From patchwork Mon Oct 12 13:30:56 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 270277 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-12.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A75FAC43457 for ; Mon, 12 Oct 2020 13:53:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 733292076E for ; Mon, 12 Oct 2020 13:53:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1602510833; bh=vOWJK81gI4SZUmr6nCexPxODyzmE8BKlV1U476drK1E=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=VK+3N7gB7c+9sBFYqD7xQC7dOV2XOn5/IX5b6O6n6N3LeR7cY1t0LtGwy2Bi2vJKp TLs02IHAmzw62+qbyTZssL6jOait+H0XbccOOz3WOaIKp9YElYSaCfrf09pzreIlcy J647dcvXy+pB7lQlA6BkQamhHNRZojlsmV24iuoY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390304AbgJLNxf (ORCPT ); Mon, 12 Oct 2020 09:53:35 -0400 Received: from mail.kernel.org ([198.145.29.99]:53876 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731419AbgJLNq5 (ORCPT ); Mon, 12 Oct 2020 09:46:57 -0400 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id C57BF2087E; Mon, 12 Oct 2020 13:46:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1602510392; bh=vOWJK81gI4SZUmr6nCexPxODyzmE8BKlV1U476drK1E=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=uDw6KnPVit8oV8H4XWiLU/62ocvmEqmwC6IFLAHLzPqXYSNDnQF45YWDef63WLX6S 4TZIiFp3TtVg9y0RWtJ4gm4IFqyee/BIdRbaetZj5CRPu2e2AGzFxpu1deOb8vq9An R5BrV7VMwJcCAX9apW4KszcGm0ntwZ8BjUV1MCsc= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Lu Baolu , Joerg Roedel , Sasha Levin Subject: [PATCH 5.8 052/124] iommu/vt-d: Fix lockdep splat in iommu_flush_dev_iotlb() Date: Mon, 12 Oct 2020 15:30:56 +0200 Message-Id: <20201012133149.373348876@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20201012133146.834528783@linuxfoundation.org> References: <20201012133146.834528783@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Lu Baolu [ Upstream commit 1a3f2fd7fc4e8f24510830e265de2ffb8e3300d2 ] Lock(&iommu->lock) without disabling irq causes lockdep warnings. [ 12.703950] ======================================================== [ 12.703962] WARNING: possible irq lock inversion dependency detected [ 12.703975] 5.9.0-rc6+ #659 Not tainted [ 12.703983] -------------------------------------------------------- [ 12.703995] systemd-udevd/284 just changed the state of lock: [ 12.704007] ffffffffbd6ff4d8 (device_domain_lock){..-.}-{2:2}, at: iommu_flush_dev_iotlb.part.57+0x2e/0x90 [ 12.704031] but this lock took another, SOFTIRQ-unsafe lock in the past: [ 12.704043] (&iommu->lock){+.+.}-{2:2} [ 12.704045] and interrupts could create inverse lock ordering between them. [ 12.704073] other info that might help us debug this: [ 12.704085] Possible interrupt unsafe locking scenario: [ 12.704097] CPU0 CPU1 [ 12.704106] ---- ---- [ 12.704115] lock(&iommu->lock); [ 12.704123] local_irq_disable(); [ 12.704134] lock(device_domain_lock); [ 12.704146] lock(&iommu->lock); [ 12.704158] [ 12.704164] lock(device_domain_lock); [ 12.704174] *** DEADLOCK *** Signed-off-by: Lu Baolu Link: https://lore.kernel.org/r/20200927062428.13713-1-baolu.lu@linux.intel.com Signed-off-by: Joerg Roedel Signed-off-by: Sasha Levin --- drivers/iommu/intel/iommu.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c index fbe0b0cc56edf..24a84d294fd01 100644 --- a/drivers/iommu/intel/iommu.c +++ b/drivers/iommu/intel/iommu.c @@ -2617,7 +2617,7 @@ static struct dmar_domain *dmar_insert_one_dev_info(struct intel_iommu *iommu, } /* Setup the PASID entry for requests without PASID: */ - spin_lock(&iommu->lock); + spin_lock_irqsave(&iommu->lock, flags); if (hw_pass_through && domain_type_is_si(domain)) ret = intel_pasid_setup_pass_through(iommu, domain, dev, PASID_RID2PASID); @@ -2627,7 +2627,7 @@ static struct dmar_domain *dmar_insert_one_dev_info(struct intel_iommu *iommu, else ret = intel_pasid_setup_second_level(iommu, domain, dev, PASID_RID2PASID); - spin_unlock(&iommu->lock); + spin_unlock_irqrestore(&iommu->lock, flags); if (ret) { dev_err(dev, "Setup RID2PASID failed\n"); dmar_remove_one_dev_info(dev);