glibc/sysdeps/x86/dl-get-cpu-features.c
Florian Weimer b62928f907 x86: In ld.so, diagnose missing APX support in APX-only builds
At this point, this is mainly a tool for testing the early ld.so
CPU compatibility diagnostics: GCC uses the new instructions in most
functions, so it's easy to spot if some of the early code is not
built correctly.

Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
2024-04-25 17:20:28 +02:00

87 lines
3.2 KiB
C

/* Initialize CPU feature data via IFUNC relocation.
Copyright (C) 2015-2024 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
<https://www.gnu.org/licenses/>. */
#include <ldsodefs.h>
#ifdef SHARED
# include <cpu-features.c>
# include <gcc-macros.h>
/* 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;
void (*const __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);
# if IS_IN (rtld)
/* See isa-level.c. */
# if defined GCCMACRO__GCC_HAVE_SYNC_COMPARE_AND_SWAP_16 \
&& defined HAVE_X86_LAHF_SAHF && defined GCCMACRO__POPCNT__ \
&& defined GCCMACRO__SSE3__ && defined GCCMACRO__SSSE3__ \
&& defined GCCMACRO__SSE4_1__ && defined GCCMACRO__SSE4_2__
if (!(cpu_features->isa_1 & GNU_PROPERTY_X86_ISA_1_V2))
_dl_fatal_printf ("\
Fatal glibc error: CPU does not support x86-64-v%d\n", 2);
# if defined GCCMACRO__AVX__ && defined GCCMACRO__AVX2__ \
&& defined GCCMACRO__F16C__ && defined GCCMACRO__FMA__ \
&& defined GCCMACRO__LZCNT__ && defined HAVE_X86_MOVBE
if (!(cpu_features->isa_1 & GNU_PROPERTY_X86_ISA_1_V3))
_dl_fatal_printf ("\
Fatal glibc error: CPU does not support x86-64-v%d\n", 3);
# if defined GCCMACRO__AVX512F__ && defined GCCMACRO__AVX512BW__ \
&& defined GCCMACRO__AVX512CD__ && defined GCCMACRO__AVX512DQ__ \
&& defined GCCMACRO__AVX512VL__
if (!(cpu_features->isa_1 & GNU_PROPERTY_X86_ISA_1_V4))
_dl_fatal_printf ("\
Fatal glibc error: CPU does not support x86-64-v%d\n", 4);
# endif /* ISA level 4 */
# endif /* ISA level 3 */
# endif /* ISA level 2 */
# ifdef GCCMACRO__APX_F__
if (!CPU_FEATURE_USABLE_P (cpu_features, APX_F))
_dl_fatal_printf ("\
Fatal glibc error: CPU does not support APX\n");
# endif
# endif /* IS_IN (rtld) */
}
}
__ifunc (__x86_cpu_features, __x86_cpu_features, NULL, void,
_dl_x86_init_cpu_features);
#endif
#undef _dl_x86_get_cpu_features
const struct cpu_features *
_dl_x86_get_cpu_features (void)
{
return &GLRO(dl_x86_cpu_features);
}