xref: /illumos-gate/usr/src/lib/libc/port/gen/memset_s.c (revision 8119dad84d6416f13557b0ba8e2aaf9064cbcfd3)
1 /*
2  * Copyright (c) 2017 Juniper Networks.  All rights reserved.
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  * 1. Redistributions of source code must retain the above copyright
8  *    notice, this list of conditions and the following disclaimer.
9  * 2. Redistributions in binary form must reproduce the above copyright
10  *    notice, this list of conditions and the following disclaimer in the
11  *    documentation and/or other materials provided with the distribution.
12  *
13  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
14  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
17  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
23  * SUCH DAMAGE.
24  */
25 
26 /*
27  * Copyright 2018 Nexenta Systems, Inc.
28  */
29 
30 #define	__STDC_WANT_LIB_EXT1__	1
31 
32 #include "lint.h"
33 
34 #include <errno.h>
35 #include <stddef.h>
36 #include <stdint.h>
37 #include <string.h>
38 
39 #include "libc.h"
40 
41 /* __memset_vp is a volatile pointer to memset() function */
42 static void *(*const volatile __memset_vp)(void *, int, size_t) = (memset);
43 
44 /* ISO/IEC 9899:2011 K.3.7.4.1 */
45 errno_t
46 memset_s(void *s, rsize_t smax, int c, rsize_t n)
47 {
48 	errno_t ret;
49 	rsize_t lim;
50 	unsigned char v;
51 
52 	ret = EINVAL;
53 	lim = n < smax ? n : smax;
54 	v = (unsigned char)c;
55 	if (s == NULL) {
56 		__throw_constraint_handler_s("memset_s: s is NULL", ret);
57 	} else if (smax > RSIZE_MAX) {
58 		__throw_constraint_handler_s("memset_s: smax > RSIZE_MAX",
59 		    ret);
60 	} else {
61 		/*
62 		 * Both s and smax are valid, fill the memory buffer using
63 		 * memset() called through a volatile pointer to guarantee
64 		 * it will not be optimized away.
65 		 */
66 		(void) (*__memset_vp)(s, v, lim);
67 
68 		if (n > RSIZE_MAX) {
69 			__throw_constraint_handler_s("memset_s: n > RSIZE_MAX",
70 			    ret);
71 		} else if (n > smax) {
72 			__throw_constraint_handler_s("memset_s: n > smax", ret);
73 		} else {
74 			ret = 0;
75 		}
76 	}
77 	return (ret);
78 }
79