RHEA-2015:2039 - Product Enhancement Advisory

Topic

New devtoolset-4-gdb packages are now available as a part of Red Hat Developer
Toolset 4.0 for Red Hat Enterprise Linux.

Description

The GNU Debugger (GDB) allows users to debug programs written in various
programming languages including C, C++, and Fortran. The devtoolset-4-gdb
packages provide the Red Hat Developer Toolset version of GDB.

This enhancement update adds the devtoolset-4-gdb packages to Red Hat Developer
Toolset 4.0 for Red Hat Enterprise Linux. These packages include GDB 7.10, which
is the latest stable release of GDB. It provides numerous bug fixes and
enhancements over the version included in Red Hat Developer Toolset 3.1. Among
others:

• GDB now honors the content of the /proc/PID/coredump_filter file for the

"gcore" command. GDB also introduces a new command: "set use-coredump-filter
on|off". Previously, GDB could generate needlessly large core files.

• The "info source" command can now be run to display the compiler version and

command-line arguments used for compiling the debugged program if these were
included in the debugging information.

• GDB can now transparently debug processes in containers. This is enabled by

the new automatic location and retrieval of executable files from remote
targets. GDB and gdbserver are now also able to access executable and shared
library files without the "set sysroot" and "file" commands when attaching to
processes running in different mount namespaces from the debugger.

• The HISTSIZE environment variable has been deprecated; use the GDBHISTSIZE

variable instead.

• Support for fork events on extended-remote Linux targets has been added.
• GDB now supports the compilation and injection of source code into the

inferior. GDB will use GCC 5.0 or higher built with libcc1.so to compile the
source code to object code, and if successful, inject and execute that code
within the current context of the inferior. Currently, the C language is
supported. See sub-commands starting with "compile".

• GDB now supports a new command, "queue-signal", to queue a signal to be

delivered to the thread when it is later resumed.

• GDB can now limit the maximum number of candidates to be considered during

tab-completion by the "set max-completions" command. This is to prevent debugger
from becoming temporarily unresponsive on a large number of candidates.

• Auto-loading of Python scripts contained in the .debug_gdb_scripts special

section is now supported.

• For details regarding further changes, for example, new remote packets, Python

scripting support, new commands, or new command-line options, see Appendix A.6.
Changes in GDB in the Red Hat Developer Toolset 4.0 User Guide linked from the
References section below.

(BZ#1223958)

This update also fixes the following bug:

• Red Hat Developer Toolset version of GDB bundles Python Pretty Printers for

Red Hat Developer Toolset GCC's libstdc++ data types (such as "unordered_map"
template). This is because Red Hat Developer Toolset GCC supports more data
types than the standard system Red Hat Enterprise Linux GCC and therefore the
standard system Python Pretty Printers are insufficient for Red Hat Developer
Toolset GDB. These Pretty Printers are used only in the Red Hat Developer
Toolset deployment of GDB. Prior to this update, Red Hat Developer Toolset GDB
contained bundled Pretty Printers from an earlier version of GCC than the one
shipped in Red Hat Developer Toolset as the mentioned GDB. Consequently, certain
data types (particularly the C++11 ones) produced by Red Hat Developer Toolset
GCC were unsupported by Red Hat Developer Toolset GDB in Red Hat Developer
Toolset. This bug has been fixed, Red Hat Developer Toolset GDB's bundled Pretty
Printers now match those of Red Hat Developer Toolset GCC. As a result, C++11
data types (such as "unordered_map" template) can be printed in a human readable
form by the associated Pretty Printer. (BZ#1239290)

All users who require devtoolset-4-gdb are advised to install these new
packages.

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 Software Collections (for RHEL Server) 1 for RHEL 7.7 x86_64
• Red Hat Software Collections (for RHEL Server) 1 for RHEL 7.6 x86_64
• Red Hat Software Collections (for RHEL Server) 1 for RHEL 7.5 x86_64
• Red Hat Software Collections (for RHEL Server) 1 for RHEL 7.4 x86_64
• Red Hat Software Collections (for RHEL Server) 1 for RHEL 7.3 x86_64
• Red Hat Software Collections (for RHEL Server) 1 for RHEL 7.2 x86_64
• Red Hat Software Collections (for RHEL Server) 1 for RHEL 7.1 x86_64
• Red Hat Software Collections (for RHEL Server) 1 for RHEL 7 x86_64
• Red Hat Software Collections (for RHEL Server) 1 for RHEL 6.7 x86_64
• Red Hat Software Collections (for RHEL Server) 1 for RHEL 6.6 x86_64
• Red Hat Software Collections (for RHEL Server) 1 for RHEL 6 x86_64
• Red Hat Software Collections (for RHEL Workstation) 1 for RHEL 7 x86_64
• Red Hat Software Collections (for RHEL Workstation) 1 for RHEL 6 x86_64
• Red Hat Software Collections (for RHEL Server) from RHUI 1 for RHEL 7 x86_64
• Red Hat Software Collections (for RHEL Server) from RHUI 1 for RHEL 6 x86_64

Fixes

• BZ - 1262589 - gstack in DTS defaults to "/usr/bin/gdb"

CVEs

(none)

References

• https://access.redhat.com/documentation/en-US/Red_Hat_Developer_Toolset/4/html/User_Guide/sect-Changes_in_Version_4.0-GDB.html