1 #include <linux/tty.h> 2 #include <linux/module.h> 3 #include <linux/kallsyms.h> 4 #include <linux/semaphore.h> 5 #include <linux/sched.h> 6 7 /* Legacy tty mutex glue */ 8 9 /* 10 * Getting the big tty mutex. 11 */ 12 13 void __lockfunc tty_lock(struct tty_struct *tty) 14 { 15 if (tty->magic != TTY_MAGIC) { 16 printk(KERN_ERR "L Bad %p\n", tty); 17 WARN_ON(1); 18 return; 19 } 20 tty_kref_get(tty); 21 mutex_lock(&tty->legacy_mutex); 22 } 23 EXPORT_SYMBOL(tty_lock); 24 25 void __lockfunc tty_unlock(struct tty_struct *tty) 26 { 27 if (tty->magic != TTY_MAGIC) { 28 printk(KERN_ERR "U Bad %p\n", tty); 29 WARN_ON(1); 30 return; 31 } 32 mutex_unlock(&tty->legacy_mutex); 33 tty_kref_put(tty); 34 } 35 EXPORT_SYMBOL(tty_unlock); 36 37 /* 38 * Getting the big tty mutex for a pair of ttys with lock ordering 39 * On a non pty/tty pair tty2 can be NULL which is just fine. 40 */ 41 void __lockfunc tty_lock_pair(struct tty_struct *tty, 42 struct tty_struct *tty2) 43 { 44 if (tty < tty2) { 45 tty_lock(tty); 46 tty_lock(tty2); 47 } else { 48 if (tty2 && tty2 != tty) 49 tty_lock(tty2); 50 tty_lock(tty); 51 } 52 } 53 EXPORT_SYMBOL(tty_lock_pair); 54 55 void __lockfunc tty_unlock_pair(struct tty_struct *tty, 56 struct tty_struct *tty2) 57 { 58 tty_unlock(tty); 59 if (tty2 && tty2 != tty) 60 tty_unlock(tty2); 61 } 62 EXPORT_SYMBOL(tty_unlock_pair); 63