| | 1 | // SPDX-License-Identifier: GPL-2.0 |
| | 2 | #include <linux/tty.h> |
| | 3 | #include <linux/module.h> |
| | 4 | #include <linux/kallsyms.h> |
| | 5 | #include <linux/semaphore.h> |
| | 6 | #include <linux/sched.h> |
| | 7 | |
| | 8 | /* Legacy tty mutex glue */ |
| | 9 | |
| | 10 | /* |
| | 11 | * Getting the big tty mutex. |
| | 12 | */ |
| | 13 | |
| | 14 | void tty_lock(struct tty_struct *tty) |
| | 15 | { |
| | 16 | if (WARN(tty->magic != TTY_MAGIC, "L Bad %p\n", tty)) |
| | 17 | return; |
| | 18 | tty_kref_get(tty); |
| | 19 | mutex_lock(&tty->legacy_mutex); |
| | 20 | } |
| | 21 | EXPORT_SYMBOL(tty_lock); |
| | 22 | |
| | 23 | int tty_lock_interruptible(struct tty_struct *tty) |
| | 24 | { |
| | 25 | int ret; |
| | 26 | |
| | 27 | if (WARN(tty->magic != TTY_MAGIC, "L Bad %p\n", tty)) |
| | 28 | return -EIO; |
| | 29 | tty_kref_get(tty); |
| | 30 | ret = mutex_lock_interruptible(&tty->legacy_mutex); |
| | 31 | if (ret) |
| | 32 | tty_kref_put(tty); |
| | 33 | return ret; |
| | 34 | } |
| | 35 | |
| | 36 | void tty_unlock(struct tty_struct *tty) |
| | 37 | { |
| | 38 | if (WARN(tty->magic != TTY_MAGIC, "U Bad %p\n", tty)) |
| | 39 | return; |
| | 40 | mutex_unlock(&tty->legacy_mutex); |
| | 41 | tty_kref_put(tty); |
| | 42 | } |
| | 43 | EXPORT_SYMBOL(tty_unlock); |
| | 44 | |
| | 45 | void tty_lock_slave(struct tty_struct *tty) |
| | 46 | { |
| | 47 | if (tty && tty != tty->link) |
| | 48 | tty_lock(tty); |
| | 49 | } |
| | 50 | |
| | 51 | void tty_unlock_slave(struct tty_struct *tty) |
| | 52 | { |
| | 53 | if (tty && tty != tty->link) |
| | 54 | tty_unlock(tty); |
| | 55 | } |
| | 56 | |
| | 57 | void tty_set_lock_subclass(struct tty_struct *tty) |
| | 58 | { |
| | 59 | lockdep_set_subclass(&tty->legacy_mutex, TTY_LOCK_SLAVE); |
| | 60 | } |
projects / mirror_ubuntu-eoan-kernel.git / blame_incremental