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2021-12-05elf: execve statically linked programs instead of crashing [BZ #28648]Florian Weimer1-0/+4
Programs without dynamic dependencies and without a program interpreter are now run via execve. Previously, the dynamic linker either crashed while attempting to read a non-existing dynamic segment (looking for DT_AUDIT/DT_DEPAUDIT data), or the self-relocated in the static PIE executable crashed because the outer dynamic linker had already applied RELRO protection. <dl-execve.h> is needed because execve is not available in the dynamic loader on Hurd. Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
2021-11-10Support C2X printf %b, %BJoseph Myers1-0/+4
C2X adds a printf %b format (see <http://www.open-std.org/jtc1/sc22/wg14/www/docs/n2630.pdf>, accepted for C2X), for outputting integers in binary. It also has recommended practice for a corresponding %B format (like %b, but %#B starts the output with 0B instead of 0b). Add support for these formats to glibc. One existing test uses %b as an example of an unknown format, to test how glibc printf handles unknown formats; change that to %v. Use of %b and %B as user-registered format specifiers continues to work (and we already have a test that covers that, tst-printfsz.c). Note that C2X also has scanf %b support, plus support for binary constants starting 0b in strtol (base 0 and 2) and scanf %i (strtol base 0 and scanf %i coming from a previous paper that added binary integer literals). I intend to implement those features in a separate patch or patches; as discussed in the thread starting at <https://sourceware.org/pipermail/libc-alpha/2020-December/120414.html>, they will be more complicated because they involve adding extra public symbols to ensure compatibility with existing code that might not expect 0b constants to be handled by strtol base 0 and 2 and scanf %i, whereas simply adding a new format specifier poses no such compatibility concerns. Note that the actual conversion from integer to string uses existing code in _itoa.c. That code has special cases for bases 8, 10 and 16, probably so that the compiler can optimize division by an integer constant in the code for those bases. If desired such special cases could easily be added for base 2 as well, but that would be an optimization, not actually needed for these printf formats to work. Tested for x86_64 and x86. Also tested with build-many-glibcs.py for aarch64-linux-gnu with GCC mainline to make sure that the test does indeed build with GCC 12 (where format checking warnings are enabled for most of the test).
2021-10-26NEWS: Add item for __memcmpeqNoah Goldstein1-0/+4
2021-10-21elf: Fix slow DSO sorting behavior in dynamic loader (BZ #17645)Chung-Lin Tang1-0/+9
This second patch contains the actual implementation of a new sorting algorithm for shared objects in the dynamic loader, which solves the slow behavior that the current "old" algorithm falls into when the DSO set contains circular dependencies. The new algorithm implemented here is simply depth-first search (DFS) to obtain the Reverse-Post Order (RPO) sequence, a topological sort. A new l_visited:1 bitfield is added to struct link_map to more elegantly facilitate such a search. The DFS algorithm is applied to the input maps[nmap-1] backwards towards maps[0]. This has the effect of a more "shallow" recursion depth in general since the input is in BFS. Also, when combined with the natural order of processing l_initfini[] at each node, this creates a resulting output sorting closer to the intuitive "left-to-right" order in most cases. Another notable implementation adjustment related to this _dl_sort_maps change is the removing of two char arrays 'used' and 'done' in _dl_close_worker to represent two per-map attributes. This has been changed to simply use two new bit-fields l_map_used:1, l_map_done:1 added to struct link_map. This also allows discarding the clunky 'used' array sorting that _dl_sort_maps had to sometimes do along the way. Tunable support for switching between different sorting algorithms at runtime is also added. A new tunable 'glibc.rtld.dynamic_sort' with current valid values 1 (old algorithm) and 2 (new DFS algorithm) has been added. At time of commit of this patch, the default setting is 1 (old algorithm). Signed-off-by: Chung-Lin Tang <cltang@codesourcery.com> Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
2021-10-11elf: Remove Intel MPX support (lazy PLT, ld.so profile, and LD_AUDIT)Fangrui Song1-0/+2
Intel MPX failed to gain wide adoption and has been deprecated for a while. GCC 9.1 removed Intel MPX support. Linux kernel removed MPX in 2019. This patch removes the support code from the dynamic loader. Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
2021-10-04Update to Unicode 14.0.0 [BZ #28390]Mike FABIAN1-0/+4
Unicode 14.0.0 Support: Character encoding, character type info, and transliteration tables are all updated to Unicode 14.0.0, using the generator scripts contributed by Mike FABIAN (Red Hat). Total added characters in newly generated CHARMAP: 838 Total removed characters in newly generated WIDTH: 1 (Characters not in WIDTH get width 1 by default, i.e. these have width 1 now.) removed: <U1734> 0 : eaw=N category=Mc bidi=L name=HANUNOO SIGN PAMUDPOD That seems intentional, the character had category Mn (Mark, nonspacing) before and now has Mc (Mark, spacing combining) Total changed characters in newly generated WIDTH: 0 Total added characters in newly generated WIDTH: 175
2021-09-30Add C2X _PRINTF_NAN_LEN_MAXJoseph Myers1-0/+2
C2X adds a macro _PRINTF_NAN_LEN_MAX to <stdio.h>, giving the maximum length of printf output for a NaN. glibc never includes an n-char-sequence in its printf output for NaNs, so the correct value for glibc is 4 ("-nan" or "-NAN"); define the macro accordingly. This patch makes the macro definition conditional on __GLIBC_USE (ISOC2X), as is generally done with features from new standard versions. The name is in the implementation namespace for older standards, so it would also be possible to define it unconditionally. Tested for x86_64.
2021-09-30Add exp10 macro to <tgmath.h> (bug 26108)Joseph Myers1-0/+3
glibc has had exp10 functions since long before they were standardized; now they are standardized in TS 18661-4 and C2X, they are also specified there to have a corresponding type-generic macro. Add one to <tgmath.h>, so fixing bug 26108. glibc doesn't have other functions from TS 18661-4 yet, but when added, it will be natural to add the type-generic macro for each function family at the same time as the functions. Tested for x86_64.
2021-09-28Add fmaximum, fminimum functionsJoseph Myers1-0/+7
C2X adds new <math.h> functions for floating-point maximum and minimum, corresponding to the new operations that were added in IEEE 754-2019 because of concerns about the old operations not being associative in the presence of signaling NaNs. fmaximum and fminimum handle NaNs like most <math.h> functions (any NaN argument means the result is a quiet NaN). fmaximum_num and fminimum_num handle both quiet and signaling NaNs the way fmax and fmin handle quiet NaNs (if one argument is a number and the other is a NaN, return the number), but still raise "invalid" for a signaling NaN argument, making them exceptions to the normal rule that a function with a floating-point result raising "invalid" also returns a quiet NaN. fmaximum_mag, fminimum_mag, fmaximum_mag_num and fminimum_mag_num are corresponding functions returning the argument with greatest or least absolute value. All these functions also treat +0 as greater than -0. There are also corresponding <tgmath.h> type-generic macros. Add these functions to glibc. The implementations use type-generic templates based on those for fmax, fmin, fmaxmag and fminmag, and test inputs are based on those for those functions with appropriate adjustments to the expected results. The RISC-V maintainers might wish to add optimized versions of fmaximum_num and fminimum_num (for float and double), since RISC-V (F extension version 2.2 and later) provides instructions corresponding to those functions - though it might be at least as useful to add architecture-independent built-in functions to GCC and teach the RISC-V back end to expand those functions inline, which is what you generally want for functions that can be implemented with a single instruction. Tested for x86_64 and x86, and with build-many-glibcs.py.
2021-09-24Define __STDC_IEC_60559_BFP__ and __STDC_IEC_60559_COMPLEX__Joseph Myers1-0/+3
TS 18661-1 and C2X specify predefined macros __STDC_IEC_60559_BFP__ and __STDC_IEC_60559_COMPLEX__, making __STDC_IEC_559__ and __STDC_IEC_559_COMPLEX__ obsolescent (but still included in the standard). Now that we have all the functions from TS 18661-1, define these macros in stdc-predef.h, under the same conditions in which the older macros are defined, since support for the floating-point features in TS 18661-1 is now at the same level as that for those in C11 and before (all library functions and other library APIs present, but no standard pragma support). The macros are defined for now with their TS 18661-1 values. C2X will give them new values (listed as yyyymmL in the working drafts until the final standard), at which point there will be the question of what value to use in stdc-predef.h (where it could depend on __STDC_VERSION__, but not on feature test macros defined by the user). My inclination then would be to use the C2X value unconditionally rather than using an older value to indicate TS support, and only have any C standard version conditionals for the value when subsequent C standard versions define further values. (Note that I'm also inclined, when we implement the C2X change to the return types of fromfp functions, to make that change unconditional much like the change made to the types of totalorder functions, with the old version only supported with compat symbols for already-linked programs and not as an API for newly built objects. So using the C2X value would also accurately reflect not supporting the versions of APIs in the TS where those ended up being incompatible with the first version actually added to the standard.) Tested for x86_64.
2021-09-22Add narrowing fma functionsJoseph Myers1-0/+3
This patch adds the narrowing fused multiply-add functions from TS 18661-1 / TS 18661-3 / C2X to glibc's libm: ffma, ffmal, dfmal, f32fmaf64, f32fmaf32x, f32xfmaf64 for all configurations; f32fmaf64x, f32fmaf128, f64fmaf64x, f64fmaf128, f32xfmaf64x, f32xfmaf128, f64xfmaf128 for configurations with _Float64x and _Float128; __f32fmaieee128 and __f64fmaieee128 aliases in the powerpc64le case (for calls to ffmal and dfmal when long double is IEEE binary128). Corresponding tgmath.h macro support is also added. The changes are mostly similar to those for the other narrowing functions previously added, especially that for sqrt, so the description of those generally applies to this patch as well. As with sqrt, I reused the same test inputs in auto-libm-test-in as for non-narrowing fma rather than adding extra or separate inputs for narrowing fma. The tests in libm-test-narrow-fma.inc also follow those for non-narrowing fma. The non-narrowing fma has a known bug (bug 6801) that it does not set errno on errors (overflow, underflow, Inf * 0, Inf - Inf). Rather than fixing this or having narrowing fma check for errors when non-narrowing does not (complicating the cases when narrowing fma can otherwise be an alias for a non-narrowing function), this patch does not attempt to check for errors from narrowing fma and set errno; the CHECK_NARROW_FMA macro is still present, but as a placeholder that does nothing, and this missing errno setting is considered to be covered by the existing bug rather than needing a separate open bug. missing-errno annotations are duly added to many of the auto-libm-test-in test inputs for fma. This completes adding all the new functions from TS 18661-1 to glibc, so will be followed by corresponding stdc-predef.h changes to define __STDC_IEC_60559_BFP__ and __STDC_IEC_60559_COMPLEX__, as the support for TS 18661-1 will be at a similar level to that for C standard floating-point facilities up to C11 (pragmas not implemented, but library functions done). (There are still further changes to be done to implement changes to the types of fromfp functions from N2548.) Tested as followed: natively with the full glibc testsuite for x86_64 (GCC 11, 7, 6) and x86 (GCC 11); with build-many-glibcs.py with GCC 11, 7 and 6; cross testing of math/ tests for powerpc64le, powerpc32 hard float, mips64 (all three ABIs, both hard and soft float). The different GCC versions are to cover the different cases in tgmath.h and tgmath.h tests properly (GCC 6 has _Float* only as typedefs in glibc headers, GCC 7 has proper _Float* support, GCC 8 adds __builtin_tgmath).
2021-09-19Extend struct r_debug to support multiple namespaces [BZ #15971]H.J. Lu1-1/+10
Glibc does not provide an interface for debugger to access libraries loaded in multiple namespaces via dlmopen. The current rtld-debugger interface is described in the file: elf/rtld-debugger-interface.txt under the "Standard debugger interface" heading. This interface only provides access to the first link-map (LM_ID_BASE). 1. Bump r_version to 2 when multiple namespaces are used. This triggers the GDB bug: https://sourceware.org/bugzilla/show_bug.cgi?id=28236 2. Add struct r_debug_extended to extend struct r_debug into a linked-list, where each element correlates to an unique namespace. 3. Initialize the r_debug_extended structure. Bump r_version to 2 for the new namespace and add the new namespace to the namespace linked list. 4. Add _dl_debug_update to return the address of struct r_debug' of a namespace. 5. Add a hidden symbol, _r_debug_extended, for struct r_debug_extended. 6. Provide the symbol, _r_debug, with size of struct r_debug, as an alias of _r_debug_extended, for programs which reference _r_debug. This fixes BZ #15971. Reviewed-by: Florian Weimer <fweimer@redhat.com>
2021-09-10Add narrowing square root functionsJoseph Myers1-0/+7
This patch adds the narrowing square root functions from TS 18661-1 / TS 18661-3 / C2X to glibc's libm: fsqrt, fsqrtl, dsqrtl, f32sqrtf64, f32sqrtf32x, f32xsqrtf64 for all configurations; f32sqrtf64x, f32sqrtf128, f64sqrtf64x, f64sqrtf128, f32xsqrtf64x, f32xsqrtf128, f64xsqrtf128 for configurations with _Float64x and _Float128; __f32sqrtieee128 and __f64sqrtieee128 aliases in the powerpc64le case (for calls to fsqrtl and dsqrtl when long double is IEEE binary128). Corresponding tgmath.h macro support is also added. The changes are mostly similar to those for the other narrowing functions previously added, so the description of those generally applies to this patch as well. However, the not-actually-narrowing cases (where the two types involved in the function have the same floating-point format) are aliased to sqrt, sqrtl or sqrtf128 rather than needing a separately built not-actually-narrowing function such as was needed for add / sub / mul / div. Thus, there is no __nldbl_dsqrtl name for ldbl-opt because no such name was needed (whereas the other functions needed such a name since the only other name for that entry point was e.g. f32xaddf64, not reserved by TS 18661-1); the headers are made to arrange for sqrt to be called in that case instead. The DIAG_* calls in sysdeps/ieee754/soft-fp/s_dsqrtl.c are because they were observed to be needed in GCC 7 testing of riscv32-linux-gnu-rv32imac-ilp32. The other sysdeps/ieee754/soft-fp/ files added didn't need such DIAG_* in any configuration I tested with build-many-glibcs.py, but if they do turn out to be needed in more files with some other configuration / GCC version, they can always be added there. I reused the same test inputs in auto-libm-test-in as for non-narrowing sqrt rather than adding extra or separate inputs for narrowing sqrt. The tests in libm-test-narrow-sqrt.inc also follow those for non-narrowing sqrt. Tested as followed: natively with the full glibc testsuite for x86_64 (GCC 11, 7, 6) and x86 (GCC 11); with build-many-glibcs.py with GCC 11, 7 and 6; cross testing of math/ tests for powerpc64le, powerpc32 hard float, mips64 (all three ABIs, both hard and soft float). The different GCC versions are to cover the different cases in tgmath.h and tgmath.h tests properly (GCC 6 has _Float* only as typedefs in glibc headers, GCC 7 has proper _Float* support, GCC 8 adds __builtin_tgmath).
2021-09-06Add generic C.UTF-8 locale (Bug 17318)Carlos O'Donell1-1/+9
We add a new C.UTF-8 locale. This locale is not builtin to glibc, but is provided as a distinct locale. The locale provides full support for UTF-8 and this includes full code point sorting via STRCMP-based collation (strcmp or wcscmp). The collation uses a new keyword 'codepoint_collation' which drops all collation rules and generates an empty zero rules collation to enable STRCMP usage in collation. This ensures that we get full code point sorting for C.UTF-8 with a minimal 1406 bytes of overhead (LC_COLLATE structure information and ASCII collating tables). The new locale is added to SUPPORTED. Minimal test data for specific code points (minus those not supported by collate-test) is provided in C.UTF-8.in, and this verifies code point sorting is working reasonably across the range. The locale was tested manually with the full set of code points without failure. The locale is harmonized with locales already shipping in various downstream distributions. A new tst-iconv9 test is added which verifies the C.UTF-8 locale is generally usable. Testing for fnmatch, regexec, and recomp is provided by extending bug-regex1, bugregex19, bug-regex4, bug-regex6, transbug, tst-fnmatch, tst-regcomp-truncated, and tst-regex to use C.UTF-8. Tested on x86_64 or i686 without regression. Reviewed-by: Florian Weimer <fweimer@redhat.com>
2021-08-01Open master branch for glibc 2.35 developmentglibc-2.34.9000Carlos O'Donell1-0/+24
2021-08-01Update NEWS.Carlos O'Donell1-4/+172
Suggestions by Florian Weimer, Andreas Schwab, and Alexander Monakov. See: https://sourceware.org/pipermail/libc-alpha/2021-July/129356.html https://sourceware.org/pipermail/libc-alpha/2021-July/129357.html https://sourceware.org/pipermail/libc-alpha/2021-July/129361.html
2021-08-01NEWS: Fix typos, grammar, and missing wordsMark Harris1-12/+13
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2021-07-22Remove malloc hooks [BZ #23328]Siddhesh Poyarekar1-0/+10
Make malloc hooks symbols compat-only so that new applications cannot link against them and remove the declarations from the API. Also remove the unused malloc-hooks.h. Finally, mark all symbols in libc_malloc_debug.so as compat so that the library cannot be linked against. Add a note about the deprecation in NEWS. Reviewed-by: Carlos O'Donell <carlos@redhat.com> Tested-by: Carlos O'Donell <carlos@redhat.com>
2021-07-22Move malloc_{g,s}et_state to libc_malloc_debugSiddhesh Poyarekar1-0/+5
These deprecated functions are only safe to call from __malloc_initialize_hook and as a result, are not useful in the general case. Move the implementations to libc_malloc_debug so that existing binaries that need it will now have to preload the debug DSO to work correctly. This also allows simplification of the core malloc implementation by dropping all the undumping support code that was added to make malloc_set_state work. One known breakage is that of ancient emacs binaries that depend on this. They will now crash when running with this libc. With LD_BIND_NOW=1, it will terminate immediately because of not being able to find malloc_set_state but with lazy binding it will crash in unpredictable ways. It will need a preloaded libc_malloc_debug.so so that its initialization hook is executed to allow its malloc implementation to work properly. Reviewed-by: Carlos O'Donell <carlos@redhat.com> Tested-by: Carlos O'Donell <carlos@redhat.com>
2021-07-22Move malloc hooks into a compat DSOSiddhesh Poyarekar1-0/+6
Remove all malloc hook uses from core malloc functions and move it into a new library libc_malloc_debug.so. With this, the hooks now no longer have any effect on the core library. libc_malloc_debug.so is a malloc interposer that needs to be preloaded to get hooks functionality back so that the debugging features that depend on the hooks, i.e. malloc-check, mcheck and mtrace work again. Without the preloaded DSO these debugging features will be nops. These features will be ported away from hooks in subsequent patches. Similarly, legacy applications that need hooks functionality need to preload libc_malloc_debug.so. The symbols exported by libc_malloc_debug.so are maintained at exactly the same version as libc.so. Finally, static binaries will no longer be able to use malloc debugging features since they cannot preload the debugging DSO. Reviewed-by: Carlos O'Donell <carlos@redhat.com> Tested-by: Carlos O'Donell <carlos@redhat.com>
2021-07-22Remove __morecore and __default_morecoreSiddhesh Poyarekar1-0/+5
Make the __morecore and __default_morecore symbols compat-only and remove their declarations from the API. Also, include morecore.c directly into malloc.c; this should ideally get merged into malloc in a future cleanup. Reviewed-by: Carlos O'Donell <carlos@redhat.com> Tested-by: Carlos O'Donell <carlos@redhat.com>
2021-07-19resolv: Deprecate legacy interfaces in libresolvFlorian Weimer1-0/+14
Debugging interfaces: p_*, fp_*, and sym_* could conceivably be used to produce debug out, but these functions have not been updated to parse more resource records, so they are not very useful today. Likewise for ns_sprintrr and ns_sprintrrf. ns_format_ttl and ns_parse_ttl are related to these. Internal implementation details: res_isourserver is probably only useful in the implementation of a stub resolver, and so is res_nameinquery. Unclear semantics and bad performance: ns_samedomain, ns_subdomain, ns_makecanon, ns_samename do textual converions & copies instead of checking equivalence of the wire format. inet_neta cannot handle IPv6 addresses. res_hostalias has been superseded by getaddrinfo with AI_CANONNAME. hostalias is not thread-safe. Some functions have int as size arguments instead of size_t, so they do not follow current coding practices. However, dn_expand and b64_ntop are somewhat widely used (to name just two examples), so deprecating them seems problematic. Reviewed-by: Carlos O'Donell <carlos@systemhalted.org>
2021-07-09Define PTHREAD_STACK_MIN to sysconf(_SC_THREAD_STACK_MIN)H.J. Lu1-2/+6
The constant PTHREAD_STACK_MIN may be too small for some processors. Rename _SC_SIGSTKSZ_SOURCE to _DYNAMIC_STACK_SIZE_SOURCE. When _DYNAMIC_STACK_SIZE_SOURCE or _GNU_SOURCE are defined, define PTHREAD_STACK_MIN to sysconf(_SC_THREAD_STACK_MIN) which is changed to MIN (PTHREAD_STACK_MIN, sysconf(_SC_MINSIGSTKSZ)). Consolidate <bits/local_lim.h> with <bits/pthread_stack_min.h> to provide a constant target specific PTHREAD_STACK_MIN value. Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2021-07-08posix: Add posix_spawn_file_actions_addclosefrom_npAdhemerval Zanella1-0/+5
This patch adds a way to close a range of file descriptors on posix_spawn as a new file action. The API is similar to the one provided by Solaris 11 [1], where the file action causes the all open file descriptors greater than or equal to input on to be closed when the new process is spawned. The function posix_spawn_file_actions_addclosefrom_np is safe to be implemented by iterating over /proc/self/fd, since the Linux spawni.c helper process does not use CLONE_FILES, so its has own file descriptor table and any failure (in /proc operation) aborts the process creation and returns an error to the caller. I am aware that this file action might be redundant to the current approach of POSIX in promoting O_CLOEXEC in more interfaces. However O_CLOEXEC is still not the default and for some specific usages, the caller needs to close all possible file descriptors to avoid them leaking. Some examples are CPython (discussed in BZ#10353) and OpenJDK jspawnhelper [2] (where OpenJDK spawns a helper process to exactly closes all file descriptors). Most likely any environment which calls functions that might open file descriptor under the hood and aim to use posix_spawn might face the same requirement. Checked on x86_64-linux-gnu and i686-linux-gnu on kernel 5.11 and 4.15. [1] https://docs.oracle.com/cd/E36784_01/html/E36874/posix-spawn-file-actions-addclosefrom-np-3c.html [2] https://github.com/openjdk/jdk/blob/master/src/java.base/unix/native/libjava/childproc.c#L82
2021-07-08io: Add closefrom [BZ #10353]Adhemerval Zanella1-0/+4
The function closes all open file descriptors greater than or equal to input argument. Negative values are clamped to 0, i.e, it will close all file descriptors. As indicated by the bug report, this is a common symbol provided by different systems (Solaris, OpenBSD, NetBSD, FreeBSD) and, although its has inherent issues with not taking in consideration internal libc file descriptors (such as syslog), this is also a common feature used in multiple projects [1][2][3][4][5]. The Linux fallback implementation iterates over /proc and close all file descriptors sequentially. Although it was raised the questioning whether getdents on /proc/self/fd might return disjointed entries when file descriptor are closed; it does not seems the case on my testing on multiple kernel (v4.18, v5.4, v5.9) and the same strategy is used on different projects [1][2][3][5]. Also, the interface is set a fail-safe meaning that a failure in the fallback results in a process abort. Checked on x86_64-linux-gnu and i686-linux-gnu on kernel 5.11 and 4.15. [1] https://github.com/systemd/systemd/blob/5238e9575906297608ff802a27e2ff9effa3b338/src/basic/fd-util.c#L217 [2] https://github.com/lxc/lxc/blob/ddf4b77e11a4d08f09b7b9cd13e593f8c047edc5/src/lxc/start.c#L236 [3] https://github.com/python/cpython/blob/9e4f2f3a6b8ee995c365e86d976937c141d867f8/Modules/_posixsubprocess.c#L220 [4] https://github.com/rust-lang/rust/blob/5f47c0613ed4eb46fca3633c1297364c09e5e451/src/libstd/sys/unix/process2.rs#L303-L308 [5] https://github.com/openjdk/jdk/blob/master/src/java.base/unix/native/libjava/childproc.c#L82
2021-07-08linux: Add close_rangeAdhemerval Zanella1-0/+3
It was added on Linux 5.9 (278a5fbaed89) with CLOSE_RANGE_CLOEXEC added on 5.11 (582f1fb6b721f). Although FreeBSD has added the same syscall, this only adds the symbol on Linux ports. This syscall is required to provided a fail-safe way to implement the closefrom symbol (BZ #10353). Checked on x86_64-linux-gnu and i686-linux-gnu on kernel 5.11 and 4.15.
2021-07-03mtrace: Deprecate mallwatch and tr_breakSiddhesh Poyarekar1-0/+4
The variable and function pair appear to provide a way for users to set conditional breakpoints in mtrace when a specific address is returned by the allocator. This can be achieved by using conditional breakpoints in gdb so it is redundant. There is no documentation of this interface in the manual either, so it appears to have been a hack that got added to debug malloc. Deprecate these symbols and do not call tr_break anymore. Reviewed-by: DJ Delorie <dj@redhat.com> Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2021-06-28posix: Add _Fork [BZ #4737]Adhemerval Zanella1-0/+8
Austin Group issue 62 [1] dropped the async-signal-safe requirement for fork and provided a async-signal-safe _Fork replacement that does not run the atfork handlers. It will be included in the next POSIX standard. It allow to close a long standing issue to make fork AS-safe (BZ#4737). As indicated on the bug, besides the internal lock for the atfork handlers itself; there is no guarantee that the handlers itself will not introduce more AS-safe issues. The idea is synchronize fork with the required internal locks to allow children in multithread processes to use mostly of standard function (even though POSIX states only AS-safe function should be used). On signal handles, _Fork should be used intead and only AS-safe functions should be used. For testing, the new tst-_Fork only check basic usage. I also added a new tst-mallocfork3 which uses the same strategy to check for deadlock of tst-mallocfork2 but using threads instead of subprocesses (and it does deadlock if it replaces _Fork with fork). [1] https://austingroupbugs.net/view.php?id=62
2021-06-28nptl: Add glibc.pthread.stack_cache_size tunableFlorian Weimer1-0/+3
The valgrind/helgrind test suite needs a way to make stack dealloction more prompt, and this feature seems to be generally useful. Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
2021-06-28Install shared objects under their ABI namesFlorian Weimer1-0/+8
Previously, the installed objects were named like libc-2.33.so, and the ABI soname libc.so.6 was just a symbolic link. The Makefile targets to install these symbolic links are no longer needed after this, so they are removed with this commit. The more general $(make-link) command (which invokes scripts/rellns-sh) is retained because other symbolic links are still needed. Reviewed-by: Carlos O'Donell <carlos@redhat.com> Tested-by: Carlos O'Donell <carlos@rehdat.com>
2021-06-24* NEWS: Clarify _TIME_BITS change.Paul Eggert1-1/+3
2021-06-23nptl: Use SA_RESTART for SIGCANCEL handlerAdhemerval Zanella1-0/+8
The usage of signals to implementation pthread cancellation is an implementation detail and should not be visible through cancellation entrypoints. However now that pthread_cancel always send the SIGCANCEL, some entrypoint might be interruptable and return EINTR to the caller (for instance on sem_wait). Using SA_RESTART hides this, since the cancellation handler should either act uppon cancellation (if asynchronous cancellation is enable) or ignore the cancellation internal signal. Checked on x86_64-linux-gnu and i686-linux-gnu.
2021-06-23doc: _TIME_BITS defaults may changePaul Eggert1-1/+1
* NEWS: Don't imply the default will always be 32-bit. * manual/creature.texi (Feature Test Macros): Say that _TIME_BITS and _FILE_OFFSET_BITS defaults may change in future releases.
2021-06-23Add NEWS item for gconv-modules.d changeSiddhesh Poyarekar1-0/+8
Reviewed-by: DJ Delorie <dj@redhat.com>
2021-06-15y2038: Add support for 64-bit time on legacy ABIsAdhemerval Zanella1-0/+5
A new build flag, _TIME_BITS, enables the usage of the newer 64-bit time symbols for legacy ABI (where 32-bit time_t is default). The 64 bit time support is only enabled if LFS (_FILE_OFFSET_BITS=64) is also used. Different than LFS support, the y2038 symbols are added only for the required ABIs (armhf, csky, hppa, i386, m68k, microblaze, mips32, mips64-n32, nios2, powerpc32, sparc32, s390-32, and sh). The ABIs with 64-bit time support are unchanged, both for symbol and types redirection. On Linux the full 64-bit time support requires a minimum of kernel version v5.1. Otherwise, the 32-bit fallbacks are used and might results in error with overflow return code (EOVERFLOW). The i686-gnu does not yet support 64-bit time. This patch exports following rediretions to support 64-bit time: * libc: adjtime adjtimex clock_adjtime clock_getres clock_gettime clock_nanosleep clock_settime cnd_timedwait ctime ctime_r difftime fstat fstatat futimens futimes futimesat getitimer getrusage gettimeofday gmtime gmtime_r localtime localtime_r lstat_time lutimes mktime msgctl mtx_timedlock nanosleep nanosleep ntp_gettime ntp_gettimex ppoll pselec pselect pthread_clockjoin_np pthread_cond_clockwait pthread_cond_timedwait pthread_mutex_clocklock pthread_mutex_timedlock pthread_rwlock_clockrdlock pthread_rwlock_clockwrlock pthread_rwlock_timedrdlock pthread_rwlock_timedwrlock pthread_timedjoin_np recvmmsg sched_rr_get_interval select sem_clockwait semctl semtimedop sem_timedwait setitimer settimeofday shmctl sigtimedwait stat thrd_sleep time timegm timerfd_gettime timerfd_settime timespec_get utime utimensat utimes utimes wait3 wait4 * librt: aio_suspend mq_timedreceive mq_timedsend timer_gettime timer_settime * libanl: gai_suspend Reviewed-by: Lukasz Majewski <lukma@denx.de> Reviewed-by: Carlos O'Donell <carlos@redhat.com> Tested-by: Carlos O'Donell <carlos@redhat.com>
2021-06-10Add build option to disable usage of scv on powerpcMatheus Castanho1-0/+3
Commit 68ab82f56690ada86ac1e0c46bad06ba189a10ef added support for the scv syscall ABI on powerpc. Since then systems that have kernel and processor support started using scv. However adding the proper support for a new syscall ABI requires changes to several other projects (e.g. qemu, valgrind, strace, kernel), which are gradually receiving support. Meanwhile, having a way to disable scv on glibc at build time can be useful for distros that may encounter conflicts with projects that still do not support the scv ABI, buying time until proper support is added. This commit adds a --disable-scv option that disables scv support and uses sc for all syscalls, like before commit 68ab82f56690ada86ac1e0c46bad06ba189a10ef. Reviewed-by: Raphael M Zinsly <rzinsly@linux.ibm.com>
2021-06-01Use __pthread_attr_copy in mq_notify (bug 27896)Andreas Schwab1-0/+4
Make a deep copy of the pthread attribute object to remove a potential use-after-free issue.
2021-06-01Update floating-point feature test macro handling for C2XJoseph Myers1-0/+6
ISO C2X has made some changes to the handling of feature test macros related to features from the floating-point TSes, and to exactly what such features are present in what headers, that require corresponding changes in glibc. * For the few features that were controlled by __STDC_WANT_IEC_60559_BFP_EXT__ (and the corresponding DFP macro) in C2X, there is now instead a new feature test macro __STDC_WANT_IEC_60559_EXT__ covering both binary and decimal FP. This controls CR_DECIMAL_DIG in <float.h> (provided by GCC; I implemented support for the new feature test macro for GCC 11) and the totalorder and payload functions in <math.h>. C2X no longer says anything about __STDC_WANT_IEC_60559_BFP_EXT__ (so it's appropriate for that macro to continue to enable exactly the features from TS 18661-1). * The SNAN macros for each floating-point type have moved to <float.h> (and been renamed in the process). Thus, the copies in <math.h> should only be defined for __STDC_WANT_IEC_60559_BFP_EXT__, not for C2X. * The fmaxmag and fminmag functions have been removed (replaced by new functions for the new min/max operations in IEEE 754-2019). Thus those should also only be declared for __STDC_WANT_IEC_60559_BFP_EXT__. * The _FloatN / _FloatNx handling for the last two points in glibc is trickier, since __STDC_WANT_IEC_60559_TYPES_EXT__ is still in C2X (the integration of TS 18661-3 as an Annex, that is, which hasn't yet been merged into the C standard git repository but has been accepted by WG14), so C2X with that macro should not declare some things that are declared for older standards with that macro. The approach taken here is to provide the declarations (when __STDC_WANT_IEC_60559_TYPES_EXT__ is enabled) only when (defined __USE_GNU || !__GLIBC_USE (ISOC2X)), so if C2X features are enabled then those declarations (that are only in TS 18661-3 and not in C2X) will only be provided if _GNU_SOURCE is defined as well. Thus _GNU_SOURCE remains a superset of the TS features as well as of C2X. Some other somewhat related changes in C2X are not addressed here. There's an open proposal not to include the fmin and fmax functions for the _FloatN / _FloatNx types, given the new min/max operations, which could be handled like the previous point if adopted. And the fromfp functions have been changed to return a result in floating type rather than intmax_t / uintmax_t; my inclination there is to treat that like that change of totalorder type (new symbol versions etc. for the ABI change; old versions become compat symbols and are no longer supported as an API). Tested for x86_64 and x86.
2021-05-17Add C2X timespec_getresJoseph Myers1-0/+2
ISO C2X adds a timespec_getres function alongside the C11 timespec_get, with functionality similar to that of POSIX clock_getres (including allowing a NULL pointer to be passed to the function). Implement this function for glibc, similarly to the implementation of timespec_get. This includes a basic test like that of timespec_get, but no documentation in the manual, given that TIME_UTC and timespec_get aren't documented in the manual at all. The handling of 64-bit time follows that in timespec_get; people maintaining patch series for 64-bit time will need to update them accordingly (to export __timespec_getres64, redirect calls in time.h and run the test for _TIME_BITS=64). Tested for x86_64 and x86, and (previous version; only testcase differs) with build-many-glibcs.py.
2021-05-03linux: Add execveat system call wrapperAlexandra Hájková1-0/+5
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. Checked on x86_64-linux-gnu and powerpc64le-linux-gnu. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
2021-05-03nptl: Move pthread_yield into libc, as a compatibility symbolFlorian Weimer1-0/+3
And deprecate it in <pthread.h>, redirecting it to sched_yield for the time being. The symbol was moved using scripts/move-symbol-to-libc.py. No GLIBC_2.34 symbol version is added because of the compatibility symbol status. Reviewed-by: Carlos O'Donell <carlos@redhat.com> Tested-by: Carlos O'Donell <carlos@redhat.com>
2021-04-23nptl: Move pthread_mutexattr_setrobust into libcFlorian Weimer1-0/+4
And pthread_mutexattr_getrobust_np as a compat symbol. The symbols were moved using scripts/move-symbol-to-libc.py.
2021-04-23nptl: Move pthread_mutexattr_getrobust into libcFlorian Weimer1-0/+4
And pthread_mutexattr_getrobust_np as a compat symbol. The symbols were moved using scripts/move-symbol-to-libc.py.
2021-04-21nptl: Move pthread_mutex_consistent into libcFlorian Weimer1-1/+3
And deprecated pthread_mutex_consistent_np, its old name. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
2021-03-09NEWS: Add entry for CVE-2021-27645DJ Delorie1-1/+4
2021-03-02ld.so: Implement the --list-diagnostics optionFlorian Weimer1-0/+4
2021-02-23NEWS: Add missing bug closuresSamuel Thibault1-5/+6
2021-02-08linux: Require /dev/shm as the shared memory file systemFlorian Weimer1-1/+4
Previously, glibc would pick an arbitrary tmpfs file system from /proc/mounts if /dev/shm was not available. This could lead to an unsuitable file system being picked for the backing storage for shm_open, sem_open, and related functions. This patch introduces a new function, __shm_get_name, which builds the file name under the appropriate (now hard-coded) directory. It is called from the various shm_* and sem_* function. Unlike the SHM_GET_NAME macro it replaces, the callers handle the return values and errno updates. shm-directory.c is moved directly into the posix subdirectory because it can be implemented directly using POSIX functionality. It resides in libc because it is needed by both librt and nptl/htl. In the sem_open implementation, tmpfname is initialized directly from a string constant. This happens to remove one alloca call. Checked on x86_64-linux-gnu.
2021-02-01Move _SC_MINSIGSTKSZ/_SC_SIGSTKSZ entry in NEWSH.J. Lu1-6/+4
Move _SC_MINSIGSTKSZ/_SC_SIGSTKSZ entry to 2.34 section.
2021-02-01sysconf: Add _SC_MINSIGSTKSZ/_SC_SIGSTKSZ [BZ #20305]H.J. Lu1-0/+5
Add _SC_MINSIGSTKSZ for the minimum signal stack size derived from AT_MINSIGSTKSZ, which is the minimum number of bytes of free stack space required in order to gurantee successful, non-nested handling of a single signal whose handler is an empty function, and _SC_SIGSTKSZ which is the suggested minimum number of bytes of stack space required for a signal stack. If AT_MINSIGSTKSZ isn't available, sysconf (_SC_MINSIGSTKSZ) returns MINSIGSTKSZ. On Linux/x86 with XSAVE, the signal frame used by kernel is composed of the following areas and laid out as: ------------------------------ | alignment padding | ------------------------------ | xsave buffer | ------------------------------ | fsave header (32-bit only) | ------------------------------ | siginfo + ucontext | ------------------------------ Compute AT_MINSIGSTKSZ value as size of xsave buffer + size of fsave header (32-bit only) + size of siginfo and ucontext + alignment padding. If _SC_SIGSTKSZ_SOURCE or _GNU_SOURCE are defined, MINSIGSTKSZ and SIGSTKSZ are redefined as /* Default stack size for a signal handler: sysconf (SC_SIGSTKSZ). */ # undef SIGSTKSZ # define SIGSTKSZ sysconf (_SC_SIGSTKSZ) /* Minimum stack size for a signal handler: SIGSTKSZ. */ # undef MINSIGSTKSZ # define MINSIGSTKSZ SIGSTKSZ Compilation will fail if the source assumes constant MINSIGSTKSZ or SIGSTKSZ. The reason for not simply increasing the kernel's MINSIGSTKSZ #define (apart from the fact that it is rarely used, due to glibc's shadowing definitions) was that userspace binaries will have baked in the old value of the constant and may be making assumptions about it. For example, the type (char [MINSIGSTKSZ]) changes if this #define changes. This could be a problem if an newly built library tries to memcpy() or dump such an object defined by and old binary. Bounds-checking and the stack sizes passed to things like sigaltstack() and makecontext() could similarly go wrong.