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=-8.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 02A21C31E4B for ; Thu, 13 Jun 2019 17:15:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C5D422053B for ; Thu, 13 Jun 2019 17:15:00 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=arista.com header.i=@arista.com header.b="o0tcrE69" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729021AbfFMRO7 (ORCPT ); Thu, 13 Jun 2019 13:14:59 -0400 Received: from smtp.aristanetworks.com ([52.0.43.43]:48988 "EHLO smtp.aristanetworks.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728803AbfFLVwd (ORCPT ); Wed, 12 Jun 2019 17:52:33 -0400 Received: from smtp.aristanetworks.com (localhost [127.0.0.1]) by smtp.aristanetworks.com (Postfix) with ESMTP id 4416C30DD5A8; Wed, 12 Jun 2019 14:52:32 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=arista.com; s=Arista-A; t=1560376352; bh=0YAEwRV8pxaKDZriNp5u14v56Dsy6P+WWcBl+ItO2zQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=o0tcrE69nlTRCy8oBfpiQeJnWgJI43UMXL1JcrYTR2TXwxuLOjTUIkPuuv7MXRqf3 YDdo4KeSF7MlOXZXb7AcDS73JCOrcTPDsNRD4rK+wv47rTdNi/Dc4KogK0ScKquYPV Ayw16OMjHVDyyC60fkrTALrVED6wYi0cwq1M46w3MRBQiHsWK1VL5/PNAqeW/k71J+ 4XnRx4EtiNG+hmSo4aT7WSqrihEBBWcbcaJ+WnRm/tK4ynARFh/fm+IltVeyrfW6d2 B0MazUx5XKO6Am0eX+nacKTrwXnAepR4LkQz0xllOJX0zJAdCpdDjGtbXR9W0xEe3g 5b148ONyu7h9A== Received: from chmeee (unknown [10.80.4.152]) by smtp.aristanetworks.com (Postfix) with ESMTP id 2AD1730DD5A5; Wed, 12 Jun 2019 14:52:32 -0700 (PDT) Received: from kevmitch by chmeee with local (Exim 4.92) (envelope-from ) id 1hbBAV-0003KF-JQ; Wed, 12 Jun 2019 14:52:31 -0700 From: Kevin Mitchell To: Joerg Roedel Cc: iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org, Kevin Mitchell Subject: [PATCH 1/3] iommu/amd: make iommu_disable safer Date: Wed, 12 Jun 2019 14:52:03 -0700 Message-Id: <20190612215203.12711-2-kevmitch@arista.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190612215203.12711-1-kevmitch@arista.com> References: <20190612215203.12711-1-kevmitch@arista.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Make it safe to call iommu_disable during early init error conditions before mmio_base is set, but after the struct amd_iommu has been added to the amd_iommu_list. For example, this happens if firmware fails to fill in mmio_phys in the ACPI table leading to a NULL pointer dereference in iommu_feature_disable. Signed-off-by: Kevin Mitchell --- drivers/iommu/amd_iommu_init.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/iommu/amd_iommu_init.c b/drivers/iommu/amd_iommu_init.c index f773792d77fd..3798d7303c99 100644 --- a/drivers/iommu/amd_iommu_init.c +++ b/drivers/iommu/amd_iommu_init.c @@ -424,6 +424,9 @@ static void iommu_enable(struct amd_iommu *iommu) static void iommu_disable(struct amd_iommu *iommu) { + if (!iommu->mmio_base) + return; + /* Disable command buffer */ iommu_feature_disable(iommu, CONTROL_CMDBUF_EN); -- 2.20.1