glibc/misc/getauxval.c
Brooks Moses b9ab448f98 Add error reporting (via errno) to getauxval().
[BZ 15846] As discussed in the recent thread on my $EXEC_ORIGIN patch
and in BZ 15846, getauxval() presently has no unambiguous way of
reporting an error condition.  It currently returns zero on error, but
this may also be a valid result for some auxv entries.  As there is no
clear invalid result for all current and future auxv entries, this patch
sets errno (following a suggestion in the BZ entry).

This version of the patch also adds documentation and tests for the
value-not-found conditions in getauxval().
2013-12-18 10:52:37 -08:00

42 lines
1.2 KiB
C

/* Copyright (C) 2012-2013 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
<http://www.gnu.org/licenses/>. */
#include <sys/auxv.h>
#include <errno.h>
#include <ldsodefs.h>
unsigned long int
__getauxval (unsigned long int type)
{
ElfW(auxv_t) *p;
if (type == AT_HWCAP)
return GLRO(dl_hwcap);
else if (type == AT_HWCAP2)
return GLRO(dl_hwcap2);
for (p = GLRO(dl_auxv); p->a_type != AT_NULL; p++)
if (p->a_type == type)
return p->a_un.a_val;
__set_errno (ENOENT);
return 0;
}
weak_alias (__getauxval, getauxval)