RHBA-2013:0282 - Bug Fix Advisory

Topic

Updated strace packages that fix two bugs and add one enhancement are now
available for Red Hat Enterprise Linux 6.

Description

The strace packages provide a utility to intercept and record the system calls
called and received by a running process. The strace utility can print a record
of each system call, its arguments and its return value. The strace utility is
useful for diagnosing, debugging and instructional purposes.

This update fixes the following bugs:

• Prior to this update, the strace utility extracted arguments for the

"semtimedop" system call from the wrong location on the IBM System z platforms.
As a consequence, arguments for the "semtimedop" system call were incorrectly
displayed. This update modifies strace to extract the arguments from the correct
memory location so that the arguments for the "semtimedop" system call are
displayed as expected. (BZ#759569)

• Prior to this update, the strace utility used special breakpoints to trace

fork/vfork/clone system calls. As a consequence, sometimes strace could cause
applications to crash when following fork/vfork/clone system calls. This update
modifies strace to use PTRACE_SETOPTIONS to set the behavior at fork/vfork/clone
system calls and applications no longer crash. (BZ#837183)

This update also adds the following enhancement:

• Prior to this update, strace incorrectly decoded system calls when tracing a

32-bit process on a 64-bit machine, because strace on IBM System z platforms is
not multi-arch aware. This update provides an additional strace executable
(strace32) which can be used to trace 32-bit processes on 64-bit machines.
(BZ#809917)

All users of strace are advised to upgrade to these updated packages, which fix
these bugs and add this enhancement.

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

• Red Hat Enterprise Linux Server 6 x86_64
• Red Hat Enterprise Linux Server 6 i386
• Red Hat Enterprise Linux Server - Extended Life Cycle Support 6 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support 6 i386
• Red Hat Enterprise Linux Workstation 6 x86_64
• Red Hat Enterprise Linux Workstation 6 i386
• Red Hat Enterprise Linux Desktop 6 x86_64
• Red Hat Enterprise Linux Desktop 6 i386
• Red Hat Enterprise Linux for IBM z Systems 6 s390x
• Red Hat Enterprise Linux for Power, big endian 6 ppc64
• Red Hat Enterprise Linux for Scientific Computing 6 x86_64
• Red Hat Enterprise Linux Server from RHUI 6 x86_64
• Red Hat Enterprise Linux Server from RHUI 6 i386
• Red Hat Enterprise Linux Server - Extended Life Cycle Support (for IBM z Systems) 6 s390x

Fixes

• BZ - 809917 - s390x strace problems with 31-bit executables

CVEs

(none)

References

(none)