1 /* $OpenBSD: reallocarray.c,v 1.1 2014/05/08 21:43:49 deraadt 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 "config.h" 19 #include <sys/types.h> 20 #include <errno.h> 21 #ifdef HAVE_STDINT_H 22 #include <stdint.h> 23 #endif 24 #include <limits.h> 25 #include <stdlib.h> 26 27 /* 28 * This is sqrt(SIZE_MAX+1), as s1*s2 <= SIZE_MAX 29 * if both s1 < MUL_NO_OVERFLOW and s2 < MUL_NO_OVERFLOW 30 */ 31 #define MUL_NO_OVERFLOW ((size_t)1 << (sizeof(size_t) * 4)) 32 33 void * 34 reallocarray(void *optr, size_t nmemb, size_t size) 35 { 36 if ((nmemb >= MUL_NO_OVERFLOW || size >= MUL_NO_OVERFLOW) && 37 nmemb > 0 && SIZE_MAX / nmemb < size) { 38 errno = ENOMEM; 39 return NULL; 40 } 41 return realloc(optr, size * nmemb); 42 } 43