1 /* $OpenBSD: resolve.h,v 1.99 2021/11/12 22:28:13 guenther 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 /* 81 * Structure describing a loaded object. 82 * The head of this struct must be compatible 83 * with struct link_map in sys/link.h 84 */ 85 struct elf_object { 86 Elf_Addr obj_base; /* object's address '0' base */ 87 char *load_name; /* Pointer to object name */ 88 Elf_Dyn *load_dyn; /* Pointer to object dynamic data */ 89 struct elf_object *next; 90 struct elf_object *prev; 91 /* End struct link_map compatible */ 92 Elf_Addr load_base; /* Base address of loadable segments */ 93 94 struct load_list *load_list; 95 96 u_int32_t load_size; 97 98 union { 99 u_long info[DT_NUM + DT_PROCNUM]; 100 struct { 101 Elf_Addr null; /* Not used */ 102 Elf_Addr needed; /* Not used */ 103 Elf_Addr pltrelsz; 104 Elf_Addr *pltgot; 105 Elf_Addr *hash; 106 const char *strtab; 107 const Elf_Sym *symtab; 108 Elf_RelA *rela; 109 Elf_Addr relasz; 110 Elf_Addr relaent; 111 Elf_Addr strsz; 112 Elf_Addr syment; 113 initfunc *init; 114 initfunc *fini; 115 const char *soname; 116 const char *rpath; 117 Elf_Addr symbolic; 118 Elf_Rel *rel; 119 Elf_Addr relsz; 120 Elf_Addr relent; 121 Elf_Addr pltrel; 122 Elf_Addr debug; 123 Elf_Addr textrel; 124 Elf_Addr jmprel; 125 Elf_Addr bind_now; 126 initarrayfunc **init_array; 127 initfunc **fini_array; 128 Elf_Addr init_arraysz; 129 Elf_Addr fini_arraysz; 130 const char *runpath; 131 Elf_Addr flags; 132 Elf_Addr encoding; 133 initarrayfunc **preinit_array; 134 Elf_Addr preinit_arraysz; 135 Elf_Addr unassigned; 136 Elf_Addr relrsz; 137 Elf_Relr *relr; 138 } u; 139 } Dyn; 140 #define dyn Dyn.u 141 142 Elf_Addr relacount; /* DT_RELACOUNT */ 143 Elf_Addr relcount; /* DT_RELCOUNT */ 144 145 int status; 146 #define STAT_RELOC_DONE 0x001 147 #define STAT_GOT_DONE 0x002 148 #define STAT_INIT_DONE 0x004 149 #define STAT_FINI_DONE 0x008 150 #define STAT_FINI_READY 0x010 151 #define STAT_UNLOADED 0x020 152 #define STAT_NODELETE 0x040 153 #define STAT_GNU_HASH 0x080 154 #define STAT_VISIT_INITFIRST 0x100 155 #define STAT_VISIT_INIT 0x200 156 157 Elf_Phdr *phdrp; 158 int phdrc; 159 160 int obj_type; 161 #define OBJTYPE_LDR 1 162 #define OBJTYPE_EXE 2 163 #define OBJTYPE_LIB 3 164 #define OBJTYPE_DLO 4 165 int obj_flags; /* c.f. <sys/exec_elf.h> DF_1_* */ 166 167 /* shared by ELF and GNU hash */ 168 u_int32_t nbuckets; 169 u_int32_t nchains; /* really, number of symbols */ 170 union { 171 struct { 172 /* specific to ELF hash */ 173 const Elf_Hash_Word *buckets; 174 const Elf_Hash_Word *chains; 175 } u_elf; 176 struct { 177 /* specific to GNU hash */ 178 const Elf_Word *buckets; 179 const Elf_Word *chains; 180 const Elf_Addr *bloom; 181 Elf_Word mask_bm; 182 Elf_Word shift2; 183 Elf_Word symndx; 184 } u_gnu; 185 } hash_u; 186 #define buckets_elf hash_u.u_elf.buckets 187 #define chains_elf hash_u.u_elf.chains 188 #define buckets_gnu hash_u.u_gnu.buckets 189 #define chains_gnu hash_u.u_gnu.chains 190 #define bloom_gnu hash_u.u_gnu.bloom 191 #define mask_bm_gnu hash_u.u_gnu.mask_bm 192 #define shift2_gnu hash_u.u_gnu.shift2 193 #define symndx_gnu hash_u.u_gnu.symndx 194 195 struct object_vector child_vec; /* direct dep libs of object */ 196 struct object_vector grpsym_vec; /* ordered complete dep list */ 197 TAILQ_HEAD(,dep_node) grpref_list; /* refs to other load groups */ 198 199 int refcount; /* dep libs only */ 200 int opencount; /* # dlopen() & exe */ 201 int grprefcount; /* load group refs */ 202 #define OBJECT_REF_CNT(object) \ 203 ((object->refcount + object->opencount + object->grprefcount)) 204 #define OBJECT_DLREF_CNT(object) \ 205 ((object->opencount + object->grprefcount)) 206 207 /* object that caused this module to be loaded, used in symbol lookup */ 208 elf_object_t *load_object; 209 struct sod sod; 210 211 /* for object confirmation */ 212 dev_t dev; 213 ino_t inode; 214 215 /* thread local storage info */ 216 Elf_Addr tls_fsize; 217 Elf_Addr tls_msize; 218 Elf_Addr tls_align; 219 const void *tls_static_data; 220 int tls_offset; 221 222 /* relro bits */ 223 Elf_Addr relro_addr; 224 Elf_Addr relro_size; 225 226 /* generation number of last grpsym insert on this object */ 227 unsigned int grpsym_gen; 228 229 char **rpath; 230 char **runpath; 231 232 /* nonzero if trace enabled for this object */ 233 int traced; 234 }; 235 236 struct dep_node { 237 TAILQ_ENTRY(dep_node) next_sib; 238 elf_object_t *data; 239 }; 240 241 242 /* Please don't rename or make hidden; gdb(1) knows about these. */ 243 Elf_Addr _dl_bind(elf_object_t *object, int index); 244 void _dl_debug_state(void); 245 246 /* exported to the application */ 247 extern char *__progname; 248 249 __BEGIN_HIDDEN_DECLS 250 void _dl_handle_nodelete(elf_object_t *_object); 251 void _dl_add_object(elf_object_t *object); 252 elf_object_t *_dl_finalize_object(const char *objname, Elf_Dyn *dynp, 253 Elf_Phdr *phdrp, int phdrc, const int objtype, const long lbase, 254 const long obase); 255 void _dl_remove_object(elf_object_t *object); 256 void _dl_cleanup_objects(void); 257 258 elf_object_t *_dl_load_shlib(const char *, elf_object_t *, int, int); 259 elf_object_t *_dl_tryload_shlib(const char *libname, int type, int flags); 260 261 int _dl_md_reloc(elf_object_t *object, int rel, int relsz); 262 int _dl_md_reloc_got(elf_object_t *object, int lazy); 263 264 struct sym_res { 265 const Elf_Sym *sym; 266 const elf_object_t *obj; 267 }; 268 269 struct sym_res _dl_find_symbol(const char *name, int flags, 270 const Elf_Sym *ref_sym, elf_object_t *object); 271 272 /* 273 * defines for _dl_find_symbol() flag field, three bits of meaning 274 * myself - clear: search all objects, set: search only this object 275 * warnnotfound - clear: no warning, set: warn if not found 276 * inplt - clear: possible plt ref set: real matching function. 277 * 278 * inplt - due to how ELF handles function addresses in shared libraries 279 * &func may actually refer to the plt entry in the main program 280 * rather than the actual function address in the .so file. 281 * This rather bizarre behavior is documented in the SVR4 ABI. 282 * when getting the function address to relocate a PLT entry 283 * the 'real' function address is necessary, not the possible PLT address. 284 */ 285 /* myself */ 286 #define SYM_SEARCH_ALL 0x00 287 #define SYM_SEARCH_SELF 0x01 288 #define SYM_SEARCH_OTHER 0x02 289 #define SYM_SEARCH_NEXT 0x04 290 /* warnnotfound */ 291 #define SYM_NOWARNNOTFOUND 0x00 292 #define SYM_WARNNOTFOUND 0x10 293 /* inplt */ 294 #define SYM_NOTPLT 0x00 295 #define SYM_PLT 0x20 296 297 #define SYM_DLSYM 0x40 298 299 int _dl_load_dep_libs(elf_object_t *object, int flags, int booting); 300 int _dl_rtld(elf_object_t *object); 301 void _dl_call_init(elf_object_t *object); 302 void _dl_link_child(elf_object_t *dep, elf_object_t *p); 303 void _dl_link_grpsym(elf_object_t *object); 304 void _dl_cache_grpsym_list_setup(elf_object_t *_object); 305 void _dl_link_grpref(elf_object_t *load_group, elf_object_t *load_object); 306 void _dl_link_dlopen(elf_object_t *dep); 307 void _dl_unlink_dlopen(elf_object_t *dep); 308 void _dl_notify_unload_shlib(elf_object_t *object); 309 void _dl_unload_shlib(elf_object_t *object); 310 void _dl_unload_dlopen(void); 311 312 void _dl_run_all_dtors(void); 313 314 int _dl_match_file(struct sod *sodp, const char *name, int namelen); 315 char *_dl_find_shlib(struct sod *sodp, char **searchpath, int nohints); 316 void _dl_load_list_free(struct load_list *load_list); 317 318 typedef void lock_cb(int); 319 void _dl_thread_kern_go(lock_cb *); 320 lock_cb *_dl_thread_kern_stop(void); 321 322 char *_dl_getenv(const char *, char **) __boot; 323 void _dl_unsetenv(const char *, char **) __boot; 324 325 void _dl_trace_setup(char **) __boot; 326 void _dl_trace_object_setup(elf_object_t *); 327 int _dl_trace_plt(const elf_object_t *, const char *); 328 329 /* tib.c */ 330 void _dl_allocate_tls_offsets(void) __boot; 331 void _dl_allocate_first_tib(void) __boot; 332 void _dl_set_tls(elf_object_t *_object, Elf_Phdr *_ptls, Elf_Addr _libaddr, 333 const char *_libname); 334 extern int _dl_tib_static_done; 335 336 extern elf_object_t *_dl_objects; 337 extern int object_count; /* how many objects are currently loaded */ 338 339 extern elf_object_t *_dl_loading_object; 340 341 extern struct r_debug *_dl_debug_map; 342 343 extern int _dl_pagesz; 344 extern int _dl_errno; 345 346 extern char **_dl_libpath; 347 348 extern int _dl_bindnow; 349 extern int _dl_traceld; 350 extern int _dl_debug; 351 352 extern char *_dl_preload; 353 extern char *_dl_tracefmt1; 354 extern char *_dl_tracefmt2; 355 extern char *_dl_traceprog; 356 357 extern void *_dl_exec_hint; 358 359 extern int _dl_trust; 360 361 #define DL_DEB(P) do { if (_dl_debug) _dl_printf P ; } while (0) 362 363 #define DL_NOT_FOUND 1 364 #define DL_CANT_OPEN 2 365 #define DL_NOT_ELF 3 366 #define DL_CANT_OPEN_REF 4 367 #define DL_CANT_MMAP 5 368 #define DL_NO_SYMBOL 6 369 #define DL_INVALID_HANDLE 7 370 #define DL_INVALID_CTL 8 371 #define DL_NO_OBJECT 9 372 #define DL_CANT_FIND_OBJ 10 373 #define DL_CANT_LOAD_OBJ 11 374 #define DL_INVALID_MODE 12 375 376 #define ELF_ROUND(x,malign) (((x) + (malign)-1) & ~((malign)-1)) 377 #define ELF_TRUNC(x,malign) ((x) & ~((malign)-1)) 378 379 /* symbol lookup cache */ 380 typedef struct sym_cache { 381 const elf_object_t *obj; 382 const Elf_Sym *sym; 383 int flags; 384 } sym_cache; 385 386 TAILQ_HEAD(dlochld, dep_node); 387 extern struct dlochld _dlopened_child_list; 388 __END_HIDDEN_DECLS 389 390 #endif /* _RESOLVE_H_ */ 391