resolve.h revision 1.88
1/* $OpenBSD: resolve.h,v 1.88 2018/12/05 04:28:32 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 41struct 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 */ 55typedef struct elf_object elf_object_t; 56struct 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#define STAT_GNU_HASH 0x100 123 124 Elf_Phdr *phdrp; 125 int phdrc; 126 127 int obj_type; 128#define OBJTYPE_LDR 1 129#define OBJTYPE_EXE 2 130#define OBJTYPE_LIB 3 131#define OBJTYPE_DLO 4 132 int obj_flags; /* c.f. <sys/exec_elf.h> DF_1_* */ 133 134 /* shared by ELF and GNU hash */ 135 u_int32_t nbuckets; 136 u_int32_t nchains; /* really, number of symbols */ 137 union { 138 struct { 139 /* specific to ELF hash */ 140 const Elf_Word *buckets; 141 const Elf_Word *chains; 142 } u_elf; 143 struct { 144 /* specific to GNU hash */ 145 const Elf32_Word *buckets; 146 const Elf32_Word *chains; 147 const Elf_Addr *bloom; 148 Elf32_Word mask_bm; 149 Elf32_Word shift2; 150 Elf32_Word symndx; 151 } u_gnu; 152 } hash_u; 153#define buckets_elf hash_u.u_elf.buckets 154#define chains_elf hash_u.u_elf.chains 155#define buckets_gnu hash_u.u_gnu.buckets 156#define chains_gnu hash_u.u_gnu.chains 157#define bloom_gnu hash_u.u_gnu.bloom 158#define mask_bm_gnu hash_u.u_gnu.mask_bm 159#define shift2_gnu hash_u.u_gnu.shift2 160#define symndx_gnu hash_u.u_gnu.symndx 161 162 TAILQ_HEAD(,dep_node) child_list; /* direct dep libs of object */ 163 TAILQ_HEAD(,dep_node) grpsym_list; /* ordered complete dep list */ 164 TAILQ_HEAD(,dep_node) grpref_list; /* refs to other load groups */ 165 166 int refcount; /* dep libs only */ 167 int opencount; /* # dlopen() & exe */ 168 int grprefcount; /* load group refs */ 169#define OBJECT_REF_CNT(object) \ 170 ((object->refcount + object->opencount + object->grprefcount)) 171#define OBJECT_DLREF_CNT(object) \ 172 ((object->opencount + object->grprefcount)) 173 174 /* object that caused this module to be loaded, used in symbol lookup */ 175 elf_object_t *load_object; 176 struct sod sod; 177 178 /* for object confirmation */ 179 dev_t dev; 180 ino_t inode; 181 182 /* thread local storage info */ 183 Elf_Addr tls_fsize; 184 Elf_Addr tls_msize; 185 Elf_Addr tls_align; 186 const void *tls_static_data; 187 int tls_offset; 188 189 /* relro bits */ 190 Elf_Addr relro_addr; 191 Elf_Addr relro_size; 192 193 /* generation number of last grpsym insert on this object */ 194 unsigned int grpsym_gen; 195 196 char **rpath; 197 char **runpath; 198 199 /* nonzero if trace enabled for this object */ 200 int traced; 201}; 202 203struct dep_node { 204 TAILQ_ENTRY(dep_node) next_sib; 205 elf_object_t *data; 206}; 207 208 209/* Please don't rename or make hidden; gdb(1) knows about these. */ 210Elf_Addr _dl_bind(elf_object_t *object, int index); 211void _dl_debug_state(void); 212 213/* exported to the application */ 214extern char *__progname; 215 216__BEGIN_HIDDEN_DECLS 217void _dl_add_object(elf_object_t *object); 218elf_object_t *_dl_finalize_object(const char *objname, Elf_Dyn *dynp, 219 Elf_Phdr *phdrp, int phdrc, const int objtype, const long lbase, 220 const long obase); 221void _dl_remove_object(elf_object_t *object); 222void _dl_cleanup_objects(void); 223 224elf_object_t *_dl_load_shlib(const char *, elf_object_t *, int, int); 225elf_object_t *_dl_tryload_shlib(const char *libname, int type, int flags); 226 227int _dl_md_reloc(elf_object_t *object, int rel, int relsz); 228int _dl_md_reloc_got(elf_object_t *object, int lazy); 229 230Elf_Addr _dl_find_symbol(const char *name, const Elf_Sym **this, 231 int flags, const Elf_Sym *ref_sym, elf_object_t *object, 232 const elf_object_t **pobj); 233Elf_Addr _dl_find_symbol_bysym(elf_object_t *req_obj, unsigned int symidx, 234 const Elf_Sym **ref, int flags, const Elf_Sym *ref_sym, 235 const elf_object_t **pobj); 236/* 237 * defines for _dl_find_symbol() flag field, three bits of meaning 238 * myself - clear: search all objects, set: search only this object 239 * warnnotfound - clear: no warning, set: warn if not found 240 * inplt - clear: possible plt ref set: real matching function. 241 * 242 * inplt - due to how ELF handles function addresses in shared libraries 243 * &func may actually refer to the plt entry in the main program 244 * rather than the actual function address in the .so file. 245 * This rather bizarre behavior is documented in the SVR4 ABI. 246 * when getting the function address to relocate a PLT entry 247 * the 'real' function address is necessary, not the possible PLT address. 248 */ 249/* myself */ 250#define SYM_SEARCH_ALL 0x00 251#define SYM_SEARCH_SELF 0x01 252#define SYM_SEARCH_OTHER 0x02 253#define SYM_SEARCH_NEXT 0x04 254/* warnnotfound */ 255#define SYM_NOWARNNOTFOUND 0x00 256#define SYM_WARNNOTFOUND 0x10 257/* inplt */ 258#define SYM_NOTPLT 0x00 259#define SYM_PLT 0x20 260 261#define SYM_DLSYM 0x40 262 263int _dl_load_dep_libs(elf_object_t *object, int flags, int booting); 264int _dl_rtld(elf_object_t *object); 265void _dl_call_init(elf_object_t *object); 266void _dl_link_child(elf_object_t *dep, elf_object_t *p); 267void _dl_link_grpsym(elf_object_t *object, int checklist); 268void _dl_cache_grpsym_list(elf_object_t *object); 269void _dl_cache_grpsym_list_setup(elf_object_t *object); 270void _dl_link_grpref(elf_object_t *load_group, elf_object_t *load_object); 271void _dl_link_dlopen(elf_object_t *dep); 272void _dl_unlink_dlopen(elf_object_t *dep); 273void _dl_notify_unload_shlib(elf_object_t *object); 274void _dl_unload_shlib(elf_object_t *object); 275void _dl_unload_dlopen(void); 276 277void _dl_run_all_dtors(void); 278 279int _dl_match_file(struct sod *sodp, const char *name, int namelen); 280char *_dl_find_shlib(struct sod *sodp, char **searchpath, int nohints); 281void _dl_load_list_free(struct load_list *load_list); 282 283typedef void lock_cb(int); 284void _dl_thread_kern_go(lock_cb *); 285lock_cb *_dl_thread_kern_stop(void); 286 287char *_dl_getenv(const char *, char **); 288void _dl_unsetenv(const char *, char **); 289 290void _dl_trace_setup(char **); 291void _dl_trace_object_setup(elf_object_t *); 292int _dl_trace_plt(const elf_object_t *, const char *); 293 294/* tib.c */ 295void _dl_allocate_tls_offsets(void); 296void _dl_allocate_first_tib(void); 297void _dl_set_tls(elf_object_t *_object, Elf_Phdr *_ptls, Elf_Addr _libaddr, 298 const char *_libname); 299extern int _dl_tib_static_done; 300 301extern elf_object_t *_dl_objects; 302extern elf_object_t *_dl_last_object; 303 304extern elf_object_t *_dl_loading_object; 305 306extern struct r_debug *_dl_debug_map; 307 308extern int _dl_pagesz; 309extern int _dl_errno; 310 311extern char **_dl_libpath; 312 313extern int _dl_bindnow; 314extern int _dl_traceld; 315extern int _dl_debug; 316 317extern char *_dl_preload; 318extern char *_dl_tracefmt1; 319extern char *_dl_tracefmt2; 320extern char *_dl_traceprog; 321 322extern int _dl_trust; 323 324#define DL_DEB(P) do { if (_dl_debug) _dl_printf P ; } while (0) 325 326#define DL_NOT_FOUND 1 327#define DL_CANT_OPEN 2 328#define DL_NOT_ELF 3 329#define DL_CANT_OPEN_REF 4 330#define DL_CANT_MMAP 5 331#define DL_NO_SYMBOL 6 332#define DL_INVALID_HANDLE 7 333#define DL_INVALID_CTL 8 334#define DL_NO_OBJECT 9 335#define DL_CANT_FIND_OBJ 10 336#define DL_CANT_LOAD_OBJ 11 337#define DL_INVALID_MODE 12 338 339#define ELF_ROUND(x,malign) (((x) + (malign)-1) & ~((malign)-1)) 340#define ELF_TRUNC(x,malign) ((x) & ~((malign)-1)) 341 342/* symbol lookup cache */ 343typedef struct sym_cache { 344 const elf_object_t *obj; 345 const Elf_Sym *sym; 346 int flags; 347} sym_cache; 348 349extern sym_cache *_dl_symcache; 350extern int _dl_symcachestat_hits; 351extern int _dl_symcachestat_lookups; 352TAILQ_HEAD(dlochld, dep_node); 353extern struct dlochld _dlopened_child_list; 354__END_HIDDEN_DECLS 355 356#endif /* _RESOLVE_H_ */ 357