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 1.3 2003/07/18 05:12:41 dillon 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 82 struct common_symbol { 83 STAILQ_ENTRY(common_symbol) link; 84 char* name; 85 caddr_t address; 86 }; 87 88 struct linker_file { 89 int refs; /* reference count */ 90 int userrefs; /* kldload(2) count */ 91 int flags; 92 #define LINKER_FILE_LINKED 0x1 /* file has been fully linked */ 93 TAILQ_ENTRY(linker_file) link; /* list of all loaded files */ 94 char* filename; /* file which was loaded */ 95 int id; /* unique id */ 96 caddr_t address; /* load address */ 97 size_t size; /* size of file */ 98 int ndeps; /* number of dependancies */ 99 linker_file_t* deps; /* list of dependancies */ 100 STAILQ_HEAD(, common_symbol) common; /* list of common symbols */ 101 TAILQ_HEAD(, module) modules; /* modules in this file */ 102 void* priv; /* implementation data */ 103 104 struct linker_file_ops* ops; 105 }; 106 107 /* 108 * Object implementing a class of file (a.out, elf, etc.) 109 */ 110 typedef struct linker_class *linker_class_t; 111 typedef TAILQ_HEAD(, linker_class) linker_class_list_t; 112 113 struct linker_class_ops { 114 /* 115 * Load a file, returning the new linker_file_t in *result. If 116 * the class does not recognise the file type, zero should be 117 * returned, without modifying *result. If the file is 118 * recognised, the file should be loaded, *result set to the new 119 * file and zero returned. If some other error is detected an 120 * appropriate errno should be returned. 121 */ 122 int (*load_file)(const char* filename, linker_file_t* result); 123 }; 124 125 struct linker_class { 126 TAILQ_ENTRY(linker_class) link; /* list of all file classes */ 127 const char* desc; /* description (e.g. "a.out") */ 128 void* priv; /* implementation data */ 129 130 struct linker_class_ops *ops; 131 }; 132 133 /* 134 * The file which is currently loading. Used to register modules with 135 * the files which contain them. 136 */ 137 extern linker_file_t linker_current_file; 138 139 /* 140 * The "file" for the kernel. 141 */ 142 extern linker_file_t linker_kernel_file; 143 144 /* 145 * Add a new file class to the linker. 146 */ 147 int linker_add_class(const char* _desc, void* _priv, 148 struct linker_class_ops* _ops); 149 150 /* 151 * Load a file, trying each file class until one succeeds. 152 */ 153 int linker_load_file(const char* _filename, linker_file_t* _result); 154 155 /* 156 * Find a currently loaded file given its filename. 157 */ 158 linker_file_t linker_find_file_by_name(const char* _filename); 159 160 /* 161 * Find a currently loaded file given its file id. 162 */ 163 linker_file_t linker_find_file_by_id(int _fileid); 164 165 /* 166 * Called from a class handler when a file is laoded. 167 */ 168 linker_file_t linker_make_file(const char* _filename, void* _priv, 169 struct linker_file_ops* _ops); 170 171 /* 172 * Unload a file, freeing up memory. 173 */ 174 int linker_file_unload(linker_file_t _file); 175 176 /* 177 * Add a dependancy to a file. 178 */ 179 int linker_file_add_dependancy(linker_file_t _file, linker_file_t _dep); 180 181 /* 182 * Lookup a symbol in a file. If deps is TRUE, look in dependancies 183 * if not found in file. The symbol's value is returned in the 184 * caddr_t. An error is returned, 0 if no error occured. 185 */ 186 int linker_file_lookup_symbol(linker_file_t _file, const char* _name, 187 int _deps, caddr_t *); 188 189 /* 190 * Search the linker path for the module. Return the full pathname in 191 * a malloc'ed buffer. 192 */ 193 char *linker_search_path(const char *_filename); 194 195 /* 196 * DDB Helpers, tuned specifically for ddb/db_kld.c 197 */ 198 int linker_ddb_lookup(const char *_symstr, c_linker_sym_t *_sym); 199 int linker_ddb_search_symbol(caddr_t _value, c_linker_sym_t *_sym, 200 long *_diffp); 201 int linker_ddb_symbol_values(c_linker_sym_t _sym, linker_symval_t *_symval); 202 203 204 #endif /* _KERNEL */ 205 206 /* 207 * Module information subtypes 208 */ 209 #define MODINFO_END 0x0000 /* End of list */ 210 #define MODINFO_NAME 0x0001 /* Name of module (string) */ 211 #define MODINFO_TYPE 0x0002 /* Type of module (string) */ 212 #define MODINFO_ADDR 0x0003 /* Loaded address */ 213 #define MODINFO_SIZE 0x0004 /* Size of module */ 214 #define MODINFO_EMPTY 0x0005 /* Has been deleted */ 215 #define MODINFO_ARGS 0x0006 /* Parameters string */ 216 #define MODINFO_METADATA 0x8000 /* Module-specfic */ 217 218 #define MODINFOMD_AOUTEXEC 0x0001 /* a.out exec header */ 219 #define MODINFOMD_ELFHDR 0x0002 /* ELF header */ 220 #define MODINFOMD_SSYM 0x0003 /* start of symbols */ 221 #define MODINFOMD_ESYM 0x0004 /* end of symbols */ 222 #define MODINFOMD_DYNAMIC 0x0005 /* _DYNAMIC pointer */ 223 #define MODINFOMD_NOCOPY 0x8000 /* don't copy this metadata to the kernel */ 224 225 #define MODINFOMD_DEPLIST (0x4001 | MODINFOMD_NOCOPY) /* depends on */ 226 227 #ifdef _KERNEL 228 229 /* 230 * Module lookup 231 */ 232 extern caddr_t preload_metadata; 233 extern caddr_t preload_search_by_name(const char *_name); 234 extern caddr_t preload_search_by_type(const char *_type); 235 extern caddr_t preload_search_next_name(caddr_t _base); 236 extern caddr_t preload_search_info(caddr_t _mod, int _inf); 237 extern void preload_delete_name(const char *_name); 238 extern void preload_bootstrap_relocate(vm_offset_t _offset); 239 240 #ifdef KLD_DEBUG 241 242 extern int kld_debug; 243 #define KLD_DEBUG_FILE 1 /* file load/unload */ 244 #define KLD_DEBUG_SYM 2 /* symbol lookup */ 245 246 #define KLD_DPF(cat, args) \ 247 do { \ 248 if (kld_debug & KLD_DEBUG_##cat) printf args; \ 249 } while (0) 250 251 #else 252 253 #define KLD_DPF(cat, args) 254 255 #endif 256 257 /* Support functions */ 258 int elf_reloc(linker_file_t _lf, const void *_rel, int _type, 259 const char *_sym); 260 /* values for type */ 261 #define ELF_RELOC_REL 1 262 #define ELF_RELOC_RELA 2 263 264 #endif /* _KERNEL */ 265 266 struct kld_file_stat { 267 int version; /* set to sizeof(linker_file_stat) */ 268 char name[MAXPATHLEN]; 269 int refs; 270 int id; 271 caddr_t address; /* load address */ 272 size_t size; /* size in bytes */ 273 }; 274 275 struct kld_sym_lookup { 276 int version; /* set to sizeof(struct kld_sym_lookup) */ 277 char *symname; /* Symbol name we are looking up */ 278 u_long symvalue; 279 size_t symsize; 280 }; 281 #define KLDSYM_LOOKUP 1 282 283 #ifndef _KERNEL 284 285 #include <sys/cdefs.h> 286 287 __BEGIN_DECLS 288 int kldload(const char* _file); 289 int kldunload(int _fileid); 290 int kldfind(const char* _file); 291 int kldnext(int _fileid); 292 int kldstat(int _fileid, struct kld_file_stat* _stat); 293 int kldfirstmod(int _fileid); 294 int kldsym(int _fileid, int _cmd, void *_data); 295 __END_DECLS 296 297 #endif 298 299 #endif /* !_SYS_LINKER_H_ */ 300