Blame string/explicit_bzero.c

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/* Erasure of sensitive data, generic implementation.
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   Copyright (C) 2016-2018 Free Software Foundation, Inc.
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   This file is part of the GNU C Library.
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   The GNU C Library is free software; you can redistribute it and/or
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   modify it under the terms of the GNU Lesser General Public
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   License as published by the Free Software Foundation; either
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   version 2.1 of the License, or (at your option) any later version.
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   The GNU C Library is distributed in the hope that it will be useful,
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   but WITHOUT ANY WARRANTY; without even the implied warranty of
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   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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   Lesser General Public License for more details.
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   You should have received a copy of the GNU Lesser General Public
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   License along with the GNU C Library; if not, see
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   <http://www.gnu.org/licenses/>.  */
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/* An assembler implementation of explicit_bzero can be created as an
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   assembler alias of an optimized bzero implementation.
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   Architecture-specific implementations also need to define
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   __explicit_bzero_chk.  */
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#include <string.h>
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/* glibc-internal users use __explicit_bzero_chk, and explicit_bzero
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   redirects to that.  */
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#undef explicit_bzero
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/* Set LEN bytes of S to 0.  The compiler will not delete a call to
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   this function, even if S is dead after the call.  */
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void
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explicit_bzero (void *s, size_t len)
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{
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  memset (s, '\0', len);
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  /* Compiler barrier.  */
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  asm volatile ("" ::: "memory");
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}