calog/vendor/postgres/src/port/explicit_bzero.c

57 lines
1.1 KiB
C
Vendored

/*-------------------------------------------------------------------------
*
* explicit_bzero.c
*
* Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
*
* IDENTIFICATION
* src/port/explicit_bzero.c
*
*-------------------------------------------------------------------------
*/
#define __STDC_WANT_LIB_EXT1__ 1 /* needed to access memset_s() */
#include "c.h"
#if HAVE_DECL_MEMSET_S
void
explicit_bzero(void *buf, size_t len)
{
(void) memset_s(buf, len, 0, len);
}
#elif defined(WIN32)
void
explicit_bzero(void *buf, size_t len)
{
(void) SecureZeroMemory(buf, len);
}
#else
/*
* Indirect call through a volatile pointer to hopefully avoid dead-store
* optimisation eliminating the call. (Idea taken from OpenSSH.) We can't
* assume bzero() is present either, so for simplicity we define our own.
*/
static void
bzero2(void *buf, size_t len)
{
memset(buf, 0, len);
}
static void (*volatile bzero_p) (void *, size_t) = bzero2;
void
explicit_bzero(void *buf, size_t len)
{
bzero_p(buf, len);
}
#endif