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 1.6 2004/02/25 17:38:51 joerg Exp $ 28 */ 29 30 #ifndef _SYS_LINKER_H_ 31 #define _SYS_LINKER_H_ 32 33 #ifdef _KERNEL 34 35 #include <machine/elf.h> 36 37 #ifdef MALLOC_DECLARE 38 MALLOC_DECLARE(M_LINKER); 39 #endif 40 41 /* 42 * Object representing a file which has been loaded by the linker. 43 */ 44 typedef struct linker_file* linker_file_t; 45 typedef TAILQ_HEAD(, linker_file) linker_file_list_t; 46 47 typedef caddr_t linker_sym_t; /* opaque symbol */ 48 typedef c_caddr_t c_linker_sym_t; /* const opaque symbol */ 49 50 /* 51 * expanded out linker_sym_t 52 */ 53 typedef struct linker_symval { 54 const char* name; 55 caddr_t value; 56 size_t size; 57 } linker_symval_t; 58 59 struct linker_file_ops { 60 /* 61 * Lookup a symbol in the file's symbol table. If the symbol is 62 * not found then return ENOENT, otherwise zero. If the symbol 63 * found is a common symbol, return with *address set to zero and 64 * *size set to the size of the common space required. Otherwise 65 * set *address the value of the symbol. 66 */ 67 int (*lookup_symbol)(linker_file_t, const char* name, 68 c_linker_sym_t* sym); 69 70 int (*symbol_values)(linker_file_t, c_linker_sym_t, 71 linker_symval_t*); 72 73 int (*search_symbol)(linker_file_t, caddr_t value, 74 c_linker_sym_t* sym, long* diffp); 75 76 /* 77 * Unload a file, releasing dependancies and freeing storage. 78 */ 79 void (*unload)(linker_file_t); 80 81 int (*lookup_set)(linker_file_t, const char *name, 82 void ***firstp, void ***lastp, int *countp); 83 }; 84 85 struct common_symbol { 86 STAILQ_ENTRY(common_symbol) link; 87 char* name; 88 caddr_t address; 89 }; 90 91 struct linker_file { 92 int refs; /* reference count */ 93 int userrefs; /* kldload(2) count */ 94 int flags; 95 #define LINKER_FILE_LINKED 0x1 /* file has been fully linked */ 96 TAILQ_ENTRY(linker_file) link; /* list of all loaded files */ 97 char* filename; /* file which was loaded */ 98 int id; /* unique id */ 99 caddr_t address; /* load address */ 100 size_t size; /* size of file */ 101 int ndeps; /* number of dependancies */ 102 linker_file_t* deps; /* list of dependancies */ 103 STAILQ_HEAD(, common_symbol) common; /* list of common symbols */ 104 TAILQ_HEAD(, module) modules; /* modules in this file */ 105 void* priv; /* implementation data */ 106 107 struct linker_file_ops* ops; 108 }; 109 110 /* 111 * Object implementing a class of file (a.out, elf, etc.) 112 */ 113 typedef struct linker_class *linker_class_t; 114 typedef TAILQ_HEAD(, linker_class) linker_class_list_t; 115 116 struct linker_class_ops { 117 /* 118 * Load a file, returning the new linker_file_t in *result. If 119 * the class does not recognise the file type, zero should be 120 * returned, without modifying *result. If the file is 121 * recognised, the file should be loaded, *result set to the new 122 * file and zero returned. If some other error is detected an 123 * appropriate errno should be returned. 124 */ 125 int (*load_file)(const char* filename, linker_file_t* result); 126 }; 127 128 struct linker_class { 129 TAILQ_ENTRY(linker_class) link; /* list of all file classes */ 130 const char* desc; /* description (e.g. "a.out") */ 131 void* priv; /* implementation data */ 132 133 struct linker_class_ops *ops; 134 }; 135 136 /* 137 * The file which is currently loading. Used to register modules with 138 * the files which contain them. 139 */ 140 extern linker_file_t linker_current_file; 141 142 /* 143 * The "file" for the kernel. 144 */ 145 extern linker_file_t linker_kernel_file; 146 147 /* 148 * Add a new file class to the linker. 149 */ 150 int linker_add_class(const char* _desc, void* _priv, 151 struct linker_class_ops* _ops); 152 153 /* 154 * Load a file, trying each file class until one succeeds. 155 */ 156 int linker_load_file(const char* _filename, linker_file_t* _result); 157 158 /* 159 * Find a currently loaded file given its filename. 160 */ 161 linker_file_t linker_find_file_by_name(const char* _filename); 162 163 /* 164 * Find a currently loaded file given its file id. 165 */ 166 linker_file_t linker_find_file_by_id(int _fileid); 167 168 /* 169 * Called from a class handler when a file is laoded. 170 */ 171 linker_file_t linker_make_file(const char* _filename, void* _priv, 172 struct linker_file_ops* _ops); 173 174 /* 175 * Unload a file, freeing up memory. 176 */ 177 int linker_file_unload(linker_file_t _file); 178 179 /* 180 * Add a dependancy to a file. 181 */ 182 int linker_file_add_dependancy(linker_file_t _file, linker_file_t _dep); 183 184 /* 185 * Lookup a symbol in a file. If deps is TRUE, look in dependancies 186 * if not found in file. The symbol's value is returned in the 187 * caddr_t. An error is returned, 0 if no error occured. 188 */ 189 int linker_file_lookup_symbol(linker_file_t _file, const char* _name, 190 int _deps, caddr_t *); 191 192 193 /* 194 * Lookup a linker set in a file. Return pointers to the first entry, 195 * last + 1, and count of entries. Use: for (p = start; p < stop; p++) {} 196 * void *start is really: "struct yoursetmember ***start;" 197 */ 198 int linker_file_lookup_set(linker_file_t _file, const char *_name, 199 void *_start, void *_stop, int *_count); 200 201 /* 202 * Search the linker path for the module. Return the full pathname in 203 * a malloc'ed buffer. 204 */ 205 char *linker_search_path(const char *_filename); 206 207 /* 208 * DDB Helpers, tuned specifically for ddb/db_kld.c 209 */ 210 int linker_ddb_lookup(const char *_symstr, c_linker_sym_t *_sym); 211 int linker_ddb_search_symbol(caddr_t _value, c_linker_sym_t *_sym, 212 long *_diffp); 213 int linker_ddb_symbol_values(c_linker_sym_t _sym, linker_symval_t *_symval); 214 215 216 #endif /* _KERNEL */ 217 218 /* 219 * Module information subtypes 220 */ 221 #define MODINFO_END 0x0000 /* End of list */ 222 #define MODINFO_NAME 0x0001 /* Name of module (string) */ 223 #define MODINFO_TYPE 0x0002 /* Type of module (string) */ 224 #define MODINFO_ADDR 0x0003 /* Loaded address */ 225 #define MODINFO_SIZE 0x0004 /* Size of module */ 226 #define MODINFO_EMPTY 0x0005 /* Has been deleted */ 227 #define MODINFO_ARGS 0x0006 /* Parameters string */ 228 #define MODINFO_METADATA 0x8000 /* Module-specfic */ 229 230 #define MODINFOMD_AOUTEXEC 0x0001 /* a.out exec header */ 231 #define MODINFOMD_ELFHDR 0x0002 /* ELF header */ 232 #define MODINFOMD_SSYM 0x0003 /* start of symbols */ 233 #define MODINFOMD_ESYM 0x0004 /* end of symbols */ 234 #define MODINFOMD_DYNAMIC 0x0005 /* _DYNAMIC pointer */ 235 #define MODINFOMD_ENVP 0x0006 /* (from 5.x) envp[] */ 236 #define MODINFOMD_HOWTO 0x0007 /* (from 5.x) boothowto */ 237 #define MODINFOMD_KERNEND 0x0008 /* (from 5.x) kernend */ 238 #define MODINFOMD_NOCOPY 0x8000 /* don't copy this metadata to the kernel */ 239 240 #define MODINFOMD_DEPLIST (0x4001 | MODINFOMD_NOCOPY) /* depends on */ 241 242 #ifdef _KERNEL 243 #define MD_FETCH(mdp, info, type) ({ \ 244 type *__p; \ 245 __p = (type *)preload_search_info((mdp), MODINFO_METADATA | (info)); \ 246 __p ? *__p : 0; \ 247 }) 248 #endif 249 250 #define LINKER_HINTS_VERSION 1 /* linker.hints file version */ 251 252 #ifdef _KERNEL 253 254 /* 255 * Module lookup 256 */ 257 extern caddr_t preload_metadata; 258 extern caddr_t preload_search_by_name(const char *); 259 extern caddr_t preload_search_by_type(const char *); 260 extern caddr_t preload_search_next_name(caddr_t); 261 extern caddr_t preload_search_info(caddr_t, int); 262 extern void preload_delete_name(const char *); 263 extern void preload_bootstrap_relocate(vm_offset_t); 264 extern struct mod_metadata *find_mod_metadata(const char *); 265 266 267 #ifdef KLD_DEBUG 268 269 extern int kld_debug; 270 #define KLD_DEBUG_FILE 1 /* file load/unload */ 271 #define KLD_DEBUG_SYM 2 /* symbol lookup */ 272 273 #define KLD_DPF(cat, args) \ 274 do { \ 275 if (kld_debug & KLD_DEBUG_##cat) printf args; \ 276 } while (0) 277 278 #else 279 280 #define KLD_DPF(cat, args) 281 282 #endif 283 284 /* Support functions */ 285 int elf_reloc(linker_file_t, const void *, int, const char *); 286 287 /* values for type */ 288 #define ELF_RELOC_REL 1 289 #define ELF_RELOC_RELA 2 290 291 #endif /* _KERNEL */ 292 293 struct kld_file_stat { 294 int version; /* set to sizeof(linker_file_stat) */ 295 char name[MAXPATHLEN]; 296 int refs; 297 int id; 298 caddr_t address; /* load address */ 299 size_t size; /* size in bytes */ 300 }; 301 302 struct kld_sym_lookup { 303 int version; /* set to sizeof(struct kld_sym_lookup) */ 304 char *symname; /* Symbol name we are looking up */ 305 u_long symvalue; 306 size_t symsize; 307 }; 308 #define KLDSYM_LOOKUP 1 309 310 #ifndef _KERNEL 311 312 #include <sys/cdefs.h> 313 314 __BEGIN_DECLS 315 int kldload(const char *); 316 int kldunload(int); 317 int kldfind(const char *); 318 int kldnext(int); 319 int kldstat(int, struct kld_file_stat *); 320 int kldfirstmod(int); 321 int kldsym(int, int, void *); 322 __END_DECLS 323 324 #endif 325 326 #endif /* !_SYS_LINKER_H_ */ 327