Re: [PATCH 6.12] sched/eevdf: Fix se->slice being set to U64_MAX and resulting crash

[Sasha Levin <sashal@kernel.org>]

[ Sasha's backport helper bot ]

Hi,

✅ All tests passed successfully. No issues detected.
No action required from the submitter.

The upstream commit SHA1 provided is correct: bbce3de72be56e4b5f68924b7da9630cc89aa1a8

WARNING: Author mismatch between patch and upstream commit:
Backport author: Omar Sandoval<osandov@osandov.com>
Commit author: Omar Sandoval<osandov@fb.com>

Status in newer kernel trees:
6.14.y | Present (different SHA1: 50a665496881)

Note: The patch differs from the upstream commit:
---
1:  bbce3de72be56 ! 1:  878496a829cec sched/eevdf: Fix se->slice being set to U64_MAX and resulting crash
    @@ Metadata
      ## Commit message ##
         sched/eevdf: Fix se->slice being set to U64_MAX and resulting crash
     
    +    commit bbce3de72be56e4b5f68924b7da9630cc89aa1a8 upstream.
    +
         There is a code path in dequeue_entities() that can set the slice of a
         sched_entity to U64_MAX, which sometimes results in a crash.
     
    @@ Commit message
     
      ## kernel/sched/fair.c ##
     @@ kernel/sched/fair.c: static int dequeue_entities(struct rq *rq, struct sched_entity *se, int flags)
    - 		h_nr_idle = task_has_idle_policy(p);
    - 		if (task_sleep || task_delayed || !se->sched_delayed)
    - 			h_nr_runnable = 1;
    + 		idle_h_nr_running = task_has_idle_policy(p);
    + 		if (!task_sleep && !task_delayed)
    + 			h_nr_delayed = !!se->sched_delayed;
     -	} else {
     -		cfs_rq = group_cfs_rq(se);
     -		slice = cfs_rq_min_slice(cfs_rq);
---

Results of testing on various branches:

| Branch                    | Patch Apply | Build Test |
|---------------------------|-------------|------------|
| stable/linux-6.12.y       |  Success    |  Success   |