// SPDX-License-Identifier: GPL-2.0 /* * Copyright (C) 1991, 1992 Linus Torvalds */ /* * 'tty_io.c' gives an orthogonal feeling to tty's, be they consoles * or rs-channels. It also implements echoing, cooked mode etc. * * Kill-line thanks to John T Kohl, who also corrected VMIN = VTIME = 0. * * Modified by Theodore Ts'o, 9/14/92, to dynamically allocate the * tty_struct and tty_queue structures. Previously there was an array * of 256 tty_struct's which was statically allocated, and the * tty_queue structures were allocated at boot time. Both are now * dynamically allocated only when the tty is open. * * Also restructured routines so that there is more of a separation * between the high-level tty routines (tty_io.c and tty_ioctl.c) and * the low-level tty routines (serial.c, pty.c, console.c). This * makes for cleaner and more compact code. -TYT, 9/17/92 * * Modified by Fred N. van Kempen, 01/29/93, to add line disciplines * which can be dynamically activated and de-activated by the line * discipline handling modules (like SLIP). * * NOTE: pay no attention to the line discipline code (yet); its * interface is still subject to change in this version... * -- TYT, 1/31/92 * * Added functionality to the OPOST tty handling. No delays, but all * other bits should be there. * -- Nick Holloway <[email protected]>, 27th May 1993. * * Rewrote canonical mode and added more termios flags. * -- [email protected] (J. Cowley), 13Jan94 * * Reorganized FASYNC support so mouse code can share it. * -- [email protected], 9Sep95 * * New TIOCLINUX variants added. * -- [email protected], 19-Nov-95 * * Restrict vt switching via ioctl() * -- [email protected], 5-Dec-95 * * Move console and virtual terminal code to more appropriate files, * implement CONFIG_VT and generalize console device interface. * -- Marko Kohtala <[email protected]>, March 97 * * Rewrote tty_init_dev and tty_release_dev to eliminate races. * -- Bill Hawes <[email protected]>, June 97 * * Added devfs support. * -- C. Scott Ananian <[email protected]>, 13-Jan-1998 * * Added support for a Unix98-style ptmx device. * -- C. Scott Ananian <[email protected]>, 14-Jan-1998 * * Reduced memory usage for older ARM systems * -- Russell King <[email protected]> * * Move do_SAK() into process context. Less stack use in devfs functions. * alloc_tty_struct() always uses kmalloc() * -- Andrew Morton <[email protected]> 17Mar01 */ #include <linux/types.h> #include <linux/major.h> #include <linux/errno.h> #include <linux/signal.h> #include <linux/fcntl.h> #include <linux/sched/signal.h> #include <linux/sched/task.h> #include <linux/interrupt.h> #include <linux/tty.h> #include <linux/tty_driver.h> #include <linux/tty_flip.h> #include <linux/devpts_fs.h> #include <linux/file.h> #include <linux/fdtable.h> #include <linux/console.h> #include <linux/timer.h> #include <linux/ctype.h> #include <linux/kd.h> #include <linux/mm.h> #include <linux/string.h> #include <linux/slab.h> #include <linux/poll.h> #include <linux/ppp-ioctl.h> #include <linux/proc_fs.h> #include <linux/init.h> #include <linux/module.h> #include <linux/device.h> #include <linux/wait.h> #include <linux/bitops.h> #include <linux/delay.h> #include <linux/seq_file.h> #include <linux/serial.h> #include <linux/ratelimit.h> #include <linux/compat.h> #include <linux/uaccess.h> #include <linux/termios_internal.h> #include <linux/fs.h> #include <linux/kbd_kern.h> #include <linux/vt_kern.h> #include <linux/selection.h> #include <linux/kmod.h> #include <linux/nsproxy.h> #include "tty.h" #undef TTY_DEBUG_HANGUP #ifdef TTY_DEBUG_HANGUP #define tty_debug_hangup … #else #define tty_debug_hangup(tty, f, args...) … #endif #define TTY_PARANOIA_CHECK … #define CHECK_TTY_COUNT … struct ktermios tty_std_termios = …; EXPORT_SYMBOL(…); /* This list gets poked at by procfs and various bits of boot up code. This * could do with some rationalisation such as pulling the tty proc function * into this file. */ LIST_HEAD(…); /* linked list of tty drivers */ /* Mutex to protect creating and releasing a tty */ DEFINE_MUTEX(…) …; static ssize_t tty_read(struct kiocb *, struct iov_iter *); static ssize_t tty_write(struct kiocb *, struct iov_iter *); static __poll_t tty_poll(struct file *, poll_table *); static int tty_open(struct inode *, struct file *); #ifdef CONFIG_COMPAT static long tty_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg); #else #define tty_compat_ioctl … #endif static int __tty_fasync(int fd, struct file *filp, int on); static int tty_fasync(int fd, struct file *filp, int on); static void release_tty(struct tty_struct *tty, int idx); /** * free_tty_struct - free a disused tty * @tty: tty struct to free * * Free the write buffers, tty queue and tty memory itself. * * Locking: none. Must be called after tty is definitely unused */ static void free_tty_struct(struct tty_struct *tty) { … } static inline struct tty_struct *file_tty(struct file *file) { … } int tty_alloc_file(struct file *file) { … } /* Associate a new file with the tty structure */ void tty_add_file(struct tty_struct *tty, struct file *file) { … } /** * tty_free_file - free file->private_data * @file: to free private_data of * * This shall be used only for fail path handling when tty_add_file was not * called yet. */ void tty_free_file(struct file *file) { … } /* Delete file from its tty */ static void tty_del_file(struct file *file) { … } /** * tty_name - return tty naming * @tty: tty structure * * Convert a tty structure into a name. The name reflects the kernel naming * policy and if udev is in use may not reflect user space * * Locking: none */ const char *tty_name(const struct tty_struct *tty) { … } EXPORT_SYMBOL(…); const char *tty_driver_name(const struct tty_struct *tty) { … } static int tty_paranoia_check(struct tty_struct *tty, struct inode *inode, const char *routine) { … } /* Caller must hold tty_lock */ static void check_tty_count(struct tty_struct *tty, const char *routine) { … } /** * get_tty_driver - find device of a tty * @device: device identifier * @index: returns the index of the tty * * This routine returns a tty driver structure, given a device number and also * passes back the index number. * * Locking: caller must hold tty_mutex */ static struct tty_driver *get_tty_driver(dev_t device, int *index) { … } /** * tty_dev_name_to_number - return dev_t for device name * @name: user space name of device under /dev * @number: pointer to dev_t that this function will populate * * This function converts device names like ttyS0 or ttyUSB1 into dev_t like * (4, 64) or (188, 1). If no corresponding driver is registered then the * function returns -%ENODEV. * * Locking: this acquires tty_mutex to protect the tty_drivers list from * being modified while we are traversing it, and makes sure to * release it before exiting. */ int tty_dev_name_to_number(const char *name, dev_t *number) { … } EXPORT_SYMBOL_GPL(…); #ifdef CONFIG_CONSOLE_POLL /** * tty_find_polling_driver - find device of a polled tty * @name: name string to match * @line: pointer to resulting tty line nr * * This routine returns a tty driver structure, given a name and the condition * that the tty driver is capable of polled operation. */ struct tty_driver *tty_find_polling_driver(char *name, int *line) { … } EXPORT_SYMBOL_GPL(…); #endif static ssize_t hung_up_tty_read(struct kiocb *iocb, struct iov_iter *to) { … } static ssize_t hung_up_tty_write(struct kiocb *iocb, struct iov_iter *from) { … } /* No kernel lock held - none needed ;) */ static __poll_t hung_up_tty_poll(struct file *filp, poll_table *wait) { … } static long hung_up_tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { … } static long hung_up_tty_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { … } static int hung_up_tty_fasync(int fd, struct file *file, int on) { … } static void tty_show_fdinfo(struct seq_file *m, struct file *file) { … } static const struct file_operations tty_fops = …; static const struct file_operations console_fops = …; static const struct file_operations hung_up_tty_fops = …; static DEFINE_SPINLOCK(redirect_lock); static struct file *redirect; /** * tty_wakeup - request more data * @tty: terminal * * Internal and external helper for wakeups of tty. This function informs the * line discipline if present that the driver is ready to receive more output * data. */ void tty_wakeup(struct tty_struct *tty) { … } EXPORT_SYMBOL_GPL(…); /** * tty_release_redirect - Release a redirect on a pty if present * @tty: tty device * * This is available to the pty code so if the master closes, if the slave is a * redirect it can release the redirect. */ static struct file *tty_release_redirect(struct tty_struct *tty) { … } /** * __tty_hangup - actual handler for hangup events * @tty: tty device * @exit_session: if non-zero, signal all foreground group processes * * This can be called by a "kworker" kernel thread. That is process synchronous * but doesn't hold any locks, so we need to make sure we have the appropriate * locks for what we're doing. * * The hangup event clears any pending redirections onto the hung up device. It * ensures future writes will error and it does the needed line discipline * hangup and signal delivery. The tty object itself remains intact. * * Locking: * * BTM * * * redirect lock for undoing redirection * * file list lock for manipulating list of ttys * * tty_ldiscs_lock from called functions * * termios_rwsem resetting termios data * * tasklist_lock to walk task list for hangup event * * * ->siglock to protect ->signal/->sighand * */ static void __tty_hangup(struct tty_struct *tty, int exit_session) { … } static void do_tty_hangup(struct work_struct *work) { … } /** * tty_hangup - trigger a hangup event * @tty: tty to hangup * * A carrier loss (virtual or otherwise) has occurred on @tty. Schedule a * hangup sequence to run after this event. */ void tty_hangup(struct tty_struct *tty) { … } EXPORT_SYMBOL(…); /** * tty_vhangup - process vhangup * @tty: tty to hangup * * The user has asked via system call for the terminal to be hung up. We do * this synchronously so that when the syscall returns the process is complete. * That guarantee is necessary for security reasons. */ void tty_vhangup(struct tty_struct *tty) { … } EXPORT_SYMBOL(…); /** * tty_vhangup_self - process vhangup for own ctty * * Perform a vhangup on the current controlling tty */ void tty_vhangup_self(void) { … } /** * tty_vhangup_session - hangup session leader exit * @tty: tty to hangup * * The session leader is exiting and hanging up its controlling terminal. * Every process in the foreground process group is signalled %SIGHUP. * * We do this synchronously so that when the syscall returns the process is * complete. That guarantee is necessary for security reasons. */ void tty_vhangup_session(struct tty_struct *tty) { … } /** * tty_hung_up_p - was tty hung up * @filp: file pointer of tty * * Return: true if the tty has been subject to a vhangup or a carrier loss */ int tty_hung_up_p(struct file *filp) { … } EXPORT_SYMBOL(…); void __stop_tty(struct tty_struct *tty) { … } /** * stop_tty - propagate flow control * @tty: tty to stop * * Perform flow control to the driver. May be called on an already stopped * device and will not re-call the &tty_driver->stop() method. * * This functionality is used by both the line disciplines for halting incoming * flow and by the driver. It may therefore be called from any context, may be * under the tty %atomic_write_lock but not always. * * Locking: * flow.lock */ void stop_tty(struct tty_struct *tty) { … } EXPORT_SYMBOL(…); void __start_tty(struct tty_struct *tty) { … } /** * start_tty - propagate flow control * @tty: tty to start * * Start a tty that has been stopped if at all possible. If @tty was previously * stopped and is now being started, the &tty_driver->start() method is invoked * and the line discipline woken. * * Locking: * flow.lock */ void start_tty(struct tty_struct *tty) { … } EXPORT_SYMBOL(…); static void tty_update_time(struct tty_struct *tty, bool mtime) { … } /* * Iterate on the ldisc ->read() function until we've gotten all * the data the ldisc has for us. * * The "cookie" is something that the ldisc read function can fill * in to let us know that there is more data to be had. * * We promise to continue to call the ldisc until it stops returning * data or clears the cookie. The cookie may be something that the * ldisc maintains state for and needs to free. */ static ssize_t iterate_tty_read(struct tty_ldisc *ld, struct tty_struct *tty, struct file *file, struct iov_iter *to) { … } /** * tty_read - read method for tty device files * @iocb: kernel I/O control block * @to: destination for the data read * * Perform the read system call function on this terminal device. Checks * for hung up devices before calling the line discipline method. * * Locking: * Locks the line discipline internally while needed. Multiple read calls * may be outstanding in parallel. */ static ssize_t tty_read(struct kiocb *iocb, struct iov_iter *to) { … } void tty_write_unlock(struct tty_struct *tty) { … } int tty_write_lock(struct tty_struct *tty, bool ndelay) { … } /* * Split writes up in sane blocksizes to avoid * denial-of-service type attacks */ static ssize_t iterate_tty_write(struct tty_ldisc *ld, struct tty_struct *tty, struct file *file, struct iov_iter *from) { … } #ifdef CONFIG_PRINT_QUOTA_WARNING /** * tty_write_message - write a message to a certain tty, not just the console. * @tty: the destination tty_struct * @msg: the message to write * * This is used for messages that need to be redirected to a specific tty. We * don't put it into the syslog queue right now maybe in the future if really * needed. * * We must still hold the BTM and test the CLOSING flag for the moment. * * This function is DEPRECATED, do not use in new code. */ void tty_write_message(struct tty_struct *tty, char *msg) { if (tty) { mutex_lock(&tty->atomic_write_lock); tty_lock(tty); if (tty->ops->write && tty->count > 0) tty->ops->write(tty, msg, strlen(msg)); tty_unlock(tty); tty_write_unlock(tty); } } #endif static ssize_t file_tty_write(struct file *file, struct kiocb *iocb, struct iov_iter *from) { … } /** * tty_write - write method for tty device file * @iocb: kernel I/O control block * @from: iov_iter with data to write * * Write data to a tty device via the line discipline. * * Locking: * Locks the line discipline as required * Writes to the tty driver are serialized by the atomic_write_lock * and are then processed in chunks to the device. The line * discipline write method will not be invoked in parallel for * each device. */ static ssize_t tty_write(struct kiocb *iocb, struct iov_iter *from) { … } ssize_t redirected_tty_write(struct kiocb *iocb, struct iov_iter *iter) { … } /** * tty_send_xchar - send priority character * @tty: the tty to send to * @ch: xchar to send * * Send a high priority character to the tty even if stopped. * * Locking: none for xchar method, write ordering for write method. */ int tty_send_xchar(struct tty_struct *tty, u8 ch) { … } /** * pty_line_name - generate name for a pty * @driver: the tty driver in use * @index: the minor number * @p: output buffer of at least 6 bytes * * Generate a name from a @driver reference and write it to the output buffer * @p. * * Locking: None */ static void pty_line_name(struct tty_driver *driver, int index, char *p) { … } /** * tty_line_name - generate name for a tty * @driver: the tty driver in use * @index: the minor number * @p: output buffer of at least 7 bytes * * Generate a name from a @driver reference and write it to the output buffer * @p. * * Locking: None */ static ssize_t tty_line_name(struct tty_driver *driver, int index, char *p) { … } /** * tty_driver_lookup_tty() - find an existing tty, if any * @driver: the driver for the tty * @file: file object * @idx: the minor number * * Return: the tty, if found. If not found, return %NULL or ERR_PTR() if the * driver lookup() method returns an error. * * Locking: tty_mutex must be held. If the tty is found, bump the tty kref. */ static struct tty_struct *tty_driver_lookup_tty(struct tty_driver *driver, struct file *file, int idx) { … } /** * tty_init_termios - helper for termios setup * @tty: the tty to set up * * Initialise the termios structure for this tty. This runs under the * %tty_mutex currently so we can be relaxed about ordering. */ void tty_init_termios(struct tty_struct *tty) { … } EXPORT_SYMBOL_GPL(…); /** * tty_standard_install - usual tty->ops->install * @driver: the driver for the tty * @tty: the tty * * If the @driver overrides @tty->ops->install, it still can call this function * to perform the standard install operations. */ int tty_standard_install(struct tty_driver *driver, struct tty_struct *tty) { … } EXPORT_SYMBOL_GPL(…); /** * tty_driver_install_tty() - install a tty entry in the driver * @driver: the driver for the tty * @tty: the tty * * Install a tty object into the driver tables. The @tty->index field will be * set by the time this is called. This method is responsible for ensuring any * need additional structures are allocated and configured. * * Locking: tty_mutex for now */ static int tty_driver_install_tty(struct tty_driver *driver, struct tty_struct *tty) { … } /** * tty_driver_remove_tty() - remove a tty from the driver tables * @driver: the driver for the tty * @tty: tty to remove * * Remove a tty object from the driver tables. The tty->index field will be set * by the time this is called. * * Locking: tty_mutex for now */ static void tty_driver_remove_tty(struct tty_driver *driver, struct tty_struct *tty) { … } /** * tty_reopen() - fast re-open of an open tty * @tty: the tty to open * * Re-opens on master ptys are not allowed and return -%EIO. * * Locking: Caller must hold tty_lock * Return: 0 on success, -errno on error. */ static int tty_reopen(struct tty_struct *tty) { … } /** * tty_init_dev - initialise a tty device * @driver: tty driver we are opening a device on * @idx: device index * * Prepare a tty device. This may not be a "new" clean device but could also be * an active device. The pty drivers require special handling because of this. * * Locking: * The function is called under the tty_mutex, which protects us from the * tty struct or driver itself going away. * * On exit the tty device has the line discipline attached and a reference * count of 1. If a pair was created for pty/tty use and the other was a pty * master then it too has a reference count of 1. * * WSH 06/09/97: Rewritten to remove races and properly clean up after a failed * open. The new code protects the open with a mutex, so it's really quite * straightforward. The mutex locking can probably be relaxed for the (most * common) case of reopening a tty. * * Return: new tty structure */ struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx) { … } /** * tty_save_termios() - save tty termios data in driver table * @tty: tty whose termios data to save * * Locking: Caller guarantees serialisation with tty_init_termios(). */ void tty_save_termios(struct tty_struct *tty) { … } EXPORT_SYMBOL_GPL(…); /** * tty_flush_works - flush all works of a tty/pty pair * @tty: tty device to flush works for (or either end of a pty pair) * * Sync flush all works belonging to @tty (and the 'other' tty). */ static void tty_flush_works(struct tty_struct *tty) { … } /** * release_one_tty - release tty structure memory * @work: work of tty we are obliterating * * Releases memory associated with a tty structure, and clears out the * driver table slots. This function is called when a device is no longer * in use. It also gets called when setup of a device fails. * * Locking: * takes the file list lock internally when working on the list of ttys * that the driver keeps. * * This method gets called from a work queue so that the driver private * cleanup ops can sleep (needed for USB at least) */ static void release_one_tty(struct work_struct *work) { … } static void queue_release_one_tty(struct kref *kref) { … } /** * tty_kref_put - release a tty kref * @tty: tty device * * Release a reference to the @tty device and if need be let the kref layer * destruct the object for us. */ void tty_kref_put(struct tty_struct *tty) { … } EXPORT_SYMBOL(…); /** * release_tty - release tty structure memory * @tty: tty device release * @idx: index of the tty device release * * Release both @tty and a possible linked partner (think pty pair), * and decrement the refcount of the backing module. * * Locking: * tty_mutex * takes the file list lock internally when working on the list of ttys * that the driver keeps. */ static void release_tty(struct tty_struct *tty, int idx) { … } /** * tty_release_checks - check a tty before real release * @tty: tty to check * @idx: index of the tty * * Performs some paranoid checking before true release of the @tty. This is a * no-op unless %TTY_PARANOIA_CHECK is defined. */ static int tty_release_checks(struct tty_struct *tty, int idx) { … } /** * tty_kclose - closes tty opened by tty_kopen * @tty: tty device * * Performs the final steps to release and free a tty device. It is the same as * tty_release_struct() except that it also resets %TTY_PORT_KOPENED flag on * @tty->port. */ void tty_kclose(struct tty_struct *tty) { … } EXPORT_SYMBOL_GPL(…); /** * tty_release_struct - release a tty struct * @tty: tty device * @idx: index of the tty * * Performs the final steps to release and free a tty device. It is roughly the * reverse of tty_init_dev(). */ void tty_release_struct(struct tty_struct *tty, int idx) { … } EXPORT_SYMBOL_GPL(…); /** * tty_release - vfs callback for close * @inode: inode of tty * @filp: file pointer for handle to tty * * Called the last time each file handle is closed that references this tty. * There may however be several such references. * * Locking: * Takes BKL. See tty_release_dev(). * * Even releasing the tty structures is a tricky business. We have to be very * careful that the structures are all released at the same time, as interrupts * might otherwise get the wrong pointers. * * WSH 09/09/97: rewritten to avoid some nasty race conditions that could * lead to double frees or releasing memory still in use. */ int tty_release(struct inode *inode, struct file *filp) { … } /** * tty_open_current_tty - get locked tty of current task * @device: device number * @filp: file pointer to tty * @return: locked tty of the current task iff @device is /dev/tty * * Performs a re-open of the current task's controlling tty. * * We cannot return driver and index like for the other nodes because devpts * will not work then. It expects inodes to be from devpts FS. */ static struct tty_struct *tty_open_current_tty(dev_t device, struct file *filp) { … } /** * tty_lookup_driver - lookup a tty driver for a given device file * @device: device number * @filp: file pointer to tty * @index: index for the device in the @return driver * * If returned value is not erroneous, the caller is responsible to decrement * the refcount by tty_driver_kref_put(). * * Locking: %tty_mutex protects get_tty_driver() * * Return: driver for this inode (with increased refcount) */ static struct tty_driver *tty_lookup_driver(dev_t device, struct file *filp, int *index) { … } static struct tty_struct *tty_kopen(dev_t device, int shared) { … } /** * tty_kopen_exclusive - open a tty device for kernel * @device: dev_t of device to open * * Opens tty exclusively for kernel. Performs the driver lookup, makes sure * it's not already opened and performs the first-time tty initialization. * * Claims the global %tty_mutex to serialize: * * concurrent first-time tty initialization * * concurrent tty driver removal w/ lookup * * concurrent tty removal from driver table * * Return: the locked initialized &tty_struct */ struct tty_struct *tty_kopen_exclusive(dev_t device) { … } EXPORT_SYMBOL_GPL(…); /** * tty_kopen_shared - open a tty device for shared in-kernel use * @device: dev_t of device to open * * Opens an already existing tty for in-kernel use. Compared to * tty_kopen_exclusive() above it doesn't ensure to be the only user. * * Locking: identical to tty_kopen() above. */ struct tty_struct *tty_kopen_shared(dev_t device) { … } EXPORT_SYMBOL_GPL(…); /** * tty_open_by_driver - open a tty device * @device: dev_t of device to open * @filp: file pointer to tty * * Performs the driver lookup, checks for a reopen, or otherwise performs the * first-time tty initialization. * * * Claims the global tty_mutex to serialize: * * concurrent first-time tty initialization * * concurrent tty driver removal w/ lookup * * concurrent tty removal from driver table * * Return: the locked initialized or re-opened &tty_struct */ static struct tty_struct *tty_open_by_driver(dev_t device, struct file *filp) { … } /** * tty_open - open a tty device * @inode: inode of device file * @filp: file pointer to tty * * tty_open() and tty_release() keep up the tty count that contains the number * of opens done on a tty. We cannot use the inode-count, as different inodes * might point to the same tty. * * Open-counting is needed for pty masters, as well as for keeping track of * serial lines: DTR is dropped when the last close happens. * (This is not done solely through tty->count, now. - Ted 1/27/92) * * The termios state of a pty is reset on the first open so that settings don't * persist across reuse. * * Locking: * * %tty_mutex protects tty, tty_lookup_driver() and tty_init_dev(). * * @tty->count should protect the rest. * * ->siglock protects ->signal/->sighand * * Note: the tty_unlock/lock cases without a ref are only safe due to %tty_mutex */ static int tty_open(struct inode *inode, struct file *filp) { … } /** * tty_poll - check tty status * @filp: file being polled * @wait: poll wait structures to update * * Call the line discipline polling method to obtain the poll status of the * device. * * Locking: locks called line discipline but ldisc poll method may be * re-entered freely by other callers. */ static __poll_t tty_poll(struct file *filp, poll_table *wait) { … } static int __tty_fasync(int fd, struct file *filp, int on) { … } static int tty_fasync(int fd, struct file *filp, int on) { … } static bool tty_legacy_tiocsti __read_mostly = … IS_ENABLED(…); /** * tiocsti - fake input character * @tty: tty to fake input into * @p: pointer to character * * Fake input to a tty device. Does the necessary locking and input management. * * FIXME: does not honour flow control ?? * * Locking: * * Called functions take tty_ldiscs_lock * * current->signal->tty check is safe without locks */ static int tiocsti(struct tty_struct *tty, u8 __user *p) { … } /** * tiocgwinsz - implement window query ioctl * @tty: tty * @arg: user buffer for result * * Copies the kernel idea of the window size into the user buffer. * * Locking: @tty->winsize_mutex is taken to ensure the winsize data is * consistent. */ static int tiocgwinsz(struct tty_struct *tty, struct winsize __user *arg) { … } /** * tty_do_resize - resize event * @tty: tty being resized * @ws: new dimensions * * Update the termios variables and send the necessary signals to peform a * terminal resize correctly. */ int tty_do_resize(struct tty_struct *tty, struct winsize *ws) { … } EXPORT_SYMBOL(…); /** * tiocswinsz - implement window size set ioctl * @tty: tty side of tty * @arg: user buffer for result * * Copies the user idea of the window size to the kernel. Traditionally this is * just advisory information but for the Linux console it actually has driver * level meaning and triggers a VC resize. * * Locking: * Driver dependent. The default do_resize method takes the tty termios * mutex and ctrl.lock. The console takes its own lock then calls into the * default method. */ static int tiocswinsz(struct tty_struct *tty, struct winsize __user *arg) { … } /** * tioccons - allow admin to move logical console * @file: the file to become console * * Allow the administrator to move the redirected console device. * * Locking: uses redirect_lock to guard the redirect information */ static int tioccons(struct file *file) { … } /** * tiocsetd - set line discipline * @tty: tty device * @p: pointer to user data * * Set the line discipline according to user request. * * Locking: see tty_set_ldisc(), this function is just a helper */ static int tiocsetd(struct tty_struct *tty, int __user *p) { … } /** * tiocgetd - get line discipline * @tty: tty device * @p: pointer to user data * * Retrieves the line discipline id directly from the ldisc. * * Locking: waits for ldisc reference (in case the line discipline is changing * or the @tty is being hungup) */ static int tiocgetd(struct tty_struct *tty, int __user *p) { … } /** * send_break - performed time break * @tty: device to break on * @duration: timeout in mS * * Perform a timed break on hardware that lacks its own driver level timed * break functionality. * * Locking: * @tty->atomic_write_lock serializes */ static int send_break(struct tty_struct *tty, unsigned int duration) { … } /** * tty_get_tiocm - get tiocm status register * @tty: tty device * * Obtain the modem status bits from the tty driver if the feature * is supported. */ int tty_get_tiocm(struct tty_struct *tty) { … } EXPORT_SYMBOL_GPL(…); /** * tty_tiocmget - get modem status * @tty: tty device * @p: pointer to result * * Obtain the modem status bits from the tty driver if the feature is * supported. Return -%ENOTTY if it is not available. * * Locking: none (up to the driver) */ static int tty_tiocmget(struct tty_struct *tty, int __user *p) { … } /** * tty_tiocmset - set modem status * @tty: tty device * @cmd: command - clear bits, set bits or set all * @p: pointer to desired bits * * Set the modem status bits from the tty driver if the feature * is supported. Return -%ENOTTY if it is not available. * * Locking: none (up to the driver) */ static int tty_tiocmset(struct tty_struct *tty, unsigned int cmd, unsigned __user *p) { … } /** * tty_get_icount - get tty statistics * @tty: tty device * @icount: output parameter * * Gets a copy of the @tty's icount statistics. * * Locking: none (up to the driver) */ int tty_get_icount(struct tty_struct *tty, struct serial_icounter_struct *icount) { … } EXPORT_SYMBOL_GPL(…); static int tty_tiocgicount(struct tty_struct *tty, void __user *arg) { … } static int tty_set_serial(struct tty_struct *tty, struct serial_struct *ss) { … } static int tty_tiocsserial(struct tty_struct *tty, struct serial_struct __user *ss) { … } static int tty_tiocgserial(struct tty_struct *tty, struct serial_struct __user *ss) { … } /* * if pty, return the slave side (real_tty) * otherwise, return self */ static struct tty_struct *tty_pair_get_tty(struct tty_struct *tty) { … } /* * Split this up, as gcc can choke on it otherwise.. */ long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { … } #ifdef CONFIG_COMPAT struct serial_struct32 { … }; static int compat_tty_tiocsserial(struct tty_struct *tty, struct serial_struct32 __user *ss) { … } static int compat_tty_tiocgserial(struct tty_struct *tty, struct serial_struct32 __user *ss) { … } static long tty_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { … } #endif static int this_tty(const void *t, struct file *file, unsigned fd) { … } /* * This implements the "Secure Attention Key" --- the idea is to * prevent trojan horses by killing all processes associated with this * tty when the user hits the "Secure Attention Key". Required for * super-paranoid applications --- see the Orange Book for more details. * * This code could be nicer; ideally it should send a HUP, wait a few * seconds, then send a INT, and then a KILL signal. But you then * have to coordinate with the init process, since all processes associated * with the current tty must be dead before the new getty is allowed * to spawn. * * Now, if it would be correct ;-/ The current code has a nasty hole - * it doesn't catch files in flight. We may send the descriptor to ourselves * via AF_UNIX socket, close it and later fetch from socket. FIXME. * * Nasty bug: do_SAK is being called in interrupt context. This can * deadlock. We punt it up to process context. AKPM - 16Mar2001 */ void __do_SAK(struct tty_struct *tty) { … } static void do_SAK_work(struct work_struct *work) { … } /* * The tq handling here is a little racy - tty->SAK_work may already be queued. * Fortunately we don't need to worry, because if ->SAK_work is already queued, * the values which we write to it will be identical to the values which it * already has. --akpm */ void do_SAK(struct tty_struct *tty) { … } EXPORT_SYMBOL(…); /* Must put_device() after it's unused! */ static struct device *tty_get_device(struct tty_struct *tty) { … } /** * alloc_tty_struct - allocate a new tty * @driver: driver which will handle the returned tty * @idx: minor of the tty * * This subroutine allocates and initializes a tty structure. * * Locking: none - @tty in question is not exposed at this point */ struct tty_struct *alloc_tty_struct(struct tty_driver *driver, int idx) { … } /** * tty_put_char - write one character to a tty * @tty: tty * @ch: character to write * * Write one byte to the @tty using the provided @tty->ops->put_char() method * if present. * * Note: the specific put_char operation in the driver layer may go * away soon. Don't call it directly, use this method * * Return: the number of characters successfully output. */ int tty_put_char(struct tty_struct *tty, u8 ch) { … } EXPORT_SYMBOL_GPL(…); static int tty_cdev_add(struct tty_driver *driver, dev_t dev, unsigned int index, unsigned int count) { … } /** * tty_register_device - register a tty device * @driver: the tty driver that describes the tty device * @index: the index in the tty driver for this tty device * @device: a struct device that is associated with this tty device. * This field is optional, if there is no known struct device * for this tty device it can be set to NULL safely. * * This call is required to be made to register an individual tty device * if the tty driver's flags have the %TTY_DRIVER_DYNAMIC_DEV bit set. If * that bit is not set, this function should not be called by a tty * driver. * * Locking: ?? * * Return: A pointer to the struct device for this tty device (or * ERR_PTR(-EFOO) on error). */ struct device *tty_register_device(struct tty_driver *driver, unsigned index, struct device *device) { … } EXPORT_SYMBOL(…); static void tty_device_create_release(struct device *dev) { … } /** * tty_register_device_attr - register a tty device * @driver: the tty driver that describes the tty device * @index: the index in the tty driver for this tty device * @device: a struct device that is associated with this tty device. * This field is optional, if there is no known struct device * for this tty device it can be set to %NULL safely. * @drvdata: Driver data to be set to device. * @attr_grp: Attribute group to be set on device. * * This call is required to be made to register an individual tty device if the * tty driver's flags have the %TTY_DRIVER_DYNAMIC_DEV bit set. If that bit is * not set, this function should not be called by a tty driver. * * Locking: ?? * * Return: A pointer to the struct device for this tty device (or * ERR_PTR(-EFOO) on error). */ struct device *tty_register_device_attr(struct tty_driver *driver, unsigned index, struct device *device, void *drvdata, const struct attribute_group **attr_grp) { … } EXPORT_SYMBOL_GPL(…); /** * tty_unregister_device - unregister a tty device * @driver: the tty driver that describes the tty device * @index: the index in the tty driver for this tty device * * If a tty device is registered with a call to tty_register_device() then * this function must be called when the tty device is gone. * * Locking: ?? */ void tty_unregister_device(struct tty_driver *driver, unsigned index) { … } EXPORT_SYMBOL(…); /** * __tty_alloc_driver - allocate tty driver * @lines: count of lines this driver can handle at most * @owner: module which is responsible for this driver * @flags: some of %TTY_DRIVER_ flags, will be set in driver->flags * * This should not be called directly, some of the provided macros should be * used instead. Use IS_ERR() and friends on @retval. */ struct tty_driver *__tty_alloc_driver(unsigned int lines, struct module *owner, unsigned long flags) { … } EXPORT_SYMBOL(…); static void destruct_tty_driver(struct kref *kref) { … } /** * tty_driver_kref_put - drop a reference to a tty driver * @driver: driver of which to drop the reference * * The final put will destroy and free up the driver. */ void tty_driver_kref_put(struct tty_driver *driver) { … } EXPORT_SYMBOL(…); /** * tty_register_driver - register a tty driver * @driver: driver to register * * Called by a tty driver to register itself. */ int tty_register_driver(struct tty_driver *driver) { … } EXPORT_SYMBOL(…); /** * tty_unregister_driver - unregister a tty driver * @driver: driver to unregister * * Called by a tty driver to unregister itself. */ void tty_unregister_driver(struct tty_driver *driver) { … } EXPORT_SYMBOL(…); dev_t tty_devnum(struct tty_struct *tty) { … } EXPORT_SYMBOL(…); void tty_default_fops(struct file_operations *fops) { … } static char *tty_devnode(const struct device *dev, umode_t *mode) { … } const struct class tty_class = …; static int __init tty_class_init(void) { … } postcore_initcall(tty_class_init); /* 3/2004 jmc: why do these devices exist? */ static struct cdev tty_cdev, console_cdev; static ssize_t show_cons_active(struct device *dev, struct device_attribute *attr, char *buf) { … } static DEVICE_ATTR(active, S_IRUGO, show_cons_active, NULL); static struct attribute *cons_dev_attrs[] = …; ATTRIBUTE_GROUPS(…); static struct device *consdev; void console_sysfs_notify(void) { … } static struct ctl_table tty_table[] = …; /* * Ok, now we can initialize the rest of the tty devices and can count * on memory allocations, interrupts etc.. */ int __init tty_init(void) { … }
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