GNU C Library NEWS -- history of user-visible changes.
-Copyright (C) 1992-2021 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:
-* Add _SC_MINSIGSTKSZ and _SC_SIGSTKSZ. When _SC_SIGSTKSZ_SOURCE or
- _GNU_SOURCE are defined, MINSIGSTKSZ and SIGSTKSZ are no longer
+* 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).
+ 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
__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
* 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
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:
- [The release manager will add the list generated by
- scripts/list-fixed-bugs.py just before the 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
projects / thirdparty / glibc.git / blobdiff