1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
|
/* $OpenBSD: resolve.h,v 1.57 2008/05/05 02:29:02 kurt Exp $ */
/*
* Copyright (c) 1998 Per Fogelstrom, Opsycon AB
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
* OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
*/
#ifndef _RESOLVE_H_
#define _RESOLVE_H_
#include <sys/queue.h>
#include <link.h>
#include <dlfcn.h>
struct load_list {
struct load_list *next;
void *start;
size_t size;
int prot;
Elf_Addr moff;
long foff;
};
/*
* Structure describing a loaded object.
* The head of this struct must be compatible
* with struct link_map in sys/link.h
*/
typedef struct elf_object elf_object_t;
struct elf_object {
Elf_Addr obj_base; /* object's address '0' base */
char *load_name; /* Pointer to object name */
Elf_Dyn *load_dyn; /* Pointer to object dynamic data */
struct elf_object *next;
struct elf_object *prev;
/* End struct link_map compatible */
Elf_Addr load_base; /* Base address of loadable segments */
struct load_list *load_list;
u_int32_t load_size;
Elf_Addr got_addr;
Elf_Addr got_start;
size_t got_size;
Elf_Addr plt_start;
size_t plt_size;
union {
u_long info[DT_NUM + DT_PROCNUM];
struct {
Elf_Addr null; /* Not used */
Elf_Addr needed; /* Not used */
Elf_Addr pltrelsz;
Elf_Addr *pltgot;
Elf_Addr *hash;
const char *strtab;
const Elf_Sym *symtab;
Elf_RelA *rela;
Elf_Addr relasz;
Elf_Addr relaent;
Elf_Addr strsz;
Elf_Addr syment;
void (*init)(void);
void (*fini)(void);
const char *soname;
const char *rpath;
Elf_Addr symbolic;
Elf_Rel *rel;
Elf_Addr relsz;
Elf_Addr relent;
Elf_Addr pltrel;
Elf_Addr debug;
Elf_Addr textrel;
Elf_Addr jmprel;
} u;
} Dyn;
#define dyn Dyn.u
int status;
#define STAT_RELOC_DONE 0x01
#define STAT_GOT_DONE 0x02
#define STAT_INIT_DONE 0x04
#define STAT_FINI_DONE 0x08
#define STAT_FINI_READY 0x10
#define STAT_UNLOADED 0x20
Elf_Phdr *phdrp;
int phdrc;
int obj_type;
#define OBJTYPE_LDR 1
#define OBJTYPE_EXE 2
#define OBJTYPE_LIB 3
#define OBJTYPE_DLO 4
int obj_flags;
Elf_Word *buckets;
u_int32_t nbuckets;
Elf_Word *chains;
u_int32_t nchains;
Elf_Dyn *dynamic;
TAILQ_HEAD(,dep_node) child_list; /* direct dep libs of object */
TAILQ_HEAD(,dep_node) grpsym_list; /* ordered complete dep list */
TAILQ_HEAD(,dep_node) grpref_list; /* refs to other load groups */
int refcount; /* dep libs only */
int opencount; /* # dlopen() & exe */
int grprefcount; /* load group refs */
#define OBJECT_REF_CNT(object) \
((object->refcount + object->opencount + object->grprefcount))
#define OBJECT_DLREF_CNT(object) \
((object->opencount + object->grprefcount))
/* object that caused this module to be loaded, used in symbol lookup */
elf_object_t *load_object;
void *prebind_data;
/* for object confirmation */
dev_t dev;
ino_t inode;
};
struct dep_node {
TAILQ_ENTRY(dep_node) next_sib;
elf_object_t *data;
};
void _dl_rt_resolve(void);
void _dl_add_object(elf_object_t *object);
elf_object_t *_dl_finalize_object(const char *objname, Elf_Dyn *dynp,
Elf_Phdr *phdrp, int phdrc, const int objtype, const long lbase,
const long obase);
void _dl_remove_object(elf_object_t *object);
void _dl_cleanup_objects(void);
elf_object_t *_dl_lookup_object(const char *objname);
elf_object_t *_dl_load_shlib(const char *, elf_object_t *, int, int);
elf_object_t *_dl_tryload_shlib(const char *libname, int type, int flags);
int _dl_md_reloc(elf_object_t *object, int rel, int relsz);
int _dl_md_reloc_got(elf_object_t *object, int lazy);
Elf_Addr _dl_find_symbol(const char *name, const Elf_Sym **this,
int flags, const Elf_Sym *ref_sym, elf_object_t *object,
const elf_object_t **pobj);
Elf_Addr _dl_find_symbol_bysym(elf_object_t *req_obj, unsigned int symidx,
const Elf_Sym **ref, int flags, const Elf_Sym *ref_sym,
const elf_object_t **pobj);
/*
* defines for _dl_find_symbol() flag field, three bits of meaning
* myself - clear: search all objects, set: search only this object
* warnnotfound - clear: no warning, set: warn if not found
* inplt - clear: possible plt ref set: real matching function.
*
* inplt - due to how ELF handles function addresses in shared libraries
* &func may actually refer to the plt entry in the main program
* rather than the actual function address in the .so file.
* This rather bizarre behavior is documented in the SVR4 ABI.
* when getting the function address to relocate a PLT entry
* the 'real' function address is necessary, not the possible PLT address.
*/
/* myself */
#define SYM_SEARCH_ALL 0x00
#define SYM_SEARCH_SELF 0x01
#define SYM_SEARCH_OTHER 0x02
#define SYM_SEARCH_NEXT 0x04
#define SYM_SEARCH_OBJ 0x08
/* warnnotfound */
#define SYM_NOWARNNOTFOUND 0x00
#define SYM_WARNNOTFOUND 0x10
/* inplt */
#define SYM_NOTPLT 0x00
#define SYM_PLT 0x20
#define SYM_DLSYM 0x40
int _dl_load_dep_libs(elf_object_t *object, int flags, int booting);
int _dl_rtld(elf_object_t *object);
void _dl_call_init(elf_object_t *object);
void _dl_link_child(elf_object_t *dep, elf_object_t *p);
void _dl_link_grpsym(elf_object_t *object);
void _dl_cache_grpsym_list(elf_object_t *object);
void _dl_link_grpref(elf_object_t *load_group, elf_object_t *load_object);
void _dl_link_dlopen(elf_object_t *dep);
void _dl_unlink_dlopen(elf_object_t *dep);
void _dl_notify_unload_shlib(elf_object_t *object);
void _dl_unload_shlib(elf_object_t *object);
void _dl_unload_dlopen(void);
void _dl_run_all_dtors(void);
/* Please don't rename; gdb(1) knows about this. */
Elf_Addr _dl_bind(elf_object_t *object, int index);
int _dl_match_file(struct sod *sodp, char *name, int namelen);
char *_dl_find_shlib(struct sod *sodp, const char *searchpath, int nohints);
void _dl_load_list_free(struct load_list *load_list);
void _dl_thread_kern_go(void);
void _dl_thread_kern_stop(void);
void _dl_thread_bind_lock(int);
extern elf_object_t *_dl_objects;
extern elf_object_t *_dl_last_object;
extern elf_object_t *_dl_loading_object;
extern const char *_dl_progname;
extern struct r_debug *_dl_debug_map;
extern int _dl_pagesz;
extern int _dl_errno;
extern char *_dl_libpath;
extern char *_dl_preload;
extern char *_dl_bindnow;
extern char *_dl_traceld;
extern char *_dl_tracefmt1;
extern char *_dl_tracefmt2;
extern char *_dl_traceprog;
extern char *_dl_debug;
#define DL_DEB(P) do { if (_dl_debug) _dl_printf P ; } while (0)
#define DL_NOT_FOUND 1
#define DL_CANT_OPEN 2
#define DL_NOT_ELF 3
#define DL_CANT_OPEN_REF 4
#define DL_CANT_MMAP 5
#define DL_NO_SYMBOL 6
#define DL_INVALID_HANDLE 7
#define DL_INVALID_CTL 8
#define DL_NO_OBJECT 9
#define DL_CANT_FIND_OBJ 10
#define DL_CANT_LOAD_OBJ 11
#define ELF_ROUND(x,malign) (((x) + (malign)-1) & ~((malign)-1))
#define ELF_TRUNC(x,malign) ((x) & ~((malign)-1))
/* symbol lookup cache */
typedef struct sym_cache {
const elf_object_t *obj;
const Elf_Sym *sym;
int flags;
} sym_cache;
extern sym_cache *_dl_symcache;
extern int _dl_symcachestat_hits;
extern int _dl_symcachestat_lookups;
TAILQ_HEAD(dlochld, dep_node);
extern struct dlochld _dlopened_child_list;
#endif /* _RESOLVE_H_ */
|
