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2021-09-03Remove "Contributed by" linesSiddhesh Poyarekar4-5/+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>
2021-08-31configure: Allow LD to be LLD 13.0.0 or above [BZ #26558]Fangrui Song1-0/+4
When using LLD (LLVM linker) as the linker, configure prints a confusing message. *** These critical programs are missing or too old: GNU ld LLD>=13.0.0 can build glibc --enable-static-pie. (8.0.0 needs one workaround for -Wl,-defsym=_begin=0. 9.0.0 works with --disable-static-pie). XFAIL two tests sysdeps/x86/tst-ifunc-isa-* which have the BZ #28154 issue (LLD follows the PowerPC port of GNU ld for ifunc by placing IRELATIVE relocations in .rela.dyn, triggering a glibc ifunc fragility). The set of dynamic symbols is the same with GNU ld and LLD, modulo unused SHN_ABS version node symbols. For comparison, gold does not support --enable-static-pie yet (--no-dynamic-linker is unsupported BZ #22221), yet has 6 failures more than LLD. gold linked libc.so has larger .dynsym differences with GNU ld and LLD (non-default version symbols are changed to default versions by a version script BZ #28196).
2021-08-19x86: fix Autoconf caching of instruction support checks [BZ #27991]Matt Whitlock2-37/+53
The Autoconf documentation for the AC_CACHE_CHECK macro states: The commands-to-set-it must have no side effects except for setting the variable cache-id, see below. However, the tests for support of -msahf and -mmovbe were embedded in the commands-to-set-it for lib_cv_include_x86_isa_level. This had the consequence that libc_cv_have_x86_lahf_sahf and libc_cv_have_x86_movbe were not defined whenever lib_cv_include_x86_isa_level was read from cache. These variables' being undefined meant that their unquoted use in later test expressions led to the 'test' built-in's misparsing its arguments and emitting errors like "test: =: unexpected operator" or "test: =: unary operator expected", depending on the particular shell. This commit refactors the tests for LAHF/SAHF and MOVBE instruction support into their own AC_CACHE_CHECK macro invocations to obey the rule that the commands-to-set-it must have no side effects other than setting the variable named by cache-id. Signed-off-by: Matt Whitlock <sourceware@mattwhitlock.name> Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
2021-07-28x86-64: Add Avoid_Short_Distance_REP_MOVSBH.J. Lu4-0/+20
commit 3ec5d83d2a237d39e7fd6ef7a0bc8ac4c171a4a5 Author: H.J. Lu <hjl.tools@gmail.com> Date: Sat Jan 25 14:19:40 2020 -0800 x86-64: Avoid rep movsb with short distance [BZ #27130] introduced some regressions on Intel processors without Fast Short REP MOV (FSRM). Add Avoid_Short_Distance_REP_MOVSB to avoid rep movsb with short distance only on Intel processors with FSRM. bench-memmove-large on Skylake server shows that cycles of __memmove_evex_unaligned_erms improves for the following data size: before after Improvement length=4127, align1=3, align2=0: 479.38 349.25 27% length=4223, align1=9, align2=5: 405.62 333.25 18% length=8223, align1=3, align2=0: 786.12 496.38 37% length=8319, align1=9, align2=5: 727.50 501.38 31% length=16415, align1=3, align2=0: 1436.88 840.00 41% length=16511, align1=9, align2=5: 1375.50 836.38 39% length=32799, align1=3, align2=0: 2890.00 1860.12 36% length=32895, align1=9, align2=5: 2891.38 1931.88 33%
2021-07-23x86: Install <bits/platform/x86.h> [BZ #27958]H.J. Lu12-553/+557
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>
2021-07-23Fix build and tests with --disable-tunablesSiddhesh Poyarekar1-2/+6
Remove unused code and declare __libc_mallopt when !IS_IN (libc) to allow the debug hook to build with --disable-tunables. Also, run tst-ifunc-isa-2* tests only when tunables are enabled since the result depends on it. Tested on x86_64. Reported-by: Matheus Castanho <msc@linux.ibm.com> Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2021-07-19elf: Fix tst-cpu-features-cpuinfo on some AMD systems (BZ #28090)Adhemerval Zanella3-1/+16
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>
2021-07-01x86: Check RTM_ALWAYS_ABORT for RTM [BZ #28033]H.J. Lu5-6/+11
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.
2021-06-24x86: Fix tst-cpu-features-cpuinfo on Ryzen 9 (BZ #27873)Adhemerval Zanella3-4/+34
AMD define different flags for IRPB, IBRS, and STIPBP [1], so new x86_64_cpu are added and IBRS_IBPB is only tested for Intel. The SSDB is also defined and implemented different on AMD [2], and also a new AMD_SSDB flag is added. It should map to the cpuinfo 'ssdb' on recent AMD cpus. It fixes tst-cpu-features-cpuinfo and tst-cpu-features-cpuinfo-static on recent AMD cpus. Checked on x86_64-linux-gnu on AMD Ryzen 9 5900X. [1] https://developer.amd.com/wp-content/resources/Architecture_Guidelines_Update_Indirect_Branch_Control.pdf [2] https://bugzilla.kernel.org/show_bug.cgi?id=199889 Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
2021-06-23x86: Copy IBT and SHSTK usable only if CET is enabledH.J. Lu1-2/+5
IBT and SHSTK usable bits are copied from CPUID feature bits and later cleared if kernel doesn't support CET. Copy IBT and SHSTK usable only if CET is enabled so that they aren't set on CET capable processors with non-CET enabled glibc.
2021-06-03dlfcn: Cleanups after -ldl is no longer requiredFlorian Weimer1-11/+2
This commit removes the ELF constructor and internal variables from dlfcn/dlfcn.c. The file now serves the same purpose as nptl/libpthread-compat.c, so it is renamed to dlfcn/libdl-compat.c. The use of libdl-shared-only-routines ensures that libdl.a is empty. This commit adjusts the test suite not to use $(libdl). The libdl.so symbolic link is no longer installed. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
2021-05-24Properly check stack alignment [BZ #27901]H.J. Lu1-0/+28
1. Replace if ((((uintptr_t) &_d) & (__alignof (double) - 1)) != 0) which may be optimized out by compiler, with int __attribute__ ((weak, noclone, noinline)) is_aligned (void *p, int align) { return (((uintptr_t) p) & (align - 1)) != 0; } 2. Add TEST_STACK_ALIGN_INIT to TEST_STACK_ALIGN. 3. Add a common TEST_STACK_ALIGN_INIT to check 16-byte stack alignment for both i386 and x86-64. 4. Update powerpc to use TEST_STACK_ALIGN_INIT. Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2021-05-03x86: Set rep_movsb_threshold to 2112 on processors with FSRMH.J. Lu1-0/+4
The glibc memcpy benchmark on Intel Core i7-1065G7 (Ice Lake) showed that REP MOVSB became faster after 2112 bytes: Vector Move REP MOVSB length=2112, align1=0, align2=0: 24.20 24.40 length=2112, align1=1, align2=0: 26.07 23.13 length=2112, align1=0, align2=1: 27.18 28.13 length=2112, align1=1, align2=1: 26.23 25.16 length=2176, align1=0, align2=0: 23.18 22.52 length=2176, align1=2, align2=0: 25.45 22.52 length=2176, align1=0, align2=2: 27.14 27.82 length=2176, align1=2, align2=2: 22.73 25.56 length=2240, align1=0, align2=0: 24.62 24.25 length=2240, align1=3, align2=0: 29.77 27.15 length=2240, align1=0, align2=3: 35.55 29.93 length=2240, align1=3, align2=3: 34.49 25.15 length=2304, align1=0, align2=0: 34.75 26.64 length=2304, align1=4, align2=0: 32.09 22.63 length=2304, align1=0, align2=4: 28.43 31.24 Use REP MOVSB for data size > 2112 bytes in memcpy on processors with fast short REP MOVSB (FSRM). * sysdeps/x86/dl-cacheinfo.h (dl_init_cacheinfo): Set rep_movsb_threshold to 2112 on processors with fast short REP MOVSB (FSRM).
2021-04-22x86: tst-cpu-features-supports.c: Update AMX checkH.J. Lu1-3/+3
Pass "amx-bf16", "amx-int8" and "amx-tile", instead of "amx_bf16", "amx_int8" and "amx_tile", to __builtin_cpu_supports for GCC 11.
2021-04-21nptl: Remove longjmp, siglongjmp from libpthreadFlorian Weimer1-71/+0
The definitions in libc are sufficient, the forwarders are no longer needed. The symbols have been moved using scripts/move-symbol-to-libc.py. s390-linux-gnu and s390x-linux-gnu need a new version placeholder to keep the GLIBC_2.19 symbol version in libpthread. Tested on i386-linux-gnu, powerpc64le-linux-gnu, s390x-linux-gnu, x86_64-linux-gnu. Built with build-many-glibcs.py. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
2021-03-30Move __isnanf128 to libc.soSiddhesh Poyarekar1-0/+1
All of the isnan functions are in libc.so due to printf_fp, so move __isnanf128 there too for consistency. Reviewed-by: Tulio Magno Quites Machado Filho <tuliom@ascii.art.br> Reviewed-by: Florian Weimer <fweimer@redhat.com>
2021-03-29x86: Add string/memory function tests in RTM regionH.J. Lu12-0/+618
At function exit, AVX optimized string/memory functions have VZEROUPPER which triggers RTM abort. When such functions are called inside a transactionally executing RTM region, RTM abort causes severe performance degradation. Add tests to verify that string/memory functions won't cause RTM abort in RTM region.
2021-03-29x86: Set Prefer_No_VZEROUPPER and add Prefer_AVX2_STRCMPH.J. Lu3-2/+21
1. Set Prefer_No_VZEROUPPER if RTM is usable to avoid RTM abort triggered by VZEROUPPER inside a transactionally executing RTM region. 2. Since to compare 2 32-byte strings, 256-bit EVEX strcmp requires 2 loads, 3 VPCMPs and 2 KORDs while AVX2 strcmp requires 1 load, 2 VPCMPEQs, 1 VPMINU and 1 VPMOVMSKB, AVX2 strcmp is faster than EVEX strcmp. Add Prefer_AVX2_STRCMP to prefer AVX2 strcmp family functions.
2021-03-29x86: Properly disable XSAVE related features [BZ #27605]H.J. Lu2-0/+56
1. Support GLIBC_TUNABLES=glibc.cpu.hwcaps=-XSAVE. 2. Disable all features which depend on XSAVE: a. If OSXSAVE is disabled by glibc tunables. Or b. If both XSAVE and XSAVEC aren't usable.
2021-03-24elf: Fix not compiling ifunc tests that need gcc ifunc supportSamuel Thibault1-0/+2
2021-03-15Build get-cpuid-feature-leaf.c without stack-protector [BZ #27555]Siddhesh Poyarekar2-0/+4
__x86_get_cpuid_feature_leaf is called during early startup, before the stack check guard is initialized and is hence not safe to build with stack-protector. Additionally, IFUNC resolvers for static tst-ifunc-isa tests get called too early for stack protector to be useful, so fix them to disable stack protector for the resolver functions. This fixes all failures seen with --enable-stack-protector=all configuration. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
2021-03-15x86: Handle _SC_LEVEL1_ICACHE_LINESIZE [BZ #27444]H.J. Lu7-0/+79
commit 2d651eb9265d1366d7b9e881bfddd46db9c1ecc4 Author: H.J. Lu <hjl.tools@gmail.com> Date: Fri Sep 18 07:55:14 2020 -0700 x86: Move x86 processor cache info to cpu_features missed _SC_LEVEL1_ICACHE_LINESIZE. 1. Add level1_icache_linesize to struct cpu_features. 2. Initialize level1_icache_linesize by calling handle_intel, handle_zhaoxin and handle_amd with _SC_LEVEL1_ICACHE_LINESIZE. 3. Return level1_icache_linesize for _SC_LEVEL1_ICACHE_LINESIZE. Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2021-03-06x86: Set minimum x86-64 level marker [BZ #27318]H.J. Lu3-11/+58
Since the full ISA set used in an ELF binary is unknown to compiler, an x86-64 ISA level marker indicates the minimum, not maximum, ISA set required to run such an ELF binary. We never guarantee a library with an x86-64 ISA level v3 marker doesn't contain other ISAs beyond x86-64 ISA level v3, like AVX VNNI. We check the x86-64 ISA level marker for the minimum ISA set. Since -march=sandybridge enables only some ISAs in x86-64 ISA level v3, we should set the needed ISA marker to v2. Otherwise, libc is compiled with -march=sandybridge will fail to run on Sandy Bridge: $ ./elf/ld.so ./libc.so ./libc.so: (p) CPU ISA level is lower than required: needed: 7; got: 3 Set the minimum, instead of maximum, x86-64 ISA level marker should have no impact on the glibc-hwcaps directory assignment logic in ldconfig nor ld.so.
2021-03-02x86: Add CPU-specific diagnostics to ld.so --list-diagnosticsFlorian Weimer2-0/+120
2021-03-02x86: Automate generation of PREFERRED_FEATURE_INDEX_1 bitfieldFlorian Weimer2-34/+51
Use a .def file to define the bitfield layout, so that it is possible to iterate over field members using the preprocessor.
2021-02-22x86: Use x86/nptl/pthreaddef.hH.J. Lu1-0/+49
1. Move sysdeps/i386/nptl/pthreaddef.h to sysdeps/x86/nptl/pthreaddef.h. 2. Remove sysdeps/x86_64/nptl/pthreaddef.h. Reviewed-by: DJ Delorie <dj@redhat.com>
2021-02-22x86: Remove unused variables for raw cache sizes from cacheinfo.hFlorian Weimer1-12/+0
2021-02-22<bits/platform/x86.h>: Correct x86_cpu_TBMH.J. Lu1-1/+1
x86_cpu_TBM should be x86_cpu_index_80000001_ecx + 21.
2021-02-12x86: Remove the extra space between "# endif"H.J. Lu1-1/+1
Remove the extra space between "# endif" left over from commit f380868f6dcfdeae8d449d556298d9c41012ed8d Author: H.J. Lu <hjl.tools@gmail.com> Date: Thu Dec 24 15:43:34 2020 -0800 Remove _ISOMAC check from <cpu-features.h>
2021-02-10x86: Use SIZE_MAX instead of (long int)-1 for tunable range valueSiddhesh Poyarekar1-5/+5
The tunable types are SIZE_T, so set the ranges to the correct maximum value, i.e. SIZE_MAX.
2021-02-10tunables: Simplify TUNABLE_SET interfaceSiddhesh Poyarekar1-9/+6
The TUNABLE_SET interface took a primitive C type argument, which resulted in inconsistent type conversions internally due to incorrect dereferencing of types, especialy on 32-bit architectures. This change simplifies the TUNABLE setting logic along with the interfaces. Now all numeric tunable values are stored as signed numbers in tunable_num_t, which is intmax_t. All calls to set tunables cast the input value to its primitive type and then to tunable_num_t for storage. This relies on gcc-specific (although I suspect other compilers woul also do the same) unsigned to signed integer conversion semantics, i.e. the bit pattern is conserved. The reverse conversion is guaranteed by the standard.
2021-02-07x86: Add PTWRITE feature detection [BZ #27346]H.J. Lu9-5/+44
1. Add CPUID_INDEX_14_ECX_0 for CPUID leaf 0x14 to detect PTWRITE feature in EBX of CPUID leaf 0x14 with ECX == 0. 2. Add PTWRITE detection to CPU feature tests. 3. Add 2 static CPU feature tests.
2021-02-02x86: Adding an upper bound for Enhanced REP MOVSB.Sajan Karumanchi3-1/+20
In the process of optimizing memcpy for AMD machines, we have found the vector move operations are outperforming enhanced REP MOVSB for data transfers above the L2 cache size on Zen3 architectures. To handle this use case, we are adding an upper bound parameter on enhanced REP MOVSB:'__x86_rep_movsb_stop_threshold'. As per large-bench results, we are configuring this parameter to the L2 cache size for AMD machines and applicable from Zen3 architecture supporting the ERMS feature. For architectures other than AMD, it is the computed value of non-temporal threshold parameter. Reviewed-by: Premachandra Mallappa <premachandra.mallappa@amd.com>
2021-02-01sysconf: Add _SC_MINSIGSTKSZ/_SC_SIGSTKSZ [BZ #20305]H.J. Lu2-0/+30
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.
2021-01-29x86: Properly set usable CET feature bits [BZ #26625]H.J. Lu10-13/+120
commit 94cd37ebb293321115a36a422b091fdb72d2fb08 Author: H.J. Lu <hjl.tools@gmail.com> Date: Wed Sep 16 05:27:32 2020 -0700 x86: Use HAS_CPU_FEATURE with IBT and SHSTK [BZ #26625] broke GLIBC_TUNABLES=glibc.cpu.hwcaps=-IBT,-SHSTK since it can no longer disable IBT nor SHSTK. Handle IBT and SHSTK with: 1. Revert commit 94cd37ebb293321115a36a422b091fdb72d2fb08. 2. Clears the usable CET feature bits if kernel doesn't support CET. 3. Add GLIBC_TUNABLES tests without dlopen. 4. Add tests to verify that CPU_FEATURE_USABLE on IBT and SHSTK matches _get_ssp. 5. Update GLIBC_TUNABLES tests with dlopen to verify that CET is disabled with GLIBC_TUNABLES. Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2021-01-25Fix misplaced constAndreas Schwab2-2/+2
Constify __x86_cacheinfo_p and __x86_cpu_features_p, not their pointer target types.
2021-01-22x86: Properly match CPU features in /proc/cpuinfo [BZ #27222]H.J. Lu1-13/+30
Search " YYY " and " YYY\n", instead of "YYY", to avoid matching "XXXYYYZZZ" with "YYY". Update /proc/cpuinfo CPU feature names: /proc/cpuinfo glibc ------------------------------------------------ avx512vbmi AVX512_VBMI dts DS pni SSE3 tsc_deadline_timer TSC_DEADLINE
2021-01-21x86: Check ifunc resolver with CPU_FEATURE_USABLE [BZ #27072]H.J. Lu6-0/+184
Check ifunc resolver with CPU_FEATURE_USABLE and tunables in dynamic and static executables to verify that CPUID features are initialized early in static PIE. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
2021-01-21Use hidden visibility for early static PIE codeSzabolcs Nagy1-0/+5
Extern symbol access in position independent code usually involves GOT indirection which needs RELATIVE reloc in a static linked PIE. (On some targets this is avoided e.g. because the linker can relax a GOT access to a pc-relative access, but this is not generally true.) Code that runs before static PIE self relocation must avoid relying on dynamic relocations which can be ensured by using hidden visibility. However we cannot just make all symbols hidden: On i386, all calls to IFUNC functions must go through PLT and calls to hidden functions CANNOT go through PLT in PIE since EBX used in PIE PLT may not be set up for local calls to hidden IFUNC functions. This patch aims to make symbol references hidden in code that is used before and by _dl_relocate_static_pie when building a static PIE libc. Note: for an object that is used in the startup code, its references and definition may not have consistent visibility: it is only forced hidden in the startup code. This is needed for fixing bug 27072. Co-authored-by: H.J. Lu <hjl.tools@gmail.com> Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
2021-01-21<sys/platform/x86.h>: Remove the C preprocessor magicH.J. Lu12-832/+1153
In <sys/platform/x86.h>, define CPU features as enum instead of using the C preprocessor magic to make it easier to wrap this functionality in other languages. Move the C preprocessor magic to internal header for better GCC codegen when more than one features are checked in a single expression as in x86-64 dl-hwcaps-subdirs.c. 1. Rename COMMON_CPUID_INDEX_XXX to CPUID_INDEX_XXX. 2. Move CPUID_INDEX_MAX to sysdeps/x86/include/cpu-features.h. 3. Remove struct cpu_features and __x86_get_cpu_features from <sys/platform/x86.h>. 4. Add __x86_get_cpuid_feature_leaf to <sys/platform/x86.h> and put it in libc. 5. Make __get_cpu_features() private to glibc. 6. Replace __x86_get_cpu_features(N) with __get_cpu_features(). 7. Add _dl_x86_get_cpu_features to GLIBC_PRIVATE. 8. Use a single enum index for each CPU feature detection. 9. Pass the CPUID feature leaf to __x86_get_cpuid_feature_leaf. 10. Return zero struct cpuid_feature for the older glibc binary with a smaller CPUID_INDEX_MAX [BZ #27104]. 11. Inside glibc, use the C preprocessor magic so that cpu_features data can be loaded just once leading to more compact code for glibc. 256 bits are used for each CPUID leaf. Some leaves only contain a few features. We can add exceptions to such leaves. But it will increase code sizes and it is harder to provide backward/forward compatibilities when new features are added to such leaves in the future. When new leaves are added, _rtld_global_ro offsets will change which leads to race condition during in-place updates. We may avoid in-place updates by 1. Rename the old glibc. 2. Install the new glibc. 3. Remove the old glibc. NB: A function, __x86_get_cpuid_feature_leaf , is used to avoid the copy relocation issue with IFUNC resolver as shown in IFUNC resolver tests.
2021-01-14x86: Move x86 processor cache info to cpu_featuresH.J. Lu5-412/+551
1. Move x86 processor cache info to _dl_x86_cpu_features in ld.so. 2. Update tunable bounds with TUNABLE_SET_WITH_BOUNDS. 3. Move x86 cache info initialization to dl-cacheinfo.h and initialize x86 cache info in init_cpu_features (). 4. Put x86 cache info for libc in cacheinfo.h, which is included in libc-start.c in libc.a and is included in cacheinfo.c in libc.so. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
2021-01-14Fix x86 build with --enable-tunable=noAdhemerval Zanella1-0/+1
Checked on x86_64-linux-gnu.
2021-01-13ldconfig/x86: Store ISA level in cache and aux cacheH.J. Lu1-0/+31
Store ISA level in the portion of the unused upper 32 bits of the hwcaps field in cache and the unused pad field in aux cache. ISA level is stored and checked only for shared objects in glibc-hwcaps subdirectories. The shared objects in the default directories aren't checked since there are no fallbacks for these shared objects. Tested on x86-64-v2, x86-64-v3 and x86-64-v4 machines with --disable-hardcoded-path-in-tests and --enable-hardcoded-path-in-tests.
2021-01-13x86: Set header.feature_1 in TCB for always-on CET [BZ #27177]H.J. Lu3-1/+11
Update dl_cet_check() to set header.feature_1 in TCB when both IBT and SHSTK are always on.
2021-01-07x86: Support GNU_PROPERTY_X86_ISA_1_V[234] marker [BZ #26717]H.J. Lu17-41/+607
GCC 11 supports -march=x86-64-v[234] to enable x86 micro-architecture ISA levels: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97250 and -mneeded to emit GNU_PROPERTY_X86_ISA_1_NEEDED property with GNU_PROPERTY_X86_ISA_1_V[234] marker: https://gitlab.com/x86-psABIs/x86-64-ABI/-/merge_requests/13 Binutils support for GNU_PROPERTY_X86_ISA_1_V[234] marker were added by commit b0ab06937385e0ae25cebf1991787d64f439bf12 Author: H.J. Lu <hjl.tools@gmail.com> Date: Fri Oct 30 06:49:57 2020 -0700 x86: Support GNU_PROPERTY_X86_ISA_1_BASELINE marker and commit 32930e4edbc06bc6f10c435dbcc63131715df678 Author: H.J. Lu <hjl.tools@gmail.com> Date: Fri Oct 9 05:05:57 2020 -0700 x86: Support GNU_PROPERTY_X86_ISA_1_V[234] marker GNU_PROPERTY_X86_ISA_1_NEEDED property in x86 ELF binaries indicate the micro-architecture ISA level required to execute the binary. The marker must be added by programmers explicitly in one of 3 ways: 1. Pass -mneeded to GCC. 2. Add the marker in the linker inputs as this patch does. 3. Pass -z x86-64-v[234] to the linker. Add GNU_PROPERTY_X86_ISA_1_BASELINE and GNU_PROPERTY_X86_ISA_1_V[234] marker support to ld.so if binutils 2.32 or newer is used to build glibc: 1. Add GNU_PROPERTY_X86_ISA_1_BASELINE and GNU_PROPERTY_X86_ISA_1_V[234] markers to elf.h. 2. Add GNU_PROPERTY_X86_ISA_1_BASELINE and GNU_PROPERTY_X86_ISA_1_V[234] marker to abi-note.o based on the ISA level used to compile abi-note.o, assuming that the same ISA level is used to compile the whole glibc. 3. Add isa_1 to cpu_features to record the supported x86 ISA level. 4. Rename _dl_process_cet_property_note to _dl_process_property_note and add GNU_PROPERTY_X86_ISA_1_V[234] marker detection. 5. Update _rtld_main_check and _dl_open_check to check loaded objects with the incompatible ISA level. 6. Add a testcase to verify that dlopen an x86-64-v4 shared object fails on lesser platforms. 7. Use <get-isa-level.h> in dl-hwcaps-subdirs.c and tst-glibc-hwcaps.c. Tested under i686, x32 and x86-64 modes on x86-64-v2, x86-64-v3 and x86-64-v4 machines. Marked elf/tst-isa-level-1 with x86-64-v4, ran it on x86-64-v3 machine and got: [hjl@gnu-cfl-2 build-x86_64-linux]$ ./elf/tst-isa-level-1 ./elf/tst-isa-level-1: CPU ISA level is lower than required [hjl@gnu-cfl-2 build-x86_64-linux]$
2021-01-04Drop nan-pseudo-number.h usage from testsSiddhesh Poyarekar1-1/+0
Make the tests use TEST_COND_intel96 to decide on whether to build the unnormal tests instead of the macro in nan-pseudo-number.h and then drop the header inclusion. This unbreaks test runs on all architectures that do not have ldbl-96. Also drop the HANDLE_PSEUDO_NUMBERS macro since it is not used anywhere.
2021-01-02Update copyright dates with scripts/update-copyrightsPaul Eggert81-81/+81
I used these shell commands: ../glibc/scripts/update-copyrights $PWD/../gnulib/build-aux/update-copyright (cd ../glibc && git commit -am"[this commit message]") and then ignored the output, which consisted lines saying "FOO: warning: copyright statement not found" for each of 6694 files FOO. I then removed trailing white space from benchtests/bench-pthread-locks.c and iconvdata/tst-iconv-big5-hkscs-to-2ucs4.c, to work around this diagnostic from Savannah: remote: *** pre-commit check failed ... remote: *** error: lines with trailing whitespace found remote: error: hook declined to update refs/heads/master
2020-12-30x86 long double: Consider pseudo numbers as signalingSiddhesh Poyarekar1-0/+30
Add support to treat pseudo-numbers specially and implement x86 version to consider all of them as signaling. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
2020-12-24Remove _ISOMAC check from <cpu-features.h>H.J. Lu1-81/+75
Remove _ISOMAC check from <cpu-features.h> since it isn't an installer header file.
2020-12-24x86: Remove the duplicated CPU_FEATURE_CPU_PH.J. Lu1-2/+0
CPU_FEATURE_CPU_P is defined in sysdeps/x86/sys/platform/x86.h. Remove the duplicated CPU_FEATURE_CPU_P in sysdeps/x86/include/cpu-features.h.