reallocarray.c (1374B)
1 /* $OpenBSD: reallocarray.c,v 1.3 2015/09/13 08:31:47 guenther Exp $ */ 2 /* 3 * Copyright (c) 2008 Otto Moerbeek <otto@drijf.net> 4 * 5 * Permission to use, copy, modify, and distribute this software for any 6 * purpose with or without fee is hereby granted, provided that the above 7 * copyright notice and this permission notice appear in all copies. 8 * 9 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 15 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 16 */ 17 18 #include <errno.h> 19 #include <stdint.h> 20 #include <stdlib.h> 21 22 #include "reallocarray.h" 23 24 /* 25 * This is sqrt(SIZE_MAX+1), as s1*s2 <= SIZE_MAX 26 * if both s1 < MUL_NO_OVERFLOW and s2 < MUL_NO_OVERFLOW 27 */ 28 #define MUL_NO_OVERFLOW ((size_t)1 << (sizeof(size_t) * 4)) 29 30 void* reallocarray(void* optr, size_t nmemb, size_t size) { 31 if ((nmemb >= MUL_NO_OVERFLOW || size >= MUL_NO_OVERFLOW) && nmemb > 0 && 32 SIZE_MAX / nmemb < size) { 33 errno = ENOMEM; 34 return NULL; 35 } 36 return realloc(optr, size * nmemb); 37 }