RHBA-2013:0420 - Bug Fix Advisory

Topic

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

Description

The gcc packages provide compilers for C, C++, Java, Fortran, Objective C, and
Ada 95 GNU, as well as related support libraries.

This update fixes the following bugs:

• Due to the incorrect size of a pointer in GCC GNAT code, GNAT used an

incorrect function of the libgcc library when compiling 32-bit Ada binaries on
PowerPC architecture. Consequently, these programs could not be linked and the
compilation failed. This update fixes the problem so that the sizeof operator
now returns the correct size of a pointer, and the appropriate function from
libgcc is called. GNAT compiles Ada binaries as expected in this scenario.
(BZ#801144)

• The Standard Template Library (STL) contained an incomplete move semantics

implementation, which could cause GCC to generate incorrect code. The incorrect
headers have been fixed so that GCC now produce the expected code when depending
on move semantics. (BZ#808590)

• GCC did not, under certain circumstances, handle generating a CPU instruction

sequence that would be independent of indexed addressing on PowerPC
architecture. As a consequence, an internal compiler error occurred if the
"__builtin_bswap64" built-in function was called with the "-mcpu=power6" option.
This update corrects the relevant code so that GCC now generates an alternate
instruction sequence that does not depend on indexed addressing in this
scenario. (BZ#819100)

• A bug in converting the exception handling region could cause an internal

compiler error to occur when compiling profile data with the "-fprofile-use" and
"-freorder-basic-blocks-and-partition" options. This update fixes the erroneous
code and the compilation of profile data now proceeds as expected in this
scenario. (BZ#821901)

• Previously, GCC did not properly handle certain situations when an enumeration

was type cast using the static_cast operator. Consequently, an enumeration item
could have been assigned an integer value greater than the highest value of the
enumeration's range. If the compiled code contained testing conditions using
such enumerations, those checks were incorrectly removed from the code during
code optimization. With this update, GCC was modified to handle enumeration type
casting properly and C++ now no longer removes the mentioned checks. (BZ#826882)

• Previously, when comparing the trees equality, the members of a union or

structure were not handled properly in the C++ compiler. This led to an internal
compiler error. This update modifies GCC so that unions and structures are now
handled correctly and code that uses tree equality comparing is now compiled
successfully. (BZ#831832)

• GCC previously processed the "srak" instructions without the z196 flag, which

enables a compiler to work with these instructions. Consequently, some binaries,
such as Firefox, could not be compiled on IBM System z and IBM S/390
architectures. With this update, GCC has been modified to support the z196 flag
for the srak instructions, and binaries requiring these instructions can now be
compiled successfully on IBM System z and IBM S/390 architectures. (BZ#867878)

All users of gcc 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.

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/knowledge/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 - 826882 - g++44 code crashes when compiled with -O2 -fPIC and -O3 -fPIC
• BZ - 867878 - s390 build fails with Error: Unrecognized opcode: `srak'

CVEs

(none)

References

(none)