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_ */