RHBA-2012:0238 - Bug Fix Advisory

Topic

An updated gdb package that fixes multiple bugs is now available for Red Hat
Enterprise Linux 5.

Description

The GNU Debugger (GDB) allows users to debug programs written in C, C++, and
other languages by executing them in a controlled fashion and then printing out
their data.

This update fixes the following bugs:

• GDB could stop with an error when trying to access the libpthread shared

library before the library was relocated. With this update, GDB lets the library
relocations be resolved first, allowing GDB to debug programs properly under
these circumstances. (BZ#658851)

• Modifying a string in the executable using the "-write" command line option

could fail with an error if the executable was not running. With this update,
GDB can modify executables even before they are started. (BZ#696148)

• When printing data from a string buffer of constant size, GDB, by default,

also prints the data following after the first zero byte ("\0") of the string.
To display only the data before the zero byte, the "set print null-stop" option
has to be set. Previously with this option set, GDB did not display any string
content due to an incorrect zero byte test condition in the code. The test
condition has been corrected and GDB now properly displays data located before
the first zero byte. (BZ#720717)

• GDB convenience variables allow a user to store and retrieve arbitrary data of

arbitrary data types. Previously, when the GDB convenience variable contained a
structure data type, accessing a field of the structure caused an internal
error. With this update, this problem has been corrected, and GDB now works with
structure convenience variables correctly. (BZ#727726)

• When loading a core dump file for debugging, GDB could incorrectly interpret

inappropriate memory content as the pthread_t identifier if the version of the
glibc library installed on the system did not match the glibc version used to
create the core dump file. Consequently, initialization of the libthread_db
library failed due to an unexpected value of pthread_t, which led to a GDB
internal error. With this update, GDB only displays a warning message and
successfully loads the core file. Instead of the pthread_t identifiers, which
are unavailable in this failure scenario, GDB displays the LWP (light-weight
process) identifiers that match the Linux TID (Thread Identifier) values of the
threads found in the core file. (BZ#748267)

All GDB users are advised to upgrade to this updated package, which fixes these
bugs.

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/kb/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 - 658851 - _dl_debug_state() RT_CONSISTENT called too early

CVEs

(none)

References

(none)