Synopsis

Red Hat Enterprise MRG Realtime 2.1 kernel bug fix update

Type/Severity

Bug Fix Advisory

Topic

Updated kernel-rt packages that fix several bugs are now available for Red Hat
Enterprise MRG 2.1.

Description

The kernel-rt packages contain the Linux kernel, the core of any Linux operating
system.

This update provides a build of the kernel-rt package for MRG 2.1, which is
layered on Red Hat Enterprise Linux 6.

This update fixes the following bugs:

• Previously, while working with an open file, the epoll kernel code was calling
  poll operations of another open file without holding the file's lock.
  Consequently, a deadlock in the code could occur when using the system console.
  Now, an upstream patch to use the ep_poll_nested() function has been provided
  and the system console now works correctly in the described scenario.
  (BZ#675885)
  
• The i7core_edac code did multiple probes for the same hardware component. As a
  consequence, boot time error message about the code being unable to create a
  duplicate file in the /sys/devices/ directory was returned. With this update,
  duplicate probe code has been removed and the error messages are no longer
  returned in the described scenario. (BZ#773746)
  
• A previous Realtime work queue patch introduced a race conditions in the CPU
  hotplug code. Consequently, the system could become unresponsive in this code.
  This update reverts a few past updates to the work queue, which turned out to be
  unnecessary, and the hangs no longer occur in the described scenario.
  (BZ#787331)
  
• The CONFIG_CC_OPTIMIZE_FOR_SIZE configuration parameter, which was previously
  introduced to MRG Realtime, caused the gcc compiler to produce code prone to
  cache line bouncing. As a result, the kernel performance was decreased. This
  update turns off this parameter, thus improving cache utilization and
  performance. (BZ#796297)
  
• Previously, configuration files in MRG Realtime and Red Hat Enterprise Linux 6
  were not synchronized regarding modules and built-ins. Consequently, the
  mkinitrd daemon failed to find code that was part of a module in Red Hat
  Enterprise Linux 6 but part of a built-in in MRG Realtime. Now, the
  configuration files have been synchronized between these two products and
  mkinitrd correctly finds and sets up kernel components such as kdump.
  (BZ#804119, BZ#756631)
  

Users of the Realtime capabilities of Red Hat Enterprise MRG 2.1, which is
layered on Red Hat Enterprise Linux 6, are advised to upgrade to these updated
packages, which fix these bugs. Note that the system must be rebooted for this
update to take effect.

Solution

Before applying this update, make sure all previously-released errata
relevant to your system have been applied.

This update is available via the Red Hat Network. Details on how to
use the Red Hat Network to apply this update are available at
https://access.redhat.com/knowledge/articles/11258

Affected Products

• MRG Realtime 2 x86_64

Fixes

• BZ - 675885 - kernel: epoll: Prevent deadlock through unsafe ->f_op->poll() calls [mrg-2.1]
• BZ - 787331 - System hang running Java tests on 3.0.9-rt26.45.el6rt.x86_64 kernel
• BZ - 796297 - turn off CONFIG_CC_OPTIMIZE_FOR_SIZE

CVEs

• CVE-2011-1083

References

(none)

MRG Realtime 2

SRPM
kernel-rt-3.0.25-rt44.57.el6rt.src.rpm	SHA-256: 280f98ee0ce981b6cabde82bcb5caf6c9ac8e3241188b0dddc1507e4686c1606
x86_64
kernel-rt-3.0.25-rt44.57.el6rt.x86_64.rpm	SHA-256: d633b1a68907bcd8917d89e3ed52e3d7c5954f535c66f402846b7247151e957a
kernel-rt-debug-3.0.25-rt44.57.el6rt.x86_64.rpm	SHA-256: 3fabbd4274fe4a28aee19b6cef3fd25688e5ba1889b473fb26449e3d14ae1e31
kernel-rt-debug-debuginfo-3.0.25-rt44.57.el6rt.x86_64.rpm	SHA-256: de8a72ce825664269a6b872e4534582611da86272c349f751eb7ae61c7ea58ed
kernel-rt-debug-devel-3.0.25-rt44.57.el6rt.x86_64.rpm	SHA-256: 98de4384d42180c4b32a1575d8e533de53441fb2671b1a2903d1593d471f5a8e
kernel-rt-debuginfo-3.0.25-rt44.57.el6rt.x86_64.rpm	SHA-256: ee2882ab5141ca4403be810478313cd139891dd89a556be1f4925965167e35d8
kernel-rt-debuginfo-common-x86_64-3.0.25-rt44.57.el6rt.x86_64.rpm	SHA-256: 047051e92eed373e87c5bcdbf7b348beb19251b11d9e4eca315975c2116a55df
kernel-rt-devel-3.0.25-rt44.57.el6rt.x86_64.rpm	SHA-256: b55df5967d831f01129ebca8f1d824ec72b0ef59b75c9e1820812d0e9945230e
kernel-rt-doc-3.0.25-rt44.57.el6rt.noarch.rpm	SHA-256: e4555891a03f8ed7af0b2809a5aca23ab91155b628e88955fb1be298ace68588
kernel-rt-firmware-3.0.25-rt44.57.el6rt.noarch.rpm	SHA-256: 4a2fd568e21c24ab9395aad6e55dfb2863ed8f24aa6b5e9fc82142816f85d821
kernel-rt-trace-3.0.25-rt44.57.el6rt.x86_64.rpm	SHA-256: c71555d4d8c4dfe4f53320d9b8e8d3255d83874c4528fbf2c877cfc85e96f14f
kernel-rt-trace-debuginfo-3.0.25-rt44.57.el6rt.x86_64.rpm	SHA-256: 08cd9e86b3b7f13aeb19d24aec01c907c6563e16a44ee2c7a6b7b2da300043cf
kernel-rt-trace-devel-3.0.25-rt44.57.el6rt.x86_64.rpm	SHA-256: 173583fc3bffcab8eec11a70d01c67597d55ce52f2d9a050ee27f4f81f02c66d
kernel-rt-vanilla-3.0.25-rt44.57.el6rt.x86_64.rpm	SHA-256: c80f027de83aa63fb9b1327b51e0fe4db66ff97e408d362f33d1521efc0ca191
kernel-rt-vanilla-debuginfo-3.0.25-rt44.57.el6rt.x86_64.rpm	SHA-256: e013ed27346ffe7541c2cf5847011639dc8dab5e03e9d9fd634f49a831a075ec
kernel-rt-vanilla-devel-3.0.25-rt44.57.el6rt.x86_64.rpm	SHA-256: 0e4ba49a14e3eb8c62ada9d250d0a6f0473d693c373cd6799497e2c1b1039d36