1/* SPDX-License-Identifier: GPL-2.0 */
  2/*
  3 * TTY core internal functions
  4 */
  5
  6#ifndef _TTY_INTERNAL_H
  7#define _TTY_INTERNAL_H
  8
  9#define tty_msg(fn, tty, f, ...) \
 10	fn("%s %s: " f, tty_driver_name(tty), tty_name(tty), ##__VA_ARGS__)
 11
 12#define tty_debug(tty, f, ...)	tty_msg(pr_debug, tty, f, ##__VA_ARGS__)
 13#define tty_notice(tty, f, ...)	tty_msg(pr_notice, tty, f, ##__VA_ARGS__)
 14#define tty_warn(tty, f, ...)	tty_msg(pr_warn, tty, f, ##__VA_ARGS__)
 15#define tty_err(tty, f, ...)	tty_msg(pr_err, tty, f, ##__VA_ARGS__)
 16
 17#define tty_info_ratelimited(tty, f, ...) \
 18		tty_msg(pr_info_ratelimited, tty, f, ##__VA_ARGS__)
 19
 20/*
 21 * Lock subclasses for tty locks
 22 *
 23 * TTY_LOCK_NORMAL is for normal ttys and master ptys.
 24 * TTY_LOCK_SLAVE is for slave ptys only.
 25 *
 26 * Lock subclasses are necessary for handling nested locking with pty pairs.
 27 * tty locks which use nested locking:
 28 *
 29 * legacy_mutex - Nested tty locks are necessary for releasing pty pairs.
 30 *		  The stable lock order is master pty first, then slave pty.
 31 * termios_rwsem - The stable lock order is tty_buffer lock->termios_rwsem.
 32 *		   Subclassing this lock enables the slave pty to hold its
 33 *		   termios_rwsem when claiming the master tty_buffer lock.
 34 * tty_buffer lock - slave ptys can claim nested buffer lock when handling
 35 *		     signal chars. The stable lock order is slave pty, then
 36 *		     master.
 37 */
 38enum {
 39	TTY_LOCK_NORMAL = 0,
 40	TTY_LOCK_SLAVE,
 41};
 42
 43/* Values for tty->flow_change */
 44#define TTY_THROTTLE_SAFE	1
 45#define TTY_UNTHROTTLE_SAFE	2
 46
 47static inline void __tty_set_flow_change(struct tty_struct *tty, int val)
 48{
 49	tty->flow_change = val;
 50}
 51
 52static inline void tty_set_flow_change(struct tty_struct *tty, int val)
 53{
 54	tty->flow_change = val;
 55	smp_mb();
 56}
 57
 58int tty_ldisc_lock(struct tty_struct *tty, unsigned long timeout);
 59void tty_ldisc_unlock(struct tty_struct *tty);
 60
 61int __tty_check_change(struct tty_struct *tty, int sig);
 62int tty_check_change(struct tty_struct *tty);
 63void __stop_tty(struct tty_struct *tty);
 64void __start_tty(struct tty_struct *tty);
 65void tty_vhangup_session(struct tty_struct *tty);
 66void tty_open_proc_set_tty(struct file *filp, struct tty_struct *tty);
 67int tty_signal_session_leader(struct tty_struct *tty, int exit_session);
 68void session_clear_tty(struct pid *session);
 69void tty_buffer_free_all(struct tty_port *port);
 70void tty_buffer_flush(struct tty_struct *tty, struct tty_ldisc *ld);
 71void tty_buffer_init(struct tty_port *port);
 72void tty_buffer_set_lock_subclass(struct tty_port *port);
 73bool tty_buffer_restart_work(struct tty_port *port);
 74bool tty_buffer_cancel_work(struct tty_port *port);
 75void tty_buffer_flush_work(struct tty_port *port);
 76speed_t tty_termios_input_baud_rate(struct ktermios *termios);
 77void tty_ldisc_hangup(struct tty_struct *tty, bool reset);
 78int tty_ldisc_reinit(struct tty_struct *tty, int disc);
 79long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
 80long tty_jobctrl_ioctl(struct tty_struct *tty, struct tty_struct *real_tty,
 81		       struct file *file, unsigned int cmd, unsigned long arg);
 82void tty_default_fops(struct file_operations *fops);
 83struct tty_struct *alloc_tty_struct(struct tty_driver *driver, int idx);
 84int tty_alloc_file(struct file *file);
 85void tty_add_file(struct tty_struct *tty, struct file *file);
 86void tty_free_file(struct file *file);
 87int tty_release(struct inode *inode, struct file *filp);
 88
 89#define tty_is_writelocked(tty)  (mutex_is_locked(&tty->atomic_write_lock))
 90
 91int tty_ldisc_setup(struct tty_struct *tty, struct tty_struct *o_tty);
 92void tty_ldisc_release(struct tty_struct *tty);
 93int __must_check tty_ldisc_init(struct tty_struct *tty);
 94void tty_ldisc_deinit(struct tty_struct *tty);
 95
 96void tty_sysctl_init(void);
 97
 98/* tty_audit.c */
 99#ifdef CONFIG_AUDIT
100void tty_audit_add_data(struct tty_struct *tty, const void *data, size_t size);
101void tty_audit_tiocsti(struct tty_struct *tty, char ch);
102#else
103static inline void tty_audit_add_data(struct tty_struct *tty, const void *data,
104				      size_t size)
105{
106}
107static inline void tty_audit_tiocsti(struct tty_struct *tty, char ch)
108{
109}
110#endif
111
112ssize_t redirected_tty_write(struct kiocb *, struct iov_iter *);
113
114#endif