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 #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 int load_flags); 139 }; 140 141 #define LINKER_LOAD_FILE_PRELOAD 0x0001 142 143 struct linker_class { 144 TAILQ_ENTRY(linker_class) link; /* list of all file classes */ 145 const char* desc; /* description (e.g. "a.out") */ 146 void* priv; /* implementation data */ 147 148 struct linker_class_ops *ops; 149 }; 150 151 /* 152 * The file which is currently loading. Used to register modules with 153 * the files which contain them. 154 */ 155 extern linker_file_t linker_current_file; 156 157 /* 158 * The "file" for the kernel. 159 */ 160 extern linker_file_t linker_kernel_file; 161 162 /* 163 * Add a new file class to the linker. 164 */ 165 int linker_add_class(const char* _desc, void* _priv, 166 struct linker_class_ops* _ops); 167 168 /* 169 * Load a file, trying each file class until one succeeds. 170 */ 171 int linker_load_file(const char *_filename, linker_file_t *_result, 172 int _load_flags); 173 174 /* 175 * Find a currently loaded file given its filename. 176 */ 177 linker_file_t linker_find_file_by_name(const char* _filename); 178 179 /* 180 * Find a currently loaded file given its file id. 181 */ 182 linker_file_t linker_find_file_by_id(int _fileid); 183 184 /* 185 * Called from a class handler when a file is laoded. 186 */ 187 linker_file_t linker_make_file(const char* _filename, void* _priv, 188 struct linker_file_ops* _ops); 189 190 /* 191 * Unload a file, freeing up memory. 192 */ 193 int linker_file_unload(linker_file_t _file); 194 195 /* 196 * Add a dependancy to a file. 197 */ 198 void linker_file_add_dependancy(linker_file_t _file, linker_file_t _dep); 199 200 /* 201 * Lookup a symbol in a file. If deps is TRUE, look in dependancies 202 * if not found in file. The symbol's value is returned in the 203 * caddr_t. An error is returned, 0 if no error occured. 204 */ 205 int linker_file_lookup_symbol(linker_file_t _file, const char* _name, 206 int _deps, caddr_t *); 207 208 209 /* 210 * Lookup a linker set in a file. Return pointers to the first entry, 211 * last + 1, and count of entries. Use: for (p = start; p < stop; p++) {} 212 * void *start is really: "struct yoursetmember ***start;" 213 */ 214 int linker_file_lookup_set(linker_file_t _file, const char *_name, 215 void *_start, void *_stop, int *_count); 216 217 /* 218 * Search the linker path for the module. Return the full pathname in 219 * a malloc'ed buffer. 220 */ 221 char *linker_search_path(const char *_filename); 222 223 /* 224 * DDB Helpers, tuned specifically for ddb/db_kld.c 225 */ 226 int linker_ddb_lookup(const char *_symstr, c_linker_sym_t *_sym); 227 int linker_ddb_search_symbol(caddr_t _value, c_linker_sym_t *_sym, 228 long *_diffp); 229 int linker_ddb_symbol_values(c_linker_sym_t _sym, linker_symval_t *_symval); 230 231 232 #endif /* _KERNEL */ 233 234 /* 235 * Module information subtypes 236 */ 237 #define MODINFO_END 0x0000 /* End of list */ 238 #define MODINFO_NAME 0x0001 /* Name of module (string) */ 239 #define MODINFO_TYPE 0x0002 /* Type of module (string) */ 240 #define MODINFO_ADDR 0x0003 /* Loaded address */ 241 #define MODINFO_SIZE 0x0004 /* Size of module */ 242 #define MODINFO_EMPTY 0x0005 /* Has been deleted */ 243 #define MODINFO_ARGS 0x0006 /* Parameters string */ 244 #define MODINFO_METADATA 0x8000 /* Module-specfic */ 245 246 #define MODINFOMD_AOUTEXEC 0x0001 /* a.out exec header */ 247 #define MODINFOMD_ELFHDR 0x0002 /* ELF header */ 248 #define MODINFOMD_SSYM 0x0003 /* start of symbols */ 249 #define MODINFOMD_ESYM 0x0004 /* end of symbols */ 250 #define MODINFOMD_DYNAMIC 0x0005 /* _DYNAMIC pointer */ 251 #define MODINFOMD_ENVP 0x0006 /* (from 5.x) envp[] */ 252 #define MODINFOMD_HOWTO 0x0007 /* (from 5.x) boothowto */ 253 #define MODINFOMD_KERNEND 0x0008 /* (from 5.x) kernend */ 254 #define MODINFOMD_NOCOPY 0x8000 /* don't copy this metadata to the kernel */ 255 256 #define MODINFOMD_DEPLIST (0x4001 | MODINFOMD_NOCOPY) /* depends on */ 257 258 #ifdef _KERNEL 259 #define MD_FETCH(mdp, info, type) ({ \ 260 type *__p; \ 261 __p = (type *)preload_search_info((mdp), MODINFO_METADATA | (info)); \ 262 __p ? *__p : 0; \ 263 }) 264 #endif 265 266 #define LINKER_HINTS_VERSION 1 /* linker.hints file version */ 267 268 #ifdef _KERNEL 269 270 /* 271 * Module lookup 272 */ 273 extern caddr_t preload_metadata; 274 extern caddr_t preload_search_by_name(const char *); 275 extern caddr_t preload_search_by_type(const char *); 276 extern caddr_t preload_search_next_name(caddr_t); 277 extern caddr_t preload_search_info(caddr_t, int); 278 extern void preload_delete_name(const char *); 279 extern void preload_bootstrap_relocate(vm_offset_t); 280 extern struct mod_metadata *find_mod_metadata(const char *); 281 282 283 #ifdef KLD_DEBUG 284 285 extern int kld_debug; 286 #define KLD_DEBUG_FILE 1 /* file load/unload */ 287 #define KLD_DEBUG_SYM 2 /* symbol lookup */ 288 289 #define KLD_DPF(cat, args) \ 290 do { \ 291 if (kld_debug & KLD_DEBUG_##cat) kprintf args; \ 292 } while (0) 293 294 #else 295 296 #define KLD_DPF(cat, args) 297 298 #endif 299 300 /* Support functions */ 301 int elf_reloc(linker_file_t, const void *, int, const char *); 302 303 /* values for type */ 304 #define ELF_RELOC_REL 1 305 #define ELF_RELOC_RELA 2 306 307 #endif /* _KERNEL */ 308 309 struct kld_file_stat { 310 int version; /* set to sizeof(linker_file_stat) */ 311 char name[MAXPATHLEN]; 312 int refs; 313 int id; 314 caddr_t address; /* load address */ 315 size_t size; /* size in bytes */ 316 }; 317 318 struct kld_sym_lookup { 319 int version; /* set to sizeof(struct kld_sym_lookup) */ 320 const char *symname; /* Symbol name we are looking up */ 321 u_long symvalue; 322 size_t symsize; 323 }; 324 325 #define KLDSYM_LOOKUP 1 326 327 #ifndef _KERNEL 328 329 #ifndef _SYS_CDEFS_H_ 330 #include <sys/cdefs.h> 331 #endif 332 333 __BEGIN_DECLS 334 int kldload(const char *); 335 int kldunload(int); 336 int kldfind(const char *); 337 int kldnext(int); 338 int kldstat(int, struct kld_file_stat *); 339 int kldfirstmod(int); 340 int kldsym(int, int, void *); 341 __END_DECLS 342 343 #endif 344 345 #endif /* !_SYS_LINKER_H_ */ 346