[tip: sched/urgent] sched/deadline: Initialize ->dl_boosted

[tip-bot2 for Juri Lelli]

The following commit has been merged into the sched/urgent branch of tip:

Commit-ID:     1863cc11225e3ea2cd005473f9addc52513ab1bc
Gitweb:        https://git.kernel.org/tip/1863cc11225e3ea2cd005473f9addc52513ab1bc
Author:        Juri Lelli <juri.lelli@xxxxxxxxxx>
AuthorDate:    Wed, 17 Jun 2020 09:29:19 +02:00
Committer:     Ingo Molnar <mingo@xxxxxxxxxx>
CommitterDate: Tue, 23 Jun 2020 10:42:39 +02:00

sched/deadline: Initialize ->dl_boosted

syzbot reported the following warning triggered via SYSC_sched_setattr():

  WARNING: CPU: 0 PID: 6973 at kernel/sched/deadline.c:593 setup_new_dl_entity /kernel/sched/deadline.c:594 [inline]
  WARNING: CPU: 0 PID: 6973 at kernel/sched/deadline.c:593 enqueue_dl_entity /kernel/sched/deadline.c:1370 [inline]
  WARNING: CPU: 0 PID: 6973 at kernel/sched/deadline.c:593 enqueue_task_dl+0x1c17/0x2ba0 /kernel/sched/deadline.c:1441

This happens because the ->dl_boosted flag is currently not initialized by
__dl_clear_params() (unlike the other flags) and setup_new_dl_entity()
rightfully complains about it.

Initialize dl_boosted to 0.

Fixes: 2d3d891d3344 ("sched/deadline: Add SCHED_DEADLINE inheritance logic")
Reported-by: syzbot+5ac8bac25f95e8b221e7@xxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Juri Lelli <juri.lelli@xxxxxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Tested-by: Daniel Wagner <dwagner@xxxxxxx>
Link: https://lkml.kernel.org/r/20200617072919.818409-1-juri.lelli@xxxxxxxxxx
---
 kernel/sched/deadline.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
index 504d2f5..f63f337 100644
--- a/kernel/sched/deadline.c
+++ b/kernel/sched/deadline.c
@@ -2692,6 +2692,7 @@ void __dl_clear_params(struct task_struct *p)
 	dl_se->dl_bw			= 0;
 	dl_se->dl_density		= 0;
 
+	dl_se->dl_boosted		= 0;
 	dl_se->dl_throttled		= 0;
 	dl_se->dl_yielded		= 0;
 	dl_se->dl_non_contending	= 0;