| // SPDX-License-Identifier: GPL-2.0 |
| #include <linux/tty.h> |
| #include <linux/module.h> |
| #include <linux/kallsyms.h> |
| #include <linux/semaphore.h> |
| #include <linux/sched.h> |
| |
| /* Legacy tty mutex glue */ |
| |
| /* |
| * Getting the big tty mutex. |
| */ |
| |
| void tty_lock(struct tty_struct *tty) |
| { |
| if (WARN(tty->magic != TTY_MAGIC, "L Bad %p\n", tty)) |
| return; |
| tty_kref_get(tty); |
| mutex_lock(&tty->legacy_mutex); |
| } |
| EXPORT_SYMBOL(tty_lock); |
| |
| int tty_lock_interruptible(struct tty_struct *tty) |
| { |
| int ret; |
| |
| if (WARN(tty->magic != TTY_MAGIC, "L Bad %p\n", tty)) |
| return -EIO; |
| tty_kref_get(tty); |
| ret = mutex_lock_interruptible(&tty->legacy_mutex); |
| if (ret) |
| tty_kref_put(tty); |
| return ret; |
| } |
| |
| void tty_unlock(struct tty_struct *tty) |
| { |
| if (WARN(tty->magic != TTY_MAGIC, "U Bad %p\n", tty)) |
| return; |
| mutex_unlock(&tty->legacy_mutex); |
| tty_kref_put(tty); |
| } |
| EXPORT_SYMBOL(tty_unlock); |
| |
| void tty_lock_slave(struct tty_struct *tty) |
| { |
| if (tty && tty != tty->link) |
| tty_lock(tty); |
| } |
| |
| void tty_unlock_slave(struct tty_struct *tty) |
| { |
| if (tty && tty != tty->link) |
| tty_unlock(tty); |
| } |
| |
| void tty_set_lock_subclass(struct tty_struct *tty) |
| { |
| lockdep_set_subclass(&tty->legacy_mutex, TTY_LOCK_SLAVE); |
| } |