glibc/debug/explicit_bzero_chk.c

45 lines
1.8 KiB
C

/* Generic implementation of __explicit_bzero_chk.
Copyright (C) 1991-2016 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Torbjorn Granlund (tege@sics.se).
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/>. */
/* This is the generic definition of __explicit_bzero_chk. The
__explicit_bzero_chk symbol is used as the implementation of
explicit_bzero throughout glibc. If this file is overriden by an
architecture, both __explicit_bzero_chk and
__explicit_bzero_chk_internal have to be defined (the latter not as
an IFUNC). */
#include <string.h>
void
__explicit_bzero_chk (void *dst, size_t len, size_t dstlen)
{
/* Inline __memset_chk to avoid a PLT reference to __memset_chk. */
if (__glibc_unlikely (dstlen < len))
__chk_fail ();
memset (dst, '\0', len);
/* Compiler barrier. */
asm volatile ("" ::: "memory");
}
/* libc-internal references use the hidden
__explicit_bzero_chk_internal symbol. This is necessary if
__explicit_bzero_chk is implemented as an IFUNC because some
targets do not support hidden references to IFUNC symbols. */
strong_alias (__explicit_bzero_chk, __explicit_bzero_chk_internal)