From: Tejun Heo <t...@kernel.org>
commit 6b115bf58e6f013ca75e7115aabcbd56c20ff31d upstream.
cgroup_release() calls cgroup_subsys->release() which is used by the
pids controller to uncharge its pid. We want to use it to manage
iteration of dying tasks which requires putting it before
__unhash_process(). Move cgroup_release() above __exit_signal().
While this makes it uncharge before the pid is freed, pid is RCU freed
anyway and the window is very narrow.
Signed-off-by: Tejun Heo <t...@kernel.org>
Cc: Oleg Nesterov <o...@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
kernel/exit.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -193,6 +193,7 @@ repeat:
rcu_read_unlock();
proc_flush_task(p);
+ cgroup_release(p);
write_lock_irq(&tasklist_lock);
ptrace_release_task(p);
@@ -218,7 +219,6 @@ repeat:
}
write_unlock_irq(&tasklist_lock);
- cgroup_release(p);
release_thread(p);
call_rcu(&p->rcu, delayed_put_task_struct);
