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 C4A6E3E6DE4 for ; Mon, 18 May 2026 11:48:27 +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=1779104907; cv=none; b=IDi5a4hACTYCLqxqNHM3qRaiS/eajN96uVmfJsxt7VrveJDZ2MoxqzCRbII16WQ6eHR0q6/mqZSi6juG64b7AujW4aa4VRJTSjm4sYtCMQUwOUg8DK0sBI8DB9T/jDnaDK/n7aZ6OdRo5YY4u9mjer47R21FXiXSQMnZZnFvh8s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779104907; c=relaxed/simple; bh=cTCWTFviCDAZ311FSdj9ulxiVG8gs0Bxn7kbhVx2FlI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=oc37/vjN9CHil2Ke6aogTwgGGnDfeeF5TliqS0HlhdfxSVQFklB2/TB6us6zxtOr6i+pyEUwM2MSLIY/JLJOR+Da7nmzexRkiw/DhT6OyFmd6DGE+QMjCVgfy49GNChndrtiJLFJdA/OL/HABkir7IpBwysygh+3Qkc7YUfB4oI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ND0E+zry; 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="ND0E+zry" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 19859C2BCB7; Mon, 18 May 2026 11:48:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1779104907; bh=cTCWTFviCDAZ311FSdj9ulxiVG8gs0Bxn7kbhVx2FlI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ND0E+zryIFyeBHnxVQdk9p6tAU9kAogAkdKwuaS8zg5JwyW2DD/gG0Na5ezQuGV65 FwozTvldTJI4+iZSd+auCaOaR6KxRHo6vXzZTQfeQ7sqUNdZtASHicodvjTGUn7uvD 6d2mOEHgQg4HNAz23sR63szTTkeunVzLpaC/gFZwCG3qjj5R7rIBYgFFxWAAnuNrL9 9dWCw+YAWEqOCIiNOgbBIW9DVPfzWvdqaJR6Wi+41IHFjMo3DPRAzcu7Sfhhr8v2i5 XD6Ohvf6zncdp8NCygz463OeRCc/BZPT0G2pF+0SANwoQ43NgrLoiORaRLO67xwAeA WcxWDRGvIr0Bw== From: Sasha Levin To: stable@vger.kernel.org Cc: Tejun Heo , Chris Mason , Andrea Righi , Sasha Levin Subject: [PATCH 6.18.y] sched_ext: Pass held rq to SCX_CALL_OP() for core_sched_before Date: Mon, 18 May 2026 07:48:25 -0400 Message-ID: <20260518114825.789656-1-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <2026051216-garage-angles-0119@gregkh> References: <2026051216-garage-angles-0119@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Tejun Heo [ Upstream commit 4155fb489fa175ec74eedde7d02219cf2fe74303 ] scx_prio_less() runs from core-sched's pick_next_task() path with rq locked but invokes ops.core_sched_before() with NULL locked_rq, leaving scx_locked_rq_state NULL. If the BPF callback calls a kfunc that re-acquires rq based on scx_locked_rq() - e.g. scx_bpf_cpuperf_set(cpu) - it re-acquires the already-held rq. Pass task_rq(a). Fixes: 7b0888b7cc19 ("sched_ext: Implement core-sched support") Cc: stable@vger.kernel.org # v6.12+ Reported-by: Chris Mason Signed-off-by: Tejun Heo Reviewed-by: Andrea Righi [ adapted call to use stable's single `sch`/`SCX_KF_REST` mask and `scx_rq_bypassing(task_rq(a))` signature ] Signed-off-by: Sasha Levin --- kernel/sched/ext.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/sched/ext.c b/kernel/sched/ext.c index 177bbf31116d0..29d3663fe4dcf 100644 --- a/kernel/sched/ext.c +++ b/kernel/sched/ext.c @@ -2522,7 +2522,7 @@ bool scx_prio_less(const struct task_struct *a, const struct task_struct *b, if (SCX_HAS_OP(sch, core_sched_before) && !scx_rq_bypassing(task_rq(a))) return SCX_CALL_OP_2TASKS_RET(sch, SCX_KF_REST, core_sched_before, - NULL, + task_rq(a), (struct task_struct *)a, (struct task_struct *)b); else -- 2.53.0