openssh/openbsd-compat/explicit_bzero.c
Damien Miller 3d673d103b - (djm) [openbsd-compat/explicit_bzero.c] implement explicit_bzero()
using memset_s() where possible; improve fallback to indirect bzero
   via a volatile pointer to give it more of a chance to avoid being
   optimised away.
2014-08-27 06:32:01 +10:00

41 lines
728 B
C

/* OPENBSD ORIGINAL: lib/libc/string/explicit_bzero.c */
/* $OpenBSD: explicit_bzero.c,v 1.1 2014/01/22 21:06:45 tedu Exp $ */
/*
* Public domain.
* Written by Ted Unangst
*/
#include "includes.h"
/*
* explicit_bzero - don't let the compiler optimize away bzero
*/
#ifndef HAVE_EXPLICIT_BZERO
#ifdef HAVE_MEMSET_S
void
explicit_bzero(void *p, size_t n)
{
(void)memset_s(p, n, 0, n);
}
#else /* HAVE_MEMSET_S */
/*
* Indirect bzero through a volatile pointer to hopefully avoid
* dead-store optimisation eliminating the call.
*/
static void (* volatile ssh_bzero)(void *, size_t) = bzero;
void
explicit_bzero(void *p, size_t n)
{
ssh_bzero(p, n);
}
#endif /* HAVE_MEMSET_S */
#endif /* HAVE_EXPLICIT_BZERO */