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Bug 629761

Summary: [RHEL 5.5] e100/e1000*/igb*/ixgb*: Add missing read memory barrier
Product: Red Hat Enterprise Linux 5 Reporter: Andy Gospodarek <agospoda>
Component: kernelAssignee: Andy Gospodarek <agospoda>
Status: CLOSED ERRATA QA Contact: Network QE <network-qe>
Severity: medium Docs Contact:
Priority: low    
Version: 5.5CC: dtian, hjia, jeffrey.t.kirsher, john.ronciak, peterm
Target Milestone: rc   
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2011-01-13 21:15:12 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:

Description Andy Gospodarek 2010-09-02 21:25:13 UTC
We should add the following upstream commit:

commit 2d0bb1c1f4524befe9f0fcf0d0cd3081a451223f
Author: Jeff Kirsher <jeffrey.t.kirsher>
Date:   Sun Aug 8 16:02:31 2010 +0000

    e100/e1000*/igb*/ixgb*: Add missing read memory barrier

    Based on patches from Sonny Rao and Milton Miller...

    Combined the patches to fix up clean_tx_irq and clean_rx_irq.

    The PowerPC architecture does not require loads to independent bytes
    to be ordered without adding an explicit barrier.

    In ixgbe_clean_rx_irq we load the status bit then load the packet data.
    With packet split disabled if these loads go out of order we get a
    stale packet, but we will notice the bad sequence numbers and drop it.

    The problem occurs with packet split enabled where the TCP/IP header
    and data are in different descriptors. If the reads go out of order
    we may have data that doesn't match the TCP/IP header. Since we use
    hardware checksumming this bad data is never verified and it makes it
    all the way to the application.

    This bug was found during stress testing and adding this barrier has
    been shown to fix it.  The bug can manifest as a data integrity issue
    (bad payload data) or as a BUG in skb_pull().

    This was a nasty bug to hunt down, if people agree with the fix I think
    it's a candidate for stable.

    Previously Submitted to e1000-devel only for ixgbe

    http://marc.info/?l=e1000-devel&m=126593062701537&w=3

    We've now seen this problem hit with other device drivers (e1000e mostly)
    So I'm resubmitting with fixes for other Intel Device Drivers with
    similar issues.

Comment 1 RHEL Program Management 2010-09-02 21:39:25 UTC
This request was evaluated by Red Hat Product Management for inclusion in a Red
Hat Enterprise Linux maintenance release.  Product Management has requested
further review of this request by Red Hat Engineering, for potential
inclusion in a Red Hat Enterprise Linux Update release for currently deployed
products.  This request is not yet committed for inclusion in an Update
release.

Comment 4 Jarod Wilson 2010-09-15 14:01:51 UTC
in kernel-2.6.18-221.el5
You can download this test kernel from http://people.redhat.com/jwilson/el5

Detailed testing feedback is always welcomed.

Comment 8 Dayong Tian 2010-12-08 01:52:36 UTC
The patch was included and applied in kernel 2.6.18-236.el5:

[root@intel-s3e8132-01 SPECS]# grep 629761 kernel-2.6.spec
- [net] e100*/igb*/ixgb*: add missing read memory barrier (Andy Gospodarek) [629761]

[root@intel-s3e8132-01 SPECS]# grep -i "Patch25604" kernel-2.6.spec
Patch25604: linux-2.6-net-e100-igb-ixgb-add-missing-read-memory-barrier.patch
%patch25604 -p1

Comment 10 errata-xmlrpc 2011-01-13 21:15:12 UTC
An advisory has been issued which should help the problem
described in this bug report. This report is therefore being
closed with a resolution of ERRATA. For more information
on therefore solution and/or where to find the updated files,
please follow the link below. You may reopen this bug report
if the solution does not work for you.

http://rhn.redhat.com/errata/RHSA-2011-0017.html