Commit | Line | Data |
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b07471fa AB |
1 | #include <linux/tty.h> |
2 | #include <linux/module.h> | |
3 | #include <linux/kallsyms.h> | |
4 | #include <linux/semaphore.h> | |
5 | #include <linux/sched.h> | |
6 | ||
89c8d91e AC |
7 | /* Legacy tty mutex glue */ |
8 | ||
9 | enum { | |
10 | TTY_MUTEX_NORMAL, | |
11 | TTY_MUTEX_NESTED, | |
12 | }; | |
fde86d31 | 13 | |
b07471fa AB |
14 | /* |
15 | * Getting the big tty mutex. | |
16 | */ | |
89c8d91e AC |
17 | |
18 | static void __lockfunc tty_lock_nested(struct tty_struct *tty, | |
19 | unsigned int subclass) | |
b07471fa | 20 | { |
89c8d91e | 21 | if (tty->magic != TTY_MAGIC) { |
7a0c4eda | 22 | pr_err("L Bad %p\n", tty); |
89c8d91e AC |
23 | WARN_ON(1); |
24 | return; | |
25 | } | |
26 | tty_kref_get(tty); | |
27 | mutex_lock_nested(&tty->legacy_mutex, subclass); | |
28 | } | |
29 | ||
30 | void __lockfunc tty_lock(struct tty_struct *tty) | |
31 | { | |
32 | return tty_lock_nested(tty, TTY_MUTEX_NORMAL); | |
b07471fa AB |
33 | } |
34 | EXPORT_SYMBOL(tty_lock); | |
35 | ||
89c8d91e | 36 | void __lockfunc tty_unlock(struct tty_struct *tty) |
b07471fa | 37 | { |
89c8d91e | 38 | if (tty->magic != TTY_MAGIC) { |
7a0c4eda | 39 | pr_err("U Bad %p\n", tty); |
89c8d91e AC |
40 | WARN_ON(1); |
41 | return; | |
42 | } | |
43 | mutex_unlock(&tty->legacy_mutex); | |
44 | tty_kref_put(tty); | |
b07471fa AB |
45 | } |
46 | EXPORT_SYMBOL(tty_unlock); | |
89c8d91e AC |
47 | |
48 | /* | |
49 | * Getting the big tty mutex for a pair of ttys with lock ordering | |
50 | * On a non pty/tty pair tty2 can be NULL which is just fine. | |
51 | */ | |
52 | void __lockfunc tty_lock_pair(struct tty_struct *tty, | |
53 | struct tty_struct *tty2) | |
54 | { | |
55 | if (tty < tty2) { | |
56 | tty_lock(tty); | |
57 | tty_lock_nested(tty2, TTY_MUTEX_NESTED); | |
58 | } else { | |
59 | if (tty2 && tty2 != tty) | |
60 | tty_lock(tty2); | |
61 | tty_lock_nested(tty, TTY_MUTEX_NESTED); | |
62 | } | |
63 | } | |
64 | EXPORT_SYMBOL(tty_lock_pair); | |
65 | ||
66 | void __lockfunc tty_unlock_pair(struct tty_struct *tty, | |
67 | struct tty_struct *tty2) | |
68 | { | |
69 | tty_unlock(tty); | |
70 | if (tty2 && tty2 != tty) | |
71 | tty_unlock(tty2); | |
72 | } | |
73 | EXPORT_SYMBOL(tty_unlock_pair); |