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* AArch64: Remove Falkor memcpyWilco Dijkstra2024-04-081-1/+1
| | | | | | | | | | | The latest implementations of memcpy are actually faster than the Falkor implementations [1], so remove the falkor/phecda ifuncs for memcpy and the now unused IS_FALKOR/IS_PHECDA defines. [1] https://sourceware.org/pipermail/libc-alpha/2022-December/144227.html Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org> (cherry picked from commit 2f5524cc5381eb75fef55f7901bb907bd5628333)
* gmon: Revert addition of tunables to preserve GLIBC_PRIVATE ABIFlorian Weimer2023-04-281-59/+0
| | | | | | | | Otherwise, processes are likely to crash during concurrent updates to a new glibc version on the stable release branch. The test gmon/tst-mcount-overflow depends on those tunables, so it has to be removed as well.
* gmon: improve mcount overflow handling [BZ# 27576]Simon Kissane2023-04-281-0/+59
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When mcount overflows, no gmon.out file is generated, but no message is printed to the user, leaving the user with no idea why, and thinking maybe there is some bug - which is how BZ 27576 ended up being logged. Print a message to stderr in this case so the user knows what is going on. As a comment in sys/gmon.h acknowledges, the hardcoded MAXARCS value is too small for some large applications, including the test case in that BZ. Rather than increase it, add tunables to enable MINARCS and MAXARCS to be overridden at runtime (glibc.gmon.minarcs and glibc.gmon.maxarcs). So if a user gets the mcount overflow error, they can try increasing maxarcs (they might need to increase minarcs too if the heuristic is wrong in their case.) Note setting minarcs/maxarcs too large can cause monstartup to fail with an out of memory error. If you set them large enough, it can cause an integer overflow in calculating the buffer size. I haven't done anything to defend against that - it would not generally be a security vulnerability, since these tunables will be ignored in suid/sgid programs (due to the SXID_ERASE default), and if you can set GLIBC_TUNABLES in the environment of a process, you can take it over anyway (LD_PRELOAD, LD_LIBRARY_PATH, etc). I thought about modifying the code of monstartup to defend against integer overflows, but doing so is complicated, and I realise the existing code is susceptible to them even prior to this change (e.g. try passing a pathologically large highpc argument to monstartup), so I decided just to leave that possibility in-place. Add a test case which demonstrates mcount overflow and the tunables. Document the new tunables in the manual. Signed-off-by: Simon Kissane <skissane@gmail.com> Reviewed-by: DJ Delorie <dj@redhat.com> (cherry picked from commit 31be941e4367c001b2009308839db5c67bf9dcbc)
* x86: Add bounds `x86_non_temporal_threshold`Noah Goldstein2022-07-181-1/+1
| | | | | | | | | | | | | | | | | The lower-bound (16448) and upper-bound (SIZE_MAX / 16) are assumed by memmove-vec-unaligned-erms. The lower-bound is needed because memmove-vec-unaligned-erms unrolls the loop aggressively in the L(large_memset_4x) case. The upper-bound is needed because memmove-vec-unaligned-erms right-shifts the value of `x86_non_temporal_threshold` by LOG_4X_MEMCPY_THRESH (4) which without a bound may overflow. The lack of lower-bound can be a correctness issue. The lack of upper-bound cannot. (cherry picked from commit b446822b6ae4e8149902a78cdd4a886634ad6321)
* dlfcn: Implement the RTLD_DI_PHDR request type for dlinfoFlorian Weimer2022-05-111-3/+12
| | | | | | | | | | The information is theoretically available via dl_iterate_phdr as well, but that approach is very slow if there are many shared objects. Reviewed-by: Carlos O'Donell <carlos@redhat.com> Tested-by: Carlos O'Donell <carlos@rehdat.com> (cherry picked from commit d056c212130280c0a54d9a4f72170ec621b70ce5)
* manual: Document the dlinfo functionFlorian Weimer2022-05-111-1/+70
| | | | | | Reviewed-by: Carlos O'Donell <carlos@redhat.com> Tested-by: Carlos O'Donell <carlos@rehdat.com> (cherry picked from commit 93804a1ee084d4bdc620b2b9f91615c7da0fabe1)
* manual: Clarify that abbreviations of long options are allowedSiddhesh Poyarekar2022-05-041-1/+2
| | | | | | | | | | | The man page and code comments clearly state that abbreviations of long option names are recognized correctly as long as they are unique. Document this fact in the glibc manual as well. Signed-off-by: Siddhesh Poyarekar <siddhesh@sourceware.org> Reviewed-by: Florian Weimer <fweimer@redhat.com> Reviewed-by: Andreas Schwab <schwab@linux-m68k.org> (cherry picked from commit db1efe02c9f15affc3908d6ae73875b82898a489)
* INSTALL: Rephrase -with-default-link documentationFlorian Weimer2022-04-261-5/+5
| | | | | Reviewed-by: Carlos O'Donell <carlos@redhat.com> (cherry picked from commit c935789bdf40ba22b5698da869d3a4789797e09f)
* Default to --with-default-link=no (bug 25812)Florian Weimer2022-04-221-0/+6
| | | | | | | | | | | This is necessary to place the libio vtables into the RELRO segment. New tests elf/tst-relro-ldso and elf/tst-relro-libc are added to verify that this is what actually happens. The new tests fail on ia64 due to lack of (default) RELRO support inbutils, so they are XFAILed there. (cherry picked from commit 198abcbb94618730dae1b3f4393efaa49e0ec8c7)
* nptl: Handle spurious EINTR when thread cancellation is disabled (BZ#29029)Adhemerval Zanella2022-04-151-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Some Linux interfaces never restart after being interrupted by a signal handler, regardless of the use of SA_RESTART [1]. It means that for pthread cancellation, if the target thread disables cancellation with pthread_setcancelstate and calls such interfaces (like poll or select), it should not see spurious EINTR failures due the internal SIGCANCEL. However recent changes made pthread_cancel to always sent the internal signal, regardless of the target thread cancellation status or type. To fix it, the previous semantic is restored, where the cancel signal is only sent if the target thread has cancelation enabled in asynchronous mode. The cancel state and cancel type is moved back to cancelhandling and atomic operation are used to synchronize between threads. The patch essentially revert the following commits: 8c1c0aae20 nptl: Move cancel type out of cancelhandling 2b51742531 nptl: Move cancel state out of cancelhandling 26cfbb7162 nptl: Remove CANCELING_BITMASK However I changed the atomic operation to follow the internal C11 semantic and removed the MACRO usage, it simplifies a bit the resulting code (and removes another usage of the old atomic macros). Checked on x86_64-linux-gnu, i686-linux-gnu, aarch64-linux-gnu, and powerpc64-linux-gnu. [1] https://man7.org/linux/man-pages/man7/signal.7.html Reviewed-by: Florian Weimer <fweimer@redhat.com> Tested-by: Aurelien Jarno <aurelien@aurel32.net> (cherry-picked from commit 404656009b459658138ed1bd18f3c6cf3863e6a6)
* Update install.texi, and regenerate INSTALL.Carlos O'Donell2022-02-031-9/+12
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* Linux: Use ptrdiff_t for __rseq_offsetFlorian Weimer2022-02-021-1/+1
| | | | | | | | This matches the data size initial-exec relocations use on most targets. Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* x86_64: Document libmvec vector functions accuracy [BZ #28766]Sunil K Pandey2022-01-191-2/+3
| | | | | | | Document maximum 4 ulps accuracy for x86_64 libmvec functions. This fixes BZ #28766. Reviewed-By: Paul Zimmermann <Paul.Zimmermann@inria.fr>
* Add --with-rtld-early-cflags configure optionFlorian Weimer2022-01-141-0/+7
| | | | | Reviewed-by: H.J. Lu <hjl.tools@gmail.com> Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* manual: Drop obsolete @refillSiddhesh Poyarekar2022-01-1210-21/+21
| | | | | | | | The @refill command has been obsolete for a while and now texinfo has started warning about it. Reviewed-by: Florian Weimer <fweimer@redhat.com> Signed-off-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
* math: Fix float conversion regressions with gcc-12 [BZ #28713]Szabolcs Nagy2022-01-101-3/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Converting double precision constants to float is now affected by the runtime dynamic rounding mode instead of being evaluated at compile time with default rounding mode (except static object initializers). This can change the computed result and cause performance regression. The known correctness issues (increased ulp errors) are already fixed, this patch fixes remaining cases of unnecessary runtime conversions. Add float M_* macros to math.h as new GNU extension API. To avoid conversions the new M_* macros are used and instead of casting double literals to float, use float literals (only required if the conversion is inexact). The patch was tested on aarch64 where the following symbols had new spurious conversion instructions that got fixed: __clog10f __gammaf_r_finite@GLIBC_2.17 __j0f_finite@GLIBC_2.17 __j1f_finite@GLIBC_2.17 __jnf_finite@GLIBC_2.17 __kernel_casinhf __lgamma_negf __log1pf __y0f_finite@GLIBC_2.17 __y1f_finite@GLIBC_2.17 cacosf cacoshf casinhf catanf catanhf clogf gammaf_positive Fixes bug 28713. Reviewed-by: Paul Zimmermann <Paul.Zimmermann@inria.fr>
* Update copyright dates with scripts/update-copyrightsPaul Eggert2022-01-0148-48/+48
| | | | | | | | | | | | | | | | | | | | | | | 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
* elf: Add _dl_find_object functionFlorian Weimer2021-12-285-13/+140
| | | | | | | | | | | | | | | | | | | | | | | | | It can be used to speed up the libgcc unwinder, and the internal _dl_find_dso_for_object function (which is used for caller identification in dlopen and related functions, and in dladdr). _dl_find_object is in the internal namespace due to bug 28503. If libgcc switches to _dl_find_object, this namespace issue will be fixed. It is located in libc for two reasons: it is necessary to forward the call to the static libc after static dlopen, and there is a link ordering issue with -static-libgcc and libgcc_eh.a because libc.so is not a linker script that includes ld.so in the glibc build tree (so that GCC's internal -lc after libgcc_eh.a does not pick up ld.so). It is necessary to do the i386 customization in the sysdeps/x86/bits/dl_find_object.h header shared with x86-64 because otherwise, multilib installations are broken. The implementation uses software transactional memory, as suggested by Torvald Riegel. Two copies of the supporting data structures are used, also achieving full async-signal-safety. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* stdio: Implement %#m for vfprintf and related functionsFlorian Weimer2021-12-231-2/+6
| | | | | | | | | %#m prints errno as an error constant if one is available, or a decimal number as a fallback. This intends to address the gap that strerrorname_np does not work well with printf for unknown error codes due to its NULL return values in those cases. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* nss: Use "files dns" as the default for the hosts database (bug 28700)Florian Weimer2021-12-171-3/+2
| | | | | | | | | | | | | | | | | | This matches what is currently in nss/nsswitch.conf. The new ordering matches what most distributions use in their installed configuration files. It is common to add localhost to /etc/hosts because the name does not exist in the DNS, but is commonly used as a host name. With the built-in "dns [!UNAVAIL=return] files" default, dns is searched first and provides an answer for "localhost" (NXDOMAIN). We never look at the files database as a result, so the contents of /etc/hosts is ignored. This means that "getent hosts localhost" fail without a /etc/nsswitch.conf file, even though the host name is listed in /etc/hosts. Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* malloc: Add Huge Page support for mmapAdhemerval Zanella2021-12-151-0/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | With the morecore hook removed, there is not easy way to provide huge pages support on with glibc allocator without resorting to transparent huge pages. And some users and programs do prefer to use the huge pages directly instead of THP for multiple reasons: no splitting, re-merging by the VM, no TLB shootdowns for running processes, fast allocation from the reserve pool, no competition with the rest of the processes unlike THP, no swapping all, etc. This patch extends the 'glibc.malloc.hugetlb' tunable: the value '2' means to use huge pages directly with the system default size, while a positive value means and specific page size that is matched against the supported ones by the system. Currently only memory allocated on sysmalloc() is handled, the arenas still uses the default system page size. To test is a new rule is added tests-malloc-hugetlb2, which run the addes tests with the required GLIBC_TUNABLE setting. On systems without a reserved huge pages pool, is just stress the mmap(MAP_HUGETLB) allocation failure. To improve test coverage it is required to create a pool with some allocated pages. Checked on x86_64-linux-gnu. Reviewed-by: DJ Delorie <dj@redhat.com>
* malloc: Add madvise support for Transparent Huge PagesAdhemerval Zanella2021-12-151-0/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | Linux Transparent Huge Pages (THP) current supports three different states: 'never', 'madvise', and 'always'. The 'never' is self-explanatory and 'always' will enable THP for all anonymous pages. However, 'madvise' is still the default for some system and for such case THP will be only used if the memory range is explicity advertise by the program through a madvise(MADV_HUGEPAGE) call. To enable it a new tunable is provided, 'glibc.malloc.hugetlb', where setting to a value diffent than 0 enables the madvise call. This patch issues the madvise(MADV_HUGEPAGE) call after a successful mmap() call at sysmalloc() with sizes larger than the default huge page size. The madvise() call is disable is system does not support THP or if it has the mode set to "never" and on Linux only support one page size for THP, even if the architecture supports multiple sizes. To test is a new rule is added tests-malloc-hugetlb1, which run the addes tests with the required GLIBC_TUNABLE setting. Checked on x86_64-linux-gnu. Reviewed-by: DJ Delorie <dj@redhat.com>
* elf: Use new dependency sorting algorithm by defaultFlorian Weimer2021-12-141-1/+1
| | | | | | | The default has to change eventually, and there are no known failures that require a delay. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* Replace --enable-static-pie with --disable-default-pieSiddhesh Poyarekar2021-12-131-9/+7
| | | | | | | | | | | | | | | | | | | | | | | | Build glibc programs and tests as PIE by default and enable static-pie automatically if the architecture and toolchain supports it. Also add a new configuration option --disable-default-pie to prevent building programs as PIE. Only the following architectures now have PIE disabled by default because they do not work at the moment. hppa, ia64, alpha and csky don't work because the linker is unable to handle a pcrel relocation generated from PIE objects. The microblaze compiler is currently failing with an ICE. GNU hurd tries to enable static-pie, which does not work and hence fails. All these targets have default PIE disabled at the moment and I have left it to the target maintainers to enable PIE on their targets. build-many-glibcs runs clean for all targets. I also tested x86_64 on Fedora and Ubuntu, to verify that the default build as well as --disable-default-pie work as expected with both system toolchains. Signed-off-by: Siddhesh Poyarekar <siddhesh@sourceware.org> Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* nptl: Add public rseq symbols and <sys/rseq.h>Florian Weimer2021-12-091-0/+81
| | | | | | | | | | | | | The relationship between the thread pointer and the rseq area is made explicit. The constant offset can be used by JIT compilers to optimize rseq access (e.g., for really fast sched_getcpu). Extensibility is provided through __rseq_size and __rseq_flags. (In the future, the kernel could request a different rseq size via the auxiliary vector.) Co-Authored-By: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
* nptl: Add glibc.pthread.rseq tunable to control rseq registrationFlorian Weimer2021-12-091-0/+10
| | | | | | | | This tunable allows applications to register the rseq area instead of glibc. Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com> Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
* Add --with-timeoutfactor=NUM to specify TIMEOUTFACTORH.J. Lu2021-12-041-0/+5
| | | | | | | | | On Ice Lake and Tiger Lake laptops, some test programs timeout when there are 3 "make check -j8" runs in parallel. Add --with-timeoutfactor=NUM to specify an integer to scale the timeout of test programs, which can be overriden by TIMEOUTFACTOR environment variable. Reviewed-by: Florian Weimer <fweimer@redhat.com>
* Support C2X printf %b, %BJoseph Myers2021-11-101-9/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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).
* elf: Fix slow DSO sorting behavior in dynamic loader (BZ #17645)Chung-Lin Tang2021-10-211-0/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* manual: Update _TIME_BITS to clarify it's user definedStafford Horne2021-10-181-2/+2
| | | | | | | | | | The current language reads "This macro determines...", changing to "Define this macro...". This is consistent with other feature macro documentation language. When I first read the previous language it seems to indicate that the macro is already defined. By changing the language to "Define this macro..." it's clear that its the user's responsibility to define it.
* Add C2X _PRINTF_NAN_LEN_MAXJoseph Myers2021-09-301-1/+4
| | | | | | | | | | | | | | 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.
* Add fmaximum, fminimum functionsJoseph Myers2021-09-281-4/+106
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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.
* Add narrowing fma functionsJoseph Myers2021-09-221-0/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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).
* Add narrowing square root functionsJoseph Myers2021-09-101-0/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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).
* Remove "Contributed by" linesSiddhesh Poyarekar2021-09-032-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | We stopped adding "Contributed by" or similar lines in sources in 2012 in favour of git logs and keeping the Contributors section of the glibc manual up to date. Removing these lines makes the license header a bit more consistent across files and also removes the possibility of error in attribution when license blocks or files are copied across since the contributed-by lines don't actually reflect reality in those cases. Move all "Contributed by" and similar lines (Written by, Test by, etc.) into a new file CONTRIBUTED-BY to retain record of these contributions. These contributors are also mentioned in manual/contrib.texi, so we just maintain this additional record as a courtesy to the earlier developers. The following scripts were used to filter a list of files to edit in place and to clean up the CONTRIBUTED-BY file respectively. These were not added to the glibc sources because they're not expected to be of any use in future given that this is a one time task: https://gist.github.com/siddhesh/b5ecac94eabfd72ed2916d6d8157e7dc https://gist.github.com/siddhesh/15ea1f5e435ace9774f485030695ee02 Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* llio.texi: Wording fixes in description of closefrom()Michael Kerrisk2021-08-261-2/+2
| | | | | | | | | | | Fix two problems. Rather than "larger than", better English is "greater than". Then there is a wordinig error on the following line: "then lowfd" appears to be cruft. Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
* Update install.texi, and regenerate INSTALL.Carlos O'Donell2021-08-011-4/+4
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* manual: Drop the .so suffix in libc_malloc_debug descriptionSiddhesh Poyarekar2021-07-272-4/+4
| | | | | | | All references to libraries in the manual are without the .so prefix, so do the same for libc_malloc_debug. Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* manual: Document unsupported cases for interpositionSiddhesh Poyarekar2021-07-231-0/+7
| | | | | | | | | | These functions call the core allocator functions (realloc and malloc respectively) and are hence guaranteed to allocate memory using the correct functions when multiple allocators are interposed. Having these functions interposed in one allocator and not another may result in confusion, hence discourage interposing them altogether. Reviewed-by: Florian Weimer <fweimer@redhat.com>
* x86: Install <bits/platform/x86.h> [BZ #27958]H.J. Lu2021-07-231-8/+10
| | | | | | | | | | | | | | | 1. Install <bits/platform/x86.h> for <sys/platform/x86.h> which includes <bits/platform/x86.h>. 2. Rename HAS_CPU_FEATURE to CPU_FEATURE_PRESENT which checks if the processor has the feature. 3. Rename CPU_FEATURE_USABLE to CPU_FEATURE_ACTIVE which checks if the feature is active. There may be other preconditions, like sufficient stack space or further setup for AMX, which must be satisfied before the feature can be used. This fixes BZ #27958. Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* Remove malloc hooks [BZ #23328]Siddhesh Poyarekar2021-07-221-185/+6
| | | | | | | | | | | | | | 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>
* Move malloc hooks into a compat DSOSiddhesh Poyarekar2021-07-222-4/+16
| | | | | | | | | | | | | | | | | | | | | | | | 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>
* elf: Fix tst-cpu-features-cpuinfo on some AMD systems (BZ #28090)Adhemerval Zanella2021-07-191-0/+3
| | | | | | | | | | | | | | | The SSBD feature is implemented in 2 different ways on AMD processors: newer systems (Zen3) provides AMD_SSBD (function 8000_0008, EBX[24]), while older system provides AMD_VIRT_SSBD (function 8000_0008, EBX[25]). However for AMD_VIRT_SSBD, kernel shows both 'ssdb' and 'virt_ssdb' on /proc/cpuinfo; while for AMD_SSBD only 'ssdb' is provided. This now check is AMD_SSBD is set to check for 'ssbd', otherwise check if AMD_VIRT_SSDB is set to check for 'virt_ssbd'. Checked on x86_64-linux-gnu on a Ryzen 9 5900x. Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
* Define PTHREAD_STACK_MIN to sysconf(_SC_THREAD_STACK_MIN)H.J. Lu2021-07-091-2/+2
| | | | | | | | | | | | | 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>
* io: Add closefrom [BZ #10353]Adhemerval Zanella2021-07-081-0/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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
* linux: Add close_rangeAdhemerval Zanella2021-07-081-0/+51
| | | | | | | | | | 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.
* glibc.malloc.check: Fix nit in documentationSiddhesh Poyarekar2021-07-072-6/+6
| | | | | | | The tunable will not work with *any* non-zero tunable value since its list of allowed values is 0-3. Fix the documentation to reflect that. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* manual: fix description for preadv()Armin Brauns2021-07-061-1/+1
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* x86: Check RTM_ALWAYS_ABORT for RTM [BZ #28033]H.J. Lu2021-07-011-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | From https://www.intel.com/content/www/us/en/support/articles/000059422/processors.html * Intel TSX will be disabled by default. * The processor will force abort all Restricted Transactional Memory (RTM) transactions by default. * A new CPUID bit CPUID.07H.0H.EDX[11](RTM_ALWAYS_ABORT) will be enumerated, which is set to indicate to updated software that the loaded microcode is forcing RTM abort. * On processors that enumerate support for RTM, the CPUID enumeration bits for Intel TSX (CPUID.07H.0H.EBX[11] and CPUID.07H.0H.EBX[4]) continue to be set by default after microcode update. * Workloads that were benefited from Intel TSX might experience a change in performance. * System software may use a new bit in Model-Specific Register (MSR) 0x10F TSX_FORCE_ABORT[TSX_CPUID_CLEAR] functionality to clear the Hardware Lock Elision (HLE) and RTM bits to indicate to software that Intel TSX is disabled. 1. Add RTM_ALWAYS_ABORT to CPUID features. 2. Set RTM usable only if RTM_ALWAYS_ABORT isn't set. This skips the string/tst-memchr-rtm etc. testcases on the affected processors, which always fail after a microcde update. 3. Check RTM feature, instead of usability, against /proc/cpuinfo. This fixes BZ #28033.
* posix: Add _Fork [BZ #4737]Adhemerval Zanella2021-06-281-15/+26
| | | | | | | | | | | | | | | | | | | | | | | | | 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
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