diff options
Diffstat (limited to 'include/linux/tty.h')
| -rw-r--r-- | include/linux/tty.h | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/include/linux/tty.h b/include/linux/tty.h index 7d66ae508e5c..849659908f23 100644 --- a/include/linux/tty.h +++ b/include/linux/tty.h @@ -14,6 +14,23 @@ #include <linux/llist.h> +/* + * Lock subclasses for tty locks + * + * TTY_LOCK_NORMAL is for normal ttys and master ptys. + * TTY_LOCK_SLAVE is for slave ptys only. + * + * Lock subclasses are necessary for handling nested locking with pty pairs. + * tty locks which use nested locking: + * + * legacy_mutex - Nested tty locks are necessary for releasing pty pairs. + * The stable lock order is master pty first, then slave pty. + */ + +enum { + TTY_LOCK_NORMAL = 0, + TTY_LOCK_SLAVE, +}; /* * (Note: the *_driver.minor_start values 1, 64, 128, 192 are |