resolve.h revision 1.101
1/* $OpenBSD: resolve.h,v 1.101 2022/08/20 14:11:31 sthen 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 52struct 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 61typedef void initarrayfunc(int, const char **, char **, dl_cb_cb *); 62typedef void initfunc(void); /* also fini and fini_array functions */ 63 64/* Alpha uses 8byte entries for DT_HASH */ 65#ifdef __alpha__ 66typedef uint64_t Elf_Hash_Word; 67#else 68typedef uint32_t Elf_Hash_Word; 69#endif 70 71typedef struct elf_object elf_object_t; 72 73struct object_vector { 74 int len; 75 int alloc; 76 elf_object_t **vec; 77}; 78void 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 <link_elf.h> 84 */ 85struct 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 236struct 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. */ 243Elf_Addr _dl_bind(elf_object_t *object, int index); 244void _dl_debug_state(void); 245 246/* exported to the application */ 247extern char *__progname; 248 249__BEGIN_HIDDEN_DECLS 250void _dl_handle_nodelete(elf_object_t *_object); 251void _dl_add_object(elf_object_t *object); 252elf_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); 255void _dl_remove_object(elf_object_t *object); 256void _dl_cleanup_objects(void); 257 258void _dl_handle_already_loaded(elf_object_t *_object, int _flags); 259elf_object_t *_dl_load_shlib(const char *, elf_object_t *, int, int); 260elf_object_t *_dl_tryload_shlib(const char *libname, int type, int flags); 261 262int _dl_md_reloc(elf_object_t *object, int rel, int relsz); 263int _dl_md_reloc_got(elf_object_t *object, int lazy); 264 265struct sym_res { 266 const Elf_Sym *sym; 267 const elf_object_t *obj; 268}; 269 270struct sym_res _dl_find_symbol(const char *name, int flags, 271 const Elf_Sym *ref_sym, elf_object_t *object); 272 273/* 274 * defines for _dl_find_symbol() flag field, three bits of meaning 275 * myself - clear: search all objects, set: search only this object 276 * warnnotfound - clear: no warning, set: warn if not found 277 * inplt - clear: possible plt ref set: real matching function. 278 * 279 * inplt - due to how ELF handles function addresses in shared libraries 280 * &func may actually refer to the plt entry in the main program 281 * rather than the actual function address in the .so file. 282 * This rather bizarre behavior is documented in the SVR4 ABI. 283 * when getting the function address to relocate a PLT entry 284 * the 'real' function address is necessary, not the possible PLT address. 285 */ 286/* myself */ 287#define SYM_SEARCH_ALL 0x00 288#define SYM_SEARCH_SELF 0x01 289#define SYM_SEARCH_OTHER 0x02 290#define SYM_SEARCH_NEXT 0x04 291/* warnnotfound */ 292#define SYM_NOWARNNOTFOUND 0x00 293#define SYM_WARNNOTFOUND 0x10 294/* inplt */ 295#define SYM_NOTPLT 0x00 296#define SYM_PLT 0x20 297 298#define SYM_DLSYM 0x40 299 300int _dl_load_dep_libs(elf_object_t *object, int flags, int booting); 301int _dl_rtld(elf_object_t *object); 302void _dl_call_init(elf_object_t *object); 303void _dl_link_child(elf_object_t *dep, elf_object_t *p); 304void _dl_link_grpsym(elf_object_t *object); 305void _dl_cache_grpsym_list_setup(elf_object_t *_object); 306void _dl_link_grpref(elf_object_t *load_group, elf_object_t *load_object); 307void _dl_link_dlopen(elf_object_t *dep); 308void _dl_unlink_dlopen(elf_object_t *dep); 309void _dl_notify_unload_shlib(elf_object_t *object); 310void _dl_unload_shlib(elf_object_t *object); 311void _dl_unload_dlopen(void); 312 313void _dl_run_all_dtors(void); 314 315int _dl_match_file(struct sod *sodp, const char *name, int namelen); 316char *_dl_find_shlib(struct sod *sodp, char **searchpath, int nohints); 317void _dl_load_list_free(struct load_list *load_list); 318 319typedef void lock_cb(int); 320void _dl_thread_kern_go(lock_cb *); 321lock_cb *_dl_thread_kern_stop(void); 322 323char *_dl_getenv(const char *, char **) __boot; 324void _dl_unsetenv(const char *, char **) __boot; 325 326void _dl_trace_setup(char **) __boot; 327void _dl_trace_object_setup(elf_object_t *); 328int _dl_trace_plt(const elf_object_t *, const char *); 329 330/* tib.c */ 331void _dl_allocate_tls_offsets(void) __boot; 332void _dl_allocate_first_tib(void) __boot; 333void _dl_set_tls(elf_object_t *_object, Elf_Phdr *_ptls, Elf_Addr _libaddr, 334 const char *_libname); 335extern int _dl_tib_static_done; 336 337extern elf_object_t *_dl_objects; 338extern int object_count; /* how many objects are currently loaded */ 339 340extern elf_object_t *_dl_loading_object; 341 342extern struct r_debug *_dl_debug_map; 343 344extern int _dl_pagesz; 345extern int _dl_errno; 346 347extern char **_dl_libpath; 348 349extern int _dl_bindnow; 350extern int _dl_traceld; 351extern int _dl_debug; 352 353extern char *_dl_preload; 354extern char *_dl_tracefmt1; 355extern char *_dl_tracefmt2; 356extern char *_dl_traceprog; 357 358extern void *_dl_exec_hint; 359 360extern int _dl_trust; 361 362#define DL_DEB(P) do { if (_dl_debug) _dl_printf P ; } while (0) 363 364#define DL_NOT_FOUND 1 365#define DL_CANT_OPEN 2 366#define DL_NOT_ELF 3 367#define DL_CANT_OPEN_REF 4 368#define DL_CANT_MMAP 5 369#define DL_NO_SYMBOL 6 370#define DL_INVALID_HANDLE 7 371#define DL_INVALID_CTL 8 372#define DL_NO_OBJECT 9 373#define DL_CANT_FIND_OBJ 10 374#define DL_CANT_LOAD_OBJ 11 375#define DL_INVALID_MODE 12 376 377#define ELF_ROUND(x,malign) (((x) + (malign)-1) & ~((malign)-1)) 378#define ELF_TRUNC(x,malign) ((x) & ~((malign)-1)) 379 380/* symbol lookup cache */ 381typedef struct sym_cache { 382 const elf_object_t *obj; 383 const Elf_Sym *sym; 384 int flags; 385} sym_cache; 386 387TAILQ_HEAD(dlochld, dep_node); 388extern struct dlochld _dlopened_child_list; 389__END_HIDDEN_DECLS 390 391#endif /* _RESOLVE_H_ */ 392