explicit_bzero.c revision 295367 
1/* OPENBSD ORIGINAL: lib/libc/string/explicit_bzero.c */
2/*	$OpenBSD: explicit_bzero.c,v 1.1 2014/01/22 21:06:45 tedu Exp $ */
3/*
4 * Public domain.
5 * Written by Ted Unangst
6 */
7
8#include "includes.h"
9
10/*
11 * explicit_bzero - don't let the compiler optimize away bzero
12 */
13
14#ifndef HAVE_EXPLICIT_BZERO
15
16#ifdef HAVE_MEMSET_S
17
18void
19explicit_bzero(void *p, size_t n)
20{
21	(void)memset_s(p, n, 0, n);
22}
23
24#else /* HAVE_MEMSET_S */
25
26/*
27 * Indirect bzero through a volatile pointer to hopefully avoid
28 * dead-store optimisation eliminating the call.
29 */
30static void (* volatile ssh_bzero)(void *, size_t) = bzero;
31
32void
33explicit_bzero(void *p, size_t n)
34{
35	ssh_bzero(p, n);
36}
37
38#endif /* HAVE_MEMSET_S */
39
40#endif /* HAVE_EXPLICIT_BZERO */
41