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=-18.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,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 5487BC433B4 for ; Wed, 14 Apr 2021 08:29:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 35881610E8 for ; Wed, 14 Apr 2021 08:29:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344492AbhDNIaK (ORCPT ); Wed, 14 Apr 2021 04:30:10 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39420 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1350064AbhDNI3f (ORCPT ); Wed, 14 Apr 2021 04:29:35 -0400 Received: from mail-wm1-x333.google.com (mail-wm1-x333.google.com [IPv6:2a00:1450:4864:20::333]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 73E5DC061574 for ; Wed, 14 Apr 2021 01:29:13 -0700 (PDT) Received: by mail-wm1-x333.google.com with SMTP id o21-20020a1c4d150000b029012e52898006so428071wmh.0 for ; Wed, 14 Apr 2021 01:29:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=epXw3irDvsvZFL4o434NpborWULmmHYE5K7OMVRyRAI=; b=p7Sxm7w9vNyyhaZiiyz/88cew7fUg3K8H2EC02WrUDTOxJ+2hC/CbH8VY3rrYvX7eO uXMzbiDRMr6+nUahA7p0JZigYAC26pMFHDdVxyyTBvUtSCN17kVwhxyOtanZ2m1yrU0a PIzpBpDOKr+9R/QEzcW2792Htj+Sp/VfoWh6o0mux4Fa8voOp7Fv7ufJr7RHhlXRQmhP oaymv49jrNB2zFc/5CRVufR87V5BwOu1+7EZ1mEtQP/dNOzv+xaz6A5TPrLkgu2nffad Frd3gdc3Xk7xN5YU2hiw2L6CdAZFkZkbMw4G9LTDk8d3atgG7ZlqgojFSKM36b+gAg9q 25XQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=epXw3irDvsvZFL4o434NpborWULmmHYE5K7OMVRyRAI=; b=VfK45o42K4AOGQBXzAQ3Zjnd9LpPB4/TMQtMteIFACbjY5I2PEg0Rs6OnNPZiDUyMM Z4cSzbUIsMHnom0Uzn5oPKb1lcua25J+sdTnJu+dSz8CgwXM7V8g/jeqqyRv6pMf0xmE l0vLDRqwGYM+MrA9PeXESlmLUhsFfKNVCMH8LfMWIvjNoZ+GcWvuWrIF2ghmCNfNqTDp pL5snxwFvfUZGXoFns30k/SIApDGW/VBre4ddBCeZc7BdiIBH/B4MaonQlYlbi9k82nc wV5bn+TQjfsupmbM6g3MnvOXcQOK2RAXtu6msaIMYnX3RlD9jVVKSHWfzSuqMKaDb2OQ OrNA== X-Gm-Message-State: AOAM532MDAz7/4Kkd74gxgSYXY1P2gR8UdHv+zg62YFPQPKyDUHI/jNY slfYkvC3QUstPW+/aDuTIGXG6g== X-Google-Smtp-Source: ABdhPJwM8rnaaPmIEmSVIcO5Ix/lhhztBwn1RzthnOJVzNgGDiuXonPn4QdXuKllPtda2dypc+NOZQ== X-Received: by 2002:a7b:c8ce:: with SMTP id f14mr1765553wml.113.1618388952091; Wed, 14 Apr 2021 01:29:12 -0700 (PDT) Received: from localhost.localdomain ([2001:1715:4e26:a7e0:116c:c27a:3e7f:5eaf]) by smtp.gmail.com with ESMTPSA id c12sm23850730wro.6.2021.04.14.01.29.11 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 14 Apr 2021 01:29:11 -0700 (PDT) From: Jean-Philippe Brucker To: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, x86@kernel.org Cc: hpa@zytor.com, linux-kernel@vger.kernel.org, joro@8bytes.org, will@kernel.org, iommu@lists.linux-foundation.org, robin.murphy@arm.com, hch@lst.de, Jean-Philippe Brucker Subject: [PATCH] x86/dma: Tear down DMA ops on driver unbind Date: Wed, 14 Apr 2021 10:26:34 +0200 Message-Id: <20210414082633.877461-1-jean-philippe@linaro.org> X-Mailer: git-send-email 2.31.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Since commit 08a27c1c3ecf ("iommu: Add support to change default domain of an iommu group") a user can switch a device between IOMMU and direct DMA through sysfs. This doesn't work for AMD IOMMU at the moment because dev->dma_ops is not cleared when switching from a DMA to an identity IOMMU domain. The DMA layer thus attempts to use the dma-iommu ops on an identity domain, causing an oops: # echo 0000:00:05.0 > /sys/sys/bus/pci/drivers/e1000e/unbind # echo identity > /sys/bus/pci/devices/0000:00:05.0/iommu_group/type # echo 0000:00:05.0 > /sys/sys/bus/pci/drivers/e1000e/bind ... [ 190.017587] BUG: kernel NULL pointer dereference, address: 0000000000000028 ... [ 190.027375] Call Trace: [ 190.027561] iommu_dma_alloc+0xd0/0x100 [ 190.027840] e1000e_setup_tx_resources+0x56/0x90 [ 190.028173] e1000e_open+0x75/0x5b0 Implement arch_teardown_dma_ops() on x86 to clear the device's dma_ops pointer during driver unbind. Fixes: 08a27c1c3ecf ("iommu: Add support to change default domain of an iommu group") Signed-off-by: Jean-Philippe Brucker --- arch/x86/Kconfig | 1 + arch/x86/kernel/pci-dma.c | 7 +++++++ 2 files changed, 8 insertions(+) diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 2792879d398e..2c90f8de3e20 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -85,6 +85,7 @@ config X86 select ARCH_HAS_STRICT_MODULE_RWX select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE select ARCH_HAS_SYSCALL_WRAPPER + select ARCH_HAS_TEARDOWN_DMA_OPS if IOMMU_DMA select ARCH_HAS_UBSAN_SANITIZE_ALL select ARCH_HAS_DEBUG_WX select ARCH_HAVE_NMI_SAFE_CMPXCHG diff --git a/arch/x86/kernel/pci-dma.c b/arch/x86/kernel/pci-dma.c index de234e7a8962..60a4ec22d849 100644 --- a/arch/x86/kernel/pci-dma.c +++ b/arch/x86/kernel/pci-dma.c @@ -154,3 +154,10 @@ static void via_no_dac(struct pci_dev *dev) DECLARE_PCI_FIXUP_CLASS_FINAL(PCI_VENDOR_ID_VIA, PCI_ANY_ID, PCI_CLASS_BRIDGE_PCI, 8, via_no_dac); #endif + +#ifdef CONFIG_ARCH_HAS_TEARDOWN_DMA_OPS +void arch_teardown_dma_ops(struct device *dev) +{ + set_dma_ops(dev, NULL); +} +#endif -- 2.31.1