kern/src/kreallocarray.c

/*
 * Copyright (c) 2008 Otto Moerbeek <otto@drijf.net>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <ros/common.h>
#include <kmalloc.h>

/*
 * This is sqrt(SIZE_MAX+1), as s1*s2 <= SIZE_MAX
 * if both s1 < MUL_NO_OVERFLOW and s2 < MUL_NO_OVERFLOW
 */
enum {
	MUL_NO_OVERFLOW = ((size_t)1 << (sizeof(size_t) * 4))
};

void *kreallocarray(void *optr, size_t nmemb, size_t size, int flags)
{
	if (((nmemb >= MUL_NO_OVERFLOW) || (size >= MUL_NO_OVERFLOW)) &&
	    (nmemb > 0) && ((SIZE_MAX / nmemb) < size)) {
		return NULL;
	}
	return krealloc(optr, size * nmemb, flags);
}

void *kmalloc_array(size_t nmemb, size_t size, int flags)
{
	if (((nmemb >= MUL_NO_OVERFLOW) || (size >= MUL_NO_OVERFLOW)) &&
	    (nmemb > 0) && ((SIZE_MAX / nmemb) < size)) {
		return NULL;
	}
	return kmalloc(size * nmemb, flags);
}