/* Erasure of sensitive data, generic implementation. Copyright (C) 2016-2018 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 General Public License as published by the Free Software Foundation; either version 3 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 General Public License for more details. You should have received a copy of the GNU General Public License along with the GNU C Library; if not, see . */ /* 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. */ #if !_LIBC # include #endif #include /* 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) { #ifdef HAVE_EXPLICIT_MEMSET explicit_memset (s, 0, len); #else memset (s, '\0', len); # if defined __GNUC__ && !defined __clang__ /* Compiler barrier. */ asm volatile ("" ::: "memory"); # endif #endif }