| 1 | |
| 2 | #include <linux/tty.h>
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| 3 | #include <linux/module.h>
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| 4 | #include <linux/kallsyms.h>
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| 5 | #include <linux/semaphore.h>
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| 6 | #include <linux/sched.h>
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| 7 | #include "tty.h"
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| 8 |
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| 9 |
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| 10 |
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| 11 | |
| 12 | * Getting the big tty mutex.
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| 13 |
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| 14 |
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| 15 | void tty_lock(struct tty_struct *tty)
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| 16 | {
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| 17 | tty_kref_get(tty);
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| 18 | mutex_lock(&tty->legacy_mutex);
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| 19 | }
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| 20 | EXPORT_SYMBOL(tty_lock);
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| 21 |
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| 22 | int tty_lock_interruptible(struct tty_struct *tty)
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| 23 | {
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| 24 | int ret;
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| 25 |
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| 26 | tty_kref_get(tty);
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| 27 | ret = mutex_lock_interruptible(&tty->legacy_mutex);
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| 28 | if (ret)
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| 29 | tty_kref_put(tty);
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| 30 | return ret;
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| 31 | }
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| 32 |
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| 33 | void tty_unlock(struct tty_struct *tty)
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| 34 | {
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| 35 | mutex_unlock(&tty->legacy_mutex);
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| 36 | tty_kref_put(tty);
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| 37 | }
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| 38 | EXPORT_SYMBOL(tty_unlock);
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| 39 |
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| 40 | void tty_lock_slave(struct tty_struct *tty)
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| 41 | {
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| 42 | if (tty && tty != tty->link)
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| 43 | tty_lock(tty);
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| 44 | }
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| 45 |
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| 46 | void tty_unlock_slave(struct tty_struct *tty)
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| 47 | {
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| 48 | if (tty && tty != tty->link)
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| 49 | tty_unlock(tty);
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| 50 | }
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| 51 |
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| 52 | void tty_set_lock_subclass(struct tty_struct *tty)
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| 53 | {
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| 54 | lockdep_set_subclass(&tty->legacy_mutex, TTY_LOCK_SLAVE);
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| 55 | }
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