GNU C Library NEWS -- history of user-visible changes.
-Copyright (C) 1992-2020 Free Software Foundation, Inc.
+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 2.35
+
+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.
+
+* 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.
+
+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.
+
+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 2.34
+
+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.
+
+* 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:
+
+* 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
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:
- [Add deprecations, removals and changes affecting compatibility here]
+* 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:
- [Add changes to build and runtime requirements here]
+* 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:
- [Add security related changes here]
+ 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:
- [The release manager will add the list generated by
- scripts/list-fixed-bugs.py just before the 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
- arc-linux-gnuhf
- arceb-linux-gnu
- The arc* ABI is little-endian while arceb is big-endian. All ABIs use
+ 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 the -mabi=ieeelongdouble to compile C code on supported GCC
+ using -mabi=ieeelongdouble to compile C code on supported GCC
toolchains. It is recommended to use GCC 8 or newer when testing
this option.
several APIs have been annotated with GCC 'access' attribute. This
should help GCC 10 issue better warnings.
-* On Linux, functions the pthread_attr_setsigmask_np and
+* 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.
libpthread.
* The functions sigabbrev_np and sigdescr_np have been added. The
- sigabbrev_np 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
+ 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.
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 returns error number name (e.g. "EINVAL" for EINVAL) while
- strerrordesc_np returns string describing error number
+ 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.
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 depended on libnsl
+ 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
* 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 from <stdio.h>. They are exported solely as
+ 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.
[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 ouput to _IO_stdout instead of stdout
+ [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
[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 oupts a wrong value of DBL_MAX on ppc64 and
+ [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
The following bugs are resolved with this release:
- [4099] stdio: Overly agressive caching by stream i/o functions.
+ [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
* The following bugs are resolved with this release:
- 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
+ 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.
latest files released from Berkeley.
\f
----------------------------------------------------------------------
-Copyright information:
-
-Copyright (C) 1992-2020 Free Software Foundation, Inc.
+Copying conditions:
Permission is granted to anyone to make or distribute verbatim copies
of this document as received, in any medium, provided that the