From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A5B69C4332F for ; Tue, 18 Oct 2022 00:12:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231573AbiJRAMx (ORCPT ); Mon, 17 Oct 2022 20:12:53 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37788 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231354AbiJRAKz (ORCPT ); Mon, 17 Oct 2022 20:10:55 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B6E1D88DF5; Mon, 17 Oct 2022 17:08:57 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 2950B61314; Tue, 18 Oct 2022 00:08:55 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6F727C433D7; Tue, 18 Oct 2022 00:08:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1666051734; bh=MYsXPCCZudwVdMZHgFFQW2l401Y+tXJbW6caoYc4ohE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=D+2BYc6fywgJi/EV4UJ6395U56JGi6Gc7TGgvnNRluriwwEub6emL2YjYTEyttUuu b+e3jbwpX9W7WOlk0BvHIOFv8OObdhX5h9HkPv9piggo1r5mBznnK1u2M6zKtuzK9Q PdzwjAAKQICVCiTkC1Gy2n0MQR5tBPETUNxRWDhi9HHeYzkV1o13KW2+LgXUJzzqOs AYDfmrGgPQBDnlEuqC6w//dEzUqGqoRgQKHcrh3+itYFHrczzMM4LuaWNhDBxv9dzi CKFWmGpTxxkiOQvNFAqAkwxqBJ74rnb1fswkEaQX2p3Gs/Xf255DfsTFTY3gWBjjir rjAKbdDzs1+Gg== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Robin Murphy , Kevin Tian , Joerg Roedel , Sasha Levin , dwmw2@infradead.org, baolu.lu@linux.intel.com, joro@8bytes.org, will@kernel.org, iommu@lists.linux.dev Subject: [PATCH AUTOSEL 5.19 07/29] iommu/vt-d: Handle race between registration and device probe Date: Mon, 17 Oct 2022 20:08:16 -0400 Message-Id: <20221018000839.2730954-7-sashal@kernel.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20221018000839.2730954-1-sashal@kernel.org> References: <20221018000839.2730954-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Robin Murphy [ Upstream commit c919739ce4721ecf7b96b99253b032df30fcf19b ] Currently we rely on registering all our instances before initially allowing any .probe_device calls via bus_set_iommu(). In preparation for phasing out the latter, make sure we won't inadvertently return success for a device associated with a known but not yet registered instance, otherwise we'll run straight into iommu_group_get_for_dev() trying to use NULL ops. That also highlights an issue with intel_iommu_get_resv_regions() taking dmar_global_lock from within a section where intel_iommu_init() already holds it, which already exists via probe_acpi_namespace_devices() when an ANDD device is probed, but gets more obvious with the upcoming change to iommu_device_register(). Since they are both read locks it manages not to deadlock in practice, and a more in-depth rework of this locking is underway, so no attempt is made to address it here. Reviewed-by: Kevin Tian Signed-off-by: Robin Murphy Link: https://lore.kernel.org/r/579f2692291bcbfc3ac64f7456fcff0d629af131.1660572783.git.robin.murphy@arm.com Signed-off-by: Joerg Roedel Signed-off-by: Sasha Levin --- drivers/iommu/intel/iommu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c index 3ed15e8ca677..690fad0d37f8 100644 --- a/drivers/iommu/intel/iommu.c +++ b/drivers/iommu/intel/iommu.c @@ -4586,7 +4586,7 @@ static struct iommu_device *intel_iommu_probe_device(struct device *dev) u8 bus, devfn; iommu = device_to_iommu(dev, &bus, &devfn); - if (!iommu) + if (!iommu || !iommu->iommu.ops) return ERR_PTR(-ENODEV); info = kzalloc(sizeof(*info), GFP_KERNEL); -- 2.35.1