From: David Vernet <void@manifault.com>
To: Tejun Heo <tj@kernel.org>
Cc: linux-kernel@vger.kernel.org
Subject: Re: [PATCH sched_ext/for-6.12] sched_ext: Fix unsafe list iteration in process_ddsp_deferred_locals()
Date: Thu, 8 Aug 2024 13:21:22 -0500 [thread overview]
Message-ID: <20240808182122.GF6223@maniforge> (raw)
In-Reply-To: <ZrPWYqSbif3eTME4@slm.duckdns.org>
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On Wed, Aug 07, 2024 at 10:17:38AM -1000, Tejun Heo wrote:
> process_ddsp_deferred_locals() executes deferred direct dispatches to the
> local DSQs of remote CPUs. It iterates the tasks on
> rq->scx.ddsp_deferred_locals list, removing and calling
> dispatch_to_local_dsq() on each. However, the list is protected by the rq
> lock that can be dropped by dispatch_to_local_dsq() temporarily, so the list
> can be modified during the iteration, which can lead to oopses and other
> failures.
>
> Fix it by popping from the head of the list instead of iterating the list.
>
> Signed-off-by: Tejun Heo <tj@kernel.org>
> Fixes: 5b26f7b920f7 ("sched_ext: Allow SCX_DSQ_LOCAL_ON for direct dispatches")
Acked-by: David Vernet <void@manifault.com>
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next prev parent reply other threads:[~2024-08-08 18:21 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-08-07 20:17 [PATCH sched_ext/for-6.12] sched_ext: Fix unsafe list iteration in process_ddsp_deferred_locals() Tejun Heo
2024-08-08 18:21 ` David Vernet [this message]
2024-08-08 23:36 ` Tejun Heo
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