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