1 /* $OpenBSD: resolve.h,v 1.96 2019/10/04 17:42:16 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_PREINIT_ARRAYSZ + 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 } u; 136 } Dyn; 137 #define dyn Dyn.u 138 139 Elf_Addr relacount; /* DT_RELACOUNT */ 140 Elf_Addr relcount; /* DT_RELCOUNT */ 141 142 int status; 143 #define STAT_RELOC_DONE 0x001 144 #define STAT_GOT_DONE 0x002 145 #define STAT_INIT_DONE 0x004 146 #define STAT_FINI_DONE 0x008 147 #define STAT_FINI_READY 0x010 148 #define STAT_UNLOADED 0x020 149 #define STAT_NODELETE 0x040 150 #define STAT_GNU_HASH 0x080 151 #define STAT_VISIT_INITFIRST 0x100 152 #define STAT_VISIT_INIT 0x200 153 154 Elf_Phdr *phdrp; 155 int phdrc; 156 157 int obj_type; 158 #define OBJTYPE_LDR 1 159 #define OBJTYPE_EXE 2 160 #define OBJTYPE_LIB 3 161 #define OBJTYPE_DLO 4 162 int obj_flags; /* c.f. <sys/exec_elf.h> DF_1_* */ 163 164 /* shared by ELF and GNU hash */ 165 u_int32_t nbuckets; 166 u_int32_t nchains; /* really, number of symbols */ 167 union { 168 struct { 169 /* specific to ELF hash */ 170 const Elf_Hash_Word *buckets; 171 const Elf_Hash_Word *chains; 172 } u_elf; 173 struct { 174 /* specific to GNU hash */ 175 const Elf_Word *buckets; 176 const Elf_Word *chains; 177 const Elf_Addr *bloom; 178 Elf_Word mask_bm; 179 Elf_Word shift2; 180 Elf_Word symndx; 181 } u_gnu; 182 } hash_u; 183 #define buckets_elf hash_u.u_elf.buckets 184 #define chains_elf hash_u.u_elf.chains 185 #define buckets_gnu hash_u.u_gnu.buckets 186 #define chains_gnu hash_u.u_gnu.chains 187 #define bloom_gnu hash_u.u_gnu.bloom 188 #define mask_bm_gnu hash_u.u_gnu.mask_bm 189 #define shift2_gnu hash_u.u_gnu.shift2 190 #define symndx_gnu hash_u.u_gnu.symndx 191 192 struct object_vector child_vec; /* direct dep libs of object */ 193 struct object_vector grpsym_vec; /* ordered complete dep list */ 194 TAILQ_HEAD(,dep_node) grpref_list; /* refs to other load groups */ 195 196 int refcount; /* dep libs only */ 197 int opencount; /* # dlopen() & exe */ 198 int grprefcount; /* load group refs */ 199 #define OBJECT_REF_CNT(object) \ 200 ((object->refcount + object->opencount + object->grprefcount)) 201 #define OBJECT_DLREF_CNT(object) \ 202 ((object->opencount + object->grprefcount)) 203 204 /* object that caused this module to be loaded, used in symbol lookup */ 205 elf_object_t *load_object; 206 struct sod sod; 207 208 /* for object confirmation */ 209 dev_t dev; 210 ino_t inode; 211 212 /* thread local storage info */ 213 Elf_Addr tls_fsize; 214 Elf_Addr tls_msize; 215 Elf_Addr tls_align; 216 const void *tls_static_data; 217 int tls_offset; 218 219 /* relro bits */ 220 Elf_Addr relro_addr; 221 Elf_Addr relro_size; 222 223 /* generation number of last grpsym insert on this object */ 224 unsigned int grpsym_gen; 225 226 char **rpath; 227 char **runpath; 228 229 /* nonzero if trace enabled for this object */ 230 int traced; 231 }; 232 233 struct dep_node { 234 TAILQ_ENTRY(dep_node) next_sib; 235 elf_object_t *data; 236 }; 237 238 239 /* Please don't rename or make hidden; gdb(1) knows about these. */ 240 Elf_Addr _dl_bind(elf_object_t *object, int index); 241 void _dl_debug_state(void); 242 243 /* exported to the application */ 244 extern char *__progname; 245 246 __BEGIN_HIDDEN_DECLS 247 void _dl_add_object(elf_object_t *object); 248 elf_object_t *_dl_finalize_object(const char *objname, Elf_Dyn *dynp, 249 Elf_Phdr *phdrp, int phdrc, const int objtype, const long lbase, 250 const long obase); 251 void _dl_remove_object(elf_object_t *object); 252 void _dl_cleanup_objects(void); 253 254 elf_object_t *_dl_load_shlib(const char *, elf_object_t *, int, int); 255 elf_object_t *_dl_tryload_shlib(const char *libname, int type, int flags); 256 257 int _dl_md_reloc(elf_object_t *object, int rel, int relsz); 258 int _dl_md_reloc_got(elf_object_t *object, int lazy); 259 260 struct sym_res { 261 const Elf_Sym *sym; 262 const elf_object_t *obj; 263 }; 264 265 struct sym_res _dl_find_symbol(const char *name, int flags, 266 const Elf_Sym *ref_sym, elf_object_t *object); 267 268 /* 269 * defines for _dl_find_symbol() flag field, three bits of meaning 270 * myself - clear: search all objects, set: search only this object 271 * warnnotfound - clear: no warning, set: warn if not found 272 * inplt - clear: possible plt ref set: real matching function. 273 * 274 * inplt - due to how ELF handles function addresses in shared libraries 275 * &func may actually refer to the plt entry in the main program 276 * rather than the actual function address in the .so file. 277 * This rather bizarre behavior is documented in the SVR4 ABI. 278 * when getting the function address to relocate a PLT entry 279 * the 'real' function address is necessary, not the possible PLT address. 280 */ 281 /* myself */ 282 #define SYM_SEARCH_ALL 0x00 283 #define SYM_SEARCH_SELF 0x01 284 #define SYM_SEARCH_OTHER 0x02 285 #define SYM_SEARCH_NEXT 0x04 286 /* warnnotfound */ 287 #define SYM_NOWARNNOTFOUND 0x00 288 #define SYM_WARNNOTFOUND 0x10 289 /* inplt */ 290 #define SYM_NOTPLT 0x00 291 #define SYM_PLT 0x20 292 293 #define SYM_DLSYM 0x40 294 295 int _dl_load_dep_libs(elf_object_t *object, int flags, int booting); 296 int _dl_rtld(elf_object_t *object); 297 void _dl_call_init(elf_object_t *object); 298 void _dl_link_child(elf_object_t *dep, elf_object_t *p); 299 void _dl_link_grpsym(elf_object_t *object); 300 void _dl_cache_grpsym_list_setup(elf_object_t *_object); 301 void _dl_link_grpref(elf_object_t *load_group, elf_object_t *load_object); 302 void _dl_link_dlopen(elf_object_t *dep); 303 void _dl_unlink_dlopen(elf_object_t *dep); 304 void _dl_notify_unload_shlib(elf_object_t *object); 305 void _dl_unload_shlib(elf_object_t *object); 306 void _dl_unload_dlopen(void); 307 308 void _dl_run_all_dtors(void); 309 310 int _dl_match_file(struct sod *sodp, const char *name, int namelen); 311 char *_dl_find_shlib(struct sod *sodp, char **searchpath, int nohints); 312 void _dl_load_list_free(struct load_list *load_list); 313 314 typedef void lock_cb(int); 315 void _dl_thread_kern_go(lock_cb *); 316 lock_cb *_dl_thread_kern_stop(void); 317 318 char *_dl_getenv(const char *, char **) __boot; 319 void _dl_unsetenv(const char *, char **) __boot; 320 321 void _dl_trace_setup(char **) __boot; 322 void _dl_trace_object_setup(elf_object_t *); 323 int _dl_trace_plt(const elf_object_t *, const char *); 324 325 /* tib.c */ 326 void _dl_allocate_tls_offsets(void) __boot; 327 void _dl_allocate_first_tib(void) __boot; 328 void _dl_set_tls(elf_object_t *_object, Elf_Phdr *_ptls, Elf_Addr _libaddr, 329 const char *_libname); 330 extern int _dl_tib_static_done; 331 332 extern elf_object_t *_dl_objects; 333 extern int object_count; /* how many objects are currently loaded */ 334 335 extern elf_object_t *_dl_loading_object; 336 337 extern struct r_debug *_dl_debug_map; 338 339 extern int _dl_pagesz; 340 extern int _dl_errno; 341 342 extern char **_dl_libpath; 343 344 extern int _dl_bindnow; 345 extern int _dl_traceld; 346 extern int _dl_debug; 347 348 extern char *_dl_preload; 349 extern char *_dl_tracefmt1; 350 extern char *_dl_tracefmt2; 351 extern char *_dl_traceprog; 352 353 extern int _dl_trust; 354 355 #define DL_DEB(P) do { if (_dl_debug) _dl_printf P ; } while (0) 356 357 #define DL_NOT_FOUND 1 358 #define DL_CANT_OPEN 2 359 #define DL_NOT_ELF 3 360 #define DL_CANT_OPEN_REF 4 361 #define DL_CANT_MMAP 5 362 #define DL_NO_SYMBOL 6 363 #define DL_INVALID_HANDLE 7 364 #define DL_INVALID_CTL 8 365 #define DL_NO_OBJECT 9 366 #define DL_CANT_FIND_OBJ 10 367 #define DL_CANT_LOAD_OBJ 11 368 #define DL_INVALID_MODE 12 369 370 #define ELF_ROUND(x,malign) (((x) + (malign)-1) & ~((malign)-1)) 371 #define ELF_TRUNC(x,malign) ((x) & ~((malign)-1)) 372 373 /* symbol lookup cache */ 374 typedef struct sym_cache { 375 const elf_object_t *obj; 376 const Elf_Sym *sym; 377 int flags; 378 } sym_cache; 379 380 TAILQ_HEAD(dlochld, dep_node); 381 extern struct dlochld _dlopened_child_list; 382 __END_HIDDEN_DECLS 383 384 #endif /* _RESOLVE_H_ */ 385