glibc/sysdeps/unix/sysv/linux/dl-parse_auxv.h
Florian Weimer 73fc4e28b9 Linux: Consolidate auxiliary vector parsing (redo)
And optimize it slightly.

This is commit 8c8510ab27 revised.

In _dl_aux_init in elf/dl-support.c, use an explicit loop
and -fno-tree-loop-distribute-patterns to avoid memset.

Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
2022-02-28 11:50:41 +01:00

62 lines
2.2 KiB
C

/* Parse the Linux auxiliary vector.
Copyright (C) 1995-2022 Free Software Foundation, Inc.
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
<https://www.gnu.org/licenses/>. */
#include <elf.h>
#include <entry.h>
#include <fpu_control.h>
#include <ldsodefs.h>
#include <link.h>
typedef ElfW(Addr) dl_parse_auxv_t[AT_MINSIGSTKSZ + 1];
/* Copy the auxiliary vector into AUXV_VALUES and set up GLRO
variables. */
static inline
void _dl_parse_auxv (ElfW(auxv_t) *av, dl_parse_auxv_t auxv_values)
{
auxv_values[AT_ENTRY] = (ElfW(Addr)) ENTRY_POINT;
auxv_values[AT_PAGESZ] = EXEC_PAGESIZE;
auxv_values[AT_FPUCW] = _FPU_DEFAULT;
/* NB: Default to a constant CONSTANT_MINSIGSTKSZ. */
_Static_assert (__builtin_constant_p (CONSTANT_MINSIGSTKSZ),
"CONSTANT_MINSIGSTKSZ is constant");
auxv_values[AT_MINSIGSTKSZ] = CONSTANT_MINSIGSTKSZ;
for (; av->a_type != AT_NULL; av++)
if (av->a_type <= AT_MINSIGSTKSZ)
auxv_values[av->a_type] = av->a_un.a_val;
GLRO(dl_pagesize) = auxv_values[AT_PAGESZ];
__libc_enable_secure = auxv_values[AT_SECURE];
GLRO(dl_platform) = (void *) auxv_values[AT_PLATFORM];
GLRO(dl_hwcap) = auxv_values[AT_HWCAP];
GLRO(dl_hwcap2) = auxv_values[AT_HWCAP2];
GLRO(dl_clktck) = auxv_values[AT_CLKTCK];
GLRO(dl_fpu_control) = auxv_values[AT_FPUCW];
_dl_random = (void *) auxv_values[AT_RANDOM];
GLRO(dl_minsigstacksize) = auxv_values[AT_MINSIGSTKSZ];
GLRO(dl_sysinfo_dso) = (void *) auxv_values[AT_SYSINFO_EHDR];
#ifdef NEED_DL_SYSINFO
if (GLRO(dl_sysinfo_dso) != NULL)
GLRO(dl_sysinfo) = auxv_values[AT_SYSINFO];
#endif
DL_PLATFORM_AUXV
}