From patchwork Thu Feb 4 16:58:31 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Daniel Vetter X-Patchwork-Id: 1436145 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=linux-pci-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dkim=pass (1024-bit key; secure) header.d=ffwll.ch header.i=@ffwll.ch header.a=rsa-sha256 header.s=google header.b=aJ5+DhwQ; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4DWlPV1HxVz9sXh for ; Fri, 5 Feb 2021 04:08:30 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238277AbhBDRIN (ORCPT ); Thu, 4 Feb 2021 12:08:13 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58256 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238287AbhBDRAM (ORCPT ); Thu, 4 Feb 2021 12:00:12 -0500 Received: from mail-wm1-x335.google.com (mail-wm1-x335.google.com [IPv6:2a00:1450:4864:20::335]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 63229C0617AA for ; Thu, 4 Feb 2021 08:58:43 -0800 (PST) Received: by mail-wm1-x335.google.com with SMTP id j11so3749265wmi.3 for ; Thu, 04 Feb 2021 08:58:43 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ffwll.ch; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=zfjsqmGSrFdwKv6gPk+ED4Gyd+jw5WiGxS5237MFi+M=; b=aJ5+DhwQrPybxXlfb906b5cOoXqV3+BEzRNaODlgcUeZEihmbGyFqInXWRKhUtRcBb kV1JlIXsN/H9/ywDpKO+frxErEGohc9ib+E0uHFogDM0U0dQ89h8KGu5yffJo80lIAtT UAwiQzvCPO4zBLBzmVgGmSMpEEerY8KT11ZQ0= 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:in-reply-to :references:mime-version:content-transfer-encoding; bh=zfjsqmGSrFdwKv6gPk+ED4Gyd+jw5WiGxS5237MFi+M=; b=i0Ghx6gmbE+CVc1ONhy4YMpbt//B8weohZpcvLkky9jJ5bWGdTP9pMkIW1mzMbISCi LH11+WfiUULpbukyBgfdrxhBEj3zu1qfUFZV4z+F6+5hf3WEtLP7ZZcm8peLVtXkTnvC dpDyIyuBrkS55+8qlrgOkgUjT2AVE/XsHm3LkeldfKfK/JRqBhIymfapIKdoOrrQFHkX +85tGzZBcDfG/VkD/FhvKLXVCRYDK8hNu8wpmKdPeaEOxrUgYndQ1LcYaGzgt5PKhWzA Op2eVfwvqgNcFncgcuC3PXaNUkyLOKSCPjso0SsTzMKA2B9PZnyuYnMu3m8PQStnvufQ Vlhw== X-Gm-Message-State: AOAM531PoLl7Z4ThY2yKmHeuROPj/47FPkgn8XukXXq+v3VvSbrtwj8+ 3FxXsf4NJoI2+SXx7ON88cPUsw== X-Google-Smtp-Source: ABdhPJxAhpv3Tii2s/pNvg41KfaTlUA/3DjBqaXWiLy9Id66LvhcG0GjOf8lXMNmb3BMhPDKwGE71w== X-Received: by 2002:a1c:3587:: with SMTP id c129mr117766wma.76.1612457922116; Thu, 04 Feb 2021 08:58:42 -0800 (PST) Received: from phenom.ffwll.local ([2a02:168:57f4:0:efd0:b9e5:5ae6:c2fa]) by smtp.gmail.com with ESMTPSA id i64sm6700187wmi.19.2021.02.04.08.58.40 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 04 Feb 2021 08:58:40 -0800 (PST) From: Daniel Vetter To: LKML Cc: DRI Development , Daniel Vetter , Bjorn Helgaas , Dan Williams , Daniel Vetter , Stephen Rothwell , Jason Gunthorpe , Kees Cook , Andrew Morton , John Hubbard , =?utf-8?b?SsOpcsO0bWUgR2xpc3Nl?= , Jan Kara , Greg Kroah-Hartman , linux-mm@kvack.org, linux-arm-kernel@lists.infradead.org, linux-samsung-soc@vger.kernel.org, linux-media@vger.kernel.org, linux-pci@vger.kernel.org Subject: [PATCH 2/2] PCI: Revoke mappings like devmem Date: Thu, 4 Feb 2021 17:58:31 +0100 Message-Id: <20210204165831.2703772-3-daniel.vetter@ffwll.ch> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210204165831.2703772-1-daniel.vetter@ffwll.ch> References: <20210204165831.2703772-1-daniel.vetter@ffwll.ch> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org Since 3234ac664a87 ("/dev/mem: Revoke mappings when a driver claims the region") /dev/kmem zaps ptes when the kernel requests exclusive acccess to an iomem region. And with CONFIG_IO_STRICT_DEVMEM, this is the default for all driver uses. Except there's two more ways to access PCI BARs: sysfs and proc mmap support. Let's plug that hole. For revoke_devmem() to work we need to link our vma into the same address_space, with consistent vma->vm_pgoff. ->pgoff is already adjusted, because that's how (io_)remap_pfn_range works, but for the mapping we need to adjust vma->vm_file->f_mapping. The cleanest way is to adjust this at at ->open time: - for sysfs this is easy, now that binary attributes support this. We just set bin_attr->mapping when mmap is supported - for procfs it's a bit more tricky, since procfs pci access has only one file per device, and access to a specific resources first needs to be set up with some ioctl calls. But mmap is only supported for the same resources as sysfs exposes with mmap support, and otherwise rejected, so we can set the mapping unconditionally at open time without harm. A special consideration is for arch_can_pci_mmap_io() - we need to make sure that the ->f_mapping doesn't alias between ioport and iomem space. There's only 2 ways in-tree to support mmap of ioports: generic pci mmap (ARCH_GENERIC_PCI_MMAP_RESOURCE), and sparc as the single architecture hand-rolling. Both approach support ioport mmap through a special pfn range and not through magic pte attributes. Aliasing is therefore not a problem. The only difference in access checks left is that sysfs PCI mmap does not check for CAP_RAWIO. I'm not really sure whether that should be added or not. Acked-by: Bjorn Helgaas Reviewed-by: Dan Williams Signed-off-by: Daniel Vetter Cc: Stephen Rothwell Cc: Jason Gunthorpe Cc: Kees Cook Cc: Dan Williams Cc: Andrew Morton Cc: John Hubbard Cc: Jérôme Glisse Cc: Jan Kara Cc: Dan Williams Cc: Greg Kroah-Hartman Cc: linux-mm@kvack.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-samsung-soc@vger.kernel.org Cc: linux-media@vger.kernel.org Cc: Bjorn Helgaas Cc: linux-pci@vger.kernel.org --- drivers/pci/pci-sysfs.c | 4 ++++ drivers/pci/proc.c | 1 + 2 files changed, 5 insertions(+) diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c index 0c45b4f7b214..f8afd54ca3e1 100644 --- a/drivers/pci/pci-sysfs.c +++ b/drivers/pci/pci-sysfs.c @@ -942,6 +942,7 @@ void pci_create_legacy_files(struct pci_bus *b) b->legacy_io->read = pci_read_legacy_io; b->legacy_io->write = pci_write_legacy_io; b->legacy_io->mmap = pci_mmap_legacy_io; + b->legacy_io->mapping = iomem_get_mapping(); pci_adjust_legacy_attr(b, pci_mmap_io); error = device_create_bin_file(&b->dev, b->legacy_io); if (error) @@ -954,6 +955,7 @@ void pci_create_legacy_files(struct pci_bus *b) b->legacy_mem->size = 1024*1024; b->legacy_mem->attr.mode = 0600; b->legacy_mem->mmap = pci_mmap_legacy_mem; + b->legacy_io->mapping = iomem_get_mapping(); pci_adjust_legacy_attr(b, pci_mmap_mem); error = device_create_bin_file(&b->dev, b->legacy_mem); if (error) @@ -1169,6 +1171,8 @@ static int pci_create_attr(struct pci_dev *pdev, int num, int write_combine) res_attr->mmap = pci_mmap_resource_uc; } } + if (res_attr->mmap) + res_attr->mapping = iomem_get_mapping(); res_attr->attr.name = res_attr_name; res_attr->attr.mode = 0600; res_attr->size = pci_resource_len(pdev, num); diff --git a/drivers/pci/proc.c b/drivers/pci/proc.c index 3a2f90beb4cb..9bab07302bbf 100644 --- a/drivers/pci/proc.c +++ b/drivers/pci/proc.c @@ -298,6 +298,7 @@ static int proc_bus_pci_open(struct inode *inode, struct file *file) fpriv->write_combine = 0; file->private_data = fpriv; + file->f_mapping = iomem_get_mapping(); return 0; }