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 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=ham 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 023FCC433DF for ; Mon, 12 Oct 2020 13:44:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C5C7922273 for ; Mon, 12 Oct 2020 13:44:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1602510279; bh=9jf8/2pMdLGUD/SuF7vDmhqV2XjIPuHv9JsZXVZ+gzo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=H43qDbeiyPQLIGZqQBETeJaGTbWfOawltHaDQhVtEzjhcw45QurO/hRwsOUyfr6j+ eZLfm95VQSOFrP3Kx7TjjUyVJ4kCTzcUNZg8vj8VP7yq5uq0WXkd+poXiiHH3x/5ib VZPBsoZqi4oEdvv7U3Li+ZoS6lpEl/PAzmuJAVkM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389527AbgJLNoi (ORCPT ); Mon, 12 Oct 2020 09:44:38 -0400 Received: from mail.kernel.org ([198.145.29.99]:48386 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730666AbgJLNnL (ORCPT ); Mon, 12 Oct 2020 09:43:11 -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 1880920678; Mon, 12 Oct 2020 13:43:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1602510189; bh=9jf8/2pMdLGUD/SuF7vDmhqV2XjIPuHv9JsZXVZ+gzo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=GeMTLIcgIPtlZdah33jk57+5QbGAhi/mKiGiTsbtbrIOhGjrN2iaXJ8Fqfkn+96CW juHMqcYncYcjT7VL+qi4OrLt9TeKklR4FQPWBXhpKTuCyQwLu942OfhRlZLLjQDEcK TcAPVbEAS95QnfY8A/oKPplw7eQPukeRFZsKG57c= 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 5.4 48/85] iommu/vt-d: Fix lockdep splat in iommu_flush_dev_iotlb() Date: Mon, 12 Oct 2020 15:27:11 +0200 Message-Id: <20201012132635.176466904@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20201012132632.846779148@linuxfoundation.org> References: <20201012132632.846779148@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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 2ffec65df3889..1147626f0d253 100644 --- a/drivers/iommu/intel-iommu.c +++ b/drivers/iommu/intel-iommu.c @@ -2560,14 +2560,14 @@ 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); 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); -- 2.25.1