RHBA-2009:0380 - Bug Fix Advisory

Topic

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

Description

The ltrace utility is a debugging program that runs a specified command
until the command exits. While the command is executing, ltrace intercepts
and records both the dynamic library calls called by the executed process
and the signals received by the executed process. The ltrace utility can
also intercept and print system calls executed by the process.

This updated ltrace package includes fixes for the following bugs:

• in some cases, when tracing the process that used fork system call, the

kernel may have reported certain events in the forked child even before it
reported that the fork had occurred in the first place. With this update,
ltrace now anticipates this behavior, thus resolving the issue.

• on IBM System z machines, ltrace would crash when attempting to trace

binaries that called functions with five or more arguments. This has been
fixed with this update and ltrace now works as expected.

• when ltrace's '-o' option, which writes the output to a file, was used

alongside the '-c' option, which counts time and calls for each library
call and reports a summary, ltrace sent the output to standard error as
usual instead of to the file designated on the command line. With this
updated package, ltrace sends the output to the designated file when it is
called with the '-c' option, thus resolving this issue.

• ltrace was not able to trace a binary that was called using the "exec"

system call. With this update, ltrace is now able to do so.

• the ltrace(1) man page incorrectly claimed that ltrace could not trace

64-bit binaries, and has been corrected.

• a bug in which ltrace would become unresponsive (i.e. "hang") while

tracing a child process with the '-f' option, which traces child processes
as they are created by currently traced processes as a result of the fork
or clone system calls. To correct for this, ltrace now tests for the
situation in which it fails to attach to a newly-forked process, thus
resolving the issue.

All users of ltrace are advised to 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.

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/docs/DOC-11259

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 - 265941 - ltrace can't follow the child process.
• BZ - 483350 - [RHEL5U3] man page of ltrace
• BZ - 485779 - LTC26611-Ltrace with -c omit execl call

CVEs

(none)

References

(none)