From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 E4F133FC5B0; Wed, 20 May 2026 17:59:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779299969; cv=none; b=ixk0toxQeTe/pK+NYpUv87tGtj1CADPuWmxUWcTFMiNDTqw79XzGGRMCsbzv9GpXmu+uLbBttBqjnfQV6Tstw0GTadaWqCMI/rYozn6h5X7U6SHlBB9bVKXeamLe50CCKJcFfPjWMi1z67AcuQTKnBw1ClPtCnI1PcAn9kWlpQI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779299969; c=relaxed/simple; bh=WtOuvgI9nuDP7EN0lkRdDmL6k/OfdK25oMFoMLVgEzc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=f1XXFFvOkQhbV9jNLBMK5MbJXpCamq31lwe6LPlwBkF87io+kehBxDZQpejdPwSm4E6Z1FYh6LqCHHhiJsUFZikwkHteOFl1Tca+lU1PlDtucLq5qo8PWBRLH1oQF2jR+HYhWXTz6jpHRpNlB7+LJafagFd3z8AYdh1OpsN3wXM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=bUrnsunu; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="bUrnsunu" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2C5FE1F00893; Wed, 20 May 2026 17:59:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1779299965; bh=J8ekor1fDo/mnaITJgdbwVK2xw7992KJvvzXr6eSe7E=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=bUrnsunu/8sDQ5RAJa+cX1eq69mMXWJOh+7Lyvwm23423Iksr96hGuP1gxDm5mGTn GoIylh9DG0keUwzfq/FAtGvRZzVaGR2WmjZBzjmyT+lKHSuCW+p/n7HbyemZEVBC5a +WmIqwETSRCBUKJI7bzHwKg/gQVz0j0oDWKPqpP4= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Chris Mason , Tejun Heo , Andrea Righi , Sasha Levin Subject: [PATCH 6.18 954/957] sched_ext: Pass held rq to SCX_CALL_OP() for core_sched_before Date: Wed, 20 May 2026 18:23:57 +0200 Message-ID: <20260520162155.292541619@linuxfoundation.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260520162134.554764788@linuxfoundation.org> References: <20260520162134.554764788@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ 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 Signed-off-by: Greg Kroah-Hartman --- kernel/sched/ext.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/kernel/sched/ext.c +++ b/kernel/sched/ext.c @@ -2522,7 +2522,7 @@ bool scx_prio_less(const struct task_str 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