glibc/misc/getauxval.c
Florian Weimer 562ef5e69e misc: Add internal __getauxval2 function
The explicit error return value (without in-band signaling) avoids
complicated steps to detect errors based on whether errno has been
updated.

Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
2020-10-27 16:34:37 +01:00

68 lines
1.6 KiB
C

/* Copyright (C) 2012-2020 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 <sys/auxv.h>
#include <errno.h>
#include <ldsodefs.h>
#include <stdbool.h>
bool
__getauxval2 (unsigned long int type, unsigned long int *result)
{
#ifdef HAVE_AUX_VECTOR
ElfW(auxv_t) *p;
#endif
if (type == AT_HWCAP)
{
*result = GLRO(dl_hwcap);
return true;
}
else if (type == AT_HWCAP2)
{
*result = GLRO(dl_hwcap2);
return true;
}
#ifdef HAVE_AUX_VECTOR
for (p = GLRO(dl_auxv); p->a_type != AT_NULL; p++)
if (p->a_type == type)
{
*result = p->a_un.a_val;
return true;
}
#endif
return false;
}
libc_hidden_def (__getauxval2)
unsigned long int
__getauxval (unsigned long int type)
{
unsigned long int result;
if (__getauxval2 (type, &result))
return result;
__set_errno (ENOENT);
return 0;
}
weak_alias (__getauxval, getauxval)
libc_hidden_def (__getauxval)