From mboxrd@z Thu Jan 1 00:00:00 1970 From: Luca Boccassi Subject: [PATCH v4 2/2] virtio: fix PCI config err handling Date: Fri, 24 Aug 2018 18:14:20 +0100 Message-ID: <20180824171420.31246-2-bluca@debian.org> References: <20180820164421.28763-1-bluca@debian.org> <20180824171420.31246-1-bluca@debian.org> Cc: maxime.coquelin@redhat.com, zhihong.wang@intel.com, tiwei.bie@intel.com, bruce.richardson@intel.com, brian.russell@intl.att.com To: dev@dpdk.org Return-path: Received: from mail-wr1-f68.google.com (mail-wr1-f68.google.com [209.85.221.68]) by dpdk.org (Postfix) with ESMTP id 8A2221AEEE for ; Fri, 24 Aug 2018 19:14:28 +0200 (CEST) Received: by mail-wr1-f68.google.com with SMTP id k5-v6so8058952wre.10 for ; Fri, 24 Aug 2018 10:14:28 -0700 (PDT) In-Reply-To: <20180824171420.31246-1-bluca@debian.org> List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" From: Brian Russell In virtio_read_caps and vtpci_msix_detect, rte_pci_read_config returns the number of bytes read from PCI config or < 0 on error. If less than the expected number of bytes are read then log the failure and return rather than carrying on with garbage. Fixes: 6ba1f63b5ab0 ("virtio: support specification 1.0") Signed-off-by: Brian Russell Signed-off-by: Luca Boccassi --- v2: handle additional rte_pci_read_config incomplete reads v3: do not handle rte_pci_read_config of virtio cap, added in v2, as it's less clear what the right thing to do there is v4: do a more robust check - first check what the vendor is, and skip the cap entirely if it's not what we are looking for. drivers/net/virtio/virtio_pci.c | 57 ++++++++++++++++++++++++--------- 1 file changed, 42 insertions(+), 15 deletions(-) diff --git a/drivers/net/virtio/virtio_pci.c b/drivers/net/virtio/virtio_pci.c index 6bd22e54a6..cfefa9789b 100644 --- a/drivers/net/virtio/virtio_pci.c +++ b/drivers/net/virtio/virtio_pci.c @@ -567,16 +567,30 @@ virtio_read_caps(struct rte_pci_device *dev, struct virtio_hw *hw) } ret = rte_pci_read_config(dev, &pos, 1, PCI_CAPABILITY_LIST); - if (ret < 0) { - PMD_INIT_LOG(DEBUG, "failed to read pci capability list"); + if (ret != 1) { + PMD_INIT_LOG(DEBUG, + "failed to read pci capability list, ret %d", ret); return -1; } while (pos) { + ret = rte_pci_read_config(dev, &cap, 2, pos); + if (ret != 2) { + PMD_INIT_LOG(DEBUG, + "failed to read pci cap at pos: %x ret %d", + pos, ret); + break; + } + if (cap.cap_vndr != PCI_CAP_ID_MSIX && + cap.cap_vndr != PCI_CAP_ID_VNDR) { + goto next; + } + ret = rte_pci_read_config(dev, &cap, sizeof(cap), pos); - if (ret < 0) { - PMD_INIT_LOG(ERR, - "failed to read pci cap at pos: %x", pos); + if (ret != sizeof(cap)) { + PMD_INIT_LOG(DEBUG, + "failed to read pci cap at pos: %x ret %d", + pos, ret); break; } @@ -689,25 +703,38 @@ enum virtio_msix_status vtpci_msix_detect(struct rte_pci_device *dev) { uint8_t pos; - struct virtio_pci_cap cap; int ret; ret = rte_pci_read_config(dev, &pos, 1, PCI_CAPABILITY_LIST); - if (ret < 0) { - PMD_INIT_LOG(DEBUG, "failed to read pci capability list"); + if (ret != 1) { + PMD_INIT_LOG(DEBUG, + "failed to read pci capability list, ret %d", ret); return VIRTIO_MSIX_NONE; } while (pos) { - ret = rte_pci_read_config(dev, &cap, sizeof(cap), pos); - if (ret < 0) { - PMD_INIT_LOG(ERR, - "failed to read pci cap at pos: %x", pos); + uint8_t cap[2]; + + ret = rte_pci_read_config(dev, cap, sizeof(cap), pos); + if (ret != sizeof(cap)) { + PMD_INIT_LOG(DEBUG, + "failed to read pci cap at pos: %x ret %d", + pos, ret); break; } - if (cap.cap_vndr == PCI_CAP_ID_MSIX) { - uint16_t flags = ((uint16_t *)&cap)[1]; + if (cap[0] == PCI_CAP_ID_MSIX) { + uint16_t flags; + + ret = rte_pci_read_config(dev, &flags, sizeof(flags), + pos + sizeof(cap)); + if (ret != sizeof(flags)) { + PMD_INIT_LOG(DEBUG, + "failed to read pci cap at pos:" + " %x ret %d", pos + sizeof(cap), + ret); + break; + } if (flags & PCI_MSIX_ENABLE) return VIRTIO_MSIX_ENABLED; @@ -715,7 +742,7 @@ vtpci_msix_detect(struct rte_pci_device *dev) return VIRTIO_MSIX_DISABLED; } - pos = cap.cap_next; + pos = cap[1]; } return VIRTIO_MSIX_NONE; -- 2.18.0