[PATCH] tty: fix the locking for signal->session in disassociate_ctty

commit 24ec839c43 while fixing the locking for
signal->tty got the locking wrong for signal->session.  This places our
accesses of signal->session back under the tasklist_lock where they belong.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Eric W. Biederman 2007-02-12 00:52:53 -08:00 committed by Linus Torvalds
parent 680a967100
commit 2ea81868d8

View file

@ -1496,7 +1496,6 @@ void disassociate_ctty(int on_exit)
{
struct tty_struct *tty;
int tty_pgrp = -1;
int session;
lock_kernel();
@ -1530,7 +1529,6 @@ void disassociate_ctty(int on_exit)
spin_lock_irq(&current->sighand->siglock);
current->signal->tty_old_pgrp = 0;
session = process_session(current);
spin_unlock_irq(&current->sighand->siglock);
mutex_lock(&tty_mutex);
@ -1549,7 +1547,7 @@ void disassociate_ctty(int on_exit)
/* Now clear signal->tty under the lock */
read_lock(&tasklist_lock);
session_clear_tty(session);
session_clear_tty(process_session(current));
read_unlock(&tasklist_lock);
unlock_kernel();
}