ptrace: wait_task_zombie: s/->parent/->real_parent/

Change wait_task_zombie() to use ->real_parent instead of ->parent.  We
could even use current afaics, but ->real_parent is more clean.

We know that the child is not ptrace_reparented() and thus they are equal.
 But we should avoid using task_struct->parent, we are going to remove it.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 4 insertions, 4 deletions

diff --git a/kernel/exit.c b/kernel/exit.c
index 938cceebb9ad..826e1dc8168b 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -1204,7 +1204,7 @@ static int wait_task_zombie(struct task_struct *p, int options,
                  * p->signal fields, because they are only touched by
                  * __exit_signal, which runs with tasklist_lock
                  * write-locked anyway, and so is excluded here.  We do
-                 * need to protect the access to p->parent->signal fields,
+                 * need to protect the access to parent->signal fields,
                  * as other threads in the parent group can be right
                  * here reaping other children at the same time.
                  *
@@ -1213,8 +1213,8 @@ static int wait_task_zombie(struct task_struct *p, int options,
                  * group including the group leader.
                  */
                 thread_group_cputime(p, &cputime);
-                spin_lock_irq(&p->parent->sighand->siglock);
-                psig = p->parent->signal;
+                spin_lock_irq(&p->real_parent->sighand->siglock);
+                psig = p->real_parent->signal;
                 sig = p->signal;
                 psig->cutime =
                         cputime_add(psig->cutime,
@@ -1245,7 +1245,7 @@ static int wait_task_zombie(struct task_struct *p, int options,
                         sig->oublock + sig->coublock;
                 task_io_accounting_add(&psig->ioac, &p->ioac);
                 task_io_accounting_add(&psig->ioac, &sig->ioac);
-                spin_unlock_irq(&p->parent->sighand->siglock);
+                spin_unlock_irq(&p->real_parent->sighand->siglock);
         }
 
         /*