Issued:
2012-04-18
Updated:
2012-04-18

RHBA-2012:0496 - Red Hat Enterprise MRG Realtime 2.1 kernel bug fix update

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

ProductVersionArch
MRG Realtime2x86_64

Updated Packages

  • kernel-rt-trace-devel-3.0.25-rt44.57.el6rt.x86_64.rpm
  • kernel-rt-debuginfo-common-x86_64-3.0.25-rt44.57.el6rt.x86_64.rpm
  • kernel-rt-debuginfo-3.0.25-rt44.57.el6rt.x86_64.rpm
  • kernel-rt-trace-debuginfo-3.0.25-rt44.57.el6rt.x86_64.rpm
  • kernel-rt-devel-3.0.25-rt44.57.el6rt.x86_64.rpm
  • kernel-rt-trace-3.0.25-rt44.57.el6rt.x86_64.rpm
  • kernel-rt-doc-3.0.25-rt44.57.el6rt.noarch.rpm
  • kernel-rt-firmware-3.0.25-rt44.57.el6rt.noarch.rpm
  • kernel-rt-vanilla-3.0.25-rt44.57.el6rt.x86_64.rpm
  • kernel-rt-debug-debuginfo-3.0.25-rt44.57.el6rt.x86_64.rpm
  • kernel-rt-3.0.25-rt44.57.el6rt.x86_64.rpm
  • kernel-rt-debug-devel-3.0.25-rt44.57.el6rt.x86_64.rpm
  • kernel-rt-3.0.25-rt44.57.el6rt.src.rpm
  • kernel-rt-debug-3.0.25-rt44.57.el6rt.x86_64.rpm
  • kernel-rt-vanilla-debuginfo-3.0.25-rt44.57.el6rt.x86_64.rpm
  • kernel-rt-vanilla-devel-3.0.25-rt44.57.el6rt.x86_64.rpm

Fixes

CVEs

References

(none)

Additional information