cgroup: Call cgroup_release() before __exit_signal()

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 <[email protected]> Cc: Oleg Nesterov <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
JerzyD72 · Aug 9, 2019 · 7528e95 · 7528e95
1 parent e6e9bce
commit 7528e95
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/kernel/exit.c b/kernel/exit.c
@@ -194,6 +194,7 @@ void release_task(struct task_struct *p)
 	rcu_read_unlock();
 
 	proc_flush_task(p);
+	cgroup_release(p);
 
 	write_lock_irq(&tasklist_lock);
 	ptrace_release_task(p);
@@ -219,7 +220,6 @@ void release_task(struct task_struct *p)
 	}
 
 	write_unlock_irq(&tasklist_lock);
-	cgroup_release(p);
 	release_thread(p);
 	call_rcu(&p->rcu, delayed_put_task_struct);