RE: [PATCH RFC] pci: Blacklist vpd access for buggy devices

[Jordan_Hargrave]

From: Babu Moger [babu.moger@xxxxxxxxxx]
Sent: Monday, January 11, 2016 4:49 PM
To: bhelgaas@xxxxxxxxxx
Cc: linux-pci@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; alexander.duyck@xxxxxxxxx; hare@xxxxxxx; mkubecek@xxxxxxxx; shane.seymour@xxxxxxx; myron.stowe@xxxxxxxxx; VenkatKumar.Duvvuru@xxxxxxxxx; Hargrave, Jordan
Subject: Re: [PATCH RFC] pci: Blacklist vpd access for buggy devices

Sorry. Missed Jordan.

On 1/11/2016 3:13 PM, Babu Moger wrote:
> 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 bffadffd43d4 ("PCI: fix VPD limit quirk
> for Broadcom 5708S"))
>
> 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 0x80.
>
> Also look at the threds
>
> https://lkml.org/lkml/2015/11/10/557
> https://lkml.org/lkml/2015/12/29/315
>
> Signed-off-by: Babu Moger <babu.moger@xxxxxxxxxx>
> ---
>
> NOTE:
> Jordan, Are you sure all the devices in PCI_VENDOR_ID_ATHEROS and
> PCI_VENDOR_ID_ATTANSIC have this problem. You have used PCI_ANY_ID.
> I felt it is too broad. Can you please check.
>

I don't actually have that hardware, it was a bugfix for biosdevname for RedHat.  We were getting
'BUG: soft lockup - CPU#0 stuck for 23s!'  when attempting to read the vpd area.

Certainly 0x1969:0x1026 experienced this.

09:00.0 Ethernet controller: Atheros Communications AR8121/AR8113/AR8114 Gigabit or Fast Ethernet (rev b0)
        Subsystem: Atheros Communications AR8121/AR8113/AR8114 Gigabit or Fast Ethernet
        Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx+
        Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx-
        Latency: 0, Cache Line Size: 64 bytes
        Interrupt: pin A routed to IRQ 46
        Region 0: Memory at c0300000 (64-bit, non-prefetchable) [size=256K]
        Region 2: I/O ports at 3000 [size=128]
        Capabilities: [40] Power Management version 2
                Flags: PMEClk- DSI- D1- D2- AuxCurrent=0mA PME(D0-,D1-,D2-,D3hot+,D3cold+)
                Status: D0 NoSoftRst- PME-Enable- DSel=0 DScale=0 PME-
        Capabilities: [48] MSI: Enable+ Count=1/1 Maskable- 64bit+
                Address: 00000000fee0300c  Data: 41a1
        Capabilities: [58] Express (v1) Endpoint, MSI 00
                DevCap: MaxPayload 4096 bytes, PhantFunc 0, Latency L0s <4us, L1 unlimited
                        ExtTag- AttnBtn+ AttnInd+ PwrInd+ RBE- FLReset-
                DevCtl: Report errors: Correctable- Non-Fatal- Fatal- Unsupported-
                        RlxdOrd- ExtTag- PhantFunc- AuxPwr- NoSnoop-
                        MaxPayload 128 bytes, MaxReadReq 512 bytes
                DevSta: CorrErr- UncorrErr+ FatalErr- UnsuppReq+ AuxPwr+ TransPend-
                LnkCap: Port #0, Speed 2.5GT/s, Width x1, ASPM L0s, Latency L0 unlimited, L1 unlimited
                        ClockPM- Surprise- LLActRep- BwNot-
                LnkCtl: ASPM Disabled; RCB 64 bytes Disabled- Retrain- CommClk+
                        ExtSynch- ClockPM- AutWidDis- BWInt- AutBWInt-
                LnkSta: Speed 2.5GT/s, Width x1, TrErr- Train- SlotClk+ DLActive- BWMgmt- ABWMgmt-
        Capabilities: [6c] Vital Product Data
                Unknown small resource type 0b, will not decode more.
        Capabilities: [100 v1] Advanced Error Reporting
                UESta:  DLP- SDES- TLP- FCP- CmpltTO- CmpltAbrt- UnxCmplt- RxOF- MalfTLP- ECRC- UnsupReq+ ACSViol-
                UEMsk:  DLP- SDES- TLP- FCP- CmpltTO- CmpltAbrt- UnxCmplt- RxOF- MalfTLP- ECRC- UnsupReq- ACSViol-
                UESvrt: DLP+ SDES- TLP- FCP+ CmpltTO- CmpltAbrt- UnxCmplt- RxOF+ MalfTLP+ ECRC- UnsupReq- ACSViol-
                CESta:  RxErr- BadTLP- BadDLLP- Rollover- Timeout- NonFatalErr-
                CEMsk:  RxErr- BadTLP- BadDLLP- Rollover- Timeout- NonFatalErr-
                AERCap: First Error Pointer: 14, GenCap+ CGenEn- ChkCap+ ChkEn-
        Capabilities: [180 v1] Device Serial Number ff-2e-05-c3-00-23-8b-ff
        Kernel driver in use: ATL1E
00: 69 19 26 10 07 04 10 00 b0 00 00 02 10 00 00 00
10: 04 00 30 c0 00 00 00 00 01 30 00 00 00 00 00 00
20: 00 00 00 00 00 00 00 00 00 00 00 00 69 19 26 10
30: 00 00 00 00 40 00 00 00 00 00 00 00 0a 01 00 00
40: 01 48 02 c0 00 00 00 00 05 58 81 00 0c 30 e0 fe
50: 00 00 00 00 a1 41 00 00 10 6c 01 00 85 7f 04 05
60: 00 20 1a 00 11 f4 03 00 40 00 11 10 03 00 00 80
70: 5a ff 88 14 00 00 00 00 00 00 00 00 00 00 00 00
80: 00 00 00 00 69 19 26 10 00 00 00 00 00 00 00 00
90: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
a0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
b0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
c0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
d0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
e0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
f0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

>  drivers/pci/quirks.c |   41 +++++++++++++++++++++++++++++++++++++++++
>  1 files changed, 41 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
> index b03373f..8abcee5 100644
> --- a/drivers/pci/quirks.c
> +++ b/drivers/pci/quirks.c
> @@ -2123,6 +2123,47 @@ 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/<id>/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.
> + * Apparently, some vendors have not implemented this VPD headers properly.
> + * Adding a generic function disable vpd data for these buggy adapters
> + * Add the DECLARE_PCI_FIXUP_FINAL line below with the specific with
> + * vendor and device of interest to use this quirk.
> + */
> +static void quirk_blacklist_vpd(struct pci_dev *dev)
> +{
> +     if (dev->vpd) {
> +             dev->vpd->len = 0;
> +             dev_warn(&dev->dev, "PCI vpd access has been disabled due to firmware bug\n");
> +     }
> +}
> +
> +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_LSI_LOGIC, 0x0060,
> +             quirk_blacklist_vpd);
> +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_LSI_LOGIC, 0x007c,
> +             quirk_blacklist_vpd);
> +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_LSI_LOGIC, 0x0413,
> +             quirk_blacklist_vpd);
> +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_LSI_LOGIC, 0x0078,
> +             quirk_blacklist_vpd);
> +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_LSI_LOGIC, 0x0079,
> +             quirk_blacklist_vpd);
> +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_LSI_LOGIC, 0x0073,
> +             quirk_blacklist_vpd);
> +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_LSI_LOGIC, 0x0071,
> +             quirk_blacklist_vpd);
> +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_LSI_LOGIC, 0x005b,
> +             quirk_blacklist_vpd);
> +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_LSI_LOGIC, 0x002f,
> +             quirk_blacklist_vpd);
> +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_LSI_LOGIC, 0x005d,
> +             quirk_blacklist_vpd);
> +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_LSI_LOGIC, 0x005f,
> +             quirk_blacklist_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
>