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Diffstat (limited to '')
-rw-r--r-- | drivers/tty/tty_mutex.c | 60 |
1 files changed, 60 insertions, 0 deletions
diff --git a/drivers/tty/tty_mutex.c b/drivers/tty/tty_mutex.c new file mode 100644 index 000000000..2640635ee --- /dev/null +++ b/drivers/tty/tty_mutex.c @@ -0,0 +1,60 @@ +// 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); +} |