morpheus-base

morpheus base system
git clone git://git.2f30.org/morpheus-base.git
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reallocarray.c (1356B)


      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 <sys/types.h>
     19 #include <errno.h>
     20 #include <stdint.h>
     21 #include <stdlib.h>
     22 
     23 /*
     24  * This is sqrt(SIZE_MAX+1), as s1*s2 <= SIZE_MAX
     25  * if both s1 < MUL_NO_OVERFLOW and s2 < MUL_NO_OVERFLOW
     26  */
     27 #define MUL_NO_OVERFLOW	(1UL << (sizeof(size_t) * 4))
     28 
     29 void *
     30 reallocarray(void *optr, size_t nmemb, size_t size)
     31 {
     32 	if ((nmemb >= MUL_NO_OVERFLOW || size >= MUL_NO_OVERFLOW) &&
     33 	    nmemb > 0 && SIZE_MAX / nmemb < size) {
     34 		errno = ENOMEM;
     35 		return NULL;
     36 	}
     37 	return realloc(optr, size * nmemb);
     38 }