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Commit ea648a47 authored by Peter Hurley's avatar Peter Hurley Committed by Greg Kroah-Hartman
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tty: Refactor session leader SIGHUP from __tty_hangup() 



Reduce complexity of __tty_hangup(); separate SIGHUP signalling
into tty_signal_session_leader().

Signed-off-by: default avatarPeter Hurley <peter@hurleysoftware.com>
Acked-by: default avatarJiri Slaby <jslaby@suse.cz>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent f3c8279d

drivers/tty/tty_io.c

+50 −31
Original line number Diff line number Diff line
@@ -532,6 +532,51 @@ void tty_wakeup(struct tty_struct *tty) 


EXPORT_SYMBOL_GPL(tty_wakeup);



/**

 *	tty_signal_session_leader	- sends SIGHUP to session leader

 *

 *	Send SIGHUP and SIGCONT to the session leader and its

 *	process group.

 *

 *	Returns the number of processes in the session with this tty

 *	as their controlling terminal. This value is used to drop

 *	tty references for those processes.

 */

static int tty_signal_session_leader(struct tty_struct *tty)

{

	struct task_struct *p;

	unsigned long flags;

	int refs = 0;



	read_lock(&tasklist_lock);

	if (tty->session) {

		do_each_pid_task(tty->session, PIDTYPE_SID, p) {

			spin_lock_irq(&p->sighand->siglock);

			if (p->signal->tty == tty) {

				p->signal->tty = NULL;

				/* We defer the dereferences outside fo

				   the tasklist lock */

				refs++;

			}

			if (!p->signal->leader) {

				spin_unlock_irq(&p->sighand->siglock);

				continue;

			}

			__group_send_sig_info(SIGHUP, SEND_SIG_PRIV, p);

			__group_send_sig_info(SIGCONT, SEND_SIG_PRIV, p);

			put_pid(p->signal->tty_old_pgrp);  /* A noop */

			spin_lock_irqsave(&tty->ctrl_lock, flags);

			if (tty->pgrp)

				p->signal->tty_old_pgrp = get_pid(tty->pgrp);

			spin_unlock_irqrestore(&tty->ctrl_lock, flags);

			spin_unlock_irq(&p->sighand->siglock);

		} while_each_pid_task(tty->session, PIDTYPE_SID, p);

	}

	read_unlock(&tasklist_lock);



	return refs;

}



/**

 *	__tty_hangup		-	actual handler for hangup events

 *	@work: tty device
@@ -558,11 +603,10 @@ static void __tty_hangup(struct tty_struct *tty) 
{

	struct file *cons_filp = NULL;

	struct file *filp, *f = NULL;

	struct task_struct *p;

	struct tty_file_private *priv;

	int    closecount = 0, n;

	unsigned long flags;

	int refs = 0;

	int refs;



	if (!tty)

		return;
@@ -605,31 +649,10 @@ static void __tty_hangup(struct tty_struct *tty) 
	 */

	tty_ldisc_hangup(tty);



	read_lock(&tasklist_lock);

	if (tty->session) {

		do_each_pid_task(tty->session, PIDTYPE_SID, p) {

			spin_lock_irq(&p->sighand->siglock);

			if (p->signal->tty == tty) {

				p->signal->tty = NULL;

				/* We defer the dereferences outside fo

				   the tasklist lock */

				refs++;

			}

			if (!p->signal->leader) {

				spin_unlock_irq(&p->sighand->siglock);

				continue;

			}

			__group_send_sig_info(SIGHUP, SEND_SIG_PRIV, p);

			__group_send_sig_info(SIGCONT, SEND_SIG_PRIV, p);

			put_pid(p->signal->tty_old_pgrp);  /* A noop */

			spin_lock_irqsave(&tty->ctrl_lock, flags);

			if (tty->pgrp)

				p->signal->tty_old_pgrp = get_pid(tty->pgrp);

			spin_unlock_irqrestore(&tty->ctrl_lock, flags);

			spin_unlock_irq(&p->sighand->siglock);

		} while_each_pid_task(tty->session, PIDTYPE_SID, p);

	}

	read_unlock(&tasklist_lock);

	refs = tty_signal_session_leader(tty);

	/* Account for the p->signal references we killed */

	while (refs--)

		tty_kref_put(tty);



	spin_lock_irqsave(&tty->ctrl_lock, flags);

	clear_bit(TTY_THROTTLED, &tty->flags);
@@ -642,10 +665,6 @@ static void __tty_hangup(struct tty_struct *tty) 
	tty->ctrl_status = 0;

	spin_unlock_irqrestore(&tty->ctrl_lock, flags);



	/* Account for the p->signal references we killed */

	while (refs--)

		tty_kref_put(tty);



	/*

	 * If one of the devices matches a console pointer, we

	 * cannot just call hangup() because that will cause