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* regex: Unnest nested functions in regcomp.cFangrui Song2021-11-021-223/+241
| | | | | | | | | | | | | | | | | This refactor moves four functions out of a nested scope and converts them into static always_inline functions. collseqwc, table_size, symb_table, extra are now initialized to zero because they are passed as function arguments. On x86-64, .text is 16 byte larger likely due to the 4 stores. This is nothing compared to the amount of work that regcomp has to do looking up the collation weights, or other functions. If the non-buildable `sysdeps/generic/dl-machine.h` doesn't count, this patch removes the last `auto inline` usage from glibc. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org> Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* Use Linux 5.15 in build-many-glibcs.pyJoseph Myers2021-11-021-1/+1
| | | | | | | This patch makes build-many-glibcs.py use Linux 5.15. Tested with build-many-glibcs.py (host-libraries, compilers and glibcs builds).
* elf: Assume disjointed .rela.dyn and .rela.plt for loaderAdhemerval Zanella2021-11-021-23/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | The patch removes the the ELF_DURING_STARTUP optimization and assume both .rel.dyn and .rel.plt might not be subsequent. This allows some code simplification since relocation will be handled independently where it is done on bootstrap. At least on x86_64_64, I can not measure any performance implications. Running 10000 time the command LD_DEBUG=statistics ./elf/ld.so ./libc.so And filtering the "total startup time in dynamic loader" result, the geometric mean is: patched master Ryzen 7 5900x 24140 24952 i7-4510U 45957 45982 (The results do show some variation, I did not make any statistical analysis). It also allows build arm with lld, since it inserts ".ARM.exidx" between ".rel.dyn" and ".rel.plt" for the loader. Checked on x86_64-linux-gnu and arm-linux-gnueabihf. Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
* i386: Explain why __HAVE_64B_ATOMICS has to be 0Florian Weimer2021-11-021-0/+4
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* benchtests: Add hypotfAdhemerval Zanella2021-11-012-0/+1008
| | | | | | | Based on random input arguments. About 85% tuples have exponents of the two arguments close together (+-1 range). Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
* benchtests: Make hypot input randomAdhemerval Zanella2021-11-011-12/+1003
| | | | | | | | Instead of inputs based on the algorithm implementation details. About 85% tuples have exponents of the two arguments close together (+-1 range). Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
* arm: Use have-mtls-dialect-gnu2 to check for ARM TLS descriptors supportAdhemerval Zanella2021-11-011-6/+1
| | | | | | | The lld linker does not support TLSDESC for arm. The have-arm-tls-desc is a leftover of 56583289b1 to support NaCL. Reviewed-by: Fangrui Song <maskray@google.com>
* arm: Use internal symbol for _dl_argv on _dl_start_userAdhemerval Zanella2021-11-011-1/+1
| | | | | | | | | | | | The lld does not support R_ARM_GOTOFF32 to preemptible symbol (_dl_argv has default visibility). Use the internal alias instead (one option would to use HIDDEN_JUMPTARGET, bu the macro is not defined for !__ASSEMBLER__ and I made this patch arm-specific to avoid require to check extensivelly on other architecture it this might break something). Checked on arm-linux-gnueabihf. Reviewed-by: Fangrui Song <maskray@google.com>
* x86-64: Remove Prefer_AVX2_STRCMPH.J. Lu2021-11-015-15/+2
| | | | | | | | | Remove Prefer_AVX2_STRCMP to enable EVEX strcmp. When comparing 2 32-byte strings, EVEX strcmp has been improved to require 1 load, 1 VPTESTM, 1 VPCMP, 1 KMOVD and 1 INCL instead of 2 loads, 3 VPCMPs, 2 KORDs, 1 KMOVD and 1 TESTL while AVX2 strcmp requires 1 load, 2 VPCMPEQs, 1 VPMINU, 1 VPMOVMSKB and 1 TESTL. EVEX strcmp is now faster than AVX2 strcmp by up to 40% on Tiger Lake and Ice Lake.
* x86-64: Improve EVEX strcmp with masked loadH.J. Lu2021-11-011-218/+243
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In strcmp-evex.S, to compare 2 32-byte strings, replace VMOVU (%rdi, %rdx), %YMM0 VMOVU (%rsi, %rdx), %YMM1 /* Each bit in K0 represents a mismatch in YMM0 and YMM1. */ VPCMP $4, %YMM0, %YMM1, %k0 VPCMP $0, %YMMZERO, %YMM0, %k1 VPCMP $0, %YMMZERO, %YMM1, %k2 /* Each bit in K1 represents a NULL in YMM0 or YMM1. */ kord %k1, %k2, %k1 /* Each bit in K1 represents a NULL or a mismatch. */ kord %k0, %k1, %k1 kmovd %k1, %ecx testl %ecx, %ecx jne L(last_vector) with VMOVU (%rdi, %rdx), %YMM0 VPTESTM %YMM0, %YMM0, %k2 /* Each bit cleared in K1 represents a mismatch or a null CHAR in YMM0 and 32 bytes at (%rsi, %rdx). */ VPCMP $0, (%rsi, %rdx), %YMM0, %k1{%k2} kmovd %k1, %ecx incl %ecx jne L(last_vector) It makes EVEX strcmp faster than AVX2 strcmp by up to 40% on Tiger Lake and Ice Lake. Co-Authored-By: Noah Goldstein <goldstein.w.n@gmail.com>
* benchtests: Add acosf function to bench-mathSunil K Pandey2021-10-292-0/+2710
| | | | | | | | | | | | | | | | | | Add acosf function to bench-math and copy acosf-inputs to benchtests. Motivation for this patch is to prepare for upcoming libmvec new functions. Float and double version of libmvec functions stays together. acosf-inputs file generated from acos-inputs file using following scaling formula: f = d * (FLT_MAX/DBL_MAX) Where d is input(double) and f is output(float). If scaled float value is duplicate in new input file, nextafterf() function used to find next float value, ensuring no duplicates. Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
* benchtests: Improve bench-memcpy-randomWilco Dijkstra2021-10-291-26/+28
| | | | | | | | Improve the random memcpy benchmark. Double the number of tests and increase the size of the memory region to test between 32KB and 1024KB. This improves accuracy on modern cores. Clean up formatting of the frequency array. Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
* Disable -Waggressive-loop-optimizations warnings in tst-dynarray.cJoseph Myers2021-10-291-0/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | My build-many-glibcs.py bot shows -Waggressive-loop-optimizations errors building the glibc testsuite for 32-bit architectures with GCC mainline, which seem to have appeared between GCC commits 4abc0c196b10251dc80d0743ba9e8ab3e56c61ed and d8edfadfc7a9795b65177a50ce44fd348858e844: In function 'dynarray_long_noscratch_resize', inlined from 'test_long_overflow' at tst-dynarray.c:489:5, inlined from 'do_test' at tst-dynarray.c:571:3: ../malloc/dynarray-skeleton.c:391:36: error: iteration 1073741823 invokes undefined behavior [-Werror=aggressive-loop-optimizations] 391 | DYNARRAY_ELEMENT_INIT (&list->u.dynarray_header.array[i]); tst-dynarray.c:39:37: note: in definition of macro 'DYNARRAY_ELEMENT_INIT' 39 | #define DYNARRAY_ELEMENT_INIT(e) (*(e) = 23) | ^ In file included from tst-dynarray.c:42: ../malloc/dynarray-skeleton.c:389:37: note: within this loop 389 | for (size_t i = old_size; i < size; ++i) | ~~^~~~~~ In function 'dynarray_long_resize', inlined from 'test_long_overflow' at tst-dynarray.c:479:5, inlined from 'do_test' at tst-dynarray.c:571:3: ../malloc/dynarray-skeleton.c:391:36: error: iteration 1073741823 invokes undefined behavior [-Werror=aggressive-loop-optimizations] 391 | DYNARRAY_ELEMENT_INIT (&list->u.dynarray_header.array[i]); tst-dynarray.c:27:37: note: in definition of macro 'DYNARRAY_ELEMENT_INIT' 27 | #define DYNARRAY_ELEMENT_INIT(e) (*(e) = 17) | ^ In file included from tst-dynarray.c:28: ../malloc/dynarray-skeleton.c:389:37: note: within this loop 389 | for (size_t i = old_size; i < size; ++i) | ~~^~~~~~ I don't know what GCC change made these errors appear, or why they only appear for 32-bit architectures. However, the warnings appear to be both true (that iteration would indeed involve undefined behavior if executed) and useless in this particular case (that iteration is never executed, because the allocation size overflows and so the allocation fails - but the check for allocation size overflow is in a separate source file and so can't be seen by the compiler when compiling this test). So use the DIAG_* macros to disable -Waggressive-loop-optimizations around the calls in question to dynarray_long_resize and dynarray_long_noscratch_resize in this test. Tested with build-many-glibcs.py (GCC mainline) for arm-linux-gnueabi, where it restores a clean testsuite build.
* Fix compiler issue with mmap_internalStafford Horne2021-10-291-0/+2
| | | | | | | | | | | | | | Compiling mmap_internal fails to compile when we use -1 for MMAP2_PAGE_UNIT on 32 bit architectures. The error is as follows: ../sysdeps/unix/sysv/linux/mmap_internal.h:30:8: error: unknown type name 'uint64_t' | 30 | static uint64_t page_unit; | | ^~~~~~~~ Fix by adding including stdint.h.
* Check if linker also support -mtls-dialect=gnu2Adhemerval Zanella2021-10-292-4/+4
| | | | | | | | | Since some linkers (for instance lld for i386) does not support it for all architectures. Checked on i686-linux-gnu. Reviewed-by: Fangrui Song <maskray@google.com>
* Fix LIBC_PROG_BINUTILS for -fuse-ld=lldAdhemerval Zanella2021-10-292-2/+10
| | | | | | | | | | | | | | | | | | | | | | | | | GCC does not print the correct linker when -fuse-ld=lld is used with the -print-prog-name=ld: $ gcc -v 2>&1 | tail -n 1 gcc version 11.2.0 (Ubuntu 11.2.0-7ubuntu2) $ gcc ld This is different than for gold: $ gcc -fuse-ld=gold -print-prog-name=ld ld.gold Using ld.lld as the static linker name prints the expected result. This is only required when -fuse-ld=lld is used, if lld is used as the 'ld' programs (through a symlink) LIBC_PROG_BINUTILS works as expected. Checked on x86_64-linux-gnu. Reviewed-by: Fangrui Song <maskray@google.com>
* elf: Disable ifuncmain{1,5,5pic,5pie} when using LLDAdhemerval Zanella2021-10-291-4/+13
| | | | | | | | | These tests takes the address of a protected symbol (foo_protected) and lld does not support copy relocations on protected data symbols. Checked on x86_64-linux-gnu. Reviewed-by: Fangrui Song <maskray@google.com>
* Handle NULL input to malloc_usable_size [BZ #28506]Siddhesh Poyarekar2021-10-293-35/+25
| | | | | | | | | | Hoist the NULL check for malloc_usable_size into its entry points in malloc-debug and malloc and assume non-NULL in all callees. This fixes BZ #28506 Signed-off-by: Siddhesh Poyarekar <siddhesh@sourceware.org> Reviewed-by: Florian Weimer <fweimer@redhat.com> Reviewed-by: Richard W.M. Jones <rjones@redhat.com>
* x86_64: Add memcmpeq.S to fix disable-multi-arch buildNoah Goldstein2021-10-281-0/+21
| | | | | | | | | | | | | | | | The following commit: commit cf4fd28ea453d1a9cec93939bc88b58ccef5437a Author: Noah Goldstein <goldstein.w.n@gmail.com> Date: Tue Oct 26 19:43:18 2021 -0500 Broke --disable-multi-arch build for x86_64 because x86_64/memcmpeq.S was not defined outside of multiarch and the alias for __memcmpeq in x86_64/memcmp.S was removed. This commit fixes that issue by adding x86_64/memcmpeq.S. make xcheck passes on x86_64 with and without --disable-multi-arch
* login: Add back libutil as an empty libraryStafford Horne2021-10-291-1/+3
| | | | | | There are several packages like sysvinit and buildroot that expect -lutil to work. Rather than impacting them with having to change the linker flags provide an empty libutil.a.
* riscv: Fix incorrect jal with HIDDEN_JUMPTARGETFangrui Song2021-10-282-3/+4
| | | | | | | | | | | | | | | | A non-local STV_DEFAULT defined symbol is by default preemptible in a shared object. j/jal cannot target a preemptible symbol. On other architectures, such a jump instruction either causes PLT [BZ #18822], or if short-ranged, sometimes rejected by the linker (but not by GNU ld's riscv port [ld PR/28509]). Use HIDDEN_JUMPTARGET to target a non-preemptible symbol instead. With this patch, ld.so and libc.so can be linked with LLD if source files are compiled/assembled with -mno-relax/-Wa,-mno-relax. Acked-by: Palmer Dabbelt <palmer@dabbelt.com> Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* x86_64: Add evex optimized __memcmpeq in memcmpeq-evex.SNoah Goldstein2021-10-273-6/+304
| | | | | | | | | | | | | No bug. This commit adds new optimized __memcmpeq implementation for evex. The primary optimizations are: 1) skipping the logic to find the difference of the first mismatched byte. 2) not updating src/dst addresses as the non-equals logic does not need to be reused by different areas.
* x86_64: Add avx2 optimized __memcmpeq in memcmpeq-avx2.SNoah Goldstein2021-10-274-9/+308
| | | | | | | | | | | | | No bug. This commit adds new optimized __memcmpeq implementation for avx2. The primary optimizations are: 1) skipping the logic to find the difference of the first mismatched byte. 2) not updating src/dst addresses as the non-equals logic does not need to be reused by different areas.
* x86_64: Add sse2 optimized __memcmpeq in memcmp-sse2.SNoah Goldstein2021-10-271-4/+51
| | | | | | No bug. This commit does not modify any of the memcmp implementation. It just adds __memcmpeq ifdefs to skip obvious cases where computing the proper 1/-1 required by memcmp is not needed.
* x86_64: Add support for __memcmpeq using sse2, avx2, and evexNoah Goldstein2021-10-2712-9/+202
| | | | | | No bug. This commit adds support for __memcmpeq to be implemented seperately from memcmp. Support is added for versions optimized with sse2, avx2, and evex.
* Benchtests: Add benchtests for __memcmpeqNoah Goldstein2021-10-273-7/+29
| | | | | | No bug. This commit adds __memcmpeq benchmarks. The benchmarks just use the existing ones in memcmp. This will be useful for testing implementations of __memcmpeq that do not just alias memcmp.
* String: Add __memcmpeq as build targetNoah Goldstein2021-10-272-1/+25
| | | | | | No bug. This commit just adds __memcmpeq as a build target so that implementations for __memcmpeq that are not just aliases to memcmp can be supported.
* NEWS: Add item for __memcmpeqNoah Goldstein2021-10-261-0/+4
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* String: Add tests for __memcmpeqNoah Goldstein2021-10-263-14/+45
| | | | | | | | | | No bug. This commit adds tests for the new function __memcmpeq. The new tests use the existing tests in 'test-memcmp.c' but relax the result requirement to only check for zero or non-zero returns. All string tests include test-memcmpeq are passing.
* String: Add hidden defs for __memcmpeq() to enable internal usageNoah Goldstein2021-10-2627-0/+38
| | | | | | | | No bug. This commit adds hidden defs for all declarations of __memcmpeq. This enables usage of __memcmpeq without the PLT for usage internal to GLIBC.
* String: Add support for __memcmpeq() ABI on all targetsNoah Goldstein2021-10-2664-0/+120
| | | | | | | | | | | | | | | | | | | | | | | | | No bug. This commit adds support for __memcmpeq() as a new ABI for all targets. In this commit __memcmpeq() is implemented only as an alias to the corresponding targets memcmp() implementation. __memcmpeq() is added as a new symbol starting with GLIBC_2.35 and defined in string.h with comments explaining its behavior. Basic tests that it is callable and works where added in string/tester.c As discussed in the proposal "Add new ABI '__memcmpeq()' to libc" __memcmpeq() is essentially a reserved namespace for bcmp(). The means is shares the same specifications as memcmp() except the return value for non-equal byte sequences is any non-zero value. This is less strict than memcmp()'s return value specification and can be better optimized when a boolean return is all that is needed. __memcmpeq() is meant to only be called by compilers if they can prove that the return value of a memcmp() call is only used for its boolean value. All tests in string/tester.c passed. As well build succeeds on x86_64-linux-gnu target.
* configure: Don't check LD -v --help for LIBC_LINKER_FEATUREFangrui Song2021-10-253-66/+48
| | | | | | | | | When LIBC_LINKER_FEATURE is used to check a linker option with the equal sign, it will likely fail because the LD -v --help output may look like `-z lam-report=[none|warning|error]` while the needle is something like `-z lam-report=warning`. The LD -v --help filter doesn't save much time, so just remove it.
* elf: Make global.out depend on reldepmod4.so [BZ #28457]H.J. Lu2021-10-251-1/+1
| | | | | | The global test is linked with globalmod1.so which dlopens reldepmod4.so. Make global.out depend on reldepmod4.so. This fixes BZ #28457. Reviewed-by: Florian Weimer <fweimer@redhat.com>
* x86: Replace sse2 instructions with avx in memcmp-evex-movbe.SNoah Goldstein2021-10-231-2/+2
| | | | | | | | | | | | | | This commit replaces two usages of SSE2 'movups' with AVX 'vmovdqu'. it could potentially be dangerous to use SSE2 if this function is ever called without using 'vzeroupper' beforehand. While compilers appear to use 'vzeroupper' before function calls if AVX2 has been used, using SSE2 here is more brittle. Since it is not absolutely necessary it should be avoided. It costs 2-extra bytes but the extra bytes should only eat into alignment padding. Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
* bench-math: Sort and put each bench per lineH.J. Lu2021-10-231-6/+62
| | | | | | Sort and put each math bench per line to prepare for new math benches. Reviewed-by: Noah Goldstein <goldstein.w.n@gmail.com>
* x86_64: Add missing libmvec ABI testsSunil K Pandey2021-10-2243-8/+152
| | | | | | Add vector ABI tests for cos, exp, log, pow and sin functions. Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
* elf: Fix e6fd79f379 build with --enable-tunables=noAdhemerval Zanella2021-10-211-0/+9
| | | | | | The _dl_sort_maps_init() is not defined when tunables is not enabled. Checked on x86_64-linux-gnu.
* elf: Fix slow DSO sorting behavior in dynamic loader (BZ #17645)Chung-Lin Tang2021-10-2114-42/+269
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* elf: Testing infrastructure for ld.so DSO sorting (BZ #17645)Chung-Lin Tang2021-10-2110-1/+1884
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is the first of a 2-part patch set that fixes slow DSO sorting behavior in the dynamic loader, as reported in BZ #17645. In order to facilitate such a large modification to the dynamic loader, this first patch implements a testing framework for validating shared object sorting behavior, to enable comparison between old/new sorting algorithms, and any later enhancements. This testing infrastructure consists of a Python script scripts/dso-ordering-test.py' which takes in a description language, consisting of strings that describe a set of link dependency relations between DSOs, and generates testcase programs and Makefile fragments to automatically test the described situation, for example: a->b->c->d # four objects linked one after another a->[bc]->d;b->c # a depends on b and c, which both depend on d, # b depends on c (b,c linked to object a in fixed order) a->b->c;{+a;%a;-a} # a, b, c serially dependent, main program uses # dlopen/dlsym/dlclose on object a a->b->c;{}!->[abc] # a, b, c serially dependent; multiple tests generated # to test all permutations of a, b, c ordering linked # to main program (Above is just a short description of what the script can do, more documentation is in the script comments.) Two files containing several new tests, elf/dso-sort-tests-[12].def are added, including test scenarios for BZ #15311 and Redhat issue #1162810 [1]. Due to the nature of dynamic loader tests, where the sorting behavior and test output occurs before/after main(), generating testcases to use support/test-driver.c does not suffice to control meaningful timeout for ld.so. Therefore a new utility program 'support/test-run-command', based on test-driver.c/support_test_main.c has been added. This does the same testcase control, but for a program specified through a command-line rather than at the source code level. This utility is used to run the dynamic loader testcases generated by dso-ordering-test.py. [1] https://bugzilla.redhat.com/show_bug.cgi?id=1162810 Signed-off-by: Chung-Lin Tang <cltang@codesourcery.com> Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* iconv: Use TIMEOUTFACTOR for iconv test timeoutStafford Horne2021-10-211-1/+4
| | | | | | | | | | | Currently the timeout for each iconv test is hard coded to 3 seconds. On my OpenRISC test platform this is too slow and the test fails with a HANG error. This change uses the available TIMEOUTFACTOR to compute the timeout. The default value is still 3. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* posix: Remove alloca usage for internal fnmatch implementationAdhemerval Zanella2021-10-212-127/+87
| | | | | | | This patch replaces the internal fnmatch pattern list generation to use a dynamic array. Checked on x86_64-linux-gnu.
* Add alloc_align attribute to memalign et alJonathan Wakely2021-10-214-5/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | GCC 4.9.0 added the alloc_align attribute to say that a function argument specifies the alignment of the returned pointer. Clang supports the attribute too. Using the attribute can allow a compiler to generate better code if it knows the returned pointer has a minimum alignment. See https://gcc.gnu.org/PR60092 for more details. GCC implicitly knows the semantics of aligned_alloc and posix_memalign, but not the obsolete memalign. As a result, GCC generates worse code when memalign is used, compared to aligned_alloc. Clang knows about aligned_alloc and memalign, but not posix_memalign. This change adds a new __attribute_alloc_align__ macro to <sys/cdefs.h> and then uses it on memalign (where it helps GCC) and aligned_alloc (where GCC and Clang already know the semantics, but it doesn't hurt) and xposix_memalign. It can't be used on posix_memalign because that doesn't return a pointer (the allocated pointer is returned via a void** parameter instead). Unlike the alloc_size attribute, alloc_align only allows a single argument. That means the new __attribute_alloc_align__ macro doesn't really need to be used with double parentheses to protect a comma between its arguments. For consistency with __attribute_alloc_size__ this patch defines it the same way, so that double parentheses are required. Signed-off-by: Jonathan Wakely <jwakely@redhat.com> Reviewed-by: Carlos O'Donell <carlos@redhat.com> Tested-by: Carlos O'Donell <carlos@redhat.com>
* linux: Fix a possibly non-constant expression in _Static_assertFangrui Song2021-10-201-3/+3
| | | | | | | | | | | | | | | | According to C11 6.6p6, `const int` as an operand may not make up a constant expression. GCC -O0 errors: ../sysdeps/unix/sysv/linux/opendir.c:107:19: error: static_assert expression is not an integral constant expression _Static_assert (allocation_size >= sizeof (struct dirent64), -O2 -Wpedantic has a similar warning. See https://gcc.gnu.org/PR102502 for GCC's inconsistency. Use enum which is guaranteed to be a constant expression. This also makes the file compilable with Clang. Fixes: 4b962c9e859de23b461d61f860dbd3f21311e83a ("linux: Simplify opendir buffer allocation")
* x86-64: Add sysdeps/x86_64/fpu/MakeconfigH.J. Lu2021-10-203-139/+155
| | | | | | | | | | 1. Add sysdeps/x86_64/fpu/Makeconfig to auto-generate libmvec.mk, which contains libmvec ABI test dependencies and CFLAGS, in the build directory. 2. Include libmvec.mk for libmvec ABI test dependencies and CFLAGS. Tested on SSE4, AVX, AVX2 and AVX512 machines. Reviewed-by: Noah Goldstein <goldstein.w.n@gmail.com>
* stdlib: Fix tst-canon-bz26341 when the glibc build current working directory ↵omain GEISSLER2021-10-201-0/+6
| | | | is itself using symlinks.
* powerpc: Remove backtrace implementationAdhemerval Zanella2021-10-205-277/+0
| | | | | | | | | | | | | | | The powerpc optimization to provide a fast stacktrace requires some ad-hoc code to handle Linux signal frames and the change is fragile once the kernel decides to slight change its execution sequence [1]. The generic implementation work as-is and it should be future proof since the kernel provides the expected CFI directives in vDSO shared page. Checked on powerpc-linux-gnu, powerpc64le-linux-gnu, and powerpc64-linux-gnu. [1] https://sourceware.org/pipermail/libc-alpha/2021-January/122027.html
* Correct access attribute on memfrob (bug 28475)Joseph Myers2021-10-204-4/+4
| | | | | | | | | | | | | | | | | | | | | | | As noted in bug 28475, the access attribute on memfrob in <string.h> is incorrect: the function both reads and writes the memory pointed to by its argument, so it needs to use __read_write__, not __write_only__. This incorrect attribute results in a build failure for accessing uninitialized memory for s390x-linux-gnu-O3 with build-many-glibcs.py using GCC mainline. Correct the attribute. Fixing this shows up that some calls to memfrob in elf/ tests are reading uninitialized memory; I'm not entirely sure of the purpose of those calls, but guess they are about ensuring that the stack space is indeed allocated at that point in the function, and so it matters that they are calling a function whose semantics are unknown to the compiler. Thus, change the first memfrob call in those tests to use explicit_bzero instead, as suggested by Florian in <https://sourceware.org/pipermail/libc-alpha/2021-October/132119.html>, to avoid the use of uninitialized memory. Tested for x86_64, and with build-many-glibcs.py (GCC mainline) for s390x-linux-gnu-O3.
* debug: Add tests for _FORTIFY_SOURCE=3Siddhesh Poyarekar2021-10-204-50/+69
| | | | | | | Add some testing coverage for _FORTIFY_SOURCE=3. Signed-off-by: Siddhesh Poyarekar <siddhesh@sourceware.org> Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* Make sure that the fortified function conditionals are constantSiddhesh Poyarekar2021-10-207-438/+226
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In _FORTIFY_SOURCE=3, the size expression may be non-constant, resulting in branches in the inline functions remaining intact and causing a tiny overhead. Clang (and in future, gcc) make sure that the -1 case is always safe, i.e. any comparison of the generated expression with (size_t)-1 is always false so that bit is taken care of. The rest is avoidable since we want the _chk variant whenever we have a size expression and it's not -1. Rework the conditionals in a uniform way to clearly indicate two conditions at compile time: - Either the size is unknown (-1) or we know at compile time that the operation length is less than the object size. We can call the original function in this case. It could be that either the length, object size or both are non-constant, but the compiler, through range analysis, is able to fold the *comparison* to a constant. - The size and length are known and the compiler can see at compile time that operation length > object size. This is valid grounds for a warning at compile time, followed by emitting the _chk variant. For everything else, emit the _chk variant. This simplifies most of the fortified function implementations and at the same time, ensures that only one call from _chk or the regular function is emitted. Signed-off-by: Siddhesh Poyarekar <siddhesh@sourceware.org> Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* Don't add access size hints to fortifiable functionsSiddhesh Poyarekar2021-10-209-26/+42
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In the context of a function definition, the size hints imply that the size of an object pointed to by one parameter is another parameter. This doesn't make sense for the fortified versions of the functions since that's the bit it's trying to validate. This is harmless with __builtin_object_size since it has fairly simple semantics when it comes to objects passed as function parameters. With __builtin_dynamic_object_size we could (as my patchset for gcc[1] already does) use the access attribute to determine the object size in the general case but it misleads the fortified functions. Basically the problem occurs when access attributes are present on regular functions that have inline fortified definitions to generate _chk variants; the attributes get inherited by these definitions, causing problems when analyzing them. For example with poll(fds, nfds, timeout), nfds is hinted using the __attr_access as being the size of fds. Now, when analyzing the inline function definition in bits/poll2.h, the compiler sees that nfds is the size of fds and tries to use that information in the function body. In _FORTIFY_SOURCE=3 case, where the object size could be a non-constant expression, this information results in the conclusion that nfds is the size of fds, which defeats the purpose of the implementation because we're trying to check here if nfds does indeed represent the size of fds. Hence for this case, it is best to not have the access attribute. With the attributes gone, the expression evaluation should get delayed until the function is actually inlined into its destinations. Disable the access attribute for fortified function inline functions when building at _FORTIFY_SOURCE=3 to make this work better. The access attributes remain for the _chk variants since they can be used by the compiler to warn when the caller is passing invalid arguments. [1] https://gcc.gnu.org/pipermail/gcc-patches/2021-October/581125.html Signed-off-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
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