1/* $NetBSD: ssp.h,v 1.16 2023/11/15 03:14:16 christos Exp $ */
2
3/*-
4 * Copyright (c) 2006, 2011, 2023 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Christos Zoulas.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31#ifndef _SSP_SSP_H_
32#define _SSP_SSP_H_
33
34#include <sys/cdefs.h>
35
36#if !defined(__cplusplus)
37# if _FORTIFY_SOURCE > 0 && !defined(__lint__) && \
38 (__OPTIMIZE__ > 0 || defined(__clang__)) && __GNUC_PREREQ__(4, 1)
39# if _FORTIFY_SOURCE > 2 && __has_builtin(__builtin_dynamic_object_size)
40# define __SSP_FORTIFY_LEVEL 3
41# elif _FORTIFY_SOURCE > 1
42# define __SSP_FORTIFY_LEVEL 2
43# else
44# define __SSP_FORTIFY_LEVEL 1
45# endif
46# else
47# define __SSP_FORTIFY_LEVEL 0
48# endif
49#else
50# define __SSP_FORTIFY_LEVEL 0
51#endif
52
53/* __ssp_real is used by the implementation in libc */
54#if __SSP_FORTIFY_LEVEL == 0
55#define __ssp_real_(fun) fun
56#else
57#define __ssp_real_(fun) __ssp_real_ ## fun
58#endif
59#define __ssp_real(fun) __ssp_real_(fun)
60
61#ifndef __ssp_inline
62#define __ssp_inline extern __inline \
63 __attribute__((__always_inline__, __gnu_inline__))
64#endif
65
66#if __SSP_FORTIFY_LEVEL > 2
67# define __ssp_bos(ptr) __builtin_dynamic_object_size(ptr, 1)
68# define __ssp_bos0(ptr) __builtin_dynamic_object_size(ptr, 0)
69#else
70# define __ssp_bos(ptr) __builtin_object_size(ptr, __SSP_FORTIFY_LEVEL > 1)
71# define __ssp_bos0(ptr) __builtin_object_size(ptr, 0)
72#endif
73
74#define __ssp_check(buf, len, bos) \
75 if (bos(buf) != (size_t)-1 && len > bos(buf)) \
76 __chk_fail()
77#define __ssp_redirect_raw(rtype, fun, symbol, args, call, cond, bos) \
78rtype __ssp_real_(fun) args __RENAME(symbol); \
79__ssp_inline rtype fun args __RENAME(__ssp_protected_ ## fun); \
80__ssp_inline rtype fun args { \
81 if (cond) \
82 __ssp_check(__buf, __len, bos); \
83 return __ssp_real_(fun) call; \
84}
85
86#define __ssp_redirect(rtype, fun, args, call) \
87 __ssp_redirect_raw(rtype, fun, fun, args, call, 1, __ssp_bos)
88#define __ssp_redirect0(rtype, fun, args, call) \
89 __ssp_redirect_raw(rtype, fun, fun, args, call, 1, __ssp_bos0)
90
91#define __ssp_overlap(a, b, l) \
92 (((a) <= (b) && (b) < (a) + (l)) || ((b) <= (a) && (a) < (b) + (l)))
93
94__BEGIN_DECLS
95void __stack_chk_fail(void) __dead;
96void __chk_fail(void) __dead;
97__END_DECLS
98
99#endif /* _SSP_SSP_H_ */