resolve.h revision 1.52
1/* $OpenBSD: resolve.h,v 1.52 2006/06/16 21:34:53 kettenis 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 36struct load_list { 37 struct load_list *next; 38 void *start; 39 size_t size; 40 int prot; 41 Elf_Addr moff; 42 long foff; 43}; 44 45/* 46 * Structure describing a loaded object. 47 * The head of this struct must be compatible 48 * with struct link_map in sys/link.h 49 */ 50typedef struct elf_object elf_object_t; 51struct elf_object { 52 Elf_Addr load_addr; /* Real load address */ 53 char *load_name; /* Pointer to object name */ 54 Elf_Dyn *load_dyn; /* Pointer to object dynamic data */ 55 struct elf_object *next; 56 struct elf_object *prev; 57/* End struct link_map compatible */ 58 Elf_Addr load_offs; /* Load offset from link address */ 59 60 struct load_list *load_list; 61 62 u_int32_t load_size; 63 Elf_Addr got_addr; 64 Elf_Addr got_start; 65 size_t got_size; 66 Elf_Addr plt_start; 67 size_t plt_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 } u; 97 } Dyn; 98#define dyn Dyn.u 99 100 int status; 101#define STAT_RELOC_DONE 0x01 102#define STAT_GOT_DONE 0x02 103#define STAT_INIT_DONE 0x04 104#define STAT_FINI_DONE 0x08 105#define STAT_FINI_READY 0x10 106#define STAT_UNLOADED 0x20 107 108 Elf_Phdr *phdrp; 109 int phdrc; 110 111 int obj_type; 112#define OBJTYPE_LDR 1 113#define OBJTYPE_EXE 2 114#define OBJTYPE_LIB 3 115#define OBJTYPE_DLO 4 116 int obj_flags; 117 118 Elf_Word *buckets; 119 u_int32_t nbuckets; 120 Elf_Word *chains; 121 u_int32_t nchains; 122 Elf_Dyn *dynamic; 123 124 TAILQ_HEAD(,dep_node) child_list; /* direct dep libs of object */ 125 TAILQ_HEAD(,dep_node) grpsym_list; /* ordered complete dep list */ 126 TAILQ_HEAD(,dep_node) grpref_list; /* refs to other load groups */ 127 128 int refcount; /* dep libs only */ 129 int opencount; /* # dlopen() & exe */ 130 int grprefcount; /* load group refs */ 131#define OBJECT_REF_CNT(object) \ 132 ((object->refcount + object->opencount + object->grprefcount)) 133#define OBJECT_DLREF_CNT(object) \ 134 ((object->opencount + object->grprefcount)) 135 136 /* object that caused this module to be loaded, used in symbol lookup */ 137 elf_object_t *load_object; 138 139 void *prebind_data; 140 141 /* for object confirmation */ 142 dev_t dev; 143 ino_t inode; 144}; 145 146struct dep_node { 147 TAILQ_ENTRY(dep_node) next_sib; 148 elf_object_t *data; 149}; 150 151void _dl_rt_resolve(void); 152 153void _dl_add_object(elf_object_t *object); 154elf_object_t *_dl_finalize_object(const char *objname, Elf_Dyn *dynp, 155 const long *, const int objtype, const long laddr, const long loff); 156void _dl_remove_object(elf_object_t *object); 157void _dl_cleanup_objects(void); 158 159elf_object_t *_dl_lookup_object(const char *objname); 160elf_object_t *_dl_load_shlib(const char *, elf_object_t *, int, int); 161elf_object_t *_dl_tryload_shlib(const char *libname, int type, int flags); 162 163int _dl_md_reloc(elf_object_t *object, int rel, int relsz); 164void _dl_md_reloc_got(elf_object_t *object, int lazy); 165 166Elf_Addr _dl_find_symbol(const char *name, const Elf_Sym **this, 167 int flags, const Elf_Sym *ref_sym, elf_object_t *object, 168 const elf_object_t **pobj); 169Elf_Addr _dl_find_symbol_bysym(elf_object_t *req_obj, unsigned int symidx, 170 const Elf_Sym **ref, int flags, const Elf_Sym *ref_sym, 171 const elf_object_t **pobj); 172/* 173 * defines for _dl_find_symbol() flag field, three bits of meaning 174 * myself - clear: search all objects, set: search only this object 175 * warnnotfound - clear: no warning, set: warn if not found 176 * inplt - clear: possible plt ref set: real matching function. 177 * 178 * inplt - due to how ELF handles function addresses in shared libraries 179 * &func may actually refer to the plt entry in the main program 180 * rather than the actual function address in the .so file. 181 * This rather bizarre behavior is documented in the SVR4 ABI. 182 * when getting the function address to relocate a PLT entry 183 * the 'real' function address is necessary, not the possible PLT address. 184 */ 185/* myself */ 186#define SYM_SEARCH_ALL 0x00 187#define SYM_SEARCH_SELF 0x01 188#define SYM_SEARCH_OTHER 0x02 189#define SYM_SEARCH_NEXT 0x04 190#define SYM_SEARCH_OBJ 0x08 191/* warnnotfound */ 192#define SYM_NOWARNNOTFOUND 0x00 193#define SYM_WARNNOTFOUND 0x10 194/* inplt */ 195#define SYM_NOTPLT 0x00 196#define SYM_PLT 0x20 197 198#define SYM_DLSYM 0x40 199 200int _dl_load_dep_libs(elf_object_t *object, int flags, int booting); 201int _dl_rtld(elf_object_t *object); 202void _dl_call_init(elf_object_t *object); 203void _dl_link_child(elf_object_t *dep, elf_object_t *p); 204void _dl_link_grpsym(elf_object_t *object); 205void _dl_cache_grpsym_list(elf_object_t *object); 206void _dl_link_grpref(elf_object_t *load_group, elf_object_t *load_object); 207void _dl_link_dlopen(elf_object_t *dep); 208void _dl_unlink_dlopen(elf_object_t *dep); 209void _dl_notify_unload_shlib(elf_object_t *object); 210void _dl_unload_shlib(elf_object_t *object); 211void _dl_unload_dlopen(void); 212 213void _dl_run_all_dtors(void); 214 215/* Please don't rename; gdb(1) knows about this. */ 216Elf_Addr _dl_bind(elf_object_t *object, int index); 217 218int _dl_match_file(struct sod *sodp, char *name, int namelen); 219char *_dl_find_shlib(struct sod *sodp, const char *searchpath, int nohints); 220void _dl_load_list_free(struct load_list *load_list); 221 222void _dl_thread_kern_go(void); 223void _dl_thread_kern_stop(void); 224 225extern elf_object_t *_dl_objects; 226extern elf_object_t *_dl_last_object; 227 228extern elf_object_t *_dl_loading_object; 229 230extern const char *_dl_progname; 231extern struct r_debug *_dl_debug_map; 232 233extern int _dl_pagesz; 234extern int _dl_errno; 235 236extern char *_dl_libpath; 237extern char *_dl_preload; 238extern char *_dl_bindnow; 239extern char *_dl_traceld; 240extern char *_dl_debug; 241 242#define DL_DEB(P) do { if (_dl_debug) _dl_printf P ; } while (0) 243 244#define DL_NOT_FOUND 1 245#define DL_CANT_OPEN 2 246#define DL_NOT_ELF 3 247#define DL_CANT_OPEN_REF 4 248#define DL_CANT_MMAP 5 249#define DL_NO_SYMBOL 6 250#define DL_INVALID_HANDLE 7 251#define DL_INVALID_CTL 8 252#define DL_NO_OBJECT 9 253#define DL_CANT_FIND_OBJ 10 254#define DL_CANT_LOAD_OBJ 11 255 256#define ELF_ROUND(x,malign) (((x) + (malign)-1) & ~((malign)-1)) 257#define ELF_TRUNC(x,malign) ((x) & ~((malign)-1)) 258 259/* symbol lookup cache */ 260typedef struct sym_cache { 261 const elf_object_t *obj; 262 const Elf_Sym *sym; 263 int flags; 264} sym_cache; 265 266extern sym_cache *_dl_symcache; 267extern int _dl_symcachestat_hits; 268extern int _dl_symcachestat_lookups; 269TAILQ_HEAD(dlochld, dep_node); 270extern struct dlochld _dlopened_child_list; 271 272 273#endif /* _RESOLVE_H_ */ 274