glibc/string/explicit_bzero.c

39 lines
1.4 KiB
C

/* Erasure of sensitive data, generic implementation.
Copyright (C) 2016-2023 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/>. */
/* An assembler implementation of explicit_bzero can be created as an
assembler alias of an optimized bzero implementation.
Architecture-specific implementations also need to define
__explicit_bzero_chk. */
#include <string.h>
/* glibc-internal users use __explicit_bzero_chk, and explicit_bzero
redirects to that. */
#undef explicit_bzero
/* Set LEN bytes of S to 0. The compiler will not delete a call to
this function, even if S is dead after the call. */
void
explicit_bzero (void *s, size_t len)
{
memset (s, '\0', len);
/* Compiler barrier. */
asm volatile ("" ::: "memory");
}