1 /*- 2 * Copyright (c) 1997-2000 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 * $FreeBSD$ 27 */ 28 29 #ifndef _SYS_LINKER_H_ 30 #define _SYS_LINKER_H_ 31 32 #ifdef _KERNEL 33 34 #include <machine/elf.h> 35 #include <sys/kobj.h> 36 37 #ifdef MALLOC_DECLARE 38 MALLOC_DECLARE(M_LINKER); 39 #endif 40 41 struct mod_depend; 42 43 /* 44 * Object representing a file which has been loaded by the linker. 45 */ 46 typedef struct linker_file* linker_file_t; 47 typedef TAILQ_HEAD(, linker_file) linker_file_list_t; 48 49 typedef caddr_t linker_sym_t; /* opaque symbol */ 50 typedef c_caddr_t c_linker_sym_t; /* const opaque symbol */ 51 typedef int (*linker_function_name_callback_t)(const char *, void *); 52 53 /* 54 * expanded out linker_sym_t 55 */ 56 typedef struct linker_symval { 57 const char* name; 58 caddr_t value; 59 size_t size; 60 } linker_symval_t; 61 62 typedef int (*linker_function_nameval_callback_t)(linker_file_t, int, linker_symval_t *, void *); 63 64 struct common_symbol { 65 STAILQ_ENTRY(common_symbol) link; 66 char* name; 67 caddr_t address; 68 }; 69 70 struct linker_file { 71 KOBJ_FIELDS; 72 int refs; /* reference count */ 73 int userrefs; /* kldload(2) count */ 74 int flags; 75 #define LINKER_FILE_LINKED 0x1 /* file has been fully linked */ 76 TAILQ_ENTRY(linker_file) link; /* list of all loaded files */ 77 char* filename; /* file which was loaded */ 78 char* pathname; /* file name with full path */ 79 int id; /* unique id */ 80 caddr_t address; /* load address */ 81 size_t size; /* size of file */ 82 caddr_t ctors_addr; /* address of .ctors */ 83 size_t ctors_size; /* size of .ctors */ 84 int ndeps; /* number of dependencies */ 85 linker_file_t* deps; /* list of dependencies */ 86 STAILQ_HEAD(, common_symbol) common; /* list of common symbols */ 87 TAILQ_HEAD(, module) modules; /* modules in this file */ 88 TAILQ_ENTRY(linker_file) loaded; /* preload dependency support */ 89 int loadcnt; /* load counter value */ 90 91 /* 92 * Function Boundary Tracing (FBT) or Statically Defined Tracing (SDT) 93 * fields. 94 */ 95 int nenabled; /* number of enabled probes. */ 96 int fbt_nentries; /* number of fbt entries created. */ 97 }; 98 99 /* 100 * Object implementing a class of file (a.out, elf, etc.) 101 */ 102 typedef struct linker_class *linker_class_t; 103 typedef TAILQ_HEAD(, linker_class) linker_class_list_t; 104 105 struct linker_class { 106 KOBJ_CLASS_FIELDS; 107 TAILQ_ENTRY(linker_class) link; /* list of all file classes */ 108 }; 109 110 /* 111 * Function type used when iterating over the list of linker files. 112 */ 113 typedef int linker_predicate_t(linker_file_t, void *); 114 115 /* 116 * The "file" for the kernel. 117 */ 118 extern linker_file_t linker_kernel_file; 119 120 /* 121 * Obtain a reference to a module, loading it if required. 122 */ 123 int linker_reference_module(const char* _modname, struct mod_depend *_verinfo, 124 linker_file_t* _result); 125 126 /* 127 * Release a reference to a module, unloading it if there are no more 128 * references. Note that one should either provide a module name and 129 * optional version info or a linker file, but not both. 130 */ 131 int linker_release_module(const char *_modname, struct mod_depend *_verinfo, 132 linker_file_t _file); 133 134 /* 135 * Iterate over all of the currently loaded linker files calling the 136 * predicate function while the function returns 0. Returns the value 137 * returned by the last predicate function. 138 */ 139 int linker_file_foreach(linker_predicate_t *_predicate, void *_context); 140 141 /* 142 * Lookup a symbol in a file. If deps is TRUE, look in dependencies 143 * if not found in file. 144 */ 145 caddr_t linker_file_lookup_symbol(linker_file_t _file, const char* _name, 146 int _deps); 147 148 /* 149 * Lookup a linker set in a file. Return pointers to the first entry, 150 * last + 1, and count of entries. Use: for (p = start; p < stop; p++) {} 151 * void *start is really: "struct yoursetmember ***start;" 152 */ 153 int linker_file_lookup_set(linker_file_t _file, const char *_name, 154 void *_start, void *_stop, int *_count); 155 156 /* 157 * List all functions in a file. 158 */ 159 int linker_file_function_listall(linker_file_t, 160 linker_function_nameval_callback_t, void *); 161 162 /* 163 * Functions soley for use by the linker class handlers. 164 */ 165 int linker_add_class(linker_class_t _cls); 166 int linker_file_unload(linker_file_t _file, int flags); 167 int linker_load_dependencies(linker_file_t _lf); 168 linker_file_t linker_make_file(const char* _filename, linker_class_t _cls); 169 170 /* 171 * DDB Helpers, tuned specifically for ddb/db_kld.c 172 */ 173 int linker_ddb_lookup(const char *_symstr, c_linker_sym_t *_sym); 174 int linker_ddb_search_symbol(caddr_t _value, c_linker_sym_t *_sym, 175 long *_diffp); 176 int linker_ddb_symbol_values(c_linker_sym_t _sym, linker_symval_t *_symval); 177 int linker_ddb_search_symbol_name(caddr_t value, char *buf, u_int buflen, 178 long *offset); 179 180 /* 181 * stack(9) helper for situations where kernel locking is required. 182 */ 183 int linker_search_symbol_name(caddr_t value, char *buf, u_int buflen, 184 long *offset); 185 186 187 /* HWPMC helper */ 188 void *linker_hwpmc_list_objects(void); 189 190 #endif /* _KERNEL */ 191 192 /* 193 * Module information subtypes 194 */ 195 #define MODINFO_END 0x0000 /* End of list */ 196 #define MODINFO_NAME 0x0001 /* Name of module (string) */ 197 #define MODINFO_TYPE 0x0002 /* Type of module (string) */ 198 #define MODINFO_ADDR 0x0003 /* Loaded address */ 199 #define MODINFO_SIZE 0x0004 /* Size of module */ 200 #define MODINFO_EMPTY 0x0005 /* Has been deleted */ 201 #define MODINFO_ARGS 0x0006 /* Parameters string */ 202 #define MODINFO_METADATA 0x8000 /* Module-specfic */ 203 204 #define MODINFOMD_AOUTEXEC 0x0001 /* a.out exec header */ 205 #define MODINFOMD_ELFHDR 0x0002 /* ELF header */ 206 #define MODINFOMD_SSYM 0x0003 /* start of symbols */ 207 #define MODINFOMD_ESYM 0x0004 /* end of symbols */ 208 #define MODINFOMD_DYNAMIC 0x0005 /* _DYNAMIC pointer */ 209 /* These values are MD on these two platforms */ 210 #if !defined(__sparc64__) && !defined(__powerpc__) 211 #define MODINFOMD_ENVP 0x0006 /* envp[] */ 212 #define MODINFOMD_HOWTO 0x0007 /* boothowto */ 213 #define MODINFOMD_KERNEND 0x0008 /* kernend */ 214 #endif 215 #define MODINFOMD_SHDR 0x0009 /* section header table */ 216 #define MODINFOMD_CTORS_ADDR 0x000a /* address of .ctors */ 217 #define MODINFOMD_CTORS_SIZE 0x000b /* size of .ctors */ 218 #define MODINFOMD_NOCOPY 0x8000 /* don't copy this metadata to the kernel */ 219 220 #define MODINFOMD_DEPLIST (0x4001 | MODINFOMD_NOCOPY) /* depends on */ 221 222 #ifdef _KERNEL 223 #define MD_FETCH(mdp, info, type) ({ \ 224 type *__p; \ 225 __p = (type *)preload_search_info((mdp), MODINFO_METADATA | (info)); \ 226 __p ? *__p : 0; \ 227 }) 228 #endif 229 230 #define LINKER_HINTS_VERSION 1 /* linker.hints file version */ 231 #define LINKER_HINTS_MAX (1 << 20) /* Allow at most 1MB for linker.hints */ 232 233 #ifdef _KERNEL 234 235 /* 236 * Module lookup 237 */ 238 extern vm_offset_t preload_addr_relocate; 239 extern caddr_t preload_metadata; 240 241 extern void * preload_fetch_addr(caddr_t _mod); 242 extern size_t preload_fetch_size(caddr_t _mod); 243 extern caddr_t preload_search_by_name(const char *_name); 244 extern caddr_t preload_search_by_type(const char *_type); 245 extern caddr_t preload_search_next_name(caddr_t _base); 246 extern caddr_t preload_search_info(caddr_t _mod, int _inf); 247 extern void preload_delete_name(const char *_name); 248 extern void preload_bootstrap_relocate(vm_offset_t _offset); 249 250 #ifdef KLD_DEBUG 251 252 extern int kld_debug; 253 #define KLD_DEBUG_FILE 1 /* file load/unload */ 254 #define KLD_DEBUG_SYM 2 /* symbol lookup */ 255 256 #define KLD_DPF(cat, args) \ 257 do { \ 258 if (kld_debug & KLD_DEBUG_##cat) printf args; \ 259 } while (0) 260 261 #else 262 263 #define KLD_DPF(cat, args) 264 265 #endif 266 267 typedef Elf_Addr elf_lookup_fn(linker_file_t, Elf_Size, int); 268 269 /* Support functions */ 270 int elf_reloc(linker_file_t _lf, Elf_Addr base, const void *_rel, int _type, elf_lookup_fn _lu); 271 int elf_reloc_local(linker_file_t _lf, Elf_Addr base, const void *_rel, int _type, elf_lookup_fn _lu); 272 Elf_Addr elf_relocaddr(linker_file_t _lf, Elf_Addr addr); 273 const Elf_Sym *elf_get_sym(linker_file_t _lf, Elf_Size _symidx); 274 const char *elf_get_symname(linker_file_t _lf, Elf_Size _symidx); 275 276 typedef struct linker_ctf { 277 const uint8_t *ctftab; /* Decompressed CTF data. */ 278 int ctfcnt; /* Number of CTF data bytes. */ 279 const Elf_Sym *symtab; /* Ptr to the symbol table. */ 280 int nsym; /* Number of symbols. */ 281 const char *strtab; /* Ptr to the string table. */ 282 int strcnt; /* Number of string bytes. */ 283 uint32_t **ctfoffp; /* Ptr to array of obj/fnc offsets. */ 284 uint32_t **typoffp; /* Ptr to array of type offsets. */ 285 long *typlenp; /* Ptr to number of type data entries. */ 286 } linker_ctf_t; 287 288 int linker_ctf_get(linker_file_t, linker_ctf_t *); 289 290 int elf_cpu_load_file(linker_file_t); 291 int elf_cpu_unload_file(linker_file_t); 292 293 /* values for type */ 294 #define ELF_RELOC_REL 1 295 #define ELF_RELOC_RELA 2 296 297 /* 298 * This is version 1 of the KLD file status structure. It is identified 299 * by its _size_ in the version field. 300 */ 301 struct kld_file_stat_1 { 302 int version; /* set to sizeof(struct kld_file_stat_1) */ 303 char name[MAXPATHLEN]; 304 int refs; 305 int id; 306 caddr_t address; /* load address */ 307 size_t size; /* size in bytes */ 308 }; 309 #endif /* _KERNEL */ 310 311 struct kld_file_stat { 312 int version; /* set to sizeof(struct kld_file_stat) */ 313 char name[MAXPATHLEN]; 314 int refs; 315 int id; 316 caddr_t address; /* load address */ 317 size_t size; /* size in bytes */ 318 char pathname[MAXPATHLEN]; 319 }; 320 321 struct kld_sym_lookup { 322 int version; /* set to sizeof(struct kld_sym_lookup) */ 323 char *symname; /* Symbol name we are looking up */ 324 u_long symvalue; 325 size_t symsize; 326 }; 327 #define KLDSYM_LOOKUP 1 328 329 /* 330 * Flags for kldunloadf() and linker_file_unload() 331 */ 332 #define LINKER_UNLOAD_NORMAL 0 333 #define LINKER_UNLOAD_FORCE 1 334 335 #ifndef _KERNEL 336 337 #include <sys/cdefs.h> 338 339 __BEGIN_DECLS 340 int kldload(const char* _file); 341 int kldunload(int _fileid); 342 int kldunloadf(int _fileid, int flags); 343 int kldfind(const char* _file); 344 int kldnext(int _fileid); 345 int kldstat(int _fileid, struct kld_file_stat* _stat); 346 int kldfirstmod(int _fileid); 347 int kldsym(int _fileid, int _cmd, void *_data); 348 __END_DECLS 349 350 #endif 351 352 #endif /* !_SYS_LINKER_H_ */ 353