1 /* $OpenBSD: reallocarray.c,v 1.2 2014/12/08 03:45:00 bcook 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 /* OPENBSD ORIGINAL: lib/libc/stdlib/reallocarray.c */ 19 20 #include "includes.h" 21 #ifndef HAVE_REALLOCARRAY 22 23 #include <sys/types.h> 24 #include <errno.h> 25 #ifdef HAVE_STDINT_H 26 #include <stdint.h> 27 #endif 28 #include <stdlib.h> 29 30 /* 31 * This is sqrt(SIZE_MAX+1), as s1*s2 <= SIZE_MAX 32 * if both s1 < MUL_NO_OVERFLOW and s2 < MUL_NO_OVERFLOW 33 */ 34 #define MUL_NO_OVERFLOW ((size_t)1 << (sizeof(size_t) * 4)) 35 36 void * 37 reallocarray(void *optr, size_t nmemb, size_t size) 38 { 39 if ((nmemb >= MUL_NO_OVERFLOW || size >= MUL_NO_OVERFLOW) && 40 nmemb > 0 && SIZE_MAX / nmemb < size) { 41 errno = ENOMEM; 42 return NULL; 43 } 44 return realloc(optr, size * nmemb); 45 } 46 #endif /* HAVE_REALLOCARRAY */ 47