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=-19.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,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 D5183C43217 for ; Tue, 12 Jan 2021 13:14:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A176A2311E for ; Tue, 12 Jan 2021 13:14:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733084AbhALNOL (ORCPT ); Tue, 12 Jan 2021 08:14:11 -0500 Received: from mail.kernel.org ([198.145.29.99]:53818 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2404121AbhALM5r (ORCPT ); Tue, 12 Jan 2021 07:57:47 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id C719C2333D; Tue, 12 Jan 2021 12:56:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1610456197; bh=zLYawgbkxTGvzeINYqmnu2PERnl3cvpEaR0b/BUkCDA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=l66f19BeB76GRBoCMvC7bMI3PlTsCgW0V7KMc1JVg/uU1KR+jnlDacG5dcEUUPRDS ElC9MePLgd2a916CB0urItgjAFunmDFuzXu15aSn0u3rPDZ2gyNAhuJZqIfxEpJDDR JaJF7/IrkR0g3xpjXUtf8T7Qc0m9yqQO7eHkSqiTgd0d+sRz5J2rClwHaRRzdy6NJY JwPoDpgR70ScTNhzsK3p/eZLqx4Wu5I+mngjDPstAQ7Ca291qeuFai+JgltORzsz06 ItT3ev9kJVQeV4zdOG+NrxZ9gKpbLmYLMaZXmRfwWIl+i95vQMjO8fwuJCqiVaOIz8 bYsXjs3VUxicg== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Lu Baolu , Will Deacon , Sasha Levin , iommu@lists.linux-foundation.org Subject: [PATCH AUTOSEL 5.10 47/51] iommu/vt-d: Fix lockdep splat in sva bind()/unbind() Date: Tue, 12 Jan 2021 07:55:29 -0500 Message-Id: <20210112125534.70280-47-sashal@kernel.org> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20210112125534.70280-1-sashal@kernel.org> References: <20210112125534.70280-1-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: Lu Baolu [ Upstream commit 420d42f6f9db27d88bc4f83e3e668fcdacbf7e29 ] Lock(&iommu->lock) without disabling irq causes lockdep warnings. ======================================================== WARNING: possible irq lock inversion dependency detected 5.11.0-rc1+ #828 Not tainted -------------------------------------------------------- kworker/0:1H/120 just changed the state of lock: ffffffffad9ea1b8 (device_domain_lock){..-.}-{2:2}, at: iommu_flush_dev_iotlb.part.0+0x32/0x120 but this lock took another, SOFTIRQ-unsafe lock in the past: (&iommu->lock){+.+.}-{2:2} and interrupts could create inverse lock ordering between them. other info that might help us debug this: Possible interrupt unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&iommu->lock); local_irq_disable(); lock(device_domain_lock); lock(&iommu->lock); lock(device_domain_lock); *** DEADLOCK *** Signed-off-by: Lu Baolu Link: https://lore.kernel.org/r/20201231005323.2178523-5-baolu.lu@linux.intel.com Signed-off-by: Will Deacon Signed-off-by: Sasha Levin --- drivers/iommu/intel/svm.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c index 3242ebd0bca36..267001e8076cd 100644 --- a/drivers/iommu/intel/svm.c +++ b/drivers/iommu/intel/svm.c @@ -281,6 +281,7 @@ int intel_svm_bind_gpasid(struct iommu_domain *domain, struct device *dev, struct dmar_domain *dmar_domain; struct device_domain_info *info; struct intel_svm *svm = NULL; + unsigned long iflags; int ret = 0; if (WARN_ON(!iommu) || !data) @@ -381,12 +382,12 @@ int intel_svm_bind_gpasid(struct iommu_domain *domain, struct device *dev, * each bind of a new device even with an existing PASID, we need to * call the nested mode setup function here. */ - spin_lock(&iommu->lock); + spin_lock_irqsave(&iommu->lock, iflags); ret = intel_pasid_setup_nested(iommu, dev, (pgd_t *)(uintptr_t)data->gpgd, data->hpasid, &data->vendor.vtd, dmar_domain, data->addr_width); - spin_unlock(&iommu->lock); + spin_unlock_irqrestore(&iommu->lock, iflags); if (ret) { dev_err_ratelimited(dev, "Failed to set up PASID %llu in nested mode, Err %d\n", data->hpasid, ret); @@ -486,6 +487,7 @@ intel_svm_bind_mm(struct device *dev, unsigned int flags, struct device_domain_info *info; struct intel_svm_dev *sdev; struct intel_svm *svm = NULL; + unsigned long iflags; int pasid_max; int ret; @@ -605,14 +607,14 @@ intel_svm_bind_mm(struct device *dev, unsigned int flags, } } - spin_lock(&iommu->lock); + spin_lock_irqsave(&iommu->lock, iflags); ret = intel_pasid_setup_first_level(iommu, dev, mm ? mm->pgd : init_mm.pgd, svm->pasid, FLPT_DEFAULT_DID, (mm ? 0 : PASID_FLAG_SUPERVISOR_MODE) | (cpu_feature_enabled(X86_FEATURE_LA57) ? PASID_FLAG_FL5LP : 0)); - spin_unlock(&iommu->lock); + spin_unlock_irqrestore(&iommu->lock, iflags); if (ret) { if (mm) mmu_notifier_unregister(&svm->notifier, mm); @@ -632,14 +634,14 @@ intel_svm_bind_mm(struct device *dev, unsigned int flags, * Binding a new device with existing PASID, need to setup * the PASID entry. */ - spin_lock(&iommu->lock); + spin_lock_irqsave(&iommu->lock, iflags); ret = intel_pasid_setup_first_level(iommu, dev, mm ? mm->pgd : init_mm.pgd, svm->pasid, FLPT_DEFAULT_DID, (mm ? 0 : PASID_FLAG_SUPERVISOR_MODE) | (cpu_feature_enabled(X86_FEATURE_LA57) ? PASID_FLAG_FL5LP : 0)); - spin_unlock(&iommu->lock); + spin_unlock_irqrestore(&iommu->lock, iflags); if (ret) { kfree(sdev); goto out; -- 2.27.0