1 /* $NetBSD: reallocarr.c,v 1.5 2015/08/20 22:27:49 kamil Exp $ */ 2 3 /*- 4 * Copyright (c) 2015 Joerg Sonnenberger <joerg@NetBSD.org>. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in 15 * the documentation and/or other materials provided with the 16 * distribution. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 19 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 20 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 21 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 22 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 23 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING, 24 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 25 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 26 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 27 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 28 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32 #if HAVE_NBTOOL_CONFIG_H 33 #include "nbtool_config.h" 34 #endif 35 36 #include <sys/cdefs.h> 37 __RCSID("$NetBSD: reallocarr.c,v 1.5 2015/08/20 22:27:49 kamil Exp $"); 38 39 #include "namespace.h" 40 #include <errno.h> 41 /* Old POSIX has SIZE_MAX in limits.h */ 42 #include <limits.h> 43 #include <stdint.h> 44 #include <stdlib.h> 45 #include <string.h> 46 47 #ifdef _LIBC 48 #ifdef __weak_alias 49 __weak_alias(reallocarr, _reallocarr) 50 #endif 51 #endif 52 53 #define SQRT_SIZE_MAX (((size_t)1) << (sizeof(size_t) * CHAR_BIT / 2)) 54 55 #if !HAVE_REALLOCARR 56 int 57 reallocarr(void *ptr, size_t number, size_t size) 58 { 59 int saved_errno, result; 60 void *optr; 61 void *nptr; 62 63 saved_errno = errno; 64 memcpy(&optr, ptr, sizeof(ptr)); 65 if (number == 0 || size == 0) { 66 free(optr); 67 nptr = NULL; 68 memcpy(ptr, &nptr, sizeof(ptr)); 69 errno = saved_errno; 70 return 0; 71 } 72 73 /* 74 * Try to avoid division here. 75 * 76 * It isn't possible to overflow during multiplication if neither 77 * operand uses any of the most significant half of the bits. 78 */ 79 if (__predict_false((number|size) >= SQRT_SIZE_MAX && 80 number > SIZE_MAX / size)) { 81 errno = saved_errno; 82 return EOVERFLOW; 83 } 84 85 nptr = realloc(optr, number * size); 86 if (__predict_false(nptr == NULL)) { 87 result = errno; 88 } else { 89 result = 0; 90 memcpy(ptr, &nptr, sizeof(ptr)); 91 } 92 errno = saved_errno; 93 return result; 94 } 95 #endif 96