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