xref: /kernel/linux/linux-5.10/drivers/tty/tty.h (revision 8c2ecf20)
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_info(tty, f, ...)	tty_msg(pr_info, tty, f, ##__VA_ARGS__)
14#define tty_notice(tty, f, ...)	tty_msg(pr_notice, tty, f, ##__VA_ARGS__)
15#define tty_warn(tty, f, ...)	tty_msg(pr_warn, tty, f, ##__VA_ARGS__)
16#define tty_err(tty, f, ...)	tty_msg(pr_err, tty, f, ##__VA_ARGS__)
17
18#define tty_info_ratelimited(tty, f, ...) \
19		tty_msg(pr_info_ratelimited, tty, f, ##__VA_ARGS__)
20
21/*
22 * Lock subclasses for tty locks
23 *
24 * TTY_LOCK_NORMAL is for normal ttys and master ptys.
25 * TTY_LOCK_SLAVE is for slave ptys only.
26 *
27 * Lock subclasses are necessary for handling nested locking with pty pairs.
28 * tty locks which use nested locking:
29 *
30 * legacy_mutex - Nested tty locks are necessary for releasing pty pairs.
31 *		  The stable lock order is master pty first, then slave pty.
32 * termios_rwsem - The stable lock order is tty_buffer lock->termios_rwsem.
33 *		   Subclassing this lock enables the slave pty to hold its
34 *		   termios_rwsem when claiming the master tty_buffer lock.
35 * tty_buffer lock - slave ptys can claim nested buffer lock when handling
36 *		     signal chars. The stable lock order is slave pty, then
37 *		     master.
38 */
39enum {
40	TTY_LOCK_NORMAL = 0,
41	TTY_LOCK_SLAVE,
42};
43
44/* Values for tty->flow_change */
45#define TTY_THROTTLE_SAFE	1
46#define TTY_UNTHROTTLE_SAFE	2
47
48static inline void __tty_set_flow_change(struct tty_struct *tty, int val)
49{
50	tty->flow_change = val;
51}
52
53static inline void tty_set_flow_change(struct tty_struct *tty, int val)
54{
55	tty->flow_change = val;
56	smp_mb();
57}
58
59int tty_ldisc_lock(struct tty_struct *tty, unsigned long timeout);
60void tty_ldisc_unlock(struct tty_struct *tty);
61
62int __tty_check_change(struct tty_struct *tty, int sig);
63int tty_check_change(struct tty_struct *tty);
64void __stop_tty(struct tty_struct *tty);
65void __start_tty(struct tty_struct *tty);
66void tty_write_unlock(struct tty_struct *tty);
67int tty_write_lock(struct tty_struct *tty, bool ndelay);
68void tty_vhangup_session(struct tty_struct *tty);
69void tty_open_proc_set_tty(struct file *filp, struct tty_struct *tty);
70int tty_signal_session_leader(struct tty_struct *tty, int exit_session);
71void session_clear_tty(struct pid *session);
72void tty_buffer_free_all(struct tty_port *port);
73void tty_buffer_flush(struct tty_struct *tty, struct tty_ldisc *ld);
74void tty_buffer_init(struct tty_port *port);
75void tty_buffer_set_lock_subclass(struct tty_port *port);
76bool tty_buffer_restart_work(struct tty_port *port);
77bool tty_buffer_cancel_work(struct tty_port *port);
78void tty_buffer_flush_work(struct tty_port *port);
79speed_t tty_termios_input_baud_rate(struct ktermios *termios);
80void tty_ldisc_hangup(struct tty_struct *tty, bool reset);
81int tty_ldisc_reinit(struct tty_struct *tty, int disc);
82long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
83long tty_jobctrl_ioctl(struct tty_struct *tty, struct tty_struct *real_tty,
84		       struct file *file, unsigned int cmd, unsigned long arg);
85void tty_default_fops(struct file_operations *fops);
86struct tty_struct *alloc_tty_struct(struct tty_driver *driver, int idx);
87int tty_alloc_file(struct file *file);
88void tty_add_file(struct tty_struct *tty, struct file *file);
89void tty_free_file(struct file *file);
90int tty_release(struct inode *inode, struct file *filp);
91
92#define tty_is_writelocked(tty)  (mutex_is_locked(&tty->atomic_write_lock))
93
94int tty_ldisc_setup(struct tty_struct *tty, struct tty_struct *o_tty);
95void tty_ldisc_release(struct tty_struct *tty);
96int __must_check tty_ldisc_init(struct tty_struct *tty);
97void tty_ldisc_deinit(struct tty_struct *tty);
98
99void tty_sysctl_init(void);
100
101/* tty_audit.c */
102#ifdef CONFIG_AUDIT
103void tty_audit_add_data(struct tty_struct *tty, const void *data, size_t size);
104void tty_audit_tiocsti(struct tty_struct *tty, char ch);
105#else
106static inline void tty_audit_add_data(struct tty_struct *tty, const void *data,
107				      size_t size)
108{
109}
110static inline void tty_audit_tiocsti(struct tty_struct *tty, char ch)
111{
112}
113#endif
114
115ssize_t redirected_tty_write(struct kiocb *, struct iov_iter *);
116
117#endif
118