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 * $Id: linker.h,v 1.8 1998/10/09 23:07:27 peter 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 48 /* 49 * expanded out linker_sym_t 50 */ 51 typedef struct linker_symval { 52 const char* name; 53 caddr_t value; 54 size_t size; 55 } linker_symval_t; 56 57 struct linker_file_ops { 58 /* 59 * Lookup a symbol in the file's symbol table. If the symbol is 60 * not found then return ENOENT, otherwise zero. If the symbol 61 * found is a common symbol, return with *address set to zero and 62 * *size set to the size of the common space required. Otherwise 63 * set *address the value of the symbol. 64 */ 65 int (*lookup_symbol)(linker_file_t, const char* name, 66 linker_sym_t* sym); 67 68 int (*symbol_values)(linker_file_t, linker_sym_t, 69 linker_symval_t*); 70 71 int (*search_symbol)(linker_file_t, caddr_t value, 72 linker_sym_t* sym, long* diffp); 73 74 /* 75 * Unload a file, releasing dependancies and freeing storage. 76 */ 77 void (*unload)(linker_file_t); 78 }; 79 80 struct common_symbol { 81 STAILQ_ENTRY(common_symbol) link; 82 char* name; 83 caddr_t address; 84 }; 85 86 struct linker_file { 87 int refs; /* reference count */ 88 int userrefs; /* kldload(2) count */ 89 TAILQ_ENTRY(linker_file) link; /* list of all loaded files */ 90 char* filename; /* file which was loaded */ 91 int id; /* unique id */ 92 caddr_t address; /* load address */ 93 size_t size; /* size of file */ 94 int ndeps; /* number of dependancies */ 95 linker_file_t* deps; /* list of dependancies */ 96 STAILQ_HEAD(, common_symbol) common; /* list of common symbols */ 97 TAILQ_HEAD(, module) modules; /* modules in this file */ 98 void* priv; /* implementation data */ 99 100 struct linker_file_ops* ops; 101 }; 102 103 /* 104 * Object implementing a class of file (a.out, elf, etc.) 105 */ 106 typedef struct linker_class *linker_class_t; 107 typedef TAILQ_HEAD(, linker_class) linker_class_list_t; 108 109 struct linker_class_ops { 110 /* 111 * Load a file, returning the new linker_file_t in *result. If 112 * the class does not recognise the file type, zero should be 113 * returned, without modifying *result. If the file is 114 * recognised, the file should be loaded, *result set to the new 115 * file and zero returned. If some other error is detected an 116 * appropriate errno should be returned. 117 */ 118 int (*load_file)(const char* filename, linker_file_t* result); 119 }; 120 121 struct linker_class { 122 TAILQ_ENTRY(linker_class) link; /* list of all file classes */ 123 const char* desc; /* description (e.g. "a.out") */ 124 void* priv; /* implementation data */ 125 126 struct linker_class_ops *ops; 127 }; 128 129 /* 130 * The file which is currently loading. Used to register modules with 131 * the files which contain them. 132 */ 133 extern linker_file_t linker_current_file; 134 135 /* 136 * Add a new file class to the linker. 137 */ 138 int linker_add_class(const char* desc, void* priv, 139 struct linker_class_ops* ops); 140 141 /* 142 * Load a file, trying each file class until one succeeds. 143 */ 144 int linker_load_file(const char* filename, linker_file_t* result); 145 146 /* 147 * Find a currently loaded file given its filename. 148 */ 149 linker_file_t linker_find_file_by_name(const char* filename); 150 151 /* 152 * Find a currently loaded file given its file id. 153 */ 154 linker_file_t linker_find_file_by_id(int fileid); 155 156 /* 157 * Called from a class handler when a file is laoded. 158 */ 159 linker_file_t linker_make_file(const char* filename, void* priv, 160 struct linker_file_ops* ops); 161 162 /* 163 * Unload a file, freeing up memory. 164 */ 165 int linker_file_unload(linker_file_t file); 166 167 /* 168 * Add a dependancy to a file. 169 */ 170 int linker_file_add_dependancy(linker_file_t file, linker_file_t dep); 171 172 /* 173 * Lookup a symbol in a file. If deps is TRUE, look in dependancies 174 * if not found in file. 175 */ 176 caddr_t linker_file_lookup_symbol(linker_file_t file, const char* name, 177 int deps); 178 179 /* 180 * Search the linker path for the module. Return the full pathname in 181 * a malloc'ed buffer. 182 */ 183 char *linker_search_path(const char *filename); 184 185 /* 186 * DDB Helpers, tuned specifically for ddb/db_kld.c 187 */ 188 int linker_ddb_lookup(char *symstr, linker_sym_t *sym); 189 int linker_ddb_search_symbol(caddr_t value, linker_sym_t *sym, long *diffp); 190 int linker_ddb_symbol_values(linker_sym_t sym, linker_symval_t *symval); 191 192 193 #endif /* KERNEL */ 194 195 /* 196 * Module information subtypes 197 */ 198 #define MODINFO_END 0x0000 /* End of list */ 199 #define MODINFO_NAME 0x0001 /* Name of module (string) */ 200 #define MODINFO_TYPE 0x0002 /* Type of module (string) */ 201 #define MODINFO_ADDR 0x0003 /* Loaded address */ 202 #define MODINFO_SIZE 0x0004 /* Size of module */ 203 #define MODINFO_EMPTY 0x0005 /* Has been deleted */ 204 #define MODINFO_METADATA 0x8000 /* Module-specfic */ 205 206 #define MODINFOMD_AOUTEXEC 0x0001 /* a.out exec header */ 207 #define MODINFOMD_ELFHDR 0x0002 /* ELF header */ 208 #define MODINFOMD_SSYM 0x0003 /* start of symbols */ 209 #define MODINFOMD_ESYM 0x0004 /* end of symbols */ 210 #define MODINFOMD_DYNAMIC 0x0005 /* _DYNAMIC pointer */ 211 #define MODINFOMD_NOCOPY 0x8000 /* don't copy this metadata to the kernel */ 212 213 #define MODINFOMD_DEPLIST (0x4001 | MODINFOMD_NOCOPY) /* depends on */ 214 215 #ifdef KERNEL 216 217 /* 218 * Module lookup 219 */ 220 extern caddr_t preload_metadata; 221 extern caddr_t preload_search_by_name(const char *name); 222 extern caddr_t preload_search_by_type(const char *type); 223 extern caddr_t preload_search_next_name(caddr_t base); 224 extern caddr_t preload_search_info(caddr_t mod, int inf); 225 extern void preload_delete_name(const char *name); 226 extern void preload_bootstrap_relocate(vm_offset_t offset); 227 228 #ifdef KLD_DEBUG 229 230 extern int kld_debug; 231 #define KLD_DEBUG_FILE 1 /* file load/unload */ 232 #define KLD_DEBUG_SYM 2 /* symbol lookup */ 233 234 #define KLD_DPF(cat, args) \ 235 do { \ 236 if (kld_debug & KLD_DEBUG_##cat) printf args; \ 237 } while (0) 238 239 #else 240 241 #define KLD_DPF(cat, args) 242 243 #endif 244 245 /* Support functions */ 246 int elf_reloc(linker_file_t lf, const void *rel, int type, const char *sym); 247 /* values for type */ 248 #define ELF_RELOC_REL 1 249 #define ELF_RELOC_RELA 2 250 251 #endif /* KERNEL */ 252 253 struct kld_file_stat { 254 int version; /* set to sizeof(linker_file_stat) */ 255 char name[MAXPATHLEN]; 256 int refs; 257 int id; 258 caddr_t address; /* load address */ 259 size_t size; /* size in bytes */ 260 }; 261 262 #ifndef KERNEL 263 264 #include <sys/cdefs.h> 265 266 __BEGIN_DECLS 267 int kldload(const char* file); 268 int kldunload(int fileid); 269 int kldfind(const char* file); 270 int kldnext(int fileid); 271 int kldstat(int fileid, struct kld_file_stat* stat); 272 int kldfirstmod(int fileid); 273 __END_DECLS 274 275 #endif 276 277 #endif /* !_SYS_LINKER_H_ */ 278