[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>
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);