Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752630AbbKKTay (ORCPT ); Wed, 11 Nov 2015 14:30:54 -0500 Received: from mail-ob0-f175.google.com ([209.85.214.175]:33403 "EHLO mail-ob0-f175.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752109AbbKKTaP (ORCPT ); Wed, 11 Nov 2015 14:30:15 -0500 MIME-Version: 1.0 In-Reply-To: <1447257297-198460-1-git-send-email-babu.moger@oracle.com> References: <1447257297-198460-1-git-send-email-babu.moger@oracle.com> Date: Wed, 11 Nov 2015 12:30:14 -0700 Message-ID: Subject: Re: [PATCH v2] pci: Limit VPD length for megaraid_sas adapter From: Myron Stowe To: Babu Moger Cc: Bjorn Helgaas , linux-pci , LKML Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5204 Lines: 124 On Wed, Nov 11, 2015 at 8:54 AM, Babu Moger wrote: > Changes since v1 -> v2 > Removed the changes in pci_id.h. Kept all the vendor > ids in quirks.c > > Reading or Writing of PCI VPD data causes system panic. > We saw this problem by running "lspci -vvv" in the beginning. > However this can be easily reproduced by running > cat /sys/bus/devices/XX../vpd > > VPD length has been set as 32768 by default. Accessing vpd > will trigger read/write of 32k. This causes problem as we > could read data beyond the VPD end tag. Behaviour is un- > predictable when this happens. I see some other adapter doing > similar quirks(commit id bffadffd43d438c3143b8d172a463de89345b836) > > I see there is an attempt to fix this right way. > https://patchwork.ozlabs.org/patch/534843/ or > https://lkml.org/lkml/2015/10/23/97 > > Tried to fix it this way, but problem is I dont see the proper > start/end TAGs(at least for this adapter) at all. The data is > mostly junk or zeros. This patch fixes the issue by setting the > vpd length to 0. > > Signed-off-by: Babu Moger > --- > drivers/pci/quirks.c | 38 ++++++++++++++++++++++++++++++++++++++ > 1 files changed, 38 insertions(+), 0 deletions(-) > > diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c > index b03373f..f739e47 100644 > --- a/drivers/pci/quirks.c > +++ b/drivers/pci/quirks.c > @@ -2123,6 +2123,44 @@ static void quirk_via_cx700_pci_parking_caching(struct pci_dev *dev) > DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_VIA, 0x324e, quirk_via_cx700_pci_parking_caching); > > /* > + * A read/write to sysfs entry ('/sys/bus/pci/devices//vpd') > + * will dump 32k of data. The default length is set as 32768. > + * Reading a full 32k will cause an access beyond the VPD end tag. > + * The system behaviour at that point is mostly unpredictable. > + * Also I dont believe vendors have implemented this VPD headers properly. > + * Atleast I dont see it in following megaraid sas controller. > + * That is why adding the quirk here. > + */ > +static void quirk_megaraid_sas_limit_vpd(struct pci_dev *dev) > +{ > + if (dev->vpd) > + dev->vpd->len = 0; > +} > + > +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_LSI_LOGIC, 0x0060, > + quirk_megaraid_sas_limit_vpd); > +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_LSI_LOGIC, 0x007c, > + quirk_megaraid_sas_limit_vpd); > +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_LSI_LOGIC, 0x0413, > + quirk_megaraid_sas_limit_vpd); > +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_LSI_LOGIC, 0x0078, > + quirk_megaraid_sas_limit_vpd); > +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_LSI_LOGIC, 0x0079, > + quirk_megaraid_sas_limit_vpd); > +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_LSI_LOGIC, 0x0073, > + quirk_megaraid_sas_limit_vpd); > +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_LSI_LOGIC, 0x0071, > + quirk_megaraid_sas_limit_vpd); > +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_LSI_LOGIC, 0x005b, > + quirk_megaraid_sas_limit_vpd); > +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_LSI_LOGIC, 0x002f, > + quirk_megaraid_sas_limit_vpd); > +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_LSI_LOGIC, 0x005d, > + quirk_megaraid_sas_limit_vpd); > +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_LSI_LOGIC, 0x005f, > + quirk_megaraid_sas_limit_vpd); > + > +/* > * For Broadcom 5706, 5708, 5709 rev. A nics, any read beyond the > * VPD end tag will hang the device. This problem was initially > * observed when a vpd entry was created in sysfs > -- > 1.7.1 > Just to confirm, I've encountered similar results on a MegaRAID SAS 2208 - $ lspci -vvv -s 02:00.0 02:00.0 RAID bus controller: LSI Logic / Symbios Logic MegaRAID SAS 2208 [Thunderbolt] (rev 05) Capabilities: [d0] Vital Product Data Unknown small resource type 00, will not decode more. $ cat /sys/devices/pci0000:00/0000:00:02.2/0000:02:00.0/vpd | od -A x -t x1z -v 000000 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >................< * 007ff0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >................< 008000 and got the following on the NIC related ports of a Brocade device - $ lspci -vvv -s 03:00.0 03:00.0 Fibre Channel: Brocade Communications Systems, Inc. 1010/1020/1007/1741 10Gbps CNA (rev 01) Capabilities: [a0] Vital Product Data No end tag found $ cat /sys/devices/pci0000:00/0000:00:02.0/0000:03:00.0/vpd | od -A x -t x1z -v 000000 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >................< * 007ff0 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >................< 008000 > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/