RHBA-2015:1298 - Bug Fix Advisory

Topic

Updated valgrind packages that fix several bugs are now available for Red Hat
Enterprise Linux 6.

Description

Valgrind is an instrumentation framework that is used for debugging memory,
detecting memory leaks, and profiling applications.

This update fixes the following bugs:

• Valgrind did not recognize Intel Memory Protection Extensions (MPX)

instructions or instructions using the MPX bnd prefix. Consequently, Valgrind
terminated programs that used MPX instructions with a SIGKILL signal. Valgrind
now recognizes the new MPX instructions and bnd prefixes. All new MPX
instructions are currently implemented as no operation instructions, and the bnd
prefix is ignored. As a result, programs using MPX instructions or bnd prefixes
run under Valgrind as if the MPX was not enabled on the CPU and are no longer
terminated. (BZ#1196273)

• Valgrind was unable to emulate a total LL cache size other than a power of

two. Consequently, when detecting CPU caches, Valgrind refused to run the
cachegrind tool with a warning message. Now, Valgrind forces down the cache size
it emulates to the nearest power of two below the value detected. As a result,
cachegrind can be run on systems detected as having a CPU cache size other than
a power of two and returns a warning message to indicate the difference between
the detected or specified cache size and the emulated cache size. (BZ#1163777)

• Valgrind assumed that a processor that supported the Advanced Vector

Extensions 2 (AVX2) instruction set also always supported the Leading Zeros
Count (LZCNT) instruction. This is not always true under QEMU, which can support
AVX2 instructions, but not LZCNT. Consequently, Valgrind failed to run under
QEMU when AVX2 instructions were enabled. Valgrind has been fixed to be able to
run when the AVX2 instruction set is supported but the LZCNT instruction is not,
and Valgrind now runs under QEMU as expected. (BZ#1158802)

• Previously, 32-bit PowerPC (ppc32) binaries that were compiled against the

valgrind.h header file to include Valgrind client requests could unexpectedly
clobber a register (r0) causing subtle bugs. This problem has been addressed in
the client-request code sequence for the ppc32 architecture. Existing ppc32
binaries need to be recompiled against the new valgrind.h header file to fix the
bug. Valgrind now also detects the erroneous code sequences in binaries that
have not been recompiled and returns a warning message. (BZ#1142151)

• Valgrind was unable to handle the SIOCETHTOOL ioctl (0x8946), which queries or

controls network driver and hardware settings. As a consequence, programs
running under Valgrind that use SIOCETHTOOL received a warning message, and
arguments were not tracked by Valgrind. Valgrind now correctly recognizes the
SIOCETHTOOL ioctl, and the described problem no longer occurs. (BZ#1191404)

• Valgrind was unable to recognize the getpriority() and setpriority() system

calls on 64-bit PowerPC systems. Consequently, programs running under Valgrind
that used the mentioned system calls returned an error message, and arguments to
the system call were not tracked. Valgrind has been fixed to recognize the
system calls on 64-bit PowerPC systems, and system call arguments are now
correctly tracked by Valgrind on all supported architectures. (BZ#1191414)

• Previously, on the IBM System z architecture, Valgrind did not recognize

certain code jumps that depended only on whether the highest bit of a
conditional register was fully defined. Consequently, when a program used a
combination of the IBM System z LTG + JHE instructions (jump if >= 0) or LTG +
JL instructions (jump if < 0), Valgrind reported the following error message:
"Conditional jump or move depends on uninitialised value(s)". Valgrind has been
fixed to recognize these instruction patterns as jumps that depend only on
whether or not the highest bit is set or unset (defined), and the described
problem no longer occurs. (BZ#1133040)

Users of valgrind are advised to upgrade to these updated packages, which fix
these bugs.

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 Workstation 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 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 Desktop 6 x86_64
• Red Hat Enterprise Linux Desktop 6 i386
• Red Hat Enterprise Linux Server - Extended Life Cycle Support (for IBM z Systems) 6 s390x
• Red Hat Enterprise Linux Server - Extended Life Cycle Support Extension 6 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support Extension 6 i386
• Red Hat Enterprise Linux Server - Extended Life Cycle Support Extension (for IBM z Systems) 6 s390x

Fixes

• BZ - 1158802 - are_valid_hwcaps() assertion fail makes valgrind unusable on (qemu emulated) Haswell x86_64
• BZ - 1191404 - Warning: noted but unhandled ioctl 0x8946 (SIOCETHTOOL) with no size/direction hints

CVEs

(none)

References

(none)