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 */
38 enum {
39 TTY_LOCK_NORMAL = 0,
40 TTY_LOCK_SLAVE,
41 };
42
43 /* Values for tty->flow_change */
44 enum tty_flow_change {
45 TTY_FLOW_NO_CHANGE,
46 TTY_THROTTLE_SAFE,
47 TTY_UNTHROTTLE_SAFE,
48 };
49
__tty_set_flow_change(struct tty_struct * tty,enum tty_flow_change val)50 static inline void __tty_set_flow_change(struct tty_struct *tty,
51 enum tty_flow_change val)
52 {
53 tty->flow_change = val;
54 }
55
tty_set_flow_change(struct tty_struct * tty,enum tty_flow_change val)56 static inline void tty_set_flow_change(struct tty_struct *tty,
57 enum tty_flow_change val)
58 {
59 tty->flow_change = val;
60 smp_mb();
61 }
62
63 int tty_ldisc_lock(struct tty_struct *tty, unsigned long timeout);
64 void tty_ldisc_unlock(struct tty_struct *tty);
65
66 int __tty_check_change(struct tty_struct *tty, int sig);
67 int tty_check_change(struct tty_struct *tty);
68 void __stop_tty(struct tty_struct *tty);
69 void __start_tty(struct tty_struct *tty);
70 void tty_write_unlock(struct tty_struct *tty);
71 int tty_write_lock(struct tty_struct *tty, bool ndelay);
72 void tty_vhangup_session(struct tty_struct *tty);
73 void tty_open_proc_set_tty(struct file *filp, struct tty_struct *tty);
74 int tty_signal_session_leader(struct tty_struct *tty, int exit_session);
75 void session_clear_tty(struct pid *session);
76 void tty_buffer_free_all(struct tty_port *port);
77 void tty_buffer_flush(struct tty_struct *tty, struct tty_ldisc *ld);
78 void tty_buffer_init(struct tty_port *port);
79 void tty_buffer_set_lock_subclass(struct tty_port *port);
80 bool tty_buffer_restart_work(struct tty_port *port);
81 bool tty_buffer_cancel_work(struct tty_port *port);
82 void tty_buffer_flush_work(struct tty_port *port);
83 speed_t tty_termios_input_baud_rate(const struct ktermios *termios);
84 void tty_ldisc_hangup(struct tty_struct *tty, bool reset);
85 int tty_ldisc_reinit(struct tty_struct *tty, int disc);
86 long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
87 long tty_jobctrl_ioctl(struct tty_struct *tty, struct tty_struct *real_tty,
88 struct file *file, unsigned int cmd, unsigned long arg);
89 void tty_default_fops(struct file_operations *fops);
90 struct tty_struct *alloc_tty_struct(struct tty_driver *driver, int idx);
91 int tty_alloc_file(struct file *file);
92 void tty_add_file(struct tty_struct *tty, struct file *file);
93 void tty_free_file(struct file *file);
94 int tty_release(struct inode *inode, struct file *filp);
95
96 #define tty_is_writelocked(tty) (mutex_is_locked(&tty->atomic_write_lock))
97
98 int tty_ldisc_setup(struct tty_struct *tty, struct tty_struct *o_tty);
99 void tty_ldisc_release(struct tty_struct *tty);
100 int __must_check tty_ldisc_init(struct tty_struct *tty);
101 void tty_ldisc_deinit(struct tty_struct *tty);
102
103 extern int tty_ldisc_autoload;
104
105 /* tty_audit.c */
106 #ifdef CONFIG_AUDIT
107 void tty_audit_add_data(const struct tty_struct *tty, const void *data,
108 size_t size);
109 void tty_audit_tiocsti(const struct tty_struct *tty, u8 ch);
110 #else
tty_audit_add_data(const struct tty_struct * tty,const void * data,size_t size)111 static inline void tty_audit_add_data(const struct tty_struct *tty,
112 const void *data, size_t size)
113 {
114 }
tty_audit_tiocsti(const struct tty_struct * tty,u8 ch)115 static inline void tty_audit_tiocsti(const struct tty_struct *tty, u8 ch)
116 {
117 }
118 #endif
119
120 ssize_t redirected_tty_write(struct kiocb *, struct iov_iter *);
121
122 int tty_insert_flip_string_and_push_buffer(struct tty_port *port,
123 const u8 *chars, size_t cnt);
124
125 #endif
126