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 #include <string.h>
10
11 /*
12 * explicit_bzero - don't let the compiler optimize away bzero
13 */
14
15 #ifndef HAVE_EXPLICIT_BZERO
16
17 #ifdef HAVE_MEMSET_S
18
19 void
explicit_bzero(void * p,size_t n)20 explicit_bzero(void *p, size_t n)
21 {
22 (void)memset_s(p, n, 0, n);
23 }
24
25 #else /* HAVE_MEMSET_S */
26
27 /*
28 * Indirect bzero through a volatile pointer to hopefully avoid
29 * dead-store optimisation eliminating the call.
30 */
31 static void* (* volatile ssh_memset)(void *, int, size_t) = memset;
32
33 void
explicit_bzero(void * p,size_t n)34 explicit_bzero(void *p, size_t n)
35 {
36 ssh_memset(p, 0, n);
37 }
38
39 #endif /* HAVE_MEMSET_S */
40
41 #endif /* HAVE_EXPLICIT_BZERO */
42