From: Tejun Heo <tj@kernel.org>
To: sashiko-bot@kernel.org
Cc: sched-ext@lists.linux.dev
Subject: Re: [PATCH v2 sched_ext/for-7.3 19/36] sched_ext: Add per-shard cap delegation for sub-schedulers
Date: Mon, 06 Jul 2026 13:40:43 -1000 [thread overview]
Message-ID: <8777fe49a17c2f70af92fd2f8b5712af@kernel.org> (raw)
In-Reply-To: <20260706021322.72F731F000E9@smtp.kernel.org>
On Mon, 06 Jul 2026 02:13:20 +0000, sashiko-bot wrote:
> - [High] Concurrent BPF execution can trigger a NULL pointer dereference in scx_bpf_sub_caps() during scheduler initialization.
Confirmed, fixed for v3. scx_alloc_pshards() now builds the array fully
into a local and publishes it with smp_wmb() + WRITE_ONCE(); the reader takes
it with READ_ONCE() into a local before dereferencing. This is plain
publish-ordering (message passing), not RCU - pshard lifetime is separately
covered by the sched's RCU-work teardown.
next prev parent reply other threads:[~2026-07-06 23:40 UTC|newest]
Thread overview: 73+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-07-06 1:40 [PATCHSET v2 sched_ext/for-7.3] sched_ext: Capability-based CPU delegation for sub-schedulers Tejun Heo
2026-07-06 1:40 ` [PATCH v2 sched_ext/for-7.3 01/36] sched_ext: Add SCX_CALL_CID_OP_TASK() for cid-form op dispatch Tejun Heo
2026-07-06 1:40 ` [PATCH v2 sched_ext/for-7.3 02/36] sched_ext: Rename extra_enq_flags to remote_activate_enq_flags Tejun Heo
2026-07-06 1:40 ` [PATCH v2 sched_ext/for-7.3 03/36] sched_ext: Fix premature ops->priv publication in scx_alloc_and_add_sched() Tejun Heo
2026-07-06 1:40 ` [PATCH v2 sched_ext/for-7.3 04/36] tools/sched_ext: scx - Fix cmask_subset(), cmask_equal() and cmask_weight() Tejun Heo
2026-07-06 1:40 ` [PATCH v2 sched_ext/for-7.3 05/36] sched_ext: Use READ_ONCE/WRITE_ONCE in cmask word ops and drop _RACY variants Tejun Heo
2026-07-06 1:40 ` [PATCH v2 sched_ext/for-7.3 06/36] tools/sched_ext: scx_qmap - Use bare u64/u32/s32 integer types Tejun Heo
2026-07-06 1:40 ` [PATCH v2 sched_ext/for-7.3 07/36] sched_ext: Reject direct slice and dsq_vtime writes for cid-form schedulers Tejun Heo
2026-07-06 1:40 ` [PATCH v2 sched_ext/for-7.3 08/36] sched_ext: Make scx_bpf_kick_cid() return void Tejun Heo
2026-07-06 1:40 ` [PATCH v2 sched_ext/for-7.3 09/36] sched_ext: Make the kick machinery per-sched Tejun Heo
2026-07-06 1:40 ` [PATCH v2 sched_ext/for-7.3 10/36] sched_ext: Add ops.init_cids() to finalize the cid layout before init Tejun Heo
2026-07-06 2:08 ` sashiko-bot
2026-07-06 23:40 ` Tejun Heo
2026-07-06 1:40 ` [PATCH v2 sched_ext/for-7.3 11/36] sched_ext: Add CID sharding Tejun Heo
2026-07-06 1:53 ` sashiko-bot
2026-07-06 23:40 ` Tejun Heo
2026-07-06 1:40 ` [PATCH v2 sched_ext/for-7.3 12/36] sched_ext: Add shard boundaries to scx_bpf_cid_override() Tejun Heo
2026-07-06 1:40 ` [PATCH v2 sched_ext/for-7.3 13/36] sched_ext: Defer scx_sched kobj sysfs add into the enable workfns Tejun Heo
2026-07-06 1:40 ` [PATCH v2 sched_ext/for-7.3 14/36] sched_ext: Add per-shard scx_sched storage scaffolding Tejun Heo
2026-07-06 1:40 ` [PATCH v2 sched_ext/for-7.3 15/36] sched_ext: Add scx_cmask_ref for validated arena cmask access Tejun Heo
2026-07-06 1:58 ` sashiko-bot
2026-07-06 23:40 ` Tejun Heo
2026-07-06 9:04 ` Andrea Righi
2026-07-06 23:40 ` Tejun Heo
2026-07-06 1:40 ` [PATCH v2 sched_ext/for-7.3 16/36] sched_ext: Build the set_cmask scratch from trusted geometry Tejun Heo
2026-07-06 1:59 ` sashiko-bot
2026-07-06 23:40 ` Tejun Heo
2026-07-06 1:40 ` [PATCH v2 sched_ext/for-7.3 17/36] sched_ext: RCU-protect the sub-sched tree's children/sibling lists Tejun Heo
2026-07-06 2:08 ` sashiko-bot
2026-07-06 23:40 ` Tejun Heo
2026-07-06 1:40 ` [PATCH v2 sched_ext/for-7.3 18/36] sched_ext: Add scx_skip_subtree_pre() Tejun Heo
2026-07-06 1:40 ` [PATCH v2 sched_ext/for-7.3 19/36] sched_ext: Add per-shard cap delegation for sub-schedulers Tejun Heo
2026-07-06 2:13 ` sashiko-bot
2026-07-06 23:40 ` Tejun Heo [this message]
2026-07-06 1:40 ` [PATCH v2 sched_ext/for-7.3 20/36] sched_ext: Add coalescing sub_caps_updated() notifier " Tejun Heo
2026-07-06 2:06 ` sashiko-bot
2026-07-06 23:40 ` Tejun Heo
2026-07-06 1:40 ` [PATCH v2 sched_ext/for-7.3 21/36] sched_ext: Maintain per-cpu effective cap copies for single-read checks Tejun Heo
2026-07-06 2:07 ` sashiko-bot
2026-07-06 23:40 ` Tejun Heo
2026-07-06 1:40 ` [PATCH v2 sched_ext/for-7.3 22/36] sched_ext: Add sub_ecaps_updated() effective-cap change notifier Tejun Heo
2026-07-06 2:09 ` sashiko-bot
2026-07-06 23:40 ` Tejun Heo
2026-07-06 1:40 ` [PATCH v2 sched_ext/for-7.3 23/36] sched_ext: Generalize local-DSQ handling to rq-owned DSQs Tejun Heo
2026-07-06 1:40 ` [PATCH v2 sched_ext/for-7.3 24/36] sched_ext: Add reject DSQ for cap-rejected dispatches Tejun Heo
2026-07-06 2:08 ` sashiko-bot
2026-07-06 23:40 ` Tejun Heo
2026-07-06 1:40 ` [PATCH v2 sched_ext/for-7.3 25/36] sched_ext: Add the SCX_CAP_ENQ_IMMED cap Tejun Heo
2026-07-06 2:10 ` sashiko-bot
2026-07-06 23:40 ` Tejun Heo
2026-07-06 1:40 ` [PATCH v2 sched_ext/for-7.3 26/36] sched_ext: Assign a unique id to each scheduler instance Tejun Heo
2026-07-06 1:40 ` [PATCH v2 sched_ext/for-7.3 27/36] sched_ext: Route task slice writes through set_task_slice() Tejun Heo
2026-07-06 2:05 ` sashiko-bot
2026-07-06 23:40 ` Tejun Heo
2026-07-06 9:10 ` Andrea Righi
2026-07-06 23:40 ` Tejun Heo
2026-07-06 1:40 ` [PATCH v2 sched_ext/for-7.3 28/36] sched_ext: Tie cpu occupancy to SCX_CAP_BASE through the task slice Tejun Heo
2026-07-06 2:07 ` sashiko-bot
2026-07-06 23:40 ` Tejun Heo
2026-07-06 1:40 ` [PATCH v2 sched_ext/for-7.3 29/36] sched_ext: Add the SCX_CAP_ENQ cap Tejun Heo
2026-07-06 1:40 ` [PATCH v2 sched_ext/for-7.3 30/36] sched_ext: Gate kicks on SCX_CAP_BASE and preemption on SCX_CAP_PREEMPT Tejun Heo
2026-07-06 1:40 ` [PATCH v2 sched_ext/for-7.3 31/36] sched_ext: Authorize remote-move inserts against the placing scheduler Tejun Heo
2026-07-06 1:40 ` [PATCH v2 sched_ext/for-7.3 32/36] sched_ext: Route ops.update_idle() to sub-schedulers and re-notify owed scheds Tejun Heo
2026-07-06 1:40 ` [PATCH v2 sched_ext/for-7.3 33/36] sched_ext: Replay ecaps notifications suppressed by bypass Tejun Heo
2026-07-06 2:11 ` sashiko-bot
2026-07-06 23:40 ` Tejun Heo
2026-07-06 1:40 ` [PATCH v2 sched_ext/for-7.3 34/36] sched_ext: Add scx_bpf_sub_kill() to evict a child sub-scheduler Tejun Heo
2026-07-06 2:12 ` sashiko-bot
2026-07-06 23:40 ` Tejun Heo
2026-07-06 1:40 ` [PATCH v2 sched_ext/for-7.3 35/36] tools/sched_ext: scx_qmap - Expand hierarchical sub-scheduling Tejun Heo
2026-07-06 2:10 ` sashiko-bot
2026-07-06 23:40 ` Tejun Heo
2026-07-06 1:40 ` [PATCH v2 sched_ext/for-7.3 36/36] tools/sched_ext: scx_qmap - Add sub-sched cap fault injection Tejun Heo
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