From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4E8CA44E045; Wed, 21 Jan 2026 23:11:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769037115; cv=none; b=SiRWS/LETyBUVD7OqmnLUebB4FmjsHHMnr04AincSz+2hFGAWoW/UDZMluLuFrtknFXucqabVjiHkFAPrWhLibqHyuWr+X5dcs4ufPMxectMqx6bMc7e8GlgBBTUrI14j3KAbOH7xP6/5izUoEczdvHrTseRFh9nOo1/YWabQ4o= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769037115; c=relaxed/simple; bh=C/Y4hUHIvAXYWz1dKkRKihlgeUbRO1EcIFmjBPShaGA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=RFT7Uvc9bAruczzY15hpq1hwHwri0uHjjiuSeULNcfHojNM7/qrBjcU/6aRtQQg6vOmE/PfW0D98IRdnpV0LxPfuJrIF689mwA1KtSGktcaKCyGaInWUXnRVFHIdvVAqmZCU5iA6igMHkQcp/v8oRUNzJJxqQAg/ZCcOSM5/b1c= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=P5DhL6J1; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="P5DhL6J1" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0B06EC19422; Wed, 21 Jan 2026 23:11:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1769037114; bh=C/Y4hUHIvAXYWz1dKkRKihlgeUbRO1EcIFmjBPShaGA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=P5DhL6J1Iv6nuKfsZkmiklb3vH1jVDlh0nw7YUpGSonk4/hHbuiqFGwvXvp6/ZIUc LW9cg+OqqbSORwR3df5qUMDT8lls7tvKOQI3TKEMd8WL4dn/R0BVLxV/D9/hRW4WI/ pok298c8QewbyFKPmssB+94SIIdlxSHHF4tit+7kaaz3tk+L369Xy+NePdFykCLAT+ CprMh+dKX87ZlIo1ju3SNL1iHBKgeZXvixSMTSveFIFE7sC0w0PUnuYGfyWSj+RyoF 9VbWbJfk0mixrggvqzwop77gbaC2J1jsAtBP0shj0TCoLQXM3zNsGCNymjEsMEpJtV LdTqwosJnoq8A== From: Tejun Heo To: linux-kernel@vger.kernel.org, sched-ext@lists.linux.dev Cc: void@manifault.com, andrea.righi@linux.dev, changwoo@igalia.com, emil@etsalapatis.com, Tejun Heo Subject: [PATCH 12/34] sched_ext: scx_dsq_move() should validate the task belongs to the right scheduler Date: Wed, 21 Jan 2026 13:11:18 -1000 Message-ID: <20260121231140.832332-13-tj@kernel.org> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20260121231140.832332-1-tj@kernel.org> References: <20260121231140.832332-1-tj@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit scx_bpf_dsq_move[_vtime]() calls scx_dsq_move() to move task from a DSQ to another. However, @p doesn't necessarily have to come form the containing iteration and can thus be a task which belongs to another scx_sched. Verify that @p is on the same scx_sched as the DSQ being iterated. Signed-off-by: Tejun Heo --- kernel/sched/ext.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/kernel/sched/ext.c b/kernel/sched/ext.c index aad3af8e8377..07cd130f62fb 100644 --- a/kernel/sched/ext.c +++ b/kernel/sched/ext.c @@ -6463,8 +6463,8 @@ static const struct btf_kfunc_id_set scx_kfunc_set_enqueue_dispatch = { static bool scx_dsq_move(struct bpf_iter_scx_dsq_kern *kit, struct task_struct *p, u64 dsq_id, u64 enq_flags) { - struct scx_sched *sch = scx_root; struct scx_dispatch_q *src_dsq = kit->dsq, *dst_dsq; + struct scx_sched *sch = src_dsq->sched; struct rq *this_rq, *src_rq, *locked_rq; bool dispatched = false; bool in_balance; @@ -6481,6 +6481,11 @@ static bool scx_dsq_move(struct bpf_iter_scx_dsq_kern *kit, if (unlikely(READ_ONCE(scx_aborting))) return false; + if (unlikely(!scx_task_on_sched(sch, p))) { + scx_error(sch, "scx_bpf_dsq_move[_vtime]() on %s[%d] but the task belongs to a different scheduler", + p->comm, p->pid); + } + /* * Can be called from either ops.dispatch() locking this_rq() or any * context where no rq lock is held. If latter, lock @p's task_rq which -- 2.52.0