1/* Generic implementation of __explicit_bzero_chk.
2 Copyright (C) 1991-2023 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <https://www.gnu.org/licenses/>. */
18
19/* This is the generic definition of __explicit_bzero_chk. The
20 __explicit_bzero_chk symbol is used as the implementation of
21 explicit_bzero throughout glibc. If this file is overriden by an
22 architecture, both __explicit_bzero_chk and
23 __explicit_bzero_chk_internal have to be defined (the latter not as
24 an IFUNC). */
25
26#include <string.h>
27
28void
29__explicit_bzero_chk (void *dst, size_t len, size_t dstlen)
30{
31 /* Inline __memset_chk to avoid a PLT reference to __memset_chk. */
32 if (__glibc_unlikely (dstlen < len))
33 __chk_fail ();
34 memset (dst, '\0', len);
35 /* Compiler barrier. */
36 asm volatile ("" ::: "memory");
37}
38
39/* libc-internal references use the hidden
40 __explicit_bzero_chk_internal symbol. This is necessary if
41 __explicit_bzero_chk is implemented as an IFUNC because some
42 targets do not support hidden references to IFUNC symbols. */
43strong_alias (__explicit_bzero_chk, __explicit_bzero_chk_internal)
44