1/*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 1999 John D. Polstra
5 * Copyright (c) 1999,2001 Peter Wemm <peter@FreeBSD.org>
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 */
29
30#ifndef _SYS_LINKER_SET_H_
31#define _SYS_LINKER_SET_H_
32
33/*
34 * The following macros are used to declare global sets of objects, which
35 * are collected by the linker into a `linker_set' as defined below.
36 * For ELF, this is done by constructing a separate segment for each set.
37 */
38
39#if defined(__powerpc64__) && (!defined(_CALL_ELF) || _CALL_ELF == 1)
40/*
41 * ELFv1 pointers to functions are actaully pointers to function
42 * descriptors.
43 *
44 * Move the symbol pointer from ".text" to ".data" segment, to make
45 * the GCC compiler happy:
46 */
47#define	__MAKE_SET_CONST
48#else
49#define	__MAKE_SET_CONST const
50#endif
51
52/*
53 * Private macros, not to be used outside this header file.
54 */
55
56/*
57 * The userspace address sanitizer inserts redzones around global variables,
58 * violating the assumption that linker set elements are packed.
59 */
60#ifdef _KERNEL
61#define	__NOASAN
62#else
63#define	__NOASAN	__nosanitizeaddress
64#endif
65
66#define __MAKE_SET_QV(set, sym, qv)			\
67	__WEAK(__CONCAT(__start_set_,set));		\
68	__WEAK(__CONCAT(__stop_set_,set));		\
69	static void const * qv				\
70	__NOASAN					\
71	__set_##set##_sym_##sym __section("set_" #set)	\
72	__used = &(sym)
73#define __MAKE_SET(set, sym)	__MAKE_SET_QV(set, sym, __MAKE_SET_CONST)
74
75/*
76 * Public macros.
77 */
78#define TEXT_SET(set, sym)	__MAKE_SET(set, sym)
79#define DATA_SET(set, sym)	__MAKE_SET(set, sym)
80#define DATA_WSET(set, sym)	__MAKE_SET_QV(set, sym, )
81#define BSS_SET(set, sym)	__MAKE_SET(set, sym)
82#define ABS_SET(set, sym)	__MAKE_SET(set, sym)
83#define SET_ENTRY(set, sym)	__MAKE_SET(set, sym)
84
85/*
86 * Initialize before referring to a given linker set.
87 */
88#define SET_DECLARE(set, ptype)					\
89	extern ptype __weak_symbol *__CONCAT(__start_set_,set);	\
90	extern ptype __weak_symbol *__CONCAT(__stop_set_,set)
91
92#define SET_BEGIN(set)							\
93	(&__CONCAT(__start_set_,set))
94#define SET_LIMIT(set)							\
95	(&__CONCAT(__stop_set_,set))
96
97/*
98 * Iterate over all the elements of a set.
99 *
100 * Sets always contain addresses of things, and "pvar" points to words
101 * containing those addresses.  Thus is must be declared as "type **pvar",
102 * and the address of each set item is obtained inside the loop by "*pvar".
103 */
104#define SET_FOREACH(pvar, set)						\
105	for (pvar = SET_BEGIN(set); pvar < SET_LIMIT(set); pvar++)
106
107#define SET_ITEM(set, i)						\
108	((SET_BEGIN(set))[i])
109
110/*
111 * Provide a count of the items in a set.
112 */
113#define SET_COUNT(set)							\
114	(SET_LIMIT(set) - SET_BEGIN(set))
115
116#endif	/* _SYS_LINKER_SET_H_ */
117