[PATCH v4 18/23] sched: Fix try_invoke_on_locked_down_task() semantics

[Masami Hiramatsu]

From: Peter Zijlstra <pet...@infradead.org>

Signed-off-by: Peter Zijlstra (Intel) <pet...@infradead.org>
---
 kernel/sched/core.c |    9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 2d95dc3f4644..13b0db2d0be2 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -3006,15 +3006,14 @@ try_to_wake_up(struct task_struct *p, unsigned int 
state, int wake_flags)
  */
 bool try_invoke_on_locked_down_task(struct task_struct *p, bool (*func)(struct 
task_struct *t, void *arg), void *arg)
 {
-       bool ret = false;
        struct rq_flags rf;
+       bool ret = false;
        struct rq *rq;
 
-       lockdep_assert_irqs_enabled();
-       raw_spin_lock_irq(&p->pi_lock);
+       raw_spin_lock_irqsave(&p->pi_lock, rf.flags);
        if (p->on_rq) {
                rq = __task_rq_lock(p, &rf);
-               if (task_rq(p) == rq)
+               if (task_rq(p) == rq && rq->curr != p)
                        ret = func(p, arg);
                rq_unlock(rq, &rf);
        } else {
@@ -3028,7 +3027,7 @@ bool try_invoke_on_locked_down_task(struct task_struct 
*p, bool (*func)(struct t
                                ret = func(p, arg);
                }
        }
-       raw_spin_unlock_irq(&p->pi_lock);
+       raw_spin_unlock_irqrestore(&p->pi_lock, rf.flags);
        return ret;
 }