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 */ 28 29 #ifndef _SYS_LINKER_H_ 30 #define _SYS_LINKER_H_ 31 32 #ifndef _SYS_TYPES_H_ 33 #include <sys/types.h> 34 #endif 35 #ifndef _SYS_PARAM_H_ 36 #include <sys/param.h> 37 #endif 38 39 #ifdef _KERNEL 40 41 #ifndef _SYS_QUEUE_H_ 42 #include <sys/queue.h> 43 #endif 44 #include <machine/elf.h> 45 46 #include <sys/module.h> 47 48 #ifdef MALLOC_DECLARE 49 MALLOC_DECLARE(M_LINKER); 50 #endif 51 52 /* 53 * Object representing a file which has been loaded by the linker. 54 */ 55 typedef struct linker_file* linker_file_t; 56 typedef TAILQ_HEAD(, linker_file) linker_file_list_t; 57 58 typedef caddr_t linker_sym_t; /* opaque symbol */ 59 typedef c_caddr_t c_linker_sym_t; /* const opaque symbol */ 60 61 /* 62 * expanded out linker_sym_t 63 */ 64 typedef struct linker_symval { 65 const char* name; 66 caddr_t value; 67 size_t size; 68 } linker_symval_t; 69 70 struct linker_file_ops { 71 /* 72 * Lookup a symbol in the file's symbol table. If the symbol is 73 * not found then return ENOENT, otherwise zero. If the symbol 74 * found is a common symbol, return with *address set to zero and 75 * *size set to the size of the common space required. Otherwise 76 * set *address the value of the symbol. 77 */ 78 int (*lookup_symbol)(linker_file_t, const char* name, 79 c_linker_sym_t* sym); 80 81 int (*symbol_values)(linker_file_t, c_linker_sym_t, 82 linker_symval_t*); 83 84 int (*search_symbol)(linker_file_t, caddr_t value, 85 c_linker_sym_t* sym, long* diffp); 86 87 /* 88 * Completes the loading task started in preload_file. 89 */ 90 int (*preload_finish)(linker_file_t); 91 92 /* 93 * Unload a file, releasing dependancies and freeing storage. 94 */ 95 void (*unload)(linker_file_t); 96 97 int (*lookup_set)(linker_file_t, const char *name, 98 void ***firstp, void ***lastp, int *countp); 99 }; 100 101 struct common_symbol { 102 STAILQ_ENTRY(common_symbol) link; 103 char* name; 104 caddr_t address; 105 }; 106 107 struct linker_file { 108 int refs; /* reference count */ 109 int userrefs; /* kldload(2) count */ 110 int flags; 111 #define LINKER_FILE_LINKED 0x1 /* file has been fully linked */ 112 TAILQ_ENTRY(linker_file) link; /* list of all loaded files */ 113 char* filename; /* file which was loaded */ 114 char* pathname; /* file name with full path */ 115 int id; /* unique id */ 116 caddr_t address; /* load address */ 117 size_t size; /* size of file */ 118 int ndeps; /* number of dependancies */ 119 linker_file_t* deps; /* list of dependancies */ 120 STAILQ_HEAD(, common_symbol) common; /* list of common symbols */ 121 TAILQ_HEAD(, module) modules; /* modules in this file */ 122 TAILQ_ENTRY(linker_file) loaded; /* preload dependency support */ 123 void* priv; /* implementation data */ 124 125 struct linker_file_ops* ops; 126 }; 127 128 /* 129 * Object implementing a class of file (a.out, elf, etc.) 130 */ 131 typedef struct linker_class *linker_class_t; 132 typedef TAILQ_HEAD(, linker_class) linker_class_list_t; 133 134 struct linker_class_ops { 135 /* 136 * Load a file, returning the new linker_file_t in *result. If 137 * the class does not recognise the file type, zero should be 138 * returned, without modifying *result. If the file is 139 * recognised, the file should be loaded, *result set to the new 140 * file and zero returned. If some other error is detected an 141 * appropriate errno should be returned. 142 */ 143 int (*load_file)(const char *filename, linker_file_t *result); 144 /* 145 * Same as load_file, but does not load dependencies. Necessary 146 * for tentatively loading (loader-)preloaded modules. 147 */ 148 int (*preload_file)(const char *filename, linker_file_t *result); 149 }; 150 151 struct linker_class { 152 TAILQ_ENTRY(linker_class) link; /* list of all file classes */ 153 const char* desc; /* description (e.g. "a.out") */ 154 void* priv; /* implementation data */ 155 156 struct linker_class_ops *ops; 157 }; 158 159 /* 160 * Function type used when iterating over the list of linker files. 161 */ 162 typedef int linker_predicate_t(linker_file_t, void *); 163 164 /* 165 * The file which is currently loading. Used to register modules with 166 * the files which contain them. 167 */ 168 extern linker_file_t linker_current_file; 169 170 /* 171 * The "file" for the kernel. 172 */ 173 extern linker_file_t linker_kernel_file; 174 175 /* 176 * Add a new file class to the linker. 177 */ 178 int linker_add_class(const char* _desc, void* _priv, 179 struct linker_class_ops* _ops); 180 181 /* 182 * Load a file, trying each file class until one succeeds. 183 */ 184 int linker_load_file(const char *_filename, linker_file_t *_result); 185 186 /* 187 * Find a currently loaded file given its filename. 188 */ 189 linker_file_t linker_find_file_by_name(const char* _filename); 190 191 /* 192 * Find a currently loaded file given its file id. 193 */ 194 linker_file_t linker_find_file_by_id(int _fileid); 195 196 /* 197 * Called from a class handler when a file is laoded. 198 */ 199 linker_file_t linker_make_file(const char* _filename, void* _priv, 200 struct linker_file_ops* _ops); 201 202 /* 203 * Unload a file, freeing up memory. 204 */ 205 int linker_file_unload(linker_file_t _file); 206 207 /* 208 * Add a dependancy to a file. 209 */ 210 void linker_file_add_dependancy(linker_file_t _file, linker_file_t _dep); 211 212 int linker_load_dependencies(linker_file_t lf); 213 214 /* 215 * Iterate over all of the currently loaded linker files calling the 216 * predicate function while the function returns 0. Returns the value 217 * returned by the last predicate function. 218 */ 219 int linker_file_foreach(linker_predicate_t *_predicate, void *_context); 220 221 /* 222 * Lookup a symbol in a file. If deps is TRUE, look in dependancies 223 * if not found in file. The symbol's value is returned in the 224 * caddr_t. An error is returned, 0 if no error occured. 225 */ 226 int linker_file_lookup_symbol(linker_file_t _file, const char* _name, 227 int _deps, caddr_t *); 228 229 230 /* 231 * Lookup a linker set in a file. Return pointers to the first entry, 232 * last + 1, and count of entries. Use: for (p = start; p < stop; p++) {} 233 * void *start is really: "struct yoursetmember ***start;" 234 */ 235 int linker_file_lookup_set(linker_file_t _file, const char *_name, 236 void *_start, void *_stop, int *_count); 237 238 /* 239 * Search the linker path for the module. Return the full pathname in 240 * a malloc'ed buffer. 241 */ 242 char *linker_search_path(const char *_filename); 243 244 int linker_reference_module(const char *modname, struct mod_depend *verinfo, 245 linker_file_t *retult); 246 int linker_release_module(const char *modname, struct mod_depend *verinfo, 247 linker_file_t lf); 248 249 /* 250 * DDB Helpers, tuned specifically for ddb/db_kld.c 251 */ 252 int linker_ddb_lookup(const char *_symstr, c_linker_sym_t *_sym); 253 int linker_ddb_search_symbol(caddr_t _value, c_linker_sym_t *_sym, 254 long *_diffp); 255 int linker_ddb_symbol_values(c_linker_sym_t _sym, linker_symval_t *_symval); 256 257 258 #endif /* _KERNEL */ 259 260 /* 261 * Module information subtypes 262 */ 263 #define MODINFO_END 0x0000 /* End of list */ 264 #define MODINFO_NAME 0x0001 /* Full path name of module (string) */ 265 #define MODINFO_TYPE 0x0002 /* Type of module (string) */ 266 #define MODINFO_ADDR 0x0003 /* Loaded address */ 267 #define MODINFO_SIZE 0x0004 /* Size of module */ 268 #define MODINFO_EMPTY 0x0005 /* Has been deleted */ 269 #define MODINFO_ARGS 0x0006 /* Parameters string */ 270 #define MODINFO_METADATA 0x8000 /* Module-specfic */ 271 272 #define MODINFOMD_AOUTEXEC 0x0001 /* a.out exec header */ 273 #define MODINFOMD_ELFHDR 0x0002 /* ELF header */ 274 #define MODINFOMD_SSYM 0x0003 /* start of symbols */ 275 #define MODINFOMD_ESYM 0x0004 /* end of symbols */ 276 #define MODINFOMD_DYNAMIC 0x0005 /* _DYNAMIC pointer */ 277 #define MODINFOMD_ENVP 0x0006 /* (from 5.x) envp[] */ 278 #define MODINFOMD_HOWTO 0x0007 /* (from 5.x) boothowto */ 279 #define MODINFOMD_KERNEND 0x0008 /* (from 5.x) kernend */ 280 #define MODINFOMD_SHDR 0x0009 /* section header table */ 281 #define MODINFOMD_FW_HANDLE 0x000a /* Firmware dependent handle */ 282 #define MODINFOMD_NOCOPY 0x8000 /* don't copy this metadata to the kernel */ 283 284 #define MODINFOMD_DEPLIST (0x4001 | MODINFOMD_NOCOPY) /* depends on */ 285 286 #ifdef _KERNEL 287 #define MD_FETCH(mdp, info, type) ({ \ 288 type *__p; \ 289 __p = (type *)preload_search_info((mdp), MODINFO_METADATA | (info)); \ 290 __p ? *__p : 0; \ 291 }) 292 #endif 293 294 #define LINKER_HINTS_VERSION 1 /* linker.hints file version */ 295 296 #ifdef _KERNEL 297 298 /* 299 * Module lookup 300 */ 301 extern caddr_t preload_metadata; 302 caddr_t preload_search_by_name(const char *); 303 caddr_t preload_search_by_type(const char *); 304 caddr_t preload_search_next_name(caddr_t); 305 caddr_t preload_search_info(caddr_t, int); 306 void preload_delete_name(const char *); 307 void preload_bootstrap_relocate(vm_offset_t); 308 extern struct mod_metadata *find_mod_metadata(const char *); 309 310 #ifdef KLD_DEBUG 311 312 extern int kld_debug; 313 #define KLD_DEBUG_FILE 1 /* file load/unload */ 314 #define KLD_DEBUG_SYM 2 /* symbol lookup */ 315 316 #define KLD_DPF(cat, args) \ 317 do { \ 318 if (kld_debug & KLD_DEBUG_##cat) kprintf args; \ 319 } while (0) 320 321 #else 322 323 #define KLD_DPF(cat, args) 324 325 #endif 326 327 typedef int elf_lookup_fn(linker_file_t, Elf_Size, int, Elf_Addr *); 328 329 /* Support functions */ 330 int elf_reloc(linker_file_t, Elf_Addr, const void *, int, elf_lookup_fn); 331 int elf_reloc_local(linker_file_t, Elf_Addr, const void *, int, elf_lookup_fn); 332 Elf_Addr elf_relocaddr(linker_file_t, Elf_Addr); 333 334 /* values for type */ 335 #define ELF_RELOC_REL 1 336 #define ELF_RELOC_RELA 2 337 338 #endif /* _KERNEL */ 339 340 struct kld_file_stat { 341 int version; /* set to sizeof(linker_file_stat) */ 342 char name[MAXPATHLEN]; 343 char pathname[MAXPATHLEN]; 344 int refs; 345 int id; 346 caddr_t address; /* load address */ 347 size_t size; /* size in bytes */ 348 }; 349 350 struct kld_sym_lookup { 351 int version; /* set to sizeof(struct kld_sym_lookup) */ 352 const char *symname; /* Symbol name we are looking up */ 353 u_long symvalue; 354 size_t symsize; 355 }; 356 357 #define KLDSYM_LOOKUP 1 358 359 #ifndef _KERNEL 360 361 #ifndef _SYS_CDEFS_H_ 362 #include <sys/cdefs.h> 363 #endif 364 365 __BEGIN_DECLS 366 int kldload(const char *); 367 int kldunload(int); 368 int kldfind(const char *); 369 int kldnext(int); 370 int kldstat(int, struct kld_file_stat *); 371 int kldfirstmod(int); 372 int kldsym(int, int, void *); 373 __END_DECLS 374 375 #endif 376 377 #endif /* !_SYS_LINKER_H_ */ 378