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 * $FreeBSD: src/sys/sys/linker.h,v 1.17.2.1 2002/03/11 01:13:53 dd Exp $ 27 * $DragonFly: src/sys/sys/linker.h,v 1.10 2006/12/23 00:27:03 swildner Exp $ 28 */ 29 30 #ifndef _SYS_LINKER_H_ 31 #define _SYS_LINKER_H_ 32 33 #ifndef _SYS_TYPES_H_ 34 #include <sys/types.h> 35 #endif 36 #ifndef _SYS_PARAM_H_ 37 #include <sys/param.h> 38 #endif 39 40 #ifdef _KERNEL 41 42 #ifndef _SYS_QUEUE_H_ 43 #include <sys/queue.h> 44 #endif 45 #ifndef _MACHINE_ELF_H_ 46 #include <machine/elf.h> 47 #endif 48 49 #ifdef MALLOC_DECLARE 50 MALLOC_DECLARE(M_LINKER); 51 #endif 52 53 /* 54 * Object representing a file which has been loaded by the linker. 55 */ 56 typedef struct linker_file* linker_file_t; 57 typedef TAILQ_HEAD(, linker_file) linker_file_list_t; 58 59 typedef caddr_t linker_sym_t; /* opaque symbol */ 60 typedef c_caddr_t c_linker_sym_t; /* const opaque symbol */ 61 62 /* 63 * expanded out linker_sym_t 64 */ 65 typedef struct linker_symval { 66 const char* name; 67 caddr_t value; 68 size_t size; 69 } linker_symval_t; 70 71 struct linker_file_ops { 72 /* 73 * Lookup a symbol in the file's symbol table. If the symbol is 74 * not found then return ENOENT, otherwise zero. If the symbol 75 * found is a common symbol, return with *address set to zero and 76 * *size set to the size of the common space required. Otherwise 77 * set *address the value of the symbol. 78 */ 79 int (*lookup_symbol)(linker_file_t, const char* name, 80 c_linker_sym_t* sym); 81 82 int (*symbol_values)(linker_file_t, c_linker_sym_t, 83 linker_symval_t*); 84 85 int (*search_symbol)(linker_file_t, caddr_t value, 86 c_linker_sym_t* sym, long* diffp); 87 88 /* 89 * Unload a file, releasing dependancies and freeing storage. 90 */ 91 void (*unload)(linker_file_t); 92 93 int (*lookup_set)(linker_file_t, const char *name, 94 void ***firstp, void ***lastp, int *countp); 95 }; 96 97 struct common_symbol { 98 STAILQ_ENTRY(common_symbol) link; 99 char* name; 100 caddr_t address; 101 }; 102 103 struct linker_file { 104 int refs; /* reference count */ 105 int userrefs; /* kldload(2) count */ 106 int flags; 107 #define LINKER_FILE_LINKED 0x1 /* file has been fully linked */ 108 TAILQ_ENTRY(linker_file) link; /* list of all loaded files */ 109 char* filename; /* file which was loaded */ 110 int id; /* unique id */ 111 caddr_t address; /* load address */ 112 size_t size; /* size of file */ 113 int ndeps; /* number of dependancies */ 114 linker_file_t* deps; /* list of dependancies */ 115 STAILQ_HEAD(, common_symbol) common; /* list of common symbols */ 116 TAILQ_HEAD(, module) modules; /* modules in this file */ 117 void* priv; /* implementation data */ 118 119 struct linker_file_ops* ops; 120 }; 121 122 /* 123 * Object implementing a class of file (a.out, elf, etc.) 124 */ 125 typedef struct linker_class *linker_class_t; 126 typedef TAILQ_HEAD(, linker_class) linker_class_list_t; 127 128 struct linker_class_ops { 129 /* 130 * Load a file, returning the new linker_file_t in *result. If 131 * the class does not recognise the file type, zero should be 132 * returned, without modifying *result. If the file is 133 * recognised, the file should be loaded, *result set to the new 134 * file and zero returned. If some other error is detected an 135 * appropriate errno should be returned. 136 */ 137 int (*load_file)(const char* filename, linker_file_t* result); 138 }; 139 140 struct linker_class { 141 TAILQ_ENTRY(linker_class) link; /* list of all file classes */ 142 const char* desc; /* description (e.g. "a.out") */ 143 void* priv; /* implementation data */ 144 145 struct linker_class_ops *ops; 146 }; 147 148 /* 149 * The file which is currently loading. Used to register modules with 150 * the files which contain them. 151 */ 152 extern linker_file_t linker_current_file; 153 154 /* 155 * The "file" for the kernel. 156 */ 157 extern linker_file_t linker_kernel_file; 158 159 /* 160 * Add a new file class to the linker. 161 */ 162 int linker_add_class(const char* _desc, void* _priv, 163 struct linker_class_ops* _ops); 164 165 /* 166 * Load a file, trying each file class until one succeeds. 167 */ 168 int linker_load_file(const char* _filename, linker_file_t* _result); 169 170 /* 171 * Find a currently loaded file given its filename. 172 */ 173 linker_file_t linker_find_file_by_name(const char* _filename); 174 175 /* 176 * Find a currently loaded file given its file id. 177 */ 178 linker_file_t linker_find_file_by_id(int _fileid); 179 180 /* 181 * Called from a class handler when a file is laoded. 182 */ 183 linker_file_t linker_make_file(const char* _filename, void* _priv, 184 struct linker_file_ops* _ops); 185 186 /* 187 * Unload a file, freeing up memory. 188 */ 189 int linker_file_unload(linker_file_t _file); 190 191 /* 192 * Add a dependancy to a file. 193 */ 194 int linker_file_add_dependancy(linker_file_t _file, linker_file_t _dep); 195 196 /* 197 * Lookup a symbol in a file. If deps is TRUE, look in dependancies 198 * if not found in file. The symbol's value is returned in the 199 * caddr_t. An error is returned, 0 if no error occured. 200 */ 201 int linker_file_lookup_symbol(linker_file_t _file, const char* _name, 202 int _deps, caddr_t *); 203 204 205 /* 206 * Lookup a linker set in a file. Return pointers to the first entry, 207 * last + 1, and count of entries. Use: for (p = start; p < stop; p++) {} 208 * void *start is really: "struct yoursetmember ***start;" 209 */ 210 int linker_file_lookup_set(linker_file_t _file, const char *_name, 211 void *_start, void *_stop, int *_count); 212 213 /* 214 * Search the linker path for the module. Return the full pathname in 215 * a malloc'ed buffer. 216 */ 217 char *linker_search_path(const char *_filename); 218 219 /* 220 * DDB Helpers, tuned specifically for ddb/db_kld.c 221 */ 222 int linker_ddb_lookup(const char *_symstr, c_linker_sym_t *_sym); 223 int linker_ddb_search_symbol(caddr_t _value, c_linker_sym_t *_sym, 224 long *_diffp); 225 int linker_ddb_symbol_values(c_linker_sym_t _sym, linker_symval_t *_symval); 226 227 228 #endif /* _KERNEL */ 229 230 /* 231 * Module information subtypes 232 */ 233 #define MODINFO_END 0x0000 /* End of list */ 234 #define MODINFO_NAME 0x0001 /* Name of module (string) */ 235 #define MODINFO_TYPE 0x0002 /* Type of module (string) */ 236 #define MODINFO_ADDR 0x0003 /* Loaded address */ 237 #define MODINFO_SIZE 0x0004 /* Size of module */ 238 #define MODINFO_EMPTY 0x0005 /* Has been deleted */ 239 #define MODINFO_ARGS 0x0006 /* Parameters string */ 240 #define MODINFO_METADATA 0x8000 /* Module-specfic */ 241 242 #define MODINFOMD_AOUTEXEC 0x0001 /* a.out exec header */ 243 #define MODINFOMD_ELFHDR 0x0002 /* ELF header */ 244 #define MODINFOMD_SSYM 0x0003 /* start of symbols */ 245 #define MODINFOMD_ESYM 0x0004 /* end of symbols */ 246 #define MODINFOMD_DYNAMIC 0x0005 /* _DYNAMIC pointer */ 247 #define MODINFOMD_ENVP 0x0006 /* (from 5.x) envp[] */ 248 #define MODINFOMD_HOWTO 0x0007 /* (from 5.x) boothowto */ 249 #define MODINFOMD_KERNEND 0x0008 /* (from 5.x) kernend */ 250 #define MODINFOMD_NOCOPY 0x8000 /* don't copy this metadata to the kernel */ 251 252 #define MODINFOMD_DEPLIST (0x4001 | MODINFOMD_NOCOPY) /* depends on */ 253 254 #ifdef _KERNEL 255 #define MD_FETCH(mdp, info, type) ({ \ 256 type *__p; \ 257 __p = (type *)preload_search_info((mdp), MODINFO_METADATA | (info)); \ 258 __p ? *__p : 0; \ 259 }) 260 #endif 261 262 #define LINKER_HINTS_VERSION 1 /* linker.hints file version */ 263 264 #ifdef _KERNEL 265 266 /* 267 * Module lookup 268 */ 269 extern caddr_t preload_metadata; 270 extern caddr_t preload_search_by_name(const char *); 271 extern caddr_t preload_search_by_type(const char *); 272 extern caddr_t preload_search_next_name(caddr_t); 273 extern caddr_t preload_search_info(caddr_t, int); 274 extern void preload_delete_name(const char *); 275 extern void preload_bootstrap_relocate(vm_offset_t); 276 extern struct mod_metadata *find_mod_metadata(const char *); 277 278 279 #ifdef KLD_DEBUG 280 281 extern int kld_debug; 282 #define KLD_DEBUG_FILE 1 /* file load/unload */ 283 #define KLD_DEBUG_SYM 2 /* symbol lookup */ 284 285 #define KLD_DPF(cat, args) \ 286 do { \ 287 if (kld_debug & KLD_DEBUG_##cat) kprintf args; \ 288 } while (0) 289 290 #else 291 292 #define KLD_DPF(cat, args) 293 294 #endif 295 296 /* Support functions */ 297 int elf_reloc(linker_file_t, const void *, int, const char *); 298 299 /* values for type */ 300 #define ELF_RELOC_REL 1 301 #define ELF_RELOC_RELA 2 302 303 #endif /* _KERNEL */ 304 305 struct kld_file_stat { 306 int version; /* set to sizeof(linker_file_stat) */ 307 char name[MAXPATHLEN]; 308 int refs; 309 int id; 310 caddr_t address; /* load address */ 311 size_t size; /* size in bytes */ 312 }; 313 314 struct kld_sym_lookup { 315 int version; /* set to sizeof(struct kld_sym_lookup) */ 316 const char *symname; /* Symbol name we are looking up */ 317 u_long symvalue; 318 size_t symsize; 319 }; 320 321 #define KLDSYM_LOOKUP 1 322 323 #ifndef _KERNEL 324 325 #ifndef _SYS_CDEFS_H_ 326 #include <sys/cdefs.h> 327 #endif 328 329 __BEGIN_DECLS 330 int kldload(const char *); 331 int kldunload(int); 332 int kldfind(const char *); 333 int kldnext(int); 334 int kldstat(int, struct kld_file_stat *); 335 int kldfirstmod(int); 336 int kldsym(int, int, void *); 337 __END_DECLS 338 339 #endif 340 341 #endif /* !_SYS_LINKER_H_ */ 342