rtld: Implement DT_RUNPATH and -z nodefaultlib
[dragonfly.git] / libexec / rtld-elf / rtld.h
CommitLineData
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1/*-
2 * Copyright 1996, 1997, 1998, 1999, 2000 John D. Polstra.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
15 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
18 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
19 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
20 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
21 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
23 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 *
f4f4bfd5 25 * $FreeBSD$
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26 */
27
28#ifndef RTLD_H /* { */
29#define RTLD_H 1
30
31#include <machine/elf.h>
32#include <sys/types.h>
33#include <sys/queue.h>
34
35#include <elf-hints.h>
36#include <link.h>
abfcd5b1 37#include <stdarg.h>
fcf53d9b 38#include <setjmp.h>
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39#include <stddef.h>
40
fcf53d9b 41#include "rtld_lock.h"
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42#include "rtld_machdep.h"
43
44#ifndef STANDARD_LIBRARY_PATH
45#define STANDARD_LIBRARY_PATH "/usr/lib"
46#endif
47
48#define NEW(type) ((type *) xmalloc(sizeof(type)))
49#define CNEW(type) ((type *) xcalloc(sizeof(type)))
50
51/* We might as well do booleans like C++. */
52typedef unsigned char bool;
53#define false 0
54#define true 1
55
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56extern size_t tls_last_offset;
57extern size_t tls_last_size;
58extern size_t tls_static_space;
59extern int tls_dtv_generation;
60extern int tls_max_index;
61
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62extern int main_argc;
63extern char **main_argv;
64extern char **environ;
65
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66struct stat;
67struct Struct_Obj_Entry;
68
69/* Lists of shared objects */
70typedef struct Struct_Objlist_Entry {
71 STAILQ_ENTRY(Struct_Objlist_Entry) link;
72 struct Struct_Obj_Entry *obj;
73} Objlist_Entry;
74
75typedef STAILQ_HEAD(Struct_Objlist, Struct_Objlist_Entry) Objlist;
76
77/* Types of init and fini functions */
78typedef void (*InitFunc)(void);
7f5c8f97 79typedef void (*InitArrFunc)(int, char **, char **);
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80
81/* Lists of shared object dependencies */
82typedef struct Struct_Needed_Entry {
83 struct Struct_Needed_Entry *next;
84 struct Struct_Obj_Entry *obj;
85 unsigned long name; /* Offset of name in string table */
86} Needed_Entry;
87
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88typedef struct Struct_Name_Entry {
89 STAILQ_ENTRY(Struct_Name_Entry) link;
90 char name[1];
91} Name_Entry;
92
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93/* Lock object */
94typedef struct Struct_LockInfo {
95 void *context; /* Client context for creating locks */
96 void *thelock; /* The one big lock */
97 /* Debugging aids. */
98 volatile int rcount; /* Number of readers holding lock */
99 volatile int wcount; /* Number of writers holding lock */
100 /* Methods */
101 void *(*lock_create)(void *context);
102 void (*rlock_acquire)(void *lock);
103 void (*wlock_acquire)(void *lock);
104 void (*rlock_release)(void *lock);
105 void (*wlock_release)(void *lock);
106 void (*lock_destroy)(void *lock);
107 void (*context_destroy)(void *context);
108} LockInfo;
109
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110typedef struct Struct_Ver_Entry {
111 Elf_Word hash;
112 unsigned int flags;
113 const char *name;
114 const char *file;
115} Ver_Entry;
116
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117typedef struct Struct_Sym_Match_Result {
118 const Elf_Sym *sym_out;
119 const Elf_Sym *vsymp;
120 int vcount;
121} Sym_Match_Result;
122
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123#define VER_INFO_HIDDEN 0x01
124
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125/*
126 * Shared object descriptor.
127 *
128 * Items marked with "(%)" are dynamically allocated, and must be freed
129 * when the structure is destroyed.
130 *
131 * CAUTION: It appears that the JDK port peeks into these structures.
132 * It looks at "next" and "mapbase" at least. Don't add new members
133 * near the front, until this can be straightened out.
134 */
135typedef struct Struct_Obj_Entry {
136 /*
137 * These two items have to be set right for compatibility with the
138 * original ElfKit crt1.o.
139 */
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140 Elf_Size magic; /* Magic number (sanity check) */
141 Elf_Size version; /* Version number of struct format */
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142
143 struct Struct_Obj_Entry *next;
144 char *path; /* Pathname of underlying file (%) */
167f7029 145 char *origin_path; /* Directory path of origin file */
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146 int refcount;
147 int dl_refcount; /* Number of times loaded by dlopen */
148
149 /* These items are computed by map_object() or by digest_phdr(). */
150 caddr_t mapbase; /* Base address of mapped region */
151 size_t mapsize; /* Size of mapped region in bytes */
152 size_t textsize; /* Size of text segment in bytes */
153 Elf_Addr vaddrbase; /* Base address in shared object file */
154 caddr_t relocbase; /* Relocation constant = mapbase - vaddrbase */
155 const Elf_Dyn *dynamic; /* Dynamic section */
156 caddr_t entry; /* Entry point */
157 const Elf_Phdr *phdr; /* Program header if it is mapped, else NULL */
158 size_t phsize; /* Size of program header in bytes */
159 const char *interp; /* Pathname of the interpreter, if any */
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160 caddr_t relro_page; /* Address of first page of read-only data */
161 size_t relro_size; /* Size of relro page(s) in bytes */
e9de6dcc 162 Elf_Word stack_flags;
984263bc 163
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164 /* TLS information */
165 int tlsindex; /* Index in DTV for this module */
166 void *tlsinit; /* Base address of TLS init block */
167 size_t tlsinitsize; /* Size of TLS init block for this module */
168 size_t tlssize; /* Size of TLS block for this module */
169 size_t tlsoffset; /* Offset of static TLS block for this module */
170 size_t tlsalign; /* Alignment of static TLS block */
171
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172 /* Items from the dynamic section. */
173 Elf_Addr *pltgot; /* PLT or GOT, depending on architecture */
174 const Elf_Rel *rel; /* Relocation entries */
175 unsigned long relsize; /* Size in bytes of relocation info */
176 const Elf_Rela *rela; /* Relocation entries with addend */
177 unsigned long relasize; /* Size in bytes of addend relocation info */
178 const Elf_Rel *pltrel; /* PLT relocation entries */
179 unsigned long pltrelsize; /* Size in bytes of PLT relocation info */
180 const Elf_Rela *pltrela; /* PLT relocation entries with addend */
181 unsigned long pltrelasize; /* Size in bytes of PLT addend reloc info */
182 const Elf_Sym *symtab; /* Symbol table */
183 const char *strtab; /* String table */
184 unsigned long strsize; /* Size in bytes of string table */
185
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186 const Elf_Verneed *verneed; /* Required versions. */
187 Elf_Word verneednum; /* Number of entries in verneed table */
188 const Elf_Verdef *verdef; /* Provided versions. */
189 Elf_Word verdefnum; /* Number of entries in verdef table */
190 const Elf_Versym *versyms; /* Symbol versions table */
191
d697cc44 192 const Elf_Hashelt *buckets; /* Hash table buckets array */
984263bc 193 unsigned long nbuckets; /* Number of buckets */
d697cc44 194 const Elf_Hashelt *chains; /* Hash table chain array */
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195 unsigned long nchains; /* Number of entries in chain array */
196
197 Elf32_Word nbuckets_gnu; /* Number of GNU hash buckets*/
198 Elf32_Word symndx_gnu; /* 1st accessible symbol on dynsym table */
199 Elf32_Word maskwords_bm_gnu; /* Bloom filter words - 1 (bitmask) */
200 Elf32_Word shift2_gnu; /* Bloom filter shift count */
201 Elf32_Word dynsymcount; /* Total entries in dynsym table */
202 Elf_Addr *bloom_gnu; /* Bloom filter used by GNU hash func */
203 const Elf_Hashelt *buckets_gnu; /* GNU hash table bucket array */
204 const Elf_Hashelt *chain_zero_gnu; /* GNU hash table value array (Zeroed) */
984263bc 205
fcf53d9b 206 char *rpath; /* Search path specified in object */
4f0bc915 207 char *runpath; /* Search path with different priority */
984263bc 208 Needed_Entry *needed; /* Shared objects needed by this one (%) */
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209 Needed_Entry *needed_filtees;
210 Needed_Entry *needed_aux_filtees;
984263bc 211
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212 STAILQ_HEAD(, Struct_Name_Entry) names; /* List of names for this object we
213 know about. */
214 Ver_Entry *vertab; /* Versions required /defined by this object */
215 int vernum; /* Number of entries in vertab */
216
217 Elf_Addr init; /* Initialization function to call */
218 Elf_Addr fini; /* Termination function to call */
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219 Elf_Addr preinit_array; /* Pre-initialization array of functions */
220 Elf_Addr init_array; /* Initialization array of functions */
221 Elf_Addr fini_array; /* Termination array of functions */
222 int preinit_array_num; /* Number of entries in preinit_array */
223 int init_array_num; /* Number of entries in init_array */
224 int fini_array_num; /* Number of entries in fini_array */
fcf53d9b 225
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226 int32_t osrel; /* OSREL note value */
227
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228 bool mainprog : 1; /* True if this is the main program */
229 bool rtld : 1; /* True if this is the dynamic linker */
230 bool textrel : 1; /* True if there are relocations to text seg */
231 bool symbolic : 1; /* True if generated with "-Bsymbolic" */
232 bool bind_now : 1; /* True if all relocations should be made first */
233 bool traced : 1; /* Already printed in ldd trace output */
234 bool jmpslots_done : 1; /* Already have relocated the jump slots */
235 bool init_done : 1; /* Already have added object to init list */
236 bool tls_done : 1; /* Already allocated offset for static TLS */
237 bool phdr_alloc : 1; /* Phdr is allocated and needs to be freed. */
238 bool z_origin : 1; /* Process rpath and soname tokens */
239 bool z_nodelete : 1; /* Do not unload the object and dependencies */
240 bool z_noopen : 1; /* Do not load on dlopen */
35b2b265 241 bool z_loadfltr : 1; /* Immediately load filtees */
4f0bc915 242 bool z_nodeflib : 1; /* Don't search default /usr/lib path */
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243 bool ref_nodel : 1; /* Refcount increased to prevent dlclose */
244 bool init_scanned: 1; /* Object is already on init list. */
245 bool on_fini_list: 1; /* Object is already on fini list. */
246 bool dag_inited : 1; /* Object has its DAG initialized. */
35b2b265 247 bool filtees_loaded : 1; /* Filtees loaded */
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248 bool irelative : 1; /* Object has R_MACHDEP_IRELATIVE relocs */
249 bool gnu_ifunc : 1; /* Object has references to STT_GNU_IFUNC */
7f5c8f97 250 bool crt_no_init : 1; /* Object's crt does not call _init/_fini */
e64cf055 251 bool note_present : 1; /* True if at least one PT_NOTE header found */
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252 bool valid_hash_sysv : 1; /* A valid System V hash hash tag is available */
253 bool valid_hash_gnu : 1; /* A valid GNU hash tag is available */
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254
255 struct link_map linkmap; /* For GDB and dlinfo() */
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256 Objlist dldags; /* Object belongs to these dlopened DAGs (%) */
257 Objlist dagmembers; /* DAG has these members (%) */
258 dev_t dev; /* Object's filesystem's device */
259 ino_t ino; /* Object's inode number */
30aefd4f 260 void *priv; /* Platform-dependent */
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261} Obj_Entry;
262
263#define RTLD_MAGIC 0xd550b87a
264#define RTLD_VERSION 1
265
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266#define RTLD_FUNCTRACE "_rtld_functrace"
267
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268/* Flags to be passed into symlook_ family of functions. */
269#define SYMLOOK_IN_PLT 0x01 /* Lookup for PLT symbol */
30aefd4f 270#define SYMLOOK_DLSYM 0x02 /* Return newest versioned symbol. Used by
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271 dlsym. */
272
273/* Flags for load_object(). */
274#define RTLD_LO_NOLOAD 0x01 /* dlopen() specified RTLD_NOLOAD. */
275#define RTLD_LO_DLOPEN 0x02 /* Load_object() called from dlopen(). */
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276#define RTLD_LO_TRACE 0x04 /* Only tracing. */
277#define RTLD_LO_NODELETE 0x08 /* Loaded object cannot be closed. */
278#define RTLD_LO_FILTEES 0x10 /* Loading filtee. */
fcf53d9b 279
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280/*
281 * Symbol cache entry used during relocation to avoid multiple lookups
282 * of the same symbol.
283 */
284typedef struct Struct_SymCache {
285 const Elf_Sym *sym; /* Symbol table entry */
286 const Obj_Entry *obj; /* Shared object which defines it */
287} SymCache;
288
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289/*
290 * This structure provides a reentrant way to keep a list of objects and
291 * check which ones have already been processed in some way.
292 */
293typedef struct Struct_DoneList {
294 const Obj_Entry **objs; /* Array of object pointers */
295 unsigned int num_alloc; /* Allocated size of the array */
296 unsigned int num_used; /* Number of array slots used */
297} DoneList;
298
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299struct Struct_RtldLockState {
300 int lockstate;
301 sigjmp_buf env;
302};
303
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304struct fill_search_info_args {
305 int request;
306 unsigned int flags;
307 struct dl_serinfo *serinfo;
308 struct dl_serpath *serpath;
309 char *strspace;
310};
311
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312/*
313 * The pack of arguments and results for the symbol lookup functions.
314 */
315typedef struct Struct_SymLook {
316 const char *name;
317 unsigned long hash;
7629c631 318 uint_fast32_t hash_gnu;
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319 const Ver_Entry *ventry;
320 int flags;
321 const Obj_Entry *defobj_out;
322 const Elf_Sym *sym_out;
323 struct Struct_RtldLockState *lockstate;
324} SymLook;
325
fcf53d9b 326void _rtld_error(const char *, ...) __printflike(1, 2);
b2cf2649 327const char *rtld_strerror(int);
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328Obj_Entry *map_object(int, const char *, const struct stat *);
329void *xcalloc(size_t);
330void *xmalloc(size_t);
331char *xstrdup(const char *);
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332extern Elf_Addr _GLOBAL_OFFSET_TABLE_[];
333
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334void dump_relocations(Obj_Entry *);
335void dump_obj_relocations(Obj_Entry *);
336void dump_Elf_Rel(Obj_Entry *, const Elf_Rel *, u_long);
337void dump_Elf_Rela(Obj_Entry *, const Elf_Rela *, u_long);
338
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339/*
340 * Function declarations.
341 */
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342const char *basename(const char *);
343unsigned long elf_hash(const char *);
344const Elf_Sym *find_symdef(unsigned long, const Obj_Entry *,
35b2b265 345 const Obj_Entry **, int, SymCache *, struct Struct_RtldLockState *);
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346void init_pltgot(Obj_Entry *);
347void lockdflt_init(void);
7f5c8f97 348void digest_notes(Obj_Entry *, Elf_Addr, Elf_Addr);
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349void obj_free(Obj_Entry *);
350Obj_Entry *obj_new(void);
351void _rtld_bind_start(void);
0e63a289 352void *rtld_resolve_ifunc(const Obj_Entry *obj, const Elf_Sym *def);
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353void symlook_init(SymLook *, const char *);
354int symlook_obj(SymLook *, const Obj_Entry *);
fcf53d9b 355void *tls_get_addr_common(Elf_Addr** dtvp, int index, size_t offset);
a1eee96a 356struct tls_tcb *allocate_tls(Obj_Entry *);
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357void free_tls(struct tls_tcb *);
358void *allocate_module_tls(int index);
359bool allocate_tls_offset(Obj_Entry *obj);
360void free_tls_offset(Obj_Entry *obj);
361const Ver_Entry *fetch_ventry(const Obj_Entry *obj, unsigned long);
362
363/*
364 * MD function declarations.
365 */
366int do_copy_relocations(Obj_Entry *);
35b2b265 367int reloc_non_plt(Obj_Entry *, Obj_Entry *, struct Struct_RtldLockState *);
fcf53d9b 368int reloc_plt(Obj_Entry *);
35b2b265 369int reloc_jmpslots(Obj_Entry *, struct Struct_RtldLockState *);
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370int reloc_iresolve(Obj_Entry *, struct Struct_RtldLockState *);
371int reloc_gnu_ifunc(Obj_Entry *, struct Struct_RtldLockState *);
fcf53d9b 372void allocate_initial_tls(Obj_Entry *);
139b8f34 373
984263bc 374#endif /* } */