return 0; 205 } 206 return -EINTR; 207 } 208 209 /** 210 * vt_waitactive - active console wait 211 * @n: new console 212 * 213 * Helper for event waits. Used to implement the legacy 214 * event waiting ioctls in terms of events 215 */ 216 217 int vt_waitactive(int n) 218 { 219 struct vt_event_wait vw; 220 do { 221 vw.event.event = VT_EVENT_SWITCH; 222 __vt_event_queue(&vw); 223 if (n == fg_console + 1) { 224 __vt_event_dequeue(&vw); 225 break; 226 } 227 __vt_event_wait(&vw); 228 __vt_event_dequeue(&vw); 229 if (vw.done == 0) 230 return -EINTR; 231 } while (vw.event.newev != n); 232 return 0; 233 } 234 235 /* 236 * these are the valid i/o ports we're allowed to change. they map all the 237 * video ports 238 */ 239 #define GPFIRST 0x3b4 240 #define GPLAST 0x3df 241 #define GPNUM (GPLAST - GPFIRST + 1) 242 243 /* 244 * currently, setting the mode from KD_TEXT to KD_GRAPHICS doesn't do a whole 245 * lot. i'm not sure if it should do any restoration of modes or what... 246 * 247 * XXX It should at least call into the driver, fbdev's definitely need to 248 * restore their engine state. --BenH 249 */ 250 static int vt_kdsetmode(struct vc_data *vc, unsigned long mode) 251 { 252 switch (mode) { 253 case KD_GRAPHICS: 254 break; 255 case KD_TEXT0: 256 case KD_TEXT1: 257 mode = KD_TEXT; 258 fallthrough; 259 case KD_TEXT: 260 break; 261 default: 262 return -EINVAL; 263 } 264 265 /* FIXME: this needs the console lock extending */ 266 if (vc->vc_mode == mode) 267 return 0; 268 269 vc->vc_mode = mode; 270 if (vc->vc_num != fg_console) 271 return 0; 272 273 /* explicitly blank/unblank the screen if switching modes */ 274 console_lock(); 275 if (mode == KD_TEXT) 276 do_unblank_screen(1); 277 else 278 do_blank_screen(1); 279 console_unlock(); 280 281 return 0; 282 } 283 284 static int vt_k_ioctl(struct tty_struct *tty, unsigned int cmd, 285 unsigned long arg, bool perm) 286 { 287 struct vc_data *vc = tty->driver_data; 288 void __user *up = (void __user *)arg; 289 unsigned int console = vc->vc_num; 290 int ret; 291 292 switch (cmd) { 293 case KIOCSOUND: 294 if (!perm) 295 return -EPERM; 296 /* 297 * The use of PIT_TICK_RATE is historic, it used to be 298 * the platform-dependent CLOCK_TICK_RATE between 2.6.12 299 * and 2.6.36, which was a minor but unfortunate ABI 300 * change. kd_mksound is locked by the input layer. 301 */ 302 if (arg) 303 arg = PIT_TICK_RATE / arg; 304 kd_mksound(arg, 0); 305 break; 306 307 case KDMKTONE: 308 if (!perm) 309 return -EPERM; 310 { 311 unsigned int ticks, count; 312 313 /* 314 * Generate the tone for the appropriate number of ticks. 315 * If the time is zero, turn off sound ourselves. 316 */ 317 ticks = msecs_to_jiffies((arg >> 16) & 0xffff); 318 count = ticks ? (arg & 0xffff) : 0; 319 if (count) 320 count = PIT_TICK_RATE / count; 321 kd_mksound(count, ticks); 322 break; 323 } 324 325 case KDGKBTYPE: 326 /* 327 * this is naïve. 328 */ 329 return put_user(KB_101, (char __user *)arg); 330 331 /* 332 * These cannot be implemented on any machine that implements 333 * ioperm() in user level (such as Alpha PCs) or not at all. 334 * 335 * XXX: you should never use these, just call ioperm directly.. 336 */ 337 #ifdef CONFIG_X86 338 case KDADDIO: 339 case KDDELIO: 340 /* 341 * KDADDIO and KDDELIO may be able to add ports beyond what 342 * we reject here, but to be safe... 343 * 344 * These are locked internally via sys_ioperm 345 */ 346 if (arg < GPFIRST || arg > GPLAST) 347 return -EINVAL; 348 349 return ksys_ioperm(arg, 1, (cmd == KDADDIO)) ? -ENXIO : 0; 350 351 case KDENABIO: 352 case KDDISABIO: 353 return ksys_ioperm(GPFIRST, GPNUM, 354 (cmd == KDENABIO)) ? -ENXIO : 0; 355 #endif 356 357 /* Linux m68k/i386 interface for setting the keyboard delay/repeat rate */ 358 359 case KDKBDREP: 360 { 361 struct kbd_repeat kbrep; 362 363 if (!capable(CAP_SYS_TTY_CONFIG)) 364 return -EPERM; 365 366 if (copy_from_user(&kbrep, up, sizeof(struct kbd_repeat))) 367 return -EFAULT; 368 369 ret = kbd_rate(&kbrep); 370 if (ret) 371 return ret; 372 if (copy_to_user(up, &kbrep, sizeof(struct kbd_repeat))) 373 return -EFAULT; 374 break; 375 } 376 377 case KDSETMODE: 378 if (!perm) 379 return -EPERM; 380 381 return vt_kdsetmode(vc, arg); 382 383 case KDGETMODE: 384 return put_user(vc->vc_mode, (int __user *)arg); 385 386 case KDMAPDISP: 387 case KDUNMAPDISP: 388 /* 389 * these work like a combination of mmap and KDENABIO. 390 * this could be easily finished. 391 */ 392 return -EINVAL; 393 394 case KDSKBMODE: 395 if (!perm) 396 return -EPERM; 397 ret = vt_do_kdskbmode(console, arg); 398 if (ret) 399 return ret; 400 tty_ldisc_flush(tty); 401 break; 402 403 case KDGKBMODE: 404 return put_user(vt_do_kdgkbmode(console), (int __user *)arg); 405 406 /* this could be folded into KDSKBMODE, but for compatibility 407 reasons it is not so easy to fold KDGKBMETA into KDGKBMODE */ 408 case KDSKBMETA: 409 return vt_do_kdskbmeta(console, arg); 410 411 case KDGKBMETA: 412 /* FIXME: should review whether this is worth locking */ 413 return put_user(vt_do_kdgkbmeta(console), (int __user *)arg); 414 415 case KDGETKEYCODE: 416 case KDSETKEYCODE: 417 if(!capable(CAP_SYS_TTY_CONFIG)) 418 perm = 0; 419 return vt_do_kbkeycode_ioctl(cmd, up, perm); 420 421 case KDGKBENT: 422 case KDSKBENT: 423 return vt_do_kdsk_ioctl(cmd, up, perm, console); 424 425 case KDGKBSENT: 426 case KDSKBSENT: 427 return vt_do_kdgkb_ioctl(cmd, up, perm); 428 429 /* Diacritical processing. Handled in keyboard.c as it has 430 to operate on the keyboard locks and structures */ 431 case KDGKBDIACR: 432 case KDGKBDIACRUC: 433 case KDSKBDIACR: 434 case KDSKBDIACRUC: 435 return vt_do_diacrit(cmd, up, perm); 436 437 /* the ioctls below read/set the flags usually shown in the leds */ 438 /* don't use them - they will go away without warning */ 439 case KDGKBLED: 440 case KDSKBLED: 441 case KDGETLED: 442 case KDSETLED: 443 return vt_do_kdskled(console, cmd, arg, perm); 444 445 /* 446 * A process can indicate its willingness to accept signals 447 * generated by pressing an appropriate key combination. 448 * Thus, one can have a daemon that e.g. spawns a new console 449 * upon a keypress and then changes to it. 450 * See also the kbrequest field of inittab(5). 451 */ 452 case KDSIGACCEPT: 453 if (!perm || !capable(CAP_KILL)) 454 return -EPERM; 455 if (!valid_signal(arg) || arg < 1 || arg == SIGKILL) 456 return -EINVAL; 457 458 spin_lock_irq(&vt_spawn_con.lock); 459 put_pid(vt_spawn_con.pid); 460 vt_spawn_con.pid = get_pid(task_pid(current)); 461 vt_spawn_con.sig = arg; 462 spin_unlock_irq(&vt_spawn_con.lock); 463 break; 464 465 case KDFONTOP: { 466 struct console_font_op op; 467 468 if (copy_from_user(&op, up, sizeof(op))) 469 return -EFAULT; 470 if (!perm && op.op != KD_FONT_OP_GET) 471 return -EPERM; 472 ret = con_font_op(vc, &op); 473 if (ret) 474 return ret; 475 if (copy_to_user(up, &op, sizeof(op))) 476 return -EFAULT; 477 break; 478 } 479 480 default: 481 return -ENOIOCTLCMD; 482 } 483 484 return 0; 485 } 486 487 static inline int do_unimap_ioctl(int cmd, struct unimapdesc __user *user_ud, 488 bool perm, struct vc_data *vc) 489 { 490 struct unimapdesc tmp; 491 492 if (copy_from_user(&tmp, user_ud, sizeof tmp)) 493 return -EFAULT; 494 switch (cmd) { 495 case PIO_UNIMAP: 496 if (!perm) 497 return -EPERM; 498 return con_set_unimap(vc, tmp.entry_ct, tmp.entries); 499 case GIO_UNIMAP: 500 if (!perm && fg_console != vc->vc_num) 501 return -EPERM; 502 return con_get_unimap(vc, tmp.entry_ct, &(user_ud->entry_ct), 503 tmp.entries); 504 } 505 return 0; 506 } 507 508 static int vt_io_ioctl(struct vc_data *vc, unsigned int cmd, void __user *up, 509 bool perm) 510 { 511 switch (cmd) { 512 case PIO_CMAP: 513 if (!perm) 514 return -EPERM; 515 return con_set_cmap(up); 516 517 case GIO_CMAP: 518 return con_get_cmap(up); 519 520 case PIO_SCRNMAP: 521 if (!perm) 522 return -EPERM; 523 return con_set_trans_old(up); 524 525 case GIO_SCRNMAP: 526 return con_get_trans_old(up); 527 528 case PIO_UNISCRNMAP: 529 if (!perm) 530 return -EPERM; 531 return con_set_trans_new(up); 532 533 case GIO_UNISCRNMAP: 534 return con_get_trans_new(up); 535 536 case PIO_UNIMAPCLR: 537 if (!perm) 538 return -EPERM; 539 con_clear_unimap(vc); 540 break; 541 542 case PIO_UNIMAP: 543 case GIO_UNIMAP: 544 return do_unimap_ioctl(cmd, up, perm, vc); 545 546 default: 547 return -ENOIOCTLCMD; 548 } 549 550 return 0; 551 } 552 553 static int vt_reldisp(struct vc_data *vc, unsigned int swtch) 554 { 555 int newvt, ret; 556 557 if (vc->vt_mode.mode != VT_PROCESS) 558 return -EINVAL; 559 560 /* Switched-to response */ 561 if (vc->vt_newvt < 0) { 562 /* If it's just an ACK, ignore it */ 563 return swtch == VT_ACKACQ ? 0 : -EINVAL; 564 } 565 566 /* Switching-from response */ 567 if (swtch == 0) { 568 /* Switch disallowed, so forget we were trying to do it. */ 569 vc->vt_newvt = -1; 570 return 0; 571 } 572 573 /* The current vt has been released, so complete the switch. */ 574 newvt = vc->vt_newvt; 575 vc->vt_newvt = -1; 576 ret = vc_allocate(newvt); 577 if (ret) 578 return ret; 579 580 /* 581 * When we actually do the console switch, make sure we are atomic with 582 * respect to other console switches.. 583 */ 584 complete_change_console(vc_cons[newvt].d); 585 586 return 0; 587 } 588 589 static int vt_setactivate(struct vt_setactivate __user *sa) 590 { 591 struct vt_setactivate vsa; 592 struct vc_data *nvc; 593 int ret; 594 595 if (copy_from_user(&vsa, sa, sizeof(vsa))) 596 return -EFAULT; 597 if (vsa.console == 0 || vsa.console > MAX_NR_CONSOLES) 598 return -ENXIO; 599 600 vsa.console = array_index_nospec(vsa.console, MAX_NR_CONSOLES + 1); 601 vsa.console--; 602 console_lock(); 603 ret = vc_allocate(vsa.console); 604 if (ret) { 605 console_unlock(); 606 return ret; 607 } 608 609 /* 610 * This is safe providing we don't drop the console sem between 611 * vc_allocate and finishing referencing nvc. 612 */ 613 nvc = vc_cons[vsa.console].d; 614 nvc->vt_mode = vsa.mode; 615 nvc->vt_mode.frsig = 0; 616 put_pid(nvc->vt_pid); 617 nvc->vt_pid = get_pid(task_pid(current)); 618 console_unlock(); 619 620 /* Commence switch and lock */ 621 /* Review set_console locks */ 622 set_console(vsa.console); 623 624 return 0; 625 } 626 627 /* deallocate a single console, if possible (leave 0) */ 628 static int vt_disallocate(unsigned int vc_num) 629 { 630 struct vc_data *vc = NULL; 631 int ret = 0; 632 633 console_lock(); 634 if (vt_busy(vc_num)) 635 ret = -EBUSY; 636 else if (vc_num) 637 vc = vc_deallocate(vc_num); 638 console_unlock(); 639 640 if (vc && vc_num >= MIN_NR_CONSOLES) 641 tty_port_put(&vc->port); 642 643 return ret; 644 } 645 646 /* deallocate all unused consoles, but leave 0 */ 647 static void vt_disallocate_all(void) 648 { 649 struct vc_data *vc[MAX_NR_CONSOLES]; 650 int i; 651 652 console_lock(); 653 for (i = 1; i < MAX_NR_CONSOLES; i++) 654 if (!vt_busy(i)) 655 vc[i] = vc_deallocate(i); 656 else 657 vc[i] = NULL; 658 console_unlock(); 659 660 for (i = 1; i < MAX_NR_CONSOLES; i++) { 661 if (vc[i] && i >= MIN_NR_CONSOLES) 662 tty_port_put(&vc[i]->port); 663 } 664 } 665 666 static int vt_resizex(struct vc_data *vc, struct vt_consize __user *cs) 667 { 668 struct vt_consize v; 669 int i; 670 671 if (copy_from_user(&v, cs, sizeof(struct vt_consize))) 672 return -EFAULT; 673 674 if (v.v_vlin) 675 pr_info_once("\"struct vt_consize\"->v_vlin is ignored. Please report if you need this.\n"); 676 if (v.v_clin) 677 pr_info_once("\"struct vt_consize\"->v_clin is ignored. Please report if you need this.\n"); 678 679 console_lock(); 680 for (i = 0; i < MAX_NR_CONSOLES; i++) { 681 vc = vc_cons[i].d; 682 683 if (vc) { 684 vc->vc_resize_user = 1; 685 vc_resize(vc, v.v_cols, v.v_rows); 686 } 687 } 688 console_unlock(); 689 690 return 0; 691 } 692 693 /* 694 * We handle the console-specific ioctl's here. We allow the 695 * capability to modify any console, not just the fg_console. 696 */ 697 int vt_ioctl(struct tty_struct *tty, 698 unsigned int cmd, unsigned long arg) 699 { 700 struct vc_data *vc = tty->driver_data; 701 void __user *up = (void __user *)arg; 702 int i, perm; 703 int ret; 704 705 /* 706 * To have permissions to do most of the vt ioctls, we either have 707 * to be the owner of the tty, or have CAP_SYS_TTY_CONFIG. 708 */ 709 perm = 0; 710 if (current->signal->tty == tty || capable(CAP_SYS_TTY_CONFIG)) 711 perm = 1; 712 713 ret = vt_k_ioctl(tty, cmd, arg, perm); 714 if (ret != -ENOIOCTLCMD) 715 return ret; 716 717 ret = vt_io_ioctl(vc, cmd, up, perm); 718 if (ret != -ENOIOCTLCMD) 719 return ret; 720 721 switch (cmd) { 722 case TIOCLINUX: 723 return tioclinux(tty, arg); 724 case VT_SETMODE: 725 { 726 struct vt_mode tmp; 727 728 if (!perm) 729 return -EPERM; 730 if (copy_from_user(&tmp, up, sizeof(struct vt_mode))) 731 return -EFAULT; 732 if (tmp.mode != VT_AUTO && tmp.mode != VT_PROCESS) 733 return -EINVAL; 734 735 console_lock(); 736 vc->vt_mode = tmp; 737 /* the frsig is ignored, so we set it to 0 */ 738 vc->vt_mode.frsig = 0; 739 put_pid(vc->vt_pid); 740 vc->vt_pid = get_pid(task_pid(current)); 741 /* no switch is required -- saw@shade.msu.ru */ 742 vc->vt_newvt = -1; 743 console_unlock(); 744 break; 745 } 746 747 case VT_GETMODE: 748 { 749 struct vt_mode tmp; 750 int rc; 751 752 console_lock(); 753 memcpy(&tmp, &vc->vt_mode, sizeof(struct vt_mode)); 754 console_unlock(); 755 756 rc = copy_to_user(up, &tmp, sizeof(struct vt_mode)); 757 if (rc) 758 return -EFAULT; 759 break; 760 } 761 762 /* 763 * Returns global vt state. Note that VT 0 is always open, since 764 * it's an alias for the current VT, and people can't use it here. 765 * We cannot return state for more than 16 VTs, since v_state is short. 766 */ 767 case VT_GETSTATE: 768 { 769 struct vt_stat __user *vtstat = up; 770 unsigned short state, mask; 771 772 if (put_user(fg_console + 1, &vtstat->v_active)) 773 return -EFAULT; 774 775 state = 1; /* /dev/tty0 is always open */ 776 console_lock(); /* required by vt_in_use() */ 777 for (i = 0, mask = 2; i < MAX_NR_CONSOLES && mask; 778 ++i, mask <<= 1) 779 if (vt_in_use(i)) 780 state |= mask; 781 console_unlock(); 782 return put_user(state, &vtstat->v_state); 783 } 784 785 /* 786 * Returns the first available (non-opened) console. 787 */ 788 case VT_OPENQRY: 789 console_lock(); /* required by vt_in_use() */ 790 for (i = 0; i < MAX_NR_CONSOLES; ++i) 791 if (!vt_in_use(i)) 792 break; 793 console_unlock(); 794 i = i < MAX_NR_CONSOLES ? (i+1) : -1; 795 return put_user(i, (int __user *)arg); 796 797 /* 798 * ioctl(fd, VT_ACTIVATE, num) will cause us to switch to vt # num, 799 * with num >= 1 (switches to vt 0, our console, are not allowed, just 800 * to preserve sanity). 801 */ 802 case VT_ACTIVATE: 803 if (!perm) 804 return -EPERM; 805 if (arg == 0 || arg > MAX_NR_CONSOLES) 806 return -ENXIO; 807 808 arg--; 809 console_lock(); 810 ret = vc_allocate(arg); 811 console_unlock(); 812 if (ret) 813 return ret; 814 set_console(arg); 815 break; 816 817 case VT_SETACTIVATE: 818 if (!perm) 819 return -EPERM; 820 821 return vt_setactivate(up); 822 823 /* 824 * wait until the specified VT has been activated 825 */ 826 case VT_WAITACTIVE: 827 if (!perm) 828 return -EPERM; 829 if (arg == 0 || arg > MAX_NR_CONSOLES) 830 return -ENXIO; 831 return vt_waitactive(arg); 832 833 /* 834 * If a vt is under process control, the kernel will not switch to it 835 * immediately, but postpone the operation until the process calls this 836 * ioctl, allowing the switch to complete. 837 * 838 * According to the X sources this is the behavior: 839 * 0: pending switch-from not OK 840 * 1: pending switch-from OK 841 * 2: completed switch-to OK 842 */ 843 case VT_RELDISP: 844 if (!perm) 845 return -EPERM; 846 847 console_lock(); 848 ret = vt_reldisp(vc, arg); 849 console_unlock(); 850 851 return ret; 852 853 854 /* 855 * Disallocate memory associated to VT (but leave VT1) 856 */ 857 case VT_DISALLOCATE: 858 if (arg > MAX_NR_CONSOLES) 859 return -ENXIO; 860 861 if (arg == 0) 862 vt_disallocate_all(); 863 else 864 return vt_disallocate(--arg); 865 break; 866 867 case VT_RESIZE: 868 { 869 struct vt_sizes __user *vtsizes = up; 870 struct vc_data *vc; 871 ushort ll,cc; 872 873 if (!perm) 874 return -EPERM; 875 if (get_user(ll, &vtsizes->v_rows) || 876 get_user(cc, &vtsizes->v_cols)) 877 return -EFAULT; 878 879 console_lock(); 880 for (i = 0; i < MAX_NR_CONSOLES; i++) { 881 vc = vc_cons[i].d; 882 883 if (vc) { 884 vc->vc_resize_user = 1; 885 /* FIXME: review v tty lock */ 886 vc_resize(vc_cons[i].d, cc, ll); 887 } 888 } 889 console_unlock(); 890 break; 891 } 892 893 case VT_RESIZEX: 894 if (!perm) 895 return -EPERM; 896 897 return vt_resizex(vc, up); 898 899 case VT_LOCKSWITCH: 900 if (!capable(CAP_SYS_TTY_CONFIG)) 901 return -EPERM; 902 vt_dont_switch = true; 903 break; 904 case VT_UNLOCKSWITCH: 905 if (!capable(CAP_SYS_TTY_CONFIG)) 906 return -EPERM; 907 vt_dont_switch = false; 908 break; 909 case VT_GETHIFONTMASK: 910 return put_user(vc->vc_hi_font_mask, 911 (unsigned short __user *)arg); 912 case VT_WAITEVENT: 913 return vt_event_wait_ioctl((struct vt_event __user *)arg); 914 default: 915 return -ENOIOCTLCMD; 916 } 917 918 return 0; 919 } 920 921 void reset_vc(struct vc_data *vc) 922 { 923 vc->vc_mode = KD_TEXT; 924 vt_reset_unicode(vc->vc_num); 925 vc->vt_mode.mode = VT_AUTO; 926 vc->vt_mode.waitv = 0; 927 vc->vt_mode.relsig = 0; 928 vc->vt_mode.acqsig = 0; 929 vc->vt_mode.frsig = 0; 930 put_pid(vc->vt_pid); 931 vc->vt_pid = NULL; 932 vc->vt_newvt = -1; 933 reset_palette(vc); 934 } 935 936 void vc_SAK(struct work_struct *work) 937 { 938 struct vc *vc_con = 939 container_of(work, struct vc, SAK_work); 940 struct vc_data *vc; 941 struct tty_struct *tty; 942 943 console_lock(); 944 vc = vc_con->d; 945 if (vc) { 946 /* FIXME: review tty ref counting */ 947 tty = vc->port.tty; 948 /* 949 * SAK should also work in all raw modes and reset 950 * them properly. 951 */ 952 if (tty) 953 __do_SAK(tty); 954 reset_vc(vc); 955 } 956 console_unlock(); 957 } 958 959 #ifdef CONFIG_COMPAT 960 961 struct compat_console_font_op { 962 compat_uint_t op; /* operation code KD_FONT_OP_* */ 963 compat_uint_t flags; /* KD_FONT_FLAG_* */ 964 compat_uint_t width, height; /* font size */ 965 compat_uint_t charcount; 966 compat_caddr_t data; /* font data with height fixed to 32 */ 967 }; 968 969 static inline int 970 compat_kdfontop_ioctl(struct compat_console_font_op __user *fontop, 971 int perm, struct console_font_op *op, struct vc_data *vc) 972 { 973 int i; 974 975 if (copy_from_user(op, fontop, sizeof(struct compat_console_font_op))) 976 return -EFAULT; 977 if (!perm && op->op != KD_FONT_OP_GET) 978 return -EPERM; 979 op->data = compat_ptr(((struct compat_console_font_op *)op)->data); 980 i = con_font_op(vc, op); 981 if (i) 982 return i; 983 ((struct compat_console_font_op *)op)->data = (unsigned long)op->data; 984 if (copy_to_user(fontop, op, sizeof(struct compat_console_font_op))) 985 return -EFAULT; 986 return 0; 987 } 988 989 struct compat_unimapdesc { 990 unsigned short entry_ct; 991 compat_caddr_t entries; 992 }; 993 994 static inline int 995 compat_unimap_ioctl(unsigned int cmd, struct compat_unimapdesc __user *user_ud, 996 int perm, struct vc_data *vc) 997 { 998 struct compat_unimapdesc tmp; 999 struct unipair __user *tmp_entries; 1000 1001 if (copy_from_user(&tmp, user_ud, sizeof tmp)) 1002 return -EFAULT; 1003 tmp_entries = compat_ptr(tmp.entries); 1004 switch (cmd) { 1005 case PIO_UNIMAP: 1006 if (!perm) 1007 return -EPERM; 1008 return con_set_unimap(vc, tmp.entry_ct, tmp_entries); 1009 case GIO_UNIMAP: 1010 if (!perm && fg_console != vc->vc_num) 1011 return -EPERM; 1012 return con_get_unimap(vc, tmp.entry_ct, &(user_ud->entry_ct), tmp_entries); 1013 } 1014 return 0; 1015 } 1016 1017 long vt_compat_ioctl(struct tty_struct *tty, 1018 unsigned int cmd, unsigned long arg) 1019 { 1020 struct vc_data *vc = tty->driver_data; 1021 struct console_font_op op; /* used in multiple places here */ 1022 void __user *up = compat_ptr(arg); 1023 int perm; 1024 1025 /* 1026 * To have permissions to do most of the vt ioctls, we either have 1027 * to be the owner of the tty, or have CAP_SYS_TTY_CONFIG. 1028 */ 1029 perm = 0; 1030 if (current->signal->tty == tty || capable(CAP_SYS_TTY_CONFIG)) 1031 perm = 1; 1032 1033 switch (cmd) { 1034 /* 1035 * these need special handlers for incompatible data structures 1036 */ 1037 1038 case KDFONTOP: 1039 return compat_kdfontop_ioctl(up, perm, &op, vc); 1040 1041 case PIO_UNIMAP: 1042 case GIO_UNIMAP: 1043 return compat_unimap_ioctl(cmd, up, perm, vc); 1044 1045 /* 1046 * all these treat 'arg' as an integer 1047 */ 1048 case KIOCSOUND: 1049 case KDMKTONE: 1050 #ifdef CONFIG_X86 1051 case KDADDIO: 1052 case KDDELIO: 1053 #endif 1054 case KDSETMODE: 1055 case KDMAPDISP: 1056 case KDUNMAPDISP: 1057 case KDSKBMODE: 1058 case KDSKBMETA: 1059 case KDSKBLED: 1060 case KDSETLED: 1061 case KDSIGACCEPT: 1062 case VT_ACTIVATE: 1063 case VT_WAITACTIVE: 1064 case VT_RELDISP: 1065 case VT_DISALLOCATE: 1066 case VT_RESIZE: 1067 case VT_RESIZEX: 1068 return vt_ioctl(tty, cmd, arg); 1069 1070 /* 1071 * the rest has a compatible data structure behind arg, 1072 * but we have to convert it to a proper 64 bit pointer. 1073 */ 1074 default: 1075 return vt_ioctl(tty, cmd, (unsigned long)up); 1076 } 1077 } 1078 1079 1080 #endif /* CONFIG_COMPAT */ 1081 1082 1083 /* 1084 * Performs the back end of a vt switch. Called under the console 1085 * semaphore. 1086 */ 1087 static void complete_change_console(struct vc_data *vc) 1088 { 1089 unsigned char old_vc_mode; 1090 int old = fg_console; 1091 1092 last_console = fg_console; 1093 1094 /* 1095 * If we're switching, we could be going from KD_GRAPHICS to 1096 * KD_TEXT mode or vice versa, which means we need to blank or 1097 * unblank the screen later. 1098 */ 1099 old_vc_mode = vc_cons[fg_console].d->vc_mode; 1100 switch_screen(vc); 1101 1102 /* 1103 * This can't appear below a successful kill_pid(). If it did, 1104 * then the *blank_screen operation could occur while X, having 1105 * received acqsig, is waking up on another processor. This 1106 * condition can lead to overlapping accesses to the VGA range 1107 * and the framebuffer (causing system lockups). 1108 * 1109 * To account for this we duplicate this code below only if the 1110 * controlling process is gone and we've called reset_vc. 1111 */ 1112 if (old_vc_mode != vc->vc_mode) { 1113 if (vc->vc_mode == KD_TEXT) 1114 do_unblank_screen(1); 1115 else 1116 do_blank_screen(1); 1117 } 1118 1119 /* 1120 * If this new console is under process control, send it a signal 1121 * telling it that it has acquired. Also check if it has died and 1122 * clean up (similar to logic employed in change_console()) 1123 */ 1124 if (vc->vt_mode.mode == VT_PROCESS) { 1125 /* 1126 * Send the signal as privileged - kill_pid() will 1127 * tell us if the process has gone or something else 1128 * is awry 1129 */ 1130 if (kill_pid(vc->vt_pid, vc->vt_mode.acqsig, 1) != 0) { 1131 /* 1132 * The controlling process has died, so we revert back to 1133 * normal operation. In this case, we'll also change back 1134 * to KD_TEXT mode. I'm not sure if this is strictly correct 1135 * but it saves the agony when the X server dies and the screen 1136 * remains blanked due to KD_GRAPHICS! It would be nice to do 1137 * this outside of VT_PROCESS but there is no single process 1138 * to account for and tracking tty count may be undesirable. 1139 */ 1140 reset_vc(vc); 1141 1142 if (old_vc_mode != vc->vc_mode) { 1143 if (vc->vc_mode == KD_TEXT) 1144 do_unblank_screen(1); 1145 else 1146 do_blank_screen(1); 1147 } 1148 } 1149 } 1150 1151 /* 1152 * Wake anyone waiting for their VT to activate 1153 */ 1154 vt_event_post(VT_EVENT_SWITCH, old, vc->vc_num); 1155 return; 1156 } 1157 1158 /* 1159 * Performs the front-end of a vt switch 1160 */ 1161 void change_console(struct vc_data *new_vc) 1162 { 1163 struct vc_data *vc; 1164 1165 if (!new_vc || new_vc->vc_num == fg_console || vt_dont_switch) 1166 return; 1167 1168 /* 1169 * If this vt is in process mode, then we need to handshake with 1170 * that process before switching. Essentially, we store where that 1171 * vt wants to switch to and wait for it to tell us when it's done 1172 * (via VT_RELDISP ioctl). 1173 * 1174 * We also check to see if the controlling process still exists. 1175 * If it doesn't, we reset this vt to auto mode and continue. 1176 * This is a cheap way to track process control. The worst thing 1177 * that can happen is: we send a signal to a process, it dies, and 1178 * the switch gets "lost" waiting for a response; hopefully, the 1179 * user will try again, we'll detect the process is gone (unless 1180 * the user waits just the right amount of time :-) and revert the 1181 * vt to auto control. 1182 */ 1183 vc = vc_cons[fg_console].d; 1184 if (vc->vt_mode.mode == VT_PROCESS) { 1185 /* 1186 * Send the signal as privileged - kill_pid() will 1187 * tell us if the process has gone or something else 1188 * is awry. 1189 * 1190 * We need to set vt_newvt *before* sending the signal or we 1191 * have a race. 1192 */ 1193 vc->vt_newvt = new_vc->vc_num; 1194 if (kill_pid(vc->vt_pid, vc->vt_mode.relsig, 1) == 0) { 1195 /* 1196 * It worked. Mark the vt to switch to and 1197 * return. The process needs to send us a 1198 * VT_RELDISP ioctl to complete the switch. 1199 */ 1200 return; 1201 } 1202 1203 /* 1204 * The controlling process has died, so we revert back to 1205 * normal operation. In this case, we'll also change back 1206 * to KD_TEXT mode. I'm not sure if this is strictly correct 1207 * but it saves the agony when the X server dies and the screen 1208 * remains blanked due to KD_GRAPHICS! It would be nice to do 1209 * this outside of VT_PROCESS but there is no single process 1210 * to account for and tracking tty count may be undesirable. 1211 */ 1212 reset_vc(vc); 1213 1214 /* 1215 * Fall through to normal (VT_AUTO) handling of the switch... 1216 */ 1217 } 1218 1219 /* 1220 * Ignore all switches in KD_GRAPHICS+VT_AUTO mode 1221 */ 1222 if (vc->vc_mode == KD_GRAPHICS) 1223 return; 1224 1225 complete_change_console(new_vc); 1226 } 1227 1228 /* Perform a kernel triggered VT switch for suspend/resume */ 1229 1230 static int disable_vt_switch; 1231 1232 int vt_move_to_console(unsigned int vt, int alloc) 1233 { 1234 int prev; 1235 1236 console_lock(); 1237 /* Graphics mode - up to X */ 1238 if (disable_vt_switch) { 1239 console_unlock(); 1240 return 0; 1241 } 1242 prev = fg_console; 1243 1244 if (alloc && vc_allocate(vt)) { 1245 /* we can't have a free VC for now. Too bad, 1246 * we don't want to mess the screen for now. */ 1247 console_unlock(); 1248 return -ENOSPC; 1249 } 1250 1251 if (set_console(vt)) { 1252 /* 1253 * We're unable to switch to the SUSPEND_CONSOLE. 1254 * Let the calling function know so it can decide 1255 * what to do. 1256 */ 1257 console_unlock(); 1258 return -EIO; 1259 } 1260 console_unlock(); 1261 if (vt_waitactive(vt + 1)) { 1262 pr_debug("Suspend: Can't switch VCs."); 1263 return -EINTR; 1264 } 1265 return prev; 1266 } 1267 1268 /* 1269 * Normally during a suspend, we allocate a new console and switch to it. 1270 * When we resume, we switch back to the original console. This switch 1271 * can be slow, so on systems where the framebuffer can handle restoration 1272 * of video registers anyways, there's little point in doing the console 1273 * switch. This function allows you to disable it by passing it '0'. 1274 */ 1275 void pm_set_vt_switch(int do_switch) 1276 { 1277 console_lock(); 1278 disable_vt_switch = !do_switch; 1279 console_unlock(); 1280 } 1281 EXPORT_SYMBOL(pm_set_vt_switch); 1282