From patchwork Fri May 22 13:01:45 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sai Prakash Ranjan X-Patchwork-Id: 189020 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=-9.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, 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 EE08EC433E0 for ; Fri, 22 May 2020 13:02:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CC71F20723 for ; Fri, 22 May 2020 13:02:10 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=mg.codeaurora.org header.i=@mg.codeaurora.org header.b="xV1/xTIp" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729344AbgEVNCJ (ORCPT ); Fri, 22 May 2020 09:02:09 -0400 Received: from mail27.static.mailgun.info ([104.130.122.27]:47069 "EHLO mail27.static.mailgun.info" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729334AbgEVNCI (ORCPT ); Fri, 22 May 2020 09:02:08 -0400 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1590152527; h=Content-Transfer-Encoding: MIME-Version: Message-Id: Date: Subject: Cc: To: From: Sender; bh=aZcjMzyQhmF408KAg+aRhNzpY4xzo8oNxhr6p1nbQUY=; b=xV1/xTIpd6GiytgwzC3Ns1UZXI6nMlrP67slC4FHVvZ2pUz5Aa7195kowF1wM0CEcw0xJRAB 0zh85nb15ZMDIRK9PVyDQdFtK3//v+VSL0/88nMEUTbzHitQ2wCM3DVr7O2Ig16TnZ6S2+o0 l1RG/sY2E7DGLx9amJHdB0uTEdg= X-Mailgun-Sending-Ip: 104.130.122.27 X-Mailgun-Sid: WyI1MzIzYiIsICJsaW51eC1hcm0tbXNtQHZnZXIua2VybmVsLm9yZyIsICJiZTllNGEiXQ== Received: from smtp.codeaurora.org (ec2-35-166-182-171.us-west-2.compute.amazonaws.com [35.166.182.171]) by mxa.mailgun.org with ESMTP id 5ec7cd47.7f12840a2c38-smtp-out-n05; Fri, 22 May 2020 13:01:59 -0000 (UTC) Received: by smtp.codeaurora.org (Postfix, from userid 1001) id 1EAC6C433CB; Fri, 22 May 2020 13:01:59 +0000 (UTC) Received: from blr-ubuntu-311.qualcomm.com (blr-bdr-fw-01_GlobalNAT_AllZones-Outside.qualcomm.com [103.229.18.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: saiprakash.ranjan) by smtp.codeaurora.org (Postfix) with ESMTPSA id 29C5BC433C6; Fri, 22 May 2020 13:01:53 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 29C5BC433C6 Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; spf=none smtp.mailfrom=saiprakash.ranjan@codeaurora.org From: Sai Prakash Ranjan To: Will Deacon , Robin Murphy , Joerg Roedel , Joerg Roedel Cc: iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Evan Green , Douglas Anderson , Sai Prakash Ranjan Subject: [PATCH] iommu: Fix group refcount in iommu_alloc_default_domain() Date: Fri, 22 May 2020 18:31:45 +0530 Message-Id: <20200522130145.30067-1-saiprakash.ranjan@codeaurora.org> X-Mailer: git-send-email 2.22.0 MIME-Version: 1.0 Sender: linux-arm-msm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org Since the change to move default domain allocation to probe, there is a refcount decrement missing for the group in iommu_alloc_default_domain(). Because of this missing refcount decrement, the device is never released from the group as the devices_kobj refcount never reaches 0 in iommu_group_remove_device() leading to a lot of issues. One such case is that this will lead to a different group allocation on every reload of the module which configures iommu such as the ath10k module which then finally fails to attach this device to the SMMU with -ENOSPC error in __arm_smmu_alloc_bitmap() once the count of module reload crosses the number of context banks. This will then lead to NULL pointer deference in the next reload of the module. Add the missing refcount decrement(iommu_group_put()) in iommu_alloc_default_domain() to fix this issue. Call trace: ... platform wifi-firmware.0: Adding to iommu group 82 ath10k_snoc 18800000.wifi: could not attach device: -28 platform wifi-firmware.0: Removing from iommu group 82 ath10k_snoc 18800000.wifi: failed to initialize firmware: -28 ath10k_snoc: probe of 18800000.wifi failed with error -28 platform wifi-firmware.0: Adding to iommu group 83 Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000 Mem abort info: ESR = 0x96000006 EC = 0x25: DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 Data abort info: ISV = 0, ISS = 0x00000006 CM = 0, WnR = 0 user pgtable: 4k pages, 39-bit VAs, pgdp=0000000177a53000 [0000000000000000] pgd=00000001e74f5003, pud=00000001e74f5003, pmd=0000000000000000 Internal error: Oops: 96000006 [#1] PREEMPT SMP pstate: 60400009 (nZCv daif +PAN -UAO) arm_smmu_flush_iotlb_all+0x20/0x6c iommu_create_device_direct_mappings+0x17c/0x1d8 iommu_probe_device+0xc0/0x100 of_iommu_configure+0x108/0x240 of_dma_configure+0x130/0x1d0 ath10k_fw_init+0xc4/0x1c4 [ath10k_snoc] ath10k_snoc_probe+0x5cc/0x678 [ath10k_snoc] platform_drv_probe+0x90/0xb0 really_probe+0x134/0x2ec driver_probe_device+0x64/0xfc device_driver_attach+0x4c/0x6c __driver_attach+0xac/0xc0 bus_for_each_dev+0x8c/0xd4 driver_attach+0x2c/0x38 bus_add_driver+0xfc/0x1d0 driver_register+0x64/0xf8 __platform_driver_register+0x4c/0x58 init_module+0x20/0x1000 [ath10k_snoc] do_one_initcall+0x13c/0x2d0 do_init_module+0x58/0x1dc load_module+0xde0/0xf10 __arm64_sys_finit_module+0xb0/0xe0 el0_svc_common+0xa4/0x154 el0_svc_compat_handler+0x2c/0x38 el0_svc_compat+0x8/0x10 Code: d503201f f85b8268 b4000248 f8560e74 (f9400280) ---[ end trace e5c1470a584952a0 ]--- Kernel panic - not syncing: Fatal exception Signed-off-by: Sai Prakash Ranjan --- drivers/iommu/iommu.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index a4c2f122eb8b..05f7b77c432f 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -1491,6 +1491,7 @@ static int iommu_alloc_default_domain(struct device *dev) { struct iommu_group *group; unsigned int type; + int ret; group = iommu_group_get(dev); if (!group) @@ -1501,7 +1502,11 @@ static int iommu_alloc_default_domain(struct device *dev) type = iommu_get_def_domain_type(dev); - return iommu_group_alloc_default_domain(dev->bus, group, type); + ret = iommu_group_alloc_default_domain(dev->bus, group, type); + + iommu_group_put(group); + + return ret; } /**