2 * Copyright (c) 2020 The FreeBSD Foundation
4 * This software was developed by Emmanuel Vadot under sponsorship
5 * from the FreeBSD Foundation.
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 #ifndef __LINUX_OVERFLOW_H__
32 #define __LINUX_OVERFLOW_H__
34 #include <sys/stdint.h>
35 #include <sys/types.h>
38 #define __has_builtin(x) 0
41 #if __has_builtin(__builtin_add_overflow)
42 #define check_add_overflow(a, b, c) \
43 __builtin_add_overflow(a, b, c)
45 #error "Compiler does not support __builtin_add_overflow"
48 #if __has_builtin(__builtin_mul_overflow)
49 #define check_mul_overflow(a, b, c) \
50 __builtin_mul_overflow(a, b, c)
53 array_size(size_t x, size_t y)
57 if (__builtin_mul_overflow(x, y, &retval))
62 #error "Compiler does not support __builtin_mul_overflow"
65 #endif /* __LINUX_OVERFLOW_H__ */