From patchwork Mon Feb 15 08:42:01 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hannes Reinecke X-Patchwork-Id: 8311551 X-Patchwork-Delegate: bhelgaas@google.com Return-Path: X-Original-To: patchwork-linux-pci@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id B7781C02AA for ; Mon, 15 Feb 2016 08:42:33 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id B181F20435 for ; Mon, 15 Feb 2016 08:42:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AAF1220483 for ; Mon, 15 Feb 2016 08:42:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752485AbcBOIm2 (ORCPT ); Mon, 15 Feb 2016 03:42:28 -0500 Received: from mx2.suse.de ([195.135.220.15]:47447 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752365AbcBOImZ (ORCPT ); Mon, 15 Feb 2016 03:42:25 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (charybdis-ext.suse.de [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id F2527AD7D; Mon, 15 Feb 2016 08:42:23 +0000 (UTC) From: Hannes Reinecke To: Bjorn Helgaas Cc: Alexander Duyck , linux-pci@vger.kernel.org, Babu Moger , Jordan Hargrave , Hannes Reinecke , Bjorn Helgaas Subject: [PATCHv3 3/4] pci: Determine actual VPD size on first access Date: Mon, 15 Feb 2016 09:42:01 +0100 Message-Id: <1455525722-122040-4-git-send-email-hare@suse.de> X-Mailer: git-send-email 1.8.5.6 In-Reply-To: <1455525722-122040-1-git-send-email-hare@suse.de> References: <1455525722-122040-1-git-send-email-hare@suse.de> Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org X-Spam-Status: No, score=-5.3 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY, URIBL_SBL autolearn=ham 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 PCI-2.2 VPD entries have a maximum size of 32k, but might actually be smaller than that. To figure out the actual size one has to read the VPD area until the 'end marker' is reached. Trying to read VPD data beyond that marker results in 'interesting' effects, from simple read errors to crashing the card. And to make matters worse not every PCI card implements this properly, leaving us with no 'end' marker or even completely invalid data. This patch tries to determine the size of the VPD data when it's first accessed. If no valid data can be read an I/O error will be returned when reading or writing the sysfs attribute. As the amount of VPD data is unknown initially the size of the sysfs attribute will always be set to '0'. Cc: Alexander Duyck Cc: Bjorn Helgaas Signed-off-by: Hannes Reinecke --- drivers/pci/access.c | 84 +++++++++++++++++++++++++++++++++++++++++++++++-- drivers/pci/pci-sysfs.c | 2 +- 2 files changed, 82 insertions(+), 4 deletions(-) diff --git a/drivers/pci/access.c b/drivers/pci/access.c index 8c05b5c..253e0c8 100644 --- a/drivers/pci/access.c +++ b/drivers/pci/access.c @@ -283,10 +283,63 @@ struct pci_vpd_pci22 { struct pci_vpd base; struct mutex lock; u16 flag; - bool busy; + u8 busy:1; + u8 valid:1; u8 cap; }; +/** + * pci_vpd_size - determine actual size of Vital Product Data + * @dev: pci device struct + * @old_size: current assumed size, also maximum allowed size + */ +static size_t pci_vpd_pci22_size(struct pci_dev *dev, size_t old_size) +{ + size_t off = 0; + unsigned char header[1+2]; /* 1 byte tag, 2 bytes length */ + + while (off < old_size && + pci_read_vpd(dev, off, 1, header) == 1) { + unsigned char tag; + + if (header[0] & PCI_VPD_LRDT) { + /* Large Resource Data Type Tag */ + tag = pci_vpd_lrdt_tag(header); + /* Only read length from known tag items */ + if ((tag == PCI_VPD_LTIN_ID_STRING) || + (tag == PCI_VPD_LTIN_RO_DATA) || + (tag == PCI_VPD_LTIN_RW_DATA)) { + if (pci_read_vpd(dev, off+1, 2, + &header[1]) != 2) { + dev_dbg(&dev->dev, + "invalid large VPD tag %02x size at offset %zu", + tag, off + 1); + return 0; + } + off += PCI_VPD_LRDT_TAG_SIZE + + pci_vpd_lrdt_size(header); + } + } else { + /* Short Resource Data Type Tag */ + off += PCI_VPD_SRDT_TAG_SIZE + + pci_vpd_srdt_size(header); + tag = pci_vpd_srdt_tag(header); + } + if (tag == PCI_VPD_STIN_END) /* End tag descriptor */ + return off; + if ((tag != PCI_VPD_LTIN_ID_STRING) && + (tag != PCI_VPD_LTIN_RO_DATA) && + (tag != PCI_VPD_LTIN_RW_DATA)) { + dev_dbg(&dev->dev, + "invalid %s VPD tag %02x at offset %zu", + (header[0] & PCI_VPD_LRDT) ? "large" : "short", + tag, off); + return 0; + } + } + return 0; +} + /* * Wait for last operation to complete. * This code has to spin since there is no other notification from the PCI @@ -337,9 +390,23 @@ static ssize_t pci_vpd_pci22_read(struct pci_dev *dev, loff_t pos, size_t count, loff_t end = pos + count; u8 *buf = arg; - if (pos < 0 || pos > vpd->base.len || end > vpd->base.len) + if (pos < 0) return -EINVAL; + if (!vpd->valid) { + vpd->valid = true; + vpd->base.len = pci_vpd_pci22_size(dev, vpd->base.len); + } + if (vpd->base.len == 0) + return -EIO; + + if (end > vpd->base.len) { + if (pos > vpd->base.len) + return 0; + end = vpd->base.len; + count = end - pos; + } + if (mutex_lock_killable(&vpd->lock)) return -EINTR; @@ -389,7 +456,17 @@ static ssize_t pci_vpd_pci22_write(struct pci_dev *dev, loff_t pos, size_t count loff_t end = pos + count; int ret = 0; - if (pos < 0 || (pos & 3) || (count & 3) || end > vpd->base.len) + if (pos < 0 || (pos & 3) || (count & 3)) + return -EINVAL; + + if (!vpd->valid) { + vpd->valid = true; + vpd->base.len = pci_vpd_pci22_size(dev, vpd->base.len); + } + if (vpd->base.len == 0) + return -EIO; + + if (end > vpd->base.len) return -EINVAL; if (mutex_lock_killable(&vpd->lock)) @@ -496,6 +573,7 @@ int pci_vpd_pci22_init(struct pci_dev *dev) mutex_init(&vpd->lock); vpd->cap = cap; vpd->busy = false; + vpd->valid = false; dev->vpd = &vpd->base; return 0; } diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c index a730f54..ed39c09 100644 --- a/drivers/pci/pci-sysfs.c +++ b/drivers/pci/pci-sysfs.c @@ -1323,7 +1323,7 @@ static int pci_create_capabilities_sysfs(struct pci_dev *dev) return -ENOMEM; sysfs_bin_attr_init(attr); - attr->size = dev->vpd->len; + attr->size = 0; attr->attr.name = "vpd"; attr->attr.mode = S_IRUSR | S_IWUSR; attr->read = read_vpd_attr;