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 * Copyright (c) 2023 Jessica Clarke <jrtc27@FreeBSD.org> 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28 * SUCH DAMAGE. 29 */ 30 31 #ifndef _SYS_LINKER_SET_H_ 32 #define _SYS_LINKER_SET_H_ 33 34 #include <mach-o/dyld.h> 35 #include <mach-o/getsect.h> 36 37 /* 38 * The following macros are used to declare global sets of objects, which 39 * are collected by the linker into a `linker_set' as defined below. 40 * For Mach-O, this is done by constructing a separate section for each set. 41 */ 42 43 #define __MAKE_SET_CONST const 44 45 /* 46 * Private macros, not to be used outside this header file. 47 */ 48 49 /* 50 * The userspace address sanitizer inserts redzones around global variables, 51 * violating the assumption that linker set elements are packed. 52 */ 53 #define __NOASAN __nosanitizeaddress 54 55 #define __MAKE_SET_QV(set, sym, qv) \ 56 static void const * qv \ 57 __NOASAN \ 58 __set_##set##_sym_##sym __section("__DATA,set_" #set) \ 59 __used = &(sym) 60 #define __MAKE_SET(set, sym) __MAKE_SET_QV(set, sym, __MAKE_SET_CONST) 61 62 static inline __pure2 uint8_t * 63 __set_getsectiondata(const char *segname, const char *sectname, 64 unsigned long *size) 65 { 66 uint32_t image_count, image_index; 67 const struct mach_header *mh; 68 uint8_t *ret; 69 70 image_count = _dyld_image_count(); 71 for (image_index = 0; image_index < image_count; ++image_index) { 72 mh = _dyld_get_image_header(image_index); 73 if (mh == NULL) 74 continue; 75 76 ret = getsectiondata((const struct mach_header_64 *)mh, 77 segname, sectname, size); 78 if (ret != NULL) 79 return (ret); 80 } 81 82 return (NULL); 83 } 84 85 #define __SET_RANGE(set) ({ \ 86 unsigned long __set_size; \ 87 char *__set_data; \ 88 __set_data = __set_getsectiondata("__DATA", \ 89 "set_" #set, &__set_size); \ 90 (struct { \ 91 __CONCAT(__typeof_set_,set) **begin; \ 92 __CONCAT(__typeof_set_,set) **limit; \ 93 }){ \ 94 .begin = (__CONCAT(__typeof_set_,set) **)__set_data, \ 95 .limit = (__CONCAT(__typeof_set_,set) **)(__set_data + \ 96 __set_size) \ 97 }; \ 98 }) 99 100 /* 101 * Public macros. 102 */ 103 #define TEXT_SET(set, sym) __MAKE_SET(set, sym) 104 #define DATA_SET(set, sym) __MAKE_SET(set, sym) 105 #define DATA_WSET(set, sym) __MAKE_SET_QV(set, sym, ) 106 #define BSS_SET(set, sym) __MAKE_SET(set, sym) 107 #define ABS_SET(set, sym) __MAKE_SET(set, sym) 108 #define SET_ENTRY(set, sym) __MAKE_SET(set, sym) 109 110 /* 111 * Initialize before referring to a given linker set. 112 */ 113 #define SET_DECLARE(set, ptype) \ 114 typedef ptype __CONCAT(__typeof_set_,set) 115 116 #define SET_BEGIN(set) \ 117 (__SET_RANGE(set).begin) 118 #define SET_LIMIT(set) \ 119 (__SET_RANGE(set).limit) 120 121 /* 122 * Iterate over all the elements of a set. 123 * 124 * Sets always contain addresses of things, and "pvar" points to words 125 * containing those addresses. Thus is must be declared as "type **pvar", 126 * and the address of each set item is obtained inside the loop by "*pvar". 127 */ 128 #define SET_FOREACH(pvar, set) \ 129 for (pvar = SET_BEGIN(set); pvar < SET_LIMIT(set); pvar++) 130 131 #define SET_ITEM(set, i) \ 132 ((SET_BEGIN(set))[i]) 133 134 /* 135 * Provide a count of the items in a set. 136 */ 137 #define SET_COUNT(set) \ 138 (SET_LIMIT(set) - SET_BEGIN(set)) 139 140 #endif /* _SYS_LINKER_SET_H_ */ 141