1 /* 2 * Copyright (C) 1991, 1992 Linus Torvalds 3 * 4 * Added support for a Unix98-style ptmx device. 5 * -- C. Scott Ananian <cananian@alumni.princeton.edu>, 14-Jan-1998 6 * 7 * When reading this code see also fs/devpts. In particular note that the 8 * driver_data field is used by the devpts side as a binding to the devpts 9 * inode. 10 */ 11 12 #include <linux/module.h> 13 14 #include <linux/errno.h> 15 #include <linux/interrupt.h> 16 #include <linux/tty.h> 17 #include <linux/tty_flip.h> 18 #include <linux/fcntl.h> 19 #include <linux/sched.h> 20 #include <linux/string.h> 21 #include <linux/major.h> 22 #include <linux/mm.h> 23 #include <linux/init.h> 24 #include <linux/device.h> 25 #include <linux/uaccess.h> 26 #include <linux/bitops.h> 27 #include <linux/devpts_fs.h> 28 #include <linux/slab.h> 29 #include <linux/mutex.h> 30 31 32 #ifdef CONFIG_UNIX98_PTYS 33 static struct tty_driver *ptm_driver; 34 static struct tty_driver *pts_driver; 35 static DEFINE_MUTEX(devpts_mutex); 36 #endif 37 38 static void pty_close(struct tty_struct *tty, struct file *filp) 39 { 40 BUG_ON(!tty); 41 if (tty->driver->subtype == PTY_TYPE_MASTER) 42 WARN_ON(tty->count > 1); 43 else { 44 if (tty->count > 2) 45 return; 46 } 47 wake_up_interruptible(&tty->read_wait); 48 wake_up_interruptible(&tty->write_wait); 49 tty->packet = 0; 50 /* Review - krefs on tty_link ?? */ 51 if (!tty->link) 52 return; 53 tty->link->packet = 0; 54 set_bit(TTY_OTHER_CLOSED, &tty->link->flags); 55 wake_up_interruptible(&tty->link->read_wait); 56 wake_up_interruptible(&tty->link->write_wait); 57 if (tty->driver->subtype == PTY_TYPE_MASTER) { 58 set_bit(TTY_OTHER_CLOSED, &tty->flags); 59 #ifdef CONFIG_UNIX98_PTYS 60 if (tty->driver == ptm_driver) { 61 mutex_lock(&devpts_mutex); 62 devpts_pty_kill(tty->link); 63 mutex_unlock(&devpts_mutex); 64 } 65 #endif 66 tty_unlock(tty); 67 tty_vhangup(tty->link); 68 tty_lock(tty); 69 } 70 } 71 72 /* 73 * The unthrottle routine is called by the line discipline to signal 74 * that it can receive more characters. For PTY's, the TTY_THROTTLED 75 * flag is always set, to force the line discipline to always call the 76 * unthrottle routine when there are fewer than TTY_THRESHOLD_UNTHROTTLE 77 * characters in the queue. This is necessary since each time this 78 * happens, we need to wake up any sleeping processes that could be 79 * (1) trying to send data to the pty, or (2) waiting in wait_until_sent() 80 * for the pty buffer to be drained. 81 */ 82 static void pty_unthrottle(struct tty_struct *tty) 83 { 84 tty_wakeup(tty->link); 85 set_bit(TTY_THROTTLED, &tty->flags); 86 } 87 88 /** 89 * pty_space - report space left for writing 90 * @to: tty we are writing into 91 * 92 * The tty buffers allow 64K but we sneak a peak and clip at 8K this 93 * allows a lot of overspill room for echo and other fun messes to 94 * be handled properly 95 */ 96 97 static int pty_space(struct tty_struct *to) 98 { 99 int n = 8192 - to->buf.memory_used; 100 if (n < 0) 101 return 0; 102 return n; 103 } 104 105 /** 106 * pty_write - write to a pty 107 * @tty: the tty we write from 108 * @buf: kernel buffer of data 109 * @count: bytes to write 110 * 111 * Our "hardware" write method. Data is coming from the ldisc which 112 * may be in a non sleeping state. We simply throw this at the other 113 * end of the link as if we were an IRQ handler receiving stuff for 114 * the other side of the pty/tty pair. 115 */ 116 117 static int pty_write(struct tty_struct *tty, const unsigned char *buf, int c) 118 { 119 struct tty_struct *to = tty->link; 120 121 if (tty->stopped) 122 return 0; 123 124 if (c > 0) { 125 /* Stuff the data into the input queue of the other end */ 126 c = tty_insert_flip_string(to, buf, c); 127 /* And shovel */ 128 if (c) { 129 tty_flip_buffer_push(to); 130 tty_wakeup(tty); 131 } 132 } 133 return c; 134 } 135 136 /** 137 * pty_write_room - write space 138 * @tty: tty we are writing from 139 * 140 * Report how many bytes the ldisc can send into the queue for 141 * the other device. 142 */ 143 144 static int pty_write_room(struct tty_struct *tty) 145 { 146 if (tty->stopped) 147 return 0; 148 return pty_space(tty->link); 149 } 150 151 /** 152 * pty_chars_in_buffer - characters currently in our tx queue 153 * @tty: our tty 154 * 155 * Report how much we have in the transmit queue. As everything is 156 * instantly at the other end this is easy to implement. 157 */ 158 159 static int pty_chars_in_buffer(struct tty_struct *tty) 160 { 161 return 0; 162 } 163 164 /* Set the lock flag on a pty */ 165 static int pty_set_lock(struct tty_struct *tty, int __user *arg) 166 { 167 int val; 168 if (get_user(val, arg)) 169 return -EFAULT; 170 if (val) 171 set_bit(TTY_PTY_LOCK, &tty->flags); 172 else 173 clear_bit(TTY_PTY_LOCK, &tty->flags); 174 return 0; 175 } 176 177 /* Send a signal to the slave */ 178 static int pty_signal(struct tty_struct *tty, int sig) 179 { 180 unsigned long flags; 181 struct pid *pgrp; 182 183 if (tty->link) { 184 spin_lock_irqsave(&tty->link->ctrl_lock, flags); 185 pgrp = get_pid(tty->link->pgrp); 186 spin_unlock_irqrestore(&tty->link->ctrl_lock, flags); 187 188 kill_pgrp(pgrp, sig, 1); 189 put_pid(pgrp); 190 } 191 return 0; 192 } 193 194 static void pty_flush_buffer(struct tty_struct *tty) 195 { 196 struct tty_struct *to = tty->link; 197 unsigned long flags; 198 199 if (!to) 200 return; 201 /* tty_buffer_flush(to); FIXME */ 202 if (to->packet) { 203 spin_lock_irqsave(&tty->ctrl_lock, flags); 204 tty->ctrl_status |= TIOCPKT_FLUSHWRITE; 205 wake_up_interruptible(&to->read_wait); 206 spin_unlock_irqrestore(&tty->ctrl_lock, flags); 207 } 208 } 209 210 static int pty_open(struct tty_struct *tty, struct file *filp) 211 { 212 int retval = -ENODEV; 213 214 if (!tty || !tty->link) 215 goto out; 216 217 retval = -EIO; 218 if (test_bit(TTY_OTHER_CLOSED, &tty->flags)) 219 goto out; 220 if (test_bit(TTY_PTY_LOCK, &tty->link->flags)) 221 goto out; 222 if (tty->link->count != 1) 223 goto out; 224 225 clear_bit(TTY_OTHER_CLOSED, &tty->link->flags); 226 set_bit(TTY_THROTTLED, &tty->flags); 227 retval = 0; 228 out: 229 return retval; 230 } 231 232 static void pty_set_termios(struct tty_struct *tty, 233 struct ktermios *old_termios) 234 { 235 tty->termios->c_cflag &= ~(CSIZE | PARENB); 236 tty->termios->c_cflag |= (CS8 | CREAD); 237 } 238 239 /** 240 * pty_do_resize - resize event 241 * @tty: tty being resized 242 * @ws: window size being set. 243 * 244 * Update the termios variables and send the necessary signals to 245 * peform a terminal resize correctly 246 */ 247 248 int pty_resize(struct tty_struct *tty, struct winsize *ws) 249 { 250 struct pid *pgrp, *rpgrp; 251 unsigned long flags; 252 struct tty_struct *pty = tty->link; 253 254 /* For a PTY we need to lock the tty side */ 255 mutex_lock(&tty->termios_mutex); 256 if (!memcmp(ws, &tty->winsize, sizeof(*ws))) 257 goto done; 258 259 /* Get the PID values and reference them so we can 260 avoid holding the tty ctrl lock while sending signals. 261 We need to lock these individually however. */ 262 263 spin_lock_irqsave(&tty->ctrl_lock, flags); 264 pgrp = get_pid(tty->pgrp); 265 spin_unlock_irqrestore(&tty->ctrl_lock, flags); 266 267 spin_lock_irqsave(&pty->ctrl_lock, flags); 268 rpgrp = get_pid(pty->pgrp); 269 spin_unlock_irqrestore(&pty->ctrl_lock, flags); 270 271 if (pgrp) 272 kill_pgrp(pgrp, SIGWINCH, 1); 273 if (rpgrp != pgrp && rpgrp) 274 kill_pgrp(rpgrp, SIGWINCH, 1); 275 276 put_pid(pgrp); 277 put_pid(rpgrp); 278 279 tty->winsize = *ws; 280 pty->winsize = *ws; /* Never used so will go away soon */ 281 done: 282 mutex_unlock(&tty->termios_mutex); 283 return 0; 284 } 285 286 /* Traditional BSD devices */ 287 #ifdef CONFIG_LEGACY_PTYS 288 289 static int pty_install(struct tty_driver *driver, struct tty_struct *tty) 290 { 291 struct tty_struct *o_tty; 292 int idx = tty->index; 293 int retval; 294 295 o_tty = alloc_tty_struct(); 296 if (!o_tty) 297 return -ENOMEM; 298 if (!try_module_get(driver->other->owner)) { 299 /* This cannot in fact currently happen */ 300 retval = -ENOMEM; 301 goto err_free_tty; 302 } 303 initialize_tty_struct(o_tty, driver->other, idx); 304 305 /* We always use new tty termios data so we can do this 306 the easy way .. */ 307 retval = tty_init_termios(tty); 308 if (retval) 309 goto err_deinit_tty; 310 311 retval = tty_init_termios(o_tty); 312 if (retval) 313 goto err_free_termios; 314 315 /* 316 * Everything allocated ... set up the o_tty structure. 317 */ 318 driver->other->ttys[idx] = o_tty; 319 tty_driver_kref_get(driver->other); 320 if (driver->subtype == PTY_TYPE_MASTER) 321 o_tty->count++; 322 /* Establish the links in both directions */ 323 tty->link = o_tty; 324 o_tty->link = tty; 325 326 tty_driver_kref_get(driver); 327 tty->count++; 328 driver->ttys[idx] = tty; 329 return 0; 330 err_free_termios: 331 tty_free_termios(tty); 332 err_deinit_tty: 333 deinitialize_tty_struct(o_tty); 334 module_put(o_tty->driver->owner); 335 err_free_tty: 336 free_tty_struct(o_tty); 337 return retval; 338 } 339 340 static int pty_bsd_ioctl(struct tty_struct *tty, 341 unsigned int cmd, unsigned long arg) 342 { 343 switch (cmd) { 344 case TIOCSPTLCK: /* Set PT Lock (disallow slave open) */ 345 return pty_set_lock(tty, (int __user *) arg); 346 case TIOCSIG: /* Send signal to other side of pty */ 347 return pty_signal(tty, (int) arg); 348 } 349 return -ENOIOCTLCMD; 350 } 351 352 static int legacy_count = CONFIG_LEGACY_PTY_COUNT; 353 module_param(legacy_count, int, 0); 354 355 /* 356 * The master side of a pty can do TIOCSPTLCK and thus 357 * has pty_bsd_ioctl. 358 */ 359 static const struct tty_operations master_pty_ops_bsd = { 360 .install = pty_install, 361 .open = pty_open, 362 .close = pty_close, 363 .write = pty_write, 364 .write_room = pty_write_room, 365 .flush_buffer = pty_flush_buffer, 366 .chars_in_buffer = pty_chars_in_buffer, 367 .unthrottle = pty_unthrottle, 368 .set_termios = pty_set_termios, 369 .ioctl = pty_bsd_ioctl, 370 .resize = pty_resize 371 }; 372 373 static const struct tty_operations slave_pty_ops_bsd = { 374 .install = pty_install, 375 .open = pty_open, 376 .close = pty_close, 377 .write = pty_write, 378 .write_room = pty_write_room, 379 .flush_buffer = pty_flush_buffer, 380 .chars_in_buffer = pty_chars_in_buffer, 381 .unthrottle = pty_unthrottle, 382 .set_termios = pty_set_termios, 383 .resize = pty_resize 384 }; 385 386 static void __init legacy_pty_init(void) 387 { 388 struct tty_driver *pty_driver, *pty_slave_driver; 389 390 if (legacy_count <= 0) 391 return; 392 393 pty_driver = alloc_tty_driver(legacy_count); 394 if (!pty_driver) 395 panic("Couldn't allocate pty driver"); 396 397 pty_slave_driver = alloc_tty_driver(legacy_count); 398 if (!pty_slave_driver) 399 panic("Couldn't allocate pty slave driver"); 400 401 pty_driver->driver_name = "pty_master"; 402 pty_driver->name = "pty"; 403 pty_driver->major = PTY_MASTER_MAJOR; 404 pty_driver->minor_start = 0; 405 pty_driver->type = TTY_DRIVER_TYPE_PTY; 406 pty_driver->subtype = PTY_TYPE_MASTER; 407 pty_driver->init_termios = tty_std_termios; 408 pty_driver->init_termios.c_iflag = 0; 409 pty_driver->init_termios.c_oflag = 0; 410 pty_driver->init_termios.c_cflag = B38400 | CS8 | CREAD; 411 pty_driver->init_termios.c_lflag = 0; 412 pty_driver->init_termios.c_ispeed = 38400; 413 pty_driver->init_termios.c_ospeed = 38400; 414 pty_driver->flags = TTY_DRIVER_RESET_TERMIOS | TTY_DRIVER_REAL_RAW; 415 pty_driver->other = pty_slave_driver; 416 tty_set_operations(pty_driver, &master_pty_ops_bsd); 417 418 pty_slave_driver->driver_name = "pty_slave"; 419 pty_slave_driver->name = "ttyp"; 420 pty_slave_driver->major = PTY_SLAVE_MAJOR; 421 pty_slave_driver->minor_start = 0; 422 pty_slave_driver->type = TTY_DRIVER_TYPE_PTY; 423 pty_slave_driver->subtype = PTY_TYPE_SLAVE; 424 pty_slave_driver->init_termios = tty_std_termios; 425 pty_slave_driver->init_termios.c_cflag = B38400 | CS8 | CREAD; 426 pty_slave_driver->init_termios.c_ispeed = 38400; 427 pty_slave_driver->init_termios.c_ospeed = 38400; 428 pty_slave_driver->flags = TTY_DRIVER_RESET_TERMIOS | 429 TTY_DRIVER_REAL_RAW; 430 pty_slave_driver->other = pty_driver; 431 tty_set_operations(pty_slave_driver, &slave_pty_ops_bsd); 432 433 if (tty_register_driver(pty_driver)) 434 panic("Couldn't register pty driver"); 435 if (tty_register_driver(pty_slave_driver)) 436 panic("Couldn't register pty slave driver"); 437 } 438 #else 439 static inline void legacy_pty_init(void) { } 440 #endif 441 442 /* Unix98 devices */ 443 #ifdef CONFIG_UNIX98_PTYS 444 445 static struct cdev ptmx_cdev; 446 447 static int pty_unix98_ioctl(struct tty_struct *tty, 448 unsigned int cmd, unsigned long arg) 449 { 450 switch (cmd) { 451 case TIOCSPTLCK: /* Set PT Lock (disallow slave open) */ 452 return pty_set_lock(tty, (int __user *)arg); 453 case TIOCGPTN: /* Get PT Number */ 454 return put_user(tty->index, (unsigned int __user *)arg); 455 case TIOCSIG: /* Send signal to other side of pty */ 456 return pty_signal(tty, (int) arg); 457 } 458 459 return -ENOIOCTLCMD; 460 } 461 462 /** 463 * ptm_unix98_lookup - find a pty master 464 * @driver: ptm driver 465 * @idx: tty index 466 * 467 * Look up a pty master device. Called under the tty_mutex for now. 468 * This provides our locking. 469 */ 470 471 static struct tty_struct *ptm_unix98_lookup(struct tty_driver *driver, 472 struct inode *ptm_inode, int idx) 473 { 474 /* Master must be open via /dev/ptmx */ 475 return ERR_PTR(-EIO); 476 } 477 478 /** 479 * pts_unix98_lookup - find a pty slave 480 * @driver: pts driver 481 * @idx: tty index 482 * 483 * Look up a pty master device. Called under the tty_mutex for now. 484 * This provides our locking for the tty pointer. 485 */ 486 487 static struct tty_struct *pts_unix98_lookup(struct tty_driver *driver, 488 struct inode *pts_inode, int idx) 489 { 490 struct tty_struct *tty; 491 492 mutex_lock(&devpts_mutex); 493 tty = devpts_get_tty(pts_inode, idx); 494 mutex_unlock(&devpts_mutex); 495 /* Master must be open before slave */ 496 if (!tty) 497 return ERR_PTR(-EIO); 498 return tty; 499 } 500 501 static void pty_unix98_shutdown(struct tty_struct *tty) 502 { 503 tty_driver_remove_tty(tty->driver, tty); 504 /* We have our own method as we don't use the tty index */ 505 kfree(tty->termios); 506 } 507 508 /* We have no need to install and remove our tty objects as devpts does all 509 the work for us */ 510 511 static int pty_unix98_install(struct tty_driver *driver, struct tty_struct *tty) 512 { 513 struct tty_struct *o_tty; 514 int idx = tty->index; 515 516 o_tty = alloc_tty_struct(); 517 if (!o_tty) 518 return -ENOMEM; 519 if (!try_module_get(driver->other->owner)) { 520 /* This cannot in fact currently happen */ 521 goto err_free_tty; 522 } 523 initialize_tty_struct(o_tty, driver->other, idx); 524 525 tty->termios = kzalloc(sizeof(struct ktermios[2]), GFP_KERNEL); 526 if (tty->termios == NULL) 527 goto err_free_mem; 528 *tty->termios = driver->init_termios; 529 tty->termios_locked = tty->termios + 1; 530 531 o_tty->termios = kzalloc(sizeof(struct ktermios[2]), GFP_KERNEL); 532 if (o_tty->termios == NULL) 533 goto err_free_mem; 534 *o_tty->termios = driver->other->init_termios; 535 o_tty->termios_locked = o_tty->termios + 1; 536 537 tty_driver_kref_get(driver->other); 538 if (driver->subtype == PTY_TYPE_MASTER) 539 o_tty->count++; 540 /* Establish the links in both directions */ 541 tty->link = o_tty; 542 o_tty->link = tty; 543 /* 544 * All structures have been allocated, so now we install them. 545 * Failures after this point use release_tty to clean up, so 546 * there's no need to null out the local pointers. 547 */ 548 tty_driver_kref_get(driver); 549 tty->count++; 550 return 0; 551 err_free_mem: 552 deinitialize_tty_struct(o_tty); 553 kfree(o_tty->termios); 554 kfree(tty->termios); 555 module_put(o_tty->driver->owner); 556 err_free_tty: 557 free_tty_struct(o_tty); 558 return -ENOMEM; 559 } 560 561 static void ptm_unix98_remove(struct tty_driver *driver, struct tty_struct *tty) 562 { 563 } 564 565 static void pts_unix98_remove(struct tty_driver *driver, struct tty_struct *tty) 566 { 567 } 568 569 static const struct tty_operations ptm_unix98_ops = { 570 .lookup = ptm_unix98_lookup, 571 .install = pty_unix98_install, 572 .remove = ptm_unix98_remove, 573 .open = pty_open, 574 .close = pty_close, 575 .write = pty_write, 576 .write_room = pty_write_room, 577 .flush_buffer = pty_flush_buffer, 578 .chars_in_buffer = pty_chars_in_buffer, 579 .unthrottle = pty_unthrottle, 580 .set_termios = pty_set_termios, 581 .ioctl = pty_unix98_ioctl, 582 .shutdown = pty_unix98_shutdown, 583 .resize = pty_resize 584 }; 585 586 static const struct tty_operations pty_unix98_ops = { 587 .lookup = pts_unix98_lookup, 588 .install = pty_unix98_install, 589 .remove = pts_unix98_remove, 590 .open = pty_open, 591 .close = pty_close, 592 .write = pty_write, 593 .write_room = pty_write_room, 594 .flush_buffer = pty_flush_buffer, 595 .chars_in_buffer = pty_chars_in_buffer, 596 .unthrottle = pty_unthrottle, 597 .set_termios = pty_set_termios, 598 .shutdown = pty_unix98_shutdown 599 }; 600 601 /** 602 * ptmx_open - open a unix 98 pty master 603 * @inode: inode of device file 604 * @filp: file pointer to tty 605 * 606 * Allocate a unix98 pty master device from the ptmx driver. 607 * 608 * Locking: tty_mutex protects the init_dev work. tty->count should 609 * protect the rest. 610 * allocated_ptys_lock handles the list of free pty numbers 611 */ 612 613 static int ptmx_open(struct inode *inode, struct file *filp) 614 { 615 struct tty_struct *tty; 616 int retval; 617 int index; 618 619 nonseekable_open(inode, filp); 620 621 retval = tty_alloc_file(filp); 622 if (retval) 623 return retval; 624 625 /* find a device that is not in use. */ 626 mutex_lock(&devpts_mutex); 627 index = devpts_new_index(inode); 628 if (index < 0) { 629 retval = index; 630 goto err_file; 631 } 632 633 mutex_unlock(&devpts_mutex); 634 635 mutex_lock(&tty_mutex); 636 tty = tty_init_dev(ptm_driver, index); 637 638 if (IS_ERR(tty)) { 639 retval = PTR_ERR(tty); 640 goto out; 641 } 642 643 /* The tty returned here is locked so we can safely 644 drop the mutex */ 645 mutex_unlock(&tty_mutex); 646 647 set_bit(TTY_PTY_LOCK, &tty->flags); /* LOCK THE SLAVE */ 648 649 tty_add_file(tty, filp); 650 651 retval = devpts_pty_new(inode, tty->link); 652 if (retval) 653 goto err_release; 654 655 retval = ptm_driver->ops->open(tty, filp); 656 if (retval) 657 goto err_release; 658 659 tty_unlock(tty); 660 return 0; 661 err_release: 662 tty_unlock(tty); 663 tty_release(inode, filp); 664 return retval; 665 out: 666 mutex_unlock(&tty_mutex); 667 devpts_kill_index(inode, index); 668 err_file: 669 mutex_unlock(&devpts_mutex); 670 tty_free_file(filp); 671 return retval; 672 } 673 674 static struct file_operations ptmx_fops; 675 676 static void __init unix98_pty_init(void) 677 { 678 ptm_driver = alloc_tty_driver(NR_UNIX98_PTY_MAX); 679 if (!ptm_driver) 680 panic("Couldn't allocate Unix98 ptm driver"); 681 pts_driver = alloc_tty_driver(NR_UNIX98_PTY_MAX); 682 if (!pts_driver) 683 panic("Couldn't allocate Unix98 pts driver"); 684 685 ptm_driver->driver_name = "pty_master"; 686 ptm_driver->name = "ptm"; 687 ptm_driver->major = UNIX98_PTY_MASTER_MAJOR; 688 ptm_driver->minor_start = 0; 689 ptm_driver->type = TTY_DRIVER_TYPE_PTY; 690 ptm_driver->subtype = PTY_TYPE_MASTER; 691 ptm_driver->init_termios = tty_std_termios; 692 ptm_driver->init_termios.c_iflag = 0; 693 ptm_driver->init_termios.c_oflag = 0; 694 ptm_driver->init_termios.c_cflag = B38400 | CS8 | CREAD; 695 ptm_driver->init_termios.c_lflag = 0; 696 ptm_driver->init_termios.c_ispeed = 38400; 697 ptm_driver->init_termios.c_ospeed = 38400; 698 ptm_driver->flags = TTY_DRIVER_RESET_TERMIOS | TTY_DRIVER_REAL_RAW | 699 TTY_DRIVER_DYNAMIC_DEV | TTY_DRIVER_DEVPTS_MEM; 700 ptm_driver->other = pts_driver; 701 tty_set_operations(ptm_driver, &ptm_unix98_ops); 702 703 pts_driver->driver_name = "pty_slave"; 704 pts_driver->name = "pts"; 705 pts_driver->major = UNIX98_PTY_SLAVE_MAJOR; 706 pts_driver->minor_start = 0; 707 pts_driver->type = TTY_DRIVER_TYPE_PTY; 708 pts_driver->subtype = PTY_TYPE_SLAVE; 709 pts_driver->init_termios = tty_std_termios; 710 pts_driver->init_termios.c_cflag = B38400 | CS8 | CREAD; 711 pts_driver->init_termios.c_ispeed = 38400; 712 pts_driver->init_termios.c_ospeed = 38400; 713 pts_driver->flags = TTY_DRIVER_RESET_TERMIOS | TTY_DRIVER_REAL_RAW | 714 TTY_DRIVER_DYNAMIC_DEV | TTY_DRIVER_DEVPTS_MEM; 715 pts_driver->other = ptm_driver; 716 tty_set_operations(pts_driver, &pty_unix98_ops); 717 718 if (tty_register_driver(ptm_driver)) 719 panic("Couldn't register Unix98 ptm driver"); 720 if (tty_register_driver(pts_driver)) 721 panic("Couldn't register Unix98 pts driver"); 722 723 /* Now create the /dev/ptmx special device */ 724 tty_default_fops(&ptmx_fops); 725 ptmx_fops.open = ptmx_open; 726 727 cdev_init(&ptmx_cdev, &ptmx_fops); 728 if (cdev_add(&ptmx_cdev, MKDEV(TTYAUX_MAJOR, 2), 1) || 729 register_chrdev_region(MKDEV(TTYAUX_MAJOR, 2), 1, "/dev/ptmx") < 0) 730 panic("Couldn't register /dev/ptmx driver\n"); 731 device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 2), NULL, "ptmx"); 732 } 733 734 #else 735 static inline void unix98_pty_init(void) { } 736 #endif 737 738 static int __init pty_init(void) 739 { 740 legacy_pty_init(); 741 unix98_pty_init(); 742 return 0; 743 } 744 module_init(pty_init); 745