1 /*- 2 * Copyright (c) 1997 Doug Rabson 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 * 26 * $Id: linker.h,v 1.4 1998/08/12 08:44:21 dfr Exp $ 27 */ 28 29 #ifndef _SYS_LINKER_H_ 30 #define _SYS_LINKER_H_ 31 32 #ifdef KERNEL 33 34 #ifdef MALLOC_DECLARE 35 MALLOC_DECLARE(M_LINKER); 36 #endif 37 38 /* 39 * Object representing a file which has been loaded by the linker. 40 */ 41 typedef struct linker_file* linker_file_t; 42 typedef TAILQ_HEAD(, linker_file) linker_file_list_t; 43 44 typedef caddr_t linker_sym_t; /* opaque symbol */ 45 46 /* 47 * expanded out linker_sym_t 48 */ 49 typedef struct linker_symval { 50 const char* name; 51 caddr_t value; 52 size_t size; 53 } linker_symval_t; 54 55 struct linker_file_ops { 56 /* 57 * Lookup a symbol in the file's symbol table. If the symbol is 58 * not found then return ENOENT, otherwise zero. If the symbol 59 * found is a common symbol, return with *address set to zero and 60 * *size set to the size of the common space required. Otherwise 61 * set *address the value of the symbol. 62 */ 63 int (*lookup_symbol)(linker_file_t, const char* name, 64 linker_sym_t* sym); 65 66 void (*symbol_values)(linker_file_t, linker_sym_t, 67 linker_symval_t*); 68 69 int (*search_symbol)(linker_file_t, caddr_t value, 70 linker_sym_t* sym, long* diffp); 71 72 /* 73 * Unload a file, releasing dependancies and freeing storage. 74 */ 75 void (*unload)(linker_file_t); 76 }; 77 78 struct common_symbol { 79 STAILQ_ENTRY(common_symbol) link; 80 char* name; 81 caddr_t address; 82 }; 83 84 struct linker_file { 85 int refs; /* reference count */ 86 int userrefs; /* modload(2) count */ 87 TAILQ_ENTRY(linker_file) link; /* list of all loaded files */ 88 char* filename; /* file which was loaded */ 89 int id; /* unique id */ 90 caddr_t address; /* load address */ 91 size_t size; /* size of file */ 92 int ndeps; /* number of dependancies */ 93 linker_file_t* deps; /* list of dependancies */ 94 STAILQ_HEAD(, common_symbol) common; /* list of common symbols */ 95 TAILQ_HEAD(, module) modules; /* modules in this file */ 96 void* priv; /* implementation data */ 97 98 struct linker_file_ops* ops; 99 }; 100 101 /* 102 * Object implementing a class of file (a.out, elf, etc.) 103 */ 104 typedef struct linker_class *linker_class_t; 105 typedef TAILQ_HEAD(, linker_class) linker_class_list_t; 106 107 struct linker_class_ops { 108 /* 109 * Load a file, returning the new linker_file_t in *result. If 110 * the class does not recognise the file type, zero should be 111 * returned, without modifying *result. If the file is 112 * recognised, the file should be loaded, *result set to the new 113 * file and zero returned. If some other error is detected an 114 * appropriate errno should be returned. 115 */ 116 int (*load_file)(const char* filename, linker_file_t* result); 117 }; 118 119 struct linker_class { 120 TAILQ_ENTRY(linker_class) link; /* list of all file classes */ 121 const char* desc; /* description (e.g. "a.out") */ 122 void* priv; /* implementation data */ 123 124 struct linker_class_ops *ops; 125 }; 126 127 /* 128 * The file which is currently loading. Used to register modules with 129 * the files which contain them. 130 */ 131 extern linker_file_t linker_current_file; 132 133 /* 134 * Add a new file class to the linker. 135 */ 136 int linker_add_class(const char* desc, void* priv, 137 struct linker_class_ops* ops); 138 139 /* 140 * Load a file, trying each file class until one succeeds. 141 */ 142 int linker_load_file(const char* filename, linker_file_t* result); 143 144 /* 145 * Find a currently loaded file given its filename. 146 */ 147 linker_file_t linker_find_file_by_name(const char* filename); 148 149 /* 150 * Find a currently loaded file given its file id. 151 */ 152 linker_file_t linker_find_file_by_id(int fileid); 153 154 /* 155 * Called from a class handler when a file is laoded. 156 */ 157 linker_file_t linker_make_file(const char* filename, void* priv, 158 struct linker_file_ops* ops); 159 160 /* 161 * Unload a file, freeing up memory. 162 */ 163 int linker_file_unload(linker_file_t file); 164 165 /* 166 * Add a dependancy to a file. 167 */ 168 int linker_file_add_dependancy(linker_file_t file, linker_file_t dep); 169 170 /* 171 * Lookup a symbol in a file. If deps is TRUE, look in dependancies 172 * if not found in file. 173 */ 174 caddr_t linker_file_lookup_symbol(linker_file_t file, const char* name, 175 int deps); 176 177 /* 178 * Module information subtypes 179 */ 180 #define MODINFO_NAME 0x0000 181 #define MODINFO_TYPE 0x0001 182 #define MODINFO_ADDR 0x0002 183 #define MODINFO_SIZE 0x0003 184 #define MODINFO_METADATA 0x8000 185 186 #define MODINFOMD_AOUTEXEC 0x0001 /* a.out exec header */ 187 #define MODINFOMD_ELFHDR 0x0002 /* ELF header */ 188 #define MODINFOMD_NOCOPY 0x8000 /* don't copy this metadata to the kernel */ 189 190 #define KLD_IDENT_SYMNAME "kld_identifier_" 191 #define MODINFOMD_KLDIDENT (MODINFOMD_NOCOPY | 0x4000) 192 #define MODINFOMD_KLDDEP (MODINFOMD_NOCOPY | 0x4001) 193 194 #ifdef KLD_DEBUG 195 196 extern int kld_debug; 197 #define KLD_DEBUG_FILE 1 /* file load/unload */ 198 #define KLD_DEBUG_SYM 2 /* symbol lookup */ 199 200 #define KLD_DPF(cat, args) \ 201 do { \ 202 if (KLD_debug & KLD_DEBUG_##cat) printf args; \ 203 } while (0) 204 205 #else 206 207 #define KLD_DPF(cat, args) 208 209 #endif 210 211 #endif /* KERNEL */ 212 213 struct kld_file_stat { 214 int version; /* set to sizeof(linker_file_stat) */ 215 char name[MAXPATHLEN]; 216 int refs; 217 int id; 218 caddr_t address; /* load address */ 219 size_t size; /* size in bytes */ 220 }; 221 222 #ifndef KERNEL 223 224 #include <sys/cdefs.h> 225 226 __BEGIN_DECLS 227 int kldload(const char* file); 228 int kldunload(int fileid); 229 int kldfind(const char* file); 230 int kldnext(int fileid); 231 int kldstat(int fileid, struct kld_file_stat* stat); 232 int kldfirstmod(int fileid); 233 __END_DECLS 234 235 #endif 236 237 #endif /* !_SYS_LINKER_H_ */ 238