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* x86: Fix overflow bug with wmemchr-sse2 and wmemchr-avx2 [BZ #27974]Noah Goldstein2022-01-271-19/+58
| | | | | | | | | | | | | | This commit fixes the bug mentioned in the previous commit. The previous implementations of wmemchr in these files relied on n * sizeof(wchar_t) which was not guranteed by the standard. The new overflow tests added in the previous commit now pass (As well as all the other tests). Signed-off-by: Noah Goldstein <goldstein.w.n@gmail.com> Reviewed-by: H.J. Lu <hjl.tools@gmail.com> (cherry picked from commit 645a158978f9520e74074e8c14047503be4db0f0)
* x86-64 memchr/wmemchr: Properly handle the length parameter [BZ# 24097]H.J. Lu2019-01-211-3/+7
| | | | | | | | | | | | | | | | | | | | | | On x32, the size_t parameter may be passed in the lower 32 bits of a 64-bit register with the non-zero upper 32 bits. The string/memory functions written in assembly can only use the lower 32 bits of a 64-bit register as length or must clear the upper 32 bits before using the full 64-bit register for length. This pach fixes memchr/wmemchr for x32. Tested on x86-64 and x32. On x86-64, libc.so is the same with and withou the fix. [BZ# 24097] CVE-2019-6488 * sysdeps/x86_64/memchr.S: Use RDX_LP for length. Clear the upper 32 bits of RDX register. * sysdeps/x86_64/multiarch/memchr-avx2.S: Likewise. * sysdeps/x86_64/x32/Makefile (tests): Add tst-size_t-memchr and tst-size_t-wmemchr. * sysdeps/x86_64/x32/test-size_t.h: New file. * sysdeps/x86_64/x32/tst-size_t-memchr.c: Likewise. * sysdeps/x86_64/x32/tst-size_t-wmemchr.c: Likewise.
* Update copyright dates with scripts/update-copyrights.Joseph Myers2019-01-011-1/+1
| | | | | | | * All files with FSF copyright notices: Update copyright dates using scripts/update-copyrights. * locale/programs/charmap-kw.h: Regenerated. * locale/programs/locfile-kw.h: Likewise.
* Update copyright dates with scripts/update-copyrights.Joseph Myers2018-01-011-1/+1
| | | | | | | * All files with FSF copyright notices: Update copyright dates using scripts/update-copyrights. * locale/programs/charmap-kw.h: Regenerated. * locale/programs/locfile-kw.h: Likewise.
* x86-64: Optimize memchr/rawmemchr/wmemchr with SSE2/AVX2H.J. Lu2017-06-091-25/+40
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | SSE2 memchr is extended to support wmemchr. AVX2 memchr/rawmemchr/wmemchr are added to search 32 bytes with a single vector compare instruction. AVX2 memchr/rawmemchr/wmemchr are as fast as SSE2 memchr/rawmemchr/wmemchr for small sizes and up to 1.5X faster for larger sizes on Haswell and Skylake. Select AVX2 memchr/rawmemchr/wmemchr on AVX2 machines where vzeroupper is preferred and AVX unaligned load is fast. NB: It uses TZCNT instead of BSF since TZCNT produces the same result as BSF for non-zero input. TZCNT is faster than BSF and is executed as BSF if machine doesn't support TZCNT. * sysdeps/x86_64/memchr.S (MEMCHR): New. Depending on if USE_AS_WMEMCHR is defined. (PCMPEQ): Likewise. (memchr): Renamed to ... (MEMCHR): This. Support wmemchr if USE_AS_WMEMCHR is defined. Replace pcmpeqb with PCMPEQ. * sysdeps/x86_64/multiarch/Makefile (sysdep_routines): Add memchr-sse2, rawmemchr-sse2, memchr-avx2, rawmemchr-avx2, wmemchr-sse4_1, wmemchr-avx2 and wmemchr-c. * sysdeps/x86_64/multiarch/ifunc-avx2.h: New file. * sysdeps/x86_64/multiarch/memchr-avx2.S: Likewise. * sysdeps/x86_64/multiarch/memchr-sse2.S: Likewise. * sysdeps/x86_64/multiarch/memchr.c: Likewise. * sysdeps/x86_64/multiarch/rawmemchr-avx2.S: Likewise. * sysdeps/x86_64/multiarch/rawmemchr-sse2.S: Likewise. * sysdeps/x86_64/multiarch/rawmemchr.c: Likewise. * sysdeps/x86_64/multiarch/wmemchr-avx2.S: Likewise. * sysdeps/x86_64/multiarch/wmemchr-sse2.S: Likewise. * sysdeps/x86_64/multiarch/wmemchr.c: Likewise. * sysdeps/x86_64/multiarch/ifunc-impl-list.c (__libc_ifunc_impl_list): Test __memchr_avx2, __memchr_sse2, __rawmemchr_avx2, __rawmemchr_sse2, __wmemchr_avx2 and __wmemchr_sse2.
* x86_64: Remove redundant REX bytes from memchr.SH.J. Lu2017-05-301-14/+14
| | | | | | | | | By x86-64 specification, 32-bit destination registers are zero-extended to 64 bits. There is no need to use 64-bit registers when only the lower 32 bits are non-zero. * sysdeps/x86_64/memchr.S (MEMCHR): Use 32-bit registers for the lower 32 bits.
* x86: Optimize SSE2 memchr overflow calculationH.J. Lu2017-05-191-8/+6
| | | | | | | | | | | | | | | | | | | | | | | SSE2 memchr computes "edx + ecx - 16" where ecx is less than 16. Use "edx - (16 - ecx)", instead of satured math, to avoid possible addition overflow. This replaces add %ecx, %edx sbb %eax, %eax or %eax, %edx sub $16, %edx with neg %ecx add $16, %ecx sub %ecx, %edx It is the same for x86_64, except for rcx/rdx, instead of ecx/edx. * sysdeps/i386/i686/multiarch/memchr-sse2.S (MEMCHR): Use "edx + ecx - 16" to avoid possible addition overflow. * sysdeps/x86_64/memchr.S (memchr): Likewise.
* Update copyright dates with scripts/update-copyrights.Joseph Myers2017-01-011-1/+1
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* Fix x86_64 memchr for large input sizesAdhemerval Zanella2016-12-271-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Current optimized memchr for x86_64 does for input arguments pointers module 64 in range of [49,63] if there is no searchr char in the rest of 64-byte block a pointer addition which might overflow: * sysdeps/x86_64/memchr.S 77 .p2align 4 78 L(unaligned_no_match): 79 add %rcx, %rdx Add (uintptr_t)s % 16 to n in %rdx. 80 sub $16, %rdx 81 jbe L(return_null) This patch fixes by adding a saturated math that sets a maximum pointer value if it overflows (UINTPTR_MAX). Checked on x86_64-linux-gnu and powerpc64-linux-gnu. [BZ# 19387] * sysdeps/x86_64/memchr.S (memchr): Avoid overflow in pointer addition. * string/test-memchr.c (do_test): Remove alignment limitation. (test_main): Add test that trigger BZ# 19387.
* Update copyright dates with scripts/update-copyrights.Joseph Myers2016-01-041-1/+1
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* Update copyright dates with scripts/update-copyrights.Joseph Myers2015-01-021-1/+1
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* Update copyright notices with scripts/update-copyrightsAllan McRae2014-01-011-1/+1
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* Update copyright notices with scripts/update-copyrights.Joseph Myers2013-01-021-1/+1
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* Replace FSF snail mail address with URLs.Paul Eggert2012-02-091-3/+2
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* Improve 64 bit memchr, memrchr, rawmemchr with SSE2Liubov Dmitrieva2011-10-071-36/+280
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* Fix x86-64 memchr for large lengths.Jakub Jelinek2009-06-161-3/+3
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* * sysdeps/x86_64/memchr.S: Handle invalid buffer pointers whenUlrich Drepper2009-05-091-0/+2
| | | | count is zero.
* * sysdeps/x86_64/rawmemchr.S: New file.Ulrich Drepper2009-04-101-2/+1
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* * string/stratcliff.c (do_test): Add memchr tests..Ulrich Drepper2009-04-071-4/+4
| | | | | * sysdeps/x86_64/memchr.S: Fix handling of end of buffer after first read quad word.
* * sysdeps/x86_64/memchr.S: New file.Ulrich Drepper2009-04-071-0/+67
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