/* Erasure of sensitive data, generic implementation.
Copyright (C) 2016-2022 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.
+ This file 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,
+ This file 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.
+ 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
- <https://www.gnu.org/licenses/>. */
+ You should have received a copy of the GNU Lesser General Public License
+ along with this program. If not, see <https://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. */
-
-#if !_LIBC
-# include <config.h>
-#endif
-
-/* memset_s need this define */
-#if HAVE_MEMSET_S
-# define __STDC_WANT_LIB_EXT1__ 1
-#endif
+#include <config.h>
#include <string.h>
-#if defined _WIN32 && !defined __CYGWIN__
-# define WIN32_LEAN_AND_MEAN
-# include <windows.h>
-#endif
-
-#if _LIBC
-/* glibc-internal users use __explicit_bzero_chk, and explicit_bzero
- redirects to that. */
-# undef explicit_bzero
-#endif
-
/* 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)
{
-#if defined _WIN32 && !defined __CYGWIN__
- (void) SecureZeroMemory (s, len);
-#elif HAVE_EXPLICIT_MEMSET
- explicit_memset (s, '\0', len);
-#elif HAVE_MEMSET_S
- (void) memset_s (s, len, '\0', len);
-#elif defined __GNUC__ && !defined __clang__
- memset (s, '\0', len);
- /* Compiler barrier. */
- __asm__ volatile ("" ::: "memory");
-#elif defined __clang__
- memset (s, '\0', len);
- /* Compiler barrier. */
- /* With asm ("" ::: "memory") LLVM analyzes uses of 's' and finds that the
- whole thing is dead and eliminates it. Use 'g' to work around this
- problem. See <https://bugs.llvm.org/show_bug.cgi?id=15495#c11>. */
- __asm__ volatile ("" : : "g"(s) : "memory");
-#else
- /* Invoke memset through a volatile function pointer. This defeats compiler
- optimizations. */
- void * (* const volatile volatile_memset) (void *, int, size_t) = memset;
- (void) volatile_memset (s, '\0', len);
-#endif
+ memset_explicit (s, 0, len);
}