1 /* $OpenBSD: resolve.h,v 1.108 2024/05/21 05:00:47 jsg Exp $ */ 2 3 /* 4 * Copyright (c) 1998 Per Fogelstrom, Opsycon AB 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS 16 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 17 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY 19 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 * 27 */ 28 29 #ifndef _RESOLVE_H_ 30 #define _RESOLVE_H_ 31 32 #include <sys/queue.h> 33 #include <dlfcn.h> 34 #include <link.h> 35 #include <tib.h> 36 37 #define __relro __attribute__((section(".data.rel.ro"))) 38 39 #ifndef __boot 40 # if DO_CLEAN_BOOT 41 # define __boot __attribute__((section(".boot.text"))) 42 # define __boot_data __attribute__((section(".boot.data"))) 43 # else 44 # define __boot 45 # define __boot_data 46 # endif 47 #endif 48 49 /* Number of low tags that are used saved internally (0 .. DT_NUM-1) */ 50 #define DT_NUM (DT_RELR + 1) 51 52 struct load_list { 53 struct load_list *next; 54 void *start; 55 size_t size; 56 int prot; 57 Elf_Addr moff; 58 long foff; 59 }; 60 61 typedef void initarrayfunc(int, const char **, char **, dl_cb_cb *); 62 typedef void initfunc(void); /* also fini and fini_array functions */ 63 64 /* Alpha uses 8byte entries for DT_HASH */ 65 #ifdef __alpha__ 66 typedef uint64_t Elf_Hash_Word; 67 #else 68 typedef uint32_t Elf_Hash_Word; 69 #endif 70 71 typedef struct elf_object elf_object_t; 72 73 struct object_vector { 74 int len; 75 int alloc; 76 elf_object_t **vec; 77 }; 78 void object_vec_grow(struct object_vector *_vec, int _more); 79 80 struct addr_range { 81 vaddr_t start; 82 vaddr_t end; 83 }; 84 85 struct range_vector { 86 struct addr_range slice[40]; 87 int count; 88 }; 89 90 /* 91 * Structure describing a loaded object. 92 * The head of this struct must be compatible 93 * with struct link_map in <link_elf.h> 94 */ 95 struct elf_object { 96 Elf_Addr obj_base; /* object's address '0' base */ 97 char *load_name; /* Pointer to object name */ 98 Elf_Dyn *load_dyn; /* Pointer to object dynamic data */ 99 struct elf_object *next; 100 struct elf_object *prev; 101 /* End struct link_map compatible */ 102 Elf_Addr load_base; /* Base address of loadable segments */ 103 104 struct load_list *load_list; 105 106 u_int32_t load_size; 107 108 union { 109 u_long info[DT_NUM + DT_PROCNUM]; 110 struct { 111 Elf_Addr null; /* Not used */ 112 Elf_Addr needed; /* Not used */ 113 Elf_Addr pltrelsz; 114 Elf_Addr *pltgot; 115 Elf_Addr *hash; 116 const char *strtab; 117 const Elf_Sym *symtab; 118 Elf_RelA *rela; 119 Elf_Addr relasz; 120 Elf_Addr relaent; 121 Elf_Addr strsz; 122 Elf_Addr syment; 123 initfunc *init; 124 initfunc *fini; 125 const char *soname; 126 const char *rpath; 127 Elf_Addr symbolic; 128 Elf_Rel *rel; 129 Elf_Addr relsz; 130 Elf_Addr relent; 131 Elf_Addr pltrel; 132 Elf_Addr debug; 133 Elf_Addr textrel; 134 Elf_Addr jmprel; 135 Elf_Addr bind_now; 136 initarrayfunc **init_array; 137 initfunc **fini_array; 138 Elf_Addr init_arraysz; 139 Elf_Addr fini_arraysz; 140 const char *runpath; 141 Elf_Addr flags; 142 Elf_Addr encoding; 143 initarrayfunc **preinit_array; 144 Elf_Addr preinit_arraysz; 145 Elf_Addr unassigned; 146 Elf_Addr relrsz; 147 Elf_Relr *relr; 148 } u; 149 } Dyn; 150 #define dyn Dyn.u 151 152 Elf_Addr relacount; /* DT_RELACOUNT */ 153 Elf_Addr relcount; /* DT_RELCOUNT */ 154 155 int status; 156 #define STAT_RELOC_DONE 0x001 157 #define STAT_GOT_DONE 0x002 158 #define STAT_INIT_DONE 0x004 159 #define STAT_FINI_DONE 0x008 160 #define STAT_FINI_READY 0x010 161 #define STAT_UNLOADED 0x020 162 #define STAT_NODELETE 0x040 163 #define STAT_GNU_HASH 0x080 164 #define STAT_VISIT_INITFIRST 0x100 165 #define STAT_VISIT_INIT 0x200 166 167 Elf_Phdr *phdrp; 168 int phdrc; 169 170 int obj_type; 171 #define OBJTYPE_LDR 1 172 #define OBJTYPE_EXE 2 173 #define OBJTYPE_LIB 3 174 #define OBJTYPE_DLO 4 175 int obj_flags; /* c.f. <sys/exec_elf.h> DF_1_* */ 176 int nodelete; 177 178 /* shared by ELF and GNU hash */ 179 u_int32_t nbuckets; 180 u_int32_t nchains; /* really, number of symbols */ 181 union { 182 struct { 183 /* specific to ELF hash */ 184 const Elf_Hash_Word *buckets; 185 const Elf_Hash_Word *chains; 186 } u_elf; 187 struct { 188 /* specific to GNU hash */ 189 const Elf_Word *buckets; 190 const Elf_Word *chains; 191 const Elf_Addr *bloom; 192 Elf_Word mask_bm; 193 Elf_Word shift2; 194 Elf_Word symndx; 195 } u_gnu; 196 } hash_u; 197 #define buckets_elf hash_u.u_elf.buckets 198 #define chains_elf hash_u.u_elf.chains 199 #define buckets_gnu hash_u.u_gnu.buckets 200 #define chains_gnu hash_u.u_gnu.chains 201 #define bloom_gnu hash_u.u_gnu.bloom 202 #define mask_bm_gnu hash_u.u_gnu.mask_bm 203 #define shift2_gnu hash_u.u_gnu.shift2 204 #define symndx_gnu hash_u.u_gnu.symndx 205 206 struct object_vector child_vec; /* direct dep libs of object */ 207 struct object_vector grpsym_vec; /* ordered complete dep list */ 208 TAILQ_HEAD(,dep_node) grpref_list; /* refs to other load groups */ 209 210 int refcount; /* dep libs only */ 211 int opencount; /* # dlopen() & exe */ 212 int grprefcount; /* load group refs */ 213 #define OBJECT_REF_CNT(object) \ 214 ((object->refcount + object->opencount + object->grprefcount)) 215 #define OBJECT_DLREF_CNT(object) \ 216 ((object->opencount + object->grprefcount)) 217 218 /* object that caused this module to be loaded, used in symbol lookup */ 219 elf_object_t *load_object; 220 struct sod sod; 221 222 /* for object confirmation */ 223 dev_t dev; 224 ino_t inode; 225 226 /* thread local storage info */ 227 Elf_Addr tls_fsize; 228 Elf_Addr tls_msize; 229 Elf_Addr tls_align; 230 const void *tls_static_data; 231 int tls_offset; 232 233 /* relro bits */ 234 Elf_Addr relro_addr; 235 Elf_Addr relro_size; 236 237 /* generation number of last grpsym insert on this object */ 238 unsigned int grpsym_gen; 239 240 char **rpath; 241 char **runpath; 242 243 /* nonzero if trace enabled for this object */ 244 int traced; 245 246 struct range_vector imut; 247 struct range_vector mut; 248 int islibc; 249 }; 250 251 struct dep_node { 252 TAILQ_ENTRY(dep_node) next_sib; 253 elf_object_t *data; 254 }; 255 256 257 /* Please don't rename or make hidden; gdb(1) knows about these. */ 258 Elf_Addr _dl_bind(elf_object_t *object, int index); 259 void _dl_debug_state(void); 260 261 /* exported to the application */ 262 extern char *__progname; 263 264 __BEGIN_HIDDEN_DECLS 265 void _dl_handle_nodelete(elf_object_t *_object); 266 void _dl_add_object(elf_object_t *object); 267 elf_object_t *_dl_finalize_object(const char *objname, Elf_Dyn *dynp, 268 Elf_Phdr *phdrp, int phdrc, const int objtype, const long lbase, 269 const long obase); 270 void _dl_remove_object(elf_object_t *object); 271 void _dl_cleanup_objects(void); 272 273 void _dl_handle_already_loaded(elf_object_t *_object, int _flags); 274 elf_object_t *_dl_load_shlib(const char *, elf_object_t *, 275 int, int, int nodelete); 276 elf_object_t *_dl_tryload_shlib(const char *libname, int type, 277 int flags, int nodelete); 278 279 int _dl_md_reloc(elf_object_t *object, int rel, int relsz); 280 int _dl_md_reloc_got(elf_object_t *object, int lazy); 281 282 struct sym_res { 283 const Elf_Sym *sym; 284 const elf_object_t *obj; 285 }; 286 287 struct sym_res _dl_find_symbol(const char *name, int flags, 288 const Elf_Sym *ref_sym, elf_object_t *object); 289 290 /* 291 * defines for _dl_find_symbol() flag field, three bits of meaning 292 * myself - clear: search all objects, set: search only this object 293 * warnnotfound - clear: no warning, set: warn if not found 294 * inplt - clear: possible plt ref set: real matching function. 295 * 296 * inplt - due to how ELF handles function addresses in shared libraries 297 * &func may actually refer to the plt entry in the main program 298 * rather than the actual function address in the .so file. 299 * This rather bizarre behavior is documented in the SVR4 ABI. 300 * when getting the function address to relocate a PLT entry 301 * the 'real' function address is necessary, not the possible PLT address. 302 */ 303 /* myself */ 304 #define SYM_SEARCH_ALL 0x00 305 #define SYM_SEARCH_SELF 0x01 306 #define SYM_SEARCH_OTHER 0x02 307 #define SYM_SEARCH_NEXT 0x04 308 /* warnnotfound */ 309 #define SYM_NOWARNNOTFOUND 0x00 310 #define SYM_WARNNOTFOUND 0x10 311 /* inplt */ 312 #define SYM_NOTPLT 0x00 313 #define SYM_PLT 0x20 314 315 #define SYM_DLSYM 0x40 316 317 int _dl_load_dep_libs(elf_object_t *object, int flags, int booting); 318 int _dl_rtld(elf_object_t *object); 319 void _dl_call_init(elf_object_t *object); 320 void _dl_link_child(elf_object_t *dep, elf_object_t *p); 321 void _dl_link_grpsym(elf_object_t *object); 322 void _dl_cache_grpsym_list_setup(elf_object_t *_object); 323 void _dl_link_grpref(elf_object_t *load_group, elf_object_t *load_object); 324 void _dl_link_dlopen(elf_object_t *dep); 325 void _dl_notify_unload_shlib(elf_object_t *object); 326 void _dl_unload_shlib(elf_object_t *object); 327 void _dl_unload_dlopen(void); 328 329 void _dl_run_all_dtors(void); 330 331 int _dl_match_file(struct sod *sodp, const char *name, int namelen); 332 char *_dl_find_shlib(struct sod *sodp, char **searchpath, int nohints); 333 void _dl_load_list_free(struct load_list *load_list); 334 335 void _dl_push_range_size(struct range_vector *v, vaddr_t start, vsize_t len); 336 void _dl_apply_immutable(elf_object_t *object); 337 338 typedef void lock_cb(int); 339 void _dl_thread_kern_go(lock_cb *); 340 lock_cb *_dl_thread_kern_stop(void); 341 342 int _dl_islibc(Elf_Dyn *_dynp, Elf_Addr loff); 343 void _dl_pin(int, Elf_Phdr *, void *, size_t, void *, size_t); 344 345 char *_dl_getenv(const char *, char **) __boot; 346 void _dl_unsetenv(const char *, char **) __boot; 347 348 void _dl_trace_setup(char **) __boot; 349 void _dl_trace_object_setup(elf_object_t *); 350 int _dl_trace_plt(const elf_object_t *, const char *); 351 352 /* dlfcn.c */ 353 void _dl_show_objects(elf_object_t *_object); 354 355 /* tib.c */ 356 void _dl_allocate_tls_offsets(void) __boot; 357 void _dl_allocate_first_tib(void) __boot; 358 void _dl_set_tls(elf_object_t *_object, Elf_Phdr *_ptls, Elf_Addr _libaddr, 359 const char *_libname); 360 extern int _dl_tib_static_done; 361 362 extern elf_object_t *_dl_objects; 363 extern int object_count; /* how many objects are currently loaded */ 364 365 extern elf_object_t *_dl_loading_object; 366 367 extern struct r_debug *_dl_debug_map; 368 369 extern int _dl_pagesz; 370 extern int _dl_errno; 371 372 extern char **_dl_libpath; 373 374 extern int _dl_bindnow; 375 extern int _dl_traceld; 376 extern int _dl_debug; 377 378 extern char *_dl_preload; 379 extern char *_dl_tracefmt1; 380 extern char *_dl_tracefmt2; 381 extern char *_dl_traceprog; 382 383 extern void *_dl_exec_hint; 384 385 extern int _dl_trust; 386 387 #define DL_DEB(P) do { if (_dl_debug) _dl_printf P ; } while (0) 388 389 #define DL_NOT_FOUND 1 390 #define DL_CANT_OPEN 2 391 #define DL_NOT_ELF 3 392 #define DL_CANT_OPEN_REF 4 393 #define DL_CANT_MMAP 5 394 #define DL_NO_SYMBOL 6 395 #define DL_INVALID_HANDLE 7 396 #define DL_INVALID_CTL 8 397 #define DL_NO_OBJECT 9 398 #define DL_CANT_FIND_OBJ 10 399 #define DL_CANT_LOAD_OBJ 11 400 #define DL_INVALID_MODE 12 401 402 #define ELF_ROUND(x,malign) (((x) + (malign)-1) & ~((malign)-1)) 403 #define ELF_TRUNC(x,malign) ((x) & ~((malign)-1)) 404 405 /* symbol lookup cache */ 406 typedef struct sym_cache { 407 const elf_object_t *obj; 408 const Elf_Sym *sym; 409 int flags; 410 } sym_cache; 411 412 TAILQ_HEAD(dlochld, dep_node); 413 extern struct dlochld _dlopened_child_list; 414 __END_HIDDEN_DECLS 415 416 #endif /* _RESOLVE_H_ */ 417