| * drivers/char/tty_lock.c |
| #include <linux/module.h> |
| #include <linux/kallsyms.h> |
| #include <linux/semaphore.h> |
| * This mutex is taken and released by tty_lock() and tty_unlock(), |
| * replacing the older big kernel lock. |
| * It can no longer be taken recursively, and does not get |
| * released implicitly while sleeping. |
| static DEFINE_MUTEX(big_tty_mutex); |
| struct task_struct *__big_tty_mutex_owner; |
| EXPORT_SYMBOL_GPL(__big_tty_mutex_owner); |
| * Getting the big tty mutex. |
| void __lockfunc tty_lock(void) |
| struct task_struct *task = current; |
| WARN_ON(__big_tty_mutex_owner == task); |
| mutex_lock(&big_tty_mutex); |
| __big_tty_mutex_owner = task; |
| void __lockfunc tty_unlock(void) |
| struct task_struct *task = current; |
| WARN_ON(__big_tty_mutex_owner != task); |
| __big_tty_mutex_owner = NULL; |
| mutex_unlock(&big_tty_mutex); |
| EXPORT_SYMBOL(tty_unlock); |