/* Initialize CPU feature data via IFUNC relocation. Copyright (C) 2015-2021 Free Software Foundation, Inc. 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 . */ #include #ifdef SHARED # include /* NB: Normally, DL_PLATFORM_INIT calls init_cpu_features to initialize CPU features in dynamic executable. But when loading ld.so inside of static executable, DL_PLATFORM_INIT isn't called and IFUNC relocation is used to call init_cpu_features. In static executable, it is called once by IFUNC relocation. In dynamic executable, it is called twice by DL_PLATFORM_INIT and by IFUNC relocation. */ extern void __x86_cpu_features (void) attribute_hidden; const void (*__x86_cpu_features_p) (void) attribute_hidden = __x86_cpu_features; void _dl_x86_init_cpu_features (void) { struct cpu_features *cpu_features = __get_cpu_features (); if (cpu_features->basic.kind == arch_kind_unknown) init_cpu_features (cpu_features); } __ifunc (__x86_cpu_features, __x86_cpu_features, NULL, void, _dl_x86_init_cpu_features); #endif #undef __x86_get_cpu_features const struct cpu_features * __x86_get_cpu_features (unsigned int max) { if (max > COMMON_CPUID_INDEX_MAX) return NULL; return &GLRO(dl_x86_cpu_features); }