sched: Fix race in task_group()

[pandora-kernel.git] / kernel / sched / core.c

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 536b213..5d011ef 100644 (file)
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -1096,7 +1096,7 @@ void set_task_cpu(struct task_struct *p, unsigned int new_cpu)
         * a task's CPU. ->pi_lock for waking tasks, rq->lock for runnable tasks.
         *
         * sched_move_task() holds both and thus holding either pins the cgroup,
-        * see set_task_rq().
+        * see task_group().
         *
         * Furthermore, all task_rq users should acquire both locks, see
         * task_rq_lock().
@@ -7658,6 +7658,7 @@ void sched_destroy_group(struct task_group *tg)
  */
 void sched_move_task(struct task_struct *tsk)
 {
+       struct task_group *tg;
        int on_rq, running;
        unsigned long flags;
        struct rq *rq;
@@ -7672,6 +7673,12 @@ void sched_move_task(struct task_struct *tsk)
        if (unlikely(running))
                tsk->sched_class->put_prev_task(rq, tsk);
 
+       tg = container_of(task_subsys_state_check(tsk, cpu_cgroup_subsys_id,
+                               lockdep_is_held(&tsk->sighand->siglock)),
+                         struct task_group, css);
+       tg = autogroup_task_group(tsk, tg);
+       tsk->sched_task_group = tg;
+
 #ifdef CONFIG_FAIR_GROUP_SCHED
        if (tsk->sched_class->task_move_group)
                tsk->sched_class->task_move_group(tsk, on_rq);