The race is in unlocked task_rq() access. In pair with parallel call of sched_setaffinity() it may be a reason of corruption of internal rq's data.
Signed-off-by: Kirill Tkhai <[email protected]> CC: Juri Lelli <[email protected]> CC: Peter Zijlstra <[email protected]> CC: Ingo Molnar <[email protected]> Cc: <[email protected]> # v3.14 --- kernel/sched/deadline.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c index 800e99b..ffb023a 100644 --- a/kernel/sched/deadline.c +++ b/kernel/sched/deadline.c @@ -513,9 +513,16 @@ static enum hrtimer_restart dl_task_timer(struct hrtimer *timer) struct sched_dl_entity, dl_timer); struct task_struct *p = dl_task_of(dl_se); - struct rq *rq = task_rq(p); + struct rq *rq; +again: + rq = task_rq(p); raw_spin_lock(&rq->lock); + if (unlikely(rq != task_rq(p))) { + raw_spin_unlock(&rq->lock); + goto again; + } + /* * We need to take care of a possible races here. In fact, the * task might have changed its scheduling policy to something -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
