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=-9.8 required=3.0 tests=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 8B2FAC433E0 for ; Tue, 19 May 2020 13:28:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 65ADA207D8 for ; Tue, 19 May 2020 13:28:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728982AbgESN2f (ORCPT ); Tue, 19 May 2020 09:28:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47136 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728725AbgESN2f (ORCPT ); Tue, 19 May 2020 09:28:35 -0400 Received: from theia.8bytes.org (8bytes.org [IPv6:2a01:238:4383:600:38bc:a715:4b6d:a889]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4320BC08C5C0 for ; Tue, 19 May 2020 06:28:35 -0700 (PDT) Received: by theia.8bytes.org (Postfix, from userid 1000) id 7785F386; Tue, 19 May 2020 15:28:33 +0200 (CEST) From: Joerg Roedel To: iommu@lists.linux-foundation.org Cc: Joerg Roedel , Matthias Brugger , Marek Szyprowski , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org, Joerg Roedel , Yong Wu Subject: [PATCH] iommu: Don't call .probe_finalize() under group->mutex Date: Tue, 19 May 2020 15:28:24 +0200 Message-Id: <20200519132824.15163-1-joro@8bytes.org> X-Mailer: git-send-email 2.17.1 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Joerg Roedel The .probe_finalize() call-back of some IOMMU drivers calls into arm_iommu_attach_device(). This function will call back into the IOMMU core code, where it tries to take group->mutex again, resulting in a deadlock. As there is no reason why .probe_finalize() needs to be called under that mutex, move it after the lock has been released to fix the deadlock. Cc: Yong Wu Reported-by: Yong Wu Fixes: deac0b3bed26 ("iommu: Split off default domain allocation from group assignment") Signed-off-by: Joerg Roedel --- drivers/iommu/iommu.c | 28 ++++++++++++++++++---------- 1 file changed, 18 insertions(+), 10 deletions(-) diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 629d209b8e88..d5d9fcbc9714 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -1683,17 +1683,8 @@ static void probe_alloc_default_domain(struct bus_type *bus, static int iommu_group_do_dma_attach(struct device *dev, void *data) { struct iommu_domain *domain = data; - const struct iommu_ops *ops; - int ret; - - ret = __iommu_attach_device(domain, dev); - - ops = domain->ops; - - if (ret == 0 && ops->probe_finalize) - ops->probe_finalize(dev); - return ret; + return __iommu_attach_device(domain, dev); } static int __iommu_group_dma_attach(struct iommu_group *group) @@ -1702,6 +1693,21 @@ static int __iommu_group_dma_attach(struct iommu_group *group) iommu_group_do_dma_attach); } +static int iommu_group_do_probe_finalize(struct device *dev, void *data) +{ + struct iommu_domain *domain = data; + + if (domain->ops->probe_finalize) + domain->ops->probe_finalize(dev); + + return 0; +} + +static void __iommu_group_dma_finalize(struct iommu_group *group) +{ + __iommu_group_for_each_dev(group, group->default_domain, + iommu_group_do_probe_finalize); +} static int iommu_do_create_direct_mappings(struct device *dev, void *data) { struct iommu_group *group = data; @@ -1754,6 +1760,8 @@ int bus_iommu_probe(struct bus_type *bus) if (ret) break; + + __iommu_group_dma_finalize(group); } return ret; -- 2.25.1