X-Git-Url: http://www.pilppa.org/gitweb/gitweb.cgi?a=blobdiff_plain;f=drivers%2Fchar%2Ftty_io.c;h=f40298e9873a0f274a8563181efa394d0e04bf50;hb=934e6ebf96e8c1a0f299e64129fdaebc1132a427;hp=b5f57d0b30ee1bdb5e931825010c59ab0b2627a2;hpb=2cb5998b5f0ccc886fdda3509059eef297b49577;p=linux-2.6-omap-h63xx.git

diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c
index b5f57d0b30e..f40298e9873 100644
--- a/drivers/char/tty_io.c
+++ b/drivers/char/tty_io.c
@@ -739,13 +739,11 @@ void tty_vhangup_self(void)
 {
 	struct tty_struct *tty;
 
-	mutex_lock(&tty_mutex);
 	tty = get_current_tty();
 	if (tty) {
 		tty_vhangup(tty);
 		tty_kref_put(tty);
 	}
-	mutex_unlock(&tty_mutex);
 }
 
 /**
@@ -801,11 +799,9 @@ void disassociate_ctty(int on_exit)
 	struct pid *tty_pgrp = NULL;
 
 
-	mutex_lock(&tty_mutex);
 	tty = get_current_tty();
 	if (tty) {
 		tty_pgrp = get_pid(tty->pgrp);
-		mutex_unlock(&tty_mutex);
 		lock_kernel();
 		if (on_exit && tty->driver->type != TTY_DRIVER_TYPE_PTY)
 			tty_vhangup(tty);
@@ -822,7 +818,6 @@ void disassociate_ctty(int on_exit)
 			kill_pgrp(old_pgrp, SIGCONT, on_exit);
 			put_pid(old_pgrp);
 		}
-		mutex_unlock(&tty_mutex);
 		return;
 	}
 	if (tty_pgrp) {
@@ -837,7 +832,6 @@ void disassociate_ctty(int on_exit)
 	current->signal->tty_old_pgrp = NULL;
 	spin_unlock_irq(&current->sighand->siglock);
 
-	mutex_lock(&tty_mutex);
 	tty = get_current_tty();
 	if (tty) {
 		unsigned long flags;
@@ -854,7 +848,6 @@ void disassociate_ctty(int on_exit)
 		       " = NULL", tty);
 #endif
 	}
-	mutex_unlock(&tty_mutex);
 
 	/* Now clear signal->tty under the lock */
 	read_lock(&tasklist_lock);
@@ -3180,14 +3173,11 @@ static void proc_set_tty(struct task_struct *tsk, struct tty_struct *tty)
 struct tty_struct *get_current_tty(void)
 {
 	struct tty_struct *tty;
-	WARN_ON_ONCE(!mutex_is_locked(&tty_mutex));
+	unsigned long flags;
+
+	spin_lock_irqsave(&current->sighand->siglock, flags);
 	tty = tty_kref_get(current->signal->tty);
-	/*
-	 * session->tty can be changed/cleared from under us, make sure we
-	 * issue the load. The obtained pointer, when not NULL, is valid as
-	 * long as we hold tty_mutex.
-	 */
-	barrier();
+	spin_unlock_irqrestore(&current->sighand->siglock, flags);
 	return tty;
 }
 EXPORT_SYMBOL_GPL(get_current_tty);