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 #define TTY_THROTTLE_SAFE 1
45 #define TTY_UNTHROTTLE_SAFE 2
46
__tty_set_flow_change(struct tty_struct * tty,int val)47 static inline void __tty_set_flow_change(struct tty_struct *tty, int val)
48 {
49 tty->flow_change = val;
50 }
51
tty_set_flow_change(struct tty_struct * tty,int val)52 static inline void tty_set_flow_change(struct tty_struct *tty, int val)
53 {
54 tty->flow_change = val;
55 smp_mb();
56 }
57
58 int tty_ldisc_lock(struct tty_struct *tty, unsigned long timeout);
59 void tty_ldisc_unlock(struct tty_struct *tty);
60
61 int __tty_check_change(struct tty_struct *tty, int sig);
62 int tty_check_change(struct tty_struct *tty);
63 void __stop_tty(struct tty_struct *tty);
64 void __start_tty(struct tty_struct *tty);
65 void tty_write_unlock(struct tty_struct *tty);
66 int tty_write_lock(struct tty_struct *tty, bool ndelay);
67 void tty_vhangup_session(struct tty_struct *tty);
68 void tty_open_proc_set_tty(struct file *filp, struct tty_struct *tty);
69 int tty_signal_session_leader(struct tty_struct *tty, int exit_session);
70 void session_clear_tty(struct pid *session);
71 void tty_buffer_free_all(struct tty_port *port);
72 void tty_buffer_flush(struct tty_struct *tty, struct tty_ldisc *ld);
73 void tty_buffer_init(struct tty_port *port);
74 void tty_buffer_set_lock_subclass(struct tty_port *port);
75 bool tty_buffer_restart_work(struct tty_port *port);
76 bool tty_buffer_cancel_work(struct tty_port *port);
77 void tty_buffer_flush_work(struct tty_port *port);
78 speed_t tty_termios_input_baud_rate(struct ktermios *termios);
79 void tty_ldisc_hangup(struct tty_struct *tty, bool reset);
80 int tty_ldisc_reinit(struct tty_struct *tty, int disc);
81 long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
82 long tty_jobctrl_ioctl(struct tty_struct *tty, struct tty_struct *real_tty,
83 struct file *file, unsigned int cmd, unsigned long arg);
84 void tty_default_fops(struct file_operations *fops);
85 struct tty_struct *alloc_tty_struct(struct tty_driver *driver, int idx);
86 int tty_alloc_file(struct file *file);
87 void tty_add_file(struct tty_struct *tty, struct file *file);
88 void tty_free_file(struct file *file);
89 int tty_release(struct inode *inode, struct file *filp);
90
91 #define tty_is_writelocked(tty) (mutex_is_locked(&tty->atomic_write_lock))
92
93 int tty_ldisc_setup(struct tty_struct *tty, struct tty_struct *o_tty);
94 void tty_ldisc_release(struct tty_struct *tty);
95 int __must_check tty_ldisc_init(struct tty_struct *tty);
96 void tty_ldisc_deinit(struct tty_struct *tty);
97
98 void tty_sysctl_init(void);
99
100 /* tty_audit.c */
101 #ifdef CONFIG_AUDIT
102 void tty_audit_add_data(struct tty_struct *tty, const void *data, size_t size);
103 void tty_audit_tiocsti(struct tty_struct *tty, char ch);
104 #else
tty_audit_add_data(struct tty_struct * tty,const void * data,size_t size)105 static inline void tty_audit_add_data(struct tty_struct *tty, const void *data,
106 size_t size)
107 {
108 }
tty_audit_tiocsti(struct tty_struct * tty,char ch)109 static inline void tty_audit_tiocsti(struct tty_struct *tty, char ch)
110 {
111 }
112 #endif
113
114 ssize_t redirected_tty_write(struct kiocb *, struct iov_iter *);
115
116 int tty_insert_flip_string_and_push_buffer(struct tty_port *port,
117 const unsigned char *chars, size_t cnt);
118
119 #endif
120