commit 3cfd0885fac78c130a119ed576d18b5948fa2a5a
author Alan Cox <alan@lxorguk.ukuu.org.uk> Fri Sep 29 02:00:41 2006 -0700
committer Linus Torvalds <torvalds@g5.osdl.org> Fri Sep 29 09:18:16 2006 -0700
tree 9a49ab330a39fc32cff3208038f1cef7763780aa
parent 808a0d389ff8d85017ec811085a6083394c02caf

[PATCH] tty: stop the tty vanishing under procfs access

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

fs/proc/array.c

diff --git a/fs/proc/array.c b/fs/proc/array.c
index 0b615d6..c0e5549 100644
--- a/fs/proc/array.c
+++ b/fs/proc/array.c
@@ -347,6 +347,8 @@
 	sigemptyset(&sigign);
 	sigemptyset(&sigcatch);
 	cutime = cstime = utime = stime = cputime_zero;
+
+	mutex_lock(&tty_mutex);
 	read_lock(&tasklist_lock);
 	if (task->sighand) {
 		spin_lock_irq(&task->sighand->siglock);
@@ -388,6 +390,7 @@
 	}
 	ppid = pid_alive(task) ? task->group_leader->real_parent->tgid : 0;
 	read_unlock(&tasklist_lock);
+	mutex_unlock(&tty_mutex);
 
 	if (!whole || num_threads<2)
 		wchan = get_wchan(task);