RHEA-2009:0184 - Product Enhancement Advisory

Topic

Updated systemtap packages that add enhancements are now available.

Description

SystemTap provides an instrumentation infrastructure for systems running
the Linux 2.6 kernel. Developers can write scripts to collect data on the
operation of the system.

These updated packages add the following enhancements:

• An initial implementation of user-space probing. With debugging

information available, probes such as the following now work:

probe process("ls").function("*").call { log ($$parms) }

• Several extensions of the probing blacklist and the trace management

component, which increase robustness.

• Several extensions of the scripting language and translator automation to

make some common tracing operations more compact.

• An avahi-based compile client/server script suite have been added, which

permit a systemtap development environment (stap, gcc, kernel
devel/debuginfo) to be installed at a central remote server that clients
can automatically use. This prototype is bundled into the systemtap-client
and systemtap-server subrpms.

• the systemtap packages have been updated to the latest upstream version,

as of September 2008. For further information, refer to the
"/usr/share/doc/systemtap-[version]/NEWS" file.

Note: the Linux kernel may become unstable with excessive wildcard usage
that probes every part of the kernel. As well, certain test suite failures
(which do not pose any major issues) can occur due to debuginfo limitations
or incomplete tapset porting.

SystemTap is no longer a technical preview, and now has production
support. It is recommended to run scripts on development machines
before deployment in production environments. Since SystemTap is an
optional diagnostic tool, if it causes problems, users can simply stop
using the tool in that way. Options such as "-g" for Guru mode, and "-D*",
allow users to disable several security checks. Scripts using these options
may not be supported.

Red Hat plans to fix problems in SystemTap, or the Linux kernel,
as they arise in connection with new scripts. In some cases, a fix may
include extending the blacklist for known areas of the Linux kernel that
are unsafe to probe. In such a case, scripts causing these problems would
have to be changed.

Users of systemtap are advised to upgrade to these updated packages, which
add these enhancements.

Solution

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

This update is available via Red Hat Network. Details on how to use
the Red Hat Network to apply this update are available at
http://kbase.redhat.com/faq/FAQ_58_10188

Affected Products

• Red Hat Enterprise Linux Server 5 x86_64
• Red Hat Enterprise Linux Server 5 ia64
• Red Hat Enterprise Linux Server 5 i386
• Red Hat Enterprise Linux Workstation 5 x86_64
• Red Hat Enterprise Linux Workstation 5 i386
• Red Hat Enterprise Linux Desktop 5 x86_64
• Red Hat Enterprise Linux Desktop 5 i386
• Red Hat Enterprise Linux for IBM z Systems 5 s390x
• Red Hat Enterprise Linux for Power, big endian 5 ppc
• Red Hat Enterprise Linux Server from RHUI 5 x86_64
• Red Hat Enterprise Linux Server from RHUI 5 i386

Fixes

• BZ - 441859 - rhel5.3: systemtap refresh
• BZ - 464010 - uprobes on cloney shells can cause SEGV
• BZ - 467652 - Systemtap regression "-c" doesn't allow for shell redirection.
• BZ - 468139 - regression: Unused (unread ?) global variables are being displayed.
• BZ - 468759 - misinherited uretprobes
• BZ - 469199 - systemtap testsuite regressions
• BZ - 469201 - syscall tapset broken on s390x
• BZ - 469203 - vfs tapset broken on RHEL5.3

CVEs

(none)

References

(none)