1 /** $MirOS: src/libexec/ld.so/resolve.h,v 1.2 2006/08/30 04:28:25 tg Exp $ */ 2 /* $OpenBSD: resolve.h,v 1.52 2006/06/16 21:34:53 kettenis Exp $ */ 3 4 /* 5 * Copyright (c) 1998 Per Fogelstrom, Opsycon AB 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS 17 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 18 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY 20 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 * 28 */ 29 30 #ifndef _RESOLVE_H_ 31 #define _RESOLVE_H_ 32 33 #include <sys/queue.h> 34 #include <link.h> 35 #include <dlfcn.h> 36 #include <stdbool.h> 37 38 struct load_list { 39 struct load_list *next; 40 void *start; 41 size_t size; 42 int prot; 43 Elf_Addr moff; 44 long foff; 45 }; 46 47 /* 48 * Structure describing a loaded object. 49 * The head of this struct must be compatible 50 * with struct link_map in sys/link.h 51 */ 52 typedef struct elf_object elf_object_t; 53 struct elf_object { 54 Elf_Addr load_addr; /* Real load address */ 55 char *load_name; /* Pointer to object name */ 56 Elf_Dyn *load_dyn; /* Pointer to object dynamic data */ 57 struct elf_object *next; 58 struct elf_object *prev; 59 /* End struct link_map compatible */ 60 Elf_Addr load_offs; /* Load offset from link address */ 61 62 struct load_list *load_list; 63 64 u_int32_t load_size; 65 Elf_Addr got_addr; 66 Elf_Addr got_start; 67 size_t got_size; 68 Elf_Addr plt_start; 69 size_t plt_size; 70 71 union { 72 u_long info[DT_NUM + DT_PROCNUM]; 73 struct { 74 Elf_Addr null; /* Not used */ 75 Elf_Addr needed; /* Not used */ 76 Elf_Addr pltrelsz; 77 Elf_Addr *pltgot; 78 Elf_Addr *hash; 79 const char *strtab; 80 const Elf_Sym *symtab; 81 Elf_RelA *rela; 82 Elf_Addr relasz; 83 Elf_Addr relaent; 84 Elf_Addr strsz; 85 Elf_Addr syment; 86 void (*init)(void); 87 void (*fini)(void); 88 const char *soname; 89 const char *rpath; 90 Elf_Addr symbolic; 91 Elf_Rel *rel; 92 Elf_Addr relsz; 93 Elf_Addr relent; 94 Elf_Addr pltrel; 95 Elf_Addr debug; 96 Elf_Addr textrel; 97 Elf_Addr jmprel; 98 } u; 99 } Dyn; 100 #define dyn Dyn.u 101 102 int status; 103 #define STAT_RELOC_DONE 0x01 104 #define STAT_GOT_DONE 0x02 105 #define STAT_INIT_DONE 0x04 106 #define STAT_FINI_DONE 0x08 107 #define STAT_FINI_READY 0x10 108 #define STAT_UNLOADED 0x20 109 110 Elf_Phdr *phdrp; 111 int phdrc; 112 113 int obj_type; 114 #define OBJTYPE_LDR 1 115 #define OBJTYPE_EXE 2 116 #define OBJTYPE_LIB 3 117 #define OBJTYPE_DLO 4 118 int obj_flags; 119 120 Elf_Word *buckets; 121 u_int32_t nbuckets; 122 Elf_Word *chains; 123 u_int32_t nchains; 124 Elf_Dyn *dynamic; 125 126 TAILQ_HEAD(,dep_node) child_list; /* direct dep libs of object */ 127 TAILQ_HEAD(,dep_node) grpsym_list; /* ordered complete dep list */ 128 TAILQ_HEAD(,dep_node) grpref_list; /* refs to other load groups */ 129 130 int refcount; /* dep libs only */ 131 int opencount; /* # dlopen() & exe */ 132 int grprefcount; /* load group refs */ 133 #define OBJECT_REF_CNT(object) \ 134 ((object->refcount + object->opencount + object->grprefcount)) 135 #define OBJECT_DLREF_CNT(object) \ 136 ((object->opencount + object->grprefcount)) 137 138 /* object that caused this module to be loaded, used in symbol lookup */ 139 elf_object_t *load_object; 140 141 void *prebind_data; 142 143 /* for object confirmation */ 144 dev_t dev; 145 ino_t inode; 146 }; 147 148 struct dep_node { 149 TAILQ_ENTRY(dep_node) next_sib; 150 elf_object_t *data; 151 }; 152 153 void _dl_rt_resolve(void); 154 155 void _dl_add_object(elf_object_t *object); 156 elf_object_t *_dl_finalize_object(const char *objname, Elf_Dyn *dynp, 157 const long *, const int objtype, const long laddr, const long loff); 158 void _dl_remove_object(elf_object_t *object); 159 void _dl_cleanup_objects(void); 160 161 elf_object_t *_dl_lookup_object(const char *objname); 162 elf_object_t *_dl_load_shlib(const char *, elf_object_t *, int, int); 163 elf_object_t *_dl_tryload_shlib(const char *libname, int type, int flags); 164 165 int _dl_md_reloc(elf_object_t *object, int rel, int relsz); 166 void _dl_md_reloc_got(elf_object_t *object, int lazy); 167 168 Elf_Addr _dl_find_symbol(const char *name, const Elf_Sym **this, 169 int flags, const Elf_Sym *ref_sym, elf_object_t *object, 170 const elf_object_t **pobj); 171 Elf_Addr _dl_find_symbol_bysym(elf_object_t *req_obj, unsigned int symidx, 172 const Elf_Sym **ref, int flags, const Elf_Sym *ref_sym, 173 const elf_object_t **pobj); 174 /* 175 * defines for _dl_find_symbol() flag field, three bits of meaning 176 * myself - clear: search all objects, set: search only this object 177 * warnnotfound - clear: no warning, set: warn if not found 178 * inplt - clear: possible plt ref set: real matching function. 179 * 180 * inplt - due to how ELF handles function addresses in shared libraries 181 * &func may actually refer to the plt entry in the main program 182 * rather than the actual function address in the .so file. 183 * This rather bizarre behavior is documented in the SVR4 ABI. 184 * when getting the function address to relocate a PLT entry 185 * the 'real' function address is necessary, not the possible PLT address. 186 */ 187 /* myself */ 188 #define SYM_SEARCH_ALL 0x00 189 #define SYM_SEARCH_SELF 0x01 190 #define SYM_SEARCH_OTHER 0x02 191 #define SYM_SEARCH_NEXT 0x04 192 #define SYM_SEARCH_OBJ 0x08 193 /* warnnotfound */ 194 #define SYM_NOWARNNOTFOUND 0x00 195 #define SYM_WARNNOTFOUND 0x10 196 /* inplt */ 197 #define SYM_NOTPLT 0x00 198 #define SYM_PLT 0x20 199 200 #define SYM_DLSYM 0x40 201 202 int _dl_load_dep_libs(elf_object_t *object, int flags, int booting); 203 int _dl_rtld(elf_object_t *object); 204 void _dl_call_init(elf_object_t *object); 205 void _dl_link_child(elf_object_t *dep, elf_object_t *p); 206 void _dl_link_grpsym(elf_object_t *object); 207 void _dl_cache_grpsym_list(elf_object_t *object); 208 void _dl_link_grpref(elf_object_t *load_group, elf_object_t *load_object); 209 void _dl_link_dlopen(elf_object_t *dep); 210 void _dl_unlink_dlopen(elf_object_t *dep); 211 void _dl_notify_unload_shlib(elf_object_t *object); 212 void _dl_unload_shlib(elf_object_t *object); 213 void _dl_unload_dlopen(void); 214 215 void _dl_run_all_dtors(void); 216 217 /* Please don't rename; gdb(1) knows about this. */ 218 Elf_Addr _dl_bind(elf_object_t *object, int index); 219 220 int _dl_match_file(struct sod *sodp, char *name, int namelen); 221 char *_dl_find_shlib(struct sod *sodp, const char *searchpath, int nohints); 222 void _dl_load_list_free(struct load_list *load_list); 223 224 void _dl_thread_kern_go(void); 225 void _dl_thread_kern_stop(void); 226 227 extern elf_object_t *_dl_objects; 228 extern elf_object_t *_dl_last_object; 229 230 extern elf_object_t *_dl_loading_object; 231 232 extern const char *_dl_progname; 233 extern struct r_debug *_dl_debug_map; 234 235 extern int _dl_pagesz; 236 extern int _dl_errno; 237 238 extern char *_dl_libpath; 239 extern char *_dl_preload; 240 extern char *_dl_bindnow; 241 extern bool _dl_traceld; 242 extern char *_dl_debug; 243 244 #define DL_DEB(P) do { if (_dl_debug) _dl_printf P ; } while (0) 245 246 #define DL_NOT_FOUND 1 247 #define DL_CANT_OPEN 2 248 #define DL_NOT_ELF 3 249 #define DL_CANT_OPEN_REF 4 250 #define DL_CANT_MMAP 5 251 #define DL_NO_SYMBOL 6 252 #define DL_INVALID_HANDLE 7 253 #define DL_INVALID_CTL 8 254 #define DL_NO_OBJECT 9 255 #define DL_CANT_FIND_OBJ 10 256 #define DL_CANT_LOAD_OBJ 11 257 258 #define ELF_ROUND(x,malign) (((x) + (malign)-1) & ~((malign)-1)) 259 #define ELF_TRUNC(x,malign) ((x) & ~((malign)-1)) 260 261 /* symbol lookup cache */ 262 typedef struct sym_cache { 263 const elf_object_t *obj; 264 const Elf_Sym *sym; 265 int flags; 266 } sym_cache; 267 268 extern sym_cache *_dl_symcache; 269 extern int _dl_symcachestat_hits; 270 extern int _dl_symcachestat_lookups; 271 TAILQ_HEAD(dlochld, dep_node); 272 extern struct dlochld _dlopened_child_list; 273 274 275 #endif /* _RESOLVE_H_ */ 276