Synopsis

elfutils bug fix and enhancement update

Type/Severity

Product Enhancement Advisory

Topic

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

Description

The elfutils packages contain a number of utility programs and libraries related
to the creation and maintenance of executable code.

The elfutils packages have been upgraded to upstream version 0.158, which
provides a number of bug fixes and enhancements over the previous version. The
most notable additions include:

• This update introduces an eu-stack tool that retrieves the backtrace of a

process or a core file.

• The elfutils libdwfl() functions have been extended to provide support for

associating a process state to a Dwfl object. A state can be attached to a
process or a core file using the new dwfl_core_file_attach() and
dwfl_linux_proc_attach() functions. When a state is attached to a Dwfl object, a
new function, dwfl_getthreads(), can be used to iterate over the running
threads. It is possible for each thread to unwind and inspect the frames on the
call stack using the new dwfl_getthread_frames() function.

• The libraries and utilities provide various improvements to recognize DWARF

version 4, DWARF GNU tool chain extensions (typed DWARF stack, call_site,
entry_value, DW_AT_high_pc, DW_OP_GNU_parameter_ref, and experimental support
for DWZ multifiles), and new functions to handle DWARF location expressions.

• The eu-readelf utility now supports the "/SYM64/" special entry to read 64-bit

ar archive files used on IBM System z architecture.
(BZ#755728, BZ#1059897)

This update also fixes the following bugs:

• Prior to this update, the eu-readelf utility was unable to read a corrupted

ELF file with a missing string table. As a consequence, eu-readelf terminated
unexpectedly with a segmentation fault. With this update, eu-readelf has been
fixed to skip the data sections with a non-existent string table and read only
valid data. As a result, eu-readelf no longer crashes in this scenario.
(BZ#1101440)

• Previously, due to bugs in certain tool chain utilities, the main ELF file and

the separate debuginfo file had different header types or flags. As a
consequence, the eu-unstrip utility was unable to combine the ELF file and the
separate debuginfo file. The same problem occurred when the main ELF file was
prelinked after the debug information was separated into a debuginfo file. With
this update, eu-unstrip displays a warning message similar to "ELF header
identification (e_ident) different" and shows which header field does not match
if the stripped and unstripped files cannot be combined. Also, the "--force"
option has been added so that the user can ignore the warning and combine such
files anyway. Additionally, eu-unstrip prints a warning message if the DWARF
data need adjusting for prelinking bias. As a result, eu-unstrip now prints
appropriate warning messages and the mismatching main ELF and separate debuginfo
files can be recombined into one using the "--force" option. (BZ#806474)

Users of elfutils 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.

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/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 - 755728 - Rebase elfutils to 0.158 in RHEL 6.6
• BZ - 806474 - eu-unstrip unwilling to reassembled corrupted separate debuginfo
• BZ - 1059897 - Support 64-bit /SYM64/ symbol table

CVEs

(none)

References

(none)