summaryrefslogtreecommitdiff
path: root/include/libc-symbols.h
AgeCommit message (Collapse)Author
2026-01-01Update copyright dates with scripts/update-copyrightsPaul Eggert
2025-12-09Handle clang -Wignored-attributes on weak aliasesAdhemerval Zanella
Clang issues a warning for double alias redirection, indicating that thei original symbol is used even if a weak definition attempts to override it. For instance, in the construction: int __internal_impl (...) {} weak_alias (__internal_impl, external_impl); #if SOMETHING weak_alias (external_impl, another_external_impl) #endif Clang warns that another_external_impl always resolves to __internal_impl, even if external_impl is a weak reference. Using the internal symbol for both aliases resolves this warning. This issue also occurs with certain libc_hidden_def usage: int __internal_impl (...) {} weak_alias (__internal_impl, __internal_alias) libc_hidden_weak (__internal_alias) In this case, using a strong_alias is sufficient to avoid the warning (since the alias is internal, there is no need to use a weak alias). However, for the constructions like: int __internal_impl (...) {} weak_alias (__internal_impl, __internal_alias) libc_hidden_def (__internal_alias) weak_alias (__internal_impl, external_alias) libc_hidden_def (external_alias) Clang warns that the internal external_alias will always resolve to __GI___internal_impl, even if a weak definition of __GI_internal_impl is overridden. For this case, a new macro named static_weak_alias is used to create a strong alias for SHARED, or a weak_alias otherwise. With these changes, there is no need to check and enable the -Wno-ignored-attributes suppression when using clang. Checked with a build on affected ABIs, and a full check on aarch64, armhf, i686, and x86_64. Reviewed-by: Sam James <sam@gentoo.org>
2025-10-21elf: Suppress unused function clang warning for __ifunc_resolverAdhemerval Zanella
The __ifunc_resolver macro expands to: extern __typeof (__redirect_name) name __attribute__ ((ifunc ("iname_ifunc"))); static __typeof (__redirect_name) *name_ifunc (void) { [...] }; And although NAME_IFUNC is and alias for NAME, clang still emits an 'unused function 'name_ifunc' [-Werror,-Wunused-function]' warning. The static is used to avoid name pollution on static linkage. Reviewed-by: Sam James <sam@gentoo.org>
2025-05-27Fix comment typo in libc-symbols.hJonathan Wakely
Reviewed-by: Sam James <sam@gentoo.org>
2025-01-01Update copyright dates with scripts/update-copyrightsPaul Eggert
2024-12-23Fix build without stack protector [BZ #32494]H.J. Lu
Without stack protector, inhibit_stack_protector is undefined during build: In file included from <command-line>: ./../include/libc-symbols.h:665:3: error: expected ';' before '__typeof' 665 | __typeof (type_name) *name##_ifunc (__VA_ARGS__) \ | ^~~~~~~~ ./../include/libc-symbols.h:676:3: note: in expansion of macro '__ifunc_resolver' 676 | __ifunc_resolver (type_name, name, expr, init, static, __VA_ARGS__) | ^~~~~~~~~~~~~~~~ ./../include/libc-symbols.h:703:3: note: in expansion of macro '__ifunc_args' 703 | __ifunc_args (type_name, name, expr, init, arg) | ^~~~~~~~~~~~ ./../include/libc-symbols.h:790:3: note: in expansion of macro '__ifunc' 790 | __ifunc (redirected_name, name, expr, void, INIT_ARCH) | ^~~~~~~ ../sysdeps/x86_64/multiarch/memchr.c:29:1: note: in expansion of macro 'libc_ifunc_redirected' 29 | libc_ifunc_redirected (__redirect_memchr, memchr, IFUNC_SELECTOR ()); | ^~~~~~~~~~~~~~~~~~~~~ 1. Fix a typo in include/libc-symbols.h to define inhibit_stack_protector for build. 2. Don't include <config.h> in include/libc-symbols.h since it has been included in include/libc-misc.h. 3. Change #include "libc-misc.h" to #include <libc-misc.h> in string/test-string.h. This fixes BZ #32494. Signed-off-by: H.J. Lu <hjl.tools@gmail.com> Reviewed-by: Sam James <sam@gentoo.org>
2024-12-22Add include/libc-misc.hH.J. Lu
Add include/libc-misc.h to provide miscellaneous definitions for both glibc build and test: 1. Move inhibit_stack_protector to libc-misc.h and add Clang support. 2. Add test_inhibit_stack_protector for glibc testing. 3. Move inhibit_loop_to_libcall to libc-misc.h. 4. Add test_cc_inhibit_loop_to_libcall to handle TEST_CC != CC and replace inhibit_loop_to_libcall with test_cc_inhibit_loop_to_libcall in glibc tests. Signed-off-by: H.J. Lu <hjl.tools@gmail.com> Co-Authored-By: Adhemerval Zanella <adhemerval.zanella@linaro.org> Reviewed-by: Sam James <sam@gentoo.org>
2024-03-01riscv: Enable multi-arg ifunc resolversEvan Green
RISC-V is apparently the first architecture to pass more than one argument to ifunc resolvers. The helper macros in libc-symbols.h, __ifunc_resolver(), __ifunc(), and __ifunc_hidden(), are incompatible with this. These macros have an "arg" (non-final) parameter that represents the parameter signature of the ifunc resolver. The result is an inability to pass the required comma through in a single preprocessor argument. Rearrange the __ifunc_resolver() macro to be variadic, and pass the types as those variable parameters. Move the guts of __ifunc() and __ifunc_hidden() into new macros, __ifunc_args(), and __ifunc_args_hidden(), that pass the variable arguments down through to __ifunc_resolver(). Then redefine __ifunc() and __ifunc_hidden(), which are used in a bunch of places, to simply shuffle the arguments down into __ifunc_args[_hidden]. Finally, define a riscv-ifunc.h header, which provides convenience macros to those looking to write ifunc selectors that use both arguments. Signed-off-by: Evan Green <evan@rivosinc.com> Reviewed-by: Florian Weimer <fweimer@redhat.com> Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-01-01Update copyright dates with scripts/update-copyrightsPaul Eggert
2023-12-20aarch64: Add half-width versions of AdvSIMD f32 libmvec routinesJoe Ramsay
Compilers may emit calls to 'half-width' routines (two-lane single-precision variants). These have been added in the form of wrappers around the full-width versions, where the low half of the vector is simply duplicated. This will perform poorly when one lane triggers the special-case handler, as there will be a redundant call to the scalar version, however this is expected to be rare at Ofast. Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
2023-06-02Fix all the remaining misspellings -- BZ 25337Paul Pluzhnikov
2023-03-27libio: Remove the usage of __libc_IO_vtablesAdhemerval Zanella Netto
Instead of using a special ELF section along with a linker script directive to put the IO vtables within the RELRO section, the libio vtables are all moved to an array marked as data.relro (so linker will place in the RELRO segment without the need of extra directives). To avoid static linking namespace issues and including all vtable referenced objects, all required function pointers are set to weak alias. Checked on x86_64-linux-gnu, i686-linux-gnu, and aarch64-linux-gnu. Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2023-03-27Move libc_freeres_ptrs and libc_subfreeres to hidden/weak functionsAdhemerval Zanella Netto
They are both used by __libc_freeres to free all library malloc allocated resources to help tooling like mtrace or valgrind with memory leak tracking. The current scheme uses assembly markers and linker script entries to consolidate the free routine function pointers in the RELRO segment and to be freed buffers in BSS. This patch changes it to use specific free functions for libc_freeres_ptrs buffers and call the function pointer array directly with call_function_static_weak. It allows the removal of both the internal macros and the linker script sections. Checked on x86_64-linux-gnu, i686-linux-gnu, and aarch64-linux-gnu. Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2023-01-06Update copyright dates with scripts/update-copyrightsJoseph Myers
2022-07-04libc-symbols.h: remove unused macrosFangrui Song
Beside weak_hidden_alias/declare_symbol_alias/hidden_data_ver, many *_hidden_* macros are removed. If there is a rare need to use one, one may write something like `#if IS_IN (libm)\nhidden_def (...)\n#endif` instead. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
2022-06-24misc: Optimize internal usage of __libc_single_threadedAdhemerval Zanella
By adding an internal alias to avoid the GOT indirection. On some architecture, __libc_single_thread may be accessed through copy relocations and thus it requires to update also the copies default copy. This is done by adding a new internal macro, libc_hidden_data_{proto,def}, which has an addition argument that specifies the alias name (instead of default __GI_ one). Checked on x86_64-linux-gnu and i686-linux-gnu. Reviewed-by: Fangrui Song <maskray@google.com>
2022-05-13Add declare_object_symbol_alias for assembly codes (BZ #28128)H.J. Lu
There are 2 problems in: #define declare_symbol_alias(symbol, original, type, size) \ declare_symbol_alias_1 (symbol, original, type, size) #ifdef __ASSEMBLER__ # define declare_symbol_alias_1(symbol, original, type, size) \ strong_alias (original, symbol); \ .type C_SYMBOL_NAME (symbol), %##type; \ .size C_SYMBOL_NAME (symbol), size 1. .type and .size are substituted by arguments. 2. %##type is expanded to "% type" due to the GCC bug: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101613 But assembler doesn't support "% type". Workaround BZ #28128 by 1. Don't define declare_symbol_alias for assembly codes. 2. Define declare_object_symbol_alias for assembly codes. Reviewed-by: Fangrui Song <maskray@google.com>
2022-01-01Update copyright dates with scripts/update-copyrightsPaul Eggert
I used these shell commands: ../glibc/scripts/update-copyrights $PWD/../gnulib/build-aux/update-copyright (cd ../glibc && git commit -am"[this commit message]") and then ignored the output, which consisted lines saying "FOO: warning: copyright statement not found" for each of 7061 files FOO. I then removed trailing white space from math/tgmath.h, support/tst-support-open-dev-null-range.c, and sysdeps/x86_64/multiarch/strlen-vec.S, to work around the following obscure pre-commit check failure diagnostics from Savannah. I don't know why I run into these diagnostics whereas others evidently do not. remote: *** 912-#endif remote: *** 913: remote: *** 914- remote: *** error: lines with trailing whitespace found ... remote: *** error: sysdeps/unix/sysv/linux/statx_cp.c: trailing lines
2021-07-07nss_files: Move into libcFlorian Weimer
This is the first step towards fixing bug 27959. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
2021-04-16Set the retain attribute on _elf_set_element if CC supports [BZ #27492]Fangrui Song
So that text_set_element/data_set_element/bss_set_element defined variables will be retained by the linker. Note: 'used' and 'retain' are orthogonal: 'used' makes sure the variable will not be optimized out; 'retain' prevents section garbage collection if the linker support SHF_GNU_RETAIN. GNU ld 2.37 and LLD 13 will support -z start-stop-gc which allow C identifier name sections to be GCed even if there are live __start_/__stop_ references. Without the change, there are some static linking problems, e.g. _IO_cleanup (libio/genops.c) may be discarded by ld --gc-sections, so stdout is not flushed on exit. Note: GCC may warning 'retain' attribute ignored while __has_attribute(retain) is 1 (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99587). Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
2021-03-25Support for multiple versions in versioned_symbol, compat_symbolFlorian Weimer
This essentially folds compat_symbol_unique functionality into compat_symbol. This change eliminates the need for intermediate aliases for defining multiple symbol versions, for both compat_symbol and versioned_symbol. Some binutils versions do not suport multiple versions per symbol on some targets, so aliases are automatically introduced, similar to what compat_symbol_unique did. To reduce symbol table sizes, a configure check is added to avoid these aliases if they are not needed. The new mechanism works with data symbols as well as function symbols, due to the way an assembler-level redirect is used. It is not compatible with weak symbols for old binutils versions, which is why the definition of __malloc_initialize_hook had to be changed. This is not a loss of functionality because weak symbols do not matter to dynamic linking. The placeholder symbol needs repeating in nptl/libpthread-compat.c now that compat_symbol is used, but that seems more obvious than introducing yet another macro. A subtle difference was that compat_symbol_unique made the symbol global automatically. compat_symbol does not do this, so static had to be removed from the definition of __libpthread_version_placeholder. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
2021-03-25Change how the symbol_version_reference macro is definedFlorian Weimer
A subsequent change will require including <config.h> for defining symbol_version_reference. <libc-symbol.h> should not include <config.h> for _ISOMAC, so it cannot define symbol_version_reference anymore, but symbol_version_reference is needed <shlib-compat.h> even for _ISOMAC. Moving the definition of symbol_version_reference to a separate file <libc-symver.h> makes it possible to use a single definition for both cases. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
2021-03-09<shlib-compat.h>: Support compat_symbol_reference for _ISOMACFlorian Weimer
This is helpful for testing compat symbols in cases where _ISOMAC is activated implicitly due to -DMODULE_NAME=testsuite and cannot be disabled easily.
2021-01-27Revert "Make libc symbols hidden in static PIE" [BZ #27237]Szabolcs Nagy
This reverts commit 2682695e5c7acf1e60dd3b5c3a14d4e82416262c. Fixes bug 27237. That commit turned out to be too intrusive affecting crt files, test system and benchmark files. They should not be affected, but the build system does not set the MODULE_NAME and LIBC_NONSHARED reliably.
2021-01-21Make libc symbols hidden in static PIESzabolcs Nagy
Hidden visibility can avoid indirections and RELATIVE relocs in static PIE libc. The check should use IS_IN_LIB instead of IS_IN(libc) since all symbols are defined locally in static PIE and the optimization is useful in all libraries not just libc. However the test system links objects from libcrypt.a into dynamic linked test binaries where hidden visibility does not work. I think mixing static and shared libc components in the same binary should not be supported usage, but to be safe only use hidden in libc.a. On some targets (i386) this optimization cannot be applied because hidden visibility PIE ifunc functions don't work, so it is gated by NO_HIDDEN_EXTERN_FUNC_IN_PIE. From -static-pie linked 'int main(){}' this shaves off 71 relative relocs on aarch64 and reduces code size by about 2k. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
2021-01-02Update copyright dates with scripts/update-copyrightsPaul Eggert
I used these shell commands: ../glibc/scripts/update-copyrights $PWD/../gnulib/build-aux/update-copyright (cd ../glibc && git commit -am"[this commit message]") and then ignored the output, which consisted lines saying "FOO: warning: copyright statement not found" for each of 6694 files FOO. I then removed trailing white space from benchtests/bench-pthread-locks.c and iconvdata/tst-iconv-big5-hkscs-to-2ucs4.c, to work around this diagnostic from Savannah: remote: *** pre-commit check failed ... remote: *** error: lines with trailing whitespace found remote: error: hook declined to update refs/heads/master
2020-12-16Mark __libc_freeres_fn as used [BZ #27002]H.J. Lu
GCC 11 with commit 6fbec038f7a7ddf29f074943611b53210d17c40c Author: H.J. Lu <hjl.tools@gmail.com> Date: Mon Feb 3 11:55:43 2020 -0800 Use SHF_GNU_RETAIN to preserve symbol definitions places used symbols in SECTION_RETAIN sections if assembler supports it. Mark __libc_freeres_fn as used to avoid gconv_dl.c: In function 'free_mem': gconv_dl.c:191:1: error: 'do_release_all' without 'used' attribute and 'free_mem' with 'used' attribute are placed in a section with the same name [-Werror=attributes] 191 | do_release_all (void *nodep) | ^~~~~~~~~~~~~~ In file included from <command-line>: gconv_dl.c:202:18: note: 'free_mem' was declared here 202 | libc_freeres_fn (free_mem) | ^~~~~~~~ ./../include/libc-symbols.h:316:15: note: in definition of macro 'libc_freeres_fn' 316 | static void name (void) | ^~~~ cc1: all warnings being treated as errors
2020-12-04symbols: Add defines for libanl's libanl_hidden_{def|proto}Lukasz Majewski
The __gai_suspend_time64, which supports 64 bit time on ports with __WORDSIZE == 32 && __TIMESIZE != 64, shall be exported from libanl (the same library from which original gai_suspend is exported). Up till now there were no defines for this library. This commit adds them.
2020-11-11hurd: keep only required PLTs in ld.soSamuel Thibault
We need NO_RTLD_HIDDEN because of the need for PLT calls in ld.so. See Roland's comment in https://sourceware.org/bugzilla/show_bug.cgi?id=15605 "in the Hurd it's crucial that calls like __mmap be the libc ones instead of the rtld-local ones after the bootstrap phase, when the dynamic linker is being used for dlopen and the like." We used to just avoid all hidden use in the rtld ; this commit switches to keeping only those that should use PLT calls, i.e. essentially those defined in sysdeps/mach/hurd/dl-sysdep.c: __assert_fail __assert_perror_fail __*stat64 _exit This fixes a few startup issues, notably the call to __tunable_get_val that is made before PLTs are set up.
2020-07-13Remove --enable-obsolete-rpc configure flagPetr Vorel
Sun RPC was removed from glibc. This includes rpcgen program, librpcsvc, and Sun RPC headers. Also test for bug #20790 was removed (test for rpcgen). Backward compatibility for old programs is kept only for architectures and ABIs that have been added in or before version 2.28. libtirpc is mature enough, librpcsvc and rpcgen are provided in rpcsvc-proto project. NOTE: libnsl code depends on Sun RPC (installed libnsl headers use installed Sun RPC headers), thus --enable-obsolete-rpc was a dependency for --enable-obsolete-nsl (removed in a previous commit). The arc ABI list file has to be updated because the port was added with the sunrpc symbols Tested-by: Carlos O'Donell <carlos@redhat.com> Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2020-07-08Remove --enable-obsolete-nsl configure flagPetr Vorel
this means that *always* libnsl is only built as shared library for backward compatibility and the NSS modules libnss_nis and libnss_nisplus are not built at all, 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 TIRPC, which additionally support IPv6, are available from <https://github.com/thkukuk/>. This change does not affect libnss_compat which does not depended on libnsl since 2.27 and thus can be used without NIS. libnsl code depends on Sun RPC, e.g. on --enable-obsolete-rpc (installed libnsl headers use installed Sun RPC headers), which will be removed in the following commit.
2020-05-20<libc-symbols.h>: Add libpthread hidden alias supportFlorian Weimer
Reviewed-by: Carlos O'Donell <carlos@redhat.com> Tested-by: Carlos O'Donell <carlos@redhat.com>
2020-03-25ldbl-128ibm-compat: PLT redirects for using ldbl redirects internallyPaul E. Murphy
Tweak the PLT bypass magic when building glibc with long double redirects. This is made more difficult by the fact we only get one chance to redirect functions. This happens via the public headers. There are roughly three classes of redirect we need to attend to today: 1. Simple redirects, redirected via cdef macro overrides and and new libc_hidden_ldbl_proto macro. 2. Internal usage of internal API, e.g __snprintf, which has no direct analogue. This is bypassed directly on case-by- case basis. 3. Double redirects, e.g sscanf and related. These require a heavier handed approach of macro renaming to existing symbols. Most simple redirects are handled via 1. Ideally, the libc_* macro would live in libc-symbols.h, but in practice the macros needed for it to do anything useful live in cdefs.h, so they are defined in the local override. Notably, the internal name of the asprintf generated for ieee ldbl redirects is renamed to work with internal prefixed usage. This resolves the local plt usage introduced when building glibc with ldbl == ieee128 on ppc64le. Reviewed-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
2020-02-25nss_nis: Use NSS_DECLARE_MODULE_FUNCTIONSFlorian Weimer
This commit removes the minor optimization based on strong aliases because it loses type safety.
2020-02-15ld.so: Do not export free/calloc/malloc/realloc functions [BZ #25486]Florian Weimer
Exporting functions and relying on symbol interposition from libc.so makes the choice of implementation dependent on DT_NEEDED order, which is not what some compiler drivers expect. This commit replaces one magic mechanism (symbol interposition) with another one (preprocessor-/compiler-based redirection). This makes the hand-over from the minimal malloc to the full malloc more explicit. Removing the ABI symbols is backwards-compatible because libc.so is always in scope, and the dynamic loader will find the malloc-related symbols there since commit f0b2132b35248c1f4a80f62a2c38cddcc802aa8c ("ld.so: Support moving versioned symbols between sonames [BZ #24741]"). Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2020-01-01Update copyright dates with scripts/update-copyrights.Joseph Myers
2019-09-07Prefer https to http for gnu.org and fsf.org URLsPaul Eggert
Also, change sources.redhat.com to sourceware.org. This patch was automatically generated by running the following shell script, which uses GNU sed, and which avoids modifying files imported from upstream: sed -ri ' s,(http|ftp)(://(.*\.)?(gnu|fsf|sourceware)\.org($|[^.]|\.[^a-z])),https\2,g s,(http|ftp)(://(.*\.)?)sources\.redhat\.com($|[^.]|\.[^a-z]),https\2sourceware.org\4,g ' \ $(find $(git ls-files) -prune -type f \ ! -name '*.po' \ ! -name 'ChangeLog*' \ ! -path COPYING ! -path COPYING.LIB \ ! -path manual/fdl-1.3.texi ! -path manual/lgpl-2.1.texi \ ! -path manual/texinfo.tex ! -path scripts/config.guess \ ! -path scripts/config.sub ! -path scripts/install-sh \ ! -path scripts/mkinstalldirs ! -path scripts/move-if-change \ ! -path INSTALL ! -path locale/programs/charmap-kw.h \ ! -path po/libc.pot ! -path sysdeps/gnu/errlist.c \ ! '(' -name configure \ -execdir test -f configure.ac -o -f configure.in ';' ')' \ ! '(' -name preconfigure \ -execdir test -f preconfigure.ac ';' ')' \ -print) and then by running 'make dist-prepare' to regenerate files built from the altered files, and then executing the following to cleanup: chmod a+x sysdeps/unix/sysv/linux/riscv/configure # Omit irrelevant whitespace and comment-only changes, # perhaps from a slightly-different Autoconf version. git checkout -f \ sysdeps/csky/configure \ sysdeps/hppa/configure \ sysdeps/riscv/configure \ sysdeps/unix/sysv/linux/csky/configure # Omit changes that caused a pre-commit check to fail like this: # remote: *** error: sysdeps/powerpc/powerpc64/ppc-mcount.S: trailing lines git checkout -f \ sysdeps/powerpc/powerpc64/ppc-mcount.S \ sysdeps/unix/sysv/linux/s390/s390-64/syscall.S # Omit change that caused a pre-commit check to fail like this: # remote: *** error: sysdeps/sparc/sparc64/multiarch/memcpy-ultra3.S: last line does not end in newline git checkout -f sysdeps/sparc/sparc64/multiarch/memcpy-ultra3.S
2019-01-01Update copyright dates with scripts/update-copyrights.Joseph Myers
* All files with FSF copyright notices: Update copyright dates using scripts/update-copyrights. * locale/programs/charmap-kw.h: Regenerated. * locale/programs/locfile-kw.h: Likewise.
2018-11-13Add hidden_tls_def macros, fix powerpc-soft build with GCC 9.Joseph Myers
Soft-float powerpc fails to build with current GCC mainline because of use of libc_hidden_data_def for TLS variables, resulting in a non-TLS alias being defined, to which the tls_model attribute is now copied, resulting in a warning about it being ignored. The problem here appears to be the non-TLS alias. This patch adds a hidden_tls_def macro family, corresponding to the hidden_tls_proto macros, to define TLS aliases properly in such a case, and uses it for those powerpc soft-float variables. Tested with build-many-glibcs.py compilers build for powerpc-linux-gnu soft-float. Also tested for x86_64. * include/libc-symbols.h [SHARED && !NO_HIDDEN && !__ASSEMBLER__] (__hidden_ver2): New macro. Use old definition of __hidden_ver1 with additional parameter thread. [SHARED && !NO_HIDDEN && !__ASSEMBLER__] (__hidden_ver1): Define in terms of __hidden_ver2. (hidden_tls_def): New macro. (libc_hidden_tls_def): Likewise. (rtld_hidden_tls_def): Likewise. (libm_hidden_tls_def): Likewise. (libmvec_hidden_tls_def): Likewise. (libresolv_hidden_tls_def): Likewise. (librt_hidden_tls_def): Likewise. (libdl_hidden_tls_def): Likewise. (libnss_files_hidden_tls_def): Likewise. (libnsl_hidden_tls_def): Likewise. (libnss_nisplus_hidden_tls_def): Likewise. (libutil_hidden_tls_def): Likewise. (libutil_hidden_tls_def): Likweise. * sysdeps/powerpc/nofpu/sim-full.c (__sim_exceptions_thread): Use libc_hidden_tls_def. (__sim_disabled_exceptions_thread): Likewise. (__sim_round_mode_thread): Likewise.
2018-11-09Add support for GCC 9 attribute copy.Martin Sebor
GCC 9 has gained an enhancement to help detect attribute mismatches between alias declarations and their targets. It consists of a new warning, -Wattribute-alias, an enhancement to an existing warning, -Wmissing-attributes, and a new attribute called copy. The purpose of the warnings is to help identify either possible bugs (an alias declared with more restrictive attributes than its target promises) or optimization or diagnostic opportunities (an alias target missing some attributes that it could be declared with that might benefit analysis and code generation). The purpose of the new attribute is to easily apply (almost) the same set of attributes to one declaration as those already present on another. As expected (and intended) the enhancement triggers warnings for many alias declarations in Glibc code. This change, tested on x86_64-linux, avoids all instances of the new warnings by making use of the attribute where appropriate. To fully benefit from the enhancement Glibc will need to be compiled with -Wattribute-alias=2 and remaining warnings reviewed and dealt with (there are a couple of thousand but most should be straightforward to deal with). ChangeLog: * include/libc-symbols.h (__attribute_copy__): Define macro unless it's already defined. (_strong_alias): Use __attribute_copy__. (_weak_alias, __hidden_ver1, __hidden_nolink2): Same. * misc/sys/cdefs.h (__attribute_copy__): New macro. * sysdeps/x86_64/multiarch/memchr.c (memchr): Use __attribute_copy__. * sysdeps/x86_64/multiarch/memcmp.c (memcmp): Same. * sysdeps/x86_64/multiarch/mempcpy.c (mempcpy): Same. * sysdeps/x86_64/multiarch/memset.c (memset): Same. * sysdeps/x86_64/multiarch/stpcpy.c (stpcpy): Same. * sysdeps/x86_64/multiarch/strcat.c (strcat): Same. * sysdeps/x86_64/multiarch/strchr.c (strchr): Same. * sysdeps/x86_64/multiarch/strcmp.c (strcmp): Same. * sysdeps/x86_64/multiarch/strcpy.c (strcpy): Same. * sysdeps/x86_64/multiarch/strcspn.c (strcspn): Same. * sysdeps/x86_64/multiarch/strlen.c (strlen): Same. * sysdeps/x86_64/multiarch/strncmp.c (strncmp): Same. * sysdeps/x86_64/multiarch/strncpy.c (strncpy): Same. * sysdeps/x86_64/multiarch/strnlen.c (strnlen): Same. * sysdeps/x86_64/multiarch/strpbrk.c (strpbrk): Same. * sysdeps/x86_64/multiarch/strrchr.c (strrchr): Same. * sysdeps/x86_64/multiarch/strspn.c (strspn): Same.
2018-06-29libc: Extend __libc_freeres framework (Bug 23329).Carlos O'Donell
The __libc_freeres framework does not extend to non-libc.so objects. This causes problems in general for valgrind and mtrace detecting unfreed objects in both libdl.so and libpthread.so. This change is a pre-requisite to properly moving the malloc hooks out of malloc since such a move now requires precise accounting of all allocated data before destructors are run. This commit adds a proper hook in libc.so.6 for both libdl.so and for libpthread.so, this ensures that shm-directory.c which uses freeit () to free memory is called properly. We also remove the nptl_freeres hook and fall back to using weak-ref-and-check idiom for a loaded libpthread.so, thus making this process similar for all DSOs. Lastly we follow best practice and use explicit free calls for both libdl.so and libpthread.so instead of the generic hook process which has undefined order. Tested on x86_64 with no regressions. Signed-off-by: DJ Delorie <dj@redhat.com> Signed-off-by: Carlos O'Donell <carlos@redhat.com>
2018-01-01Update copyright dates with scripts/update-copyrights.Joseph Myers
* All files with FSF copyright notices: Update copyright dates using scripts/update-copyrights. * locale/programs/charmap-kw.h: Regenerated. * locale/programs/locfile-kw.h: Likewise.
2017-10-04Don't use hidden visibility in libc.a with PIE on i386H.J. Lu
On i386, when multi-arch is enabled, all external functions must be called via PIC PLT in PIE, which requires setting up EBX register, since they may be IFUNC functions. * config.h.in (NO_HIDDEN_EXTERN_FUNC_IN_PIE): New. * include/libc-symbols.h (__hidden_proto_hiddenattr): Add check for PIC and NO_HIDDEN_EXTERN_FUNC_IN_PIE. * sysdeps/i386/configure.ac (NO_HIDDEN_EXTERN_FUNC_IN_PIE): New AC_DEFINE if multi-arch is enabled. * sysdeps/i386/configure: Regenerated.
2017-10-03Introduce NO_RTLD_HIDDEN, make hurd use it instead of NO_HIDDENSamuel Thibault
On the Hurd, the rtld needs to see its own dumb versions of a few functions (defined in sysdeps/mach/hurd/dl-sysdep.c) overridden by libc's versions once loaded. rtld should thus not have hidden attribute for these. To achieve this, the Hurd port used to just define NO_HIDDEN, which disables it completely. For now, this changes that to disabling it for all rtld functions, for simplicity. See Roland's comment on https://sourceware.org/bugzilla/show_bug.cgi?id=15605#c5 The ld.so numbers remain at 8 .rel.plt 000000c8 00000c24 00000c24 00000c24 2**2 CONTENTS, ALLOC, LOAD, READONLY, DATA 9 .plt 000001a0 00000cf0 00000cf0 00000cf0 2**4 CONTENTS, ALLOC, LOAD, READONLY, CODE 10 .plt.got 00000010 00000e90 00000e90 00000e90 2**3 CONTENTS, ALLOC, LOAD, READONLY, CODE 18 .got.plt 00000070 0002d000 0002d000 0002c000 2**2 CONTENTS, ALLOC, LOAD, DATA which is about 3 times as much as on Linux. The libc.so numbers get divided by 3 (the remainings are mostly RPC stub calls) * include/libc-symbols.h [NO_RTLD_HIDDEN] (rtld_hidden_proto, rtld_hidden_tls_proto, rtld_hidden_def, rtld_hidden_weak, rtld_hidden_rtld_hidden_ver, data_def, rtld_hidden_data_weak, rtld_hidden_data_ver): Define to empty. * include/assert.h [IS_IN(rtld) && NO_RTLD_HIDDEN] (__assert_fail, __assert_perror_fail): Likewise. * include/dirent.h [IS_IN(rtld) && NO_RTLD_HIDDEN] (__rewinddir): Likewise. * include/libc-internal.h [IS_IN(rtld) && NO_RTLD_HIDDEN] (__profile_frequency): Likewise. * include/setjmp.h (__sigsetjmp): Likewise. * include/signal.h [IS_IN(rtld) && NO_RTLD_HIDDEN] (__sigaction, __libc_sigaction): Likewise. * include/stdlib.h [NO_RTLD_HIDDEN] (unsetenv, __strtoul_internal): Do not set hidden attribute. * include/string.h [IS_IN(rtld) && NO_RTLD_HIDDEN] (__stpcpy, __strdup, __strerror_t, __strsep_g, memchr, memcmp, memcpy, memmove, memset, rawmemchr, stpcpy, strchr, strcmp, strlen, strnlen, strsep): Likewise. * include/sys/stat.h [IS_IN(rtld) && NO_RTLD_HIDDEN] (__fxstat, __fxstat64, __lxstat, __lxstat64, __xstat, __xstat64, __fxstatat64): Likewise. * include/sys/utsname.h [IS_IN(rtld) && NO_RTLD_HIDDEN] (__uname): Likewise. * include/sysdeps/generic/_itoa.h [IS_IN(rtld) && NO_RTLD_HIDDEN] (_itoa_upper_digits, _itoa_lower_digits): Likewise. * sysdeps/mach/hurd/configure.ac (NO_HIDDEN): Do not set. (NO_RTLD_HIDDEN): Set. * sysdeps/mach/hurd/configure: Refresh. * config.h.in: Refresh.
2017-08-31libc-symbols.h: Remove definition of internal_functionFlorian Weimer
2017-08-22Fix remaining return type of ifunc resolver declarationGabriel F. T. Gomes
Since Martin Sebor's commit commit ee4e992ebe5f9712faedeefe8958b67d61eaa0f2 Author: Martin Sebor <msebor@redhat.com> Date: Tue Aug 22 09:35:23 2017 -0600 Declare ifunc resolver to return a pointer to the same type as the target function to help GCC detect incompatibilities between the two when it's enhanced to do so. builds for powerpc64le fail in the declaration of some ifunc resolvers, because the ifunc is declared with unmatching return types. One of the declarations comes from the __ifunc_resolver macro, which was patched by the aforementioned commit: /* Helper / base macros for indirect function symbols. */ #define __ifunc_resolver(type_name, name, expr, arg, init, classifier) \ classifier inhibit_stack_protector \ __typeof (type_name) *name##_ifunc (arg) \ whereas the other comes from the unpatched __ifunc macro when HAVE_GCC_IFUNC is not defined: # define __ifunc(type_name, name, expr, arg, init) \ extern __typeof (type_name) name; \ void *name##_ifunc (arg) __asm__ (#name); \ This patch changes the return type of the ifunc resolver in the __ifunc macro, so that it matches the return type of the target function, similarly to what the aforementioned commit does. Tested for powerpc64le and s390x with unpatched GCC. * include/libc-symbols.h: [!defined HAVE_GCC_IFUNC] (__ifunc): Change the return type of the ifunc resolver to match the return type of the target function.
2017-08-22Declare ifunc resolver to return a pointer to the same type as the targetMartin Sebor
function to help GCC detect incompatibilities between the two when it's enhanced to do so.
2017-08-22Add hidden visibility to internal function prototypesH.J. Lu
Add hidden visibility to internal function prototypes to allow direct access to internal functions within libc.a without using GOT when the compiler defaults to -fPIE. Size comparison of elf/ldconfig when the compiler defaults to -fPIE: On x86-64: text data bss dec hex Before: 619646 20132 5488 645266 9d892 After : 619502 20132 5488 645122 9d802 On i686: text data bss dec hex Before: 550333 10748 3060 564141 89bad After : 546453 10732 3060 560245 88c75 * include/libc-symbols.h (__hidden_proto_hiddenattr): New for building libc.a. (hidden_proto): Likewise. (hidden_tls_proto): Likewise. (__hidden_proto): Likewise. (Reapplied after the revert in df1deda60050cc8a68156cf6c81ad42363647a29.)
2017-08-21Revert "Add hidden visibility to internal function prototypes".Joseph Myers
The commit commit 568ff4296c72534e49c8d9c83c33f3a0069cccc7 Author: H.J. Lu <hjl.tools@gmail.com> Date: Mon Aug 21 05:50:38 2017 -0700 Add hidden visibility to internal function prototypes breaks the build of the testsuite for many platforms: https://sourceware.org/ml/libc-testresults/2017-q3/msg00300.html The errors are of the following form, building math/atest-exp: [...] /scratch/jmyers/glibc-bot/build/glibcs/aarch64-linux-gnu/glibc/stdlib/rshift.o: In function `__mpn_rshift': /scratch/jmyers/glibc-bot/build/glibcs/aarch64-linux-gnu/glibc-src/stdlib/rshift.c:45: undefined reference to `__assert_fail' /scratch/jmyers/glibc-bot/install/compilers/aarch64-linux-gnu/lib/gcc/aarch64-glibc-linux-gnu/7.2.1/../../../../aarch64-glibc-linux-gnu/bin/ld: /scratch/jmyers/glibc-bot/build/glibcs/aarch64-linux-gnu/glibc/math/atest-exp: hidden symbol `__assert_fail' isn't defined /scratch/jmyers/glibc-bot/install/compilers/aarch64-linux-gnu/lib/gcc/aarch64-glibc-linux-gnu/7.2.1/../../../../aarch64-glibc-linux-gnu/bin/ld: final link failed: Bad value This test is using various objects from the build of libc. Some of those objects contain references to __assert_fail. Because those references are hidden, they cannot refer to __assert_fail from libc.so. Given the tests using internal objects those symbols in libc.a can't safely be made hidden, so this patch reverts the problem commit until any alternative approach that doesn't break the build can be found.
2017-08-21Add hidden visibility to internal function prototypesH.J. Lu
Add hidden visibility to internal function prototypes to allow direct access to internal functions within libc.a without using GOT when the compiler defaults to -fPIE. Size comparison of elf/ldconfig when the compiler defaults to -fPIE: On x86-64: text data bss dec hex Before: 619646 20132 5488 645266 9d892 After : 619502 20132 5488 645122 9d802 On i686: text data bss dec hex Before: 550333 10748 3060 564141 89bad After : 546453 10732 3060 560245 88c75 * include/libc-symbols.h (__hidden_proto_hiddenattr): New for building libc.a. (hidden_proto): Likewise. (hidden_tls_proto): Likewise. (__hidden_proto): Likewise.
generated by cgit v1.3 (git 2.53.0) at 2026-04-23 21:34:33 +0000