1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 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 * $FreeBSD: releng/12.2/sys/sys/linker_set.h 331290 2018-03-21 10:26:39Z kib $ 30 */ 31 32 #ifndef _SYS_LINKER_SET_H_ 33 #define _SYS_LINKER_SET_H_ 34 35 /* 36 * The following macros are used to declare global sets of objects, which 37 * are collected by the linker into a `linker_set' as defined below. 38 * For ELF, this is done by constructing a separate segment for each set. 39 */ 40 41 #if defined(__powerpc64__) && (!defined(_CALL_ELF) || _CALL_ELF == 1) 42 /* 43 * ELFv1 pointers to functions are actaully pointers to function 44 * descriptors. 45 * 46 * Move the symbol pointer from ".text" to ".data" segment, to make 47 * the GCC compiler happy: 48 */ 49 #define __MAKE_SET_CONST 50 #else 51 #define __MAKE_SET_CONST const 52 #endif 53 54 #define __GLOBL1(sym) __asm__(".globl " #sym) 55 #define __GLOBL(sym) __GLOBL1(sym) 56 /* 57 * Function or variable should not be sanitized, i.e. by AddressSanitizer. 58 * GCC has the nosanitize attribute, but as a function attribute only, and 59 * warns on use as a variable attribute. 60 */ 61 #if __has_attribute(no_sanitize) && defined(__clang__) 62 #define __nosanitizeaddress __attribute__((no_sanitize("address"))) 63 #else 64 #define __nosanitizeaddress 65 #endif 66 67 /* 68 * Private macros, not to be used outside this header file. 69 */ 70 #ifdef __GNUCLIKE___SECTION 71 #define __MAKE_SET_QV(set, sym, qv) \ 72 __GLOBL(__CONCAT(__start_set_,set)); \ 73 __GLOBL(__CONCAT(__stop_set_,set)); \ 74 static void const * qv \ 75 __set_##set##_sym_##sym __section(".set_" #set) \ 76 __nosanitizeaddress \ 77 __used = &(sym) 78 #define __MAKE_SET(set, sym) __MAKE_SET_QV(set, sym, __MAKE_SET_CONST) 79 #else /* !__GNUCLIKE___SECTION */ 80 #error this file needs to be ported to your compiler 81 #endif /* __GNUCLIKE___SECTION */ 82 83 /* 84 * Public macros. 85 */ 86 #define TEXT_SET(set, sym) __MAKE_SET(set, sym) 87 #define DATA_SET(set, sym) __MAKE_SET(set, sym) 88 #define DATA_WSET(set, sym) __MAKE_SET_QV(set, sym, ) 89 #define BSS_SET(set, sym) __MAKE_SET(set, sym) 90 #define ABS_SET(set, sym) __MAKE_SET(set, sym) 91 #define SET_ENTRY(set, sym) __MAKE_SET(set, sym) 92 93 /* 94 * Initialize before referring to a given linker set. 95 */ 96 #define SET_DECLARE(set, ptype) \ 97 extern ptype __attribute__((__weak__)) *__CONCAT(__start_set_,set); \ 98 extern ptype __attribute__((__weak__)) *__CONCAT(__stop_set_,set) 99 100 #define SET_BEGIN(set) \ 101 (&__CONCAT(__start_set_,set)) 102 #define SET_LIMIT(set) \ 103 (&__CONCAT(__stop_set_,set)) 104 105 /* 106 * Iterate over all the elements of a set. 107 * 108 * Sets always contain addresses of things, and "pvar" points to words 109 * containing those addresses. Thus is must be declared as "type **pvar", 110 * and the address of each set item is obtained inside the loop by "*pvar". 111 */ 112 #define SET_FOREACH(pvar, set) \ 113 for (pvar = SET_BEGIN(set); pvar < SET_LIMIT(set); pvar++) 114 115 #define SET_ITEM(set, i) \ 116 ((SET_BEGIN(set))[i]) 117 118 /* 119 * Provide a count of the items in a set. 120 */ 121 #define SET_COUNT(set) \ 122 (SET_LIMIT(set) - SET_BEGIN(set)) 123 124 #endif /* _SYS_LINKER_SET_H_ */ 125