reallocarray.c (1306B)
1/* 2 * Copyright (c) 2008 Otto Moerbeek <otto@drijf.net> 3 * 4 * Permission to use, copy, modify, and distribute this software for any 5 * purpose with or without fee is hereby granted, provided that the above 6 * copyright notice and this permission notice appear in all copies. 7 * 8 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 9 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 10 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 11 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 12 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 13 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 14 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 15 */ 16 17#include <sys/types.h> 18#include <errno.h> 19#include <stdint.h> 20#include <stdlib.h> 21 22#include "compat.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 (1UL << (sizeof(size_t) * 4)) 29 30void * 31reallocarray(void *optr, size_t nmemb, size_t size) 32{ 33 if ((nmemb >= MUL_NO_OVERFLOW || size >= MUL_NO_OVERFLOW) && 34 nmemb > 0 && SIZE_MAX / nmemb < size) { 35 errno = ENOMEM; 36 return NULL; 37 } 38 return realloc(optr, size * nmemb); 39}