1 /* $OpenBSD: resolve.h,v 1.85 2018/10/23 04:01:45 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 <link.h> 34 #include <dlfcn.h> 35 36 #define __relro __attribute__((section(".data.rel.ro"))) 37 38 /* Number of low tags that are used saved internally (0 .. DT_NUM-1) */ 39 #define DT_NUM (DT_PREINIT_ARRAYSZ + 1) 40 41 struct load_list { 42 struct load_list *next; 43 void *start; 44 size_t size; 45 int prot; 46 Elf_Addr moff; 47 long foff; 48 }; 49 50 /* 51 * Structure describing a loaded object. 52 * The head of this struct must be compatible 53 * with struct link_map in sys/link.h 54 */ 55 typedef struct elf_object elf_object_t; 56 struct elf_object { 57 Elf_Addr obj_base; /* object's address '0' base */ 58 char *load_name; /* Pointer to object name */ 59 Elf_Dyn *load_dyn; /* Pointer to object dynamic data */ 60 struct elf_object *next; 61 struct elf_object *prev; 62 /* End struct link_map compatible */ 63 Elf_Addr load_base; /* Base address of loadable segments */ 64 65 struct load_list *load_list; 66 67 u_int32_t load_size; 68 69 union { 70 u_long info[DT_NUM + DT_PROCNUM]; 71 struct { 72 Elf_Addr null; /* Not used */ 73 Elf_Addr needed; /* Not used */ 74 Elf_Addr pltrelsz; 75 Elf_Addr *pltgot; 76 Elf_Addr *hash; 77 const char *strtab; 78 const Elf_Sym *symtab; 79 Elf_RelA *rela; 80 Elf_Addr relasz; 81 Elf_Addr relaent; 82 Elf_Addr strsz; 83 Elf_Addr syment; 84 void (*init)(void); 85 void (*fini)(void); 86 const char *soname; 87 const char *rpath; 88 Elf_Addr symbolic; 89 Elf_Rel *rel; 90 Elf_Addr relsz; 91 Elf_Addr relent; 92 Elf_Addr pltrel; 93 Elf_Addr debug; 94 Elf_Addr textrel; 95 Elf_Addr jmprel; 96 Elf_Addr bind_now; 97 void (**init_array)(void); 98 void (**fini_array)(void); 99 Elf_Addr init_arraysz; 100 Elf_Addr fini_arraysz; 101 const char *runpath; 102 Elf_Addr flags; 103 Elf_Addr encoding; 104 void (**preinit_array)(void); 105 Elf_Addr preinit_arraysz; 106 } u; 107 } Dyn; 108 #define dyn Dyn.u 109 110 Elf_Addr relacount; /* DT_RELACOUNT */ 111 Elf_Addr relcount; /* DT_RELCOUNT */ 112 113 int status; 114 #define STAT_RELOC_DONE 0x01 115 #define STAT_GOT_DONE 0x02 116 #define STAT_INIT_DONE 0x04 117 #define STAT_FINI_DONE 0x08 118 #define STAT_FINI_READY 0x10 119 #define STAT_UNLOADED 0x20 120 #define STAT_NODELETE 0x40 121 #define STAT_VISITED 0x80 122 123 Elf_Phdr *phdrp; 124 int phdrc; 125 126 int obj_type; 127 #define OBJTYPE_LDR 1 128 #define OBJTYPE_EXE 2 129 #define OBJTYPE_LIB 3 130 #define OBJTYPE_DLO 4 131 int obj_flags; /* c.f. <sys/exec_elf.h> DF_1_* */ 132 133 Elf_Word *buckets; 134 u_int32_t nbuckets; 135 Elf_Word *chains; 136 u_int32_t nchains; 137 Elf_Dyn *dynamic; 138 139 TAILQ_HEAD(,dep_node) child_list; /* direct dep libs of object */ 140 TAILQ_HEAD(,dep_node) grpsym_list; /* ordered complete dep list */ 141 TAILQ_HEAD(,dep_node) grpref_list; /* refs to other load groups */ 142 143 int refcount; /* dep libs only */ 144 int opencount; /* # dlopen() & exe */ 145 int grprefcount; /* load group refs */ 146 #define OBJECT_REF_CNT(object) \ 147 ((object->refcount + object->opencount + object->grprefcount)) 148 #define OBJECT_DLREF_CNT(object) \ 149 ((object->opencount + object->grprefcount)) 150 151 /* object that caused this module to be loaded, used in symbol lookup */ 152 elf_object_t *load_object; 153 struct sod sod; 154 155 /* for object confirmation */ 156 dev_t dev; 157 ino_t inode; 158 159 /* thread local storage info */ 160 Elf_Addr tls_fsize; 161 Elf_Addr tls_msize; 162 Elf_Addr tls_align; 163 const void *tls_static_data; 164 int tls_offset; 165 166 /* relro bits */ 167 Elf_Addr relro_addr; 168 Elf_Addr relro_size; 169 170 /* generation number of last grpsym insert on this object */ 171 unsigned int grpsym_gen; 172 173 char **rpath; 174 char **runpath; 175 176 /* nonzero if trace enabled for this object */ 177 int traced; 178 }; 179 180 struct dep_node { 181 TAILQ_ENTRY(dep_node) next_sib; 182 elf_object_t *data; 183 }; 184 185 186 /* Please don't rename or make hidden; gdb(1) knows about these. */ 187 Elf_Addr _dl_bind(elf_object_t *object, int index); 188 void _dl_debug_state(void); 189 190 /* exported to the application */ 191 extern char *__progname; 192 193 __BEGIN_HIDDEN_DECLS 194 void _dl_add_object(elf_object_t *object); 195 elf_object_t *_dl_finalize_object(const char *objname, Elf_Dyn *dynp, 196 Elf_Phdr *phdrp, int phdrc, const int objtype, const long lbase, 197 const long obase); 198 void _dl_remove_object(elf_object_t *object); 199 void _dl_cleanup_objects(void); 200 void *_dl_protect_segment(elf_object_t *_object, Elf_Addr _addr, 201 const char *_start_sym, const char *_end_sym, int _prot); 202 203 elf_object_t *_dl_load_shlib(const char *, elf_object_t *, int, int); 204 elf_object_t *_dl_tryload_shlib(const char *libname, int type, int flags); 205 206 int _dl_md_reloc(elf_object_t *object, int rel, int relsz); 207 int _dl_md_reloc_got(elf_object_t *object, int lazy); 208 209 Elf_Addr _dl_find_symbol(const char *name, const Elf_Sym **this, 210 int flags, const Elf_Sym *ref_sym, elf_object_t *object, 211 const elf_object_t **pobj); 212 Elf_Addr _dl_find_symbol_bysym(elf_object_t *req_obj, unsigned int symidx, 213 const Elf_Sym **ref, int flags, const Elf_Sym *ref_sym, 214 const elf_object_t **pobj); 215 /* 216 * defines for _dl_find_symbol() flag field, three bits of meaning 217 * myself - clear: search all objects, set: search only this object 218 * warnnotfound - clear: no warning, set: warn if not found 219 * inplt - clear: possible plt ref set: real matching function. 220 * 221 * inplt - due to how ELF handles function addresses in shared libraries 222 * &func may actually refer to the plt entry in the main program 223 * rather than the actual function address in the .so file. 224 * This rather bizarre behavior is documented in the SVR4 ABI. 225 * when getting the function address to relocate a PLT entry 226 * the 'real' function address is necessary, not the possible PLT address. 227 */ 228 /* myself */ 229 #define SYM_SEARCH_ALL 0x00 230 #define SYM_SEARCH_SELF 0x01 231 #define SYM_SEARCH_OTHER 0x02 232 #define SYM_SEARCH_NEXT 0x04 233 #define SYM_SEARCH_OBJ 0x08 234 /* warnnotfound */ 235 #define SYM_NOWARNNOTFOUND 0x00 236 #define SYM_WARNNOTFOUND 0x10 237 /* inplt */ 238 #define SYM_NOTPLT 0x00 239 #define SYM_PLT 0x20 240 241 #define SYM_DLSYM 0x40 242 243 int _dl_load_dep_libs(elf_object_t *object, int flags, int booting); 244 int _dl_rtld(elf_object_t *object); 245 void _dl_call_init(elf_object_t *object); 246 void _dl_link_child(elf_object_t *dep, elf_object_t *p); 247 void _dl_link_grpsym(elf_object_t *object, int checklist); 248 void _dl_cache_grpsym_list(elf_object_t *object); 249 void _dl_cache_grpsym_list_setup(elf_object_t *object); 250 void _dl_link_grpref(elf_object_t *load_group, elf_object_t *load_object); 251 void _dl_link_dlopen(elf_object_t *dep); 252 void _dl_unlink_dlopen(elf_object_t *dep); 253 void _dl_notify_unload_shlib(elf_object_t *object); 254 void _dl_unload_shlib(elf_object_t *object); 255 void _dl_unload_dlopen(void); 256 257 void _dl_run_all_dtors(void); 258 259 int _dl_match_file(struct sod *sodp, const char *name, int namelen); 260 char *_dl_find_shlib(struct sod *sodp, char **searchpath, int nohints); 261 void _dl_load_list_free(struct load_list *load_list); 262 263 typedef void lock_cb(int); 264 void _dl_thread_kern_go(lock_cb *); 265 lock_cb *_dl_thread_kern_stop(void); 266 267 char *_dl_getenv(const char *, char **); 268 void _dl_unsetenv(const char *, char **); 269 270 void _dl_trace_setup(char **); 271 void _dl_trace_object_setup(elf_object_t *); 272 int _dl_trace_plt(const elf_object_t *, const char *); 273 274 /* tib.c */ 275 void _dl_allocate_tls_offsets(void); 276 void _dl_allocate_first_tib(void); 277 void _dl_set_tls(elf_object_t *_object, Elf_Phdr *_ptls, Elf_Addr _libaddr, 278 const char *_libname); 279 extern int _dl_tib_static_done; 280 281 extern elf_object_t *_dl_objects; 282 extern elf_object_t *_dl_last_object; 283 284 extern elf_object_t *_dl_loading_object; 285 286 extern struct r_debug *_dl_debug_map; 287 288 extern int _dl_pagesz; 289 extern int _dl_errno; 290 291 extern char **_dl_libpath; 292 293 extern int _dl_bindnow; 294 extern int _dl_traceld; 295 extern int _dl_debug; 296 297 extern char *_dl_preload; 298 extern char *_dl_tracefmt1; 299 extern char *_dl_tracefmt2; 300 extern char *_dl_traceprog; 301 302 extern int _dl_trust; 303 304 #define DL_DEB(P) do { if (_dl_debug) _dl_printf P ; } while (0) 305 306 #define DL_NOT_FOUND 1 307 #define DL_CANT_OPEN 2 308 #define DL_NOT_ELF 3 309 #define DL_CANT_OPEN_REF 4 310 #define DL_CANT_MMAP 5 311 #define DL_NO_SYMBOL 6 312 #define DL_INVALID_HANDLE 7 313 #define DL_INVALID_CTL 8 314 #define DL_NO_OBJECT 9 315 #define DL_CANT_FIND_OBJ 10 316 #define DL_CANT_LOAD_OBJ 11 317 #define DL_INVALID_MODE 12 318 319 #define ELF_ROUND(x,malign) (((x) + (malign)-1) & ~((malign)-1)) 320 #define ELF_TRUNC(x,malign) ((x) & ~((malign)-1)) 321 322 /* symbol lookup cache */ 323 typedef struct sym_cache { 324 const elf_object_t *obj; 325 const Elf_Sym *sym; 326 int flags; 327 } sym_cache; 328 329 extern sym_cache *_dl_symcache; 330 extern int _dl_symcachestat_hits; 331 extern int _dl_symcachestat_lookups; 332 TAILQ_HEAD(dlochld, dep_node); 333 extern struct dlochld _dlopened_child_list; 334 __END_HIDDEN_DECLS 335 336 #endif /* _RESOLVE_H_ */ 337