From patchwork Wed Oct 15 12:03:40 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lorenzo Pieralisi X-Patchwork-Id: 5085361 X-Patchwork-Delegate: bhelgaas@google.com Return-Path: X-Original-To: patchwork-linux-pci@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id DE8B99F349 for ; Wed, 15 Oct 2014 12:03:21 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id E5B5020136 for ; Wed, 15 Oct 2014 12:03:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F11B8200F2 for ; Wed, 15 Oct 2014 12:03:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752389AbaJOMDN (ORCPT ); Wed, 15 Oct 2014 08:03:13 -0400 Received: from service87.mimecast.com ([91.220.42.44]:55452 "EHLO service87.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751533AbaJOMDN (ORCPT ); Wed, 15 Oct 2014 08:03:13 -0400 Received: from cam-owa2.Emea.Arm.com (fw-tnat.cambridge.arm.com [217.140.96.21]) by service87.mimecast.com; Wed, 15 Oct 2014 13:03:09 +0100 Received: from red-moon.cambridge.arm.com ([10.1.255.212]) by cam-owa2.Emea.Arm.com with Microsoft SMTPSVC(6.0.3790.3959); Wed, 15 Oct 2014 13:03:06 +0100 From: Lorenzo Pieralisi To: linux-kernel@vger.kernel.org Cc: Arnd Bergmann , Bjorn Helgaas , Benjamin Herrenschmidt , Russell King , "David S. Miller" , Michal Simek , Martin Wilck , "Derrick J. Wong" , Linux PCI Subject: [PATCH RFC 1/2] drivers: pci: fix pci_mmap_fits() implementation for procfs mmap Date: Wed, 15 Oct 2014 13:03:40 +0100 Message-Id: <1413374624-30066-1-git-send-email-lorenzo.pieralisi@arm.com> X-Mailer: git-send-email 2.1.2 X-OriginalArrivalTime: 15 Oct 2014 12:03:06.0415 (UTC) FILETIME=[FAD28BF0:01CFE86F] X-MC-Unique: 114101513030901001 Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The addresses stored in PCI device resources for memory spaces correspond to CPU physical addresses, which do not necessarily map 1:1 to PCI bus addresses as programmed in PCI devices configuration spaces. Therefore, the changes applied by commits: 8c05cd08a7504b855c26526 3b519e4ea618b6943a82931 imply that the sanity checks carried out in pci_mmap_fits() to ensure that the user executes an mmap of a "real" pci resource are erroneous when executed through procfs. Some platforms (ie SPARC) expect the offset value to be passed in (procfs mapping) to be the PCI BAR configuration value as read from the PCI device configuration space, not the fixed-up CPU physical address that is present in PCI device resources. The required pgoff (offset in mmap syscall) value passed from userspace is supposed to represent the resource value exported through /proc/bus/pci/devices when the resource is mmapped though procfs (and 0 when the mapping is carried out through sysfs resource files), which corresponds to the PCI resource filtered through the pci_resource_to_user() API. This patch converts the PCI resource to the expected "user visible" value through pci_resource_to_user() before carrying out sanity checks in pci_mmap_fits() so that the check is carried out on the resource values as expected from the userspace mmap API. Cc: Arnd Bergmann Cc: Bjorn Helgaas Cc: Benjamin Herrenschmidt Cc: Russell King Cc: David S. Miller Cc: Michal Simek Cc: Martin Wilck Cc: Derrick J. Wong Signed-off-by: Lorenzo Pieralisi --- drivers/pci/pci-sysfs.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c index 92b6d9a..777d8bc 100644 --- a/drivers/pci/pci-sysfs.c +++ b/drivers/pci/pci-sysfs.c @@ -963,17 +963,20 @@ void pci_remove_legacy_files(struct pci_bus *b) int pci_mmap_fits(struct pci_dev *pdev, int resno, struct vm_area_struct *vma, enum pci_mmap_api mmap_api) { - unsigned long nr, start, size, pci_start; + unsigned long nr, start, size, pci_offset; + resource_size_t pci_start, pci_end; if (pci_resource_len(pdev, resno) == 0) return 0; nr = vma_pages(vma); start = vma->vm_pgoff; + pci_resource_to_user(pdev, resno, &pdev->resource[resno], + &pci_start, &pci_end); size = ((pci_resource_len(pdev, resno) - 1) >> PAGE_SHIFT) + 1; - pci_start = (mmap_api == PCI_MMAP_PROCFS) ? - pci_resource_start(pdev, resno) >> PAGE_SHIFT : 0; - if (start >= pci_start && start < pci_start + size && - start + nr <= pci_start + size) + pci_offset = (mmap_api == PCI_MMAP_PROCFS) ? + pci_start >> PAGE_SHIFT : 0; + if (start >= pci_offset && start < pci_offset + size && + start + nr <= pci_offset + size) return 1; return 0; }