posix: Use 64 bit stat for fpathconf (_PC_ASYNC_IO) (BZ# 29208)

[glibc.git] / NEWS

GNU C Library NEWS -- history of user-visible changes.
Copyright (C) 1992-2022 Free Software Foundation, Inc.
See the end for copying conditions.

Please send GNU C library bug reports via <https://sourceware.org/bugzilla/>
using `glibc' in the "product" field.
\f
Version 2.36

Major new features:

* Support for DT_RELR relative relocation format has been added to
  glibc.  This is a new ELF dynamic tag that improves the size of
  relative relocations in shared object files and position independent
  executables (PIE).  DT_RELR generation requires linker support for
  -z pack-relative-relocs option, which is supported for some targets
  in recent binutils versions.  Lazy binding doesn't apply to DT_RELR.

* On Linux, the pidfd_open, pidfd_getfd, and pidfd_send_signal functions
  have been added.  The pidfd functionality provides access to a process
  while avoiding the issue of PID reuse on tranditional Unix systems.

Deprecated and removed features, and other changes affecting compatibility:

* Support for prelink will be removed in the next release; this includes
  removal of the LD_TRACE_PRELINKING, and LD_USE_LOAD_BIAS, environment
  variables and their functionality in the dynamic loader.

* The Linux kernel version check has been removed along with the
  LD_ASSUME_KERNEL environment variable.  The minimum kernel used to built
  glibc is still provided through NT_GNU_ABI_TAG ELF note and also printed
  when libc.so is issued directly.

* On Linux, The LD_LIBRARY_VERSION environment variable has been removed.

Changes to build and runtime requirements:

  [Add changes to build and runtime requirements here]

Security related changes:

  [Add security related changes here]

The following bugs are resolved with this release:

  [The release manager will add the list generated by
  scripts/list-fixed-bugs.py just before the release.]

\f
Version 2.35

Major new features:

* Unicode 14.0.0 Support: Character encoding, character type info, and
  transliteration tables are all updated to Unicode 14.0.0, using
  generator scripts contributed by Mike FABIAN (Red Hat).

* Bump r_version in the debugger interface to 2 and add a new field,
  r_next, support multiple namespaces.

* Support for the C.UTF-8 locale has been added to glibc.  The locale
  supports full code-point sorting for all valid Unicode code points.  A
  limitation in the framework for fnmatch, regexec, and regcomp requires
  a compromise to save space and only ASCII-based range expressions are
  supported for now (see bug 28255).  The full size of the locale is
  only ~400KiB, with 346KiB coming from LC_CTYPE information for
  Unicode.  This locale harmonizes downstream C.UTF-8 already shipping
  in various downstream distributions.  The locale is not built into
  glibc, and must be installed.

* <math.h> functions that round their results to a narrower type, and
  corresponding <tgmath.h> macros, are added from TS 18661-1:2014, TS
  18661-3:2015 and draft ISO C2X:

  - fsqrt, fsqrtl, dsqrtl and corresponding fMsqrtfN, fMsqrtfNx,
    fMxsqrtfN and fMxsqrtfNx functions.

  - ffma, ffmal, dfmal and corresponding fMfmafN, fMfmafNx, fMxfmafN and
    fMxfmafNx functions.

* <math.h> functions for floating-point maximum and minimum,
  corresponding to new operations in IEEE 754-2019, and corresponding
  <tgmath.h> macros, are added from draft ISO C2X: fmaximum,
  fmaximum_num, fmaximum_mag, fmaximum_mag_num, fminimum, fminimum_num,
  fminimum_mag, fminimum_mag_num and corresponding functions for float,
  long double, _FloatN and _FloatNx.

* <math.h> macros for single-precision float constants are added as a
  GNU extension: M_Ef, M_LOG2Ef, M_LOG10Ef, M_LN2f, M_LN10f, M_PIf,
  M_PI_2f, M_PI_4f, M_1_PIf, M_2_PIf, M_2_SQRTPIf, M_SQRT2f and
  M_SQRT1_2f.

* The __STDC_IEC_60559_BFP__ and __STDC_IEC_60559_COMPLEX__ macros are
  predefined as specified in TS 18661-1:2014.

* The exp10 functions in <math.h> now have a corresponding type-generic
  macro in <tgmath.h>.

* The ISO C2X macro _PRINTF_NAN_LEN_MAX has been added to <stdio.h>.

* printf-family functions now support the %b format for output of
  integers in binary, as specified in draft ISO C2X, and the %B variant
  of that format recommended by draft ISO C2X.

* A new DSO sorting algorithm has been added in the dynamic linker that uses
  topological sorting by depth-first search (DFS), solving performance issues
  of the existing sorting algorithm when encountering particular circular
  object dependency cases.

* A new tunable, glibc.rtld.dynamic_sort, can be used to select between
  the two DSO sorting algorithms.  The default setting of '2' uses the
  new DFS-based algorithm.  The setting '1' switches to the old
  algorithm used in glibc 2.33 and earlier.

* ABI support for a new function '__memcmpeq'. '__memcmpeq' is meant
  to be used by compilers for optimizing usage of 'memcmp' when its
  return value is only used for its boolean status.

* Support for automatically registering threads with the Linux rseq
  system call has been added.  This system call is implemented starting
  from Linux 4.18.  The Restartable Sequences ABI accelerates user-space
  operations on per-cpu data.  It allows user-space to perform updates
  on per-cpu data without requiring heavy-weight atomic operations.
  Automatically registering threads allows all libraries, including
  libc, to make immediate use of the rseq support by using the
  documented ABI, via the __rseq_flags, __rseq_offset, and __rseq_size
  variables.  The GNU C Library manual has details on integration of
  Restartable Sequences.

* A symbolic link to the dynamic linker is now installed under
  /usr/bin/ld.so (or more precisely, '${bindir}/ld.so').

* All programs and the testsuite in glibc are now built as position independent
  executables (PIE) by default on toolchains and architectures that support it.
  Further, if the toolchain and architecture supports it, even static programs
  are built as PIE and the resultant glibc can be used to build static PIE
  executables.  A new option --disable-default-pie has been added to disable
  this behavior and get a non-PIE build.  This option replaces
  --enable-static-pie, which no longer has any effect on the build
  configuration.

* On Linux, a new tunable, glibc.malloc.hugetlb, can be used to
  either make malloc issue madvise plus MADV_HUGEPAGE on mmap and sbrk
  or to use huge pages directly with mmap calls with the MAP_HUGETLB
  flags).  The former can improve performance when Transparent Huge Pages
  is set to 'madvise' mode while the latter uses the system reserved
  huge pages.

* The printf family of functions now handles the flagged %#m conversion
  specifier, printing errno as an error constant (similar to strerrorname_np).

* The function _dl_find_object has been added.  In-process unwinders
  can use it to efficiently locate unwinding information for a code
  address.

* Support for OpenRISC running on Linux has been added.  This port requires
  as least binutils 2.35, GCC 11, and Linux 5.4.  Currently only soft-float
  ABI is supported:

    - or1k-linux-gnu

  The OpenRISC ABI is 32-bit big-endian and uses 64-bit time (y2038 safe) and
  64-bit file offsets (LFS default).

* A new configure option, --with-rtld-early-cflags, can be used to
  specify additional compiler flags for building the early startup code
  of the dynamic linker.  On targets which have CPU compatibility
  checks, this can help to ensure that proper diagnostics are printed if
  the dynamic loader runs on an incompatible CPU.

* On Linux, the epoll_pwait2 function has been added.  It is similar to
  epoll_wait with the difference the timeout has nanoseconds resolution.

* The function posix_spawn_file_actions_addtcsetpgrp_np has been added,
  enabling posix_spawn and posix_spawnp to set the controlling terminal in
  the new process in a race free manner.  This function is a GNU extension.

* Source fortification (_FORTIFY_SOURCE) level 3 is now available for
  applications compiling with glibc and gcc 12 and later. Level 3 leverages
  the __builtin_dynamic_object_size function to deliver additional
  fortification balanced against additional runtime cost (checking non-constant
  bounds).

* The audit libraries will avoid unnecessary slowdown if it is not required
  PLT tracking (by not implementing the la_pltenter or la_pltexit callbacks).

Deprecated and removed features, and other changes affecting compatibility:

* On x86-64, the LD_PREFER_MAP_32BIT_EXEC environment variable support
  has been removed since the first PT_LOAD segment is no longer executable
  due to defaulting to -z separate-code.

* The r_version update in the debugger interface makes the glibc binary
  incompatible with GDB binaries built without the following commits:

  c0154a4a21a gdb: Don't assume r_ldsomap when r_version > 1 on Linux
  4eb629d50d4 gdbserver: Check r_version < 1 for Linux debugger interface

  when audit modules or dlmopen are used.

* Intel MPX support (lazy PLT, ld.so profile, and LD_AUDIT) has been removed.

* The --enable-static-pie option is no longer available.  The glibc build
  configuration script now automatically detects static-pie support in the
  toolchain and architecture and enables it if available.

* The catchsegv script and associated libSegFault.so shared object have
  been removed.  There are widely-deployed out-of-process alternatives for
  catching coredumps and backtraces.

* Support for prelink will be removed in the next release; this includes
  removal of the LD_TRACE_PRELINKING, and LD_USE_LOAD_BIAS, environment
  variables and their functionality in the dynamic loader.

* The LD_TRACE_PRELINKING environment variable has been removed.  Similar
  functionality to obtain the program mapping address can be achieved by
  using LD_TRACE_LOADED_OBJECTS to value of 2.

* The LD_USE_LOAD_BIAS has been removed.  The variable was mainly used to
  support prelink PIE binaries.

Changes to build and runtime requirements:

* The audit module interface version LAV_CURRENT is increased to enable
  proper bind-now support.  The loader now advertises via the la_symbind
  flags that PLT trace is not possible.  New audit modules require the
  new dynamic loader supporing the latest LAV_CURRENT version. Old audit
  modules are still loaded for all targets except aarch64.

* The audit interface on aarch64 is extended to support both the indirect
  result location register (x8) and NEON Q register.  Old audit modules are
  rejected by the loader.  Audit modules must be rebuilt to use the newer
  structure sizes and the latest module interface version for LAV_CURRENT.

Security related changes:

  CVE-2022-23219: Passing an overlong file name to the clnt_create
  legacy function could result in a stack-based buffer overflow when
  using the "unix" protocol.  Reported by Martin Sebor.

  CVE-2022-23218: Passing an overlong file name to the svcunix_create
  legacy function could result in a stack-based buffer overflow.

  CVE-2021-3998: Passing a path longer than PATH_MAX to the realpath
  function could result in a memory leak and potential access of
  uninitialized memory.  Reported by Qualys.

  CVE-2021-3999: Passing a buffer of size exactly 1 byte to the getcwd
  function may result in an off-by-one buffer underflow and overflow
  when the current working directory is longer than PATH_MAX and also
  corresponds to the / directory through an unprivileged mount
  namespace.  Reported by Qualys.

The following bugs are resolved with this release:

  [12889] nptl: Race condition in pthread_kill
  [14232] nptl: tst-cancel7 and tst-cancelx7 race condition
  [14913] libc: [mips] Clean up MIPS 64-bit register-dump.h output
  [15310] dynamic-link: _dl_sort_fini is O(n^3) causing slow exit when
    many dsos
  [15333] libc: Use 64-bit stat functions in installed programs
  [15533] dynamic-link: LD_AUDIT introduces an avoidable performance
    degradation
  [15971] dynamic-link: No interface for debugger access to libraries
    loaded with dlmopen
  [17318] locale: [RFE] Provide a C.UTF-8 locale by default
  [17645] dynamic-link: RFE: Improve performance of dynamic loader for
    deeply nested DSO dependencies.
  [19193] nptl: pthread_kill, pthread_cancel return ESRCH for a thread
    ID whose lifetime has not ended
  [22542] network: buffer overflow in sunrpc clnt_create
    (CVE-2022-23219)
  [22716] malloc: [PATCH] mtrace.pl: use TRACE_PRELINKING instead of
    TRACE_LOADED_OBJECTS
  [25947] malloc: memory leak in muntrace
  [26045] math: fmaxf(inf, nan) does not always work
  [26108] math: exp10() has problems with <tgmath.h>
  [26779] build: benign use after realloc at localealias.c:329
  [27609] dynamic-link: [2.32/2.33/2.34 Regression] In elf/dl-open.c
    (_dl_open) we might use __LM_ID_CALLER to index GL(dl_ns)[]
  [27945] build: build-many-glibcs.py doesn't configure GCC with
    --enable-initfini-array
  [27991] build: x86: sysdeps/x86/configure.ac breaks when
    libc_cv_include_x86_isa_level is loaded from cache
  [28036] nptl: Incorrect types for pthread_mutexattr_set/getrobust_np
    in __REDIRECT_NTH macro
  [28061] dynamic-link: A failing dlmopen called by an auditor crashed
  [28062] dynamic-link: Suppress audit calls when a (new) namespace is
    empty
  [28126] libc: nftw aborts for paths longer than PATH_MAX
  [28129] dynamic-link: Unnecessary check DT_DEBUG in ld.so
  [28153] libc: [test] gmon/tst-gmon-gprof* may have a f3 line when
    built with ld.lld
  [28182] libc: _TIME_BITS=64 in C++ has issues with fcntl, ioctl, prctl
  [28185] math: Inaccurate j0f function (again)
  [28199] locale: iconvconfig prefix flag behaves differently in glibc
    2.34
  [28203] dynamic-link: aarch64: elf_machine_{load_address,dynamic}
    should drop _GLOBAL_OFFSET_TABLE_[0] in favor of __ehdr_start for
    robustness
  [28213] librt: NULL pointer dereference in mq_notify (CVE-2021-38604)
  [28223] libc: mips: clone does not align stack
  [28253] dynamic-link: Missing colon in LD_SHOW_AUXV output after
    AT_MINSIGSTKSZ
  [28256] malloc: Conditional jump or move depends on uninitialised
    value(s) in __GI___tunables_init
  [28260] build: io/tst-closefrom, misc/tst-close_range, posix/tst-
    spawn5 fail if stray fds are open
  [28310] libc: Do not use affinity mask for sysconf
    (_SC_NPROCESSORS_CONF)
  [28338] time: undefined behavior in __tzfile_compute with oddball TZif
    file
  [28340] dynamic-link: ld.so crashes while loading a DSO with a read-
    only dynamic section
  [28349] libc: Segfault for ping -R on qemux86 caused by recvmsg()
  [28350] libc: ping receives SIGABRT on lib32-qemux86-64 caused by
    recvmsg()
  [28353] network: Race condition on __opensock
  [28357] dynamic-link: deadlock between pthread_create and ctors
  [28358] math: f64xdivf128 and f64xmulf128 spurious underflows
  [28361] nptl: Fix for bug 12889 causes setxid deadlock
  [28368] build: -Waddress instances in stdio-common/vfprintf-internal.c
  [28390] localedata: Update locale data to Unicode 14.0.0
  [28397] math: tgmath.h should not define fmaxmag, fminmag macros for
    C2X
  [28400] libc: [2.35 Regression] string/test-strncasecmp: cannot set
    locale "en_US.UTF-8"
  [28407] nptl: pthread_kill assumes that kill (getpid ()) is equivalent
    to tgkill (getpid (), gettid())
  [28455] dynamic-link: -Wl,--enable-new-dtags doesn't work
  [28457] dynamic-link: Missing reldepmod4.so dependency for
    globalmod1.so
  [28469] time: linux: struct timex is not correctly set for 32-bit
    systems with TIMESIZE=64
  [28470] regex: Buffer read overrun in regular expression searching
  [28475] string: Incorrect access attribute on memfrob
  [28524] libc: Conversion from ISO-2022-JP-3 with iconv may emit
    spurious NUL character on state reset
  [28532] libc: powerpc64[le]: CFI for assembly templated syscalls is
    incorrect
  [28550] dynamic-link: FAIL: tst-dso-
    ordering9_112-ecbda(GLIBC_TUNABLES=glibc.rtld.dynamic_sort=1)
    execution test
  [28554] build: Undefined generate-md5
  [28572] libc: Misaligned accesses in test-memcpy and test-mempcpy on
    hppa
  [28607] nptl: Masked signals are delivered on thread exit
  [28624] libc: openjdk 8/9 assume uni processor and gets stuck due to
    lack of cpu counting /proc fallback with glibc 2.34
  [28646] string: [2.35 Regression] mock -r fedora-36-x86_64
    /tmp/java-1.8.0-openjdk-1.8.0.312.b07-2.fc36.src.rpm& fails to build
  [28648] dynamic-link: Running ld.so on statically linked binaries
    crashes
  [28656] dynamic-link: LD_PREFER_MAP_32BIT_EXEC no longer works due to
    binutils changes
  [28676] dynamic-link: p_align on PT_LOAD segment in DSO isn't honored
  [28678] nptl: nptl/tst-create1 hangs sporadically
  [28688] dynamic-link: PT_LOAD p_align check is too strict
  [28700] nss: "dns [!UNAVAIL=return] files" default for hosts database
    is not useful
  [28707] time: assert in tzfile.c __tzfile_read striking with truncated
    timezones generated by tzcode-2021d and later
  [28713] math: GCC 12 miscompiles libm
  [28732] dynamic-link: FAIL: elf/tst-dl_find_object
  [28738] build: LIBC_LINKER_FEATURE doesn't work on linker -z option
  [28745] dynamic-link: _dl_find_object miscompilation on powerpc64le
  [28746] libc: _FORTIFY_SOURCE does not work for stpcpy
  [28749] libc: Inconsistency detected by ld.so: rtld.c: 1632: dl_main:
    Assertion `GL(dl_rtld_map).l_libname' failed!
  [28755] string: overflow bug in wcsncmp_avx2 and wcsncmp_evex
  [28757] nptl: GDB printer tests failed with new GDB
  [28765] math: x86_64 libmvec atan2 accuracy
  [28766] manual: Document libmvec accuracy
  [28768] network: Buffer overflow in svcunix_create with long pathnames
    (CVE-2022-23218)
  [28769] libc: Off-by-one buffer overflow/underflow in getcwd()
    (CVE-2021-3999)
  [28770] libc: Unexpected return value from realpath() for too long
    results (CVE-2021-3998)
  [28771] libc: %ebx optimization macros are incompatible with .altmacro
    in Systemtap probes
  [28780] build: --disable-default-pie doesn't work on static programs
  [28782] libc: x86-64 ISA level for glibc itself is always
    x86-64-baseline
  [28792] glob: possible wrong behaviour with patterns with double [
    with no closing ]
  [28837] libc: FAIL: socket/tst-socket-timestamp-compat
  [28847] locale: Empty mon_decimal_point in LC_MONETARY results in non-
    empty mon_decimal_point_wc

\f
Version 2.34

Major new features:

* In order to support smoother in-place-upgrades and to simplify
  the implementation of the runtime all functionality formerly
  implemented in the libraries libpthread, libdl, libutil, libanl has
  been integrated into libc.  New applications do not need to link with
  -lpthread, -ldl, -lutil, -lanl anymore.  For backwards compatibility,
  empty static archives libpthread.a, libdl.a, libutil.a, libanl.a are
  provided, so that the linker options keep working.  Applications which
  have been linked against glibc 2.33 or earlier continue to load the
  corresponding shared objects (which are now empty).  The integration
  of those libraries into libc means that additional symbols become
  available by default.  This can cause applications that contain weak
  references to take unexpected code paths that would only have been
  used in previous glibc versions when e.g. preloading libpthread.so.0,
  potentially exposing application bugs.

* When _DYNAMIC_STACK_SIZE_SOURCE or _GNU_SOURCE are defined,
  PTHREAD_STACK_MIN is no longer constant and is redefined to
  sysconf(_SC_THREAD_STACK_MIN).  This supports dynamic sized register
  sets for modern architectural features like Arm SVE.

* Add _SC_MINSIGSTKSZ and _SC_SIGSTKSZ.  When _DYNAMIC_STACK_SIZE_SOURCE
  or _GNU_SOURCE are defined, MINSIGSTKSZ and SIGSTKSZ are no longer
  constant on Linux.  MINSIGSTKSZ is redefined to sysconf(_SC_MINSIGSTKSZ)
  and SIGSTKSZ is redefined to sysconf (_SC_SIGSTKSZ).  This supports
  dynamic sized register sets for modern architectural features like
  Arm SVE.

* The dynamic linker implements the --list-diagnostics option, printing
  a dump of information related to IFUNC resolver operation and
  glibc-hwcaps subdirectory selection.

* On Linux, the function execveat has been added.  It operates similar to
  execve and it is is already used to implement fexecve without requiring
  /proc to be mounted.  However, different than fexecve, if the syscall is not
  supported by the kernel an error is returned instead of trying a fallback.

* The ISO C2X function timespec_getres has been added.

* The feature test macro __STDC_WANT_IEC_60559_EXT__, from draft ISO
  C2X, is supported to enable declarations of functions defined in Annex F
  of C2X.  Those declarations are also enabled when
  __STDC_WANT_IEC_60559_BFP_EXT__, as specified in TS 18661-1, is
  defined, and when _GNU_SOURCE is defined.

* On powerpc64*, glibc can now be compiled without scv support using the
  --disable-scv configure option.

* Add support for 64-bit time_t on configurations like x86 where time_t
  is traditionally 32-bit.  Although time_t still defaults to 32-bit on
  these configurations, this default may change in future versions.
  This is enabled with the _TIME_BITS preprocessor macro set to 64 and is
  only supported when LFS (_FILE_OFFSET_BITS=64) is also enabled.  It is
  only enabled for Linux and the full support requires a minimum kernel
  version of 5.1.

* The main gconv-modules file in glibc now contains only a small set of
  essential converter modules and the rest have been moved into a supplementary
  configuration file gconv-modules-extra.conf in the gconv-modules.d directory
  in the same GCONV_PATH.  Similarly, external converter modules directories
  may have supplementary configuration files in a gconv-modules.d directory
  with names ending with .conf to logically classify the converter modules in
  that directory.

* On Linux, a new tunable, glibc.pthread.stack_cache_size, can be used
  to configure the size of the thread stack cache.

* The function _Fork has been added as an async-signal-safe fork replacement
  since Austin Group issue 62 droped the async-signal-safe requirement for
  fork (and it will be included in the future POSIX standard).  The new _Fork
  function does not run any atfork function neither resets any internal state
  or lock (such as the malloc one), and only sets up a minimal state required
  to call async-signal-safe functions (such as raise or execve).  This function
  is currently a GNU extension.

* On Linux, the close_range function has been added.  It allows efficiently
  closing a range of file descriptors on recent kernels (version 5.9).

* The function closefrom has been added.  It closes all file descriptors
  greater than or equal to a given integer.  This function is a GNU extension,
  although it is also present in other systems.

* The posix_spawn_file_actions_addclosefrom_np function has been added,
  enabling posix_spawn and posix_spawnp to close all file descriptors greater
  than or equal to a given integer.  This function is a GNU extension,
  although Solaris also provides a similar function.

* When invoked explicitly, the dynamic linker now uses the kernel to
  execute programs that do not have any dynamic dependency (that is,
  they are statically linked).  This feature is Linux-specific.

Deprecated and removed features, and other changes affecting compatibility:

* The function pthread_mutex_consistent_np has been deprecated; programs
  should use the equivalent standard function pthread_mutex_consistent
  instead.

* The function pthread_mutexattr_getrobust_np has been deprecated;
  programs should use the equivalent standard function
  pthread_mutexattr_getrobust instead.

* The function pthread_mutexattr_setrobust_np has been deprecated;
  programs should use the equivalent standard function
  pthread_mutexattr_setrobust instead.

* The function pthread_yield has been deprecated; programs should use
  the equivalent standard function sched_yield instead.

* The function inet_neta declared in <arpa/inet.h> has been deprecated.

* Various rarely-used functions declared in <resolv.h> and
  <arpa/nameser.h> have been deprecated.  Applications are encouraged to
  use dedicated DNS processing libraries if applicable.  For <resolv.h>,
  this affects the functions dn_count_labels, fp_nquery, fp_query,
  fp_resstat, hostalias, loc_aton, loc_ntoa, p_cdname, p_cdnname,
  p_class, p_fqname, p_fqnname, p_option, p_query, p_rcode, p_time,
  p_type, putlong, putshort, res_hostalias, res_isourserver,
  res_nameinquery, res_queriesmatch, res_randomid, sym_ntop, sym_ntos,
  sym_ston.  For <arpa/nameser.h>, the functions ns_datetosecs,
  ns_format_ttl, ns_makecanon, ns_parse_ttl, ns_samedomain, ns_samename,
  ns_sprintrr, ns_sprintrrf, ns_subdomain have been deprecated.

* Various symbols previously defined in libresolv have been moved to libc
  in order to prepare for libresolv moving entirely into libc (see earlier
  entry for merging libraries into libc).  The symbols __dn_comp,
  __dn_expand, __dn_skipname, __res_dnok, __res_hnok, __res_mailok,
  __res_mkquery, __res_nmkquery, __res_nquery, __res_nquerydomain,
  __res_nsearch, __res_nsend, __res_ownok, __res_query, __res_querydomain,
  __res_search, __res_send formerly in libresolv have been renamed and no
  longer have a __ prefix.  They are now available in libc.

* The pthread cancellation handler is now installed with SA_RESTART and
  pthread_cancel will always send the internal SIGCANCEL on a cancellation
  request.  It should not be visible to applications since the cancellation
  handler should either act upon cancellation (if asynchronous cancellation
  is enabled) or ignore the cancellation internal signal.  However there are
  buggy kernel interfaces (for instance some CIFS versions) that could still
  see a spurious EINTR error when cancellation interrupts a blocking syscall.

* Previously, glibc installed its various shared objects under versioned
  file names such as libc-2.33.so.  The ABI sonames (e.g., libc.so.6)
  were provided as symbolic links.  Starting with glibc 2.34, the shared
  objects are installed under their ABI sonames directly, without
  symbolic links.  This increases compatibility with distribution
  package managers that delete removed files late during the package
  upgrade or downgrade process.

* The symbols mallwatch and tr_break are now deprecated and no longer used in
  mtrace.  Similar functionality can be achieved by using conditional
  breakpoints within mtrace functions from within gdb.

* The __morecore and __after_morecore_hook malloc hooks and the default
  implementation __default_morecore have been removed from the API.  Existing
  applications will continue to link against these symbols but the interfaces
  no longer have any effect on malloc.

* Debugging features in malloc such as the MALLOC_CHECK_ environment variable
  (or the glibc.malloc.check tunable), mtrace() and mcheck() have now been
  disabled by default in the main C library.  Users looking to use these
  features now need to preload a new debugging DSO libc_malloc_debug.so to get
  this functionality back.

* The deprecated functions malloc_get_state and malloc_set_state have been
  moved from the core C library into libc_malloc_debug.so.  Legacy applications
  that still use these functions will now need to preload libc_malloc_debug.so
  in their environment using the LD_PRELOAD environment variable.

* The deprecated memory allocation hooks __malloc_hook, __realloc_hook,
  __memalign_hook and __free_hook are now removed from the API.  Compatibility
  symbols are present to support legacy programs but new applications can no
  longer link to these symbols.  These hooks no longer have any effect on glibc
  functionality.  The malloc debugging DSO libc_malloc_debug.so currently
  supports hooks and can be preloaded to get this functionality back for older
  programs.  However this is a transitional measure and may be removed in a
  future release of the GNU C Library.  Users may port away from these hooks by
  writing and preloading their own malloc interposition library.

Changes to build and runtime requirements:

* On Linux, the shm_open, sem_open, and related functions now expect the
  file shared memory file system to be mounted at /dev/shm.  These functions
  no longer search among the system's mount points for a suitable
  replacement if /dev/shm is not available.

Security related changes:

  CVE-2021-27645: The nameserver caching daemon (nscd), when processing
  a request for netgroup lookup, may crash due to a double-free,
  potentially resulting in degraded service or Denial of Service on the
  local system.  Reported by Chris Schanzle.

  CVE-2021-33574: The mq_notify function has a potential use-after-free
  issue when using a notification type of SIGEV_THREAD and a thread
  attribute with a non-default affinity mask.

  CVE-2021-35942: The wordexp function may overflow the positional
  parameter number when processing the expansion resulting in a crash.
  Reported by Philippe Antoine.

The following bugs are resolved with this release:

  [4737] libc: fork is not async-signal-safe
  [5781] math: Slow dbl-64 sin/cos/sincos for special values
  [10353] libc: Methods for deleting all file descriptors greater than
    given integer (closefrom)
  [14185] glob: fnmatch() fails when '*' wildcard is applied on the file
    name containing multi-byte character(s)
  [14469] math: Inaccurate j0f function
  [14470] math: Inaccurate j1f function
  [14471] math: Inaccurate y0f function
  [14472] math: Inaccurate y1f function
  [14744] nptl: kill -32 $pid or kill -33 $pid on a process cancels a
    random thread
  [15271] dynamic-link: dlmopen()ed shared library with LM_ID_NEWLM
    crashes if it fails dlsym() twice
  [15648] nptl: multiple definition of `__lll_lock_wait_private'
  [16063] nptl: Provide a pthread_once variant in libc directly
  [17144] libc: syslog is not thread-safe if NO_SIGPIPE is not defined
  [17145] libc: syslog with LOG_CONS leaks console file descriptor
  [17183] manual: description of ENTRY struct in <search.h> in glibc
    manual is incorrect
  [18435] nptl: pthread_once hangs when init routine throws an exception
  [18524] nptl: Missing calloc error checking in
    __cxa_thread_atexit_impl
  [19329] dynamic-link: dl-tls.c assert failure at concurrent
    pthread_create and dlopen
  [19366] nptl: returning from a thread should disable cancellation
  [19511] nptl: 8MB memory leak in pthread_create in case of failure
    when non-root user changes priority
  [20802] dynamic-link: getauxval NULL pointer dereference after static
    dlopen
  [20813] nptl: pthread_exit is inconsistent between libc and libpthread
  [22057] malloc: malloc_usable_size is broken with mcheck
  [22668] locale: LC_COLLATE: the last character of ellipsis is not
    ordered correctly
  [23323] libc: [RFE] CSU startup hardening.
  [23328] malloc: Remove malloc hooks and ensure related APIs return no
    data.
  [23462] dynamic-link: Static binary with dynamic string tokens ($LIB,
    $PLATFORM, $ORIGIN) crashes
  [23489] libc: "gcc -lmcheck" aborts on free when using posix_memalign
  [23554] nptl: pthread_getattr_np reports wrong stack size with
    MULTI_PAGE_ALIASING
  [24106] libc: Bash interpreter in ldd script is taken from host
  [24773] dynamic-link: dlerror in an secondary namespace does not use
    the right free implementation
  [25036] localedata: Update collation order for Swedish
  [25383] libc: where_is_shmfs/__shm_directory/SHM_GET_NAME may cause
    shm_open to pick wrong directory
  [25680] dynamic-link: ifuncmain9picstatic and ifuncmain9picstatic
    crash in IFUNC resolver due to stack canary (--enable-stack-
    protector=all)
  [26874] build: -Warray-bounds in _IO_wdefault_doallocate
  [26983] math: [x86_64] x86_64 tgamma has too large ULP error
  [27111] dynamic-link: pthread_create and tls access use link_map
    objects that may be concurrently freed by dlclose
  [27132] malloc: memusagestat is linked to system librt, leading to
    undefined symbols on major version upgrade
  [27136] dynamic-link: dtv setup at thread creation may leave an entry
    uninitialized
  [27249] libc: libSegFault.so does not output signal number properly
  [27304] nptl: pthread_cond_destroy does not pass private flag to futex
    system calls
  [27318] dynamic-link: glibc fails to load binaries when built with
    -march=sandybridge:  CPU ISA level is lower than required
  [27343] nss: initgroups() SIGSEGVs when called on a system without
    nsswich.conf (in a chroot)
  [27346] dynamic-link: x86: PTWRITE feature check is missing
  [27389] network: NSS chroot hardening causes regressions in chroot
    deployments
  [27403] dynamic-link: aarch64: tlsdesc htab is not freed on dlclose
  [27444] libc: sysconf reports unsupported option (-1) for
    _SC_LEVEL1_ICACHE_LINESIZE on X86 since v2.33
  [27462] nscd: double-free in nscd (CVE-2021-27645)
  [27468] malloc: aarch64: realloc crash with heap tagging: FAIL:
    malloc/tst-malloc-thread-fail
  [27498] dynamic-link: __dl_iterate_phdr lacks unwinding information
  [27511] libc: S390 memmove assumes Vector Facility when MIE Facility 3
    is present
  [27522] glob: glob, glob64 incorrectly marked as __THROW
  [27555] dynamic-link: Static tests fail with --enable-stack-
    protector=all
  [27559] libc: fstat(AT_FDCWD) succeeds (it shouldn't) and returns
    information for the current directory
  [27577] dynamic-link: elf/ld.so --help doesn't work
  [27605] libc: tunables can't control xsave/xsavec selection in
    dl_runtime_resolve_*
  [27623] libc: powerpc: Missing registers in sc[v] clobbers list
  [27645] libc: [linux] sysconf(_SC_NPROCESSOR...) breaks down on
    containers
  [27646] dynamic-link: Linker error for non-existing NSS symbols (e.g.
    _nss_files_getcanonname_r) from within a dlmopen namespace.
  [27648] libc: FAIL: misc/tst-select
  [27650] stdio: vfscanf returns too early if a match is longer than
    INT_MAX
  [27651] libc: Performance regression after updating to 2.33
  [27655] string: Wrong size calculation in string/test-strnlen.c
  [27706] libc: select fails to update timeout on error
  [27709] libc: arm: FAIL: debug/tst-longjmp_chk2
  [27721] dynamic-link: x86: ld_audit ignores bind now for TLSDESC and
    tries resolving them lazily
  [27744] nptl: Support different libpthread/ld.so load orders in
    libthread_db
  [27749] libc: Data race __run_exit_handlers
  [27761] libc: getconf: Segmentation fault when passing '-vq' as
    argument
  [27832] nss: makedb.c:797:7: error: 'writev' specified size 4294967295
    exceeds maximum object size 2147483647
  [27870] malloc: MALLOC_CHECK_ causes realloc(valid_ptr, TOO_LARGE) to
    not set ENOMEM
  [27872] build: Obsolete configure option --enable-stackguard-
    randomization
  [27873] build: tst-cpu-features-cpuinfo fail when building on AMD cpu
  [27882] localedata: Use U+00AF MACRON in more EBCDIC charsets
  [27892] libc: powerpc: scv ABI error handling fails to check
    IS_ERR_VALUE
  [27896] nptl: mq_notify does not handle separately allocated thread
    attributes (CVE-2021-33574)
  [27901] libc: TEST_STACK_ALIGN doesn't work
  [27902] libc: The x86-64 clone wrapper fails to align child stack
  [27914] nptl: Install SIGSETXID handler with SA_ONSTACK
  [27939] libc: aarch64: clone does not align the stack
  [27968] libc: s390x: clone does not align the stack
  [28011] libc: Wild read in wordexp (parse_param) (CVE-2021-35942)
  [28024] string: s390(31bit): Wrong result of memchr (MEMCHR_Z900_G5)
    with n >= 0x80000000
  [28028] malloc: malloc: tcache shutdown sequence does not work if the
    thread never allocated anything
  [28033] libc: Need to check RTM_ALWAYS_ABORT for RTM
  [28064] string: x86_64:wcslen implementation list has wcsnlen
  [28067] libc: FAIL: posix/tst-spawn5
  [28068] malloc: FAIL: malloc/tst-mallocalign1-mcheck
  [28071] time: clock_gettime, gettimeofday, time lost vDSO acceleration
    on older kernels
  [28075] nis: Out-of-bounds static buffer read in nis_local_domain
  [28089] build: tst-tls20 fails when linker defaults to --as-needed
  [28090] build: elf/tst-cpu-features-cpuinfo-static fails on certain
    AMD64 cpus
  [28091] network: ns_name_skip may return 0 for domain names without
    terminator

\f
Version 2.33

Major new features:

* The dynamic linker accepts the --list-tunables argument which prints
  all the supported tunables.  This option is disable if glibc is
  configured with tunables disabled (--enable-tunables=no).

* The dynamic linker accepts the --argv0 argument and provides opportunity
  to change argv[0] string.

* The dynamic linker loads optimized implementations of shared objects
  from subdirectories under the glibc-hwcaps directory on the library
  search path if the system's capabilities meet the requirements for
  that subdirectory.  Initially supported subdirectories include
  "power9" and "power10" for the powerpc64le-linux-gnu architecture,
  "z13", "z14", "z15" for s390x-linux-gnu, and "x86-64-v2", "x86-64-v3",
  "x86-64-v4" for x86_64-linux-gnu.  In the x86_64-linux-gnu case, the
  subdirectory names correspond to the vendor-independent x86-64
  microarchitecture levels defined in the x86-64 psABI supplement.

* The new --help option of the dynamic linker provides usage and
  information and library search path diagnostics.

* The mallinfo2 function is added to report statistics as per mallinfo,
  but with larger field widths to accurately report values that are
  larger than fit in an integer.

* Add <sys/platform/x86.h> to provide query macros for x86 CPU features.

* Support for the RISC-V ISA running on Linux has been expanded to run on
  32-bit hardware.  This is supported for the following ISA and ABI pairs:

    - rv32imac ilp32
    - rv32imafdc ilp32
    - rv32imafdc ilp32d

  The 32-bit RISC-V port requires at least Linux 5.4, GCC 7.1 and binutils
  2.28.

* A new fortification level _FORTIFY_SOURCE=3 is available.  At this level,
  glibc may use additional checks that may have an additional performance
  overhead.  At present these checks are available only on LLVM 9 and later.
  The latest GCC available at this time (10.2) does not support this level of
  fortification.

Deprecated and removed features, and other changes affecting compatibility:

* The mallinfo function is marked deprecated.  Callers should call
  mallinfo2 instead.

* When dlopen is used in statically linked programs, alternative library
  implementations from HWCAP subdirectories are no longer loaded.
  Instead, the default implementation is used.

* The deprecated <sys/vtimes.h> header and the function vtimes have been
  removed.  To support old binaries, the vtimes function continues to exist
  as a compatibility symbol.  Applications should use the getrlimit or
  prlimit.

* Following a change in the tzdata 2018a release upstream, the zdump
  program is now installed in the /usr/bin subdirectory.  Previously,
  the /usr/sbin subdirectory was used.

* On s390(x), the type float_t is now derived from the macro
  __FLT_EVAL_METHOD__ that is defined by the compiler, instead of being
  hardcoded to double.  This does not affect the ABI of any libraries
  that are part of the GNU C Library, but may affect the ABI of other
  libraries that use this type in their interfaces.  The new definition
  improves consistency with compiler behavior in many scenarios.

* A future version of glibc will stop loading shared objects from the
  "tls" subdirectories on the library search path, the subdirectory that
  corresponds to the AT_PLATFORM system name, and also stop employing
  the legacy AT_HWCAP search mechanism.  Applications should switch to
  the new glibc-hwcaps mechanism instead; if they do not do that, only
  the baseline version (directly from the search path directory) will be
  loaded.

Changes to build and runtime requirements:

* On Linux, the system administrator needs to configure /dev/pts with
  the intended access modes for pseudo-terminals.  glibc no longer
  attemps to adjust permissions of terminal devices.  The previous glibc
  defaults ("tty" group, user read/write and group write) already
  corresponded to what most systems used, so that grantpt did not
  perform any adjustments.

* On Linux, the posix_openpt and getpt functions no longer attempt to
  use legacy (BSD) pseudo-terminals and assume that if /dev/ptmx exists
  (and pseudo-terminals are supported), a devpts file system is mounted
  on /dev/pts.  Current systems already meet these requirements.

* s390x requires GCC 7.1 or newer.  See gcc Bug 98269.

Security related changes:

  CVE-2021-3326: An assertion failure during conversion from the
  ISO-20220-JP-3 character set using the iconv function has been fixed.
  This assertion was triggered by certain valid inputs in which the
  converted output contains a combined sequence of two wide characters
  crossing a buffer boundary.  Reported by Tavis Ormandy.

  CVE-2020-27618: An infinite loop has been fixed in the iconv program when
  invoked with input containing redundant shift sequences in the IBM1364,
  IBM1371, IBM1388, IBM1390, or IBM1399 character sets.

  CVE-2020-29562: An assertion failure has been fixed in the iconv function
  when invoked with UCS4 input containing an invalid character.

  CVE-2019-25013: A buffer overflow has been fixed in the iconv function when
  invoked with EUC-KR input containing invalid multibyte input sequences.

The following bugs are resolved with this release:

  [10635] libc: realpath portability patches
  [16124] dynamic-link: ld.so should allow to change argv[0]
  [17924] malloc: 'free' should not set errno
  [18683] libc: Linux faccessat implementation can incorrectly ignore
    AT_EACCESS
  [22899] libc: Use 64-bit readdir() in generic POSIX getcwd()
  [23091] hurd: missing waitid support
  [23249] libc: Epyc and other current AMD CPUs do not select the
    "haswell" platform subdirectory
  [24080] dynamic-link: Definition of "haswell" platform is inconsistent
    with GCC
  [24202] libc: m68k setjmp() saves incorrect 'a5' register in --enable-
    stack-protector=all
  [24941] libc: Make grantpt usable after multi-threaded fork in more
    cases
  [24970] libc: realpath mishandles EOVERFLOW; stat not needed anyway
  [24973] locale: iconv encounters segmentation fault when converting
    0x00 0xfe in EUC-KR to UTF-8 (CVE-2019-25013)
  [25399] string: undefined reference to `__warn_memset_zero_len' when
    changing gnuc version
  [25859] libc: glibc parser for /sys/devices/system/cpu/online is
    incorrect
  [25938] dynamic-link: ld.so.cache should store meaning of hwcap mask
    bits
  [25971] libc: s390 bits/hwcap.h out of sync with kernel
  [26053] libc: unlockpt fails with ENOTTY for non-ptmx descriptors
  [26100] libc: Race in syslog(3) with regards to tag printing.
  [26124] libc: Export <cpu-features.h>
  [26130] nscd: Inconsistent nscd cache during pruning
  [26203] libc: GLRO(dl_x86_cpu_features) may not be intialized
  [26224] locale: iconv hangs when converting some invalid inputs from
    several IBM character sets (CVE-2020-27618)
  [26341] libc: realpath cyclically call __alloca(path_max) to consume
    too much stack space
  [26343] manual: invalid documented return type for strerrorname_np(),
    strerrordesc_np(), sigdescr_np(), sigabbrev_np()
  [26376] libc: Namespace violation in stdio.h and sys/stat.h if build
    with optimization.
  [26383] locale: bind_textdomain_codeset doesn't accept //TRANSLIT
    anymore
  [26394] time: [2.33 Regression] FAIL: nptl/tst-join14
  [26534] math: libm.so 2.32 SIGILL in pow() due to FMA4 instruction on
    non-FMA4 system
  [26552] dynamic-link: CPU_FEATURE_USABLE_P should be more conservative
  [26553] libc: mtx_init allows type set to "mtx_recursive" only
  [26555] string: strerrorname_np does not return the documented value
  [26592] libc: pointer arithmetic overflows in realpath
  [26600] network: Transaction ID collisions cause slow DNS lookups in
    getaddrinfo
  [26606] libc: [2.33 Regression] pselect is broken on x32
  [26615] libc: powerpc: libc segfaults when LD_PRELOADed with libgcc
  [26620] glob: fnmatch with collating symbols results in segmentation
    fault
  [26625] libc: [2.33 Regression] CET is disabled
  [26636] libc: 32-bit shmctl(IPC_INFO) crashes when shminfo struct is
    at the end of a memory mapping
  [26637] libc: semctl SEM_STAT_ANY fails to pass the buffer specified
    by the caller to the kernel
  [26639] libc: msgctl IPC_INFO and MSG_INFO return garbage
  [26647] build: [-Werror=array-parameter=] due to different
    declarations for __sigsetjmp
  [26648] libc: mkstemp is likely to fail on systems with non-stricly-
    monotonic clocks
  [26649] stdio: printf should handle non-normal x86 long double numbers
    gracefully (CVE-2020-29573)
  [26686] build: -Warray-parameter instances building with GCC 11
  [26687] build: -Warray-bounds instances building with GCC 11
  [26690] stdio: Aliasing violation in __vfscanf_internal
  [26691] nptl: Use a minimum guard size of 64 KiB on aarch64
  [26726] build: GCC warning calling new_composite_name with an array of
    one element
  [26736] libc: FAIL: misc/tst-sysvshm-linux
  [26737] libc: Random FAIL: rt/tst-shm
  [26791] libc: Missing O_CLOEXEC in sysconf.c
  [26798] dynamic-link: aarch64: variant PCS symbols may be incorrectly
    lazy bound
  [26801] nptl: pthread_mutex_clocklock with CLOCK_MONOTONIC can fail on
    PI mutexes
  [26818] string: aarch64: string tests may run ifunc variants that are
    not safe
  [26821] libc: Memory leak test failures on Fedora 33
  [26824] libc: FAIL: elf/tst-cpu-features-supports with recent trunk:
    FSGSBASE/LM/RDRAND check failure
  [26833] time: adjtime() with delta == NULL segfaults on armv7 32bit
    platform
  [26853] libc: aarch64: Missing unwind information in statically linked
    startup code
  [26923] locale: Assertion failure in iconv when converting invalid
    UCS4 (CVE-2020-29562)
  [26926] dynamic-link: aarch64: library dependencies are not bti
    protected
  [26932] libc: sh: Multiple floating point functions defined as stubs
    only since 2.31
  [26964] nptl: pthread_mutex_timedlock returning EAGAIN after futex is
    locked
  [26988] dynamic-link: aarch64: BTI mprotect address is not page
    aligned
  [27002] build: libc_freeres_fn build failure with GCC 11
  [27004] dynamic-link: ld.so is miscompiled by GCC 11
  [27008] dynamic-link: ld.so.cache should have endianness markup
  [27042] libc: [alpha] anonymous union in struct stat confuses
    detection logic
  [27053] libc: Conformance regression in system(3) (and probably also
    pclose(3))
  [27072] dynamic-link: static pie ifunc resolvers run before hwcap is
    setup
  [27077] network: Do not reload /etc/nsswitch.conf from chroot
  [27083] libc: Unsafe unbounded alloca in addmntent
  [27104] dynamic-link: The COMMON_CPUID_INDEX_MAX handshake does not
    work
  [27130] string: "rep movsb" performance issue
  [27150] libc: alpha: wait4() is unavailable in static linking
  [27177] dynamic-link:
    GLIBC_TUNABLES=glibc.cpu.x86_ibt=on:glibc.cpu.x86_shstk=on doesn't
    work
  [27222] dynamic-link: Incorrect sysdeps/x86/tst-cpu-features-cpuinfo.c
  [27237] malloc: deadlock in malloc/tst-malloc-stats-cancellation
  [27256] locale: Assertion failure in ISO-2022-JP-3 gconv module
    related to combining characters (CVE-2021-3326)

\f
Version 2.32

Major new features:

* Unicode 13.0.0 Support: Character encoding, character type info, and
  transliteration tables are all updated to Unicode 13.0.0, using
  generator scripts contributed by Mike FABIAN (Red Hat).

* New locale added: ckb_IQ (Kurdish/Sorani spoken in Iraq)

* Support for Synopsys ARC HS cores (ARCv2 ISA) running Linux has been
  added. This port requires at least binutils-2.32, gcc-8.3 and Linux-5.1.
  Three ABIs are supported:

     - arc-linux-gnu
     - arc-linux-gnuhf
     - arceb-linux-gnu

  The arc* ABIs are little-endian while arceb is big-endian.  All ABIs use
  64-bit time (y2038 safe) and 64-bit file offsets (LFS default).

* The GNU C Library now loads audit modules listed in the DT_AUDIT and
  DT_DEPAUDIT dynamic section entries of the main executable.

* powerpc64le supports IEEE128 long double libm/libc redirects when
  using -mabi=ieeelongdouble to compile C code on supported GCC
  toolchains.  It is recommended to use GCC 8 or newer when testing
  this option.

* To help detect buffer overflows and other out-of-bounds accesses
  several APIs have been annotated with GCC 'access' attribute.  This
  should help GCC 10 issue better warnings.

* On Linux, functions pthread_attr_setsigmask_np and
  pthread_attr_getsigmask_np have been added.  They allow applications
  to specify the signal mask of a thread created with pthread_create.

* The GNU C Library now provides the header file <sys/single_threaded.h>
  which declares the variable __libc_single_threaded.  Applications are
  encouraged to use this variable for single-thread optimizations,
  instead of weak references to symbols historically defined in
  libpthread.

* The functions sigabbrev_np and sigdescr_np have been added.  The
  sigabbrev_np function returns the abbreviated signal name (e.g. "HUP" for
  SIGHUP) while sigdescr_np returns a string describing the signal number
  (e.g "Hangup" for SIGHUP).  Different than strsignal, sigdescr_np does not
  attempt to translate the return description, both functions return
  NULL for an invalid signal number.

  They should be used instead of sys_siglist or sys_sigabbrev and they
  are both thread and async-signal safe.  These functions are GNU extensions.

* The functions strerrorname_np and strerrordesc_np have been added.  The
  strerroname_np function returns error number name (e.g. "EINVAL" for EINVAL)
  while strerrordesc_np returns a string describing the error number
  (e.g "Invalid argument" for EINVAL).  Different than strerror,
  strerrordesc_np does not attempt to translate the return description, both
  functions return NULL for an invalid error number.

  They should be used instead of sys_errlist and sys_nerr, both are
  thread and async-signal safe.  These functions are GNU extensions.

* AArch64 now supports standard branch protection security hardening
  in glibc when it is built with a GCC that is configured with
  --enable-standard-branch-protection (or if -mbranch-protection=standard
  flag is passed when building both GCC target libraries and glibc,
  in either case a custom GCC is needed).  This includes branch target
  identification (BTI) and pointer authentication for return addresses
  (PAC-RET).  They require armv8.5-a and armv8.3-a architecture
  extensions respectively for the protection to be effective,
  otherwise the used instructions are nops.  User code can use PAC-RET
  without libc support, but BTI requires a libc that is built with BTI
  support, otherwise runtime objects linked into user code will not be
  BTI compatible.

Deprecated and removed features, and other changes affecting compatibility:

* Remove configure option --enable-obsolete-rpc.  Sun RPC is removed
  from glibc.  This includes the rpcgen program, librpcsvc, and the Sun
  RPC header files.  Backward compatibility for old programs is kept
  only for architectures and ABIs that have been added in or before
  glibc 2.31.  New programs need to use TI-RPC
  <http://git.linux-nfs.org/?p=steved/libtirpc.git;a=summary> and
  rpcsvc-proto <https://github.com/thkukuk/rpcsvc-proto>.

* Remove configure option --enable-obsolete-nsl.  libnsl is only built
  as shared library for backward compatibility and the NSS modules "nis"
  and "nisplus" are not built at all and libnsl's headers aren't
  installed.  This compatibility is kept only for architectures and ABIs
  that have been added in or before version 2.28.  Replacement
  implementations based on TI-RPC, which additionally support IPv6, are
  available from <https://github.com/thkukuk/>.  This change does not
  affect the "compat" NSS module, which does not depend on libnsl
  since 2.27 and thus can be used without NIS.

* The deprecated <sys/sysctl.h> header and the sysctl function have been
  removed.  To support old binaries, the sysctl function continues to
  exist as a compatibility symbol (on those architectures which had it),
  but always fails with ENOSYS.  This reflects the removal of the system
  call from all architectures, starting with Linux 5.5.

* The sstk function is no longer available to newly linked binaries.
  Its implementation always returned with a failure, and the function
  was not declared in any header file.

* The legacy signal handling functions siginterrupt, sigpause, sighold,
  sigrelse, sigignore and sigset, and the sigmask macro have been
  deprecated.  Applications should use the sigsuspend, sigprocmask and
  sigaction functions instead.

* ldconfig now defaults to the new format for ld.so.cache. glibc has
  already supported this format for almost 20 years.

* The deprecated arrays sys_siglist, _sys_siglist, and sys_sigabbrev
  are no longer available to newly linked binaries, and their declarations
  have been removed from <string.h>.  They are exported solely as
  compatibility symbols to support old binaries.  All programs should use
  strsignal instead.

* The deprecated symbols sys_errlist, _sys_errlist, sys_nerr, and _sys_nerr
  are no longer available to newly linked binaries, and their declarations
  have been removed from <stdio.h>.  They are exported solely as
  compatibility symbols to support old binaries.  All programs should use
  strerror or strerror_r instead.

* Both strerror and strerror_l now share the same internal buffer in the
  calling thread, meaning that the returned string pointer may be invalided
  or contents might be overwritten on subsequent calls in the same thread or
  if the thread is terminated.  It makes strerror MT-safe.

* Using weak references to libpthread functions such as pthread_create
  or pthread_key_create to detect the singled-threaded nature of a
  program is an obsolescent feature.  Future versions of glibc will
  define pthread_create within libc.so.6 itself, so such checks will
  always flag the program as multi-threaded.  Applications should check
  the __libc_single_threaded variable declared in
  <sys/single_threaded.h> instead.

* The "files" NSS module no longer supports the "key" database (used for
  secure RPC).  The contents of the /etc/publickey file will be ignored,
  regardless of the settings in /etc/nsswitch.conf.  (This method of
  storing RPC keys only supported the obsolete and insecure AUTH_DES
  flavor of secure RPC.)

* The __morecore and __after_morecore_hook malloc hooks and the default
  implementation __default_morecore have been deprecated.  Applications
  should use malloc interposition to change malloc behavior, and mmap to
  allocate anonymous memory.  A future version of glibc may require that
  applications which use the malloc hooks must preload a special shared
  object, to enable the hooks.

* The hesiod NSS module has been deprecated and will be removed in a
  future version of glibc.  System administrators are encouraged to
  switch to other approaches for networked account databases, such as
  LDAP.

Changes to build and runtime requirements:

* powerpc64le requires GCC 7.4 or newer.  This is required for supporting
  long double redirects.

Security related changes:

  CVE-2016-10228: An infinite loop has been fixed in the iconv program when
  invoked with the -c option and when processing invalid multi-byte input
  sequences.  Reported by Jan Engelhardt.

  CVE-2020-10029: Trigonometric functions on x86 targets suffered from stack
  corruption when they were passed a pseudo-zero argument.  Reported by Guido
  Vranken / ForAllSecure Mayhem.

  CVE-2020-1752: A use-after-free vulnerability in the glob function when
  expanding ~user has been fixed.

  CVE-2020-6096: A signed comparison vulnerability in the ARMv7 memcpy and
  memmove functions has been fixed.  Discovered by Jason Royes and Samual
  Dytrych of the Cisco Security Assessment and Penetration Team (See
  TALOS-2020-1019).

The following bugs are resolved with this release:

  [9809] localedata: ckb_IQ: new Kurdish Sorani locale
  [10441] manual: Backtraces code example lacks error checking
  [10815] librt: [timer_create / SIGEV_THREAD] signalmask of
    timer_sigev_thread dangerous
  [14231] stdio: stdio-common tests memory requirements
  [14578] libc: /proc-based emulation for lchmod, fchmodat
  [16272] dynamic-link: dlopen()ing a DT_FILTER library crashes if
    filtee has constructor
  [19519] locale: iconv(1) with -c option hangs on illegal multi-byte
    sequences (CVE-2016-10228)
  [19737] admin: Doc page “20.5.2 Infinity and NaN” has incorrect HTML
    character entities for infinity & pi
  [20338] libc: Parsing of /etc/gshadow can return bad pointers causing
    segfaults in applications
  [20543] libc: Please move from .gnu.linkonce to comdat
  [22489] network: gcc warns about implicit convertion in
    ICMP6_FILTER_SETPASS with -Wsign-conversion
  [22525] localedata: or_IN  LC_COLLATE does not use copy "iso14651_t1"
  [23294] math: Complex _FloatN functions are redirected to the wrong
    function with -mlong-double-64
  [23296] libc: Data race in setting function descriptor during lazy
    binding
  [23668] dynamic-link: ldconfig: Default to the new format for
    ld.so.cache
  [23819] hurd: hurd: Add C11 thread support
  [23990] build: test-container error out on failure to exec child.
  [23991] build: shell-container typo in run_command_array
  [24638] manual: Error in example of parsing a template string
  [24654] manual: Wrong declaration of wcschr in libc manual
  [24943] dynamic-link: Support DT_AUDIT, DT_DEPAUDIT in the dynamic
    linker
  [25051] dynamic-link: aarch64, powerpc64 uses surplus static tls for
    dynamically loaded dsos
  [25098] nptl: nptl: ctype classification functions are not AS-Safe
  [25219] libc: improve out-of-bounds checking with GCC 10 attribute
    access
  [25262] libc: getcontext/setcontext/swapcontext unnecessarily save and
    restore EAX, ECX and EDX
  [25397] dynamic-link: Legacy bitmap doesn't cover jitted code
  [25414] glob: 'glob' use-after-free bug (CVE-2020-1752)
  [25420] network: Race condition in resolv_conf.c can result in caching
    stale configuration forever
  [25487] math: sinl() stack corruption from crafted input
    (CVE-2020-10029)
  [25506] build: configure: broken detection of STT_GNU_IFUNC when GCC
    defaults to PIE
  [25523] libc: MIPS/Linux inline syscall template is miscompiled
  [25620] libc: Signed comparison vulnerability in the ARMv7 memcpy()
    (CVE-2020-6096)
  [25623] libc: test-sysvmsg, test-sysvsem, test-sysvshm fail with 2.31
    on 32 bit and old kernel
  [25635] libc: arm: Wrong sysdep order selection for soft-fp
  [25639] localedata: Some names of days and months wrongly spelt in
    Occitan
  [25657] libc: sigprocmask() and sigisemptyset() manipulate different
    amount of sigset_t bytes
  [25691] stdio: printf: memory leak when printing long multibyte
    strings
  [25715] libc: system() returns wrong errors when posix_spawn fails
  [25733] malloc: mallopt(M_MXFAST) can set global_max_fast to 0
  [25734] locale: mbrtowc with Big5-HKSCS fails to reset conversion
    state for conversions that produce two Unicode code points
  [25765] nptl: Incorrect futex syscall in __pthread_disable_asynccancel
    for linux x86_64 leads to livelock
  [25788] dynamic-link: [i386] -fno-omit-frame-pointer in CFLAGS causes
    test failures, invalid instruction in ld.so
  [25790] glob: Typo in tst-fnmatch.input
  [25810] libc: x32: Incorrect syscall entries with pointer, off_t and
    size_t
  [25819] localedata: Update locale data to Unicode 13.0.0
  [25824] libc: Abnormal function of strnlen in aarch64
  [25887] dynamic-link: Wasted space in _dl_x86_feature_1[1]
  [25896] libc: Incorrect prctl
  [25902] libc: Bad LOADARGS_N
  [25905] dynamic-link: VSX registers are corrupted during PLT
    resolution when glibc is built with --disable-multi-arch and --with-
    cpu=power9
  [25933] string: Off by one error in __strncmp_avx2 when
    length=VEC_SIZE*4 and strings are at page boundaries can cause a
    segfault
  [25942] nptl: Deadlock on stack_cache_lock between __nptl_setxid and
    exiting detached thread
  [25966] libc: Incorrect access of __x86_shared_non_temporal_threshold
    for x32
  [25976] nss: internal_end*ent in nss_compat may clobber errno, hiding
    ERANGE
  [25999] nptl: Use-after-free issue in pthread_getaddr_default_np
  [26073] math: getpayload() has wrong return value
  [26076] dynamic-link: dlmopen crashes after failing to load
    dependencies in audit mode
  [26120] localedata: column width of  of some Korean
    JUNGSEONG/JONGSEONG characters wrong (should be 0)
  [26128] libc: Incorrect bit_cpu_CLFLUSHOPT
  [26133] libc: Incorrect need_arch_feature_F16C
  [26137] libc: strtod() triggers exception FE_INEXACT on reasonable
    input
  [26149] libc: PKU is usable only if OSPKE is set
  [26173] libc: powerpc64*: Add @notoc to calls to functions that do not
    preserve r2
  [26208] libc: Incorrect bit_cpu_CLFSH
  [26210] network: Incorrect use of hidden symbols for global sunrpc
    variables
  [26211] stdio: printf integer overflow calculating allocation size
  [26214] stdio: printf_fp double free
  [26215] stdio: printf_fp memory leak
  [26232] time: FAIL: support/tst-timespec for 32-bit targets
  [26258] nss: nss_compat should not read input files with mmap
  [26332] string: Incorrect cache line size load causes memory
    corruption in memset

\f
Version 2.31

Major new features:

* The GNU C Library now supports a feature test macro _ISOC2X_SOURCE to
  enable features from the draft ISO C2X standard.  Only some features from
  this draft standard are supported by the GNU C Library, and as the draft
  is under active development, the set of features enabled by this macro is
  liable to change.  Features from C2X are also enabled by _GNU_SOURCE, or
  by compiling with "gcc -std=gnu2x".

* The <math.h> functions that round their results to a narrower type now
  have corresponding type-generic macros in <tgmath.h>, as defined in TS
  18661-1:2014 and TS 18661-3:2015 as amended by the resolution of
  Clarification Request 13 to TS 18661-3.

* The function pthread_clockjoin_np has been added, enabling join with a
  terminated thread with a specific clock.  It allows waiting against
  CLOCK_MONOTONIC and CLOCK_REALTIME.  This function is a GNU extension.

* New locale added: mnw_MM (Mon language spoken in Myanmar).

* The DNS stub resolver will optionally send the AD (authenticated data) bit
  in queries if the trust-ad option is set via the options directive in
  /etc/resolv.conf (or if RES_TRUSTAD is set in _res.options).  In this
  mode, the AD bit, as provided by the name server, is available to
  applications which call res_search and related functions.  In the default
  mode, the AD bit is not set in queries, and it is automatically cleared in
  responses, indicating a lack of DNSSEC validation.  (Therefore, the name
  servers and the network path to them are treated as untrusted.)

Deprecated and removed features, and other changes affecting compatibility:

* The totalorder and totalordermag functions, and the corresponding
  functions for other floating-point types, now take pointer arguments to
  avoid signaling NaNs possibly being converted to quiet NaNs in argument
  passing.  This is in accordance with the resolution of Clarification
  Request 25 to TS 18661-1, as applied for C2X.  Existing binaries that pass
  floating-point arguments directly will continue to work.

* The obsolete function stime is no longer available to newly linked
  binaries, and its declaration has been removed from <time.h>.
  Programs that set the system time should use clock_settime instead.

* We plan to remove the obsolete function ftime, and the header <sys/timeb.h>,
  in a future version of glibc.  In this release, the header still exists
  but calling ftime will cause a compiler warning.  All programs should use
  gettimeofday or clock_gettime instead.

* The gettimeofday function no longer reports information about a
  system-wide time zone.  This 4.2-BSD-era feature has been deprecated for
  many years, as it cannot handle the full complexity of the world's
  timezones, but hitherto we have supported it on a best-effort basis.
  Changes required to support 64-bit time_t on 32-bit architectures have
  made this no longer practical.

  As of this release, callers of gettimeofday with a non-null 'tzp' argument
  should expect to receive a 'struct timezone' whose tz_minuteswest and
  tz_dsttime fields are zero.  (For efficiency reasons, this does not always
  happen on a few Linux-based ports.  This will be corrected in a future
  release.)

  All callers should supply a null pointer for the 'tzp' argument to
  gettimeofday.  For accurate information about the time zone associated
  with the current time, use the localtime function.

  gettimeofday itself is obsolescent according to POSIX.  We have no plans
  to remove access to this function, but portable programs should consider
  using clock_gettime instead.

* The settimeofday function can still be used to set a system-wide time
  zone when the operating system supports it.  This is because the Linux
  kernel reused the API, on some architectures, to describe a system-wide
  time-zone-like offset between the software clock maintained by the kernel,
  and the "RTC" clock that keeps time when the system is shut down.

  However, to reduce the odds of this offset being set by accident,
  settimeofday can no longer be used to set the time and the offset
  simultaneously.  If both of its two arguments are non-null, the call
  will fail (setting errno to EINVAL).

  Callers attempting to set this offset should also be prepared for the call
  to fail and set errno to ENOSYS; this already happens on the Hurd and on
  some Linux architectures.  The Linux kernel maintainers are discussing a
  more principled replacement for the reused API.  After a replacement
  becomes available, we will change settimeofday to fail with ENOSYS on all
  platforms when its 'tzp' argument is not a null pointer.

  settimeofday itself is obsolescent according to POSIX.  Programs that set
  the system time should use clock_settime and/or the adjtime family of
  functions instead.  We may cease to make settimeofday available to newly
  linked binaries after there is a replacement for Linux's time-zone-like
  offset API.

* SPARC ISA v7 is no longer supported.  v8 is still supported, but only if
  the optional CAS instruction is implemented (for instance, LEON processors
  are still supported, but SuperSPARC processors are not).

  As the oldest 64-bit SPARC ISA is v9, this only affects 32-bit
  configurations.

* If a lazy binding failure happens during dlopen, during the execution of
  an ELF constructor, the process is now terminated.  Previously, the
  dynamic loader would return NULL from dlopen, with the lazy binding error
  captured in a dlerror message.  In general, this is unsafe because
  resetting the stack in an arbitrary function call is not possible.

* For MIPS hard-float ABIs, the GNU C Library will be configured to need an
  executable stack unless explicitly configured at build time to require
  minimum kernel version 4.8 or newer.  This is because executing
  floating-point branches on a non-executable stack on Linux kernels prior to
  4.8 can lead to application crashes for some MIPS configurations. While
  currently PT_GNU_STACK is not widely used on MIPS, future releases of GCC are
  expected to enable non-executable stack by default  with PT_GNU_STACK by
  default and is thus likely to trigger a crash on older kernels.

  The GNU C Library can be built with --enable-kernel=4.8.0 in order to keep a
  non-executable stack while dropping support for older kernels.

* System call wrappers for time system calls now use the new time64 system
  calls when available. On 32-bit targets, these wrappers attempt to call
  the new system calls first and fall back to the older 32-bit time system
  calls if they are not present.  This may cause issues in environments
  that cannot handle unsupported system calls gracefully by returning
  -ENOSYS. Seccomp sandboxes are affected by this issue.

Changes to build and runtime requirements:

* It is no longer necessary to have recent Linux kernel headers to build
  working (non-stub) system call wrappers on all architectures except 64-bit
  RISC-V.  64-bit RISC-V requires a minimum kernel headers version of 5.0.

* The ChangeLog file is no longer present in the toplevel directory of the
  source tree.  ChangeLog files are located in the ChangeLog.old directory as
  ChangeLog.N where the highest N has the latest entries.

Security related changes:

  CVE-2020-1751: A defect in the PowerPC backtrace function could cause an
  out-of-bounds write when executed in a signal frame context.

  CVE-2019-19126: ld.so failed to ignore the LD_PREFER_MAP_32BIT_EXEC
  environment variable during program execution after a security
  transition, allowing local attackers to restrict the possible mapping
  addresses for loaded libraries and thus bypass ASLR for a setuid
  program.  Reported by Marcin Kościelnicki.

The following bugs are resolved with this release:

  [12031] localedata: iconv -t ascii//translit with Greek characters
  [15813] libc: Multiple issues in __gen_tempname
  [17726] libc: [arm, sparc] profil_counter should be compat symbol
  [18231] libc: ipc_perm struct's mode member has wrong type in sys/ipc.h
  [19767] libc: vdso is not used with static linking
  [19903] hurd: Shared mappings not being inherited by children processes
  [20358] network: RES_USE_DNSSEC sets DO; should also have a way to set AD
  [20839] dynamic-link: Incomplete rollback of dynamic linker state on
    linking failure
  [23132] localedata: Missing transliterations in Miscellaneous Mathematical
    Symbols-A/B Unicode blocks
  [23518] libc: Eliminate __libc_utmp_jump_table
  [24026] malloc: malloc_info() returns wrong numbers
  [24054] localedata: Many locales are missing date_fmt
  [24214] dynamic-link: user defined ifunc resolvers may run in ldd mode
  [24304] dynamic-link: Lazy binding failure during ELF
    constructors/destructors is not fatal
  [24376] libc: RISC-V symbol size confusion with _start
  [24682] localedata: zh_CN first weekday should be Monday per GB/T
    7408-2005
  [24824] libc: test-in-container does not install charmap files compatible
    with localedef
  [24844] regex: regex bad pointer / leakage if malloc fails
  [24867] malloc: Unintended malloc_info formatting changes
  [24879] libc: login: utmp alarm timer can arrive after lock acquisition
  [24880] libc: login: utmp implementation uses struct flock with fcntl64
  [24882] libc: login: pututline uses potentially outdated cache
  [24899] libc: Missing nonstring attributes in <utmp.h>, <utmpx.h>
  [24902] libc: login: Repeating pututxline on EINTR/EAGAIN causes stale
    utmp entries
  [24916] dynamic-link: [MIPS] Highest EI_ABIVERSION value not raised to
    ABSOLUTE ABI
  [24930] dynamic-link: dlopen of PIE executable can result in
    _dl_allocate_tls_init assertion failure
  [24950] localedata: Top-of-tree glibc does not build with top-of-tree GCC
    (stringop-overflow error)
  [24959] time: librt IFUNC resolvers for clock_gettime and clock_*
    functions other  can lead to crashes
  [24967] libc: jemalloc static linking causes runtime failure
  [24986] libc: alpha: new getegid, geteuid and getppid syscalls used
    unconditionally
  [25035] libc: sbrk() failure handled poorly in tunables_strdup
  [25087] dynamic-link: ldconfig mishandles unusual .dynstr placement
  [25097] libc: new -Warray-bounds with GCC 10
  [25112] dynamic-link: dlopen must not make new objects accessible when it
    still can fail with an error
  [25139] localedata: Please add the new mnw_MM locale
  [25149] regex: Array bounds violation in proceed_next_node
  [25157] dynamic-link: Audit cookie for the dynamic loader is not
    initialized correctly
  [25189] libc: glibc's __glibc_has_include causes issues with clang
    -frewrite-includes
  [25194] malloc: malloc.c: do_set_mxfast incorrectly casts the mallopt
    value to an unsigned
  [25204] dynamic-link: LD_PREFER_MAP_32BIT_EXEC not ignored in setuid
    binaries (CVE-2019-19126)
  [25225] libc: ld.so fails to link on x86 if GCC defaults to -fcf-
    protection
  [25226] string: strstr: Invalid result if needle crosses page on s390-z15
    ifunc variant.
  [25232] string: <string.h> does not enable const correctness for strchr et
    al. for Clang++
  [25233] localedata: Consider "." as the thousands separator for sl_SI
    (Slovenian)
  [25241] nptl: __SIZEOF_PTHREAD_MUTEX_T defined twice for x86
  [25251] build: Failure to run tests when CFLAGS contains -DNDEBUG.
  [25271] libc: undeclared identifier PTHREAD_MUTEX_DEFAULT when compiling
    with -std=c11
  [25323] localedata: km_KH: d_t_fmt contains "m" instead of "%M"
  [25324] localedata: lv_LV: d_t_fmt contains suspicious words in the time
    part
  [25396] dynamic-link: Failing dlopen can leave behind dangling GL
    (dl_initfirst) link map pointer
  [25401] malloc: pvalloc must not have __attribute_alloc_size__
  [25423] libc: Array overflow in backtrace on powerpc
  [25425] network: Missing call to __resolv_context_put in
    getaddrinfo.c:gethosts

\f
Version 2.30

Major new features:

* Unicode 12.1.0 Support: Character encoding, character type info, and
  transliteration tables are all updated to Unicode 12.1.0, using
  generator scripts contributed by Mike FABIAN (Red Hat).

* The dynamic linker accepts the --preload argument to preload shared
  objects, in addition to the LD_PRELOAD environment variable.

* The twalk_r function has been added.  It is similar to the existing
  twalk function, but it passes an additional caller-supplied argument
  to the callback function.

* On Linux, the getdents64, gettid, and tgkill functions have been added.

* Minguo (Republic of China) calendar support has been added as an
  alternative calendar for the following locales: zh_TW, cmn_TW, hak_TW,
  nan_TW, lzh_TW.

* The entry for the new Japanese era has been added for ja_JP locale.

* Memory allocation functions malloc, calloc, realloc, reallocarray, valloc,
  pvalloc, memalign, and posix_memalign fail now with total object size
  larger than PTRDIFF_MAX.  This is to avoid potential undefined behavior with
  pointer subtraction within the allocated object, where results might
  overflow the ptrdiff_t type.

* The dynamic linker no longer refuses to load objects which reference
  versioned symbols whose implementation has moved to a different soname
  since the object has been linked.  The old error message, symbol
  FUNCTION-NAME, version SYMBOL-VERSION not defined in file DSO-NAME with
  link time reference, is gone.

* Add new POSIX-proposed pthread_cond_clockwait, pthread_mutex_clocklock,
  pthread_rwlock_clockrdlock, pthread_rwlock_clockwrlock and sem_clockwait
  functions.  These behave similarly to their "timed" equivalents, but also
  accept a clockid_t parameter to determine which clock their timeout should
  be measured against.  All functions allow waiting against CLOCK_MONOTONIC
  and CLOCK_REALTIME.  The decision of which clock to be used is made at the
  time of the wait (unlike with pthread_condattr_setclock, which requires
  the clock choice at initialization time).

* On AArch64 the GNU IFUNC resolver call ABI changed: old resolvers still
  work, new resolvers can use a second argument which can be extended in
  the future, currently it contains the AT_HWCAP2 value.

Deprecated and removed features, and other changes affecting compatibility:

* The copy_file_range function fails with ENOSYS if the kernel does not
  support the system call of the same name.  Previously, user space
  emulation was performed, but its behavior did not match the kernel
  behavior, which was deemed too confusing.  Applications which use the
  copy_file_range function can no longer rely on glibc to provide a fallback
  on kernels that do not support the copy_file_range system call, and if
  this function returns ENOSYS, they will need to use their own fallback.
  Support for copy_file_range for most architectures was added in version
  4.5 of the mainline Linux kernel.

* The functions clock_gettime, clock_getres, clock_settime,
  clock_getcpuclockid, clock_nanosleep were removed from the librt library
  for new applications (on architectures which had them).  Instead, the
  definitions in libc will be used automatically, which have been available
  since glibc 2.17.

* The obsolete and never-implemented XSI STREAMS header files <stropts.h>
  and <sys/stropts.h> have been removed.

* Support for the "inet6" option in /etc/resolv.conf and the RES_USE_INET6
  resolver flag (deprecated in glibc 2.25) have been removed.

* The obsolete RES_INSECURE1 and RES_INSECURE2 option flags for the DNS stub
  resolver have been removed from <resolv.h>.

* With --enable-bind-now, installed programs are now linked with the
  BIND_NOW flag.

* Support for the PowerPC SPE ISA extension (powerpc-*-*gnuspe*
  configurations) has been removed, following the deprecation of this
  subarchitecture in version 8 of GCC, and its removal in version 9.

* On 32-bit Arm, support for the port-based I/O emulation and the <sys/io.h>
  header have been removed.

* The Linux-specific <sys/sysctl.h> header and the sysctl function have been
  deprecated and will be removed from a future version of glibc.
  Application should directly access /proc instead.  For obtaining random
  bits, the getentropy function can be used.

Changes to build and runtime requirements:

* GCC 6.2 or later is required to build the GNU C Library.

  Older GCC versions and non-GNU compilers are still supported when
  compiling programs that use the GNU C Library.

Security related changes:

  CVE-2019-7309: x86-64 memcmp used signed Jcc instructions to check
  size.  For x86-64, memcmp on an object size larger than SSIZE_MAX
  has undefined behavior.  On x32, the size_t argument may be passed
  in the lower 32 bits of the 64-bit RDX register with non-zero upper
  32 bits.  When it happened with the sign bit of RDX register set,
  memcmp gave the wrong result since it treated the size argument as
  zero.  Reported by H.J. Lu.

  CVE-2019-9169: Attempted case-insensitive regular-expression match
  via proceed_next_node in posix/regexec.c leads to heap-based buffer
  over-read.  Reported by Hongxu Chen.

The following bugs are resolved with this release:

  [2872] locale: Transliteration Cyrillic -> ASCII fails
  [6399] libc: gettid() should have a wrapper
  [16573] malloc: mtrace hangs when MALLOC_TRACE is defined
  [16976] glob: fnmatch unbounded stack VLA for collating symbols
  [17396] localedata: globbing for locale by [[.collating-element.]]
  [18035] dynamic-link: pldd does no longer work, enters infinite loop
  [18465] malloc: memusagestat is built using system C library
  [18830] locale: iconv -c -f ascii with >buffer size worth of input before
    invalid input drops valid char
  [20188] nptl: libpthread IFUNC resolver for vfork can lead to crash
  [20568] locale: Segfault with wide characters and setlocale/fgetwc/UTF-8
  [21897] localedata: Afar locales: Fix mon, abmon, and abday
  [22964] localedata: The Japanese Era name will be changed on May 1, 2019
  [23352] malloc: __malloc_check_init still defined in public header
    malloc.h.
  [23403] nptl: Wrong alignment of TLS variables
  [23501] libc: nftw() doesn't return dangling symlink's inode
  [23733] malloc: Check the count before calling tcache_get()
  [23741] malloc: Missing __attribute_alloc_size__ in many allocation
    functions
  [23831] localedata: nl_NL missing LC_NUMERIC thousands_sep
  [23844] nptl: pthread_rwlock_trywrlock results in hang
  [23983] argparse: Missing compat versions of argp_failure and argp_error
    for long double = double
  [23984] libc: Missing compat versions of err.h and error.h functions for
    long double = double
  [23996] localedata: Dutch salutations
  [24040] libc: riscv64: unterminated call chain in __thread_start
  [24047] network: libresolv should use IP_RECVERR/IPV6_RECVERR to avoid
    long timeouts
  [24051] stdio: puts and putchar output to _IO_stdout instead of stdout
  [24059] nss: nss_files: get_next_alias calls fgets_unlocked without
    checking for NULL.
  [24114] regex: regexec buffer read overrun in "grep -i
    '\(\(\)*.\)*\(\)\(\)\1'"
  [24122] libc: Segfaults if 0 returned from la_version
  [24153] stdio: Some input functions do not react to stdin assignment
  [24155] string: x32 memcmp can treat positive length as 0 (if sign bit in
    RDX is set) (CVE-2019-7309)
  [24161] nptl: __run_fork_handlers self-deadlocks in malloc/tst-mallocfork2
  [24164] libc: Systemtap probes need to use "nr" constraint on 32-bit Arm,
    not the default "nor"
  [24166] dynamic-link: Dl_serinfo.dls_serpath[1] in dlfcn.h causes UBSAN
    false positives, change to modern flexible array
  [24180] nptl: pthread_mutex_trylock does not use the correct order of
    instructions while maintaining the robust mutex list due to missing
    compiler barriers.
  [24194] librt: Non-compatibility symbols for clock_gettime etc. cause
    unnecessary librt dependencies
  [24200] localedata: Revert first_weekday removal in en_IE locale
  [24211] nptl: Use-after-free in Systemtap probe in pthread_join
  [24215] nptl: pthread_timedjoin_np should be a cancellation point
  [24216] malloc: Check for large bin list corruption when inserting
    unsorted chunk
  [24228] stdio: old x86 applications that use legacy libio crash on exit
  [24231] dynamic-link: [sparc64] R_SPARC_H34 implementation falls through
    to R_SPARC_H44
  [24293] localedata: Missing Minguo calendar support for TW locales
  [24296] localedata: Orthographic mistakes in 'day' and 'abday' sections in
    tt_RU (Tatar) locale
  [24307] localedata: Update locale data to Unicode 12.0.0
  [24323] dynamic-link: dlopen should not be able open PIE objects
  [24335] build: "Obsolete types detected" with Linux 5.0 headers
  [24369] localedata: Orthographic mistakes in 'mon' and 'abmon' sections in
    tt_RU (Tatar) locale
  [24370] localedata: Add lang_name for tt_RU locale
  [24372] locale: Binary locale files are not architecture independent
  [24394] time: strptime %Ey mis-parses final year of era
  [24476] dynamic-link: __libc_freeres triggers bad free in libdl if dlerror
    was not used
  [24506] dynamic-link: FAIL: elf/tst-pldd with --enable-hardcoded-path-in-
    tests
  [24531] malloc: Malloc tunables give tcache assertion failures
  [24532] libc: conform/arpa/inet.h failures due to linux kernel 64-bit
    time_t changes
  [24535] localedata: Update locale data to Unicode 12.1.0
  [24537] build: nptl/tst-eintr1 test case can hit task limits on some
    kernels and break testing
  [24544] build: elf/tst-pldd doesn't work if you install with a --prefix
  [24556] build: [GCC 9] error: ‘%s’ directive argument is null
    [-Werror=format-overflow=]
  [24570] libc: alpha: compat msgctl uses __IPC_64
  [24584] locale: Data race in __wcsmbs_clone_conv
  [24588] stdio: Remove codecvt vtables from libio
  [24603] math: sysdeps/ieee754/dbl-64/branred.c is slow when compiled with
    -O3 -march=skylake
  [24614] localedata: nl_NL LC_MONETARY doesn't match CLDR 35
  [24632] stdio: Old binaries which use freopen with default stdio handles
    crash
  [24640] libc: __ppc_get_timebase_freq() always return 0 when using static
    linked glibc
  [24652] localedata: szl_PL spelling correction
  [24695] nss: nss_db: calling getpwent after endpwent crashes
  [24696] nss: endgrent() clobbers errno=ERRNO for 'group: db files' entry
    in /etc/nsswitch.conf
  [24699] libc: mmap64 with very large offset broken on MIPS64 n32
  [24740] libc: getdents64 type confusion
  [24741] dynamic-link: ld.so should not require that a versioned symbol is
    always implemented in the same library
  [24744] libc: Remove copy_file_range emulation
  [24757] malloc: memusagestat is linked against system libpthread
  [24794] libc: Partial test suite run builds corrupt test-in-container
    testroot

\f
Version 2.29

Major new features:

* The getcpu wrapper function has been added, which returns the currently
  used CPU and NUMA node.  This function is Linux-specific.

* A new convenience target has been added for distribution maintainers
  to build and install all locales as directories with files.  The new
  target is run by issuing the following command in your build tree:
  'make localedata/install-locale-files', with an optional DESTDIR
  to set the install root if you wish to install into a non-default
  configured location.

* Optimized generic exp, exp2, log, log2, pow, sinf, cosf, sincosf and tanf.

* The reallocarray function is now declared under _DEFAULT_SOURCE, not just
  for _GNU_SOURCE, to match BSD environments.

* For powercp64le ABI, Transactional Lock Elision is now enabled iff kernel
  indicates that it will abort the transaction prior to entering the kernel
  (PPC_FEATURE2_HTM_NOSC on hwcap2).  On older kernels the transaction is
  suspended, and this caused some undefined side-effects issues by aborting
  transactions manually.  Glibc avoided it by abort transactions manually on
  each syscall, but it lead to performance issues on newer kernels where the
  HTM state is saved and restore lazily (the state being saved even when the
  process actually does not use HTM).

* The functions posix_spawn_file_actions_addchdir_np and
  posix_spawn_file_actions_addfchdir_np have been added, enabling
  posix_spawn and posix_spawnp to run the new process in a different
  directory.  These functions are GNU extensions.  The function
  posix_spawn_file_actions_addchdir_np is similar to the Solaris function
  of the same name.

* The popen and system do not run atfork handlers anymore (BZ#17490).
  Although it is a possible POSIX violation, the POSIX rationale in
  pthread_atfork documentation regarding atfork handlers is to handle
  inconsistent mutex state after a fork call in a multi-threaded process.
  In both popen and system there is no direct access to user-defined mutexes.

* Support for the C-SKY ABIV2 running on Linux has been added.  This port
  requires at least binutils-2.32, gcc-9.0, and linux-4.20.  Two ABIs are
  supported:
    - C-SKY ABIV2 soft-float little-endian
    - C-SKY ABIV2 hard-float little-endian

* strftime's default formatting of a locale's alternative year (%Ey)
  has been changed to zero-pad the year to a minimum of two digits,
  like "%y".  This improves the display of Japanese era years during
  the first nine years of a new era, and is expected to be harmless
  for all other locales (only Japanese locales regularly have
  alternative year numbers less than 10).  Zero-padding can be
  overridden with the '_' or '-' flags (which are GNU extensions).

* As a GNU extension, the '_' and '-' flags can now be applied to
  "%EY" to control how the year number is formatted; they have the
  same effect that they would on "%Ey".

Deprecated and removed features, and other changes affecting compatibility:

* The glibc.tune tunable namespace has been renamed to glibc.cpu and the
  tunable glibc.tune.cpu has been renamed to glibc.cpu.name.

* The type of the pr_uid and pr_gid members of struct elf_prpsinfo, defined
  in <sys/procfs.h>, has been corrected to match the type actually used by
  the Linux kernel.  This affects the size and layout of that structure on
  MicroBlaze, MIPS (n64 ABI only), Nios II and RISC-V.

* For the MIPS n32 ABI, the type of the pr_sigpend and pr_sighold members of
  struct elf_prstatus, and the pr_flag member of struct elf_prpsinfo,
  defined in <sys/procfs.h>, has been corrected to match the type actually
  used by the Linux kernel.  This affects the size and layout of those
  structures.

* An archaic GNU extension to scanf, under which '%as', '%aS', and '%a[...]'
  meant to scan a string and allocate space for it with malloc, is now
  restricted to programs compiled in C89 or C++98 mode with _GNU_SOURCE
  defined.  This extension conflicts with C99's use of '%a' to scan a
  hexadecimal floating-point number, which is now available to programs
  compiled as C99 or C++11 or higher, regardless of _GNU_SOURCE.

  POSIX.1-2008 includes the feature of allocating a buffer for string input
  with malloc, using the modifier letter 'm' instead.  Programs using
  '%as', '%aS', or '%a[...]' with the old GNU meaning should change to
  '%ms', '%mS', or '%m[...]' respectively.  Programs that wish to use the
  C99 '%a' no longer need to avoid _GNU_SOURCE.

  GCC's -Wformat warnings can detect most uses of this extension, as long
  as all functions that call vscanf, vfscanf, or vsscanf are annotated with
  __attribute__ ((format (scanf, ...))).

Changes to build and runtime requirements:

* Python 3.4 or later is required to build the GNU C Library.

* On most architectures, GCC 5 or later is required to build the GNU C
  Library.  (On powerpc64le, GCC 6.2 or later is still required, as before.)

  Older GCC versions and non-GNU compilers are still supported when
  compiling programs that use the GNU C Library.

Security related changes:

  CVE-2018-19591: A file descriptor leak in if_nametoindex can lead to a
  denial of service due to resource exhaustion when processing getaddrinfo
  calls with crafted host names.  Reported by Guido Vranken.

  CVE-2019-6488: On x32, the size_t parameter may be passed in the lower
  32 bits of a 64-bit register with with non-zero upper 32 bit.  When it
  happened, accessing the 32-bit size_t value as the full 64-bit register
  in the assembly string/memory functions would cause a buffer overflow.
  Reported by H.J. Lu.

  CVE-2016-10739: The getaddrinfo function could successfully parse IPv4
  addresses with arbitrary trailing characters, potentially leading to data
  or command injection issues in applications.

The following bugs are resolved with this release:

  [10425] localedata: it_IT/it_CH: LC_TIME format is wrong
  [10496] localedata: 12h time representation in multiple locales faulty
  [10797] localedata: it_IT locale numeric does not have a separator for
    thousands
  [11319] libc: dprintf doesn't handle errors properly
  [16346] time: mktime: potentially unsafe use of localtime_offset
  [17248] build: glibc should not sort CFLAGS (support gcc plugins and
    --param options)
  [17405] libc: Implement posix_spawn_file_actions_addchdir_np,
    posix_spawn_file_actions_addfchdir_np
  [17426] localedata: Indian locales: set the correct date format
  [17490] stdio: popen should not invoke atfork handlers
  [17783] libc: TIOCSER_TEMT conditions inconsistent
  [18040] regex: use-after-free in regexec/get_subexp
  [18093] libc: Corrupted aux-cache causes ldconfig to segfault
  [20018] network: getaddrinfo should reject IP addresses with trailing
    characters (CVE-2016-10739)
  [20209] localedata: Spelling mistake for Sunday in Greenlandic kl_GL
  [20271] libc: Missing "\n" in __libc_fatal calls
  [20480] dynamic-link: Patch: ifunc not executable, crashes sudo qemu
  [20544] libc: RFE: atexit, __cxa_atexit, on_exit should assert function
    pointer argument is non-NULL
  [21037] stdio: open_memstream and freopen
  [21286] libc: bits/siginfo.h  is missing enum definition for TRAP_HWBKPT
  [21716] time: Crash in glibc's mktime in low-memory situations
  [22834] stdio: Subprocess forked by popen may crash in Linux when
    multithreads call popen
  [22927] network: crash in vn_gai_enqueue_request if requests_tail was NULL
    and pthread_create fails.
  [23032] hurd: sysdeps/htl/pt-barrier-init.c:39: bad call to memcmp ?
  [23125] libc: riscv64: endless loop when throwing an exception from a
    constructor
  [23275] nptl: Race in pthread_mutex_lock while promoting to
    PTHREAD_MUTEX_ELISION_NP.
  [23400] libc: stdlib/test-bz22786.c creates temporary files in glibc
    source tree
  [23479] math: [mips] bits/fenv.h should not define some macros for soft-
    float
  [23490] libc: sysdeps/unix/sysv/linux/x86/tst-cet-property-2.c:49: off by
    one error
  [23497] libc: readdir64@GLIBC_2.1 cannot parse the kernel directory stream
  [23509] dynamic-link: CET enabled glibc is incompatible with the older
    linker
  [23520] nscd: nscd: Use-after-free in addgetnetgrentX and its callers
  [23521] nss: get_next_alias nss_files file stream leak
  [23538] nptl: Hang in pthread_cond_broadcast
  [23562] libc: Wrong type for si_band in Linux-specific siginfo_t
  [23578] regex: Invalid memory access if regex pattern contains NUL byte
  [23579] libc: Errors misreported in preadv2
  [23597] build: support/test-container.c doesn't work with different
    filesystems
  [23603] time: mktime signed integer overflow on large timestamps
  [23606] libc: Missing ENDBR32 in sysdeps/i386/start.S
  [23614] libc: powerpc: missing CFI register information in __mpn_*
    functions
  [23637] string: Generic strstr/strcasestr fails with huge needles
  [23640] libc: no way to easily clear FD_CLOEXEC in
    posix_spawn_file_actions_adddup2()
  [23649] libc: [microblaze/mips/nios2/riscv] sys/procfs.h pr_uid, pr_gid
    have wrong type
  [23656] libc: [mips n32] sys/procfs.h pr_sigpend, pr_sighold, pr_flag have
    wrong type
  [23679] libc: gethostid: Missing NULL check for gethostbyname_r result
  [23689] libc: Bug in documentation for rusage.ru_ixrss in
    bits/types/struct_rusage.h
  [23690] dynamic-link: Segfault in _dl_profile_fixup with a high number of
    threads
  [23707] dynamic-link: Missing unwind info in sysdeps/powerpc/powerpc32/dl-
    start.S
  [23709] string: glibc 2.25 lacks sse2 optimized strstr()
  [23716] dynamic-link: _dl_runtime_resolve_shstk isn't selected properly
  [23717] libc: glibc: stdlib/tst-setcontext9 test suite failure on
    powerpc64le
  [23724] localedata: Albanian date formats are incorrect
  [23735] math: libnldbl_nonshared.a references internal libm symbols
  [23740] localedata: kl_GL: Month names and date formats need update
  [23744] regex: regex refactorings to remove BE, avoid duplication
  [23745] time: mktime fix for Gnulib + coreutils
  [23758] time: Improve the width of alternate representation for year in
    strftime
  [23783] libc: [mips] Missing CMSPAR bits/termios.h
  [23789] time: mktime does not set errno on failure
  [23791] localedata: Wrong monetary format for ca_ES locale
  [23793] locale: c32rtomb and mbrtoc32 should not alias wcrtomb and mbrtowc
  [23794] locale: c16rtomb does not handle surrogate pairs
  [23821] libc: si_band in siginfo_t has wrong type long int on sparc64
  [23822] math: ia64 static libm.a is missing exp2f, log2f and powf symbols
  [23836] time: time/tst-mktime2 test failure on Arm (32-bit)
  [23848] libc: [sparc] Some socket syscalls wrongly assumed to be present
  [23861] nptl: rdlock stalls indefinitely on an unlocked pthread rwlock
  [23862] libc: [sh] missing kernel-features.h undefines
  [23864] libc: [riscv] missing kernel-features.h undefines
  [23867] libc: [arm/microblaze] __ASSUME_MLOCK2 incorrect
  [23907] malloc: Incorrect double-free malloc tcache check disregards
    tcache size
  [23913] libc: off-by-one in function maybe_script_execute in
    sysdeps/posix/spawni.c
  [23915] libc: [arm] __ASSUME_COPY_FILE_RANGE incorrect
  [23923] locale: Add --no-hard-links option to localedef
  [23927] network: Linux if_nametoindex() does not close descriptor
    (CVE-2018-19591)
  [23961] math: powf can overflow to inf without setting errno in non-
    nearest rounding mode
  [23967] libc: [2.28 Regression]: New sigaction implementation breaks m68k
  [23972] libc: __old_getdents64 uses wrong d_off value on overflow
  [23993] libc: glibc 2.29 doesn't build with gcc 4.9
  [23995] localedata: Remove execution flags from localedata/locales/bi_VU
  [24011] localedata: Fixed small type in comment for locale bs_BA
  [24018] libc: gettext() may return NULL
  [24022] build: riscv build failure with Linux kernel 4.20-rc7
  [24023] build: [2.29 Regression] FAIL: elf/check-localplt
  [24024] string: strerror() might set errno to ENOMEM due to -fno-math-
    error
  [24027] malloc: glibc: realloc() ncopies 32-bit integer overflow
  [24034] libc: tst-cancel21-static fails with SIGBUS on pre-ARMv7 when
    using GCC 8
  [24046] localedata: en_US locale doesn't define date_fmt
  [24063] manual: @var{errno} should be @code{errno}
  [24066] soft-fp: Inconsistent _FP_W_TYPE_SIZE check
  [24088] libc: VSCR field is not being correctly read in ucontext_t on
    ppc64le
  [24096] time: Specifying '_' or '-' flag for "%EY" does not produce the
    expected result
  [24097] string: Can't use 64-bit register for size_t in assembly codes for
    x32 (CVE-2019-6488)
  [24110] hurd: SS_DISABLE never set in stack_t value returned by
    sigaltstack
  [24112] network: Do not send DNS queries for non-host names (where all
    answers will be rejected)
  [24130] libc: alpha __remqu corrupts $f3 register

\f
Version 2.28

Major new features:

* The localization data for ISO 14651 is updated to match the 2016
  Edition 4 release of the standard, this matches data provided by
  Unicode 9.0.0.  This update introduces significant improvements to the
  collation of Unicode characters.  This release deviates slightly from
  the standard in that the collation element ordering for lowercase and
  uppercase LATIN script characters is adjusted to ensure that regular
  expressions with ranges like [a-z] and [A-Z] don't interleave e.g. A
  is not matched by [a-z].  With the update many locales have been
  updated to take advantage of the new collation information.  The new
  collation information has increased the size of the compiled locale
  archive or binary locales.

* The GNU C Library can now be compiled with support for Intel CET, AKA
  Intel Control-flow Enforcement Technology.  When the library is built
  with --enable-cet, the resulting glibc is protected with indirect
  branch tracking (IBT) and shadow stack (SHSTK).  CET-enabled glibc is
  compatible with all existing executables and shared libraries.  This
  feature is currently supported on i386, x86_64 and x32 with GCC 8 and
  binutils 2.29 or later.  Note that CET-enabled glibc requires CPUs
  capable of multi-byte NOPs, like x86-64 processors as well as Intel
  Pentium Pro or newer.  NOTE: --enable-cet has been tested for i686,
  x86_64 and x32 on non-CET processors.  --enable-cet has been tested
  for x86_64 and x32 on CET SDVs, but Intel CET support hasn't been
  validated for i686.

* The GNU C Library now has correct support for ABSOLUTE symbols
  (SHN_ABS-relative symbols).  Previously such ABSOLUTE symbols were
  relocated incorrectly or in some cases discarded.  The GNU linker can
  make use of the newer semantics, but it must communicate it to the
  dynamic loader by setting the ELF file's identification (EI_ABIVERSION
  field) to indicate such support is required.

* Unicode 11.0.0 Support: Character encoding, character type info, and
  transliteration tables are all updated to Unicode 11.0.0, using
  generator scripts contributed by Mike FABIAN (Red Hat).

* <math.h> functions that round their results to a narrower type are added
  from TS 18661-1:2014 and TS 18661-3:2015:

  - fadd, faddl, daddl and corresponding fMaddfN, fMaddfNx, fMxaddfN and
    fMxaddfNx functions.

  - fsub, fsubl, dsubl and corresponding fMsubfN, fMsubfNx, fMxsubfN and
    fMxsubfNx functions.

  - fmul, fmull, dmull and corresponding fMmulfN, fMmulfNx, fMxmulfN and
    fMxmulfNx functions.

  - fdiv, fdivl, ddivl and corresponding fMdivfN, fMdivfNx, fMxdivfN and
    fMxdivfNx functions.

* Two grammatical forms of month names are now supported for the following
  languages: Armenian, Asturian, Catalan, Czech, Kashubian, Occitan, Ossetian,
  Scottish Gaelic, Upper Sorbian, and Walloon.  The following languages now
  support two grammatical forms in abbreviated month names: Catalan, Greek,
  and Kashubian.

* Newly added locales: Lower Sorbian (dsb_DE) and Yakut (sah_RU) also
  include the support for two grammatical forms of month names.

* Building and running on GNU/Hurd systems now works without out-of-tree
  patches.

* The renameat2 function has been added, a variant of the renameat function
  which has a flags argument.  If the flags are zero, the renameat2 function
  acts like renameat.  If the flag is not zero and there is no kernel
  support for renameat2, the function will fail with an errno value of
  EINVAL.  This is different from the existing gnulib function renameatu,
  which performs a plain rename operation in case of a RENAME_NOREPLACE
  flags and a non-existing destination (and therefore has a race condition
  that can clobber the destination inadvertently).

* The statx function has been added, a variant of the fstatat64
  function with an additional flags argument.  If there is no direct
  kernel support for statx, glibc provides basic stat support based on
  the fstatat64 function.

* IDN domain names in getaddrinfo and getnameinfo now use the system libidn2
  library if installed.  libidn2 version 2.0.5 or later is recommended.  If
  libidn2 is not available, internationalized domain names are not encoded
  or decoded even if the AI_IDN or NI_IDN flags are passed to getaddrinfo or
  getnameinfo.  (getaddrinfo calls with non-ASCII names and AI_IDN will fail
  with an encoding error.)  Flags which used to change the IDN encoding and
  decoding behavior (AI_IDN_ALLOW_UNASSIGNED, AI_IDN_USE_STD3_ASCII_RULES,
  NI_IDN_ALLOW_UNASSIGNED, NI_IDN_USE_STD3_ASCII_RULES) have been
  deprecated.  They no longer have any effect.

* Parsing of dynamic string tokens in DT_RPATH, DT_RUNPATH, DT_NEEDED,
  DT_AUXILIARY, and DT_FILTER has been expanded to support the full
  range of ELF gABI expressions including such constructs as
  '$ORIGIN$ORIGIN' (if valid).  For SUID/GUID applications the rules
  have been further restricted, and where in the past a dynamic string
  token sequence may have been interpreted as a literal string it will
  now cause a load failure.  These load failures were always considered
  unspecified behaviour from the perspective of the dynamic loader, and
  for safety are now load errors e.g. /foo/${ORIGIN}.so in DT_NEEDED
  results in a load failure now.

* Support for ISO C threads (ISO/IEC 9899:2011) has been added.  The
  implementation includes all the standard functions provided by
  <threads.h>:

  - thrd_current, thrd_equal, thrd_sleep, thrd_yield, thrd_create,
    thrd_detach, thrd_exit, and thrd_join for thread management.

  - mtx_init, mtx_lock, mtx_timedlock, mtx_trylock, mtx_unlock, and
    mtx_destroy for mutual exclusion.

  - call_once for function call synchronization.

  - cnd_broadcast, cnd_destroy, cnd_init, cnd_signal, cnd_timedwait, and
    cnd_wait for conditional variables.

  - tss_create, tss_delete, tss_get, and tss_set for thread-local storage.

  Application developers must link against libpthread to use ISO C threads.

Deprecated and removed features, and other changes affecting compatibility:

* The nonstandard header files <libio.h> and <_G_config.h> are no longer
  installed.  Software that was using either header should be updated to
  use standard <stdio.h> interfaces instead.

* The stdio functions 'getc' and 'putc' are no longer defined as macros.
  This was never required by the C standard, and the macros just expanded
  to call alternative names for the same functions.  If you hoped getc and
  putc would provide performance improvements over fgetc and fputc, instead
  investigate using (f)getc_unlocked and (f)putc_unlocked, and, if
  necessary, flockfile and funlockfile.

* All stdio functions now treat end-of-file as a sticky condition.  If you
  read from a file until EOF, and then the file is enlarged by another
  process, you must call clearerr or another function with the same effect
  (e.g. fseek, rewind) before you can read the additional data.  This
  corrects a longstanding C99 conformance bug.  It is most likely to affect
  programs that use stdio to read interactive input from a terminal.
  (Bug #1190.)

* The macros 'major', 'minor', and 'makedev' are now only available from
  the header <sys/sysmacros.h>; not from <sys/types.h> or various other
  headers that happen to include <sys/types.h>.  These macros are rarely
  used, not part of POSIX nor XSI, and their names frequently collide with
  user code; see https://sourceware.org/bugzilla/show_bug.cgi?id=19239 for
  further explanation.

  <sys/sysmacros.h> is a GNU extension.  Portable programs that require
  these macros should first include <sys/types.h>, and then include
  <sys/sysmacros.h> if __GNU_LIBRARY__ is defined.

* The tilegx*-*-linux-gnu configurations are no longer supported.

* The obsolete function ustat is no longer available to newly linked
  binaries; the headers <ustat.h> and <sys/ustat.h> have been removed.  This
  function has been deprecated in favor of fstatfs and statfs.

* The obsolete function nfsservctl is no longer available to newly linked
  binaries.  This function was specific to systems using the Linux kernel
  and could not usefully be used with the GNU C Library on systems with
  version 3.1 or later of the Linux kernel.

* The obsolete function name llseek is no longer available to newly linked
  binaries.  This function was specific to systems using the Linux kernel
  and was not declared in a header.  Programs should use the lseek64 name
  for this function instead.

* The AI_IDN_ALLOW_UNASSIGNED and NI_IDN_ALLOW_UNASSIGNED flags for the
  getaddrinfo and getnameinfo functions have been deprecated.  The behavior
  previously selected by them is now always enabled.

* The AI_IDN_USE_STD3_ASCII_RULES and NI_IDN_USE_STD3_ASCII_RULES flags for
  the getaddrinfo and getnameinfo functions have been deprecated.  The STD3
  restriction (rejecting '_' in host names, among other things) has been
  removed, for increased compatibility with non-IDN name resolution.

* The fcntl function now have a Long File Support variant named fcntl64.  It
  is added to fix some Linux Open File Description (OFD) locks usage on non
  LFS mode.  As for others *64 functions, fcntl64 semantics are analogous with
  fcntl and LFS support is handled transparently.  Also for Linux, the OFD
  locks act as a cancellation entrypoint.

* The obsolete functions encrypt, encrypt_r, setkey, setkey_r, cbc_crypt,
  ecb_crypt, and des_setparity are no longer available to newly linked
  binaries, and the headers <rpc/des_crypt.h> and <rpc/rpc_des.h> are no
  longer installed.  These functions encrypted and decrypted data with the
  DES block cipher, which is no longer considered secure.  Software that
  still uses these functions should switch to a modern cryptography library,
  such as libgcrypt.

* Reflecting the removal of the encrypt and setkey functions above, the
  macro _XOPEN_CRYPT is no longer defined.  As a consequence, the crypt
  function is no longer declared unless _DEFAULT_SOURCE or _GNU_SOURCE is
  enabled.

* The obsolete function fcrypt is no longer available to newly linked
  binaries.  It was just another name for the standard function crypt,
  and it has not appeared in any header file in many years.

* We have tentative plans to hand off maintenance of the passphrase-hashing
  library, libcrypt, to a separate development project that will, we hope,
  keep up better with new passphrase-hashing algorithms.  We will continue
  to declare 'crypt' in <unistd.h>, and programs that use 'crypt' or
  'crypt_r' should not need to change at all; however, distributions will
  need to install <crypt.h> and libcrypt from a separate project.

  In this release, if the configure option --disable-crypt is used, glibc
  will not install <crypt.h> or libcrypt, making room for the separate
  project's versions of these files.  The plan is to make this the default
  behavior in a future release.

Changes to build and runtime requirements:

  GNU make 4.0 or later is now required to build glibc.

Security related changes:

  CVE-2016-6261, CVE-2016-6263, CVE-2017-14062: Various vulnerabilities have
  been fixed by removing the glibc-internal IDNA implementation and using
  the system-provided libidn2 library instead.  Originally reported by Hanno
  Böck and Christian Weisgerber.

  CVE-2017-18269: An SSE2-based memmove implementation for the i386
  architecture could corrupt memory.  Reported by Max Horn.

  CVE-2018-11236: Very long pathname arguments to realpath function could
  result in an integer overflow and buffer overflow.  Reported by Alexey
  Izbyshev.

  CVE-2018-11237: The mempcpy implementation for the Intel Xeon Phi
  architecture could write beyond the target buffer, resulting in a buffer
  overflow.  Reported by Andreas Schwab.

The following bugs are resolved with this release:

  [1190] stdio: fgetc()/fread() behaviour is not POSIX compliant
  [6889] manual: 'PWD' mentioned but not specified
  [13575] libc: SSIZE_MAX defined as LONG_MAX is inconsistent with ssize_t,
    when __WORDSIZE != 64
  [13762] regex: re_search etc. should return -2 on memory exhaustion
  [13888] build: /tmp usage during testing
  [13932] math: dbl-64 pow unexpectedly slow for some inputs
  [14092] nptl: Support C11 threads
  [14095] localedata: Review / update collation data from Unicode / ISO
    14651
  [14508] libc: -Wformat warnings
  [14553] libc: Namespace pollution loff_t in sys/types.h
  [14890] libc: Make NT_PRFPREG canonical.
  [15105] libc: Extra PLT references with -Os
  [15512] libc: __bswap_constant_16 not compiled when -Werror -Wsign-
    conversion is given
  [16335] manual: Feature test macro documentation incomplete and out of
    date
  [16552] libc: Unify umount implementations in terms of umount2
  [17082] libc: htons et al.: statement-expressions prevent use on global
    scope with -O1 and higher
  [17343] libc: Signed integer overflow in /stdlib/random_r.c
  [17438] localedata: pt_BR: wrong d_fmt delimiter
  [17662] libc: please implement binding for the new renameat2 syscall
  [17721] libc: __restrict defined as /* Ignore */ even in c11
  [17979] libc: inconsistency between uchar.h and stdint.h
  [18018] dynamic-link: Additional $ORIGIN handling issues (CVE-2011-0536)
  [18023] libc: extend_alloca is broken (questionable pointer comparison,
    horrible machine code)
  [18124] libc: hppa: setcontext erroneously returns -1 as exit code for
    last constant.
  [18471] libc: llseek should be a compat symbol
  [18473] soft-fp: [powerpc-nofpu] __sqrtsf2, __sqrtdf2 should be compat
    symbols
  [18991] nss: nss_files skips large entry in database
  [19239] libc: Including stdlib.h ends up with macros major and minor being
    defined
  [19463] libc: linknamespace failures when compiled with -Os
  [19485] localedata: csb_PL: Update month translations + add yesstr/nostr
  [19527] locale: Normalized charset name not recognized by setlocale
  [19667] string: Missing Sanity Check for malloc calls in file 'testcopy.c'
  [19668] libc: Missing Sanity Check for malloc() in file 'tst-setcontext-
    fpscr.c'
  [19728] network: out of bounds stack read in libidn function
    idna_to_ascii_4i (CVE-2016-6261)
  [19729] network: out of bounds heap read on invalid utf-8 inputs in
    stringprep_utf8_nfkc_normalize (CVE-2016-6263)
  [19818] dynamic-link: Absolute (SHN_ABS) symbols incorrectly relocated by
    the base address
  [20079] libc: Add SHT_X86_64_UNWIND to elf.h
  [20251] libc: 32bit programs pass garbage in struct flock for OFD locks
  [20419] dynamic-link: files with large allocated notes crash in
    open_verify
  [20530] libc: bswap_16 should use __builtin_bswap16() when available
  [20890] dynamic-link: ldconfig: fsync the files before atomic rename
  [20980] manual: CFLAGS environment variable replaces vital options
  [21163] regex: Assertion failure in pop_fail_stack when executing a
    malformed regexp (CVE-2015-8985)
  [21234] manual: use of CFLAGS makes glibc detect no optimization
  [21269] dynamic-link: i386 sigaction sa_restorer handling is wrong
  [21313] build: Compile Error GCC 5.4.0 MIPS with -0S
  [21314] build: Compile Error GCC 5.2.0 MIPS with -0s
  [21508] locale: intl/tst-gettext failure with latest msgfmt
  [21547] localedata: Tibetan script collation broken (Dzongkha and Tibetan)
  [21812] network: getifaddrs() returns entries with ifa_name == NULL
  [21895] libc: ppc64 setjmp/longjmp not fully interoperable with static
    dlopen
  [21942] dynamic-link: _dl_dst_substitute incorrectly handles $ORIGIN: with
    AT_SECURE=1
  [22241] localedata: New locale: Yakut (Sakha) locale for Russia (sah_RU)
  [22247] network: Integer overflow in the decode_digit function in
    puny_decode.c in libidn (CVE-2017-14062)
  [22342] nscd: NSCD not properly caching netgroup
  [22391] nptl: Signal function clear NPTL internal symbols inconsistently
  [22550] localedata: es_ES locale (and  other es_* locales):  collation
    should treat ñ  as a primary different character,  sync the collation
    for Spanish with CLDR
  [22638] dynamic-link: sparc: static binaries are broken if glibc is built
    by gcc configured with --enable-default-pie
  [22639] time: year 2039 bug for localtime etc. on 64-bit platforms
  [22644] string: memmove-sse2-unaligned on 32bit x86 produces garbage when
    crossing 2GB threshold (CVE-2017-18269)
  [22646] localedata: redundant data (LC_TIME) for es_CL, es_CU, es_EC and
    es_BO
  [22735] time: Misleading typo in time.h source comment regarding
    CLOCKS_PER_SECOND
  [22753] libc: preadv2/pwritev2 fallback code should handle offset=-1
  [22761] libc: No trailing `%n' conversion specifier in FMT passed from
    `__assert_perror_fail ()' to `__assert_fail_base ()'
  [22766] libc: all glibc internal dlopen should use RTLD_NOW for robust
    dlopen failures
  [22786] libc: Stack buffer overflow in realpath() if input size is close
    to SSIZE_MAX (CVE-2018-11236)
  [22787] dynamic-link: _dl_check_caller returns false when libc is linked
    through an absolute DT_NEEDED path
  [22792] build: tcb-offsets.h dependency dropped
  [22797] libc: pkey_get() uses non-reserved name of argument
  [22807] libc: PTRACE_* constants missing for powerpc
  [22818] glob: posix/tst-glob_lstat_compat failure on alpha
  [22827] dynamic-link: RISC-V ELF64 parser mis-reads flag in ldconfig
  [22830] malloc: malloc_stats doesn't restore cancellation state on stderr
  [22848] localedata: ca_ES: update date definitions from CLDR
  [22862] build: _DEFAULT_SOURCE is defined even when _ISOC11_SOURCE is
  [22884] math: RISCV fmax/fmin handle signalling NANs incorrectly
  [22896] localedata: Update locale data for an_ES
  [22902] math: float128 test failures with GCC 8
  [22918] libc: multiple common of `__nss_shadow_database'
  [22919] libc: sparc32: backtrace yields infinite backtrace with
    makecontext
  [22926] libc: FTBFS on powerpcspe
  [22932] localedata: lt_LT: Update of abbreviated month names from CLDR
    required
  [22937] localedata: Greek (el_GR, el_CY) locales actually need ab_alt_mon
  [22947] libc: FAIL: misc/tst-preadvwritev2
  [22963] localedata: cs_CZ: Add alternative month names
  [22987] math: [powerpc/sparc] fdim inlines errno, exceptions handling
  [22996] localedata: change LC_PAPER to en_US in es_BO locale
  [22998] dynamic-link: execstack tests are disabled when SELinux is
    disabled
  [23005] network: Crash in __res_context_send after memory allocation
    failure
  [23007] math: strtod cannot handle -nan
  [23024] nss: getlogin_r is performing NSS lookups when loginid isn't set
  [23036] regex: regex equivalence class regression
  [23037] libc: initialize msg_flags to zero for sendmmsg() calls
  [23069] libc: sigaction broken on riscv64-linux-gnu
  [23094] localedata: hr_HR: wrong thousands_sep and mon_thousands_sep
  [23102] dynamic-link: Incorrect parsing of multiple consecutive $variable
    patterns in runpath entries (e.g. $ORIGIN$ORIGIN)
  [23137] nptl: s390: pthread_join sometimes block indefinitely (on 31bit
    and libc build with -Os)
  [23140] localedata: More languages need two forms of month names
  [23145] libc: _init/_fini aren't marked as hidden
  [23152] localedata: gd_GB: Fix typo in "May" (abbreviated)
  [23171] math: C++ iseqsig for long double converts arguments to double
  [23178] nscd: sudo will fail when it is run in concurrent with commands
    that changes /etc/passwd
  [23196] string: __mempcpy_avx512_no_vzeroupper mishandles large copies
    (CVE-2018-11237)
  [23206] dynamic-link: static-pie + dlopen breaks debugger interaction
  [23208] localedata: New locale - Lower Sorbian (dsb)
  [23233] regex: Memory leak in build_charclass_op function in file
    posix/regcomp.c
  [23236] stdio: Harden function pointers in _IO_str_fields
  [23250] nptl: Offset of __private_ss differs from GCC
  [23253] math: tgamma test suite failures on i686 with -march=x86-64
    -mtune=generic -mfpmath=sse
  [23259] dynamic-link: Unsubstituted ${ORIGIN} remains in DT_NEEDED for
    AT_SECURE
  [23264] libc: posix_spawnp wrongly executes ENOEXEC in non compat mode
  [23266] nis: stringop-truncation warning with new gcc8.1 in nisplus-
    parser.c
  [23272] math: fma(INFINITY,INFIITY,0.0) should be INFINITY
  [23277] math: nan function should not have const attribute
  [23279] math: scanf and strtod wrong for some hex floating-point
  [23280] math: wscanf rounds wrong; wcstod is ok for negative numbers and
    directed rounding
  [23290] localedata: IBM273 is not equivalent to ISO-8859-1
  [23303] build: undefined reference to symbol
    '__parse_hwcap_and_convert_at_platform@@GLIBC_2.23'
  [23307] dynamic-link: Absolute symbols whose value is zero ignored in
    lookup
  [23313] stdio: libio vtables validation and standard file object
    interposition
  [23329] libc: The __libc_freeres infrastructure is not properly run across
    DSO boundaries.
  [23349] libc: Various glibc headers no longer compatible with
    <linux/time.h>
  [23351] malloc: Remove unused code related to heap dumps and malloc
    checking
  [23363] stdio: stdio-common/tst-printf.c has non-free license
  [23396] regex: Regex equivalence regression in single-byte locales
  [23422] localedata: oc_FR: More updates of locale data
  [23442] build: New warning with GCC 8
  [23448] libc: Out of bounds access in IBM-1390 converter
  [23456] libc: Wrong index_cpu_LZCNT
  [23458] build: tst-get-cpu-features-static isn't added to tests
  [23459] libc: COMMON_CPUID_INDEX_80000001 isn't populated for Intel
    processors
  [23467] dynamic-link: x86/CET: A property note parser bug

\f
Version 2.27

Major new features:

* The GNU C Library can now be compiled with support for building static
  PIE executables (See --enable-static-pie in INSTALL).  These static PIE
  executables are like static executables but can be loaded at any address
  and provide additional security hardening benefits at the cost of some
  memory and performance.  When the library is built with --enable-static-pie
  the resulting libc.a is usable with GCC 8 and above to create static PIE
  executables using the GCC option '-static-pie'.  This feature is currently
  supported on i386, x86_64 and x32 with binutils 2.29 or later, and on
  aarch64 with binutils 2.30 or later.

* Optimized x86-64 asin, atan2, exp, expf, log, pow, atan, sin, cosf,
  sinf, sincosf and tan with FMA, contributed by Arjan van de Ven and
  H.J. Lu from Intel.

* Optimized x86-64 trunc and truncf for processors with SSE4.1.

* Optimized generic expf, exp2f, logf, log2f, powf, sinf, cosf and sincosf.

* In order to support faster and safer process termination the malloc API
  family of functions will no longer print a failure address and stack
  backtrace after detecting heap corruption.  The goal is to minimize the
  amount of work done after corruption is detected and to avoid potential
  security issues in continued process execution.  Reducing shutdown time
  leads to lower overall process restart latency, so there is benefit both
  from a security and performance perspective.

* The abort function terminates the process immediately, without flushing
  stdio streams.  Previous glibc versions used to flush streams, resulting
  in deadlocks and further data corruption.  This change also affects
  process aborts as the result of assertion failures.

* On platforms where long double has the IEEE binary128 format (aarch64,
  alpha, mips64, riscv, s390 and sparc), the math library now implements
  _Float128 interfaces for that type, as defined by ISO/IEC TS 18661-3:2015.
  These are the same interfaces added in version 2.26 for some platforms where
  this format is supported but is not the format of long double.

* On platforms with support for _Float64x (aarch64, alpha, i386, ia64,
  mips64, powerpc64le, riscv, s390, sparc and x86_64), the math library now
  implements interfaces for that type, as defined by ISO/IEC TS
  18661-3:2015.  These are corresponding interfaces to those supported for
  _Float128.

* The math library now implements interfaces for the _Float32, _Float64 and
  _Float32x types, as defined by ISO/IEC TS 18661-3:2015.  These are
  corresponding interfaces to those supported for _Float128.

* glibc now implements the memfd_create and mlock2 functions on Linux.

* Support for memory protection keys was added.  The <sys/mman.h> header now
  declares the functions pkey_alloc, pkey_free, pkey_mprotect, pkey_set,
  pkey_get.

* The copy_file_range function was added.

* Optimized memcpy, mempcpy, memmove, and memset for sparc M7.

* The ldconfig utility now processes `include' directives using the C/POSIX
  collation ordering.  Previous glibc versions used locale-specific
  ordering, the change might break systems that relied on that.

* Support for two grammatical forms of month names has been added.
  In a call to strftime, the "%B" and "%b" format specifiers will now
  produce the grammatical form required when the month is used as part
  of a complete date.  New "%OB" and "%Ob" specifiers produce the form
  required when the month is named by itself.  For instance, in Greek
  and in many Slavic and Baltic languages, "%B" will produce the month
  in genitive case, and "%OB" will produce the month in nominative case.

  In a call to strptime, "%B", "%b", "%h", "%OB", "%Ob", and "%Oh"
  are all valid and will all accept any known form of month
  name---standalone or complete, abbreviated or full.  In a call to
  nl_langinfo, the query constants MON_1..12 and ABMON_1..12 return
  the strings used by "%B" and "%b", respectively.  New query
  constants ALTMON_1..12 and _NL_ABALTMON_1..12 return the strings
  used by "%OB" and "%Ob", respectively.

  In a locale definition file, use "alt_mon" and "ab_alt_mon" to
  define the strings for %OB and %Ob, respectively; these have the
  same syntax as "mon" and "abmon".  These arrays are optional; if they
  are not provided then they have the same content as "mon" and "abmon",
  respectively.

  These features are provided for locales which define "alt_mon" and/or
  "ab_alt_mon" in their locale source data.  This release includes such
  alternative month name data for the following languages: Belarusian,
  Croatian, Greek, Lithuanian, Polish, Russian, and Ukrainian.

  This feature is currently a GNU extension, but it is expected to
  be added to the next revision of POSIX, and it is also already
  available on some BSD-derived operating systems.

  This feature will cause existing statically compiled applications
  to fail to load locales and fall back to the builtin C/POSIX locales.
  See notes below for other changes affecting compatibility.

* Support for the RISC-V ISA running on Linux has been added.  This port
  requires at least binutils-2.30, gcc-7.3.0, and linux-4.15; and is supported
  for the following ISA and ABI pairs:

    - rv64imac lp64
    - rv64imafdc lp64
    - rv64imafdc lp64d

Deprecated and removed features, and other changes affecting compatibility:

* Statically compiled applications attempting to load locales compiled for the
  GNU C Library version 2.27 will fail and fall back to the builtin C/POSIX
  locale.  The reason for this is that the addition of the new "%OB" and "%Ob",
  support for two grammatical forms of the month names, also extends the locale
  data binary format.  Static applications needing locale support must be
  recompiled to match the runtime and data they are deployed with. In some
  distributions there is an upgrade window where dynamically linked applications
  may use a new library but the old locale data and also fall back to the
  builtin C/POSIX locales; restarting the application process is sufficient to
  fix this.

* Support for statically linked applications which call dlopen is deprecated
  and will be removed in a future version of glibc.  Applications which call
  dlopen need to be linked dynamically instead.

* Support for old programs which use internal stdio data structures and
  functions is deprecated.  This includes programs which use the C++ streams
  provided by libstdc++ in GCC 2.95.  Programs which use the internal
  symbols _IO_adjust_wcolumn, _IO_default_doallocate, _IO_default_finish,
  _IO_default_pbackfail, _IO_default_uflow, _IO_default_xsgetn,
  _IO_default_xsputn, _IO_doallocbuf, _IO_do_write, _IO_file_attach,
  _IO_file_close, _IO_file_close_it, _IO_file_doallocate, _IO_file_fopen,
  _IO_file_init, _IO_file_jumps, _IO_fileno, _IO_file_open,
  _IO_file_overflow, _IO_file_read, _IO_file_seek, _IO_file_seekoff,
  _IO_file_setbuf, _IO_file_stat, _IO_file_sync, _IO_file_underflow,
  _IO_file_write, _IO_file_xsputn, _IO_flockfile, _IO_flush_all,
  _IO_flush_all_linebuffered, _IO_free_backup_area, _IO_free_wbackup_area,
  _IO_init, _IO_init_marker, _IO_init_wmarker, _IO_iter_begin, _IO_iter_end,
  _IO_iter_file, _IO_iter_next, _IO_least_wmarker, _IO_link_in,
  _IO_list_all, _IO_list_lock, _IO_list_resetlock, _IO_list_unlock,
  _IO_marker_delta, _IO_marker_difference, _IO_remove_marker, _IO_seekmark,
  _IO_seekwmark, _IO_str_init_readonly, _IO_str_init_static,
  _IO_str_overflow, _IO_str_pbackfail, _IO_str_seekoff, _IO_str_underflow,
  _IO_switch_to_main_wget_area, _IO_switch_to_wget_mode,
  _IO_unsave_wmarkers, _IO_wdefault_doallocate, _IO_wdefault_finish,
  _IO_wdefault_pbackfail, _IO_wdefault_setbuf, _IO_wdefault_uflow,
  _IO_wdefault_xsgetn, _IO_wdefault_xsputn, _IO_wdoallocbuf, _IO_wdo_write,
  _IO_wfile_jumps, _IO_wfile_overflow, _IO_wfile_sync, _IO_wfile_underflow,
  _IO_wfile_xsputn, _IO_wmarker_delta, or _IO_wsetb may stop working with a
  future version of glibc.  Unlike other symbol removals, these old
  applications will not be supported using compatibility symbols.

* On GNU/Linux, the obsolete Linux constant PTRACE_SEIZE_DEVEL is no longer
  defined by <sys/ptrace.h>.

* libm no longer supports SVID error handling (calling a user-provided
  matherr function on error) or the _LIB_VERSION variable to control error
  handling.  (SVID error handling and the _LIB_VERSION variable still work
  for binaries linked against older versions of the GNU C Library.)  The
  libieee.a library is no longer provided.  math.h no longer defines struct
  exception, or the macros X_TLOSS, DOMAIN, SING, OVERFLOW, UNDERFLOW,
  TLOSS, PLOSS and HUGE.

* The libm functions pow10, pow10f and pow10l are no longer supported for
  new programs.  Programs should use the standard names exp10, exp10f and
  exp10l for these functions instead.

* The mcontext_t type is no longer the same as struct sigcontext.  On
  platforms where it was previously the same, this changes the C++ name
  mangling for interfaces involving this type.

* The add-ons mechanism for building additional packages at the same time as
  glibc has been removed.  The --enable-add-ons configure option is now
  ignored.

* The --without-fp configure option is now ignored.  Whether hardware
  floating-point instructions are used is now configured based on whether
  the compiler used at configure time (without any options implied by a
  --with-cpu= configure option) uses such instructions.

* The res_hnok, res_dnok, res_mailok and res_ownok functions now check that
  the specified string can be parsed as a domain name.

* In the malloc_info output, the <heap> element may contain another <aspace>
  element, "subheaps", which contains the number of sub-heaps.

* The libresolv function p_secstodate is no longer supported for new
  programs.

* The tilepro-*-linux-gnu configuration is no longer supported.

* The nonstandard header files <libio.h> and <_G_config.h> are deprecated
  and will be removed in a future release.  Software that is still using
  either header should be updated to use standard <stdio.h> interfaces
  instead.

  libio.h was originally the header for a set of supported GNU extensions,
  but they have not been maintained as such in many years, they are now
  standing in the way of improvements to stdio, and we don't think there are
  any remaining external users.  _G_config.h was never intended for public
  use, but predates the bits convention.

Changes to build and runtime requirements:

* bison version 2.7 or later is required to generate code in the 'intl'
  subdirectory.

Security related changes:

  CVE-2009-5064: The ldd script would sometimes run the program under
  examination directly, without preventing code execution through the
  dynamic linker.  (The glibc project disputes that this is a security
  vulnerability; only trusted binaries must be examined using the ldd
  script.)

  CVE-2017-15670: The glob function, when invoked with GLOB_TILDE,
  suffered from a one-byte overflow during ~ operator processing (either
  on the stack or the heap, depending on the length of the user name).
  Reported by Tim Rühsen.

  CVE-2017-15671: The glob function, when invoked with GLOB_TILDE,
  would sometimes fail to free memory allocated during ~ operator
  processing, leading to a memory leak and, potentially, to a denial
  of service.

  CVE-2017-15804: The glob function, when invoked with GLOB_TILDE and
  without GLOB_NOESCAPE, could write past the end of a buffer while
  unescaping user names.  Reported by Tim Rühsen.

  CVE-2017-17426: The malloc function, when called with an object size near
  the value SIZE_MAX, would return a pointer to a buffer which is too small,
  instead of NULL.  This was a regression introduced with the new malloc
  thread cache in glibc 2.26.  Reported by Iain Buclaw.

  CVE-2017-1000408: Incorrect array size computation in _dl_init_paths leads
  to the allocation of too much memory.  (This is not a security bug per se,
  it is mentioned here only because of the CVE assignment.)  Reported by
  Qualys.

  CVE-2017-1000409: Buffer overflow in _dl_init_paths due to miscomputation
  of the number of search path components.  (This is not a security
  vulnerability per se because no trust boundary is crossed if the fix for
  CVE-2017-1000366 has been applied, but it is mentioned here only because
  of the CVE assignment.)  Reported by Qualys.

  CVE-2017-16997: Incorrect handling of RPATH or RUNPATH containing $ORIGIN
  for AT_SECURE or SUID binaries could be used to load libraries from the
  current directory.

  CVE-2018-1000001: Buffer underflow in realpath function when getcwd function
  succeeds without returning an absolute path due to unexpected behaviour
  of the Linux kernel getcwd syscall.  Reported by halfdog.

  CVE-2018-6485: The posix_memalign and memalign functions, when called with
  an object size near the value of SIZE_MAX, would return a pointer to a
  buffer which is too small, instead of NULL.  Reported by Jakub Wilk.

  CVE-2018-6551: The malloc function, when called with an object size near
  the value of SIZE_MAX, would return a pointer to a buffer which is too
  small, instead of NULL.

The following bugs are resolved with this release:

  [866] glob: glob should match dangling symlinks
  [1062] glob: sysdeps/generic/glob.c merge from gnulib (part 3 of 3)
  [2522] localedata: ca_ES@valencia: new Valencian (meridional Catalan)
    locale
  [5997] math: Very slow execution of sinf function
  [10580] localedata: hr_HR: updated locale
  [10871] locale: 'mon' array should contain both nominative and genitive
    cases
  [12349] localedata: eu_ES: incorrect thousands separator
  [13605] localedata: shn_MM: new Shan locale
  [13805] localedata: ru_RU: currency should use ',' as radix point
  [13953] localedata: km_KH: locale update
  [13994] localedata: mjw_IN: new locale
  [14121] build: make writes .mo files in po directory
  [14333] libc: Fix the race between atexit() and exit()
  [14681] dynamic-link: _dl_get_origin leaks memory via executable link map.
  [14925] localedata: bn_*: LC_IDENTIFICATION.language key should be
    "Bangla"
  [15260] localedata: LC_MESSAGES.{yes,no}{str,expr}: various errors
  [15261] localedata: LC_MESSAGES.yesexpr/noexpr: inconsistent use of full-
    width Latin characters
  [15332] localedata: es_CU: locale update
  [15436] stdio: Don't close or flush stdio streams on abort
  [15537] localedata: lv_LV: invalid collation for Latvian diacritical
    letters
  [16148] localedata: ca_ES: incorrect thousands separator
  [16750] dynamic-link: ldd should not try to execute the binaries
    (CVE-2009-5064)
  [16777] localedata: pl_PL: incorrect thousands separator in locale
  [16905] localedata: hanzi: new collation
  [17563] localedata: cmn_TW: add hanzi collation
  [17750] localedata: wrong collation order of diacritics in most locales
  [17804] libc: scandirat fails with ENOMEM because it checks for errno even
    if malloc succeeded
  [17956] build: Build fails on missing definitions from header file
    nss/nss.h when Mozilla NSS is used for cryptography
  [18203] libc: realpath() does not handle unreachable paths correctly
  [18572] dynamic-link: [arm] Lazy TLSDESC relocation has data race
  [18812] localedata: kab_DZ: new Kabyle Algeria locale
  [18822] libc: Internal functions are called via PLT
  [18858] string: _HAVE_STRING_ARCH_xxx aren't defined for i386 nor x86_64
  [19170] libc: __gmon_start__ defined in hppa in crtn.S
  [19574] libc: glibc should support building static PIE binaries
  [19852] localedata: charmaps/UTF-8: incorrect wcwidth for U+3099 and
    U+309A
  [19971] glob: glob: Do not skip entries with zero d_ino values
  [19982] localedata: fr.po: spelling mistake for error code EXDEV
  [20008] localedata: km_KH: convert to translit_neutral
  [20009] localedata: tr_TR: convert LC_CTYPE to i18n
  [20142] math: [x86_64] Add SSE4.1 trunc, truncf
  [20204] dynamic-link: _dl_open_hook and _dlfcn_hook hardening
  [20482] localedata: de_CH: abbreviated weekdays should be two letters
  [20498] localedata: miq_NI: new Mískitu / Miskito (miq) language locale
    for Nicaragua
  [20532] nss: getaddrinfo uses errno and h_errno without guaranteeing
    they're set, wrong errors returned by gaih_inet when lookup functions
    are not found.
  [20756] localedata: [PATCH] Use Unicode wise thousands separator
  [20826] network: posix/tst-getaddrinfo5 fails on hosts without network
    access
  [20952] localedata: yuw_PG: new locale
  [21084] localedata: charmaps/IBM858: new codepage
  [21161] manual: [PATCH] fix typo in manual/arith.texi on strtoul prototype
  [21242] libc: assert gives pedantic warning in old gcc versions
  [21265] dynamic-link: _dl_runtime_resolve isn't compatible with Intel C++
    __regcall calling convention
  [21309] math: signed integer overflow in sysdeps/ieee754/dbl-64/e_pow.c
  [21326] libc: C99 functions are not declared for C++11 and later if
    _GNU_SOURCE is not predefined by g++
  [21457] libc: sys/ucontext.h namespace
  [21530] libc: tmpfile() should be implemented using O_TMPFILE
  [21660] math: GCC fails to compile a formula with tgmath.h
  [21672] nptl: sys-libs/glibc on ia64 crashes on thread exit: signal
    SIGSEGV, Segmentation fault: pthread_create.c:432: __madvise
    (pd->stackblock, freesize - PTHREAD_STACK_MIN, MADV_DONTNEED);
  [21684] math: tgmath.h handling of complex integers
  [21685] math: tgmath.h handling of bit-fields
  [21686] math: tgmath.h handling of __int128
  [21706] localedata: yesstr and nostr  are missing for Breton [LC_MESSAGES]
    locale
  [21745] libc: [powerpc64le] Extra PLT reference with --enable-stack-
    protector=all
  [21750] localedata: column width of characters incompatible with classical
    wcwidth
  [21754] malloc: malloc: Perform as little work as possible after heap
    consistency check failures
  [21780] libc: hppa: p{read,write}v2 does not set ENOSUP on invalid flag
  [21790] libc: Missing __memset_zero_constant_len_parameter in libc.so
  [21791] string: Unused XXX_chk_XXX functions in libc.a
  [21815] dynamic-link: FAIL: elf/tst-prelink-cmp with GCC is defaulted to
    PIE
  [21836] localedata: Removed redundant data (LC_MONETARY) in various Indian
    locales
  [21845] localedata: Added new Locale bho_NP
  [21853] localedata: Fix abday Which looks same as day in zh_SG
  [21854] localedata: Added New Locale en_SC
  [21864] libc: xmalloc.o is compiled with -DMODULE_NAME=libc
  [21871] dynamic-link: _dl_runtime_resolve_avx_opt is slower than
    _dl_runtime_resolve_avx_slow
  [21885] network: getaddrinfo: gethosts does not release resolver context
    on memory allocation failure
  [21899] libc: XPG4.2 sigaction namespace
  [21908] dynamic-link: dynamic linker broke on ia64 (mmap2 consolidation is
    the suspect)
  [21913] libc: static binaries SIGSEGV in __brk when host's gcc is pie-by-
    default (i386)
  [21915] nss: nss_files can return with NSS_STATUS_SUCCESS and a clobbered
    errno value, causing getaddrinfo to fail
  [21920] localedata: Fix p_cs_precedes/n_cs_precedes for mt_MT
  [21922] network: getaddrinfo with AF_INET/AF_INET6 returns EAI_NONAME
    instead of EAI_NODATA
  [21928] libc: sys/ptrace.h: remove obsolete temporary development Linux
    constant PTRACE_SEIZE_DEVEL
  [21930] math: C-only gcc builtins used in <math.h> isinf
  [21932] network: Unpaired __resolv_context_get in generic get*_r
    implementation
  [21941] math: powerpc: Wrong register constraint for xssqrtqp in sqrtf128
  [21944] libc: sigval namespace
  [21951] localedata: Update hanzi collation by stroke
  [21955] math: Wrong alignment of  L(SP_RANGE)/L(SP_INF_0) in
    sysdeps/x86_64/fpu/e_expf.S
  [21956] libc: Stack allocation in MIPS syscall impl (ubounded stack
    allocation in syscall loops)
  [21959] localedata: Fix Country name for xh_ZA
  [21960] localedata: Fix abmon for bem_ZM
  [21966] math: AVX2 mathvec functions use FMA without checking
  [21967] math: When 512-bit AVX2 wrapper functions in mathvec are used?
  [21971] localedata: Added New Locale for mfe_MU
  [21972] libc: assert macro requires operator== (int) for its argument type
  [21973] math: [sparc] libm missing sqrtl compat symbol
  [21974] libc: Remove __bb_init_func and __bb_exit_func
  [21982] string: stratcliff.c: error: assuming signed overflow does not
    occur with -O3
  [21986] stdio: __guess_grouping is called incorrectly
  [21987] math: [sparc32] wrong bits/long-double.h installed
  [22019] localedata: Wrong placement of monetary symbol in el_GR (negative
    amounts)
  [22022] localedata: Missing country_name for mni_IN
  [22023] localedata: Removed redundant data (LC_TIME and LC_MESSAGES) for
    niu_NZ
  [22025] locale: iconv: Inconsistency between pointer mangling and NULL
    checks
  [22026] locale: iconv_open: heap overflow on gconv_init failure
  [22028] math: bits/math-finite.h _MSUF_ expansion namespace
  [22035] math: [m68k] bits/math-inline.h macro namespace
  [22038] localedata: Fix abbreviated weeks and months for Somali
  [22044] localedata: Remove redundant data for Limburgish Language
  [22050] malloc: Linking with -lmcheck does not hook
    __malloc_initialize_hook correctly
  [22051] libc: zero terminator in the middle of glibc's .eh_frame
  [22052] malloc: malloc failed to compile with GCC 7 and -O3
  [22070] localedata: charmaps/UTF-8: wcwidth for
    Prepended_Concatenation_Mark codepoints set to 0 (should be 1)
  [22074] localedata: charmaps/UTF-8: wcwidth for U+1160-U+11FF (Hangul
    Jungseong and Jongseong) should be 0
  [22078] nss: nss_files performance issue in multi mode
  [22082] math: bits/math-finite.h exp10 condition
  [22086] libc: pcprofiledump incorrect cross-endian condition
  [22093] dynamic-link: ld.so no longer searches in .../x86_64
  [22095] network: Name server address allocation memory leak in resolv.conf
    parsing after OOM
  [22096] network: __resolv_conf_attach can incorrectly free passed conf
    object
  [22100] localedata: om_KE: LC_TIME: copy redundant data from om_ET
  [22101] dynamic-link: Dynamic loader must ignore "debug" shared objects
    e.g. ET_GNU_DEBUG_*
  [22111] malloc: malloc: per thread cache is not returned when thread exits
  [22112] localedata: Fix LC_TELEPHONE/LC_NAME for az_AZ
  [22134] libc: [linux] implement fexecve with execveat
  [22142] libc: [powerpc] printf outputs a wrong value of DBL_MAX on ppc64 and
    ppc64le
  [22145] libc: ttyname() gives up too early in the face of namespaces
  [22146] math: C++ build issue with float128 on x86_64
  [22153] nptl: nptl: save error code before process termination
  [22156] libc: [hppa,ia64,microblaze] Executable stack default
  [22159] malloc: malloc: MALLOC_CHECK_ broken with --enable-tunables=no
  [22161] nscd: nscd cache prune for netgroups hangs after timeout bump
  [22165] libc: [hppa] Text relocations in libc.so
  [22180] libc: destructor registered via __cxa_atexit is called twice
  [22183] glob: commit 5554304f0ddd ("posix: Allow glob to match dangling
    symlinks") cause "make" segfaults
  [22189] math: [powerpc] math_private.h definitions of math_opt_barrier and
    math_force_eval
  [22207] libc: FAIL: stdlib/test-atexit-race
  [22225] math: nearbyint arithmetic moved before feholdexcept
  [22229] math: [sparc32] missing copysignl, fabsl, fmal compat symbols
  [22235] math: iscanonical in C++ and float128
  [22243] math: log2(0) and log10(0) are wrong in downward rounding without
    the svid compat wrapper
  [22244] math: ynf and yn are wrong without the svid compat wrapper
  [22273] libc: Improper assert in Linux posix_spawn implementation
  [22284] libc: -pg -pie doesn't work
  [22292] locale: localedef exits with error 4 when it should be error 1
  [22294] locale: Allow "" for int_currency_symbol definition in locales.
  [22295] locale: Don't warn on non-symbolic characters in locale sources in
    --verbose.
  [22296] math: glibc 2.26: signbit build issue with Gcc 5.5.0 on x86_64
  [22298] nptl: x32: lockups on recursive pthread_mutex_lock after upgrade
    to 2.26
  [22299] dynamic-link: Problem with $PLATFORM on x86_64 platform
  [22320] glob: Buffer overflow in glob with GLOB_TILDE (CVE-2017-15670)
  [22321] libc: sysconf(_SC_IOV_MAX) returns -1 on Linux
  [22322] libc: [mips64] wrong bits/long-double.h installed
  [22325] glob: Memory leak in glob with GLOB_TILDE (CVE-2017-15671)
  [22332] glob: Buffer overflow in glob with GLOB_TILDE in unescaping
    (CVE-2017-15804)
  [22336] localedata: cs_CZ LC_COLLATE does not use i18n
  [22343] malloc: Integer overflow in posix_memalign
  [22347] libc: getrandom() returns the number of bytes that were copied  to
    the buffer even though the comments say "Return 0 on success and -1 on
    failure."
  [22353] string: sysdeps/i386/i586/strcpy.S isn't maintainable
  [22362] libc: Installed crt1.o, crti,.o and crtn.o files are used with
    -m32
  [22370] dynamic-link: Incorrect note padding check
  [22375] libc: malloc returns pointer from tcache_get when should return
    NULL (CVE-2017-17426)
  [22377] math: iseqsig, float128 and C++
  [22382] localedata: Error in tpi_PG locale
  [22387] localedata: Replace unicode sequences <Uxxxx> for characters
    inside the ASCII printable range
  [22402] math: [powerpc64le] __MATH_TG does not support _Float128 for
    -mlong-double-64
  [22403] localedata: Slash needs escaping in some locales
  [22408] malloc: malloc_info access heaps without arena lock, ignores heaps
  [22409] network: res_hnok does not accept some host names used on the
    Internet
  [22412] network: res_dnok, res_hnok should perform syntax checks
  [22413] network: ns_name_pton ignores syntactically invalid trailing
    backslash
  [22415] stdio: setvbuf can lead to invalid free/segfault
  [22432] build: Non-deterministic build
  [22439] malloc: malloc_info should compute summary statistics for all sub-
    heaps in an arena
  [22442] network: if_nametoindex could report index for the wrong
    networking interface
  [22446] build: aliasing violation calling readlink in handle_request
  [22447] build: unsafe call to strlen with a non-string in getlogin_r.c
  [22457] libc: Generic preadv/pwritev incorrectly calls __posix_memalign
  [22459] libc: FAIL: elf/check-localplt with __stack_chk_fail related to
    __nscd_hash/__nss_hash
  [22463] network: p_secstodate overflow handling
  [22469] localedata: pl_PL LC_COLLATE does not use i18n
  [22478] libc: sigwait can fail with EINTR
  [22505] libc: ldconfig processes include directive in locale-specific
    order
  [22515] localedata: hsb_DE LC_COLLATE does not use copy "iso14651_t1"
  [22517] localedata: et_EE LC_COLLATE does not use copy "iso14651_t1"
  [22519] localedata: is_IS LC_COLLATE does not use copy "iso14651_t1"
  [22524] localedata: lt_LT  LC_COLLATE does not use copy "iso14651_t1"
  [22527] localedata: tr_TR  LC_COLLATE does not use copy "iso14651_t1"
  [22534] localedata: Collation rules for Serbian and Bosnian should be the
    same as for Croatian
  [22561] math: [DR#471] cacosh (0 + iNaN) should return NaN +/- i pi/2
  [22568] math: [DR#471] ctanh (0 + iNaN), ctanh (0 + i Inf)
  [22577] libc: missing newline after "cannot allocate TLS data structures
    for initial thread"
  [22588] manual: manual/conf.texi: missing underscore in front of
    SC_SSIZE_MAX
  [22593] math: nextafter and nexttoward are declared with const attribute
  [22596] manual: manual: finite(nan) wrongly described as returning nonzero
  [22603] string: ia64 memchr overflows internal pointer check
  [22605] libc: SH clone does not set the exit code correctly
  [22606] dynamic-link: Incorrect array size computation in _dl_init_paths
    (CVE-2017-1000408)
  [22607] dynamic-link: Buffer Overflow in _dl_init_paths (CVE-2017-1000409)
  [22611] malloc: malloc/tst-realloc wrongly assumes that errno must not be
    modified in case of success
  [22614] build: gcc: error: unrecognized command line option ‘-no-pie’
  [22615] manual: manual: ambiguous wording about errno value in case of
    success
  [22624] libc: MIPS setjmp() saves incorrect 'o0' register in --enable-
    stack-protector=all
  [22625] dynamic-link: RPATH $ORIGIN replaced by PWD for AT_SECURE/SUID
    binaries or if /proc is not mounted (CVE-2017-16997)
  [22627] dynamic-link: $ORIGIN in $LD_LIBRARY_PATH is substituted twice
  [22630] build: $(no-pie-ldflag) is no longer effective
  [22631] math: [m68k] Bad const attributes in bits/mathinline.h
  [22635] nptl: pthread_self returns NULL before libpthread is loaded
  [22636] nptl: PTHREAD_STACK_MIN is too small on x86-64
  [22637] nptl: guard size is subtracted from thread stack size instead of
    adding it on top
  [22648] libc: getrlimit/setrlimit with RLIM_INFINITY broken on alpha
  [22657] localedata: hu_HU: Avoid double space in date
  [22660] math: fmax, fmin sNaN handling on alpha
  [22664] libc: New warning of GCC8
  [22665] math: alpha: ceil and floor raise inexact exceptions
  [22666] math: alpha: trunc raise inexact exceptions
  [22667] libc: makecontext lacks stack alignment on i386
  [22678] libc: prlimit fails for RLIM_INFINITY values on 32-bit machines
  [22679] libc: getcwd(3) can succeed without returning an absolute path
    (CVE-2018-1000001)
  [22685] libc: PowerPC: Static AT_SECURE binaries segfault with lock-
    elision and tunables
  [22687] math: [powerpc-nofpu] complex long double functions spurious
    "invalid" exception
  [22688] math: [powerpc-nofpu] remainderl wrong sign of zero result
  [22690] math: [ldbl-128ibm] lrintl, lroundl missing "invalid" exceptions
  [22691] math: [powerpc-nofpu] fmaxmagl, fminmagl spurious "invalid"
    exception
  [22693] math: [ldbl-128ibm] log1pl (-qNaN) spurious "invalid" exception
  [22697] math: [powerpc] llround spurious "inexact" exceptions on 32-bit
    power4
  [22701] nis: Incomplete removal of libnsl
  [22702] math: [powerpc-nofpu] nearbyintl traps with trapping "inexact"
  [22707] libc: Missing defines in elf.h for DF_1_STUB and DF_1_PIE.
  [22715] dynamic-link: FAIL: elf/tst-audit10
  [22719] libc: Backtrace tests fail on hppa
  [22742] libc: [aarch64] mcontext_t __reserved field got renamed
  [22743] nptl: __pthread_register_cancel corrupts stack after f81ddabffd
  [22765] crypt: (struct crypt_data *data)->initialized is not set to zero
    before the first call to crypt_r () in crypt/badsalttest.c

\f
Version 2.26

Major new features:

* A per-thread cache has been added to malloc. Access to the cache requires
  no locks and therefore significantly accelerates the fast path to allocate
  and free small amounts of memory. Refilling an empty cache requires locking
  the underlying arena. Performance measurements show significant gains in a
  wide variety of user workloads. Workloads were captured using a special
  instrumented malloc and analyzed with a malloc simulator. Contributed by
  DJ Delorie with the help of Florian Weimer, and Carlos O'Donell.

* Unicode 10.0.0 Support: Character encoding, character type info, and
  transliteration tables are all updated to Unicode 10.0.0, using
  generator scripts contributed by Mike FABIAN (Red Hat).
  These updates cause user visible changes, especially the changes in
  wcwidth for many emoji characters cause problems when emoji sequences
  are rendered with pango, see for example:
  https://bugzilla.gnome.org/show_bug.cgi?id=780669#c5

* Collation of Hungarian has been overhauled and is now consistent with "The
  Rules of Hungarian Orthography, 12th edition" (Bug 18934).  Contributed by
  Egmont Koblinger.

* Improvements to the DNS stub resolver, contributed by Florian Weimer:

  - The GNU C Library will now detect when /etc/resolv.conf has been
    modified and reload the changed configuration.  The new resolver option
    “no-reload” (RES_NORELOAD) disables this behavior.

  - The GNU C Library now supports an arbitrary number of search domains
    (configured using the “search” directive in /etc/resolv.conf);
    previously, there was a hard limit of six domains.  For backward
    compatibility, applications that directly modify the ‘_res’ global
    object are still limited to six search domains.

  - When the “rotate” (RES_ROTATE) resolver option is active, the GNU C
    Library will now randomly pick a name server from the configuration as a
    starting point.  (Previously, the second name server was always used.)

* The tunables feature is now enabled by default.  This allows users to tweak
  behavior of the GNU C Library using the GLIBC_TUNABLES environment variable.

* New function reallocarray, which resizes an allocated block (like realloc)
  to the product of two sizes, with a guaranteed clean failure upon integer
  overflow in the multiplication.  Originally from OpenBSD, contributed by
  Dennis Wölfing and Rüdiger Sonderfeld.

* New wrappers for the Linux-specific system calls preadv2 and pwritev2.
  These are extended versions of preadv and pwritev, respectively, taking an
  additional flags argument.  The set of supported flags depends on the
  running kernel; full support currently requires kernel 4.7 or later.

* posix_spawnattr_setflags now supports the flag POSIX_SPAWN_SETSID, to
  create a new session ID for the spawned process.  This feature is
  scheduled to be added to the next major revision of POSIX; for the time
  being, it is available under _GNU_SOURCE.

* errno.h is now safe to use from C-preprocessed assembly language on all
  supported operating systems.  In this context, it will only define the
  Exxxx constants, as preprocessor macros expanding to integer literals.

* On ia64, powerpc64le, x86-32, and x86-64, the math library now implements
  128-bit floating point as defined by ISO/IEC/IEEE 60559:2011 (IEEE
  754-2008) and ISO/IEC TS 18661-3:2015.  Contributed by Paul E. Murphy,
  Gabriel F. T. Gomes, Tulio Magno Quites Machado Filho, and Joseph Myers.

  To compile programs that use this feature, the compiler must support
  128-bit floating point with the type name _Float128 (as defined by TS
  18661-3) or __float128 (the nonstandard name used by GCC for C++, and for
  C prior to version 7).  _GNU_SOURCE or __STDC_WANT_IEC_60559_TYPES_EXT__
  must be defined to make the new interfaces visible.

  The new functions and macros correspond to those present for other
  floating-point types (except for a few obsolescent interfaces not
  supported for the new type), with F128 or f128 suffixes; for example,
  strtof128, HUGE_VAL_F128 and cosf128.  Following TS 18661-3, there are no
  printf or scanf formats for the new type; the strfromf128 and strtof128
  interfaces should be used instead.

Deprecated and removed features, and other changes affecting compatibility:

* The synchronization that pthread_spin_unlock performs has been changed to
  now be equivalent to a C11 atomic store with release memory order to the
  spin lock's memory location.  Previously, several (but not all)
  architectures used stronger synchronization (e.g., containing what is
  often called a full barrier).  This change can improve performance, but
  may affect odd fringe uses of spin locks that depend on the previous
  behavior (e.g., using spin locks as atomic variables to try to implement
  Dekker's mutual exclusion algorithm).

* The port to Native Client running on ARMv7-A (--host=arm-nacl) has been
  removed.

* Sun RPC is deprecated.  The rpcgen program, librpcsvc, and Sun RPC headers
  will only be built and installed when the GNU C Library is configured with
  --enable-obsolete-rpc.  This allows alternative RPC implementations, such
  as TIRPC or rpcsvc-proto, to be used.

* The NIS(+) name service modules, libnss_nis, libnss_nisplus, and
  libnss_compat, are deprecated, and will not be built or installed by
  default.

  The NIS(+) support library, libnsl, is also deprecated.  By default, a
  compatibility shared library will be built and installed, but not headers
  or development libraries. Only a few NIS-related programs require this
  library.  (In particular, the GNU C Library has never required programs
  that use 'gethostbyname' to be linked with libnsl.)

  Replacement implementations based on TIRPC, which additionally support
  IPv6, are available from <https://github.com/thkukuk/>.  The configure
  option --enable-obsolete-nsl will cause libnsl's headers, and the NIS(+)
  name service modules, to be built and installed.

* The DNS stub resolver no longer performs EDNS fallback.  If EDNS or DNSSEC
  support is enabled, the configured recursive resolver must support EDNS.
  (Responding to EDNS-enabled queries with responses which are not
  EDNS-enabled is fine, but FORMERR responses are not.)

* res_mkquery and res_nmkquery no longer support the IQUERY opcode.  DNS
  servers have not supported this opcode for a long time.

* The _res_opcodes variable has been removed from libresolv.  It had been
  exported by accident.

* <string.h> no longer includes inline versions of any string functions,
  as this kind of optimization is better done by the compiler.  The macros
  __USE_STRING_INLINES and __NO_STRING_INLINES no longer have any effect.

* The nonstandard header <xlocale.h> has been removed.  Most programs should
  use <locale.h> instead.  If you have a specific need for the definition of
  locale_t with no other declarations, please contact
  libc-alpha@sourceware.org and explain.

* The obsolete header <sys/ultrasound.h> has been removed.

* The obsolete signal constant SIGUNUSED is no longer defined by <signal.h>.

* The obsolete function cfree has been removed.  Applications should use
  free instead.

* The stack_t type no longer has the name struct sigaltstack.  This changes
  the C++ name mangling for interfaces involving this type.

* The ucontext_t type no longer has the name struct ucontext.  This changes
  the C++ name mangling for interfaces involving this type.

* On M68k GNU/Linux and MIPS GNU/Linux, the fpregset_t type no longer has
  the name struct fpregset.  On Nios II GNU/Linux, the mcontext_t type no
  longer has the name struct mcontext.  On SPARC GNU/Linux, the struct
  mc_fq, struct rwindow, struct fpq and struct fq types are no longer
  defined in sys/ucontext.h, the mc_fpu_t type no longer has the name struct
  mc_fpu, the gwindows_t type no longer has the name struct gwindows and the
  fpregset_t type no longer has the name struct fpu.  This changes the C++
  name mangling for interfaces involving those types.

* On S/390 GNU/Linux, the constants defined by <sys/ptrace.h> have been
  synced with the kernel:

    - PTRACE_GETREGS, PTRACE_SETREGS, PTRACE_GETFPREGS and PTRACE_SETFPREGS
      are not supported on this architecture and have been removed.

    - PTRACE_SINGLEBLOCK, PTRACE_SECCOMP_GET_FILTER, PTRACE_PEEKUSR_AREA,
      PTRACE_POKEUSR_AREA, PTRACE_GET_LAST_BREAK, PTRACE_ENABLE_TE,
      PTRACE_DISABLE_TE and PTRACE_TE_ABORT_RAND have been added.

  Programs that assume the GET/SETREGS ptrace requests are universally
  available will now fail to build, instead of malfunctioning at runtime.

Changes to build and runtime requirements:

* Linux kernel 3.2 or later is required at runtime, on all architectures
  supported by that kernel.  (This is a change from version 2.25 only for
  x86-32 and x86-64.)

* GNU Binutils 2.25 or later is now required to build the GNU C Library.

* On most architectures, GCC 4.9 or later is required to build the GNU C
  Library.  On powerpc64le, GCC 6.2 or later is required.

  Older GCC versions and non-GNU compilers are still supported when
  compiling programs that use the GNU C Library.  (We do not know exactly
  how old, and some GNU extensions to C may be _de facto_ required.  If you
  are interested in helping us make this statement less vague, please
  contact libc-alpha@sourceware.org.)

Security related changes:

* The DNS stub resolver limits the advertised UDP buffer size to 1200 bytes,
  to avoid fragmentation-based spoofing attacks (CVE-2017-12132).

* LD_LIBRARY_PATH is now ignored in binaries running in privileged AT_SECURE
  mode to guard against local privilege escalation attacks (CVE-2017-1000366).

* Avoid printing a backtrace from the __stack_chk_fail function since it is
  called on a corrupt stack and a backtrace is unreliable on a corrupt stack
  (CVE-2010-3192).

* A use-after-free vulnerability in clntudp_call in the Sun RPC system has been
  fixed (CVE-2017-12133).

The following bugs are resolved with this release:

  [984] network: Respond to changed resolv.conf in gethostbyname
  [5010] network: sunrpc service cleanup causes unwanted port mapper traffic
  [12068] localedata: sc_IT: misspelled yesexpr/day/abday/mon/abmon/date_fmt
    fields
  [12189] libc: __stack_chk_fail should not attempt a backtrace
    (CVE-2010-3192)
  [14096] time: Race condition on timezone/tst-timezone.out
  [14172] localedata: az_IR: new locale
  [14995] build: glibc fails to build if gold is the default linker, even if
    ld.bfd is available
  [15998] build: [powerpc] Set arch_minimum_kernel for powerpc LE
  [16637] network: inet_pton function is accepting IPv6 with bad format
  [16640] string: string/strtok.c: undefined behaviour inconsistent between
    x86 and other generic code
  [16875] localedata: ko_KR: fix lang_name
  [17225] localedata: ar_SY: localized month names for May and June are
    incorrect
  [17297] localedata: da_DK: wrong date_fmt string
  [18907] stdio: Incorrect order of __wur __THROW in <printf.h>
  [18934] localedata: hu_HU: collate: fix multiple bugs and add tests
  [18988] nptl: pthread wastes memory with mlockall(MCL_FUTURE)
  [19066] localedata: ar_SA abbreviated day and month names are in English
  [19569] network: resolv: Support an arbitrary number of search domains
  [19570] network: Implement random DNS server selection in the stub
    resolver
  [19838] locale: localedef fails on PA-RISC
  [19919] localedata: iso14651_t1_common: Correct the Malayalam sorting
    order of 0D36 and 0D37
  [19922] localedata: iso14651_t1_common: Define collation for Malayalam
    chillu characters
  [20098] libc: FAIL: debug/backtrace-tst on hppa
  [20257] network: sunrpc: clntudp_call does not enforce timeout when
    receiving data
  [20275] localedata: locale day/abday/mon/abmon should not have trailing
    whitespace
  [20313] localedata: Update locale data to Unicode 9.0
  [20424] manual: Document how to provide a malloc replacement
  [20496] localedata: agr_PE: new language locale Awajún / Aguaruna (agr)
    for Peru
  [20686] locale: Add el_GR@euro to SUPPORTED.
  [20831] dynamic-link: _dl_map_segments does not test for __mprotect
    failures consistently
  [21015] dynamic-link: Document and fix --enable-bind-now
  [21016] nptl: pthread_cond support is broken on hppa
  [21029] libc: glibc-2.23 (and later) fails to compile with -fno-omit-
    frame-pointer on i386
  [21049] libc: segfault in longjmp_chk() due to clobbered processor
    register
  [21075] libc: unused assigment to %g4 in sparc/sparc{64,32}/clone.S
  [21088] libc: Build fails with --enable-static-nss
  [21094] math: cosf(1.57079697) has 3 ulp error on targets where the
    generic c code is used
  [21109] libc: Tunables broken on big-endian
  [21112] math: powf has large ulp errors with base close to 1 and exponent
    around 4000
  [21115] network: sunrpc: Use-after-free in error path in clntudp_call
    (CVE-2017-12133)
  [21120] malloc: glibc malloc is incompatible with GCC 7
  [21130] math: Incorrect return from y0l (-inf) and y1l (-inf) when linking
    with -lieee
  [21134] math: Exception (divide by zero) not set for y0/y1 (0.0) and y0/y1
    (-0.0) when linking with -lieee
  [21171] math: log10, log2 and lgamma return incorrect results
  [21179] libc: handle R_SPARC_DISP64 and R_SPARC_REGISTER relocs
  [21182] libc: __memchr_sse2: regression in glibc-2.25 on i686
  [21207] localedata: ce_RU: update weekdays from CLDR
  [21209] dynamic-link: LD_HWCAP_MASK read in setuid binaries
  [21217] localedata: Update months from CLDR-31
  [21232] libc: miss posix_fadvise64 on MIPS64 when static linking
  [21243] libc: support_delete_temp_file should issue warning for failed
    remove()
  [21244] libc: support resolv_test_start() socket fd close should be
    checked for errors.
  [21253] libc: localedef randomly segfaults when using -fstack-check due to
    new posix_spawn implementation
  [21258] dynamic-link: Branch predication in _dl_runtime_resolve_avx512_opt
    leads to lower CPU frequency
  [21259] libc: [alpha] termios.h missing IXANY for POSIX
  [21261] libc: [sparc64] bits/setjmp.h namespace
  [21267] network: [mips] bits/socket.h IOC* namespace
  [21268] libc: [alpha] termios.h NL2, NL3 namespace
  [21270] libc: mmap64 silently truncates large offset values
  [21275] libc: posix_spawn always crashes on ia64 now
  [21277] libc: [alpha] termios.h missing IUCLC for UNIX98 and older
  [21280] math: [powerpc] logbl for POWER7 return incorrect results
  [21289] libc: Incorrect declaration for 32-bit platforms with
    _FILE_OFFSET_BITS=64 causes build error
  [21295] network: GETAI(AF_UNSPEC) drops IPv6 addresses if nss module does
    not support gethostbyname4_r
  [21298] nptl: rwlock can deadlock on frequent reader/writer phase
    switching
  [21338] malloc: mallopt M_ARENA_MAX doesn't set the maximum number of
    arenas
  [21340] libc: Support POSIX_SPAWN_SETSID
  [21357] libc: unwind-dw2-fde deadlock when using AddressSanitizer
  [21359] network: ns_name_pack needs additional byte in destination buffer
  [21361] network: resolv: Reduce advertised EDNS0 buffer size to guard
    against fragmentation attacks (CVE-2017-12132)
  [21369] network: resolv: Remove EDNS fallback
  [21371] libc: Missing timespec definition when compiled with _XOPEN_SOURCE
    and _POSIX_C_SOURCE
  [21386] nptl: Assertion in fork for distinct parent PID is incorrect
  [21391] dynamic-link: x86: Set dl_platform and dl_hwcap from CPU features
  [21393] stdio: Missing dup3 error check in freopen, freopen64
  [21396] libc: Use AVX2 memcpy/memset on Skylake server
  [21399] localedata: Bad description for U00EC in
    localedata/charmaps/CP1254
  [21411] malloc: realloc documentation error
  [21426] network: sys/socket.h uio.h namespace
  [21428] libc: [aarch64] tst-backtrace5 testsuite failure
  [21445] libc: signal.h bsd_signal namespace
  [21455] network: Network headers stdint.h namespace
  [21474] network: resolv: res_init does not use RES_DFLRETRY (2) but 4 for
    retry value
  [21475] network: resolv: Overlong search path is truncated mid-label
  [21511] libc: sigstack namespace
  [21512] libc: clone() ends up calling exit_group() through _exit() wrapper
  [21514] libc: sysdeps/unix/sysv/linux/sys/syscall.h:31:27: fatal error:
    bits/syscall.h: No  such file or directory
  [21517] libc: struct sigaltstack namespace
  [21528] dynamic-link: Duplicated minimal strtoul implementations in ld.so
  [21533] localedata: Update locale data to Unicode 10.0
  [21537] libc:
    ../sysdeps/unix/sysv/linux/s390/s390-32/__makecontext_ret.S:44: Error:
    junk at end of line, first unrecognized character is `@'
  [21538] libc: SIG_HOLD missing for XPG4
  [21539] libc: S390: Mismatch between kernel and glibc ptrace.h with
    request 12: PTRACE_SINGLEBLOCK vs PTRACE_GETREGS.
  [21542] libc: Use conservative default for sysconf (_SC_NPROCESSORS_ONLN)
  [21543] libc: sigevent namespace
  [21548] libc: [mips] get/set/make/swap context for MIPS O32 assume wrong
    size for general purpose registers in mcontext_t structure
  [21550] libc: sigwait namespace
  [21552] libc: XPG4 bsd_signal namespace
  [21554] libc: sigpause namespace
  [21560] libc: sys/wait.h signal.h namespace
  [21561] libc: waitid namespace
  [21573] nptl: GCC 7: /usr/bin/install: cannot remove
    '/usr/include/stdlib.h': Permission denied
  [21575] libc: sys/wait.h missing struct rusage definition
  [21584] libc: sigaltstack etc namespace
  [21597] libc: siginterrupt namespace
  [21607] math: hppa: FAIL: math/test-tgmath
  [21609] dynamic-link: Incomplete workaround for GCC __tls_get_addr ABI
    issue on x86-64
  [21622] libc: [tile] missing SA_* for POSIX.1:2008
  [21624] dynamic-link: ld.so: Unsafe alloca allows local attackers to alias
    stack and heap (CVE-2017-1000366)
  [21625] libc: wait3 namespace
  [21654] nss: Incorrect pointer alignment in NSS group merge result
    construction
  [21657] network: Parse interface zone id for node-local multicast
  [21662] string: memcmp-avx2-movbe.S lacks saturating subtraction for
    between_2_3
  [21666] libc: .symver is used on common symbol
  [21668] network: resolv: res_init cross-thread broadcast introduces race
    conditions
  [21687] math: tgmath.h totalorder, totalordermag return type
  [21694] locale: Current Glibc Locale Does Not Support Tok-Pisin and Fiji
    Hindi Locale
  [21696] libc: Incorrect assumption of of __cpu_mask in
    posix/sched_cpucount.c
  [21697] libc: sysdeps/posix/spawni.c: 2 * suspicious condition ?
  [21706] localedata: yesstr and nostr  are missing for Breton [LC_MESSAGES]
    locale
  [21707] math: ppc64le: Invalid IFUNC resolver from libgcc calls getauxval,
    leading to relocation crash
  [21709] libc: resolv_conf.c:552: update_from_conf: Assertion
    `resolv_conf_matches (resp, conf)' failed.
  [21710] localedata: Added Samoan language locale for Samoa
  [21711] localedata: Pashto yesstr/nostr locale are missing
  [21715] nptl: sysdeps/nptl/bits/pthreadtypes.h: typedef guard
    __have_pthread_attr_t can cause redefinition of typedef ‘pthread_attr_t’
  [21721] localedata: Incorrect Full Weekday names for ks_IN@devanagari
  [21723] localedata: yesstr/nostr missing for Chinese language locale
  [21724] localedata: yesstr and nostr  are missing for  Xhosa [LC_MESSAGES]
    locale
  [21727] localedata: yesstr and nostr  are missing for Tsonga [LC_MESSAGES]
    locale
  [21728] localedata: New Locale for Tongan language
  [21729] localedata: incorrect LC_NAME fields for hi_IN
  [21733] localedata: yesstr and nostr  are missing for zh_HK
  [21734] localedata: Missing yesstr and nostr  are for kw_GB
  [21738] libc: misc/tst-preadvwritev2 and misc/tst-preadvwritev64v2 fail
  [21741] libc: Undefined __memmove_chk_XXX and __memset_chk_XXX in libc.a
  [21742] libc: _dl_num_cache_relocations is undefined in libc.a
  [21743] localedata: ks_IN@devanagari: abday strings mismatch the day
    strings
  [21744] libc: Tests failing on --enable-tunables --enable-stack-
    protector=all
  [21749] localedata: Wrong abbreviated day name (“abday”) for
    ar_JO/ar_LB/ar_SY
  [21756] localedata: missing yesstr, nostr  for nds_DE and nds_NL
  [21757] localedata: missing yesstr, nostr  for pap_AW and pap_CW
  [21759] localedata: missing yesstr and nostr for Tigrinya
  [21760] localedata: Fix LC_MESSAGES and LC_ADDRESS for anp_IN
  [21766] localedata: Wrong LC_MESSAGES for om_ET Locale
  [21767] localedata: Missing Bislama locales
  [21768] localedata: Missing yesstr and nostr for aa_ET
  [21770] localedata: Missing  Field in li_NL
  [21778] nptl: Robust mutex may deadlock
  [21779] libc: MicroBlaze segfaults when loading libpthread
  [21783] localedata: Fix int_select international_call_prefixes
  [21784] localedata: Inconsistency  in country_isbn
  [21788] localedata: Missing  Country Postal Abbreviations
  [21794] localedata: Added-country_isbn-for-Italy
  [21795] localedata: Add/Fix country_isbn for France
  [21796] localedata: Added country_isbn for Republic of Korea
  [21797] localedata: Fix inconsistency in country_isbn and missing prefixes
  [21799] localedata: Added int_select international_call_prefixes
  [21801] localedata: Added int_select international_call_prefixes
  [21804] nptl: Double semicolon in thread-shared-types.h
  [21807] localedata: LC_ADDRESS fix for pap_CW
  [21808] localedata: Fix LC_ADDRESS for pap_AW
  [21821] localedata: Added country_name in mai_IN
  [21822] localedata: Fix LC_TIME for mai_IN
  [21823] localedata: missing yesstr, nostr  for sa_IN
  [21825] localedata: Fix name_mrs for mag_IN
  [21828] localedata: 2.26 changelog should mention user visible changes
    with unicode 9.0
  [21835] localedata: Added Maithili language locale for Nepal
  [21838] localedata: Removed redundant data for the_NP
  [21839] localedata: Fix LC_MONETARY for ta_LK
  [21844] localedata: Fix Latin characters and Months Sequence.
  [21848] localedata: Fix mai_NP Title Name

\f
Version 2.25

* The feature test macro __STDC_WANT_LIB_EXT2__, from ISO/IEC TR
  24731-2:2010, is supported to enable declarations of functions from that
  TR.  Note that not all functions from that TR are supported by the GNU C
  Library.

* The feature test macro __STDC_WANT_IEC_60559_BFP_EXT__, from ISO/IEC TS
  18661-1:2014, is supported to enable declarations of functions and macros
  from that TS.  Note that not all features from that TS are supported by
  the GNU C Library.

* The feature test macro __STDC_WANT_IEC_60559_FUNCS_EXT__, from ISO/IEC TS
  18661-4:2015, is supported to enable declarations of functions and macros
  from that TS.  Note that most features from that TS are not supported by
  the GNU C Library.

* The nonstandard feature selection macros _REENTRANT and _THREAD_SAFE are
  now treated as compatibility synonyms for _POSIX_C_SOURCE=199506L.
  Since the GNU C Library defaults to a much newer revision of POSIX, this
  will only affect programs that specifically request an old conformance
  mode.  For instance, a program compiled with -std=c89 -D_REENTRANT will
  see a change in the visible declarations, but a program compiled with
  just -D_REENTRANT, or -std=c99 -D_POSIX_C_SOURCE=200809L -D_REENTRANT,
  will not.

  Some C libraries once required _REENTRANT and/or _THREAD_SAFE to be
  defined by all multithreaded code, but glibc has not required this for
  many years.

* The inclusion of <sys/sysmacros.h> by <sys/types.h> is deprecated.  This
  means that in a future release, the macros “major”, “minor”, and “makedev”
  will only be available from <sys/sysmacros.h>.

  These macros are not part of POSIX nor XSI, and their names frequently
  collide with user code; see for instance glibc bug 19239 and Red Hat bug
  130601.  <stdlib.h> includes <sys/types.h> under _GNU_SOURCE, and C++ code
  presently cannot avoid being compiled under _GNU_SOURCE, exacerbating the
  problem.

* New <fenv.h> features from TS 18661-1:2014 are added to libm: the
  fesetexcept, fetestexceptflag, fegetmode and fesetmode functions, the
  femode_t type and the FE_DFL_MODE and FE_SNANS_ALWAYS_SIGNAL macros.

* Integer width macros from TS 18661-1:2014 are added to <limits.h>:
  CHAR_WIDTH, SCHAR_WIDTH, UCHAR_WIDTH, SHRT_WIDTH, USHRT_WIDTH, INT_WIDTH,
  UINT_WIDTH, LONG_WIDTH, ULONG_WIDTH, LLONG_WIDTH, ULLONG_WIDTH; and to
  <stdint.h>: INT8_WIDTH, UINT8_WIDTH, INT16_WIDTH, UINT16_WIDTH,
  INT32_WIDTH, UINT32_WIDTH, INT64_WIDTH, UINT64_WIDTH, INT_LEAST8_WIDTH,
  UINT_LEAST8_WIDTH, INT_LEAST16_WIDTH, UINT_LEAST16_WIDTH,
  INT_LEAST32_WIDTH, UINT_LEAST32_WIDTH, INT_LEAST64_WIDTH,
  UINT_LEAST64_WIDTH, INT_FAST8_WIDTH, UINT_FAST8_WIDTH, INT_FAST16_WIDTH,
  UINT_FAST16_WIDTH, INT_FAST32_WIDTH, UINT_FAST32_WIDTH, INT_FAST64_WIDTH,
  UINT_FAST64_WIDTH, INTPTR_WIDTH, UINTPTR_WIDTH, INTMAX_WIDTH,
  UINTMAX_WIDTH, PTRDIFF_WIDTH, SIG_ATOMIC_WIDTH, SIZE_WIDTH, WCHAR_WIDTH,
  WINT_WIDTH.

* New <math.h> features are added from TS 18661-1:2014:

  - Signaling NaN macros: SNANF, SNAN, SNANL.

  - Nearest integer functions: roundeven, roundevenf, roundevenl, fromfp,
    fromfpf, fromfpl, ufromfp, ufromfpf, ufromfpl, fromfpx, fromfpxf,
    fromfpxl, ufromfpx, ufromfpxf, ufromfpxl.

  - llogb functions: the llogb, llogbf and llogbl functions, and the
    FP_LLOGB0 and FP_LLOGBNAN macros.

  - Max-min magnitude functions: fmaxmag, fmaxmagf, fmaxmagl, fminmag,
    fminmagf, fminmagl.

  - Comparison macros: iseqsig.

  - Classification macros: iscanonical, issubnormal, iszero.

  - Total order functions: totalorder, totalorderf, totalorderl,
    totalordermag, totalordermagf, totalordermagl.

  - Canonicalize functions: canonicalize, canonicalizef, canonicalizel.

  - NaN functions: getpayload, getpayloadf, getpayloadl, setpayload,
    setpayloadf, setpayloadl, setpayloadsig, setpayloadsigf, setpayloadsigl.

* The functions strfromd, strfromf, and strfroml, from ISO/IEC TS 18661-1:2014,
  are added to libc.  They convert a floating-point number into string.

* Most of glibc can now be built with the stack smashing protector enabled.
  It is recommended to build glibc with --enable-stack-protector=strong.
  Implemented by Nick Alcock (Oracle).

* The function explicit_bzero, from OpenBSD, has been added to libc.  It is
  intended to be used instead of memset() to erase sensitive data after use;
  the compiler will not optimize out calls to explicit_bzero even if they
  are "unnecessary" (in the sense that no _correct_ program can observe the
  effects of the memory clear).

* On ColdFire, MicroBlaze, Nios II and SH3, the float_t type is now defined
  to float instead of double.  This does not affect the ABI of any libraries
  that are part of the GNU C Library, but may affect the ABI of other
  libraries that use this type in their interfaces.

* On x86_64, when compiling with -mfpmath=387 or -mfpmath=sse+387, the
  float_t and double_t types are now defined to long double instead of float
  and double.  These options are not the default, and this does not affect
  the ABI of any libraries that are part of the GNU C Library, but it may
  affect the ABI of other libraries that use this type in their interfaces,
  if they are compiled or used with those options.

* The getentropy and getrandom functions, and the <sys/random.h> header file
  have been added.

* The buffer size for byte-oriented stdio streams is now limited to 8192
  bytes by default.  Previously, on Linux, the default buffer size on most
  file systems was 4096 bytes (and thus remains unchanged), except on
  network file systems, where the buffer size was unpredictable and could be
  as large as several megabytes.

* The <sys/quota.h> header now includes the <linux/quota.h> header.  Support
  for the Linux quota interface which predates kernel version 2.4.22 has
  been removed.

* The malloc_get_state and malloc_set_state functions have been removed.
  Already-existing binaries that dynamically link to these functions will
  get a hidden implementation in which malloc_get_state is a stub.  As far
  as we know, these functions are used only by GNU Emacs and this change
  will not adversely affect already-built Emacs executables.  Any undumped
  Emacs executables, which normally exist only during an Emacs build, should
  be rebuilt by re-running “./configure; make” in the Emacs build tree.

* The “ip6-dotint” and “no-ip6-dotint” resolver options, and the
  corresponding RES_NOIP6DOTINT flag from <resolv.h> have been removed.
  “no-ip6-dotint” had already been the default, and support for the
  “ip6-dotint” option was removed from the Internet in 2006.

* The "ip6-bytestring" resolver option and the corresponding RES_USEBSTRING
  flag from <resolv.h> have been removed.  The option relied on a
  backwards-incompatible DNS extension which was never deployed on the
  Internet.

* The flags RES_AAONLY, RES_PRIMARY, RES_NOCHECKNAME, RES_KEEPTSIG,
  RES_BLAST defined in the <resolv.h> header file have been deprecated.
  They were already unimplemented.

* The "inet6" option in /etc/resolv.conf and the RES_USE_INET6 flag for
  _res.flags are deprecated.  The flag was standardized in RFC 2133, but
  removed again from the IETF name lookup interface specification in RFC
  2553.  Applications should use getaddrinfo instead.

* DNSSEC-related declarations and definitions have been removed from the
  <arpa/nameser.h> header file, and libresolv will no longer attempt to
  decode the data part of DNSSEC record types.  Previous versions of glibc
  only implemented minimal support for the previous version of DNSSEC, which
  is incompatible with the currently deployed version.

* The resource record type classification macros ns_t_qt_p, ns_t_mrr_p,
  ns_t_rr_p, ns_t_udp_p, ns_t_xfr_p have been removed from the
  <arpa/nameser.h> header file because the distinction between RR types and
  meta-RR types is not officially standardized, subject to revision, and
  thus not suitable for encoding in a macro.

* The types res_sendhookact, res_send_qhook, re_send_rhook, and the qhook
  and rhook members of the res_state type in <resolv.h> have been removed.
  The glibc stub resolver did not support these hooks, but the header file
  did not reflect that.

* For multi-arch support it is recommended to use a GCC which has
  been built with support for GNU indirect functions.  This ensures
  that correct debugging information is generated for functions
  selected by IFUNC resolvers.  This support can either be enabled by
  configuring GCC with '--enable-gnu-indirect-function', or by
  enabling it by default by setting 'default_gnu_indirect_function'
  variable for a particular architecture in the GCC source file
  'gcc/config.gcc'.

* GDB pretty printers have been added for mutex and condition variable
  structures in POSIX Threads. When installed and loaded in gdb these pretty
  printers show various pthread variables in human-readable form when read
  using the 'print' or 'display' commands in gdb.

* Tunables feature added to allow tweaking of the runtime for an application
  program.  This feature can be enabled with the '--enable-tunables' configure
  flag.  The GNU C Library manual has details on usage and README.tunables has
  instructions on adding new tunables to the library.

* A new version of condition variables functions have been implemented in
  the NPTL implementation of POSIX Threads to provide stronger ordering
  guarantees.

* A new version of pthread_rwlock functions have been implemented to use a more
  scalable algorithm primarily through not using a critical section anymore to
  make state changes.

Security related changes:

* On ARM EABI (32-bit), generating a backtrace for execution contexts which
  have been created with makecontext could fail to terminate due to a
  missing .cantunwind annotation.  This has been observed to lead to a hang
  (denial of service) in some Go applications compiled with gccgo.  Reported
  by Andreas Schwab.  (CVE-2016-6323)

* The DNS stub resolver functions would crash due to a NULL pointer
  dereference when processing a query with a valid DNS question type which
  was used internally in the implementation.  The stub resolver now uses a
  question type which is outside the range of valid question type values.
  (CVE-2015-5180)

The following bugs are resolved with this release:

  [4099] stdio: Overly aggressive caching by stream i/o functions.
  [7065] build: Support building glibc with -fstack-protector or -fstack-
    protector-all
  [9842] localedata: en_CA: incorrect date format
  [13165] nptl: pthread_cond_wait() can consume a signal that was sent
    before it started waiting
  [14139] manual: Do not hardcode platform names in manual/libm-err-tab.pl
  [15765] nptl: sem_open is wrongly a cancellation point
  [16421] network: IN6_IS_ADDR_UNSPECIFIED can use undefined s6_addr32
  [16458] libc: endian.h and netinet/in.h byte order macros return values of
    wrong type
  [16628] dynamic-link: Segfault after a binary without pthread dlopen()s a
    library linked with pthread
  [16630] nptl: Use SYSENTER for pthread_cond_broadcast/signal() (i.e. fix
    "FIXME: Ingo" issue)
  [16907] libc: <argp.h> compiled with --std=cXX disables __attribute__
  [17252] libc: getrandom and getentropy syscall
  [17730] malloc: thread-local storage is sometimes improperly free()'d
    after being __libc_memalign()'d
  [18241] stdio: failed fseek on memstream does not set errno and can fail
    when it shouldnt
  [18243] nptl: sem_wait, sem_timedwait are cancellation points shm_open is
    not
  [18463] nptl: pthread_cond_broadcast issue when surrounded by
    PTHREAD_PRIO_INHERIT mutex on ARM
  [18784] network: res_query and related function crash for special record
    type queries (CVE-2015-5180)
  [19380] math: strtod does not raise "inexact"
  [19387] string: Integer overflow in memchr
  [19390] string: Integer overflow in strncat
  [19398] build: linknamespace tests fail with massively parallel build
  [19402] nptl: Deadlock with robust shared mutex and asynchronous
    termination
  [19469] malloc: M_PERTURB in test-skeleton.c invalidates malloc tests
  [19473] malloc: Turn malloc_get_state etc. in compatibility symbols
  [19514] libc: [PATCH] Fix spelling errors in spelling
    "implement"/"implementation" in several places
  [19582] network: Deprecate RES_USE_INET6
  [19673] manual: clog10 docs appear to be erroneous
  [19810] dynamic-link: dlopen with both RTLD_NOLOAD and RTLD_NODELETE
    causes a segmentation fault
  [19826] libc: invalid pointer returned from __tls_get_addr with static
    linking
  [20016] network: resolv: Remove hooks support from the API
  [20019] dynamic-link: NULL pointer dereference in libc.so.6 IFUNC due to
    uninitialized GOT
  [20033] math: [x86_64] vectorized math function don't call the __finite
    versions
  [20116] nptl: use after free in pthread_create
  [20181] stdio: open_memstream(): writes not at end of stream corrupt data
  [20292] dynamic-link: Comparison in elf/dl-open.c _dl_addr_inside_object
    is always true.
  [20311] nptl: please install proc_service.h
  [20366] libc: Compilation errors in installed headers in strict-compliance
    modes
  [20370] malloc: malloc: Arena free list management is still racy
    (incorrect fix in bug 19243)
  [20386] libc: assert (X = 0) does not result in GCC warning
  [20432] malloc: malloc: Minimize interface required for interposition
  [20435] libc: Missing unwind info in __startcontext causes infinite loop
    in _Unwind_Backtrace (CVE-2016-6323)
  [20444] hurd: recvmsg: PF_LOCAL sockets and msg_name lead to SIGLOST
  [20452] nptl: Addition of sysdep.o to libpthread.a breaks relinking
    libpthread.a
  [20455] math: [powerpc] fesetexceptflag fails to clear FE_INVALID
  [20459] localedata: et_EE: locale has wrong {p,n}_cs_precedes value
  [20477] network: resolv: incorrect double-checked locking related to
    _res_hconf
  [20478] libc: libc_ifunc macro and similar usages leads to false debug-
    information.
  [20495] math: x86_64 performance degradation due to AVX/SSE transition
    penalty
  [20497] localedata: lt_LT: LC_TIME d_fmt used is obsolete
  [20508] dynamic-link: _dl_runtime_resolve_avx/_dl_runtime_profile_avx512
    cause transition penalty
  [20517] math: sparcv9 missing fdiml compat symbol
  [20524] manual: strverscmp is inconsistent
  [20525] libc: <sys/quota.h> should be based on kernel headers
  [20539] math: GCC 7 -static -lm fails to link at -O3
  [20554] libc: ld: bss-plt forced due to /usr/lib/libc_nonshared.a(ppc-
    mcount.oS)
  [20558] string: POSIX bcopy/bzero decls do not implement Object Size
    Checking
  [20591] network: Remove obsolete DNSSEC support
  [20592] network: DNS resource record type classification macros in
    <arpa/nameser.h> are incorrect
  [20593] network: Update DNS RR type definitions
  [20611] network: getaddrinfo accepts invalid numeric scope IDs
  [20615] build: glibc build fails when using --with-cpu=power9 --enable-
    multi-arch
  [20629] network: libresolv: Remove support for bitstring labels
    (RES_USEBSTRING)
  [20647] libc: GLIBC quitting every program - glibc on Pentium-S leads to
    assertion: "maxidx >= 2"
  [20660] math: [arm] Use VSQRT
  [20662] libc: checking whether x86_64-pc-linux-gnu-gcc implicitly enables
    -fstack-protector no (32bit gcc 6.2.0 pie and ssp enable)
  [20689] libc: Test for FMA should also check for AVX.
  [20707] glob: gl_pathv entries not set to NULL with GLOB_DOOFFS
  [20715] math: iszero macro breaks existing code
  [20718] math: [powerpc] copysignl raises "invalid" for sNaN
  [20728] libc: powerpc: Missing TOC stub in clone
  [20729] build: glibc-2.24 fails to build for i486 with -Os
  [20750] build: Build fails with default PIE enabled gcc-6.x
  [20768] math: [alpha] sqrt fegetenv namespace
  [20785] libc: binutils 2.28 fails to assemble power6/memset.S file in
    glibc
  [20787] math: float_t is defined as float incorrectly on x86_64 even if
    __FLT_EVAL_METHOD__ is 2
  [20790] network: rpcgen buffer overrun in get_prog_declaration
  [20822] nptl: race condition in __lll_unlock_elision on powerpc
  [20829] libc: crypt snprintf namespace
  [20847] libc: tst-vfork3 failure
  [20855] math: Default bits/mathdef.h has inappropriate float_t
  [20859] math: [sh4] FP_ILOGB0 invalid
  [20864] localedata: iconv: cp936 missing single-byte euro sign (0x80,
    U+20AC), not same as GBK
  [20915] dynamic-link: global-dynamic TLS broken on aarch64
  [20916] math: pow handling of sNaN arguments
  [20918] build: Building with --enable-nss-crypt fails tst-linkall-static.
  [20919] math: Bad pow (qNaN, 0) result with -lieee
  [20940] math: hypot sNaN handling
  [20947] math: fmax, fmin sNaN handling
  [20956] libc: debug/tst-backtrace3-6 don't work with -O3 anymore
  [20964] network: sunrpc: Stack-based buffer overflow in getrpcport with
    RES_USE_INET6
  [20971] string: powerpc64/power7 memchr overflows internal pointer check
  [20973] nptl: robust mutexes: Lost wake-ups
  [20974] locale: bs_BA: yesexpr/noexpr regexes accept any character
  [20978] nis: strlen on null pointer in nss_nisplus
  [20985] nptl: robust mutexes: lowlevelrobustlock assembly on x86 blocks on
    wrong condition
  [21014] string: i686 memchr overflows internal pointer check
  [21019] libc: [mips] n32 lseek incorrect on overflow
  [21022] libc: [microblaze] __backtrace get_frame_size namespace
  [21026] libc: [MIPS] readahead syscall is broken on n64
  [21028] math: Fallback fesetexceptflag should always succeed
  [21045] libc: [powerpc-nofpu] swapcontext does not restore signal mask
  [21047] math: arm: fpu_control.h: _FPU_GETCW/_FPU_SETCW is rejected by
    clang
  [21053] libc: [SH] Namespace pollution from sys/ucontext.h
  [21061] librt: [microblaze] librt lost clock_* exports
  [21073] libc: tunables: insecure environment variables passed to
    subprocesses with AT_SECURE
  [21081] string: Missing vzeroupper in memset-vec-unaligned-erms.S
\f
Version 2.24

* The minimum Linux kernel version that this version of the GNU C Library
  can be used with is 3.2, except on i[4567]86 and x86_64, where Linux
  kernel version 2.6.32 or later suffices (on architectures that already
  required kernel versions more recent than 3.2, those requirements remain
  unchanged).  Linux 3.2 or later kernel headers are required on all
  architectures.

* The pap_AN locale has been deleted.  This has been deprecated for a long
  time.  It has been replaced by pap_AW & pap_CW, both of which have long
  been included in previous releases.

* The readdir_r and readdir64_r functions have been deprecated.  It is
  recommended to use readdir and readdir64 instead.

* The type “union wait” has been removed.  It was deprecated in the early
  1990s and never part of POSIX.  Application code should use the int type
  instead of “union wait”.

* A new NSS action is added to facilitate large distributed system
  administration.  The action, MERGE, allows remote user stores like LDAP
  to be merged into local user stores like /etc/groups in order to provide
  easy to use, updated, and managed sets of merged credentials.  The new
  action can be used by configuring it in /etc/nsswitch.conf:
  group: files [SUCCESS=merge] nis
  Implemented by Stephen Gallagher (Red Hat).

* The deprecated __malloc_initialize_hook variable has been removed from the
  API.

* The long unused localedef --old-style option has been removed.  It hasn't
  done anything in over 16 years.  Scripts using this option can safely
  drop it.

* nextupl, nextup, nextupf, nextdownl, nextdown and nextdownf are added to
  libm.  They are defined by TS 18661 and IEEE754-2008.  The nextup functions
  return the next representable value in the direction of positive infinity
  and the nextdown functions return the next representable value in the
  direction of negative infinity.  These are currently enabled as GNU
  extensions.

Security related changes:

* An unnecessary stack copy in _nss_dns_getnetbyname_r was removed.  It
  could result in a stack overflow when getnetbyname was called with an
  overly long name.  (CVE-2016-3075)

* Previously, getaddrinfo copied large amounts of address data to the stack,
  even after the fix for CVE-2013-4458 has been applied, potentially
  resulting in a stack overflow.  getaddrinfo now uses a heap allocation
  instead.  Reported by Michael Petlan.  (CVE-2016-3706)

* The glob function suffered from a stack-based buffer overflow when it was
  called with the GLOB_ALTDIRFUNC flag and encountered a long file name.
  Reported by Alexander Cherepanov.  (CVE-2016-1234)

* The Sun RPC UDP client could exhaust all available stack space when
  flooded with crafted ICMP and UDP messages.  Reported by Aldy Hernandez'
  alloca plugin for GCC.  (CVE-2016-4429)

* The IPv6 name server management code in libresolv could result in a memory
  leak for each thread which is created, performs a failing naming lookup,
  and exits.  Over time, this could result in a denial of service due to
  memory exhaustion.  Reported by Matthias Schiffer.  (CVE-2016-5417)

The following bugs are resolved with this release:

  [1170] localedata: ne_NP: update Nepali locale definition file
  [3629] manual: stpcpy description in string.texi refers to MS-DOG instead
    of MS-DOS.
  [6527] malloc: [powerpc] Malloc alignment insufficient for PowerPC
  [6796] math: fdim() does not set errno on overflow
  [10354] libc: posix_spawn should use vfork() in more cases than presently
  [11213] localedata: localedata: add copyright disclaimer to locale files
  [12143] localedata: chr_US: new Cherokee locale
  [12450] localedata: sgs_LT: new locale
  [12676] localedata: ln_CD: new locale
  [13237] localedata: LC_ADDRESS.country_name: update all locales w/latest
    CLDR data
  [13304] math: fma, fmaf, fmal produce wrong results
  [14259] build: --localedir arg to configure is ignored
  [14499] nptl: Does posix_spawn invoke atfork handlers / use vfork?
  [14750] libc: Race condition in posix_spawn vfork usage vs signal handlers
  [14934] localedata: es_CL: wrong first weekday chilean locale
  [15262] localedata: LC_MESSAGES.yesexpr/noexpr: inconsistent use of
    romanisation
  [15263] localedata: LC_MESSAGES.yesexpr/noexpr: inconsistent use of 1/0
    and +/-
  [15264] localedata: LC_MESSAGES.yesstr/nostr: lacking in many locales
  [15368] nptl: raise() is not async-signal-safe
  [15479] math: ceil, floor, round and trunc raise inexact exception
  [15578] localedata: kk_KZ: various updates
  [16003] localedata: pap_AN: punt old locale
  [16137] localedata: iw_IL: punt old locale
  [16190] localedata: eo: new esperanto locale
  [16374] localedata: lv_LV: change currency symbol in LC_MONETARY to euro
  [16742] malloc: race condition: pthread_atfork() called before first
    malloc() results in unexpected locking behaviour/deadlocks
  [16975] localedata: LC_MESSAGES.yesexpr/noexpr: revisit capitalization in
    all locales
  [16983] localedata: postal_fmt does not allow %l and %n modifiers
  [17565] localedata: pt_PT: wrong (work-)week start
  [17899] math: [powerpc] floorl returns negative zero with FE_DOWNWARD
  [17950] build: Build fails with -msse
  [18205] localedata: be_BY*: wrong first_weekday and first_workday
  [18433] libc: posix_spawn does not return correctly upon failure to
    execute
  [18453] localedata: charmaps/IBM875: incorrect codes
  [18712] string: bits/string2.h incompatible with -O2 -Werror=packed
    -Wsystem-headers
  [18896] localedata: he_IL: improvements for currency
  [18911] localedata: ro_RO: Correcting week day name for "Tuesday" in
    Romanian locale data
  [18960] locale: s390: _nl_locale_subfreeres uses larl opcode on misaligned
    symbol
  [19056] libc: Deprecate readdir_r
  [19133] localedata: pt_*: days & months should be lowercase in Portuguese
    language
  [19198] localedata: nl_NL: small improvements for Dutch locales
  [19257] network: Per-thread memory leak in __res_vinit with IPv6
    nameservers (CVE-2016-5417)
  [19269] build: tst-audit4 and tst-audit10 failures with gcc-6 on non avx
    machine
  [19400] locale: Language missing in  "iso-639.def", trivial fix in
    description
  [19431] malloc: Deadlock between fflush, getdelim, and fork
  [19505] libc: Incorrect file descriptor validity checks in
    posix_spawn_file_actions_add{open,close,dup2}
  [19509] dynamic-link: dlsym, dlvsym do not report errors through dlerror
    when using RTLD_NEXT
  [19512] locale: Stale `#ifndef HAVE_BUILTIN_EXPECT' in
    `intl/{gettextP,loadinfo}.h'
  [19534] libc: execle, execlp may use malloc
  [19568] localedata: *_CH: Swiss locales have inconsistent start of week
  [19573] network: res_nclose and __res_maybe_init disagree about name
    server initialization, breaking Hesiod
  [19575] localedata: Status of GB18030 tables
  [19581] localedata: sr_* date_fmt string contains additional newline
  [19583] string: SSSE3_Fast_Copy_Backward flag needs to be enabled for AMD
    Excavator core
  [19592] math: [ldbl-128ibm] ceill incorrect in non-default rounding modes
  [19593] math: [ldbl-128ibm] truncl incorrect in non-default rounding modes
  [19594] math: [ldbl-128ibm] roundl incorrect in non-default rounding modes
  [19595] math: [ldbl-128ibm] fmodl incorrect for results in subnormal
    double range
  [19602] math: [ldbl-128ibm] fmodl handling of equal arguments with low
    part zero incorrect
  [19603] math: [ldbl-128ibm] remainderl, remquol incorrect sign handling in
    equality tests
  [19610] dynamic-link: ldconfig -X removes stale symbolic links
  [19613] libc: s390x (64 bit) macro expansion WCOREDUMP and others
  [19633] locale: strfmon_l applies global locale to number formatting
  [19642] network: Memory leak in getnameinfo
  [19648] libc: test-skeleton.c: Do not set RLIMIT_DATA
  [19653] libc: Potential for NULL pointer dereference (CWE-476) in
    glibc-2.22
  [19654] math: [x86_64] Need testcase for BZ #19590 fix
  [19671] localedata: Missing Sanity Check for malloc() in 'tst-fmon.c' &
    'tst-numeric.c'
  [19674] math: [ldbl-128ibm] powl incorrect overflow handling
  [19677] math: [ldbl-128ibm] remainderl equality test incorrect for zero
    low part
  [19678] math: [ldbl-128ibm] nextafterl, nexttowardl incorrect sign of zero
    result
  [19679] dynamic-link: gcc-4.9.3 C++ exception handling broken due to
    unaligned stack
  [19726] locale: Converting UCS4LE to INTERNAL with iconv() does not update
    pointers and lengths in error-case.
  [19727] locale: Converting from/to UTF-xx with iconv() does not always
    report errors on UTF-16 surrogates values.
  [19755] nscd: nscd assertion failure in gc
  [19758] dynamic-link: Typo in EXTRA_LD_ENVVARS for x86-64
  [19759] libc: mempcpy shouldn't be inlined
  [19762] dynamic-link: HAS_CPU_FEATURE/HAS_ARCH_FEATURE are easy to misuse
  [19765] libc: s390 needs an optimized mempcpy
  [19779] glob: glob: buffer overflow with GLOB_ALTDIRFUNC due to incorrect
    NAME_MAX limit assumption (CVE-2016-1234)
  [19783] build: benchtests don't support --enable-hardcoded-path-in-tests
  [19787] network: Missing and incorrect truncation checks in getnameinfo
  [19790] math: [ldbl-128ibm] nearbyintl incorrect in non-default rounding
    modes
  [19791] network: Assertion failure in res_query.c with un-connectable name
    server addresses
  [19792] libc: MIPS: backtrace yields infinite backtrace with makecontext
  [19822] math: libm.so install clobbers old version
  [19825] network: resolv: send_vc can return uninitialized data in second
    response to getaddrinfo
  [19830] network: nss_dns: should check RDATA length against buffer length
  [19831] network: nss_dns: getaddrinfo returns uninitialized data when
    confronted with A/AAAA records of invalid size
  [19837] nss: nss_db: No retries for some long lines with a larger buffer
  [19848] math: powl(10,n) for n=-4,-5,-6,-7 is off by more than 1 ULP
  [19853] stdio: Printing IBM long double in decimal with high precision is
    sometimes incorrect
  [19860] build: x86_64: compile errors for tst-audit10 and tst-auditmod10b
  [19861] nptl: libpthread IFUNC resolver for fork can lead to crash
  [19862] network: resolv, nss_dns: Remove remaining logging of unexpected
    record types
  [19865] network: Assertion failure or memory leak in
    _nss_dns_getcanonname_r
  [19868] network: nss_dns: netent code does not skip over non-PTR records
  [19879] network: nss_dns: Stack overflow in getnetbyname implementation
    (CVE-2016-3075)
  [19881] string: Improve x86-64 memset
  [19907] string: Incorrect memcpy tests
  [19916] dynamic-link: S390: fprs/vrs are not saved/restored while
    resolving symbols
  [19925] libc: termios.h XCASE namespace
  [19928] string: memmove-vec-unaligned-erms.S is slow with large data size
  [19929] libc: limits.h NL_NMAX namespace
  [19931] stdio: Memory leak in vfprintf
  [19957] libc: clone(CLONE_VM) access invalid parent memory
  [19963] localedata: en_IL: New locale
  [19989] stdio: stdio.h cuserid namespace
  [19994] network: getaddrinfo does not restore RES_USE_INET6 flag in
    gethosts
  [19996] locale: langinfo.h nl_langinfo_l namespace
  [20005] stdio: fflush on a file opened with fmemopen resets position to 0
  [20010] network: getaddrinfo: Stack overflow in hostent translation
    (CVE-2016-3706)
  [20012] stdio: libio: fmemopen append mode failure
  [20014] stdio: stdio.h namespace for pre-threads POSIX
  [20017] network: resolv: Use gmtime_r instead of gmtime in p_secstodate
  [20023] libc: fcntl.h timespec namespace
  [20024] math: [x86_64] vectorized sincos trashes the stack
  [20031] network: nss_hesiod: Heap overflow in get_txt_records
  [20041] time: sys/time.h timespec namespace
  [20043] libc: unistd.h missing cuserid for UNIX98 and before
  [20044] libc: unistd.h missing pthread_atfork for UNIX98
  [20051] libc: ttyslot in wrong header under wrong conditions
  [20054] libc: gethostname not declared for XPG4
  [20055] libc: termios.h missing tcgetsid for XPG4
  [20072] dynamic-link: x86 init_cpu_features is called twice in static
    executable
  [20073] libc: sys/stat.h fchmod namespace
  [20074] libc: stdlib.h rand_r namespace
  [20076] libc: sys/stat.h missing S_IFSOCK, S_ISSOCK for XPG4
  [20094] libc: stdlib.h should not declare grantpt, ptsname, unlockpt for
    XPG3
  [20111] libc: struct sockaddr_storage cannot be aggregate-copied
  [20112] network: sunrpc: stack (frame) overflow in Sun RPC clntudp_call
    (CVE-2016-4429)
  [20115] string: Extra alignment in memset-vec-unaligned-erms.S
  [20119] libc: Wrong mask for processors level type from CPUID
  [20139] dynamic-link: Upper part of zmm is zeroed if Glibc is built with
    AS not supporting AVX512
  [20151] math: [ldbl-128/ldbl-128ibm] j0l, j1l, y0l, y1l return sNaN for
    sNaN argument
  [20153] math: [ldbl-128ibm] sqrtl (sNaN) returns sNaN
  [20156] math: [ldbl-128ibm] ceill, rintl etc. return sNaN for sNaN
    argument
  [20157] math: [powerpc] fabsl (sNaN) wrongly raises "invalid"
  [20160] math: [powerpc] ceil, rint etc. return sNaN for sNaN input
  [20178] libc: posix_spawn{p} should not call exit
  [20191] stdio: libio: vtables hardening
  [20195] string: FMA4 detection requires CPUID execution with register
    eax=0x80000001
  [20198] libc: quick_exit incorrectly destroys C++11 thread objects.
  [20205] math: [i386/x86_64] nextafterl incorrect incrementing negative
    subnormals
  [20212] math: acos (sNaN) returns sNaN
  [20213] math: asin (sNaN) returns sNaN
  [20214] network: Linux header sync with linux/in6.h and ipv6.h again.
  [20218] math: [i386] asinhl (sNaN) returns sNaN
  [20219] math: [i386] atanhl (sNaN) returns sNaN
  [20222] stdio: fopencookie: Mangle function pointers
  [20224] math: [i386] cbrtl (sNaN) returns sNaN
  [20225] math: ldexp, scalbn, scalbln return sNaN for sNaN input
  [20226] math: [i386/x86_64] expl, exp10l, expm1l return sNaN for sNaN
    input
  [20227] math: [i386/x86_64] logl (sNaN) returns sNaN
  [20228] math: [i386/x86_64] log10l (sNaN) returns sNaN
  [20229] math: [i386/x86_64] log1pl (sNaN) returns sNaN
  [20232] math: [ldbl-128] expm1l (sNaN) returns sNaN
  [20233] math: [ldbl-128ibm] expm1l (sNaN) returns sNaN
  [20234] math: [ldbl-128ibm] log1pl (sNaN) returns sNaN
  [20235] math: [i386/x86_64] log2l (sNaN) returns sNaN
  [20237] nss: nss_db: get*ent segfaults without preceding set*ent
  [20240] math: modf (sNaN) returns sNaN
  [20248] libc: debug/tst-longjump_chk2 calls printf from a signal handler
  [20250] math: frexp (sNaN) returns sNaN
  [20252] math: atan2 (sNaN, qNaN) fails to raise "invalid"
  [20255] math: [i386] fdim, fdimf return with excess range and precision /
    double rounding
  [20256] math: [i386/x86_64] fdiml returns sNaN for sNaN input
  [20260] string: ../sysdeps/x86/bits/string.h:1092:3: error: array
    subscript is below array bounds [-Werror=array-bounds]
  [20262] nis: _nss_nis_initgroups_dyn always returns NSS_STATUS_NOTFOUND
  [20263] nptl: robust mutex deadlocks if other thread requests timedlock
    (Only arm/linux)
  [20277] libc: $dp is not initialized correctly in sysdeps/hppa/start.S
  [20284] malloc: malloc: Corrupt arena avoidance causes unnecessary mmap
    fallbacks
  [20296] math: [i386/x86_64] scalbl returns sNaN for sNaN input, missing
    "invalid" exceptions
  [20314] nptl: make[4]: *** [/usr/include/stdlib.h] Error 1
  [20316] localedata: id_ID: Februari instead of Pebruari
  [20327] string: POWER8 strcasecmp returns incorrect result
  [20347] math: Failure: Test: j0_downward (0xap+0)
  [20348] libc: FAIL: misc/tst-preadvwritev64
  [20349] libc: 64-bit value is passed differently in p{readv,writev}{64}
  [20350] libc: There is no test for p{read,write}64
  [20357] math: Incorrect cos result for 1.5174239687223976
  [20384] build: Don't run libmvec-sincos-avx* tests on non avx machines
\f
Version 2.23

* Unicode 8.0.0 Support: Character encoding, character type info, and
  transliteration tables are all updated to Unicode 8.0.0, using new
  and/or improved generator scripts contributed by Mike FABIAN (Red Hat).
  These updates cause user visible changes, such as the fixes for bugs
  89, 16061, and 18568.

* sched_setaffinity, pthread_setaffinity_np no longer attempt to guess the
  kernel-internal CPU set size.  This means that requests that change the
  CPU affinity which failed before (for example, an all-ones CPU mask) will
  now succeed.  Applications that need to determine the effective CPU
  affinities need to call sched_getaffinity or pthread_getaffinity_np after
  setting it because the kernel can adjust it (and the previous size check
  would not detect this in the majority of cases).

* The fts.h header can now be used with -D_FILE_OFFSET_BITS=64.  With LFS
  the following new symbols are used: fts64_children, fts64_close,
  fts64_open, fts64_read and fts64_set.

* getaddrinfo now detects certain invalid responses on an internal netlink
  socket.  If such responses are received, an affected process will
  terminate with an error message of "Unexpected error <number> on netlink
  descriptor <number>" or "Unexpected netlink response of size <number> on
  descriptor <number>".  The most likely cause for these errors is a
  multi-threaded application which erroneously closes and reuses the netlink
  file descriptor while it is used by getaddrinfo.

* A defect in the malloc implementation, present since glibc 2.15 (2012) or
  glibc 2.10 via --enable-experimental-malloc (2009), could result in the
  unnecessary serialization of memory allocation requests across threads.
  The defect is now corrected.  Users should see a substantial increase in
  the concurent throughput of allocation requests for applications which
  trigger this bug.  Affected applications typically create and
  destroy threads frequently.  (Bug 19048 was reported and analyzed by
  Ericsson.)

* There is now a --disable-timezone-tools configure option for disabling the
  building and installing of the timezone related utilities (zic, zdump, and
  tzselect).  This is useful for people who build the timezone data and code
  independent of the GNU C Library.

* The obsolete header <regexp.h> has been removed.  Programs that require
  this header must be updated to use <regex.h> instead.

* The obsolete functions bdflush, create_module, get_kernel_syms,
  query_module and uselib are no longer available to newly linked binaries;
  the header <sys/kdaemon.h> has been removed.  These functions and header
  were specific to systems using the Linux kernel and could not usefully be
  used with the GNU C Library on systems with version 2.6 or later of the
  Linux kernel.

* Optimized string, wcsmbs and memory functions for IBM z13.
  Implemented by Stefan Liebler.

* Newly linked programs that define a variable called signgam will no longer
  have it set by the lgamma, lgammaf and lgammal functions.  Programs that
  require signgam to be set by those functions must ensure that they use the
  variable provided by the GNU C Library and declared in <math.h>, without
  defining their own copy.

* The minimum GCC version that can be used to build this version of the GNU
  C Library is GCC 4.7.  Older GCC versions, and non-GNU compilers, can
  still be used to compile programs using the GNU C Library.

Security related changes:

* An out-of-bounds value in a broken-out struct tm argument to strftime no
  longer causes a crash.  Reported by Adam Nielsen.  (CVE-2015-8776)

* The LD_POINTER_GUARD environment variable can no longer be used to disable
  the pointer guard feature.  It is always enabled.  Previously,
  LD_POINTER_GUARD could be used to disable security hardening in binaries
  running in privileged AT_SECURE mode.  Reported by Hector Marco-Gisbert.
  (CVE-2015-8777)

* An integer overflow in hcreate and hcreate_r could lead to an
  out-of-bounds memory access.  Reported by Szabolcs Nagy.  (CVE-2015-8778)

* The catopen function no longer has unbounded stack usage.  Reported by
  Max.  (CVE-2015-8779)

* The nan, nanf and nanl functions no longer have unbounded stack usage
  depending on the length of the string passed as an argument to the
  functions.  Reported by Joseph Myers.  (CVE-2014-9761)

* A stack-based buffer overflow was found in libresolv when invoked from
  libnss_dns, allowing specially crafted DNS responses to seize control
  of execution flow in the DNS client.  The buffer overflow occurs in
  the functions send_dg (send datagram) and send_vc (send TCP) for the
  NSS module libnss_dns.so.2 when calling getaddrinfo with AF_UNSPEC
  family.  The use of AF_UNSPEC triggers the low-level resolver code to
  send out two parallel queries for A and AAAA.  A mismanagement of the
  buffers used for those queries could result in the response of a query
  writing beyond the alloca allocated buffer created by
  _nss_dns_gethostbyname4_r.  Buffer management is simplified to remove
  the overflow.  Thanks to the Google Security Team and Red Hat for
  reporting the security impact of this issue, and Robert Holiday of
  Ciena for reporting the related bug 18665. (CVE-2015-7547)

The following bugs are resolved with this release:

  [89] localedata: Locales nb_NO and nn_NO should transliterate æøå
  [887] math: Math library function "logb" and "nextafter" inconsistent
  [2542] math: Incorrect return from float gamma (-0X1.FA471547C2FE5P+1)
  [2543] math: Incorrect return from float gamma (-0X1.9260DCP+1)
  [2558] math: Incorrect return from double gamma (-0X1.FA471547C2FE5P+1)
  [2898] libc: [improve]  warning: the use  of `mktemp' is dangerous, better
    use `mkstemp'
  [4404] localedata: German translation of "Alarm clock" is misleading
  [6799] math: nextafter() and nexttoward() doen't set errno on
    overflow/underflow errors
  [6803] math: scalb(), scalbln(), scalbn() do not set errno on
    overflow/underflow
  [10432] nis: _nss_nis_setnetgrent assertion failure
  [11460] libc: fts has no LFS support
  [12926] network: getaddrinfo()/make_request() may spin forever
  [13065] nptl: Race condition in pthread barriers
  [13690] nptl: pthread_mutex_unlock potentially cause invalid access
  [14341] dynamic-link: Dynamic linker crash when DT_JMPREL and DT_REL{,A}
    are not contiguous
  [14551] math: [ldbl-128ibm] strtold overflow handling for IBM long double
  [14912] libc: Rename non-installed bits/*.h headers
  [15002] libc: Avoid undefined behavior in posix_fallocate overflow check
  [15367] math: Let gcc use __builtin_isinf
  [15384] math: One constant fewer in ieee754/dbl-64/wordsize-64/s_finite.c
  [15421] math: lgamma wrongly sets signgam for ISO C
  [15470] math: [arm] On ARM llrintl() and llroundl() do not raise
    FE_INVALID with argument out of range
  [15491] math: [i386/x86_64] x86 nearbyint implementations wrongly clear
    all exceptions
  [15786] dynamic-link: ifunc resolver functions can smash function
    arguments
  [15918] math: Unnecessary check for equality in hypotf()
  [16061] localedata: Review / update transliteration data
  [16068] math: [i386/x86_64] x86 and x86_64 fesetenv exclude state they
    should include
  [16141] time: strptime %z offset restriction
  [16171] math: drem should be alias of remainder
  [16296] math: fegetround is pure?
  [16347] math: [ldbl-128ibm] ldbl-128/e_lgammal_r.c may not be suitable.
  [16364] libc: sleep may leave SIGCHLD blocked on sync cancellation on
    GNU/Linux
  [16399] math: [mips] lrint / llrint / lround / llround missing exceptions
  [16415] math: Clean up ldbl-128 / ldbl-128ibm expm1l for large positive
    arguments
  [16422] math: [powerpc] math-float, math-double failing llrint tests with
    "Exception "Inexact" set" on ppc32
  [16495] localedata: nl_NL: date_fmt: shuffle year/month around
  [16517] math: Missing underflow exception from tanf/tan/tanl
  [16519] math: Missing underflow exception from sinhf
  [16520] math: Missing underflow exception from tanhf
  [16521] math: Missing underflow exception from exp2
  [16620] math: [ldbl-128ibm] exp10l spurious overflows / bad directed
    rounding results
  [16734] stdio: fopen calls mmap to allocate its buffer
  [16961] math: nan function incorrect handling of bad sequences
  [16962] math: nan function unbounded stack allocation (CVE-2014-9761)
  [16973] localedata: Fix lang_lib/lang_term as per ISO 639-2
  [16985] locale: localedef: confusing error message when opening output
    fails
  [17118] math: ctanh(INFINITY + 2 * I) returns incorrect value
  [17197] locale: Redundant shift character in iconv conversion output at
    block boundary
  [17243] libc: trunk/posix/execl.c:53: va_args problem ?
  [17244] libc: trunk/sysdeps/unix/sysv/linux/semctl.c:116: va_args muxup ?
  [17250] dynamic-link: static linking breaks nss loading
    (getaddrinfo/getpwnam/etc...)
  [17404] libc: atomic_exchange_rel lacking a barrier on MIPS16, GCC before
    4.7?
  [17441] math: isnan() should use __builtin_isnan() in GCC
  [17514] nptl: Assert failure unlocking ERRORCHECK mutex after timedlock
    (related to lock elision)
  [17787] manual: Exponent on page 324 of the PDF ends prematurely
  [17886] time: strptime should be able to parse "Z" as a timezone with %z
  [17887] time: strptime should be able to parse "+01:00" style timezones
  [17905] libc: catopen() Multiple unbounded stack allocations
    (CVE-2015-8779)
  [18084] libc: backtrace (..., 0) dumps core on x86
  [18086] libc: nice() sets errno to 0 on success
  [18240] libc: hcreate, hcreate_r should fail with ENOMEM if element count
    is too large (CVE-2015-8778)
  [18251] dynamic-link: SONAME missing when audit modules provides path
  [18265] libc: add attributes for wchar string and memory functions
  [18370] math: csqrt missing underflows
  [18421] libc: [hppa] read-only segment has dynamic relocations
  [18472] libc: Obsolete syscall wrappers should be compat symbols
  [18480] libc: hppa glibc miscompilation in sched_setaffinity()
  [18491] localedata: Update tr_TR LC_CTYPE as part of Unicode updates
  [18525] localedata: Remove locale timezone information
  [18560] libc: [powerpc] spurious bits/ipc.h definitions
  [18568] localedata: Update locale data to Unicode 8.0
  [18589] locale: sort-test.sh fails at random
  [18595] math: ctan, ctanh missing underflows
  [18604] libc: assert macro-expands its argument
  [18610] math: S390: fetestexcept() reports any exception if DXC-code
    contains a vector instruction exception.
  [18611] math: j1, jn missing errno setting on underflow
  [18618] localedata: sync Chechen locale definitions with other *_RU
    locales
  [18647] math: powf(-0x1.000002p0, 0x1p30) returns 0 instead of +inf
  [18661] libc: Some x86-64 assembly codes don't align stack to 16 bytes
  [18665] network: In send_dg, the recvfrom function is NOT always using the
    buffer size of a newly created buffer (CVE-2015-7547)
  [18674] libc: [i386] trunk/sysdeps/i386/tst-auditmod3b.c:84: possible
    missing break ?
  [18675] libc: fpathconf(_PC_NAME_MAX) fails against large filesystems for
    32bit processes
  [18681] libc: regexp.h is obsolete and buggy, and should be desupported
  [18699] math: tilegx cproj() for various complex infinities does not yield
    infinity
  [18724] libc: Harden put*ent functions against data injection
  [18743] nptl: PowerPC: findutils testcase fails with --enable-lock-elision
  [18755] build: build errors with -DNDEBUG
  [18757] stdio: fmemopen fails to set errno on failure
  [18778] dynamic-link: ld.so crashes if failed dlopen causes libpthread to
    be forced unloaded
  [18781] libc: openat64 lacks O_LARGEFILE
  [18787] libc: [hppa] sysdeps/unix/sysv/linux/hppa/bits/atomic.h:71:6:
    error: can’t find a register in class ‘R1_REGS’ while reloading ‘asm’
  [18789] math: [ldbl-128ibm] sinhl inaccurate near 0
  [18790] math: [ldbl-128ibm] tanhl inaccurate
  [18795] libc: stpncpy fortification misses buffer lengths that are
    statically too large
  [18796] build: build fails for --disable-mathvec
  [18803] math: hypot missing underflows
  [18820] stdio: fmemopen may leak memory on failure
  [18823] math: csqrt spurious underflows
  [18824] math: fma spurious underflows
  [18825] math: pow missing underflows
  [18857] math: [ldbl-128ibm] nearbyintl wrongly uses signaling comparisons
  [18868] nptl: pthread_barrier_init typo has in-theory-undefined behavior
  [18870] build: sem_open.c fails to compile with missing symbol
    FUTEX_SHARED
  [18872] stdio: Fix memory leak in printf_positional
  [18873] libc: posix_fallocate overflow check ineffective
  [18875] math: Excess precision leads incorrect libm
  [18877] libc: arm: mmap offset regression
  [18887] libc: memory corruption when using getmntent on blank lines
  [18918] localedata: hu_HU: change time to HH:MM:SS format
  [18921] libc: Regression: extraneous stat() and fstat() performed by
    opendir()
  [18928] dynamic-link: LD_POINTER_GUARD is not ignored for privileged
    binaries (CVE-2015-8777)
  [18951] math: tgamma missing underflows
  [18952] math: [ldbl-128/ldbl-128ibm] lgammal spurious "invalid", incorrect
    signgam
  [18953] localedata: lt_LT: change currency symbol to the euro
  [18956] math: powf inaccuracy
  [18961] math: [i386] exp missing underflows
  [18966] math: [i386] exp10 missing underflows
  [18967] math: math.h XSI POSIX namespace (gamma, isnan, scalb)
  [18969] build: multiple string test failures due to missing locale
    dependencies
  [18970] libc: Reference of pthread_setcancelstate in libc.a
  [18977] math: float / long double Bessel functions not in XSI POSIX
  [18980] math: i386 libm functions return with excess range and precision
  [18981] math: i386 scalb*, ldexp return with excess range and precision
  [18982] stdio: va_list and vprintf
  [18985] time: Passing out of range data to strftime() causes a segfault
    (CVE-2015-8776)
  [19003] math: [x86_64] fma4 version of pow inappropriate contraction
  [19007] libc: FAIL: elf/check-localplt with -z now and binutils 2.26
  [19012] locale: iconv_open leaks memory on error path
  [19016] math: clog, clog10 inaccuracy
  [19018] nptl: Mangle function pointers in tls_dtor_list
  [19032] math: [i386] acosh (-qNaN) spurious "invalid" exception
  [19046] math: ldbl-128 / ldbl-128ibm lgamma bad overflow handling
  [19048] malloc: malloc: arena free list can become cyclic, increasing
    contention
  [19049] math: [powerpc] erfc incorrect zero sign
  [19050] math: [powerpc] log* incorrect zero sign
  [19058] math: [x86_64] Link fail with -fopenmp and -flto
  [19059] math: nexttoward overflow incorrect in non-default rounding modes
  [19071] math: ldbl-96 lroundl incorrect just below powers of 2
  [19074] network: Data race in _res_hconf_reorder_addrs
  [19076] math: [ldbl-128ibm] log1pl (-1) wrong sign of infinity
  [19077] math: [ldbl-128ibm] logl (1) incorrect sign of zero result
  [19078] math: [ldbl-128ibm] expl overflow incorrect in non-default
    rounding modes
  [19079] math: dbl-64/wordsize-64 lround based on llround incorrect for
    ILP32
  [19085] math: ldbl-128 lrintl, lroundl missing exceptions for 32-bit long
  [19086] manual: posix_fallocate64 documented argument order is wrong.
  [19088] math: lround, llround missing exceptions close to overflow
    threshold
  [19094] math: lrint, llrint missing exceptions close to overflow threshold
  [19095] math: dbl-64 lrint incorrect for 64-bit long
  [19122] dynamic-link: Unnecessary PLT relocations in librtld.os
  [19124] dynamic-link: ld.so failed to build with older assmebler
  [19125] math: [powerpc32] llroundf, llround incorrect exceptions
  [19129] dynamic-link: [arm] Concurrent lazy TLSDESC resolution can crash
  [19134] math: [powerpc32] lround, lroundf spurious exceptions
  [19137] libc: i386/epoll_pwait.S doesn't support cancellation
  [19143] nptl: Remove CPU set size checking from sched_setaffinity,
    pthread_setaffinity_np
  [19156] math: [ldbl-128] j0l spurious underflows
  [19164] nptl: tst-getcpu fails with many possible CPUs
  [19168] math: math/test-ildoubl and math/test-ldouble failure
  [19174] nptl: PowerPC: TLE enabled pthread mutex performs poorly.
  [19178] dynamic-link: ELF_RTYPE_CLASS_EXTERN_PROTECTED_DATA confuses
    prelink
  [19181] math: [i386/x86_64] fesetenv (FE_DFL_ENV), fesetenv
    (FE_NOMASK_ENV) do not clear SSE exceptions
  [19182] malloc: malloc deadlock between ptmalloc_lock_all and
    _int_new_arena/reused_arena
  [19189] math: [ldbl-128] log1pl (-qNaN) spurious "invalid" exception
  [19201] math: dbl-64 remainder incorrect sign of zero result
  [19205] math: bits/math-finite.h conditions do not match math.h and
    bits/mathcalls.h
  [19209] math: bits/math-finite.h wrongly maps ldexp to scalbn
  [19211] math: lgamma functions do not set signgam for -ffinite-math-only
    for C99-based standards
  [19212] libc: features.h not -Wundef clean
  [19213] math: [i386/x86_64] log* (1) incorrect zero sign for -ffinite-
    math-only
  [19214] libc: Family and model identification for AMD CPU's are incorrect.
  [19219] libc: GLIBC build fails for ia64 with missing __nearbyintl
  [19228] math: [powerpc] nearbyint wrongly clears "inexact", leaves traps
    disabled
  [19235] math: [powerpc64] lround, lroundf, llround, llroundf spurious
    "inexact" exceptions
  [19238] math: [powerpc] round, roundf spurious "inexact" for integer
    arguments
  [19242] libc: strtol incorrect in Turkish locales
  [19243] malloc: reused_arena can pick an arena on the free list, leading
    to an assertion failure and reference count corruption
  [19253] time: tzset() ineffective when temporary TZ did not include DST
    rules
  [19266] math: strtod ("NAN(I)") incorrect in Turkish locales
  [19270] math: [hppa] Shared libm missing __isnanl
  [19285] libc: [hppa] sysdeps/unix/sysv/linux/hppa/bits/mman.h: missing
    MAP_HUGETLB and MAP_STACK defines
  [19313] nptl: Wrong __cpu_mask for x32
  [19347] libc: grantpt: try to force a specific gid even without pt_chown
  [19349] math: [ldbl-128ibm] tanhl inaccurate for small arguments
  [19350] math: [ldbl-128ibm] sinhl spurious overflows
  [19351] math: [ldbl-128ibm] logl inaccurate near 1
  [19363] time: x32: times() return value wrongly truncates/sign extends
    from 32bit
  [19367] dynamic-link: Improve branch prediction on Silvermont
  [19369] network: Default domain name not reset by res_ninit when "search"
    / "domain" entry is removed from resolv.conf
  [19375] math: powerpc: incorrect results for POWER7 logb with negative
    subnormals
  [19385] localedata: bg_BG: time separator should be colon, not comma
  [19408] libc: linux personality syscall wrapper may erroneously return an
    error on 32-bit architectures
  [19415] libc: dladdr returns wrong names on hppa
  [19432] libc: iconv rejects redundant escape sequences in IBM900, IBM903,
    IBM905, IBM907, and IBM909
  [19439] math: Unix98 isinf and isnan functions conflict with C++11
  [19443] build: build failures with -DDEBUG
  [19451] build: Make check fails on test-double-vlen2
  [19462] libc: Glibc failed to build with -Os
  [19465] math: Wrong code with -Os
  [19466] time: time/tst-mktime2.c is compiled into an infinite loop with
    -Os
  [19467] string: Fast_Unaligned_Load needs to be enabled for Excavator core
    CPU's.
  [19475] libc: Glibc 2.22 doesn't build on sparc [PATCH]
  [19486] math: S390: Math tests fail with "Exception Inexact set".
  [19529] libc: [ARM]: FAIL: stdlib/tst-makecontext
  [19550] libc: [mips] mmap negative offset handling inconsistent with other
    architectures
  [19590] math: Fail to build shared objects that use libmvec.so functions.
\f
Version 2.22

* The following bugs are resolved with this release:

  438, 2981, 4719, 6544, 6792, 11216, 12836, 13028, 13064, 13151, 13152,
  14094, 14113, 14292, 14841, 14906, 14958, 15319, 15467, 15790, 15969,
  16159, 16339, 16350, 16351, 16352, 16353, 16361, 16512, 16526, 16538,
  16559, 16560, 16704, 16783, 16850, 17053, 17090, 17195, 17269, 17293,
  17322, 17403, 17475, 17523, 17542, 17569, 17581, 17588, 17596, 17620,
  17621, 17628, 17631, 17692, 17711, 17715, 17776, 17779, 17792, 17833,
  17836, 17841, 17912, 17916, 17930, 17932, 17944, 17949, 17964, 17965,
  17967, 17969, 17977, 17978, 17987, 17991, 17996, 17998, 17999, 18007,
  18019, 18020, 18029, 18030, 18032, 18034, 18036, 18038, 18039, 18042,
  18043, 18046, 18047, 18049, 18068, 18078, 18080, 18093, 18100, 18104,
  18110, 18111, 18116, 18125, 18128, 18134, 18138, 18185, 18196, 18197,
  18206, 18210, 18211, 18217, 18219, 18220, 18221, 18234, 18244, 18245,
  18247, 18287, 18319, 18324, 18333, 18346, 18371, 18383, 18397, 18400,
  18409, 18410, 18412, 18418, 18422, 18434, 18444, 18457, 18468, 18469,
  18470, 18479, 18483, 18495, 18496, 18497, 18498, 18502, 18507, 18508,
  18512, 18513, 18519, 18520, 18522, 18527, 18528, 18529, 18530, 18532,
  18533, 18534, 18536, 18539, 18540, 18542, 18544, 18545, 18546, 18547,
  18549, 18553, 18557, 18558, 18569, 18583, 18585, 18586, 18592, 18593,
  18594, 18602, 18612, 18613, 18619, 18633, 18635, 18641, 18643, 18648,
  18657, 18676, 18694, 18696, 18887.

* Cache information can be queried via sysconf() function on s390 e.g. with
  _SC_LEVEL1_ICACHE_SIZE as argument.

* A buffer overflow in gethostbyname_r and related functions performing DNS
  requests has been fixed.  If the NSS functions were called with a
  misaligned buffer, the buffer length change due to pointer alignment was
  not taken into account.  This could result in application crashes or,
  potentially arbitrary code execution, using crafted, but syntactically
  valid DNS responses.  (CVE-2015-1781)

* The time zone file parser has been made more robust against crafted time
  zone files, avoiding heap buffer overflows related to the processing of
  the tzh_ttisstdcnt and tzh_ttisgmtcnt fields, and a stack overflow due to
  large time zone data files.  Overly long time zone specifiers in the TZ
  variable no longer result in stack overflows and crashes.

* A powerpc and powerpc64 optimization for TLS, similar to TLS descriptors
  for LD and GD on x86 and x86-64, has been implemented.  You will need
  binutils-2.24 or later to enable this optimization.

* Character encoding and ctype tables were updated to Unicode 7.0.0, using
  new generator scripts contributed by Pravin Satpute and Mike FABIAN (Red
  Hat).  These updates cause user visible changes, such as the fix for bug
  17998.

* CVE-2014-8121 The NSS backends shared internal state between the getXXent
  and getXXbyYY NSS calls for the same database, causing a denial-of-service
  condition in some applications.

* Added vector math library named libmvec with the following vectorized x86_64
  implementations: cos, cosf, sin, sinf, sincos, sincosf, log, logf, exp, expf,
  pow, powf.
  The library can be disabled with --disable-mathvec. Use of the functions is
  enabled with -fopenmp -ffast-math starting from -O1 for GCC version >= 4.9.0.
  Shared library libmvec.so is linked in as needed when using -lm (no need to
  specify -lmvec explicitly for not static builds).
  Visit <https://sourceware.org/glibc/wiki/libmvec> for detailed information.

* A new fmemopen implementation has been added with the goal of POSIX
  compliance. The new implementation fixes the following long-standing
  issues: BZ#6544, BZ#11216, BZ#12836, BZ#13151, BZ#13152, and BZ#14292. The
  old implementation is still present for use be by existing binaries.

* The 32-bit sparc sigaction ABI was inadvertently broken in the 2.20 and 2.21
  releases.  It has been fixed to match 2.19 and older, but binaries built
  against 2.20 and 2.21 might need to be recompiled.  See BZ#18694.

* Port to Native Client running on ARMv7-A (--host=arm-nacl).
  Contributed by Roland McGrath (Google).

* The header <regexp.h> is deprecated, and will be removed in a future
  release.  Use of this header will trigger a deprecation warning.
  Application developers should update their code to use <regex.h> instead.

  This header was formerly part of SUS, but was deprecated in 1994 and
  removed from the standard in 2001.  Also, the glibc implementation
  leaks memory.  See BZ#18681 for more details.
\f
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 CVE-2015-1473 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, and switches to malloc from alloca as
  intended.

* 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 application 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.
\f
Version 2.20

* The following bugs are resolved with this release:

  6804, 9894, 11505, 12994, 13347, 13651, 14308, 14770, 15119, 15132, 15347,
  15514, 15698, 15804, 15894, 15946, 16002, 16064, 16095, 16194, 16198,
  16275, 16284, 16287, 16315, 16348, 16349, 16354, 16357, 16362, 16447,
  16516, 16532, 16539, 16545, 16561, 16562, 16564, 16574, 16599, 16600,
  16609, 16610, 16611, 16613, 16619, 16623, 16629, 16632, 16634, 16639,
  16642, 16648, 16649, 16670, 16674, 16677, 16680, 16681, 16683, 16689,
  16695, 16701, 16706, 16707, 16712, 16713, 16714, 16724, 16731, 16739,
  16740, 16743, 16754, 16758, 16759, 16760, 16770, 16786, 16789, 16791,
  16796, 16799, 16800, 16815, 16823, 16824, 16831, 16838, 16839, 16849,
  16854, 16876, 16877, 16878, 16882, 16885, 16888, 16890, 16892, 16912,
  16915, 16916, 16917, 16918, 16922, 16927, 16928, 16932, 16943, 16958,
  16965, 16966, 16967, 16977, 16978, 16984, 16990, 16996, 17009, 17022,
  17031, 17042, 17048, 17050, 17058, 17061, 17062, 17069, 17075, 17078,
  17079, 17084, 17086, 17088, 17092, 17097, 17125, 17135, 17137, 17150,
  17153, 17187, 17213, 17259, 17261, 17262, 17263, 17319, 17325, 17354.

* Reverted change of ABI data structures for s390 and s390x:
  On s390 and s390x the size of struct ucontext and jmp_buf was increased in
  2.19. This change is reverted in 2.20. The introduced 2.19 symbol versions
  of getcontext, setjmp, _setjmp, __sigsetjmp, longjmp, _longjmp, siglongjmp
  are preserved pointing straight to the same implementation as the old ones.
  Given that, new callers will simply provide a too-big buffer to these
  functions. Any applications/libraries out there that embed jmp_buf or
  ucontext_t in an ABI-relevant data structure that have already been rebuilt
  against 2.19 headers will have to rebuilt again. This is necessary in any
  case to revert the breakage in their ABI caused by the glibc change.

* Support for file description locks is added to systems running the
  Linux kernel. The standard file locking interfaces are extended to
  operate on file descriptions, not file descriptors, via the use of
  F_OFD_GETLK, F_OFD_SETLK, and F_OFD_SETLKW. File description locks
  are associated with an open file instead of a process.

* Optimized strchr implementation for AArch64.  Contributed by ARM Ltd.

* The minimum Linux kernel version that this version of the GNU C Library
  can be used with is 2.6.32.

* Running the testsuite no longer terminates as soon as a test fails.
  Instead, a file tests.sum (xtests.sum from "make xcheck") is generated,
  with PASS or FAIL lines for individual tests.  A summary of the results is
  printed, including a list of failing lists, and "make check" exits with
  error status if there were any unexpected failures.  "make check
  stop-on-test-failure=y" may be used to keep the old behavior.

* The am33 port, which had not worked for several years, has been removed
  from ports.

* The _BSD_SOURCE and _SVID_SOURCE feature test macros are no longer
  supported; they now act the same as _DEFAULT_SOURCE (but generate a
  warning).  Except for cases where _BSD_SOURCE enabled BSD interfaces that
  conflicted with POSIX (support for which was removed in 2.19), the
  interfaces those macros enabled remain available when compiling with
  _GNU_SOURCE defined, with _DEFAULT_SOURCE defined, or without any feature
  test macros defined.

* Optimized strcmp implementation for ARMv7.  Contributed by ARM Ltd.

* Added support for TX lock elision of pthread mutexes on s390 and s390x.
  This may improve lock scaling of existing programs on TX capable systems.
  The lock elision code is only built with --enable-lock-elision=yes and
  then requires a GCC version supporting the TX builtins.  With lock elision
  default mutexes are elided via __builtin_tbegin, if the cpu supports
  transactions. By default lock elision is not enabled and the elision code
  is not built.

* CVE-2014-4043 The posix_spawn_file_actions_addopen implementation did not
  copy the path argument.  This allowed programs to cause posix_spawn to
  deference a dangling pointer, or use an unexpected pathname argument if
  the string was modified after the posix_spawn_file_actions_addopen
  invocation.

* All supported architectures now use the main glibc sysdeps directory
  instead of some being in a separate "ports" directory (which was
  distributed separately before glibc 2.17).

* The NPTL implementation of POSIX pthreads is no longer an "add-on".
  On configurations that support it (all Linux configurations), it's now
  used regardless of the --enable-add-ons switch to configure.  It is no
  longer possible to build such configurations without pthreads support.

* Locale names, including those obtained from environment variables (LANG
  and the LC_* variables), are more tightly checked for proper syntax.
  setlocale will now fail (with EINVAL) for locale names that are overly
  long, contain slashes without starting with a slash, or contain ".." path
  components. (CVE-2014-0475)  Previously, some valid locale names were
  silently replaced with the "C" locale when running in AT_SECURE mode
  (e.g., in a SUID program).  This is no longer necessary because of the
  additional checks.

* On x86-64, the dynamic linker's lazy-binding support is now compatible
  with application code using Intel MPX instructions.  (With all previous
  versions, the MPX register state could be clobbered when making calls
  into or out of a shared library.)  Note that while the new dynamic
  linker is compatible with all known x86 hardware whether or not it
  supports Intel MPX, some x86 instruction-set emulators might fail to
  handle the new instruction encodings.  This is known to affect Valgrind
  versions up through 3.9 (but will be fixed in the forthcoming 3.10
  release), and might affect other tools that do instruction emulation.

* Support for loadable gconv transliteration modules has been removed.
  The support for transliteration modules has been non-functional for
  over a decade, and the removal is prompted by security defects.  The
  normal gconv conversion modules are still supported.  Transliteration
  with //TRANSLIT is still possible, and the //IGNORE specifier
  continues to be  supported. (CVE-2014-5119)

* Decoding a crafted input sequence in the character sets IBM933, IBM935,
  IBM937, IBM939, IBM1364 could result in an out-of-bounds array read,
  resulting a denial-of-service security vulnerability in applications which
  use functions related to iconv. (CVE-2014-6040)
\f
Version 2.19

* The following bugs are resolved with this release:

  156, 387, 431, 762, 832, 926, 2801, 4772, 6786, 6787, 6807, 6810, 6981,
  7003, 9721, 9954, 10253, 10278, 11087, 11157, 11214, 12100, 12486, 12751,
  12986, 13028, 13982, 13985, 14029, 14032, 14120, 14143, 14155, 14286,
  14547, 14699, 14752, 14782, 14876, 14910, 15004, 15048, 15073, 15089,
  15128, 15218, 15268, 15277, 15308, 15362, 15374, 15400, 15425, 15427,
  15483, 15522, 15531, 15532, 15593, 15601, 15608, 15609, 15610, 15632,
  15640, 15670, 15672, 15680, 15681, 15723, 15734, 15735, 15736, 15748,
  15749, 15754, 15760, 15763, 15764, 15797, 15799, 15825, 15843, 15844,
  15846, 15847, 15849, 15850, 15855, 15856, 15857, 15859, 15867, 15886,
  15887, 15890, 15892, 15893, 15895, 15897, 15901, 15905, 15909, 15915,
  15917, 15919, 15921, 15923, 15939, 15941, 15948, 15963, 15966, 15968,
  15985, 15988, 15997, 16032, 16034, 16036, 16037, 16038, 16041, 16046,
  16055, 16071, 16072, 16074, 16077, 16078, 16103, 16112, 16143, 16144,
  16146, 16150, 16151, 16153, 16167, 16169, 16172, 16195, 16214, 16245,
  16271, 16274, 16283, 16289, 16293, 16314, 16316, 16330, 16337, 16338,
  16356, 16365, 16366, 16369, 16372, 16375, 16379, 16381, 16384, 16385,
  16386, 16387, 16390, 16394, 16398, 16400, 16407, 16408, 16414, 16430,
  16431, 16453, 16474, 16506, 16510, 16529

* Slovenian translations for glibc messages have been contributed by the
  Translation Project's Slovenian team of translators.

* The public headers no longer use __unused nor __block.  This change is to
  support compiling programs that are derived from BSD sources and use
  __unused internally, and to support compiling with Clang's -fblock
  extension which uses __block.

* CVE-2012-4412 The strcoll implementation caches indices and rules for
  large collation sequences to optimize multiple passes.  This cache
  computation may overflow for large collation sequences and may cause a
  stack or buffer overflow.  This is now fixed to use a slower algorithm
  which does not use a cache if there is an integer overflow.

* CVE-2012-4424 The strcoll implementation uses malloc to cache indices and
  rules for large collation sequences to optimize multiple passes and falls
  back to alloca if malloc fails, resulting in a possible stack overflow.
  The implementation now falls back to an uncached collation sequence lookup
  if malloc fails.

* CVE-2013-4788 The pointer guard used for pointer mangling was not
  initialized for static applications resulting in the security feature
  being disabled. The pointer guard is now correctly initialized to a
  random value for static applications. Existing static applications need
  to be recompiled to take advantage of the fix (bug 15754).

* CVE-2013-4237 The readdir_r function could write more than NAME_MAX bytes
  to the d_name member of struct dirent, or omit the terminating NUL
  character.  (Bugzilla #14699).

* CVE-2013-4332 The pvalloc, valloc, memalign, posix_memalign and
  aligned_alloc functions could allocate too few bytes or corrupt the
  heap when passed very large allocation size values (Bugzilla #15855,
  #15856, #15857).

* CVE-2013-4458 Stack overflow in getaddrinfo with large number of results
  for AF_INET6 has been fixed (Bugzilla #16072).

* New locales: ak_GH, anp_IN, ar_SS, cmn_TW, hak_TW, lzh_TW, nan_TW, pap_AW,
  pap_CW, quz_PE, the_NP.

* Substantially revised locales: gd_GB, ht_HT

* The LC_ADDRESS field was updated to support country_car for almost all
  supported locales.

* ISO 1427 definitions were updated.

* ISO 3166 definitions were updated.

* The localedef utility now supports --big-endian and --little-endian
  command-line options to generate locales for a different system from that
  for which the C library was built.

* Binary locale files now only depend on the endianness of the system for
  which they are generated and not on other properties of that system.  As a
  consequence, binary files generated with new localedef may be incompatible
  with old versions of the GNU C Library, and binary files generated with
  old localedef may be incompatible with this version of the GNU C Library,
  in the following circumstances:

  + Locale files may be incompatible on m68k systems.

  + Locale archive files (but not separate files for individual locales) may
    be incompatible on systems where plain "char" is signed.

* The configure option --disable-versioning has been removed.  Builds with
  --disable-versioning had not worked for several years.

* ISO 639 definitions were updated for Chiga (cgg) and Chinese (gan, hak, czh,
  cjy, lzh, cmn, mnp, cdo, czo, cpx, wuu, hsn, yue).

* SystemTap probes for malloc have been introduced.

* SystemTap probes for slow multiple precision fallback paths of
  transcendental functions have been introduced.

* Support for powerpc64le has been added.

* The soft-float powerpc port now supports e500 processors.

* Support for STT_GNU_IFUNC symbols added for ppc32/power4+ and ppc64.

* A new feature test macro _DEFAULT_SOURCE is available to enable the same
  set of header declarations that are enabled by default, even when other
  feature test macros or compiler options such as -std=c99 would otherwise
  disable some of those declarations.

* The _BSD_SOURCE feature test macro no longer enables BSD interfaces that
  conflict with POSIX.  The libbsd-compat library (which was a dummy library
  that did nothing) has also been removed.

* Preliminary documentation about Multi-Thread, Async-Signal and
  Async-Cancel Safety has been added.

* Change of ABI data structures for s390 and s390x:
  On s390 and s390x the size of struct ucontext and jmp_buf was increased to
  allow for future hardware extensions. All library functions that accept or
  return these structures were versioned in order to provide backwards
  compatibility with existing code. However, not all cases can be handled
  with interface versioning. If an application embeds either structure into
  another structure and that structure is passed to another compilation unit
  which expects the newer larger-sized object then any access to the new
  fields will result in undefined behaviour. Similarly any access to fields
  that were moved by the enlarging of the structures will cause undefined
  behaviour. To fix the undefined behaviour all objects that are part of the
  final in-memory image must agree on the size of structures, and this may
  require recompilation.
\f
Version 2.18

* The following bugs are resolved with this release:

  2546, 2560, 5159, 6809, 7006, 10060, 10062, 10283, 10357, 10686, 11120,
  11561, 12310, 12387, 12492, 12515, 12723, 13550, 13889, 13951, 13988,
  14142, 14176, 14200, 14256, 14280, 14293, 14317, 14327, 14478, 14496,
  14582, 14686, 14812, 14888, 14894, 14907, 14908, 14909, 14920, 14941,
  14952, 14964, 14981, 14982, 14985, 14991, 14994, 14996, 15000, 15003,
  15006, 15007, 15014, 15020, 15022, 15023, 15036, 15054, 15055, 15062,
  15078, 15084, 15085, 15086, 15100, 15160, 15214, 15221, 15232, 15234,
  15283, 15285, 15287, 15304, 15305, 15307, 15309, 15327, 15330, 15335,
  15336, 15337, 15339, 15342, 15346, 15359, 15361, 15366, 15380, 15381,
  15394, 15395, 15405, 15406, 15409, 15416, 15418, 15419, 15423, 15424,
  15426, 15429, 15431, 15432, 15441, 15442, 15448, 15465, 15480, 15485,
  15488, 15490, 15492, 15493, 15497, 15506, 15529, 15536, 15553, 15577,
  15583, 15618, 15627, 15631, 15654, 15655, 15666, 15667, 15674, 15711,
  15755, 15759.

* CVE-2013-2207 Incorrectly granting access to another user's pseudo-terminal
  has been fixed by disabling the use of pt_chown (Bugzilla #15755).
  Distributions can re-enable building and using pt_chown via the new configure
  option `--enable-pt_chown'.  Enabling the use of pt_chown carries with it
  considerable security risks and should only be used if the distribution
  understands and accepts the risks.

* CVE-2013-0242 Buffer overrun in regexp matcher has been fixed (Bugzilla
  #15078).

* CVE-2013-1914 Stack overflow in getaddrinfo with many results has been
  fixed (Bugzilla #15330).

* Add support for calling C++11 thread_local object destructors on thread
  and program exit.  This needs compiler support for offloading C++11
  destructor calls to glibc.

* Improved worst case performance of libm functions with double inputs and
  output.

* Support for priority inherited mutexes in pthread condition variables on
  non-x86 architectures.

* Port to Xilinx MicroBlaze contributed by David Holsgrove.

* Optimized string functions for AArch64.  Implemented by Marcus Shawcroft.

* Optimized string functions for ARM.  Implemented by Will Newton and
  Richard Henderson.

* Optimized libm functions for SPARC.  Implemented by David S. Miller.

* Support for building more of ARM glibc as Thumb-2 code.  Implemented by
  Richard Henderson.

* Support for building most of MIPS glibc as MIPS16 code.  Implemented by
  Chung-Lin Tang, Maciej W. Rozycki and Maxim Kuvyrkov.

* Added a benchmark framework to track performance of functions in glibc.

* New <math.h> macro named issignaling to check for a signaling NaN (sNaN).
  It is based on draft TS 18661 and currently enabled as a GNU extension.

* On Linux, the clock function now uses the clock_gettime system call
  for improved precision, rather than old times system call.

* Added support for version-3 tz format files.  This is needed when using
  the tz database release 2013e or later, and affects a few unusual cases --
  currently only TZ='America/Godthab' for time stamps after 2037.

* Added new API functions pthread_getattr_default_np and
  pthread_setattr_default_np to get and set the default pthread
  attributes of a process.

* Added support for TSX lock elision for pthread mutexes on i386 and x86-64.
  This may improve lock scaling of existing programs on TSX capable systems.
  When the --enable-lock-elision=yes parameter is specified at configure
  time lock elision will be enabled by default for all PTHREAD_MUTEX_DEFAULT
  mutexes.

* Support added for AT_HWCAP2 (to coincide with Linux kernel 3.10
  availability).  Implemented by Ryan S. Arnold.

* Support added for POWER8 platform.  Implemented by Ryan S. Arnold.
\f
Version 2.17

* The following bugs are resolved with this release:

  1349, 3439, 3479, 3665, 5044, 5246, 5298, 5400, 6530, 6677, 6778, 6808,
  9685, 9914, 10014, 10038, 10114, 10191, 10631, 10873, 11438, 11607, 11638,
  11741, 12140, 13013, 13412, 13542, 13601, 13603, 13604, 13629, 13679,
  13696, 13698, 13717, 13741, 13759, 13761, 13763, 13881, 13939, 13950,
  13952, 13966, 14042, 14047, 14090, 14150, 14151, 14152, 14154, 14157,
  14166, 14173, 14195, 14197, 14237, 14246, 14251, 14252, 14283, 14298,
  14303, 14307, 14328, 14331, 14336, 14337, 14347, 14349, 14368, 14376,
  14417, 14447, 14459, 14476, 14477, 14501, 14505, 14510, 14516, 14518,
  14519, 14530, 14532, 14538, 14543, 14544, 14545, 14557, 14562, 14568,
  14576, 14579, 14583, 14587, 14595, 14602, 14610, 14621, 14638, 14645,
  14648, 14652, 14660, 14661, 14669, 14672, 14683, 14694, 14716, 14719,
  14743, 14767, 14783, 14784, 14785, 14793, 14796, 14797, 14801, 14803,
  14805, 14807, 14811, 14815, 14821, 14822, 14824, 14828, 14831, 14833,
  14835, 14838, 14856, 14863, 14865, 14866, 14868, 14869, 14871, 14872,
  14879, 14889, 14893, 14898, 14914.

* Optimization of memcpy for MIPS.

* CVE-2011-4609 svc_run() produces high cpu usage when accept fails with
  EMFILE has been fixed (Bugzilla #14889).

* The add-on ports collection is now distributed in the "ports" subdirectory
  of the main GNU C Library distribution, rather than separately.

* Port to ARM AArch64 contributed by Linaro.

* Support for STT_GNU_IFUNC symbols added for s390 and s390x.
  Optimized versions of memcpy, memset, and memcmp added for System z10 and
  zEnterprise z196.
  Implemented by Andreas Krebbel.

* The new function secure_getenv allows secure access to the environment,
  returning NULL if running in a SUID/SGID process.  This function replaces
  the internal function __secure_getenv.

* SystemTap static probes have been added into the dynamic linker.
  Implemented by Gary Benson.

* Optimizations of string functions strstr, strcasestr and memmem.
  Implemented by Maxim Kuvyrkov.

* The minimum Linux kernel version that this version of the GNU C Library
  can be used with is 2.6.16.

* Optimizations of string functions memchr, wcschr, wcscpy, and wcsrchr for
  powerpc POWER7.  Implemented by Will Schmidt.

* New configure option --disable-nscd builds the C library such that it
  never attempts to contact the Name Service Caching Daemon (nscd).
  New configure option --disable-build-nscd avoids building nscd itself;
  this is the default if --disable-nscd is used.

* Improved support for cross-compilation, including cross-testing and
  bootstrap builds without a previously built glibc.

* Several testsuite tests are now able to test multiple IFUNC variants of an
  interface, rather than just testing the one that would be chooen by
  default.

* New configure options --with-bugurl and --with-pkgversion, for
  distributors to use to embed their bug-reporting and package version
  information in --help and --version output.

* The ttyname and ttyname_r functions on Linux now fall back to searching for
  the tty file descriptor in /dev/pts or /dev if /proc is not available.  This
  allows creation of chroots without the procfs mounted on /proc.

* The `crypt' function now fails if passed salt bytes that violate the
  specification for those values.  On Linux, the `crypt' function will
  consult /proc/sys/crypto/fips_enabled to determine if "FIPS mode" is
  enabled, and fail on encrypted strings using the MD5 or DES algorithm
  when the mode is enabled.

* The `clock_*' suite of functions (declared in <time.h>) is now available
  directly in the main C library.  Previously it was necessary to link with
  -lrt to use these functions.  This change has the effect that a
  single-threaded program that uses a function such as `clock_gettime' (and
  is not linked with -lrt) will no longer implicitly load the pthreads
  library at runtime and so will not suffer the overheads associated with
  multi-thread support in other code such as the C++ runtime library.

* New locales: ayc_PE, doi_IN, ia_FR, mni_IN, nhn_MX, niu_NU, niu_NZ,
  sat_IN, and szl_PL.
\f
Version 2.16

* The following bugs are resolved with this release:

  174, 208, 350, 369, 411, 706, 766, 2074, 2541, 2547, 2548, 2550, 2551,
  2552, 2553, 2554, 2562, 2563, 2565, 2566, 2570, 2576, 2636, 2678, 3335,
  3440, 3748, 3768, 3866, 3868, 3906, 3976, 3992, 4026, 4108, 4596, 4822,
  5077, 5461, 5805, 5993, 6471, 6486, 6578, 6649, 6730, 6770, 6794, 6884,
  6890, 6894, 6895, 6907, 6911, 6959, 7064, 9739, 9902, 10110, 10135, 10140,
  10153, 10210, 10254, 10346, 10375, 10545, 10716, 10846, 10882, 11174,
  11261, 11322, 11365, 11451, 11494, 11521, 11677, 11837, 11959, 12047,
  12097, 12193, 12194, 12297, 12298, 12301, 12340, 12354, 12416, 12495,
  13058, 13223, 13361, 13525, 13526, 13527, 13528, 13529, 13530, 13531,
  13532, 13533, 13547, 13551, 13552, 13553, 13555, 13556, 13559, 13563,
  13566, 13576, 13579, 13583, 13592, 13594, 13613, 13618, 13637, 13656,
  13658, 13673, 13691, 13695, 13704, 13705, 13706, 13718, 13726, 13738,
  13739, 13743, 13750, 13758, 13760, 13761, 13775, 13786, 13787, 13792,
  13806, 13824, 13840, 13841, 13844, 13846, 13848, 13851, 13852, 13854,
  13871, 13872, 13873, 13879, 13882, 13883, 13884, 13885, 13886, 13892,
  13895, 13908, 13910, 13911, 13912, 13913, 13914, 13915, 13916, 13917,
  13918, 13919, 13920, 13921, 13922, 13923, 13924, 13926, 13927, 13928,
  13938, 13941, 13942, 13954, 13955, 13956, 13963, 13967, 13968, 13970,
  13973, 13979, 13983, 13986, 13996, 14012, 14027, 14033, 14034, 14036,
  14040, 14043, 14044, 14048, 14049, 14050, 14053, 14055, 14059, 14064,
  14075, 14080, 14083, 14103, 14104, 14109, 14112, 14117, 14122, 14123,
  14134, 14153, 14183, 14188, 14199, 14210, 14218, 14229, 14241, 14273,
  14277, 14278.

* Support for the x32 ABI on x86-64 added.  The x32 target is selected by
  configuring glibc with:
        BUILD_CC='gcc' CC='gcc -mx32' CXX='g++ -mx32'
  Visit <https://sites.google.com/site/x32abi/> for more x32 ABI info.
  Implemented by H.J. Lu.

* ISO C11 support:

  + define static_assert

  + do not declare gets

  + declare at_quick_exit and quick_exit also for ISO C11

  + aligned_alloc.  NB: The code is deliberately allows the size parameter
    to not be a multiple of the alignment.  This is a moronic requirement
    in the standard but it is only a requirement on the caller, not the
    implementation.

  + timespec_get added

  + uchar.h support added

  + CMPLX, CMPLXF, CMPLXL added

  Implemented by Ulrich Drepper.

* Support for the IA-64 has been moved to ports.

* Remove support for anything but ELF binary format

* Checking versions of poll, ppoll added.
  Implemented by Ulrich Drepper.

* More generic and 64-bit performance optimizations to math functions.
  Implemented by Ulrich Drepper.

* New configure option --enable-obsolete-rpc makes the deprecated RPC
  headers and functions available at compile time as they were before
  version 2.14.  This option will be removed at some time in the future
  after the TI-RPC library becomes fully sufficient for the needs of
  existing applications.

* Compatibility code for Linux kernel versions before 2.4 has been removed.
  Note that glibc is not expected to work with any Linux kernel version
  before 2.6.

* New header <sys/auxv.h> and function getauxval allowing easy access to
  the AT_* key-value pairs passed from the Linux kernel.  The header also
  defines the HWCAP_* bits associated with the AT_HWCAP key.

* New locales: mag_IN

* New configure option --enable-systemtap builds SystemTap static probes
  into libc for setjmp and longjmp and into libpthread for various operations.
  So far the setjmp/longjmp probes and some of the libpthread probes are
  provided only for i*86 and x86_64.
  Implemented by Roland McGrath and Rayson Ho.

* Optimized expf for x86-32 and x86-64.  Implemented by Liubov Dmitrieva.

* More optimized functions for PowerPC.  Implemented by Adhemerval Zanella
  and Will Schmidt.

* More optimized functions for SPARC.  Implemented by David S. Miller.

* Improved support for cross-compilation, especially bootstrap builds
  without a previously built glibc.

* Ports for the TILE-Gx and TILEPro families of processors.  Contributed by
  Chris Metcalf from Tilera.

* Support for the old ARM ABI has been removed from ports.  Only the EABI is
  now supported for ARM processors.

* The hard-float variant of the ARM EABI now uses /lib/ld-linux-armhf.so.3
  as the name of the dynamic linker, to distinguish it from the
  /lib/ld-linux.so.3 dynamic linker used for the base EABI.

* Support for CRIS has been removed from ports.

* A new class of installed header has been documented for low-level
  platform-specific functionality.  PowerPC added the first instance with a
  function to provide time base register access.  Contributed by Tulio
  Magno Quites Machado Filho.

* ix86 configurations now install header files that are consistent with
  what x86-64 configurations install.  These same header files can be used
  for -m32, -m64, or -mx32 builds.
  Contributed by H.J. Lu.

* Math library bug fixes.  A thorough audit of all open math library bugs was
  conducted by Joseph Myers.  Significant progress was made on many math
  library bugs resulting in more accurate exceptions and function results.
  Many thanks to all those that contributed including Andreas Jaeger for his
  patch review and work on the x87 trigonometric instruction issues.

* Timezone data is no longer installed.  Timezone-related binaries and scripts
  will continue to be installed.  Users should obtain their timezone data from
  their distribution provider or from the tzdata package at
  <ftp://munnari.oz.au/pub/>.
\f
Version 2.15

* The following bugs are resolved with this release:

  6779, 6783, 9696, 10103, 10709, 11589, 11929, 12403, 12786, 12840, 12847,
  12868, 12852, 12874, 12885, 12892, 12906, 12907, 12922, 12935, 12962,
  13007, 13021, 13061, 13062, 13067, 13068, 13085, 13088, 13090, 13092,
  13096, 13114, 13118, 13123, 13134, 13138, 13147, 13150, 13166, 13179,
  13185, 13189, 13192, 13268, 13276, 13282, 13291, 13305, 13328, 13335,
  13337, 13344, 13358, 13367, 13413, 13416, 13423, 13439, 13446, 13472,
  13484, 13506, 13515, 13523, 13524, 13538, 13540

* New program pldd to list loaded object of a process
  Implemented by Ulrich Drepper.

* Add nss_db support back to glibc.  No more dependency on Berkeley db
  and support for initgroups lookups.
  Implemented by Ulrich Drepper.

* Optimized strcpy, strncpy, stpcpy, stpncpy for SSE2 and SSSE3 on x86-32.
  Contributed by HJ Lu.

* Improved strcpy, strncpy, stpcpy, stpncpy for SSE2 and SSSE3 on x86-64.
  Contributed by HJ Lu.

* Optimized strcat, strncat on x86-64 and optimized wcscmp, wcslen, strnlen
  on x86-32 and x86-64.
  Contributed by Liubov Dmitrieva.

* Optimized strchr and strrchr for SSE on x86-32.
  Contributed by Liubov Dmitrieva.

* Optimized memchr, memrchr, rawmemchr, memcmp, wmemcmp, wcschr, wcscpy
  for x86-64 and x86-32.
  Contributed by Liubov Dmitrieva.

* New interfaces: scandirat, scandirat64
  Implemented by Ulrich Drepper.

* Checking versions of FD_SET, FD_CLR, and FD_ISSET added.
  Implemented by Ulrich Drepper.

* nscd now also caches the netgroup database.
  Implemented by Ulrich Drepper.

* Integrate libm with gcc's -ffinite-math-only option.
  Implemented by Ulrich Drepper.

* Lots of generic, 64-bit, and x86-64-specific performance optimizations
  to math functions.  Implemented by Ulrich Drepper.

* Optimized strcasecmp and strncasecmp for AVX on x86-64.
  Implemented by Ulrich Drepper.

* New Linux interfaces: process_vm_readv, process_vm_writev

* Optimized strcasecmp and strncasecmp for SSSE3 and SSE4.2 on x86-32.
  Implemented by Ulrich Drepper.

* Optimized nearbyint and strcasecmp for PPC.
  Implemented by Adhemerval Zanella.

* New locales: bho_IN, unm_US, es_CU, ta_LK
\f
Version 2.14

* The following bugs are resolved with this release:

  386, 6420, 7101, 9730, 9732, 9809, 10138, 10149, 10157, 11099, 11257,
  11258, 11487, 11532, 11558, 11578, 11634, 11653, 11668, 11697, 11724,
  11781, 11799, 11820, 11837, 11857, 11884, 11892, 11895, 11901, 11945,
  11947, 11952, 11987, 12052, 12083, 12158, 12178, 12200, 12346, 12350,
  12393, 12420, 12432, 12445, 12449, 12453, 12454, 12460, 12469, 12489,
  12509, 12510, 12511, 12518, 12527, 12541, 12545, 12551, 12582, 12583,
  12587, 12597, 12601, 12611, 12625, 12626, 12631, 12650, 12653, 12655,
  12660, 12671, 12681, 12684, 12685, 12711, 12713, 12714, 12717, 12723,
  12724, 12734, 12738, 12746, 12766, 12775, 12777, 12782, 12788, 12792,
  12795, 12811, 12813, 12814, 12841

* The RPC implementation in libc is obsoleted.  Old programs keep working
  but new programs cannot be linked with the routines in libc anymore.
  Programs in need of RPC functionality must be linked against TI-RPC.
  The TI-RPC implementation is IPv6 enabled and there are other benefits.

  Visible changes of this change include (obviously) the inability to link
  programs using RPC functions without referencing the TI-RPC library and the
  removal of the RPC headers from the glibc headers.
  Implemented by Ulrich Drepper.

* New Linux interfaces: clock_adjtime, name_to_handle_at, open_by_handle_at,
  syncfs, setns, sendmmsg

* New locales: os_RU, bem_ZA, en_ZA, ff_SN, sw_KE, sw_TZ, lb_LU, wae_CH,
  yue_HK, lij_IT, mhr_RU

* New encodings: CP770, CP771, CP772, CP773, CP774

* New program sotruss to trace calls through PLTs
  Implemented by Ulrich Drepper.

* The malloc hook implementation is marked deprecated and will be removed
  from the default implementation in the next version.  The design never
  worked ever since the introduction of threads.  Even programs which do
  not create threads themselves can use multiple threads created internally.
\f
Version 2.13

* The following bugs are resolved with this release:

  3268, 6812, 7066, 10085, 10484, 10563, 10851, 11149, 11155, 11577, 11611,
  11640, 11655, 11701, 11840, 11856, 11883, 11903, 11904, 11968, 11979,
  12005, 12037, 12067, 12077, 12078, 12092, 12093, 12107, 12108, 12113,
  12140, 12159, 12167, 12191, 12194, 12201, 12204, 12205, 12207, 12348,
  12378, 12394, 12397

* New Linux interfaces: prlimit, prlimit64, fanotify_init, fanotify_mark

* POWER7 optimizations: memset, memcmp, strncmp

* New optimized string functions for x86-64: strnlen (SSE2),
  strcasecmp (SSE2, SSSE3, SSE4.2), strncasecmp (SSE2, SSSE3, SSE4.2)
  Implemented by Ulrich Drepper.
\f
Version 2.12

* The following bugs are resolved with this release:

  3662, 4457, 5553, 10162, 10401, 10414, 10554, 10824, 10864, 10915,
  10918, 10936, 10939, 10958, 10968, 10969, 10972, 10992, 11000, 11001,
  11007, 11010, 11027, 11039, 11040, 11041, 11043, 11046, 11056, 11070,
  11093, 11115, 11125, 11126, 11127, 11134, 11141, 11149, 11183, 11184,
  11185, 11186, 11187, 11188, 11189, 11190, 11191, 11192, 11193, 11194,
  11200, 11230, 11235, 11242, 11254, 11258, 11271, 11272, 11276, 11279,
  11287, 11292, 11319, 11332, 11333, 11387, 11389, 11390, 11394, 11397,
  11410, 11438, 11449, 11470, 11471, 11520, 11537, 11538, 11571

* New interfaces: pthread_getname_np, pthread_setname_np

* New Linux interface: recvmmsg

* STT_GNU_IFUNC implemented for Sparc by David Miller.

* The dynamic linker now recognizes supported ABI versions from the
  EI_ABIVERSION field in the ELF header.
  Implemented by Ulrich Drepper.

* New NIS mode selector ADJUNCT_AS_SHADOW.  The passwd.adjunct.byname table
  will not be used to fill in password fields in the passwd.byname replies.
  Instead it is used to synthesize the shadow.byname table, should it be
  missing.  This is a useful mode in some installations involving Solaris.
  Implemented by Ulrich Drepper.

* New locales: kok_IN, sq_MK, cv_RU
\f
Version 2.11

* The following bugs are resolved with this release:

  3270, 7094, 9924, 9986, 10011, 10085, 10107, 10159, 10162, 10166, 10183,
  10195, 10196, 10200, 10203, 10207, 10211, 10213, 10217, 10221, 10229,
  10262, 10286, 10312, 10315, 10319, 10349, 10360, 10391, 10402, 10416,
  10418, 10422, 10425, 10446, 10448, 10452, 10540, 10553, 10560, 10564,
  10609, 10643, 10692, 10713, 10717, 10730, 10731, 10742, 10780, 10784,
  10789, 10817, 10823, 10840, 10847

* New interfaces: execvpe, pthread_sigqueue, mkstemps, mkstemps64, mkostemps,
  mkostemps64
  Implemented by Ulrich Drepper.

* Checking version of longjmp added that fails if an uninitialized stack
  frame would be created.  Implemented by Ulrich Drepper.

* STT_GNU_IFUNC is now supported in static executables.
  Implemented by H.J. Lu.

* STT_GNU_IFUNC implemented for PPC by Alan Modra.

* New optimized string functions for x86-64: strstr, strcasestr, memcmp,
  strcspn, strpbrk, strspn, strcpy, stpcpy, strncpy, strcmp (SSE2, SSE4.2),
  strncmp (SSE2, SSE4.2), strchr (SSE4.2), strrchr (SSE4.2).
  Contributed by H.J. Lu.

  strlen, rawmemchr, strcmp (SSSE3), strncmp (SSSE3).
  Implemented by Ulrich Drepper.

* New optimized string functions for x86: strlen, strcspn, strspn, strpbrk,
  strstr, strcasestr.
  Contributed by H.J. Lu.

* Support for fma instruction in AVX on x86-64.
  Implemented by H.J. Lu and Ulrich Drepper.

* AVX support in x86-64 auditing support in ld.so.
  Implemented by H.J. Lu.

* STB_GNU_UNIQUE support added.
  Implemented by Ulrich Drepper.

* Implement second fallback mode for optimized DNS lookup for even more
  broken environments.  If two requests from the same port are not
  handled correctly close the socket and open a new one before sending
  the second request.  The 'single-request-reopen' option in /etc/resolv.conf
  can be used to select this mode right away, instead of rediscovering the
  necessity is every process again.
  Implemented by Ulrich Drepper.

* New resolver flag RES_USE_DNSSEC to enable use of verified lookup.
  Implemented by Adam Tkac.

* Optimized iconv conversions for S390x.
  Implemented by Andreas Krebbel.

* Using condvars with PI mutexes is now more efficient due to kernel
  support for requeueing to PI futexes.  NPTL support added for x86-64.
  Implemented by Ulrich Drepper.

* New locales: ps_AF, my_MM
\f
Version 2.10

* The following bugs are resolved with this release:

  697, 5381, 5807, 6411, 6545, 7040, 7058, 7067, 7080, 7083, 7095, 7098,
  9677, 9694, 9697, 9701, 9704, 9705, 9706, 9720, 9726, 9730, 9733, 9736,
  9741, 9750, 9753, 9759, 9781, 9791, 9793, 9823, 9833, 9844, 9880, 9881,
  9891, 9893, 9895, 9913, 9916, 9920, 9948, 9955, 9957, 9963, 9985, 10052,
  10069, 10086, 10087, 10090, 10092, 10093, 10100, 10118, 10128

* New interfaces: preadv, preadv64, pwritev, pwritev64, malloc_info
  Implemented by Ulrich Drepper.

* New Linux interfaces: accept4, fallocate, fallocate64.
  Implemented by Ulrich Drepper.

* Correct declarations of string function when used in C++ code.  This
  could lead to compile errors for invalid C++ code.

* XPG7/POSIX 2008 compilation environment.  Many GNU-specific functions are
  now in POSIX.

* New POSIX 2008 interface: psiginfo
  Implemented by Ulrich Drepper.

* New ISO C++1x interfaces: quick_exit, at_quick_exit
  Implemented by Ulrich Drepper.

* Support for selecting between multiple function definitions at runtime
  using STT_GNU_IFUNC symbols.  Implemented by Ulrich Drepper.

* The libcrypt library can now use the hash function implementations in
  NSS.  Implemented by Ulrich Drepper.

* The malloc implementation can be compiled to be less memory efficient
  but higher performing in multi-threaded programs.
  Implemented by Ulrich Drepper.

* New locales: nan_TW@latin, ks_IN

* Faster strlen, strchr, strchrnul, strrchr, memchr, and rawmemchr for x86-64.
  Implemented by Ulrich Drepper.

* Extended printf hook support.  It is possible to use user-defined types
  and extend existing format specifiers.
  Implemented by Ulrich Drepper.

* Handling for group shadow files has been added.
  Implemented by Ulrich Drepper.

* DNS IPv4-IPv6 parallel lookup now deals better with broken DNS
  servers (the case, e.g., for some people using the built-in DNS
  server in ADSL modems/routers).  There is a once-per-process timeout
  in case of a broken server.  To avoid it, users can run nscd or put
  'options single-request' in /etc/resolv.conf.
  Implemented by Ulrich Drepper.
\f
Version 2.9

* The following bugs are resolved with this release:

  2447, 3406, 5209, 5210, 5381, 5794, 5814, 5911, 6428, 6438, 6442, 6447,
  6461, 6472, 6505, 6544, 6589, 6612, 6634, 6653, 6654, 6657, 6698, 6712,
  6713, 6719, 6723, 6724, 6740, 6763, 6771, 6790, 6791, 6817, 6824, 6839,
  6843, 6845, 6856, 6857, 6860, 6867, 6875, 6919, 6920, 6942, 6947, 6955,
  6966, 6968, 6974, 6980, 6995, 7008, 7009, 7029

* Unified lookup for getaddrinfo: IPv4 and IPv6 addresses are now looked
  up at the same time.  Implemented by Ulrich Drepper.

* TLS descriptors for LD and GD on x86 and x86-64.
  Implemented by Alexandre Oliva.

* getaddrinfo now handles DCCP and UDPlite.
  Implemented by Ulrich Drepper.

* New fixed-size conversion macros: htobe16, htole16, be16toh, le16toh,
  htobe32, htole32, be32toh, le32toh, htobe64, htole64, be64toh, le64toh.
  Implemented by Ulrich Drepper.

* New implementation of memmem, strstr, and strcasestr which is O(n).
  Implemented by Eric Blake.

* New Linux interfaces: inotify_init1, dup3, epoll_create1, pipe2

* Implement "e" option for popen to open file descriptor with the
  close-on-exec flag set.  Implemented by Ulrich Drepper.

* Implement "b" mode for fmemopen.  In this mode writes writes don't
  implicitly add a NUL byte and seeks from the end of the buffer really
  use the buffer end, not the string length as the basis.
  Implemented by Ulrich Drepper.

* Many functions, exported and internal, now atomically set the close-on-exec
  flag when run on a sufficiently new kernel.  Implemented by Ulrich Drepper.

* Sorting rules for some Indian languages (Kannada, Gurumukhi, Telugu,
  Sinhala)
  Implemented by Pravin Satpute.

* New locales: sd_IN, sd_IN@devanagari, ks_IN@devanagari, ht_HT, en_AG, nl_AW.
\f
Version 2.8

* The following bugs are resolved with this release:

  2549, 3112, 4314, 4407, 4997, 5012, 5040, 5112, 5204, 5208, 5209, 5220,
  5222, 5224, 5225, 5237, 5238, 5240, 5245, 5277, 5346, 5375, 5378, 5382,
  5424, 5427, 5428, 5435, 5436, 5439, 5441, 5442, 5443, 5451, 5452, 5454,
  5455, 5463, 5464, 5465, 5475, 5477, 5478, 5520, 5541, 5545, 5553, 5600,
  5602, 5607, 5614, 5627, 5628, 5736, 5737, 5741, 5753, 5760, 5762, 5768,
  5774, 5777, 5778, 5779, 5786, 5790, 5818, 5854, 5857, 5903, 5939, 5979,
  5983, 5995, 5998, 6004, 6007, 6020, 6021, 6024, 6040, 6042

* New locales: bo_CN, bo_IN, shs_CA.

* New encoding: HP-ROMAN9, HP-GREEK8, HP-THAI8, HP-TURKISH8.

* Sorting rules for some Indian languages (Devanagari and Gujarati).
  Implemented by Pravin Satpute.

* IPV6 addresses in /etc/resolv.conf can now have a scope ID

* nscd caches now all timeouts for DNS entries
  Implemented by Ulrich Drepper.

* nscd is more efficient and wakes up less often.
  Implemented by Ulrich Drepper.

* More checking functions: asprintf, dprintf, obstack_printf, vasprintf,
  vdprintf, and obstack_vprintf.
  Implemented by Jakub Jelinek.

* Faster memset for x86-64.
  Implemented by Harsha Jagasia and H.J. Lu.

* Faster memcpy on x86.
  Implemented by Ulrich Drepper.

* ARG_MAX is not anymore constant on Linux.  Use sysconf(_SC_ARG_MAX).
  Implemented by Ulrich Drepper.

* Faster sqrt and sqrtf implemention for some PPC variants.
  Implemented by Steven Munroe.
\f
Version 2.7

* The following bugs are resolved with this release:

  4125, 4126, 4178, 4359, 4407, 4512, 4514, 4525, 4554, 4556, 4557, 4566,
  4582, 4586, 4588, 4599, 4610, 4647, 4702, 4705, 4726, 4745, 4772, 4773,
  4775, 4776, 4792, 4813, 4814, 4816, 4833, 4858, 4860, 4896, 4905, 4925,
  4936, 4937, 4938, 4941, 4946, 4963, 4972, 5010, 5028, 5043, 5058, 5063,
  5071, 5103, 5104, 5112, 5113, 5184, 5186

* More checking functions: fread, fread_unlocked, open*, mq_open.
  Implemented by Jakub Jelinek and Ulrich Drepper.

* Extend fortification to C++.  Implemented by Jakub Jelinek.

* Implement 'm' modifier for scanf.  Add stricter C99/SUS compliance
  by not recognizing 'a' as a modifier when those specs are requested.
  Implemented by Jakub Jelinek.

* PPC optimizations to math and string functions.
  Implemented by Steven Munroe.

* New interfaces: mkostemp, mkostemp64.  Like mkstemp* but allow additional
  options to be passed.  Implemented by Ulrich Drepper.

* More CPU set manipulation functions.  Implemented by Ulrich Drepper.

* New Linux interfaces: signalfd, eventfd, eventfd_read, and eventfd_write.
  Implemented by Ulrich Drepper.

* Handle private futexes in the NPTL implementation.
  Implemented by Jakub Jelinek and Ulrich Drepper.

* Add support for O_CLOEXEC.  Implement in Hurd.  Use throughout libc.
  Implemented by Roland McGrath and Ulrich Drepper.

* Linux/x86-64 vDSO support.  Implemented by Ulrich Drepper.

* SHA-256 and SHA-512 based password encryption.
  Implemented by Ulrich Drepper.

* New locales: ber_DZ, ber_MA, en_NG, fil_PH, fur_IT, fy_DE, ha_NG, ig_NG,
  ik_CA, iu_CA, li_BE, li_NL, nds_DE, nds_NL, pap_AN, sc_IT, tk_TM, ug_CN,
  yo_NG.

+ New iconv modules: MAC-CENTRALEUROPE, ISO-8859-9E, KOI8-RU.
  Implemented by Ulrich Drepper.
\f
Version 2.6

* The following bugs are resolved with this release:

  3156, 3213, 3285, 3291, 3306, 3313, 3320, 3322, 3325, 3326, 3334, 3348,
  3352, 3363, 3369, 3426, 3427, 3429, 3451, 3458, 3465, 3480, 3483, 3493,
  3514, 3515, 3559, 3632, 3664, 3673, 3674, 3745, 3747, 3818, 3840, 3842,
  3851, 3855, 3884, 3885, 3902, 3905, 3919, 3944, 3954, 3955, 3957, 3991,
  3995, 3996, 4024, 4040, 4069, 4070, 4074, 4076, 4096, 4101, 4102, 4114,
  4130, 4131, 4181, 4276, 4306, 4342, 4344, 4349, 4364, 4368, 4381, 4392,
  4403, 4405, 4406, 4411, 4438, 4439, 4455, 4456, 4465, 4512, 4514, 4586,
  4702, 4858

* New Linux interfaces: epoll_pwait, sched_getcpu.

* New generic interfaces: strerror_l.

* nscd can now cache the services database.   Implemented by Ulrich Drepper.
\f
Version 2.5

* The following bugs are resolved with this release:

  39, 68, 192, 352, 388, 531, 935, 1006, 1201, 1203, 1386, 1782, 1783, 1784,
  1785, 1786, 1787, 1951, 1974, 1996, 2072, 2098, 2125, 2134, 2158, 2182,
  2349, 2376, 2386, 2389, 2415, 2418, 2420, 2423, 2450, 2451, 2466, 2472,
  2473, 2477, 2498, 2499, 2501, 2502, 2505, 2507, 2508, 2509, 2517, 2526,
  2569, 2571, 2592, 2611, 2625, 2632, 2644, 2662, 2680, 2683, 2684, 2693,
  2695, 2703, 2734, 2751, 2764, 2766, 2775, 2792, 2821, 2823, 2832, 2841,
  2843, 2883, 2892, 2908, 2914, 2926, 2961, 2978, 2980, 2987, 2997, 2998,
  3013, 3018, 3034, 3040, 3044, 3123, 3124, 3137, 3138, 3143, 3155, 3189,
  3225, 3251, 3252, 3253, 3273

* For Linux, the sorting of addresses returned by getaddrinfo now also
  handles rules 3, 4, and 7 from RFC 3484.  I.e., all rules are handled.
  Implemented by Ulrich Drepper.

* Allow system admin to configure getaddrinfo with the /etc/gai.conf file.
  Implemented by Ulrich Drepper.

* New Linux interfaces: splice, tee, sync_file_range, vmsplice.

* New iconv module for MIK.  Contributed by Alexander Shopov.

* For sites with broken group and/or passwd database, the auto-propagate
  option of nscd can prevent creating ID lookup entries from the results
  of a name lookup and vice versa.   This usually is no problem but some
  site might have problems with the default behavior.
  Implemented by Ulrich Drepper.

* Iterating over entire database in NIS can be slow.  With the
  SETENT_BATCH_READ option in /etc/default/nss a system admin can decide
  to trade time for memory.  The entire database will be read at once.
  Implemented by Ulrich Drepper.

* The interfaces introduced in RFC 3542 have been implemented by
  Ulrich Drepper.

* Support for the new ELF hash table format was added by Ulrich Drepper.

* Support for priority inheritance mutexes added by Jakub Jelinek and
  Ulrich Drepper.

* Support for priority protected mutexes added by Jakub Jelinek.

* New locales: nr_ZA, pa_PK, ca_AD, ca_FR, ca_IT, el_CY, tr_CY, as_IN,
  or_IN, csb_PL, fy_NL, sr_ME.
\f
Version 2.4

* More overflow detection functions.

* New iconv converters for IBM1025, IBM1122, IBM1137, IBM1153,
  IBM1154, IBM1155, IBM1156, IBM1157, and IBM1158 contributed by Jiro Sekiba.

  More converters for IBM803, IBM901, IBM902, IBM921, IBM1008, IBM1097,
  IBM1112, IBM1123, IBM1130, IBM1140, IBM1141, IBM1142, IBM1143, IBM1144,
  IBM1145, IBM1146, IBM1147, IBM1148, IBM1149, IBM1166, IBM1167, IBM4517,
  IBM4899, IBM4909, IBM4971, IBM5347, IBM9030, IBM9066, IBM9448, IBM12712,
  IBM16804, IBM1364, IBM1371, IBM1388, IBM1390, and IBM1399 contributed
  by Masahide Washizawa.

* It is now possible to install audit libraries for the dynamic linker using
  LD_AUDIT.  Implemented by Ulrich Drepper.

* The LinuxThreads add-on, providing pthreads on Linux 2.4 kernels, is no
  longer supported.  The new NPTL implementation requires Linux 2.6 kernels.
  For a libc and libpthread that works well on Linux 2.4 kernels, we
  recommend using the stable 2.3 branch.

* The new function open_wmemstream acts like open_memstream,
  but uses a wchar_t wide character buffer.

* The new function ppoll is an improved version of poll, similar to pselect.

* New interfaces: fdopendir, openat, fstatat, fchmodat, fchownat,
  futimesat, faccessat, mkdirat, mkfifoat, mknodat,
  renameat, unlinkat, linkat, symlinkat, readlinkat.

* New Linux kernel system calls: unshare,
  inotify_init, inotify_add_watch, inotify_rm_watch.

* The euidaccess function is now also known by the alias eaccess,
  for compatibility with some other systems.

* Timezone data updated to 2006b version.
\f
Version 2.3.6

* The following bugs are resolved with this release:

  38, 253, 549, 622, 653, 721, 758, 851, 877, 915, 934, 955, 961,
  1016, 1037, 1076, 1079, 1080, 1081, 1082, 1083, 1084, 1085, 1086,
  1087, 1088, 1090, 1091, 1092, 1093, 1094, 1095, 1096, 1097, 1098,
  1099, 1100, 1101, 1102, 1103, 1104, 1105, 1106, 1107, 1108, 1109,
  1110, 1111, 1112, 1113, 1125, 1137, 1138, 1249, 1250, 1251, 1252,
  1253, 1254, 1350, 1358, 1394, 1438, 1498, 1534

  Visit <https://sourceware.org/bugzilla/> for the details of each bug.

* As of this release, GCC 4 can be used to compile the C Library.

* Timezone data updated to 2005m version.
\f
Version 2.3.5

* The following bugs are resolved with this release:

  284, 592, 602, 626, 633, 640, 650, 661, 671, 681, 693, 700, 710, 719,
  722, 723, 725, 726, 727, 728, 729, 730, 731, 732, 733, 734, 735, 736,
  737, 738, 739, 740, 741, 742, 743, 744, 745, 765, 767, 768, 769, 776,
  777, 787, 821, 822, 823, 825

  Visit <https://sourceware.org/bugzilla/> for the details of each bug.
\f
Version 2.3.4

* Support for RFC 3678.  Real implementations exist only for Linux so far.
  Implemented by Ulrich Drepper.

* nscd can now cache entries persistently.  Expiring entries are reloaded.
  For speedups the cache can be shared in memory with client processes.
  Implemented by Ulrich Drepper.

* nscd can now perform SELinux checks.
  Implemented by Matthew Rickard <mjricka@epoch.ncsc.mil>.

* getaddrinfo queries are now cached.  Canonical name lookup is performed
  efficiently.
  Implemented by Ulrich Drepper.

* The nothrow function attribute is used when headers are used by gcc when
  compiling C code.  This can avoid significant amounts of exception
  handling data.

* The malloc functions perform more error checking and are stricter when
  it comes to reacting on errors.  The default action is to terminate
  the process after showing an error message.  Implemented by Ulrich Drepper.

* Reverse lookups of IPv6 addresses does not use bit string or .ip6.int
  lookups anymore unless explicitly requested.  Implemented by Ulrich Drepper.

* Namespaces in ld.so are implemented.  DSOs can be loaded in separate
  namespaces using the new function dlmopen().  This feature is of course,
  like most other dynamic loading functionality, not available in statically
  linked applications.  Implemented by Ulrich Drepper.

* Low-overhead boundary checking variants of string and some stdio functions
  were added.  These are to be used in conjunction with a gcc patch by
  Jakub Jelinek which adds calls to these functions if possible.
  Implemented by Jakub Jelinek and Ulrich Drepper.

* Old code for several operating systems and machine architectures that
  have not been in working condition in a long time have been removed from
  the main source tree maintained by the GNU C Library's maintainers.
  These files are now reside in the separate `ports' source module
  that is usable as an add-on when building the library.
\f
Version 2.3.3

* New functions `dladdr1' and `dlinfo' in <dlfcn.h> provide more ways to
  interrogate the dynamic linker, compatible with the Solaris interface.

* ELF thread-local storage support (TLS) now works on PowerPC and PowerPC64;
  implemented by Paul Mackerras, Steven Munroe, and Roland McGrath.

* getifaddrs now uses the netlink interface on Linux to get its information.
  Implemented by Thorsten Kukuk.

* getaddrinfo now implements AI_V4MAPPED, AI_ALL, and AI_ADDRCONF.
  Implemented by Ulrich Drepper.

* support for non-executable stacks on x86 has been added.  Changes mostly
  by Roland McGrath.

* regex is now much faster for multibyte locales.  Changes by Jakub Jelinek
  and Ulrich Drepper.

* getaddrinfo now performs destination address selection according to
  RFC 3484.
\f
Version 2.3.2

* Thread-safe interfaces for many functions that access locale data
  were added in version 2.3, but these features were omitted from NEWS.
  Many functions have variants with an `_l' suffix that take a `locale_t'
  object as a parameter rather than consulting the current locale.
  The new functions `newlocale', `duplocale', and `freelocale' in <locale.h>
  create and maintain `locale_t' objects.  Additionally, the new function
  `uselocale' sets "the current locale" (as used by functions not so
  parameterized) set for an individual thread.  These features were added
  in version 2.3, implemented by Ulrich Drepper and Roland McGrath.

* The functions getresuid, getresgid, setresuid, and setresgid, which
  have long been available on Linux, are now declared in <unistd.h>
  and are now also available on the Hurd.

* ELF thread-local storage support (TLS) now works on x86-64.

* The new dynamic string token $LIB is expanded in shared library names.
  This normally expands to lib, but on some 64-bit platforms to lib64 instead.

* Aldy Hernandez contributed complete software floating point support for
  PowerPC machines with no FPU.

* fexecve is implemented on Linux.

* The `btowc' function should work at least twice as fast due to
  specialized callbacks in the iconv modules.  Implemented by Bruno Haible.

* With approriate thread add-ons cancelable functions are now implemented
  in libc.so as well.  No need to call the function in libpthread.  This
  change allowed to finally disable the incorrect and expensive handling
  of weak definition in ld.so.

* Yet more PLT entries in libc.so have been removed.  We finally arrived
  at the bare minimum.  Startup times improved appropriately.

* Support for the new Linux/x86 system call interface was added.  The
  AT_SYSINFO auxiliary vector entry is recognized and handled.
\f
Version 2.3

* Masahide Washizawa contributed iconv modules for IBM1163 and IBM1164
  charsets.

* iconv (the program and the interface) now accepts empty names (excluding
  options like //TRANSLIT) to mean "use charset of current locale".

* localedef can now transliterate characters in strings which are not in
  the provided charmap.  The information from the input locale is used.

* Prelinking support was added for ELF targets.  This requires additional
  tools and recent versions of the GNU binutils.  Contributed by Jakub Jelinek.

* Read-only stdio streams now use mmap to speed up operation by eliminating
  copying and buffer underflows.  To use add 'm' to the mode string of
  the fopen/fdopen/freopen call.  Implemented by Ulrich Drepper.

* The malloc functions were completely rewritten by Wolfram Gloger based
  on Doug Lea's malloc-2.7.0.c.

* Isamu Hasegawa contributed a completely new and POSIX-conformant
  implementation of regex.

* Bruno Haible upgraded the iconv and locale implementation to support
  Unicode 3.2.

* Contents of the LC_* and LANG environment variables in the CEN style are
  not recognized anymore.   It never was used.  Change by Ulrich Drepper.

* The runtime (ld.so, libc, libpthread for Linux) now can handle the ELF
  thread-local storage (TLS) ABI on some platforms.
  Changes by Ulrich Drepper.  SH support by Kaz Kojima.

* Bruno Haible contributed iconv converters for ISO-2022-JP-3, SHIFT JIS-X0213,
  EUC-JISX0213, and TSCII.

* New header <ifaddrs.h> with functions `getifaddrs' and `freeifaddrs':
  BSD-compatible interface for getting all network interface addresses.
  Implementation for IPv4 by Roland McGrath.

* Loading of locale data is faster due to the introduction of a locale
  archive.  Implemented by Roland McGrath and Ulrich Drepper.

* Startup times are significantly reduced by not using exported functions
  inside the library itself.  Changes by Jakub Jelinek, Roland McGrath,
  and Ulrich Drepper.

* Steven Munroe contributed a port to PowerPC64/Linux.
\f
Version 2.2.6

* The Hurd now uses the GNU libio implementation of stdio rather than the
  old GNU stdio implementation, and uses a new ABI (libc.so.0.3).

* The Hurd on x86 now has the `ioperm' function and <sys/io.h> header file
  with the same behavior as the Linux system call of the same name.
\f
Version 2.2.5

* Stephen Moshier implemented log2, log10, powl and cbrtl for the
  128-bit long double format.

* Masahide Washizawa contributed iconv modules for IBM1132, IBM1133, IBM1160,
  IBM1161, and IBM1162 charsets.

* Andreas Jaeger contributed a port to x86-64/Linux.

* Peter Bruin contributed a port to PowerPC/Hurd.

* libc functions using I/O streams now can handle wide-oriented streams
  as well.

* optimizations in the dynamic linker.  Binaries created by recent binutils
  versions start up quicker due to reduced time spent on relocations.

* Support for use of gcc3 added by Jakub Jelinek and HJ Lu.
\f
Version 2.2.4

* Stephen Moshier implemented cosh, expm1, log1p, acos, sinh, tanh,
  asinh, atanh, j0 for the 128-bit long double format.

* Bruno Haible updated all the code handling Unicode in some form to
  support Unicode 3.1.

* Speed of regex for single-byte locales is back to previous levels.
  Patch by Isamu Hasegawa.

* Alpha, SPARC, and IA-64 now also using floating stacks.

* Startup time of internationalized applications greatly improved through
  iconv cache.  Use iconvconfig to generate the cache file.
  Contributed by Ulrich Drepper.

* The IA-64 specific part of ld.so was rewritten to eliminate some pretty
  severe performance problems.  Patch by David Mosberger.

* The Hurd port got a lot more functionality like AIO, various stdio
  extensions, etc.  Mainly done by Roland McGrath.

* mtrace can now lookup symbols in shared libraries.
\f
Version 2.2.3

* Intel's IA-64 math library is largely integrated.  It provides fast and
  accurate implementatations for most basic and standard math functions
  in float, double, and long double format.

* Stephen Moshier implemented j0, j1, jn, y0, y1, yn, lgamma, erf, erfc,
  and asin for the 96-bit long double format and asin, log, tan for the
  128-bit long double format.

* The beginning of a last-bit accurate math library by IBM Haifa were added.
  The basic double functions exist today.  Contributed by Abraham Ziv
  <ziv@il.ibm.com>, Moshe Olshansky <olshansk@il.ibm.com>, Ealan Henis
  <ealan@il.ibm.com>, and Anna Reitman <reitman@il.ibm.com>.

* An asynchronous name lookup library was added.  The interface is designed
  after POSIX AIO.  The proposal was circulated beforehand to get comments.
  No negative ones came in.  Implemented by Ulrich Drepper.

* Port to S390/64bit contributed by Martin Schwidefsky
  <schwidefsky@de.ibm.com>.

* David Mosberger <davidm@hpl.hp.com> implemented the setcontext family
  of functions for Linux/IA-64.

* The RPC code is now thread safe.  Threads can now use the same service
  of different services at the same time.  Patch by Eric Norum
  <eric.norum@usask.ca> with some help by Ulrich Drepper.

* Martin Schwidefsky <schwidefsky@de.ibm.com> implemented the setcontext
  family of functions for Linux/S390.

* Ulrich Drepper <drepper@redhat.com> implemented the setcontext family
  of functions for Linux/x86.

* Port to Linux/CRIS contributed by Axis Communications.
\f
Version 2.2.2

* Lots of headers were cleaned up.  Using the tool in the conform/ subdir
  we can now check for namespace violations and missing declarations.  The
  result is that almost all headers are now Unix-compliant (as defined in
  the upcoming XPG6).  The negative side is that some programs might need
  corrections, too, if they depend on the incorrect form of the headers in
  previous versions which defined too many symbols and included too many
  other headers.

* regex now handles multibyte character sets correctly.
  Contributed by Isamu Hasegawa <isamu@yamato.ibm.com>.

* iconv (the program) does now conform to the upcoming XPG6 and handles
  charmaps.  Instead of the charset names the path of charmaps can be
  provided and the conversion happens based on this data.
  Contributed by Ulrich Drepper.

* The locale program now provides detailed information about the installed
  locales.  While

    locale -a

  only lists the names of the supported locales

    locale -a --verbose

  provides details such as country, language, and codeset name.
  Contributed by Ulrich Drepper.
\f
Version 2.2.1

* The gencat program now parses the input file according to the charset
  selected by the LC_CTYPE category.  This is important for stateful
  character sets.  To make generating catalogs easier there is a way
  to overwrite the charset selected by the locale: before the first
  message or $ quote line the catalog can contain a line like

    $ codeset=ISO-8859-2

  to select the charset (ISO-8859-2 in this case).

  Implemented by Shinya Hanataka and Ulrich Drepper.

* New codeset conversion modules: IBM-922  (Estonia PC codeset),
  IBM-1124 (Ukraine PC codeset), IBM-1129 (Vietnamese PC codeset).
  Contributed by Masahide Washizawa <washi@jp.ibm.com>.

* Optimized string functions for Alpha ev6 and ev67 by Richard Henderson
  <rth@redhat.com> and Rick Gorton <rick.gorton@alpha-processor.com>.

* The LANGUAGE environment variable is now ignored unless the locale is
  changed from the default "C" locale.

* The usual bug fixes.
\f
Version 2.2

* Greg McGary added runtime support for bounds checking using gcc's
  new -fbounded-pointers option.  ix86 target is complete.  PowerPC
  is in progress.

* Thorsten Kukuk added secure mode support to nscd.

* The Berkeley db libraries have been removed.

  Related, the nss_db module is now in a separate package since it
  obviously requires a database library being available.

* Wide character I/O streams implemented by Ulrich Drepper.

* Functions from the extended socket API added by Ulrich Drepper.

* Functions feenableexcept and fedisableexcept to control the
  behaviour of individual exceptions have been added by Andreas Jaeger.

* ldconfig program added by Andreas Jaeger and Jakub Jelinek.

* The resolver code has been updated from bind 8.2.3-T5B which supports
  threads.  The integration was done by Andreas Jaeger, Adam D. Bradley,
  and Mark Kettenis.

  This change could in some situations effect backward compatibility.  Since
  now `_res' is a thread-local instead of a global variable, modifying it
  in one thread does not have any effect in other threads.

  The resolver library was also extended to allow IPv6 as the transport
  protocol for the requests.  This work was done by Stig Venaas.

* Compatibility code for K&R C compilers has been removed from the
  header files.  A ISO C compiler is needed to use the library
  (conforming to either C89 or C99 standard).

* Complete rewrite of the localedef program to support multibyte character
  sets.  Implement handling of ISO 14651 and ISO 14652.  Rewrite strcoll,
  strxfrm, wcscoll, and wcsxfrm functions.  Make isw*() functions work.
  Implemented by Ulrich Drepper.

  Bruno Haible significantly improved the generation and use of the data
  structures for the wide character tables.

* Plural handling in gettext implemented by Ulrich Drepper.

* The utmp daemon has been removed.

* The port to MIPS-Linux has been finished by Andreas Jaeger.

* A port to Hitachi SH3 and SH4 has been contributed by Kazumoto Kojima
  and Yutaka Niibe.

* POSIX clocks and timers implemented by Kaz Kylheku and Ulrich Drepper.

* POSIX barriers implemented by Kaz Kylheku.

* POSIX spawn function family implemented by Ulrich Drepper.

* POSIX spinlocks are now available.

* Timed wait functions for mutex, rwlock, and semaphores are implemented.

* the configure option --enable-kernel=X.Y.Z allows to strip out
  compatibility for kernel versions before X.Y.Z.  This is currently only
  implemented for Linux.

* the sockaddr_in6 structure changed.  The IPv6 working group added a new
  field sin6_scope_id.  This means that all programs using IPv6 should be
  recompiled.  Don't expect binary compatibility with previous glibc
  versions.

* various conversion modules for IBM character sets contributed by
  Masahide Washizawa.

* IA-64 port by Jes Sorensen and HJ Lu.
\f
Version 2.1.3

* bug fixes

\f
Version 2.1.2

* bug fixes

\f
Version 2.1.1

* New ISO C 9x function _Exit, imaxabs, and imaxdiv are added.

* New xdr functions are added; some rpc functions are now 64bit clean.

* Fixed a number of bugs and memory leaks (especially in NIS+ code).

* Fixed known incompatibilities with glibc 2.0.

* New functions lock64, strchrnul, rawmemchr, getutmp and getutmpx.

* Optimized a number of functions (especially the ELF dynamic loader).

* Update timezone data files.

* lots of charmaps corrections

* some new locale definitions and charmaps

\f
Version 2.1

* Richard Henderson corrected size of struct timeval on Linux/Alpha to
  conform to POSIX member type requirements.  Symbol versions have been
  adjusted as needed within the library, and for direct use by applications,
  but there is potential for problems if third-party libraries use
  struct timeval as part of their interface.  This does not present
  a problem for X and other "essential" system libraries.

* An additional locale model to support C++ Standard Library locale
  model and probably more was implemented by Ulrich Drepper.

* Eric Youngdale and Ulrich Drepper implemented versioning of objects on
  symbol level.

* Miles Bader provided the `argp' function family to support hierachical
  command line argument parsing, layered on top of getopt.

* strtod accepts new hexadecimal floating-point format from ISO C 9X.

* printf has two new specifiers %a and %A to print hexadecimal flaoting-point
  numbers.

* scanf recognizes the %a and %A format for scanning floating point numbers.

* the new headers <stdint.h> and <inttypes.h> from ISO C 9X provides
  information and interfaces for the available integer types.

* about 130 new math functions were added to implement the ISO C9x math
  library.

* the new header <complex.h> contains definitions of the complex math
  functions from ISO C 9X.

* the new header <tgmath.h> defines generic macros to use complex or
  real valued functions.

* Thorsten Kukuk provided an implementation for NIS+, securelevel 0, 1 and 2.

* Andreas Jaeger provided a test suite for the math library.

* Mark Kettenis implemented the utmpx interface and an utmp daemon.

* Ulrich Drepper added character set conversion functions (iconv).

* Optimized string functions have been added.

* The localedata addon is now part of glibc.

* An implementation of profiling shared libraries was added by Ulrich Drepper.

* Thorsten Kukuk and Ulrich Drepper provided an implementation for a caching
  daemon for NSS (nscd).

  Missing a better place here are some numbers on improvements.  Under
  Linux 2.1.125 un-tar-ing the kernel sources takes

                                  user  system     wall

    using local files           12.19s   6.88s   22.91s

    using NIS                   13.92s   8.91s   26.34s

    using NIS & nscd            10.37s   7.34s   25.30s

    using NIS+                  27.57s  30.37s  640.46s

    using NIS+ & nscd           10.25s   7.83s   26.51s

    using NIS & old nscd [1]    13.83s   8.32s   29.60s

  Keep in mind that non-namelookup related operations dominate above times.
  It was just a common complain that using NIS+ unpacking the kernel is
  horribly slow.

  [1] The old nscd implementation is not available anymore since it was
  distributed with glibc up to version 2.0.98 and thus is now replaced.

* Tim Waugh provided an implementation of the POSIX.2 wordexp function family.

* Mark Kettenis provided a Hesiod NSS module.

* The ELF dynamic loader knows how to process dynamic string tokens ($ORIGIN
  and $PLATFORM) in RPATHs and similar strings (Ulrich Drepper).

* rcmd can now handle netgroups (Dick Streefland).

* A port to the ARM was contributed by Phil Blundell, Pat Beirne and Scott
  Bambrough.

* Support for the IPv6 protocol has been added to the socket API, as per the
  latest draft standards.

* Support for Linux 2.2 has been added.

* Interface changes relative to the latest 2.0.x release:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
addseverity                     NEW: Unix98
alphasort64                     NEW: LFS
argp_err_exit_status            NEW: argp, GNU ext
argp_error                      NEW: argp, GNU ext
argp_failure                    NEW: argp, GNU ext
argp_help                       NEW: argp, GNU ext
argp_parse                      NEW: argp, GNU ext
argp_program_bug_address        NEW: argp, GNU ext
argp_program_version            NEW: argp, GNU ext
argp_program_version_hook       NEW: argp, GNU ext
argp_state_help                 NEW: argp, GNU ext
argp_usage                      NEW: argp, GNU ext
authdes_create                  NEW: Secure RPC
authdes_getucred                NEW: Secure RPC
authdes_pk_create               NEW: Secure RPC
backtrace                       NEW: GNU ext.
backtrace_symbols               NEW: GNU ext.
backtrace_symbols_fd            NEW: GNU ext.
cacos                           NEW: ISO C 9x
cacosf                          NEW: ISO C 9x
cacosh                          NEW: ISO C 9x
cacoshf                         NEW: ISO C 9x
cacoshl                         NEW: ISO C 9x
cacosl                          NEW: ISO C 9x
capget                          NEW: kernel
capset                          NEW: kernel
carg                            NEW: ISO C 9x
cargf                           NEW: ISO C 9x
cargl                           NEW: ISO C 9x
casin                           NEW: ISO C 9x
casinf                          NEW: ISO C 9x
casinh                          NEW: ISO C 9x
casinhf                         NEW: ISO C 9x
casinhl                         NEW: ISO C 9x
casinl                          NEW: ISO C 9x
catan                           NEW: ISO C 9x
catanf                          NEW: ISO C 9x
catanh                          NEW: ISO C 9x
catanhf                         NEW: ISO C 9x
catanhl                         NEW: ISO C 9x
catanl                          NEW: ISO C 9x
cbc_crypt                       NEW: Secure RPC
ccos                            NEW: ISO C 9x
ccosf                           NEW: ISO C 9x
ccosh                           NEW: ISO C 9x
ccoshf                          NEW: ISO C 9x
ccoshl                          NEW: ISO C 9x
ccosl                           NEW: ISO C 9x
cexp                            NEW: ISO C 9x
cexpf                           NEW: ISO C 9x
cexpl                           NEW: ISO C 9x
cimag                           NEW: ISO C 9x
cimagf                          NEW: ISO C 9x
cimagl                          NEW: ISO C 9x
clearerr_locked                 REMOVED
clntunix_create                 NEW: sunrpc ext
clog                            NEW: ISO C 9x
clog10                          NEW: ISO C 9x
clog10f                         NEW: ISO C 9x
clog10l                         NEW: ISO C 9x
clogf                           NEW: ISO C 9x
clogl                           NEW: ISO C 9x
conj                            NEW: ISO C 9x
conjf                           NEW: ISO C 9x
conjl                           NEW: ISO C 9x
cpow                            NEW: ISO C 9x
cpowf                           NEW: ISO C 9x
cpowl                           NEW: ISO C 9x
cproj                           NEW: ISO C 9x
cprojf                          NEW: ISO C 9x
cprojl                          NEW: ISO C 9x
creal                           NEW: ISO C 9x
crealf                          NEW: ISO C 9x
creall                          NEW: ISO C 9x
creat64                         NEW: LFS
csin                            NEW: ISO C 9x
csinf                           NEW: ISO C 9x
csinh                           NEW: ISO C 9x
csinhf                          NEW: ISO C 9x
csinhl                          NEW: ISO C 9x
csinl                           NEW: ISO C 9x
csqrt                           NEW: ISO C 9x
csqrtf                          NEW: ISO C 9x
csqrtl                          NEW: ISO C 9x
ctan                            NEW: ISO C 9x
ctanf                           NEW: ISO C 9x
ctanh                           NEW: ISO C 9x
ctanhf                          NEW: ISO C 9x
ctanhl                          NEW: ISO C 9x
ctanl                           NEW: ISO C 9x
des_setparity                   NEW: Secure RPC
ecb_crypt                       NEW: Secure RPC
endutxent                       NEW: Unix98
exp10                           NEW: ISO C 9x
exp10f                          NEW: ISO C 9x
exp10l                          NEW: ISO C 9x
exp2                            NEW: ISO C 9x
exp2f                           NEW: ISO C 9x
exp2l                           NEW: ISO C 9x
fattach                         NEW: STREAMS
fdetach                         NEW: STREAMS
fdim                            NEW: ISO C 9x
fdimf                           NEW: ISO C 9x
fdiml                           NEW: ISO C 9x
feclearexcept                   NEW: ISO C 9x
fegetenv                        NEW: ISO C 9x
fegetexceptflag                 NEW: ISO C 9x
fegetround                      NEW: ISO C 9x
feholdexcept                    NEW: ISO C 9x
feof_locked                     REMOVED
feraiseexcept                   NEW: ISO C 9x
ferror_locked                   REMOVED
fesetenv                        NEW: ISO C 9x
fesetexceptflag                 NEW: ISO C 9x
fesetround                      NEW: ISO C 9x
fetestexcept                    NEW: ISO C 9x
feupdateenv                     NEW: ISO C 9x
fflush_locked                   REMOVED
ffsl                            NEW: GNU ext.
ffsll                           NEW: GNU ext.
fgetpos64                       NEW: LFS
fgets_unlocked                  NEW: GNU ext.
fileno_locked                   REMOVED
fma                             NEW: ISO C 9x
fmaf                            NEW: ISO C 9x
fmal                            NEW: ISO C 9x
fmax                            NEW: ISO C 9x
fmaxf                           NEW: ISO C 9x
fmaxl                           NEW: ISO C 9x
fmin                            NEW: ISO C 9x
fminf                           NEW: ISO C 9x
fminl                           NEW: ISO C 9x
fmtmsg                          NEW: Unix98
fopen64                         NEW: LFS
fputc_locked                    REMOVED
fputs_unlocked                  NEW: GNU ext.
fread_unlocked                  NEW: GNU ext.
freopen64                       NEW: LFS
fseeko                          NEW: Unix98
fsetpos64                       NEW: LFS
fstatfs64                       NEW: LFS
fstatvfs                        NEW: Unix98
fstatvfs64                      NEW: LFS
ftello                          NEW: Unix98
ftello64                        NEW: LFS
ftruncate64                     NEW: LFS
ftw64                           NEW: LFS
fwrite_unlocked                 NEW: GNU ext.
gai_strerror                    NEW: IPv6
gamma_r                         REMOVED
gammaf_r                        REMOVED
gammal_r                        REMOVED
getchar_locked                  REMOVED
getdate                         NEW: Unix98
getdate_err                     NEW: Unix98
getdate_r                       NEW: GNU ext.
getmsg                          NEW: STREAMS
getnameinfo                     NEW: IPv6
getnetname                      NEW: Secure RPC
getpmsg                         NEW: STREAMS
getpt                           NEW: Unix98 PTY
getrlimit64                     NEW: LFS
getutxent                       NEW: Unix98
getutxid                        NEW: Unix98
getutxline                      NEW: Unix98
glob64                          NEW: GNU ext.
globfree64                      NEW: GNU ext.
gnu_get_libc_release            NEW: GNU ext.
gnu_get_libc_version            NEW: GNU ext.
grantpt                         NEW: Unix98 PTY
host2netname                    NEW: Secure RPC
iconv                           NEW: iconv
iconv_close                     NEW: iconv
iconv_open                      NEW: iconv
if_freenameindex                NEW: IPv6
if_indextoname                  NEW: IPv6
if_nameindex                    NEW: IPv6
if_nametoindex                  NEW: IPv6
in6addr_any                     NEW: IPv6
in6addr_loopback                NEW: IPv6
inet6_isipv4mapped              NEW: IPv6
isastream                       NEW: STREAMS
iswblank                        NEW: GNU ext.
key_decryptsession              NEW: Secure RPC
key_decryptsession_pk           NEW: Secure RPC
key_encryptsession              NEW: Secure RPC
key_encryptsession_pk           NEW: Secure RPC
key_gendes                      NEW: Secure RPC
key_get_conv                    NEW: Secure RPC
key_secretkey_is_set            NEW: Secure RPC
key_setnet                      NEW: Secure RPC
key_setsecret                   NEW: Secure RPC
llrint                          NEW: ISO C 9x
llrintf                         NEW: ISO C 9x
llrintl                         NEW: ISO C 9x
llround                         NEW: ISO C 9x
llroundf                        NEW: ISO C 9x
llroundl                        NEW: ISO C 9x
log2                            NEW: ISO C 9x
log2f                           NEW: ISO C 9x
log2l                           NEW: ISO C 9x
lrint                           NEW: ISO C 9x
lrintf                          NEW: ISO C 9x
lrintl                          NEW: ISO C 9x
lround                          NEW: ISO C 9x
lroundf                         NEW: ISO C 9x
lroundl                         NEW: ISO C 9x
lseek64                         NEW: LFS
makecontext                     NEW: Unix98
mempcpy                         NEW: GNU ext.
mmap64                          NEW: LFS
moncontrol                      REMOVED
modify_ldt                      NEW: kernel
nan                             NEW: ISO C 9x
nanf                            NEW: ISO C 9x
nanl                            NEW: ISO C 9x
nearbyint                       NEW: ISO C 9x
nearbyintf                      NEW: ISO C 9x
nearbyintl                      NEW: ISO C 9x
netname2host                    NEW: Secure RPC
netname2user                    NEW: Secure RPC
nexttoward                      NEW: ISO C 9x
nexttowardf                     NEW: ISO C 9x
nexttowardl                     NEW: ISO C 9x
nftw                            NEW: Unix98
nftw64                          NEW: LFS
open64                          NEW: LFS
passwd2des                      NEW: Secure RPC
pow10                           NEW: GNU ext.
pow10f                          NEW: GNU ext.
pow10l                          NEW: GNU ext.
pread                           NEW: Unix98
pread64                         NEW: LFS
printf_size                     NEW: GNU ext.
printf_size_info                NEW: GNU ext.
profil_counter                  REMOVED
pthread_mutexattr_getkind_np    REPLACED
pthread_mutexattr_setkind_np    REPLACED
ptsname                         NEW: Unix98 PTY
ptsname_r                       NEW: Unix98 PTY
putc_locked                     REMOVED
putchar_locked                  REMOVED
putgrent                        NEW: GNU ext.
putmsg                          NEW: STREAMS
putpmsg                         NEW: STREAMS
pututxline                      NEW: Unix98
pwrite                          NEW: Unix98
pwrite64                        NEW: LFS
readdir64                       NEW: LFS
readdir64_r                     NEW: LFS
remquo                          NEW: ISO C 9x
remquof                         NEW: ISO C 9x
remquol                         NEW: ISO C 9x
round                           NEW: ISO C 9x
roundf                          NEW: ISO C 9x
roundl                          NEW: ISO C 9x
rtime                           NEW: GNU ext.
scalbln                         NEW: ISO C 9x
scalblnf                        NEW: ISO C 9x
scalblnl                        NEW: ISO C 9x
scandir64                       NEW: LFS
sendfile                        NEW: kernel
setcontext                      NEW: Unix98
setrlimit64                     NEW: LFS
setutxent                       NEW: Unix98
sighold                         NEW: Unix98
sigignore                       NEW: Unix98
sigqueue                        NEW: POSIX.1b
sigrelse                        NEW: Unix98
sigset                          NEW: POSIX.1b
sigtimedwait                    NEW: POSIX.1b
sigwaitinfo                     NEW: POSIX.1b
sincos                          NEW: GNU ext.
sincosf                         NEW: GNU ext.
sincosl                         NEW: GNU ext.
statfs64                        NEW: LFS
statvfs                         NEW: Unix98
statvfs64                       NEW: LFS
strcasestr                      NEW: GNU ext.
strtoimax                       NEW: ISO C 9x
strtoumax                       NEW: ISO C 9x
strverscmp                      NEW: GNU ext.
svcauthdes_stats                NEW: Secure RPC
svcunix_create                  NEW: sunrpc etx
svcunixfd_create                NEW: sunrpc ext
swapcontext                     NEW: Unix98
tcgetsid                        NEW: Unix98 PTY
tdestroy                        NEW: GNU ext.
tgamma                          NEW: ISO C 9x
tgammaf                         NEW: ISO C 9x
tgammal                         NEW: ISO C 9x
tmpfile64                       NEW: LFS
trunc                           NEW: ISO C 9x
truncate64                      NEW: LFS
truncf                          NEW: ISO C 9x
truncl                          NEW: ISO C 9x
umount2                         NEW: kernel
unlockpt                        NEW: Unix98 PTY
updwtmpx                        NEW: Unix98
user2netname                    NEW: Secure RPC
utmpxname                       NEW: Unix98
versionsort                     NEW: GNU ext.
versionsort64                   NEW: GNU ext.
waitid                          NEW: Unix98
wcscasecmp                      NEW: GNU ext.
wcsncasecmp                     NEW: GNU ext.
wcsnlen                         NEW: GNU ext.
wcstoimax                       NEW: ISO C 9x
wcstoll                         NEW: ISO C 9x
wcstoull                        NEW: ISO C 9x
wcstoumax                       NEW: ISO C 9x
wcswcs                          NEW: Unix98
wordexp                         NEW: POSIX.2
wordfree                        NEW: POSIX.2
write_profiling                 REMOVED
xdecrypt                        NEW: Secure RPC
xdr_authdes_cred                NEW: Secure RPC
xdr_authdes_verf                NEW: Secure RPC
xdr_cryptkeyarg                 NEW: Secure RPC
xdr_cryptkeyarg2                NEW: Secure RPC
xdr_cryptkeyres                 NEW: Secure RPC
xdr_getcredres                  NEW: Secure RPC
xdr_key_netstarg                NEW: Secure RPC
xdr_key_netstres                NEW: Secure RPC
xdr_keybuf                      NEW: Secure RPC
xdr_keystatus                   NEW: Secure RPC
xdr_netnamestr                  NEW: Secure RPC
xdr_sizeof                      NEW: Secure RPC
xdr_unixcred                    NEW: sunrpc ext
xencrypt                        NEW: Secure RPC
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
\f
Version 2.0.6

* more bug fixes

\f
Version 2.0.5

* more bug fixes

* inet_ntoa is thread-safe

* updwtmp is moved from libutil to libc

* rewrite of cbrt function

* update of timezone data
\f
Version 2.0.4

* more bug fixes
\f
Version 2.0.3

* more bug fixes
\f
Version 2.0.2

* more bug fixes

* add atoll function

* fix complex problems in Berkeley DB code

* fix math functions
\f
Version 2.0.1

* fixed lots of header problems (especially Linux/GNU specific)

* dynamic loader preserves all registers

* Roland McGrath provided support for handling of auxiliary objects in
  the ELF dynamic loader.

* support for parallel builds is improved
\f
Version 2.0

* GNU extensions are no longer declared by default.  To enable them you
  must define the macro `_GNU_SOURCE' in your program or compile with
  `-D_GNU_SOURCE'.

* The library has changed from using GNU ld symbol aliases to using weak
  symbols where available.  The ELF object file format supports weak
  symbols; GNU ld also supports weak symbols in the a.out format.  (There
  is also now support for other GNU ld extensions in ELF.  Use the
  `--with-elf' option to configure to indicate you have ELF, and
  `--with-gnu-ld' if using GNU ld.)  This change resulted in the deletion
  of many files which contained only symbol aliases, reducing the size of
  the source and the compiled library; many other files were renamed to
  less cryptic names previously occupied by the symbol alias files.
  There is a new header file <elf.h> for programs which operate on
  files in the ELF format.

* Converted to Autoconf version 2, so `configure' has more options.
  Run `configure --help' to see the details.

* The library can now be configured to build profiling, highly-optimized
  (but undebuggable), and/or shared libraries (ELF with GNU ld only).  The
  `--enable-profile', `--enable-omitfp', and `--enable-shared' options to
  `configure' enable building these extra libraries.  The shared library is
  built by default when using both ELF and GNU ld.  When shared libraries
  are enabled, the new library `-ldl' is available for arbitrary run-time
  loading of shared objects; its interface is defined in <dlfcn.h>.  The
  new header file <link.h> gives access to the internals of the run-time
  dynamic linker, `ld.so'.  The shell script `ldd' is similar to the
  application of same name on other systems and it provides information
  about dynamically linked binaries.

* The C library now provides the run-time support code for profiling
  executables compiled with `-pg'.  Programs can control the profiling code
  through the interface in <sys/gmon.h>.  The `gmon.out' files written by
  the GNU C library can be read only by GNU `gprof' (from GNU binutils);
  the support for this file format was contributed by David Mosberger-Tang.

* The math code has been replaced with a math library based on fdlibm from
  Sun, and modified by JT Conklin and Ulrich Drepper with i387 support, by
  Ian Taylor with `float' functions and by Ulrich Drepper with `long double'
  functions.  The math functions now reside in a separate library,  so
  programs using them will need to use `-lm' their linking commands.

* John C. Bowman contributed optimized ix87 assembler inline functions.

* Ulrich Drepper has contributed support for an `/etc/nsswitch.conf'
  mechanism similar to that found in Solaris 2.  This is now used for the
  group, passwd, hosts, networks, services, protocols, rpc, ethers,
  shadow, netgroup, publickey, and alias databases.  The `nsswitch.conf'
  file controls what services are used for each individual database.  This
  works by loading shared libraries with names specified in `nsswitch.conf',
  so service modules can be changed or added at any time without even
  relinking any program.  Currently there are the file, db, and NIS based
  NSS services available.

* The new functions `strtoq' and `strtouq' parse integer values from
  strings, like `strtol' and `strtoul', but they return `long long int' and
  `unsigned long long int' values, respectively (64-bit quantities).

* The new functions `strtof' and `strtold' parse floating-point values from
  strings, like `strtod', but they return `float' and `long double' values,
  respectively (on some machines `double' and `long double' are the same).

* Ulrich Drepper has contributed new implementations of the floating-point
  printing and reading code used in the `printf' family of functions and
  `strtod', `strtof', and `strtold'.  These new functions are perfectly
  accurate, and much faster than the old ones.

* The implementation of the POSIX locale model was completely rewritten by
  Ulrich Drepper.  This includes the new programs `localedef' and `locale'
  to compile the POSIX locale definition.

* The former dummy implementations of the strcoll and strxfrm function are
  now replaced by fully functional code contributed by Ulrich Drepper.  The
  collation information comes from the POSIX locale definitions.

* The new header <langinfo.h> defines an interface for accessing
  various locale-dependent data (using the locale chosen with `setlocale').

* Ulrich Drepper has contributed a new suite of functions for operation on
  wide-character and multibyte-character strings, in <wchar.h>;
  and classification and case conversion of wide characters, in <wctype.h>.
  These new functions are conforming to the ISO C, Amendement 1 specification.

* There is now a second implementation of the standard I/O library available.
  It comes from GNU libg++ as was written by Per Bothner, heavily modified
  by Hongjiu Lu and made thread safe by Ulrich Drepper.

* You can now use positional parameter specifications in format strings
  for the `printf' and `scanf' families of functions.  For example,
  `printf ("Number %2$d, Mr %1$s\n", "Jones", 6);'' prints
  ``Number 6, Mr Jones''.  This is mainly useful when providing different
  format strings for different languages, whose grammars may dictate
  different orderings of the values being printed.  To support this
  feature, the interface for `register_printf_handler' has changed; see
  the header file <printf.h> for details.

* The `printf' and `scanf' families of functions now understand a new
  formatting flag for numeric conversions: the ' flag (e.g. %'d or %'f) says
  to group numbers as indicated by the locale; for `scanf' and friends, this
  says to accept as valid only a number with all the proper grouping
  separators in the right places.  In the default "C" locale, numbers are
  not grouped; but locales for specific countries will define the usual
  conventions (i.e. separate thousands with `,' in the US locale).

* The pgrp functions have been regularized, slightly incompatibly but much
  less confusingly.  The core functions are now `getpgid' and `setpgid',
  which take arguments for the PID to operate on; the POSIX.1 `getpgrp' (no
  argument) and BSD `setpgrp' (identical to `setpgid') functions are
  provided for compatibility.  There is no longer an incompatible `getpgrp'
  with an argument declared under _BSD_SOURCE; no BSD code uses it.

* The new header file <fts.h> and suite of functions simplify programs that
  operate on directory trees.  This code comes from 4.4 BSD.

* The resolver code has been updated from the BIND 4.9.5-P1 release.
  Parts of the code were heavily modified by Ulrich Drepper to fit in the
  NSS scheme used in glibc.

* There is a new malloc debugging hook `__memalign_hook'.

* There are new typedefs `ushort' for `unsigned short int' and `uint' for
  `unsigned int' in <sys/types.h>.  These are for compatibility only and
  their use is discouraged.

* The `-lmcheck' library to enable standard malloc debugging hooks is now
  done differently, so that it works even without GNU ld.

* New function `euidaccess' checks allowed access to a file like `access',
  but using the effective IDs instead of the real IDs.

* The time zone data files have been updated for the latest and greatest
  local time conventions of the countries of the world.

* The new function `dirfd' extracts the file descriptor used by a DIR stream;
  see <dirent.h>.

* The new functions `ecvt', `fcvt', and `gcvt' provide an obsolete interface
  for formatting floating-point numbers.  They are provided only for
  compatibility; new programs should use `sprintf' instead.  There are
  also equivalent function for the `long double' floating-point type and
  all functions also exist in a reentrant form.

* The new auxiliary library `-lutil' from 4.4 BSD contains various
  functions for maintaining the login-record files (primarily of use to
  system programs such as `login'), and convenient functions for
  allocating and initializing a pseudo-terminal (pty) device.

* Ulrich Drepper has contributed new support for System V style
  shared memory and IPC on systems that support it.

* Ulrich Drepper has contributed several miscellaneous new functions found
  in System V: The `hsearch' family of functions provide an effective
  implementation of hash tables; `a64l' and `l64a' provide a very simple
  binary to ASCII mapping; `drand48' and friends provide a 48-bit random
  number generator.

* Ulrich Drepper has contributed new reentrant counterparts for the
  `random' and `hsearch' families of functions; `random_r', `hsearch_r', etc.

* Ulrich Drepper has contributed new, highly-optimized versions of several
  string functions for the i486/Pentium family of processors.

* Ulrich Drepper has updated the Linux-specific code, based largely
  on work done in Hongjiu Lu's version of GNU libc for Linux.
  The GNU library now supports Linux versions 2.0.10 and later,
  using the ELF object file format (i[3456]86-*-linux).

* Andreas Schwab has ported the C library to Linux/m68k (m68k-*-linux).

* David Mosberger-Tang and Richard Henderson have ported the C library
  to Linux/Alpha (alpha-*-linux).  Richard Henderson contributed the
  dynamic linking support for ELF/Alpha.

* Richard Henderson contributed several Alpha optimized assembler function
  for arithmetic and string handling.

* Ulrich Drepper has contributed a new set of message catalog functions to
  support multiple languages using the <libintl.h> interface, for use with
  his new package GNU gettext.  Translation volunteers have contributed
  catalogs of the library's messages in Spanish, German, and Korean.

* For compatibility with XPG4, Ulrich Drepper has contributed the `gencat'
  program and the `catgets' function for reading the catalog files it
  creates.  (The <libintl.h> interface is preferred; we include the
  <nl_types.h> interface using `catgets' only for source compatibility with
  programs already written to use it.)

* New header file <values.h> gives SVID-compatible names for <limits.h>
  constants.

* Various new macros, declarations, and small header files for compatibility
  with 4.4 BSD.

* New function `group_member' is a convenient way to check if a process has
  a given effective group ID.

* When using GCC 2.7 and later, the socket functions are now declared in a
  special way so that passing an argument of type `struct sockaddr_in *',
  `struct sockaddr_ns *', or `struct sockaddr_un *' instead of the generic
  `struct sockaddr *' type, does not generate a type-clash warning.

* New function `error' declared in header file <error.h> is a convenient
  function for printing error messages and optionally exiting; this is the
  canonical function used in GNU programs.  The new functions `err', `warn',
  and friends in header file <err.h> are the canonical 4.4 BSD interface for
  doing the same thing.

* The <glob.h> interface has several new flags from 4.4 BSD that extend the
  POSIX.2 `glob' function to do ~ and {...} expansion.

* New function `unsetenv' complements `setenv' for compatibility with 4.4 BSD.
  `clearenv' which is used in POSIX.9 is also available.

* New function `getsid' returns session ID number on systems that support it.

* We have incorporated the 4.4 BSD `db' library (version 1.85).  New header
  files <db.h> and <mpool.h> provide a rich set of functions for several
  types of simple databases stored in memory and in files, and <ndbm.h> is
  an old `ndbm'-compatible interface using the `db' functions.  Link with
  `-ldb' to get these functions.

* New macro `strdupa' copies a string like `strdup', but uses local stack
  space from `alloca' instead of dynamic heap space from `malloc'.

* New function `strnlen' is like `strlen' but searches only a given maximum
  number of characters for the null terminator.  `stpncpy', `strndup' and
  `strndupa' are similar variants for the `stpcpy', `strdup' and `strdupa'
  function.

* New function `statfs' in header <sys/statfs.h>.

* The new <argz.h> and <envz.h> interfaces contributed by Miles Bader
  provide convenient functions for operating on blocks of null-terminated
  strings.

* A new suite of functions in <utmp.h> handle all the details of reading
  and writing the utmp file.

* An implementation of the NIS/YP(tm) based NSS service was contributed by
  Thorsten Kukuk.

* Paul Eggert and Ulrich Drepper modified the `strftime' function to be
  completely POSIX compliant and also implemented the extended functionality
  to handle alternate digit representation and alternate era date formats.

* Ulrich Drepper provided an implementation of the `strptime' function
  defined in XPG4.2 which transforms a string into a `struct tm' value.

* Paul Eggert provided the tzselect shell script as part of the timezone
  code.  The shell script makes it easy to select the correct timezone
  specification.

* The implementation of the malloc family of functions is completely replaced
  by a new implementation by Doug Lea with many improvements by Wolfram Gloger.
  The implementation uses the mmap function (if available) and it is
  optimized for the use in multi threaded programs.

* Ulrich Drepper contributed a MD5 "encryption" for the crypt family of
  functions.  This new functionality is usable by specifying a special
  salt string and it is compatible with implementation on *BSD systems.

* Lots of functions from the XPG4.2 standard were added by Ulrich Drepper:
  `getsubopt' to handle second level command line options, `bsd_signal'
  to access BSD style `signal' functionality, the obsolete `regexp' style
  expression matcher.

* the `lchown' function is available on system which support this
  functionality.

* The implementation of the shadow password handling function was contributed
  by Ulrich Drepper.

* David Mosberger-Tang changed the SunRPC implementation to be 64bit safe.

* POSIX.1g support was added.  The <sys/select.h> header is available,
  `isfdtype' and `pselect' are implemented.  Craig Metz contributed an
  implementation of `getaddrinfo'.
\f
Version 1.09

* For cross-compilation you should now set `BUILD_CC' instead of `HOST_CC'.

* New header file <fstab.h> and new functions `getfsspec', `getfsent' and
  friends, for parsing /etc/fstab.  This code comes from 4.4 BSD.

* The new function `daemon' from 4.4 BSD is useful for server programs that
  want to put themselves in the background.

* Joel Sherrill has contributed support for several standalone boards that
  run without an operating system.

* `printf', `scanf' and friends now accept a `q' type modifier for long
  long int as well as `ll'.  Formats using these might be `%qu' or `%lld'.

* All of the code taken from BSD (notably most of the math and networking
  routines) has been updated from the BSD 4.4-Lite release.

* The resolver code has been updated from the BIND-4.9.3-BETA9 release.

* The new functions `getdomainname' and `setdomainname' fetch or change the
  YP/NIS domain name.  These are system calls which exist on systems which
  have YP (aka NIS).

* The time zone data files have been updated for the latest international
  conventions.

* The SunRPC programs `portmap' and `rpcinfo' are now installed in
  $(sbindir) (usually /usr/local/sbin) instead of $(bindir).
\f
Version 1.08

* The C library now includes support for Sun RPC, from Sun's free
  RPCSRC-4.0 distribution.  The `portmap', `rpcinfo', and `rpcgen' programs
  are included.  (There is still no support for YP.)

* Tom Quinn has contributed a port of the C library to SGI machines running
  Irix 4 (mips-sgi-irix4).

* The new `lockf' function is a simplified interface to the locking
  facilities of `fcntl', included for compatibility.

* New time functions `timegm', `timelocal', and `dysize' for compatibility.

* New header file <sys/timeb.h> and new function `ftime' for compatibility.

* New header files <poll.h> and <sys/poll.h> and new function `poll' for
  compatibility.

* The error message printed by `assert' for a failed assertion now includes
  the name of the program (if using GNU ld) and the name of the calling
  function (with versions of GCC that support this).

* The `psignal' function is now declared in <signal.h>, not <stdio.h>.

* The library now includes the <sys/mman.h> header file and memory
  management functions `mmap', `munmap', `mprotect', `msync', and
  `madvise', on systems that support those facilities.

* The interface for `mcheck' has changed slightly: the function called to
  abort the program when an allocation inconsistency is detected now takes
  an argument that indicates the type of failure.  The new function
  `mprobe' lets you request a consistency check for a particular block at
  any time (checks are normally done only when you call `free' or `realloc'
  on a block).

* It is now possible to easily cross-compile the C library, building on one
  system a library to run on another machine and/or operating system.  All
  you need to do is set the variable `HOST_CC' in `configparms' to the
  native compiler for programs to run on the machine you are building on (a
  few generator programs are used on Unix systems); set `CC' to the
  cross-compiler.

* The new function `fexecve' (only implemented on the GNU system) executes
  a program file given a file descriptor already open on the file.
\f
Version 1.07

* Brendan Kehoe has contributed most of a port to the DEC Alpha
  running OSF/1 (alpha-dec-osf1).  He says it is 75% complete.

* You can set the variable `libprefix' in `configparms' to specify a prefix
  to be prepended to installed library files; this makes it easy to install
  the GNU C library to be linked as `-lgnuc' or whatever.

* The new `stpncpy' is a cross between `stpcpy' and `strncpy': It
  copies a limited number of characters from a string, and returns the
  address of the last character written.

* You no longer need to check for whether the installed `stddef.h' is
  compatible with the GNU C library.  configure now checks for you.

* You can now define a per-stream `fileno' function to convert the
  stream's cookie into an integral file descriptor.

* ``malloc (0)'' no longer returns a null pointer.  Instead, it
  allocates zero bytes of storage, and returns a unique pointer which
  you can pass to `realloc' or `free'.  The behavior is undefined if
  you dereference this pointer.

* The C library now runs on Sony NEWS m68k machines running either
  NewsOS 3 or NewsOS 4.

* The new `syscall' function is a system-dependent primitive function
  for invoking system calls.  It has the canonical behavior on Unix
  systems, including unreliable return values for some calls (such as
  `pipe', `fork' and `getppid').

* The error code `EWOULDBLOCK' is now obsolete; it is always defined
  to `EAGAIN', which is the preferred name.  On systems whose kernels
  use two distinct codes, the C library now translates EWOULDBLOCK to
  EAGAIN in every system call function.
\f
Version 1.06

* The GNU C Library Reference Manual is now distributed with the library.
  `make dvi' will produce a DVI file of the printed manual.
  `make info' will produce Info files that you can read on line using C-h i
  in Emacs or the `info' program.
  Please send comments on the manual to bug-glibc-manual@gnu.org.

* The library now supports SVR4 on i386s (i386-unknown-sysv4).

* Brendan Kehoe has contributed a port to Sun SPARCs running Solaris 2.

* Jason Merrill has contributed a port to the Sequent Symmetry running
  Dynix version 3 (i386-sequent-dynix).

* The library has been ported to i386s running SCO 3.2.4 (also known as SCO
  ODT 2.0; i386-unknown-sco3.2.4) or SCO 3.2 (i386-unknown-sco3.2).

* New function `memory_warnings' lets you arrange to get warnings when
  malloc is running out of memory to allocate, like Emacs gives you.

* The C library now contains the relocating allocator used in Emacs 19 for
  its editing buffers.  This allocator (ralloc) minimizes allocation
  overhead and fragmentation by moving allocated regions around whenever it
  needs to.  You always refer to a ralloc'd region with a "handle" (a
  pointer to a pointer--an object of type `void **').

* There is a new `printf' format: `%m' gives you the string corresponding
  to the error code in `errno'.

* In `scanf' formats, you can now use `%as' or `%a[' to do the normal `%s'
  or `%[' conversion, but instead of filling in a fixed-sized buffer you
  pass, the `a' modifier says to fill in a `char **' you pass with a
  malloc'd string.

* The `fnmatch' function supports the new flag bits `FNM_LEADING_DIR' and
  `FNM_CASEFOLD'.  `FNM_LEADING_DIR' lets a pattern like `foo*' match a
  name like `foo/bar'.  `FNM_CASEFOLD' says to ignore case in matching.

* `mkstemp' is a traditional Unix function to atomically create and open a
  uniquely-named temporary file.
\f
Version 1.05

* The standard location for the file that says what the local timezone is
  has changed again.  It is now `/usr/local/etc/localtime' (or more
  precisely, `${prefix}/etc/localtime') rather than `/etc/localtime'.

* The distribution no longer contains any files with names longer than 14
  characters.

* `struct ttyent' has two new flag bits: TTY_TRUSTED and TTY_CONSOLE.
  These are set by the new `trusted' and `console' keywords in `/etc/ttys'.

* New functions `ttyslot' and `syslog' from 4.4 BSD.
\f
Version 1.04

* The configuration process has changed quite a bit.  The `configure'
  script is now used just like the configuration scripts for other GNU
  packages.  The `sysdeps' directory hierarchy is much rearranged.
  The file `INSTALL' explains the new scheme in detail.

* The header files no longer need to be processed into ANSI C and
  traditional C versions.  There is just one set of files to install, and
  it will work with ANSI or old C compilers (including `gcc -traditional').

* Brendan Kehoe and Ian Lance Taylor have ported the library to the
  MIPS DECStation running Ultrix 4.

* The Sun 4 startup code (crt0) can now properly load SunOS 4 shared libraries.
  Tom Quinn contributed the initial code.  The GNU C library can NOT yet be
  made itself into a shared library.

* Yet further improved support for the i386, running 4.3 BSD-like systems
  (such as Mach 3 with the Unix single-server), or System V.

* New function `strncasecmp' to do case-insensitive string comparison
  with limited length.

* New function `strsep' is a reentrant alternative to `strtok'.

* New functions `scandir' and `alphasort' for searching directories.

* New function `setenv' is a better interface to `putenv'.

* Ian Lance Taylor has contributed an implementation of the SVID `ftw'
  function for traversing a directory tree.

* The GNU obstack package is now also part of the C library.
  The new function `open_obstack_stream' creates a stdio stream that
  writes onto an obstack; `obstack_printf' and `obstack_vprintf' do
  formatted output directly to an obstack.

* Miscellaneous new functions: reboot, nice, sigaltstack (4.4 BSD only),
  cfmakeraw, getusershell, getpass, swab, getttyent, seteuid, setegid.

* `FNM_FILE_NAME' is another name for `FNM_PATHNAME', used with `fnmatch'.

* The new functions `strfry' and `memfrob' do mysterious and wonderful
  things to your strings.

* There are some new test programs: test-fseek, testmb, and testrand.

* Some work has been done to begin porting the library to 4.4 BSD and Linux.
  These ports are not finished, but are a good starting place for really
  supporting those systems.

* `/etc/localtime' is now the standard location for the file that says what
  the local timezone is, rather than `/usr/local/lib/zoneinfo/localtime'.
  This follows the general principle that `/etc' is the place for all local
  configuration files.

* The C library header files now use `extern "C"' when used by the C++
  compiler, so the C library should now work with C++ code.

* The header file <bstring.h> is gone.  <string.h> now declares bcopy,
  bcmp, bzero, and ffs.  (Update: nowadays these functions are declared
  in <strings.h>.)

* Mike Haertel (of GNU e?grep and malloc fame) has written a new sorting
  function which uses the `merge sort' algorithm, and is said to be
  significantly faster than the old GNU `qsort' function.  Merge sort is
  now the standard `qsort' function.  The new algorithm can require a lot
  of temporary storage; so, the old sorting function is called when the
  required storage is not available.

* The C library now includes Michael Glad's Ultra Fast Crypt, which
  provides the Unix `crypt' function, plus some other entry points.

* The code and header files taken from 4.4 BSD have been updated with the
  latest files released from Berkeley.
\f
----------------------------------------------------------------------
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   Permission is granted to distribute modified versions
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\f
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