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 #ifdef _KERNEL 33 34 #include <machine/elf.h> 35 36 #ifdef MALLOC_DECLARE 37 MALLOC_DECLARE(M_LINKER); 38 #endif 39 40 /* 41 * Object representing a file which has been loaded by the linker. 42 */ 43 typedef struct linker_file* linker_file_t; 44 typedef TAILQ_HEAD(, linker_file) linker_file_list_t; 45 46 typedef caddr_t linker_sym_t; /* opaque symbol */ 47 typedef c_caddr_t c_linker_sym_t; /* const opaque symbol */ 48 49 /* 50 * expanded out linker_sym_t 51 */ 52 typedef struct linker_symval { 53 const char* name; 54 caddr_t value; 55 size_t size; 56 } linker_symval_t; 57 58 struct linker_file_ops { 59 /* 60 * Lookup a symbol in the file's symbol table. If the symbol is 61 * not found then return ENOENT, otherwise zero. If the symbol 62 * found is a common symbol, return with *address set to zero and 63 * *size set to the size of the common space required. Otherwise 64 * set *address the value of the symbol. 65 */ 66 int (*lookup_symbol)(linker_file_t, const char* name, 67 c_linker_sym_t* sym); 68 69 int (*symbol_values)(linker_file_t, c_linker_sym_t, 70 linker_symval_t*); 71 72 int (*search_symbol)(linker_file_t, caddr_t value, 73 c_linker_sym_t* sym, long* diffp); 74 75 /* 76 * Unload a file, releasing dependancies and freeing storage. 77 */ 78 void (*unload)(linker_file_t); 79 }; 80 81 struct common_symbol { 82 STAILQ_ENTRY(common_symbol) link; 83 char* name; 84 caddr_t address; 85 }; 86 87 struct linker_file { 88 int refs; /* reference count */ 89 int userrefs; /* kldload(2) count */ 90 int flags; 91 #define LINKER_FILE_LINKED 0x1 /* file has been fully linked */ 92 TAILQ_ENTRY(linker_file) link; /* list of all loaded files */ 93 char* filename; /* file which was loaded */ 94 int id; /* unique id */ 95 caddr_t address; /* load address */ 96 size_t size; /* size of file */ 97 int ndeps; /* number of dependancies */ 98 linker_file_t* deps; /* list of dependancies */ 99 STAILQ_HEAD(, common_symbol) common; /* list of common symbols */ 100 TAILQ_HEAD(, module) modules; /* modules in this file */ 101 void* priv; /* implementation data */ 102 103 struct linker_file_ops* ops; 104 }; 105 106 /* 107 * Object implementing a class of file (a.out, elf, etc.) 108 */ 109 typedef struct linker_class *linker_class_t; 110 typedef TAILQ_HEAD(, linker_class) linker_class_list_t; 111 112 struct linker_class_ops { 113 /* 114 * Load a file, returning the new linker_file_t in *result. If 115 * the class does not recognise the file type, zero should be 116 * returned, without modifying *result. If the file is 117 * recognised, the file should be loaded, *result set to the new 118 * file and zero returned. If some other error is detected an 119 * appropriate errno should be returned. 120 */ 121 int (*load_file)(const char* filename, linker_file_t* result); 122 }; 123 124 struct linker_class { 125 TAILQ_ENTRY(linker_class) link; /* list of all file classes */ 126 const char* desc; /* description (e.g. "a.out") */ 127 void* priv; /* implementation data */ 128 129 struct linker_class_ops *ops; 130 }; 131 132 /* 133 * The file which is currently loading. Used to register modules with 134 * the files which contain them. 135 */ 136 extern linker_file_t linker_current_file; 137 138 /* 139 * The "file" for the kernel. 140 */ 141 extern linker_file_t linker_kernel_file; 142 143 /* 144 * Add a new file class to the linker. 145 */ 146 int linker_add_class(const char* _desc, void* _priv, 147 struct linker_class_ops* _ops); 148 149 /* 150 * Load a file, trying each file class until one succeeds. 151 */ 152 int linker_load_file(const char* _filename, linker_file_t* _result); 153 154 /* 155 * Find a currently loaded file given its filename. 156 */ 157 linker_file_t linker_find_file_by_name(const char* _filename); 158 159 /* 160 * Find a currently loaded file given its file id. 161 */ 162 linker_file_t linker_find_file_by_id(int _fileid); 163 164 /* 165 * Called from a class handler when a file is laoded. 166 */ 167 linker_file_t linker_make_file(const char* _filename, void* _priv, 168 struct linker_file_ops* _ops); 169 170 /* 171 * Unload a file, freeing up memory. 172 */ 173 int linker_file_unload(linker_file_t _file); 174 175 /* 176 * Add a dependancy to a file. 177 */ 178 int linker_file_add_dependancy(linker_file_t _file, linker_file_t _dep); 179 180 /* 181 * Lookup a symbol in a file. If deps is TRUE, look in dependancies 182 * if not found in file. 183 */ 184 caddr_t linker_file_lookup_symbol(linker_file_t _file, const char* _name, 185 int _deps); 186 187 /* 188 * Search the linker path for the module. Return the full pathname in 189 * a malloc'ed buffer. 190 */ 191 char *linker_search_path(const char *_filename); 192 193 /* 194 * DDB Helpers, tuned specifically for ddb/db_kld.c 195 */ 196 int linker_ddb_lookup(const char *_symstr, c_linker_sym_t *_sym); 197 int linker_ddb_search_symbol(caddr_t _value, c_linker_sym_t *_sym, 198 long *_diffp); 199 int linker_ddb_symbol_values(c_linker_sym_t _sym, linker_symval_t *_symval); 200 201 202 #endif /* _KERNEL */ 203 204 /* 205 * Module information subtypes 206 */ 207 #define MODINFO_END 0x0000 /* End of list */ 208 #define MODINFO_NAME 0x0001 /* Name of module (string) */ 209 #define MODINFO_TYPE 0x0002 /* Type of module (string) */ 210 #define MODINFO_ADDR 0x0003 /* Loaded address */ 211 #define MODINFO_SIZE 0x0004 /* Size of module */ 212 #define MODINFO_EMPTY 0x0005 /* Has been deleted */ 213 #define MODINFO_ARGS 0x0006 /* Parameters string */ 214 #define MODINFO_METADATA 0x8000 /* Module-specfic */ 215 216 #define MODINFOMD_AOUTEXEC 0x0001 /* a.out exec header */ 217 #define MODINFOMD_ELFHDR 0x0002 /* ELF header */ 218 #define MODINFOMD_SSYM 0x0003 /* start of symbols */ 219 #define MODINFOMD_ESYM 0x0004 /* end of symbols */ 220 #define MODINFOMD_DYNAMIC 0x0005 /* _DYNAMIC pointer */ 221 #define MODINFOMD_NOCOPY 0x8000 /* don't copy this metadata to the kernel */ 222 223 #define MODINFOMD_DEPLIST (0x4001 | MODINFOMD_NOCOPY) /* depends on */ 224 225 #ifdef _KERNEL 226 227 /* 228 * Module lookup 229 */ 230 extern caddr_t preload_metadata; 231 extern caddr_t preload_search_by_name(const char *_name); 232 extern caddr_t preload_search_by_type(const char *_type); 233 extern caddr_t preload_search_next_name(caddr_t _base); 234 extern caddr_t preload_search_info(caddr_t _mod, int _inf); 235 extern void preload_delete_name(const char *_name); 236 extern void preload_bootstrap_relocate(vm_offset_t _offset); 237 238 #ifdef KLD_DEBUG 239 240 extern int kld_debug; 241 #define KLD_DEBUG_FILE 1 /* file load/unload */ 242 #define KLD_DEBUG_SYM 2 /* symbol lookup */ 243 244 #define KLD_DPF(cat, args) \ 245 do { \ 246 if (kld_debug & KLD_DEBUG_##cat) printf args; \ 247 } while (0) 248 249 #else 250 251 #define KLD_DPF(cat, args) 252 253 #endif 254 255 /* Support functions */ 256 int elf_reloc(linker_file_t _lf, const void *_rel, int _type, 257 const char *_sym); 258 /* values for type */ 259 #define ELF_RELOC_REL 1 260 #define ELF_RELOC_RELA 2 261 262 #endif /* _KERNEL */ 263 264 struct kld_file_stat { 265 int version; /* set to sizeof(linker_file_stat) */ 266 char name[MAXPATHLEN]; 267 int refs; 268 int id; 269 caddr_t address; /* load address */ 270 size_t size; /* size in bytes */ 271 }; 272 273 struct kld_sym_lookup { 274 int version; /* set to sizeof(struct kld_sym_lookup) */ 275 char *symname; /* Symbol name we are looking up */ 276 u_long symvalue; 277 size_t symsize; 278 }; 279 #define KLDSYM_LOOKUP 1 280 281 #ifndef _KERNEL 282 283 #include <sys/cdefs.h> 284 285 __BEGIN_DECLS 286 int kldload(const char* _file); 287 int kldunload(int _fileid); 288 int kldfind(const char* _file); 289 int kldnext(int _fileid); 290 int kldstat(int _fileid, struct kld_file_stat* _stat); 291 int kldfirstmod(int _fileid); 292 int kldsym(int _fileid, int _cmd, void *_data); 293 __END_DECLS 294 295 #endif 296 297 #endif /* !_SYS_LINKER_H_ */ 298