tty: Refactor session leader SIGHUP from __tty_hangup()
Reduce complexity of __tty_hangup(); separate SIGHUP signalling
into tty_signal_session_leader().
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Acked-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
index 05400ac..706c23b 100644
--- a/drivers/tty/tty_io.c
+++ b/drivers/tty/tty_io.c
@@ -533,6 +533,51 @@
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 @@
{
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 @@
*/
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 @@
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