| /* 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 Lesser General Public |
| License as published by the Free Software Foundation; either |
| version 2.1 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 |
| Lesser General Public License for more details. |
| |
| You should have received a copy of the GNU Lesser General Public |
| License along with the GNU C Library; if not, see |
| <http://www.gnu.org/licenses/>. */ |
| |
| /* 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. */ |
| |
| #include <string.h> |
| |
| /* 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) |
| { |
| memset (s, '\0', len); |
| /* Compiler barrier. */ |
| asm volatile ("" ::: "memory"); |
| } |