1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright (C) 1991, 1992 Linus Torvalds 4 */ 5 6 /* 7 * 'tty_io.c' gives an orthogonal feeling to tty's, be they consoles 8 * or rs-channels. It also implements echoing, cooked mode etc. 9 * 10 * Kill-line thanks to John T Kohl, who also corrected VMIN = VTIME = 0. 11 * 12 * Modified by Theodore Ts'o, 9/14/92, to dynamically allocate the 13 * tty_struct and tty_queue structures. Previously there was an array 14 * of 256 tty_struct's which was statically allocated, and the 15 * tty_queue structures were allocated at boot time. Both are now 16 * dynamically allocated only when the tty is open. 17 * 18 * Also restructured routines so that there is more of a separation 19 * between the high-level tty routines (tty_io.c and tty_ioctl.c) and 20 * the low-level tty routines (serial.c, pty.c, console.c). This 21 * makes for cleaner and more compact code. -TYT, 9/17/92 22 * 23 * Modified by Fred N. van Kempen, 01/29/93, to add line disciplines 24 * which can be dynamically activated and de-activated by the line 25 * discipline handling modules (like SLIP). 26 * 27 * NOTE: pay no attention to the line discipline code (yet); its 28 * interface is still subject to change in this version... 29 * -- TYT, 1/31/92 30 * 31 * Added functionality to the OPOST tty handling. No delays, but all 32 * other bits should be there. 33 * -- Nick Holloway <alfie@dcs.warwick.ac.uk>, 27th May 1993. 34 * 35 * Rewrote canonical mode and added more termios flags. 36 * -- julian@uhunix.uhcc.hawaii.edu (J. Cowley), 13Jan94 37 * 38 * Reorganized FASYNC support so mouse code can share it. 39 * -- ctm@ardi.com, 9Sep95 40 * 41 * New TIOCLINUX variants added. 42 * -- mj@k332.feld.cvut.cz, 19-Nov-95 43 * 44 * Restrict vt switching via ioctl() 45 * -- grif@cs.ucr.edu, 5-Dec-95 46 * 47 * Move console and virtual terminal code to more appropriate files, 48 * implement CONFIG_VT and generalize console device interface. 49 * -- Marko Kohtala <Marko.Kohtala@hut.fi>, March 97 50 * 51 * Rewrote tty_init_dev and tty_release_dev to eliminate races. 52 * -- Bill Hawes <whawes@star.net>, June 97 53 * 54 * Added devfs support. 55 * -- C. Scott Ananian <cananian@alumni.princeton.edu>, 13-Jan-1998 56 * 57 * Added support for a Unix98-style ptmx device. 58 * -- C. Scott Ananian <cananian@alumni.princeton.edu>, 14-Jan-1998 59 * 60 * Reduced memory usage for older ARM systems 61 * -- Russell King <rmk@arm.linux.org.uk> 62 * 63 * Move do_SAK() into process context. Less stack use in devfs functions. 64 * alloc_tty_struct() always uses kmalloc() 65 * -- Andrew Morton <andrewm@uow.edu.eu> 17Mar01 66 */ 67 68 #include <linux/types.h> 69 #include <linux/major.h> 70 #include <linux/errno.h> 71 #include <linux/signal.h> 72 #include <linux/fcntl.h> 73 #include <linux/sched/signal.h> 74 #include <linux/sched/task.h> 75 #include <linux/interrupt.h> 76 #include <linux/tty.h> 77 #include <linux/tty_driver.h> 78 #include <linux/tty_flip.h> 79 #include <linux/devpts_fs.h> 80 #include <linux/file.h> 81 #include <linux/fdtable.h> 82 #include <linux/console.h> 83 #include <linux/timer.h> 84 #include <linux/ctype.h> 85 #include <linux/kd.h> 86 #include <linux/mm.h> 87 #include <linux/string.h> 88 #include <linux/slab.h> 89 #include <linux/poll.h> 90 #include <linux/ppp-ioctl.h> 91 #include <linux/proc_fs.h> 92 #include <linux/init.h> 93 #include <linux/module.h> 94 #include <linux/device.h> 95 #include <linux/wait.h> 96 #include <linux/bitops.h> 97 #include <linux/delay.h> 98 #include <linux/seq_file.h> 99 #include <linux/serial.h> 100 #include <linux/ratelimit.h> 101 #include <linux/compat.h> 102 #include <linux/uaccess.h> 103 #include <linux/termios_internal.h> 104 #include <linux/fs.h> 105 106 #include <linux/kbd_kern.h> 107 #include <linux/vt_kern.h> 108 #include <linux/selection.h> 109 110 #include <linux/kmod.h> 111 #include <linux/nsproxy.h> 112 #include "tty.h" 113 114 #undef TTY_DEBUG_HANGUP 115 #ifdef TTY_DEBUG_HANGUP 116 # define tty_debug_hangup(tty, f, args...) tty_debug(tty, f, ##args) 117 #else 118 # define tty_debug_hangup(tty, f, args...) do { } while (0) 119 #endif 120 121 #define TTY_PARANOIA_CHECK 1 122 #define CHECK_TTY_COUNT 1 123 124 struct ktermios tty_std_termios = { /* for the benefit of tty drivers */ 125 .c_iflag = ICRNL | IXON, 126 .c_oflag = OPOST | ONLCR, 127 .c_cflag = B38400 | CS8 | CREAD | HUPCL, 128 .c_lflag = ISIG | ICANON | ECHO | ECHOE | ECHOK | 129 ECHOCTL | ECHOKE | IEXTEN, 130 .c_cc = INIT_C_CC, 131 .c_ispeed = 38400, 132 .c_ospeed = 38400, 133 /* .c_line = N_TTY, */ 134 }; 135 EXPORT_SYMBOL(tty_std_termios); 136 137 /* This list gets poked at by procfs and various bits of boot up code. This 138 * could do with some rationalisation such as pulling the tty proc function 139 * into this file. 140 */ 141 142 LIST_HEAD(tty_drivers); /* linked list of tty drivers */ 143 144 /* Mutex to protect creating and releasing a tty */ 145 DEFINE_MUTEX(tty_mutex); 146 147 static ssize_t tty_read(struct kiocb *, struct iov_iter *); 148 static ssize_t tty_write(struct kiocb *, struct iov_iter *); 149 static __poll_t tty_poll(struct file *, poll_table *); 150 static int tty_open(struct inode *, struct file *); 151 #ifdef CONFIG_COMPAT 152 static long tty_compat_ioctl(struct file *file, unsigned int cmd, 153 unsigned long arg); 154 #else 155 #define tty_compat_ioctl NULL 156 #endif 157 static int __tty_fasync(int fd, struct file *filp, int on); 158 static int tty_fasync(int fd, struct file *filp, int on); 159 static void release_tty(struct tty_struct *tty, int idx); 160 161 /** 162 * free_tty_struct - free a disused tty 163 * @tty: tty struct to free 164 * 165 * Free the write buffers, tty queue and tty memory itself. 166 * 167 * Locking: none. Must be called after tty is definitely unused 168 */ 169 static void free_tty_struct(struct tty_struct *tty) 170 { 171 tty_ldisc_deinit(tty); 172 put_device(tty->dev); 173 kvfree(tty->write_buf); 174 kfree(tty); 175 } 176 177 static inline struct tty_struct *file_tty(struct file *file) 178 { 179 return ((struct tty_file_private *)file->private_data)->tty; 180 } 181 182 int tty_alloc_file(struct file *file) 183 { 184 struct tty_file_private *priv; 185 186 priv = kmalloc(sizeof(*priv), GFP_KERNEL); 187 if (!priv) 188 return -ENOMEM; 189 190 file->private_data = priv; 191 192 return 0; 193 } 194 195 /* Associate a new file with the tty structure */ 196 void tty_add_file(struct tty_struct *tty, struct file *file) 197 { 198 struct tty_file_private *priv = file->private_data; 199 200 priv->tty = tty; 201 priv->file = file; 202 203 spin_lock(&tty->files_lock); 204 list_add(&priv->list, &tty->tty_files); 205 spin_unlock(&tty->files_lock); 206 } 207 208 /** 209 * tty_free_file - free file->private_data 210 * @file: to free private_data of 211 * 212 * This shall be used only for fail path handling when tty_add_file was not 213 * called yet. 214 */ 215 void tty_free_file(struct file *file) 216 { 217 struct tty_file_private *priv = file->private_data; 218 219 file->private_data = NULL; 220 kfree(priv); 221 } 222 223 /* Delete file from its tty */ 224 static void tty_del_file(struct file *file) 225 { 226 struct tty_file_private *priv = file->private_data; 227 struct tty_struct *tty = priv->tty; 228 229 spin_lock(&tty->files_lock); 230 list_del(&priv->list); 231 spin_unlock(&tty->files_lock); 232 tty_free_file(file); 233 } 234 235 /** 236 * tty_name - return tty naming 237 * @tty: tty structure 238 * 239 * Convert a tty structure into a name. The name reflects the kernel naming 240 * policy and if udev is in use may not reflect user space 241 * 242 * Locking: none 243 */ 244 const char *tty_name(const struct tty_struct *tty) 245 { 246 if (!tty) /* Hmm. NULL pointer. That's fun. */ 247 return "NULL tty"; 248 return tty->name; 249 } 250 EXPORT_SYMBOL(tty_name); 251 252 const char *tty_driver_name(const struct tty_struct *tty) 253 { 254 if (!tty || !tty->driver) 255 return ""; 256 return tty->driver->name; 257 } 258 259 static int tty_paranoia_check(struct tty_struct *tty, struct inode *inode, 260 const char *routine) 261 { 262 #ifdef TTY_PARANOIA_CHECK 263 if (!tty) { 264 pr_warn("(%d:%d): %s: NULL tty\n", 265 imajor(inode), iminor(inode), routine); 266 return 1; 267 } 268 #endif 269 return 0; 270 } 271 272 /* Caller must hold tty_lock */ 273 static void check_tty_count(struct tty_struct *tty, const char *routine) 274 { 275 #ifdef CHECK_TTY_COUNT 276 struct list_head *p; 277 int count = 0, kopen_count = 0; 278 279 spin_lock(&tty->files_lock); 280 list_for_each(p, &tty->tty_files) { 281 count++; 282 } 283 spin_unlock(&tty->files_lock); 284 if (tty->driver->type == TTY_DRIVER_TYPE_PTY && 285 tty->driver->subtype == PTY_TYPE_SLAVE && 286 tty->link && tty->link->count) 287 count++; 288 if (tty_port_kopened(tty->port)) 289 kopen_count++; 290 if (tty->count != (count + kopen_count)) { 291 tty_warn(tty, "%s: tty->count(%d) != (#fd's(%d) + #kopen's(%d))\n", 292 routine, tty->count, count, kopen_count); 293 } 294 #endif 295 } 296 297 /** 298 * get_tty_driver - find device of a tty 299 * @device: device identifier 300 * @index: returns the index of the tty 301 * 302 * This routine returns a tty driver structure, given a device number and also 303 * passes back the index number. 304 * 305 * Locking: caller must hold tty_mutex 306 */ 307 static struct tty_driver *get_tty_driver(dev_t device, int *index) 308 { 309 struct tty_driver *p; 310 311 list_for_each_entry(p, &tty_drivers, tty_drivers) { 312 dev_t base = MKDEV(p->major, p->minor_start); 313 314 if (device < base || device >= base + p->num) 315 continue; 316 *index = device - base; 317 return tty_driver_kref_get(p); 318 } 319 return NULL; 320 } 321 322 /** 323 * tty_dev_name_to_number - return dev_t for device name 324 * @name: user space name of device under /dev 325 * @number: pointer to dev_t that this function will populate 326 * 327 * This function converts device names like ttyS0 or ttyUSB1 into dev_t like 328 * (4, 64) or (188, 1). If no corresponding driver is registered then the 329 * function returns -%ENODEV. 330 * 331 * Locking: this acquires tty_mutex to protect the tty_drivers list from 332 * being modified while we are traversing it, and makes sure to 333 * release it before exiting. 334 */ 335 int tty_dev_name_to_number(const char *name, dev_t *number) 336 { 337 struct tty_driver *p; 338 int ret; 339 int index, prefix_length = 0; 340 const char *str; 341 342 for (str = name; *str && !isdigit(*str); str++) 343 ; 344 345 if (!*str) 346 return -EINVAL; 347 348 ret = kstrtoint(str, 10, &index); 349 if (ret) 350 return ret; 351 352 prefix_length = str - name; 353 354 guard(mutex)(&tty_mutex); 355 356 list_for_each_entry(p, &tty_drivers, tty_drivers) 357 if (prefix_length == strlen(p->name) && strncmp(name, 358 p->name, prefix_length) == 0) { 359 if (index < p->num) { 360 *number = MKDEV(p->major, p->minor_start + index); 361 return 0; 362 } 363 } 364 365 return -ENODEV; 366 } 367 EXPORT_SYMBOL_GPL(tty_dev_name_to_number); 368 369 #ifdef CONFIG_CONSOLE_POLL 370 371 /** 372 * tty_find_polling_driver - find device of a polled tty 373 * @name: name string to match 374 * @line: pointer to resulting tty line nr 375 * 376 * This routine returns a tty driver structure, given a name and the condition 377 * that the tty driver is capable of polled operation. 378 */ 379 struct tty_driver *tty_find_polling_driver(char *name, int *line) 380 { 381 struct tty_driver *p, *res = NULL; 382 int tty_line = 0; 383 int len; 384 char *str, *stp; 385 386 for (str = name; *str; str++) 387 if ((*str >= '0' && *str <= '9') || *str == ',') 388 break; 389 if (!*str) 390 return NULL; 391 392 len = str - name; 393 tty_line = simple_strtoul(str, &str, 10); 394 395 mutex_lock(&tty_mutex); 396 /* Search through the tty devices to look for a match */ 397 list_for_each_entry(p, &tty_drivers, tty_drivers) { 398 if (!len || strncmp(name, p->name, len) != 0) 399 continue; 400 stp = str; 401 if (*stp == ',') 402 stp++; 403 if (*stp == '\0') 404 stp = NULL; 405 406 if (tty_line >= 0 && tty_line < p->num && p->ops && 407 p->ops->poll_init && !p->ops->poll_init(p, tty_line, stp)) { 408 res = tty_driver_kref_get(p); 409 *line = tty_line; 410 break; 411 } 412 } 413 mutex_unlock(&tty_mutex); 414 415 return res; 416 } 417 EXPORT_SYMBOL_GPL(tty_find_polling_driver); 418 #endif 419 420 static ssize_t hung_up_tty_read(struct kiocb *iocb, struct iov_iter *to) 421 { 422 return 0; 423 } 424 425 static ssize_t hung_up_tty_write(struct kiocb *iocb, struct iov_iter *from) 426 { 427 return -EIO; 428 } 429 430 /* No kernel lock held - none needed ;) */ 431 static __poll_t hung_up_tty_poll(struct file *filp, poll_table *wait) 432 { 433 return EPOLLIN | EPOLLOUT | EPOLLERR | EPOLLHUP | EPOLLRDNORM | EPOLLWRNORM; 434 } 435 436 static long hung_up_tty_ioctl(struct file *file, unsigned int cmd, 437 unsigned long arg) 438 { 439 return cmd == TIOCSPGRP ? -ENOTTY : -EIO; 440 } 441 442 static long hung_up_tty_compat_ioctl(struct file *file, 443 unsigned int cmd, unsigned long arg) 444 { 445 return cmd == TIOCSPGRP ? -ENOTTY : -EIO; 446 } 447 448 static int hung_up_tty_fasync(int fd, struct file *file, int on) 449 { 450 return -ENOTTY; 451 } 452 453 static void tty_show_fdinfo(struct seq_file *m, struct file *file) 454 { 455 struct tty_struct *tty = file_tty(file); 456 457 if (tty && tty->ops && tty->ops->show_fdinfo) 458 tty->ops->show_fdinfo(tty, m); 459 } 460 461 static const struct file_operations tty_fops = { 462 .read_iter = tty_read, 463 .write_iter = tty_write, 464 .splice_read = copy_splice_read, 465 .splice_write = iter_file_splice_write, 466 .poll = tty_poll, 467 .unlocked_ioctl = tty_ioctl, 468 .compat_ioctl = tty_compat_ioctl, 469 .open = tty_open, 470 .release = tty_release, 471 .fasync = tty_fasync, 472 .show_fdinfo = tty_show_fdinfo, 473 }; 474 475 static const struct file_operations console_fops = { 476 .read_iter = tty_read, 477 .write_iter = redirected_tty_write, 478 .splice_read = copy_splice_read, 479 .splice_write = iter_file_splice_write, 480 .poll = tty_poll, 481 .unlocked_ioctl = tty_ioctl, 482 .compat_ioctl = tty_compat_ioctl, 483 .open = tty_open, 484 .release = tty_release, 485 .fasync = tty_fasync, 486 }; 487 488 static const struct file_operations hung_up_tty_fops = { 489 .read_iter = hung_up_tty_read, 490 .write_iter = hung_up_tty_write, 491 .poll = hung_up_tty_poll, 492 .unlocked_ioctl = hung_up_tty_ioctl, 493 .compat_ioctl = hung_up_tty_compat_ioctl, 494 .release = tty_release, 495 .fasync = hung_up_tty_fasync, 496 }; 497 498 static DEFINE_SPINLOCK(redirect_lock); 499 static struct file *redirect; 500 501 /** 502 * tty_wakeup - request more data 503 * @tty: terminal 504 * 505 * Internal and external helper for wakeups of tty. This function informs the 506 * line discipline if present that the driver is ready to receive more output 507 * data. 508 */ 509 void tty_wakeup(struct tty_struct *tty) 510 { 511 struct tty_ldisc *ld; 512 513 if (test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags)) { 514 ld = tty_ldisc_ref(tty); 515 if (ld) { 516 if (ld->ops->write_wakeup) 517 ld->ops->write_wakeup(tty); 518 tty_ldisc_deref(ld); 519 } 520 } 521 wake_up_interruptible_poll(&tty->write_wait, EPOLLOUT); 522 } 523 EXPORT_SYMBOL_GPL(tty_wakeup); 524 525 /** 526 * tty_release_redirect - Release a redirect on a pty if present 527 * @tty: tty device 528 * 529 * This is available to the pty code so if the master closes, if the slave is a 530 * redirect it can release the redirect. 531 */ 532 static struct file *tty_release_redirect(struct tty_struct *tty) 533 { 534 struct file *f = NULL; 535 536 spin_lock(&redirect_lock); 537 if (redirect && file_tty(redirect) == tty) { 538 f = redirect; 539 redirect = NULL; 540 } 541 spin_unlock(&redirect_lock); 542 543 return f; 544 } 545 546 /** 547 * __tty_hangup - actual handler for hangup events 548 * @tty: tty device 549 * @exit_session: if non-zero, signal all foreground group processes 550 * 551 * This can be called by a "kworker" kernel thread. That is process synchronous 552 * but doesn't hold any locks, so we need to make sure we have the appropriate 553 * locks for what we're doing. 554 * 555 * The hangup event clears any pending redirections onto the hung up device. It 556 * ensures future writes will error and it does the needed line discipline 557 * hangup and signal delivery. The tty object itself remains intact. 558 * 559 * Locking: 560 * * BTM 561 * 562 * * redirect lock for undoing redirection 563 * * file list lock for manipulating list of ttys 564 * * tty_ldiscs_lock from called functions 565 * * termios_rwsem resetting termios data 566 * * tasklist_lock to walk task list for hangup event 567 * 568 * * ->siglock to protect ->signal/->sighand 569 * 570 */ 571 static void __tty_hangup(struct tty_struct *tty, int exit_session) 572 { 573 struct file *cons_filp = NULL; 574 struct file *filp, *f; 575 struct tty_file_private *priv; 576 int closecount = 0, n; 577 int refs; 578 579 if (!tty) 580 return; 581 582 f = tty_release_redirect(tty); 583 584 tty_lock(tty); 585 586 if (test_bit(TTY_HUPPED, &tty->flags)) { 587 tty_unlock(tty); 588 return; 589 } 590 591 /* 592 * Some console devices aren't actually hung up for technical and 593 * historical reasons, which can lead to indefinite interruptible 594 * sleep in n_tty_read(). The following explicitly tells 595 * n_tty_read() to abort readers. 596 */ 597 set_bit(TTY_HUPPING, &tty->flags); 598 599 /* inuse_filps is protected by the single tty lock, 600 * this really needs to change if we want to flush the 601 * workqueue with the lock held. 602 */ 603 check_tty_count(tty, "tty_hangup"); 604 605 spin_lock(&tty->files_lock); 606 /* This breaks for file handles being sent over AF_UNIX sockets ? */ 607 list_for_each_entry(priv, &tty->tty_files, list) { 608 filp = priv->file; 609 if (filp->f_op->write_iter == redirected_tty_write) 610 cons_filp = filp; 611 if (filp->f_op->write_iter != tty_write) 612 continue; 613 closecount++; 614 __tty_fasync(-1, filp, 0); /* can't block */ 615 filp->f_op = &hung_up_tty_fops; 616 } 617 spin_unlock(&tty->files_lock); 618 619 refs = tty_signal_session_leader(tty, exit_session); 620 /* Account for the p->signal references we killed */ 621 while (refs--) 622 tty_kref_put(tty); 623 624 tty_ldisc_hangup(tty, cons_filp != NULL); 625 626 spin_lock_irq(&tty->ctrl.lock); 627 clear_bit(TTY_THROTTLED, &tty->flags); 628 clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags); 629 put_pid(tty->ctrl.session); 630 put_pid(tty->ctrl.pgrp); 631 tty->ctrl.session = NULL; 632 tty->ctrl.pgrp = NULL; 633 tty->ctrl.pktstatus = 0; 634 spin_unlock_irq(&tty->ctrl.lock); 635 636 /* 637 * If one of the devices matches a console pointer, we 638 * cannot just call hangup() because that will cause 639 * tty->count and state->count to go out of sync. 640 * So we just call close() the right number of times. 641 */ 642 if (cons_filp) { 643 if (tty->ops->close) 644 for (n = 0; n < closecount; n++) 645 tty->ops->close(tty, cons_filp); 646 } else if (tty->ops->hangup) 647 tty->ops->hangup(tty); 648 /* 649 * We don't want to have driver/ldisc interactions beyond the ones 650 * we did here. The driver layer expects no calls after ->hangup() 651 * from the ldisc side, which is now guaranteed. 652 */ 653 set_bit(TTY_HUPPED, &tty->flags); 654 clear_bit(TTY_HUPPING, &tty->flags); 655 tty_unlock(tty); 656 657 if (f) 658 fput(f); 659 } 660 661 static void do_tty_hangup(struct work_struct *work) 662 { 663 struct tty_struct *tty = 664 container_of(work, struct tty_struct, hangup_work); 665 666 __tty_hangup(tty, 0); 667 } 668 669 /** 670 * tty_hangup - trigger a hangup event 671 * @tty: tty to hangup 672 * 673 * A carrier loss (virtual or otherwise) has occurred on @tty. Schedule a 674 * hangup sequence to run after this event. 675 */ 676 void tty_hangup(struct tty_struct *tty) 677 { 678 tty_debug_hangup(tty, "hangup\n"); 679 schedule_work(&tty->hangup_work); 680 } 681 EXPORT_SYMBOL(tty_hangup); 682 683 /** 684 * tty_vhangup - process vhangup 685 * @tty: tty to hangup 686 * 687 * The user has asked via system call for the terminal to be hung up. We do 688 * this synchronously so that when the syscall returns the process is complete. 689 * That guarantee is necessary for security reasons. 690 */ 691 void tty_vhangup(struct tty_struct *tty) 692 { 693 tty_debug_hangup(tty, "vhangup\n"); 694 __tty_hangup(tty, 0); 695 } 696 EXPORT_SYMBOL(tty_vhangup); 697 698 699 /** 700 * tty_vhangup_self - process vhangup for own ctty 701 * 702 * Perform a vhangup on the current controlling tty 703 */ 704 void tty_vhangup_self(void) 705 { 706 struct tty_struct *tty; 707 708 tty = get_current_tty(); 709 if (tty) { 710 tty_vhangup(tty); 711 tty_kref_put(tty); 712 } 713 } 714 715 /** 716 * tty_vhangup_session - hangup session leader exit 717 * @tty: tty to hangup 718 * 719 * The session leader is exiting and hanging up its controlling terminal. 720 * Every process in the foreground process group is signalled %SIGHUP. 721 * 722 * We do this synchronously so that when the syscall returns the process is 723 * complete. That guarantee is necessary for security reasons. 724 */ 725 void tty_vhangup_session(struct tty_struct *tty) 726 { 727 tty_debug_hangup(tty, "session hangup\n"); 728 __tty_hangup(tty, 1); 729 } 730 731 /** 732 * tty_hung_up_p - was tty hung up 733 * @filp: file pointer of tty 734 * 735 * Return: true if the tty has been subject to a vhangup or a carrier loss 736 */ 737 int tty_hung_up_p(struct file *filp) 738 { 739 return (filp && filp->f_op == &hung_up_tty_fops); 740 } 741 EXPORT_SYMBOL(tty_hung_up_p); 742 743 void __stop_tty(struct tty_struct *tty) 744 { 745 if (tty->flow.stopped) 746 return; 747 tty->flow.stopped = true; 748 if (tty->ops->stop) 749 tty->ops->stop(tty); 750 } 751 752 /** 753 * stop_tty - propagate flow control 754 * @tty: tty to stop 755 * 756 * Perform flow control to the driver. May be called on an already stopped 757 * device and will not re-call the &tty_driver->stop() method. 758 * 759 * This functionality is used by both the line disciplines for halting incoming 760 * flow and by the driver. It may therefore be called from any context, may be 761 * under the tty %atomic_write_lock but not always. 762 * 763 * Locking: 764 * flow.lock 765 */ 766 void stop_tty(struct tty_struct *tty) 767 { 768 unsigned long flags; 769 770 spin_lock_irqsave(&tty->flow.lock, flags); 771 __stop_tty(tty); 772 spin_unlock_irqrestore(&tty->flow.lock, flags); 773 } 774 EXPORT_SYMBOL(stop_tty); 775 776 void __start_tty(struct tty_struct *tty) 777 { 778 if (!tty->flow.stopped || tty->flow.tco_stopped) 779 return; 780 tty->flow.stopped = false; 781 if (tty->ops->start) 782 tty->ops->start(tty); 783 tty_wakeup(tty); 784 } 785 786 /** 787 * start_tty - propagate flow control 788 * @tty: tty to start 789 * 790 * Start a tty that has been stopped if at all possible. If @tty was previously 791 * stopped and is now being started, the &tty_driver->start() method is invoked 792 * and the line discipline woken. 793 * 794 * Locking: 795 * flow.lock 796 */ 797 void start_tty(struct tty_struct *tty) 798 { 799 unsigned long flags; 800 801 spin_lock_irqsave(&tty->flow.lock, flags); 802 __start_tty(tty); 803 spin_unlock_irqrestore(&tty->flow.lock, flags); 804 } 805 EXPORT_SYMBOL(start_tty); 806 807 static void tty_update_time(struct tty_struct *tty, bool mtime) 808 { 809 time64_t sec = ktime_get_real_seconds(); 810 struct tty_file_private *priv; 811 812 spin_lock(&tty->files_lock); 813 list_for_each_entry(priv, &tty->tty_files, list) { 814 struct inode *inode = file_inode(priv->file); 815 struct timespec64 time = mtime ? inode_get_mtime(inode) : inode_get_atime(inode); 816 817 /* 818 * We only care if the two values differ in anything other than the 819 * lower three bits (i.e every 8 seconds). If so, then we can update 820 * the time of the tty device, otherwise it could be construded as a 821 * security leak to let userspace know the exact timing of the tty. 822 */ 823 if ((sec ^ time.tv_sec) & ~7) { 824 if (mtime) 825 inode_set_mtime(inode, sec, 0); 826 else 827 inode_set_atime(inode, sec, 0); 828 } 829 } 830 spin_unlock(&tty->files_lock); 831 } 832 833 /* 834 * Iterate on the ldisc ->read() function until we've gotten all 835 * the data the ldisc has for us. 836 * 837 * The "cookie" is something that the ldisc read function can fill 838 * in to let us know that there is more data to be had. 839 * 840 * We promise to continue to call the ldisc until it stops returning 841 * data or clears the cookie. The cookie may be something that the 842 * ldisc maintains state for and needs to free. 843 */ 844 static ssize_t iterate_tty_read(struct tty_ldisc *ld, struct tty_struct *tty, 845 struct file *file, struct iov_iter *to) 846 { 847 void *cookie = NULL; 848 unsigned long offset = 0; 849 ssize_t retval = 0; 850 size_t copied, count = iov_iter_count(to); 851 u8 kernel_buf[64]; 852 853 do { 854 ssize_t size = min(count, sizeof(kernel_buf)); 855 856 size = ld->ops->read(tty, file, kernel_buf, size, &cookie, offset); 857 if (!size) 858 break; 859 860 if (size < 0) { 861 /* Did we have an earlier error (ie -EFAULT)? */ 862 if (retval) 863 break; 864 retval = size; 865 866 /* 867 * -EOVERFLOW means we didn't have enough space 868 * for a whole packet, and we shouldn't return 869 * a partial result. 870 */ 871 if (retval == -EOVERFLOW) 872 offset = 0; 873 break; 874 } 875 876 copied = copy_to_iter(kernel_buf, size, to); 877 offset += copied; 878 count -= copied; 879 880 /* 881 * If the user copy failed, we still need to do another ->read() 882 * call if we had a cookie to let the ldisc clear up. 883 * 884 * But make sure size is zeroed. 885 */ 886 if (unlikely(copied != size)) { 887 count = 0; 888 retval = -EFAULT; 889 } 890 } while (cookie); 891 892 /* We always clear tty buffer in case they contained passwords */ 893 memzero_explicit(kernel_buf, sizeof(kernel_buf)); 894 return offset ? offset : retval; 895 } 896 897 898 /** 899 * tty_read - read method for tty device files 900 * @iocb: kernel I/O control block 901 * @to: destination for the data read 902 * 903 * Perform the read system call function on this terminal device. Checks 904 * for hung up devices before calling the line discipline method. 905 * 906 * Locking: 907 * Locks the line discipline internally while needed. Multiple read calls 908 * may be outstanding in parallel. 909 */ 910 static ssize_t tty_read(struct kiocb *iocb, struct iov_iter *to) 911 { 912 struct file *file = iocb->ki_filp; 913 struct inode *inode = file_inode(file); 914 struct tty_struct *tty = file_tty(file); 915 struct tty_ldisc *ld; 916 ssize_t ret; 917 918 if (tty_paranoia_check(tty, inode, "tty_read")) 919 return -EIO; 920 if (!tty || tty_io_error(tty)) 921 return -EIO; 922 923 /* We want to wait for the line discipline to sort out in this 924 * situation. 925 */ 926 ld = tty_ldisc_ref_wait(tty); 927 if (!ld) 928 return hung_up_tty_read(iocb, to); 929 ret = -EIO; 930 if (ld->ops->read) 931 ret = iterate_tty_read(ld, tty, file, to); 932 tty_ldisc_deref(ld); 933 934 if (ret > 0) 935 tty_update_time(tty, false); 936 937 return ret; 938 } 939 940 void tty_write_unlock(struct tty_struct *tty) 941 { 942 mutex_unlock(&tty->atomic_write_lock); 943 wake_up_interruptible_poll(&tty->write_wait, EPOLLOUT); 944 } 945 946 int tty_write_lock(struct tty_struct *tty, bool ndelay) 947 { 948 if (!mutex_trylock(&tty->atomic_write_lock)) { 949 if (ndelay) 950 return -EAGAIN; 951 if (mutex_lock_interruptible(&tty->atomic_write_lock)) 952 return -ERESTARTSYS; 953 } 954 return 0; 955 } 956 957 /* 958 * Split writes up in sane blocksizes to avoid 959 * denial-of-service type attacks 960 */ 961 static ssize_t iterate_tty_write(struct tty_ldisc *ld, struct tty_struct *tty, 962 struct file *file, struct iov_iter *from) 963 { 964 size_t chunk, count = iov_iter_count(from); 965 ssize_t ret, written = 0; 966 967 ret = tty_write_lock(tty, file->f_flags & O_NDELAY); 968 if (ret < 0) 969 return ret; 970 971 /* 972 * We chunk up writes into a temporary buffer. This 973 * simplifies low-level drivers immensely, since they 974 * don't have locking issues and user mode accesses. 975 * 976 * But if TTY_NO_WRITE_SPLIT is set, we should use a 977 * big chunk-size.. 978 * 979 * The default chunk-size is 2kB, because the NTTY 980 * layer has problems with bigger chunks. It will 981 * claim to be able to handle more characters than 982 * it actually does. 983 */ 984 chunk = 2048; 985 if (test_bit(TTY_NO_WRITE_SPLIT, &tty->flags)) 986 chunk = 65536; 987 if (count < chunk) 988 chunk = count; 989 990 /* write_buf/write_cnt is protected by the atomic_write_lock mutex */ 991 if (tty->write_cnt < chunk) { 992 u8 *buf_chunk; 993 994 if (chunk < 1024) 995 chunk = 1024; 996 997 buf_chunk = kvmalloc(chunk, GFP_KERNEL | __GFP_RETRY_MAYFAIL); 998 if (!buf_chunk) { 999 ret = -ENOMEM; 1000 goto out; 1001 } 1002 kvfree(tty->write_buf); 1003 tty->write_cnt = chunk; 1004 tty->write_buf = buf_chunk; 1005 } 1006 1007 /* Do the write .. */ 1008 for (;;) { 1009 size_t size = min(chunk, count); 1010 1011 ret = -EFAULT; 1012 if (copy_from_iter(tty->write_buf, size, from) != size) 1013 break; 1014 1015 ret = ld->ops->write(tty, file, tty->write_buf, size); 1016 if (ret <= 0) 1017 break; 1018 1019 written += ret; 1020 if (ret > size) 1021 break; 1022 1023 /* FIXME! Have Al check this! */ 1024 if (ret != size) 1025 iov_iter_revert(from, size-ret); 1026 1027 count -= ret; 1028 if (!count) 1029 break; 1030 ret = -ERESTARTSYS; 1031 if (signal_pending(current)) 1032 break; 1033 cond_resched(); 1034 } 1035 if (written) { 1036 tty_update_time(tty, true); 1037 ret = written; 1038 } 1039 out: 1040 tty_write_unlock(tty); 1041 return ret; 1042 } 1043 1044 #ifdef CONFIG_PRINT_QUOTA_WARNING 1045 /** 1046 * tty_write_message - write a message to a certain tty, not just the console. 1047 * @tty: the destination tty_struct 1048 * @msg: the message to write 1049 * 1050 * This is used for messages that need to be redirected to a specific tty. We 1051 * don't put it into the syslog queue right now maybe in the future if really 1052 * needed. 1053 * 1054 * We must still hold the BTM and test the CLOSING flag for the moment. 1055 * 1056 * This function is DEPRECATED, do not use in new code. 1057 */ 1058 void tty_write_message(struct tty_struct *tty, char *msg) 1059 { 1060 if (tty) { 1061 mutex_lock(&tty->atomic_write_lock); 1062 tty_lock(tty); 1063 if (tty->ops->write && tty->count > 0) 1064 tty->ops->write(tty, msg, strlen(msg)); 1065 tty_unlock(tty); 1066 tty_write_unlock(tty); 1067 } 1068 } 1069 #endif 1070 1071 static ssize_t file_tty_write(struct file *file, struct kiocb *iocb, struct iov_iter *from) 1072 { 1073 struct tty_struct *tty = file_tty(file); 1074 struct tty_ldisc *ld; 1075 ssize_t ret; 1076 1077 if (tty_paranoia_check(tty, file_inode(file), "tty_write")) 1078 return -EIO; 1079 if (!tty || !tty->ops->write || tty_io_error(tty)) 1080 return -EIO; 1081 /* Short term debug to catch buggy drivers */ 1082 if (tty->ops->write_room == NULL) 1083 tty_err(tty, "missing write_room method\n"); 1084 ld = tty_ldisc_ref_wait(tty); 1085 if (!ld) 1086 return hung_up_tty_write(iocb, from); 1087 if (!ld->ops->write) 1088 ret = -EIO; 1089 else 1090 ret = iterate_tty_write(ld, tty, file, from); 1091 tty_ldisc_deref(ld); 1092 return ret; 1093 } 1094 1095 /** 1096 * tty_write - write method for tty device file 1097 * @iocb: kernel I/O control block 1098 * @from: iov_iter with data to write 1099 * 1100 * Write data to a tty device via the line discipline. 1101 * 1102 * Locking: 1103 * Locks the line discipline as required 1104 * Writes to the tty driver are serialized by the atomic_write_lock 1105 * and are then processed in chunks to the device. The line 1106 * discipline write method will not be invoked in parallel for 1107 * each device. 1108 */ 1109 static ssize_t tty_write(struct kiocb *iocb, struct iov_iter *from) 1110 { 1111 return file_tty_write(iocb->ki_filp, iocb, from); 1112 } 1113 1114 ssize_t redirected_tty_write(struct kiocb *iocb, struct iov_iter *iter) 1115 { 1116 struct file *p = NULL; 1117 1118 spin_lock(&redirect_lock); 1119 if (redirect) 1120 p = get_file(redirect); 1121 spin_unlock(&redirect_lock); 1122 1123 /* 1124 * We know the redirected tty is just another tty, we can 1125 * call file_tty_write() directly with that file pointer. 1126 */ 1127 if (p) { 1128 ssize_t res; 1129 1130 res = file_tty_write(p, iocb, iter); 1131 fput(p); 1132 return res; 1133 } 1134 return tty_write(iocb, iter); 1135 } 1136 1137 /** 1138 * tty_send_xchar - send priority character 1139 * @tty: the tty to send to 1140 * @ch: xchar to send 1141 * 1142 * Send a high priority character to the tty even if stopped. 1143 * 1144 * Locking: none for xchar method, write ordering for write method. 1145 */ 1146 int tty_send_xchar(struct tty_struct *tty, u8 ch) 1147 { 1148 bool was_stopped = tty->flow.stopped; 1149 1150 if (tty->ops->send_xchar) { 1151 down_read(&tty->termios_rwsem); 1152 tty->ops->send_xchar(tty, ch); 1153 up_read(&tty->termios_rwsem); 1154 return 0; 1155 } 1156 1157 if (tty_write_lock(tty, false) < 0) 1158 return -ERESTARTSYS; 1159 1160 down_read(&tty->termios_rwsem); 1161 if (was_stopped) 1162 start_tty(tty); 1163 tty->ops->write(tty, &ch, 1); 1164 if (was_stopped) 1165 stop_tty(tty); 1166 up_read(&tty->termios_rwsem); 1167 tty_write_unlock(tty); 1168 return 0; 1169 } 1170 1171 /** 1172 * pty_line_name - generate name for a pty 1173 * @driver: the tty driver in use 1174 * @index: the minor number 1175 * @p: output buffer of at least 6 bytes 1176 * 1177 * Generate a name from a @driver reference and write it to the output buffer 1178 * @p. 1179 * 1180 * Locking: None 1181 */ 1182 static void pty_line_name(struct tty_driver *driver, int index, char *p) 1183 { 1184 static const char ptychar[] = "pqrstuvwxyzabcde"; 1185 int i = index + driver->name_base; 1186 /* ->name is initialized to "ttyp", but "tty" is expected */ 1187 sprintf(p, "%s%c%x", 1188 driver->subtype == PTY_TYPE_SLAVE ? "tty" : driver->name, 1189 ptychar[i >> 4 & 0xf], i & 0xf); 1190 } 1191 1192 /** 1193 * tty_line_name - generate name for a tty 1194 * @driver: the tty driver in use 1195 * @index: the minor number 1196 * @p: output buffer of at least 7 bytes 1197 * 1198 * Generate a name from a @driver reference and write it to the output buffer 1199 * @p. 1200 * 1201 * Locking: None 1202 */ 1203 static ssize_t tty_line_name(struct tty_driver *driver, int index, char *p) 1204 { 1205 if (driver->flags & TTY_DRIVER_UNNUMBERED_NODE) 1206 return sprintf(p, "%s", driver->name); 1207 else 1208 return sprintf(p, "%s%d", driver->name, 1209 index + driver->name_base); 1210 } 1211 1212 /** 1213 * tty_driver_lookup_tty() - find an existing tty, if any 1214 * @driver: the driver for the tty 1215 * @file: file object 1216 * @idx: the minor number 1217 * 1218 * Return: the tty, if found. If not found, return %NULL or ERR_PTR() if the 1219 * driver lookup() method returns an error. 1220 * 1221 * Locking: tty_mutex must be held. If the tty is found, bump the tty kref. 1222 */ 1223 static struct tty_struct *tty_driver_lookup_tty(struct tty_driver *driver, 1224 struct file *file, int idx) 1225 { 1226 struct tty_struct *tty; 1227 1228 if (driver->ops->lookup) { 1229 if (!file) 1230 tty = ERR_PTR(-EIO); 1231 else 1232 tty = driver->ops->lookup(driver, file, idx); 1233 } else { 1234 if (idx >= driver->num) 1235 return ERR_PTR(-EINVAL); 1236 tty = driver->ttys[idx]; 1237 } 1238 if (!IS_ERR(tty)) 1239 tty_kref_get(tty); 1240 return tty; 1241 } 1242 1243 /** 1244 * tty_init_termios - helper for termios setup 1245 * @tty: the tty to set up 1246 * 1247 * Initialise the termios structure for this tty. This runs under the 1248 * %tty_mutex currently so we can be relaxed about ordering. 1249 */ 1250 void tty_init_termios(struct tty_struct *tty) 1251 { 1252 struct ktermios *tp; 1253 int idx = tty->index; 1254 1255 if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) 1256 tty->termios = tty->driver->init_termios; 1257 else { 1258 /* Check for lazy saved data */ 1259 tp = tty->driver->termios[idx]; 1260 if (tp != NULL) { 1261 tty->termios = *tp; 1262 tty->termios.c_line = tty->driver->init_termios.c_line; 1263 } else 1264 tty->termios = tty->driver->init_termios; 1265 } 1266 /* Compatibility until drivers always set this */ 1267 tty->termios.c_ispeed = tty_termios_input_baud_rate(&tty->termios); 1268 tty->termios.c_ospeed = tty_termios_baud_rate(&tty->termios); 1269 } 1270 EXPORT_SYMBOL_GPL(tty_init_termios); 1271 1272 /** 1273 * tty_standard_install - usual tty->ops->install 1274 * @driver: the driver for the tty 1275 * @tty: the tty 1276 * 1277 * If the @driver overrides @tty->ops->install, it still can call this function 1278 * to perform the standard install operations. 1279 */ 1280 int tty_standard_install(struct tty_driver *driver, struct tty_struct *tty) 1281 { 1282 tty_init_termios(tty); 1283 tty_driver_kref_get(driver); 1284 tty->count++; 1285 driver->ttys[tty->index] = tty; 1286 return 0; 1287 } 1288 EXPORT_SYMBOL_GPL(tty_standard_install); 1289 1290 /** 1291 * tty_driver_install_tty() - install a tty entry in the driver 1292 * @driver: the driver for the tty 1293 * @tty: the tty 1294 * 1295 * Install a tty object into the driver tables. The @tty->index field will be 1296 * set by the time this is called. This method is responsible for ensuring any 1297 * need additional structures are allocated and configured. 1298 * 1299 * Locking: tty_mutex for now 1300 */ 1301 static int tty_driver_install_tty(struct tty_driver *driver, 1302 struct tty_struct *tty) 1303 { 1304 return driver->ops->install ? driver->ops->install(driver, tty) : 1305 tty_standard_install(driver, tty); 1306 } 1307 1308 /** 1309 * tty_driver_remove_tty() - remove a tty from the driver tables 1310 * @driver: the driver for the tty 1311 * @tty: tty to remove 1312 * 1313 * Remove a tty object from the driver tables. The tty->index field will be set 1314 * by the time this is called. 1315 * 1316 * Locking: tty_mutex for now 1317 */ 1318 static void tty_driver_remove_tty(struct tty_driver *driver, struct tty_struct *tty) 1319 { 1320 if (driver->ops->remove) 1321 driver->ops->remove(driver, tty); 1322 else 1323 driver->ttys[tty->index] = NULL; 1324 } 1325 1326 /** 1327 * tty_reopen() - fast re-open of an open tty 1328 * @tty: the tty to open 1329 * 1330 * Re-opens on master ptys are not allowed and return -%EIO. 1331 * 1332 * Locking: Caller must hold tty_lock 1333 * Return: 0 on success, -errno on error. 1334 */ 1335 static int tty_reopen(struct tty_struct *tty) 1336 { 1337 struct tty_driver *driver = tty->driver; 1338 struct tty_ldisc *ld; 1339 int retval = 0; 1340 1341 if (driver->type == TTY_DRIVER_TYPE_PTY && 1342 driver->subtype == PTY_TYPE_MASTER) 1343 return -EIO; 1344 1345 if (!tty->count) 1346 return -EAGAIN; 1347 1348 if (test_bit(TTY_EXCLUSIVE, &tty->flags) && !capable(CAP_SYS_ADMIN)) 1349 return -EBUSY; 1350 1351 ld = tty_ldisc_ref_wait(tty); 1352 if (ld) { 1353 tty_ldisc_deref(ld); 1354 } else { 1355 retval = tty_ldisc_lock(tty, 5 * HZ); 1356 if (retval) 1357 return retval; 1358 1359 if (!tty->ldisc) 1360 retval = tty_ldisc_reinit(tty, tty->termios.c_line); 1361 tty_ldisc_unlock(tty); 1362 } 1363 1364 if (retval == 0) 1365 tty->count++; 1366 1367 return retval; 1368 } 1369 1370 /** 1371 * tty_init_dev - initialise a tty device 1372 * @driver: tty driver we are opening a device on 1373 * @idx: device index 1374 * 1375 * Prepare a tty device. This may not be a "new" clean device but could also be 1376 * an active device. The pty drivers require special handling because of this. 1377 * 1378 * Locking: 1379 * The function is called under the tty_mutex, which protects us from the 1380 * tty struct or driver itself going away. 1381 * 1382 * On exit the tty device has the line discipline attached and a reference 1383 * count of 1. If a pair was created for pty/tty use and the other was a pty 1384 * master then it too has a reference count of 1. 1385 * 1386 * WSH 06/09/97: Rewritten to remove races and properly clean up after a failed 1387 * open. The new code protects the open with a mutex, so it's really quite 1388 * straightforward. The mutex locking can probably be relaxed for the (most 1389 * common) case of reopening a tty. 1390 * 1391 * Return: new tty structure 1392 */ 1393 struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx) 1394 { 1395 struct tty_struct *tty; 1396 int retval; 1397 1398 /* 1399 * First time open is complex, especially for PTY devices. 1400 * This code guarantees that either everything succeeds and the 1401 * TTY is ready for operation, or else the table slots are vacated 1402 * and the allocated memory released. (Except that the termios 1403 * may be retained.) 1404 */ 1405 1406 if (!try_module_get(driver->owner)) 1407 return ERR_PTR(-ENODEV); 1408 1409 tty = alloc_tty_struct(driver, idx); 1410 if (!tty) { 1411 retval = -ENOMEM; 1412 goto err_module_put; 1413 } 1414 1415 tty_lock(tty); 1416 retval = tty_driver_install_tty(driver, tty); 1417 if (retval < 0) 1418 goto err_free_tty; 1419 1420 if (!tty->port) 1421 tty->port = driver->ports[idx]; 1422 1423 if (WARN_RATELIMIT(!tty->port, 1424 "%s: %s driver does not set tty->port. This would crash the kernel. Fix the driver!\n", 1425 __func__, tty->driver->name)) { 1426 retval = -EINVAL; 1427 goto err_release_lock; 1428 } 1429 1430 retval = tty_ldisc_lock(tty, 5 * HZ); 1431 if (retval) 1432 goto err_release_lock; 1433 tty->port->itty = tty; 1434 1435 /* 1436 * Structures all installed ... call the ldisc open routines. 1437 * If we fail here just call release_tty to clean up. No need 1438 * to decrement the use counts, as release_tty doesn't care. 1439 */ 1440 retval = tty_ldisc_setup(tty, tty->link); 1441 if (retval) 1442 goto err_release_tty; 1443 tty_ldisc_unlock(tty); 1444 /* Return the tty locked so that it cannot vanish under the caller */ 1445 return tty; 1446 1447 err_free_tty: 1448 tty_unlock(tty); 1449 free_tty_struct(tty); 1450 err_module_put: 1451 module_put(driver->owner); 1452 return ERR_PTR(retval); 1453 1454 /* call the tty release_tty routine to clean out this slot */ 1455 err_release_tty: 1456 tty_ldisc_unlock(tty); 1457 tty_info_ratelimited(tty, "ldisc open failed (%d), clearing slot %d\n", 1458 retval, idx); 1459 err_release_lock: 1460 tty_unlock(tty); 1461 release_tty(tty, idx); 1462 return ERR_PTR(retval); 1463 } 1464 1465 /** 1466 * tty_save_termios() - save tty termios data in driver table 1467 * @tty: tty whose termios data to save 1468 * 1469 * Locking: Caller guarantees serialisation with tty_init_termios(). 1470 */ 1471 void tty_save_termios(struct tty_struct *tty) 1472 { 1473 struct ktermios *tp; 1474 int idx = tty->index; 1475 1476 /* If the port is going to reset then it has no termios to save */ 1477 if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) 1478 return; 1479 1480 /* Stash the termios data */ 1481 tp = tty->driver->termios[idx]; 1482 if (tp == NULL) { 1483 tp = kmalloc(sizeof(*tp), GFP_KERNEL); 1484 if (tp == NULL) 1485 return; 1486 tty->driver->termios[idx] = tp; 1487 } 1488 *tp = tty->termios; 1489 } 1490 EXPORT_SYMBOL_GPL(tty_save_termios); 1491 1492 /** 1493 * tty_flush_works - flush all works of a tty/pty pair 1494 * @tty: tty device to flush works for (or either end of a pty pair) 1495 * 1496 * Sync flush all works belonging to @tty (and the 'other' tty). 1497 */ 1498 static void tty_flush_works(struct tty_struct *tty) 1499 { 1500 flush_work(&tty->SAK_work); 1501 flush_work(&tty->hangup_work); 1502 if (tty->link) { 1503 flush_work(&tty->link->SAK_work); 1504 flush_work(&tty->link->hangup_work); 1505 } 1506 } 1507 1508 /** 1509 * release_one_tty - release tty structure memory 1510 * @work: work of tty we are obliterating 1511 * 1512 * Releases memory associated with a tty structure, and clears out the 1513 * driver table slots. This function is called when a device is no longer 1514 * in use. It also gets called when setup of a device fails. 1515 * 1516 * Locking: 1517 * takes the file list lock internally when working on the list of ttys 1518 * that the driver keeps. 1519 * 1520 * This method gets called from a work queue so that the driver private 1521 * cleanup ops can sleep (needed for USB at least) 1522 */ 1523 static void release_one_tty(struct work_struct *work) 1524 { 1525 struct tty_struct *tty = 1526 container_of(work, struct tty_struct, hangup_work); 1527 struct tty_driver *driver = tty->driver; 1528 struct module *owner = driver->owner; 1529 1530 if (tty->ops->cleanup) 1531 tty->ops->cleanup(tty); 1532 1533 tty_driver_kref_put(driver); 1534 module_put(owner); 1535 1536 spin_lock(&tty->files_lock); 1537 list_del_init(&tty->tty_files); 1538 spin_unlock(&tty->files_lock); 1539 1540 put_pid(tty->ctrl.pgrp); 1541 put_pid(tty->ctrl.session); 1542 free_tty_struct(tty); 1543 } 1544 1545 static void queue_release_one_tty(struct kref *kref) 1546 { 1547 struct tty_struct *tty = container_of(kref, struct tty_struct, kref); 1548 1549 /* The hangup queue is now free so we can reuse it rather than 1550 * waste a chunk of memory for each port. 1551 */ 1552 INIT_WORK(&tty->hangup_work, release_one_tty); 1553 schedule_work(&tty->hangup_work); 1554 } 1555 1556 /** 1557 * tty_kref_put - release a tty kref 1558 * @tty: tty device 1559 * 1560 * Release a reference to the @tty device and if need be let the kref layer 1561 * destruct the object for us. 1562 */ 1563 void tty_kref_put(struct tty_struct *tty) 1564 { 1565 if (tty) 1566 kref_put(&tty->kref, queue_release_one_tty); 1567 } 1568 EXPORT_SYMBOL(tty_kref_put); 1569 1570 /** 1571 * release_tty - release tty structure memory 1572 * @tty: tty device release 1573 * @idx: index of the tty device release 1574 * 1575 * Release both @tty and a possible linked partner (think pty pair), 1576 * and decrement the refcount of the backing module. 1577 * 1578 * Locking: 1579 * tty_mutex 1580 * takes the file list lock internally when working on the list of ttys 1581 * that the driver keeps. 1582 */ 1583 static void release_tty(struct tty_struct *tty, int idx) 1584 { 1585 /* This should always be true but check for the moment */ 1586 WARN_ON(tty->index != idx); 1587 WARN_ON(!mutex_is_locked(&tty_mutex)); 1588 if (tty->ops->shutdown) 1589 tty->ops->shutdown(tty); 1590 tty_save_termios(tty); 1591 tty_driver_remove_tty(tty->driver, tty); 1592 if (tty->port) 1593 tty->port->itty = NULL; 1594 if (tty->link) 1595 tty->link->port->itty = NULL; 1596 if (tty->port) 1597 tty_buffer_cancel_work(tty->port); 1598 if (tty->link) 1599 tty_buffer_cancel_work(tty->link->port); 1600 1601 tty_kref_put(tty->link); 1602 tty_kref_put(tty); 1603 } 1604 1605 /** 1606 * tty_release_checks - check a tty before real release 1607 * @tty: tty to check 1608 * @idx: index of the tty 1609 * 1610 * Performs some paranoid checking before true release of the @tty. This is a 1611 * no-op unless %TTY_PARANOIA_CHECK is defined. 1612 */ 1613 static int tty_release_checks(struct tty_struct *tty, int idx) 1614 { 1615 #ifdef TTY_PARANOIA_CHECK 1616 if (idx < 0 || idx >= tty->driver->num) { 1617 tty_debug(tty, "bad idx %d\n", idx); 1618 return -1; 1619 } 1620 1621 /* not much to check for devpts */ 1622 if (tty->driver->flags & TTY_DRIVER_DEVPTS_MEM) 1623 return 0; 1624 1625 if (tty != tty->driver->ttys[idx]) { 1626 tty_debug(tty, "bad driver table[%d] = %p\n", 1627 idx, tty->driver->ttys[idx]); 1628 return -1; 1629 } 1630 if (tty->driver->other) { 1631 struct tty_struct *o_tty = tty->link; 1632 1633 if (o_tty != tty->driver->other->ttys[idx]) { 1634 tty_debug(tty, "bad other table[%d] = %p\n", 1635 idx, tty->driver->other->ttys[idx]); 1636 return -1; 1637 } 1638 if (o_tty->link != tty) { 1639 tty_debug(tty, "bad link = %p\n", o_tty->link); 1640 return -1; 1641 } 1642 } 1643 #endif 1644 return 0; 1645 } 1646 1647 /** 1648 * tty_kclose - closes tty opened by tty_kopen 1649 * @tty: tty device 1650 * 1651 * Performs the final steps to release and free a tty device. It is the same as 1652 * tty_release_struct() except that it also resets %TTY_PORT_KOPENED flag on 1653 * @tty->port. 1654 */ 1655 void tty_kclose(struct tty_struct *tty) 1656 { 1657 /* 1658 * Ask the line discipline code to release its structures 1659 */ 1660 tty_ldisc_release(tty); 1661 1662 /* Wait for pending work before tty destruction commences */ 1663 tty_flush_works(tty); 1664 1665 tty_debug_hangup(tty, "freeing structure\n"); 1666 /* 1667 * The release_tty function takes care of the details of clearing 1668 * the slots and preserving the termios structure. 1669 */ 1670 mutex_lock(&tty_mutex); 1671 tty_port_set_kopened(tty->port, 0); 1672 release_tty(tty, tty->index); 1673 mutex_unlock(&tty_mutex); 1674 } 1675 EXPORT_SYMBOL_GPL(tty_kclose); 1676 1677 /** 1678 * tty_release_struct - release a tty struct 1679 * @tty: tty device 1680 * @idx: index of the tty 1681 * 1682 * Performs the final steps to release and free a tty device. It is roughly the 1683 * reverse of tty_init_dev(). 1684 */ 1685 void tty_release_struct(struct tty_struct *tty, int idx) 1686 { 1687 /* 1688 * Ask the line discipline code to release its structures 1689 */ 1690 tty_ldisc_release(tty); 1691 1692 /* Wait for pending work before tty destruction commmences */ 1693 tty_flush_works(tty); 1694 1695 tty_debug_hangup(tty, "freeing structure\n"); 1696 /* 1697 * The release_tty function takes care of the details of clearing 1698 * the slots and preserving the termios structure. 1699 */ 1700 mutex_lock(&tty_mutex); 1701 release_tty(tty, idx); 1702 mutex_unlock(&tty_mutex); 1703 } 1704 EXPORT_SYMBOL_GPL(tty_release_struct); 1705 1706 /** 1707 * tty_release - vfs callback for close 1708 * @inode: inode of tty 1709 * @filp: file pointer for handle to tty 1710 * 1711 * Called the last time each file handle is closed that references this tty. 1712 * There may however be several such references. 1713 * 1714 * Locking: 1715 * Takes BKL. See tty_release_dev(). 1716 * 1717 * Even releasing the tty structures is a tricky business. We have to be very 1718 * careful that the structures are all released at the same time, as interrupts 1719 * might otherwise get the wrong pointers. 1720 * 1721 * WSH 09/09/97: rewritten to avoid some nasty race conditions that could 1722 * lead to double frees or releasing memory still in use. 1723 */ 1724 int tty_release(struct inode *inode, struct file *filp) 1725 { 1726 struct tty_struct *tty = file_tty(filp); 1727 struct tty_struct *o_tty = NULL; 1728 int do_sleep, final; 1729 int idx; 1730 long timeout = 0; 1731 int once = 1; 1732 1733 if (tty_paranoia_check(tty, inode, __func__)) 1734 return 0; 1735 1736 tty_lock(tty); 1737 check_tty_count(tty, __func__); 1738 1739 __tty_fasync(-1, filp, 0); 1740 1741 idx = tty->index; 1742 if (tty->driver->type == TTY_DRIVER_TYPE_PTY && 1743 tty->driver->subtype == PTY_TYPE_MASTER) 1744 o_tty = tty->link; 1745 1746 if (tty_release_checks(tty, idx)) { 1747 tty_unlock(tty); 1748 return 0; 1749 } 1750 1751 tty_debug_hangup(tty, "releasing (count=%d)\n", tty->count); 1752 1753 if (tty->ops->close) 1754 tty->ops->close(tty, filp); 1755 1756 /* If tty is pty master, lock the slave pty (stable lock order) */ 1757 tty_lock_slave(o_tty); 1758 1759 /* 1760 * Sanity check: if tty->count is going to zero, there shouldn't be 1761 * any waiters on tty->read_wait or tty->write_wait. We test the 1762 * wait queues and kick everyone out _before_ actually starting to 1763 * close. This ensures that we won't block while releasing the tty 1764 * structure. 1765 * 1766 * The test for the o_tty closing is necessary, since the master and 1767 * slave sides may close in any order. If the slave side closes out 1768 * first, its count will be one, since the master side holds an open. 1769 * Thus this test wouldn't be triggered at the time the slave closed, 1770 * so we do it now. 1771 */ 1772 while (1) { 1773 do_sleep = 0; 1774 1775 if (tty->count <= 1) { 1776 if (waitqueue_active(&tty->read_wait)) { 1777 wake_up_poll(&tty->read_wait, EPOLLIN); 1778 do_sleep++; 1779 } 1780 if (waitqueue_active(&tty->write_wait)) { 1781 wake_up_poll(&tty->write_wait, EPOLLOUT); 1782 do_sleep++; 1783 } 1784 } 1785 if (o_tty && o_tty->count <= 1) { 1786 if (waitqueue_active(&o_tty->read_wait)) { 1787 wake_up_poll(&o_tty->read_wait, EPOLLIN); 1788 do_sleep++; 1789 } 1790 if (waitqueue_active(&o_tty->write_wait)) { 1791 wake_up_poll(&o_tty->write_wait, EPOLLOUT); 1792 do_sleep++; 1793 } 1794 } 1795 if (!do_sleep) 1796 break; 1797 1798 if (once) { 1799 once = 0; 1800 tty_warn(tty, "read/write wait queue active!\n"); 1801 } 1802 schedule_timeout_killable(timeout); 1803 if (timeout < 120 * HZ) 1804 timeout = 2 * timeout + 1; 1805 else 1806 timeout = MAX_SCHEDULE_TIMEOUT; 1807 } 1808 1809 if (o_tty) { 1810 if (--o_tty->count < 0) { 1811 tty_warn(tty, "bad slave count (%d)\n", o_tty->count); 1812 o_tty->count = 0; 1813 } 1814 } 1815 if (--tty->count < 0) { 1816 tty_warn(tty, "bad tty->count (%d)\n", tty->count); 1817 tty->count = 0; 1818 } 1819 1820 /* 1821 * We've decremented tty->count, so we need to remove this file 1822 * descriptor off the tty->tty_files list; this serves two 1823 * purposes: 1824 * - check_tty_count sees the correct number of file descriptors 1825 * associated with this tty. 1826 * - do_tty_hangup no longer sees this file descriptor as 1827 * something that needs to be handled for hangups. 1828 */ 1829 tty_del_file(filp); 1830 1831 /* 1832 * Perform some housekeeping before deciding whether to return. 1833 * 1834 * If _either_ side is closing, make sure there aren't any 1835 * processes that still think tty or o_tty is their controlling 1836 * tty. 1837 */ 1838 if (!tty->count) { 1839 read_lock(&tasklist_lock); 1840 session_clear_tty(tty->ctrl.session); 1841 if (o_tty) 1842 session_clear_tty(o_tty->ctrl.session); 1843 read_unlock(&tasklist_lock); 1844 } 1845 1846 /* check whether both sides are closing ... */ 1847 final = !tty->count && !(o_tty && o_tty->count); 1848 1849 tty_unlock_slave(o_tty); 1850 tty_unlock(tty); 1851 1852 /* At this point, the tty->count == 0 should ensure a dead tty 1853 * cannot be re-opened by a racing opener. 1854 */ 1855 1856 if (!final) 1857 return 0; 1858 1859 tty_debug_hangup(tty, "final close\n"); 1860 1861 tty_release_struct(tty, idx); 1862 return 0; 1863 } 1864 1865 /** 1866 * tty_open_current_tty - get locked tty of current task 1867 * @device: device number 1868 * @filp: file pointer to tty 1869 * @return: locked tty of the current task iff @device is /dev/tty 1870 * 1871 * Performs a re-open of the current task's controlling tty. 1872 * 1873 * We cannot return driver and index like for the other nodes because devpts 1874 * will not work then. It expects inodes to be from devpts FS. 1875 */ 1876 static struct tty_struct *tty_open_current_tty(dev_t device, struct file *filp) 1877 { 1878 struct tty_struct *tty; 1879 int retval; 1880 1881 if (device != MKDEV(TTYAUX_MAJOR, 0)) 1882 return NULL; 1883 1884 tty = get_current_tty(); 1885 if (!tty) 1886 return ERR_PTR(-ENXIO); 1887 1888 filp->f_flags |= O_NONBLOCK; /* Don't let /dev/tty block */ 1889 /* noctty = 1; */ 1890 tty_lock(tty); 1891 tty_kref_put(tty); /* safe to drop the kref now */ 1892 1893 retval = tty_reopen(tty); 1894 if (retval < 0) { 1895 tty_unlock(tty); 1896 tty = ERR_PTR(retval); 1897 } 1898 return tty; 1899 } 1900 1901 /** 1902 * tty_lookup_driver - lookup a tty driver for a given device file 1903 * @device: device number 1904 * @filp: file pointer to tty 1905 * @index: index for the device in the @return driver 1906 * 1907 * If returned value is not erroneous, the caller is responsible to decrement 1908 * the refcount by tty_driver_kref_put(). 1909 * 1910 * Locking: %tty_mutex protects get_tty_driver() 1911 * 1912 * Return: driver for this inode (with increased refcount) 1913 */ 1914 static struct tty_driver *tty_lookup_driver(dev_t device, struct file *filp, 1915 int *index) 1916 { 1917 struct tty_driver *driver = NULL; 1918 1919 switch (device) { 1920 #ifdef CONFIG_VT 1921 case MKDEV(TTY_MAJOR, 0): { 1922 extern struct tty_driver *console_driver; 1923 1924 driver = tty_driver_kref_get(console_driver); 1925 *index = fg_console; 1926 break; 1927 } 1928 #endif 1929 case MKDEV(TTYAUX_MAJOR, 1): { 1930 struct tty_driver *console_driver = console_device(index); 1931 1932 if (console_driver) { 1933 driver = tty_driver_kref_get(console_driver); 1934 if (driver && filp) { 1935 /* Don't let /dev/console block */ 1936 filp->f_flags |= O_NONBLOCK; 1937 break; 1938 } 1939 } 1940 if (driver) 1941 tty_driver_kref_put(driver); 1942 return ERR_PTR(-ENODEV); 1943 } 1944 default: 1945 driver = get_tty_driver(device, index); 1946 if (!driver) 1947 return ERR_PTR(-ENODEV); 1948 break; 1949 } 1950 return driver; 1951 } 1952 1953 static struct tty_struct *tty_kopen(dev_t device, int shared) 1954 { 1955 struct tty_struct *tty; 1956 struct tty_driver *driver; 1957 int index = -1; 1958 1959 mutex_lock(&tty_mutex); 1960 driver = tty_lookup_driver(device, NULL, &index); 1961 if (IS_ERR(driver)) { 1962 mutex_unlock(&tty_mutex); 1963 return ERR_CAST(driver); 1964 } 1965 1966 /* check whether we're reopening an existing tty */ 1967 tty = tty_driver_lookup_tty(driver, NULL, index); 1968 if (IS_ERR(tty) || shared) 1969 goto out; 1970 1971 if (tty) { 1972 /* drop kref from tty_driver_lookup_tty() */ 1973 tty_kref_put(tty); 1974 tty = ERR_PTR(-EBUSY); 1975 } else { /* tty_init_dev returns tty with the tty_lock held */ 1976 tty = tty_init_dev(driver, index); 1977 if (IS_ERR(tty)) 1978 goto out; 1979 tty_port_set_kopened(tty->port, 1); 1980 } 1981 out: 1982 mutex_unlock(&tty_mutex); 1983 tty_driver_kref_put(driver); 1984 return tty; 1985 } 1986 1987 /** 1988 * tty_kopen_exclusive - open a tty device for kernel 1989 * @device: dev_t of device to open 1990 * 1991 * Opens tty exclusively for kernel. Performs the driver lookup, makes sure 1992 * it's not already opened and performs the first-time tty initialization. 1993 * 1994 * Claims the global %tty_mutex to serialize: 1995 * * concurrent first-time tty initialization 1996 * * concurrent tty driver removal w/ lookup 1997 * * concurrent tty removal from driver table 1998 * 1999 * Return: the locked initialized &tty_struct 2000 */ 2001 struct tty_struct *tty_kopen_exclusive(dev_t device) 2002 { 2003 return tty_kopen(device, 0); 2004 } 2005 EXPORT_SYMBOL_GPL(tty_kopen_exclusive); 2006 2007 /** 2008 * tty_kopen_shared - open a tty device for shared in-kernel use 2009 * @device: dev_t of device to open 2010 * 2011 * Opens an already existing tty for in-kernel use. Compared to 2012 * tty_kopen_exclusive() above it doesn't ensure to be the only user. 2013 * 2014 * Locking: identical to tty_kopen() above. 2015 */ 2016 struct tty_struct *tty_kopen_shared(dev_t device) 2017 { 2018 return tty_kopen(device, 1); 2019 } 2020 EXPORT_SYMBOL_GPL(tty_kopen_shared); 2021 2022 /** 2023 * tty_open_by_driver - open a tty device 2024 * @device: dev_t of device to open 2025 * @filp: file pointer to tty 2026 * 2027 * Performs the driver lookup, checks for a reopen, or otherwise performs the 2028 * first-time tty initialization. 2029 * 2030 * 2031 * Claims the global tty_mutex to serialize: 2032 * * concurrent first-time tty initialization 2033 * * concurrent tty driver removal w/ lookup 2034 * * concurrent tty removal from driver table 2035 * 2036 * Return: the locked initialized or re-opened &tty_struct 2037 */ 2038 static struct tty_struct *tty_open_by_driver(dev_t device, 2039 struct file *filp) 2040 { 2041 struct tty_struct *tty; 2042 struct tty_driver *driver = NULL; 2043 int index = -1; 2044 int retval; 2045 2046 mutex_lock(&tty_mutex); 2047 driver = tty_lookup_driver(device, filp, &index); 2048 if (IS_ERR(driver)) { 2049 mutex_unlock(&tty_mutex); 2050 return ERR_CAST(driver); 2051 } 2052 2053 /* check whether we're reopening an existing tty */ 2054 tty = tty_driver_lookup_tty(driver, filp, index); 2055 if (IS_ERR(tty)) { 2056 mutex_unlock(&tty_mutex); 2057 goto out; 2058 } 2059 2060 if (tty) { 2061 if (tty_port_kopened(tty->port)) { 2062 tty_kref_put(tty); 2063 mutex_unlock(&tty_mutex); 2064 tty = ERR_PTR(-EBUSY); 2065 goto out; 2066 } 2067 mutex_unlock(&tty_mutex); 2068 retval = tty_lock_interruptible(tty); 2069 tty_kref_put(tty); /* drop kref from tty_driver_lookup_tty() */ 2070 if (retval) { 2071 if (retval == -EINTR) 2072 retval = -ERESTARTSYS; 2073 tty = ERR_PTR(retval); 2074 goto out; 2075 } 2076 retval = tty_reopen(tty); 2077 if (retval < 0) { 2078 tty_unlock(tty); 2079 tty = ERR_PTR(retval); 2080 } 2081 } else { /* Returns with the tty_lock held for now */ 2082 tty = tty_init_dev(driver, index); 2083 mutex_unlock(&tty_mutex); 2084 } 2085 out: 2086 tty_driver_kref_put(driver); 2087 return tty; 2088 } 2089 2090 /** 2091 * tty_open - open a tty device 2092 * @inode: inode of device file 2093 * @filp: file pointer to tty 2094 * 2095 * tty_open() and tty_release() keep up the tty count that contains the number 2096 * of opens done on a tty. We cannot use the inode-count, as different inodes 2097 * might point to the same tty. 2098 * 2099 * Open-counting is needed for pty masters, as well as for keeping track of 2100 * serial lines: DTR is dropped when the last close happens. 2101 * (This is not done solely through tty->count, now. - Ted 1/27/92) 2102 * 2103 * The termios state of a pty is reset on the first open so that settings don't 2104 * persist across reuse. 2105 * 2106 * Locking: 2107 * * %tty_mutex protects tty, tty_lookup_driver() and tty_init_dev(). 2108 * * @tty->count should protect the rest. 2109 * * ->siglock protects ->signal/->sighand 2110 * 2111 * Note: the tty_unlock/lock cases without a ref are only safe due to %tty_mutex 2112 */ 2113 static int tty_open(struct inode *inode, struct file *filp) 2114 { 2115 struct tty_struct *tty; 2116 int noctty, retval; 2117 dev_t device = inode->i_rdev; 2118 unsigned saved_flags = filp->f_flags; 2119 2120 nonseekable_open(inode, filp); 2121 2122 retry_open: 2123 retval = tty_alloc_file(filp); 2124 if (retval) 2125 return -ENOMEM; 2126 2127 tty = tty_open_current_tty(device, filp); 2128 if (!tty) 2129 tty = tty_open_by_driver(device, filp); 2130 2131 if (IS_ERR(tty)) { 2132 tty_free_file(filp); 2133 retval = PTR_ERR(tty); 2134 if (retval != -EAGAIN || signal_pending(current)) 2135 return retval; 2136 schedule(); 2137 goto retry_open; 2138 } 2139 2140 tty_add_file(tty, filp); 2141 2142 check_tty_count(tty, __func__); 2143 tty_debug_hangup(tty, "opening (count=%d)\n", tty->count); 2144 2145 if (tty->ops->open) 2146 retval = tty->ops->open(tty, filp); 2147 else 2148 retval = -ENODEV; 2149 filp->f_flags = saved_flags; 2150 2151 if (retval) { 2152 tty_debug_hangup(tty, "open error %d, releasing\n", retval); 2153 2154 tty_unlock(tty); /* need to call tty_release without BTM */ 2155 tty_release(inode, filp); 2156 if (retval != -ERESTARTSYS) 2157 return retval; 2158 2159 if (signal_pending(current)) 2160 return retval; 2161 2162 schedule(); 2163 /* 2164 * Need to reset f_op in case a hangup happened. 2165 */ 2166 if (tty_hung_up_p(filp)) 2167 filp->f_op = &tty_fops; 2168 goto retry_open; 2169 } 2170 clear_bit(TTY_HUPPED, &tty->flags); 2171 2172 noctty = (filp->f_flags & O_NOCTTY) || 2173 (IS_ENABLED(CONFIG_VT) && device == MKDEV(TTY_MAJOR, 0)) || 2174 device == MKDEV(TTYAUX_MAJOR, 1) || 2175 (tty->driver->type == TTY_DRIVER_TYPE_PTY && 2176 tty->driver->subtype == PTY_TYPE_MASTER); 2177 if (!noctty) 2178 tty_open_proc_set_tty(filp, tty); 2179 tty_unlock(tty); 2180 return 0; 2181 } 2182 2183 2184 /** 2185 * tty_poll - check tty status 2186 * @filp: file being polled 2187 * @wait: poll wait structures to update 2188 * 2189 * Call the line discipline polling method to obtain the poll status of the 2190 * device. 2191 * 2192 * Locking: locks called line discipline but ldisc poll method may be 2193 * re-entered freely by other callers. 2194 */ 2195 static __poll_t tty_poll(struct file *filp, poll_table *wait) 2196 { 2197 struct tty_struct *tty = file_tty(filp); 2198 struct tty_ldisc *ld; 2199 __poll_t ret = 0; 2200 2201 if (tty_paranoia_check(tty, file_inode(filp), "tty_poll")) 2202 return 0; 2203 2204 ld = tty_ldisc_ref_wait(tty); 2205 if (!ld) 2206 return hung_up_tty_poll(filp, wait); 2207 if (ld->ops->poll) 2208 ret = ld->ops->poll(tty, filp, wait); 2209 tty_ldisc_deref(ld); 2210 return ret; 2211 } 2212 2213 static int __tty_fasync(int fd, struct file *filp, int on) 2214 { 2215 struct tty_struct *tty = file_tty(filp); 2216 unsigned long flags; 2217 int retval = 0; 2218 2219 if (tty_paranoia_check(tty, file_inode(filp), "tty_fasync")) 2220 goto out; 2221 2222 if (on) { 2223 retval = file_f_owner_allocate(filp); 2224 if (retval) 2225 goto out; 2226 } 2227 2228 retval = fasync_helper(fd, filp, on, &tty->fasync); 2229 if (retval <= 0) 2230 goto out; 2231 2232 if (on) { 2233 enum pid_type type; 2234 struct pid *pid; 2235 2236 spin_lock_irqsave(&tty->ctrl.lock, flags); 2237 if (tty->ctrl.pgrp) { 2238 pid = tty->ctrl.pgrp; 2239 type = PIDTYPE_PGID; 2240 } else { 2241 pid = task_pid(current); 2242 type = PIDTYPE_TGID; 2243 } 2244 get_pid(pid); 2245 spin_unlock_irqrestore(&tty->ctrl.lock, flags); 2246 __f_setown(filp, pid, type, 0); 2247 put_pid(pid); 2248 retval = 0; 2249 } 2250 out: 2251 return retval; 2252 } 2253 2254 static int tty_fasync(int fd, struct file *filp, int on) 2255 { 2256 struct tty_struct *tty = file_tty(filp); 2257 int retval = -ENOTTY; 2258 2259 tty_lock(tty); 2260 if (!tty_hung_up_p(filp)) 2261 retval = __tty_fasync(fd, filp, on); 2262 tty_unlock(tty); 2263 2264 return retval; 2265 } 2266 2267 static bool tty_legacy_tiocsti __read_mostly = IS_ENABLED(CONFIG_LEGACY_TIOCSTI); 2268 /** 2269 * tiocsti - fake input character 2270 * @tty: tty to fake input into 2271 * @p: pointer to character 2272 * 2273 * Fake input to a tty device. Does the necessary locking and input management. 2274 * 2275 * FIXME: does not honour flow control ?? 2276 * 2277 * Locking: 2278 * * Called functions take tty_ldiscs_lock 2279 * * current->signal->tty check is safe without locks 2280 */ 2281 static int tiocsti(struct tty_struct *tty, u8 __user *p) 2282 { 2283 struct tty_ldisc *ld; 2284 u8 ch; 2285 2286 if (!tty_legacy_tiocsti && !capable(CAP_SYS_ADMIN)) 2287 return -EIO; 2288 2289 if ((current->signal->tty != tty) && !capable(CAP_SYS_ADMIN)) 2290 return -EPERM; 2291 if (get_user(ch, p)) 2292 return -EFAULT; 2293 tty_audit_tiocsti(tty, ch); 2294 ld = tty_ldisc_ref_wait(tty); 2295 if (!ld) 2296 return -EIO; 2297 tty_buffer_lock_exclusive(tty->port); 2298 if (ld->ops->receive_buf) 2299 ld->ops->receive_buf(tty, &ch, NULL, 1); 2300 tty_buffer_unlock_exclusive(tty->port); 2301 tty_ldisc_deref(ld); 2302 return 0; 2303 } 2304 2305 /** 2306 * tiocgwinsz - implement window query ioctl 2307 * @tty: tty 2308 * @arg: user buffer for result 2309 * 2310 * Copies the kernel idea of the window size into the user buffer. 2311 * 2312 * Locking: @tty->winsize_mutex is taken to ensure the winsize data is 2313 * consistent. 2314 */ 2315 static int tiocgwinsz(struct tty_struct *tty, struct winsize __user *arg) 2316 { 2317 int err; 2318 2319 mutex_lock(&tty->winsize_mutex); 2320 err = copy_to_user(arg, &tty->winsize, sizeof(*arg)); 2321 mutex_unlock(&tty->winsize_mutex); 2322 2323 return err ? -EFAULT : 0; 2324 } 2325 2326 /** 2327 * tty_do_resize - resize event 2328 * @tty: tty being resized 2329 * @ws: new dimensions 2330 * 2331 * Update the termios variables and send the necessary signals to peform a 2332 * terminal resize correctly. 2333 */ 2334 int tty_do_resize(struct tty_struct *tty, struct winsize *ws) 2335 { 2336 struct pid *pgrp; 2337 2338 /* Lock the tty */ 2339 mutex_lock(&tty->winsize_mutex); 2340 if (!memcmp(ws, &tty->winsize, sizeof(*ws))) 2341 goto done; 2342 2343 /* Signal the foreground process group */ 2344 pgrp = tty_get_pgrp(tty); 2345 if (pgrp) 2346 kill_pgrp(pgrp, SIGWINCH, 1); 2347 put_pid(pgrp); 2348 2349 tty->winsize = *ws; 2350 done: 2351 mutex_unlock(&tty->winsize_mutex); 2352 return 0; 2353 } 2354 EXPORT_SYMBOL(tty_do_resize); 2355 2356 /** 2357 * tiocswinsz - implement window size set ioctl 2358 * @tty: tty side of tty 2359 * @arg: user buffer for result 2360 * 2361 * Copies the user idea of the window size to the kernel. Traditionally this is 2362 * just advisory information but for the Linux console it actually has driver 2363 * level meaning and triggers a VC resize. 2364 * 2365 * Locking: 2366 * Driver dependent. The default do_resize method takes the tty termios 2367 * mutex and ctrl.lock. The console takes its own lock then calls into the 2368 * default method. 2369 */ 2370 static int tiocswinsz(struct tty_struct *tty, struct winsize __user *arg) 2371 { 2372 struct winsize tmp_ws; 2373 2374 if (copy_from_user(&tmp_ws, arg, sizeof(*arg))) 2375 return -EFAULT; 2376 2377 if (tty->ops->resize) 2378 return tty->ops->resize(tty, &tmp_ws); 2379 else 2380 return tty_do_resize(tty, &tmp_ws); 2381 } 2382 2383 /** 2384 * tioccons - allow admin to move logical console 2385 * @file: the file to become console 2386 * 2387 * Allow the administrator to move the redirected console device. 2388 * 2389 * Locking: uses redirect_lock to guard the redirect information 2390 */ 2391 static int tioccons(struct file *file) 2392 { 2393 if (!capable(CAP_SYS_ADMIN)) 2394 return -EPERM; 2395 if (file->f_op->write_iter == redirected_tty_write) { 2396 struct file *f; 2397 2398 spin_lock(&redirect_lock); 2399 f = redirect; 2400 redirect = NULL; 2401 spin_unlock(&redirect_lock); 2402 if (f) 2403 fput(f); 2404 return 0; 2405 } 2406 if (file->f_op->write_iter != tty_write) 2407 return -ENOTTY; 2408 if (!(file->f_mode & FMODE_WRITE)) 2409 return -EBADF; 2410 if (!(file->f_mode & FMODE_CAN_WRITE)) 2411 return -EINVAL; 2412 spin_lock(&redirect_lock); 2413 if (redirect) { 2414 spin_unlock(&redirect_lock); 2415 return -EBUSY; 2416 } 2417 redirect = get_file(file); 2418 spin_unlock(&redirect_lock); 2419 return 0; 2420 } 2421 2422 /** 2423 * tiocsetd - set line discipline 2424 * @tty: tty device 2425 * @p: pointer to user data 2426 * 2427 * Set the line discipline according to user request. 2428 * 2429 * Locking: see tty_set_ldisc(), this function is just a helper 2430 */ 2431 static int tiocsetd(struct tty_struct *tty, int __user *p) 2432 { 2433 int disc; 2434 int ret; 2435 2436 if (get_user(disc, p)) 2437 return -EFAULT; 2438 2439 ret = tty_set_ldisc(tty, disc); 2440 2441 return ret; 2442 } 2443 2444 /** 2445 * tiocgetd - get line discipline 2446 * @tty: tty device 2447 * @p: pointer to user data 2448 * 2449 * Retrieves the line discipline id directly from the ldisc. 2450 * 2451 * Locking: waits for ldisc reference (in case the line discipline is changing 2452 * or the @tty is being hungup) 2453 */ 2454 static int tiocgetd(struct tty_struct *tty, int __user *p) 2455 { 2456 struct tty_ldisc *ld; 2457 int ret; 2458 2459 ld = tty_ldisc_ref_wait(tty); 2460 if (!ld) 2461 return -EIO; 2462 ret = put_user(ld->ops->num, p); 2463 tty_ldisc_deref(ld); 2464 return ret; 2465 } 2466 2467 /** 2468 * send_break - performed time break 2469 * @tty: device to break on 2470 * @duration: timeout in mS 2471 * 2472 * Perform a timed break on hardware that lacks its own driver level timed 2473 * break functionality. 2474 * 2475 * Locking: 2476 * @tty->atomic_write_lock serializes 2477 */ 2478 static int send_break(struct tty_struct *tty, unsigned int duration) 2479 { 2480 int retval; 2481 2482 if (tty->ops->break_ctl == NULL) 2483 return 0; 2484 2485 if (tty->driver->flags & TTY_DRIVER_HARDWARE_BREAK) 2486 return tty->ops->break_ctl(tty, duration); 2487 2488 /* Do the work ourselves */ 2489 if (tty_write_lock(tty, false) < 0) 2490 return -EINTR; 2491 2492 retval = tty->ops->break_ctl(tty, -1); 2493 if (!retval) { 2494 msleep_interruptible(duration); 2495 retval = tty->ops->break_ctl(tty, 0); 2496 } else if (retval == -EOPNOTSUPP) { 2497 /* some drivers can tell only dynamically */ 2498 retval = 0; 2499 } 2500 tty_write_unlock(tty); 2501 2502 if (signal_pending(current)) 2503 retval = -EINTR; 2504 2505 return retval; 2506 } 2507 2508 /** 2509 * tty_get_tiocm - get tiocm status register 2510 * @tty: tty device 2511 * 2512 * Obtain the modem status bits from the tty driver if the feature 2513 * is supported. 2514 */ 2515 int tty_get_tiocm(struct tty_struct *tty) 2516 { 2517 int retval = -ENOTTY; 2518 2519 if (tty->ops->tiocmget) 2520 retval = tty->ops->tiocmget(tty); 2521 2522 return retval; 2523 } 2524 EXPORT_SYMBOL_GPL(tty_get_tiocm); 2525 2526 /** 2527 * tty_tiocmget - get modem status 2528 * @tty: tty device 2529 * @p: pointer to result 2530 * 2531 * Obtain the modem status bits from the tty driver if the feature is 2532 * supported. Return -%ENOTTY if it is not available. 2533 * 2534 * Locking: none (up to the driver) 2535 */ 2536 static int tty_tiocmget(struct tty_struct *tty, int __user *p) 2537 { 2538 int retval; 2539 2540 retval = tty_get_tiocm(tty); 2541 if (retval >= 0) 2542 retval = put_user(retval, p); 2543 2544 return retval; 2545 } 2546 2547 /** 2548 * tty_tiocmset - set modem status 2549 * @tty: tty device 2550 * @cmd: command - clear bits, set bits or set all 2551 * @p: pointer to desired bits 2552 * 2553 * Set the modem status bits from the tty driver if the feature 2554 * is supported. Return -%ENOTTY if it is not available. 2555 * 2556 * Locking: none (up to the driver) 2557 */ 2558 static int tty_tiocmset(struct tty_struct *tty, unsigned int cmd, 2559 unsigned __user *p) 2560 { 2561 int retval; 2562 unsigned int set, clear, val; 2563 2564 if (tty->ops->tiocmset == NULL) 2565 return -ENOTTY; 2566 2567 retval = get_user(val, p); 2568 if (retval) 2569 return retval; 2570 set = clear = 0; 2571 switch (cmd) { 2572 case TIOCMBIS: 2573 set = val; 2574 break; 2575 case TIOCMBIC: 2576 clear = val; 2577 break; 2578 case TIOCMSET: 2579 set = val; 2580 clear = ~val; 2581 break; 2582 } 2583 set &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP; 2584 clear &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP; 2585 return tty->ops->tiocmset(tty, set, clear); 2586 } 2587 2588 /** 2589 * tty_get_icount - get tty statistics 2590 * @tty: tty device 2591 * @icount: output parameter 2592 * 2593 * Gets a copy of the @tty's icount statistics. 2594 * 2595 * Locking: none (up to the driver) 2596 */ 2597 int tty_get_icount(struct tty_struct *tty, 2598 struct serial_icounter_struct *icount) 2599 { 2600 memset(icount, 0, sizeof(*icount)); 2601 2602 if (tty->ops->get_icount) 2603 return tty->ops->get_icount(tty, icount); 2604 else 2605 return -ENOTTY; 2606 } 2607 EXPORT_SYMBOL_GPL(tty_get_icount); 2608 2609 static int tty_tiocgicount(struct tty_struct *tty, void __user *arg) 2610 { 2611 struct serial_icounter_struct icount; 2612 int retval; 2613 2614 retval = tty_get_icount(tty, &icount); 2615 if (retval != 0) 2616 return retval; 2617 2618 if (copy_to_user(arg, &icount, sizeof(icount))) 2619 return -EFAULT; 2620 return 0; 2621 } 2622 2623 static int tty_set_serial(struct tty_struct *tty, struct serial_struct *ss) 2624 { 2625 char comm[TASK_COMM_LEN]; 2626 int flags; 2627 2628 flags = ss->flags & ASYNC_DEPRECATED; 2629 2630 if (flags) 2631 pr_warn_ratelimited("%s: '%s' is using deprecated serial flags (with no effect): %.8x\n", 2632 __func__, get_task_comm(comm, current), flags); 2633 2634 if (!tty->ops->set_serial) 2635 return -ENOTTY; 2636 2637 return tty->ops->set_serial(tty, ss); 2638 } 2639 2640 static int tty_tiocsserial(struct tty_struct *tty, struct serial_struct __user *ss) 2641 { 2642 struct serial_struct v; 2643 2644 if (copy_from_user(&v, ss, sizeof(*ss))) 2645 return -EFAULT; 2646 2647 return tty_set_serial(tty, &v); 2648 } 2649 2650 static int tty_tiocgserial(struct tty_struct *tty, struct serial_struct __user *ss) 2651 { 2652 struct serial_struct v; 2653 int err; 2654 2655 memset(&v, 0, sizeof(v)); 2656 if (!tty->ops->get_serial) 2657 return -ENOTTY; 2658 err = tty->ops->get_serial(tty, &v); 2659 if (!err && copy_to_user(ss, &v, sizeof(v))) 2660 err = -EFAULT; 2661 return err; 2662 } 2663 2664 /* 2665 * if pty, return the slave side (real_tty) 2666 * otherwise, return self 2667 */ 2668 static struct tty_struct *tty_pair_get_tty(struct tty_struct *tty) 2669 { 2670 if (tty->driver->type == TTY_DRIVER_TYPE_PTY && 2671 tty->driver->subtype == PTY_TYPE_MASTER) 2672 tty = tty->link; 2673 return tty; 2674 } 2675 2676 /* 2677 * Split this up, as gcc can choke on it otherwise.. 2678 */ 2679 long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 2680 { 2681 struct tty_struct *tty = file_tty(file); 2682 struct tty_struct *real_tty; 2683 void __user *p = (void __user *)arg; 2684 int retval; 2685 struct tty_ldisc *ld; 2686 2687 if (tty_paranoia_check(tty, file_inode(file), "tty_ioctl")) 2688 return -EINVAL; 2689 2690 real_tty = tty_pair_get_tty(tty); 2691 2692 /* 2693 * Factor out some common prep work 2694 */ 2695 switch (cmd) { 2696 case TIOCSETD: 2697 case TIOCSBRK: 2698 case TIOCCBRK: 2699 case TCSBRK: 2700 case TCSBRKP: 2701 retval = tty_check_change(tty); 2702 if (retval) 2703 return retval; 2704 if (cmd != TIOCCBRK) { 2705 tty_wait_until_sent(tty, 0); 2706 if (signal_pending(current)) 2707 return -EINTR; 2708 } 2709 break; 2710 } 2711 2712 /* 2713 * Now do the stuff. 2714 */ 2715 switch (cmd) { 2716 case TIOCSTI: 2717 return tiocsti(tty, p); 2718 case TIOCGWINSZ: 2719 return tiocgwinsz(real_tty, p); 2720 case TIOCSWINSZ: 2721 return tiocswinsz(real_tty, p); 2722 case TIOCCONS: 2723 return real_tty != tty ? -EINVAL : tioccons(file); 2724 case TIOCEXCL: 2725 set_bit(TTY_EXCLUSIVE, &tty->flags); 2726 return 0; 2727 case TIOCNXCL: 2728 clear_bit(TTY_EXCLUSIVE, &tty->flags); 2729 return 0; 2730 case TIOCGEXCL: 2731 { 2732 int excl = test_bit(TTY_EXCLUSIVE, &tty->flags); 2733 2734 return put_user(excl, (int __user *)p); 2735 } 2736 case TIOCGETD: 2737 return tiocgetd(tty, p); 2738 case TIOCSETD: 2739 return tiocsetd(tty, p); 2740 case TIOCVHANGUP: 2741 if (!capable(CAP_SYS_ADMIN)) 2742 return -EPERM; 2743 tty_vhangup(tty); 2744 return 0; 2745 case TIOCGDEV: 2746 { 2747 unsigned int ret = new_encode_dev(tty_devnum(real_tty)); 2748 2749 return put_user(ret, (unsigned int __user *)p); 2750 } 2751 /* 2752 * Break handling 2753 */ 2754 case TIOCSBRK: /* Turn break on, unconditionally */ 2755 if (tty->ops->break_ctl) 2756 return tty->ops->break_ctl(tty, -1); 2757 return 0; 2758 case TIOCCBRK: /* Turn break off, unconditionally */ 2759 if (tty->ops->break_ctl) 2760 return tty->ops->break_ctl(tty, 0); 2761 return 0; 2762 case TCSBRK: /* SVID version: non-zero arg --> no break */ 2763 /* non-zero arg means wait for all output data 2764 * to be sent (performed above) but don't send break. 2765 * This is used by the tcdrain() termios function. 2766 */ 2767 if (!arg) 2768 return send_break(tty, 250); 2769 return 0; 2770 case TCSBRKP: /* support for POSIX tcsendbreak() */ 2771 return send_break(tty, arg ? arg*100 : 250); 2772 2773 case TIOCMGET: 2774 return tty_tiocmget(tty, p); 2775 case TIOCMSET: 2776 case TIOCMBIC: 2777 case TIOCMBIS: 2778 return tty_tiocmset(tty, cmd, p); 2779 case TIOCGICOUNT: 2780 return tty_tiocgicount(tty, p); 2781 case TCFLSH: 2782 switch (arg) { 2783 case TCIFLUSH: 2784 case TCIOFLUSH: 2785 /* flush tty buffer and allow ldisc to process ioctl */ 2786 tty_buffer_flush(tty, NULL); 2787 break; 2788 } 2789 break; 2790 case TIOCSSERIAL: 2791 return tty_tiocsserial(tty, p); 2792 case TIOCGSERIAL: 2793 return tty_tiocgserial(tty, p); 2794 case TIOCGPTPEER: 2795 /* Special because the struct file is needed */ 2796 return ptm_open_peer(file, tty, (int)arg); 2797 default: 2798 retval = tty_jobctrl_ioctl(tty, real_tty, file, cmd, arg); 2799 if (retval != -ENOIOCTLCMD) 2800 return retval; 2801 } 2802 if (tty->ops->ioctl) { 2803 retval = tty->ops->ioctl(tty, cmd, arg); 2804 if (retval != -ENOIOCTLCMD) 2805 return retval; 2806 } 2807 ld = tty_ldisc_ref_wait(tty); 2808 if (!ld) 2809 return hung_up_tty_ioctl(file, cmd, arg); 2810 retval = -EINVAL; 2811 if (ld->ops->ioctl) { 2812 retval = ld->ops->ioctl(tty, cmd, arg); 2813 if (retval == -ENOIOCTLCMD) 2814 retval = -ENOTTY; 2815 } 2816 tty_ldisc_deref(ld); 2817 return retval; 2818 } 2819 2820 #ifdef CONFIG_COMPAT 2821 2822 struct serial_struct32 { 2823 compat_int_t type; 2824 compat_int_t line; 2825 compat_uint_t port; 2826 compat_int_t irq; 2827 compat_int_t flags; 2828 compat_int_t xmit_fifo_size; 2829 compat_int_t custom_divisor; 2830 compat_int_t baud_base; 2831 unsigned short close_delay; 2832 char io_type; 2833 char reserved_char; 2834 compat_int_t hub6; 2835 unsigned short closing_wait; /* time to wait before closing */ 2836 unsigned short closing_wait2; /* no longer used... */ 2837 compat_uint_t iomem_base; 2838 unsigned short iomem_reg_shift; 2839 unsigned int port_high; 2840 /* compat_ulong_t iomap_base FIXME */ 2841 compat_int_t reserved; 2842 }; 2843 2844 static int compat_tty_tiocsserial(struct tty_struct *tty, 2845 struct serial_struct32 __user *ss) 2846 { 2847 struct serial_struct32 v32; 2848 struct serial_struct v; 2849 2850 if (copy_from_user(&v32, ss, sizeof(*ss))) 2851 return -EFAULT; 2852 2853 memcpy(&v, &v32, offsetof(struct serial_struct32, iomem_base)); 2854 v.iomem_base = compat_ptr(v32.iomem_base); 2855 v.iomem_reg_shift = v32.iomem_reg_shift; 2856 v.port_high = v32.port_high; 2857 v.iomap_base = 0; 2858 2859 return tty_set_serial(tty, &v); 2860 } 2861 2862 static int compat_tty_tiocgserial(struct tty_struct *tty, 2863 struct serial_struct32 __user *ss) 2864 { 2865 struct serial_struct32 v32; 2866 struct serial_struct v; 2867 int err; 2868 2869 memset(&v, 0, sizeof(v)); 2870 memset(&v32, 0, sizeof(v32)); 2871 2872 if (!tty->ops->get_serial) 2873 return -ENOTTY; 2874 err = tty->ops->get_serial(tty, &v); 2875 if (!err) { 2876 memcpy(&v32, &v, offsetof(struct serial_struct32, iomem_base)); 2877 v32.iomem_base = (unsigned long)v.iomem_base >> 32 ? 2878 0xfffffff : ptr_to_compat(v.iomem_base); 2879 v32.iomem_reg_shift = v.iomem_reg_shift; 2880 v32.port_high = v.port_high; 2881 if (copy_to_user(ss, &v32, sizeof(v32))) 2882 err = -EFAULT; 2883 } 2884 return err; 2885 } 2886 static long tty_compat_ioctl(struct file *file, unsigned int cmd, 2887 unsigned long arg) 2888 { 2889 struct tty_struct *tty = file_tty(file); 2890 struct tty_ldisc *ld; 2891 int retval = -ENOIOCTLCMD; 2892 2893 switch (cmd) { 2894 case TIOCOUTQ: 2895 case TIOCSTI: 2896 case TIOCGWINSZ: 2897 case TIOCSWINSZ: 2898 case TIOCGEXCL: 2899 case TIOCGETD: 2900 case TIOCSETD: 2901 case TIOCGDEV: 2902 case TIOCMGET: 2903 case TIOCMSET: 2904 case TIOCMBIC: 2905 case TIOCMBIS: 2906 case TIOCGICOUNT: 2907 case TIOCGPGRP: 2908 case TIOCSPGRP: 2909 case TIOCGSID: 2910 case TIOCSERGETLSR: 2911 case TIOCGRS485: 2912 case TIOCSRS485: 2913 #ifdef TIOCGETP 2914 case TIOCGETP: 2915 case TIOCSETP: 2916 case TIOCSETN: 2917 #endif 2918 #ifdef TIOCGETC 2919 case TIOCGETC: 2920 case TIOCSETC: 2921 #endif 2922 #ifdef TIOCGLTC 2923 case TIOCGLTC: 2924 case TIOCSLTC: 2925 #endif 2926 case TCSETSF: 2927 case TCSETSW: 2928 case TCSETS: 2929 case TCGETS: 2930 #ifdef TCGETS2 2931 case TCGETS2: 2932 case TCSETSF2: 2933 case TCSETSW2: 2934 case TCSETS2: 2935 #endif 2936 case TCGETA: 2937 case TCSETAF: 2938 case TCSETAW: 2939 case TCSETA: 2940 case TIOCGLCKTRMIOS: 2941 case TIOCSLCKTRMIOS: 2942 #ifdef TCGETX 2943 case TCGETX: 2944 case TCSETX: 2945 case TCSETXW: 2946 case TCSETXF: 2947 #endif 2948 case TIOCGSOFTCAR: 2949 case TIOCSSOFTCAR: 2950 2951 case PPPIOCGCHAN: 2952 case PPPIOCGUNIT: 2953 return tty_ioctl(file, cmd, (unsigned long)compat_ptr(arg)); 2954 case TIOCCONS: 2955 case TIOCEXCL: 2956 case TIOCNXCL: 2957 case TIOCVHANGUP: 2958 case TIOCSBRK: 2959 case TIOCCBRK: 2960 case TCSBRK: 2961 case TCSBRKP: 2962 case TCFLSH: 2963 case TIOCGPTPEER: 2964 case TIOCNOTTY: 2965 case TIOCSCTTY: 2966 case TCXONC: 2967 case TIOCMIWAIT: 2968 case TIOCSERCONFIG: 2969 return tty_ioctl(file, cmd, arg); 2970 } 2971 2972 if (tty_paranoia_check(tty, file_inode(file), "tty_ioctl")) 2973 return -EINVAL; 2974 2975 switch (cmd) { 2976 case TIOCSSERIAL: 2977 return compat_tty_tiocsserial(tty, compat_ptr(arg)); 2978 case TIOCGSERIAL: 2979 return compat_tty_tiocgserial(tty, compat_ptr(arg)); 2980 } 2981 if (tty->ops->compat_ioctl) { 2982 retval = tty->ops->compat_ioctl(tty, cmd, arg); 2983 if (retval != -ENOIOCTLCMD) 2984 return retval; 2985 } 2986 2987 ld = tty_ldisc_ref_wait(tty); 2988 if (!ld) 2989 return hung_up_tty_compat_ioctl(file, cmd, arg); 2990 if (ld->ops->compat_ioctl) 2991 retval = ld->ops->compat_ioctl(tty, cmd, arg); 2992 if (retval == -ENOIOCTLCMD && ld->ops->ioctl) 2993 retval = ld->ops->ioctl(tty, (unsigned long)compat_ptr(cmd), 2994 arg); 2995 tty_ldisc_deref(ld); 2996 2997 return retval; 2998 } 2999 #endif 3000 3001 static int this_tty(const void *t, struct file *file, unsigned fd) 3002 { 3003 if (likely(file->f_op->read_iter != tty_read)) 3004 return 0; 3005 return file_tty(file) != t ? 0 : fd + 1; 3006 } 3007 3008 /* 3009 * This implements the "Secure Attention Key" --- the idea is to 3010 * prevent trojan horses by killing all processes associated with this 3011 * tty when the user hits the "Secure Attention Key". Required for 3012 * super-paranoid applications --- see the Orange Book for more details. 3013 * 3014 * This code could be nicer; ideally it should send a HUP, wait a few 3015 * seconds, then send a INT, and then a KILL signal. But you then 3016 * have to coordinate with the init process, since all processes associated 3017 * with the current tty must be dead before the new getty is allowed 3018 * to spawn. 3019 * 3020 * Now, if it would be correct ;-/ The current code has a nasty hole - 3021 * it doesn't catch files in flight. We may send the descriptor to ourselves 3022 * via AF_UNIX socket, close it and later fetch from socket. FIXME. 3023 * 3024 * Nasty bug: do_SAK is being called in interrupt context. This can 3025 * deadlock. We punt it up to process context. AKPM - 16Mar2001 3026 */ 3027 void __do_SAK(struct tty_struct *tty) 3028 { 3029 struct task_struct *g, *p; 3030 struct pid *session; 3031 int i; 3032 unsigned long flags; 3033 3034 spin_lock_irqsave(&tty->ctrl.lock, flags); 3035 session = get_pid(tty->ctrl.session); 3036 spin_unlock_irqrestore(&tty->ctrl.lock, flags); 3037 3038 tty_ldisc_flush(tty); 3039 3040 tty_driver_flush_buffer(tty); 3041 3042 read_lock(&tasklist_lock); 3043 /* Kill the entire session */ 3044 do_each_pid_task(session, PIDTYPE_SID, p) { 3045 tty_notice(tty, "SAK: killed process %d (%s): by session\n", 3046 task_pid_nr(p), p->comm); 3047 group_send_sig_info(SIGKILL, SEND_SIG_PRIV, p, PIDTYPE_SID); 3048 } while_each_pid_task(session, PIDTYPE_SID, p); 3049 3050 /* Now kill any processes that happen to have the tty open */ 3051 for_each_process_thread(g, p) { 3052 if (p->signal->tty == tty) { 3053 tty_notice(tty, "SAK: killed process %d (%s): by controlling tty\n", 3054 task_pid_nr(p), p->comm); 3055 group_send_sig_info(SIGKILL, SEND_SIG_PRIV, p, 3056 PIDTYPE_SID); 3057 continue; 3058 } 3059 task_lock(p); 3060 i = iterate_fd(p->files, 0, this_tty, tty); 3061 if (i != 0) { 3062 tty_notice(tty, "SAK: killed process %d (%s): by fd#%d\n", 3063 task_pid_nr(p), p->comm, i - 1); 3064 group_send_sig_info(SIGKILL, SEND_SIG_PRIV, p, 3065 PIDTYPE_SID); 3066 } 3067 task_unlock(p); 3068 } 3069 read_unlock(&tasklist_lock); 3070 put_pid(session); 3071 } 3072 3073 static void do_SAK_work(struct work_struct *work) 3074 { 3075 struct tty_struct *tty = 3076 container_of(work, struct tty_struct, SAK_work); 3077 __do_SAK(tty); 3078 } 3079 3080 /* 3081 * The tq handling here is a little racy - tty->SAK_work may already be queued. 3082 * Fortunately we don't need to worry, because if ->SAK_work is already queued, 3083 * the values which we write to it will be identical to the values which it 3084 * already has. --akpm 3085 */ 3086 void do_SAK(struct tty_struct *tty) 3087 { 3088 if (!tty) 3089 return; 3090 schedule_work(&tty->SAK_work); 3091 } 3092 EXPORT_SYMBOL(do_SAK); 3093 3094 /* Must put_device() after it's unused! */ 3095 static struct device *tty_get_device(struct tty_struct *tty) 3096 { 3097 dev_t devt = tty_devnum(tty); 3098 3099 return class_find_device_by_devt(&tty_class, devt); 3100 } 3101 3102 3103 /** 3104 * alloc_tty_struct - allocate a new tty 3105 * @driver: driver which will handle the returned tty 3106 * @idx: minor of the tty 3107 * 3108 * This subroutine allocates and initializes a tty structure. 3109 * 3110 * Locking: none - @tty in question is not exposed at this point 3111 */ 3112 struct tty_struct *alloc_tty_struct(struct tty_driver *driver, int idx) 3113 { 3114 struct tty_struct *tty; 3115 3116 tty = kzalloc(sizeof(*tty), GFP_KERNEL_ACCOUNT); 3117 if (!tty) 3118 return NULL; 3119 3120 kref_init(&tty->kref); 3121 if (tty_ldisc_init(tty)) { 3122 kfree(tty); 3123 return NULL; 3124 } 3125 tty->ctrl.session = NULL; 3126 tty->ctrl.pgrp = NULL; 3127 mutex_init(&tty->legacy_mutex); 3128 mutex_init(&tty->throttle_mutex); 3129 init_rwsem(&tty->termios_rwsem); 3130 mutex_init(&tty->winsize_mutex); 3131 init_ldsem(&tty->ldisc_sem); 3132 init_waitqueue_head(&tty->write_wait); 3133 init_waitqueue_head(&tty->read_wait); 3134 INIT_WORK(&tty->hangup_work, do_tty_hangup); 3135 mutex_init(&tty->atomic_write_lock); 3136 spin_lock_init(&tty->ctrl.lock); 3137 spin_lock_init(&tty->flow.lock); 3138 spin_lock_init(&tty->files_lock); 3139 INIT_LIST_HEAD(&tty->tty_files); 3140 INIT_WORK(&tty->SAK_work, do_SAK_work); 3141 3142 tty->driver = driver; 3143 tty->ops = driver->ops; 3144 tty->index = idx; 3145 tty_line_name(driver, idx, tty->name); 3146 tty->dev = tty_get_device(tty); 3147 3148 return tty; 3149 } 3150 3151 /** 3152 * tty_put_char - write one character to a tty 3153 * @tty: tty 3154 * @ch: character to write 3155 * 3156 * Write one byte to the @tty using the provided @tty->ops->put_char() method 3157 * if present. 3158 * 3159 * Note: the specific put_char operation in the driver layer may go 3160 * away soon. Don't call it directly, use this method 3161 * 3162 * Return: the number of characters successfully output. 3163 */ 3164 int tty_put_char(struct tty_struct *tty, u8 ch) 3165 { 3166 if (tty->ops->put_char) 3167 return tty->ops->put_char(tty, ch); 3168 return tty->ops->write(tty, &ch, 1); 3169 } 3170 EXPORT_SYMBOL_GPL(tty_put_char); 3171 3172 static int tty_cdev_add(struct tty_driver *driver, dev_t dev, 3173 unsigned int index, unsigned int count) 3174 { 3175 int err; 3176 3177 /* init here, since reused cdevs cause crashes */ 3178 driver->cdevs[index] = cdev_alloc(); 3179 if (!driver->cdevs[index]) 3180 return -ENOMEM; 3181 driver->cdevs[index]->ops = &tty_fops; 3182 driver->cdevs[index]->owner = driver->owner; 3183 err = cdev_add(driver->cdevs[index], dev, count); 3184 if (err) 3185 kobject_put(&driver->cdevs[index]->kobj); 3186 return err; 3187 } 3188 3189 /** 3190 * tty_register_device - register a tty device 3191 * @driver: the tty driver that describes the tty device 3192 * @index: the index in the tty driver for this tty device 3193 * @device: a struct device that is associated with this tty device. 3194 * This field is optional, if there is no known struct device 3195 * for this tty device it can be set to NULL safely. 3196 * 3197 * This call is required to be made to register an individual tty device 3198 * if the tty driver's flags have the %TTY_DRIVER_DYNAMIC_DEV bit set. If 3199 * that bit is not set, this function should not be called by a tty 3200 * driver. 3201 * 3202 * Locking: ?? 3203 * 3204 * Return: A pointer to the struct device for this tty device (or 3205 * ERR_PTR(-EFOO) on error). 3206 */ 3207 struct device *tty_register_device(struct tty_driver *driver, unsigned index, 3208 struct device *device) 3209 { 3210 return tty_register_device_attr(driver, index, device, NULL, NULL); 3211 } 3212 EXPORT_SYMBOL(tty_register_device); 3213 3214 static void tty_device_create_release(struct device *dev) 3215 { 3216 dev_dbg(dev, "releasing...\n"); 3217 kfree(dev); 3218 } 3219 3220 /** 3221 * tty_register_device_attr - register a tty device 3222 * @driver: the tty driver that describes the tty device 3223 * @index: the index in the tty driver for this tty device 3224 * @device: a struct device that is associated with this tty device. 3225 * This field is optional, if there is no known struct device 3226 * for this tty device it can be set to %NULL safely. 3227 * @drvdata: Driver data to be set to device. 3228 * @attr_grp: Attribute group to be set on device. 3229 * 3230 * This call is required to be made to register an individual tty device if the 3231 * tty driver's flags have the %TTY_DRIVER_DYNAMIC_DEV bit set. If that bit is 3232 * not set, this function should not be called by a tty driver. 3233 * 3234 * Locking: ?? 3235 * 3236 * Return: A pointer to the struct device for this tty device (or 3237 * ERR_PTR(-EFOO) on error). 3238 */ 3239 struct device *tty_register_device_attr(struct tty_driver *driver, 3240 unsigned index, struct device *device, 3241 void *drvdata, 3242 const struct attribute_group **attr_grp) 3243 { 3244 char name[64]; 3245 dev_t devt = MKDEV(driver->major, driver->minor_start) + index; 3246 struct ktermios *tp; 3247 struct device *dev; 3248 int retval; 3249 3250 if (index >= driver->num) { 3251 pr_err("%s: Attempt to register invalid tty line number (%d)\n", 3252 driver->name, index); 3253 return ERR_PTR(-EINVAL); 3254 } 3255 3256 if (driver->type == TTY_DRIVER_TYPE_PTY) 3257 pty_line_name(driver, index, name); 3258 else 3259 tty_line_name(driver, index, name); 3260 3261 dev = kzalloc(sizeof(*dev), GFP_KERNEL); 3262 if (!dev) 3263 return ERR_PTR(-ENOMEM); 3264 3265 dev->devt = devt; 3266 dev->class = &tty_class; 3267 dev->parent = device; 3268 dev->release = tty_device_create_release; 3269 dev_set_name(dev, "%s", name); 3270 dev->groups = attr_grp; 3271 dev_set_drvdata(dev, drvdata); 3272 3273 dev_set_uevent_suppress(dev, 1); 3274 3275 retval = device_register(dev); 3276 if (retval) 3277 goto err_put; 3278 3279 if (!(driver->flags & TTY_DRIVER_DYNAMIC_ALLOC)) { 3280 /* 3281 * Free any saved termios data so that the termios state is 3282 * reset when reusing a minor number. 3283 */ 3284 tp = driver->termios[index]; 3285 if (tp) { 3286 driver->termios[index] = NULL; 3287 kfree(tp); 3288 } 3289 3290 retval = tty_cdev_add(driver, devt, index, 1); 3291 if (retval) 3292 goto err_del; 3293 } 3294 3295 dev_set_uevent_suppress(dev, 0); 3296 kobject_uevent(&dev->kobj, KOBJ_ADD); 3297 3298 return dev; 3299 3300 err_del: 3301 device_del(dev); 3302 err_put: 3303 put_device(dev); 3304 3305 return ERR_PTR(retval); 3306 } 3307 EXPORT_SYMBOL_GPL(tty_register_device_attr); 3308 3309 /** 3310 * tty_unregister_device - unregister a tty device 3311 * @driver: the tty driver that describes the tty device 3312 * @index: the index in the tty driver for this tty device 3313 * 3314 * If a tty device is registered with a call to tty_register_device() then 3315 * this function must be called when the tty device is gone. 3316 * 3317 * Locking: ?? 3318 */ 3319 void tty_unregister_device(struct tty_driver *driver, unsigned index) 3320 { 3321 device_destroy(&tty_class, MKDEV(driver->major, driver->minor_start) + index); 3322 if (!(driver->flags & TTY_DRIVER_DYNAMIC_ALLOC)) { 3323 cdev_del(driver->cdevs[index]); 3324 driver->cdevs[index] = NULL; 3325 } 3326 } 3327 EXPORT_SYMBOL(tty_unregister_device); 3328 3329 /** 3330 * __tty_alloc_driver - allocate tty driver 3331 * @lines: count of lines this driver can handle at most 3332 * @owner: module which is responsible for this driver 3333 * @flags: some of %TTY_DRIVER_ flags, will be set in driver->flags 3334 * 3335 * This should not be called directly, some of the provided macros should be 3336 * used instead. Use IS_ERR() and friends on @retval. 3337 */ 3338 struct tty_driver *__tty_alloc_driver(unsigned int lines, struct module *owner, 3339 unsigned long flags) 3340 { 3341 struct tty_driver *driver; 3342 unsigned int cdevs = 1; 3343 int err; 3344 3345 if (!lines || (flags & TTY_DRIVER_UNNUMBERED_NODE && lines > 1)) 3346 return ERR_PTR(-EINVAL); 3347 3348 driver = kzalloc(sizeof(*driver), GFP_KERNEL); 3349 if (!driver) 3350 return ERR_PTR(-ENOMEM); 3351 3352 kref_init(&driver->kref); 3353 driver->num = lines; 3354 driver->owner = owner; 3355 driver->flags = flags; 3356 3357 if (!(flags & TTY_DRIVER_DEVPTS_MEM)) { 3358 driver->ttys = kcalloc(lines, sizeof(*driver->ttys), 3359 GFP_KERNEL); 3360 driver->termios = kcalloc(lines, sizeof(*driver->termios), 3361 GFP_KERNEL); 3362 if (!driver->ttys || !driver->termios) { 3363 err = -ENOMEM; 3364 goto err_free_all; 3365 } 3366 } 3367 3368 if (!(flags & TTY_DRIVER_DYNAMIC_ALLOC)) { 3369 driver->ports = kcalloc(lines, sizeof(*driver->ports), 3370 GFP_KERNEL); 3371 if (!driver->ports) { 3372 err = -ENOMEM; 3373 goto err_free_all; 3374 } 3375 cdevs = lines; 3376 } 3377 3378 driver->cdevs = kcalloc(cdevs, sizeof(*driver->cdevs), GFP_KERNEL); 3379 if (!driver->cdevs) { 3380 err = -ENOMEM; 3381 goto err_free_all; 3382 } 3383 3384 return driver; 3385 err_free_all: 3386 kfree(driver->ports); 3387 kfree(driver->ttys); 3388 kfree(driver->termios); 3389 kfree(driver->cdevs); 3390 kfree(driver); 3391 return ERR_PTR(err); 3392 } 3393 EXPORT_SYMBOL(__tty_alloc_driver); 3394 3395 static void destruct_tty_driver(struct kref *kref) 3396 { 3397 struct tty_driver *driver = container_of(kref, struct tty_driver, kref); 3398 int i; 3399 struct ktermios *tp; 3400 3401 if (driver->flags & TTY_DRIVER_INSTALLED) { 3402 for (i = 0; i < driver->num; i++) { 3403 tp = driver->termios[i]; 3404 if (tp) { 3405 driver->termios[i] = NULL; 3406 kfree(tp); 3407 } 3408 if (!(driver->flags & TTY_DRIVER_DYNAMIC_DEV)) 3409 tty_unregister_device(driver, i); 3410 } 3411 proc_tty_unregister_driver(driver); 3412 if (driver->flags & TTY_DRIVER_DYNAMIC_ALLOC) 3413 cdev_del(driver->cdevs[0]); 3414 } 3415 kfree(driver->cdevs); 3416 kfree(driver->ports); 3417 kfree(driver->termios); 3418 kfree(driver->ttys); 3419 kfree(driver); 3420 } 3421 3422 /** 3423 * tty_driver_kref_put - drop a reference to a tty driver 3424 * @driver: driver of which to drop the reference 3425 * 3426 * The final put will destroy and free up the driver. 3427 */ 3428 void tty_driver_kref_put(struct tty_driver *driver) 3429 { 3430 kref_put(&driver->kref, destruct_tty_driver); 3431 } 3432 EXPORT_SYMBOL(tty_driver_kref_put); 3433 3434 /** 3435 * tty_register_driver - register a tty driver 3436 * @driver: driver to register 3437 * 3438 * Called by a tty driver to register itself. 3439 */ 3440 int tty_register_driver(struct tty_driver *driver) 3441 { 3442 int error; 3443 int i; 3444 dev_t dev; 3445 struct device *d; 3446 3447 if (!driver->major) { 3448 error = alloc_chrdev_region(&dev, driver->minor_start, 3449 driver->num, driver->name); 3450 if (!error) { 3451 driver->major = MAJOR(dev); 3452 driver->minor_start = MINOR(dev); 3453 } 3454 } else { 3455 dev = MKDEV(driver->major, driver->minor_start); 3456 error = register_chrdev_region(dev, driver->num, driver->name); 3457 } 3458 if (error < 0) 3459 goto err; 3460 3461 if (driver->flags & TTY_DRIVER_DYNAMIC_ALLOC) { 3462 error = tty_cdev_add(driver, dev, 0, driver->num); 3463 if (error) 3464 goto err_unreg_char; 3465 } 3466 3467 mutex_lock(&tty_mutex); 3468 list_add(&driver->tty_drivers, &tty_drivers); 3469 mutex_unlock(&tty_mutex); 3470 3471 if (!(driver->flags & TTY_DRIVER_DYNAMIC_DEV)) { 3472 for (i = 0; i < driver->num; i++) { 3473 d = tty_register_device(driver, i, NULL); 3474 if (IS_ERR(d)) { 3475 error = PTR_ERR(d); 3476 goto err_unreg_devs; 3477 } 3478 } 3479 } 3480 proc_tty_register_driver(driver); 3481 driver->flags |= TTY_DRIVER_INSTALLED; 3482 return 0; 3483 3484 err_unreg_devs: 3485 for (i--; i >= 0; i--) 3486 tty_unregister_device(driver, i); 3487 3488 mutex_lock(&tty_mutex); 3489 list_del(&driver->tty_drivers); 3490 mutex_unlock(&tty_mutex); 3491 3492 err_unreg_char: 3493 unregister_chrdev_region(dev, driver->num); 3494 err: 3495 return error; 3496 } 3497 EXPORT_SYMBOL(tty_register_driver); 3498 3499 /** 3500 * tty_unregister_driver - unregister a tty driver 3501 * @driver: driver to unregister 3502 * 3503 * Called by a tty driver to unregister itself. 3504 */ 3505 void tty_unregister_driver(struct tty_driver *driver) 3506 { 3507 unregister_chrdev_region(MKDEV(driver->major, driver->minor_start), 3508 driver->num); 3509 mutex_lock(&tty_mutex); 3510 list_del(&driver->tty_drivers); 3511 mutex_unlock(&tty_mutex); 3512 } 3513 EXPORT_SYMBOL(tty_unregister_driver); 3514 3515 dev_t tty_devnum(struct tty_struct *tty) 3516 { 3517 return MKDEV(tty->driver->major, tty->driver->minor_start) + tty->index; 3518 } 3519 EXPORT_SYMBOL(tty_devnum); 3520 3521 void tty_default_fops(struct file_operations *fops) 3522 { 3523 *fops = tty_fops; 3524 } 3525 3526 static char *tty_devnode(const struct device *dev, umode_t *mode) 3527 { 3528 if (!mode) 3529 return NULL; 3530 if (dev->devt == MKDEV(TTYAUX_MAJOR, 0) || 3531 dev->devt == MKDEV(TTYAUX_MAJOR, 2)) 3532 *mode = 0666; 3533 return NULL; 3534 } 3535 3536 const struct class tty_class = { 3537 .name = "tty", 3538 .devnode = tty_devnode, 3539 }; 3540 3541 static int __init tty_class_init(void) 3542 { 3543 return class_register(&tty_class); 3544 } 3545 3546 postcore_initcall(tty_class_init); 3547 3548 /* 3/2004 jmc: why do these devices exist? */ 3549 static struct cdev tty_cdev, console_cdev; 3550 3551 static ssize_t show_cons_active(struct device *dev, 3552 struct device_attribute *attr, char *buf) 3553 { 3554 struct console *cs[16]; 3555 int i = 0; 3556 struct console *c; 3557 ssize_t count = 0; 3558 3559 /* 3560 * Hold the console_list_lock to guarantee that no consoles are 3561 * unregistered until all console processing is complete. 3562 * This also allows safe traversal of the console list and 3563 * race-free reading of @flags. 3564 */ 3565 console_list_lock(); 3566 3567 for_each_console(c) { 3568 if (!c->device) 3569 continue; 3570 if (!(c->flags & CON_NBCON) && !c->write) 3571 continue; 3572 if ((c->flags & CON_ENABLED) == 0) 3573 continue; 3574 cs[i++] = c; 3575 if (i >= ARRAY_SIZE(cs)) 3576 break; 3577 } 3578 3579 /* 3580 * Take console_lock to serialize device() callback with 3581 * other console operations. For example, fg_console is 3582 * modified under console_lock when switching vt. 3583 */ 3584 console_lock(); 3585 while (i--) { 3586 int index = cs[i]->index; 3587 struct tty_driver *drv = cs[i]->device(cs[i], &index); 3588 3589 /* don't resolve tty0 as some programs depend on it */ 3590 if (drv && (cs[i]->index > 0 || drv->major != TTY_MAJOR)) 3591 count += tty_line_name(drv, index, buf + count); 3592 else 3593 count += sprintf(buf + count, "%s%d", 3594 cs[i]->name, cs[i]->index); 3595 3596 count += sprintf(buf + count, "%c", i ? ' ':'\n'); 3597 } 3598 console_unlock(); 3599 3600 console_list_unlock(); 3601 3602 return count; 3603 } 3604 static DEVICE_ATTR(active, S_IRUGO, show_cons_active, NULL); 3605 3606 static struct attribute *cons_dev_attrs[] = { 3607 &dev_attr_active.attr, 3608 NULL 3609 }; 3610 3611 ATTRIBUTE_GROUPS(cons_dev); 3612 3613 static struct device *consdev; 3614 3615 void console_sysfs_notify(void) 3616 { 3617 if (consdev) 3618 sysfs_notify(&consdev->kobj, NULL, "active"); 3619 } 3620 3621 static struct ctl_table tty_table[] = { 3622 { 3623 .procname = "legacy_tiocsti", 3624 .data = &tty_legacy_tiocsti, 3625 .maxlen = sizeof(tty_legacy_tiocsti), 3626 .mode = 0644, 3627 .proc_handler = proc_dobool, 3628 }, 3629 { 3630 .procname = "ldisc_autoload", 3631 .data = &tty_ldisc_autoload, 3632 .maxlen = sizeof(tty_ldisc_autoload), 3633 .mode = 0644, 3634 .proc_handler = proc_dointvec, 3635 .extra1 = SYSCTL_ZERO, 3636 .extra2 = SYSCTL_ONE, 3637 }, 3638 }; 3639 3640 /* 3641 * Ok, now we can initialize the rest of the tty devices and can count 3642 * on memory allocations, interrupts etc.. 3643 */ 3644 int __init tty_init(void) 3645 { 3646 register_sysctl_init("dev/tty", tty_table); 3647 cdev_init(&tty_cdev, &tty_fops); 3648 if (cdev_add(&tty_cdev, MKDEV(TTYAUX_MAJOR, 0), 1) || 3649 register_chrdev_region(MKDEV(TTYAUX_MAJOR, 0), 1, "/dev/tty") < 0) 3650 panic("Couldn't register /dev/tty driver\n"); 3651 device_create(&tty_class, NULL, MKDEV(TTYAUX_MAJOR, 0), NULL, "tty"); 3652 3653 cdev_init(&console_cdev, &console_fops); 3654 if (cdev_add(&console_cdev, MKDEV(TTYAUX_MAJOR, 1), 1) || 3655 register_chrdev_region(MKDEV(TTYAUX_MAJOR, 1), 1, "/dev/console") < 0) 3656 panic("Couldn't register /dev/console driver\n"); 3657 consdev = device_create_with_groups(&tty_class, NULL, 3658 MKDEV(TTYAUX_MAJOR, 1), NULL, 3659 cons_dev_groups, "console"); 3660 if (IS_ERR(consdev)) 3661 consdev = NULL; 3662 3663 #ifdef CONFIG_VT 3664 vty_init(&console_fops); 3665 #endif 3666 return 0; 3667 } 3668