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glibc/sysdeps/unix/sysv/linux/aarch64/dl-procinfo.h

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aarch64: Allow overriding HWCAP_CPUID feature check using HWCAP_MASK Now that LD_HWCAP_MASK (or glibc.tune.hwcap_mask) is read early enough to influence cpu feature check in aarch64, use it to influence multiarch selection. Setting LD_HWCAP_MASK such that it clears HWCAP_CPUID will now disable multiarch for the binary. HWCAP_CPUID is also now set in HWCAP_IMPORTANT so that it is set by default. With this patch, this feature is only usable with dyanmically linked binaries because LD_HWCAP_MASK is not read for static binaries. A future patch fixes that. * sysdeps/unix/sysv/linux/aarch64/cpu-features.c (init_cpu_features): Use glibc.tune.hwcap_mask. * sysdeps/unix/sysv/linux/aarch64/dl-procinfo.h: New file.
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/* Processor capability information handling macros - aarch64 version.
Update copyright dates with scripts/update-copyrights
2024-01-01 18:12:26 +00:00
Copyright (C) 2017-2024 Free Software Foundation, Inc.
aarch64: Allow overriding HWCAP_CPUID feature check using HWCAP_MASK Now that LD_HWCAP_MASK (or glibc.tune.hwcap_mask) is read early enough to influence cpu feature check in aarch64, use it to influence multiarch selection. Setting LD_HWCAP_MASK such that it clears HWCAP_CPUID will now disable multiarch for the binary. HWCAP_CPUID is also now set in HWCAP_IMPORTANT so that it is set by default. With this patch, this feature is only usable with dyanmically linked binaries because LD_HWCAP_MASK is not read for static binaries. A future patch fixes that. * sysdeps/unix/sysv/linux/aarch64/cpu-features.c (init_cpu_features): Use glibc.tune.hwcap_mask. * sysdeps/unix/sysv/linux/aarch64/dl-procinfo.h: New file.
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This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
Prefer https to http for gnu.org and fsf.org URLs Also, change sources.redhat.com to sourceware.org. This patch was automatically generated by running the following shell script, which uses GNU sed, and which avoids modifying files imported from upstream: sed -ri ' s,(http|ftp)(://(.*\.)?(gnu|fsf|sourceware)\.org($|[^.]|\.[^a-z])),https\2,g s,(http|ftp)(://(.*\.)?)sources\.redhat\.com($|[^.]|\.[^a-z]),https\2sourceware.org\4,g ' \ $(find $(git ls-files) -prune -type f \ ! -name '*.po' \ ! -name 'ChangeLog*' \ ! -path COPYING ! -path COPYING.LIB \ ! -path manual/fdl-1.3.texi ! -path manual/lgpl-2.1.texi \ ! -path manual/texinfo.tex ! -path scripts/config.guess \ ! -path scripts/config.sub ! -path scripts/install-sh \ ! -path scripts/mkinstalldirs ! -path scripts/move-if-change \ ! -path INSTALL ! -path locale/programs/charmap-kw.h \ ! -path po/libc.pot ! -path sysdeps/gnu/errlist.c \ ! '(' -name configure \ -execdir test -f configure.ac -o -f configure.in ';' ')' \ ! '(' -name preconfigure \ -execdir test -f preconfigure.ac ';' ')' \ -print) and then by running 'make dist-prepare' to regenerate files built from the altered files, and then executing the following to cleanup: chmod a+x sysdeps/unix/sysv/linux/riscv/configure # Omit irrelevant whitespace and comment-only changes, # perhaps from a slightly-different Autoconf version. git checkout -f \ sysdeps/csky/configure \ sysdeps/hppa/configure \ sysdeps/riscv/configure \ sysdeps/unix/sysv/linux/csky/configure # Omit changes that caused a pre-commit check to fail like this: # remote: *** error: sysdeps/powerpc/powerpc64/ppc-mcount.S: trailing lines git checkout -f \ sysdeps/powerpc/powerpc64/ppc-mcount.S \ sysdeps/unix/sysv/linux/s390/s390-64/syscall.S # Omit change that caused a pre-commit check to fail like this: # remote: *** error: sysdeps/sparc/sparc64/multiarch/memcpy-ultra3.S: last line does not end in newline git checkout -f sysdeps/sparc/sparc64/multiarch/memcpy-ultra3.S
2019-09-07 05:40:42 +00:00
<https://www.gnu.org/licenses/>. */
aarch64: Allow overriding HWCAP_CPUID feature check using HWCAP_MASK Now that LD_HWCAP_MASK (or glibc.tune.hwcap_mask) is read early enough to influence cpu feature check in aarch64, use it to influence multiarch selection. Setting LD_HWCAP_MASK such that it clears HWCAP_CPUID will now disable multiarch for the binary. HWCAP_CPUID is also now set in HWCAP_IMPORTANT so that it is set by default. With this patch, this feature is only usable with dyanmically linked binaries because LD_HWCAP_MASK is not read for static binaries. A future patch fixes that. * sysdeps/unix/sysv/linux/aarch64/cpu-features.c (init_cpu_features): Use glibc.tune.hwcap_mask. * sysdeps/unix/sysv/linux/aarch64/dl-procinfo.h: New file.
2017-04-25 17:09:17 +00:00
#ifndef _DL_PROCINFO_H
#define _DL_PROCINFO_H 1
#include <sys/auxv.h>
aarch64: Add hwcap string routines Add support for routines in dl-procinfo.h to show string versions of HWCAP entries when a program is invoked with the LD_SHOW_AUXV environment variable set and also to aid in path resolution for ldconfig. * sysdeps/unix/sysv/linux/aarch64/dl-procinfo.c (_dl_aarch64_cap_flags): New array. * sysdeps/unix/sysv/linux/aarch64/dl-procinfo.h (_dl_hwcap_string, _dl_string_hwcap, _dl_procinfo): Implement functions.
2017-05-25 10:04:55 +00:00
#include <unistd.h>
#include <ldsodefs.h>
#include <sysdep.h>
aarch64: Allow overriding HWCAP_CPUID feature check using HWCAP_MASK Now that LD_HWCAP_MASK (or glibc.tune.hwcap_mask) is read early enough to influence cpu feature check in aarch64, use it to influence multiarch selection. Setting LD_HWCAP_MASK such that it clears HWCAP_CPUID will now disable multiarch for the binary. HWCAP_CPUID is also now set in HWCAP_IMPORTANT so that it is set by default. With this patch, this feature is only usable with dyanmically linked binaries because LD_HWCAP_MASK is not read for static binaries. A future patch fixes that. * sysdeps/unix/sysv/linux/aarch64/cpu-features.c (init_cpu_features): Use glibc.tune.hwcap_mask. * sysdeps/unix/sysv/linux/aarch64/dl-procinfo.h: New file.
2017-04-25 17:09:17 +00:00
/* We cannot provide a general printing function. */
[AArch64] Fix out of bound array access regression Partially revert ea01a4da219011f4a4db97eef3c5bfc2f6e8fc6b "aarch64: Add hwcap string routines" because _dl_procinfo cannot be future proof and avoid oob access in _dl_hwcap_string.
2017-07-17 08:58:29 +00:00
#define _dl_procinfo(type, word) -1
aarch64: Add hwcap string routines Add support for routines in dl-procinfo.h to show string versions of HWCAP entries when a program is invoked with the LD_SHOW_AUXV environment variable set and also to aid in path resolution for ldconfig. * sysdeps/unix/sysv/linux/aarch64/dl-procinfo.c (_dl_aarch64_cap_flags): New array. * sysdeps/unix/sysv/linux/aarch64/dl-procinfo.h (_dl_hwcap_string, _dl_string_hwcap, _dl_procinfo): Implement functions.
2017-05-25 10:04:55 +00:00
aarch64: Remove HWCAP_CPUID from HWCAP_IMPORTANT This partially reverts commit f82e9672ad89ea1ef40bbe1af71478e255e87c5e Author: Siddhesh Poyarekar <siddhesh@sourceware.org> aarch64: Allow overriding HWCAP_CPUID feature check using HWCAP_MASK The idea was to make it possible to disable cpuid based ifunc resolution in glibc by changing the hwcap mask which the user could already control. However the hwcap mask has an orthogonal role: it specifies additional library search paths for the dynamic linker. So "cpuid" got added to the search paths when it was set in the default mask (HWCAP_IMPORTANT), which is not useful behaviour, the hwcap masking should not be reused in the cpu features code. Meanwhile there is a tunable to set the cpu explicitly so it is possible to disable the cpuid based dispatch without using a hwcap mask: GLIBC_TUNABLES=glibc.tune.cpu=generic * sysdeps/unix/sysv/linux/aarch64/cpu-features.c (init_cpu_features): Use dl_hwcap without masking. * sysdeps/unix/sysv/linux/aarch64/dl-procinfo.h (HWCAP_IMPORTANT): Remove HWCAP_CPUID.
2018-06-28 13:43:07 +00:00
/* No additional library search paths. */
aarch64: add HWCAP_ATOMICS to HWCAP_IMPORTANT This enables searching shared libraries in atomics/ when the hardware supports LSE atomics of armv8.1 so one can provide optimized variants of libraries in a portable way. LSE atomics does not affect library abi, the new instructions can interoperate with old ones. I considered the earlier comments on the patch https://sourceware.org/ml/libc-alpha/2018-04/msg00400.html https://sourceware.org/ml/libc-alpha/2018-04/msg00625.html It turns out that the way glibc dynamic linker decides on the search path is not very flexible: it wants to use hwcap bits and associated strings. So some targets reuse hwcap bits for glibc internal purposes to affect the search logic. But hwcap is an interface with the kernel, glibc should not allocate bits in it for its internal logic as that limits future hwcap extensions and confusing to users who expect to see hwcap bits in ifunc resolvers. Instead of rewriting the dynamic linker path logic (which affects all targets) this patch just uses the existing mechanism, however this means that the path name has to be the hwcap name "atomics" and cannot be changed to something more meaningful to users. It is hard to tell how much performance benefit this can give, in principle armv8.1 atomics can be better optimized in the hardware, so it can make a difference for synchronization heavy code. On some systems such multilib setup may be the only viable way to get optimized libraries used. * sysdeps/unix/sysv/linux/aarch64/dl-procinfo.h (HWCAP_IMPORTANT): Add HWCAP_ATOMICS.
2018-06-28 14:30:32 +00:00
#define HWCAP_IMPORTANT HWCAP_ATOMICS
aarch64: Allow overriding HWCAP_CPUID feature check using HWCAP_MASK Now that LD_HWCAP_MASK (or glibc.tune.hwcap_mask) is read early enough to influence cpu feature check in aarch64, use it to influence multiarch selection. Setting LD_HWCAP_MASK such that it clears HWCAP_CPUID will now disable multiarch for the binary. HWCAP_CPUID is also now set in HWCAP_IMPORTANT so that it is set by default. With this patch, this feature is only usable with dyanmically linked binaries because LD_HWCAP_MASK is not read for static binaries. A future patch fixes that. * sysdeps/unix/sysv/linux/aarch64/cpu-features.c (init_cpu_features): Use glibc.tune.hwcap_mask. * sysdeps/unix/sysv/linux/aarch64/dl-procinfo.h: New file.
2017-04-25 17:09:17 +00:00
[AArch64] Fix out of bound array access regression Partially revert ea01a4da219011f4a4db97eef3c5bfc2f6e8fc6b "aarch64: Add hwcap string routines" because _dl_procinfo cannot be future proof and avoid oob access in _dl_hwcap_string.
2017-07-17 08:58:29 +00:00
static inline const char *
__attribute__ ((unused))
_dl_hwcap_string (int idx)
{
return (unsigned)idx < _DL_HWCAP_COUNT ? GLRO(dl_aarch64_cap_flags)[idx] : "";
};
aarch64: Allow overriding HWCAP_CPUID feature check using HWCAP_MASK Now that LD_HWCAP_MASK (or glibc.tune.hwcap_mask) is read early enough to influence cpu feature check in aarch64, use it to influence multiarch selection. Setting LD_HWCAP_MASK such that it clears HWCAP_CPUID will now disable multiarch for the binary. HWCAP_CPUID is also now set in HWCAP_IMPORTANT so that it is set by default. With this patch, this feature is only usable with dyanmically linked binaries because LD_HWCAP_MASK is not read for static binaries. A future patch fixes that. * sysdeps/unix/sysv/linux/aarch64/cpu-features.c (init_cpu_features): Use glibc.tune.hwcap_mask. * sysdeps/unix/sysv/linux/aarch64/dl-procinfo.h: New file.
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/* There're no platforms to filter out. */
#define _DL_HWCAP_PLATFORM 0
#define _dl_string_platform(str) (-1)
#endif /* dl-procinfo.h */
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