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_fontx_ioctl(int cmd, 488 struct consolefontdesc __user *user_cfd, 489 struct console_font_op *op) 490 { 491 struct consolefontdesc cfdarg; 492 int i; 493 494 if (copy_from_user(&cfdarg, user_cfd, sizeof(struct consolefontdesc))) 495 return -EFAULT; 496 497 switch (cmd) { 498 case PIO_FONTX: 499 op->op = KD_FONT_OP_SET; 500 op->flags = KD_FONT_FLAG_OLD; 501 op->width = 8; 502 op->height = cfdarg.charheight; 503 op->charcount = cfdarg.charcount; 504 op->data = cfdarg.chardata; 505 return con_font_op(vc_cons[fg_console].d, op); 506 case GIO_FONTX: { 507 op->op = KD_FONT_OP_GET; 508 op->flags = KD_FONT_FLAG_OLD; 509 op->width = 8; 510 op->height = cfdarg.charheight; 511 op->charcount = cfdarg.charcount; 512 op->data = cfdarg.chardata; 513 i = con_font_op(vc_cons[fg_console].d, op); 514 if (i) 515 return i; 516 cfdarg.charheight = op->height; 517 cfdarg.charcount = op->charcount; 518 if (copy_to_user(user_cfd, &cfdarg, sizeof(struct consolefontdesc))) 519 return -EFAULT; 520 return 0; 521 } 522 } 523 return -EINVAL; 524 } 525 526 static int vt_io_fontreset(struct console_font_op *op) 527 { 528 int ret; 529 530 if (__is_defined(BROKEN_GRAPHICS_PROGRAMS)) { 531 /* 532 * With BROKEN_GRAPHICS_PROGRAMS defined, the default font is 533 * not saved. 534 */ 535 return -ENOSYS; 536 } 537 538 op->op = KD_FONT_OP_SET_DEFAULT; 539 op->data = NULL; 540 ret = con_font_op(vc_cons[fg_console].d, op); 541 if (ret) 542 return ret; 543 544 console_lock(); 545 con_set_default_unimap(vc_cons[fg_console].d); 546 console_unlock(); 547 548 return 0; 549 } 550 551 static inline int do_unimap_ioctl(int cmd, struct unimapdesc __user *user_ud, 552 struct vc_data *vc) 553 { 554 struct unimapdesc tmp; 555 556 if (copy_from_user(&tmp, user_ud, sizeof tmp)) 557 return -EFAULT; 558 switch (cmd) { 559 case PIO_UNIMAP: 560 return con_set_unimap(vc, tmp.entry_ct, tmp.entries); 561 case GIO_UNIMAP: 562 if (fg_console != vc->vc_num) 563 return -EPERM; 564 return con_get_unimap(vc, tmp.entry_ct, &(user_ud->entry_ct), 565 tmp.entries); 566 } 567 return 0; 568 } 569 570 static int vt_io_ioctl(struct vc_data *vc, unsigned int cmd, void __user *up, 571 bool perm) 572 { 573 struct console_font_op op; /* used in multiple places here */ 574 575 switch (cmd) { 576 case PIO_FONT: 577 if (!perm) 578 return -EPERM; 579 op.op = KD_FONT_OP_SET; 580 op.flags = KD_FONT_FLAG_OLD | KD_FONT_FLAG_DONT_RECALC; /* Compatibility */ 581 op.width = 8; 582 op.height = 0; 583 op.charcount = 256; 584 op.data = up; 585 return con_font_op(vc_cons[fg_console].d, &op); 586 587 case GIO_FONT: 588 op.op = KD_FONT_OP_GET; 589 op.flags = KD_FONT_FLAG_OLD; 590 op.width = 8; 591 op.height = 32; 592 op.charcount = 256; 593 op.data = up; 594 return con_font_op(vc_cons[fg_console].d, &op); 595 596 case PIO_CMAP: 597 if (!perm) 598 return -EPERM; 599 return con_set_cmap(up); 600 601 case GIO_CMAP: 602 return con_get_cmap(up); 603 604 case PIO_FONTX: 605 if (!perm) 606 return -EPERM; 607 608 fallthrough; 609 case GIO_FONTX: 610 return do_fontx_ioctl(cmd, up, &op); 611 612 case PIO_FONTRESET: 613 if (!perm) 614 return -EPERM; 615 616 return vt_io_fontreset(&op); 617 618 case PIO_SCRNMAP: 619 if (!perm) 620 return -EPERM; 621 return con_set_trans_old(up); 622 623 case GIO_SCRNMAP: 624 return con_get_trans_old(up); 625 626 case PIO_UNISCRNMAP: 627 if (!perm) 628 return -EPERM; 629 return con_set_trans_new(up); 630 631 case GIO_UNISCRNMAP: 632 return con_get_trans_new(up); 633 634 case PIO_UNIMAPCLR: 635 if (!perm) 636 return -EPERM; 637 con_clear_unimap(vc); 638 break; 639 640 case PIO_UNIMAP: 641 case GIO_UNIMAP: 642 if (!perm) 643 return -EPERM; 644 645 return do_unimap_ioctl(cmd, up, vc); 646 647 default: 648 return -ENOIOCTLCMD; 649 } 650 651 return 0; 652 } 653 654 static int vt_reldisp(struct vc_data *vc, unsigned int swtch) 655 { 656 int newvt, ret; 657 658 if (vc->vt_mode.mode != VT_PROCESS) 659 return -EINVAL; 660 661 /* Switched-to response */ 662 if (vc->vt_newvt < 0) { 663 /* If it's just an ACK, ignore it */ 664 return swtch == VT_ACKACQ ? 0 : -EINVAL; 665 } 666 667 /* Switching-from response */ 668 if (swtch == 0) { 669 /* Switch disallowed, so forget we were trying to do it. */ 670 vc->vt_newvt = -1; 671 return 0; 672 } 673 674 /* The current vt has been released, so complete the switch. */ 675 newvt = vc->vt_newvt; 676 vc->vt_newvt = -1; 677 ret = vc_allocate(newvt); 678 if (ret) 679 return ret; 680 681 /* 682 * When we actually do the console switch, make sure we are atomic with 683 * respect to other console switches.. 684 */ 685 complete_change_console(vc_cons[newvt].d); 686 687 return 0; 688 } 689 690 static int vt_setactivate(struct vt_setactivate __user *sa) 691 { 692 struct vt_setactivate vsa; 693 struct vc_data *nvc; 694 int ret; 695 696 if (copy_from_user(&vsa, sa, sizeof(vsa))) 697 return -EFAULT; 698 if (vsa.console == 0 || vsa.console > MAX_NR_CONSOLES) 699 return -ENXIO; 700 701 vsa.console = array_index_nospec(vsa.console, MAX_NR_CONSOLES + 1); 702 vsa.console--; 703 console_lock(); 704 ret = vc_allocate(vsa.console); 705 if (ret) { 706 console_unlock(); 707 return ret; 708 } 709 710 /* 711 * This is safe providing we don't drop the console sem between 712 * vc_allocate and finishing referencing nvc. 713 */ 714 nvc = vc_cons[vsa.console].d; 715 nvc->vt_mode = vsa.mode; 716 nvc->vt_mode.frsig = 0; 717 put_pid(nvc->vt_pid); 718 nvc->vt_pid = get_pid(task_pid(current)); 719 console_unlock(); 720 721 /* Commence switch and lock */ 722 /* Review set_console locks */ 723 set_console(vsa.console); 724 725 return 0; 726 } 727 728 /* deallocate a single console, if possible (leave 0) */ 729 static int vt_disallocate(unsigned int vc_num) 730 { 731 struct vc_data *vc = NULL; 732 int ret = 0; 733 734 console_lock(); 735 if (vt_busy(vc_num)) 736 ret = -EBUSY; 737 else if (vc_num) 738 vc = vc_deallocate(vc_num); 739 console_unlock(); 740 741 if (vc && vc_num >= MIN_NR_CONSOLES) 742 tty_port_put(&vc->port); 743 744 return ret; 745 } 746 747 /* deallocate all unused consoles, but leave 0 */ 748 static void vt_disallocate_all(void) 749 { 750 struct vc_data *vc[MAX_NR_CONSOLES]; 751 int i; 752 753 console_lock(); 754 for (i = 1; i < MAX_NR_CONSOLES; i++) 755 if (!vt_busy(i)) 756 vc[i] = vc_deallocate(i); 757 else 758 vc[i] = NULL; 759 console_unlock(); 760 761 for (i = 1; i < MAX_NR_CONSOLES; i++) { 762 if (vc[i] && i >= MIN_NR_CONSOLES) 763 tty_port_put(&vc[i]->port); 764 } 765 } 766 767 static int vt_resizex(struct vc_data *vc, struct vt_consize __user *cs) 768 { 769 struct vt_consize v; 770 int i; 771 772 if (copy_from_user(&v, cs, sizeof(struct vt_consize))) 773 return -EFAULT; 774 775 if (v.v_vlin) 776 pr_info_once("\"struct vt_consize\"->v_vlin is ignored. Please report if you need this.\n"); 777 if (v.v_clin) 778 pr_info_once("\"struct vt_consize\"->v_clin is ignored. Please report if you need this.\n"); 779 780 console_lock(); 781 for (i = 0; i < MAX_NR_CONSOLES; i++) { 782 vc = vc_cons[i].d; 783 784 if (vc) { 785 vc->vc_resize_user = 1; 786 vc_resize(vc, v.v_cols, v.v_rows); 787 } 788 } 789 console_unlock(); 790 791 return 0; 792 } 793 794 /* 795 * We handle the console-specific ioctl's here. We allow the 796 * capability to modify any console, not just the fg_console. 797 */ 798 int vt_ioctl(struct tty_struct *tty, 799 unsigned int cmd, unsigned long arg) 800 { 801 struct vc_data *vc = tty->driver_data; 802 void __user *up = (void __user *)arg; 803 int i, perm; 804 int ret; 805 806 /* 807 * To have permissions to do most of the vt ioctls, we either have 808 * to be the owner of the tty, or have CAP_SYS_TTY_CONFIG. 809 */ 810 perm = 0; 811 if (current->signal->tty == tty || capable(CAP_SYS_TTY_CONFIG)) 812 perm = 1; 813 814 ret = vt_k_ioctl(tty, cmd, arg, perm); 815 if (ret != -ENOIOCTLCMD) 816 return ret; 817 818 ret = vt_io_ioctl(vc, cmd, up, perm); 819 if (ret != -ENOIOCTLCMD) 820 return ret; 821 822 switch (cmd) { 823 case TIOCLINUX: 824 return tioclinux(tty, arg); 825 case VT_SETMODE: 826 { 827 struct vt_mode tmp; 828 829 if (!perm) 830 return -EPERM; 831 if (copy_from_user(&tmp, up, sizeof(struct vt_mode))) 832 return -EFAULT; 833 if (tmp.mode != VT_AUTO && tmp.mode != VT_PROCESS) 834 return -EINVAL; 835 836 console_lock(); 837 vc->vt_mode = tmp; 838 /* the frsig is ignored, so we set it to 0 */ 839 vc->vt_mode.frsig = 0; 840 put_pid(vc->vt_pid); 841 vc->vt_pid = get_pid(task_pid(current)); 842 /* no switch is required -- saw@shade.msu.ru */ 843 vc->vt_newvt = -1; 844 console_unlock(); 845 break; 846 } 847 848 case VT_GETMODE: 849 { 850 struct vt_mode tmp; 851 int rc; 852 853 console_lock(); 854 memcpy(&tmp, &vc->vt_mode, sizeof(struct vt_mode)); 855 console_unlock(); 856 857 rc = copy_to_user(up, &tmp, sizeof(struct vt_mode)); 858 if (rc) 859 return -EFAULT; 860 break; 861 } 862 863 /* 864 * Returns global vt state. Note that VT 0 is always open, since 865 * it's an alias for the current VT, and people can't use it here. 866 * We cannot return state for more than 16 VTs, since v_state is short. 867 */ 868 case VT_GETSTATE: 869 { 870 struct vt_stat __user *vtstat = up; 871 unsigned short state, mask; 872 873 if (put_user(fg_console + 1, &vtstat->v_active)) 874 return -EFAULT; 875 876 state = 1; /* /dev/tty0 is always open */ 877 console_lock(); /* required by vt_in_use() */ 878 for (i = 0, mask = 2; i < MAX_NR_CONSOLES && mask; 879 ++i, mask <<= 1) 880 if (vt_in_use(i)) 881 state |= mask; 882 console_unlock(); 883 return put_user(state, &vtstat->v_state); 884 } 885 886 /* 887 * Returns the first available (non-opened) console. 888 */ 889 case VT_OPENQRY: 890 console_lock(); /* required by vt_in_use() */ 891 for (i = 0; i < MAX_NR_CONSOLES; ++i) 892 if (!vt_in_use(i)) 893 break; 894 console_unlock(); 895 i = i < MAX_NR_CONSOLES ? (i+1) : -1; 896 return put_user(i, (int __user *)arg); 897 898 /* 899 * ioctl(fd, VT_ACTIVATE, num) will cause us to switch to vt # num, 900 * with num >= 1 (switches to vt 0, our console, are not allowed, just 901 * to preserve sanity). 902 */ 903 case VT_ACTIVATE: 904 if (!perm) 905 return -EPERM; 906 if (arg == 0 || arg > MAX_NR_CONSOLES) 907 return -ENXIO; 908 909 arg--; 910 console_lock(); 911 ret = vc_allocate(arg); 912 console_unlock(); 913 if (ret) 914 return ret; 915 set_console(arg); 916 break; 917 918 case VT_SETACTIVATE: 919 if (!perm) 920 return -EPERM; 921 922 return vt_setactivate(up); 923 924 /* 925 * wait until the specified VT has been activated 926 */ 927 case VT_WAITACTIVE: 928 if (!perm) 929 return -EPERM; 930 if (arg == 0 || arg > MAX_NR_CONSOLES) 931 return -ENXIO; 932 return vt_waitactive(arg); 933 934 /* 935 * If a vt is under process control, the kernel will not switch to it 936 * immediately, but postpone the operation until the process calls this 937 * ioctl, allowing the switch to complete. 938 * 939 * According to the X sources this is the behavior: 940 * 0: pending switch-from not OK 941 * 1: pending switch-from OK 942 * 2: completed switch-to OK 943 */ 944 case VT_RELDISP: 945 if (!perm) 946 return -EPERM; 947 948 console_lock(); 949 ret = vt_reldisp(vc, arg); 950 console_unlock(); 951 952 return ret; 953 954 955 /* 956 * Disallocate memory associated to VT (but leave VT1) 957 */ 958 case VT_DISALLOCATE: 959 if (arg > MAX_NR_CONSOLES) 960 return -ENXIO; 961 962 if (arg == 0) 963 vt_disallocate_all(); 964 else 965 return vt_disallocate(--arg); 966 break; 967 968 case VT_RESIZE: 969 { 970 struct vt_sizes __user *vtsizes = up; 971 struct vc_data *vc; 972 ushort ll,cc; 973 974 if (!perm) 975 return -EPERM; 976 if (get_user(ll, &vtsizes->v_rows) || 977 get_user(cc, &vtsizes->v_cols)) 978 return -EFAULT; 979 980 console_lock(); 981 for (i = 0; i < MAX_NR_CONSOLES; i++) { 982 vc = vc_cons[i].d; 983 984 if (vc) { 985 vc->vc_resize_user = 1; 986 /* FIXME: review v tty lock */ 987 vc_resize(vc_cons[i].d, cc, ll); 988 } 989 } 990 console_unlock(); 991 break; 992 } 993 994 case VT_RESIZEX: 995 if (!perm) 996 return -EPERM; 997 998 return vt_resizex(vc, up); 999 1000 case VT_LOCKSWITCH: 1001 if (!capable(CAP_SYS_TTY_CONFIG)) 1002 return -EPERM; 1003 vt_dont_switch = true; 1004 break; 1005 case VT_UNLOCKSWITCH: 1006 if (!capable(CAP_SYS_TTY_CONFIG)) 1007 return -EPERM; 1008 vt_dont_switch = false; 1009 break; 1010 case VT_GETHIFONTMASK: 1011 return put_user(vc->vc_hi_font_mask, 1012 (unsigned short __user *)arg); 1013 case VT_WAITEVENT: 1014 return vt_event_wait_ioctl((struct vt_event __user *)arg); 1015 default: 1016 return -ENOIOCTLCMD; 1017 } 1018 1019 return 0; 1020 } 1021 1022 void reset_vc(struct vc_data *vc) 1023 { 1024 vc->vc_mode = KD_TEXT; 1025 vt_reset_unicode(vc->vc_num); 1026 vc->vt_mode.mode = VT_AUTO; 1027 vc->vt_mode.waitv = 0; 1028 vc->vt_mode.relsig = 0; 1029 vc->vt_mode.acqsig = 0; 1030 vc->vt_mode.frsig = 0; 1031 put_pid(vc->vt_pid); 1032 vc->vt_pid = NULL; 1033 vc->vt_newvt = -1; 1034 if (!in_interrupt()) /* Via keyboard.c:SAK() - akpm */ 1035 reset_palette(vc); 1036 } 1037 1038 void vc_SAK(struct work_struct *work) 1039 { 1040 struct vc *vc_con = 1041 container_of(work, struct vc, SAK_work); 1042 struct vc_data *vc; 1043 struct tty_struct *tty; 1044 1045 console_lock(); 1046 vc = vc_con->d; 1047 if (vc) { 1048 /* FIXME: review tty ref counting */ 1049 tty = vc->port.tty; 1050 /* 1051 * SAK should also work in all raw modes and reset 1052 * them properly. 1053 */ 1054 if (tty) 1055 __do_SAK(tty); 1056 reset_vc(vc); 1057 } 1058 console_unlock(); 1059 } 1060 1061 #ifdef CONFIG_COMPAT 1062 1063 struct compat_consolefontdesc { 1064 unsigned short charcount; /* characters in font (256 or 512) */ 1065 unsigned short charheight; /* scan lines per character (1-32) */ 1066 compat_caddr_t chardata; /* font data in expanded form */ 1067 }; 1068 1069 static inline int 1070 compat_fontx_ioctl(int cmd, struct compat_consolefontdesc __user *user_cfd, 1071 int perm, struct console_font_op *op) 1072 { 1073 struct compat_consolefontdesc cfdarg; 1074 int i; 1075 1076 if (copy_from_user(&cfdarg, user_cfd, sizeof(struct compat_consolefontdesc))) 1077 return -EFAULT; 1078 1079 switch (cmd) { 1080 case PIO_FONTX: 1081 if (!perm) 1082 return -EPERM; 1083 op->op = KD_FONT_OP_SET; 1084 op->flags = KD_FONT_FLAG_OLD; 1085 op->width = 8; 1086 op->height = cfdarg.charheight; 1087 op->charcount = cfdarg.charcount; 1088 op->data = compat_ptr(cfdarg.chardata); 1089 return con_font_op(vc_cons[fg_console].d, op); 1090 case GIO_FONTX: 1091 op->op = KD_FONT_OP_GET; 1092 op->flags = KD_FONT_FLAG_OLD; 1093 op->width = 8; 1094 op->height = cfdarg.charheight; 1095 op->charcount = cfdarg.charcount; 1096 op->data = compat_ptr(cfdarg.chardata); 1097 i = con_font_op(vc_cons[fg_console].d, op); 1098 if (i) 1099 return i; 1100 cfdarg.charheight = op->height; 1101 cfdarg.charcount = op->charcount; 1102 if (copy_to_user(user_cfd, &cfdarg, sizeof(struct compat_consolefontdesc))) 1103 return -EFAULT; 1104 return 0; 1105 } 1106 return -EINVAL; 1107 } 1108 1109 struct compat_console_font_op { 1110 compat_uint_t op; /* operation code KD_FONT_OP_* */ 1111 compat_uint_t flags; /* KD_FONT_FLAG_* */ 1112 compat_uint_t width, height; /* font size */ 1113 compat_uint_t charcount; 1114 compat_caddr_t data; /* font data with height fixed to 32 */ 1115 }; 1116 1117 static inline int 1118 compat_kdfontop_ioctl(struct compat_console_font_op __user *fontop, 1119 int perm, struct console_font_op *op, struct vc_data *vc) 1120 { 1121 int i; 1122 1123 if (copy_from_user(op, fontop, sizeof(struct compat_console_font_op))) 1124 return -EFAULT; 1125 if (!perm && op->op != KD_FONT_OP_GET) 1126 return -EPERM; 1127 op->data = compat_ptr(((struct compat_console_font_op *)op)->data); 1128 i = con_font_op(vc, op); 1129 if (i) 1130 return i; 1131 ((struct compat_console_font_op *)op)->data = (unsigned long)op->data; 1132 if (copy_to_user(fontop, op, sizeof(struct compat_console_font_op))) 1133 return -EFAULT; 1134 return 0; 1135 } 1136 1137 struct compat_unimapdesc { 1138 unsigned short entry_ct; 1139 compat_caddr_t entries; 1140 }; 1141 1142 static inline int 1143 compat_unimap_ioctl(unsigned int cmd, struct compat_unimapdesc __user *user_ud, 1144 int perm, struct vc_data *vc) 1145 { 1146 struct compat_unimapdesc tmp; 1147 struct unipair __user *tmp_entries; 1148 1149 if (copy_from_user(&tmp, user_ud, sizeof tmp)) 1150 return -EFAULT; 1151 tmp_entries = compat_ptr(tmp.entries); 1152 switch (cmd) { 1153 case PIO_UNIMAP: 1154 if (!perm) 1155 return -EPERM; 1156 return con_set_unimap(vc, tmp.entry_ct, tmp_entries); 1157 case GIO_UNIMAP: 1158 if (!perm && fg_console != vc->vc_num) 1159 return -EPERM; 1160 return con_get_unimap(vc, tmp.entry_ct, &(user_ud->entry_ct), tmp_entries); 1161 } 1162 return 0; 1163 } 1164 1165 long vt_compat_ioctl(struct tty_struct *tty, 1166 unsigned int cmd, unsigned long arg) 1167 { 1168 struct vc_data *vc = tty->driver_data; 1169 struct console_font_op op; /* used in multiple places here */ 1170 void __user *up = compat_ptr(arg); 1171 int perm; 1172 1173 /* 1174 * To have permissions to do most of the vt ioctls, we either have 1175 * to be the owner of the tty, or have CAP_SYS_TTY_CONFIG. 1176 */ 1177 perm = 0; 1178 if (current->signal->tty == tty || capable(CAP_SYS_TTY_CONFIG)) 1179 perm = 1; 1180 1181 switch (cmd) { 1182 /* 1183 * these need special handlers for incompatible data structures 1184 */ 1185 case PIO_FONTX: 1186 case GIO_FONTX: 1187 return compat_fontx_ioctl(cmd, up, perm, &op); 1188 1189 case KDFONTOP: 1190 return compat_kdfontop_ioctl(up, perm, &op, vc); 1191 1192 case PIO_UNIMAP: 1193 case GIO_UNIMAP: 1194 return compat_unimap_ioctl(cmd, up, perm, vc); 1195 1196 /* 1197 * all these treat 'arg' as an integer 1198 */ 1199 case KIOCSOUND: 1200 case KDMKTONE: 1201 #ifdef CONFIG_X86 1202 case KDADDIO: 1203 case KDDELIO: 1204 #endif 1205 case KDSETMODE: 1206 case KDMAPDISP: 1207 case KDUNMAPDISP: 1208 case KDSKBMODE: 1209 case KDSKBMETA: 1210 case KDSKBLED: 1211 case KDSETLED: 1212 case KDSIGACCEPT: 1213 case VT_ACTIVATE: 1214 case VT_WAITACTIVE: 1215 case VT_RELDISP: 1216 case VT_DISALLOCATE: 1217 case VT_RESIZE: 1218 case VT_RESIZEX: 1219 return vt_ioctl(tty, cmd, arg); 1220 1221 /* 1222 * the rest has a compatible data structure behind arg, 1223 * but we have to convert it to a proper 64 bit pointer. 1224 */ 1225 default: 1226 return vt_ioctl(tty, cmd, (unsigned long)up); 1227 } 1228 } 1229 1230 1231 #endif /* CONFIG_COMPAT */ 1232 1233 1234 /* 1235 * Performs the back end of a vt switch. Called under the console 1236 * semaphore. 1237 */ 1238 static void complete_change_console(struct vc_data *vc) 1239 { 1240 unsigned char old_vc_mode; 1241 int old = fg_console; 1242 1243 last_console = fg_console; 1244 1245 /* 1246 * If we're switching, we could be going from KD_GRAPHICS to 1247 * KD_TEXT mode or vice versa, which means we need to blank or 1248 * unblank the screen later. 1249 */ 1250 old_vc_mode = vc_cons[fg_console].d->vc_mode; 1251 switch_screen(vc); 1252 1253 /* 1254 * This can't appear below a successful kill_pid(). If it did, 1255 * then the *blank_screen operation could occur while X, having 1256 * received acqsig, is waking up on another processor. This 1257 * condition can lead to overlapping accesses to the VGA range 1258 * and the framebuffer (causing system lockups). 1259 * 1260 * To account for this we duplicate this code below only if the 1261 * controlling process is gone and we've called reset_vc. 1262 */ 1263 if (old_vc_mode != vc->vc_mode) { 1264 if (vc->vc_mode == KD_TEXT) 1265 do_unblank_screen(1); 1266 else 1267 do_blank_screen(1); 1268 } 1269 1270 /* 1271 * If this new console is under process control, send it a signal 1272 * telling it that it has acquired. Also check if it has died and 1273 * clean up (similar to logic employed in change_console()) 1274 */ 1275 if (vc->vt_mode.mode == VT_PROCESS) { 1276 /* 1277 * Send the signal as privileged - kill_pid() will 1278 * tell us if the process has gone or something else 1279 * is awry 1280 */ 1281 if (kill_pid(vc->vt_pid, vc->vt_mode.acqsig, 1) != 0) { 1282 /* 1283 * The controlling process has died, so we revert back to 1284 * normal operation. In this case, we'll also change back 1285 * to KD_TEXT mode. I'm not sure if this is strictly correct 1286 * but it saves the agony when the X server dies and the screen 1287 * remains blanked due to KD_GRAPHICS! It would be nice to do 1288 * this outside of VT_PROCESS but there is no single process 1289 * to account for and tracking tty count may be undesirable. 1290 */ 1291 reset_vc(vc); 1292 1293 if (old_vc_mode != vc->vc_mode) { 1294 if (vc->vc_mode == KD_TEXT) 1295 do_unblank_screen(1); 1296 else 1297 do_blank_screen(1); 1298 } 1299 } 1300 } 1301 1302 /* 1303 * Wake anyone waiting for their VT to activate 1304 */ 1305 vt_event_post(VT_EVENT_SWITCH, old, vc->vc_num); 1306 return; 1307 } 1308 1309 /* 1310 * Performs the front-end of a vt switch 1311 */ 1312 void change_console(struct vc_data *new_vc) 1313 { 1314 struct vc_data *vc; 1315 1316 if (!new_vc || new_vc->vc_num == fg_console || vt_dont_switch) 1317 return; 1318 1319 /* 1320 * If this vt is in process mode, then we need to handshake with 1321 * that process before switching. Essentially, we store where that 1322 * vt wants to switch to and wait for it to tell us when it's done 1323 * (via VT_RELDISP ioctl). 1324 * 1325 * We also check to see if the controlling process still exists. 1326 * If it doesn't, we reset this vt to auto mode and continue. 1327 * This is a cheap way to track process control. The worst thing 1328 * that can happen is: we send a signal to a process, it dies, and 1329 * the switch gets "lost" waiting for a response; hopefully, the 1330 * user will try again, we'll detect the process is gone (unless 1331 * the user waits just the right amount of time :-) and revert the 1332 * vt to auto control. 1333 */ 1334 vc = vc_cons[fg_console].d; 1335 if (vc->vt_mode.mode == VT_PROCESS) { 1336 /* 1337 * Send the signal as privileged - kill_pid() will 1338 * tell us if the process has gone or something else 1339 * is awry. 1340 * 1341 * We need to set vt_newvt *before* sending the signal or we 1342 * have a race. 1343 */ 1344 vc->vt_newvt = new_vc->vc_num; 1345 if (kill_pid(vc->vt_pid, vc->vt_mode.relsig, 1) == 0) { 1346 /* 1347 * It worked. Mark the vt to switch to and 1348 * return. The process needs to send us a 1349 * VT_RELDISP ioctl to complete the switch. 1350 */ 1351 return; 1352 } 1353 1354 /* 1355 * The controlling process has died, so we revert back to 1356 * normal operation. In this case, we'll also change back 1357 * to KD_TEXT mode. I'm not sure if this is strictly correct 1358 * but it saves the agony when the X server dies and the screen 1359 * remains blanked due to KD_GRAPHICS! It would be nice to do 1360 * this outside of VT_PROCESS but there is no single process 1361 * to account for and tracking tty count may be undesirable. 1362 */ 1363 reset_vc(vc); 1364 1365 /* 1366 * Fall through to normal (VT_AUTO) handling of the switch... 1367 */ 1368 } 1369 1370 /* 1371 * Ignore all switches in KD_GRAPHICS+VT_AUTO mode 1372 */ 1373 if (vc->vc_mode == KD_GRAPHICS) 1374 return; 1375 1376 complete_change_console(new_vc); 1377 } 1378 1379 /* Perform a kernel triggered VT switch for suspend/resume */ 1380 1381 static int disable_vt_switch; 1382 1383 int vt_move_to_console(unsigned int vt, int alloc) 1384 { 1385 int prev; 1386 1387 console_lock(); 1388 /* Graphics mode - up to X */ 1389 if (disable_vt_switch) { 1390 console_unlock(); 1391 return 0; 1392 } 1393 prev = fg_console; 1394 1395 if (alloc && vc_allocate(vt)) { 1396 /* we can't have a free VC for now. Too bad, 1397 * we don't want to mess the screen for now. */ 1398 console_unlock(); 1399 return -ENOSPC; 1400 } 1401 1402 if (set_console(vt)) { 1403 /* 1404 * We're unable to switch to the SUSPEND_CONSOLE. 1405 * Let the calling function know so it can decide 1406 * what to do. 1407 */ 1408 console_unlock(); 1409 return -EIO; 1410 } 1411 console_unlock(); 1412 if (vt_waitactive(vt + 1)) { 1413 pr_debug("Suspend: Can't switch VCs."); 1414 return -EINTR; 1415 } 1416 return prev; 1417 } 1418 1419 /* 1420 * Normally during a suspend, we allocate a new console and switch to it. 1421 * When we resume, we switch back to the original console. This switch 1422 * can be slow, so on systems where the framebuffer can handle restoration 1423 * of video registers anyways, there's little point in doing the console 1424 * switch. This function allows you to disable it by passing it '0'. 1425 */ 1426 void pm_set_vt_switch(int do_switch) 1427 { 1428 console_lock(); 1429 disable_vt_switch = !do_switch; 1430 console_unlock(); 1431 } 1432 EXPORT_SYMBOL(pm_set_vt_switch); 1433