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 1.11 2008/02/06 22:37:46 nth 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 #include <sys/module.h> 50 51 #ifdef MALLOC_DECLARE 52 MALLOC_DECLARE(M_LINKER); 53 #endif 54 55 /* 56 * Object representing a file which has been loaded by the linker. 57 */ 58 typedef struct linker_file* linker_file_t; 59 typedef TAILQ_HEAD(, linker_file) linker_file_list_t; 60 61 typedef caddr_t linker_sym_t; /* opaque symbol */ 62 typedef c_caddr_t c_linker_sym_t; /* const opaque symbol */ 63 64 /* 65 * expanded out linker_sym_t 66 */ 67 typedef struct linker_symval { 68 const char* name; 69 caddr_t value; 70 size_t size; 71 } linker_symval_t; 72 73 struct linker_file_ops { 74 /* 75 * Lookup a symbol in the file's symbol table. If the symbol is 76 * not found then return ENOENT, otherwise zero. If the symbol 77 * found is a common symbol, return with *address set to zero and 78 * *size set to the size of the common space required. Otherwise 79 * set *address the value of the symbol. 80 */ 81 int (*lookup_symbol)(linker_file_t, const char* name, 82 c_linker_sym_t* sym); 83 84 int (*symbol_values)(linker_file_t, c_linker_sym_t, 85 linker_symval_t*); 86 87 int (*search_symbol)(linker_file_t, caddr_t value, 88 c_linker_sym_t* sym, long* diffp); 89 90 /* 91 * Completes the loading task started in preload_file. 92 */ 93 int (*preload_finish)(linker_file_t); 94 95 /* 96 * Unload a file, releasing dependancies and freeing storage. 97 */ 98 void (*unload)(linker_file_t); 99 100 int (*lookup_set)(linker_file_t, const char *name, 101 void ***firstp, void ***lastp, int *countp); 102 }; 103 104 struct common_symbol { 105 STAILQ_ENTRY(common_symbol) link; 106 char* name; 107 caddr_t address; 108 }; 109 110 struct linker_file { 111 int refs; /* reference count */ 112 int userrefs; /* kldload(2) count */ 113 int flags; 114 #define LINKER_FILE_LINKED 0x1 /* file has been fully linked */ 115 TAILQ_ENTRY(linker_file) link; /* list of all loaded files */ 116 char* filename; /* file which was loaded */ 117 int id; /* unique id */ 118 caddr_t address; /* load address */ 119 size_t size; /* size of file */ 120 int ndeps; /* number of dependancies */ 121 linker_file_t* deps; /* list of dependancies */ 122 STAILQ_HEAD(, common_symbol) common; /* list of common symbols */ 123 TAILQ_HEAD(, module) modules; /* modules in this file */ 124 TAILQ_ENTRY(linker_file) loaded; /* preload dependency support */ 125 void* priv; /* implementation data */ 126 127 struct linker_file_ops* ops; 128 }; 129 130 /* 131 * Object implementing a class of file (a.out, elf, etc.) 132 */ 133 typedef struct linker_class *linker_class_t; 134 typedef TAILQ_HEAD(, linker_class) linker_class_list_t; 135 136 struct linker_class_ops { 137 /* 138 * Load a file, returning the new linker_file_t in *result. If 139 * the class does not recognise the file type, zero should be 140 * returned, without modifying *result. If the file is 141 * recognised, the file should be loaded, *result set to the new 142 * file and zero returned. If some other error is detected an 143 * appropriate errno should be returned. 144 */ 145 int (*load_file)(const char *filename, linker_file_t *result); 146 /* 147 * Same as load_file, but does not load dependencies. Necessary 148 * for tentatively loading (loader-)preloaded modules. 149 */ 150 int (*preload_file)(const char *filename, linker_file_t *result); 151 }; 152 153 struct linker_class { 154 TAILQ_ENTRY(linker_class) link; /* list of all file classes */ 155 const char* desc; /* description (e.g. "a.out") */ 156 void* priv; /* implementation data */ 157 158 struct linker_class_ops *ops; 159 }; 160 161 /* 162 * The file which is currently loading. Used to register modules with 163 * the files which contain them. 164 */ 165 extern linker_file_t linker_current_file; 166 167 /* 168 * The "file" for the kernel. 169 */ 170 extern linker_file_t linker_kernel_file; 171 172 /* 173 * Add a new file class to the linker. 174 */ 175 int linker_add_class(const char* _desc, void* _priv, 176 struct linker_class_ops* _ops); 177 178 /* 179 * Load a file, trying each file class until one succeeds. 180 */ 181 int linker_load_file(const char *_filename, linker_file_t *_result); 182 183 /* 184 * Find a currently loaded file given its filename. 185 */ 186 linker_file_t linker_find_file_by_name(const char* _filename); 187 188 /* 189 * Find a currently loaded file given its file id. 190 */ 191 linker_file_t linker_find_file_by_id(int _fileid); 192 193 /* 194 * Called from a class handler when a file is laoded. 195 */ 196 linker_file_t linker_make_file(const char* _filename, void* _priv, 197 struct linker_file_ops* _ops); 198 199 /* 200 * Unload a file, freeing up memory. 201 */ 202 int linker_file_unload(linker_file_t _file); 203 204 /* 205 * Add a dependancy to a file. 206 */ 207 void linker_file_add_dependancy(linker_file_t _file, linker_file_t _dep); 208 209 int linker_load_dependencies(linker_file_t lf); 210 211 /* 212 * Lookup a symbol in a file. If deps is TRUE, look in dependancies 213 * if not found in file. The symbol's value is returned in the 214 * caddr_t. An error is returned, 0 if no error occured. 215 */ 216 int linker_file_lookup_symbol(linker_file_t _file, const char* _name, 217 int _deps, caddr_t *); 218 219 220 /* 221 * Lookup a linker set in a file. Return pointers to the first entry, 222 * last + 1, and count of entries. Use: for (p = start; p < stop; p++) {} 223 * void *start is really: "struct yoursetmember ***start;" 224 */ 225 int linker_file_lookup_set(linker_file_t _file, const char *_name, 226 void *_start, void *_stop, int *_count); 227 228 /* 229 * Search the linker path for the module. Return the full pathname in 230 * a malloc'ed buffer. 231 */ 232 char *linker_search_path(const char *_filename); 233 234 int linker_reference_module(const char *modname, struct mod_depend *verinfo, 235 linker_file_t *retult); 236 int linker_release_module(const char *modname, struct mod_depend *verinfo, 237 linker_file_t lf); 238 239 /* 240 * DDB Helpers, tuned specifically for ddb/db_kld.c 241 */ 242 int linker_ddb_lookup(const char *_symstr, c_linker_sym_t *_sym); 243 int linker_ddb_search_symbol(caddr_t _value, c_linker_sym_t *_sym, 244 long *_diffp); 245 int linker_ddb_symbol_values(c_linker_sym_t _sym, linker_symval_t *_symval); 246 247 248 #endif /* _KERNEL */ 249 250 /* 251 * Module information subtypes 252 */ 253 #define MODINFO_END 0x0000 /* End of list */ 254 #define MODINFO_NAME 0x0001 /* Name of module (string) */ 255 #define MODINFO_TYPE 0x0002 /* Type of module (string) */ 256 #define MODINFO_ADDR 0x0003 /* Loaded address */ 257 #define MODINFO_SIZE 0x0004 /* Size of module */ 258 #define MODINFO_EMPTY 0x0005 /* Has been deleted */ 259 #define MODINFO_ARGS 0x0006 /* Parameters string */ 260 #define MODINFO_METADATA 0x8000 /* Module-specfic */ 261 262 #define MODINFOMD_AOUTEXEC 0x0001 /* a.out exec header */ 263 #define MODINFOMD_ELFHDR 0x0002 /* ELF header */ 264 #define MODINFOMD_SSYM 0x0003 /* start of symbols */ 265 #define MODINFOMD_ESYM 0x0004 /* end of symbols */ 266 #define MODINFOMD_DYNAMIC 0x0005 /* _DYNAMIC pointer */ 267 #define MODINFOMD_ENVP 0x0006 /* (from 5.x) envp[] */ 268 #define MODINFOMD_HOWTO 0x0007 /* (from 5.x) boothowto */ 269 #define MODINFOMD_KERNEND 0x0008 /* (from 5.x) kernend */ 270 #define MODINFOMD_SHDR 0x0009 /* section header table */ 271 #define MODINFOMD_NOCOPY 0x8000 /* don't copy this metadata to the kernel */ 272 273 #define MODINFOMD_DEPLIST (0x4001 | MODINFOMD_NOCOPY) /* depends on */ 274 275 #ifdef _KERNEL 276 #define MD_FETCH(mdp, info, type) ({ \ 277 type *__p; \ 278 __p = (type *)preload_search_info((mdp), MODINFO_METADATA | (info)); \ 279 __p ? *__p : 0; \ 280 }) 281 #endif 282 283 #define LINKER_HINTS_VERSION 1 /* linker.hints file version */ 284 285 #ifdef _KERNEL 286 287 /* 288 * Module lookup 289 */ 290 extern caddr_t preload_metadata; 291 extern caddr_t preload_search_by_name(const char *); 292 extern caddr_t preload_search_by_type(const char *); 293 extern caddr_t preload_search_next_name(caddr_t); 294 extern caddr_t preload_search_info(caddr_t, int); 295 extern void preload_delete_name(const char *); 296 extern void preload_bootstrap_relocate(vm_offset_t); 297 extern struct mod_metadata *find_mod_metadata(const char *); 298 299 #ifdef KLD_DEBUG 300 301 extern int kld_debug; 302 #define KLD_DEBUG_FILE 1 /* file load/unload */ 303 #define KLD_DEBUG_SYM 2 /* symbol lookup */ 304 305 #define KLD_DPF(cat, args) \ 306 do { \ 307 if (kld_debug & KLD_DEBUG_##cat) kprintf args; \ 308 } while (0) 309 310 #else 311 312 #define KLD_DPF(cat, args) 313 314 #endif 315 316 typedef int elf_lookup_fn(linker_file_t, Elf_Size, int, Elf_Addr *); 317 318 /* Support functions */ 319 int elf_reloc(linker_file_t, Elf_Addr, const void *, int, elf_lookup_fn); 320 int elf_reloc_local(linker_file_t, Elf_Addr, const void *, int, elf_lookup_fn); 321 Elf_Addr elf_relocaddr(linker_file_t, Elf_Addr); 322 323 /* values for type */ 324 #define ELF_RELOC_REL 1 325 #define ELF_RELOC_RELA 2 326 327 #endif /* _KERNEL */ 328 329 struct kld_file_stat { 330 int version; /* set to sizeof(linker_file_stat) */ 331 char name[MAXPATHLEN]; 332 int refs; 333 int id; 334 caddr_t address; /* load address */ 335 size_t size; /* size in bytes */ 336 }; 337 338 struct kld_sym_lookup { 339 int version; /* set to sizeof(struct kld_sym_lookup) */ 340 const char *symname; /* Symbol name we are looking up */ 341 u_long symvalue; 342 size_t symsize; 343 }; 344 345 #define KLDSYM_LOOKUP 1 346 347 #ifndef _KERNEL 348 349 #ifndef _SYS_CDEFS_H_ 350 #include <sys/cdefs.h> 351 #endif 352 353 __BEGIN_DECLS 354 int kldload(const char *); 355 int kldunload(int); 356 int kldfind(const char *); 357 int kldnext(int); 358 int kldstat(int, struct kld_file_stat *); 359 int kldfirstmod(int); 360 int kldsym(int, int, void *); 361 __END_DECLS 362 363 #endif 364 365 #endif /* !_SYS_LINKER_H_ */ 366