From patchwork Fri Oct 9 07:59:33 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Daniel Vetter X-Patchwork-Id: 11825231 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id AA9D1175A for ; Fri, 9 Oct 2020 08:00:31 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 65A4322276 for ; Fri, 9 Oct 2020 08:00:31 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=ffwll.ch header.i=@ffwll.ch header.b="U+vzUSar" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 65A4322276 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ffwll.ch Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 251876EC7A; Fri, 9 Oct 2020 08:00:20 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from mail-wr1-x442.google.com (mail-wr1-x442.google.com [IPv6:2a00:1450:4864:20::442]) by gabe.freedesktop.org (Postfix) with ESMTPS id 0A35B6EC7D for ; Fri, 9 Oct 2020 08:00:17 +0000 (UTC) Received: by mail-wr1-x442.google.com with SMTP id e18so9231483wrw.9 for ; Fri, 09 Oct 2020 01:00:16 -0700 (PDT) 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=Mr0eqEhtLJlk9zvkUiO6msooid1XUy8va7iTFBhYa6o=; b=U+vzUSar2wtID/EuVPMnsGQ3mvxbnZE/AtjkzSl4866cTqT0Bce/+YpSi3OFfqGOCz +roCRyHkxz8LXBZQriCZTWPGyhTPs9bMUMnyXHelio94a0wfjayW85FaKxi67idHb1yM MDFwdizaRRBaDwf6exvt8kTlK5W9sazGrwsv0= 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=Mr0eqEhtLJlk9zvkUiO6msooid1XUy8va7iTFBhYa6o=; b=X5UTe1f3YQkJ0JW5cDdzLdTaSkA68vTBzUQKyatefiBBEEqsICAkS4mLq7XDc4PkYg NMhzBZp6h95l9JZuxYUgrQC6JGPrFBPZ7tTQcJ0yoJ6HonD4paVHU9DoEQSLn6Dfp+GT vqmk99JzrKAWjyVRWQcT1KG/inzJ4NRdTCOHVo0NKw+Xds58OLl7Vva/NpBMWMa9axJx nkamjJw5ZDzCYcE72P1WpGxn1S9IXj0Z1OkEWXo0mOpKPhOreIwbA9q6gfMaSMy6zwYv U5BN1wdUxa2hn6KDFs+kVf8elkvmUH2d3lvZGmdlnGBcUE1uZLc4Tp5ovAmD88Tgkj5D YECg== X-Gm-Message-State: AOAM532sChBZRK/MCvfwgjrNnOSWTCawahxphPRprbEE11Ci8JOcfnlj qOArgyt0vIZ2vpnCy2mOiWgyjE8jUF5cZaPW X-Google-Smtp-Source: ABdhPJyK6/zluwLchCVAu9wRdS90YK84DJ/TkLG0WrIGfx3gvXgwIQ2OcDSDDLV+etpfvi26XwXkuA== X-Received: by 2002:a5d:668b:: with SMTP id l11mr13032272wru.89.1602230415344; Fri, 09 Oct 2020 01:00:15 -0700 (PDT) Received: from phenom.ffwll.local ([2a02:168:57f4:0:efd0:b9e5:5ae6:c2fa]) by smtp.gmail.com with ESMTPSA id u17sm11634118wri.45.2020.10.09.01.00.13 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 09 Oct 2020 01:00:14 -0700 (PDT) From: Daniel Vetter To: DRI Development , LKML Subject: [PATCH v2 16/17] PCI: Revoke mappings like devmem Date: Fri, 9 Oct 2020 09:59:33 +0200 Message-Id: <20201009075934.3509076-17-daniel.vetter@ffwll.ch> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20201009075934.3509076-1-daniel.vetter@ffwll.ch> References: <20201009075934.3509076-1-daniel.vetter@ffwll.ch> MIME-Version: 1.0 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-s390@vger.kernel.org, linux-samsung-soc@vger.kernel.org, Jan Kara , Kees Cook , kvm@vger.kernel.org, Jason Gunthorpe , Daniel Vetter , linux-pci@vger.kernel.org, Greg Kroah-Hartman , linux-mm@kvack.org, =?utf-8?b?SsOpcsO0bWUgR2xpc3Nl?= , John Hubbard , Bjorn Helgaas , Daniel Vetter , Dan Williams , Andrew Morton , linux-arm-kernel@lists.infradead.org, linux-media@vger.kernel.org Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" 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. Signed-off-by: Daniel Vetter 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 --- v2: - Totally new approach: Adjust filp->f_mapping at open time. Note that this now works on all architectures, not just those support ARCH_GENERIC_PCI_MMAP_RESOURCE --- 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 6d78df981d41..cee38fcb4a86 100644 --- a/drivers/pci/pci-sysfs.c +++ b/drivers/pci/pci-sysfs.c @@ -928,6 +928,7 @@ 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) @@ -940,6 +941,7 @@ 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) @@ -1155,6 +1157,8 @@ 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; }