uclibc-ng/libc/misc/auxvt/getauxval.c

/*  Copyright (C) 2022     Ramin Seyed Moussavi
 *  An getauxval() function compatible with the glibc auxv.h
 *  that is used by uClibc-ng.
 *
 *  This library is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Library General Public
 *  License as published by the Free Software Foundation; either
 *  version 2 of the License, or (at your option) any later version.
 *
 *  This 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
 *  Library General Public License for more details.
 *
 *  You should have received a copy of the GNU Library General Public
 *  License along with this library; if not, see
 *  <http://www.gnu.org/licenses/>.
 */

#include <errno.h>
#include <ldso.h>
#include <sys/auxv.h>

unsigned long int __getauxval (unsigned long int __type)
{
	// Requested value part of cached subset of auxiliary vector?
	if (__type < AUX_MAX_AT_ID) {
		if (_dl_auxvt[__type].a_type == __type)
			return _dl_auxvt[__type].a_un.a_val;

		__set_errno (ENOENT);
		return 0;
	}

	// Otherwise we have to iterate the auxiliary vector.
	for (ElfW(auxv_t) *entry = _dl_auxv_start; entry->a_type != AT_NULL; entry++)
		if (entry->a_type == __type)
			return entry->a_un.a_val;

	__set_errno (ENOENT);
	return 0;
}

weak_alias(__getauxval, getauxval)