RHBA-2015:1308 - Bug Fix Advisory

Topic

Updated strace packages that fix several bugs and add various enhancements are
now available for Red Hat Enterprise Linux 6.

Description

The strace utility intercepts and records the system calls that are made and
received by a running process and prints a record of each system call, its
arguments, and its return value to standard error output or a file. It is often
used for problem diagnoses, debugging, and for instructional purposes.

The strace packages have been upgraded to upstream version 4.8, which provides a
number of bug fixes and enhancements over the previous version. Among others:

• This update adds several new command-line options: "-y" to print file

descriptor paths, "-P" to filter system calls based on the file descriptor
paths, and "-I" to control how interactive strace is.

• A new command-line utility, strace-log-merge, has been added. This utility can

be used to merge timestamped strace output into a single file.

• The strace utility now uses optimized interfaces to extract data from the

traced process for better performance.

• The strace utility now provides improved support for decoding of arguments for

various system calls. In addition, a number of new system calls are supported.

(BZ#919101, BZ#1056828)

This update also fixes the following bug:

• Previously, the strace utility incorrectly handled the return value from the

shmat() system call. Consequently, the return value displayed was "?" instead of
the address of the attached shared memory segment. This bug has been fixed, and
strace now displays the correct return value for the shmat() system calls.
(BZ#877193)

Users of strace are advised to upgrade to these updated packages, which fix
these bugs and add these enhancements.

Solution

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

For details on how to apply this update, refer to:

https://access.redhat.com/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 - 877193 - Strace has unknown return value for shmat syscall.
• BZ - 919101 - strace -f : straced process killed by SIGTRAP (caused by BZ#837183)
• BZ - 1056828 - strace -cf java causes Segmentation fault
• BZ - 1214041 - strace -f prevents forking on a KVM guest

CVEs

(none)

References

(none)