resolve.h revision 1.105 
1/*	$OpenBSD: resolve.h,v 1.105 2023/08/15 06:26:34 guenther 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
80struct addr_range {
81	vaddr_t start;
82	vaddr_t end;
83};
84
85struct range_vector {
86	struct addr_range slice[40];
87	int count;
88};
89
90/*
91 *  Structure describing a loaded object.
92 *  The head of this struct must be compatible
93 *  with struct link_map in <link_elf.h>
94 */
95struct elf_object {
96	Elf_Addr obj_base;		/* object's address '0' base */
97	char	*load_name;		/* Pointer to object name */
98	Elf_Dyn *load_dyn;		/* Pointer to object dynamic data */
99	struct elf_object *next;
100	struct elf_object *prev;
101/* End struct link_map compatible */
102	Elf_Addr load_base;		/* Base address of loadable segments */
103
104	struct load_list *load_list;
105
106	u_int32_t  load_size;
107
108	union {
109		u_long		info[DT_NUM + DT_PROCNUM];
110		struct {
111			Elf_Addr	null;		/* Not used */
112			Elf_Addr	needed;		/* Not used */
113			Elf_Addr	pltrelsz;
114			Elf_Addr	*pltgot;
115			Elf_Addr	*hash;
116			const char	*strtab;
117			const Elf_Sym	*symtab;
118			Elf_RelA	*rela;
119			Elf_Addr	relasz;
120			Elf_Addr	relaent;
121			Elf_Addr	strsz;
122			Elf_Addr	syment;
123			initfunc	*init;
124			initfunc	*fini;
125			const char	*soname;
126			const char	*rpath;
127			Elf_Addr	symbolic;
128			Elf_Rel		*rel;
129			Elf_Addr	relsz;
130			Elf_Addr	relent;
131			Elf_Addr	pltrel;
132			Elf_Addr	debug;
133			Elf_Addr	textrel;
134			Elf_Addr	jmprel;
135			Elf_Addr	bind_now;
136			initarrayfunc	**init_array;
137			initfunc	**fini_array;
138			Elf_Addr	init_arraysz;
139			Elf_Addr	fini_arraysz;
140			const char	*runpath;
141			Elf_Addr	flags;
142			Elf_Addr	encoding;
143			initarrayfunc	**preinit_array;
144			Elf_Addr	preinit_arraysz;
145			Elf_Addr	unassigned;
146			Elf_Addr	relrsz;
147			Elf_Relr	*relr;
148		} u;
149	} Dyn;
150#define dyn Dyn.u
151
152	Elf_Addr	relacount;	/* DT_RELACOUNT */
153	Elf_Addr	relcount;	/* DT_RELCOUNT */
154
155	int		status;
156#define	STAT_RELOC_DONE		0x001
157#define	STAT_GOT_DONE		0x002
158#define	STAT_INIT_DONE		0x004
159#define	STAT_FINI_DONE		0x008
160#define	STAT_FINI_READY		0x010
161#define	STAT_UNLOADED		0x020
162#define	STAT_NODELETE		0x040
163#define	STAT_GNU_HASH		0x080
164#define	STAT_VISIT_INITFIRST	0x100
165#define	STAT_VISIT_INIT		0x200
166
167	Elf_Phdr	*phdrp;
168	int		phdrc;
169
170	int		obj_type;
171#define	OBJTYPE_LDR	1
172#define	OBJTYPE_EXE	2
173#define	OBJTYPE_LIB	3
174#define	OBJTYPE_DLO	4
175	int		obj_flags;	/* c.f. <sys/exec_elf.h> DF_1_* */
176	int		nodelete;
177
178	/* shared by ELF and GNU hash */
179	u_int32_t	nbuckets;
180	u_int32_t	nchains;	/* really, number of symbols */
181	union {
182		struct {
183			/* specific to ELF hash */
184			const Elf_Hash_Word	*buckets;
185			const Elf_Hash_Word	*chains;
186		} u_elf;
187		struct {
188			/* specific to GNU hash */
189			const Elf_Word		*buckets;
190			const Elf_Word		*chains;
191			const Elf_Addr		*bloom;
192			Elf_Word		mask_bm;
193			Elf_Word		shift2;
194			Elf_Word		symndx;
195		} u_gnu;
196	} hash_u;
197#define buckets_elf	hash_u.u_elf.buckets
198#define chains_elf	hash_u.u_elf.chains
199#define buckets_gnu	hash_u.u_gnu.buckets
200#define chains_gnu	hash_u.u_gnu.chains
201#define bloom_gnu	hash_u.u_gnu.bloom
202#define mask_bm_gnu	hash_u.u_gnu.mask_bm
203#define shift2_gnu	hash_u.u_gnu.shift2
204#define symndx_gnu	hash_u.u_gnu.symndx
205
206	struct object_vector	child_vec;	/* direct dep libs of object */
207	struct object_vector	grpsym_vec;	/* ordered complete dep list */
208	TAILQ_HEAD(,dep_node)	grpref_list;	/* refs to other load groups */
209
210	int		refcount;	/* dep libs only */
211	int		opencount;	/* # dlopen() & exe */
212	int		grprefcount;	/* load group refs */
213#define OBJECT_REF_CNT(object) \
214    ((object->refcount + object->opencount + object->grprefcount))
215#define OBJECT_DLREF_CNT(object) \
216    ((object->opencount + object->grprefcount))
217
218	/* object that caused this module to be loaded, used in symbol lookup */
219	elf_object_t	*load_object;
220	struct sod	sod;
221
222	/* for object confirmation */
223	dev_t	dev;
224	ino_t inode;
225
226	/* thread local storage info */
227	Elf_Addr	tls_fsize;
228	Elf_Addr	tls_msize;
229	Elf_Addr	tls_align;
230	const void	*tls_static_data;
231	int		tls_offset;
232
233	/* relro bits */
234	Elf_Addr	relro_addr;
235	Elf_Addr	relro_size;
236
237	/* generation number of last grpsym insert on this object */
238	unsigned int grpsym_gen;
239
240	char **rpath;
241	char **runpath;
242
243	/* nonzero if trace enabled for this object */
244	int traced;
245
246	struct range_vector imut;
247	struct range_vector mut;
248};
249
250struct dep_node {
251	TAILQ_ENTRY(dep_node) next_sib;
252	elf_object_t *data;
253};
254
255
256/* Please don't rename or make hidden; gdb(1) knows about these. */
257Elf_Addr _dl_bind(elf_object_t *object, int index);
258void	_dl_debug_state(void);
259
260/* exported to the application */
261extern char *__progname;
262
263__BEGIN_HIDDEN_DECLS
264void _dl_handle_nodelete(elf_object_t *_object);
265void _dl_add_object(elf_object_t *object);
266elf_object_t *_dl_finalize_object(const char *objname, Elf_Dyn *dynp,
267    Elf_Phdr *phdrp, int phdrc, const int objtype, const long lbase,
268    const long obase);
269void	_dl_remove_object(elf_object_t *object);
270void	_dl_cleanup_objects(void);
271
272void _dl_handle_already_loaded(elf_object_t *_object, int _flags);
273elf_object_t *_dl_load_shlib(const char *, elf_object_t *,
274    int, int, int nodelete);
275elf_object_t *_dl_tryload_shlib(const char *libname, int type,
276    int flags, int nodelete);
277
278int _dl_md_reloc(elf_object_t *object, int rel, int relsz);
279int _dl_md_reloc_got(elf_object_t *object, int lazy);
280
281struct sym_res {
282	const Elf_Sym		*sym;
283	const elf_object_t	*obj;
284};
285
286struct sym_res _dl_find_symbol(const char *name, int flags,
287    const Elf_Sym *ref_sym, elf_object_t *object);
288
289/*
290 * defines for _dl_find_symbol() flag field, three bits of meaning
291 * myself	- clear: search all objects,	set: search only this object
292 * warnnotfound - clear: no warning,		set: warn if not found
293 * inplt	- clear: possible plt ref	set: real matching function.
294 *
295 * inplt - due to how ELF handles function addresses in shared libraries
296 * &func may actually refer to the plt entry in the main program
297 * rather than the actual function address in the .so file.
298 * This rather bizarre behavior is documented in the SVR4 ABI.
299 * when getting the function address to relocate a PLT entry
300 * the 'real' function address is necessary, not the possible PLT address.
301 */
302/* myself */
303#define SYM_SEARCH_ALL		0x00
304#define SYM_SEARCH_SELF		0x01
305#define SYM_SEARCH_OTHER	0x02
306#define SYM_SEARCH_NEXT		0x04
307/* warnnotfound */
308#define SYM_NOWARNNOTFOUND	0x00
309#define SYM_WARNNOTFOUND	0x10
310/* inplt */
311#define SYM_NOTPLT		0x00
312#define SYM_PLT			0x20
313
314#define SYM_DLSYM		0x40
315
316int _dl_load_dep_libs(elf_object_t *object, int flags, int booting);
317int _dl_rtld(elf_object_t *object);
318void _dl_call_init(elf_object_t *object);
319void _dl_link_child(elf_object_t *dep, elf_object_t *p);
320void _dl_link_grpsym(elf_object_t *object);
321void _dl_cache_grpsym_list_setup(elf_object_t *_object);
322void _dl_link_grpref(elf_object_t *load_group, elf_object_t *load_object);
323void _dl_link_dlopen(elf_object_t *dep);
324void _dl_unlink_dlopen(elf_object_t *dep);
325void _dl_notify_unload_shlib(elf_object_t *object);
326void _dl_unload_shlib(elf_object_t *object);
327void _dl_unload_dlopen(void);
328
329void _dl_run_all_dtors(void);
330
331int	_dl_match_file(struct sod *sodp, const char *name, int namelen);
332char	*_dl_find_shlib(struct sod *sodp, char **searchpath, int nohints);
333void	_dl_load_list_free(struct load_list *load_list);
334
335void _dl_find_immutables(int type, elf_object_t *object, Elf_Ehdr *);
336void _dl_push_range_size(struct range_vector *v, vaddr_t start, vsize_t len);
337void _dl_apply_immutable(elf_object_t *object);
338
339typedef void lock_cb(int);
340void	_dl_thread_kern_go(lock_cb *);
341lock_cb	*_dl_thread_kern_stop(void);
342
343char	*_dl_getenv(const char *, char **) __boot;
344void	_dl_unsetenv(const char *, char **) __boot;
345
346void	_dl_trace_setup(char **) __boot;
347void	_dl_trace_object_setup(elf_object_t *);
348int	_dl_trace_plt(const elf_object_t *, const char *);
349
350/* dlfcn.c */
351void	_dl_show_objects(elf_object_t *_object);
352
353/* tib.c */
354void	_dl_allocate_tls_offsets(void) __boot;
355void	_dl_allocate_first_tib(void) __boot;
356void	_dl_set_tls(elf_object_t *_object, Elf_Phdr *_ptls, Elf_Addr _libaddr,
357	    const char *_libname);
358extern int _dl_tib_static_done;
359
360extern elf_object_t *_dl_objects;
361extern int object_count;	/* how many objects are currently loaded */
362
363extern elf_object_t *_dl_loading_object;
364
365extern struct r_debug *_dl_debug_map;
366
367extern int  _dl_pagesz;
368extern int  _dl_errno;
369
370extern char **_dl_libpath;
371
372extern int _dl_bindnow;
373extern int _dl_traceld;
374extern int _dl_debug;
375
376extern char *_dl_preload;
377extern char *_dl_tracefmt1;
378extern char *_dl_tracefmt2;
379extern char *_dl_traceprog;
380
381extern void *_dl_exec_hint;
382
383extern int _dl_trust;
384
385#define DL_DEB(P) do { if (_dl_debug) _dl_printf P ; } while (0)
386
387#define	DL_NOT_FOUND		1
388#define	DL_CANT_OPEN		2
389#define	DL_NOT_ELF		3
390#define	DL_CANT_OPEN_REF	4
391#define	DL_CANT_MMAP		5
392#define	DL_NO_SYMBOL		6
393#define	DL_INVALID_HANDLE	7
394#define	DL_INVALID_CTL		8
395#define	DL_NO_OBJECT		9
396#define	DL_CANT_FIND_OBJ	10
397#define	DL_CANT_LOAD_OBJ	11
398#define	DL_INVALID_MODE		12
399
400#define ELF_ROUND(x,malign) (((x) + (malign)-1) & ~((malign)-1))
401#define ELF_TRUNC(x,malign) ((x) & ~((malign)-1))
402
403/* symbol lookup cache */
404typedef struct sym_cache {
405	const elf_object_t *obj;
406	const Elf_Sym	*sym;
407	int flags;
408} sym_cache;
409
410TAILQ_HEAD(dlochld, dep_node);
411extern struct dlochld _dlopened_child_list;
412__END_HIDDEN_DECLS
413
414#endif /* _RESOLVE_H_ */
415