RHBA-2005:186 - Bug Fix Advisory

Topic

An updated crash package that fixes various bugs is now available.

Description

The crash core analysis suite is a self-contained tool that can be used
to investigate either live systems, kernel core dumps created from the
netdump and diskdump packages from Red Hat Linux, the mcore kernel patch
offered by Mission Critical Linux, or the LKCD kernel patch.

This updated package addresses the following issues:

• Support for generating proper backtraces from x86_64 dumpfiles that

were generated from a NMI exception. When that happens, the kernel
panic sequence is performed while operating on the x86_64-specific NMI
exception stack, and the crash utility needed to be enhanced to start
the backtrace from the NMI exception stack, and then switch back to the
interrupt stack or process stack, whichever was being used when the
NMI switch was hit.

• Crash dumps can now be created by pressing the INIT switch on Itanium

machines. The crash "bt" (backtrace) command did not work correctly due to
the starting point of the backtrace. It was not executed on the current
process's kernel stack as in the normal case, but rather on a newly
introduced per-cpu init_handler stack.

• An SMP kernel running with maxcpus=1 on AMD64 architectures caused the

exception stack address gathering code to fail because the location of the
exception stack differed on single vs. multiprocessor kernels.

• A bt hang was the result of an IP interrupt being sent from a diskdump

process. This was then being sent to one of the other CPUs catching a
process just after it had entered the kernel to do a system_call, but
before it had a chance to call the actual system call handler function.

All users of crash should upgrade to this updated package, which
resolves these issues.

Solution

Before applying this update, make sure that all previously-released
errata relevant to your system have been applied. Use Red Hat
Network to download and update your packages. To launch the Red Hat
Update Agent, use the following command:

up2date

For information on how to install packages manually, refer to the
following Web page for the System Administration or Customization
guide specific to your system:

http://www.redhat.com/docs/manuals/enterprise/

Affected Products

• Red Hat Enterprise Linux Server 4 x86_64
• Red Hat Enterprise Linux Server 4 ia64
• Red Hat Enterprise Linux Server 4 i386
• Red Hat Enterprise Linux Workstation 4 x86_64
• Red Hat Enterprise Linux Workstation 4 ia64
• Red Hat Enterprise Linux Workstation 4 i386
• Red Hat Enterprise Linux Desktop 4 x86_64
• Red Hat Enterprise Linux Desktop 4 i386
• Red Hat Enterprise Linux for Power, big endian 4 ppc

Fixes

• BZ - 139429 - [RHEL3-U4][INIT switch] bt command doesn't work
• BZ - 139435 - [RHEL3-U4][crash] crash doesn't work with maxcpus=1 on SMP kernel
• BZ - 139437 - [RHEL3-U4][crash] bt -a hangs

CVEs

(none)

References

(none)