The GNU C Library version 2.21 is now available

["Carlos O'Donell" <carlos at redhat dot com>]

The GNU C Library
=================

The GNU C Library version 2.21 is now available.

The GNU C Library is used as *the* C library in the GNU system and
in GNU/Linux systems, as well as many other systems that use Linux
as the kernel.

The GNU C Library is primarily designed to be a portable 
and high performance C library.  It follows all relevant 
standards including ISO C11 and POSIX.1-2008.  It is also 
internationalized and has one of the most complete 
internationalization interfaces known. 

The GNU C Library webpage is at http://www.gnu.org/software/libc/

Packages for the 2.21 release may be downloaded from:
        http://ftpmirror.gnu.org/libc/
        http://ftp.gnu.org/gnu/libc/

The mirror list is at http://www.gnu.org/order/ftp.html

NEWS for version 2.21
=====================

* The following bugs are resolved with this release:

  6652, 10672, 12674, 12847, 12926, 13862, 14132, 14138, 14171, 14498,
  15215, 15378, 15884, 16009, 16418, 16191, 16469, 16576, 16617, 16618,
  16619, 16657, 16740, 16857, 17192, 17266, 17273, 17344, 17363, 17370,
  17371, 17411, 17460, 17475, 17485, 17501, 17506, 17508, 17522, 17555,
  17570, 17571, 17572, 17573, 17574, 17582, 17583, 17584, 17585, 17589,
  17594, 17601, 17608, 17616, 17625, 17630, 17633, 17634, 17635, 17647,
  17653, 17657, 17658, 17664, 17665, 17668, 17682, 17702, 17717, 17719,
  17722, 17723, 17724, 17725, 17732, 17733, 17744, 17745, 17746, 17747,
  17748, 17775, 17777, 17780, 17781, 17782, 17791, 17793, 17796, 17797,
  17801, 17803, 17806, 17834, 17844, 17848, 17868, 17869, 17870, 17885,
  17892.

* CVE-2015-1472 Under certain conditions wscanf can allocate too little
  memory for the to-be-scanned arguments and overflow the allocated
  buffer.  The implementation now correctly computes the required buffer
  size when using malloc.

* A new semaphore algorithm has been implemented in generic C code for all
  machines. Previous custom assembly implementations of semaphore were
  difficult to reason about or ensure that they were safe. The new version
  of semaphore supports machines with 64-bit or 32-bit atomic operations.
  The new semaphore algorithm is used by sem_init, sem_open, sem_post,
  sem_wait, sem_timedwait, sem_trywait, and sem_getvalue.

* Port to Altera Nios II has been contributed by Mentor Graphics.

* Optimized strcpy, stpcpy, strncpy, stpncpy, strcmp, and strncmp
  implementations for powerpc64/powerpc64le.
  Implemented by Adhemerval Zanella (IBM).

* Added support for TSX lock elision of pthread mutexes on powerpc32, powerpc64
  and powerpc64le.  This may improve lock scaling of existing programs on
  HTM capable systems.  The lock elision code is only enabled with
  --enable-lock-elision=yes.  Also, the TSX lock elision implementation for
  powerpc will issue a transaction abort on every syscall to avoid side
  effects being visible outside transactions.

* Optimized strcpy, stpcpy, strchrnul and strrchr implementations for
  AArch64.  Contributed by ARM Ltd.

* i386 memcpy functions optimized with SSE2 unaligned load/store.

* CVE-2104-7817 The wordexp function could ignore the WRDE_NOCMD flag
  under certain input conditions resulting in the execution of a shell for
  command substitution when the applicaiton did not request it. The
  implementation now checks WRDE_NOCMD immediately before executing the
  shell and returns the error WRDE_CMDSUB as expected.

* CVE-2012-3406 printf-style functions could run into a stack overflow when
  processing format strings with a large number of format specifiers.

* CVE-2014-9402 The nss_dns implementation of getnetbyname could run into an
  infinite loop if the DNS response contained a PTR record of an unexpected
  format.

* The minimum GCC version that can be used to build this version of the GNU
  C Library is GCC 4.6.  Older GCC versions, and non-GNU compilers, can
  still be used to compile programs using the GNU C Library.

* The GNU C Library is now built with -Werror by default.  This can be
  disabled by configuring with --disable-werror.

* New locales: tu_IN, bh_IN, raj_IN, ce_RU.

* The obsolete sigvec function has been removed.  This was the original
  4.2BSD interface that inspired the POSIX.1 sigaction interface, which
  programs have been using instead for about 25 years.  Of course, ABI
  compatibility for old binaries using sigvec remains intact.

* Merged gettext 0.19.3 into the intl subdirectory.  This fixes building
  with newer versions of bison.

* Support for MIPS o32 FPXX, FP64A and FP64 ABI Extensions.
  The original MIPS o32 hard-float ABI requires an FPU where double-precision
  registers overlay two consecutive single-precision registers.  MIPS32R2
  introduced a new FPU mode (FR=1) where double-precision registers extend the
  corresponding single-precision registers which is incompatible with the
  o32 hard-float ABI.  The MIPS SIMD ASE and the MIPSR6 architecture both
  require the use of FR=1 making a transition necessary.  New o32 ABI
  extensions enable users to migrate over time from the original o32 ABI
  through to the updated o32 FP64 ABI.  To achieve this the dynamic linker now
  tracks the ABI of any loaded object and verifies that new objects are
  compatible.  Mode transitions will also be requested as required and
  unsupportable objects will be rejected.  The ABI checks include both soft and
  hard float ABIs for o32, n32 and n64.

  GCC 5 with GNU binutils 2.25 onwards:
  It is strongly recommended that all o32 system libraries are built using the
  new o32 FPXX ABI (-mfpxx) to facilitate the transition as this is compatible
  with the original and all new o32 ABI extensions.  Configure a MIPS GCC
  compiler using --with-fp-32=xx to set this by default.

Contributors
============

This release was made possible by the contributions of many people.
The maintainers are grateful to everyone who has contributed
changes or bug reports.  These include:

Adhemerval Zanella
Alan Hayward
Alexandre Oliva
Allan McRae
Anders Kaseorg
Andreas Krebbel
Andreas Schwab
Andrew Pinski
Andrew Senkevich
Anton Blanchard
Arjun Shankar
Aurelien Jarno
Bram
Brooks Moses
Carlos O'Donell
Chris Metcalf
Chung-Lin Tang
David Holsgrove
David S. Miller
Eric Biggers
Florian Weimer
Gratian Crisan
H.J. Lu
J. Brown
James Lemke
Jeff Law
Jose E. Marchesi
Joseph Myers
Kaz Kojima
Kostya Serebryany
Leonhard Holz
Ma Shimiao
Maciej W. Rozycki
Marcus Shawcroft
Marek Polacek
Martin Sebor
Matthew Fortune
Mike Frysinger
OndÅej BÃlka
Paul Eggert
Paul Pluzhnikov
Petar Jovanovic
Pravin Satpute
Rajalakshmi Srinivasaraghavan
Rasmus Villemoes
Renlin Li
Richard Earnshaw
Richard Henderson
Roland McGrath
Ryan Cumming
Samuel Thibault
Siddhesh Poyarekar
Stefan Liebler
Steve Ellcey
Tatiana Udalova
Tim Lammens
Tom de Vries
Torvald Riegel
Vladimir A. Nazarenko
Wilco Dijkstra
Will Newton