LXR linux/include/linux/tty.h

   1/* SPDX-License-Identifier: GPL-2.0 */
   2#ifndef _LINUX_TTY_H
   3#define _LINUX_TTY_H
   4
   5#include <linux/fs.h>
   6#include <linux/major.h>
   7#include <linux/termios.h>
   8#include <linux/workqueue.h>
   9#include <linux/tty_buffer.h>
  10#include <linux/tty_driver.h>
  11#include <linux/tty_ldisc.h>
  12#include <linux/tty_port.h>
  13#include <linux/mutex.h>
  14#include <linux/tty_flags.h>
  15#include <uapi/linux/tty.h>
  16#include <linux/rwsem.h>
  17#include <linux/llist.h>
  18
  19
  20/*
  21 * (Note: the *_driver.minor_start values 1, 64, 128, 192 are
  22 * hardcoded at present.)
  23 */
  24#define NR_UNIX98_PTY_DEFAULT   4096      /* Default maximum for Unix98 ptys */
  25#define NR_UNIX98_PTY_RESERVE   1024      /* Default reserve for main devpts */
  26#define NR_UNIX98_PTY_MAX       (1 << MINORBITS) /* Absolute limit */
  27
  28/*
  29 * This character is the same as _POSIX_VDISABLE: it cannot be used as
  30 * a c_cc[] character, but indicates that a particular special character
  31 * isn't in use (eg VINTR has no character etc)
  32 */
  33#define __DISABLED_CHAR '\0'
  34
  35#define INTR_CHAR(tty) ((tty)->termios.c_cc[VINTR])
  36#define QUIT_CHAR(tty) ((tty)->termios.c_cc[VQUIT])
  37#define ERASE_CHAR(tty) ((tty)->termios.c_cc[VERASE])
  38#define KILL_CHAR(tty) ((tty)->termios.c_cc[VKILL])
  39#define EOF_CHAR(tty) ((tty)->termios.c_cc[VEOF])
  40#define TIME_CHAR(tty) ((tty)->termios.c_cc[VTIME])
  41#define MIN_CHAR(tty) ((tty)->termios.c_cc[VMIN])
  42#define SWTC_CHAR(tty) ((tty)->termios.c_cc[VSWTC])
  43#define START_CHAR(tty) ((tty)->termios.c_cc[VSTART])
  44#define STOP_CHAR(tty) ((tty)->termios.c_cc[VSTOP])
  45#define SUSP_CHAR(tty) ((tty)->termios.c_cc[VSUSP])
  46#define EOL_CHAR(tty) ((tty)->termios.c_cc[VEOL])
  47#define REPRINT_CHAR(tty) ((tty)->termios.c_cc[VREPRINT])
  48#define DISCARD_CHAR(tty) ((tty)->termios.c_cc[VDISCARD])
  49#define WERASE_CHAR(tty) ((tty)->termios.c_cc[VWERASE])
  50#define LNEXT_CHAR(tty) ((tty)->termios.c_cc[VLNEXT])
  51#define EOL2_CHAR(tty) ((tty)->termios.c_cc[VEOL2])
  52
  53#define _I_FLAG(tty, f) ((tty)->termios.c_iflag & (f))
  54#define _O_FLAG(tty, f) ((tty)->termios.c_oflag & (f))
  55#define _C_FLAG(tty, f) ((tty)->termios.c_cflag & (f))
  56#define _L_FLAG(tty, f) ((tty)->termios.c_lflag & (f))
  57
  58#define I_IGNBRK(tty)   _I_FLAG((tty), IGNBRK)
  59#define I_BRKINT(tty)   _I_FLAG((tty), BRKINT)
  60#define I_IGNPAR(tty)   _I_FLAG((tty), IGNPAR)
  61#define I_PARMRK(tty)   _I_FLAG((tty), PARMRK)
  62#define I_INPCK(tty)    _I_FLAG((tty), INPCK)
  63#define I_ISTRIP(tty)   _I_FLAG((tty), ISTRIP)
  64#define I_INLCR(tty)    _I_FLAG((tty), INLCR)
  65#define I_IGNCR(tty)    _I_FLAG((tty), IGNCR)
  66#define I_ICRNL(tty)    _I_FLAG((tty), ICRNL)
  67#define I_IUCLC(tty)    _I_FLAG((tty), IUCLC)
  68#define I_IXON(tty)     _I_FLAG((tty), IXON)
  69#define I_IXANY(tty)    _I_FLAG((tty), IXANY)
  70#define I_IXOFF(tty)    _I_FLAG((tty), IXOFF)
  71#define I_IMAXBEL(tty)  _I_FLAG((tty), IMAXBEL)
  72#define I_IUTF8(tty)    _I_FLAG((tty), IUTF8)
  73
  74#define O_OPOST(tty)    _O_FLAG((tty), OPOST)
  75#define O_OLCUC(tty)    _O_FLAG((tty), OLCUC)
  76#define O_ONLCR(tty)    _O_FLAG((tty), ONLCR)
  77#define O_OCRNL(tty)    _O_FLAG((tty), OCRNL)
  78#define O_ONOCR(tty)    _O_FLAG((tty), ONOCR)
  79#define O_ONLRET(tty)   _O_FLAG((tty), ONLRET)
  80#define O_OFILL(tty)    _O_FLAG((tty), OFILL)
  81#define O_OFDEL(tty)    _O_FLAG((tty), OFDEL)
  82#define O_NLDLY(tty)    _O_FLAG((tty), NLDLY)
  83#define O_CRDLY(tty)    _O_FLAG((tty), CRDLY)
  84#define O_TABDLY(tty)   _O_FLAG((tty), TABDLY)
  85#define O_BSDLY(tty)    _O_FLAG((tty), BSDLY)
  86#define O_VTDLY(tty)    _O_FLAG((tty), VTDLY)
  87#define O_FFDLY(tty)    _O_FLAG((tty), FFDLY)
  88
  89#define C_BAUD(tty)     _C_FLAG((tty), CBAUD)
  90#define C_CSIZE(tty)    _C_FLAG((tty), CSIZE)
  91#define C_CSTOPB(tty)   _C_FLAG((tty), CSTOPB)
  92#define C_CREAD(tty)    _C_FLAG((tty), CREAD)
  93#define C_PARENB(tty)   _C_FLAG((tty), PARENB)
  94#define C_PARODD(tty)   _C_FLAG((tty), PARODD)
  95#define C_HUPCL(tty)    _C_FLAG((tty), HUPCL)
  96#define C_CLOCAL(tty)   _C_FLAG((tty), CLOCAL)
  97#define C_CIBAUD(tty)   _C_FLAG((tty), CIBAUD)
  98#define C_CRTSCTS(tty)  _C_FLAG((tty), CRTSCTS)
  99#define C_CMSPAR(tty)   _C_FLAG((tty), CMSPAR)
 100
 101#define L_ISIG(tty)     _L_FLAG((tty), ISIG)
 102#define L_ICANON(tty)   _L_FLAG((tty), ICANON)
 103#define L_XCASE(tty)    _L_FLAG((tty), XCASE)
 104#define L_ECHO(tty)     _L_FLAG((tty), ECHO)
 105#define L_ECHOE(tty)    _L_FLAG((tty), ECHOE)
 106#define L_ECHOK(tty)    _L_FLAG((tty), ECHOK)
 107#define L_ECHONL(tty)   _L_FLAG((tty), ECHONL)
 108#define L_NOFLSH(tty)   _L_FLAG((tty), NOFLSH)
 109#define L_TOSTOP(tty)   _L_FLAG((tty), TOSTOP)
 110#define L_ECHOCTL(tty)  _L_FLAG((tty), ECHOCTL)
 111#define L_ECHOPRT(tty)  _L_FLAG((tty), ECHOPRT)
 112#define L_ECHOKE(tty)   _L_FLAG((tty), ECHOKE)
 113#define L_FLUSHO(tty)   _L_FLAG((tty), FLUSHO)
 114#define L_PENDIN(tty)   _L_FLAG((tty), PENDIN)
 115#define L_IEXTEN(tty)   _L_FLAG((tty), IEXTEN)
 116#define L_EXTPROC(tty)  _L_FLAG((tty), EXTPROC)
 117
 118struct device;
 119struct signal_struct;
 120struct tty_operations;
 121
 122/**
 123 * struct tty_struct - state associated with a tty while open
 124 *
 125 * @magic: magic value set early in @alloc_tty_struct to %TTY_MAGIC, for
 126 *         debugging purposes
 127 * @kref: reference counting by tty_kref_get() and tty_kref_put(), reaching zero
 128 *        frees the structure
 129 * @dev: class device or %NULL (e.g. ptys, serdev)
 130 * @driver: &struct tty_driver operating this tty
 131 * @ops: &struct tty_operations of @driver for this tty (open, close, etc.)
 132 * @index: index of this tty (e.g. to construct @name like tty12)
 133 * @ldisc_sem: protects line discipline changes (@ldisc) -- lock tty not pty
 134 * @ldisc: the current line discipline for this tty (n_tty by default)
 135 * @atomic_write_lock: protects against concurrent writers, i.e. locks
 136 *                     @write_cnt, @write_buf and similar
 137 * @legacy_mutex: leftover from history (BKL -> BTM -> @legacy_mutex),
 138 *                protecting several operations on this tty
 139 * @throttle_mutex: protects against concurrent tty_throttle_safe() and
 140 *                  tty_unthrottle_safe() (but not tty_unthrottle())
 141 * @termios_rwsem: protects @termios and @termios_locked
 142 * @winsize_mutex: protects @winsize
 143 * @termios: termios for the current tty, copied from/to @driver.termios
 144 * @termios_locked: locked termios (by %TIOCGLCKTRMIOS and %TIOCSLCKTRMIOS
 145 *                  ioctls)
 146 * @name: name of the tty constructed by tty_line_name() (e.g. ttyS3)
 147 * @flags: bitwise OR of %TTY_THROTTLED, %TTY_IO_ERROR, ...
 148 * @count: count of open processes, reaching zero cancels all the work for
 149 *         this tty and drops a @kref too (but does not free this tty)
 150 * @winsize: size of the terminal "window" (cf. @winsize_mutex)
 151 * @flow: flow settings grouped together, see also @flow.unused
 152 * @flow.lock: lock for @flow members
 153 * @flow.stopped: tty stopped/started by stop_tty()/start_tty()
 154 * @flow.tco_stopped: tty stopped/started by %TCOOFF/%TCOON ioctls (it has
 155 *                    precedence over @flow.stopped)
 156 * @flow.unused: alignment for Alpha, so that no members other than @flow.* are
 157 *               modified by the same 64b word store. The @flow's __aligned is
 158 *               there for the very same reason.
 159 * @ctrl: control settings grouped together, see also @ctrl.unused
 160 * @ctrl.lock: lock for @ctrl members
 161 * @ctrl.pgrp: process group of this tty (setpgrp(2))
 162 * @ctrl.session: session of this tty (setsid(2)). Writes are protected by both
 163 *                @ctrl.lock and @legacy_mutex, readers must use at least one of
 164 *                them.
 165 * @ctrl.pktstatus: packet mode status (bitwise OR of %TIOCPKT_ constants)
 166 * @ctrl.packet: packet mode enabled
 167 * @ctrl.unused: alignment for Alpha, see @flow.unused for explanation
 168 * @hw_stopped: not controlled by the tty layer, under @driver's control for CTS
 169 *              handling
 170 * @receive_room: bytes permitted to feed to @ldisc without any being lost
 171 * @flow_change: controls behavior of throttling, see tty_throttle_safe() and
 172 *               tty_unthrottle_safe()
 173 * @link: link to another pty (master -> slave and vice versa)
 174 * @fasync: state for %O_ASYNC (for %SIGIO); managed by fasync_helper()
 175 * @write_wait: concurrent writers are waiting in this queue until they are
 176 *              allowed to write
 177 * @read_wait: readers wait for data in this queue
 178 * @hangup_work: normally a work to perform a hangup (do_tty_hangup()); while
 179 *               freeing the tty, (re)used to release_one_tty()
 180 * @disc_data: pointer to @ldisc's private data (e.g. to &struct n_tty_data)
 181 * @driver_data: pointer to @driver's private data (e.g. &struct uart_state)
 182 * @files_lock: protects @tty_files list
 183 * @tty_files: list of (re)openers of this tty (i.e. linked &struct
 184 *             tty_file_private)
 185 * @closing: when set during close, n_tty processes only START & STOP chars
 186 * @write_buf: temporary buffer used during tty_write() to copy user data to
 187 * @write_cnt: count of bytes written in tty_write() to @write_buf
 188 * @SAK_work: if the tty has a pending do_SAK, it is queued here
 189 * @port: persistent storage for this device (i.e. &struct tty_port)
 190 *
 191 * All of the state associated with a tty while the tty is open. Persistent
 192 * storage for tty devices is referenced here as @port and is documented in
 193 * &struct tty_port.
 194 */
 195struct tty_struct {
 196        int     magic;
 197        struct kref kref;
 198        struct device *dev;
 199        struct tty_driver *driver;
 200        const struct tty_operations *ops;
 201        int index;
 202
 203        struct ld_semaphore ldisc_sem;
 204        struct tty_ldisc *ldisc;
 205
 206        struct mutex atomic_write_lock;
 207        struct mutex legacy_mutex;
 208        struct mutex throttle_mutex;
 209        struct rw_semaphore termios_rwsem;
 210        struct mutex winsize_mutex;
 211        struct ktermios termios, termios_locked;
 212        char name[64];
 213        unsigned long flags;
 214        int count;
 215        struct winsize winsize;
 216
 217        struct {
 218                spinlock_t lock;
 219                bool stopped;
 220                bool tco_stopped;
 221                unsigned long unused[0];
 222        } __aligned(sizeof(unsigned long)) flow;
 223
 224        struct {
 225                spinlock_t lock;
 226                struct pid *pgrp;
 227                struct pid *session;
 228                unsigned char pktstatus;
 229                bool packet;
 230                unsigned long unused[0];
 231        } __aligned(sizeof(unsigned long)) ctrl;
 232
 233        int hw_stopped;
 234        unsigned int receive_room;
 235        int flow_change;
 236
 237        struct tty_struct *link;
 238        struct fasync_struct *fasync;
 239        wait_queue_head_t write_wait;
 240        wait_queue_head_t read_wait;
 241        struct work_struct hangup_work;
 242        void *disc_data;
 243        void *driver_data;
 244        spinlock_t files_lock;
 245        struct list_head tty_files;
 246
 247#define N_TTY_BUF_SIZE 4096
 248
 249        int closing;
 250        unsigned char *write_buf;
 251        int write_cnt;
 252        struct work_struct SAK_work;
 253        struct tty_port *port;
 254} __randomize_layout;
 255
 256/* Each of a tty's open files has private_data pointing to tty_file_private */
 257struct tty_file_private {
 258        struct tty_struct *tty;
 259        struct file *file;
 260        struct list_head list;
 261};
 262
 263/* tty magic number */
 264#define TTY_MAGIC               0x5401
 265
 266/**
 267 * DOC: TTY Struct Flags
 268 *
 269 * These bits are used in the :c:member:`tty_struct.flags` field.
 270 *
 271 * So that interrupts won't be able to mess up the queues,
 272 * copy_to_cooked must be atomic with respect to itself, as must
 273 * tty->write.  Thus, you must use the inline functions set_bit() and
 274 * clear_bit() to make things atomic.
 275 *
 276 * TTY_THROTTLED
 277 *      Driver input is throttled. The ldisc should call
 278 *      :c:member:`tty_driver.unthrottle()` in order to resume reception when
 279 *      it is ready to process more data (at threshold min).
 280 *
 281 * TTY_IO_ERROR
 282 *      If set, causes all subsequent userspace read/write calls on the tty to
 283 *      fail, returning -%EIO. (May be no ldisc too.)
 284 *
 285 * TTY_OTHER_CLOSED
 286 *      Device is a pty and the other side has closed.
 287 *
 288 * TTY_EXCLUSIVE
 289 *      Exclusive open mode (a single opener).
 290 *
 291 * TTY_DO_WRITE_WAKEUP
 292 *      If set, causes the driver to call the
 293 *      :c:member:`tty_ldisc_ops.write_wakeup()` method in order to resume
 294 *      transmission when it can accept more data to transmit.
 295 *
 296 * TTY_LDISC_OPEN
 297 *      Indicates that a line discipline is open. For debugging purposes only.
 298 *
 299 * TTY_PTY_LOCK
 300 *      A flag private to pty code to implement %TIOCSPTLCK/%TIOCGPTLCK logic.
 301 *
 302 * TTY_NO_WRITE_SPLIT
 303 *      Prevent driver from splitting up writes into smaller chunks (preserve
 304 *      write boundaries to driver).
 305 *
 306 * TTY_HUPPED
 307 *      The TTY was hung up. This is set post :c:member:`tty_driver.hangup()`.
 308 *
 309 * TTY_HUPPING
 310 *      The TTY is in the process of hanging up to abort potential readers.
 311 *
 312 * TTY_LDISC_CHANGING
 313 *      Line discipline for this TTY is being changed. I/O should not block
 314 *      when this is set. Use tty_io_nonblock() to check.
 315 *
 316 * TTY_LDISC_HALTED
 317 *      Line discipline for this TTY was stopped. No work should be queued to
 318 *      this ldisc.
 319 */
 320#define TTY_THROTTLED           0
 321#define TTY_IO_ERROR            1
 322#define TTY_OTHER_CLOSED        2
 323#define TTY_EXCLUSIVE           3
 324#define TTY_DO_WRITE_WAKEUP     5
 325#define TTY_LDISC_OPEN          11
 326#define TTY_PTY_LOCK            16
 327#define TTY_NO_WRITE_SPLIT      17
 328#define TTY_HUPPED              18
 329#define TTY_HUPPING             19
 330#define TTY_LDISC_CHANGING      20
 331#define TTY_LDISC_HALTED        22
 332
 333static inline bool tty_io_nonblock(struct tty_struct *tty, struct file *file)
 334{
 335        return file->f_flags & O_NONBLOCK ||
 336                test_bit(TTY_LDISC_CHANGING, &tty->flags);
 337}
 338
 339static inline bool tty_io_error(struct tty_struct *tty)
 340{
 341        return test_bit(TTY_IO_ERROR, &tty->flags);
 342}
 343
 344static inline bool tty_throttled(struct tty_struct *tty)
 345{
 346        return test_bit(TTY_THROTTLED, &tty->flags);
 347}
 348
 349#ifdef CONFIG_TTY
 350void tty_kref_put(struct tty_struct *tty);
 351struct pid *tty_get_pgrp(struct tty_struct *tty);
 352void tty_vhangup_self(void);
 353void disassociate_ctty(int priv);
 354dev_t tty_devnum(struct tty_struct *tty);
 355void proc_clear_tty(struct task_struct *p);
 356struct tty_struct *get_current_tty(void);
 357/* tty_io.c */
 358int __init tty_init(void);
 359const char *tty_name(const struct tty_struct *tty);
 360struct tty_struct *tty_kopen_exclusive(dev_t device);
 361struct tty_struct *tty_kopen_shared(dev_t device);
 362void tty_kclose(struct tty_struct *tty);
 363int tty_dev_name_to_number(const char *name, dev_t *number);
 364#else
 365static inline void tty_kref_put(struct tty_struct *tty)
 366{ }
 367static inline struct pid *tty_get_pgrp(struct tty_struct *tty)
 368{ return NULL; }
 369static inline void tty_vhangup_self(void)
 370{ }
 371static inline void disassociate_ctty(int priv)
 372{ }
 373static inline dev_t tty_devnum(struct tty_struct *tty)
 374{ return 0; }
 375static inline void proc_clear_tty(struct task_struct *p)
 376{ }
 377static inline struct tty_struct *get_current_tty(void)
 378{ return NULL; }
 379/* tty_io.c */
 380static inline int __init tty_init(void)
 381{ return 0; }
 382static inline const char *tty_name(const struct tty_struct *tty)
 383{ return "(none)"; }
 384static inline struct tty_struct *tty_kopen_exclusive(dev_t device)
 385{ return ERR_PTR(-ENODEV); }
 386static inline void tty_kclose(struct tty_struct *tty)
 387{ }
 388static inline int tty_dev_name_to_number(const char *name, dev_t *number)
 389{ return -ENOTSUPP; }
 390#endif
 391
 392extern struct ktermios tty_std_termios;
 393
 394int vcs_init(void);
 395
 396extern struct class *tty_class;
 397
 398/**
 399 *      tty_kref_get            -       get a tty reference
 400 *      @tty: tty device
 401 *
 402 *      Return a new reference to a tty object. The caller must hold
 403 *      sufficient locks/counts to ensure that their existing reference cannot
 404 *      go away
 405 */
 406
 407static inline struct tty_struct *tty_kref_get(struct tty_struct *tty)
 408{
 409        if (tty)
 410                kref_get(&tty->kref);
 411        return tty;
 412}
 413
 414const char *tty_driver_name(const struct tty_struct *tty);
 415void tty_wait_until_sent(struct tty_struct *tty, long timeout);
 416void stop_tty(struct tty_struct *tty);
 417void start_tty(struct tty_struct *tty);
 418void tty_write_message(struct tty_struct *tty, char *msg);
 419int tty_send_xchar(struct tty_struct *tty, char ch);
 420int tty_put_char(struct tty_struct *tty, unsigned char c);
 421unsigned int tty_chars_in_buffer(struct tty_struct *tty);
 422unsigned int tty_write_room(struct tty_struct *tty);
 423void tty_driver_flush_buffer(struct tty_struct *tty);
 424void tty_unthrottle(struct tty_struct *tty);
 425int tty_throttle_safe(struct tty_struct *tty);
 426int tty_unthrottle_safe(struct tty_struct *tty);
 427int tty_do_resize(struct tty_struct *tty, struct winsize *ws);
 428int tty_get_icount(struct tty_struct *tty,
 429                struct serial_icounter_struct *icount);
 430int is_current_pgrp_orphaned(void);
 431void tty_hangup(struct tty_struct *tty);
 432void tty_vhangup(struct tty_struct *tty);
 433int tty_hung_up_p(struct file *filp);
 434void do_SAK(struct tty_struct *tty);
 435void __do_SAK(struct tty_struct *tty);
 436void no_tty(void);
 437speed_t tty_termios_baud_rate(struct ktermios *termios);
 438void tty_termios_encode_baud_rate(struct ktermios *termios, speed_t ibaud,
 439                speed_t obaud);
 440void tty_encode_baud_rate(struct tty_struct *tty, speed_t ibaud,
 441                speed_t obaud);
 442
 443/**
 444 *      tty_get_baud_rate       -       get tty bit rates
 445 *      @tty: tty to query
 446 *
 447 *      Returns the baud rate as an integer for this terminal. The
 448 *      termios lock must be held by the caller and the terminal bit
 449 *      flags may be updated.
 450 *
 451 *      Locking: none
 452 */
 453static inline speed_t tty_get_baud_rate(struct tty_struct *tty)
 454{
 455        return tty_termios_baud_rate(&tty->termios);
 456}
 457
 458unsigned char tty_get_char_size(unsigned int cflag);
 459unsigned char tty_get_frame_size(unsigned int cflag);
 460
 461void tty_termios_copy_hw(struct ktermios *new, struct ktermios *old);
 462int tty_termios_hw_change(const struct ktermios *a, const struct ktermios *b);
 463int tty_set_termios(struct tty_struct *tty, struct ktermios *kt);
 464
 465void tty_wakeup(struct tty_struct *tty);
 466
 467int tty_mode_ioctl(struct tty_struct *tty, unsigned int cmd, unsigned long arg);
 468int tty_perform_flush(struct tty_struct *tty, unsigned long arg);
 469struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx);
 470void tty_release_struct(struct tty_struct *tty, int idx);
 471void tty_init_termios(struct tty_struct *tty);
 472void tty_save_termios(struct tty_struct *tty);
 473int tty_standard_install(struct tty_driver *driver,
 474                struct tty_struct *tty);
 475
 476extern struct mutex tty_mutex;
 477
 478/* n_tty.c */
 479void n_tty_inherit_ops(struct tty_ldisc_ops *ops);
 480#ifdef CONFIG_TTY
 481void __init n_tty_init(void);
 482#else
 483static inline void n_tty_init(void) { }
 484#endif
 485
 486/* tty_audit.c */
 487#ifdef CONFIG_AUDIT
 488void tty_audit_exit(void);
 489void tty_audit_fork(struct signal_struct *sig);
 490int tty_audit_push(void);
 491#else
 492static inline void tty_audit_exit(void)
 493{
 494}
 495static inline void tty_audit_fork(struct signal_struct *sig)
 496{
 497}
 498static inline int tty_audit_push(void)
 499{
 500        return 0;
 501}
 502#endif
 503
 504/* tty_ioctl.c */
 505int n_tty_ioctl_helper(struct tty_struct *tty, unsigned int cmd,
 506                unsigned long arg);
 507
 508/* vt.c */
 509
 510int vt_ioctl(struct tty_struct *tty, unsigned int cmd, unsigned long arg);
 511
 512long vt_compat_ioctl(struct tty_struct *tty, unsigned int cmd,
 513                unsigned long arg);
 514
 515/* tty_mutex.c */
 516/* functions for preparation of BKL removal */
 517void tty_lock(struct tty_struct *tty);
 518int  tty_lock_interruptible(struct tty_struct *tty);
 519void tty_unlock(struct tty_struct *tty);
 520void tty_lock_slave(struct tty_struct *tty);
 521void tty_unlock_slave(struct tty_struct *tty);
 522void tty_set_lock_subclass(struct tty_struct *tty);
 523
 524#endif
 525