96 lines
2.7 KiB
C
96 lines
2.7 KiB
C
/* $NetBSD: reallocarr.c,v 1.5 2015/08/20 22:27:49 kamil Exp $ */
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/*-
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* Copyright (c) 2015 Joerg Sonnenberger <joerg@NetBSD.org>.
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in
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* the documentation and/or other materials provided with the
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* distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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* COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
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* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
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* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
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* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
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* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#if HAVE_NBTOOL_CONFIG_H
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#include "nbtool_config.h"
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#endif
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#include <sys/cdefs.h>
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__RCSID("$NetBSD: reallocarr.c,v 1.5 2015/08/20 22:27:49 kamil Exp $");
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#include "namespace.h"
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#include <errno.h>
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/* Old POSIX has SIZE_MAX in limits.h */
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#include <limits.h>
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#include <stdint.h>
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#include <stdlib.h>
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#include <string.h>
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#ifdef _LIBC
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#ifdef __weak_alias
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__weak_alias(reallocarr, _reallocarr)
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#endif
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#endif
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#define SQRT_SIZE_MAX (((size_t)1) << (sizeof(size_t) * CHAR_BIT / 2))
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#if !HAVE_REALLOCARR
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int
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reallocarr(void *ptr, size_t number, size_t size)
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{
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int saved_errno, result;
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void *optr;
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void *nptr;
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saved_errno = errno;
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memcpy(&optr, ptr, sizeof(ptr));
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if (number == 0 || size == 0) {
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free(optr);
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nptr = NULL;
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memcpy(ptr, &nptr, sizeof(ptr));
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errno = saved_errno;
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return 0;
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}
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/*
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* Try to avoid division here.
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*
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* It isn't possible to overflow during multiplication if neither
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* operand uses any of the most significant half of the bits.
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*/
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if (__predict_false((number|size) >= SQRT_SIZE_MAX &&
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number > SIZE_MAX / size)) {
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errno = saved_errno;
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return EOVERFLOW;
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}
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nptr = realloc(optr, number * size);
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if (__predict_false(nptr == NULL)) {
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result = errno;
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} else {
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result = 0;
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memcpy(ptr, &nptr, sizeof(ptr));
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}
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errno = saved_errno;
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return result;
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}
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#endif
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