// 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); }